DE1644440A1 - Process for the preparation of benzoates of basic dyes - Google Patents

Description

BADISCHE ÄHIim-t & 'SC © £ «-MrBftiK AG

Dr. Expl.

Our symbols: O.Z. 24 035 Hee / Bö Ludwigshai en / She in. ,, December 28, 1965

Process for the preparation of benzoates of basic dyes

Basic dyes, e.g. representatives of the diphenyl and triphenyl esters Xanthene series (auramine, .. methyl violet, Victoria blue, rhoda- ^ ~ min and others »)> have because of their unsurpassed color strength and Color purity is of great importance e.g. for the production of printing inks, stamp inks, marking inks, ballpoint pen pastes, Hectopaper and for dyeing paper pulp. The dyes are generally in the form of their water-soluble Chlorides used also in organic solvents, such as Alcohols, are readily soluble.

The solubility in water is different for different areas of application but undesirable because the dyeings made with these dyes are not waterproof, if not the substrate or a binder fixes the dye. If one wants to improve the water fastness of flexographic printing inks, for example, then one must A so-called laking agent, which is generally a high molecular weight organic acid, can be added to the printing ink. The resulting laking product from basic dye should easily soluble in the solvents used (alcohols, glycols)

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■ 16AAA40

borrowed, but be sparingly soluble in water. In general, besides, is the 1- to 3-fold G-ewichtsmenge laking agents such as tannins, based on dye required to obtain sufficient water fastness of the prints.

Because of the high molecular weight of those commonly used Laking agents do not use basic dyes to implement with these substances in substance because the color strength of the "laking products" obtained in this way is much less than in the case of the commercially available dyes, and the possible uses of the dye thus obtained is limited.

With the addition of the laking agents customary for basic dyes based on higher molecular weight aromatic acids, such as Tannin, · to the solutions of the basic dyes is obtained continued dyeings and prints of not always more satisfactory Waterfastness. Is the addition of water-emptying aids, like lacquers, not possible (signed inks, Stamp colors, ballpoint pen pastes etc.) then the water fastness remains the colorations unsatisfactory,

It has now been found that decomposition products of basic dyes with benzoic acids of the general formula

COOH 'I,

in which X is a hydrogen atom, a halogen atom, an amino,

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Hydroxyl, methoxyl, alkyl, benzoyl, acetyl or an esterified Carboxyl group and Y denote a hydrogen atom, a chlorine atom, a hydroxyl or an amino group, with good solubility are almost insoluble in alcohols and glycols and are therefore ideal for the production of printing inks, marking inks, Stamp inks, ballpoint pen pastes and other solutions or pastes containing dyes are suitable. The conversion products Basic dyes with the benzoic acids mentioned are obtained in a manner known per se by reacting the salts to be more basic Colorants with salts of these benzoic acids or by reaction the corresponding color bases with the free benzoic acids. However, good results can also be achieved if the benzoic acids are used first during or after the production of the preparations, e.g. the Printing inks with commercially available basic dyes added.

The basic dyes are in particular the dyes usually used for the production of the above-mentioned solutions or pastes, e.g. dyes of the diphenylmethane, triphenylmethane, Xanthene * or oxazine series, such as AuraminO (CI. 41 000), Rhodamine B (CJ. 45 970), Rhodamine 6G (CI. 45 160), Victoria blue B (CL 44 045), methyl violet (CI. 42 535), Victoria pure blue BOD (CI. 42 595) or the dyes of the formulas II and III

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984 4/0683

O, Z. 24 035

(ID

ο ei he

ΌΗ3

_HC1

CH

R = H, Cl

into consideration

The Ti betizoic acids to be converted according to the invention, the general Formula I are preferably the benzoic acid itself, o-, m- or p-chloro, amino, hydroxy or alkybenzoic acids, and dichlorobenzoic acids such as 2,4- or 2,5-dichlorobenzoic acid,

For the production of the conversion products one goes in detail two-way in such a way that the usually water-soluble parbsalts, like the chlorides or sulfates, in aqueous solution with the approximately stoichiometric amount or preferably with a small, e.g. up to 20% excess of the water-soluble salts, such as the alkali, alkaline earth or ammonium salts, the benzoic acids mentioned implements. The paraffin benzoate precipitates and can in the usual way by suction, washing and drying in pure Shape to be isolated. Basic dyes that are sparingly soluble in water

009844/0663

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Substances can be converted into benzoates, for example, in such a way that the Starting dyes in mixtures of organic solvents with water (whereby the organic solvents should advantageously not be homogeneously miscible with water) with water-soluble solvents Treated salts of benzoic acids. Compartment distilling off the solvent, preferably chloroform, the dye benzoate is made from the aqueous phase isolated as usual. Another variant of the The production of dye benzoates is the conversion of the dye bases of basic dyes with the free benzoic acids. Since the free, (( Dye bases are insoluble in water, the reaction can also be carried out here as indicated above. Come as a solvent for this purpose in particular aromatic compounds such as benzene and toluene or xylene, but also hydrocarbons such as chloroform.

