JP5076376B2 - Water-based ink composition for ballpoint pens - Google Patents

Description

  The present invention relates to a water-based ink for a ballpoint pen that does not cause a line skipping phenomenon even when writing on a paper surface partially contaminated with sebum components from the hand or the like.

Conventionally, ballpoint pens provide relatively thin handwriting compared to writing instruments with fiber nibs and resin nibs, and there is little change in handwriting width due to wear or crushing of the nibs even after long-term use. Widely used.
The writing mechanism of the ballpoint pen is such that ink attached to the ball surface is transferred to a writing surface such as paper as the ball rotates. Generally, a ballpoint pen using water-based ink has a lower ink viscosity than a ballpoint pen using oil-based ink, so that writing can be performed with a light force. However, when writing on the paper surface to which sebum components are attached, water-based ink with water as the main medium makes it difficult for the ink to ride on the sebum component, and the ball slips on the paper and does not rotate. A portion that is not ejected, that is, a so-called “handwriting stroke skip” may occur. In the case of oil-based inks containing an organic solvent as a main medium, the organic solvent and blended components have an affinity with the sebum component, and there was no problem that the ball slipped easily.
In addition, a ballpoint pen is known in which the ink storage tube is directly filled with the shredded viscosity ink, and this shredded viscosity ink has a relatively high viscosity when not writing, and suppresses ink leakage from the pen tip. At the time of writing, ink is smoothly ejected by so-called trimming deviscous viscosity in which the viscosity is lowered by the trimming force of the rotating ball. Since such ink has low fluidity to the extent that it does not leak unless a shearing force having a required magnitude is applied, the strokes of the handwriting may appear remarkably.
There is also known a water-based ink using an oily component capable of exhibiting affinity and fixing property to sebum, for example, rosin ester (Patent Document 1).
JP 61-291664 A (Claims)

  The sebum component is mainly an oil component such as fatty acid (oleic acid, linoleic acid, etc.), squalane, sterin ester, triglyceride and the like.

In the invention described in Patent Document 1, the rosin ester, which is an oily component, exists as an emulsion and is a fine sphere surrounded by an emulsifier in an aqueous medium. In this state, the affinity of the rosin ester with the sebum component and the adhesiveness to the paper surface are not exhibited, and even if such ink is applied to the ballpoint pen, the line skipping on the paper surface contaminated with the sebum component is prevented. The effect was not obtained.

The gist of the present invention is a water-based ink composition for ballpoint pens containing at least a colorant , water, and a polyoxyethylene rosin ester of 0.5% by weight or more and 5.0% by weight or less based on the total amount of the ink. is there.

  The polyoxyethylene rosin ester used in the present invention is obtained by adding polyoxyethylene to rosin extracted from pine wood, and has water solubility. Its main component is a resin acid (Abietic acid and its isomers) that has an affinity with the sebum component and also provides stickiness. Therefore, the formulated ink composition is applied to the paper surface contaminated with the sebum component. Even if it adheres easily. As a result, it is assumed that the ball rotates without slipping and the stroke of the handwriting is suppressed. In addition, since the ether group of polyoxyethylene rosin ester has a suitable affinity for ballpoint pen tips and balls such as white and stainless steel, the ball holder of the ball and the ball holder can be used. A thin ink layer is formed between the seat and the frictional resistance between the ball and the ball seat is reduced, and the ball is easily rotated.

