JP2004314629A - Ball-point pen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball-point pen which enables the ink follower to accomplish the function following the ink in matching with the ink-decreasing due to the ink-discharging while enabling the smooth writing regardless of the ball diameter and writing-speed, and which has an ink-following property for allowing use of ink until total exhaustion by scraping the ink the ink on the wall surface of ink-holding tube . <P>SOLUTION: The ball-point pen in which the ink-holding tube is directly filled with ink and the ink-follower in, is characterised in that the relationship between the shear rate and shear stress for both the above ink and ink follower is approximated with the correlation coefficient of 0.9 or higher against the flow equation of Power Law represented by the formula (1), wherein, the shear thinning viscosity index n<SB>1</SB>of the ink and the shear thinning viscosity index n<SB>2</SB>of the ink follower are specified as, n<SB>1</SB><n<SB>2</SB><1, and also the difference between n<SB>1</SB>and n<SB>2</SB>is 0.2 or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is arranged in the ink storage section so as to contact the ink and the tail end interface of the ink and move while following the ink with the movement of the interface due to the consumption of the ink, and to function as a lid. The present invention relates to a ballpoint pen in which an ink follower is directly filled in a free state without using an ink holding member such as a fiber converging body.

  There is known a ballpoint pen in which ink and an ink follower are directly filled in an ink storage tube having a ballpoint pen tip attached to one end. In recent years, pigments have been used as colorants for good smoothness of writing and fastness of handwriting, and water and water-soluble organic solvents have been used as dispersion media for these pigments. There has been proposed a ballpoint pen ink.

  In particular, in the ink for ballpoint pens, as a type that stores the ink in the ink tank in a free state, it has a relatively high viscosity when not writing, thereby restricting the movement of the ink to suppress ink leakage and the incorporation of bubbles, There is also known an ink which suppresses pigment sedimentation when the coloring material is a pigment, and imparts a shear-thinning viscosity in which the viscosity is reduced by the shearing stress of a rotating ball during writing to smoothly discharge the ink.

The ink composition imparted with such a shear-thinning viscosity has a drawback that, when an ink of several thousand mPa · s is used, the ink penetrates poorly on the writing surface, causing cracks and breaks in lines and several mPa · s. In order to solve the drawback that the ink is used and the structure becomes complicated due to the necessity of the ink storage portion and the ink conductor, attention has been paid to this.
However, since the viscosity of such an ink is as low as several mPa · s to several thousand mPa · s, the ink leaks out when left upward or sideways. Further, if a shock or the like is applied, the ink may be scattered and the hands and clothes may be stained. Therefore, a follower is provided to prevent this.

  It is desired that the ink follower has a stable followability irrespective of the ball diameter and the writing speed, in addition to the leakage prevention property and the volatilization prevention property. Even if leakage prevention and volatilization prevention are provided as ink followers, if there is no stable ink followability, the ink followers will hinder ink ejection, and will be blurred when writing due to insufficient ink ejection, making writing impossible It does not function as a ballpoint pen. Also, if there is no stable ink follow-up, the ink follower will sneak into the ink, and the ink will follow the inside of the ink container tube, and the ink follower will be inside the ink container. When viewed from above, even though it appears that there is ink, a state occurs in which no ink is present inside the ink, and there is also a problem that the depletion of ink is not clear. In order to provide such ink followability, a silicone oil is used as a base oil and one or more fatty acid amides are added (Patent Document 1), and an ink follower is added with synthetic mica (Patent Document 2). Has been proposed.

In some cases, the physical properties of the ink follower are limited in order to prevent the follower of the ink follower or the base material of the ink follower from separating with time and transferring oil to the ink side. A patent is disclosed in which tan δ at an angular frequency of 0.1 to 650 rad / sec is limited to 0.1 to 2.0 (Patent Document 3). Separately, the viscosity measurement results at any two or more points in the shear rate range of the physical properties of the ink follower from ¹ to 200 sec ^-1 are calculated by the following viscosity equation S = μD ⁿ (where S is the viscosity , D is a shear rate, μ is a non-Newtonian viscosity coefficient, and n is a non-Newtonian viscosity index. (Patent Document 4) is also disclosed.

JP 2001-347788 A JP 2000-177287 A JP-A-2001-353993 JP 2000-168291 A

  However, when using thickeners and additives, the physical properties of the ink follower may change due to variations in the thickeners and materials, and differences in the compounding method. sell. In addition, limiting the physical properties can minimize the change in physical properties due to variations in materials and compounding methods, etc., but all of these disclosures are physical limitations only for the ink follower, and depending on the combination with the ink, The ink follower can no longer follow the ink interface as the amount of ink in writing decreases, causing negative pressure in the ink storage tube, poor ink discharge from the pen tip due to air mixing in the ink storage tube, and remaining ink. The problem that it becomes difficult to visually confirm the image occurs.

  In view of the above problems, the ink follower of the present invention has a function of following the ink in accordance with the reduction of ink due to ink discharge in writing, as well as the original purpose of preventing leakage and volatilization of the ink follower. It is an object of the present invention to provide a ballpoint pen that can write well irrespective of the ball diameter and writing speed, does not leave ink on the wall surface of the ink storage tube, and has a clear ink follow-up property with clear use-up of ink.

That is, according to the present invention, in a ballpoint pen in which ink and an ink follower are directly filled in an ink storage tube, the relationship of the shear stress to the shear rate of the ink and the ink follower is represented by the following Equation (1). is approximated by the correlation coefficient 0.90 or more with respect to the equations, the shear thinning index _{n 2} of the shear thinning index _{n 1} and the ink follower of the _ink, as well as a n 1 _<n 2 <1, and _{n 1} the difference between n ₂ is ballpoint is 0.2 or less.

  The correlation coefficient is a value representing the ratio of the product of the covariance and the respective standard deviation of a two-dimensional random variable (see JIS Z 8101-1 (1999)). In this case, the coefficient indicates a coefficient derived from the shear stress and the shear rate by numerical conversion or the like, and indicates an approximation to the Power Law flow equation. The relationship between the shear stress of the ink and the shear rate of the ink follower is preferably approximated by a correlation coefficient of 0.9 or more with respect to the Power Law flow equation represented by the following (Equation 1). It is preferable that the correlation equation is approximately 0.95 or more with respect to the Power Law flow equation.

  The above-mentioned shear thinning index is one of indices indicating the shear thinning (non-Newtonian viscosity). The shear thinning (non-Newtonian viscosity) is a phenomenon in which the fluidity temporarily increases, that is, the viscosity decreases when shearing and flowing. When the value of the shear thinning index is 1, the viscosity is constant regardless of the shear rate, and is called Newtonian fluid. As the value of the shear thinning index departs from 1, the viscosity according to the shear rate changes. A substance having a shear thinning index value of more than 1 is generally called a dilatant fluid, and a substance having a shear thinning index value of less than 1 is called a non-Newtonian viscous fluid.

