JP2006265519A - Ink composition and ballpoint pen using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition of such high fanciness as to capable of developing color different from handwriting color just after written when handwriting is chafed, and to provide a ballpoint pen using the ink composition. <P>SOLUTION: The ink composition essentially comprises a flat-plate-like colorant 18-100μm in average particle size consisting of one or more pigments selected from metal-coated inorganic pigment, metal oxide-coated inorganic pigment, metallized pigment, metallic foil single substance pigment and pearl pigment, and ≥10 wt.% of a titanium oxide. The ball-point pen using this ink composition is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a highly interesting ink composition that can produce a color different from the color of a handwriting immediately after writing when the handwriting is rubbed, and a nib that forms a handwriting using the ink composition The present invention relates to a ball-point pen using a ball-point pen tip composed of a ball as a writing member and a ball holder that protrudes and holds the ball.

  Conventionally, an ink composition has been proposed in which a handwriting is composed of a plurality of hues by using a pigment having a large diameter together with a colorant that is a basic color of the handwriting.

For example, a water-based ink composition containing a water-soluble dye having a hue different from that of a flat resin pigment containing a metal layer and having a plurality of hues formed in one drawn line is disclosed (Patent Document 1). In addition, a glittering ink composition has been disclosed that allows the handwriting to visually recognize a glittering feeling different from the color of the handwriting (Patent Document 2).
JP 2003-003106 A JP 2003-012973 A

  As described above, in recent years, not only writing tools that can provide a stable handwriting with a single hue, but also writing tools that have various visual effects on the handwriting and a highly attractive writing tool have been demanded. Accepted.

  An object of the present invention is to provide an ink composition with high taste that can produce a color different from the color of a handwriting immediately after writing when the handwriting is rubbed.

  That is, the gist of the present invention is an ink composition containing at least a tabular colorant having an average particle size of 18 μm or more and 100 μm or less and at least 10% by weight of titanium oxide in the total amount of the ink composition.

  The handwriting written using the ink composition obtained in the present invention with a writing instrument such as a ballpoint pen or a marking pen, when rubbed with paper or an eraser, the color of the handwriting obtained immediately after writing changes greatly. A highly attractive visual effect can be obtained. The reason why the ink composition of the present invention can produce a color different from the color of the handwriting immediately after writing when the handwriting is rubbed to obtain a highly attractive visual effect can be inferred as follows. Immediately after writing, the tabular colorant having an average particle size of 18 μm or more and 100 μm or less used in the present invention and titanium oxide are mixed in the handwriting, but when the titanium oxide is used in an amount of 10% by weight or more based on the total amount of the ink composition. In addition, since titanium oxide forms a highly concealing coating film, the color of the flat colorant can be concealed in the handwriting immediately after writing, and the handwriting does not know that the flat colorant is contained. It can be. Even when a force sufficient to peel off the titanium oxide is applied when rubbing the handwriting, the tabular colorant has a large contact area with the paper surface, so it is difficult to peel off and remains on the handwriting. The flat colorant tends to remain in the handwriting. When the titanium oxide is peeled off by rubbing the handwriting, the color of the tabular colorant first appears on the handwriting, and changes to a color different from the color of the handwriting immediately after writing.

  The average particle diameter as used in the present invention means that the length of a straight line that can be drawn on the image of the photographed particles is maximized when a plate-like colorant is placed in a glass plate shape and an electron micrograph is taken. The measured diameter was taken as the major axis, and the square root of the product of the major axis and the minor axis when the longest diameter in the direction perpendicular to the major axis direction of the particles was taken as the minor axis. The median diameter is a particle diameter measured by a sedimentation method and corresponding to 50% of the integrated distribution curve, and is a diameter in which the amount of particles equal to or larger than this diameter is equal.

