JP2009046690A - Oily red ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide red ink which never causes precipitation of a dye even at a low temperature where the dye is apt to precipitate, and thus hardly causes blur of writing. <P>SOLUTION: The oily red ink comprises at least 2-15 wt.% red dye represented by the formula 1; 0.2-10 wt.% yellow dye represented by the formula 2; a 4C or less aliphatic alcohol; and a resin soluble in the aliphatic alcohol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an oily red ink that is suitably used for writing instruments, recorders, and jet printers and has excellent temporal stability.

  Conventionally, oil-based inks used for quick-drying marking pens and the like mainly contain oil-soluble dyes, oil-soluble resins, and solvents. Compared with water-based inks containing water-based dyes and water, oil-based inks can be written not only on ink-absorbing surfaces such as paper and cloth, but also on non-absorbing surfaces such as glass, metal, and plastic. . As solvents for oil-based inks, aromatic hydrocarbons such as toluene and xylene having high solubility in oil-soluble dyes, and glycol ethers such as ethylene glycol monomethyl ale and ethylene glycol monoethyl ether are used. However, the above-mentioned solvents are problematic in terms of safety to the human body due to their high odor and toxicity. In recent years, aliphatic alcohols having 4 or less carbon atoms, particularly highly safe ethyl alcohol, which has low odor and toxicity, are used as solvents for oil-based inks. It is requested. However, oil-soluble dyes that have been used in oil-based inks using aromatic hydrocarbons or glycol ethers as solvents have poor solubility in lower aliphatic alcohols, and it is difficult to obtain a practically sufficient concentration. It is. As a method for improving this problem so far, it is obtained by reacting a basic dye with an acid dye and / or a direct dye, an anionic surfactant, etc., which has relatively good solubility in a lower aliphatic alcohol. It has been proposed to use salt-forming oil-soluble dyes. Therefore, in the case of obtaining a red color tone in an oil-based ink using a lower aliphatic alcohol as a solvent, a salt-forming red dye represented by Formula 1 is used as a main colorant.

  However, as an oil-based red ink for marking pens, in order to increase the density of the handwriting and the vividness of the color, when adding a large amount of the red dye represented by Equation 1 or when adding a complementary yellow dye Although the initial solubility is good, there is a problem that, when stored for a long period of time, the association of dye molecules increases, and precipitates exceeding the solubility level in the solvent are formed and accumulated. The occurrence of precipitates causes problems such as wrinkles in the handwriting due to clogging in the capillary at the nib, a decrease in ink concentration, and a decrease in productivity in the manufacturing process (for example, clogging of the ink filling machine nozzle during ink filling). It is the cause.

  That is, the present invention provides a red dye represented by the following (Equation 1), a yellow dye represented by the following (Equation 2), an aliphatic alcohol having 4 or less carbon atoms, a resin soluble in the aliphatic alcohol, The red dye represented by the following (Equation 1) is 2 wt% or more and 15 wt% or less with respect to the total amount of the ink, and the yellow dye represented by the following (Equation 2) is 0. The gist of the oil-based red ink is 2% by weight or more and 10% by weight or less.

Usually, dye molecules are present in an associated state of several to several tens of units in a solution, but at a high concentration, the dye molecules are more likely to associate. Further, in the aliphatic alcohol having 4 or less carbon atoms, which is a solvent having a relatively high degree of ionic dissociation, the dissolved state of the salt-forming oil-soluble dye exists stably in an ion pair state. It seems to change to an ion pair aggregate and free ion by change. Due to these effects, when the red dye represented by Equation 1 is used as a colorant for an oily red ink using a lower aliphatic alcohol as a solvent, if the amount of dye used is increased in order to increase the density of the handwriting, a long-term It is believed that the amount of dye ion pair association increases with time, and precipitates are formed exceeding the solubility level in the solvent. The yellow dye represented by Formula 2 has a azomethine structure in which a heterocyclic ammonium group is conjugated with a Schiff base as a cation component, and a surfactant that easily forms a stable ion pair with the cation component as an anion component. It is a salt-forming oil-soluble dye. Therefore, the hue is clear and excellent temporal stability can be maintained for a long time. Therefore, when the yellow dye represented by the formula 2 is used in the composition of the oily red ink, the mutual solubility is improved without adversely affecting the red dye represented by the formula 1, and the density of the handwriting and the vividness of the color are increased. It is speculated that it is possible.
Therefore, the oil-based red ink according to the present invention does not precipitate even in a low-temperature aging test in which a dye is likely to precipitate, so that a handwriting having a high concentration can be obtained without causing handwriting blurring.

