JP2023020061A - Water-based ink composition for ballpoints - Google Patents

Abstract

To provide a water-based ink composition for a ballpoint that protects a ball from corrosion for a long period of time and can keep a smooth writing feel.SOLUTION: A water-based ink composition for a ballpoints contains at least water, a colorant, polyoxyethylene cetyl ether, and 2-pyridinethiol 1-oxide sodium.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an aqueous ink composition for ballpoint pens containing at least a colorant and water as a liquid medium.

A ball-point pen is basically composed of an ink containing tube containing ink, and a ball-point pen tip which is a pen point member connected directly or via a connecting member to the ink containing tube and allowing ink to flow therethrough. . A ball-point pen tip comprises at least a ball that contacts a writing surface to transfer ink, and a ball holder that rotatably holds the ball. As a ball for a ballpoint pen, a sintered body of tungsten carbide containing chromium, cobalt, etc. as a binding component is known, and such a material is so-called cemented carbide. Chromium, cobalt, etc., which are binding components in the cemented carbide ball, cause so-called corrosion in which the binding components are eluted into the ink by water contained in the water-based ink and oxygen present in or outside the ink. When the binding component is eluted, the tungsten carbide particles and the binding component such as cobalt are exposed on the surface of the ball.

In order to prevent this, there is an example (Patent Document 1) in which the amount of dissolved gas in the ink is reduced to a certain value or less by allowing the ink to stand under reduced pressure before being stored in the ink storage tube. An example of adding a polyphenol or a hydroquinone derivative, which is a reducing substance, is known (Patent Document 2).

JP-A-8-183923 Japanese Unexamined Patent Application Publication No. 2001-81389

In the invention described in Patent Document 1, a method is described in which the ink is left under reduced pressure before the ink is stored in the ink storage tube so that the amount of dissolved gas in the ink is reduced to a certain value or less. If the storage tube is made of resin, oxygen in the atmosphere permeates the ink storage tube over a long period of time and mixes with the ink, causing the amount of dissolved gas in the ink to exceed a certain value. could not get In the invention described in Patent Document 2, a method is described in which polyphenols and hydroquinone derivatives, which are substances having reducing properties, are added to the ink. However, there is a problem that peroxide radicals generated when a reducing substance and dissolved oxygen react with each other attack and dissolve the ball binding component. Furthermore, due to the decrease in dissolved oxygen in the ink, the oxygen concentration difference with the outside air increases, and an oxygen concentration cell is formed in the extremely small space at the tip of the ball holder, iron, the main component of the ball holder, is eluted, Furthermore, there is also the problem that the eluted iron turns into hydroxide and adheres to the surface of the ball, making the surface of the ball uneven, resulting in a loss of smoothness in writing.

The gist of the present invention is an aqueous ink composition for a ballpoint pen, comprising at least water, a colorant, polyoxyethylene cetyl ether, and sodium 2-pyridinethiol-1-oxide.

The polar groups of polyoxyethylene cetyl ether and sodium 2-pyridinethiol 1-oxide adsorb to the metal surface of the ball, forming a film on the ball surface with the hydrophobic groups facing away from the metal surface. The carbon chains of polyoxyethylene cetyl ether adsorbed on the ball metal surface cover over the 2-pyridinethiol 1-oxide sodium through hydrophobic interaction, forming a dense hydrophobic film on the ball metal surface. to form This dense hydrophobic film reduces the contact of water and oxygen with the surface of the ball, prevents elution of ball components, suppresses corrosion of the ball, and maintains a smooth writing feel.

1 is a longitudinal sectional view showing a writing instrument according to one embodiment; FIG. FIG. 2 is a longitudinal sectional view showing a refill used for the writing instrument shown in FIG. 1; 3 is an enlarged sectional view showing part I in FIG. 2; FIG. It is a longitudinal cross-sectional view of a test ball-point pen tip. 1 is a longitudinal sectional view showing a writing instrument according to one embodiment; FIG.

The coloring material used in the water-based ball-point pen ink of the present invention provides a coloring effect to the handwriting to make it visible, and includes dyes and pigments. Specific examples of dyes that can be used include acid dyes, direct dyes, basic dyes, and the like. For example, Japanol Fast Black D Conch (CI Direct Black 17), Water Black 100L (CI Direct Black 19), Water Black L-200 (CI 19), Direct Fast Black B (CI Direct Black 22), Direct Fast Black AB (32), Direct Deep Black EX (38), Direct Fast Black Conch (51), Kayaras Spragray VGN (71), Kayalas Direct Brilliant Yellow G (C.I. Direct Yellow 4) ), Direct Fast Yellow 5GL (26), Aizen Primula Yellow GCLH (44), Direct Fast Yellow R (50), Daiwa IJ Yellow 306H (123), Aizen Direct Fast Red FH (C.I. Direct Red) 1), Nippon Fast Scarlet GSX (4), Direct Fast Scarlet 4BS (23), Aizen Direct Laudurin BH (31), Direct Scarlet B (37), Kayaku Direct Scarlet 3B (39), AIZEN Primula Pink 2BLH (same as 75), Sumilite Red F3B (same as 80), Aisen Primula Red 4BH (same as 81), Kayaras Sprarubin BL (same as 83), Kayaras Light Red F5G (same as 225), Kayaras Light Red F5B (same as 226), Kayaras Light Rose FR (same as 227), Direct Sky Blue 6B (C.I. Direct Blue 1), Direct Sky Blue 5B (same as 15), Sumilite Supra Blue BRR Conch (same as 71), Daibogen Turquoise Blue S (86), Kayaras Turquoise Blue GL (86), Water Blue #3 (87), Kayaras Supra Blue FF2GL (106), Kayaras Splat Turquoise Blue FBL (199), etc. Direct dyes, 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), Aizen Opal Black WH Extra Conc (52), Sumiran Black WA (52), Ranil Black BG Extra Conch (107), Kayanol Milling Black TLB (Same 109), Suminol Milling Black B (same as 109), Kayanol Milling Black TLR (same as 110), Eisen Opal Black New Conc (same as 119), Water Black 187-L (same as 154), Water Black #256L, Kayaku Acid Brilliant Flavin FF (C. I. acid yellow 7:1), kayasil yellow GG (same as 17), xylene light yellow 2G 140% (same as 17), suminol leveling yellow NR (same as 19), daiwa tartrazine (same as 23), kayak tartrazine (same as 23), Water Yellow #1 (23), Suminol Fast Yellow R (25), Diacid Light Yellow 2GP (29), Suminol Milling Yellow O (38), Suminol Milling Yellow MR (42) ), Water Yellow #6C (42), Kayanol Yellow NFG (49), Suminol Milling Yellow 3G (72), Suminol Fast Yellow G (61), Suminol Milling Yellow G (78), Kayanol Yellow N5G (110), Suminol Milling Yellow 4G200% (141), Kayanol Yellow NG (135), Kayanol Milling Yellow 5GW (127), Kayanol Milling Yellow 6GW (142), Sumitomo Fast Scarlet A (C.I. Acid Red 8), Kayaku Silk Scarlet (9), Solar Rubin Extra (14), Daiwa New Coxin (18), Aizen Bonso RH (26), Daiwa Red 2 No. (No. 27), Suminol Leveling Brilliant Red S3B (No. 35), Kayacyl Rubinol 3GS (No. 37), Eisen Erythrosin (No. 51), Kayaku Acid Rhodamine FB (No. 52), Daiwa Red No. 106WB (No. 52) , Suminol Leveling Rubinol 3GP (57), Diacid Alizarin Rubinol F3G200% (82), Eisen Eosin GH (87), Daiwa Red No.103WB (87), Daiwa Red No104WB (92), Water Pink #2 (92), Eisen Acid Phloxin PB (92), Rose Bengal (94), Kayanol Milling Scarlet FGW (111), Kayanol Milling Brilliant Red 3BW (129), Suminol Milling Brilliant Red 3BN Conc (No.131), Sminor Milling Brilliant Red BS (No.138), Eizen Opal Pink BH (No.186), Sminor Milling Brilliant Red B Conch (No.249), Kayaku Acid Brilliant Red 3BL (No.254), Kayaku Acid Buri Lido Brilliant Red BL (265), Kayanol Milling Red G W (same as 276), Mitsui acid violet 6BN (C. I. Acid Violet 15), Mitsui Acid Violet BN (17), Sumitomo Patent Pure Blue VX (C.I. Acid Blue 1), Water Blue #106 (1), Patent Blue AF (7), Water Blue #9 (9), Daiwa Blue No. 1 (9), Water Blue #116 (15) Supranol Blue B (15), Orient Soluble Blue OBC (22), Suminol Leveling Blue 4GL (23) , Mitsui Nylon Fast Blue G (25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Saphyrol SE (43), Suminol Leveling Sky Blue R Extra Conch (62), Mitsui Nylon Fast Sky Blue B (78), Sumitomo Brilliant Indocyanin 6Bh/c (83), Sandran Cyanine N-6B 350% (90), Water Blue #105S (90), Fisco Blue 664 (90), Orient Soluble Blue OBX (93), Orient Soluble Blue OBB (93), Sumitomo Brilliant Blue 5G (103), Kayanol Milling Ultra Sky SE (112), Kayanol Milling Cyanin 5R (113), Eisen Opal Blue 2GLH (158), Water Blue #119, Daiwa Guinea Green B (C.I. Acid Green 3), Acid Brilliant Milling Green B (9), Daiwa Green #70 (16), Kayanol Cyanine Acid dyes such as Green G (25), Suminol Milling Green G (27), Eizencatilone Yellow 3GLH (CI Basic Yellow 11), Eizencatilone Brilliant Yellow 5GLH (13), Sumi Acrylic Yellow E-3RD (15), Maxiron Yellow 2RL (19), Astrazon Yellow 7GLL (21), Kayacryl Golden Yellow GL-ED (28), Astrazon Yellow 5GL (51), Eisencatilon Orange GLH (C.I. Basic Orange 21), Aizen Catilone Brown 3GLH (Same as 30), Rhodamine 6GCP (C.I. Basic Red 1), Aizen Astraphloxin (Same as 12), Sumiacryl Brilliant Red E-2B ( 15), Astrazon Red GTL (18), Eisenkatilon Brilliant Pink BG H (27), Maxiron Red GRL (46), Eisen Methyl Violet (C.I.). I. Basic Violet 1), Eisen Crystal Violet (3), Eisen Rhodamine B (10), Astrazon Blue G (C.I. Basic Blue 1), Astrazon Blue BG (3), Water Blue #10C (same 7), Methylene Blue (9), Maxiron Blue GRL (41), Aizen Catilone Blue BRLH (54), Aizen Diamond Green GH (C.I. Basic Green 1), Aizen Malachite Green (4), Basic dyes such as Bismarck Brown G (C.I. Basic Brown 1) are included.

