JP2003105246A - Water-based ink for ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based ink for a ballpoint pen having an excellent storage stability enough to cause no blur after long-term storage. SOLUTION: In a water-based ink for ballpoint pen, containing essentially a colorant, resin particles, a polyethylene glycol fatty acid eater and water, this water-based ink for the ballpoint pen contains the polyethylene glycol fatty acid ester which is solid at room temperature and has an HLB (hydrophil- lipophile balance) in the range of 11.0-20.0 and the resin particles each having a particle diameter of 0.1-20 μm. The ballpoint pen is a type of an always opened pen point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink for ballpoint pens, and in particular, such as a pen tip retractable type ballpoint pen,
The present invention relates to a stable water-based ink for a ballpoint pen, which is suitable for use in a ballpoint pen having little airtightness with respect to the tip of the ballpoint pen and does not deteriorate with time such as viscosity increase of ink and precipitation of water-soluble additives such as dyes and water-soluble polymers.

[0002]

2. Description of the Related Art Conventionally, a ballpoint pen has a relatively fine handwriting as compared with a writing tool using a fiber nib or a resin nib, and has a fiber nib or a resin nib. Compared to, it is widely used because it has less change in handwriting width due to wear and crushing of the pen tip even after long-term use. The viscosity of the water-based ink composition used for such a ballpoint pen is 1 to several mPa · s (25 ° C.).
And those of 50 to 2,000 mPa · s (25 ° C.) are known. One having a viscosity of 1 to several mPa · s (25 ° C.) is mainly used for a ballpoint pen having a structure using batting as an ink storage material, and has a viscosity of 50 to 2,000 mPa · s (25
(° C) is mainly used for a structure having a hollow cylinder as an ink storage body.

In the writing mechanism of a ballpoint pen, the ink attached to the surface of the ball is transferred to the writing surface such as paper as the ball rotates. Ballpoint pens are basically
It is necessary to satisfy the general requirements for ballpoint pens that an appropriate amount of ink is transferred to the writing surface, and further, various problems such as blurring in handwriting and ink leakage from the ballpoint pen tip at the tip of the ballpoint pen do not occur, Therefore, it is required to appropriately select an additive and adjust the physical properties.

[0004]

In particular, in a pen tip retractable type water-based ballpoint pen, the phenomenon of ink loss (the solvent etc. in the ink evaporates and the weight decreases (the solid content in the ink relatively increases)) In order to suppress the above), addition of high boiling point organic solvents and addition of moisturizers have been tried, but when stored for a long time, the solvent in the ink evaporates from the slight gap between the ball and the ballpoint pen tip opening, The viscosity of the ink rises, the following ability of the ink during writing deteriorates, and blurring occurs, or the ink dries at a part of the inside of the pen tip, and the solidified substance interferes with the ejection of ink, causing blurring. It was easy for problems such as storage to occur. Therefore, in the structure of the pen tip, by pressing the ball part from the rear end of the ball part with a spring etc., the gap between the ball and the pen tip tip part that is crimped so that the ball cannot be removed is eliminated and solvent evaporation in the ink is suppressed. Although such a structure has been put on the market, a slight gap is inevitably generated, and since the ink loss cannot be suppressed, the deterioration of the ink such as thickening and precipitation occurs over time,
Writing abnormalities such as scraping occur.

[0005]

The present invention provides a coloring material, resin particles, polyethylene glycol fatty acid ester,
A water-based ink for ball-point pens containing at least water, wherein the polyethylene glycol fatty acid ester is solid at room temperature and HLB is in the range of 11.0 to 20.0. Is.

The details will be described below. As a coloring material,
Dyes and / or pigments can be used. As the dye, any of a direct dye, an acid dye, a basic dye, and the like can be used.
Depending on the type, if the pH is low, it may corrode, so it is preferable to use a direct dye or an acid dye that is neutral to alkaline and stably dissolves. Here is an example.

Direct dyes include C.I. I. Direct Black 17, Same 19, Same 22, Same 32, Same 38, Same 5
1, 71, C.I. I. Direct Yellow 4, the same 26, the same 44, the same 50, C.I. I. Direct Red 1, 4, 3, 23, 31, 37, 39, 75, 80, 8
1, the same 83, the same 225, the same 226, the same 227, C.I. I.
Direct Blue 1, 1, 15, 71, 86, 10
6, 6, 199 and the like.