  This will be described in detail below. The red dye represented by Formula 1 is used as a main colorant. Among commercially available oil-soluble red dyes, the red dye has good solubility in aliphatic alcohols having 4 or less carbon atoms. This red dye can be easily produced by a conventionally known method. For example, an aqueous solution of a basic dye and an aqueous solution of an acid dye, a direct dye or an anionic surfactant are mixed and stirred at a temperature of room temperature to 100 ° C. Thereafter, the water-insoluble reaction product is filtered, washed with water, and dried to obtain a red dye. A specific example is C.I. I. Basiclet 1 and C.I. I. Examples of salt-forming dyes with Acid Yellow 23 include Bali First Red 1308 (manufactured by Orient Chemical Co., Ltd.) and AL Red 2308 (manufactured by Chuo Synthetic Chemical Co., Ltd.). I. Basiclet 1 and C.I. I. As a salt-forming dye with Acid Yellow 42, Spirit Red 102 (manufactured by Orient Chemical Industry Co., Ltd.) and the like are listed. I. Examples of salt-forming dyes of Basic Red 1 and dodecyl (sulfophenoxy) -benzenesulfonic acid include Spiron Red C-GH (Hodogaya Chemical Co., Ltd.). The used amount of the red dye is 2 to 15% by weight based on the total amount of the oily red ink. 2% by weight or more is preferable in that the handwriting density is suitably maintained, and there is no generation of precipitates, and good ink stability is maintained, and the ink is used for writing instruments, recorders, and jet printers. It is preferably 15% by weight or less from the viewpoint of achieving a viscosity suitable for discharge.

  The yellow dye represented by Formula 2 is used to increase the density of handwriting and the vividness of the color as an oily red ink. That is, unlike the conventionally known salt-forming yellow dyes used in oil-based inks containing aliphatic alcohols having 4 or less carbon atoms as solvents, excellent stability over time can be maintained for a long period of time. As a specific example, oil yellow CH (manufactured by Chuo Synthetic Chemical Co., Ltd.), spiron yellow C-GNH (Hodogaya Chemical Co., Ltd.) Etc.). The addition amount is 0.2 to 10% by weight based on the total amount of the oily red ink. In order to increase the density of the handwriting and the vividness of the color, 0.2% by weight is preferable, and in order to obtain an appropriate density and color, 10% by weight is preferable.

  An aliphatic alcohol having 4 or less carbon atoms is used as a solvent. Specific examples include methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, and tertiary butyl alcohol. These can be used alone or in combination, and the amount used is preferably 40 to 90% by weight based on the total amount of oily red ink.

  Resins soluble in aliphatic alcohols having 4 or less carbon atoms are used for adjusting ink viscosity and improving dye fixing properties. For example, a phenol resin, a ketone resin, a rosin resin, a butyral resin, a polyamide resin, and the like can be given. As specific examples, as phenol resins, Tamanol 100S, 510 (above, Arakawa Chemical Co., Ltd.), Hitanol 1501, 2501 (above, Hitachi Chemical Co., Ltd.), YS Polyster S145, YP -90L (above, Yashara Chemical Co., Ltd.), as ketone resin, ketone resin K-90 (Arakawa Chemical Co., Ltd.), Halon 80, 110H (above, Honshu Chemical Co., Ltd.), synthetic resin AP, The same SK, 1201 (Huls, Germany), etc., as the rosin resin, Hercolin D, Pentalin 255, 261 (Rika Hercules Co., Ltd.), Harrier Star NL, Neotor C, Gum Rosin X ( As mentioned above, manufactured by Harima Chemical Co., Ltd.), Gum Rosin WW (produced in China), Ester Gum H (produced by Arakawa Chemical Industries, Ltd.), etc. As a butyral resin, Denka Butyral # 2000-L, # 3000-1, # 3000-2, # 3000-4, # 3000-K (above, manufactured by Denki Kagaku Kogyo Co., Ltd.), ESREC BL- 1, BL-3, BL-S, BX-10 (manufactured by Sekisui Chemical Co., Ltd.) and the like as polyamide resins are AQ-nylon A-90, A-70, A-50. P-70, K-80, K-14 (above, manufactured by Toray Industries, Inc.), Newmide 825, 840 (above, manufactured by Casey Limited), Toresin F30, MF-30, EF -30T, M-20, TK5036 (above, Teikoku Sangyo Co., Ltd.), Versamide 744, 756, 711 (above, made by Henkel Hakusui Co., Ltd.), Tomide # 90, # 92 (above) , Manufactured by Fuji Chemical Industry Co., Ltd. , Sanmide 611DK-1, the same 615A (manufactured by Sanwa Chemical Industry Co., Ltd.), and the like. These can be used alone or in combination, and the amount used is preferably 1 to 20% by weight based on the total amount of oily red ink.

  In addition to the above essential components, ink viscosity modifiers, anticorrosion agents for preventing metal corrosion, and plasticizers that provide flexibility and adhesion to the ink coating are selected and used as necessary. can do. For example, examples of the viscosity modifier of the ink include high-boiling alcohol solvents such as benzyl alcohol, glycol ether solvents such as ethylene glycol monophenyl ether and propylene glycol lower alkyl ether, and ester solvents such as ethyl acetate and ethyl lactate. It is done. Examples of the metal corrosion inhibitor include benzotriazole. Examples of the plasticizer include phthalic acid esters, sebacic acid esters, phosphoric acid esters, adipic acid esters, maleic acid esters, stearic acid esters, and trimetic acid esters.

