JP2001271019A - Oily ink for ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oily ballpoint pen ink which gives good writing touch and smooth writing and scarcely changes the writing touch under an environment having a temperature difference. SOLUTION: This oily ballpoint pen ink is aracterized by comprising at least an oil-soluble dye, a resin and an organic solvent, further containing an organic pigment, and having an ink viscosity of >=2,000 mPa.s at a shear rate of 2 s-1 and a viscosity ratio of <=35 at 5 deg.C and 35 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-based ballpoint pen ink composition, and more particularly to an oil-based ballpoint pen ink composition having a good writing feel and little change in writing feeling in ballpoint pen writing under environmental conditions having a large temperature difference. About ballpoint pen.

[0002]

BACKGROUND OF THE INVENTION Numerous compositions are known for oil-based ballpoint pen inks. For example, Japanese Patent Application Laid-Open No. 08-311388 discloses that a fatty acid amide, which is a sagging agent often used in paints, is used to provide a smooth and good writing taste without sagging, blurring of handwriting, broken lines, and bleeding. The resulting ink compositions have been proposed. JP-A-10-19536
No. 5 proposes an oil-based ink composition for a ballpoint pen that does not cause ink leakage from a pen tip by adding silica having a primary average particle diameter of 7 to 40 nm.

[0003] In addition, by imparting a shear thinning viscosity to the ink, the viscosity in the ink container becomes relatively high so that the viscosity becomes low during writing. As an example to prevent leakage,
In JP-A-11-116879, a crosslinked acrylic acid polymer is blended to impart a shear thinning property to the ink. In JP-A-10-251587, an N-vinylacetamide polymer is contained. Japanese Unexamined Patent Publication No. Hei 9-78021 discloses a method of blending a cross-linked N-vinylacetamide polymer into an ink composition to suppress the dripping of ink when a ballpoint pen tip is left facing downward.
It is described that a so-called sagging prevention property is exhibited.

Further, Japanese Patent Application Laid-Open No. Hei 6-313143 discloses a composition comprising a colorant, a solvent and an additive, and having a shear rate of 400 s ^-1.
Is less than 100 mPa · s at a shear rate of 5 s ^-1
The ink for ball-point pens is characterized by having a viscosity of 1000 mPa · s or more, and prevents the bokeh phenomenon and the direct current phenomenon. JP-A-6-313144 discloses an oil-based ballpoint pen ink comprising a colorant, a solvent and an additive, wherein the solvent contains 50% by weight or more of an organic solvent having a vapor pressure of 0.1 mmHg (20 ° C.) or less, and the viscosity of the ink is increased. oily ballpoint pen ink, characterized in that but is 1000 mPa · s or higher at and a shear rate of 5s ^-1 or less 100 mPa · s at a shear rate 400 s ^-1, has been described like be prevented blobbing phenomenon, a DC phenomenon .

[0005] Further, Japanese Patent Application Laid-Open No. 6-157966 to
4,4'-diaminodicyclohexylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, P, P'-tetramethyldiaminobenzophenone, 4,4'-
By using a special chemical component such as diamino 3,3'-dimethyldiphenylmethane as a lubricant, it has excellent lubricity and suppresses corrosion or abrasion between the ball seat and the ball tip of the ballpoint pen and smooth ink spill. An oil-based ballpoint pen ink composition is described. Japanese Patent Application Laid-Open No. 11-293174 describes an oil-based ballpoint pen ink composition which has excellent lubricity over a wide range of viscosity and smooth writing by using a nonylphenol phosphate ester as a lubricant.

[0006] These conventionally known oil-based ballpoint pen ink compositions and the like have obtained effects according to their respective purposes. However, when a ballpoint pen is used under a large temperature difference between the outside air and the room, especially in summer or winter, the viscosity of the ink composition changes considerably, so that the brush feel changes and the smooth writing taste changes. In many cases, it is difficult to maintain this, and measures for this are not perfect. For this reason, there is a need for an oil-based ballpoint pen ink composition that can provide smooth writing and a good brush feel while suppressing a change in viscosity.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned circumstances, and particularly in writing with a ballpoint pen under environmental conditions having a large temperature difference, the writing feeling is good, the writing is smooth and the writing feeling is changed. It is an object of the present invention to provide an oil-based ink for a ball-point pen having a small amount.