Hereinafter, the present invention will be described in detail. The flat colorant used in the ink composition of the present invention is a particle having a large area, and since it has a large contact area with the paper surface, it is difficult to peel off even when the handwriting is rubbed, and is different from the color immediately after writing. It is used for the purpose of creating color and obtaining a highly attractive visual effect. The flat colorant has an average particle size of 18 μm or more and 100 μm or less, preferably 60 μm or less. If the average particle size is less than 18 μm, the contact area with the paper surface is small, so that it is easy to peel off when rubbed. If the average particle size is more than 100 μm, the ink composition may be clogged with the pen tip and writing may not be possible. Furthermore, those having an average particle diameter of 60 μm or less are preferable because ink discharge is good.
In addition, the flat colorant has a metal reflecting surface (a smooth surface for metal reflection, preferably a specular reflecting surface) on the particle surface or inside the particle in order to significantly change the color difference immediately after writing and after rubbing the handwriting. It is preferable to use a colorant composed of a single particle or a plurality of particles having a particle surface that has a glittering surface by reflection of light. Examples of the flat colorant having such a glittering particle surface include a metal-coated inorganic pigment which is an inorganic pigment coated with a metal (alloy), and among metal-coated inorganic pigments, flake glass is used as an inorganic pigment. Metal-coated glass flake pigment with a structure coated with (alloy), metal oxide inorganic pigment coated with metal oxide on aluminum, etc., or flake-shaped or flake-shaped product after peeling off the metal deposited layer deposited on the film Examples of the metal vapor-deposited film pigment, the metal foil simple pigment, and the pearl pigment that are obtained in this manner.

As an example of the metal-coated glass flake pigment, there is a glass flake pigment in which flaky glass is coated with a metal by an electroless plating method. For example, as a commercially available product, a glass flake pigment coated with silver is metashine. REFSX-2025PS (average particle size 25 μm), REFSX-2040PS (average particle size 40 μm), glass flake pigments coated with titanium, Metashine RCFSX-1040RS, RCFSX-1040RC (more than average particle size 40 μm) (The above, Toyo Aluminum Co., Ltd. product) Each cold, green, and red are mentioned.
Further, as the metal-coated glass flake pigment, glass flake particles in which flaky glass is coated with a metal by a sputtering method can be used. For example, as commercially available products, crystal colors GF2125 and GF2125-M coated with silver are used. (Above, average particle diameter 25 μm), GF2140, GF2140-M (above, average particle diameter 40 μm), glass flake pigment coated with nickel, chromium, molybdenum, crystal color GF2525, GF2525-M (above , GF2540, GF2540-M (above, average particle size 40 μm), glass flake pigment coated with brass, crystal color GF250 (average particle size 50 μm), coated with silver alloy As glass flake pigment, Chris Talcolor GF1345 (average particle diameter of 45 μm, glass flake pigment coated with titanium is crystal color GF1445 ”(average particle diameter of 45 μm) (manufactured by Toyo Aluminum Co., Ltd.).

  Examples of metal deposition film pigments include aluminum film flakes or flakes in which aluminum is vapor-deposited on a resin film, and the resin film is peeled off or integrated. For example, commercially available products include LG Silver # 325, Red Gold # 325, Blue Gold # 325, Red # 325, Blue # 325, Green # 325, Violet # 325, Black # 325, Copper # 325 (above, average particle size 44 μm), LG Silver # 500, Gold # 500 (above, average particle size 28 μm) (above, manufactured by Oike Industry Co., Ltd.).

  As a metal foil simple pigment, stamp method in which metal is pulverized with a reducing agent such as stearic acid and inorganic phosphoric acid in a stamp mill, ball mill method in which a drum is put in a drum together with an appropriate hard sphere, and the drum is rotated to pulverize. There are aluminum powder and bronze powder obtained by the following, for example, as WXM 5452 (average particle diameter 18 μm), 1440 (average particle diameter 30 μm), 1415 (average particle diameter 50 μm) (Toyo Aluminum ( Co., Ltd.), Super Fine No. 22000, ibid. 18000 (above, average particle size 40 μm) (above, manufactured by Daiwa Metal Powder Co., Ltd.).

Examples of the pearl pigment include SD-100 (average particle size: 20 μm), SE-100 (average particle size: 35 μm), and SF-100 (average particle size: 70 μm) (made by Topy Industries, Ltd.) as commercially available products. There is.
These flat colorants can be used alone or in combination of two or more.

  The amount of the flat colorant having an average particle size of 18 μm or more and 100 μm or less used in the present invention is preferably 2.0% by weight or more and 10% by weight or less based on the total amount of the ink composition. If it is less than 2.0% by weight, the color of the tabular colorant is poor even when the handwriting is rubbed, so that the color change is difficult to visually recognize. If it exceeds 10% by weight, the viscosity of the ink increases too much and the fluidity becomes poor. .