Specific examples of pigments include organic pigments such as azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acid dye pigments, vat dye pigments, mordant dye pigments, and natural dye pigments. Pigments, ocher, barium yellow, ultramarine blue, Prussian blue, cadmium red, barium sulfate, titanium oxide, red iron oxide, iron black, inorganic pigments such as carbon black, aluminum powder, gold powder, silver powder, copper powder, tin powder, brass powder, etc. metal powder pigments, fluorescent pigments, mica-based pigments, and the like. Specific examples of carbon black include Mitsubishi carbon black #10B, #20B, #14, #25, #30, #33, #40, #44, #45, #45L, #50, #55, #95, #260, #900, #1000, #2200B, #2300, #2350, #2400B, #2650, #2700 , #4000B, CF9, MA8, MA11, MA77, MA100, MA220, MA230, MA600 and MCF88 (manufactured by Mitsubishi Chemical Corporation), Monarch 120, Monarch 700, Monarch 800, Monarch 880, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, Morgal L, Regal 99R, Regal 250R, Regal 300R, Regal 330R, Regal 400R, Regal 500 and Regal 660R (manufactured by Cabot Corporation, USA), Pudding Printex A, Printex G, Printex U, Printex V, Printex 55, Printex 140U, Printex 140V, Printex 35, Printex 40, Printex 45, Printex Printex 85, Ninepex 35, Special Black 4, Special Black 4A, Special Black 5, Special Black 6, Special Black 100, Special Black 250, Special Black 350, Special Black 550, Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200 , Color Black S150, Color Black S160 and Color Black S170 (manufactured by Degussa Japan Co., Ltd.), Raven 5000 Ultra II, Raven 2500 Ultra, Raven 1250, Raven 760 Ultra (manufactured by Columbian Carbon Japan Co., Ltd.) , C.I. I. Pigment Black 7, and the like. Specific examples of organic pigments include C.I. I. Pigment Red 170, C.I. I. Pigment 213, C.I. I. Pigment Orange 38, C.I. I. Pigment Blue 15, C.I. I. Pigment Violet 23, 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 (CI 12710), Pigment Yellow L (CI 12720), Benzidine Yellow (CI 21090), Benzidine Yellow G (CI 21095), Benzidine Yellow GR (CI 21100), Permanent Yellow NCG (CI 20040), Vulcan Fast Yellow 5G (CI 21220), Vulcan Fast Yellow R (CI 21135), Tartrazine Lake (CI 21135). I. 19140), Quinoline Yellow Lake (CI 47005), Anthragen Yellow 6GL (CI 60520), Permanent Yellow FGL, Permanent Yellow H10G, Permanent Yellow HR, Anthrapyrimidine Yellow (CI 68420) , Sudan I (CI 12055), Permanent Orange (CI 12075), Resol Fast Orange (CI 12125), Permanent Orange GTR (CI 12305), Hansa Yellow 3R (CI 12305). 11725), Vulcan Fast Orange GG (CI 21165), Benzidine Orange G (CI 21110), Persian Orange (CI 15510), Indanthrene Brilliant Orange GK (CI 59305), Indanthrene Brilliant Orange RK (CI 59105), Indanthrene Brilliant Orange GR (CI 71105), Permanent Brown FG (CI 12480), Para Brown (CI 12071), Permanent Red 4R (CI 12120), Para Red (CI 12070), Fire Red (CI 12085), Parachlororthoaniline Red (CI 12090), Lysol Fast Scarlet, Brilliant Fast Scarlet ( CI 12315), Brilliant Carmine BS, Permanent Red F2R (C . I. 12310), Permanent Red F4R (CI 12335), Permanent Red FRL (CI 12440), Permanent Red FRLL (CI 12460), Permanent Red F4RH (CI 12420), Fast Scarlet VD , Vulcan Fast Red Toner B (CI 12320), Vulcan Fast Pink G (CI 12330), Light Fast Red Toner B (CI 12450), Light Fast Red Toner R (CI 12455) , Permanent Carmine FB (CI 12490), Pyrazolone Red (CI 12120), Risol Red (CI 15630), Lake Red C (CI 15585), Lake Red D (CI .15500), Anthocine B (CI 18030), Brilliant Scarlet G (CI 15800), Lysol Rubin GK (CI 15825), Permanent Red F5R (CI 15865), Brilliant Carmine 6B ( CI 15850), Pigment Scarlet 3B (CI 16105), Bordeaux 5B (CI 12170), Toluidine Maroon (CI 12350), Permanent Bordeaux F2R (CI 12385), Helio Bordeaux BL (CI 14830), Bordeaux 10B (CI 15880), Bon Maroon Light (CI 15825), Bon Maroon Medium (CI 15880), Eosin Lake (CI 45380) ), rhodamine lake B (CI 45170), rhodamine lake Y (CI 45160), alizarin lake (CI 58000), thioindigo red B (CI 73300), thioindigo maroon ( CI 73385), Permanent Red FGR (CI 12370), PV Carmine HR, Watching Red, Monolite Fast Red YS (CI 59300), Permanent Red BL, Fast Violet B, Methyl Violet Lake (CI 42535), Dioxazine Violet, Alkali Blue Lake (CI 42750A, CI 42770A), Peacock Blue Lake (CI 42090), Peacock Blue Lake (CI 42025) , Victoria Blue Lake (CI 44045), Phthalocyanine Blue (CI 74160), Fast Sky Blue (CI 7) 4180), indanthrene blue RS (C.I. I. 69800), Indanthrene Blue BC (CI 69825), Indigo (CI 73000), Pigment Green B (CI 10006), Naphthol Green B (CI 10020), Green Gold ( CI 12775), acid green lake, malachite green lake (CI 42000), phthalocyanine green, etc., which are used by dispersing them in a liquid medium.

When a pigment is used as the colorant, a dispersant may be used to stably disperse the pigment. As the dispersant, conventionally used water-soluble resins or water-soluble resins, and those used as dispersants for pigments such as anionic or nonionic surfactants can be used. Examples of polymer dispersants include ligninsulfonates, natural polymers such as shellac, polyacrylates, salts of styrene-acrylic acid copolymers, salts of vinylnaphthalene-maleic acid copolymers, and β-naphthalene. Examples include anionic polymers such as sodium salts and phosphates of sulfonic acid-formalin condensates, 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-acylmethyl taurine salts, polyoxyethylene alkyl ether acetates, alkylsulfocarboxylates, α- Anionic surfactants such as olefin sulfonates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates; nonionic surfactants such as polyoxyethylene alkyl ethers, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters Surfactants are included. One or more of these water-soluble resins and surfactants can be selected and used in combination. The amount used is preferably 0.05% by weight or more and 20.0% by weight or less based on 10.0% by weight of the pigment.