With respect to the ink used for the ballpoint pen, a shearing stress is applied to the ink by rotation of a ball that partially protrudes from the tip of the ballpoint pen tip. Due to the shear stress, the viscosity of the ink decreases, the ink easily flows, the ink flows out due to the head pressure, and the ink interface also advances. If the interface between the ink and the ink follower is in close contact, the force of the ink spill will also pull the ink follower, causing shear stress, and the ink follower will also temporarily decrease in viscosity, increase fluidity and follow the ink It is thought that. In addition, in the case of assisting ink writing by applying pressure such as applying a gas having a pressure higher than the atmospheric pressure behind the ink interface and pushing out the ink, not only the shear stress due to the rotation of the ball, but also the pressure The principle that the viscosity of the ink is reduced by the shear stress only when the shear stress is applied is the same.
Therefore, since both the ink and the ink follower are non-Newtonian viscous fluids (shear thinning index (non-Newtonian viscosity index) is smaller than 1), smooth writing is possible and the function of the ink follower is maintained. .

The reason why the ink follower in the present invention performs the function of following the ink in accordance with the reduction of the ink due to the ink discharge in writing and the ink follower can stably follow the ink regardless of the pen body and the writing speed is described below. I guess.
For stable ink tracking, the ink and ink follower must be non-Newtonian viscous fluids. If the ink and the ink follower are non-Newtonian viscous fluids, even if the shear stress on the wall surface is large due to the resistance to the wall surface of the ink storage tube, the viscosity decreases at the nearest portion of the wall surface of the ink storage tube due to the shear thinning. Is estimated to be larger. It is presumed that the decrease in the viscosity of the nearest part of the wall surface of the ink storage tube increases the uniformity of the velocity distribution in the ink storage tube, so that the ink can be moved while maintaining the interface between the ink and the ink follower.
On the other hand, when the ink or the ink follower is Newtonian fluid or dilatant fluid, the flow velocity at the wall portion decreases due to the resistance to the wall surface of the ink storage tube, and the velocity distribution inside the ink storage tube is maximized at the center portion of the ink storage tube. Therefore, the difference between the shear rate and the center position of the ink storage tube becomes large. Then, the ink follower sneaks into the ink, which causes problems such as unclear use-up of the ink.

In addition, since the difference in the shear thinning index between the ink and the ink follower is small, the difference in the shear rate between the ink and the ink follower on the wall surface of the ink storage tube can be kept small. It is considered that the ink moves smoothly without hindering the movement of the ink in a state of being in close contact without applying excessive force.
Further, by setting the shear thinning index of the ink follower to be larger than the shear thinning index of the ink, the ink can be stored in the ink under the shear stress at the time of writing while the interface between the ink and the ink follower is in close contact. The shear speed of the ink storage tube wall of the ink follower can be made smaller than the shear speed of the tube wall surface, and the ink moves out depending on the shear speed of the ink follower, so that the ink follower pushes out the ink. It is presumed that stable ink following becomes possible without leaving ink on the wall surface of the ink storage tube.

The ballpoint pen is preferably a ballpoint pen using a ballpoint pen tip as a pen tip, an ink having shear thinning viscosity, and an ink follower. The ink storage portion to which these pen tips are attached is disposed inside a pipe-like material or a case-like material formed of a synthetic resin such as polypropylene. Further, in the ink storage section, the other end of the pen tip mounting section is opened or a tail plug having an air hole is provided. Further, it is effective to press the ink by pressure to assist the ejection of the ink by applying compressed air into the ink tank, for example, because there is an advantage that the writing surface is not selected and it is effective. Examples thereof include an applicator such as a shear-thinning ink ball-point pen and a correction liquid using a ball-point pen tip at the pen tip.
Assuming that the ink and the ink follower to be filled are not compatible with each other, the viscosity of the ink and the ink follower is reduced by adjusting the viscosity modifier, the gelling agent, or the thickener. relationship shear stress against rate is approximated by the correlation coefficient 0.90 or more with respect to the flow equations Power Law companding together represented by equation (1), shear shear thinning index n ₁ and the ink follower in the ink thinning and exponent _{n 2,} together with an n 1 _<n 2 <1, the difference between _{n 1} and _{n 2} is required to be 0.2 or less.

  As the substrate of the ink follower, a known substrate for an ink backflow preventive, which is conventionally used, can be used. However, since the ink backflow preventer is filled in the ink storage tube so as to be in direct contact with the ink, it must not chemically react with the ink and is unlikely to be dissolved or mixed and suspended. An oil-based or hydrophobic base material is used for the ink follower fluid for the ink, and an aqueous base material is used for the oil-based ink. Further, in order to prevent the positions of the ink and the ink backflow preventer from being reversed due to buoyancy caused by the difference in specific gravity between the ink and the ink backflow preventive, it is preferable that the specific gravity difference between the ink and the ink backflow preventive is small. The specific gravity is important as a criterion for selecting a base material for preventing the positions of the ink and the ink backflow preventer from being reversed.