  Furthermore, various surfactants can also be used as a dye solubilizer, a nib drying inhibitor, an ink coatability improver, and an ink ejection improver. Specifically, alkyl sulfates, N-acyl amino acids and salts thereof, anionic surfactants such as polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl ethers, sorbitan fatty acid esters , Nonionic surfactants such as decaglycerin fatty acid esters, fluorosurfactants such as perfluoroalkyl sulfonates and polyoxyethylene perfluoroethers, silicone surfactants such as polyether-modified silicones and alcohol-modified silicones Is mentioned.

  The oily red ink of the present invention is obtained by stirring and mixing the above essential components using a conventionally known stirrer and dissolving them uniformly.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
Bali First Red 1308 (red dye represented by Formula 1 manufactured by Orient Chemical Co., Ltd.) 8 parts by weight Oil Yellow CH (yellow dye represented by Formula 2 manufactured by Chuo Synthetic Chemical Co., Ltd.)
5 parts by weight Ethyl alcohol 67 parts by weight Normal propyl alcohol 10 parts by weight Gum rosin WW (rosin resin, produced in China) 10 parts by weight The above components were stirred with a stirrer for 4 hours to obtain an oily red ink.

Example 2
Spirit Red 102 (Red dye represented by Equation 1, manufactured by Orient Kogyo Co., Ltd.)
4 parts by weight Spiron Yellow C-GNH (yellow dye represented by Formula 2, Hodogaya Chemical Co., Ltd.)
1 part by weight Isopropyl alcohol 65 parts by weight Normal butyl alcohol
17 parts by weight Synthetic resin SK (ketone resin, manufactured by Huls, Germany) 8 parts by weight Tomide # 92 (polyamide resin, manufactured by Fuji Kasei Kogyo Co., Ltd.) 5 parts by weight An ink was obtained.

Example 3
AL Red 2308 (red dye represented by Equation 1, manufactured by Chuo Synthetic Chemical Co., Ltd.)
10 parts by weight Oil yellow CH (previously described) 6 parts by weight Methyl alcohol 12 parts by weight Ethyl alcohol 60 parts by weight Tamanol 1 OOS (phenol resin, manufactured by Arakawa Chemical Co., Ltd.) 7 parts by weight Ethylene glycol monophenyl ether (viscosity control) Agent) 5 parts by weight The above components were prepared in the same manner as in Example 1 to obtain an oily red ink.

Example 4
Spiron Red C-GH (red dye represented by Equation 1, manufactured by Hodogaya Chemical Co., Ltd.)
12 parts by weight Spiron Yellow C-GNH (previously described) 8 parts by weight Ethyl alcohol 70 parts by weight Hitanol 1501 (phenol resin, manufactured by Hitachi Chemical Co., Ltd.) 3 parts by weight benzyl alcohol (viscosity modifier) 7 parts by weight In the same manner as in Example 1 to obtain an oily red ink.

Example 5
Bali First Red 1308 (previously described) 4 parts by weight Spiron Red C-GH (previously described) 3 parts by weight Oil Yellow CH (previously described) 2 parts by weight Ethyl alcohol 66 parts by weight YP-90L (phenol resin, manufactured by Yasuhara Chemical Co., Ltd.) 15 parts by weight Part Propylene glycol monomethyl ether (viscosity modifier) 10 parts by weight The above components were prepared in the same manner as in Example 1 to obtain an oily red ink.

Comparative Example 1
In Example 1, C.I. I. An oily red ink was obtained in the same manner as in Example 1 except that a salt forming dye of basic yellow 2 and dodecyl (sulfophenoxy) -benzenesulfonic acid was added.

Comparative Example 2
In Example 2, the amount of C.I. I. An oily red ink was obtained in the same manner as in Example 1 except that Solvent Yellow 82 (a salt-forming dye of a metal complex hydrochloric acid dye and a cationic activator) was added.

Comparative Example 3
An oily red ink was obtained in the same manner as in Example 1 except that the oil yellow CH was removed in Example 3 and AL Red 2308 was added by that amount.

  For the oily red inks obtained in Examples 1 to 5 and Comparative Examples 1 to 3, the ink low temperature aging test was performed.

Ink low temperature aging test After sealing the above oil-based red ink in a bottle with a lid and storing it in a -20 ° C constant temperature room for 1 month, the ink is filtered with a filter paper (manufactured by Advantech Toyo Co., Ltd.) Checked the condition.
Evaluation ○: No precipitate
Δ: Some precipitates
×: Precipitate present

  As described above in detail, the oil-based red ink according to the present invention does not precipitate even in a low-temperature aging test in which a dye is likely to precipitate, so that a handwriting having a high concentration can be obtained without causing handwriting blurring.

Claims (1)

It contains at least a red dye represented by the following (Equation 1), a yellow dye represented by the following (Equation 2), an aliphatic alcohol having 4 or less carbon atoms, and a resin soluble in the aliphatic alcohol. The red dye represented by Formula 1) is 2% by weight to 15% by weight with respect to the total amount of the ink, and the yellow dye represented by the following (Formula 2) is 0.2% by weight or more and 10% by weight with respect to the total amount of the ink. % Oil-based red ink.