As the colorant, both dyes and pigments conventionally used in water-based inks can be used without limitation. Specific examples thereof include Japan Fast Black D Conch (CI Direct Black 17), Water Black 100L (19), Water Black L-200 (19), Water Black. # 7 (19), Kaya Set Black W9 (19), Direct Fast Black B (22), Direct Fast Black AB (32), Direct Deep Black EX (38), Direct Deep Black (similar to 38) Product), Direct Fast Black Conch (same 51), Kayara Spragley VGN (71), Kayak Direct Brilliant Yellow G (CI Direct Yellow 4), Direct Fast Yellow 5GL (same 26), Eisen Buri Muraero GCLH (44), Dire Tofast Yellow R (50), Eisen Direct Fast Red FH (CI Direct Red 1), Nippon Fast Scarlet GSX (Same 4), Direct Fast Scarlet 4BS (Same 23), Eisen Direct Durin BH (Same 31) ), Direct Scarlet B (same as 37), Kayak Direct Scarlet 3B (same as 39), Eisen Blumura Binkonk 2BLH (same as 75), Sumilite Red F3B (same as 80), Eisen Blemla Red 4BH (same as 81) Rubin BL (same as 83), Kayalas Light Red F5G (same as 225), Kayaras Light Red F5B (same as 226), Kayalas Light Rose FR (same as 227) Direct Sky Blue 6B (C.I. Direct Blue 1), Direct Sky Blue 5 15), Benzo Brilliant Sky Blue 8GS (41), Sumilite Splash Blue BRR Conch (71), Dibogen Turquoise Blue S (86), Water Bull # 3 (86), Kayara Star Coyze Blue GL (86), Daiwa Blue 215H (87), Kayala Supra Blue FF2GL (106), Kayasu Supra Blue FFRL (108) Kayasu Splatter Turquoise Blue FBL (199), and the like. As acid dyes, Acid Blue Black 10B (CI Acid Black 1), Nigrosine (2), Water Black R455 (2), Water Black R510 (2), Suminol Milling Black 8BX (24) Kayanol Milling Black VLG (26) Kayanol Milling Black BR Conk (31) Mitsui Nylon Black GL (52), Eisen Opal Black WH Extra Conk (52), Sumilan Black WA (52), Ranil Black BG Extra Conc (107) Kayanol Milling Black TLB (109) Suminoll Milling Black B (109) Kayanol Milling Black TLR (110), Eisen Opal Black New Conc (119) The Turter Black 187-L (154) Acid Yellow # 10 (CI Acid Yellow 1), Kayaku Acid Brilliant Flavin FF (7: 1), Kayasil Yellow GG (17), Xylene Light Yellow 2G 140% (17) , Suminol Leveling Yellow NR (19), Water Yellow # 1 (23), Daiwa Tarrazine (25), Kyakutor Torazin (23), Suminol Fast Yellow R (25) Diacid Light Yellow 2GP (same 29), Suminol Milling Yellow O (same 38), Suminol Milling Yellow MR (same 42), Water Yellow # 6 (same 42), Kayanol Yellow NFG (same 49), Suminol Milling Yellow 3G (same) 72), Suminol Fast Yellow G (61), Suminol Nguyero G (78), Kayanol Yellow N5G (110), Suminol Milling Yellow 4G 200% (141), Kayanol Yellow NG (135), Kayanol Milling Ero-5 GW (127), Kayanol Milling Yellow 6 GW (142), Sumitomo Fast Scarlet A (CI Acid Red 8), Kayak Silk Scarlet (9), Solar Rubin Extra (14), Daiwa New Coxin (18), Water Scarlet (same as above) 18), Daiwa Red 102 (18), Eisenbonso RH (26), Daiwa Red 2 (27), Suminol Leveling Brilliant Red S3B (35), Kayasil Rubinol 3GS (37) Eisen erythrosin (51), kayak acid rhodamine F B (52), Daiwa Red 106 (52), Suminol Leveling Rubinol 3GP (57), Diacid Alizarin Rubinol F3G 200% (82), Alizarin Rubinol 5G (83), Eisen Eosin GH (87), Water Red # 2 (87), Daiwa Red 103WB (87), Water Pink # 2 (92), Eisen Acid Phloxin PB (92), Daiwa Red 104 (92), Rose Bengal (94), Kayanol Milling Scarlet FGW (111), Kayanol Milling Rubin 3BW (129), Suminol Milling Brilliant