JP2002167542A - Water base ball point ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water base ball point ink composition which has a stable ink viscosity even in a long-term storage and can prevent the settling of a colorant, or the like, and can prevent the burring of writing and the impossibility of writing due to the settling of the colorant, or the like, to a pen point when made into a ball point pen and thereafter left to stand the pen point downwardly. SOLUTION: This water base ball point ink composition comprises at least a colorant such as a dye and a pigment, an ionic polysaccharide, a smectite based clay, water, and a water-soluble organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink used for a ball-point pen having a ball-point pen tip for holding and holding a superalloy or ceramic ball as a writing member, and discharging ink by rotating the ball. More specifically, the present invention relates to a stable aqueous ink composition for ballpoint pens without deterioration such as thickening, sedimentation, and precipitation with time.

[0002]

2. Description of the Related Art Conventionally, ballpoint pens can provide relatively thin handwriting, and, compared to writing instruments having a fibrous nib or a resin nib, even when used for a long time, the handwriting due to wear or crushing of the nib. Widely used because of small change in width. The viscosity of the aqueous ink composition used for such a ballpoint pen is known to be one to several mPa · s (25 ° C.) and one to 50 to 2,000 mPa · s (25 ° C.). Those having 1 to several mPa · s (25 ° C.) are mainly used for ballpoint pens having a structure using batting as an ink occluding material, and those having 50 to 2,000 mPa · s (25 ° C.) are mainly used as ink reservoirs. It is used for a structure using a hollow cylinder.

[0003] The writing mechanism of a ball-point pen is such that ink attached to the ball surface is transferred to a writing surface such as paper as the ball rotates. Ballpoint pens basically meet the general requirements for ballpoint pens, in which an appropriate amount of ink is transferred to the surface to be written, and furthermore, there are no problems such as blurring in handwriting and ink leakage from the ballpoint pen tip at the tip of the ballpoint pen. Therefore, it is necessary to appropriately select additives and adjust physical properties.

Conventional ballpoint pen inks generally include an ink solvent which is a liquid material that dissolves or disperses an ink component such as water or an organic solvent, a colorant, a fixation to a writing surface, and adjustment of the viscosity of the ink. And the like. By the way, the pen tip discharges ink from the gap between the tips of the balls, but depending on the ink, there is a phenomenon in which the ink leaks from this part without writing, and such a phenomenon occurs. 7000 to 15000 mPa · s to prevent excessive ink leakage
Use ink that has relatively low viscosity when using ink with relatively high tackiness or imparting thixotropy to the ink and flowing when the ball rotates, but when not using the ball without rotation. I was using it.

[0005] Highly sticky ink is a technical means mainly used for oil-based ballpoint pens, but has drawbacks such as high writing resistance, heavy writing taste, and poor writing due to the high stickiness of the ink. Conversely, an aqueous ballpoint pen has conventionally used an ink provided with thixotropic properties. A typical example of a thickener that imparts its thixotropic property is
Examples include smectite-based clays such as bentonite and montmorillonite, ionic polysaccharides such as xanthan gum and welan gum, N-vinylcarboxylic amide, and acrylic acid-methacrylic acid copolymer. Inks using these thickeners have the effect of preventing blurring and line skipping due to excessive supply of ink and insufficient ink supply during writing, and also have the effect of suppressing blurring of written lines. Is to prevent the backflow of ink and the leakage of ink.

[0006] Smectite clay such as bentonite is formed by bonding basic unit crystals in such a manner that tetrahedral silicate layers sandwich an octahedron such as alumina from both sides,
Under normal humidity, two layers of water molecules are involved, and the ions between the layers are distant from each other across the water molecules.Therefore, the electrical connection is weak, and the upper and lower surfaces of the overlapping layers are tetrahedral negative. Repel each other electrically, including that they are occupied by ions. For this reason, water molecules enter between the crystal layers, and the water molecule layers are steadily stacked in a semi-solid form, pushing the layers apart, expanding the whole, and increasing the viscosity or swelling. At this time, the thickened or swollen smectites form a card house structure, and exhibit thixotropic properties when the card house structure is developed.
Inks using such smectite clay are disclosed in JP-A-6-264012 and JP-A-10-219175.
In Japanese Patent Publication No.

