JP6318522B2 - Ink tank for writing instruments - Google Patents

Description

The present invention relates to an ink tank for a writing instrument in which ink and an ink follower are directly accommodated in the ink tank.

2. Description of the Related Art Conventionally, there has been known an ink tank that uses an extruded pipe of a synthetic resin such as transparent or translucent polypropylene or polyethylene that can visually check the remaining amount of ink inside, and that contains ink directly therein. In addition, in order to prevent leakage or volatilization, an ink follower is also known in which a high-viscosity fluid that is incompatible with ink is in contact with the rear end interface of the ink.
Such an ink follower often has a high viscosity in order to prevent leakage, and it is necessary to move in the ink tank tube following the advance of the ink interface due to the volume reduction of the ink accompanying ink consumption. When the viscosity differs from that of the ink, a large flow resistance is applied to the movement, and the ink ejection during writing may be hindered by not following the speed at which the ink can move.
In order to solve these problems, an ink tank that improves the ink followability by making the inner wall surface of the ink tank as smooth as possible minimizes the movement resistance in the vicinity of the wall that hinders the ink followability of the ink follower. It has been proposed (Patent Document 1: Japanese Patent Laid-Open No. 2002-67569).
In addition, an ink tank has been proposed in which the arithmetic average roughness of the inner wall surface of the ink tank is 100 nm or more and by applying modified silicone oil, the movement resistance in the vicinity of the wall surface is reduced and the ink followability is improved ( (Patent Document 2: JP 2003-72277 A).

JP 2002-67569 A JP 2003-72277 A

When the inner wall of the ink tank is smoothed, the frictional resistance between the ink follower and the ink tank is reduced, but at the same time, the frictional resistance between the ink and the ink tank is also reduced. When the momentary strong force is applied, the ink follower and ink move backward, the worst ink scatters, dirty hands and clothes, or the ink at the tip of the pen tip is insufficient May not be formed. Attempts have been made to make the ink follower with a higher viscosity or a solid float inside the ink follower, but this does not essentially alleviate the difference in movement resistance between the ink and the ink follower. The problem was not solved.
In the case where the modified silicone oil is applied to the inner surface of the ink tank, the affinity varies depending on the type of ink used and the type of ink follower, and this also ultimately reduces the difference in movement resistance between the ink and the ink follower. It was not enough to solve the problem.
That is, the ink follower and impact resistance characteristics of the ink follower are in a trade-off relationship and have not yet been fully solved.

The present invention uses an ink and an ink follower, is less susceptible to differences in viscosity and chemicals, has excellent impact resistance and anti-backflow properties, and exhibits good ink follower ink followability. An object of the present invention is to provide an ink tank for writing instruments that does not impede.

  That is, according to the present invention, the arithmetic average waviness Wa of the irregularities formed over the entire inner wall surface in contact with the liquid in the ink tank is 0.5 μm or more and 2.1 μm or less, and the average length of the waviness curve element is WSm20.0 μm or more The ink tank of a writing instrument having a size of 60.0 μm or less is the first gist, and the arithmetic average roughness Ra of the fine unevenness formed on the uneven surface of the waviness is 0.1 μm or more and 0.5 μm or less. The ink tank of the writing instrument is the second gist, and the ink follower, which is a liquid having a low compatibility with the ink and a higher viscosity than the ink, is placed in contact with the ink interface in the ink tank. This is the third gist.

In the ink tank of the present invention, the arithmetic average waviness Wa of the irregularities formed over the entire inner wall surface in contact with the liquid is 0.5 μm or more and 2.1 μm or less, and the average length WSm of the waviness curve element is 20.0 μm or more. Since it is 60.0 μm or less, in a low-speed liquid flow such as ink movement accompanying ink consumption by writing, a fine vortex is generated around the convex portion of the swell, and the movement resistance of the entire liquid is reduced, It is assumed that the flow is laminar as a whole and ensures a smooth flow that does not impair ink ejection. The same applies to the case where an ink follower, which is a high-viscosity liquid having low compatibility with ink, is arranged at the ink interface in order to prevent ink leakage and volatilization at the ink interface, that is, the ink and the ink follower. The movement of the ink follower, which has a high viscosity and low flowability, is dominant, and it is assumed that the same fine vortex is generated between the ink follower and the inner wall of the ink tank. The ink follower also sufficiently follows the ink movement in the ink tank at a sufficiently low liquid movement speed due to ink discharge, which is outflow from a sufficiently narrow gap around the ball pen tip ball around the inner diameter, and as a result In addition, since the difference in movement resistance between the ink and the ink follower is relieved, it is presumed that the ink ejection is not hindered.
In addition, a high flow velocity is generated for a momentary strong force such as when the writing instrument is dropped from the rear end, but at this time, the ink generated around the convex portion It is presumed that the vortex of the follower and the ink is generated as a large turbulent flow, and the resisting force works against the backward movement of the ink and the ink follower, and consequently suppresses the backward movement of the ink.
Here, when the arithmetic average roughness of the fine unevenness formed by the uneven surface is Ra 0.1 μm or more and 0.5 μm or less, in a scene where a high flow velocity such as a drop impact is generated, This is preferable because the frictional resistance of the ink and the ink follower can be suppressed.

The ink tank of the present invention is provided as a part containing ink used for all writing instruments such as a fountain pen, a ballpoint pen, a fiber converging nib, and a brush tip.
Ink is connected to a member having an ink discharge port such as a pen tip directly or via a connection relay member to the ink tank. As an ink supply control mechanism, an ink occlusion body, a temporary ink reservoir member having a comb-like cross section, a valve mechanism or the like may be provided. It is also possible to provide an air circulation mechanism for taking Further, the ink tank of the present invention can be used as an exterior part of a writing instrument as it is, and it is also appropriate to cover the exterior part separately.

