JP2008088269A - Aqueous ink for ballpoint pen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide aqueous ink for ballpoint pens, reducing such an ink-stop phenomenon that, with the point of a ballpoint pen open in the atmosphere, when the point is turned upward and the rear end of the pen undergoes an impact, the ink moves to the rear end side, and thereafter written lines blur or a writing cannot be done in making a writing action. <P>SOLUTION: The aqueous ink for ballpoint pens essentially comprises a colorant, water, xanthan gum, and silica; wherein the silica is 30 m<SP>2</SP>/g or greater but less than 250 m<SP>2</SP>/g in BET specific surface area, 5-40 nm in particle size and 0.01-0.1 wt.% in content in the ink. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water-based ink for a ballpoint pen that is used in a ballpoint pen including a ballpoint pen tip that ejects ink as a writing ball rotates.

Ballpoint pens are used in many cases because they provide a relatively thin handwriting, and unlike writing instruments that have a fiber nib or resin nib, there is little change in the handwriting width due to crushing of the nib even when used for a long time. Has been. Water-based inks used in such ballpoint pens with low viscosity inks tend to flow as they are, so that ink leaks from the tip of the pen. Holding. In order to prevent ink from leaking from the nib even when ink is stored directly in the ink container, shear thinning is applied, the ink is kept at a high viscosity when standing, and shear force is applied when the ball rotates. There is known one that temporarily lowers the viscosity and causes ink to flow and eject. Typical examples of thickeners that impart shear thinning are smectite clays such as bentonite and montmorillonite, water-soluble thickening polysaccharides such as xanthan gum and welan gum, and acrylic acid-methacrylic acid copolymers. Etc. Inks using these thickeners prevent ink from leaking from the nib when not writing, or suppress writing blurring due to excessive ink supply during writing, or due to insufficient ink supply This prevents scumming and line skipping.
JP 01-016437 JP 11-148040 A JP 06-256699 A JP2001-40266

In the invention described in Patent Document 1, ionic polysaccharide xanthan gum is used as the water-soluble thickening polysaccharide, and the xanthan gum retains the pigment by forming a network structure due to steric hindrance and electric repulsion. Yes. Xanthan gum is a macromolecule having a large side chain, has a helix structure in ink containing water, and has a super-association structure in which an associated double helix structure forms a layered state. This ink has a low viscosity because the network structure easily collapses due to the shearing force between the ball and the ball seat when writing, so the ink can be ejected from the nib, but it can also be easily broken by impact. When an impact is applied with the pen tip upward with the ink removed, the ink moves to the rear end side of the pen, and when writing is performed after that, the writing line is faded or writing becomes impossible. In the invention described in Patent Document 2, two or more thickening polysaccharides, polyacrylates, and clay thickeners are used in combination, and the clay thickener takes in water molecules between crystal structures. In the case of impact, the layer of water between the crystal structures easily collapses and becomes low in viscosity. To do. In the invention described in Patent Document 3, fine particle silica is used as the inorganic fine particle thickener. Silica has a gentle three-dimensional structure due to hydrogen bonding of silanol groups on the surface of the silica, so that the gentle three-dimensional structure easily collapses when subjected to an impact, as in the ink of Patent Document 1. Ink out phenomenon occurs. Moreover, if the addition amount is increased to such an extent that it has a thickening effect, the writing quality is remarkably lowered.
Furthermore, the invention described in Patent Document 4 tries to prevent the precipitation of pigment by using a silica having a specific surface area of 250 m ² / g or more and a straight polymer, but the three-dimensional structure of silica having a large specific surface area is The ink breaks down and the ink out phenomenon occurs. Furthermore, since the straight polymer has a strong spinnability, the writing quality is remarkably lowered.

  In the present invention, when the pen tip of the ballpoint pen is open to the atmosphere, when the pen tip is upward, when the impact is applied to the rear end of the pen, the ink moves to the pen rear end side, and then writing is performed when writing is performed. It is an object of the present invention to provide a water-based ink for ballpoint pens that reduces ink out-of-line phenomena such as faint lines and inability to write.

That is, the present invention has at least a colorant, water, xanthan gum, a specific surface area by the BET method of 30 m ² / g or more and less than 250 m ² / g, a particle size of 5 nm or more and 40 nm or less and an addition amount in ink of 0. The gist of the present invention is a water-based ink for ballpoint pens containing 0.01% by weight or more and 0.1% by weight or less of silica.

