JP2002206066A - Ink for ball-point pen and ball-point pen using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink for a ball-point pen capable of reducing abrasion of a ball receiving seat by rotation of a ball during writing and resultantly carrying out the writing without being blurred until the ink is completely consumed. SOLUTION: This water-based pigment ink for the ball-point pen comprises a color pigment and a liquid medium, and further contains fine particles such as alumina, silicon carbide, chromium oxide, boron carbide, zircon, spinel, jadeite, calcium fluoride, tungsten carbide, silica, diamond, garnet, aluminum nitride or silicon nitride having >=4 new Mohs hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball holder for rotatably holding a writing ball for transferring ink by contacting a writing surface such as a sheet of paper. TECHNICAL FIELD The present invention relates to an ink used for a ball-point pen having a ball-point pen tip for discharging ink from the ink and a ball-point pen thereof.

[0002]

2. Description of the Related Art With the ink for a ballpoint pen, ink attached to the surface of a writing ball is transferred to a writing surface such as paper as the writing ball rotates, thereby forming handwriting. That is, since the writing ball rotates during writing, friction usually occurs at a portion where the writing ball contacts the ball holder. Generally, a ball holder has a portion called a ball receiving seat, which receives a writing pressure received when a writing ball comes into contact with a writing surface. The ball receiving seat has an ink for flowing ink in an ink tank. A through hole is formed. In some cases, a forced ink guide member such as a fiber convergence member is placed in the ink passage,
Even in this case, the ink guide member rarely comes into direct contact with the writing ball, and eventually the ink flowing out of the ink through hole formed in the ball receiving seat is used for writing. In addition, in the case of a circular shape similar to the cross section of the ball, the ball closes the ink hole and hinders the derivation of ink, so that several radial grooves called arrow grooves are formed. The ink holes are made polygonal or irregular so that the writing ball does not block all of the ink holes.

[0003] The friction between the writing ball and the ball holder occurs mainly at the ball seat. Generally, the ball holder is formed of a material softer than the ball, and the surface of the ball is formed with fine irregularities, and the friction may wear the ball seat. When the ball receiving seat is worn, the area of the ink through hole closed by the writing ball increases. That is, at the time of writing, the area of the effective ink through-hole that is opened when the writing ball is pressed against the ball receiving seat decreases, and when the writing ball expands beyond the arrow groove or the like, the ink through-hole is completely closed. Will be. For this reason, if writing is continued, the handwriting may be faded or may not be able to be written. This problem is particularly noticeable when using a pigment as a coloring material.

[0004] In order to solve this problem, attempts have been made to increase the lubricity of the ink by adding a water-soluble cutting oil or a lubricating oil to the ink. Regarding additives for imparting lubricity, for example, JP-A-60-63265 discloses N
An aqueous ink composition for ballpoint pens to which an oligomer of -vinyl-2-pyrrolidone is added is disclosed in JP-A-60-23837.
No. 5 discloses an aqueous ink composition for ballpoint pens to which a dithiophosphate or the like is added, and Japanese Patent Application Laid-Open No. 05-271603 discloses an aqueous pigment ink for ballpoint pens containing a dialkylthiourea.

However, these prior arts all involve adding a liquid that acts as a lubricating oil to the ink, and are sufficient to suppress wear of the ball seat, which is remarkable due to the use of the pigment. At present, no effect has been obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water-based pigment for a ball-point pen which is capable of ensuring good ink dischargeability by minimizing abrasion of a ball receiving seat due to rotation of a ball, and which can be written without rubbing until all the ink is consumed. To provide an ink.

[0007]

According to the present invention, there is provided a ballpoint pen ink comprising at least a pigment as a colorant, fine particles having a new Mohs hardness of 4 or more, and a liquid medium. Is what you do.