[0008]

As a result of various studies to solve the above-mentioned problems, the present inventors have found that when an organic pigment is dispersed and contained in the form of particles having a specific viscosity, the function as a colorant is reduced. At the same time, they found that they exhibited an excellent effect of preventing low-temperature viscosity rise, and completed the present invention. That is, the oil-based ballpoint pen ink of the present invention contains at least an oil-soluble dye, a resin, and an organic solvent, further contains an organic pigment, and has a viscosity of 2000 mPa · s at a shear rate of 2 s ^{−1 at} 35 ° C.
As described above, the viscosity ratio between 5 ° C. and 35 ° C. is 35 or less.

In the present invention, the organic pigment preferably contains 1 to 20% by weight based on the total amount of the ink. Further, in the present invention, it is particularly preferable that the organic pigment has an average particle diameter of 100 nm to 400 nm and is not dissolved in the ink but becomes fine particles and dispersed in the polyvinyl butyral resin.

[0010]

Embodiments of the present invention will be described below in detail. Oil-based ballpoint pen ink of the present invention,
The viscosity of the ink at 35 ° C. containing at least an oil-soluble dye, an organic solvent, and a resin described later and containing an organic pigment is 2000 mPa · s or more at a shear rate of 2 s ⁻¹ ,
It is important that the viscosity ratio between 5 ° C. and 35 ° C. is 35 or less. By maintaining the viscosity of the ink at 35 ° C. at 2000 mPa · s at a shear rate of 2 sec ⁻¹ , lubricity in a high-temperature environment is maintained. Viscosity 2000mPa ・
If it is less than s, the lubricity is poor and the brush feel is rough, and the brush feel is poor.

Further, the ratio between the viscosity values at 5 ° C. and 35 ° C. is 35
By keeping the temperature below, the rise in viscosity under low temperature conditions of 5 ° C is suppressed, and the writing feeling under low temperature environment is maintained, and the writing feeling under other high temperature conditions such as 35 ° C is maintained so as not to be significantly different. Is what you do. Here, the ratio of the viscosity values at 5 ° C. and 35 ° C. is 3
If it is 5 or more, the viscosity at a low temperature becomes high, and the rotation of the ball is not smooth due to the viscosity. The viscosity can be measured using a known plate-type viscometer.

The organic pigment used in the present invention has an excellent low-temperature viscosity rise preventing effect, has a reflected light in a region substantially similar to a writing line, and functions as a part of a colorant together with an oil-soluble dye. It is advantageous in oil-based ballpoint pens that require a high concentration of colorant. Preferred characteristics of such an organic pigment include an average particle size of 100 nm to 400 nm.
It is preferable that the fine particles are present in the range of nm. If it is less than 100 nm, the effect of preventing low-temperature viscosity rise will be reduced. On the other hand, when the thickness is 400 nm or more, storage stability deteriorates. Here, the average particle diameter of the fine particles is measured by a light (laser) scattering diffraction type particle size distribution analyzer.

Although it is not clear why these organic pigments have an excellent effect of preventing low-temperature viscosity rise, it is presumed that they are present in fine particles without being dissolved in the ink. For example, in the case of a substance dissolved in a solvent such as a dye or a resin, when the liquid temperature is lowered, it becomes difficult to dissolve, and the property of a solid is increased due to partial precipitation and the like, so that the viscosity sharply increases. On the other hand, when the liquid temperature rises, the degree of freedom of movement of the dissolved matter in the ink increases, so that the viscosity considerably decreases.

