US2089009A

US2089009A - Method for preparing halogenated

Info

Publication number: US2089009A
Authority: US
Publication date: 1937-08-03
Anticipated expiration: 1954-08-03

Description

Patented,fiiug. 3, 1937 STTE AENT

METHOD FOR PREPARING HALOGENATED INDANTHRONE No Drawing. Application September 10, 1934, Serial No. 743,419

9 Claims.

This invention relates to the preparation of halogen derivatives of indanthrone (N-dihydro- 1,2,2',1'-anthraquinone azine) and more particularly to the selective dehalogenation of indanthrones containing more than 2 atoms of halogen.

It is generally known that indanthrone itself which is not at all fast to chlorine may be rendered comparatively fast to bleach by the introduction of halogen into the molecule. The higher halogenated indanthrone compounds, containing more than 2 atoms of halogen per molecule, while being relatively fast to bleach, are quite easily precipitated from the solution in the vat, or as generally referred to in the trade, they lose the Vat readily, and are also very sensitive to calcareous water thus rendering them unsuitable for dyeing in the vat on commercial scale.

It has been found that the increase in the amount of halogen present in the indanthrone molecule above approximately 2 atoms increases the sensitivity of these products in the vat until those compounds containing 4 or more atoms are so Lmstablein the vat that they cannot satisfactorily be dyed in the ordinary manner.

Many attempts have been made to prepare a halogenated indanthrone which will be comparatively fast to bleach and still be sufficiently stable in the vat to be satisfactory for use in large scale dyeing operations, wherein it is necessary to hold the vat for periods of an hour or more.

A number of methods for halogenating indanthrone have been described in the literature and apparently the method by which the halogen is introduced in the indanthrone molecule is an important factor in the ultimate properties of the dyestuff. By some methods more chlorine must be introduced in the indanthrone molecule to obtain the same degree of fastness to chlorine that is obtained by the introduction of less chlorine by other methods. In the halogenation of indanthrone by the known methods a point is reached beyond which further halogenation does not increase the bleach fastness. In some cases this is. as low as 15% chlorine, while in others it is as high as 20%. It has also been found that in continuous dyeing operations on commercial scale with higher halogenated indanthrones, where the vat is held for any extended period of time, the bleach fastness of the goods dyed at the end of the period is noticeably impaired in comparison with the bleach fastness of the goods dyed at the beginning of 5 the operation. It is also known that in the Vatting of these products, the halogen content of the molecule is decreased during the vatting procedure, and it is believed that the halogen that is liberated in the vatting procedure combines with the alkali present to form. a salt which precipitates the dyestufi. Since in the vatting of the higher halogenated indanthrones the amount of halogen given on is greater than in the vatting of the lower halogenated products, more of the dyestuff is liable to be precipitated, which would app-ear at least in part to account for the decreased stability of their vats.

It has been found that dichloro-indanthrone containing the chlorine in the 3 positions is as fast to bleach as any of the higher chlorinated products prepared by known methods, and that it is also more stable in the vat than the higher halogenated products and less sensitive to calcareous water. I have also found that when this product is vatted by the normal procedure, less chlorine is liberated under the same conditions than is liberated from some dichloroindanthrone bodies which have been prepared by direct chlorination, and which because they are also deficient in bleach fastness are believed to contain part of the chlorine in other positions.

It is therefore concluded that only the halogen in the 3 positions in the indanthrone molecule exerts a favorable influence on the bleach fastness of the product and that this halogen is more firmly attached than the halogen that may be present in other positions. Because of the greater stability of this halogen, it is not so readily attacked in the vatting procedure, although it is to be understood of course that even this halogen may be split oiT by vatting at the usual vatting temperatures if the vat is held for any extended period. This invention takes ad-; vantage of my finding that the halogen present in those positions which have the least influence on good bleach fastness can be selectively re moved by controlling certain conditions in the vatting procedure, and that when this de halogenation is allowed to proceed to a substantially dihalogen body, maximum bleach fastness, stability and solubility are reached.

It is therefore an object of this invention to provide a process whereby higher halogenated indanthrone compounds are partially dehalogenated under such conditions that only that part of the halogen is removed from the indanthrone molecule which adds little or nothing to the bleach fastness of the dyeings and prints obtained from color pastes and powders produced therefrom, whereas that part of the halogen which exerts a favorable influence upon the fastness properties is invariably retained.