The reaction products obtainable according to the invention arise in excellent yield and good purity. They are excellent for the production of printing inks, e.g. for flexographic and Moisture-Set-Print or for the production of stamping inks, marking inks, ballpoint pen pastes and hectopaper. With Prints, dyeings, etc. obtained from these colors are very water-resistant. It is therefore unnecessary, e.g. the flexographic printing inks to add an additional laking agent. Furthermore, there is corrosion of the metal parts of the printing machines and the storage vessels avoided; if dye chlorides are used, considerable corrosive effects can occur. With the invention The reaction products obtainable are also dye solutions (printing inks, etc.) which are very good Excellent storage stability.

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• The benzoic acids or their salts can be added with commercially available dyes during or after the preparation of the preparations suitable for the application, such as printing inks, as has already been mentioned -fold, preferably 1 to 2 times the amount by weight of a salt, preferably an alkali salt, of a benzoic acid of the type mentioned. This also gives a printing ink which provides prints with significantly improved water resistance.

The parts given in the examples are parts by weight.

Example 1

A solution of 240 parts Rhodamiu 6G (GI 45160) in 4300 parts of water at 60 to 80 ⁰ C with a solution of 96 parts of 2,4-dichlorobenzoic acid, n 505 parts / 1 sodium hydroxide solution and 500 parts of water was added. It is stirred for a half to two hours at 7O ⁰ O. After cooling to Raumtemperatur'wird the crystalline precipitated dyestuff suction and dried. Yield: 298 parts of dye.

6G- and 2,4-dichlorobenzoic acid are used instead of rhodamine the dyes or benzoic acids given in the table below, and if one proceeds in the same way, others become Dyes obtained in the yields shown in the table.

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16UUQ

Yield example. Benzoic acid dye in a hurry

2 152 parts aur- 96! Parts 2,5-167

amine 0 (CI. Mchlorbenzoe-

41,000) acid

170 parts dye - 72.5 parts 199

substance of the formula benzoic acid III (as chloride)

4,240 parts of Rhoda- 70 parts -274 min B (CI. Salicylic acid

45 970) I.

5 240 parts Rhoda- 70th parts 265 min B (CI. anthranil-45 97Ό) acid '

Example 6

A solution of 253 parts of Victoria Blue Base B (CI, 44 045) in 900 parts of chloroform, at 50-40 ⁰ C with a solution ays 62 parts of benzoic acid, 505 parts of n / 1 sodium hydroxide solution and 500 parts of water and 1 to 2 Sttmden at reflux heated. Instead of chloroform, other base-dissolving solvents such as aliphatic and aromatic hydrocarbons can be used. After the reaction, the chloroform (high-boiling solvent, possibly under vacuum) is distilled off at normal pressure and the resinous dye is removed from the aqueous solution separated off and dried Yield: 297 parts by weight of dye.

If 79 parts are used instead of 62 parts of benzoic acid o-chlorobenzoic acid, the corresponding dye is obtained. Yield 29-8 parts.

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Example 7

1.5 parts of the 2.5 dichlorobenzoate obtainable according to Example 2 are dissolved of auramine 0 in a solution of 90 parts of 99 ^ igem Alcohol, 10 parts ethyl cellosolve and 30 parts shellac tiei • room temperature. Those made with this flexo printing ink Prints have very good waterfastness. The solutions have excellent storage stability.

Example 8

10 parts of the _{3-aminobenzoate} of rhodamine 6 G is dissolved in a solution of 36 parts of a PhthalsäurehexantriOlesters and 54 parts Diäthyle.nglykol at about 9O ⁰ C. The prints produced with this glycol printing ink (moisture set) are better waterfast than prints obtained with glycol printing inks that contain the corresponding chloride dye.

'' Example 9

25 parts of the benzoart or o-chlorobenzoate of the dye Viktoriablau B are in a solution of 25 parts of a Phthalic acid hexane triOlester and 50 parts of diethylene glycol solved approx. 90 C. The tendency to corrosion of the Ballpoint pen paste is low. As a dye, for example the benzoate of the dye of the formula III can be used.

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Claims (4)

Claims j 1.yProcess for the preparation of reaction products of basic dyes which are soluble in alcohols but practically insoluble in water, characterized in that salts of hasischer dyes with salts of benzoic acids of the general formula are used - ⁰ °° K : ■■■ * ' in which X is a hydrogen atom, a halogen atom, an amino, Hydroxyl, methoxyl, alkyl, benzoyl, acetyl or an esterified Carboxyl group and Y denotes a hydrogen atom, a chlorine atom, an amino or a hydroxyl group, or the free color bases with free benzoic acids of the general formula I. 2. The method according to claim 1, characterized in that the basic dyes auramine 0 (0.1. 41 OQO) ₁ rhodamine B (CI. 45 970), ehodamine 6S (CI. 45 160), Viktoriäblau B (Cj. 44 045) , Methyl violet (CI. 42 535), Viktoriareinblau BOB (CI. 42 595) or one of the dyes of the formulas -10- O.Z. 24 035 16UUQ or R = H oösr Ul used. 3. The method according to claim 1, characterized in that »that the benzoates of basic dyes are prepared in the preparation suitable for the application, such as a printing ink, by adding the benzoic acids or their salts only during or after the preparation with commercially available basic dyes. 4. Benzoates of basic dyes, which in the phenyl radical, the benzoic acid by halogen atoms, amino, hydroxyl, methoxy, alkyl, Benzoyl, acetyl or esterified carboxyl groups can be substituted. BADISCHE ΑΪΤΪ1ΙΪΓ- & SODA-FABRIK AG 009844/0663