Examples of pen tips that discharge a flat colorant having an average particle size of 18 μm or more and 100 μm or less to form handwriting can include markers using a fiber bundling body, valve-type applicators, etc. A ball-point pen having a ball-point pen tip that partially projects and holds the ball is preferably used. In particular, the ball, which is a writing member that transfers the ink composition to the recording surface by rotation, is a sintered body of silicon carbide, and the holes formed in the surface have a depth of 0.3 μm or more and 1.0 μm or less, average The pore diameter is preferably 1.0 μm or more and 10 μm or less. By using such a ball, even if it is a plate-like colorant having the above particle diameter, the ink composition rides well on the ball and is discharged well, so that a good handwriting is continuously obtained. It can be formed.
In addition, when the ball has an arithmetic average roughness (Ra) in a region of at least 50 μm × 50 μm on the surface of 4 nm or more and 30 nm or less, the flat colorant in the ink composition can easily ride on the ball. Since the colorant is discharged well, when the handwriting is rubbed and the titanium oxide is peeled off, a large amount of the plate-like colorant appears on the handwriting to enhance the color, which is preferable.
The arithmetic average roughness (Ra) is a three-dimensional extension of the centerline average roughness defined in JIS B0601 to the measurement surface (2500 μm ² , square with a side of 50 μm), from the reference surface to the specified surface. A value obtained by averaging the absolute values of the deviations was used. For the measurement of the surface roughness, a model name SPI3800N manufactured by Seiko Epson Corporation was used.

The titanium oxide used in the ink composition of the present invention is used to conceal the color of the flat colorant immediately after writing. The titanium oxide preferably has a median diameter of 0.1 μm or more and 10 μm or less. If it is less than 0.1 μm, it enters fibers on the paper surface, and even if the handwriting is rubbed, it is difficult to peel off. If it is more than 1.0 μm, the flat colorant may be scraped off together when it is peeled off. Further, it is preferable that the median diameter of titanium oxide is 0.5 μm or less because the concealing power of titanium oxide is maximized.
As the titanium oxide, various titanium oxides such as rutile type and anatase type can be used. As commercially available products, Titan-SR-1 (median diameter 0.21 μm), R-650 (median diameter 0.27 μm), R-3L (median diameter 0.26 μm), R-310 (median) Diameter 0.24 μm), A-110 (median diameter 0.18 μm), A-150 (median diameter 0.20 μm), R-5N (median diameter 0.24 μm) (above, Sakai Chemical Industry Co., Ltd.) Manufactured), Type-P R-580 (median diameter 0.26 μm), R-930 (median diameter 0.27 μm), A-100 (median diameter 0.20 μm), A-220 (median diameter 0. 19 μm), R-630 (median diameter 0.24 μm), R-830 (median diameter 0.24 μm) (above, manufactured by Ishihara Sangyo Co., Ltd.), Kronos KR-310 (median diameter 0.24 μm), KR-380 (median KA-10 (median diameter 0.20 μm), KA-20 (median diameter 0.20 μm), KA-30 (median diameter 0.20 μm) (above, manufactured by Titanium Industry Co., Ltd.) ), Pure Pure R-900 (median diameter 0.24 μm), R-901 (median diameter 0.27 μm) (made by DuPont Japan Limited), Titanics JR-301 (median diameter 0.3 μm), JR-805 (median diameter 0.29 μm), JR-809 (median diameter 0.29 μm), JR-603 (median diameter 0.28 μm), JR800 (median diameter 0.27 μm), JR-403 (Median diameter 0.25 μm), JR701 (median diameter 0.27 μm) (manufactured by Teika Co., Ltd.), STR-60C (median diameter 0.02 μm, Sakai Chemical Industry Co., Ltd.) ) And the titanium oxide and the like.
These titanium oxides can be used alone or in combination.

  The amount of titanium oxide used in the present invention is preferably 10% by weight or more and 50% by weight or less based on the total amount of the ink composition. If it is less than 10% by weight, the color of titanium oxide is poor, so that it is visually recognized that the flat colorant is contained before rubbing the handwriting. On the other hand, if it is 50% by weight or more, the viscosity of the ink is excessively increased and the fluidity is deteriorated.

