JP4003610B2 - Water-based ballpoint pen ink - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink for water-based ballpoint pens, and more particularly to an ink for water-based ballpoint pens that is used for water-based ballpoint pens that use balls containing a binder mainly made of metal and that has little corrosion over time.
[0002]
[Prior art]
Conventionally, balls for water-based ballpoint pens include silicon carbide balls, zirconia balls, carbide balls and the like mainly containing silicon carbide, zirconia oxide, tungsten carbide, etc., and containing a binder mainly made of metal in addition to the main components. in use. Since these balls are mainly made of a metal such as cobalt, chromium, or titanium, they have a drawback that they corrode with time and are likely to elute into the ink. In particular, balls using tungsten carbide, the main component of which is so-called carbide, are widely used as balls for water-based ballpoint pens, but these carbide balls are also susceptible to corrosion over time due to their high binder content. There are drawbacks. As a method for preventing this corrosion over time, a rust inhibitor such as benzotriazole (see Patent Document 1), benzothiadiazole (see Patent Document 2), or diisopropylammonium nitrite (see Patent Document 3) is used in the ink. Methods of adding are known.
[0003]
[Patent Document 1]
JP-B-49-45333 (page 1, column 2, line 23 to page 2, column 4, line 20)
[Patent Document 2]
JP-A-8-41409 (page 2, column 1, lines 39-48)
[Patent Document 3]
Japanese Patent Application Laid-Open No. 09-087568 (Page 2, column 1, line 41 to column 2, line 1)
[0004]
[Problems to be solved by the invention]
However, a ball containing a binder composed mainly of metal is a main component because metals such as cobalt, chromium and titanium elute into the ink over time by the action of dissolved oxygen in the ink and the binder is lost. For example, crystal grains such as silicon carbide, zirconia, tungsten carbide and the like are dropped off, and irregularities on the surface of the ball are somewhat increased, resulting in a problem that the writing feel becomes heavy or faint. The above-mentioned rust preventives used in the past cannot completely prevent the metal as a binder from eluting, and as a result, the effect of suppressing the problem that the writing quality becomes heavy or the handwriting is blurred is insufficient. Met.
An object of the present invention is a water-based ballpoint pen that uses a ball containing a binder mainly made of metal, and the ball does not easily corrode even with time, and does not cause a problem that the writing feel becomes heavy or blurs. It is to provide the ink.
[0005]
[Means for Solving the Problems]
That is, the present invention is at least 1 selected from acidic dyes and / or pigments, water-soluble organic solvents, water, 1- (2-hydroxyethylthio) -2-propanol, thiodipropylene glycol, and dithiodiglycol. A gist of the invention is a water-based ballpoint pen ink comprising seeds or two or more and sodium ascorbate or potassium hydroquinonesulfonate .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Details will be described below.
The colorant used in the present invention uses an acid dye and / or a pigment. Acid dyes include Acid Blue Black 10B (CI Acid Black 1), Nigrosine (2), Suminol Milling Black 8BX (24), Kayanol Milling Black VLG (26), Suminol Fast Black BR Conch (31), Mitsui Nylon Black GL (52), Eisen Opal Black WH Extra Conk (52), Sumilan Black WA (52), Ranil Black BG Extra Conk (107), Kayanol Milling Black TLB (Same 109), Suminol Milling Black B (Same 109), Kayanol Milling Black TLR (Same 110), Eisen Opal Black New Conque (Same 119), Water Black 187-L (Same 154), Kayaqua Acid Brilliant Flavi FF (CI Acid Yellow 7: 1), Kayasil Yellow GG (17), Xylene Light Yellow 2G 140% (17), Suminol Leveling Yellow NR (19), Daiwa Tarrazine (23), Kayaactor Thrazine (23), Suminoll Fast Yellow R (25), Diacid Light Yellow 2GP (29), Suminoll Milling O O (38), Suminoll Milling MR MR (42), Water Yellow # 6 (same 42), Kayanol Yellow NFG (49), Suminol Milling Yellow 3G (72), Suminol Fast Yellow G (61), Suminol Milling Yellow G (78), Kayanol Yellow N5G ( 110), Suminoll Milling Yellow 4G 200% (141), Kayanor Yellow NG (same as above) 35), Kayanol Milling Yellow 5 GW (127), Kayanol Milling Yellow 6 GW (142), Sumitomo Fast Scarlet A (CI Acid Red 8), Kayak Silk Scarlet (9), Solar Rubin Extra (same as above) 14), Daiwa New Coxin (18), Eisenbonso RH (26), Daiwa Red No. 2 (27), Suminol Leveling Brilliant Red S3B (35), Kayasil Rubinol 3GS (37) Eisen erythrosin (51), kayak acid rhodamine FB (52), Suminol leveling rubinol 3GP (57), diacid alizarin rubinol F3G 200% (82), Eisen eosin GH (87), water pink # 2 (92), Eisen Acid Phloxin PB (92), Rose Bengal (94), Kayanol Milling Scarlet FGW (111), Kayanol Milling Lubin 3BW (129), Suminoall Milling Brilliant Red 3BN Conch (131), Suminol Milling Brilliant Red BS (138), Eisen Opal Pink BH (186), Suminoll Milling Brilliant Red B Conch (249), Kayaku Acid Brilliant Red 3BL (254), Kayaku Acid Brilliant Brilliant Red BL (265), Kayanol Milling Red GW (276), Mitsui Acid Violet 6BN (C.I. I. Acid Violet 15), Mitsui Acid Violet BN (17), Sumitomo Patent Pure Blue VX (CI Acid Blue 1), Water Blue # 106 (1), Patent Blue AF (7), Water Blue # 9 (Same 9), Daiwa Blue No. 1 (same 9), Supranol Blue B (same 15), Orient Soluble Blue OBC (same 22), Suminol Leveling Blue 4GL (same 23), Mitsui Nylon Fast Blue G (same as above) 25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Saphirol SE (43), Suminol Leveling Sky Blue R Extraconk (62), Mitsui Nylon Fast Sky Blue B (78) , Sumitomo Brilliant Indocyanine 6Bh / (83), Sandlancyanine N-6B 350% (90), Water Blue # 115 (90), Orient Soluble Blue OBB (93), Sumitomo Brilliant Blue 5G (103), Kayanol Milling Ultra Sky SE (the 112), Kaya Nord milling cyanine 5R (the 113), Aizen opal Blue 2GLH (the 158), Daiwa Guinea green B (C.I. acid Green 3), acid Brilliant milling green B (the 9), Daiwa Green # 70 (same as 16), Cyanol Cyanine Green G (same as 25), Suminol Milling Green G (same as 27) and the like .
[0007]
As pigments, organic pigments such as azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acidic dye pigments, building dye pigments, mordant dye pigments, and natural dye pigments, ocher, barium Examples thereof include inorganic pigments such as yellow, bitumen, cadmium red, barium sulfate, titanium oxide, petiole, iron black, and carbon black, and these can be used alone or in combination.
Specific examples include aniline black (CI 50440), cyanine black, naphthol yellow S (CI 10316), Hansa Yellow 10G (CI 11710), Hansa Yellow 5G (CI 11660), Hansa Yellow. 3G (C.I. 11670), Hansa Yellow G (C.I. 11680), Hansa Yellow GR (C.I. 11730), Hansa Yellow A (C.I. 11735), Hansa Yellow RN (C.I. 11740), Hansa Yellow R (C.I. 12710), Pigment Yellow L (C.I. 12720), Benzidine Yellow (C.I. 21090), Benzidine Yellow G (C.I. 21095), Benzidine Yellow GR (C.I. 21100) ), Permanent Aero NCG (C.I. 20040), Balkan Fastoe -5G (C.I. 21220), Vulcan Fast Yellow R (C.I. 21135), Tartrazine Lake (C.I. 19140), Quinoline Yellow Lake (C.I. 47005), Anslagen Yellow 6GL (C I.60520), permanent yellow FGL, permanent yellow H10G, permanent yellow HR, anthrapyrimidine yellow (CI 68420), Sudan I (CI 12055), permanent orange (CI 12075), resole Fast Orange (C.I. 12125), Permanent Orange GTR (C.I. 12305), Hansa Yellow 3R (C.I. 11725), Vulcan Fast Orange GG (C.I. 21165), Benzidine Orange G (C.I 21110), Persian ole Di (C.I.15510), Indanthrene brilliant orange GK (C.I.59305), Indanthrene brilliant orange RK (C.I.59105), Indanthrene brilliant orange GR (C.I.71105) Permanent Brown FG (C.I. 12480), Para Brown (C.I. 12071), Permanent Red 4R (C.I. 12120), Para Red (C.I. 12070), Fire Red (C.I. 12085) ), Parachlor ortho aniline red (C.I. 12090), resol fast scarlet, brilliant fast scarlet (C.I. 12315), brilliant carmine BS, permanent red F2R (C.I. 12310), permanent red F4R (C I.1 2335), permanent red FRL (C.I. I. 12440), Permanent Red FRLL (C.I. 12460), Permanent Red F4RH (C.I. 12420), Fast Scarlet VD, Vulcan Fast Rubin B (C.I. 12320), Vulcan Fast Pink G (C.I. 12330), Light Fast Red Toner B (C.I. 12450), Light Fast Red Toner R (C.I. 12455), Permanent Carmine FB (C.I. 12490), Pyrazolone Red (C.I. 12120), Resol Red (C.I. 15630), Lake Red C (C.I. 15585), Lake Red D (C.I. 15500), Anthosine B (C.I. 18030), Brilliant Scarlet G (C.I. 15800), Risol rubin GK (C.I.158) 5), Permanent Red F5R (C.I. 15865), Brilliant Carmine 6B (C.I. 15850), Pigment Scarlet 3B (C.I. 16105), Bordeaux 5B (C.I. 12170), Toluidine Maroon (C Perm. Bordeaux F2R (C.I. 12385), Helio Bordeaux BL (C.I. 14830), Bordeaux 10B (C.I. 15880), Bon Maroon Light (C.I. 15825), Bonn Maroon Medium (C.I. 15880), Eosin Lake (C.I. 45380), Rhodamine Lake B (C.I. 45170), Rhodamine Lake Y (C.I. 45160), Alizarin Lake (C.I. 58000) ), Thioindigo red B (C.I. 73300), thioindigo Rune (C.I. 73385), Permanent Red FGR (C.I. 12370), PV Carmine HR, Watching Red, Monolite Fast Red YS (C.I. 59300), Permanent Red BL, Fast Violet B, Methyl Violet Lake (C.I. 42535), Dioxazine Violet, Alkaline Blue Lake (C.I. 42750A, C.I. 42770A), Peacock Blue Lake (C.I. 42090), Peacock Blue Lake (C.I. 42025), Victoria Blue Lake (C.I. 44045), Phthalocyanine Blue (C.I. 74160), Fast Sky Blue (C.I. 74180), Indanthrene Blue RS (C.I. 69800), Indance Ren Blue BC (C.I.6 9825), Indigo (C.I. I. 73000), Pigment Green B (C.I. 10006), Naphthol Green B (C.I. 10020), Green Gold (C.I. 12775), Acid Green Lake, Malachite Green Lake (C.I. 42000), Examples include phthalocyanine green.
The amount of these colorants used is preferably 0.5 to 30% by weight based on the total amount of ink. If it is less than 0.5% by weight, it is thin and does not perform the performance as a handwriting. If it exceeds 30% by weight, the dry-up in the chip increases and the writing performance tends to deteriorate.
[0008]
When a pigment is used as the colorant, a dispersant may be used to stably disperse the pigment. As the dispersant, those used as dispersants for pigments such as water-soluble resins or water-soluble resins generally used and anionic or nonionic surfactants can be used. Examples of the polymer dispersant include natural polymers such as lignin sulfonate and shellac, polyacrylate, salt of styrene-acrylic acid copolymer, salt of vinylnaphthalene-maleic acid copolymer, β-naphthalene Examples thereof include anionic polymers such as sodium salt and phosphate of sulfonic acid formalin condensate, and nonionic polymers such as polyvinyl alcohol and polyethylene glycol. In addition, as surfactants, alkyl sulfates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids and salts thereof, N-acyl methyl taurine salts, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylates, α- Nonionic surfactants such as olefin sulfonates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl ethers, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters Surfactant is mentioned.
[0009]
These water-soluble resins and surfactants may be used alone or in combination of two or more. The amount used is preferably 0.05 to 20 parts by weight with respect to 10 parts by weight of the pigment. If the amount is less than 0.05 parts by weight, the dispersion effect, which is the purpose of addition, is weak, and even if it exceeds 20 parts by weight, no further dispersion effect can be expected, which is uneconomical.