When an ionic polysaccharide such as xanthan gum is added to thicken the ink, the colorant such as a pigment is trapped in the network structure formed by the ionic polysaccharide, so This makes it possible to prevent the colorant from settling and the writing and writing quality of the pen from deteriorating.

[0008]

However, aqueous inks to which a smectite-based clay is added as a thickener have large variations among lots, and it is difficult to maintain a viscosity suitable for an aqueous ballpoint pen. In addition, the smectite clay has a problem that the writing taste tends to be poor depending on the amount of addition. In addition, ionic polysaccharides such as xanthan gum retain pigments in a network structure due to steric hindrance and electric repulsion, but the network structure is easily destroyed by temperature and aging, resulting in steric hindrance and electrical repulsion. The force was reduced, and aggregation and sedimentation of the pigment due to temperature change and storage over time could not be completely prevented. Also,
Since most dyes are also ionic in dyes,
It readily reacts with ionic polysaccharides, and similarly causes problems such as crystal precipitation and sedimentation.

[0009] Therefore, a ballpoint pen using a coloring agent causes poor writing due to the agglomerated coloring agent clogging the ink flow path, or causes the dye to settle on the upper portion of the ink in the container such as between the ink storage of the writing implement and the coloring agent settling. There is a problem that a color separation phenomenon occurs in which a layer having a small amount of pigment or pigment is formed.

It is an object of the present invention to provide an aqueous ballpoint pen ink composition which is excellent in stability over time without the coloring agent of the dye or pigment being coagulated or settled by storage over time or temperature change.

[0011]

SUMMARY OF THE INVENTION The gist of the present invention is to provide an aqueous ballpoint pen ink composition containing at least a colorant, an ionic polysaccharide, a smectite clay, water and a water-soluble organic solvent. I do.

Hereinafter, the present invention will be described in detail. The ionic polysaccharide is a water-soluble thickener that increases the viscosity of the entire ink and suppresses sedimentation of the coloring agent and the like contained in the ink. Further, it can be used to suppress wear and deformation of the ball receiving seat. The ionic polysaccharide to be used is preferably one having a property that a high viscosity can be obtained even with a small amount of addition and a property that the viscosity decreases when a high shearing force is applied, that is, a so-called thixotropic property. Specific examples thereof include, for example, xanthan gum, welan gum, pectin, ramzan gum and the like. The addition amount is particularly preferably 0.2 to 0.7% by weight based on the total amount of the aqueous ballpoint pen ink composition. If the amount is less than 0.2% by weight, there is a case where the effect of suppressing the sedimentation of the pigment is not effective. If the amount exceeds 0.7% by weight, the sedimentation of the pigment can be suppressed, but the mobility of the ink in the ink container becomes poor. ,
In some cases, the handwriting may be fuzzy or a problem that writing may not be possible.

Smectite clay has a crystal structure,
Since it swells with water or an organic solvent and exists in the ink in a soft form, it is easy to hold the colorant. However, when the addition amount is large, the writing taste is deteriorated. Therefore, the addition amount is 0.1 to 0.1% based on the total amount of the aqueous ballpoint pen ink composition.
1.0% by weight is preferable, and 0.3 to 0.8% by weight is more preferable. If the amount is less than 0.1% by weight, the amount of sedimentation of the pigment becomes large, and there may be a problem in storage with time. On the other hand, if the content exceeds 1.0% by weight, the writing taste may be extremely reduced. Specific examples of smectite clays are selected from natural or synthetic smectites, montmorillonite, beidellite, saponite, nontronite,
Hectorite, sauconite, stevensite and the like.