In the water-based ink for ballpoint pens of the present invention, why the ink shortage phenomenon can be reduced when the pen tip is exposed to the atmosphere and the pen tip is impacted upward is considered as follows.
By specific surface area by xanthan gum and the BET method is used in combination 30 m 2 / ^g or more 250 meters 2 / ^g than silica, it is conceivable to form a totally different structure from the structure of these two forms alone. In other words, the hydroxyl group of xanthan gum and silica form an ionic bond in the ink, and a double helix structure of xanthan gum and silica are cross-linked. In addition, by making the addition amount of silica 0.01% by weight or more and 0.1% by weight or less, a layered state of xanthan gum double helix structure is formed without the presence of a gentle three-dimensional structure of silica alone in the ink. It is in a state that does not. This structure acts to absorb and mitigate impacts and makes it possible to reduce the ink out phenomenon. Further, by mixing a mixture of xanthan gum and silica with other components, cross-linking of xanthan gum and silica becomes more appropriate, and the ink out phenomenon is further reduced.

  Hereinafter, the present invention will be described in detail. The coloring material used in the ink composition of the present invention imparts a coloring effect to the handwriting and makes it visible, and includes pigments and dyes. Specific examples of pigments include organic pigments such as azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acidic dye pigments, built dye pigments, mordant dye pigments, and natural dye pigments. Pigment, ocher, barium yellow, ultramarine, bitumen, cadmium red, barium sulfate, titanium oxide, petal, iron black, carbon black and other inorganic pigments, aluminum powder, gold powder, silver powder, copper powder, tin powder, brass powder, etc. Metal powder pigments, fluorescent pigments, mica pigments, and the like. 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 thereof include phthalocyanine green, which are used by dispersing them in a liquid medium.

Commercially available water-dispersed pigments are preferably used because of their increased handleability and productivity. Specific examples of water-dispersed pigments include FujiSP Black 8031, 8119, 8167, 8276, 8381, 8406, Fuji SP Red 5096, 5111, 5193, 5220, FujiSP Bordeaux 5500, Fuji SP Blue. 6062, 6133, 6134, 6401, Fuji SP Green 7051, Fuji SPYellow 4060, 4178, Fuji SP Violet 9011, FujiSP Pink 9524, 9527, Fuji SP Orange 534, FUJI 55 (Fuji Dye Co., Ltd.), Emacol Black CN, Emacol Blue FBB, FB, K R, EmacolGreen LXB, Emacol Violet BL, Emacol Brown 3101, Emacol Carmine FB, Emacol RedBS, Emacol Orange R, Emacol Yellow FD, IGN, G3, G, GFN, G 10G, Sandy SuperBlack K, C, Sandy Super Gray B, Sandy Super Brown SB, FRL, RR, Sandy Super Green L 5G, GXB, Sandy H Super L FBL-160, FBB, Sandye Super Violet BL H / C, BL, Sa dye Super Bordeaux FR, Sandy Super Pink FBL, F5B, Sandy Super Rubin FR, Sandy super Carminine FB, Sand Super Super FFG, S13 Same R, Same 3R, Sandye Ywlow GG, Same F3R, Same IRC, Same FGN, Same GN, Same GRS, Same GSR-130, Same GSN-130, Same GSN, Same 10GN (above, manufactured by Sanyo Dye Co., Ltd.) , RioFast Black Fx 8012, 8313, 8169, Rio Fast Red Fx 8209, 8172, Rio Fast Red S Fx 831 8316, RioFast Blue FX 8170, Rio Fast Blue FX 8170, Rio Fast Blue SFx 8312, Rio Fast Green SFx 8314, EM green G, 102, manufactured by Toyo Ink (102) 2103, 2104, 2105, 2106, 2107, 2108, 2117, 2127, 2137, 2167, 2101P, 2102P, 2103P, 2104P, 2105P, 2106P, 2106P , 2108P, 2117P, 2127P, 2127P, 2137P, 2167P, NKW-3002, 3003, 3004, 3005, 3007, 3077, 3008, 3402, 3404, 340 3407, 3408, 3477, 3602, 3603, 3604, 3604, 3605, 3607, 3777, 3608, 3702, 3703, 3704, 3705, 3777, 3708, 3708 6013, 6038, 6559 (Nippon Fluorescence 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, Kingdom Dyes Co., Ltd.), Pollux PC5T1020, Pollux Black PC8T135, Polook Thread IT1030, etc. Examples include Pollux series (Sumika Color Co., Ltd.).