The details will be described below. Pigments are those that impart a coloring effect to handwriting and make them visible, and include azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acid dye pigments, vat dye pigments, mordant dye pigments, And organic pigments such as natural dye pigments, etc., inorganic pigments such as ocher, barium yellow, ultramarine, navy blue, cadmium red, barium sulfate, titanium oxide, red iron oxide, iron black, carbon black, etc., aluminum powder, gold powder, silver powder, Examples include metal powder pigments such as copper powder, tin powder, and brass powder, fluorescent pigments, and mica pigments.
Specific examples include aniline black (CI. 5044).
0), cyanine black, naphthol yellow S (C.I.
I. 10316), Hansa Yellow 10G (CI.11
710), Hansa Yellow 5G (CI. 11660),
Hansa Yellow 3G (CI. 11670), Hansa Yellow G (CI. 11680), Hansa Yellow GR (C.I.
I. 11730), Hansa Yellow A (CI. 1173)
5), Hansa Yellow RN (CI. 11740), Hansa Yellow R (CI. 12710), Pigment Yellow L (CI. 12720), Benzidine Yellow (C.I.
I. 21090), benzidine yellow G (CI.21)
095), benzidine yellow GR (CI. 2110)
0), permanent yellow NCG (CI. 2004)
0), Vulcan Fast Yellow 5G (C.I.
0), Vulcan Fast Yellow R (CI.2113)
5), tartrazine lake (CI. 19140), quinoline yellow lake (CI. 47005), anthragen yellow 6GL (CI. 60520), permanent yellow FGL, permanent yellow H10G, permanent yellow HR, anthra Pyrimidine yellow (C.I.
I. 68420), Sudahn I (CI. 1205)
5), permanent orange (CI. 12075),
Lysole Fast Orange (CI. 12125), Permanent Orange GTR (CI. 12305), Hansa Yellow 3R (CI. 11725), Vulcan Fast Orange GG (CI. 21165), Benzidine Orange G (CI. I.21110), Persian orange (CI.15510), indanthrene brilliant orange GK (CI.59305), indanthrene brilliant orange RK (CI.59105),
Indanthrene Brilliant Orange GR (CI.7
1105), permanent brown FG (CI.12)
480), para brown (CI. 12071), permanent red 4R (CI. 12120), para red (CI. 12070), fire red (CI. 12070).
I. 12085), parachloroorthoaniline red (CI.12090), lithol fast scarlet, brilliant fast scarlet (CI.12)
315), Brilliant Carmine BS, Permanent Red F2R (CI. 12310), Permanent Red F4R (CI. 12335), Permanent Red FRL (CI. 12440), Permanent Red F
RLL (CI. 12460), permanent red F
4RH (CI. 12420), Fast Scarlet VD, Vulcan Fastorbin B (CI. 1232)
0), Vulcan Fast Pink G (C.I.
0), light fast red toner B (CI.12)
450), Light Fast Red Toner R (CI.
12455), permanent carmine FB (C.I.1)
2490), pyrazolone red (CI. 1212)
0), Risor Red (CI. 15630), Lake Red C (CI. 15585), Lake Red D
(CI. 15500), ansosine B (CI. 18)
030), Brilliant Scarlet G (CI.15)
800), Risor Rubin GK (CI. 1582)
5), permanent red F5R (CI. 1586)
5), Brilliant Carmine 6B (CI. 1585)
0), Pigment Scarlet 3B (CI. 1610)
5), Bordeaux 5B (CI. 12170), Toluidine Maroon (CI. 12350), permanent Bordeaux F2R (CI. 12385), Helio Bordeaux B
L (CI. 14830), Bordeaux 10B (CI.
15880), Bon Maroon Light (CI. 1582)
5), Bon Maroon Medium (CI. 15880),
Eosin Lake (CI. 45380), Rhodamine Lake B (CI. 45170), Rhodamine Lake Y
(C.I. 45160), alizarin lake (C.I.
58000), Thioindigo Red B (CI.733)