As the colorant, any dyes and pigments conventionally used in aqueous inks can be used without limitation.
Specific examples include Japanol Fast Black D Conch (CI Direct Black 17), Water Black 100L (19), Water Black L-200 (19), and Water Black # 7 (1).
9), Kayaset Black W9 (19), Direct Fast Black B (22), Direct Fast Black AB (32), Direct Deep Black EX
(38), Direct Deep Black (38 similar products), Direct Fast Black Conch (51),
Kayalas Sprague VGN (71), Kayak Direct Brilliant Yellow G (CI Direct Yellow 4), Direct Fast Yellow 5GL (2)
6), Aizen Brimura Yellow GCLH (44), Direct Fast Yellow (50), Aizen Direct Fast Red FH (CI Direct Red 1), Nippon Fast Scarlet GSX (4),
Direct Fast Scarlet 4BS (23), Eisen Direct Durin BH (31), Direct Scarlet B (7), Kayak Direct Scarlet 3B (39), Eisen Burimurabink 2BL
H (75), Sumilight Red F3B (80), Aizen Burimura Red 4BH (81), Kyalas Sprarubin BL (83), Kayaras Light Red F5G
(225), Kayasu Light Red F5B (22)
6), Kayalas Light Rose FR (227), Direto Sky Blue 6B (CI Direct Blue 1),
Direct Sky Blue 5B (15), Benzo Brilliant Sky Blue 8GS (41), Sumilite Supra Blue BRR Conc (71), Diebogen Turquoise Blue S (86), Water Blue # 3 (8)
6), Kayara Star Koizu Blue GL (86), Daiwa Blue 215H (87), Kayara Supra Blue F
F2GL (106), Kayaras Supra Blue FFRL
(Ibid. 108), Kayaras Splatter Turquoise Blue FBL
(1992), 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), Kayano milling black B
R Conch (31), Mitsui Nylon Black GL (52), Eisen Opal Black WH Extra Conc (52), Sumilan Black WA (52), Ranyl Black BG Extra Conc (107), Kayanol Milling Black TLB (109), Suminol Milling Black B (109), Kayanol Milling Black TLR (110), Aizen Opal Black New Conch (119), Water Black 18
7-L (154), Acid Yellow # 10 (C.I.
I. Acid Yellow 1), Kayak Acid Brilliant Flavin FF (7: 1), Kayasil Yellow GG (1)
7), xylene light yellow 2G140% (17),
Suminol Leveling Yellow NR (19), Water Yellow # 1 (23), Daiwa Trazine (2)
5) Kayaktor Trazine (23), Suminol Fast Yellow R (25), Diacid Light Yellow 2
GP (29), Suminol Milling Yellow O (3)
8), Suminol Milling Yellow MR (42), Water Yellow # 6 (42), Kayanol Yellow NF
G (49), Suminol Milling Yellow 3G (7
2), Suminol Fast Yellow G (61), Suminol Milling Yellow G (78), Kayanol Yellow N
5G (110), Suminol milling yellow 4G20
0% (141), Kayanol Yellow NG (13
5), Kayanol milling yellow 5GW (127),
Kayanol Milling Yellow 6GW (142), Sumitomo Fast Scarlet A (CI Acid Red 8), Kayak Silk Scarlet (9), Solar Rubin Extra (14), Daiwa New Koksin (18), Water Scarlet (18), Daiwa Red 102 (18), Aizen Bon Saw RH (2)
6), Daiwa Red No. 2 (27), Suminol Leveling Brilliant Red S3B (35), Kayasil Rubinol 3GS (37), Aizen Erythrosin (5)
1), kayak acid rhodamine FB (52), Daiwa Red No. 106 (52), Suminol leveling rubinol 3GP (57), diacid alizarin rubinol F3G 200% (82), alizarin rubinol 5G (52) 83), Eisen Eosin GH (87),
Water Red # 2 (87), Daiwa Red 103W
B (87), Water Pink # 2 (92), Eisen Acid Phloxine PB (92), Daiwa Red 1
No. 04 (92), Rose Bengal (94), Kayanol milling scarlet FGW (111), Kayanol milling rubin 3BW (129), Sumino milling brilliant red 3BN conch (131),
Suminol Milling Brilliant Red BS (13
8), Eisen Opal Pink BH (186), Suminol Brilliant Red B Conc (249), Kayak Acid Brilliant Red 3BL (254), Kayak Acid Brilliant Red BL (265), Kayano Milling Red GW (ibid) 276), Mitsui Acid Violet 6BN (CI Acid Violet 15), Mitsui Acid Violet BN (1)
7), Water Violet # 1 (49), Water Violet # 5 (49), Daiwa Purple No. 1 (4)
9), Ink Violet L10 (49), Sumitomo Patent Pure Blue VX (CI Acid Blue 1), Water Blue # 106 (1), Patent Blue AF (7), Water Blue # 9 (9) ), Daiwa Blue No. 1 (9), Ink Blue L20 (9),
Spnor Blue B (15), Water Blue # 1
16 (15), Orient Soluble Blue OBC (22), Orient Soluble Blue OBX (22),
Suminol Leveling Blue 4GL (23), Mitsui Nylon Fast Blue G (25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Safirol SE (43), Suminol Leveling Sky Blue R Extra Conch (6
2), Mitsui Nylon Fast Sky Blue R (7)
8), Sumitomo Brilliant Indo-Sinian 6Bh / e
(83), Sandran Cyanine N-6B 350% (90), Water Blue # 115 (90), Water Blue # 105 (90), Orient Soluble Blue OBB (93), Spranolocyanine 7BF (90) 100), Sumitomo Brilliant Blue 5G (10
3), Acid Blue (103), Asilane Brilliant Blue FFR (104), Kayanol Milling Ultra Sky SE (112), Kayanol 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
(No. 16), Kayanol Cyanine Green G (No. 2)
5), Suminol Milling Green G (No. 27), Water Orange # 17 (CI Acid Orange 5)
6) and water yellow # 2 (C.I.
I. Food Yellow 3), Food Yellow 5 (CI Food Yellow 3), Food Red 3 (CI Food Red 14), Food Blue 2 (CI Acid Blue 7)
4), Food Green No. 2 (CI Acid Green 5)
Food dyes such as Malachite Green (CI. 420)
00), Victoria Blue FB (CI. 4404)
5), methyl violet FN (C.I.
5), basic dyes such as rhodamine F4G (CI. 45160) and rhodamine 6GCP (CI. 45160).