The ink tank of the present invention can be a molded product such as an extrusion molding or injection molding of a synthetic resin, a metal pipe, or the like. As the shape, if the shape is cylindrical, the cross-sectional shape of the inner hole may not be circular. However, in the case of a polygonal shape other than a circle, the capillary force may act on the corners and ink residue may be generated, so it is necessary to take care such as forming the corners on a gentle surface. There is.
In any case, as the ink tank of the present invention, the arithmetic average waviness Wa of the irregularities formed over the entire inner wall surface in contact with the liquid is 0.5 μm to 2.1 μm, and the average length of the wavy curve element It is necessary that the WSm has irregularities of 20.0 μm or more and 60.0 μm or less.
If the average average waviness Wa and waviness curve element mean length WSm and arithmetic mean roughness Ra of the inner wall surface of the ink tank are a synthetic resin extruded pipe, the cooling water temperature for cooling the resin immediately after molding, the heat molding resin It is possible to adjust the temperature appropriately by adjusting the extraction speed, melt flow rate, etc., for example, setting the temperature of the molding resin high, setting the cooling water temperature high, or increasing the extraction speed of the thermoforming resin. When the melt flow rate (the value indicating the ease of resin flow, which is measured by the method shown in JIS K6921-2) is increased, the arithmetic average waviness Wa is high, and the waviness curve element The average length WSm tends to be longer.

When creating irregularities on the inner surface by injection molding, blasting or biaxial laser processing is applied to the outer surface of the core pin, and the core pin surface processing is transferred to the inner wall surface of the ink tank at the time of molding. It is possible to form the above uneven shape. In the case of blasting, the unevenness is a non-periodic arrangement, and in the case of laser processing, it is a periodic arrangement.
When the arithmetic average roughness Ra of the fine irregularities formed on the irregular surface of the waviness is formed, the outer surface of the core pin is subjected to blasting or biaxial laser machining, and then further blasted or biaxial. It is possible by applying laser processing etc. additionally.
As the synthetic resin to be used, resins generally used for molding can be used without limitation, and examples include polypropylene resin, polyethylene resin, polyvinyl chloride resin, methacrylic resin, polyamide resin, polycarbonate resin, polystyrene resin, acrylonitrile butadiene. Among them, styrene resin and the like can be mentioned, and among them, polypropylene resin, polyamide resin, polyvinyl chloride resin, and polyethylene resin are preferable from the viewpoints of the non-permeability of the ink solvent, transparency for visually recognizing the inner surface, and solvent resistance. .

When forming irregularities on the inner surface with a metal pipe, the irregularities are formed on the inner surface of the metal pipe by chemical etching, smaller than the inner diameter of the metal pipe, and blasted or biaxial laser processed on the outer surface in advance. The core pin is inserted into the metal pipe, and then the metal pipe inner surface is pressed against the core pin while rotating the pressure welding tool from the outer surface of the metal pipe, the surface is transferred, and the core pin is pulled out by the spring back by the pressure welding process. It can be formed by processing or the like.
As the metal material that can be used, a general metal can be used without limitation, and as an example, stainless steel, brass, titanium, aluminum, phosphor bronze, etc. can be used, but it is determined in consideration of ink and reactivity. It can be said that it is preferable.

The arithmetic average waviness Wa and the arithmetic average roughness Ra are the size of the distribution in the height direction. That is, the roughness of the surface can be shown as a numerical value. When Wa and Ra are large, the surface is rough, and when it is small, the surface is smooth.
The average length (pitch) WSm of the waviness curve element is a parameter indicating the lateral length of the uneven state, and the larger the value, the greater the distance between the top and bottom of the unevenness.

The ink stored in the ink tank forms handwriting and application marks, and can be either water-based ink using water as a main medium or oil-based ink using an organic solvent as a main medium.
The liquid medium is selected in consideration of the solubility and dispersibility of a compound such as a coloring component to be used. Consideration is also given to the control of initial brushing performance, weight loss rate over time, ink leakage performance, writing quality, squeeze and the like.
As water-based ink, in addition to water, ethanol, propanol, isopropanol, ethylene glycol, propylene glycol, 1,3-butylene glycol, diethylene glycol, triethylene glycol, glycerin, ethylene glycol monophenyl ether, benzyl alcohol, etc., as a liquid medium In this case, an organic liquid component may be contained as an oil droplet component of the emulsion.
As the oil-based ink, an organic solvent is mainly used as a liquid medium, but an auxiliary solvent may be used as a solubilizing agent for the blended components. Particularly preferred organic solvents are diethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol dibutyl ether, ethylene glycol mono Hexyl ether, ethylene glycol mono 2-ethylhexyl ether, ethylene glycol monoallyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, di Tylene glycol dibutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono 2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether , Propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol tertiary butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopro Ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether, glycol ethers such as 3-methyl-3-methoxy-1-butyl acetate, ethylene glycol, diethylene glycol, Triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, octylene glycol, glycerin, polyethylene glycol, 3-methyl-1,3-butanediol, 1,3-propanediol, 1,3-butanediol, 1, Glycols such as 5-pentanediol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 3-methoxy Ci-1-butanol, 3-methyl-3-methoxy-1-butanol, 3-methyl-3-methoxypentanol, lauryl alcohol, tridecyl alcohol, isodecyl alcohol, isotridecyl alcohol and other alcohols, methyl isopropyl Ethers such as ether, ethyl ether, ethyl propyl ether, ethyl butyl ether, isopropyl ether, butyl ether, hexyl ether and 2-ethylhexyl ether, esters such as 2-ethylhexyl acetate, isobutyl isobutyrate, ethyl lactate and butyl lactate, phenyl Glycol, phenyl diglycol, benzyl monoglycol, benzyl diglycol, propylene glycol monophenyl ether benzyl alcohol, β-phenyl ethyl alcohol, α-methyl And solvents containing aromatic rings such as benzyl alcohol.