  From these facts, as a fluid that can be used as a base material of the ink follower fluid, in the case of an aqueous ink or an oil-based ink using an alcohol-based or glycol-based solvent, specifically, di-2-ethylhexyl phthalate (specific gravity of 0.1 to 0.2) is used. 99), phthalates such as dibutyl phthalate (specific gravity 1.05), phosphates such as tricresyl phosphate (specific gravity 1.175), di-2-ethylhexyl adipate (specific gravity 0.93) and isodecyl adipate Adipates such as (specific gravity 0.92), sebacates such as di-2-ethylhexyl sebacate (specific gravity 0.92), trimellitates such as tri-2-ethylhexyl trimellitate (specific gravity 0.99) , Triethyl citrate (specific gravity 1.14) and acetyl tributyl citrate Citrate esters such as specific gravity 1.04), epoxidized vegetable oils such as epoxidized soybean oil (specific gravity 0.99) and epoxidized linseed oil (specific gravity 1.04), and epoxidized fatty acid esters (specific gravity 0.92 to 0.97) ) And polyester plasticizers (specific gravity 1.02 to 1.12). In addition, polybutene (specific gravity 0.82 to 0.90), polybutadiene (specific gravity 0.90), liquid paraffin (specific gravity 0.85 to 0.90), α-olefin oligomer (specific gravity 0.82 to 0.85), etc. Examples of the liquid oligomer and liquid rubber include polydimethyl silicone (specific gravity 0.75 to 1.00), polyether-modified silicon (specific gravity 1.00 to 1.10), and fluorine-modified silicon (specific gravity 1.25 to 1.30). ) And mineral oils such as paraffinic, naphthenic and aroma-based process oils (specific gravity 0.85 to 1.05) and extender oils, vegetable oils, polyoxyethylene hydrogenated castor oils, and petrolatum oils and fats Phosphalol NF46 (specific gravity 1.76), NF68 (specific gravity 1.78), NF100 (specific gravity 1.79) ( And fluoroalkoxycyclotriphosphazenes such as those manufactured by Otsuka Chemical Co., Ltd., and empara K43 (chlorine content 42 to 44%, specific gravity 1.12 to 1.15) and K45 (chlorine content 44 to 46). %, Specific gravity 1.15 to 1.18), K47 (chlorine content 47 to 49%, specific gravity 1.19 to 1.22), K50 (chlorine content 50 to 52%, specific gravity 1.23 to 1) .26) (both manufactured by Ajinomoto Co., Inc.). In the case of an ink using a hydrocarbon solvent having a small polarity, a solvent having a large polarity is used. Specifically, in addition to water, polypolar alcohols having high polarities such as ethylene glycol, propylene glycol, glycerin, glycerin monoacetate, diethylene glycol, tetraethylene glycol, trimethylolethane, trimethylolpropane, 1,3-butanediol, , 4-butanediol, 1,4-butenediol, polypropylene glycol, polyethylene glycol and the like can be used. These can be used alone or as a mixture. These can be used alone or in combination of two or more.

  As the gelling agent and / or thickening agent for the ink follower fluid in the present invention, conventionally known ones can be used. As a specific example, when a low-polarity solvent is used for the base material of the follower fluid, Aerosil R972, R974, and 200 (made by Nippon Aerosil Co., Ltd.) made of fine particle silica, and Disparon A670- made of fatty acid amide are used. Cellulose-based materials such as 20M and 6900-20X (all manufactured by Kusumoto Kasei Co., Ltd.) and Thoroid (manufactured by Sansei Co., Ltd.), as well as metal soaps, bentonite, and dextrin can be used. Guar gum, hydroxypropylated guar gum, carboxymethyl hydroxypropylated guar gum, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, xanthan gum, welan gum, ramzan gum, gellan gum, alginic acid, alginic acid Water-soluble polysaccharides, such as oda, ammonium alginate, potassium alginate, propylene glycol alginate, locust bean gum, tamarind gum, gum arabic, tragacanth gum, karaya gum, carrageenan, succinoglucan, polyacrylic acid, polyvinyl alcohol, polyethylene oxide, Synthetic polymers such as polyvinylpyrrolidone, alkyl acrylate / acrylamide copolymers, N-vinylacetamide co-crosslinked products, and viscous minerals such as smectite can be added. These can be used alone or in combination of two or more. Can be used. It is considered that the structure of such a gelling agent can be strengthened by simply adding a large amount of the gelling agent. May not be possible. Preferably, the total weight% of the gelling agent is from 3% by weight to 7% by weight.

  In addition, sorbitan fatty acid esters and glycerin fatty acid esters are used to prevent ink adhesion to the inner wall of the ink storage tube, methacrylate copolymers are used to prevent low writability at low temperatures, and various other additives are appropriately used. It can be used as needed. In addition, a float that stabilizes the interface shape of the backflow prevention body by immersing all or part of the backflow prevention body in the state of being placed at the interface of the ink used in the form of the writing instrument can also be provided.

  When water is used as the base material, an appropriate amount of an antiseptic / antifungal agent such as sodium dehydroacetate, 1,2-benzothiazolin-3-one, and sodium benzoate can be added to prevent mold generation of the ink follower fluid. . In addition, in the case of a material that easily evaporates, such as water, a non-volatile and / or hardly volatile organic solvent which is insoluble and / or hardly soluble in the base material, or a material obtained by adjusting the viscosity thereof, A molded article such as synthetic rubber, elastomer, or plastic having elasticity may be used as a floating body at the rear end interface of the follower fluid.

  In producing the ink follower fluid of the present invention, various conventionally known methods can be employed. For example, it can be easily obtained by heating and mixing (90 to 160 ° C.) the above components with a stirrer, or can be easily obtained by dissolving and dispersing with a propeller stirrer or the like.

  Calculation of each constant of the flow equation in the present invention, the value of the viscosity at the time of changing the rotation speed by three or more points using a normal rotational viscometer, if the correlation coefficient is 0.90 or more, It can be calculated by fitting to the Power Law flow equation, or by calculating a flow curve using a rheometer for measuring a viscoelastic fluid.