As the pigment, conventionally known pigments can be used.
Specific examples include Special Black 6 and S
170, S610, 5, 5, 4, 4A, 550,
35, 250, 100, Printex 150
T, U, V, 140U, 140V, 95, 90, 85, 80, 75, 55, 45, 45, P, XE2, L6, L, 300 # 30, # 35, # 35, # 25, # 200, #A, #G (above, manufactured by Tegusa Japan Ltd.), # 2400B, # 235
0, # 2300, # 2200B, # 1000, # 95
0, # 900, # 850, # MCF88, MA600,
MA100, MA100, MA7, MA11, # 50,
# 52, # 45, # 44, # 40, # 33, # 32, #
30, CF9, # 20B, # 4000B (Mitsubishi Chemical Industries, Ltd.), MONARCH 1300, 10
0, 1000, 900, 880, 800, 7
00, MOGUL, REGAL 400R, 660
R, 500R, 330R, 300R, 99R,
ELFTEX 8, 12 and BLACK PEARLS
2000 (above, USA, Cabot Co. LTD
Manufactured), Raven 7000, 5750, 525
0, 5000, 3500, 2000, 150
0, 1255, 1250, 1200, 117
0, 1060, 1040, 1035, 102
0, 1000, 890H, 890, 850, 790, 780, 760, 500, 450, 430, 420, 410, 22, 16, and 1
4, 825, oil Beads, H20, C,
Carbon blacks such as Conductex 975, 900, and SC (all manufactured by Colombian Carbon Japan Co., Ltd.), KA-10, 10P, 15 and 2,
0, 30, 30, 35, 60, 80, 90, KR-
Titanium oxides such as 310, 380, 460, and 480 (manufactured by Titanium Industry Co., Ltd.), P25 (manufactured by Nippon Aerosil Co., Ltd.), BS-605, and 607 (manufactured by Toyo Aluminum Co., Ltd.) ), Bronze powder P-555, P
-777 (above, manufactured by Nakajima Metal Foil Industry Co., Ltd.), Bronze Powder 3L5, 3L7 (above, Fukuda Metal Foil Industry Co., Ltd.)
Metal powder pigments, such as black iron oxide, yellow iron oxide,
Inorganic pigments such as red iron oxide, ultramarine blue, navy blue, cobalt blue, chrome green, and chromium oxide, Hansa Yellow-10
G, 5G, 3G, 4, GR, A, Benzidine Yellow, Permanent Yellow NCG, Tartrazine Lake, Quinoline Yellow, Sudahn 1, Permanent Orange, Indus Ren Brilliant Orange GN, Permanent Brown FG, Para Brown, Permanent Red 4R, Fire Red, Brilliant Carmin BS,
Organic pigments such as pyrazolone red, lake red C, quinacridone red, brilliant carmine 6B, bordeaux 5B, thioindigo red, fast violet B, dioxane violet, alkali blue lake, phthalocyanine blue, indigo, acid green lake, and phthalocyanine green. Can be In addition, inorganic fluorescent pigments such as zinc sulfide, zinc silicate, zinc cadmium sulfate, calcium sulfide, strontium sulfide, and calcium tungstate may be used. The above-mentioned coloring agents can be used alone or in combination with others, and the amount used varies depending on the color tone and the like. Since problems occur, the content is preferably 0.1 to 40% by weight based on the total amount of the aqueous ballpoint pen ink composition.