In the case of pigments, it is further advantageous in producing pigment inks to use an aqueous ink base dispersed in an aqueous medium. Specifically, Fuji SP Black 8031, 8119, 8167, 8276, 8276, 8381, 8406, Fuji SP Red 5096, 5111, 5193, 5220, Fuji SP Bordeaux 5500, Fuji SP Blue 6062, 6133. 6134, 6401, Fuji SP Green 7051, Fuji SP Yellow 4060, 4178, Fuji SP Violet 9011, Fuji SP Pink 9524, 9527, Fuji SP Orange 534, FUji SP B 543, FUji SP Orange 534, FUji SP Orange 534, FUji SP Orange 534 (Fuji Dye Co., Ltd.), Emacol Black CN, Emacol Blue FBB, FB, KR, Emacol G reen LXB, Emacol Violet BL, Emacol Brown 3101, Emacol Carmine FB, Emacol Red BS, Emacol Orange R, Emacol Yellow FD, IRN, 3601, GGN, G GN, G , 10G, Sandy Super Black K, C, Sandy Super Gray B, Sandy Super Brown SB, FRL, RR, Sandy Super Green L5G, Sandy Super H L, GB, Sandy Super H H, FBL-160, FBB, Sandye Super Violet BL H / C, BL, Sandye Sup r Bordeaux FR, Sandy Super Pink FBL, F5B, Sandy Super Rubin FR, Sandy super Carminine FB, Sandy Super Red FFG, Sand RR, BS, Sandy Super Red FFG, Sandy Super Red FFG, Sandy Super GFF 3R, Sandye Ywlow GG, F3R, IRC, FGN, GN, GRS, GSR-130, GSN-130, GSN, 10GN (above, Sanyo Dye Co., Ltd.), Rio Fast BlackFx 8012, 8313, 8169, Rio Fast Red Fx8209, 8172, Rio Fast Red S Fx 8315, 8316, Rio F st Blue Fx 8170, Rio Fast Blue FX 8170, Rio Fast Blue S Fx 8312, Rio Fast Green S Fx 8314 (above, manufactured by Toyo Ink Co., Ltd.), NKW-2101, 2102, 2103, 2103, 2103 2106, 2107, 2108, 2117, 2127, 2137, 2137, 2167, 2101P, 2102P, 2103P, 2104P, 2105P, 2106P, 2107P, 2108P, 2117P, 2127P, 2137P, 2167P, NKW-3002, 3003, 3004, 3005, 3007, 3077, 3008, 3402, 3404, 3405, 3407, 3408, 3477, 36 2, 3603, 3604, 3605, 3607, 3607, 3707, 3608, 3702, 3703, 3704, 3705, 3777, 3708, 6013, 6038, 6559 (above, Japan) Fluorescent Co., Ltd.), Cosmo Color S1000F Series (Toyo Soda Co., Ltd.), Victoria Yellow G-11, G-20, Victoria Orange G-16, G-21, Victoria Red G-19, G -22, Victoria Pink G-17, G-23, Victoria Green G-18, G-24, Victoria Blue G-15, G-25 (above, manufactured by Gokoku Color Co., Ltd.), Pollux PC5T1020, Pollux Pollux series such as Black PC8T135, Polook Thread IT1030 (above, Sumika Color Co., Ltd.) ) Are those like, these are what can be used in combination to select one or more.
[0010]
1- (2-hydroxyethylthio) -2-propanol, thiodipropylene glycol, and dithiodiglycol are used to prevent the metal, which is a binder in the ball, from eluting into the ink over time. Thus, one or more selected from these can be used.
Specific examples thereof include MTG-10PX (1- (2-hydroxyethylthio) -2-propanol, manufactured by Meisei Chemical Industry Co., Ltd.), dithiodiglycol (manufactured by Morton), and the like.
The amount used is preferably 0.5% to 20% by weight based on the total ink, and if it is less than 0.5% by weight, the effect of preventing ball corrosion is insufficient. However, the drastic improvement in corrosion prevention effect cannot be obtained, and there is no point in adding it.
[0011]
In order to remove dissolved oxygen and dissolved gas in the ink, various reducing compounds such as ascorbic acid, kojic acid and salts thereof, hydroquinone and / or derivatives thereof, and sulfites are used.