Acid dyes include C.I. I. Acid Black 1, Same 2, Same 24, Same 26, Same 31, Same 52, Same 1
07, 109, 110, 119, 154, C.I.
I. Acid Yellow 7: 1, 17th, 19th, 23rd,
Ibid 25, ibid 29, ibid 38, ibid 42, ibid 49, ibid 72, ibid 61, ibid 78, ibid 110, ibid 141, ibid 135, ibid 12
7, 142, C.I. I. Acid Red 8、9、1
4, ibid 18, ibid 26, ibid 27, ibid 35, ibid 37, ibid 5
1, 52, 57, 82, 87, 92, 9
4, ibid 111, ibid 129, ibid 131, ibid 138, ibid 18
6, 249, 254, 265, 276, C.I.
I. Acid Violet 15, 17, 17, C.I. I. Acid Blue 1, 7, 7, 9, 15, 22, 23,
25, 40, 41, 43, 62, 78, 83, 90, 93, 103, 112, 11
3, 158, C.I. I. Acid Green 3, the same 9, the same 16, the same 25, the same 27 and the like.

As the basic dye, C.I. I. Basic Blue 7, C.I. I. Basic Red 1 and the like can be mentioned.

As the pigment, conventionally known pigments can be used, and specific examples thereof include Special Black 6,
Same S170, Same S610, Same 5, Same 4, Same 4A, Same 55
0, 35, 250, 100, Printex 1
50T, U, V, 140U, 140V, 9
5, ibid 90, ibid 85, ibid 80, ibid 75, ibid 55, ibid 4
5, same P, same XE2, same L6, same L, same 300, same 3
0, the same 3, the same 35, the same 25, the same 200, the same A, the same G (above, manufactured by Degussa Japan KK), # 2400B, # 2.
350, # 2300, # 2200B, # 1000, # 9
50, # 900, # 850, # MCF88, MA60
0, MA100, MA7, MA11, # 50, # 52,
# 45, # 44, # 40, # 33, # 32, # 30, C
F9, # 20B, # 4000B, (all manufactured by Mitsubishi Kasei Co., Ltd.), MONARCH 1300, 100, 1000, 900, 880, 800, 700,
MOGULL, REGAL 400R, 660R, 500R, 330R, 300R, 99R, ELF
TEX 8, 12 and BLACK PEARLS 20
00 (above, Cabot Co. Ltd., USA), Ra
ven7000, 5750, 5250, 500
0, 3500, 2000, 1500, 125
5, same 1250, same 1200, same 1170, same 106
0, 1040, 1035, 1020, 100
0, 890H, 890, 850, 790, 7
80, 760, 500, 450, 430, 4
20, the same 410, the same 22, the same 16, the same 14, the same 825o
il Beads, H20, C, Conducte
x975, 900, SC (above, Colombian
Carbon black such as Carbon Japan Co., Ltd., KA
-10, the same 10P, the same 15, the same 20, the same 30, the same 35,
60, 80, 90, KR-310, 380, 460, 480 (above, manufactured by Titanium Industry Co., Ltd.), P2.
5 (manufactured by Nippon Aerosil Co., Ltd.), titanium oxide, BS
-605, 607 (above, manufactured by Toyo Aluminum Co., Ltd.), bronze powder P-555, P-777 (above, manufactured by Nakajima Metal Foil Industry Co., Ltd.), bronze powder 3L5, 3
L7 (above, manufactured by Fukuda Metal Foil Industry Co., Ltd.) and other metal powder pigments, and inorganic pigments such as black iron oxide, yellow iron oxide, red iron oxide, ultramarine blue, navy blue, cobalt blue, chrome green, and chromium oxide, Hansa Yellow-10G, 5G, 3G, 4, GR, A, Benzidine Yellow, Permanent Yellow NCG, Tartrazine Lake, Quinoline Yellow, Sudan 1, Permanent Orange, Induslen Brilliant Orange GN, Permanent Brown F
G, Para Brown, Permanent Red 4R, Fire Red, Brilliant Carmine BS, Pyrazolone Red, Lake Red C, Quinacridone Red, Brilliant Carmine 6B, Bordeaux 5B, Thioindigo Red,
Fast violet B, dioxazine violet,
Organic pigments such as alkali blue lake, phthalocyanine blue, indigo, acid green lake, phthalocyanine green and the like can be mentioned. In addition to these, inorganic fluorescent pigments such as zinc sulfide, zinc silicate, zinc cadmium sulfate, calcium sulfide, strontium sulfide, and calcium tungstate can be cited. Coloring agents such as the above dyes and pigments can be used alone or in combination with others, and the amount used varies depending on the color tone, etc.,
When the amount is small, the color development of the ink is poor, and when the amount is large, the colorant is insufficiently dispersed and various problems occur, so 0.1 to 40% by weight is preferable with respect to the total amount of the water-based ink for a ballpoint pen.