When a pigment is used, it is preferable to use a dispersant in combination. As the dispersant, a water-soluble resin or a water-soluble resin which is conventionally generally used, or a dispersant which is used as a pigment dispersant such as an anionic or nonionic surfactant can be used. As an example, as a polymer dispersant, gum arabic, natural gums such as tragacanth gum, glucosides such as saponin, methylcellulose, carboxycellulose, cellulose derivatives such as hydroxymethylcellulose, lignin sulfonate,
Natural polymers such as shellac, polyacrylates, salts of styrene-acrylic acid copolymers, salts of vinylnaphthalene-maleic acid copolymers, sodium salts of β-naphthalenesulfonic acid formalin condensates, phosphates and the like Examples include anionic polymers and nonionic polymers such as polyvinyl alcohol and polyethylene glycol. As surfactants, alkyl sulfates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids and salts thereof, N-acylmethyl taurine salts, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylates, α- Olefin sulfonates, alkyl phosphates,
Nonionic surfactants such as polyoxyethylene alkyl ethers, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters are included. These water-soluble resins and surfactants may be used alone or in combination of two or more. When the amount is small, the dispersing effect to be added is weakened, and when the amount is large, the dissolution balance of each composition in the ink is lost, and there is a concern that various problems may occur.
It is preferably from 1 to 20% by weight based on the total amount of the aqueous ballpoint pen ink composition.