However, in the present invention, even when the liquid temperature rises and falls, the dispersion of the viscosity of the ink is suppressed by the finely divided organic pigment, so that the change in the viscosity is suppressed and the above-described effect is not exhibited. It is thought. In the present invention, an organic pigment is used as a viscosity modifier. However, as is conventionally seen, the use of an organic pigment alone alone results in a low writing line density and it is difficult to adjust the viscosity. Therefore, it is used as a coloring agent in combination with a dye. As the pigment, there is carbon black or the like as an inorganic pigment, but the inorganic pigment is not suitable for the present invention probably because it is hard.

As the organic pigment preferably used in the present invention, various pigments can be used, for example, azo-condensed azo pigments, phthalocyanine pigments, anthraquinone pigments, quinacdrine pigments, isoindolinone pigments, Organic pigments such as diketopyrrolopyrrole pigments and various lake pigments are exemplified. In particular, the organic pigment used in the present invention may be any organic solvent used, preferably those which are not dissolved in an alcohol-based solvent and are uniformly dispersed in a polyvinyl butyral resin, and commercially available blue, red, yellow, green, and the like. Organic pigments can be used.

More specifically, as the blue organic pigment, various blue pigments can be used.
Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16
, 17, 28, 29, and 36, CI Pigment Blue 60, and the like, which may be surface-treated with a surfactant or the like during the pigment production stage. In particular, specific examples of blue pigments include Graphtol Blue 2GLS and Sandorin manufactured by Clariant.
Blue RL, Sandorin Blue 91052, Lutetiac from ICI
yanine CSN, Mobay Palomar Blue B4806, Pal
omar Blue B4707, Endurophtal Blue BT from Worlee
-788D, Phtalocyanine Blue RS1517C from Cappelle
Heliogen Blue L6920, Heliogen Blue manufactured by BASF
L6875F, Heliogen Blue L6901F, Heliogen Blue 6905
F, Heliogen Blue L6975F, Heliogen Blue 6989F, H
eliogen Blue L7072D, Heliogen Blue L7080, Heliog
en Blue L7101F, Heliogen Blue L6700F,

Monastral Blue FBN manufactured by Zeneca, Mon
astral Blue CSN, Monastral BlueFNX, Mondite Blue
RL, Catulia Cyanie L.PS, Woo S from Francolor
Cyanie Blue A-1700, Cyanie Blue B-7000 made by ung
, Cyanie Blue B-7800, Cyanie Blue B-8000, Sun
Sunfast Blue 249-1282, Francolor Cat
ulia Cyaninel.JS, Hostaperm Blue B manufactured by Hoechst
LF, Renol Bue A2RE, Irgalite Blue GLNF, Irgalite Blue GLVD, Irgal from Ciba Specialty Chemicals
ite Blue ATC, CROMOPHTAL Blue A3R, MICROLITH Blu
e 4G-WA, MICROLITH Blue 4G-A, Shepherd So
vereign Blue385, Holland Blue212, Kingfisher Blue
211, OIympic Blue 190,

Ultramarine Blue, Dai Colo manufactured by Luh
r Italy Blue EP37, Chromofine Blue4920, W
Orlee's Endurophtal Blue BT-729D, Heubach's Heucosine Blue G1737, Heucosine Blue HS-5000,
Lackecht Blue G1737, Kenalake LF from Kenalake
BRX, Chromofine Blue 4930 manufactured by Dainichi Seika Kogyo Co., Ltd.
, Chromofine Blue 5188, Chromofine Blue SR5020
, Fastogen Blue 50 manufactured by Dainippon Ink and Chemicals, Inc.
30L, Fastogen Blue 5420SD, Fastogen Blue5502, F
Astogen Blue TGR-F, Fastogen Blue EP-7, Cyanine Blue G-134, Cyanine Blue SAS,
There are pigments such as Cyanine Blue KRS and Cyanine Blue 4033.