Commercially available water-dispersible pigments are preferably used because they are easier to handle and more productive. Specific examples of water dispersion type pigments include Fuji SP Black 8031, Fuji 8119, Fuji 8167, Fuji 8276, Fuji 8381, Fuji 8406, Fuji SP Red 5096, Fuji 5111, Fuji 5193, Fuji 5220, Fuji SP Bordeaux 5500, Fuji ＳＰ Ｂｌｕｅ ６０６２、同６１３３、同６１３４、同６４０１、Ｆｕｊｉ ＳＰ Ｇｒｅｅｎ ７０５１、Ｆｕｊｉ ＳＰ Ｙｅｌｌｏｗ４０６０、同４１７８、Ｆｕｊｉ ＳＰ Ｖｉｏｌｅｔ ９０１１、ＦｕｊｉＳＰ Ｐｉｎｋ ９５２４、同９５２７、Ｆｕｊｉ ＳＰ Ｏｒａｎｇｅ ５３４、ＦＵｊｉ ＳＰ Ｂｒｏｗｎ ３０７４、ＦＵＪＩ ＳＰ ＲＥＤ 5543, 5544 (manufactured by Fuji Pigment Co., Ltd.), Emacol Black CN, Emacol Blue FBB, Emacol FB, Emacol KR, Emacol Green LXB, Emacol Violet BL, Emacol Brown3101, Emacol Carmmine FB, Emacol Red BS , Emacol Yellow FD, IRN, 3601, FGN, GN, GG, F5G, F7G, 10GN, 10G, Sandye Super Black K, C, Sandye Super Gray B, Sandye Super Brown SB, FRL, RR, Sandye Super Green L5G, GXB, Sandye Super Navy Blue HRL, GLL, HB, FBL-H, FBL-160, FBB, Sandye Super Violet BL H/C, BL, Sandye Ｓｕｐｅｒ Ｂｏｒｄｅａｕｘ ＦＲ、Ｓａｎｄｙｅ Ｓｕｐｅｒ Ｐｉｎｋ ＦＢＬ、同Ｆ５Ｂ、Ｓａｎｄｙｅ Ｓｕｐｅｒ Ｒｕｂｉｎｅ ＦＲ、Ｓａｎｄｙｅ ｓｕｐｅｒＣａｒｍｍｉｎｅ ＦＢ、Ｓａｎｄｙｅ Ｓｕｐｅｒ Ｒｅｄ ＦＦＧ、同ＲＲ、同ＢＳ、同１３１５、Ｓａｎｄｙｅ Ｓｕｐｅｒ Ｏｒａｎｇｅ ＦＬ、同Ｒ、同ＢＯ、Ｓａｎｄｙｅ Ｇｏｌｄ Ｙｅｌｌｏｗ ５ＧＲ , R, 3R, Sandye Y wllow GG, F3R, IRC, FGN, GN, GRS, GSR-130, GSN-130, GSN, 10GN (manufactured by Sanyo Pigment Co., Ltd.), Rio Fast Black Fx 8012,同８３１３、同８１６９、Ｒｉｏ Ｆａｓｔ Ｒｅｄ Ｆｘ ８２０９、同８１７２、Ｒｉｏ Ｆａｓｔ Ｒｅｄ Ｓ Ｆｘ ８３１５、同８３１６、Ｒｉｏ Ｆａｓｔ Ｂｌｕｅ Ｆｘ ８１７０、Ｒｉｏ Ｆａｓｔ Ｂｌｕｅ ＦＸ ８１７０、Ｒｉｏ Ｆａｓｔ Ｂｌｕｅ Ｓ Ｆｘ ８３１２、Ｒｉｏ Ｆａｓｔ Ｇｒｅｅｎ Ｓ Ｆｘ ８３１４ , EM green G, (manufactured by Toyo Ink Co., Ltd.), NKW-2101, 2102, 2103, 2104, 2105, 2106, 2107, 2108, 2117, 2127, 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, 3602, 3603, 3604, 3605, 3607, 3677, 3608, 3702, 3703, 3704, 3705, 3777, 3708, 6013, 6038, 6559 (manufactured by Nippon Kanko Co., Ltd.), Cosmocolor S1000F series (manufactured by Toyo Soda Co., Ltd.), Victoria Yellow G-11, Victoria G-20, Victoria Orange G-16, Victoria G-21, Victoria Red G-19, Victoria G-22, Victoria Pink G-17, Victoria G-23, Victoria Green G-18, G-24, Victoria Blue G-15, G-25 (manufactured by Mikuni Color Co., Ltd.), Pollux series such as Pollux PC5T1020, Pollux Black PC8T135, Pollux Red IT1030 (manufactured by Sumika Color Co., Ltd.) ) and the like. The above dyes and pigments can be used singly or in combination.

Water is used as the main solvent for the ink. In the present invention, the main solvent means a solvent that accounts for 50% by weight or more of the total amount of solvent in the total amount of the ink composition. It is preferable to use ion-exchanged water or purified water.
Furthermore, conventionally known organic solvents can be used in combination for the purpose of various ink qualities, such as prevention of ink freezing at low temperatures and prevention of drying of the ink at the nib of the pen. Specific examples of organic solvents include ethylene glycol, diethylene glycol, triethylene glycol, hexylene glycol, 1,2-propanediol, 1,3-butanediol, 2-ethyl-1,3-hexane glycol, propylene glycol, and polypropylene glycol. , dipropylene glycol, polyethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, thiodiethylene glycol, glycerin, diglycerin, benzyl glycol, glycols such as benzyl diglycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether , diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, dipropylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl Glycol ethers such as ether, ethylene glycol monophenyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monophenyl ether , ethanol, 1-propanol, 2-propanol, butyl alcohol, isopropyl alcohol, 3-methyl-3-methoxy-1-butanol, benzyl alcohol, α-methylbenzyl alcohol, lauryl alcohol, tridecyl alcohol, isododecyl alcohol, iso Examples include alcohol solvents such as tridecyl alcohol, propylene glycol methyl ether acetate, propylene glycol diacetate, 2-pyrrolidone, N-methyl-2-pyrrolidone, sulfolane, γ-butyrolactone, 2-phenoxyethanol and the like. One or more of these can be selected and used in combination. Moreover, the amount used is preferably 2.0% by weight or more and 50.0% by weight or less based on the total amount of the ink. When the content is 2.0% by weight or more and 50.0% by weight or less, the effect of preventing the tip of the pen from drying out is easily obtained, which is preferable. The amount of water used in the present invention is preferably 30% by weight or more with respect to the total amount of the ink composition.

2-Pyridinethiol 1-oxide sodium is adsorbed on the surface of the ball, forms a dense film with polyoxyethylene cetyl ether, and is used to prevent elution of binding components of the ball. Examples of 2-pyridinethiol 1-oxide sodium include Sanai Bac Sodium Omazine and San Ibac P-100 manufactured by Sanai Oil Co., Ltd., and Sodium Omazine manufactured by Lonza Japan. The amount of sodium 2-pyridinethiol 1-oxide used is preferably 0.001% by weight or more and 1.00% by weight or less, more preferably 0.05% by weight or more and 0.50% by weight or less, relative to the total amount of the ink composition. . When it is 0.001% by weight or more and 1.00% by weight or less with respect to the total amount of the ink composition, it is preferable because it is easy to form a denser film with polyoxyethylene cetyl ether and it is easy to prevent elution of the binding component of the ball. A content of 0.005% by weight or more and 0.50% by weight or less is particularly preferable because the effect can be exhibited more easily.

Polyoxyethylene cetyl ether is used to adsorb to the surface of the ball, form a dense film through hydrophobic interaction with sodium 2-pyridinethiol 1-oxide, and prevent elution of binding components of the ball. Examples of polyoxyethylene cetyl ether include NIKKOL BC-2 (HLB value 8.0), NIKKOL BC-5.5 (HLB value 10.5), and BC-7 (HLB value 11.0) manufactured by Nikko Chemicals Co., Ltd. 5), BC-10 (HLB value 13.5), BC-15 (HLB value 15.5), BC-20 (HLB value 17.0), BC-23 (HLB value 18.0) , the same BC-25 (HLB value 18.5), the same BC-30 (HLB value 19.5), the same BC-40 (HLB value 20.0), NOF Corporation nonionic P-202 (HLB 5.3), P-207 (HLB value 11.2), P-208 (HLB value 11.9), P-210 (HLB value 12.9), P-213 (HLB value 14 .1), same P-220 (HLB value 15.7), same P-223 (HLB value 16.1), same P-230 (HLB value 16.9), same P-240 (HLB value 17.6 ), EMALEX 102 (HLB value 5), 103 (HLB value 6), 104 (HLB value 7), 105 (HLB value 8), 107 (HLB value 10) manufactured by Nippon Emulsion Co., Ltd. 112 (HLB value 12), 115 (HLB value 13), 117 (HLB value 13), 120 (HLB value 14), 125 (HLB value 15), BLAUNON CH- manufactured by Aoki Oil Industry Co., Ltd. 302 (HLB value 5.7), CH-305 (HLB value 9.4), CH-308 (HLB value 11.4), CH-310 (HLB value 13.2), CH-310 ( HLB value 12.9), CH-313 (HLB value 13.7), CH-315 (HLB value 14.3), CH-320 (HLB value 15.5), CH-325 (HLB value 16.3), CH-330 (HLB value 16.7), CH-340 (HLB value 17.4), CH-340F (HLB value 17.4), CR-640 (HLB value 17.4) 6) and CR-640F (HLB value 17.6). The HLB value of polyoxyethylene cetyl ether is preferably 8 or more and less than 14, more preferably 8 or more and less than 12. When the HLB value is 8 or more, the polyoxyethylene cetyl ether tends to be stably dispersed in the ink composition, and the polyoxyethylene cetyl ether existing on the ball surface tends to become more dense, which prevents the elution of the binding components of the ball. It is preferable because it is easy to prevent. On the other hand, when the HLB value is less than 14, the carbon chain of polyoxyethylene cetyl ether can more easily cover 2-pyridinethiol 1-oxide sodium, the hydrophobic film becomes stronger, and the binding component of the ball becomes stronger. It is preferable because the effect of preventing elution is likely to be exhibited, and an HLB value of less than 12 is particularly preferable because the effect is more likely to be exhibited. When the amount of polyoxyethylene cetyl ether used is 0.1% by weight or more relative to the total amount of the ink composition, it is easy to form a denser film, and it is easier to prevent elution of the binding component of the ball. On the other hand, when it is 3.0% by weight or less with respect to the total amount of the ink composition, ink ejection from the pen tip tends to be stable, which is preferable. Polyoxyethylene cetyl ether may be blended after preparing a polyoxyethylene cetyl ether dispersion by adding polyoxyethylene cetyl ether to deionized water and mixing and stirring in advance. Mixing and stirring may be performed by heating.