As specific examples of the dye, any of acid dyes, direct dyes, basic dyes and the like can be used. For example, Japanol Fast Black D Conch (CI Direct Black 17), Water Black 100L (19), Water Black L-200 (19), Direct Fast Black B (22), Direct Fast Black AB (32), Direct Deep Black EX (38), Direct Fast Black Conk (51), Kayala Spragley VGN (71), Kayalas Direct Brilliant Yellow G (CI Direct Yellow 4) ), Direct Fast Yellow 5GL (26), Eisen Primula Yellow GCLH (44), Direct Fast Yellow R (50), Eisen Direct Fast Red FH (CI Direct Red 1), Nippon Fast Scarlet G X (4), Direct Fast Scarlet 4BS (23), Eisen Direct Rhodulin BH (31), Direct Scarlet B (37), Kayak Direct Scarlet 3B (39), Eisen Primula Pink 2BLH (75) ), Sumilite Red F3B (80), Eisen Primula Red 4BH (81), Kayara Spral Bin BL (83), Kayara Light Red F5G (225), Kayara Light Red F5B (226), Caillas Light Rose FR (same as 227), Direct Sky Blue 6B (CI Direct Blue 1), Direct Sky Blue 5B (same as 15), Sumilite Splash Blue BRR Conch (same as 71), Dibogen Turquoise Blue S 86), Water Blue # 3 (same as above) 6), direct dyes such as Kayala Star Coyze Blue GL (86), Kayala Supra Blue FF2GL (106), Kayara Supra Turquoise Blue FBL (199), Acid Blue Black 10B (CI Acid Black) 1), Nigrosine (2), Suminol Milling Black 8BX (24), Kayanol Milling Black VLG (26), Suminol Fast Black BR Conk (31), Mitsui Nylon Black GL (52), Eisen Opal Black WH Extra Conk (52), Sumilan Black WA (52), Ranil Black BG Extra Conk (107), Kyanol Milling Black TLB (109), Suminol Milling Black B (109), Kaya NORMILLING BLACK TLR ( 110), Eisen Opal Black New Conque (119), Water Black 187-L (154), Kayaku Acid Brilliant Flavin FF (C.I. I. Acid Yellow 7: 1), Kayasil Yellow GG (17), Xylene Light Yellow 2G 140% (17), Suminol Leveling Yellow NR (19), Daiwa Tarrazine (23), Kayaktor Torazin (23) , Suminol Fast Yellow R (25), Diacid Light Yellow 2GP (29), Suminoll Milling O O (38), Suminol Milling MR MR (42), Water Yellow # 6 (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 4G 200% (same 141), Kayanor Yellow NG (same 135), Kayano Lumiling Yellow 5GW (127), Kayanol Milling 6GW (142), Sumitomo Fast Scarlet A (CI Acid Red 8), Kayak Silk Scarlet (9), Solar Rubin Extra (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), Eiseneosin GH (87), water pink # 2 (same) 92), Eisen Acid Phloxin PB 92), Rose Bengal (94), Cyanol Milling Scarlet FGW (111), Cyanol Milling Lubin 3BW (129), Sinoall 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 Red Brilliant Red BL (265), Kayanol Milling Red GW (276), Mitsui Acid Violet 6BN (CI Acid Violet 15), Mitsui Acid Violet BN (17), Sumitomo Patent Pure Blue VX (CI Acid Blue) 1), Water Blue # 106 (same 1), Patent Blue AF (same 7), Water Blue # 9 (same 9), Daiwa Blue 1 (same 9), Spranol Blue B (same 15), Orient Solve Blue OBC (22), Suminol Leveling Blue 4GL (23), Mitsui Nylon Fast Blue G (25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Saphirol SE (43) , Suminol Leveling Sky Blue R Extra Conk (62), Mitsui Nylon Fast Sky Blue B (78), Sumitomo Brilliant Indocyanine 6Bh / c (83), Sandlancyanine N-6B 350% (90), Water Blue # 115 (90), Orient Soluble Blue OBB The same 93), Sumitomo brilliant blue 5G (the 103), Kaya Nord 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 (same 9), Daiwa Green # 70 (same 16), Cyanol Cyanine Green G (same 25), Suminol Milling Green G (same 27), etc. Ron Yellow 3GLH (CI Basic Yellow 11), Eisen Cachiron Brilliant Yellow 5GLH (13), Sumiacryl Yellow E-3RD (15), Maxilon Yellow 2RL (19), Astrazone Yellow 7GLL (same) 21), Kayacrill Golden Yellow GL-ED (same 28), Astrazone Yellow 5GL (same 51), Eisen Cachiron Orange GLH (CI Basic Orange 21), Eisen Katyron Brown 3GLH (same 30), Rhodamine 6 GCP (C.I. Cred 1), Eisen Astrafloxin (12), Sumiacryl Brilliant Red E-2B (15), Astrazone Red GTL (18), Eisen Cathlon Brilliant Pink BGH (27), Maxilon Red GRL (same) 46), Eisenmethyl Violet (CI Basic Violet 1), Eisen Crystal Violet (Same 3), Eisen Rhodamine B (Same 10), Astrazone Blue G (CI Basic Blue 1), Astrazone Blue BG (Same 3), methylene blue (same 9), maxilon blue GRL (same 41), Eisen Cachiron blue BRLH (same 54), Eisen Diamond Green GH (CI Basic Green 1), Eisen Malachite Green (same 4) ), Bismarck Blau G include basic dye (C.I. Basic Brown 1) and the like. The above pigments and dyes can be used alone or in combination.

