JPH0120671B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an ink for an ink-type wire dot printer that moves ink adhered to the wire surface forward by sliding the wire back and forth, and transfers the ink adhered to the wire surface to a printing medium. 2. Description of the Related Art Printers such as thermal printers and wire dot printers are known as printers used for computer output recording, facsimile, and the like. Among these, wire dot printers are ribbon-type wire dot printers that print by striking an ink ribbon with a wire.The back-and-forth sliding movement of the wire moves the ink adhering to the wire surface forward, removing the ink adhering to the wire surface. Ink-type wire dot printers that transfer images onto printing media are known. Due to the mechanism of this ink-type wire dot printer, the ink is exposed to the air at the printer head, so the ink tends to evaporate. When the ink gradually dries out and you try to restart the operation, the wire becomes difficult to move and fixed ink deposits are deposited on the head, making the initial printing difficult. Therefore, attempts have been made to use aliphatic polyhydric alcohols and their derivatives as wetting agents for the purpose of suppressing drying of the ink, but although the drying of the ink can be suppressed to some extent, the printer is not operated for more than two days. When left for a long time, ink solids were observed to be deposited on the head, and the initial printing when operation was resumed was extremely unstable. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ink for an ink-type wire dot printer, which prevents ink from drying in the printer head as much as possible, and enables smooth initial printing after the printer has been stopped for a long period of time. There is a particular thing. In order to obtain the desired ink, the inventors of the present invention have finally completed the present invention as a result of detailed examination of the mechanism of an ink-type wire dot printer and the composition and substance of ink that is compatible with it.
That is, the present invention provides water-soluble dyes; water-soluble organic solvents; water; poly(alkyl vinyl ether), glue and modified products thereof, gelatin and modified products thereof,
one or a mixture of two or more selected from water-soluble polyvinyl butyral and polyethyleneimine; and urea and/or its derivatives;
The gist of the invention is an ink for ink-type wire dot printers, which has a viscosity of 3 to 12 centipoise (cP), a surface tension of 32 dyne/cm or more, and a PH of 7 or more. The present invention will be explained in detail below. The water-soluble dye used in the present invention has a pH of 7.
Those above are preferable and are soluble in water, such as direct dyes,
Acidic dyes, food-grade pigments, etc. are suitable, and specific examples include Direct Deep Black XA (similar to CI Direct Black 38), Kayaku Direct Deep Black EX (CI Direct 38), and Kayaku Direct Fast Black (CI Direct 51). , Water Black L200
(19), Water Black 100-L (19), Direct Fast Black AB (32), Direct Fast Black B (22), Kayaku Direct Brilliant Yellow G (CI Direct Yellow 4), Eisen Primula Yellow 5GLH ( 26), Eisen Primula Yellow GCLH (44), Direct Fast Yellow R (50), Kayaku Direct Scarlet B (CI Direct Red 37), Eisen Direct Fast Red FH (1), Eisen Primula Scarlet GSH (4), Eisen Direct Rodulin Red BH (31), Eisen Primra Red 48H (81), Direct Fast Scarlet 4BS (23), Kayaku Direct Scarlet 3B (39), Eisen Primra pink
2BLH (75), Kayaras Light Red F5G (same)
225), F5B (226) Kayaras Light Rose FR,
Kayaku Direct Sky Blue 6B (CI Direct Blue 1), Eisen Direct Sky Blue