The resin particles include homopolymers such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polystyrene, polymethylmethacrylate, polyacrylonitrile, polyamide, polycarbonate, polyacetal and polyethylene terephthalate, and styrene-polyethylene. It is a solid polymer fine particle made of a copolymer in which two or more kinds of monomers such as an acrylonitrile copolymer and an acrylonitrile-butadiene-styrene copolymer coexist, and makes the ball rotate smoothly to give a feeling of writing. It is used to improve or adjust the chromaticity of ink. The resin particles can be spherical or irregularly shaped, and further, solid resin particles uniform from the surface to the center, or a hollow resin in which only the outer shell is made of solid resin and the center is filled with gas or liquid. Particles can be used. Further, resin particles colored with dyes or pigments can also be used. The resin particles can be obtained as a powder of solid polymer particles or a dispersion of the solid polymer particles in an aqueous medium. Resin particles have a particle diameter of
The resin particles having a relatively uniform particle size of 0.1 to 20 μm are preferable, and when the particle size is small, the effect cannot be obtained, and when the particle size is large, separation due to clogging at the pen tip or sedimentation of the resin particles Is likely to occur. When the resin particles are powder, the addition amount of the resin particles is preferably 1 to 30% by weight based on the total amount of the water-based ink for a ballpoint pen. Further, when the resin particles are a dispersion, it varies depending on the solid content which is the content of the resin particles, but the solid content of the resin particle dispersion is preferably in the range of 1 to 20% by weight based on the total amount of the ink. If the amount of resin particles added is small, a sufficient effect cannot be obtained,
If the amount is large, no further effect is obtained and clogging of the pen tip is likely to occur. As an example of the resin particles, Fine Pearl 3000SP (crosslinked polystyrene resin particles, average particle diameter 6 μm) Fine Pearl 3000F
(Crosslinked polystyrene resin particles, average particle size 6 μm), Finepearl PB-3000 (Crosslinked polystyrene resin particles, average particle size 15 μm) Finepearl PB-300
3 (crosslinked polystyrene resin particles, average particle diameter 15 μm)
(Above, Sumitomo Chemical Co., Ltd.), SX863 (A)
(Hollow resin particle dispersion of crosslinked styrene-acrylic copolymer, solid content 21% by weight, average particle size 0.35 μm), S
X864 (B) (crosslinked styrene-acrylic copolymer hollow resin particle dispersion, solid content 40% by weight, average particle diameter 0.
49 μm), HCP8742 (crosslinked polystyrene resin particle dispersion, solid content 15% by weight, average particle size 0.5 μm)
(Above, JSR Corporation make), low-payke OP-84J
(Hollow resin particle dispersion of acrylic-styrene copolymer,
Solid content 42.5% by weight, average particle size 0.55 μm), Ropaque HP-91 (hollow resin particle dispersion of acrylic-styrene copolymer, solid content 27.5% by weight, average particle size 1 μm) (above, Rohm and Haas Japan Co., Ltd., etc. are mentioned, and these can be used 1 type or in mixture of 2 or more types.