  Moreover, a conventionally known colorant can be used in combination for color matching even with a flat colorant having an average particle size of 18 μm or more and 100 μm or less or a colorant other than titanium oxide. That is, if both the green colorant and the gold flat colorant are used, after rubbing the handwriting, the flat colorant shines gold on the green handwriting, or the green colorant and the blue flat coloration. If the agent is used together, a green handwriting dotted with blue is obtained after rubbing the handwriting. Specific examples of the pigment as the colorant include aniline black (C.I. 50440), cyanine black, naphthol yellow S (C.I. 10316), Hansa Yellow 10G (C.I. 11710), and Hansa Yellow 5G (C.I. 11660), Hansa Yellow 3G (CI 11670), Hansa Yellow G (CI 11680), Hansa Yellow GR (CI 11730), Hansa Yellow A (CI 11735), Hansa Yellow RN (C.I. 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 Yellow NCG (C.I. 20040) Vulcan Fast Yellow 5G (C.I. 21220), Vulcan Fast Yellow R (C.I. 21135), Tartrazine Lake (C.I. 19140), Quinoline Ero Lake (C.I. 47005), Anslagen Yellow 6GL (CI. 60520), permanent yellow FGL, permanent yellow H10G, permanent yellow HR, anthrapyrimidine yellow (CI. 68420), Sudan I (CI. 12055), permanent orange (CI. 12075) Resor 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.2111 ), Persian Orange (C.I. 15510), Indanthrene Brilliant Orange GK (C.I. 59305), Indanthren Brilliant Orange RK (C.I. 59105), Indanthren 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. 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 trem De F4R (C.I. I. 12335), Permanent Red FRL (C.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), risol 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. 5800), Risol Rubin GK (C.I. 15825), 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.I. 12350), Permanent Bordeaux F2R (C.I. 12385), Helio Bordeaux BL (C.I. 14830), Bordeaux 10B (C.I. 15880), Bon Maroon Wright (C.I. 15825), Bon 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), thioin Gored B (C.I. 73300), Thioindigo Maroon (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.6 9800), Indanthrene Blue BC (C.I. I. 69825), Indigo (C.I. 73000), Pigment Green B (C.I. 10006), Naphthol Green B (C.I. 10020), Green Gold (C.I. 12775), Acid Green Lake, Malachite Green Rake (C.I.42000), organic pigments such as phthalocyanine green, carbon black such as black iron oxide, furnace black, channel black, thermal black, acetylene black, yellow iron oxide, red iron oxide, ultramarine, bitumen, Inorganic pigments such as cobalt blue, titanium yellow, turquoise, molybdate orange and the like can be mentioned, and these are used by being dispersed in a liquid medium.

  When a pigment is used for an ink composition whose liquid medium is water, use of a commercially available water dispersion type is preferred because handleability and productivity increase. Specific examples of the water dispersion type include Rydye-W series (Dainippon Ink Chemical Co., Ltd.), NKW series (Nippon Fluorescent Chemical Co., Ltd.), Sandy Super series (Sanyo Dye Co., Ltd.), EM Color series, LIOFAST Color series (above, manufactured by Toyo Ink Manufacturing Co., Ltd.) and the like.

In addition, dyes can be used as colorants. As specific examples of the dye, any of acid dyes, direct dyes, basic dyes and the like can be used. For example, Japanol Fast Black D Conch (CI Direct Black 17), Water Black 100L (19), Water Black L-200 (19), Direct Fast Black B (22), Direct Fast Black AB (32), Direct Deep Black EX (38), Direct Fast Black Conk (51), Kayala Spragley VGN (71), Kayalas Direct Brilliant Yellow G (CI Direct Yellow 4) ), Direct Fast Yellow 5GL (26), Eisen Primula Yellow GCLH (44), Direct Fast Yellow R (50), Eisen Direct Fast Red FH (CI Direct Red 1), Nippon Fast Scarlet G X (4), Direct Fast Scarlet 4BS (23), Eisen Direct Rhodulin BH (31), Direct Scarlet B (37), Kayak Direct Scarlet 3B (39), Eisen Primula Pink 2BLH (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), Caillas Light Rose FR (same as 227), Direct Sky Blue 6B (CI Direct Blue 1), Direct Sky Blue 5B (same as 15), Sumilite Splash Blue BRR Conch (same as 71), Dibogen Turquoise Blue S 86), Water Blue # 3 (same as above) 6), direct dyes such as Kayala Star Coyze Blue GL (86), Kayala Supra Blue FF2GL (106), Kayara Supra Turquoise Blue FBL (199), Acid Blue Black 10B (CI Acid Black) 1), Nigrosine (2), Suminol 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 Conk (52), Sumilan Black WA (52), Ranil Black BG Extra Conk (107), Kyanol Milling Black TLB (109), Suminol Milling Black B (109), Kaya NORMILLING BLACK TLR ( 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 5GW (127), Kayanol Milling 6GW (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 Conc (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 Cachilon 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.
The above pigments and dyes can be used alone or in combination.