Red 3BN Conch (131), Suminol Milling Brilliant Red BS (138), Eisen Opal Pink BH (186), Sumi Lumpur Brilliant Red B Conch (the 249), mosquito yak Acid Brilliant Red 3BL (the 254), mosquito yak Acid Brilliant Red BL (the 265), Kaya Nord milling red GW (the 276), Mitsui Acid Violet 6BN (C. I. Acid Violet 15), Mitsui Acid Violet BN (17), Water Violet # 1 (49), Water Violet # 5 (49), Daiwa Purple 1 (49), Ink Violet L10 (49), Sumitomo Patent Pure Blue VX (CI Acid Bull-1), Water Blue # 106 (1), Patent Blue AF (7), Water Blue # 9 (9), Daiwa Blue No. 1 (9) , Ink Blue L20 (same 9), Supranol Blue B (same 15), Water Blue # 116 (same 15), Orient Soluble Blue OBC (same 22), Orient Soluble Blue OBX (same 22), Suminol Leveling Blue 4GL (23), Mitsui Nylon Fast Blue G (25), Kayasil Blue A G (40), Kayasil Blue BR (41), Mitsui Alizarin Saphirol SE (43), Suminol Leveling Sky Blue R Extraconk (62), Mitsui Nylon Fast Sky Blue R (78), Sumitomo Brilliant India Cyanine 6Bh / e (83), Sandlancyanine N-6B 350% (90), Water Blue # 115 (90), Water Blue # 105 (90), Orient Soluble Blue OBB (93), Spula Norcyanin 7BF (same as 100), Sumitomo Brilliant Blue 5G (same as 103), Acid Blue (same as 103), Asilane Brilliant Blue FFR (same as 104), Kyanol Milling Ultra Sky SE (same as 112), Kyanol Milling Cyanine 5R (113) Eisen Opal Cyanine 2GLH (158), Daiwa Guinea Green B (CI Acid Green 3) Acid Brilliant Milling Green (9), Daiwa Green # 70 (16), Kayanol Cyanine Green G (25), Sumi-Milling Green G (27), Water Orange # 17 (CI Acid Orange 56), and the like. As basic dyes, malachite green (C.I. 42000), Victoria blue FB (C.I. 44045), methyl violet FN (C.I. 42535), rhodamine F4G (C.I. 45160), rhodamine 6GCP (C.I. 45160) and the like, water yellow # 2 (CI food yellow 3), food yellow 5 (CI food yellow 3) food red 3 ( Food dyes such as CI Food Red 14), Food Blue 2 (CI Acid Blue 74) and Food Green 2 (CI Acid Green 5) can also be used.
For pigments, carbon black such as farest black, contact black, thermal black, acetylene black, black iron oxide, yellow iron oxide, red iron oxide, ultramarine, bitumen, cobalt blue, titanium yellow, turquoise, molybdate orange, titanium oxide Inorganic powders such as gold powder, silver powder, copper powder, aluminum powder, brass powder, tin powder and the like, mica-based pigments, C.I. I. PIGMENT RED2, 3, 5, 17, 17, 38, 41, 48: 2, 48: 3, 49, 50: 1, 53: 1, 57: 1, 58: 2, 60, 63: 1, 63: 2, 64: 1, 88, 112, 122, 123, 144, 146, 149, 166, 168, 170, 176, 177, 178, 179, 180, 185, 190, 194, 206, 207, 209, 216, 245, C.I. I. PIGMENT ORANGE 5, 10, 13, 16, 36, 40, 43, C.I. I. PIGMENT VIOLET 19, 23, 31, 33, 36, 38, 50, C.I. I. PIGMENT BLUE 2, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 5, 16, 17, 17, 22, 25, 60, 66, C. I. PIGMENT BROWN 25, 26, C.I. I. PIGMENT YELLOW 1, 3, 12, 13, 24, 93, 94, 95, 97, 99, 108, 109, 110, 117, 120, 139, 153, 166, 167, 173C. I. And organic pigments such as PIGMENT GREEN 7, 10, and 36. In addition, inorganic fluorescent pigments such as zinc sulfide, zinc silicate, cadmium zinc sulfate, calcium sulfide, strontium sulfide, and calcium tungstate, and other known organic fluorescent pigments can be used. The aforementioned colorants can be used alone or in combination with others. These can be used alone or in combination.