  Inks are used for the purpose of forming an image on a recording medium such as paper, and include ink in which a solute coloring material is dissolved in a solvent and ink in which a dispersoid coloring material is dispersed in a dispersion medium. Water-soluble and oil-soluble dyes are known as solute coloring materials, and organic and inorganic pigments are known as dispersoid coloring materials. As the dye, any of a water-soluble acid dye, a direct dye, a basic dye and the like can be used, and specific examples thereof include Japananol Fast Black D Conc (CI Direct Black 17) and 100 L of water black. (19), Water Black L-200 (19), Direct Fast Black B (22), Direct Fast Black AB (32), Direct Deep Black EX (38), Direct Fast Black Conc (51) ), Kayalas Sprague VGN (71), Kayalas Direct Brilliant Yellow G (CI Direct Yellow 4), Direct Fast Yellow 5GL (26), Eizen Primula Yellow GCLH (44), Direct Fast Yellow R (Id. 50), Aizendaire Tofast Red FH (CI Direct Red 1), Nippon Fast Scarlet GSX (4), Direct Fast Scarlet 4BS (23), Eisen Direct Loadurin 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), Kayaras Sprulbin BL (83), Kayara Light Red F5G (225), Kayasu Light Red F5B (226), Kayasu Light Rose FR (227), Direct Sky Blue 6B (CI Direct Blue 1), Direct Sky Blue 5B (15), Sumilite Supra Blue BRR Nuku (71), Daibogen Turquoise Blue S (86), Water Blue # 3 (86), Kayara Star Koizu Blue GL (86), Kayasu Supra Blue FF2GL (106), Kayaras Splatter Turquoise Blue Direct dyes such as FBL (199), Acid Blue Black 10B (CI Acid Black 1), Nigrosine (2), Suminol Milling Black 8BX (24), and Kayanol Milling Black VLG (26) , Suminol Fast Black BR Conc (31), Mitsui Nylon Black GL (52), Aizen Opal Black WH Extra Conc (52), Sumilan Black WA (52), Ranyl Black BG Extra Conc (107) , Kayanol Milling Black TLB (1 09), Suminol Milling Black B (109), Kayanol Milling Black TLR (110), Eisen Opal Black New Conc (119), Water Black 187-L (154), Kayaqua Acid Brilliant Flavin FF (C) . I. Acid Yellow 7: 1), Kayasil Yellow GG (17), Xylene Light Yellow 2G 140% (17), Suminol Leveling Yellow NR (19), Daiwa Trazine (23), Kayaktor Trazine (23) Suminol Fast Yellow R (25), 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 (72), Suminol Fast Yellow G (61), Suminol Milling Yellow G (78), Kayanol Yellow N5G (110), Suminol Milling Yellow 4G 200% (141), Kayanol Yellow NG (135), Kayano Lumiling Yellow 5GW (127), Kayanol Milling Yellow 6GW (142), Sumitomo Fast Scarlet A (CI Acid Red 8), Kayak Silk Scarlet (9), Solar Rubin Extra (14), Daiwa New Koksin (18), Aizen Bonsaw RH (26), Daiwa Red No. 2 (27), Suminol Leveling Brilliant Red S3B (35), Kayasil Rubinol 3GS (37), Aizen Erythrosin (37) 51), Kayak Acid Rhodamine FB (52), Suminol Leveling Rubinol 3GP (57), Diacid Alizarin Rubinol F3G 200% (82), Eisen Eosin GH (87), Water Pink # 2 (52) 92), Eisen Acid Phloxine PB 92), Rose Bengal (94), Kayanol Milling Scarlet FGW (111), Kayanol Milling Rubin 3BW (129), Sumino All Milling Brilliant Red 3BN Conch (131), Sumino Milling Brilliant Red BS (131) 138), Eisen Opal Pink BH (186), Suminol Milling Brilliant Red B Conch (249), Kayaking Acid Brilliant Red 3BL (254), Kayaking Acid Brilliant Brilliant Red BL (265), Kayano Milling Red GW (276), Mitsui Acid Violet 6BN (CI 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 (9), Daiwa Blue No. 1 (9), Spranol Blue B (15), Orient Solble Blue OBC (22), Suminol Leveling Blue 4GL (23), Mitsui Nylon Fast Blue G (25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Safirol SE (43) , Suminol Leveling Sky Blue R Extra Conc (62), Mitsui Nylon Fast Sky Blue B (78), Sumitomobrilliant Indocyanine 6Bh / c (83), Sandran cyanine N-6B 350% (90), water Blue # 115 (90), Orient Soluble Blue OBB The same 93), Sumitomo brilliant blue 5G (the 103), Kaya Nord milling Ultra Sky SE (the 112), Kaya Nord milling cyanine 5R (the 113), Aizen Opal Blue 2GLH (the 158), Daiwa Guinea green B (C. I. Acid dyes such as Acid Green 3), Acid Brilliant Milling Green B (9), Daiwa Green # 70 (16), Kayanol Cyanine Green G (25), Suminol Milling Green G (27), and Aizenkachi Ron Yellow 3GLH (C.I. Basic Yellow 11), Eisenka Chiron Brilliant Yellow 5GLH (13), Sumiacryl Yellow E-3RD (15), Maxillon Yellow 2RL (19), Astrazon Yellow 7GLL (11) 21), Kayacryl Golden Yellow GL-ED (28), Astrazon Yellow 5GL (51), Eizen Katilon Orange GLH (CI Basic Orange 21), Eizen Katilon Brown 3GLH (30), Rhodamine 6 GCP (C.I. Black Red 1), Eizen Astra Phloxine (12), Sumiacryl Brilliant Red E-2B (15), Astrazon Red GTL (18), Eizen Chiron Brilliant Pink BGH (27), Maxilon Red GRL (17) 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 (41), Aizen Katilon Blue BRLH (54), Aizen Diamond Green GH (CI Basic Green 1), Aizen Malachite Green (4) ), Bismarck Blau G include basic dye (C.I. Basic Brown 1) and the like. Examples of oil-soluble dyes include rhodamine B base (C.I. 45170B), solderan red 3R (C.I. 21260), methyl violet 2B base (C.I. 42535B), and Victoria blue F4R (C.I. 42563B). Nigrosine Base LK (CI. 50415), Balifast Yellow # 3104 (CI. 13900A), Balifast Yellow # 3105 (CI. 18690), Orient Spirit Black AB (CI. 50415), Balifast Black # 3804 (CI. 12195), Balifast Yellow # 1109, Balifast Orange # 2210, Balifast Red # 1320, Balifast Blue # 1605, Balifast Violet # 1701, Spiron Black GMH Special, SPIRON yellow C-2GH, Spiron Red C-GH, Spiron Red C-BH, Spiron Blue BPNH, Spiron Blue C-RH, SPIRON Violet C-RH, S. P. T. Orange 6, s. P. T. Blue-111 and the like.

  Pigments include organic pigments such as azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acid dye pigments, vat dye pigments, mordant dye pigments, and natural dye pigments, loess, and barium. Inorganic pigments such as yellow, dark blue, cadmium red, barium sulfate, titanium oxide, red iron oxide, iron black, carbon black and the like can be mentioned, and these can be used alone or in combination. Specific examples include TITONE SR-1, 650, R62N, R3L, and R7E (all manufactured by Sakai Chemical Industry Co., Ltd.), Kronos KR-310, KR-380, and 480 (all manufactured by titanium Kogyo Co., Ltd.), Thai Pure R-900, R-602, R-960, R-931 (all manufactured by DuPont Japan, Limited), TITANIX JR301, JR805, JR602, JR701, JR800 Titanium oxide such as (manufactured by Teica Co., Ltd.), Special Black 6, S170, S610, 5, 4, 4A, 550, 35, 250, 100, Printex 150T, U , V, 140U, 140V, 95, 90, 85, 80, 75, 55, 45, P, XE2, L , L, 300, 30, 30, 35, 25, 200, A, G (all manufactured by Degussa Japan KK), # 2400, # 2350, # 2300, # 2200B , # 1000, # 950, # 900, # 850, # MCF88, MA600, MA100, MA7, MA11, # 50, # 52, # 45, # 44, # 40, # 33, # 32, # 30, CF9, # 20B, # 4000B (Mitsubishi Chemical Industries, Ltd.), MONARCH 1300, 1100, 1000, 900, 880, 800, 700, MOGUL L, REGAL 400R, 660R, 500R, 330R, 300R, 99R, ELFTEX 8, 12 and BLACK PEARLS 2000 (all manufactured by Cabot Co. LTD, USA), RA VEN7000, 5750, 5250, 5000, 3500, 2000, 1500, 1255, 1250, 1200, 1170, 1060, 1040, 1035, 1020, 1000, 890H, Same 890, Same 850, Same 790, Same 780, Same 760, Same 500, Same 450, Same 430, Same 420, Same 410, Same 22, Same 16, Same 14, Same 825 Oil Beads, Same H20, Same C, Conductex Carbon blacks such as 975, 900, and SC (all manufactured by Colombian Carbon Japan Co., Ltd.), BS-605 and BS-607 (all manufactured by Toyo Aluminum Co., Ltd.), bronze powders P-555, and P- 777 (above, manufactured by Nakajima Metal Foil Industry Co., Ltd.), bronze powder 3L5, 3L7 (above, Fukuda Metal Foil Industry) And inorganic pigments such as black iron oxide, low-order titanium oxide, yellow iron oxide, red iron oxide, ultramarine, navy blue, cobalt blue, chrome green, and chromium oxide, and Hansa Yellow. 10G, 5G, 3G, 4, 4, GR, A, Benzidine Yellow, Permanent Yellow NCG, Tartrazine Lake, Quinoline Yellow, Sudan 1, Permanent Orange, Indus Ren Brilliant Orange GN, Permanent Brown FG, Para Brown, Permanent Red 4R, Fire Red, Brilliant Carmine BS, Pyrazon Red, Lake Red C, Quinacridone Red, Brilliant Carmine 6B, Bordeaux 5B, Thioindigo Red, Fast Violet B, Dioxazine Violet, Alkaline Blue Lake, Lid Cyanine blue, indigo, acid green lake, and organic pigments such as phthalocyanine green and the like. In addition, inorganic fluorescent pigments such as zinc sulfide, zinc silicate, zinc cadmium sulfate, calcium sulfide, strontium sulfate, and calcium tungstate can be used.