As the red organic pigment, various red pigments can be used. For example, CI Pigment Red 17, 144, 16
6, 170, 177, 202, 214, 220, 254, 255, etc., and may be surface-treated with a surfactant or the like in the pigment production stage. Specific commercial names include Chromopht manufactured by Ciba Specialty Chemicals.
al DPP RED BO, Chromophtal DPP RED BP, Chromophtal
DPP RED DPP, Irgazin DPP Red BO, Irgazin DPP Red B
TR, Chromophtal RED A 2B, Chromophtal REDA 3B, Ch
romophtal Scarlet R, Chromophtal Scarlet RN, Chrom
ophtal ScarletBR, Chromophtal Red BRN, Cinquasia
Magenta TR 235-6, Dainichi manufactured by Dainichi Seika Industry Co., Ltd.
Fast Poppy Red G, Dainichi Fast Poppy Red R, Baye
Bayerrox Red 110M, Bayerrox Red 120MN, B manufactured by r
ayerrox Red 130M,

[0020] Toluidine Red G0335C manufactured by Cappelle,
Toluidine Red RNO333C, Bonitol Red BM, Bonitol Red
4844C, Lysopac Red 4841C, Cappoxyt Red 4435B, Cap
poxyt Red 4437B, Mineral Orange Thiosol GL, Minera
l Orange Thiosol G, Mineral Orange Solipur GH, Min
eral Red Solipur 3BH, Lysopac Red 7030C, Copperas Red R9998 from Hercos, Sicored L3750 from BASF
, Lithol Scharlach L4301, Litholechtmaroon L4763,
Sicoflush-P-Maroon 4763, Paliogen Redviolet L5080
, Sicotrans Red L2817, Sicomin Red L3025, Sicomin
Red L3230s, Sico Fast Scarlet L4252,

Heucotron Red 230, Palio, manufactured by Heubach
gen Red 3880HD, Paliogen L3920, Paliogen Red L4210
Horna Molybdato from Ciba Specialty Chemicals
r.MLN-74-SQ, Horna Molybdateor.MLH-740-Q, Irgal
ite Red 3RS, Toluidine Red L, Tolu from Woo Sung
idine Red K, Bon Red SR, Bon Red 3M, Bon Red MP, Fa
st Bordeaux C, Lake Red C-500, Lake Red C-900, Fas
t Red FGR, Chromophtal Red A2B, Chropmohtal Red A3
B, Novoperm Red Violet MRSnew, Perma from Hoechst
nent Bordeaux FGR, Permanent Red FGR70, Hostaperm
Rosa E, Novoperm Reel F3RK70, Quindo from Miles
Magenta RV6832, Perrindo Maroon from Bayer Mobay
Pigments such as R6422, Graphtol Red 5BLS from Sandoz.

As the yellow organic pigment, various yellow pigments can be used. For example, CI Pigment Yellow 1, 3,
12, 13, 14, 16, 17, 55, 81, 83, 74, 93, 94, 95, 9
7, 109, 110, 120, 128, 138, 147, 154, 155, 167, 18
5, 191 and the like, and may be surface-treated with a surfactant or the like in a pigment production stage. A specific example is Paliotol Yellow 2140HD, Sico manufactured by BASF.
pal Yellow L1110, Sicotan Yellow L1912, Sicomin Ye
llow L1622, Sicomin Yellow L1630S, SicominYellow L
1635S, Sicotrans Yellow L1916, Sico Yellow 1252HD,
Paliogen Yellow L1482, Paliogen Yellow L1560, Pal
iotol Yellow D1155, Paliotol YellowL0960HD,

Horna C manufactured by Ciba Specialty Chemicals
hrome Yellow GMX AX-15, Horna Chrome Yellow GMXAH-
35, Horna Chrome Yellow GU-15-SQ, Irgazin Yellow G
O, Irgazin Yellow 2RLT, Irgazin Yellow 3RLTN, Irga
zin Yellow 5GLT, Irgazin Yellow 2GLTE, Bayer Bayferrox 915, Bayferrox 920, Bayferrox 3420, B
ayferrox 3910, Bayferrox 3920, Hoechst Novo
perm Yellow H2G, Hostaperm Yellow H4G, Hostaperm Y
ellow H3G, Hostaperm Yellow H6G, Novoperm Yellow F
2G, Novoperm Yellow HR70,