It is a further object of my invention to produce dihalogen indanthrone compounds from less desirable higher chlorinated and brominated indanthrones which are equal in fastness properties to the original higher chlorinated and brominated compounds but which are greatly improved in their stability in the vat and are less sensitive to calcarous water.

It is a still further ob'ect of my invention to provide a process wherein the dehalogenation may be carried out in ordinary tap water (as compared to distilled water).

It is a further object of this invention to provide a process for dehalogenating the higher halogenated indanthrone bodies which may be carried out at ordinary room temperatures.

It is a still further object of my invention to provide a method for vatting halogenated indanthrones containing 2 or more atoms of halogen per molecule at ordinary temperature by the use of vatting assistants.

In general my invention consists in the selective dehalogenation of known halogen-indanthrones containing more than 2 atoms of halogen per molecule which may be prepared by halogenating indanthrone by any of the known methods, such as in nitrobenzene, sulfuric acid, sulfuryl chloride, fused sulfur, acetic acid, etc., and those compounds prepared by the partial or complete replacement of bromine by chlorine, as disclosed in U. S. Patents 1,862,843, 1,862,844 and 1,862,865, by vatting in distilled or ordinary tap water at temperatures between 5 and 35 C. and in the presence of vatting assistants when necessary to maintain them in solution in the vat. The products prepared according to my invention are fully equal in bleach fastness to the parent bodies and are improved thereover in regard to solubility and stability in the vat and sensitiveness toward calcareous water in the vatted state, since only that part of the halogen is removed from the indanthrone molecule which adds little or nothing to the bleach fastness of the resulting halogen-indanthrone, whereas'that part of the halogen which exerts a favorable influence upon the bleach fastness properties of the dyestuif is invariably retained.

According to my invention, halogenated indanthrone compounds are vatted at temperatures not materially above 35 C. and preferably between 15 and 35 C. for A to 2 hours, either in distilled water or in hard water with a vatting assistant, by employing .5 to 1.0 part of sodium hydrosulfite and .5 to 1.0 part of caustic soda per part of indanthrone body. The vatting assistant may be omitted provided the vat used is very dilute, or provided distilled or very soft water is used, or when the caustic soda is replaced by an equivalent amount of potassium hydroxide, although I prefer to employ small amounts of certain vatting assistant $0 that the process may be carried out in more concentrated vats using ordinary hard water and the less expensive caustic soda.

In general, I may use any of the vatting assistants which have been described in the prior art for indanthrone colors, such as the condensation products of ethylene oxide and ammonia (U. 5. Patent 1,923,178), the polymerized ethylene oxide and condensation products of ethylene oxide described in French Patent 727,202, and preferably those Water-soluble condensation products of dichlorhydrin and epichlorhydrin with ammonia and water-soluble primary amines, which are described in U. S. Patents 1,977,251, 1,977,253 and 1,977,272. Other aliphatic amines of high molecular weight, such as polymerized ethylene diamine, have also been found to serve equally well as stabilizers for the higher halongenated indanthrone vats at ternperatures below 35 C.

While the dehalogenation reaction usually is completed to the desired degree after the vats have been kept at 3032 C. for about one-half hour, I prefer to prolong the time of vatting to at least 1 to 2 hours in order to be certain that that part of the halogen is removed completely from the indanthrone molecule, which does not influence the bleach fastness of the dyeings and prints, since I have found that my novel dehalogenating procedure does not impair the bleach fastness of the color, even when the vatting is continued for as long as 15 hours, provided that the temperature is not permitted to rise appreciably above 35 C. With conditions otherwise the same, if the vatting is carried out at 40 to 50 C. (the usual vatting temperatures), the resulting dyestuffs are noticeably inferior in bleach fastness and as a rule dye less desirable greenish-blue and dull shades.

The following examples are given to more fully illustrate my invention. The parts used are by weight.

Example 1 25 parts of an acid pasted chlorinated indanthrone compound prepared according to German Patent 331,283, and containing 17.57% chlorine is suspended in 2000 parts of ordinary water (-400 parts hardness per million). There are then added 2 parts of the hydrochloric acid addition salt of the epichlorhydrin-ammonia condensation product described in U. S. Patent 1,977,251, and the temperature is adjusted to 30 to 32 C. 20 parts. of sodium hydroxide and 25 parts of sodium hydrosulfite are now added and the vat is stirred at 30 to 35 C. for 2 hours. The indanthrone body may be isolated from this vat in any suitable manner, forinstance, by air blowing the vat for several hours and recovering the oxidized dyestuff by filtration, or the vat may be salted until the leuco compound is precipitated out of solution and the precipitate filtered off and, if desired, oxidized by treatment with oxidizing agents or simply by exposing the filtered off leuco filter cake to the air. In any case, the product obtained is substantially a dichloro-indanthrone containing 13.5 to 14% chlorine. It dyes and prints cotton in reddish-blue bright shades of equal bleach fastness in comparison with the parent body (trichloro-indanthrone), and is quite lnsensitive to calcareous water.

