JPH02150471A - Ink composition - Google Patents

Abstract

PURPOSE:To obtain an odorless ink composition having excellent solution stability, giving a dense written mark, free from tackiness and resistant to the lowering of density with water by dissolving a specific colorant in an aliphatic hydrocarbon solvent. CONSTITUTION:The objective composition is produced by reacting a basic dye (e.g. C.I. Basic Yellow 2 of formula) with an alkylphenol novolak resin (preferably soluble in an aliphatic hydrocarbon solvent and having a softening point of >=75 deg.C) in an alcohol solvent and dissolving the obtained colorant in an aliphatic hydrocarbon solvent (preferably having a boiling point of >=60 deg.C, e.g. n-hexane).

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an ink composition. For more details,
The present invention relates to an ink composition for feltbene dissolved in an aliphatic hydrocarbon solvent.

(B) Conventional technology Oil-based inks that have been used for marking paper, plastic, glass, etc. are manufactured by dissolving oil-soluble dyes, film-forming agents, etc. in aromatic hydrocarbon solvents such as toluene and xylene. was. However, the above-mentioned oil-based ink has a drawback that the odor of the solvent is strong, and it has been desired to develop an oil-based ink using a low-toxicity and odorless aliphatic hydrocarbon solvent instead of the above-mentioned solvent.

When looking at basic dyes as the pigment matrix for the colorant of the oil-based ink, basic dyes are sold in large quantities in the market as dyes for dyeing textiles, and a wide variety of them are available at low prices. However, by blending colorants, it is possible to create colorants with various hues and brightnesses as desired, but if they are water-based, they cannot be used as colorants for oil-based inks. Since it cannot be used, it is necessary to make it oily.

The coloring agent made from the basic dye is C, 1,
Basic dyes such as the coloring agent obtained by reacting Basic Red L with sodium p-laurylbenzyl sulfonate and the coloring agent obtained by reacting C,1, Basic Yellow 1 with sodium dioctyl sulfosuccinate are anionic surfactants. A coloring agent obtained by reacting with a coloring agent is known (Japanese Patent Laid-Open No. 49-28424).

(c) Problems to be Solved by the Invention The coloring agent of the basic dye made into an oil by an anionic surfactant such as sodium p-lauryl benzyl sulfonate or sodium dioctyl sulfone succinate is resistant to aliphatic saturated hydrocarbon solvents. Many have low solubility, poor solution stability, and cannot be made into deep colors.On the other hand, even if a soluble ink is selected, there are problems such as the density of the writing marks being reduced by water or becoming sticky when used as oil-based ink. However, it was not suitable as a coloring agent for oil-based inks.

This invention was made in order to solve the above-mentioned problems, and it is easy to dissolve in aliphatic hydrocarbon solvent using basic dye, and when made into oil-based ink, the writing marks are small, it dries easily, and The purpose of the present invention is to provide an ink composition that does not lose its density with water.

(d) Means for Solving the Problems The inventors conducted intensive research on a method for modifying basic dyes so that they can be dissolved in aliphatic hydrocarbon solvents, and found that basic dyes can be dissolved in alcoholic solvents. The inventors discovered that by heating with an alkylphenol novolak resin, it can be modified to be soluble in an aliphatic hydrocarbon solvent at room temperature, leading to the present invention.

According to the present invention, an ink composition is provided in which at least one colorant obtained by reacting a basic dye and an alkylphenol novolac resin in an alcohol solvent is dissolved in advance in an aliphatic hydrocarbon solvent. Ru.

In this invention, at least one colorant obtained by reacting a basic dye and an alkylphenol novolak resin in an alcohol solvent is used.

The alcohol solvent has solubility in basic dyes and alkylphenol novolak resins, and alcohols having a boiling point of usually 65 to 85°C can be used alone or in an appropriate mixture. Among these, mixed alcohols containing ethanol as a main component are used. is preferred, and can be used in an amount of 800 to 1000 parts by weight per 100 parts by weight of the basic dye, and is removed after the basic dye and alkylphenol novolac resin are dissolved and reacted.