Pigment Yellow 171 manufactured by Sanyo Dyeing Co., Ltd.
7, Pigment Yellow 1450, Pigment Yellow 1710, Pigme
nt Yellow 1711, Pigment Yellow 1707, Pigment Yello
w 8104, Pigment Yellow 1425, Light Fast Pigment Ye
llow R, Dainichi Seika Co., Ltd. SEIKA FAST YELLOW 10GH,
SEIKA FAST YELLOW A-3, SEIKA FAST YELLOW 2035, SEI
KA FAST YELLOW 2054, SEIKA FAST YELLOW 2300, SEIKA
FAST YELLOW 2200, SEIKA FAST YELLOW 2270, SEIKA FA
ST YELLOW 2400 (B), SEIKA FAST YELLOW 2500, SEIKA FAS
T YELLOW 2600, SEIKA FAST YELLOW ZAY-260, SEIKA FA
ST YELLOW 2700 (B), SEIKA FAST YELLOW 2770, Clarian
t Sandrin Yellow 4G, PV FastYellow HGR, Nov
operm Yellow FGL, Novoperm Yellow H10G01, HANSA Ye
llow 10G, PV Fast Yellow H2G-01, Permanent Yellow
There are pigments such as NCG.

As the green organic pigment, various green pigments can be used. For example, CI Pigment Green 7, 17,
36, 50, 70 and the like, which may be surface-treated with a surfactant or the like during the pigment production stage. A specific example is Chromofine manufactured by Dainippon Ink and Chemicals, Inc.
Cyanine Green 2GN, Chromofine Cyanine Green 5301,
Chromofine Cyanine Green 2GN, Dainichi Cyanine G
reen 537, Dainichi Cyanine Green FG, Dainichi Cyan
ine Green FGH, Chromofine Green 5370, Fastogen Green 5005, Fastogen Green 5710 manufactured by Dainichi Seika Co., Ltd.
Fastogen Green B, Fastogen Green S, Fastogen Green
SF, Fastogen Green SO, Fastogen Green2YK,

Heliogen Green 8680, Helio, manufactured by BASF
gen Green 8681K, Heliogen Green8682T, Heliogen Gre
en 8730, Heliogen Green 8730K, Heliogen Green A, H
eliogen Green GNA, Heliogen Green G, Heliogen Gree
n GA, Heliogen Green GN, Heliogen Green GTA, Heliog
en Green GV, Heliogen Green GWS, Heliogen Green K
8730, Heliogen Green L 8730, Fastogen Green MY, Fa
stogen Green YCN, Helio Fast Green GT, Heliogen Gre
en 6G, Heliogen Green 6GA, Heliogen Green 8GA, Hel
iogen Green 9360, Heliogen Green K9360, Heliogen G
reen L 9140, Heliogen Green L 9361,

Iragal manufactured by Ciba Specialty Chemicals
ite Fast Brilliant Green 3GL, Iragalite Fast Brill
iant Green GL, Iragalite Green GLN, Iragalite Gre
en 6G, Liofast Green B23 manufactured by Toyo Ink Manufacturing Co., Ltd.
7, Lionol Green B 201, Lionol Green Y 102, Lionol
Green YS 07, Lionol Green 2Y301, Lionol Green 2YS,
Lionol Green 6YK, Lionol Green 6YKPCN, Polymon De
velopments Ltd.Polymo Green FBH, Polymo Gre
en FGH, Polymo Green 6G, Polymo Green G, Polymo Gre
en GN, Polymo Green GN 500, S manufactured by Sanyo Pigment Co., Ltd.
anyo CyanineGreen, Sanyo Phthalocyanine Green F6G,
Sanyo Phthalocyanine Green FB, Sanyo Phthalocyani
ne Green FB Pure, SAX, SAX (pigment), Sanyo Phthalo
There are pigments such as cyanine Green 6YS.

