DE1543643B1 - Benzoldiazonium compounds and processes for their preparation - Google Patents

Description

NH ₂ · HCl

in which R ₁ and R ₂ are as defined above, are reacted with a nitrite to form the corresponding diazonium salt and the salt is isolated from the reaction mixture by precipitation as a complex salt of boron fluoride or of zinc, cadmium or tin chloride.

The invention relates to new benzene diazonium compounds the general formula

wherein R ₁ and R _{2 represent} different alkyl radicals with 2 to carbon atoms, the sum of the carbon atoms in R ₁ and R _{2 being} at least 5, and Y the radical BF ₄ , ZnCl ₃ , CdCl ₃ or 1/2 SnCl ₆ , and a method of making them. They are used in diazotype formulations in the so-called wet or semi-wet process. Diazotype processes are based on the light sensitivity of diazonium (diazo) compounds. Of these, only a few types are usable, and they are decomposed into colorless compounds upon exposure to light, particularly to rays of shorter wavelengths and the near ultraviolet. The photosensitivity varies both with the compound used and with its concentration in the formulation; the sensitivity increases as the amount of the compound in the layer decreases.

The second important component in the diazo process is the coupling component that works with the Coupling diazonium compound to form a colored azo dye. The color of this dye depends on the chemical structure of the coupler and, to a lesser extent, the diazonium compound. There the diazonium compound is decomposed under the influence of light, the coupling occurs between the unexposed parts of the image, so that as a result a positive of a positive or a Negative is obtained from a negative.

The two technically practiced variants of the diazo process differ essentially by the manner in which the coupler is applied. When dry process are the coupling components, along with stabilizing substances to maintain acidic Conditions, applied together on the paper or film base. After exposure can simply by means of an alkaline atmosphere, such as that produced by evaporation of aqueous Ammonia is generated to be developed. In modern systems, both steps are extremely quick in front of you, and in a fully automatic machine, finished prints can be made in no more than 5 seconds getting produced. In the wet or semi-wet modification of this process, only the diazo salt is used applied with a small amount of stabilizer on the base. After exposure a solution of the coupling components is applied to the sensitized surface using a measuring roller of the product applied. If the developing solution has the correct alkalinity, then through becomes practical immediate coupling of the azo dye is formed. The finished print is obtained after brief drying.

Diazo papers are very popular today because of them

1. Work very quickly, as exposure and coupling only take a few seconds take and in the dry process the print does not require a drying stage,

2. Generate a positive image and

3. work to scale.

For all positive collotype processes, especially those that produce finished copies, a diazotype collotype material is that gives printing of good color density and printing speed is highly desirable.

It has been found that the - dialkylamino - 2 - chloro - benzenediazonium halogen metals, when incorporated into diazotype collotype formulations, improved diazotype collotype materials result, which in terms of color line density and printing speed compared such diazo compounds, such as 4-benzylethylamino-benzene diazonium chlorozincate, today at

Wet or semi-wet processes commonly used Connection, represent a great improvement.

The new diazonium salts can be Ιιε ^ εείβΐΐί, by a solution of the corresponding 4-dialkylamino-2-chloro-1-aminobenzene hydrochloride in a manner known per se in an ice bath with a nitrite, such as sodium nitrite, to the corresponding diazonium salt. The diazo salts are slightly after reaction with tin (IV) chloride, which forms a double salt and is filtered off as a precipitate can be isolated from the reaction mixture. If desired, other complexing agents can be used Salts of zinc and cadmium chloride and boron fluoride are used to precipitate the diazo salt will.

Examples of 4-dialkylamino-2-chloro-benzenediazonium compounds, that can be used for such purposes are those derived from the following diamines:

^ Ethylpropylamino ^ -chlor-l-amino-benzene,
4-butylpropylamino-2-chloro-l-aminobenzene,
4-butylethylamino-2-chloro-1-aminobenzene.