In the present invention, the water-based ink composition for ballpoint pens has a high viscosity when standing still, which suppresses ink leakage from the nib, and when writing, the viscosity is reduced by the shearing force of the rotating ball, and the ink is ejected smoothly. Saccharides can be used for the purpose of obtaining shear thinning properties to allow the viscosity to increase. Specific examples include HPC-SL, HPC-L, HPC-M, HPC-H (hydroxypropyl cellulose, manufactured by Nippon Soda Co., Ltd.), Avicel PH-101, PH-102, PH-301, and M06. , TG-101, Ceorus SC-900, SC-900S, RC591S, RC-N81, RC-N30, CL-611S, DX-2, DX-3, UF-F711, Celluloses such as UF-F702, ST-100, ST-02, FD-101, FD-301, FD-F20, Ceorus Fiber DF-17 (crystalline cellulose, manufactured by Asahi Kasei Corporation), etc. , Kelzan, S, T, ST, ASX, ASXT, AR, HP, G, Ketorol CG, CG-T, CG-SFT (manufactured by Sansho Co., Ltd.), San Ace, S, C, CS, BS, NF, G, ES, NXG-S, NXG-C, Bistop D-3000-DF, D- 3000-DF-C (manufactured by San-Ei Gen FSI Co., Ltd.), Kohjin, F, T, K (manufactured by KOHJIN Co., Ltd.), Echo Gum, 630, F, Same T, Same GM, Same RD, Same SF, Same 521, Same LAX-T, Monart Gum GS, Same HP, Same HS, Same KT, Minit GR, Same MA, Same Salt (above, DSP Gokyo Food & Chemical ( Co., Ltd.), Nomucoat (manufactured by Nisshin Oil Co., Ltd.), Inagel V-7, V-7T (manufactured by Ina Food Industry Co., Ltd.), xanthan gum, leozan (succinoglucan, Sansho Co., Ltd.) ), Welan gum such as K1A96, BG3810 (manufactured by Sansho Co., Ltd.), Ramsan gum such as K1A112, K7C2433 (manufactured by Sansho Co., Ltd.), Jaguar 8111, 8600, HP-8, the same Guar gums such as HP-60 and CP-13 (manufactured by Sansho Co., Ltd.), pullulan (water-soluble polysaccharide, manufactured by Hayashibara Shoji Co., Ltd.), Rheologic 250H (manufactured by Nippon Junyaku Co., Ltd.), Junron Crosslinked acrylic acid resin such as PW111 (manufactured by Nippon Junyaku Co., Ltd.), U Jelly CP (manufactured by Showa Denko Co., Ltd.), Carbopol 934, Carbopol 940, Carbopol 941, Carbopol 980, Carbopol 981 , Carbopol 1342, Carbopol 1382, Carbopol 2984, Carbopol 5984, Carbopol ETD2020, Carbopol ETD2050, EZ-1, Pemulen TR-1, Pemulen TR-2 (manufactured by Lubrizol, United States of America) and other alkyl acrylate methacrylate copolymers, GX-205, NA-010 (manufactured by Showa Denko KK) and other N-vinylacetamide polymerized and crosslinked products, and the like. Other examples include sage eutan gum, alkasilan, alkasi gum, zeta sea gum, gellan gum, psyllium seed gum, tamarind seed gum, tragacanth gum, galactomannan, carrageenan, gati gum, karaya gum, and salts thereof. In particular, xanthan gum has a large shear thinning property, which greatly reduces the viscosity of the ink during writing. It is particularly preferred in terms of stability and compatibility with acylamino acids and/or salts thereof. Xanthan gum is a polysaccharide consisting of glucose, mannose and glucuronic acid separated and purified from the culture broth of Xanthomonas. These saccharides can be adjusted in viscosity, viscoelasticity, and shear thinning property by heat-treating the saccharides or by applying high pressure to the saccharide solution and applying high shear when passing through a nozzle. The amount of saccharide used is preferably 0.05% by weight or more and 5.0% by weight or less with respect to the total amount of the ink composition, but in order to maintain the performance as a ballpoint pen, it is 0.1% by weight or more with respect to the total amount of ink2. 0% by weight or less is more preferable. When the amount is 0.05% by weight or more based on the total amount of the ink composition, the ink is less likely to leak, which is preferable. On the other hand, when it is 5.0% by weight or less based on the total amount of the ink composition, the ink ejection from the pen tip becomes more stable, and the writing feeling becomes better, which is preferable.

Fine particles can also be added to prevent wear of the ball holder. Specific examples of fine particles include alumina, silicon carbide, chromium oxide, boron carbide, zircon, amethyst, jadeite, calcium fluoride, tungsten carbide, silica, diamond, garnet, aluminum nitride, and silicon nitride. . Among them, alumina is preferable because it can form a stronger saccharide network structure when used in combination with saccharides. As the alumina particles, high-purity alumina AKP-53 (central particle diameter 0.17 μm), AKP-50 (central particle diameter 0.20 μm), and AKP-30 (central particle diameter 0.20 μm) manufactured by Sumitomo Chemical Co., Ltd. are used. 30 μm), AKP-20 (median particle size 0.46 μm), AKP-3000 (median particle size 0.70 μm), AA-03 (median particle size 0.44 μm), AA-04 (median particle size 0.50 μm), AA-05 (median particle size 0.53 μm), AA-07 (median particle size 0.83 μm), WA#30000 (median particle size 0.35 μm) manufactured by Fujimi Incorporated Co., Ltd. , WA#20000 (median particle size 0.45 µm), WA#10000 (median particle size 0.60 µm), WA#8000 (median particle size 1.2 µm), WA#6000 (median particle size 2.0 µm), Harzok Alumina powder AP005 (central particle size 0.05 μm), AP01 (central particle size 0.1 μm), AP03 (central particle size 0.3 μm), AP1 (central particle size 1 μm), etc. manufactured by Japan Co., Ltd. be done. The median particle size of alumina was determined by adding alumina to ethanol and dispersing it with ultrasonic waves for 20 minutes. was measured using The median particle diameter is the diameter at which the larger powder and the smaller powder are equal when the powder is divided into two from a certain particle diameter. is also called The amount of these fine particles used is preferably 0.001% by weight or more and 10% by weight or less, more preferably 0.003% by weight or more and 0.05% by weight or less, relative to the total amount of the ink composition. These fine particles may be used alone or in combination of two or more.