It is solid at room temperature and has an HLB of 11.0.
The polyethylene glycol fatty acid ester in the range of up to 20.0 improves the dispersibility by increasing the affinity of the pigment or resin particles for the ink solvent, increases the viscosity of the entire ink, and stabilizes the dispersion by holding the pigment. Various problems such as prevention of ink leakage by reducing the fluidity of the ink or lowering of fluidity of the ink and improvement of writing feeling by smoothing the rotation of the ball are made less likely to occur. Polyethylene glycol fatty acid ester, which is liquid at room temperature, is difficult to obtain these effects and does not form a film. Occurs and causes blurring. Polyethylene glycol fatty acid ester having an HLB lower than 11 does not dissolve in the solvent of the ink, or has poor solubility stability even if it dissolves, and precipitates over time, causing scratches due to clogging at the pen tip and unreadable writing. It is something that ends up. In addition, polyethylene glycol fatty acid ester having an HLB of more than 20 increases the viscosity increase too much and the viscosity of the ink becomes unnecessarily high to hinder the outflow of the ink or impair the dispersibility of the resin particles to obtain a sufficient effect. I can't. Solid at room temperature and H
As an example of polyethylene glycol fatty acid ester having LB in the range of 11.0 to 20.0, NIKKOL
MYS-10 (polyethylene glycol monostearate, HLB = 11.0), NIKKOL MYS-25
(Polyethylene glycol monostearate, HLB =
15.0), NIKKOL MYS-40 (polyethylene glycol monostearate, HLB = 17.5),
NIKKOL MYS-45 (polyethylene glycol monostearate, HLB = 18.0), NIKKOL
MYS-55 (polyethylene glycol monostearate, HLB = 18.0), NIKKOL CDS-6
000P (polyethylene glycol distearate, H
LB = 16.5) (above, manufactured by Nikko Chemicals Co., Ltd.),
Pegnol 14-S (polyethylene glycol monostearate, HLB = 11.5, Toho Chemical Industry Co., Ltd.)
Manufactured), Emanone 3199 (polyethylene glycol monostearate, HLB = 19.1), Emanone 32
99 (polyethylene glycol distearate, HLB
= 18.3), Emanone 3299R (polyethylene glycol distearate, HLB = 18.3) (above,
Kaolin Co., Ltd. Morinol SA-130 (polyethylene glycol monostearate, HLB = 13.
4, Morin Chemical Industry Co., Ltd., Nonion S-4 (polyethylene glycol monostearate, HLB = 1)
1.6), nonion S-6 (polyethylene glycol monostearate, HLB = 13.6), nonion S-1
0 (Polyethylene glycol monostearate, HLB
= 15.6), nonion S-15 (polyethylene glycol monostearate, HLB = 12.8), nonion S-40 (polyethylene glycol monostearate,
HLB = 18.2) (above, NOF Corporation make) etc. are mentioned. The amount of polyethylene glycol fatty acid ester used is 0.0 based on the total amount of the water-based ink for ballpoint pens.
5 to 10.0% by weight is preferable, and when it is small, no effect is obtained, and when it is large, no further effect is obtained.

In the water-based ink for ballpoint pens according to the present invention, when a pigment is used, it is preferable to use a dispersant together. As the dispersant, a generally used polymer dispersant, or an anionic or nonionic surfactant used as a dispersant for pigments can be used. As an example, as a polymer dispersant, a salt of styrene-acrylic acid copolymer, a salt of copolymer containing styrene-alkyl acrylate as a main component, a salt of styrene-maleic acid copolymer, styrene-maleic acid. Examples thereof include water-soluble polymers such as salts of copolymers containing an alkyl ester as a main component. Further, as a surfactant, alkyl sulfate, polyoxyethylene alkyl ether sulfate, N
-Acyl amino acids and salts thereof, N-acyl methyl taurine salts, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylates, α-olefin sulfonates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, etc. Nonionic surfactants such as anionic surfactants, polyoxyethylene alkyl ethers, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters are mentioned. These water-soluble polymers and surfactants may be used alone or in combination of two or more. If the amount used is small, the dispersion effect, which is the purpose of addition, is weak, and if the amount is large, there is a concern that the dissolution balance of each composition in the ink may be disturbed and various problems may occur, so the total amount of water-based ink for ballpoint pens On the other hand, it is preferably 0.1 to 10% by weight.