As the colorant used in the ink, a dye and / or a pigment can be used. Examples of the dye include acid dyes, direct dyes, and basic dyes.
Specific examples of the dye include Japan 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 (38), Direct Fast Black Conch (51), Kayara Spragley VGN (71), Kayalas Direct Brilliant Yellow G (C.I. Direct Yellow 4), Direct Fast Yellow 5GL (same 26), Eisen Primula Aero GCLH (same 44), Direct Fast Yellow R (same 50), Eisen Direct Fast Red FH (CI Direct Red 1), Nippon Fasts Calle GSX (same 4), Direct Fast Scarlet 4BS (same 23), Eisen Direct Rhodulin BH (same 31), Direct Scarlet B (same 37), Kayak Direct Scarlet 3B (same 39), Eisen Primula Pink 2BLH (same as above) 75), Sumilite Red F3B (80), Eisen Primula Red 4BH (81), Kayara Spral Bin BL (83), Kayara Light Red F5G (225), Kayara Light Red F5B (226) , Kayara Light Rose FR (227), Direct Sky Blue 6B (CI Direct Blue 1), Direct Sky Blue 5B (15), Sumilite Splash Blue BRR Conch (71), Dibogen Turquoise Blue S (86), Water Blue # (86), Kayara Star Coyze Blue GL (86), Kayala Supra Blue FF2GL (106), Kayara Splatter Turquoise Blue FBL (199), and Acid Blue Black 10B (C.I. Acid Black 1), Nigrosine (2), Suminoll Milling Black 8BX (24), Kayanol Milling Black VLG (26), Suminol Fast Black BR Conk (31), Mitsui Nylon Black GL (52) , Eisen Opal Black WH Extra Conch (52), Sumilan Black WA (52), Ranil Black BG Extra Conk (107), Kayanol Milling Black TLB (109), Suminol Milling Black B (109) , Kayanol milling black T LR (110), Eisen Opal Black New Conque (119), Water Black 187-L (154), Kayaku Acid Brilliant Flavin FF (C.I.) I. Acid Yellow 7: 1), Kayasil Yellow GG (17), Xylene Light Yellow 2G 140% (17), Suminol Leveling Yellow NR (19), Daiwa Tarrazine (23), Kayaktor Torazin (23) , Suminol Fast Yellow R (25), Diacid Light Yellow 2GP (29), Suminoll Milling O O (38), Suminol Milling MR 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% (same 141), Kayanor Yellow NG (same 135), Kayano Lumiling Yellow 5 GW (127), Kayanol Milling 6 GW (142), Sumitomo Fast Scarlet A (CI Acid Red 8), Kayak Silk Scarlet (9), Solar Rubin Extra (14), Daiwa New Coxin (18), Eisenbonso RH (26), Daiwa Red No. 2 (27), Suminol Leveling Brilliant Red S3B (35), Kayasil Rubinol 3GS (37), Eisen Erythrosin ( 51), kayak acid rhodamine FB (52), Suminol leveling rubinol 3GP (57), diacid alizarin rubinol F3G 200% (82), Eiseneosin GH (87), water pink # 2 (same) 92), Eisen Acid Phloxin PB 92), Rose Bengal (94), Cyanol Milling Scarlet FGW (111), Cyanol Milling Lubin 3BW (129), Sinoall Milling Brilliant Red 3BN Conch (131), Suminol Milling Brilliant Red BS ( 138), Eisen Opal Pink BH (186), Suminoll Milling Brilliant Red B Conch (249), Kayaku Acid Brilliant Red 3BL (254), Kayaku Acid Brilliant Red Brilliant Red BL (265), Kayanol 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 (same 1), Patent Blue AF (same 7), Water Blue # 9 (same 9), Daiwa Blue 1 (same 9), Spranol Blue B (same 15), Orient Solve Blue OBC (22), Suminol Leveling Blue 4GL (23), Mitsui Nylon Fast Blue G (25), Kayasil Blue AGG (40), Kayasil Blue BR (41), Mitsui Alizarin Saphirol SE (43) , Suminol Leveling Sky Blue R Extra Conk (62), Mitsui Nylon Fast Sky Blue B (78), Sumitomo Brilliant Indocyanine 6Bh / c (83), Sandlancyanine 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 Green 3), Acid Brilliant Milling Green B (same 9), Daiwa Green # 70 (same 16), Cyanol Cyanine Green G (same 25), Suminol Milling Green G (same 27), etc. Ron Yellow 3GLH (CI Basic Yellow 11), Eisen Cachiron Brilliant Yellow 5GLH (13), Sumiacryl Yellow E-3RD (15), Maxilon Yellow 2RL (19), Astrazone Yellow 7GLL (same) 21), Kayacrill Golden Yellow GL-ED (same 28), Astrazone Yellow 5GL (same 51), Eisen Cachiron Orange GLH (CI Basic Orange 21), Eisen Katyron Brown 3GLH (same 30), Rhodamine 6 GCP (C.I. Cred 1), Eisen Astrafloxin (12), Sumiacryl Brilliant Red E-2B (15), Astrazone Red GTL (18), Eisen Cathlon Brilliant Pink BGH (27), Maxilon Red GRL (same) 46), Eisenmethyl Violet (CI Basic Violet 1), Eisen Crystal Violet (Same 3), Eisen Rhodamine B (Same 10), Astrazone Blue G (CI Basic Blue 1), Astrazone Blue BG (Same 3), methylene blue (same 9), maxilon blue GRL (same 41), Eisen Cachiron blue BRLH (same 54), Eisen Diamond Green GH (CI Basic Green 1), Eisen Malachite Green (same 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), Soldan Red 3R (C.I. 21260), methyl violet 2B base (C.I. 42535B), and Victoria Blue F4R (C.I. 42563B). Nigrosine Base LK (C.I. 50415), Bali First Yellow # 3104 (C.I. 13900A), Bali First Yellow # 3105 (C.I. 18690), Orient Spirit Black AB (C.I. 50415), Bali First Black # 3804 (C.I. 12195), Bali First Yellow # 1109, Bali First Orange # 2210, Bali First Red # 1320, Bali First Blue # 1605, Bali First Violet # 1701, Spiron Black MH 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.A. Orange 6, S. P. T.A. Blue-111 etc. are mentioned.