00), thioindigo maroon (CI. 7338)
5), permanent red FGR (CI. 1237)
0), PV Carmine HR, Watching Red, Monolight 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.42
750A, C.I. I. 42770A), Peacock Blue Lake (C.I. 42090), Peacock Blue Lake (C.I. 42025), Victoria Blue Lake (C.I.44045), Phthalocyanine Blue (C.I.
I. 74160), Fast Sky Blue (CI.7)
4180), Indanthrene Blue RS (CI.69)
800), Indanthrene Blue BC (CI.698)
25), Indigo (CI. 73000), Pigment Green B (CI. 10006), Naphthol Green B (CI. 10020), Green Gold (CI.
I. 12775), acid green lake, malachite green lake (CI.42000), phthalocyanine green and the like, and these are used by dispersing them in a liquid medium. Commercially available water-dispersed pigments are preferably used because they increase the handleability and productivity. As a specific example of the water dispersion type pigment, Fuji SP Black
8031, 8119, 8167, 8276, 8
381, 8406, Fuji SP Red 509
6, 5111, 5193, 5220, Fuji
SP Bordeaux 5500, Fuji SP
Blue 6062, 6133, 6134, 64
01, Fuji SP Green 7051, Fuji
iSP Yellow 4060, 4178, Fuj
iSP Violet 9011, FujiSPP
Ink 9524, same 9527, Fuji SP Or
angel 534, FUji SP Brown 30
74, FUJI SP RED 5543, 5544
(The above are manufactured by Fuji Dye Co., Ltd.), Emacol Blac
k CN, Emacol Blue FBB, FB,
Same KR, Emacol Green LXB, Emac
ol Violet BL, Emacol Brown
3101, Emacol Carmmine FB, E
macol RedBS, Emacol Orange
R, Emacol Yellow FD, IRN,
3601, FGN, GN, GG, F5G, F7G, 10GN, 10G, Sandye Sup
er Black K, C, Sandy Suppe
r Gray B, Sandy Super Bro
wnSB, FRL, RR, Sandye Suppe
r Green L5G, GXB, Sandy S
upper Navy Blue HRL, GLL, HB, FBL-H, FBL-160, FBB, S
andy Super Violet BL H /
C, BL, Sandy Super Bordea
ux FR, Sandye Super Pink F
BL, F5B, Sandy Super Rubi
ne FR, Sandy superCarmmin
e FB, Sandye Super Red FF
G, RR, BS, 1315, Sandy Su
per Orange FL, R, BO, Sand
ye Gold Yellow 5GR, R, 3
R, Sandye Ywllow GG, F3R, IRC, FGN, GN, GRS, GSR-13
0, the same GSN-130, the same GSN, the same 10GN (or more,
Sanyo Dyeing Co., Ltd.), Rio Fast Black
Fx 8012, 8313, 8169, Rio F
ast Red Fx 8209, 8172, Rio
Fast Red S Fx 8315, 831
6, Rio Fast Blue Fx 8170, R
io Fast Blue FX 8170, Rio
Fast Blue S Fx 8312, Rio F
ast Green S Fx 8314, EM gr
een G, (above, manufactured by Toyo Ink Co., Ltd.), NKW-
2101, 2102, 2103, 2104, 2
105, 2106, 2107, 2108, 21
17, 2127, 2137, 2167, 210
1P, 2102P, 2103P, 2104P, 2105P, 2106P, 2107P, 2108
P, 2117P, 2127P, 2137P, 2
167P, NKW-3002, 3003, 300
4, 3005, 3007, 3077, 300
8, 3402, 3404, 3405, 340
7, 3408, 3377, 3602, 360
3, 3604, 3605, 3607, 367
7, 3608, 3702, 3703, 370
4, 3705, 3777, 3708, 601
3, 6038, 6559 (The above are from Nippon Fluorescence Co., Ltd.)
Co., Ltd.), Cosmo Color S1000F Series (Toyo Soda Co., Ltd.), Victoria Yellow G-11, G-2
0, Victoria Orange G-16, G-21, Victoria Red G-19, G-22, Victoria Pink G-17, G-23, Victoria Green G-1
8, G-24, Victoria Blue G-15, G-
25 (above, manufactured by Mikuni Shigyo Co., Ltd.), Pollux PC5T
1020, Pollux black PC8T135, Pollux thread IT1030, and other Pollux series (all manufactured by Sumika Color Co., Ltd.).