Furthermore, the use of an aqueous ink base in which a pigment is dispersed in an aqueous medium is advantageous in the production of pigment ink. Specifically, Fuji SP Black 8
031, 8119, 8167, 8276, 83
81, 8406, 8556, 8922, Fuji
SP RED 5096, 5111, 5193,
5220, 5543, 5544, Fuji SP
Bordeaux 5500, Fuji SP Blu
e 6062, 6133, 6134, 6401,
Fuji SP Green 7051, Fuji S
P Yellow 4060, same 4178, Fuji
SP Violet 9011, Fuji SP Pi
nk 9524, same 9527, Fuji SP Ora
nge534, Fuji SP Brown 3074
(Above, Fuji dye Co., Ltd. product), Emacol Blac
k CN, Emacol Blue FBB, the same FB,
Same KR, Emacol Green LXB, Emac
ol VioletBL, Emacol Brown
3101, Emacol CarmineFB, Em
acol RED BS, Emacol Orange
R, Emacol Yellow FD, same IRN,
Same 3601, Same FGN, Same GN, Same GG, Same F5G, Same F7G, Same 10GN, Sandy Super Bl
ack K, same C, Sandye Super Gre
y B, Sandye Super Brown S
B, the same FRL, the same RR, and Sandy Super N
avy Blue HRL, same GLL, same HB, same FB
LH, FBL-160, FBB, Sandye
Super Violet BL H / C, same BL, same BLN, Sandy Super Bordeaux
FR, Sandye Super Pink FB
L, same F5B, Sandye SuperRubine
FR, Sandye Super Carmine
FB, Sandy Super Red FFG, RR, BS, Sandy Super Orange
e FL, same R, same BO, Sandye Gold Y
ellow 5GR, same R, same 3R, Sandye Y
yellow GG, F3R, IRC, FGN, GN, GRS, GSR-130, GSN-13.
0, same GSN, same 10GN (above, Sanyo Pigment Co., Ltd.
Made), Rio Fast Black Fx 801
2, 8313, 8169, Rio Fast Re
d Fx 8209, 8172, Rio Fast
Red S Fx 8315, Red 8316, Rio F
ast Blue Fx 8170, Rio Fast
Blue Fx 8170, Rio Fast Bl
ue S Fx8312, Rio Fast Green
n S Fx 8314 (above, Toyo Ink Co., Ltd.
Manufactured), NKW-2101, 2102, 2103, 2104, 2105, 2106, 2107, 2
108, 2117, 2127, 2137, 21
67, 2101P, 2102P, 2103P, 2104P, 2105P, 2106P, 2107
P, 2108P, 2117P, 2127P, 2
137P, 2167P, NKW-3002, 300
3, 3004, 3005, 3007, 307
7, 3008, 3402, 3404, 340
5, 3407, 3408, 3477, 360
2, 3603, 3604, 3605, 360
7, ibid 3677, ibid 3608, ibid 3702, ibid 370
3, 3704, 3705, 3777, 370
8, the same 6013, the same 6038, the same 6559 (above, manufactured by Nippon Fluorescent Co., Ltd.), Cosmocolor S 1000F series (manufactured by Toyo Soda Co., Ltd.), Victoria Yellow G-1
1, the same G-20, Victoria Orange G-16, the same G
-21, Victoria Red G-19, Same G-22, Victoria Pink G-17, Same G-23, Victoria Green G-18, Same G-24, Victoria Blue G
-15, G-25 (above, manufactured by Mikuni Pigment Co., Ltd.), Pollux Blue PC5T-1020, Pollux Black PC8T-135, Polook Thread IT-10.
30 and Pollux series such as Pollux Green PC-4T1021 (above, manufactured by Sumika Color Co., Ltd.) and the like, and these can be used alone or in combination of two or more.

Various water-soluble organic solvents can be used in addition to water, which is essential as a solvent or dispersion medium, and these have various qualities as an aqueous ink, for example, ink drying prevention with a pen tip, and low temperature It is used for the purpose of preventing ink freeze and pigment dispersion medium. 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 glycol Over mono butyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether,
Triethylene glycol monomethyl ether, tripropylene glycol monomethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monoethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate , Ethers such as ethylene glycol monophenyl ether and propylene glycol monophenyl ether, alcohols such as benzyl alcohol, methanol, ethanol, propanol, isopropanol and butanol, N-methyl-2-pyrrolidone and 2-pyrrolidone can be used, These can be used alone or in combination of two or more. A. When the amount used is small, insoluble / aggregate occurs 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 becomes small and its effect is small. Therefore, 5 to 40% by weight is preferable with respect to the total amount of the water-based ink for a ballpoint pen.