These organic pigment particles may be used alone or in combination of two or more. These organic pigment particles have an average particle diameter of 100 n as described above.
It is preferable to disperse the resin, particularly 1% by weight to 20% by weight, in the total amount of the ink in the form of fine particles in the range of m to 400 nm, and to disperse and contain the resin at 1% by weight or less. When the content is large, the organic pigment particles are hardly stably maintained, and storage stability is deteriorated. These organic pigment particles are preferably dispersed in a resin, especially a butyral resin.

Preferred commercially available butyral resins include Mowital B20H, B30B, B30H, B60T, manufactured by Hoechst.
B60H, B60HH, B70H, B20H, S-LEC B, BH-3, BL-1, BL-2, BL-L, BL-S, BM-1, BM- made by Sekisui Chemical Co., Ltd.
2, BM-5, BM-S, BX-L, Denka Butyral # 2000-L, # 3000-1, # 3000-2, # 3000-3, # 300 manufactured by Denki Kagaku Kogyo Co., Ltd.
0-4, # 3000-K, # 4000-1, # 5000-A, # 6000-C and the like.

The oil-soluble dye used in the present invention includes:
Although those conventionally used can be mainly used, alcohol-soluble dyes can be particularly preferably used. Specifically, Rhodam manufactured by Taoka Dye Manufacturing Co., Ltd.
ine B Base (CISolvent Red49), Soldan Red 3R (CISolvent Red 18) manufactured by Chugai Kasei Co., Ltd., National An
Methyl Violet 2B Base made by iline Div. (CISolvent V
iolet 8), Victoria Blue F4R from BASF (CISolven
t Blue 2), NIGROSINE BASE LK (CISolvent Black
5), Neozapon Yellow 081, Neozapon Yellow 157,

VALIFAST YEL manufactured by Orient Chemical Co., Ltd.
LOW 1151, VALIFAST YELLOW 3104 (CISolvent Yellow
19), VALIFAST YELLOW 3108, VALIFAST YELLOW 3105
(CISolvent Yellow 21), VALIFAST YELLOW 3150, V
ALIFAST YELLOW 4120, VALIFAST ORANGE 2210, VALIFAS
T ORANGE 3209, VALIFAST ORANGE 3210, VALIFAST RED1
306, VALIFAST RED 1355, VALIFAST RED 2303, VALIFAS
T RED 3304, VALIFASTRED 3306, VALIFAST RED 3311, V
ALIFAST RED 3312, VALIFAST RED 3320, VALIFAST RED
2310, SPIRIT BLACK AB (CISolvent Black 5), VALI
FAST BLACK 3804 (CISolvent Black 34), VALIFAST
YELLOW 1109, VALIFAST ORANGE 2210, VALIFAST RED 13
20, VALIFAST BLUE 1605, VALIFAST VIOLET 1701,

Spilon Black G manufactured by Hodogaya Chemical Industry Co., Ltd.
MH special (CISolvent Black43), Spilon Yellow C
-2GH, Spilon Yellow C-GNH, Spilon Red C-GH, Spilon
Red C-BH, Spilon Blue BPNH, SBNBlue 701, Spilo
n Blue C-RH, Spilon Violet C-RH, SPT Orange-6,
SPT Blue-111, Aizen Spilon Yellow C-2GH, Aizen
Spilon Yellow C-GNH, Aizen Spilon SBN Yellow 530,
Aizen Spilon SPT orange-6, Aizen Spilon Red C-BH,
Aizen Spilon SPT Red 533, Aizen Rhodamine B Base, W
s Simpsol Orange 24278, Simp from Simposn & Co., UK
sol Orange 24335, Simpsol Orange 24765, Simpsol Re
d 24766, Savinyl Red 24768, Simpsol Red 24780, Cla
Savinyl Red 2BLSE, Savinyl R made by riant Huningue SA
ed U-2BLSE can be exemplified.