Water is used as a main solvent for dissolving or dispersing the colorant such as the pigment. A water-soluble organic solvent may be used as necessary. Specific examples of the water-soluble organic solvent include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-butylene glycol, thiodiethylene glycol, glycerin, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and 2-pyrrolidone. And triethanolamine. These water-soluble organic solvents can be used alone or in combination of two or more.

  Xanthan gum is used as a substance that acts to absorb and relieve impact when used in combination with silica. Examples of xanthan gum include Kelzan, Kelzan S, Kelzan F, Kelzan AR, Kelzan M, Kelzan D (above, manufactured by Sanki Co., Ltd.), Kojin, Kojin F, Kojin T, Kojin K (above, Kosei Co., Ltd.) Man-made), Nom Coat (manufactured by Nissin Oil Co., Ltd.), Inager V-7, Inager V-7T (manufactured by Ina Food Industry Co., Ltd.), etc., and a plurality of types can be mixed and used.

Silica is used in combination with xanthan gum to act to absorb and reduce impact. The silica used is produced, for example, by hydrolyzing purified silicon tetrachloride in oxyhydrogen, its shape is amorphous, its particle size is 5 nm to 40 nm, and the specific surface area by the BET method is 30 m. ² / g or more and less than 250 m ² / g, and the addition amount is 0.01 wt% or more and 0.1 wt% or less.
When the specific surface area is less than 30 m ² / g or the addition amount is less than 0.01% by weight, no crosslinking is formed between the double helix structure layer of xanthan gum and silica, and the same as when xanthan gum is used alone. Ink out phenomenon occurs. In addition, when the specific surface area is 250 m ² / g or more or the addition amount is more than 0.1% by weight, the silica itself starts to act as a thickener having a structural viscosity, and is the same as when silica is used alone. Ink out phenomenon may occur or smooth writing taste may not be maintained.
Specific examples of the silica, Aerosil 50 (particle diameter 12 nm, specific surface area by the BET method: 50 ± ^15m 2 / g), the ^{130 (16nm, 130 ± 25m 2} / g), the ^{200 (12nm, 200 ± 25m 2} / g), 200CF (12 nm, 200 ± 25 m ² / g), R202 (14 nm, 100 ± 20 m ² / g), 805 (12 nm, 150 ± 25 m ² / g), 812S (7 nm, 220 ± 25 m) ² / g), R972 (16 nm, 110 ± 20 m ² / g), R974 (12 nm, 170 ± 20 m ² / g), OX (40 nm, 50 ± 15 m ² / g), etc., hydrophilic and hydrophobic Both are mentioned. These silicas can be used alone or in combination of two or more.
In addition, by mixing a mixture of xanthan gum and silica with other components, the ink running out phenomenon can be further reduced. Mixing of xanthan gum and silica is performed by, for example, mixing with an automatic mortar, ball mill, jet mill, atomizer, etc., or applying mechanical impact force with a hammer mill / hybridizer (trade name, Nara Machinery Co., Ltd.). Further, ultrafine particulate anhydrous silica can be obtained by electrostatic adsorption or physical adsorption. The mixture of xanthan gum and silica can be confirmed by the fact that silica is adsorbed on the surface of xanthan gum by observation with an electron microscope.