To adjust the viscosity of the ink or to stabilize the dispersion of the colorant and the like, a water-soluble polymer having a thickening property can be used together. Specifically, polyvinyl alcohol,
Polyvinyl methyl ether, sodium polyacrylate, carboxyvinyl monomer, polyethylene oxide, copolymer of vinyl acetate and polyvinylpyrrolidone, alkali metal salt of acrylic resin, copolymer of acrylic acid and alkylmethacrylate, gum arabic, tragacanth gum , Xanthan gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin,
Casein, dextran, semi-synthetic methyl cellulose, ethyl cellulose, hydroxyethyl cellulose,
Examples thereof include carboxymethyl cellulose, sodium starch glycolate, sodium alginate, propylene glycol alginate, and derivatives thereof.

Further, in order to suppress the outflow inhibition of the ink in the ink passage due to the generation of mold, sodium dehydroacetate, 1,2-benzothiazolin-3-one, methyl-
An appropriate amount of antiseptic and fungicide such as 2-benzimidazole carbamic acid ester and sodium benzoate may be added.

Further, a corrosion inhibitor such as benzotriazole or ethylenediaminetetraacetic acid for preventing metal corrosion, or a salt of a fatty acid such as palmitic acid, oleic acid or stearic acid for preventing ball sinking due to wear of the ball bearing seat. It can be added.

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

[0020]

[Function] The reason why the ink containing the resin particles and the polyethylene glycol fatty acid ester in combination is excellent in the stability of the ballpoint pen ink after long-term storage is presumed as follows. It is a solid at room temperature and has an HLB of 11.0 to 20.
The polyethylene glycol fatty acid ester in the range of 0 is in a substantially uniform dissolved state in the aqueous ink.
After long-term storage in this solution state, when the water content in the ink at the tip of the ballpoint pen is reduced by evaporation, the dissolved molecules solidify, and when drying progresses, they fuse together to form a thick continuous film. Since the ball is formed, the rotation of the ball is hindered, and scraping occurs. The resin particles are almost uniformly dispersed in the water-based ink. These resin particles have a hard outer shell, and they remain independent of each other even when the water content in the ink inside the ballpoint pen nibs after long-term storage is reduced and drying progresses, forming a continuous film. Since water vaporization progresses through the gaps between the resin particles, and the drying progresses even deeper inside the nib, the ink thickens or solidifies, which hinders ink flow in the ink passages, making it difficult to eject ink. Then, a blur occurs. However, it is solid at room temperature and HLB is 11.0.
When polyethylene glycol fatty acid ester in the range of up to 20.0 and resin particles are used in combination, the polyethylene glycol fatty acid ester forms micelles with the resin particles as the core in the aqueous ink. These micelles are almost evenly dispersed in the water-based ink, and when the water content in the ink of the tip of the ballpoint pen after long-term storage decreases, they fuse together to form a film. The resin particles, which are particles, have the function of softening the formation of a thick continuous film, filling the slight gap between the ball and the fore edge part, and at the same time preventing the evaporation of water inside the pen tip after a long period of time. Thickening and solidification can be suppressed, and no scraping occurs.

[0021]

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

[0022] Of the above components, the components except for Rhopaque OP-84J were mixed and dispersed in a ball mill for 12 hours. Then, Rhopaque OP-84J was added and agitated for 3 hours with a stirrer, and then coarse particles were added with a centrifuge. Was removed to obtain a black water-based ink for ballpoint pens.

[0023] After mixing the above components and stirring with a stirrer for 4 hours, coarse particles were removed with a centrifuge to obtain a red water-based ink for ballpoint pens.

[0024] The above components were mixed and mixed with a stirrer for 4 hours to obtain a blue aqueous dye ink.

[0025] After mixing the above components and performing dispersion treatment for 24 hours with a ball mill, coarse particles were removed with a centrifuge to obtain a blue water-based ink for ballpoint pens.

[0026] After mixing the above components and stirring with a stirrer for 6 hours, coarse particles were removed with a centrifuge to obtain a green water-based ink for ballpoint pens.

Comparative Example 1 A black water-based ink for ball-point pens was obtained in the same manner as in Example 1 except that the low pake OP-84J was removed and ion exchanged water was added in that amount.