  A fixing agent is used as a dispersion stabilizer such as titanium oxide for fixing solids in an ink composition such as a plate-like colorant and titanium oxide on a writing surface such as paper. A resin emulsion is mentioned. Examples of the water-soluble resin include a copolymer of monomers selected from (meth) acrylic acid, (meth) acrylic acid ester, and styrene. The monomer is used as a resin hardness imparting component monomer or a plasticity imparting component monomer, and maleic acid, 2-hydroxyethyl (meth) acrylate, or the like may be used as the crosslinking / functionalizing component monomer. The acrylic resin thus obtained is neutralized with an alkaline agent such as diethanolamine, ammonia, sodium hydroxide, potassium hydroxide, etc. to make it water-soluble. Specific examples of such resins include Joncrill J61J (30.5 wt% aqueous solution of styrene-acrylic acid ester-acrylic acid copolymer) and J62 (styrene-acrylic acid ester-acrylic acid copolymer). 34% by weight aqueous ammonia solution), J-683 (styrene-acrylic acid ester-acrylic acid copolymer), J-679 (styrene-acrylic acid ester-acrylic acid copolymer) (above, Johnson Polymer Co., Ltd.) Manufactured), Jurimer AT-210 ((meth) acrylic acid ester- (meth) acrylic acid copolymer 30 wt% aqueous ammonia solution), AT-510 ((meth) acrylic acid ester- (meth) acrylic acid co-polymer) 30% by weight aqueous ammonia solution), AT515 ((meth) acrylic acid ester- (meth) acrylic) Co-30% aqueous ammonia solution of the polymer) (or, Nippon Junyaku Co., Ltd.) and the like. Specific examples of the acrylic resin emulsion include Jonkrill Emulsion J-450, J-537, J-74J, J-790, J-741, J-775, J-7001 (above, Johnson Polymer ( Co., Ltd.), JSR acrylic emulsion AE318, AE343, AE337 (above, manufactured by Nippon Synthetic Rubber Co., Ltd.), Vinylol 1637 (manufactured by Daido Kasei Kogyo Co., Ltd.), Mobile DM772, DM774, Mobile 727, Mobile 700 (Above, manufactured by Hoechst Synthesis Co., Ltd.).

As the liquid medium for preparing the ink composition, a conventionally known organic solvent can be used in addition to water. When the liquid medium of the ink composition is water, a water-soluble organic solvent is used as necessary for various purposes such as prevention of drying of the ink composition at the nib and prevention of freezing of the ink composition at low temperatures. Also good. Specific examples of water-soluble organic solvents include glycol solvents such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, polyethylene glycol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Glycol ether solvents such as diethylene glycol monobutyl ether, ethyl lactate, 2-pyrrolidone, N-methyl-2-pyrrolidone, triethanolamine and the like can be used alone or in combination.
As the conventionally known organic solvent, ester solvents such as phenyl cellosolve, benzyl alcohol, 2-ethylhexyl acetate, isobutyl isobutyrate, and butyl lactate can be used alone or in combination.

  In addition to the components described above, a viscosity modifier can be added to adjust the viscosity of the ink composition. For example, water-soluble synthetic polymer materials such as polyvinyl alcohol, polyacrylic acid soda, polyacrylamide, polyethylene oxide, polyvinylpyrrolidone, seed polysaccharide guar gum, locust bean gum and its derivatives, microbial xanthan gum, welan gum, ramzan gum, Resins such as seaweed polysaccharide color ginnan, alginic acid and derivatives thereof, resin polysaccharide tarragant gum, cellulose resin, pyrrolidone resin and the like can be used. These viscosity modifiers can be used alone or in combination. Also, extender pigments such as silica powder, alumina, aluminum silicate, calcium carbonate, resin spheres, wetting agents and lubricants such as urea, ethylene urea, thiourea, preservatives such as benzothiazoline and omadin, benzotriazole, etc. Various additives such as rust preventives, anionic and nonionic surfactants and antifoaming agents can be used.