As pigments, organic pigments such as azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acid dye pigments, building dye pigments, mordant dye pigments, and natural dye pigments, ocher Colorants composed of inorganic pigments such as barium yellow, bitumen, cadmium red, barium sulfate, titanium oxide, dials, iron black and carbon black can be used. Specific examples include organic pigments such as azo pigments, nitroso pigments, nitro pigments, basic dye pigments, acidic dye pigments, building dye pigments, mordant dye pigments, and natural dye pigments. Inorganic pigments such as pigments, ocher, barium yellow, bitumen, cadmium red, barium sulfate, titanium oxide, dial, iron black, and carbon black can be used, and these can be used alone or in combination. Specific examples include aniline black (C.I. 50440), cyanine black, naphthol yellow S (C.I. 10316), Hansa Yellow 10G (C.I. 11710), Hansa Yellow 5G (C.I. 11660), Hansa Yellow. 3G (C.I. 11670), Hansa Yellow G (C.I. 11680), Hansa Yellow GR (C.I. 11730), Hansa Yellow A (C.I. 11735), Hansa Yellow RN (C.I. 11740), Hansa Yellow R (C.I. 12710), Pigment Yellow L (C.I. 12720), Benzidine Yellow (C.I. 21090), Benzidine Yellow G (C.I. 21095), Benzidine Yellow GR (C.I. 21100) ), Permanent Aero NCG (C.I. 20040), Balkan Fastoe -5G (C.I. 21220), Vulcan Fast Yellow R (C.I. 21135), Tartrazine Lake (C.I. 19140), Quinoline Yellow Lake (C.I. 47005), Anslagen Yellow 6GL (C I.60520), permanent yellow FGL, permanent yellow H10G, permanent yellow HR, anthrapyrimidine yellow (CI 68420), Sudan I (CI 12055), permanent orange (CI 12075), resole Fast Orange (C.I. 12125), Permanent Orange GTR (C.I. 12305), Hansa Yellow 3R (C.I. 11725), Vulcan Fast Orange GG (C.I. 21165), Benzidine Orange G (C.I 21110), Persian ole Di (C.I.15510), Indanthrene brilliant orange GK (C.I.59305), Indanthrene brilliant orange RK (C.I.59105), Indanthrene brilliant orange GR (C.I.71105) Permanent Brown FG (C.I. 12480), Para Brown (C.I. 12071), Permanent Red 4R (C.I. 12120), Para Red (C.I. 12070), Fire Red (C.I. 12085) ), Parachlor ortho aniline red (C.I. 12090), resol fast scarlet, brilliant fast scarlet (C.I. 12315), brilliant carmine BS, permanent red F2R (C.I. 12310), permanent red F4R (C I.1 2335), permanent red FRL (C.I. I. 12440), Permanent Red FRLL (C.I. 12460), Permanent Red F4RH (C.I. 12420), Fast Scarlet VD, Vulcan Fast Rubin B (C.I. 12320), Vulcan Fast Pink G (C.I. 12330), Light Fast Red Toner B (C.I. 12450), Light Fast Red Toner R (C.I. 12455), Permanent Carmine FB (C.I. 12490), Pyrazolone Red (C.I. 12120), Resol Red (C.I. 15630), Lake Red C (C.I. 15585), Lake Red D (C.I. 15500), Anthosine B (C.I. 18030), Brilliant Scarlet G (C.I. 15800), Risol rubin GK (C.I.158) 5), Permanent Red F5R (C.I. 15865), Brilliant Carmine 6B (C.I. 15850), Pigment Scarlet 3B (C.I. 16105), Bordeaux 5B (C.I. 12170), Toluidine Maroon (C Perm. Bordeaux F2R (C.I. 12385), Helio Bordeaux BL (C.I. 14830), Bordeaux 10B (C.I. 15880), Bon Maroon Light (C.I. 15825), Bonn Maroon Medium (C.I. 15880), Eosin Lake (C.I. 45380), Rhodamine Lake B (C.I. 45170), Rhodamine Lake Y (C.I. 45160), Alizarin Lake (C.I. 58000) ), Thioindigo red B (C.I. 73300), thioindigo Rune (C.I. 73385), Permanent Red FGR (C.I. 12370), PV Carmine HR, Watching Red, Monolite 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. 42750A, C.I. 42770A), Peacock Blue Lake (C.I. 42090), Peacock Blue Lake (C.I. 42025), Victoria Blue Lake (C.I. 44045), Phthalocyanine Blue (C.I. 74160), Fast Sky Blue (C.I. 74180), Indanthrene Blue RS (C.I. 69800), Indance Ren Blue BC (C.I.6 9825), Indigo (C.I. I. 73000), Pigment Green B (C.I. 10006), Naphthol Green B (C.I. 10020), Green Gold (C.I. 12775), Acid Green Lake, Malachite Green Lake (C.I. 42000), Examples include phthalocyanine green.
Furthermore, a processed pigment processed to enhance the functionality of the pigment, such as surface treatment of the pigment with a dispersing agent in order to enhance dispersibility, can also be used. Specific examples include Renol Yellow GG-HW30, HR-HW30, Orange RL-HW30, Red HF2B-HW30, FGR-HW30, F5RK-HW30, Carmine FBB-HW30, Violet RL-HW30, Blu -HW30, CF-HW30, GreenGG-HW30, BrownHFR-HW30, BlackR-HW30 (made by Clariant Japan Co., Ltd.), UTCO-001 Yellow, 012 Yellow, 021 Orange, 031 Red, 032 Red, 042 Violet, 051 Blue, 052 Blue, 061 Green, 591 Black, 591 Black, 592 Black (above, manufactured by Dainichi Seika Kogyo Co., Ltd.), MICROLITH Yello w 4G-A, MX-A, 2R-A, Brown 5R-A, Scarlet RA, Red2C-A, 3R-A, Magenta2B-A, VioletB-A, Blue4G-A, GreenG-A ( A processed pigment such as Ciba Specialty Chemicals Co., Ltd.) may be used.

  When a pigment is used as the colorant, a dispersant may be used to stably disperse the pigment. As the dispersant, those used as dispersants for pigments, such as water-soluble resins or water-soluble resins conventionally used and anionic or nonionic surfactants, can be used. Examples of the polymer dispersant include natural polymers such as lignin sulfonate and shellac, polyacrylate, styrene-acrylic acid copolymer salt, vinyl naphthalene-maleic acid copolymer salt, β-naphthalene Examples thereof include anionic polymers such as sodium salt and phosphate of sulfonic acid formalin condensate, and nonionic polymers such as polyvinyl alcohol and polyethylene glycol. In addition, as a surfactant, alkyl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether acetate, alkyl sulfocarboxylate, α-olefin sulfonate, alkyl phosphate, polyoxyethylene alkyl ether Nonionic surfactants such as anionic surfactants such as phosphates, polyoxyethylene alkyl ethers, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters can be mentioned.

  In addition to the above, viscosity modifiers consisting of resins such as polyvinylpyrrolidone and polyacrylic acid, cellulose derivatives such as hydroxypropylcellulose and carboxymethylcellulose, polysaccharides such as gar gum, xanthan gum and hyaluronic acid, alkyl sulfates, polyoxyethylene alkyls Anionic surfactants such as ether sulfate, polyoxyethylene alkyl ether acetate, alkyl sulfocarboxylate, α-olefin sulfonate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl Surfactants such as nonionic surfactants such as ethers, sorbitan alkyl esters and polyoxyethylene sorbitan alkyl esters, rust preventives such as benzotriazole and ethylenediaminetetraacetic acid, dehydro Antifungal / preservatives such as sodium acid, 1,2-benzisothiazolin-3-one, and in some cases, polyphenols such as ascorbic acid, kojic acid, hydroquinone, resorcin, catechol, pyrogallol, tannic acid, gallic acid, etc. A substance having reducibility can be used.