5BH (15), Mitsui Direct Blue 2BN (6), Kayaras Splat Turquoise Blue FBL (15)
199), Water Blue #3 (86), Water Blue #117-L (86), Kayaras Blue Gconc
(78), Kayarasu Splat Blue FF2GL (106)
direct dyes such as Nigrosine (CI acid black 2), Suminol Milling Black 8BX (CI acid black 2),
24), Kayanor Milling Black VLG (26),
Suminol Milling Black NB (29), Eisen Opal Black WH (52), Water Black 187-L (154), Fast Yellow (CI Assisted Yellow 9), Ayashiru Yellow GG (17), Mitsui Ashido Fast Yellow G ( 17), Suminol Leveling Yellow NR (19), Water Yellow #1 (23), Suminol Fast Yellow R (19),
25), Metanyl Yellow (36), Water Yellow #6 (42), Suminolph Stretch GG (CI
acid orange 19), naphthol orange (19)
20), Suminol Milling Orange R (45), Water Orange #18 (56), Solar Red
RB (CI Assisted Dred 7), Solar Rubin (14), New Kokushin (18), Daiwa Ponceau R (26), Eisen Amaranth (27), Suminol Leveling Red 6BL Extra Conc (32), Suminol Leveling Vinol 3GS (same)
37), Suprasenredo B (42), Acitrhodamine G (50), Erythrosin (51), Kayaku Acitrhodamine FB (52), Alizarin Binol R (80), Alizarin Rubinol 3G (50) 82),
Water Red #2 (87), Eisen Acid Phloxin PB (92), Water Pink #2 (92)
92), Eisen Rose Bengal (94), Suminol Brilliant Scarlet DH (97), Kayakashitsu Brilliant Red 3BL (254), Kayanol Phloxine NK (257), Mitsuyashitsu Violet 6BN (CI assisted bioreduced
15), Mitsui Shitsu Biorect BN (17),
Patent Blue V (CI Acid Blue 1), Patent Blue AF (7), Water Blue #9 (9), Water Blue #116 (15), Orient Solble Blue OBC (22), Mitsui Nylon Fast Blue G (25), Suminol Fast Blue 3G (27), Daiwa Digo Carmine (74),
Water Blue #115 (90), Orient Solble Blue OBB (93), Acid Brilliant Milling Green B (CI Acid Green 9),
There are acid dyes such as Daiwa Green #70 (CI Food Yellow 3), food colorants such as Sunset Yellow (CI Food Yellow 3), Amaranth (CI Food Red 9), and Food Green No. 2 (CI Food Green 2). , can be used as one type or a mixture of two or more types, and the amount used can be varied depending on the printing density printing medium, but it is 0.5 to 20% of the total amount of ink.
Weight percent is preferred. The water-soluble organic solvent used in the present invention is used for the purpose of preventing ink drying and promoting dye dissolution, and specific examples include ethylene glycol, propylene glycol,
1.3-butanediol, 1.4-butanediol diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, dimethyl cellosolve, diglyme, glycerin, methyl carbitol, Polyhydric alcohols such as carbitol and their derivatives, formamide, dimethyl sulfoxide,
Tetrahydrofurfuryl alcohol, tetrahydrofurandimethanol, diacetone alcohol,
2-pyrrolidone, N-methyl-2-pyrrolidone,
4-butyrolactone, sulfolane, thiodiethanol, monoethanolamine, diethanolamine, triethanolamine, ethylene carbonate, propylene carbonate, morpholine, 1-
Examples include (2-hydroxyethyl)-piperazine, which can be used alone or as a mixture of two or more, and the amount used is preferably 5 to 40% by weight based on the total amount of the ink. The amount of water used as the main solvent is based on the total amount of ink.
40-80% by weight is desirable. Urea and/or its derivatives used in the present invention are mainly used for the purpose of promoting dye dissolution and preventing drying in the printer head.
When used in combination with a water-soluble dye and a water-soluble organic solvent, it exhibits a particularly remarkable effect in preventing drying in the printer head.
Specific examples of urea and its derivatives that can be used in the present invention include urea, ethylene urea, tetramethyl urea, thiourea, and ethylene oxide adducts to urea, and the amount used is based on the total amount of ink.