  When a pigment is used, an aqueous ink base dispersed in an aqueous medium can be used. Specifically, Fuji SP Black 8031, 8119, 8167, 8276, 8381, 8406, 8SP, Fuji SP Red 5096, 5111, 5193, 5220, Fuji SP Bordeaux 5500, Fuji SP Blue 6062, 6133, 6134, 6401, Fuji SP Green 7051, Fuji SP Yellow 4060, 4178, Fuji SP Violet 9011, Fuji SP Pink 9524, 9527, Fuji SP Orange 534, FUJI SP, FUJI SP 5544 (all manufactured by Fuji Dye Co., Ltd.), Emacol Black CN, Emacol Blue FBB, and Femacol Blue FBB KR, Emacol Green LXB, Emacol Violet BL, Emacol Brown 3101, Emacol Carmine FB, EmacolRed BS, Emacol Orange R, Emacol Yellow FD, FN, FN, FN, GN, FN , 10GN, 10G, Sandy Super Black K, C, Sandye Super Gray B, Sandye Super Brown SB, FRL, RR, Sandy Super Green Green, 5GB, and LGB, LGB and LGXB FBL-H, FBL-160, FBB, SandySuper Violet BL H / C, BL, Sandy Super Bordeaux FR, Sandy Super Pink FBL, F5B, Sandy Super Rubine FR, Sandy super Carmine FB, Sandy Super Rumbo FB, Sandy Super Rumbo FB, Sandy Super Rum Same BO, Sandye Gold Yellow 5GR, Same R, Same 3R, Sameday Ywllow GG, Same F3R, Same IRC, Same FGN, Same GN, Same GRS, Same GSR-130, Same GSN-130, Same GSN, Same 10GN (more , Sanyo Dyeing Co., Ltd.), Rio Fast Black Fx 8012, 8313, 8169, Rio Fast Red Fx 8209, 81 2, Rio Fast Red S Fx 8315, 8316, Rio Fast Blue FX 8170, Rio Fast Blue FX 8170, Rio Fast Blue S FX 8312, Rio Fast Green S / F, and more. , 2102, 2103, 2104, 2105, 2106, 2107, 2108, 2117, 2127, 2137, 2167, 2101P, 2102P, 2103P, 2104P, 2105P, 2105 2106P, 2107P, 2108P, 2117P, 2127P, 2137P, 2167P, NKW-3002, 3003, 3004, 3005, 3007, 3077, 3008 3402, 3404, 3405, 3407, 3408, 3377, 3602, 3603, 3604, 3605, 3607, 3677, 3608, 3702, 3703, 3704, 3705 3777, 3708, 6013, 6038, and 6559 (all manufactured by Nippon Fluorescence Co., Ltd.), Cosmocolor S 1000F series (manufactured by Toyo Soda Co., Ltd.), Victoria Yellow G-11, and G-20 , Victoria Orange G-16, Victoria G-21, Victoria Red G-19, Victoria G-22, Victoria Pink G-17, Victoria G-23, Victoria Green G-18, Victoria G-24, Victoria Blue G-15 G-25 (above, manufactured by Mikuni Dyestuffs Co., Ltd.), Pollux PC5T1020, Pollux Black PC8 Examples include Pollux series such as T135 and Poluc thread IT1030 (all manufactured by Sumika Color Co., Ltd.), and these can be used alone or in combination of two or more.

  When a pigment is used as the colorant, a dispersant may be used to stably disperse the pigment. As the dispersant, a water-soluble resin or a water-soluble resin conventionally used generally, or a dispersant used as a pigment dispersant such as an anionic or nonionic surfactant can be used. As an example, as a polymer dispersant, natural polymers such as lignin sulfonate and shellac, polyacrylate, salt of styrene-acrylic acid copolymer, salt of vinylnaphthalene-maleic acid copolymer, β-naphthalene Examples include anionic polymers such as sodium salts and phosphates of sulfonic acid formalin condensates, and nonionic polymers such as polyvinyl alcohol and polyethylene glycol. As surfactants, alkyl sulfates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids and salts thereof, N-acylmethyl taurine salts, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylates, α- Anionic surfactants such as olefin sulfonates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, and nonionics such as polyoxyethylene alkyl ethers, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters Surfactants.