Styrene-acrylic acid resin emulsions can also be used to impart hand greasy writing stability over long distance writing. Specific examples include Joncryl 7100 (solid content acid value 51, solid content 48%, average particle size 0.10 μm) manufactured by BASF Japan Ltd., 390 (solid content acid value 54, solid content 46%, average PDX7326 (solid content acid value: 38, solid content: 38.5%, average particle size: 0.10 µm), PDX7370 (solid content acid value: 87, solid content: 42%, average particle size: 0.10 µm). 08 μm), PDX7341 (solid acid value 51, solid content 49%, average particle size 0.10 μm), 8380 (solid acid value 19, solid content 41%, average particle size 0.09 μm), 8300 ( Solid content acid value 60, solid content 43.5%, average particle size 0.09 μm), 74J (solid content acid value 51, solid content 45%, average particle size 0.08 μm), 8383 (solid content acid value 23, solid content 40%, average particle size 0.09 μm), PDX7323 (solid content acid value 87, solid content 42%, average particle size 0.08 μm), PDX7734 (solid content acid value 89, solid content 41.1 μm). 4%, average particle size 0.09 μm), PDX7775 (solid content acid value 55, solid content 45%, average particle size 0.08 μm), PDX 7741 (solid content acid value 52, solid content 49%, average particle size 0.10 μm), PDX7677 (solid content acid value 70, solid content 46%, average particle size 0.01 μm), PDX 7600 (solid content acid value 60, solid content 47%, average particle size 0.09 μm), 775 (solid content acid value 55, solid content 45%, average particle size 0.08 μm), 537 J (solid content acid value 40, solid content 46%, average particle size 0.07 μm), 352 J (solid content acid value 51, solid content 45%, average particle size 0.10 μm), 352D (solid content acid value 51, solid content 45%, average particle size 0.10 μm), PDX7145 (solid content acid value 32, solid content 50% , average particle size 0.16 μm), 538J (solid content acid value 61, solid content 45%, average particle size 0.10 μm), 8311 (solid content acid value 26, solid content 42%, average particle size 0.10 μm). 09 μm), PDX7667 (solid acid value 82, solid content 45%, average particle size 0.09 μm), PDX7700 (solid acid value 60, solid content 48%, average particle size 0.10 μm), 7641 ( Solid content acid value 60, solid content 52%, average particle size 0.10 μm), 780 (solid content acid value 46, solid content 48%, average particle size 0.10 μm), 7610 (solid content acid value 50, Solid content 52%, average particle size 0.13 μm), PDX7643 (solid content acid value 64, solid content 51.5%, average particle size 0.14 μm), PDX7690 (solid content Acid value 85, solid content 42.5%, average particle size 0.10 μm), PDX7511 (solid content acid value 54, solid content 45.0%, average particle size 0.09 μm), PDX7164 (solid content acid solid content 47.0%, average particle size 0.17 μm), same PDX7430 (solid content acid value 20, solid content 38.0%, average particle size 0.12 μm), same PDX7440 (solid content acid value 1 , solid content 48.5%, average particle size 0.25 μm), PDX7480 (solid content acid value 18, solid content 44.0%, average particle size 0.10 μm), PDX7357 (solid content acid value 59, solid content content 49.5%), PDX7616A (solid content acid value 38, solid content 44%), PDX7732 (solid content acid value 87, solid content 41.4%, average particle size 0.10 μm), PDX7787 (solid content PDX7356 (solid content acid value 78, solid content 45.5%), PDX7615 (solid content acid value 51, solid content 50.5%). 5%, average particle size 0.12 μm), PDX7158 (solid content acid value 54, solid content 41%), PDX7199 (solid content acid value 31, solid content 49.5%, average particle size 0.27 μm), PDX7538 (solid content acid value: 62, solid content: 45.5%, average particle size: 0.08 µm), PDX7780 (solid content: acid value: 46, solid content: 48%, average particle size: 0.10 µm). These styrene-acrylic acid resin emulsions may be used alone or in combination of two or more.

Various resins can be used together as a binder to fix the coloring material of the ink on the paper surface. Specifically, shellac, styrene-maleic acid copolymer, alkali metal salt, amine salt, ammonium salt of styrene-acrylic acid copolymer, 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. Water-insoluble resins such as acrylic resins, vinyl acetate resins, and styrene-butadiene copolymers can also be used. Incidentally, the water-insoluble resin is used in the form of an aqueous emulsion.

In addition to the above components, various additives conventionally used in water-based inks for writing instruments can be used as needed. For example, sugar alcohols such as sorbitol, xylite, tetrit, pentite, hexite, inositol, maltitol, maltotritol, maltotetratol, maltopentatol, maltohexatol, and maltoheptitol, and urea are used to prevent ink from evaporating. , Ethylene urea and derivatives thereof can be used, specifically, PO-10, PO-20, PO-30, PO-40 (manufactured by Towa Kasei Kogyo Co., Ltd.), SE 30, SE 100 (manufactured by Nikken Chemical Co., Ltd.), Daiator L (manufactured by Sanei Saccharification Co., Ltd.), and the like. In addition, in order to improve the writing feeling, lubricants such as polyethylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, alkali metal salts such as oleic acid, acyl amino acids, taurine, methyl taurine, and amine salts can be used. Specifically, NIKKOL sarcosinate CN-30, sarcosinate CT-30, sarcosinate LH, sarcosinate LN, sarcosinate LN-30, sarcosinate LK-30, sarcosinate MN, sarcosinate OH, sarcosinate OHV, Sarcosinate PN, CMT-30, CMT30-T, LMT, LMT-30, MMT, PMT, and SMT (manufactured by Nikko Chemicals Co., Ltd.).

In addition, fatty acid soaps, n-acyl amino acid salts, alkyl ether carboxylates, carboxylic acid salts such as acylated peptides, alkyl sulfonates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, sulfosuccinates, α-olefin sulfones acid salts, sulfonates such as N-acylsulfonates, sulfated oils, sulfate ester salts such as alkyl sulfates, alkyl ether sulfates, alkyl allyl ether sulfates, alkylamide sulfates, alkyl phosphates, alkyl Anionic surfactants such as ether phosphates, phosphate salts such as alkylallyl ether phosphates, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, poly Oxyethylene monotetradecyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene polyoxypropylene cetyl ether, polyethylene glycol monostearate, polyethylene glycol distearate, monococonut fatty acid polyoxyethylene sorbitan, polyoxyethylene sorbitan monopalmitate, Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene water-added hydrogenated castor oil, decaglyceryl monolaurate, sucrose stearate, sucrose palmitate, sucrose myristate, sucrose olein Acid esters, nonionic surfactants such as sucrose laurate, tetramethylammonium chloride, tetramethylammonium hydroxide, tetrabutylammonium chloride, dodecyldimethylbenzylammonium chloride, alkyltrimethylammonium chloride, alkyltrimethylammonium bromide, chloride Cations such as benzyltrimethylammonium, benzalkonium chloride, benzartonium bromide, benzethonium chloride, dialkyldimethylammonium chloride, monomethylamine hydrochloride, dimethylamine hydrochloride, trimethylamine hydrochloride, butylpyridinium chloride, dodecylpyridinium chloride, cetylpyridinium chloride, etc. surfactants, PEG11 methyl ether dimethicone, PEG/PPG-20/22 butyl ether dimethicone, PEG-9 dimethicone, PEG-3 dimethicone, PEG-9 methyl ether dimethicone, PEG-10 dimethicone, PEG-32 Methyl Ether Dimethicone, PEG-9 Polydimethylsiloxyethyl Dimethicone, Lauryl PEG-9 Polydimethylsiloxyethyl Dimethicone, Polyglyceryl-3 Disiloxane Dimethicone, Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Lauryl Polyglyceryl-3 Polydimethylsiloxyethyl Surface of fluorine-based surfactants such as silicone-based surfactants such as dimethicone, perfluorobutanesulfonates, perfluoroalkyl group-containing carboxylates, perfluoroalkylethylene oxide adducts, perfluoroalkyl group-containing phosphate esters, etc. Preservatives such as tension regulators, sodium dehydroacetate and 1,2-benzisothiazalin-3-one may also be used as necessary. Benzothiazoline preservatives include Proxel GXLS and Proxel GXL (manufactured by Lonza Japan Co., Ltd.). A rust inhibitor such as benzotriazole may be combined. Alkalinizing agents such as sodium hydroxide, monoethanolamine, diethanolamine, triethanolamine, amines and ammonium can also be used as pH adjusters.

The water-based ink composition for ballpoint pens of the present invention has a viscosity of 50 mPa·s or more and 30000 mPa·s or less at a temperature of 25°C and a shear rate of 0.35/s. By adjusting the viscosity at a speed of 35 / s to 50 mPa s or more and 3000 mPa s or less, the writing feel, the uniformity of the handwriting, the handwriting density, the control of the so-called ink blobs that are applied to the paper surface, and the suppression of bleeding , Ink ejection stability, Control of handwriting strike-through on paper, Suppression of handwriting blurring, Writing performance when dry, Suppression of ink dripping, Suppression of ink leakage from the gap between the ball and tip when the ballpoint pen is not in use, Writing tip It is preferable because it suppresses backflow of ink when left facing upward, and ensures writing performance such as suppression of sedimentation and separation of pigment etc. and storage stability.