Viscous fluid is placed at the ink interface position on the unsealed end side of the ink tank to follow the movement of the ink interface as the ink is consumed, drying the ink, and behind the ink (opposite the writing direction) The ink follower can also prevent the ink from moving or leaking to the ink tank and preventing ink from adhering to the wall surface of the ink tank to be used for handwriting.
Ink followers include petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, poly Nonvolatile or hardly volatile liquids such as ether-modified silicone oil and fatty acid-modified silicone oil can be used, and a gelling agent can be further added to adjust the viscosity and the like. Gelling agents include silica with a hydrophobic surface, fine particle silica with a methylated surface, aluminum silicate, swellable mica, clay-based thickeners such as bentonite and montmorillonite, magnesium stearate, stear Fatty acid metal soaps such as calcium phosphate, aluminum stearate and zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, dextrin compounds such as fatty acid dextrin, cellulose compounds and the like can be used. Furthermore, fine particles such as surfactants, resins, metal oxides and the like can be added for preventing coloration, and for preventing backflow, alcohol-based solvents and glycol-based solvents.

In addition to the ballpoint pen tip, the member having an ink discharge port used in the present invention includes a fiber converging body nib, a synthetic resin nib having a communication hole, a fountain pen, a brush, a brush, a urethane nib, and a valve applicator. Etc. can be used. Also, when using a ballpoint pen tip, a ball with a diameter of about 0.2 mm to 2.0 mm can be used. There is a tendency for the occurrence of blurring to be good. In addition, the larger the ball diameter is, the more generally the amount of discharge increases, so the shortage tends to be good.

Examples and comparative examples are shown below.
In each example, the temperature setting and the take-off speed were adjusted by extrusion molding, and the arithmetic average waviness (Wa) and waviness curves of various inner wall surfaces with a pipe having a cross section of an outer diameter of 6.15 mm and an inner diameter of 3.1 mm An element having an average length (WSm) and an arithmetic average roughness (Ra) was produced.

Example 1
A polypropylene resin (PL400A manufactured by Sun Allomer Co., Ltd .: melt flow rate 2 g / 10 min) is heated to 240 ° C. and then extruded under cooling conditions of a take-off speed of 30 m / min and a water temperature of 20 ° C. An ink tank having an average swell curve element length WSm of 48.12 μm and an arithmetic average roughness Ra of 0.23 μm was prepared.

(Refill sample 1-1)
Using the ink tank of Example 1, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 1-1.

(Refill sample 1-2)
Using the ink tank of Example 1, ink 2 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 1-2.

(Refill sample 1-3)
Using the ink tank of Example 1, only ink 1 described later was filled, the ink follower was removed, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 1-3.

(Refill sample 1-4)
Using the ink tank of Example 1, ink 2 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 1-4.

(Refill sample 1-5)
Using the ink tank of Example 1, ink 1 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.7 mm was used to prepare Refill Sample 1-5.

(Example 2)
After heating polyethylene resin (Creorex K4125 manufactured by Asahi Kasei Chemicals Corporation: melt flow rate 2.5 g / 10 min) to 220 ° C., extrusion molding is performed under cooling conditions of a take-up speed of 30 m / min and a water temperature of 20 ° C., and arithmetic of the inner wall surface An ink tank having an average waviness of 0.60 μm, an average waviness curve element length of WSm of 23.87 μm, and an arithmetic average roughness of Ra of 0.13 μm was prepared.

(Refill sample 2-1)
Using the ink tank of Example 2, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 2-1.

(Example 3)
In a mold using a core pin surface-treated with biaxial laser processing 1.8 μm, using polypropylene resin (MG2T manufactured by Novatec Co., Ltd .: melt flow rate 15 g / 10 min), heated to 230 ° C., and then injection molded. An ink tank having an arithmetic average waviness Wa of 1.86 μm on the inner wall surface and an average length WSm of 55.05 μm and an arithmetic average roughness Ra of 0.15 μm was prepared.

(Refill sample 3-1)
Using the ink tank of Example 3, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 3-1.

(Refill sample 3-2)
Using the ink tank of Example 3, ink 1 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 3-2.

(Refill sample 3-3)
Using the ink tank of Example 3, ink 2 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.7 mm was used to prepare a refill sample 3-3.

Example 4
In a mold using a core pin whose surface is processed with bead blasting 2 μm, using polypropylene resin (MG03B manufactured by Novatec Co., Ltd .: melt flow rate 30 g / 10 min), heating to 230 ° C., injection molding, An ink tank having an arithmetic average waviness Wa of 2.08 μm, an average waviness curve element length of WSm 35.46 μm, and an arithmetic average roughness Ra of 0.21 μm was prepared.

(Refill sample 4-1)
Using the ink tank of Example 4, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 4-1.

(Refill sample 4-2)
Using the ink tank of Example 4, ink 2 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 4-2.

(Refill sample 4-3)
Using the ink tank of Example 4, only ink 1 described later was filled, the ink follower was removed, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 4-3.

(Refill sample 4-4)
Using the ink tank of Example 4, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 4-4.

(Refill sample 4-5)
Using the ink tank of Example 4, ink 2 and ink follower 1 described later were filled, and a refill sample 4-5 was prepared using a ballpoint pen tip having a ball diameter of 0.7 mm.

(Example 5)
A polypropylene resin (PL500A manufactured by Sun Allomer Co., Ltd .: melt flow rate 3.3 g / 10 min) is heated to 230 ° C., and then extruded under cooling conditions of a take-up speed of 30 m / min and a water temperature of 20 ° C., and the arithmetic average waviness Wa0 of the inner wall surface An ink tank having an average length of WSm of 28.75 μm and an arithmetic average roughness Ra of 0.41 μm was prepared.

(Refill sample 5-1)
Using the ink tank of Example 5, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 5-1.

(Refill sample 5-2)
Using the ink tank of Example 5, ink 1 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 5-2.

(Refill sample 5-3)
Using the ink tank of Example 5, ink 2 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 5-3.

(Refill sample 5-4)
Using the ink tank of Example 5, ink 1 and ink follower 1 described later were filled, and a refill sample 5-5 was prepared using a ballpoint pen tip having a ball diameter of 0.7 mm.