  Various polymer compounds can be used to impart shear thinning viscosity or adjust viscosity to the ink. For example, as cross-linked polyacrylic acid, Rheogic 250H (manufactured by Nippon Pure Chemical Co., Ltd.), Junron PW111 (manufactured by Nippon Pure Chemical Co., Ltd.), U Jeri CP (manufactured by Showa Denko KK), Carbopol 934, 940, 941, 980, 981, 1342, 1382, 2984, 5984, ETD2020, ETD2050, EZ-1 (manufactured by BF Goodrich), and the like. Pemulen TR-1, TR-2 (manufactured by BF Goodrich) and the like as alkyl methacrylate acrylate copolymers; and Bengel W-200U, W-300U and W-300 as clay minerals such as bentonite. HPC-SL, L, M, and H (all manufactured by Nippon Soda Co., Ltd.), Avicel PH-101, Celluloses such as 301, M06, and TG-101 (all manufactured by Asahi Kasei Corporation), Kelzan, Kelzan S, Kelzan F, Kelzan AR, Kelzan M, and Kelzan D (all manufactured by Sansei Corporation); Xanthan gum such as kojin, kojin F, kojin T, kojin K (all manufactured by Kojin Co., Ltd.) and ultra xanthan (manufactured by Ina Food Industry Co., Ltd.), leozan (sancho ( )), Welan gum such as K1A96 (manufactured by Sansho), ramzan gum such as K1A112, K7C2433 (manufactured by Sansho), Jaguar 8111, 8600, HP-8, HP Guar gums such as -60, CP-13 (manufactured by Sansho Co., Ltd.), water-soluble polysaccharides such as pullulan (manufactured by Hayashibara Shoji), GX-205, NA-010 (manufactured by Showa Denko KK) ), Water-soluble synthetic polymers such as N-vinylacetamide polymerized cross-linked products, smecton SA (smectite, manufactured by Kunimine Kogyo Co., Ltd.), Kunipia-F, kunipia-G (Montmorillonite, manufactured by Kunimine Kogyo Co., Ltd.), Wengel HV, FW, 15, 23 (Bentonite, manufactured by Toyo Jun Yoko Co., Ltd.), Esven, C, W, N400 (quaternary ammonium cation modified Montmorillo Dispalon A670-20M (active ingredient 20%), 6900-20X (active ingredient 20%) composed of inorganic clay minerals such as Ito and Toyshun Yoko, and fatty acid amide (all manufactured by Kusumoto Kasei Co., Ltd.) ), Aerosil R972, R974 and 200 made of fine particle silica, polyvinylpyrrolidone, polyethylene oxide, N-vinylacetamide, ethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

  As a medium for dissolving or dispersing these colorants, various water-soluble organic solvents other than water are used for the purpose of preventing drying of the ink and freezing at low temperatures. Specifically, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, 2-pyrrolidone and the like can be used. In non-aqueous systems, organic solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, and propylene glycol monomethyl Ether, propylene glycol monoethyl ether, propylene glycol mononormal butyl ether, propylene glycol mononormal propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mononormal propyl ether, dipropy Glycol ether solvents such as ethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, and tripropylene glycol monobutyl ether, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, and polyethylene glycol Glycol solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, 2-ethylhexyl acetate, isobutyl isobutyrate, ethyl lactate, n-lactic acid-n- Ester solvents such as butyl, benzyl alcohol, β-phenylethyl alcohol, α-methylbenzyl alcohol, lauryl alcohol, tridecyl alcohol Alcohol solvents such as coal, isododecyl alcohol, and isotridecyl alcohol can be used.Especially, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, triethylene glycol monophenyl ether, propylene glycol monophenyl ether, dipropylene Aromatic glycol ethers such as glycol monophenyl ether, tripropylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monobenzyl ether, and aromatic alcohols such as benzyl alcohol, α-methylbenzyl alcohol, and β-phenylethyl alcohol No. When the oil-based coating liquid is used as the correction liquid, it is preferable to use a low-polarity solvent which is difficult to dissolve and dissolve handwriting. Specifically, normal hexane (boiling point 68.7 ° C.), isopentane, normal heptane (boiling point 98.4 ° C.), aliphatic hydrocarbon solvents such as normal octane, cyclopentane (boiling point 49.2 ° C.), methylcyclopentane (boiling point 71.8 ° C.), cyclohexane (boiling point 80.0 ° C.), methylcyclohexane (boiling point Alicyclic hydrocarbon solvents such as ethylcyclohexane (boiling point 132 ° C.), and Exol DSP 100/140 (initial boiling point 102 ° C., dry point 138 ° C.); D40 (Initial boiling point 153 ° C, Dry point 196 ° C), D80 (Initial boiling point 204 ° C, Dry point 230 ° C), D40 (Initial boiling point 141 ° C, Dry point 172 ° C) 110 (initial boiling point 243 ° C, end point 272 ° C), D130 (initial boiling point 277 ° C, end point 310 ° C), ISOPAR C (initial boiling point 97 ° C, dry point 104 ° C), E (initial boiling point 115 ° C) G (initial boiling point 156 ° C, dry point 175 ° C), H (initial boiling point 176 ° C, dry point 192 ° C), L (initial boiling point 188 ° C, dry point 210 ° C) And M (initial boiling point: 208 ° C., dry point: 254 ° C.) (all manufactured by Exxon Chemical Co., Ltd.). These can be used alone or in combination. If a titanium oxide having a high concealing property is used as a coloring agent and a volatile solvent having a low polar hydrocarbon and a boiling point of 40 to 150 ° C. is used as a solvent, it can be used as a correction liquid.

  Various resins can also be used in combination, such as for fixing or curing the colorant on the paper surface. Specifically, shellac, a copolymer of styrene with maleic acid or an ester thereof, and an alkali metal salt, an amine salt, an ammonium salt thereof, a copolymer of styrene with acrylic acid or an ester thereof, and an alkali metal salt thereof , Same amine salt, same ammonium salt, alkali metal salt of α-methylstyrene-acrylic acid copolymer, same amine salt, same ammonium salt, acrylic resin, maleic acid resin, urea resin, polyvinyl butyral, polyvinyl acetal, polyamide resin , Epoxy resins, polyvinyl alkyl ethers, cumarone-indene resins, polyterpenes, rosin-based resins and hydrogenated products thereof, ketone resins, polyacrylic acid-polymethacrylic acid copolymers, and phenolic resins.

  In addition to the above components, various additives conventionally used in inks for writing instruments can be appropriately used as needed. For example, use of sugar alcohols such as sorbitol and xylitol to prevent ink evaporation, and polyethylene glycol, polyoxyethylene glycol polyoxypropylene glycol, and alkali metal salts and amine salts of oleic acid to improve the writing feel. A lubricant can be used.

  Furthermore, surface tension modifiers such as various anionic, nonionic and cationic surfactants, silicon surfactants and fluorine surfactants, sodium dehydroacetate, 1,2-benzoisothiazalin-3-one. And rust preventives such as benzotriazole and ethylenediaminetetraacetic acid, and alkalinizing agents such as sodium hydroxide, alkanolamine, amine and ammonium as pH adjusters.