It is preferably 20% by weight or less. In addition, poly(alkyl vinyl ether), Niwaka and its modified products, gelatin and its modified products, water-soluble polyvinyl butyral, and polyethyleneimine used in the present invention are mainly used for the purpose of adjusting the viscosity of the ink. By adding small amounts of these water-soluble polymers, it is possible to adjust the viscosity to 3 to 12 cP without using large amounts of water-soluble organic solvents. This makes it possible to prevent the problem that it takes a long time for the printed image to dry, which occurs in some cases. In addition to the above ingredients, various anionic and /or Penetrants such as nonionic surfactants are added to the total amount of the ink at 3% by weight or less, and formalin, phenol, pentachlorophenol sodium, dehydrochloride, etc. are used to prevent ink flow inhibition due to mold growth and ink decay. A small amount of a preservative and fungicide such as sodium acetate may be added as appropriate, and if the ink comes into contact with metal parts, a corrosion inhibitor such as benzotriazole or ethylenediaminetetraacetate may be added as necessary to prevent corrosion of the metal. A rust preventive agent may also be added as appropriate. The ink of the present invention is prepared by appropriately selecting, mixing, and dissolving the above-mentioned ink components.As for the physical properties of the ink, it is necessary to adjust the viscosity to 3 to 12 cP at 25°C. This is because when printing is less than 3 cp, the head temperature is around room temperature at the beginning of printing, the ink comes out smoothly, and clear printing is possible, but as printing continues, the head temperature rises and the ink viscosity decreases. Therefore, too much ink comes out, and when the wire collides with the printing medium, the ink scatters around the dots, resulting in a disadvantage that the printing becomes smudged. Also, if it is 12cP or more,
Because the ink does not move smoothly from the ink-impregnated material to the wire, the ink does not cover the entire tip of the wire, making it impossible to print clearly. Furthermore, it is necessary to adjust the surface tension of the ink to 32 dyne/cm or higher. When the ink is set to 32 dyne/cm or less, the ink penetrates well into the printing medium (especially paper), so it dries quickly on the printing medium, which is preferable as a printer ink. This makes it unsuitable as an ink for wire dot printers that require fine print. Furthermore, the ink of the present invention needs to have a pH of 7 or higher. This is because if the pH is below 7, the metal parts used in the printer head will corrode over time. Hereinafter, the present invention will be explained in more detail with reference to Examples. In the Examples, "parts" indicate "parts by weight." Example 1 (Black ink) Water Black 100-L (Orient Chemical Co., Ltd.)
manufactured by CI Direct Black 19, 20% aqueous solution)
35.0 parts Watered #2 (manufactured by Orient Chemical Co., Ltd., CI
Ascended 87 0.2 parts Water Error #6 (manufactured by Orient Chemical Co., Ltd., CI
Acid yellow 42) 0.1 part ethylene glycol 7.0 parts thiodiethanol 8.0 parts ethylene urea 8.0 parts sodium pentachlorophenol (10% aqueous solution) 0.1 part sodium hydroxide (25% aqueous solution) 0.1 part Luvasin S (10% aqueous solution) (manufactured by BASF, Polymethyl vinyl ether) 18.0 parts Water 23.5 parts Total 100.0 parts The mixture of each component above was stirred at 30 to 40°C for 2 hours, then filtered to give a viscosity of 4.2 cP (at 2.5°C) and a surface tension of
A black ink of 43.0dyne/cm and PH9.3 was obtained. Example 2 (Blue ink) Water Blue #117-L (manufactured by Orient Chemical Co., Ltd.)
CI Direct Blue 86, 25% solution) 17.7 parts Daiwa Green #70 (manufactured by Daiwa Kasei Co., Ltd., CI Ashit Green 16) 0.3 parts Ethylene glycol 10.0 parts Propylene glycol 10.0 parts Ethylene urea 5.0 parts Epomin SP-110 (2% aqueous solution) (manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd., polyethyleneimine) 8.0 parts Sodium pentachlorophenol (10% aqueous solution) 0.1 part Sodium hydroxide (25% aqueous solution) 0.2 parts Water 48.7 parts Total 100.0 parts of each of the above components The formulation was stirred at 30-40°C for 2 hours and then filtered to give a viscosity of 4.1 cP, a surface tension of 45.3 dyne/cm,
A blue ink with a pH of 9.1 was obtained. Example 3 (Red ink) Eisenacidophloxin PB (Hodogaya Chemical Co., Ltd.)