Comparative Example 2 A red water-based ink for ball-point pens was obtained in the same manner as in Example 2 except that the emanone 3199 was removed and ion exchanged water was added in that amount.

Comparative Example 3 Emanone 1112 (polyethylene glycol monolaurate, liquid at room temperature, HLB = 13.7, Kao Corporation) was removed except for the amount of Emanone 3299 in Example 3.
A blue water-based ink for ball-point pens was obtained in the same manner as in Example 3 except that the product was added.

Comparative Example 4 In Example 4, except NIKKOL MYS-10,
NIKKOL CDS-400 (polyethylene glycol distearate, normal temperature solid, HLB = 8.
5, Nikko Chemicals Co., Ltd. was added, and after the dispersion treatment by a ball mill, the temperature was raised to 50 ° C. and stirring was carried out for 30 minutes, and a blue water-based ink for ballpoint pens was obtained in the same manner as in Example 4. It was

The water-based inks for ball-point pens obtained in Examples 1 to 5 and Comparative Examples 1 to 4 described above were pressed with a stainless ball-point pen tip (ball material: cemented carbide, spring) with a ball diameter of 0.7 mm. (1) is filled in a refill connected to one end of a transparent ink container of a polypropylene hollow shaft cylinder, incorporated into the pen tip retractable ballpoint pen shown in FIG. 1, the pen tip is exposed, and a test sample is prepared.
Leave it in a thermostatic chamber at 50 ° C for 2 months, and then at room temperature 1
After leaving for a month, the writing function was confirmed. The pen tip retractable type ball-point pen of FIG. 1 is called a knock type ball-point pen, and is attached to the inside of the exterior body 1 and the front shaft 2 which is detachably attached to the front side of the exterior body 1 (downward in the figure) by screwing or the like. The refill 5 is inserted so that it can be moved back and forth. The refill 5 is arranged so as to be biased to the rear of the exterior body 1 by an elastic member 4 such as a coil spring attached to the inside of the front shaft 2 and to be movable back and forth in response to a pressure from the rear. It The pen tip has a conventionally known pen tip retracting mechanism, for example, a retracting mechanism that locks a projection in a locking hole by repeatedly pressing an operating member 6 that is slidably attached to the rear portion of the exterior body 1. Alternatively, the pen tip of the refill 5 is repeatedly retracted and retracted by a retractable mechanism such as a retractable mechanism using a rotary cam and a retractable mechanism using a heart cam.

Confirmation of Writing Function: The test sample was taken out from the above-mentioned standing condition (left standing in a constant temperature room at 50 ° C. for 2 months and then left at room temperature for 1 month), and then the diameter of 1.5
A circular writing in which a circle of 20 cm is continuously written in a spiral shape was handwritten, and the degree of scraping was visually evaluated. The results are shown in Table 1.

[0033]

[Table 1]

[0034]

As described above in detail, the water-based ink for ballpoint pens according to the present invention does not cause ink deterioration due to thickening or solidification of the ink even after a long period of time, and is written. It has an excellent effect that no blur is generated at the time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a pen tip retractable ballpoint pen suitable for filling a water-based ink for a ballpoint pen according to the present invention.

[Explanation of symbols]

1 exterior body 2 front axis 3 gripping member 4 Repulsion member 5 Refill 6 Operation member 7 clips

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C350 GA03 HA08 NA10 NA11 NA19                 4J039 AD01 AD03 AD05 AD07 AD08                       AD10 AD11 AD12 AE06 AE07                       BC20 BD03 BD04 BE01 BE03                       BE04 BE05 CA03 CA06 EA44                       EA48 GA27

Claims (3)

[Claims] 1. A water-based ink for ball-point pens, which contains at least a coloring material, resin particles, polyethylene glycol fatty acid ester, and water, wherein the polyethylene glycol fatty acid ester is solid at room temperature and HLB is 11.0 to 20. A water-based ink for ballpoint pens, which is in the range of 0.0. 2. The particle size of the resin particles is 0.1 to 20 μm.
The water-based ink for ball-point pens according to claim 1, which is m. 3. The water-based ink for a ball-point pen according to claim 1, wherein the ball-point pen is a ball-point pen whose pen tip is always open.