Further, a dye can also be used as a coloring material by mixing with the above-mentioned coloring pigment. Specific examples of the dye include acid dyes, direct dyes, and basic dyes. Examples include 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 (3)
8), Direct Fast Black Conch (Id. 51),
Kayaras Sprague VGN (71), Kayaras Direct Brilliant Yellow G (CI Direct Yellow 4), Direct Fast Yellow 5GL (26),
Aizen Primula Yellow GCLH (44), Direct Fast Yellow R (50), Aizen Direct Fast Red FH (CI Direct Red 1), Nippon Fast Scarlet GSX (4), Direct Fast Scarlet 4BS (23) , Aizen Direct Rhodulin BH (31), Direct Scarlet B (37), Kayak Direct Scarlet 3B (39), Aizen Primula Pink 2BLH (75), Sumilight Red F3B (80), Aizen Primula Red 4BH (81), Kayalas Sprarubin BL (83), Kayalas Light Red F5G (2)
25), Kayalas Light Red F5B (226), Kayalas Light Rose FR (227), Direct Sky Blue 6B (CI Direct Blue 1), Direct Sky Blue 5B (15), Sumilite Supra Blue BRR Conc (71), Dibogen Turquoise Blue S (86), Water Blue # 3 (8)
6), direct dyes such as Kayalas Star Koiz Blue GL (86), Kayaras Supra Blue FF2GL (106), Kayaras Splatter Blue FBL (199) and Acid Blue Black 10B (CI Acid Black). 1), Nigrosine (2), Suminol Milling Black 8BX (24), Kayanol Milling Black VLG (26), Suminol Fast 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), Kayak Acid Brilliant Flavin FF (CI Acid Yellow 7: 1), Kayasil Yellow GG (17), Xylene Light Yellow 2G14
0% (17), Suminol Leveling Yellow NR (19), Daiwa Tartrazine (23), Kayaktor Trazine (23), Suminol Fast Yellow R (2)
5), Diacid Light Yellow 2GP (29), Suminol Milling Yellow O (38), Suminol Milling Yellow MR (42), Water Yellow # 6 (42), Kayanol Yellow NFG (49) , Suminol Milling Yellow 3G (id. 72), Suminol Fast Yellow G (d. 61), Suminol Milling Yellow G (d. 78), Kayanol Yellow N5G (d. 110), Sumino Milling Yellow 4G 200% (d. 141) , Kayanol Yellow NG (135), Kayanol Milling Yellow 5GW (127), Kayanol Milling Yellow 6G
W (142), Sumitomo Fast Scarlet A
(CI Acid Red 8), kayak silk scarlet (9), solar rubin extra (14),
Daiwa New Koksin (18), Aizen Bon Saw R
H (26), Daiwa Red No. 2 (27), Suminol Leveling Brilliant Red S3B (35), Kayasilrubinol 3GS (37), Aizen Erythrosin (51), Kayak Acid Rhodamine FB (5)
2), Suminol leveling rubinol 3GP (5
7), Diacid Alizarin Rubinol F3G200
% (82), Eizen Eosin GH (87), Water Pink # 2 (92), Eizen Acid Phloxine PB (92), Rose Bengal (94), Kayanol Milling Scarlet FGW (111), Kaya Noll milling rubin 3BW (129), Sumino all milling brilliant red 3BN conc (13)
1), Suminol Milling Brilliant Red BS (138), Eisen Opal Pink BH (186),
Suminol Milling Brilliant Red B Conc (2
49), kayak acid brilliant red 3BL (254), kayak acid brilliant brilliant red BL (265), kayanol milling red GW (276), Mituiacid violet 6BN (C.I.
I. Acid Violet 15), Mitsui Acid Violet BN (17), Sumitomo Patent Pure Blue VX (CI Acid Blue 1), Water Blue # 106 (1), Patent Blue AF (7), Water Blue # 9 (No. 9), Daiwa Blue No. 1 (No. 9), Spranol Blue B (No. 15), Orient Soluble Blue OBC (No. 22), Suminol Leveling Blue 4GL (No. 23), Mitsui Nylon Fast Blue G (No. 9) 25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Safirol SE (43), Suminol Leveling Sky Blue R Extra Conch (62), Mitsui Nylon Fast Sky Blue B (78) , Sumitomobrilliant indocyanine 6Bh / (The 83), sand run cyanine N-6B350% (the same 90), Water Blue # 115 (the 90), Orient Sol bulbul over OBB
(93), Sumitomo Brilliant Blue 5G (10
3), Kayanol Milling Ultra Sky SE (11
2), Kayanol milling cyanine 5R (113);
Eisen Opal Blue 2GLH (158), Daiwa Guinea Green B (CI Acid Green 3), Acid Brilliant Milling Green B (9), Daiwa Green # 70 (16), Kayanol Cyanine Green G (25) ), Acid dyes such as Suminol Milling Green G (No. 27), Aizen Katilon Yellow 3GL
H (C.I. Basic Yellow 11), Eizen Chillon Brilliant Yellow 5GLH (13), Sumiacryl Yellow E-3RD (15), Maxilon Yellow 2RL (19), Astrazon Yellow 7GLL
(21), Kayacryl Golden Yellow GL-ED
(28), Astrazon Yellow 5GL (51),
Aizen Chillon Orange GLH (CI Basic Orange 21), Aizen Chillon Brown 3GLH
(30), Rhodamine 6 GCP (CI Basic Red 1), Eisen Astraphloxin (12),
Sumiacryl Brilliant Red E-2B (15),
Astrazone Red GTL (18), Aizen Katilon Brilliant Pink BGH (27), Maxilon Red GRL (46), Aizen Methyl Violet (CI Basic Violet 1), Aizen Crystal Violet (3), Aizen Rhodamine B
(10), Astrazone Blue G (CI Basic Blue 1), Astrazone Blue BG (3), Methylene Blue (9), Maxilon Blue GRL (4)
1), Aizen Katilon Blue BRLH (54), Aizen Diamond Green GH (CI Basic Green 1), Aizen Malachite Green (4),
And basic dyes such as Bismarck Brown G (CI Basic Brown 1). The above color pigments and dyes can be used alone or in combination of two or more.