Further, using an aqueous ink base in which a pigment is dispersed in an aqueous medium is advantageous in producing a pigment ink. Specifically, Fuji SP Black 80
31, 8119, 8167, 8276, 838
1, 8406, FujiSP RED 5096, 5111, 5193, 5220, 5543, 5
544, Fuji SP Bordeaux 550
0, Fuji SPBlue 6062, 6133,
6134, 6401, Fuji SP Green
7051, Fuji SP Yellow 4060,
4178, Fuji SP Violet 901
1, 9586 Fuji SP Pink 9524,
9527, Fuji SP Orange 534,
Fuji SP Brown 3074 (all manufactured by Fuji Dye Co., Ltd.), EmacolBlack CN, Ema
col Blue FBB, FB, KR, Emac
ol Green LXB 、 Emacol Vio
t BL, Emacol Brown 3101, Em
acol Carmmine FB, Emacol R
ED BS, Emacol Orange R, Ema
col Yellow FD, the same IRN, the same 3601,
Same FGN, Same GN, Same GG, Same F5G, Same F7G, Same 1
0GN, Sndy Super Black K, C, Sndy Super Brown SB, F
RL, RR, Sandy Super Navy
Blue HRL, GLL, HB, FBL-H,
FBL-160, FBB, Sandy Suppe
r Violet BLH / C, same BL, same BLN, S
andy Super Bordeaux FR, S
andy Super Pink FBL, F5
B, SandySuper Rubine FR, S
andy Super Carmine FB, San
Dye Super RED FFG, RR, B
S, Sandye Super Orange FL,
Same R, Same BO, Sandye Gold Yellow
5GR, same R, same 3R, Sandy Yellow
GG, F3R, IRC, FGN, GN, G
RS, GSR-130, GSN-130, GS
N, 10GN (above, manufactured by Sanyo Dyeing Co., Ltd.), RioF
as Black Fx 8012, 8313, 8169, Rio Fast Red Fx 820
9, 8172, Rio Fast Red SFX
8315, 8316, Rio Fast Blue
Fx 8170, Rio Fast Blue SF
x 8312, Rio Fast Green SF
x 8314 (all manufactured by Toyo Ink Co., Ltd.), NKW-
2101, 2102, 2103, 2104, 2
105, 2106, 2107, 2108, 21
17, 2127, 2137, 3167, 210
1P, 2103P, 2104P, 2105P, 2106P, 2107P, 2108P, 2117
P, 2127P, 2137P, 2167P, NK
W-3002, 3003, 3004, 3005,
3007, 3077, 3008, 3402, 3404, 3405, 3407, 3408, 3
477, 3602, 3603, 3604, 36
05, 3607, 3677, 3608, 370
2, 3703, 3704, 3705, 377
7, 3708, 6013, 6038, 6559
(The above are manufactured by Nippon Fluorescence Co., Ltd.), Cosmo Color S 100
0F series (Toyo Soda Co., Ltd.), MiCroJe
t series (manufactured by Orient Chemical Industry Co., Ltd.), Victoria Yellow G-11, G-20, Victoria Orange G-16, G-21, Victoria Red G-1
9, G-22, Victoria Pink G-17, G-
23, Victoria Green G-18, G-24, Victoria Blue G-15, G-25 (all manufactured by Mikuni Pigment Co., Ltd.), Pollux Blue PC5T-102
0, Pollux Black PC8T-135, Pollux thread IT-1030, and other Pollux series (all manufactured by Sumika Color Co., Ltd.). These can be used alone or in combination of two or more. It is.

In addition to water, which is essential as a solvent or dispersant, various water-soluble organic solvents can be used, and these have various qualities as aqueous inks, for example, prevention of ink drying at a pen tip, It is used for purposes such as prevention of ink freezing and a dispersion medium for pigments. Specifically, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-butylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, thiodiethylene glycol, hexylene glycol, tetralin, and glycerin; 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, dipropylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene Glico Monobutyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monoethyl ether, tripropylene glycol monomethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monoethyl ether, triethylene glycol mono Ethers such as butyl ether, tripropylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, ethylene glycol monophenyl ether, and alcohols such as benzyl alcohol, methanol, ethanol, propanol, isopropanol and butanol N- methyl-2-pyrrolidone, those 2-pyrrolidone, etc. can be used, and these are to be used in combination to select one or more. When the amount is small, insoluble or agglomerated substances are generated due to insufficient dissolution or insufficient dispersion of each composition in the ink, and when the amount is large, the concentration of each composition in the ink is reduced and the effect is reduced. Since the composition becomes smaller and various problems may occur, the content is preferably 5 to 40% by weight based on the total amount of the aqueous ballpoint pen ink composition.

Tartaric acid, citric acid, and succinic acid are used as a gelling buffer to trap metal ions and to improve the stability of the ink after long-term storage, and may be used alone. , May be used together. The amount is preferably 0.1 to 5.0% by weight. If the amount is small, no effect is obtained, and if it is large, no further effect is obtained.