The diazo components derived from the above amines can be in the customary manner any suitable support, such as paper, fabric or films, for example those made of cellulose ether and -ester, regenerated cellulose, high polymers and polymerisation products. she can be used in one of the stabilized forms in which diazo components in general can be obtained from the diazotization solutions before application to the diazotype documents. to These forms include the zinc chloride, cadmium chloride, tin chloride and boron fluoride double salt, the Sulfates, chlorides and alkyl or aryl sulfonates of the diazo components. Any compound that acts as a coupling component works and is also otherwise suitable for diazotype recipes, can be used to achieve the desired color shade. the Coupling component can be used as the color-forming developer in a developing solution when so-called One component or wet development diazotype processes can be used. Examples for preferred coupling components are:

Sodium salt of 7-amino-l-naphthol-

3,6-disulfonic acid,
2,3-naphthalenediol or its 6-sulfonic acid derivative,

2-naphthol-3,6-disulfonic acid,
2,7-naphthalenediol,
8-amino-2-naphthol,

l- (7-Hydroxy-l-naphthyl) -biguanide, 8-amino-1-naphthol ^ o-disulfonic acid,
1-naphthol-4-sulfonic acid,
l-naphthol-3,8-disulfonic acid,
Phloroglucine,

m-hydroxyphenylurea, acetoacetanilide,

8-hydroxy-1-naphth- (1,2) -imidazole,
N-Cyclohexylacetoacetamide,
Resorcinol,

4,6-dichlororesorcinol, 1 - (m-hydroxyphenyl) -biguanide,
4-chlororesorcinol,
4,6-dihydroxy-2-naphthalenesulfonic acid.

In the production of photosensitive diazotype layers from application solutions which contain the inventive Containing diazo compounds as photosensitive substances will be the basis or the carrier material is sprayed in a known manner with the sensitizing solution or application solution, or immersed in it, or this is applied with brushes, the respective application method depends on the carrier used. Used as the basis for photosensitive coatings is used, then the solution is generally applied by means of a trough and a scraper, the paper being pulled through the trough and the excess solution scraped off with the scraper will. The application solution can also be brushed or sprayed onto the paper. Becomes a Footage is used as the basis, then the order solution is used to facilitate penetration solvents or swelling agents are added to the active substances, and the solution is generally applied by immersion. Except for the diazo compound and the impregnating and swelling agents the application solution may also contain dissolved metal salts that are intended to intensify the color image, z. B. aluminum sulfate and nickel sulfate, stabilizers such as thiourea, thiosinamine and Naphthalenetrisulphonic acid, acids for effecting the complete dissolution of the solid components and to help prevent pre-coupling reactions, e.g. B. citric acid, tartaric acid and boric acid, as well as hygroscopic agents such as glycol and dextrin.

The following examples illustrate the preparation of diazo-type collotype materials from the diazo compounds. Unless otherwise specified, the parts are parts by weight.

example 1

4-ethylpropylamino-2-chloro-benzenediazonium tetrafluoborate

2.5 g of 4-ethylpropylamino-2-chloro-1-aminobenzene hydrochloride are dissolved in 15 ml of 2N hydrochloric acid, cooled to 0 ° C. in an ice bath and treated dropwise with 2 ml of 5N sodium nitrite solution while stirring. 3 ml of 47% strength fluoboric acid are added to the diazonium solution, and the precipitated 4-ethylpropyl-amino-2-chloro-benzene diazonium fluorate is filtered off; Yield 36% of theory. After recrystallization from ethanol, the compound melts at 103 to 105 ^° C. and shows the following analytical values:

Calculated ... C 42.5, H 4.82, N 13.52%;
Found ... C 42.4, H 4.74, N 13.48%.