It is important that such an oil-soluble dye used in the present invention is used in combination with the above-mentioned organic pigment. In particular, the total amount of the oil-soluble dye and the organic pigment is preferably 5 to 40% by weight based on the total amount of the oil-based ink composition for ballpoint pens. Of these, the compounding amount of the oil-soluble dye is preferably 4 to 39% by weight (the organic pigment is preferably 1 to 20% by weight based on the total amount of the ink). When the amount of the oil-soluble dye is 4% by weight or less, the effect of using the oil-soluble dye in combination with the organic pigment is reduced, and the drawn line density tends to be insufficient. On the other hand, when the content is more than 39% by weight, the organic pigment is hardly maintained stably, and the storage stability is deteriorated. Further, even if a large concentration of drawing lines is used, it does not increase and is useless.

The organic solvent is added for adjusting the viscosity and accelerating the dissolution of the dye, and may be any solvent which does not dissolve the above-mentioned organic pigment particles. Examples of the organic solvent include ethylene glycol, diethylene glycol, propylene glycol and hexylene glycol. Glycol solvents, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethyl glycol monohexyl Ether, diethylene glycol monophenyl ether, propylene glycol monomethyl ether, B propylene glycol monoethyl ether, propylene glycol mono n-butyl Lutheran, propylene glycol monophenyl ether,

Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mononormal butyl ether, dipropylene glycol monophenyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol mononormal butyl ether, Ether solvents such as tripropylene glycol monophenyl ether, alcohol solvents such as benzyl alcohol and α-methylbenzyl alcohol, propylene glycol methyl ether acetate, propylene glycol diacetate, and N-methyl-2-pyrrolidone can be used. These solvents can be used alone or as a mixture. The amount used is 35 to the total amount of the oil-based ink composition for a ballpoint pen.
~ 80% by weight is preferred.

The resin is added for the purpose of improving the fixing property, preventing the show-through of handwriting, adjusting the function as an organic pigment dispersant, adjusting the viscosity, and accelerating the dissolution of the oil-soluble dye. For example, cyclohexanone, acetophenone, condensation resins of ketones such as urea and formaldehyde, condensation resins of cyclohexanone and hydrogenated resins thereof, maleic acid resin,
A copolymer of styrene and maleic acid ester, a copolymer of styrene and acrylic acid or an ester thereof, polyvinylpyrrolidone, polyvinyl butyral, polyvinyl acetal, a polyamide that is a condensate of a polymerized fatty acid and polyamines,

Epoxy resin, polyvinyl alkyl ether, cumarone-indene resin, polyterpene, xylene resin, rosin-based resin and hydrogenated products thereof, rosin-modified maleic resin, vinylpyrrolidone-vinyl acetate copolymer, polymethacrylic acid ester And polyacrylic acid-polymethacrylic acid copolymers, polyoxyethylene and phenolic resins. These resins can be used alone or as a mixture. The amount used is preferably 5 to 50% by weight based on the total amount of the oil-based ink composition for a ballpoint pen. Other additives such as a lubricant and a surfactant can be used as needed. Other additives such as a lubricant and a surfactant can be used as needed.

For the preparation of the present oil-based ballpoint pen ink, a conventionally known method for producing an ink composition can be applied.
In other words, the solvent-soluble components can be obtained by dissolving each component with a stirring and mixing machine to obtain an oil-based ink composition for a ball-point pen, and dispersing the pigment with a dispersing agent and other components using a dispersion and mixing machine, and then adding the necessary components. By mixing, an oil-based ink composition for a ballpoint pen or the like can be obtained. At the time of production, heating for dissolving solids such as dyes, and use of a filter or centrifugal separation for removing coarse particles such as organic pigments can be used as necessary.