The liquid medium dissolves or disperses the coloring material such as the above-mentioned pigments, and mainly water is preferably used. In addition to water, it is used for various qualities as a ballpoint pen, for example, for preventing ink drying at the pen tip and preventing ink from freezing at low temperatures. Specifically, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-butylene glycol, thiodiethylene glycol, and glycerin, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, and triethanolamine Can be used alone or in combination. In addition, it is also possible to use a system composed of only an organic solvent that is not dissolved or hardly soluble in water, such as phenylcellosolve or benzyl alcohol, without using water.

The fine particles are used to suppress wear of the ball seat. These fine particles have a new Mohs hardness of 4 or more. The new Mohs hardness is a kind of hardness display, and is a measure for comparing and displaying hardness. The scratches were made softer by scratching each other, and the scratch hardness was measured. A Mohs hardness tester was used for the measurement. Examples of particles having a new Mohs hardness of 4 or more include alumina, silicon carbide, chromium oxide, boron carbide, zircon, sensite, jadeite, calcium fluoride, tungsten carbide, silica, diamond, garnet, aluminum nitride, Silicon nitride and the like. It is preferable that the fine particles have a shape close to a spherical shape if possible, and those having a narrow particle size distribution by adjusting the particle size, specifically those having a particle size of 50% or more with an average particle size of ± 25%, It is preferable to use one having a diameter of 0.1 to 30 μm. If the average particle diameter is less than 0.1 μm, the effect of suppressing the wear of the ball seat may not be sufficient.
On the other hand, if the average particle size exceeds 30 μm, a problem may occur due to the size of the ink flow path of the ballpoint pen. Fine particles having a wide particle size distribution and containing coarse particles of 30 μm or more may be used after filtering and removing the ink by centrifugation. By using relatively hard fine particles having a new Mohs hardness of 4 or more, a polishing effect of the fine particles on the ball can be expected. This polishing effect is considered to be closely related to the unevenness of the ball surface and the shape and particle diameter of the fine particles. In particular, if the surface of the writing ball has an arithmetic average roughness of several nm to several tens of nm in a region of 50 μm × 50 μm and a maximum height difference of several hundred nm, the particle diameter of the fine particles is 0.1 μm. A high polishing effect can be expected if the average particle diameter is 0.1 to 20 μm.

The amount of the fine particles used is preferably 0.003 to 10% by weight based on the total amount of the ink. Usage is 0.0
If the content is less than 03% by weight, the effect of preventing the ball from sinking may not be sufficiently exhibited. If the content is 10% by weight or more, the handwriting may slightly deviate from the desired color tone, or the writing may be blurred due to clogging of the ink in the ballpoint pen tip.

Further, a viscosity modifier can be added to adjust the viscosity of the ink. For example, polyvinyl alcohol, sodium polyacrylate, polyacrylamide,
Water-soluble synthetic high molecular substances such as polyethylene oxide and polyvinylpyrrolidone, and guar gum, locust bean gum and derivatives of seed polysaccharides, microbial xanthan gum, welan gum, ramzan gum, seaweed polysaccharide carrageenan, alginic acid and derivatives, resins Resins such as polysaccharide talagant gum, cellulose-based resins, and pyrrolidone-based resins can be used. These viscosity modifiers can be used alone or in combination of two or more. Preferred viscosity of the ink is 1,000 mPa · s
(Use an E-type viscometer with a st rotor, 10 rpm at 1 rpm)
(Measured after elapse of minutes). However, 50,000 mP
If the value exceeds a · s, other problems such as impaired ink flowability may occur.

Further, humectants such as urea, ethylene urea and thiourea, and preservatives such as benzothiazoline and omazine,
Rust inhibitors such as benzotriazole, dispersants for color pigments,
Various additives such as a lubricant and an antifreezing agent can be added as needed.