  In producing the ink composition of the present invention, various conventionally known methods can be adopted, for example, by blending the above components and stirring and mixing with a stirrer such as a turbo mixer or a Henschel mixer, Further, it can be easily obtained by mixing and pulverizing with a dispersing machine such as a ball mill, a dyno mill, a sand grinder, a speed line mill, or a roll mill.

Hereinafter, it demonstrates still in detail based on an Example.
The compositions of the ink compositions of the examples and comparative examples are as follows.
Example 1
Titanics JR-800 (titanium oxide, median diameter 0.27 μm, manufactured by Teika)
23.0 parts by weight Metashine MC5150NB (blue metal-coated glass flake pigment, average particle size 50 μm
2.0 parts by weight Sandye Super Violet 1103 (purple colorant, Sanyo Dye Co., Ltd.)
7.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight water 23. 8 parts by weight Jonkrill 61J (water-soluble styrene acrylic resin, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight John Krill 790 (styrene acrylic emulsion, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight Kelzan AR 3% by weight aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.) 20.0 parts by weight Each of the above components except the above Kelzan AR 3% by weight aqueous solution was dispersed in a ball mill for 24 hours, and then Kelzan AR 3% by weight. % Aqueous solution was added and mixed with a turbo mixer for 10 minutes to obtain an ink.

Example 2
Taipure R900 (titanium oxide, median diameter 0.24 μm, manufactured by DuPont Japan Limited) 15.0 parts by weight RG Green # 325 (green metal deposited film pigment, average particle size 44 μm, manufactured by Oike Kogyo Co., Ltd.) 4.0 parts by weight Lumicol NKW-2107 (pink fluorescent color, manufactured by Nippon Fluorochemicals) 30.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2- Benzoisothiazolin-3-one, manufactured by ICI Japan Co., Ltd.) 0.2 parts by weight of water 11.8 parts by weight of Joncryl 61J (water-soluble styrene acrylic resin, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight Kelzan AR 3% by weight aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.) 20.0 parts by weight The above components were mixed with a propeller-type stirrer to obtain an ink.

Example 3
Titanics JR-301 (titanium oxide, median diameter 0.3 μm, manufactured by Teika)
30.0 parts by weight RG Red Gold # 325 (red gold metal deposited film pigment, average particle size 44 μm,
(Oike Kogyo Co., Ltd.) 10.0 parts by weight water 33.0 parts by weight Jonkrill 1535 (resin, styrene-acrylic acid copolymer, manufactured by Johnson Polymer Co., Ltd.) 10.0 parts by weight ethylene glycol 7.0 Parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight TL10 (nonionic surfactant, Nikko Chemicals Co., Ltd.) ) Manufactured) 2.2 parts by weight welan gum 0.6 parts by weight The above components were stirred and mixed with a propeller stirrer for 60 minutes to obtain an ink.

Example 4
Titanics JR-301 (titanium oxide, median diameter 0.3 μm, manufactured by Teika)
30.0 parts by weight RG Red Gold # 325 (red gold metal deposited film pigment, average particle size 44 μm,
(Oike Kogyo Co., Ltd.) 8.0 parts by weight Lumicol NKW-2108 (light blue resin dispersed pigment, manufactured by Nippon Fluorescent Chemical Co., Ltd.)
10.0 parts by weight water 25.0 parts by weight Jonkrill 1535 (resin, styrene-acrylic acid copolymer, manufactured by Johnson Polymer Co., Ltd.) 10.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight TL10 (nonionic surfactant, manufactured by Nikko Chemicals) 2.2 parts by weight Welan gum 0.6 parts by weight The above components were stirred and mixed with a propeller stirrer for 60 minutes to obtain an ink.