  As a form when used as a writing implement, a form in which a ballpoint pen tip is arranged at an end of an ink storage tube is used. Transparent or semi-transparent ink storage tubes are often used to check the remaining amount of ink.For example, polyethylene and polypropylene are often used. There is also. Further, a silicon-based or fluorine-based water-repellent or oil-repellent agent can be applied to the inner surface of the ink storage tube as needed, for example, to suppress the adhesion of the ink to the inner wall. In addition, the ink storage tube may be one in which the refill is stored in a shaft cylinder as a form of a ballpoint pen refill, or the shaft cylinder is used as an ink storage tube, and the ink is directly filled in the shaft cylinder. Is also good.

  As the ballpoint pen tip, a metal tip using metal for the ball holder and a resin tip mainly using synthetic resin can be used. As a material of the ball holder using metal, generally used materials such as nickel silver, brass and stainless steel can be used. In addition, as a main material of a ball holder mainly made of a synthetic resin, a general molding resin can be used, and 100% of these synthetic resins may be used for molding. Specifically, polyacetal resin, polybutylene terephthalate resin, aromatic nylon resin, modified polyphenylene ether resin, polyacrylate resin, and the like can be used.Polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin can be used from the viewpoint of smooth writing feel and abrasion resistance. Resins are particularly preferred. Various fillers can be added to these resins for the purpose of improving lubricity, improving wear resistance, improving strength, and the like. Examples of the filler include molybdenum, potassium titanate, glass fiber, calcium carbonate, mica and the like. The amount of these fillers is preferably 30% or less. If it exceeds 40%, the filler may be unevenly formed at the time of molding and the shape of the chip may be impaired.

  As an example of the material of the ball to be held by the ball holder, a ball such as a cemented carbide mainly containing tungsten carbide, a ball mainly containing silicon carbide, and a ball mainly containing zirconia can be used. Also, in order to prevent ink from leaking from between the ball and the ball holder as a ballpoint pen, an elastic body such as a coil spring is arranged in the ball holder to urge the ball outward, The ball may be pressed.

Hereinafter, the present invention will be described in more detail based on examples.
Ink 1
Sandy Super Black C (black aqueous pigment base, Sanyo Dyeing Co., Ltd.)
30.00 parts Glycerin 16.00 parts Ethylene glycol 14.00 parts Proxel GXL (S) (preservative, manufactured by Avicia Co., Ltd.) 0.20 parts Deionized water 39.00 parts Benzotriazole 0.30 parts Pemulen TR- 1 (acrylic acid-methacrylic acid copolymer, manufactured by BF-goodrich,
0.50 parts The above components are blended and stirred with a stirrer for 2 hours, for a black ballpoint pen having a viscosity coefficient of 3.51 Pa · s and a shear thinning index of 0.439 (correlation coefficient 0.958). A water-based ink was obtained.

Ink 2
Edible Red No. 103 (Red Dye, Daiwa Kasei Co., Ltd.) 2.00 parts Edible Red No. 104 (Red Dye, Daiwa Kasei Co., Ltd.) 3.00 parts Water Yellow # 6C (Yellow Dye, Orient Co., Ltd.) 1.50 parts ethylene glycol 9.00 parts thiodiglycol 9.00 parts benzotriazole 0.30 parts oleoyl sarcosine sodium 3.00 parts Proxel GXL (S) (described above) 0.20 parts Kerzan AR (xanthan gum, three 0.40 parts 71.60 parts of ion-exchanged water The above ingredients were mixed and stirred for 2 hours with a stirrer to give a viscosity coefficient of 5.40 Pa · s and a shear thinning index of 0.446 (phase A red aqueous ink having a relational number of 0.979) was obtained.

Ink 3
Ethylene glycol 40.00 parts Glycerin 6.00 parts Sandye SuperCarmin FB (red dispersion pigment, Sanyo Dyeing Co., Ltd.)
6.00 parts WXMU75 (aluminum paste, manufactured by Toyo Aluminum Co., Ltd.) 3.00 parts Proxel GXL (S) (described above) 0.20 parts ion-exchanged water 43.00 parts Dispant EN-120A (dispersant, Toho Chemical) 1.00 part Kelzan T (thickener, xanthan gum, manufactured by Sanseki Co., Ltd.) 0.80 part The above ingredients are blended, and the mixture is stirred with a stirrer for 2 hours to have a viscosity coefficient of 7.80 Pa. S, a red aqueous ink having a shear thinning index of 0.284 (correlation coefficient 0.965) was obtained.

Ink 4
Ethylene glycol 20.00 parts Glycerin 5.00 parts Pollux Blue PC5T-1020 (blue aqueous pigment base, manufactured by Sumika Color Co., Ltd.)
20.00 parts Proxel GXL (s) (described above) 0.20 parts Ion-exchanged water 53.80 parts Carrageenan 1.00 part The above ingredients were blended and stirred with a stirrer for 2 hours to obtain a viscosity coefficient of 0.113 Pa · s. A blue ink having a shear thinning index of 0.827 (correlation coefficient of 0.918) was obtained.

Ink 5
Oil-based ink TITONE R62N (titanium oxide, manufactured by Sakai Chemical Co., Ltd.) 55.0 parts by weight Acryloid B67 (acrylic resin, manufactured by Rohm and Haas Co., Ltd.) 9.0 parts by weight Methylcyclohexane 35.0 parts by weight Homogenol L18 (polycarboxylic acid) Type polymer surfactant, manufactured by Kao Corporation)
1.0 parts by weight The above components were dispersed in a ball mill for 24 hours to give a white ink 5 having a viscosity coefficient of 27.84 Pa · s and a shear thinning index of 0.549 (correlation coefficient 0.939). Obtained.

Ink follower 1
Polybutene HV-15 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 93.50 parts Leopard KE (gelling thickener, dextrin fatty acid ester, manufactured by Chiba Flour Milling Co., Ltd.)
3.00 parts Aerosil R972 (gelling thickener, fine particle silica, manufactured by Nippon Aerosil Co., Ltd.)
3.50 parts The above components were placed in a container, and stirred for 2 hours while heating to a temperature of 120 ° C., and the viscosity coefficient was 20.74 Pa · s and the shear thinning index was 0.594 (correlation coefficient 0.969). Ink follower 1 was obtained.

Ink follower 2
Polybutene LV-50 (Polybutene, manufactured by Nippon Petrochemical Co., Ltd.) 51.00 parts Mobil SHF1003 (α-olefin oligomer, manufactured by Mobile Chemical Product Ink, USA) 40.00 parts Leopard KL (gelling thickener) , Dextrin fatty acid ester, manufactured by Chiba Flour Milling Co., Ltd.)
2.00 parts Aerosil R972 (gelling thickener, fine particle silica, manufactured by Nippon Aerosil Co., Ltd.)
5.00 parts CDIS-400 (polyethylene glycol diisostearate, manufactured by Nikko Chemicals)
2.00 parts After kneading the above components in a kneader, the mixture is heated and stirred at 100 ° C. for 1 hour, and has an viscosity coefficient of 25.4 Pa · s and a shear thinning index of 0.560 (correlation coefficient 0.978). Got follower 2.