In the production of the ink of the present invention, various conventionally known methods can be employed. For example, the above-mentioned components are blended and stirred and mixed by a stirrer such as a turbo mixer or a Henschel mixer. , Also ball mill, sand grinder, speed line mill,
It can be easily obtained by mixing and grinding with a disperser such as a roll mill. Further, if necessary, coarse particles in the ink may be removed by filtration or centrifugation.

As shown in FIG. 1, a ball-point pen tip used as a pen point of a ball-point pen is mainly a writing ball 1 as a writing member and a ball holder 2 for holding the writing ball 1 rotatably. Things. The ball holder 2 has an inner hole 3 as an ink passage, and the tip end opening 3a is reduced in diameter to a diameter smaller than the diameter of the ball 1 by caulking after installing the ball 1. The ball 1 is prevented from falling off. Further, a plurality of inwardly projecting portions 4 are formed radially in the inner hole 3 so as to regulate the rearward movement of the ball 1 and communicate a space between the inwardly projecting portions 4 with the center hole 5. To form radial grooves 6 through which ink passes. As the writing ball 1, a so-called cemented carbide ball, which is mainly a tungsten carbide alloy, or a ceramic ball such as zirconia can be used, and the Vickers hardness (Hv) is 1000 to 300.
About 0 can be suitably used. Examples of the ball holder 2 include nickel silver, brass, and stainless steel, and those having a Vickers hardness (Hv) of about 150 to 300 can be suitably used.

When a writing ball made of tungsten carbide and a ball holder made of stainless steel are used, the writing ball has a surface of at least 50 μm × 5.
It is preferable to use one having an arithmetic mean roughness in a region of 0 μm of 5 to 25 nm and a maximum height difference of 100 to 600 nm. Furthermore, on the surface of the writing ball,
It is preferable that at least two or more concave portions having a value equal to or more than 5 times the arithmetic average roughness exist in a 50 μm line segment.
Arithmetic average roughness (Ra) is obtained by extending the center line average roughness defined in JIS B0601 three-dimensionally with respect to the measurement surface (2500 μm 2, 50 μm square), and calculating the absolute deviation from the reference surface to the specified surface. The average value was used.
Measurement of surface roughness (Model name SP manufactured by Seiko Epson Corporation)
I3800N) was used. The maximum height difference (PV) is determined by the maximum height (Zmax) and the minimum height (Zmi) on the measurement surface.
n). The number of concave portions in a 50 μm line segment is a line drawn at an arbitrary position crossing the measurement surface with respect to the measurement surface, and indicates the cross-sectional structure of the measurement portion in the line segment. is there.

[0018]

[Function] By adding fine particles having a new Mohs hardness of 4 or more to the ink, it is presumed that these fine particles act like a bearing without being crushed between the ball and the ball receiving seat. As a result of minimizing the area,
It is supposed that the fluidized bed of the ink becomes thicker, and it is considered that the friction due to the rotation of the ball is reduced and the wear of the ball receiving seat is reduced. In addition, the surface of the writing ball is polished by relatively hard fine particles such as alumina, and the surface of the writing ball becomes smooth as the ball rotates,
It is also conceivable that friction due to contact with the ball receiving seat is reduced and wear of the ball receiving seat is reduced.

[0019]

The present invention will be described below in more detail with reference to examples. Example 1 sandy super red 1315 (red dispersion pigment, manufactured by Sanyo Dyeing Co., Ltd., average particle size: 0.2 μm, solid content: 28.0%) 10.0 parts by weight Aluminum paste (WXU75c, manufactured by Toyo Aluminum Co., Ltd.) 5.0 parts by weight Resin (Johncryl J-450, styrene-acrylic emulsion manufactured by Johnson Polymer Co., Ltd.) 1.0 part by weight Ethylene glycol 35.5 parts by weight Propylene glycol 10 1.0 part by weight N-stearoyl-L-sodium glutamate (lubricant) 1.0 part by weight Water 36.7 parts by weight Xanthan gum (thickening resin) 1.0 part by weight Preservative (Proxel XL-2, ICI Japan Co., Ltd.) ), 1,2-benzisothiazolin-3-one) 0.2 parts by weight Alumina (New Mohs hardness) 0.1 part by weight The above components were stirred and mixed for 1 hour to obtain an ink.