Example 5
Titanics JR-800 (titanium oxide, median diameter 0.27 μm, manufactured by Teika)
10.0 parts by weight WXM 5452 (single piece metal foil pigment which is silver aluminum, average particle size 18 μm
5.0 parts by weight Sandye Super Violet 1103 (purple colorant, manufactured by Sanyo Dye Co., Ltd.)
7.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight water 33. 8 parts by weight Jonkrill 61J (water-soluble styrene acrylic resin, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight John Krill 790 (styrene acrylic emulsion, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight Kelzan AR 3% by weight aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.)
20.0 parts by weight Each of the above components except the above-mentioned Kelzan AR 3% by weight aqueous solution was dispersed with a ball mill for 24 hours, and then added with a Kelzan AR 3% by weight aqueous solution and stirred and mixed with a turbo mixer for 10 minutes to obtain an ink.

Example 6
Titanics JA-1 (titanium oxide, median diameter 0.18 μm, manufactured by Teika)
30.0 parts by weight RG Red Gold # 325 (red gold metal deposited film pigment, average particle size 44 μm,
(Oike Kogyo Co., Ltd.) 8.0 parts by weight Lumicol NKW-2108 (light blue resin dispersed pigment, manufactured by Nippon Fluorescent Chemical Co., Ltd.)
10.0 parts by weight water 25.0 parts by weight Jonkrill 1535 (resin, styrene-acrylic acid copolymer, manufactured by Johnson Polymer Co., Ltd.) 10.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight TL10 (nonionic surfactant, manufactured by Nikko Chemicals) 2.2 parts by weight Welan gum 0.6 parts by weight The above components were stirred and mixed with a propeller stirrer for 60 minutes to obtain an ink.

Example 7
STR-60C (titanium oxide, median diameter 0.02 μm, manufactured by Sakai Chemical Industry Co., Ltd.)
15.0 parts by weight ELG Green # 325 (green metal deposited film pigment, average particle size 44 μm, manufactured by Oike Kogyo Co., Ltd.) 4.0 parts by weight Sandye Super Violet 1103 (purple colorant, Sanyo Dye)
30.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan Ltd.) 0.2 parts by weight water 11. 8 parts by weight Jonkrill 61J (water-soluble styrene acrylic resin, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight Kelzan AR 3% by weight aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.) 20.0 parts by weight The above components were mixed with a propeller-type stirrer to obtain an ink.

Comparative Example 1
Titanics JR-800 (titanium oxide, median diameter 0.27 μm, manufactured by Teika)
9.0 parts by weight ELG Blue # 325 (blue gold metal deposited film pigment, average particle size 44 μm, manufactured by Oike Kogyo Co., Ltd.) 2.0 parts by weight Sandye Super Violet 1103 (purple colorant, Sanyo Dye Co., Ltd.) Made)
21.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan KK) 0.2 parts by weight water 23. 8 parts by weight Jonkrill 61J (water-soluble styrene acrylic resin, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight John Krill 790 (styrene acrylic emulsion, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight Kelzan AR 3% by weight aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.) 20.0 parts by weight Each of the above components except the above Kelzan AR 3% by weight aqueous solution was dispersed in a ball mill for 24 hours, and then Kelzan AR 3% by weight. % Aqueous solution was added and mixed with a turbo mixer for 10 minutes to obtain an ink.

Comparative Example 2
Titanics JR-800 (titanium oxide, median diameter 0.27 μm, manufactured by Teika)
23.0 parts by weight Metashine ME2015PS (silver metal-coated glass flake pigment, average particle size 15 μm
2.0 parts by weight Sandye Super Violet 1103 (purple colorant, manufactured by Sanyo Dye Co., Ltd.)
7.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight water 23. 8 parts by weight Jonkrill 61J (water-soluble styrene acrylic resin, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight John Krill 790 (styrene acrylic emulsion, manufactured by Johnson Polymer Co., Ltd.)
5.0 parts by weight Kelzan AR 3% by weight aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.) 20.0 parts by weight Each of the above components except the above Kelzan AR 3% by weight aqueous solution was dispersed in a ball mill for 24 hours, and then Kelzan AR 3% by weight. % Aqueous solution was added and mixed with a turbo mixer for 10 minutes to obtain an ink.