(Example 6)
Using a polypropylene resin (MG2T manufactured by Novatec Co., Ltd .: melt flow rate 15 g / 10 min) at 230 ° C. in a mold using a core pin that has been surface-processed by biaxial laser processing first time 1.8 μm and second time 0.5 μm Then, the ink tank was injection-molded to prepare an ink tank having an arithmetic average waviness Wa of 1.78 μm on the inner wall surface, an average length of waviness curve elements WSm of 50.11 μm, and an arithmetic average roughness Ra of 0.47 μm.

(Refill sample 6-1)
Using the ink tank of Example 6, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 6-1.

(Example 7)
After heating polyethylene resin (Creorex K4125 manufactured by Asahi Kasei Chemicals Corporation: melt flow rate 2.5 g / 10 min) to 220 ° C., extrusion molding is performed under cooling conditions of take-up speed 25 m / min and water temperature 20 ° C., and arithmetic of the inner wall surface An ink tank having an average waviness of 0.53 μm, an average waviness curve element length of WSm of 22.31 μm, and an arithmetic average roughness of Ra of 0.06 μm was prepared.

(Refill sample 7-1)
Using the ink tank of Example 7, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 7-1.

(Example 8)
Using a polypropylene resin (MG03B manufactured by Novatec Co., Ltd .: melt flow rate 30 g / 10 min) at 230 ° C. in a mold using a core pin that has been surface-processed by biaxial laser processing first 0.6 μm and second 0.7 μm. Then, the ink tank was injection molded to prepare an ink tank having an arithmetic average waviness Wa of 0.59 μm on the inner wall surface, an average length of waviness curve elements WSm of 25.46 μm, and an arithmetic average roughness Ra of 0.71 μm.

(Refill sample 8-1)
Using the ink tank of Example 8, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 8-1.

Example 9
Using a polypropylene resin (MG03B manufactured by Novatec Co., Ltd .: melt flow rate 30 g / 10 min) at 230 ° C. in a mold using a core pin that has been surface-processed by biaxial laser processing first 0.6 μm and second 0.7 μm. Then, the ink tank was injection-molded to prepare an ink tank having an arithmetic average waviness Wa of 1.91 μm on the inner wall surface, an average length of waviness curve elements WSm of 57.89 μm, and an arithmetic average roughness Ra of 0.07 μm.

(Refill sample 9-1)
Using the ink tank of Example 9, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 9-1.

(Example 10)
Using a polypropylene resin (MG2T manufactured by Novatec Co., Ltd .: melt flow rate 15 g / 10 min) at 230 ° C. in a mold using a core pin that has been surface-processed at the first time of 1.8 μm and second time of 0.7 μm. Then, the ink tank was injection molded to prepare an ink tank having an arithmetic average waviness Wa of 1.81 μm on the inner wall surface, an average length of waviness curve elements WSm of 49.47 μm, and an arithmetic average roughness Ra of 0.68 μm.

(Refill sample 10-1)
Using the ink tank of Example 10, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 10-1.

(Comparative Example 1)
A polypropylene resin (EA9BT manufactured by Novatec Co., Ltd .: melt flow rate 0.4 g / 10 min) is heated to 240 ° C. and then extruded under cooling conditions of a take-up speed of 30 m / min and a water temperature of 20 ° C., and the arithmetic average waviness Wa0 of the inner wall surface An ink tank having an average length of waviness curve elements of 18.24 μm and an arithmetic average roughness Ra of 0.02 μm was prepared.

(Refill sample 11-1)
Using the ink tank of Comparative Example 1, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 11-1.

(Comparative Example 2)
A polypropylene resin (EA9BT manufactured by Novatec Co., Ltd .: melt flow rate 0.4 g / 10 min) is heated to 250 ° C. and then extruded under cooling conditions of a take-up speed of 40 m / min and a water temperature of 40 ° C., and the arithmetic average waviness Wa0 of the inner wall surface An ink tank having an average length of wavy curve elements WSm of 41.96 μm and an arithmetic average roughness Ra of 0.16 μm was prepared.

(Refill sample 12-1)
Using the ink tank of Comparative Example 2, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 12-1.

(Refill sample 12-2)
Using the ink tank of Comparative Example 2, ink 2 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 12-2.

(Refill sample 12-3)
Using the ink tank of Comparative Example 2, ink 2 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 12-3.

(Refill sample 12-4)
Using the ink tank of Comparative Example 2, ink 1 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.7 mm was used to prepare a refill sample 12-4.

(Comparative Example 3)
A polypropylene resin (MG03B manufactured by Novatec Co., Ltd .: melt flow rate 30 g / 10 min) was heated to 230 ° C., and then injection-molded. Arithmetic mean waviness Wa 0.49 μm on the inner wall surface, mean length waviness curve element WSm 65.42 μm, arithmetic An ink tank having an average roughness Ra of 0.09 μm was prepared.

(Refill sample 13-1)
Using the ink tank of Comparative Example 3, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 13-1.

(Comparative Example 4)
After heating a polyethylene resin (Creorex K4125 manufactured by Asahi Kasei Chemicals Corporation: melt flow rate 2.5 g / 10 min) to 230 ° C., extrusion molding is performed under cooling conditions of a take-up speed of 40 m / min and a water temperature of 20 ° C., and arithmetic of the inner wall surface An ink tank having an average waviness Wa of 0.75 μm, an average waviness curve element length WSm of 14.17 μm, and an arithmetic average roughness Ra of 0.11 μm was prepared.

(Refill sample 14-1)
Using the ink tank of Comparative Example 4, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 14-1.

(Refill sample 14-2)
Using the ink tank of Comparative Example 4, ink 2 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 14-2.

(Refill sample 14-3)
Using the ink tank of Comparative Example 4, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 14-3.

(Refill sample 14-4)
Using the ink tank of Comparative Example 4, ink 2 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.7 mm was used to prepare a refill sample 14-4.

(Comparative Example 5)
Polypropylene resin (PL500A manufactured by Sun Allomer Co., Ltd .: melt flow rate 3.3 g / 10 min) is heated to 240 ° C. and then extruded under cooling conditions of take-up speed 40 m / min and water temperature 40 ° C., and the arithmetic average waviness Wa1 of the inner wall surface An ink tank having an average length WSm of 63.90 μm and an arithmetic average roughness Ra of 0.31 μm was prepared.

(Refill sample 15-1)
Using the ink tank of Comparative Example 5, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 15-1.