Example 2 Thai Pure R900 (titanium oxide, manufactured by Dupont Japan Limited) 28.0 parts by weight Lumicoll NKW2109 (colored resin particles, average particle size 0.4 μm, solid content 53%, manufactured by Nippon Fluorescent Co., Ltd.) 15.0 parts by weight Resin (John Grill J711, an acrylic emulsion manufactured by Johnson Polymer Co., Ltd.) 2.0 parts by weight 6% by weight aqueous solution of xanthan gum 9.0 parts by weight Ethylene glycol 5.0 parts by weight Glycerin 5. 0 parts by weight PO20 (sugar alcohol, manufactured by Towa Kasei Kogyo Co., Ltd.) 5.0 parts by weight TL20 (dispersant, manufactured by Nikko Chemicals Co., Ltd.) 1.0 part by weight Water 29.0 parts by weight Chromium oxide (new Mohs hardness) 7, average particle size 1 μm) 1.0 part by weight Among the above components, each component other than Lumicol NKW2109 and the aqueous xanthan gum solution was used. Combined, after 1 hour dispersion treatment with a ball mill, for 1 hour with stirring by adding the rest,
An ink was obtained.

Example 3 FUJI SP RED 5544 (red dispersion pigment, average particle size 0.08 μm, manufactured by Fuji Dye Co., Ltd.) 20.0 parts by weight Glycerin 15.0 parts by weight Ethylene glycol 10.0 parts by weight PO205 0.0 parts by weight Preservative (Proxel XL-2, manufactured by ICI Japan, 1,2-benzoisothiazolin-3-one) 0.2 parts by weight Acronal YJ1100D (acrylic emulsion, manufactured by Mitsubishi Chemical Corporation), solid 1.0% by weight Deionized water 38.4 parts by weight Pemulen (thickener, acrylic acid-acryl methacrylate copolymer, manufactured by Good Rich) 0.4 part by weight Alumina (new Mohs hardness 12, average) 10.0 parts by weight The above components were stirred and mixed for 1 hour to obtain an ink.

Example 4 Phthalocyanine blue (average particle size: 0.05 μm) 8.0 parts by weight Ammonium salt of styrene-acrylic acid copolymer (dispersant) 8.0 parts by weight Ethylene glycol 15.0 parts by weight Glycerin 5. 0 parts by weight Carboxymethylhydroxypropylated guar gum 0.3 parts by weight Water 61.7 parts by weight Alumina (new Mohs hardness 12, average particle size 0.5 μm) 2.0 parts by weight I got

Example 5 An ink was obtained in the same manner as in Example 1, except that calcium fluoride (new Mohs hardness 4, average particle diameter 20 μm) was used instead of alumina.

Example 6 sandy super red 1315 (red dispersion pigment, manufactured by Sanyo Dyeing Co., Ltd., average particle size: 0.2 μm, solid content: 28.0%) 10.0 parts by weight Aluminum paste (WXM0630, Toyo Aluminum Co., Ltd.) 5.0 parts by weight Resin (Johncryl J-450, styrene-acrylic emulsion manufactured by Johnson Polymer Co., Ltd.) 1.0 part by weight Ethylene glycol 40.0 parts by weight Propylene Glycol 5.0 parts by weight N-stearoyl-L-sodium glutamate (lubricant) 1.0 part by weight Water 36.7 parts by weight Xanthan gum (thickening resin) 1.0 part by weight Preservatives (Proxel XL-2, ICI Japan) 0.2 parts by weight of silicon carbide (1,2-benzisothiazolin-3-one) New Mohs hardness of 13, to obtain an average particle size 3 [mu] m) 0.1 parts by weight of the ink and mixed with stirring for 1 hour the above components.

Example 7 Fuji sp black 8922 (black dispersing pigment, manufactured by Fuji Dye Co., Ltd., average particle size 0.25 μm, solid content 20%) 30.0 parts by weight Demol N (dispersing agent, Kao Corporation) 4.0 parts by weight Ethylene glycol 21.0 parts by weight Glycerin 15.0 parts by weight Water 25.597 parts by weight Sarcosinate OH (lubricant, manufactured by Nikko Chemicals Co., Ltd.) 0.5 parts by weight Benzotriazole (rust prevention) 0.5 part by weight Preservative (Proxel XL-2, 1,2-benzoisothiazolin-3-one manufactured by ICI Japan) 2.0 parts by weight Poly-N-vinylacetamide (thickening resin) 1 0.4 parts by weight Silica (new Mohs hardness 7, average particle size 0.5 μm) 0.003 parts by weight

Example 8 An ink was obtained in the same manner as in Example 7, except that aluminum nitride (new Mohs hardness 11, average particle size 1.0 μm) was used instead of silica.