A water-soluble polymer may be used in combination for adjusting the viscosity of the ink or for stabilizing the dispersion of a coloring agent or the like. Specifically, polyvinyl alcohol, polyvinyl methyl ether, sodium polyacrylate, carboxyl vinyl monomer, polyethylene oxide, a copolymer of vinyl acetate and polyvinyl pyrrolidone, poly-N-
Vinylacetamide, alkali metal salt of acrylic resin,
Copolymers of acrylic acid and alkyl methacrylate, semi-synthetic methylcellulose, sodium starch glycolate, sodium alginate, propylene glycol alginate, and derivatives thereof, and the like.

In order to suppress the inhibition of the outflow of ink in the ink passage due to the generation of mold, sodium dehydroacetate, 1,2-benzothiazalin-3-one, methyl-
An appropriate amount of a preservative and fungicide such as 2-benzimidazole carbamic acid ester and sodium benzoate can also be added.

Further, a corrosion inhibitor such as benzotriazole and ethylenediaminetetraacetic acid for preventing metal corrosion and a fatty acid such as oleic acid as a solubilizer can be added.

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

[0024]

The water-based ink composition for ballpoint pens according to the present invention uses an ionic polysaccharide as a thickener and a smectite-based clay in combination. The problem is that the ink viscosity is stable even after long-term storage by minimizing problems such as writing taste when using smectite clay alone and adding the two types of thickeners in a well-balanced amount. Yes, it is possible to prevent the sedimentation of the coloring agent and the like. Therefore, the ball-point pen using the ink composition for an aqueous ball-point pen according to the present invention can prevent handwriting from being frayed or impossible to write due to sedimentation of the coloring agent or the like even when the pen tip is left down. .

[0025]

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

[0026] In the above components, other components except for SWN and xanthan gum were put into a stirrer, and mixed and stirred for 1 hour. After removing coarse particles, SWN and xanthan gum were added and mixed and stirred, and after filtration, aqueous solution was added. An ink composition for a ballpoint pen was obtained.

[0027] In the above components, smecton SA, other components except for xanthan gum were put into a stirrer, and mixed and stirred for 1 hour. After removing coarse particles, smecton SA and xanthan gum were added, mixed and stirred, and filtered. Thus, an aqueous ball-point pen ink composition was obtained.

Example 3 FUJI SP Black 8556 (black aqueous pigment base, manufactured by Fuji Dye Co., Ltd.) 38.0 parts by weight Glycerin 10.0 parts by weight Ethylene glycol 25.0 parts by weight Benzotriazole 0.3 parts by weight Proxel GXL (S) (described above) 0.2 parts by weight Deionized water 22.1 parts by weight SWN (described above) 1.0 parts by weight Xanthan gum (described above) 30.3 parts by weight Tartaric acid 3.0 parts by weight In the above components, SWN, xanthan gum , And other components except tartaric acid were put into a stirrer and mixed and stirred for 1 hour. After removing coarse particles, SWN, xanthan gum and tartaric acid were added and mixed and stirred. After filtration, the ink for aqueous ballpoint pen was used. A composition was obtained.

[0029] In the above components, other components except for SWN and xanthan gum were put into a stirrer, and mixed and stirred for 1 hour. After removing coarse particles, SWN and xanthan gum were added and mixed and stirred, and after filtration, aqueous solution was added. An ink composition for a ballpoint pen was obtained.

Example 5 FUJI SP Red 5544 (red aqueous pigment base, manufactured by Fuji Color Co., Ltd.) 18.0 parts by weight FUJI SP Yellow 4178 (yellow aqueous pigment base, manufactured by Fuji Color Co., Ltd.) 5.0 weight Parts Glycerin 18.0 parts by weight Ethylene glycol 23.0 parts by weight Benzotriazole 0.3 parts by weight Proxel GXL (S) (described above) 0.2 parts by weight Deionized water 31.5 parts by weight SWN (described above) 0.8 parts by weight Part Xanthan gum (described above) 0.2 part by weight 4.0 parts by weight of succinic acid 4.0 parts by weight Of the above components, other components except for SWN, xanthan gum and succinic acid are put into a stirrer, and mixed and stirred for 1 hour.
The coarse particles were removed, SWN, xanthan gum, and succinic acid were added, mixed and stirred, filtered, and then an aqueous ballpoint pen ink composition was obtained.