In addition to these, natural gum arabic, tragacanth gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, casein, dextran, semi-synthetic methylcellulose, ethylcellulose, hydroxyethylcellulose, Water-soluble thickening polysaccharides such as carboxymethylcellulose, sodium starch glycolate, sodium alginate, propylene glycol alginate, hydroxypropylated guar gum, and derivatives thereof, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, carboxyvinyl polymer, polyethylene oxide, Copolymer of vinyl acetate and polyvinylpyrrolidone, alkali metal salt of acrylic resin, acrylic acid and alkylmeta It may be used in combination of a water-soluble polymer such as a copolymer of relations.

In addition, extender pigments such as alumina, aluminum silicate, calcium carbonate, resin spheres, wetting agents and lubricants such as urea, ethylene urea, and thiourea, antiseptics such as benzothiazoline and omadin, and rust inhibitors such as benzotriazole Various additives such as anionic and nonionic surfactants, antifoaming agents and fixing agents can be used.

In producing the ink of the present invention, various conventionally known methods can be employed. For example, it can be easily obtained by blending the above components and stirring and mixing with a stirrer such as a turbo mixer or a Henschel mixer, or by dispersing with a dispersing machine such as a ball mill, sand grinder, speed line mill, or roll mill. .

Hereinafter, it demonstrates still in detail based on Examples 1-8 and Comparative Examples 1-7. In each example, “part” simply means “part by weight”.
(Example 1)
Daiwa Red 104WB (CI Acid Red 92, manufactured by Daiwa Kasei Co., Ltd.) 2.2 parts BASONY RED 540 (CI Basic Violet 10, BASF Japan Ltd.) 0.6 parts ethylene glycol 10. 2. 0 parts diethylene glycol 8.0 parts Proxel GXL (1,2-benzisothiazolin-3-one, preservative, manufactured by Avicia Co., Ltd.) 0.2 parts sarcosinate OH (oleoyl sarcosine, manufactured by Nikko Chemicals Co., Ltd.) 0 parts Kelzan AR (xanthan gum, manufactured by Sanki Co., Ltd.) 0.5 parts Aerosil 200CF (silica, 12 nm, 200 m ² / g, manufactured by Nippon Aerosil Co., Ltd.) 0.01 parts triethanolamine 2.0 parts water 73 .49 parts Among the above components, Kelzan AR and Aerosil 200CF are hybridized ( To obtain a mixed powder with good mechanical Co.). It was confirmed with an electron microscope that silica was adsorbed on the surface of xanthan gum. This powder was added while stirring the whole amount of water, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for another 5 hours until uniform, and then filtered through a 1 micron spool filter to obtain an ink.

(Example 2)
Daiwa Red 104WB (CI Acid Red 92, manufactured by Daiwa Kasei Co., Ltd.) 2.2 parts BASONY RED 540 (CI Basic Violet 10, BASF Japan Ltd.) 0.6 parts ethylene glycol 10. 2. 0 parts diethylene glycol 8.0 parts Proxel GXL (1,2-benzisothiazolin-3-one, preservative, manufactured by Avicia Co., Ltd.) 0.2 parts sarcosinate OH (oleoyl sarcosine, manufactured by Nikko Chemicals Co., Ltd.) 0 parts Kelzan AR (xanthan gum, manufactured by Sanki Co., Ltd.) 0.5 parts Aerosil 200 (silica, 12 nm, 200 m ² / g, manufactured by Nippon Aerosil Co., Ltd.) 0.05 parts Triethanolamine 2.0 parts Water 73 .45 parts Among the above components, Kelzan AR and Aerosil 200 were hybridized (Nara Machinery) To obtain a mixed powder using Ltd.)). It was confirmed that silica was adsorbed on the surface of the xanthan gum with an electron microscope. This powder was added while stirring the whole amount of water, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for another 5 hours until uniform, and then filtered through a 1 micron spool filter to obtain an ink.

(Example 3)
NKW2117 (pink aqueous pigment base, manufactured by Nippon Fluorochemicals Co., Ltd.) 50.00 parts glycerin 15.00 parts sarcosinate OH (oleoyl sarcosine, manufactured by Nikko Chemicals Co., Ltd.) 3.0 parts Kelzan AR (xanthan gum, 0.5 parts Aerosil 200CF (silica, 12 nm, 200 m ² / g, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part Water 36.60 parts Among the above components, Kelzan AR and Aerosil 200CF The powder which mixed using the automatic mortar was obtained. It was confirmed that silica was adsorbed on the surface of the xanthan gum with an electron microscope. This powder was added while stirring the whole amount of water, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for an additional hour until uniform to obtain an ink.