[0012]
In the present invention, when used for a ballpoint pen that directly fills the ink containing tube with ink, a thickener is added to the ink to prevent the ink from leaking out when the pen tip is left facing down. Thus, the ink viscosity can be adjusted. The viscosity of the ink can be adjusted by appropriately adjusting and using a thickener so as to obtain a desired viscosity. Specific examples include polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, carboxyethylcellulose, collagen, HPC-SL, L, M, H (above, Nippon Soda Co., Ltd.), Avicel PH-101. , 102, 301, M06, TG-101 (above, manufactured by Asahi Kasei Co., Ltd.), etc., Kelzan, Kelzan S, Kelzan F, Kelzan AR, Kelzan M, Kelzan D (above, Sanki Co., Ltd.) Xanthane gum such as Kojin, Kojin F, Kojin T, Kojin K (manufactured by Kojin Co., Ltd.), succinoglucan such as Leozan (manufactured by Sansho Co., Ltd.), K1A96 (manufactured by Sancho Co., Ltd.) Welan gum, etc., Lambzan gum such as K1A112, K7C2433 (manufactured by Sansho Co., Ltd.), Jaguar 8111, 860 , HP-8, HP-60, CP-13 (above, manufactured by Sansho Co., Ltd.) and other water-soluble polysaccharides such as pullulan (manufactured by Hayashibara Corporation), GX-205, NA- Water-soluble synthetic polymers such as N-vinylacetamide polymerization cross-linked products such as 010 (manufactured by Showa Denko KK), Smecton SA (Smectite, manufactured by Kunimine Kogyo Co., Ltd.), Kunipia-F, Kunipia-G (Montmorillonite, Kunimine) Kogyo Co., Ltd.), Wenger HV, FW, 15 and 23 (Bentonite, manufactured by Toyoshun Yoko Co., Ltd.), Sven, C and W, N400 (quaternary ammonium cation modified montmorillonite, Co., Ltd.) Inorganic clay minerals such as Hoyoseyo Yoko).
These thickeners with internal shear thinning decrease the viscosity of the ink during writing, and as a result, writing and line cracking are less likely to occur during writing. Ink leakage is less when left alone. Among them, xanthan gum has a particularly large ink viscosity at the time of writing. As a result, writing and line breakage are less likely to occur during writing, stability against temperature changes, stability against pH, and stability against salt. This is particularly preferable.
The above thickeners can be used in a mixture of two or more types, but the amount used depends on the properties of each thickener, so it cannot be said unconditionally, but ink ejection during writing, handwriting blurring, line breakage, ink In consideration of leakage and the like, it is preferable that the ink viscosity is 30000 mPa · s or less when the shear rate is 10 sec ⁻¹ .
[0013]
Various resins can be used in combination as a binder for fixing the ink coloring material on the paper surface. Specifically, shellac, styrene-maleic acid copolymer, alkali metal salt of styrene-acrylic acid copolymer, amine salt, ammonium salt, alkali metal salt of α-methylstyrene-acrylic acid copolymer, A water-soluble resin such as the same amine salt or the same ammonium salt can be used. In addition, water-insoluble resins such as acrylic resins, vinyl acetate resins, and styrene-butadiene copolymers can also be used. The water-insoluble resin is used in the form of an aqueous emulsion.
[0014]
Water is used as the main solvent.
In addition to water, various water-soluble organic solvents are used for the purpose of preventing ink drying and preventing freezing at low temperatures. Specifically, alcohols such as ethanol, 1-propanol, 2-propanol, butyl alcohol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, hexylene glycol, 2-ethyl 1,3- Hexane glycol, glycerin, triethylene glycol, dipropylene glycol, diglycerin, polyethylene glycol, polypropylene glycol and other glycols, ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol ethyl ether and other ethers, thiodiglycol, N-methylpyrrolidone, 2-phenoxyethanol and the like can be used.
These can be used alone or in combination of two or more. The amount used is preferably 0.5 to 40% by weight based on the total amount of ink. If it is less than 0.5% by weight, the effect of preventing drying of the coated part is weak, and there is a possibility that it cannot be used. Even if it exceeds 60% by weight, the effect is not improved and the meaning of adding cannot be found.
[0015]
In addition to the above components, various additives conventionally used in water-based inks for writing instruments can be used as necessary.
For example, sugar alcohols such as sorbit and xylit are used to prevent ink evaporation, and polyethylene glycol, polyoxyethylene glycol polyoxypropylene glycol, alkali metal salts and amine salts of oleic acid, acyl to improve writing feeling A lubricant such as an alkali metal salt such as an amino acid, taurine, or methyl taurine, or an amine salt can be used.