  Here, when a pigment is used as the colorant, it is preferable to use a dispersant in combination. However, as the dispersant, conventionally used water-soluble or water-soluble resins, anionic or nonionic surfactants, etc. Examples of pigment dispersants used in the present invention are, for example, natural rubbers such as gum arabic and tragacanth, glucosides such as saponin, cellulose derivatives such as methylcellulose, carboxycellulose, and hydroxymethylcellulose. , Natural polymers such as lignin sulfonate and shellac, polyacrylate, salt of styrene-acrylic acid copolymer, salt of vinyl naphthalene-maleic acid copolymer, sodium salt of β-naphthalene sulfonic acid formalin condensate , Phosphates, and other anionic polymers and polyvinyl alcohol Le, polyvinylpyrrolidone, such as a non-ionic polymers such as polyethylene glycol. Further, as surfactants, alkyl sulfates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids and salts thereof, N-acylmethyl taurate salts, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylic acids Anionic surfactants such as salts, α-olefin sulfonates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl ethers, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, etc. Nonionic surfactants can be mentioned. These 1 type (s) or 2 or more types can be selected and used together. The amount used is preferably 1% by weight or more and 20% by weight or less based on the total amount of the aqueous composition.

  When a pigment is used, a commercially available water-dispersed pigment is preferably used because handleability and productivity are enhanced. Specific examples of the water dispersion type include uniperse series manufactured by Ciba Specialty Chemicals Co., Ltd., Hostfine series manufactured by Clariant Japan Co., Ltd., Disperse series manufactured by Dainippon Ink & Chemicals, Inc., Ryudye series, Toyo Ink Co., Ltd. ) Rio Fast series, EM Color series, Sanyo Dye Co., Ltd. Emacol series, Sandye series, Fuji Dye Co., Ltd. FUJI SP series, Sumika Color Co., Ltd., Polux series (above, inorganic Organic pigment dispersion), NKW series manufactured by Nippon Fluorescence Co., Ltd., Cosmo Color Series manufactured by Toyo Soda Co., Ltd., Sinloi Color Base Series manufactured by Sinloi Co., Ltd. Can be mentioned. These can be used alone or in combination of two or more.

  Water is used as the main solvent.

The polyoxyethylene rosin ester is used to obtain a uniform handwriting without a line skip phenomenon when written on a paper surface contaminated with sebum components. The amount used is preferably 0.5% by weight or more and 5.0% by weight or less based on the total amount of ink as a solid content. If the amount is less than 0.5% by weight, the effect is hardly exhibited. If the amount exceeds 5.0% by weight, the adhesive strength tends to be too strong and the writing quality tends to be heavy.
The optimal addition number of ethylene oxide is preferably 30 mol or more. If it is 30 mol or less, it is difficult to dissolve in water, and the compatibility with the thickener becomes poor, so that it tends to be separated after long-term storage.
Specific examples include BLAUNON REO-30 (polyoxyethylene rosin ester (ethylene oxide addition number: 30), Aoki Yushi Co., Ltd.), BLAUNON REO-40 (same (ethylene oxide addition number: 40), the same), BLAUNON REO-50 (the same (the number of ethylene oxide addition: 50)), etc. are mentioned.

  Various polymer compounds can also be used as a viscosity modifier for imparting shear thinning to the ink or adjusting the viscosity. For example, as the cross-linked polyacrylic acid, Rheozic 250H (manufactured by Nippon Pure Chemicals Co., Ltd.), Junron PW111 (manufactured by Nippon Pure Chemicals Co., Ltd.), U Jeri CP (manufactured by Showa Denko KK), Carbopol 934, 940, 941, 980, 981, 981, 1342, 1382, 2984, 2984, ETD2020, ETD2050, EZ-1 (manufactured by BF Goodrich, USA) and the like. As acrylic acid-alkyl methacrylate copolymers, Pemulene TR-1, TR-2 (manufactured by BF Goodrich, USA) and the like, as clay minerals such as bentonite, Wengel W-200U, W-300U, W-300HP (anion polymer composite purified bentonite, manufactured by Toyosune Yoko Co., Ltd.), HPC-SL, L, M, H (above, Nippon Soda Co., Ltd.), Avicel PH-101, Celluloses such as 102, 301, M06, TG-101 (above, manufactured by Asahi Kasei Co., Ltd.), Kelzan, Kelzan S, Kelzan F, Kelzan AR, Kelzan M, Kelzan D (above, Sanki Co., Ltd.) Xanthane gum such as Kojin, Kojin F, Kojin T, Kojin K (manufactured by Kojin Co., Ltd.), succinoglucan such as Leozan (manufactured by Sanki Co., Ltd.), K1A 6 (manufactured by Sanki Co., Ltd.), etc., lanthanum such as K1A112, K7C2433 (manufactured by Sanki Co., Ltd.), Jaguar 8111, 8600, HP-8, HP-60, CP-13 ( As described above, water-soluble polysaccharides such as Guar gums (manufactured by Sanki Co., Ltd.), pullulan (manufactured by Hayashibara Co., Ltd.), zeta sea gum (manufactured by Hakuto Co., Ltd.), GX-205, NA-010 (Showa Denko Co. Water-soluble synthetic polymers such as N-vinylacetamide polymerization cross-linked products such as Smecton SA (Smectite, manufactured by Kunimine Industries Co., Ltd.), Kunipia-F, Kunipia-G (Montmorillonite, manufactured by Kunimine Industries Co., Ltd.) , Wenger HV, FW, 15 and 23 (Bentonite, manufactured by Toyoshun Yoko Co., Ltd.), S Ben, C, W and N400 (quaternary ammonium cation-modified montmorillonite, Inorganic clay minerals such as Toyshun Yoko Co., Ltd.), polyvinyl alcohol, polyvinyl methyl ether, polyethylene oxide, vinyl acetate-polyvinylpyrrolidone copolymer, alkali metal salt of acrylic resin, polyvinyl pyrrolidone, polyethylene oxide, N-vinylacetamide, Examples include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, sodium starch glycolate, sodium alginate, propylene glycol alginate, and derivatives thereof.