Example 4
NKW2117 (pink aqueous pigment base, manufactured by Nippon Fluorochemicals Co., Ltd.) 50.00 parts glycerin 15.00 parts sarcosinate OH (oleoyl sarcosine, manufactured by Nikko Chemicals Co., Ltd.) 3.0 parts Kelzan AR (xanthan gum, 0.5 parts Aerosil R972 (silica, 16 nm, 110 m ² / g, manufactured by Nippon Aerosil Co., Ltd.) 0.05 parts Water 37.10 parts Among the above components, Kelzan AR and Aerosil R972 The powder which mixed using the automatic mortar was obtained. It was confirmed that silica was adsorbed on the surface of the xanthan gum with an electron microscope. This powder was added while stirring the whole amount of water, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for an additional hour until uniform to obtain an ink.

(Example 5)
Among the components of Example 1, Kelzan AR and the whole amount of water were added with stirring, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for another 5 hours until uniform, and then filtered through a 1 micron spool filter to obtain an ink.

(Example 6)
Among the components of Example 2, Kelzan AR and the whole amount of water were added with stirring, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for another 5 hours until uniform, and then filtered through a 1 micron spool filter to obtain an ink.

(Example 7)
Among the components of Example 3, Kelzan AR and the whole amount of water were added with stirring, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for an additional hour until uniform to obtain an ink.

(Example 8)
Among the components of Example 4, Kelzan AR and the whole amount of water were added with stirring, and stirred for 1 hour with a propeller stirrer to obtain a solution. This liquid and the remaining components were mixed and stirred for an additional hour until uniform to obtain an ink.

(Comparative Example 1)
In Example 6, ink was obtained in the same manner as in Example 6 except that Aerosil 200 was removed and the amount of water was increased accordingly.

(Comparative Example 2)
In Example 6, an ink was obtained in the same manner as in Example 6 except that the amount of Aerosil 200 added was increased to 0.2% by weight and the amount of water was reduced accordingly.

(Comparative Example 3)
In Example 6, an ink was obtained in the same manner as in Example 6 except that the amount of Aerosil 200 added was increased to 0.4% by weight and the amount of water was reduced accordingly.

(Comparative Example 4)
In Example 6, except that Aerosil 200 was changed to Admafine SO-C1 (silica, 250 nm, 17.4 m ² / g, manufactured by Admatechs Co., Ltd.), ink was prepared in the same manner as in Example 6. Obtained.

(Comparative Example 5)
Ink was obtained in the same manner as in Example 6, except that Aerosil 200 was changed to Aerosil 300CF (silica, 7 nm, 300 m ² / g, manufactured by Nippon Aerosil Co., Ltd.).

(Comparative Example 6)
Ink was obtained in the same manner as in Example 6 except that Aerosil 200 was changed to Aerosil 380 (silica, 7 nm, 380 m ² / g, manufactured by Nippon Aerosil Co., Ltd.).

(Comparative Example 7)
Ink was obtained in the same manner as in Example 6 except that Aerosil 200CF was changed to AEROXIDE Alu C (alumina, 13 nm, 100 m ² / g, manufactured by Admatechs Co., Ltd.) in Example 6.

As mentioned above, about the ink obtained in Examples 1-8 and Comparative Examples 1-7, it assembled using the members other than the ink used for Hybrid (product code | symbol K103) by Pentel Co., Ltd., and was set as the test sample.
Ink out evaluation:
After writing a straight line with a length of 20 cm on writing paper (JIS P3201 writing paper A), the pen tip is faced down and dropped from 1 cm above the cedar board, and an impact is applied. Thereafter, a straight line having a length of 20 cm was written again to confirm whether the handwriting was continuous. When continuous, the height from above was increased by 1 cm, the same test was performed, and the test was continuously performed until the handwriting became discontinuous. The higher the height until the discontinuous handwriting is generated, the less the ink runs out.
The test results are shown in Table 1.

The water-based ink for a ballpoint pen according to the present invention is such that when the pen tip of the ballpoint pen is open to the atmosphere, the ink moves to the pen rear end when the pen tip is impacted when the pen tip is upward, This makes it useful to reduce the ink running out phenomenon such that the writing line becomes faint or cannot be written when writing.

Claims (2)

At least a colorant, water, xanthan gum, a BET method specific surface area of 30 m ² / g or more and less than 250 m ² / g, a particle size of 5 nm or more and 40 nm or less, and an additive amount in ink of 0.01% by weight or more 0 A water-based ink for ballpoint pens containing 1% by weight or less of silica. The method for producing a water-based ink for a ballpoint pen according to claim 1, wherein a mixture of the xanthan gum and silica is mixed with other components.