Example 2

4-butylethylamino-2-chlorobenzoldiazomumhexachlorostannate (IV)

2.6 g of 4-Butyläthylamino-2-chloro-l-amino-benzene hydrochloride are dissolved in 15 ml of 2N hydrochloric acid, cooled in an ice bath to 0 ⁰ C and treated dropwise with stirring with 2 ml of 5N sodium nitrite solution. The temperature is not allowed to rise ^{above 5 ° C.} 3 ml of 51% strength aqueous tin (IV) chloride solution are added to the diazonium solution, and the 4-butylethylamino-2-chloro which has precipitated

BenzoldiazoniumchlorostannatilV) is filtered off; Yield 37% of theory. Melting point 132.5 to 134 ° C with decomposition.

Comparative example 1

The paper backing material is coated with the following sensitization formulation at the same time:

Parts by weight of 4-propylethylamino-2-chloro-benzene-

diazonium chlorostannate (IV) 1.5

Citric acid 0.5

Aluminum sulfate 0.5

Sodium 1,3,6-naphthalene trisulfonate 2

Thiourea 0.5

Modified corn starch 15

Silica 1

Polyvinyl acetate emulsion 3

Water 100

The paper is dried and exposed under a translucent original. The exposed sheet is developed by being drawn through the following alkaline solution:

Parts by weight The paper is dried and placed under a translucent Original exposed. The exposed sheet is developed by passing through the following alkaline Solution is drawn:

Parts by weight borax 50

sodium

Thiourea

Phloroglucine

Resorcinol

Sodium isopropyl naphthalene sulfonate

20th

10

borax

sodium

Thiourea

Phloroglucine

Resorcinol

Sodium isopropyl naphthalene sulfonate

50

20th

10

Water 1000

Dense black lines are obtained. A sensitization solution according to the above, which is a conventional wet process diazo compound such as 4-benzylethylamino-benzene diazonium chlorostannate (IV) in such an amount as to achieve the same printing speed creates black lines of lower density.

Comparative example 3

Similar results are obtained using 4 - butylpropylamino - 2 - chlorobenzene diazonium tetrafluoroborate achieved when the paper backing material is used at the same time as the following sensitization recipe coated:

Water 1000

Dense black lines are obtained. A sensitization solution according to the above, which is a conventional wet process diazo compound such as 4-benzylethylamino-benzene diazonium chlorostannate (IV) in such an amount as to achieve the same printing speed creates black lines of lower color density.

Comparative example 2

The paper backing material is coated with the following sensitization formulation at the same time:

Parts by weight of 4-butylethylamino-2-chloro-benzene-

diazonium chlorostannate (IV) 1.5

Aluminum sulfate 0.5

Citric acid 0.5

Sodium 1,3,6-naphthalene trisulfonate 2

Thiourea 0.5

Modified corn starch 15

Silica 1

Polyvinyl acetate emulsion 3

Water 100

4-butylpropylamino-2-chlorobenzene parts by weight

diazonium fluorate 1.0

Citric acid * 0.5

Aluminum sulfate 0.5

Sodium 1,3> 6-naphthalene trisulfonate 2

Thiourea 0.5

modified corn starch 15

Silica 1

Polyvinyl acetate emulsion 3

Water 100

The paper is dried and exposed under a translucent original. The exposed sheet is developed by passing through the following alkaline. Solution is drawn:

borax

sodium

Thiourea

Phloroglucine ....

Resorcinol

Sodium isopropyl naphthalene sulfonate

Parts by weight

. 50 20 10

Water 1000

Dense black lines are obtained. An awareness similar to the above, the a conventional wet process diazo compound such as 4-benzylethylamino-benzene diazonium chlorostannate (IV), in such an amount that the same printing speed is achieved, creates black lines of lower density.

Claims (2)

Patent claims: 1. Benzene diazonium compounds of the general formula where R ₁ and R _{2 represent} different alkyl radicals having 2 to 4 carbon atoms, the sum of the carbon atoms in R ₁ and R _{2 being} at least 5, and Y being the radical BF ₄ , ZnCl ₃ , CdCl ₃ or 1/2 SnCl ₆ . 2. Process for preparing the benzene diazonium compounds according to claim 1, characterized in that one known per se Way, a solution of a corresponding 4-dialkylamino-2-chloro-1 - amino-benzene hydrochloride the general formula