Example 6 FUJI SP Black 8556 (black aqueous pigment base, manufactured by Fuji Color Co., Ltd.) 38.0 parts by weight Glycerin 10.0 parts by weight Ethylene glycol 25.0 parts by weight Benzotriazole 0.3 parts by weight Proxel GXL (S) (described above) 0.2 parts by weight Deionized water 22.1 parts by weight SWN (described above) 1.0 parts by weight Xanthan gum (described above) 30.3 parts by weight Citric acid 3.0 parts by weight In the above components, SWN, Xanthan gum, other ingredients except citric acid are put into a stirrer, and after mixing and stirring for 1 hour,
After removing coarse particles, adding SWN, xanthan gum, and citric acid, mixing and stirring, and filtering, an aqueous ball-point pen ink composition was obtained.

Example 7 An aqueous ballpoint pen ink composition was obtained in the same manner as in Example 4 except that the amount of smecton SA was changed to 1.2 parts by weight.

Example 8 An aqueous ball-point pen ink composition was obtained in the same manner as in Example 3, except that the amount of SWN was changed to 0.05 part by weight.

Comparative Example 1 An aqueous ink composition for a ballpoint pen was obtained in the same manner as in Example 1 except that xanthan gum was omitted.

Comparative Example 2 An aqueous ink composition for a ballpoint pen was obtained in the same manner as in Example 3 except that SWN was omitted.

Comparative Example 3 In Example 5, xanthan gum was replaced with guar gum (JAG).
A water-based ink composition for a ballpoint pen was obtained in the same manner as in Example 5 except that UAR HP-11, a non-ionic polysaccharide (manufactured by Sansei Co., Ltd.) was used.

(Stability Evaluation Test: Writing Test) A transparent ink container made of a polypropylene hollow shaft tube connected to one end of a stainless steel ballpoint pen tip (ball material: superalloy) was placed in Examples 1 to 5 and Comparative Examples. Fill the ink composition for aqueous ballpoint pens obtained in 1 to 3, and further inject an ink backflow preventer in which the α-olefin oligomer is gelled with fine particle silica and dextrin fatty acid ester into the rear end interface of the ink, and write test. A ballpoint pen was assembled (using the same weight parts as Hybrid 105 K, manufactured by Pentel Co., Ltd., and the same assembling method). After writing on the paper using the sample for writing test, the sample was left for 6 months at room temperature with the pen tip facing down, and then written on the paper again. At this time, the number of characters that can be written without blurring the handwriting was confirmed. The written characters were "country" and a maximum of 100 characters were written. Table 1 shows the test results.

Writing taste test: Monitor 1 randomly selected
0 persons rated each sample on a 5-point scale for writing taste.
The evaluation was 5 if the writing quality was excellent, 1 if the writing quality was poor, and 2 to 4 in the middle. The evaluation points were averaged for each of the test samples, and the writing taste was evaluated. Table 1 shows the results.

[0039]

[Table 1]

[0040]

As described above in detail, the aqueous ballpoint pen ink composition according to the present invention can be stored for a long time by adding the ionic polysaccharide and the smectite clay in a well-balanced amount. Even when the ink viscosity is stable, the sedimentation of the colorant and the like can be prevented. Therefore, even if the pen tip is left down after being formed into a ball-point pen, it is possible to prevent handwriting from fraying or writing failure due to sedimentation of the coloring agent or the like on the pen tip.

Claims (4)

[Claims] 1. A colorant, an ionic polysaccharide,
An aqueous ball-point pen ink composition comprising at least a smectite-based clay, water, and a water-soluble organic solvent. 2. The aqueous ink composition for a ball-point pen according to claim 1, wherein the ionic polysaccharide is xanthan gum. 3. The aqueous ink composition for a ball-point pen according to claim 1, wherein the smectite-based clay is contained in an amount of 0.1 to 1.0% by weight based on the total amount of the ink composition for an aqueous ball-point pen. 4. The aqueous ballpoint pen ink composition according to claim 1, further comprising a substance selected from tartaric acid, citric acid, and succinic acid.