6.0 parts ethylene glycol 10.0 parts diethylene glycol 10.0 parts Epomin SP-103 (5% aqueous solution) 15.0 parts sodium hydroxide (5% aqueous solution) 0.1 part sodium pentachlorophenol (10% aqueous solution) 0.1 part urea 10.0 Part water: 48.8 parts Total: 100.0 parts The mixture of each component above was stirred at 30 to 40°C for 2 hours, and then filtered to give a viscosity of 4.1 cP and a surface tension of
A red ink of 44.9dyne/cm and PH9.90 was obtained. Example 4 (yellow ink) Kayashiru Yellow GG (manufactured by Nippon Kayaku Co., Ltd., CI Acid Yellow 17) 3.0 parts ethylene glycol 10.0 parts dipropylene glycol 7.0 parts urea 5.0 parts Peptide PA-300 (5% aqueous solution) 12.0 parts Pentachloro Sodium phenol (10% aqueous solution) 0.1 part Water 62.9 parts Total 100.0 parts The mixture of each component above was stirred at 20 to 30°C for 4 hours, then filtered to give a viscosity of 4.7 cP and a surface tension of
A yellow ink of 48.2dyne/cmPH8.3 was obtained. Comparative Example 1 (Black ink) (Low surface tension ink) Water Black 100L 35.0 parts Water Red #2 0.2 parts Water Yellow #6 0.1 part Ethylene glycol 20.0 parts Ethylene urea 5.0 parts Sodium pentachlorophenol (10% aqueous solution) 0.1 Part sodium carbonate (10% aqueous solution) 0.2 parts Luvacin S (10% aqueous solution) 18.0 parts Florado FC-430 (manufactured by Sumitomo 3M Ltd., fluorine-based surfactant) 0.3 parts Water 21.1 parts Total 100.0 parts Each of the above The blend of ingredients was stirred at 20-25°C for 5 hours and then filtered to a viscosity of 4.1 cP and a surface tension of
A black ink of 29.1 dyne/cm and 9.1 was obtained. Comparative Example 2 (Blue ink) (without water-soluble polymer) Water Blue #9 4.0 parts Score Roll 900 (manufactured by Kao Soap Co., Ltd., nonionic surfactant) 0.9 parts Ethylene glycol 20.0 parts Dipropylene glycol 10.0 parts Pentachloro Sodium phenol (10% aqueous solution) 0.1 part Urea 0.5 part Water 60.0 parts Total 100.0 parts The mixture of each component above was stirred at 20-30℃ for 1 hour, then filtered to give a viscosity of 3.5 cP and a surface tension of
A blue ink of 35.2 dyne/cm and pH 8.2 was obtained. Comparative Example 3 (Red ink) (Ink not containing urea) Water Pink #2 (manufactured by Orient Chemical Co., Ltd., C.
I. Acid Dred 92) 6.0 parts Ethylene glycol 10.0 parts Dipropylene glycol 10.0 parts Epomin SP-110 (2% aqueous solution) 20.0 parts Pentachlorophenol sodium (10% aqueous solution) 0.1 part Water 53.9 parts Total 100.0 parts of each of the above components After stirring the formulation for 2 hours at 20-25°C, the viscosity was 7.2 cP and the surface tension was
A red ink of 48.1 dyne/cm and PH7.5 was obtained. Comparative Example 4 (yellow ink) (high viscosity ink) Kayashiru Yellow GG (manufactured by Nippon Kayaku Co., Ltd., CI Acid Yellow 17) 5.0 parts ethylene glycol 10.0 parts dipropylene glycol 10.0 parts urea 5.0 parts Peptide PA-300 (10% aqueous solution) ) 30.0 parts Sodium pentachlorophenol (10% aqueous solution) 0.1 part Sodium hydroxide (25% aqueous solution) 0.5 parts Water 39.4 parts Total 100.0 parts The mixture of each of the above components was stirred at 40 to 50°C for 3 hours. Viscosity 13.2cP, surface tension 48.7dyne/cm, PH
A yellow ink of 7.4 was obtained. The inks of Examples 1 to 4 and Comparative Examples 1 to 4 were used in an ink type wire dot printer to print and evaluate the inks. The results are shown in the table below.

[Table] ○: Good △: Slightly problematic ×: Poor Evaluation was performed as follows. Drying of head: After printing, the head was left indoors for 3 days without a cover, and then printing was performed again and the print quality was visually judged. Smudge resistance, scratch resistance: Printed test pattern (letters,
Visually judge the image quality (symbol): Print dryness: Immediately after printing on commercially available stock form paper (approx.
(After 2 seconds) Rub the printed surface with your finger to judge whether the printing is dirty or not. From the above results, the ink of the present invention is optimal as an ink for ink type wire dot printers.

Claims (1)

[Claims] 1 Water-soluble dye; Water-soluble organic solvent; Water; One or more selected from poly(alkyl vinyl ether), glue and modified products thereof, gelatin and modified products thereof, water-soluble polyvinyl butyral, and polyethyleneimine. mixture; urea and/or
or a derivative thereof, and has a viscosity of 3 to 12 centipoise at 25°C, a surface tension of 32 dyne/cm or more, and a pH of 7 or more.