[0016]
Furthermore, anionic, nonionic, cationic surfactants, silicone surfactants, fluorine surfactants and other surface tension modifiers, sodium dehydroacetate, 1,2-benzoisothiazin-3-one, etc. Anticorrosive agents such as benzotriazole and ethylenediaminetetraacetic acid, and alkali adjusters such as sodium hydroxide, alkanolamine, amine and ammonium can also be used as pH adjusters.
[0017]
As the ballpoint pen tip, a metal tip using metal for the ball holder and a resin tip mainly using synthetic resin can be used. Commonly used materials such as white, brass, and stainless steel can be used as the material for the ball holder using metal. Further, as a main material of the ball holder mainly made of synthetic resin, a general molding resin can be used, and 100% may be molded with these synthetic resins. Specifically, polyacetal resin, polybutylene terephthalate resin, aromatic nylon resin, modified polyphenylene ether resin, polyacrylate resin and the like can be used. Polyacetal resins, polyethylene terephthalate resins, and polybutylene terephthalate resins are particularly preferred because of the smooth writing feel.
Various fillers can be added to these resins for the purpose of improving lubricity, improving wear resistance, improving strength, and the like. Examples of the filler include molybdenum, potassium titanate, glass fiber, calcium carbonate, mica and the like. The amount of these fillers is preferably 30% or less. If added over 40%, the filler may be unevenly formed during molding and the shape of the chip may be impaired.
[0018]
Polyethylene, polypropylene, fluororesin, silicon resin, etc. can be used as the material for the ink containing tube that is directly filled with ink, but polypropylene is preferable in view of moisture permeability, transparency, cost, and the like.
[0019]
In the production of the ballpoint pen of the present invention, there is no particular problem by filling the ink by a conventional method.
For example, when ink is directly filled into the ink storage tube, the ink is allowed to stand under reduced pressure and filled with an ink in which dissolved gas in the ink is unsaturated, or a ballpoint pen filled with ink is centrifuged under normal pressure or reduced pressure. In other words, removing bubbles present in the ink or the backflow preventer is effective in the sense of preventing bubbles from being generated over time and preventing ink ejection at the tip of the chip. Here, in order to centrifuge under reduced pressure, a method of gradually reducing pressure while centrifuging or / or a method of centrifuging at first, a method of centrifuging after first depressurizing, a method of depressurizing while centrifuging and then releasing the decompression again There is a method of reducing the pressure, and in some cases, a method of repeatedly performing the pressure reduction and relaxing the pressure reduction.
[0020]
[Action]
When balls that use metals such as cobalt, chrome, titanium, etc. in the balls as binders such as silicon carbide, zirconia oxide, tungsten carbide, etc., which are the main components, are used in water-based ballpoint pens, these binders will become ink over time. Elution into the steel tends to cause so-called corrosion, but this corrosion is assumed to occur as follows.
First, when a metal or the like as a ball binding material elutes in the ink, electrons are generated, and the dissolved oxygen in the ink receives the electrons. The dissolved oxygen that has received the electrons reacts with water and becomes very reactive with a metal such as a hydroxyl radical, and binds to the eluted metal. It is assumed that corrosion progresses by repeating such a process. That is, it can be said that since the hydroxy radical formed by changing the dissolved oxygen promotes the elution of the metal, the corrosion proceeds rapidly, and the degree of the corrosion increases as the content of the metal as the binder increases.
Here, 1- (2-hydroxyethylthio) -2-propanol and thiodipropylene glycol prevent the corrosion of the ball, which is said to be so-called carbide, as compared with the conventional rust preventive agent. Whether the effect is remarkable is estimated as follows. That is, these compounds have a sulfide group or disulfide group in the molecule. The sulfur atom of the sulfide group or disulfide group has a lone electron pair, and the hydroxyl radical that promotes ball corrosion by the action of this lone electron pair is converted into a less reactive hydroxy ion, and the metal coming from the ball It is presumed that the reaction with the eluate is extremely suppressed, so that corrosion is prevented.
[0021]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples. In the examples, “parts” simply means “parts by weight”.