  A water-soluble organic solvent can be used for the purpose of preventing ink drying at the pen tip, preventing the ink from freezing at low temperatures, and the like. Specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, hexylene glycol, 1,3-butylene glycol, thiodiethylene glycol, glycerin, 2-pyrrolidone, N-methyl-2-pyrrolidone, Examples include triethanolamine. These water-soluble organic solvents can be used alone or in combination. The amount used is preferably 10% by weight or more and 60% by weight or less based on the total amount of the ink composition.

  Furthermore, wetting agents such as urea, ethylene urea and thiourea, antiseptics such as benzothiazoline and omadin, rust inhibitors such as benzotriazole, and styrene-acrylic copolymers for fixing pigments to the writing surface And alkali salts thereof, emulsions such as vinyl acetate, acrylic and styrene-acrylic resins, pH adjusters such as sodium hydroxide, 2,2-aminomethyl-1,3-propanediol, diethanolamine, silicone emulsions Various additives such as an antifoaming agent can be used as necessary.

In producing the ink composition of the present invention, various conventionally known methods can be employed.
For example, after adding water and polysaccharides to a stirrer such as a Henschel mixer with high shearing force and stirring and dissolving, add the pigment and other remaining components dispersed by a dispersing machine such as a ball mill, bead mill, and roll mill, and further mix and stir. Can be easily obtained. You may perform the removal of the foam by a defoamer, filtration of the coarse thing by a filter, etc. as needed.

(Polysaccharide solution 1)
Ion-exchanged water 73.5 parts by weight Ethylene glycol 25.0 parts by weight Proxel GXL (Antidepressant, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.5 parts by weight Zeta Seagum (Hakuto Co., Ltd.) ) Manufactured) 2.0 parts by weight These blends were placed in a Henschel mixer, stirred and dissolved at 2800 rpm for 1 hour, and then taken out to obtain a polysaccharide solution.

(Polysaccharide solution 2)
Ion-exchanged water 68.5 parts by weight Ethylene glycol 25.0 parts by weight Proxel GXL 0.5 parts by weight Kelzan AR (xanthan gum, manufactured by Sanki Co., Ltd.) 6.0 parts by weight These compounds are put in a Henschel mixer and 1400 rpm And dissolved with stirring for 30 minutes to obtain a polysaccharide solution.