Ink follower 3
Mobil SHF1003 (described above) 30.00 parts Lucant HC-100 (base material, ethylene-α-olefin oligomer,
50.00 parts Aerosil R972 (described above) 3.00 parts KF410 (methylstyryl-modified silicone oil, manufactured by Shin-Etsu Silicon Co., Ltd.)
1.50 parts The above components were placed in a container, and stirred for 2 hours while heating to a temperature of 160 ° C. The viscosity coefficient was 21.0 Pa · s, and the shear thinning index was 0.483 (correlation coefficient 0.968). Ink follower 3 was obtained.

Ink follower 4
Polybutene HV-15 (described above) 30.00 parts Lucant HC-100 (described above) 50.00 parts Aerosil R972 (described above) 3.00 parts GP-1 (thickener, N-lauroyl-L-glutamic acid-α, γ) 1.00 part: The above components were placed in a container, and the mixture was stirred for 2 hours while heating at a temperature of 160 ° C., and had a viscosity coefficient of 57.2 Pa · s and shear thinning. An ink follower 4 having an index of 0.305 (correlation coefficient 0.936) was obtained.

Ink follower 5
Polybutene LV-50 (described above) 100.00 parts An ink follower 4 having a viscosity coefficient of 1.20 Pa · s and a shear thinning index of 1.000 (correlation coefficient of 0.916) was obtained.

Ink follower 6
Glycerin 68.0 parts by weight Ethylene glycol 30.0 parts by weight NOVEMER EC-1 (viscosity modifier, manufactured by Noveon, USA) 2.0 parts by weight After stirring the above components for 1 minute, the mixture was allowed to stand at 50 ° C. for 24 hours. An ink follower 6 having a viscosity coefficient of 203.2 Pa · s and a shear thinning index of 0.563 (correlation coefficient 0.963) was obtained.

The shear thinning index and the viscosity coefficient of the inks 1 to 5 and the ink followers 1 to 6 were measured by the following methods.
A measuring jig (a combination of a cone and a parallel plate having a diameter of 40 mm and an angle of 4 ° formed by the parallel plate and the side surface of the cone) is set in a measuring machine CVO50 Rheometer (manufactured by Bohiln Instruments), and an ink backflow preventer is provided between the cone and the parallel plate. Fill. The ink backflow preventer was kept at 25 ° C., the gap was set at 0.15 mm, and the stress was set within a linear region measured in advance. The shear rate when the shear stress is continuously changed on the graph is measured to obtain a flow curve. The curve was approximated to the Power Law flow equation described above to obtain a correlation coefficient, a viscosity coefficient, and a shear thinning index.

  A combination of inks 1-4 and ink followers 1-5, a ball-point pen tip consisting of a ball (material: carbide) and a stainless steel ball holder is attached to a polypropylene ink container having an inner diameter of 3 mm, and 0.8 g of ink is applied. After filling 0.1 g of an ink follower and defoaming by centrifugation, ballpoint pens of Examples 1 to 5 and Comparative Examples 1 to 5 were obtained. The ballpoint pens of Examples 1 to 3 and Comparative Examples 3 to 5 use 0.8 mm diameter balls, and the ballpoint pens of Examples 4 and 5 and Comparative Examples 1 and 2 use 0.5 mm diameter balls. Got. Further, a combination of the ink 5 and the ink follower 6, a ball-point pen tip composed of a ball (material: carbide) having a diameter of 1.0 mm and a ball holder made of stainless steel is attached to a translucent polypropylene ink container tube having an inner diameter of 8 mm, and the ink is put into an ink container. Example 6 was obtained after 0.6 g and 1.0 g of an ink follower were charged and centrifugally defoamed.

The following quality tests were performed using this test ballpoint pen.
Table 1 shows the combinations of the ink and the ink follower and the results of the tests in Examples and Comparative Examples.
Writing Test With a spiral writing tester (manufactured by Seiki Kogyo Kenkyusho), a writing angle of 70 °, a writing load of 100 g, and a writing speed of 7 cm / sec and 10 cm / sec are used until the ink is used up. Further, in Example 6, while applying a pressure of 150 kPa, which is a difference from the atmospheric pressure (101 kPa) at a temperature of 25 ° C., from the ink storage tube open surface using a compressor, an image-writing machine writing tester (Seiki Industrial Laboratory) ) At a writing speed of 3 cm / sec, a writing angle of 70 °, and a writing load of 100 g until the ink was used up, and the ink used up state was visually checked. At the same time, the state of the handwriting was checked, and the degree of blurring of the handwriting was visually checked.

Ink leakage test In a temperature of 50 ° C. environment, the pen tip was turned up for 2 weeks to check whether or not the ink leaked.

Use up of ink ○ ・ ・ ・ The use up of ink is clear.
Δ: Ink adheres to the ink storage tube.
X: Ink adheres to the entire surface of the ink storage tube.
The remaining amount of the ink was measured from the ink filling amount and the weight of the test ballpoint pen before and after the writing test.

Blurred handwriting ○: There is no blurred handwriting.
Δ: Handwriting is blurred.
×: Handwriting is almost faded.

Ink leaks ○ ・ ・ ・ Ink does not leak.
X: Ink leaks out.

  As described above in detail, the ink pen follower for a ballpoint pen according to the present invention can write well, and provides a ballpoint pen having a clear ink-following property in which the use-up property of the ink that scrapes off the ink on the wall of the ink storage tube is clear. It is a thing.

Claims (3)

In a ballpoint pen in which ink and an ink follower are directly filled in an ink storage tube, the relationship between the shear stress of the ink and the ink follower with respect to the shear rate is a phase relationship with the Power Law flow equation expressed by the following (Equation 1). is approximated by the number 0.90 or more, and shear-thinning index _{n 2} of the shear thinning index _{n 1} and the ink follower of the _ink, as well as a n 1 _<n 2 <1, the difference between _{n 1} and _{n 2} A ballpoint pen that is 0.2 or less. The ink and ink follower, and the viscosity coefficient k ₂ of the viscosity coefficient k ₁ and the ink follower in the ink in relation to the shear stress to shear rate, respectively, ballpoint pen according to claim 1 is k 1 _{<k 2.}

The relationship between the shear stress and the shear rate of the ink and the ink follower with a correlation coefficient of 0.95 or more, which is approximated to the Power Law flow equation represented by the following (Equation 1). Item 3. The ballpoint pen according to item 2.