(Refill sample 15-2)
Using the ink tank of Comparative Example 5, ink 1 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 15-2.

(Refill sample 15-3)
Using the ink tank of Comparative Example 5, ink 2 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.7 mm was used to prepare a refill sample 15-3.

(Comparative Example 6)
In a mold using a core pin whose surface is processed with biaxial laser processing of 2.2 μm, polypropylene resin (MG03B manufactured by Novatec Co., Ltd .: melt flow rate 30 g / 10 min) is used, heated to 230 ° C., and then injection molded. An ink tank having an arithmetic average waviness Wa of 2.19 μm on the inner wall surface, an average length of waviness curve elements WSm of 13.63 μm, and an arithmetic average roughness Ra of 0.11 μm was prepared.

(Refill sample 16-1)
Using the ink tank of Comparative Example 6, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 16-1.

(Comparative Example 7)
In a mold using a core pin surface-treated with 3 μm of bead blasting, using polypropylene resin (MG03B manufactured by Novatec Co., Ltd .: melt flow rate 30 g / 10 min), heating to 230 ° C., injection molding, An ink tank having an arithmetic average waviness Wa of 3.07 μm, an average length of waviness curve elements WSm of 48.39 μm, and an arithmetic average roughness Ra of 0.24 μm was prepared.

(Refill sample 17-1)
Using the ink tank of Comparative Example 7, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 17-1.

(Refill sample 17-2)
Using the ink tank of Comparative Example 7, ink 1 and ink follower 2 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 17-2.

(Refill sample 17-3)
Using the ink tank of Comparative Example 7, ink 2 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.3 mm was used to prepare a refill sample 17-3.

(Refill sample 17-4)
Using the ink tank of Comparative Example 7, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.7 mm was used to prepare a refill sample 17-4.

(Comparative Example 8)
In a mold using a core pin surface processed with biaxial laser processing 2.4 μm, polyethylene resin (Nipolon Hard 1000 manufactured by Tosoh Corporation: melt flow rate 20 g / 10 min) is used, heated to 230 ° C., and then injection molded. Then, an ink tank having an arithmetic average waviness Wa of 2.21 μm on the inner wall surface, an average length of waviness curve elements WSm of 61.89 μm, and an arithmetic average roughness Ra of 0.13 μm was prepared.

(Refill sample 18-1)
Using the ink tank of Comparative Example 8, ink 1 and ink follower 1 described later were filled, and a ballpoint pen tip having a ball diameter of 0.5 mm was used to prepare a refill sample 18-1.

Refill samples 1-1 to 2-3, 2-1, 3-1, 4-1 to 3, 5-1 to 2, 6-1, 7-1, 8-1, 9-1, 10-1, 11- 1, 12-1 to 2, 13-1, 14-1 to 2, 15-1, 16-1, 17-1 to 2, and 18-1 ink tanks are filled with ink and ink followers, and then commercially available. Replace the ink tank of the ball pen ENERGEL (Pentel Co., Ltd., product code LRN5-A, ball diameter 0.5 mm), and place the pen tip outward so that centrifugal force works in the direction of the pen tip Then, centrifugation was performed with a centrifuge (manufactured by Kokusan Centrifuge Co., Ltd., tabletop centrifuge H-103N) to remove the gas present in the ink, and a test ballpoint pen refill sample was prepared.
In the case of the ink tanks of the refill samples 1-4, 3-2, 4-4, 5-3, 12-3, 14-3, 15-2, and 17-3, the ball diameter of the ballpoint pen tip is set to 0. After exchanging to 3 mm, arrange so that the centrifugal force works in the direction of the nib, centrifuge with a centrifuge (manufactured by domestic centrifuge Co., Ltd., tabletop centrifuge H-103N), and present in ink The gas was removed to prepare a test ballpoint pen refill sample.
Furthermore, in the case of the ink tanks of the refill samples 1-5, 3-3, 4-5, 5-4, 12-4, 14-4, 15-3, and 17-4, the ball diameter of the ballpoint pen tip is set to 0. After exchanging to 7 mm, place it so that the centrifugal force works in the direction of the pen tip as in the above sample, and centrifuge with a centrifuge (manufactured by Centrifuge Co., Ltd., tabletop centrifuge H-103N). The gas present in the ink was removed to prepare a test ballpoint pen refill sample.
This test ballpoint pen refill sample was incorporated into the exterior of a commercially available ballpoint pen (ENERGEL, manufactured by Pentel Co., Ltd., product code BL55-A) to obtain a test ballpoint pen sample.

Refill samples 1-1, 3, 5, 2-1, 3-1 to 2, 4-1, 3-4, 5-1 to 2, 4, 6-1, 7-1, 8-1, 9- 1, 10-1, 11-1, 12-1, 4, 13-1, 14-1, 3, 15-1 to 2, 16-1, 17-1 to 2, 4, 18-1 The ink is as follows.
(Ink 1) Water-based gel ink WaterBlack108L using a dye (14% aqueous solution of CI DIRECT BLACK19 (manufactured by Orient Chemical Co., Ltd.)) 45.00 parts Ethylene glycol 10.00 parts Glycerin 10.00 parts Benzotriazole 0.50 Part oleoyl sarcosine sodium 3.00 parts Proxel GXL (S) (preservative, ICI Japan Co., Ltd.) 0.20 parts Kelzan AR (Xanthan Gum, manufactured by Sanki Co., Ltd.) 0.40 parts Ion-exchanged water 30.90 parts The above components were mixed and stirred for 2 hours to obtain an ink having a viscosity of 800 mPa · s (25 ° C.).
The viscosity used in the present invention has a shear rate of 3.83 / s (25 ° C.).
Furthermore, the inks used in the refill samples 1-2, 4, 3-3, 4-2, 5, 5-3, 12-2 to 3, 14-2, 4, 15-3, and 17-3 are as follows. Street.
(Ink 2)
Daiwa Red 103WB (red dye, manufactured by Daiwa Kasei Co., Ltd.) 3.5 parts WATER YELLOW # 6C (yellow dye, manufactured by Orient Chemical Co., Ltd.)
3.5 parts glycerin 10.0 parts ethylene glycol 10.0 parts polyoxyethylene phosphate (surfactant) 1.0 part 1,2-benzisothiazolin-3-one (antifungal agent) 0.2 part benzo Triazole (rust inhibitor) 1.0 part Kelzan (xanthan gum, manufactured by Sanki Co., Ltd.) 0.4 part Sunfiber R (galactomannan, guar gum decomposed product, manufactured by Taiyo Chemical Co., Ltd.)
0.5 part peptide PRA (polypeptide, manufactured by Nippi Co., Ltd.) 2.0 part AKP-20 (alumina, manufactured by Sumitomo Chemical Co., Ltd.) 0.1 part ion-exchanged water 67.8 parts The mixture was stirred for a time to obtain an ink having a viscosity of 2100 mPa · s (25 ° C.).