Comparative Example 3
Titanics JR-301 (titanium oxide, median diameter 0.3 μm, manufactured by Teika)
30.0 parts by weight Metashine MC5150PS (silver metal coated glass flake pigment, average particle size 150μ
m, manufactured by Nippon Sheet Glass Co., Ltd.) 8.0 parts by weight Lumicol NKW-2108 (light blue resin dispersed pigment, manufactured by Nippon Fluorescent Chemical Co., Ltd.)
10.0 parts by weight water 25.0 parts by weight Jonkrill 1535 (resin, styrene-acrylic acid copolymer, manufactured by Johnson Polymer Co., Ltd.) 10.0 parts by weight ethylene glycol 7.0 parts by weight glycerin 7.0 parts by weight Proxel GXL (preservative, 1,2-benzisothiazolin-3-one, manufactured by ICI Japan) 0.2 parts by weight TL10 (nonionic surfactant, manufactured by Nikko Chemicals) 2.2 parts by weight Welan gum 0.6 parts by weight The above components were stirred and mixed with a propeller stirrer for 60 minutes to obtain an ink.

For the balls used in the ballpoint pens for evaluation in the examples and comparative examples, sintered silicon carbide bodies having various surface roughnesses (Ra) and a ball diameter of 1.0 mm were used. The surface roughness (Ra) of the balls used in the ballpoint pens for evaluation of each example and comparative example is shown below. A model name SPI3800N manufactured by Seiko Epson Corporation was used for measuring the surface roughness of the balls.
Ball a: surface roughness 0.5 nm
Ball b: surface roughness 4.0 nm
Ball c: surface roughness 15.0 nm
Ball d: surface roughness 30.0 nm
Ball e: surface roughness 50.0 nm

  Test samples prepared by filling the ink containing tubes of the ball pens described above with the above-mentioned Examples and Comparative Examples into a hybrid pen (Hybrid Gel grip DX) (product code K230) manufactured by Pentel Co., Ltd. Then, it was surface-coated by drawing a straight line densely in the vertical and horizontal directions on high-quality paper (JIS P3201 writing paper A). Pull a 3 cm x 3 cm stainless steel plate with a load of 500 g at a speed of 7 cm / second, rub the hand-painted surface twice, create a hand-rubbed handwriting, and immediately after the surface coating. The color tone of the handwriting after rubbing was visually confirmed. Moreover, the handwriting immediately after surface coating and the electron micrograph of the handwriting after rubbing a handwriting were each image | photographed, and the number of the tabular colorant which can be visually recognized per unit area 1 square cm was counted. The results are shown in Table 1.

From Table 1 above, in Examples 1 to 7, it was not visually recognized that the tabular colorant was contained in the handwriting immediately after the surface coating, but when the handwriting was rubbed with a stainless steel plate, the tabular colorant was on the handwriting. The color change of the handwriting was visually recognized immediately after the surface coating and after rubbing the handwriting. In Comparative Example 1, the color of the tabular colorant is visually recognized without rubbing the handwriting immediately after the surface coating, and in Comparative Example 2, it is visually recognized that the tabular colorant is contained in the handwriting immediately after the surface coating. However, when the handwriting was rubbed, the flat colorant peeled off together with the titanium oxide, and a satisfactory visual effect was not obtained.
Further, in Examples 1 to 7, those using balls b, c and d have a larger discharge amount of the plate-like colorant than those using balls a and e. The color change of the handwriting after rubbing became remarkable.
As described above in detail, the ink composition according to the present invention is a highly attractive ink composition capable of producing a color different from the color of the handwriting immediately after writing when the handwriting is rubbed.

Claims (4)

An ink composition comprising at least a tabular colorant having an average particle size of 18 μm or more and 100 μm or less and 10% by weight or more of titanium oxide in the total amount of the ink composition. The ink composition according to claim 1, wherein the median diameter of the titanium oxide is 0.1 μm or more and 1.0 μm or less. The said flat colorant is a 1 type, or 2 or more types of mixture chosen from a metal coating inorganic pigment, a metal oxide coating inorganic pigment, a metal vapor deposition film pigment, a metal foil simple substance pigment, and a pearl pigment. 2. The ink composition according to 2. A ballpoint pen tip comprising a ball which is a sintered body of silicon carbide and has a surface roughness (Ra) of 4 nm or more and 30 nm or less as a writing member, and a ball holder which holds the ball protruding from the tip is provided. A ballpoint pen using the ink composition according to claim 3.