The viscosity was measured with an ELD viscometer manufactured by Tokimec Co., Ltd. Example 1 and Comparative Example 1 were measured using a standard cone rotor (1 ° 34 ′ × R24) at a shear rate of 191.5-1 s. Other than that, it measured by shear rate 10-1 s using ST type | mold rotor.
[0022]
Example 1
Water Blue 105S (CI ACID BLUE90, Orient Chemical Industry Co., Ltd.)
4.0 parts ethylene glycol 5.0 parts glycerin 3.0 parts dithiodiglycol 15.0 parts benzotriazole 0.5 parts sodium ascorbate 0.4 parts proxel GXL (1,2-benzisothiazolin-3-one , Antiseptic, manufactured by ICI Co., Ltd.) 0.2 parts ion exchange water 71.9 parts The above components are mixed, stirred in a lab mixer for 1 hour and dissolved uniformly to give a blue ink having a viscosity of 2.5 mPa · s. Obtained.
[0023]
Example 2
Water Red # 2 (CI ACID RED87, manufactured by Orient Chemical Industry Co., Ltd.) 5.0 parts Water Yellow # 6C (CI ACID YELLOW23, manufactured by Orient Chemical Industry Co., Ltd.) 3.0 parts Kelzan AR (Xanthan gum, manufactured by Sanki Co., Ltd.) 0.5 parts ethylene glycol 12.0 parts glycerin 6.0 parts 1- (2-hydroxyethylthio) -2-propanol 8.0 parts hydroquinone sulfonate 0.3 parts Sarcosinate OH (N-oleoyl sarcosine, surfactant, manufactured by Nikko Chemicals Co., Ltd.)
2.5 parts benzotriazole 0.5 part Proxel GXL 0.2 part AKP-20 (alumina, particle size 0.5 μm, manufactured by Sumitomo Chemical Co., Ltd.)
0.01 parts ion-exchanged water 55.29 parts In the above components, the entire amount of Kelzan AR and 5.0 parts of water were stirred and stirred uniformly for 30 minutes in a lab mixer to prepare a Kelzan aqueous solution. Next, the total amount of AKP-20 and glycerin was mixed and stirred uniformly, and then stirred for 15 minutes with a homogenizer to prepare an alumina dispersion. The remaining components were mixed and stirred for 1 hour, then an aqueous Kelzan AR solution and an alumina dispersion were added, and further mixed and stirred for 2 hours to obtain a red ink having a viscosity of 350 mPa · s.
[0024]
Comparative Example 1
A blue ink having a viscosity of 2.3 mPa · s was obtained in the same manner as in ink example 1 except that dithiodiglycol was removed and water was added correspondingly.
[0025]
Comparative Example 2
In Example 2 of the ink, except that 1- (2-hydroxyethylthio) -2-propanol was removed and the amount of water was increased accordingly, a red ink having a viscosity of 341 mPa · s was obtained in the same manner as in Example 2 of the ink. Obtained.
[0026]
About the ink obtained above, about Example 1 and Comparative Example 1, the ink was drawn out from Ball Pentel B-50 (the ball material is cemented carbide) and filled with the inks of Example 1 and Comparative Example 1. A sample was used. For the inks of Example 2 and Comparative Example 2, the ink was extracted from the hybrid K105-A (black ink, ball material was a carbide ball (containing 10.1% cobalt and 3% chromium as a binder)). The test samples were filled with the inks of Examples and Comparative Examples.
[0027]
【The invention's effect】
Corrosion test: The test sample was passed for 3 months with the pen tip facing downward at 50 ° C., and the surface roughness of the ball was measured with a scanning probe microscope SPI-400 manufactured by Seiko Instruments Inc.
Written taste: After the test sample was passed for 3 months with the pen tip facing downward at 50 ° C., the handwriting was handwritten, and sensory evaluation was performed with respect to the written taste and the presence or absence of faintness.
Table 1 shows the results.
[0028]
[Table 1]
[0029]
As described above in detail, according to the present invention, it is possible to prevent a problem that the writing quality becomes heavier or the handwriting is faded over time.

Claims (2)

At least one acid dye and / or pigment, a water-soluble organic solvent, water, and one or more selected from 1- (2-hydroxyethylthio) -2-propanol, thiodipropylene glycol, and dithiodiglycol Water-based ballpoint pen ink comprising sodium ascorbate or potassium hydroquinonesulfonate . The water-based ballpoint pen ink according to claim 1, wherein the ink contains a thickener .