Refill samples 1-1, 2, 2-1, 3-1, 4-1, 4-5, 5-1, 3-4, 6-1, 7-1, 8-1, 9-1, 10- 1, 11-1, 12-1 to 2, 13-1, 14-1, 3-4, 15-1, 16-1, 17-1, 3-4, 18-1 used ink followers Street.
(Ink follower 1)
Polybutene 15R (polybutene, manufactured by Idemitsu Kosan Co., Ltd.) 93.00 parts by weight Leopard KE (gelling thickener, dextrin fatty acid ester, manufactured by Chiba Flour Milling Co., Ltd.)
2.00 parts by weight Aerosil R972 (previously described) 5.00 parts by weight Into the container together with the above components, stirring is performed for 2 hours while heating the temperature to 140 ° C., and an ink follower fluid having a viscosity of 40000 mPa · s (25 ° C.) is added. Obtained.
Furthermore, the ink followers used in the refill samples 1-4-5, 3-2-3, 4-2, 5-2, 12-3-4, 14-2, 15-2, 3, 17-2 are as follows. Street.
(Ink follower 2)
Mobil SHF1003 (base material, α-olefin oligomer, manufactured by Mobil Chemical Product Inc., USA) 30.0 parts Lucant HC-100 (base material, ethylene-α-olefin copolymer, manufactured by Mitsui Petrochemical Co., Ltd.) 25 .5 parts Lucant HC-40 (base material, ethylene-α-olefin copolymer, Mitsui Petrochemical Co., Ltd.) 40.0 parts Aerosil R972 (previously described) 3.0 parts KF410 (previously described) 1.5 parts together with the above components The mixture was placed in a container and stirred for 2 hours while heating the temperature to 140 ° C. to obtain an ink follower fluid having a viscosity of 45000 mPa · s (25 ° C.).

(Measurement of irregularities on the inner wall surface)
According to JIS B0601 (2001), the arithmetic mean waviness Wa, the mean length WSm of the waviness curve element, and the arithmetic mean roughness Ra were measured.
A test piece obtained by halving the ink tank with a commercially available cutter was used to obtain an uneven image on the inner wall surface under the conditions of a 50 × objective lens and a height pitch of 0.02 μm using a VK-8500 confocal laser microscope manufactured by Keyence Corporation. From the obtained concavo-convex image, after inclination correction (automatic), a cut-off value of 0.8 mm, an arithmetic average waviness Wa at an evaluation length of 200 μm, and an average length WSm of waviness curve elements are obtained, and a cut-off value of 0.08 mm is evaluated. Arithmetic mean roughness Ra was determined at a length of 50 μm. Under the above conditions, the inner wall surface of the ink tank was randomly measured at five locations, and the average values were taken as the values of arithmetic average waviness Wa, average length WSm of waviness curve elements, and arithmetic average roughness Ra.

(Ink ejection test)
Using WRITING TESTER TS-4C-10 manufactured by Seiki Kogyo Co., Ltd., using the above test ballpoint pen sample, the fine paper A defined in JIS P 3201 has a writing angle of 70 °, a writing speed of 7 cm / s, and a writing load of 981 mN. Then, a spiral writing of about 10 cm per rotation was performed under the conditions of the pen rotation, and the blur distance was measured in the handwriting from the writing start point to 100 m writing.
Then, only the writing speed was changed to 15 cm / s, and the other conditions were continued in the same manner as described above, and spiral writing was performed. The writing distance was measured from the writing start point after the speed change to 100 m writing. did.
The difference between the two values was calculated, and the degree of handwriting blur due to the difference in the ink consumption rate was evaluated.

(Checking for blurring of writing lines due to dropping)
For each test ballpoint pen sample, with the ballpoint pen tip facing the ceiling and the rear end facing the floor, a height of 1.5 m above the concrete board (from the user's chest pocket to the floor) And then writing on a writing paper defined in JIS S6054 with a writing tester (Writing Tester, MODEL SP-2, manufactured by Seiki Kogyo Co., Ltd.). Under the conditions of a speed of 7 cm / s, a writing load of 981 mN, and the presence of pen rotation, 1 m was written, and the total distance at which the handwriting was blurred was measured with a commercially available ruler.
The results of each test are listed in Table 1.

From the above results, in Examples 1 to 10, the difference between the blur distance in the pen tip drop test is 1 mm or less, and the blur distance at the writing speed of 7 cm / s in the ink ejection test and the blur distance at the writing speed of 15 cm are Since it is 10 mm or less, it is less affected by the difference in viscosity between ink and ink follower and chemical substances, has excellent impact resistance and anti-backflow properties, and exhibits good ink followability of ink follower and inhibits writing An ink tank is provided.
In Examples 1 to 6, since the arithmetic average roughness Ra of the fine unevenness formed on the uneven surface of the waviness is in the range of 0.1 μm or more and 0.5 μm or less, ink followability is suitable. Thus, it is possible to further improve the impact resistance.
Furthermore, it was possible to write well whether the ink follower was arranged in the ink tank or not, and the ink movement due to the drop impact was small.
In particular, by arranging an ink follower, a resistance acts between the ink follower and the inner wall surface of the ink tank, thereby reducing the degree of blurring caused by a drop impact.

Claims (3)

The arithmetic average waviness Wa of the irregularities formed over the entire inner wall surface in contact with the liquid in the ink tank is 0.5 μm to 2.1 μm, and the average length of the waviness curve element is WSm 20.0 μm to 60.0 μm. Ink tank for writing instruments . 2. The ink tank for a writing instrument according to claim 1, wherein an arithmetic average roughness Ra of the uneven surface is 0.1 μm or more and 0.5 μm or less. 3. The writing instrument according to claim 1, wherein an ink follower, which is a liquid having a low compatibility with the ink and a viscosity higher than that of the ink, is disposed in the ink tank in contact with the ink interface . Ink tank.