Various conventionally known methods can be employed for producing the ink composition of the present invention. For example, water, solvent, and polysaccharide are put into a high-shearing agitator such as a Henschel mixer, propeller agitator, homogenizer, turbo mixer, or high-pressure homogenizer, and after stirring and dispersing, the Henschel mixer, propeller agitator, homogenizer, or turbo mixer , a high-pressure homogenizer, a ball mill, a bead mill, a roll mill, or another dispersing machine, the colorant and other remaining ingredients are added, and the mixture is stirred to obtain the mixture. Moreover, in these preparation steps, the dispersion heat generated can be used as it is for stirring, heat can be applied, or cooling and stirring can be performed. If necessary, removal of foam by a defoamer, filtration of coarse matter by a filter, and the like may be performed. Furthermore, an aging step may be performed after preparing the ink in order to ensure sufficient dispersibility of the polysaccharide. These various mixing steps, dispersing steps, filtering steps, heating steps, or cooling steps may be performed independently, or two or more steps may be performed in parallel. When blending a material with a high specific gravity such as alumina, an alumina dispersion is prepared by adding alumina to a highly viscous liquid such as an aqueous solution containing glycerin or a thickening agent and mixing and stirring. It may be blended after preparation. In the case where an alumina dispersion is not used, immediately after alumina is added and mixed and stirred, a thickener may be added to increase the viscosity while mixing and stirring, or a thickener may be added to increase the viscosity. After that, alumina may be added and mixed and stirred. A substance such as benzotriazole that is difficult to dissolve in ion-exchanged water may be blended after preparing an ethylene glycol solution of benzotriazole by previously adding benzotriazole to ethylene glycol and mixing and stirring. Sarcosinate OHV and other substances that are difficult to dissolve in ion-exchanged water when unneutralized may be added after preparing a neutralized aqueous solution of sarcosinate OHV by neutralizing sarcosinate OHV with NaOH, triethanolamine, etc. in advance. . A deliquescent substance such as sodium hydroxide may be added after preparing an aqueous sodium hydroxide solution by adding sodium hydroxide to ion-exchanged water and mixing and stirring.

In addition, an ink backflow prevention member is arranged at the interface position of the ink in the ink storage tube to suppress unintended movement of the ink to the opposite side of the pen tip and ink leakage from the rear opening of the ink storage tube due to the movement. be able to. When the ink backflow preventive is a liquid composition, a non-volatile and/or hardly volatile liquid can be used. Specifically, petrolatum, 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 include polyether-modified silicone oil and fatty acid-modified silicone oil. These nonvolatile and/or hardly volatile liquids may be used alone or in combination of two or more. The non-volatile and/or hardly volatile liquid is preferably thickened to a suitable viscosity by adding a gelling agent. Chemically treated silica, aluminum silicate, swelling mica, hydrophobically treated clay thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate and zinc stearate, tribenzylidene Examples include sorbitol, fatty acid amides, amide-modified polyethylene wax, hydrogenated castor oil, dextrin compounds such as fatty acid dextrin, and cellulose compounds. Among them, fatty acid metal soaps, fatty acid dextrins, and amide-modified polyethylene waxes are preferably used because of their excellent gel solvent resistance. In addition, fine particles such as alcohol-based solvents, glycol-based solvents, surfactants, resins, metal oxides, etc., can be added for the purpose of adjusting gel strength and viscosity, preventing coloring of backflow preventives, and providing backflow prevention functions. . In addition, a solid such as a synthetic resin column called a float is placed in the ink backflow preventive composition to narrow the apparent space where the backflow preventive composition is placed, thereby You may make it hard to move and improve impact resistance.

Hereinafter, several embodiments of a ball-point pen using the water-based ink composition for ball-point pens of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, and are merely illustrative examples. do not have.

FIG. 1 is a vertical cross-sectional view showing a writing instrument according to one embodiment. 2 is a longitudinal sectional view showing a refill portion of the writing instrument shown in FIG. 1. FIG.
As shown in FIG. 2, the refill 200 includes a ballpoint pen tip 1 as a writing portion, an ink storage tube 3 as an ink storage portion in which an ink composition 2 supplied to the ballpoint pen tip 1 (writing portion) is stored, Prepare. A transparent member or an opaque member may be used for the ink storage tube, and an illustration or the like may be written on the ink storage tube, the ink storage tube may be colored, or the ink storage tube may be decorated with a transfer film or the like. It is preferable to use a transparent member for the ink storage tube because the remaining amount of ink and the color of the ink can be visually recognized. It is preferable to use an opaque member or a transparent member that blocks ultraviolet rays for the ink storage tube, because it is possible to suppress deterioration and discoloration of the ink due to ultraviolet rays. The inner diameter of the ink storage tube may be 1.0 mm or more and 5.0 mm or less. In particular, when the inner diameter of the ink containing tube is 1.0 mm or more and 3.1 mm or less, the shape retention of the ink backflow preventive is good, and the ink backflow preventive does not flow out or the float comes into contact with the ink backflow preventive. It is preferable because the ink backflow preventive does not flow out even if the . The thickness of the ink storage tube can be determined by the ratio of the outer diameter to the inner diameter, and the thickness of the ink storage tube may be 0.5 mm or more and 10.0 mm or less. When the thickness of the ink storage tube is 1.0 mm or more and 10.0 mm or less, the gas barrier property is high and the solvent evaporation of the ink can be prevented. Therefore, it is more preferable.

In the exemplary embodiment shown in FIGS. 1 and 2, writing instrument 100 includes refill 200 and outer body 300 . A transparent member may be used for the exterior body, or an opaque member may be used. It is preferable to use a transparent member for the outer package and the ink storage tube because the remaining amount of ink and the color of the ink can be visually recognized without removing the outer package. It is preferable to use a transparent member for the exterior body to write an illustration or the like on the ink storage tube or to color the ink storage tube, because the illustration and color of the ink storage tube can be visually recognized without removing the exterior. Furthermore, if a transparent member is used for the exterior body and an ink storage tube having the same color as the ink is used, the ink color can be visually recognized without writing. It is preferable to use an opaque member or a transparent member that blocks ultraviolet rays for the exterior, since deterioration and discoloration of the ink due to ultraviolet rays can be suppressed. An illustration or the like may be written on the exterior body, or it may be colored, or decorated with a transfer film or the like. Luster pigments such as aluminum flakes, glass flakes, pearl pigments, etc. may be used in one or more of them as appropriate in the members of the exterior body and the ink storage tube.

In the embodiment shown in FIG. 1, the exterior body 300 is composed of a barrel 4 to which the front shaft 5 and the rear shaft 6 are detachably fixed by screwing. The surface of the front axle 5 made of a relatively hard resin material is covered with a relatively soft resin material (soft member) as a grip portion 7 . Examples of relatively hard resin materials forming the front and rear barrels 5 and 6 include polycarbonate, polyethylene terephthalate, acrylic, acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene copolymer (AS), and polypropylene. etc., and a transparent member may be used, or an opaque member may be used. The relatively soft resin material (soft member) forming the grip portion 7 includes thermoplastic elastomer, soft acrylic, etc. A transparent member may be used, or an opaque member may be used. The grip portion 7 is preferably a non-slip grip such as a grip having an uneven surface, a grip having a triangular shape, a grip having a polygonal outer surface, a grip having a shape imitating a fingerprint, or the like. A crown 8 is inserted into the inner hole of the rear barrel 6 and fixed to the rear portion of the rear barrel 6 by means of concave-convex screwing. It is arranged to cover the base surface of the clip 9 attached. The head crown 8 has a cylindrical shape, and the groove formed inside it serves as the cam groove of the debit cam mechanism, which regulates the sliding position of the rotor 10 that is housed therein. As the rotor 10 rotates, the forward/backward movement position of the ball-point pen refill 200 connected thereto is defined.
A ball-point pen refill 200 is arranged in the barrel 4 so as to be movable back and forth. An elastic member 12 such as a coil spring is arranged in front of the ball-point pen refill 200 to urge the ball-point pen refill 200 rearward. The rear end of the ballpoint pen refill 200 is in contact with the tip of the rotor 10 . In other words, the pen refill 200 is a retractable writing instrument in which the ballpoint pen refill 200 retracts and retracts from the tip opening of the barrel 4 by pressing the knock 11 .

As shown in FIG. 2, the refill 200 includes a ball-point pen tip 1 having a writing ball 13, which is a writing member, and a ball holder 14 that rotatably holds the writing ball 13, and a tip holder 15 having a through hole. and an ink containing tube 3 connected to the ball-point pen tip 1 at the bottom. The ball holder 14 holds the writing ball 13 in a state in which it partially protrudes from the tip opening of the ink through hole formed as a through inner hole. A ball having a diameter of 0.18 mm or more and 2.0 mm or less can be used as the writing ball 13 . A ball with a diameter of 0.3 mm or more and 1.6 mm or less is preferable because it is less susceptible to the unevenness of the writing surface and provides a smooth writing feel. In particular, balls with a diameter of 0.8 mm or more and 1.0 mm or less are more preferable because they can achieve both a smooth writing feel and clean handwriting.
In addition, the ink composition 2 is contained in the ink containing tube 3, and an ink backflow preventer 16 incompatible with the ink composition 2 is arranged in contact with the rear end interface of the ink composition 2, A float 17 is arranged in contact with the ink backflow prevention member 16 . A ball-point pen body that does not use the exterior body 300 may be formed by arranging a tail plug or the like for preventing leakage of the ink composition 2 at the rear end of the ink containing tube 3 of the refill 200 . It is also possible to dispose a pen tip protection member such as a cap.