The basic dyes include, for example, C,t, Basic Yellow 2 CI 41000 C,1, Basic Violet 10CI 4517
GC1! , Basic Bluff CI 42595 C1! , Basic Red 1 CI 45160, etc. can be used, and usually the ink composition is
45% by weight, preferably 5 to 30% by weight.

The alkylphenol novolac resin is obtained by condensing an alkylphenol and formaldehyde with an acidic catalyst, and is soluble in an aliphatic saturated hydrocarbon solvent (wherein R preferably has 1 to 15 carbon atoms, for example, ortho, meta, or para). is an alkyl group having 4 to 8 carbon atoms, and n is an integer of 0 to 9, preferably 3 to 6).

Among these, alkylphenol novolak resins having a softening point of 75° C. or higher are particularly preferred in terms of production workability such as crushing and preparation, and film-forming properties for writing marks. The alkylphenol novolak resin is usually used in an amount of 5 to 60% by weight, preferably 8 to 35% by weight, based on the ink composition, and is used as a reactive component for modifying a basic dye into an oily one and as a coating for writing marks. Since it is used for forming a film, it may be used in excess of the amount required for the reaction when reacting with a basic dye, or it may be used in an amount necessary for the reaction, and then only the amount necessary for forming a film is added to the aliphatic dye. It may also be used after being dissolved in a hydrocarbon solvent.

The coloring agent is prepared by mixing the basic dye and the alkylphenol novolac resin in an alcohol solvent, for example,
It can be produced by heating to dissolve, reacting while continuing to reflux the alcohol, and removing the alcohol after the reaction. At least one kind of this coloring agent can be used, and two or more kinds can be used in combination.

In this invention, an aliphatic hydrocarbon solvent is used as the solvent. The aliphatic hydrocarbon solvent may have a chain, branched, or cyclic structural formula, and among these, aliphatic saturated hydrocarbon solvents with a boiling point of 60°C or higher are odorless. Moreover, it is preferable because the ink dries less before writing, such as normal hexane, isohexane, normal hebutane, normal octane, isooctane, normal decane, cyclohexane, methylcyclohexane,
Examples include Isopar E (manufactured by Exxon Chemical Co., Ltd., aliphatic saturated hydrocarbon, aniline point: 74° C.), Isopar G (same as above, aniline point: 80° C.), and these can be used alone or in an appropriate mixture. The amount used is usually 40 to 80% by weight, preferably 60% by weight based on the ink composition.
~80% by weight can be used.

In the present invention, in addition to the coloring agent and the alkylphenol novolac resin for forming a coating for the writing marks, the aliphatic hydrocarbon solvent may be added to the aliphatic hydrocarbon solvent for adjusting the strength of the coating for the writing marks. Usually 5 to 30% by weight of soluble ester gum, modified rosin resin, coumaron-indene resin, etc., based on the ink composition, and a fatty acid having 12 or more carbon atoms, such as oleic acid, which imparts smoothness to writing operations. , linoleic acid, liluic acid, etc., may be mixed in the ink composition, usually in an amount of 1 to 4% by weight.

Note that the oil-based ink composition of the present invention may be mixed with other dyes that do not disintegrate the solution state to obtain a desired color tone.

(e) Function The basic dye reacts with the alkylphenol resin in an alcoholic solvent and is modified into a coloring agent that is soluble in aliphatic hydrocarbons and has excellent solution stability at low temperatures.

(f) Example In the example of this invention, the following materials were used as main raw materials.

Ekinen F-1: Manufactured by Nippon Kaseihin Co., Ltd., ethanol 88% by weight
A mixed solvent containing 10% by weight of isopropyl alcohol.

Tamanol 510: Manufactured by Arayo Kagaku Kogyo Co., Ltd., butylphenol novolak resin, softening point (ring and ball method) 75-95°C.