Example 1
Ion-exchanged water 33.7 parts by weight Ethylene glycol 6.0 parts by weight Glycerin 14.0 parts by weight Benzotriazole 0.4 parts by weight Coatside S (Antidepressant, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.1 part by weight TSA739 (Antifoamer, silicone emulsion, manufactured by GE Toshiba Silicone Co., Ltd.)
0.1 parts by weight BLAUNON REO-30 (polyoxyethylene rosin ester, Aoki Oil & Fat Co., Ltd.)
2.5 parts by weight Sodium hydroxide neutralized 20% aqueous solution (pH 8.3) of Phosphanol RB410 (polyoxyethylene oleyl ether phosphate, manufactured by Toho Chemical Co., Ltd.) 2.0 parts by weight Jonkrill J734 (styrene / acrylic resin emulsion, manufactured by Johnson Polymer Co., Ltd.) 1.0 part by weight FUJI SP BLACK 8970 (pigment dispersion, manufactured by Fuji Dye Co., Ltd.)
25.0 parts by weight Diethanolamine (pH adjuster) 0.2 parts by weight Polysaccharide solution 1 15.0 parts by weight These compounds were put in a Henschel mixer and stirred for 5 minutes at 1400 rpm, and then mixed and stirred for 60 minutes at 2800 rpm. , Took out. Thereafter, filtration was performed, and defoaming was performed using a centrifuge (H-103N, manufactured by Kokusan Co., Ltd.) at a rotational speed of 1000 rpm until there were no fine bubbles on the surface, thereby obtaining a black water-based ink for a ballpoint pen.

(Example 2)
Ion-exchanged water 21.2 parts by weight Ethylene glycol 10.0 parts by weight Glycerin 10.0 parts by weight Benzotriazole 0.4 parts by weight Coatside S 0.1 parts by weight TSA739 (antifoaming agent, silicone emulsion, GE Toshiba Silicone Corporation ) Made)
0.1 part by weight BLAUNON REO-50 (polyoxyethylene rosin ester, manufactured by Aoki Oil & Fats Co., Ltd.) 5.0 part by weight Sodium hydroxide neutralized 20% aqueous solution of sarcosinate OH (pH 8.0)
5.0 parts by weight Jonkrill 450 (styrene / acrylic resin emulsion, manufactured by Johnson Polymer Co., Ltd.) 10.0 parts by weight FUJI SP BLACK 8970 (pigment dispersion, manufactured by Fuji Dye Co., Ltd.)
25.0 parts by weight Diethanolamine (pH adjuster) 0.2 parts by weight Polysaccharide solution 2 13.0 parts by weight These formulations were put into a Henschel mixer and stirred for 30 minutes at 1400 rpm, and then taken out. Thereafter, filtration was performed and defoaming was performed in the same manner as in Example 1 to obtain a black water-based ink for ballpoint pens.

(Example 3)
Ion-exchanged water 49.0 parts by weight Propylene glycol 10.0 parts by weight Glycerin 10.0 parts by weight Benzotriazole 0.4 part by weight Coatside S 0.1 part by weight TSA739 0.1 part by weight BLAUNON REO-40 (polyoxyethylene Rosin ester, Aoki Yushi Co., Ltd.
3.0 parts by weight Sarcosinate OH (oleoyl sarcosine, manufactured by Nikko Chemicals) 20% aqueous solution of sodium hydroxide neutralized (pH 8.0) 5.0 parts by weight Jonkrill J775 (styrene / acrylic resin) Emulsion, manufactured by Johnson Polymer Co., Ltd.) 5.0 parts by weight C.I. I. Direct Red 1 (Red Dye) 5.0 parts by weight Diethanolamine 0.4 parts by weight Polysaccharide solution 2 15.0 parts by weight These formulations were placed in a Henschel mixer and stirred for 30 minutes at 1400 rpm and then taken out. Then, filtration was performed and defoaming was performed in the same manner as in Example 1 to obtain a red water-based ink for ballpoint pens.

Example 4
In Example 1, except that BLAUNON REO-30 was reduced to 0.3 parts by weight and ion exchange water was increased by that amount, a black water-based ink for ballpoint pens was obtained.