FIG. 3 is a view showing the configuration of the ball-point pen tip 1 of the ball-point pen refill 200 according to one embodiment, and is an enlarged vertical cross-sectional view of part I of FIG. The ball-point pen tip 1 shown in FIG. 3 rotatably holds a writing ball 13 as a writing member in a ball holder 14 in a state in which a portion of the writing ball 13 protrudes from the tip opening of an ink passage hole, which is a through hole. Further, behind the writing ball 13, an intermediate ball 18 is rotatably arranged in contact with the writing ball 13, and further behind the intermediate ball 18, a coil spring 19, which is a resilient member, is attached to the intermediate ball. 18 are arranged in contact with each other. The coil spring 19 is inserted from the rear of the ball holder 14 and is pushed so as to compress the entire length of the coil spring 19 to prevent it from coming off. The writing ball 13 is urged forward via the ball 18. - 特許庁The rear end portion of the coil spring 19 is received by four projections 20 provided circumferentially at equal intervals on the inner wall surface of the rear portion of the ball holder 14 to prevent it from slipping out of the ball holder 14 . The convex portion 20 is formed by broaching the inner wall surface of the rear end of the ball holder 14 as a cut piece. In addition to broaching, the side wall of the ball holder 14 may be dented by punching or the like to form a convex portion 20 on the inner wall surface. The fixing method and shape can be selected as appropriate.

When the writing ball 13 is pressed against a writing surface such as a paper surface, the writing ball 13 moves backward, and the ink flows out from a gap formed between the writing ball 13 and the ball holder 14, which will be described later, or is conveyed outside as the ball rotates. It is to be transcribed. As for the size of the writing ball 13, a diameter of 0.18 (mm) or more and 2.0 (mm) or less, which is used in a general ballpoint pen, can be used, and it is possible to improve the writing feel and wear resistance with the ball holder. Taking this into consideration, the arithmetic mean height (Sa) of the surface is preferably 2 (nm) or more and 25 (nm) or less. The material of the writing ball is cemented carbide with tungsten carbide as the main component, metals such as stainless steel, aluminum, and iron, resin materials such as polyethylene, polypropylene, polyacetal, and polyamide, ceramics, glass, etc. However, stainless steel, cemented carbide, and ceramics are preferable in consideration of slidability with the intermediate ball, abrasion resistance, and corrosion resistance with ink.

The intermediate ball 18 is rotatably disposed in the ink passage hole behind the writing ball in contact with the writing ball. The size of the intermediate ball is not particularly limited, but considering the fluidity of the ink, the diameter of the intermediate ball is preferably 30% or more and 160% or less of the diameter of the writing ball. Considering the resulting frictional resistance, the surface arithmetic mean height (Sa) is preferably 2 (nm) or more and 25 (nm) or less. Materials for the intermediate ball 18 include cemented carbide containing tungsten carbide as a main component, metals such as stainless steel, aluminum, and iron, resin materials such as polyethylene, polypropylene, polyacetal, and polyamide, ceramics, glass, and the like. Although it can be manufactured, cemented carbide and ceramics are preferable in consideration of slidability with a writing ball, abrasion resistance, and corrosion resistance with ink.

In the present embodiment, the ball-point pen tip has the intermediate ball 18 arranged between the writing ball 13 and the coil spring 19 as described above for the purpose of improving the writing feeling. 13 is directly in contact with the writing ball 13, or a straight tip portion is formed by straightening the coil wire as it is at the tip of the coil spring 19, and the straight tip portion and the writing ball 13 are brought into contact with each other. , the writing ball 13 may be directly urged forward.
In addition, in the form of a ballpoint pen in which the tip of the ballpoint pen is protected by a cap when not in use, that is, in the form of a so-called cap type ballpoint pen, problems such as bleeding of ink from the tip of the tip and blurred writing due to drying of the ink are less likely to occur. There is no need to urge forward to ensure sealing performance, and a configuration without the coil spring 19 and the intermediate ball 18 may be used.

Next, details of the ball-point pen tip 1 will be described with reference to FIG. 4, which is an enlarged view of part II of FIG. The ball holder 14 has an ink passage hole, which is a through hole, and this ink passage hole is defined by a tip opening 21 crimped to a smaller diameter from the tip side and an internal package protrusion 22 to form a writing ball. 13 has a writing ball holding portion 23 arranged in a state of partially protruding from the tip opening 21, a center hole 24 formed in the central portion of the internal package protruding portion 22, and a rear hole 25. As shown in FIG.
The inner edge of the tip opening 21 is pressed against the writing ball 13 when caulking in order to improve sealing performance when the writing ball 13 is pressed by the coil spring 19 through the intermediate ball 18 and comes into circumferential contact. , the curved surface of the writing ball 13 is mirror-finished while being transferred. In addition, a plurality of ink passage grooves 26 are formed in the inward protruding portion 9 by cutting at equal intervals radially. The ink passage groove 26 is passed through the rear hole 25 in order to ensure the supply of ink to the writing ball holding portion 23. may A recessed ball receiving seat 27 is formed by pressing the writing ball 13 against the inward protruding portion 9. The ball receiving seat 27 abuts against the paper surface or the like during writing, and when the writing ball 13 retreats, In order to stabilize the position of the writing ball 13 and ensure smooth rotation with little unnecessary vibration, the writing ball 13 and the ball receiving seat 27 are shaped so as to be in substantially planar contact. The ink passage groove 26 has an opening outside the ball receiving seat portion 27 formed in the inward projecting portion 9 to ensure the supply of ink to the writing ball holding portion 23. be. In this embodiment, five ink passage grooves 26 are formed at equal intervals in a circumferential shape, but the size and number of the grooves are not particularly limited.

FIG. 5 is a vertical cross-sectional view showing a writing instrument in which a cap is arranged on the nib according to one embodiment. In order to protect the pen tip of the writing instrument of FIG. 5, a cap 28 is detachably attached to the pen tip. Cap 28 is also provided with clip 9 . The pen tip has a ball-point pen tip 1, which is a writing member, and an ink containing tube 3 connected to the ball-point pen tip 1 via a tip holder 15 having a through hole. A ball-point pen tip as shown in FIGS. 3 and 4 may be used as the ball-point pen tip 1 which is a writing member. The surface of the ink containing tube 3 made of a relatively hard resin material is covered with a relatively soft resin material (soft member) as the grip portion 7 . Examples of a relatively hard resin material forming the ink storage tube 3 include polycarbonate, polyethylene terephthalate, acrylic, acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene copolymer (AS), and polypropylene. be done. As the relatively soft resin material (soft member) forming the grip portion 7, thermoplastic elastomer, soft acryl, and the like can be used. The grip portion 7 is preferably a non-slip grip such as a grip having an uneven surface, a grip having a triangular shape, a grip having a polygonal outer surface, a grip having a shape imitating a fingerprint, or the like. The ink composition 2 is contained in the ink containing tube 3, and an ink backflow prevention member 16 incompatible with the ink composition 2 is arranged in contact with the rear end interface of the ink composition 2 to prevent the ink from flowing back. A float 17 is arranged in contact with the preventive body 16 . A tail plug 29 is provided at the rear end of the ink containing tube 3 to prevent the ink composition 2 from leaking out. The ball-point pen tip 1 is protected by being sealed by a packing 30 embedded inside the cap 28, and the airtightness is maintained to prevent the ink from drying. The packing 30 is made of an elastic material such as nitrile-butadiene rubber, silicone rubber, butyl rubber, etc., but it can be appropriately selected according to the type of ink to be used and the material of the cap. If there is no need to protect the ball-point pen tip with packing or maintain airtightness, packing may not be used. When using the writing instrument, the removed cap 28 can be placed on the tail plug side of the ink containing tube 3 . The ink containing tube, the grip portion, the tip holder and the cap may be made of a transparent member or may be made of an opaque member. It is preferable to use a transparent member for the ink storage tube, the grip portion, the tip holder, and the cap, since the amount of ink remaining and the color of the ink can be visually recognized without removing the cap. It is preferable to use a transparent member for the cap so that the illustration or the like can be drawn or colored on the ink reservoir tube, the grip portion, or the tip holder, because the illustration or color of the ink reservoir tube can be visually recognized without removing the cap. It is preferable to use an opaque member or a transparent member that blocks ultraviolet rays for the ink storage tube, the grip portion, the tip holder, and the cap, since deterioration and discoloration of the ink due to ultraviolet rays can be suppressed.

In the above, retractable ballpoint pens and cap type ballpoint pens have been described as examples of ballpoint pens, but ballpoint pens according to some embodiments discharge an ink composition during writing by the pressure of compressed gas or the like. It may be a ballpoint pen configured to assist.

EXAMPLES The present invention will be described in detail below with reference to examples.

(Preparation of ink composition)
Ink compositions of Examples 1-26 and Comparative Examples 1-17 having the compositions shown in Tables 1-7 were prepared.
Specifically, the following materials were used for each composition shown in Tables 1 to 7.