Bassonil Blue 636...manufactured by BASF, C,
1. Basic blues.

Flex Yellow 110...manufactured by BASF, C,
1, Basic Yellow 2゜Lunatsuk OP...
・Manufactured by Kao Corporation, oleic acid.

Isopar E: Manufactured by Exxon Chemical Co., Ltd., aliphatic saturated hydrocarbon,
Aniline point 74°C.

Example! Ekinen F-1 (60 parts by weight), Tamanol 510 (35 parts by weight)
(parts by weight) and Bassonil Blue 636 (5 parts by weight) are mixed, heated and refluxed for 60 minutes, dissolved and reacted, then poured into a boiling fan and left to cool and solidify. After that, wash with water, crush,
Dry at 0-45°C for 18 hours to obtain 38 parts by weight of blue colorant. Next, 26 parts by weight of the blue colorant and 3 parts by weight of Lunatuq 0-P were mixed with 671 parts by weight of Isopar to give 25 parts by weight.
Stir at °C and dissolve to obtain a homogeneous solution of blue ink.

It was confirmed that this blue ink is odorless and has excellent solution stability, with no precipitation of dissolved substances even when stored at -15°C for 6 months.

Example 2 Ekinen P-1 (61 parts by weight), Tamanol 510 (26 parts by weight)
Weight 111K), Bassonil Blue 636 (5 parts by weight)
and Flex Yellow 110 (3 parts by weight) are mixed, heated and refluxed for 60 minutes, and after dissolution and reaction, the reaction product is poured into boiling water and left to cool and solidify. Then washed with water, crushed,
Dry for 18 hours at 40-45°C to obtain 28 parts of green colorant. Next, 26 parts by weight of Pre-i2 green colorant and 2 parts by weight of Lunatsuk 0-P were mixed with 72 parts by weight of Isopar E.
The mixture was stirred at 5° C. to uniformly dissolve the mixture to obtain green ink.

This green ink was odorless, and no precipitates were generated even after storage at -15° C. for 6 months, and it was confirmed that the green ink was stable in solution.

Example 3 16 parts by weight of the blue colorant produced in Example 1 was dissolved in 38 tlL of n-hebutane at 25 to 30°C to obtain a blue ink. This blue ink was odorless and had excellent solution stability.

Example 4 13 parts by weight of the green colorant produced in Example 2 was added to a mixture of 36 parts of n-heptane and 1 part by weight of oleic acid for 25 to 25 parts by weight.
The mixture was stirred and dissolved at 30°C to obtain green ink.

This green ink was odorless and had excellent solution stability.

Example 5 72.9 parts by weight of Isopar E, 16 parts by weight of the blue colorant manufactured by Example Otori, 1.9 parts by weight of Lunatsuk O-P, and 9.6 parts by weight of Tespol 1040 (manufactured by Hitachi Chemical Polymer Co., Ltd., Ester Gum) Mix parts by weight and stir at 25°C,
A blue ink was obtained by uniformly dissolving the solution.

This blue ink was odorless and had excellent solution stability with no precipitates generated even after storage at -15°C for 6 months.

(g) Effects of the invention According to the invention, basic dyes can be dissolved well in aliphatic hydrocarbon solvents at low temperatures (20 to 30°C);
It is possible to provide an odorless ink composition that has good solution stability, leaves a dark writing mark, is not sticky, and does not lose its density with water.

Claims (1)

[Scope of Claims] 1. An ink composition prepared by dissolving in an aliphatic hydrocarbon solvent in advance at least one coloring agent obtained by reacting a basic dye and an alkylphenol novolak resin in an alcohol solvent. 2. The ink composition according to claim 1, wherein the alkylphenol novolak resin is soluble in an aliphatic hydrocarbon solvent and has a softening point of 75°C or higher. 3. The ink composition according to claim 1 or 2, wherein the aliphatic hydrocarbon solvent is an aliphatic saturated hydrocarbon having a boiling point of 60° C. or higher.