(Example 5)
In Example 1, a black ballpoint pen aqueous ink was obtained in the same manner as in Example 1 except that BLAUNON REO-30 was increased to 6.0 parts by weight and the amount of ion-exchanged water was reduced by that amount.
(Example 6)
Ion-exchanged water 60.3 parts by weight Ethylene glycol (water-soluble organic solvent) 12.0 parts by weight Dipropylene glycol (moisturizing solvent, water-soluble organic solvent) 8.0 parts by weight Benzotriazole (rust inhibitor) 0.2 parts by weight Topside 610 (preservative, manufactured by Permachem Asia Co., Ltd.) 0.2 parts by weight BLAUNON REO-30 (polyoxyethylene rosin ester, Aoki Yushi Co., Ltd.)
2.5 parts by weight Jonkrill 62 (dispersant, styrene / acrylic copolymer resin aqueous solution, manufactured by Johnson Polymer Co., Ltd. 8.0 parts by weight FUJI SP BLACK 8970 (pigment dispersion, manufactured by Fuji Dye Co., Ltd.)
8.5 parts by weight 20% aqueous sodium hydroxide solution (pH adjuster) 0.3 parts by weight These blends were mixed, stirred for 4 hours with a three-one mixer, further dispersed for 5 hours with a ball mill, and then taken out. Thereafter, filtration was performed to obtain a black water-based ink for ballpoint pens.

(Comparative Example 1)
A black ballpoint pen aqueous ink was obtained in the same manner as in Example 1 except that BLAUNON REO-30 was used and ion-exchanged water was increased by that amount.

(Comparative Example 2)
In Example 2, except for BLAUNON REO-50, black ester was formed in the same manner as in Example 2 except that 5.0 parts by weight of superester E-650 (rosin ester emulsion, manufactured by Arakawa Chemical Industries, Ltd.) was added. A water-based ink for ballpoint pens was obtained.

  The ink compositions obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were hybrids manufactured by Pentel Co., Ltd. (product code K105) made of a stainless steel ballpoint pen tip (ball material: cemented carbide, ball diameter: 0.7 mm). ) About 0.8 g is filled in, and the backflow preventive composition used in K105 is arranged in layers at the ink interface, and then subjected to centrifugal treatment so that the nib faces outward, and defoamed. A test ballpoint pen was created. Furthermore, 2.0 g of the water-based ink composition obtained in Example 6 was filled into a writing instrument similar to a commercially available ballpoint pen using a water-filled water-based ink (Ball Pentel B50, manufactured by Pentel Co., Ltd.) to prepare a test ballpoint pen. .

Artificial sebum prepared with the following composition is used to make 4 types of solutions diluted with acetone to 1%, 10%, 20% and 30%, and each is made uniform by spraying on fine paper (JIS P3201 writing paper A). Spray like so. This paper was dried in a thermostatic chamber adjusted at room temperature of 60 ° C. and humidity of 10% for 2 hours to remove acetone, and paper contaminated with 4 types of sebum, sebum-contaminated paper level 1 (sebum application amount 0.16 g / m ² ), sebum-contaminated paper level 2 (sebum application amount 1.5 g / m ² ), sebum-contaminated paper level 2 (sebum application amount 3.0 g / m ² ), sebum-contaminated paper level 4 (sebum application amount 4.1 g) / M ² ).

(Mixed artificial fat)
Isostearic acid 13 parts by weight Squalane 5 parts by weight Cholesterol 5 parts by weight Triglyceride 35 parts by weight Oleic acid 42 parts by weight

(Line skip test with sebum component)
On high-quality paper and high-quality paper contaminated with sebum, a rolling continuous spiral writing tester (MODEL TS-4C-20, manufactured by Seiki Kogyo Laboratories) has a writing speed of 4 m / min, a writing angle of 70 °, and a writing load of 100 g. Write 10m under the following conditions. After completion of writing, the state of the writing lines was observed, and the number of points where the handwriting was interrupted was counted.

(Writing test)
In a thermostatic chamber adjusted to a temperature of 50 ° C. and a humidity of 30%, a test ballpoint pen and a hybrid manufactured by Pentel (product code K105) are left sideways for 3 months. After 3 months, take it out from the temperature-controlled room, let it stand at room temperature for 1 hour, return it to room temperature, ask 20 monitors to write, and each test ballpoint pen is lighter and smoother than K105 = 2 points The same grade = 1 point, heavy and astringent = 0 points. The total score was calculated and used as an evaluation of writing quality.

Claims (1)

A water-based ink composition for ballpoint pens containing at least a colorant , water, and a polyoxyethylene rosin ester of 0.5 wt% or more and 5.0 wt% or less based on the total amount of the ink.