<Main solvent>
MS: ion-exchanged water <organic solvent>
SOL-1: ethylene glycol SOL-2: glycerin SOL-3: thiodiglycol

<Colorant>
Colorant-1: Water Black #256L (14% aqueous solution of black dye, manufactured by Orient Chemical Industry Co., Ltd.)
Colorant-2: Water Yellow #1 (C.I. Acid Yellow 23, manufactured by Orient Chemical Industry Co., Ltd.)
Colorant-3: Daiwa Red No103WB (C.I. Acid Red 87, manufactured by Daiwa Kasei Co., Ltd.)
Colorant-4: Daiwa Red No104WB (C.I. Acid Red 92, manufactured by Daiwa Kasei Co., Ltd.)
Colorant-5: Water Yellow #6C (C.I. Acid Yellow 42, manufactured by Orient Chemical Industry Co., Ltd.)
Colorant-6: Water Blue #119 (triphenylmethane-based blue dye, molecular formula C51H56N3NaO7S2, manufactured by Orient Chemical Industry Co., Ltd.)
Colorant-7: Daiwa Red No106WB (C.I. Acid Red 52, manufactured by Daiwa Kasei Co., Ltd.)
Colorant-8: Daiwa Blue No. 1 (C.I. Acid Blue 9, manufactured by Daiwa Kasei Co., Ltd.)
Colorant-9: Daiwa IJ Yellow 306H (CI Direct Yellow 123, manufactured by Daiwa Kasei Co., Ltd.)

<Polyoxyethylene cetyl ether>
PC-1: BC-5.5 (polyoxyethylene cetyl ether (HLB value 10.5), manufactured by Nikko Chemicals Co., Ltd.)
PC-2: BC-2 (polyoxyethylene cetyl ether (HLB value 8.0), manufactured by Nikko Chemicals Co., Ltd.)
PC-3: BC-7 (polyoxyethylene cetyl ether (HLB value 11.5), manufactured by Nikko Chemicals Co., Ltd.)
PC-4: EMALEX 115 (polyoxyethylene cetyl ether (HLB value 13.0), manufactured by Nippon Emulsion Co., Ltd.)
PC-5: EMALEX 125 (polyoxyethylene cetyl ether (HLB value 15.0), manufactured by Nippon Emulsion Co., Ltd.)
PC-6: EMALEX 104 (polyoxyethylene cetyl ether (HLB value 7.0), manufactured by Nippon Emulsion Co., Ltd.)

<2-pyridinethiol 1-oxide sodium>
SO: Sanaibac Sodium Omazine (sodium 2-pyridinethiol 1-oxide (45% solution), manufactured by Sanai Oil Co., Ltd.)

<Additive>
Additive-1: Benzotriazole Additive-2: Proxel GXL (S) (20% dipropylene glycol solution of 1,2-benzisothiazolin-3-one, manufactured by Lonza Japan Co., Ltd.)
Additive-3: AKP-50 (fine particle alumina (median particle size 0.20 μm), manufactured by Sumitomo Chemical Co., Ltd.)
Additive-4: AKP-20 (fine particle alumina (median particle size 0.46 μm), manufactured by Sumitomo Chemical Co., Ltd.)
Additive-5: Potassium hydroquinonesulfonate Additive-6: Sarcosinate OHV (N-oleoyl sarcosine, manufactured by Nikko Chemicals Co., Ltd.)

<Polysaccharides>
Polysaccharide: Kelzan AR (xanthan gum, manufactured by Sansho Co., Ltd.)

<pH adjuster>
pH adjuster: sodium hydroxide

The ink compositions of Examples 1-26 and Comparative Examples 1-17 were prepared as follows.
The entire amount of Kelzan AR as a polysaccharide was added to 10% by weight of ion-exchanged water while stirring with a propeller stirrer, and stirred for 1 hour to obtain an aqueous Kelzan AR solution. Next, the remaining ingredients were mixed, heated and stirred for 1 hour to dissolve uniformly, then Kelzan AR aqueous solution was added and further stirred for 2 hours to obtain a water-based ink composition.

The ink compositions of Examples 1 to 26 and Comparative Examples 1 to 17 are filled in the refill 200 based on the example shown in FIG. 2, housed in the outer package 300 based on the example shown in FIG. got As the ball-point pen tip of the sample ball-point pen for test, two types of ball-point pen tips with a writing ball 13 having a diameter of 0.8 (mm) and 1.0 (mm) were produced based on the example shown in FIG. Also, the diameter of the intermediate ball 18 was set to 0.8 (mm) regardless of the size of the writing ball. The material of the writing ball and the intermediate ball was a cemented carbide made by sintering tungsten carbide as a main component and chromium and cobalt as binder components. A test ballpoint pen tip with a writing ball 13 having a diameter of 0.8 (mm) is a first ballpoint pen tip (referred to as a first tip in the table), and a test ballpoint pen tip with a writing ball 13 having a diameter of 1.0 (mm). was used as a second ballpoint pen tip (referred to as a second tip in the table).

The combinations of the ink compositions of Examples 1 to 26 and Comparative Examples 1 to 17 and the first and second ballpoint pen tips are shown in the table (indicated by ○ in the corresponding combination column in the table).

The tip holder 15 of the test sample ball-point pen is molded of polybutylene terephthalate resin based on the example shown in FIG. 75 mm.

Based on the example shown in FIG. 2, the ink storage tube 3 of the sample ball-point pen for test uses a pipe molded by extrusion molding of polypropylene resin, and has an inner diameter of 4.65 mm and a thickness of 0.75 mm. and Then, 1.0 g of the ink composition and 0.1 g of the ink anti-backflow composition were filled. The ink backflow preventive composition was prepared by gelling polybutene with fine particle silica and dextrin fatty acid ester.

Using the test sample ball-point pen described above, the test described below was performed.

(Ball surface roughness test)
Roughness (arithmetic mean roughness (Ra)) of the writing ball surface of the test sample at the initial stage and after aging (a ballpoint pen sample was left in a constant temperature bath at 50 ° C and 30% RH for 90 days with the pen tip facing downward). Using a scanning probe microscope SPI-400 (manufactured by Hitachi High-Tech Science Co., Ltd.), the surface roughness (unit: nm) of an arbitrary 20 μm × 20 μm is measured, and the smaller the surface roughness, the more uneven the surface of the writing ball. It was evaluated that it was not.

(Smoothness of writing test)
Test samples at the initial stage and after aging (a ballpoint pen sample was left in a constant temperature bath at 50 ° C and 30% RH for 90 days with the pen tip facing downward) were used as high-quality paper ("Kinmari SW" manufactured by Hokuetsu Corporation Co., Ltd., paper Tribo-master (Type: TL201Sa manufactured by Trinity Lab Co., Ltd.) was applied to the F surface with a thickness (JIS P 8118) of 95 ± 3 μm and a smoothness (JIS P 8155) of 65 ± 20 seconds on the F surface (felt side (surface)). ), the writing resistance value (unit: gf) applied in the writing direction when writing a straight line of 15 cm under the writing conditions of writing speed 7 cm / sec, writing angle 70 °, writing load 100 gf was measured, It was evaluated that the smaller the writing resistance value, the smoother the writing feel.

The water-based ink compositions for ballpoint pens of Examples 1 to 26 did not cause the surface of the writing ball to become uneven even after long-term aging, and maintained good writing feel.
In particular, in Examples 1 to 15, polyoxyethylene cetyl ether and sodium 2-pyridinethiol 1-oxide form a denser film due to hydrophobic interaction, which reduces the contact of water and oxygen with the ball surface. The elution of ball components was prevented, the surface of the writing ball did not become uneven, corrosion of the ball was suppressed, and smooth writing was especially maintained.

On the other hand, Comparative Example 1 does not contain polyoxyethylene cetyl ether, Comparative Example 2 does not contain 2-pyridinethiol 1-oxide sodium, and Comparative Examples 3 to 17 contain polyoxyethylene Since neither ethylene cetyl ether nor sodium 2-pyridinethiol 1-oxide is blended, the contact of water and oxygen with the ball surface increases, and the ball components are eluted after a long period of time, and the surface of the writing ball becomes uneven. The smoothness of writing has been lost.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.

In this specification, expressions such as "same", "equal", and "homogeneous" to express that things are in an equal state not only express a strictly equal state, but also a tolerance or a degree to which the same function can be obtained. It shall also represent the state in which there is a difference between
Moreover, in this specification, the expressions “comprising”, “including”, or “having” one component are not exclusive expressions excluding the presence of other components.

1 ball-point pen tip 2 ink composition 3 ink storage tube 4 barrel 5 front barrel 6 rear barrel 7 grip portion 8 crown 9 clip 10 rotor 11 knock 12 resilient member 13 writing ball 14 ball holder 15 tip holder 16 ink backflow prevention Body 17 Float 18 Intermediate ball 19 Coil spring 20 Protrusion 21 Tip opening 22 Inner package protrusion 23 Writing ball holding part 24 Center hole 25 Rear hole 26 Ink channel 27 Ball receiving seat 28 Cap 29 Tail plug 30 Packing 100 Writing instrument 200 refill 300 exterior body

Claims (1)

An aqueous ink composition for a ballpoint pen, comprising at least water, a colorant, polyoxyethylene cetyl ether, and sodium 2-pyridinethiol 1-oxide.

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