Comparative Example 1 An ink was obtained in the same manner as in Example 1 except that water was used instead of alumina.

Comparative Example 2 An ink was obtained in the same manner as in Example 1 except that calcium carbonate (new Mohs hardness 3, average particle diameter 1.3 μm) was used instead of alumina.

Comparative Example 3 An ink was obtained in the same manner as in Example 1 except that molybdenum disulfide (new Mohs hardness 1, average particle diameter 3 μm) was used instead of alumina in Example 1.

Comparative Example 4 An ink was obtained in the same manner as in Example 1 except that oleoyl sarcosine was used instead of alumina.

Comparative Example 5 An ink was obtained in the same manner as in Example 1 except that lauroyl sarcosine was used instead of alumina.

[0032]

As described above, the inks obtained in Examples 1 to 8 and Comparative Examples 1 to 5 are used as transparent inks made of a polypropylene hollow shaft cylinder having one end connected to a stainless ballpoint pen tip (ball material: tungsten carbide). 0.8 g is directly filled in the storage tube (Pentel's hybrid,
K108), and the writing distance and the wear of the ball seat were tested. Table 1 shows the results.

Writing distance: Using a rotating continuous writing tester (spiral machine, manufactured by Seiki Kogyo Kenkyusho) at a writing speed of 7 cm / sec.
c, continuous writing was performed at a load of 100 g and an angle of 70 °, and the writing distance at which blurring occurred was measured.

Abrasion of ball seat: In the above-described writing test, the ball projection length before writing when the writing ball was turned upward with the ballpoint pen tip for writing each of Examples 1 to 8 and Comparative Examples 1 to 5 was tested. The amount of wear (the length in the longitudinal direction) of the ball receiving seat was measured from the difference from the later ball projection length. In the comparative example, the filled ink composition remained, but the ink was not discharged. Therefore, the abrasion of the ball receiving seat was measured from the difference from the ball protrusion length after 500 m continuous writing. In addition, the ball protrusion length measured the length from the front-end | tip of a ball holder to the front-end | tip of a ball using the tool microscope.

[0035]

[Table 1]

As described in detail above, the ink for a ball-point pen according to the present invention has a low wear of the ball receiving seat, and therefore has the object of writing without blurring until all the filled ink is consumed. It is a useful thing that can be sufficiently achieved.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view of a main part showing an example of a ballpoint pen tip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Writing ball 2 Ball holder 3 Inner hole 3a Tip opening 4 Inward protruding part 5 Center hole 6 Radial groove

Claims (9)

[Claims] 1. An ink for a ballpoint pen, comprising at least a pigment as a coloring material, fine particles having a new Mohs hardness of 4 or more, and a liquid medium. 2. The method according to claim 1, wherein the fine particles have a particle size of 0.1 μm or more
2. The ink for a ball-point pen according to claim 1, which has a thickness of 0 [mu] m or less. 3. The fine particles are selected from alumina, silicon carbide, chromium oxide, boron carbide, zircon, senolite, jadeite, calcium fluoride, tungsten carbide, silica, diamond, garnet, aluminum nitride, and silicon nitride. The ballpoint pen ink according to claim 1, wherein the ink is one kind or a mixture of two or more kinds. 4. The ink for a ball-point pen according to claim 1, wherein a compounding weight ratio of the fine particles to the pigment is 0.02% or more and 50% or less. 5. The ballpoint pen ink according to claim 1, wherein the fine particles are alumina, and the liquid medium contains at least water. 6. The ballpoint pen ink according to claim 5, wherein the amount of the alumina added is 0.003% by weight or more and 10% by weight or less based on the total amount of the ink. 7. The ballpoint pen according to claim 5, wherein the ratio of the average particle size A of the alumina to the average particle size B of the pigment is A / B ≧ 1.0. For ink. 8. A ball-point pen tip which uses the ink according to claim 1 to hold a writing ball made of tungsten carbide rotatably with a stainless steel ball holder as a pen point of a ball-point pen. The writing ball has at least 50 μm × 50 μm on the surface.
Characterized in that the arithmetic average roughness in the region is 5 to 25 nm and the maximum height difference is 100 nm or more and 600 nm or less. 9. The surface of the writing ball has a size of 50 μm.
9. The method according to claim 8, wherein there are at least two recesses in the line segment m, the recesses being at least five times the arithmetic average roughness.
The ballpoint pen described in 1.