[0039]

EXAMPLES The present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples of the present invention, but the present invention is not limited by the Examples. An oil-based ballpoint pen ink comprising a combination of an oil-soluble dye, various organic pigment particles, an organic solvent, a resin and a lubricant was produced by the following production method. In the production of the ink, the organic pigment is first dispersed with a resin as a dispersant, and is usually dispersed using a well-known method, such as a ball mill or a three roll.
After transferring it to a container equipped with a reflux condenser and a stirrer, the other components were charged, and the mixture was stirred at 60 ° C. for 10 hours. The oil-based ink compositions of Comparative Examples 1 and 2 were prepared. The numerical values of the compositions in Table 1 indicate parts by weight. The viscosity of the ink was measured using a cone-plate viscometer (TV-2, manufactured by Tokimec Co., Ltd.).
0 type).

[0040]

[Table 1]

Each of the inks for oil-based ballpoint pens prepared in the above Examples and Comparative Examples was filled into a polypropylene tube and a refill having a stainless steel tip (ball is a super-steel alloy, having a diameter of 0.7 mm), and then filled with commercially available Mitsubishi pencil. Assembled on the shaft of SA-R manufactured by Co., Ltd. and finished to an oil-based ballpoint pen. The following brush test was conducted using these refills or oil-based ballpoint pens, and the results are shown in Table 2.

<Brush Feeling Test> An oil-based ballpoint pen and writing paper were left in an environmental test room at 5 ° C. for one day, and then “Mitsubishi Pencil” was written by hand at 5 ° C., and the written state was judged. In the same manner, leave in advance at 35 ° C. and 80% humidity, and then manually write “Mitsubishi Pencil” at 35 ° C. and 80% humidity,
It was determined in the written state.

[0043]

[Table 2]

[0044]

The oil-based ballpoint pen ink of the present invention has a composition of 35
By maintaining a viscosity of 2,000 mPa · s or more at a shear rate of 2 sec ⁻¹ at a viscosity of ° C., lubricity in a high-temperature environment is maintained. Also 5
By setting the ratio of the viscosity value between 35 ° C. and 35 ° C. to 35 or less, the brush feel in a low-temperature environment is not much different from other temperature conditions such as 35 ° C. As described above, the organic pigment has an excellent low-temperature viscosity increase prevention effect, has a reflected light in a region substantially similar to the writing line, and functions as a part of the coloring agent, so that the oily pigment which requires a high concentration of the coloring agent is required. It is advantageous in ballpoint pens. Therefore, under a high temperature such as outside of summer, a smooth writing taste is maintained. Also, when writing under low temperature conditions such as outside of winter and when there is a lot of ingress and egress between high temperature and room temperature, the viscosity does not easily change depending on the outside air temperature. And
In addition, it exhibits excellent effects such as writing with little change in writing feeling.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Morita 1091 Tateishi, Fujioka-shi, Gunma Mitsubishi Pencil Co., Ltd. Inside Gunma R & D Center (72) Kyoko Kobayashi 1091 Tateishi, Fujioka-shi, Gunma Mitsubishi Pencil Co., Ltd. F term in development center (reference) 4J039 AD07 BC10 BC11 BC14 BC15 BC25 BC69 BC73 BE01 BE02 BE07 CA04 CA07 DA01 EA42 EA48 GA27

Claims (3)

[Claims] 1. An ink containing at least an oil-soluble dye, a resin and an organic solvent, and further containing an organic pigment, wherein the viscosity of the ink at 35 ° C. is 2000 mPa · s or more at a shear rate of 2 s ⁻¹ and the viscosity at 5 ° C. and 35 ° C. An oil-based ballpoint pen ink having a ratio of 35 or less. 2. The method according to claim 1, wherein the amount of the organic pigment is 1 to 1 with respect to the total amount of the ink.
2. The ballpoint pen ink according to claim 1, comprising 20% by weight. 3. The ball-point pen ink according to claim 1, wherein the organic pigment has an average particle diameter of 100 nm to 400 nm, is not dissolved in the ink, becomes fine particles, and is dispersed in the polyvinyl butyral resin. .