When the same halogenated indanthrone body as used above is vatted in the ordinary manner with alkaline hydrosulfite and in distilled water at temperatures of 50-55 C. and in the absence of a vatting assistant. for 12 hours and the product isolated in the same manner, :a chlor'mated indanthrone of 12.4% chlorine content is obtained which dyes cotton in shades which are somewhat more greenish and duller and which are distinctly less fast to bleach than dyeings obtained from the parent triohloro-indanthrone.

Example 2 A dyestuif paste containing 100 parts of a trichloro-indanthrone prepared by chlorinating indanthrone in nitrobenzene suspension with chlorine gas until the chlorine content was 18.2%, is suspended in 9500 parts of ordinary water (75-100 parts hardness per million), containing 10 parts of the condensation product of epichlorhydrin and ethylene diamine, described in U. S. Patent 1,977,253. There are then added parts of caustic soda. The temperature is adjusted to 32 C. and 100 parts of sodium hydrosulfite are stirred in the suspension. The vat is stirred for 2 hours at 32 to 34 C. and the product isolated in either of the ways disclosed in Example 1. The product thus obtained is a dichloro-indanthrone containing 13.1% chlorine. It dyes cotton bright blue shades of equal bleach fastness in comparison with dyeings obtained from the original trichloro-indanthrone, and is insensitive to calcareous water containing 75 parts hardness per million.

Example 3 A color paste containing 100 parts of the bromine containing chlorinated indanthrone body described in U. S. Patent 1,862,843, Example 4 (containing 14.5-15.5% chlorine and 1.'5-3.'0% bromine), is suspended in 9000 parts of ordinary hard water, containing 15 parts of the condensation product of epichlorhydrin and monomethylamine, described in US. Patent 1,977,253.

There are then added at 30 C. 75 parts of caustic soda and parts of sodium hydrosulfite and thevat is stirred at 28 to 32 C. "for 1 hours and then salted with parts of common salt. The mass is air blown for 2 to 3 hours or until the oxidation to a bright blue precipitate is complete. The product is filtered off, the cake is washed alkali free with cold water. The dyestuff thus obtained contains 11.5 to 12.5% chlorine and 0.5 to 1.5% bromine on the solids basis. It dyes and prints cotton in reddish-blue shades, which are equally as bright and fully equal in fastness towards chlorine in comparison with the parent body. The vatted product, which contains less chlorine and bromine, is practically insensitive towards calcareous water, whereas the unvatted starting material, containing more chlorine and bromine, cannot be vatted successfully in water of about 100 parts hardness per million.

In place of the 15 parts of the condensation product of epichlorhydrin and monomethylamine, 20 parts of the assistant described in Example 2 of French Patent 727,202 (diethyleneglycol heated with ethylene oxide and the reaction product condensed with oleic acid), or 20 parts of the condensation product of ethylene oxide with ammonia, described in U. S. Patent 1,923,- 178, may be used to maintain the halogenated indanthrone body in solution during the vatting procedure. Similar results are obtained to those described above.

When distilled water is employed for the vatting procedure (at 28 to 32 C.) or when postassium hydroxide is used in equimolar amounts instead of caustic soda in distilled'or hard water, the vatting assistant may be omitted and the same end product is obtained as long as the Example 4 100. parts of the bromine containing chlorinated indanthrone body used in the'preceding example are suspended in 9000 parts of ordinary tap Water (containing '7 5-100 parts hardness per million). There are then added at 30 C. 112 parts of potassium hydroxide and 100 parts of. sodium hydrosulfite. The vat is stirred for 1 hours during which time no precipitation takes place. There are then added 100 parts of sodium chloride. The precipitate is filtered 01-1, and the filter cake is suspended in 300 parts of water and air blown for 3 hours. The resulting dyestufi dyes cotton in bright blue shades of equal bleach fastness in comparison with the starting material and is substantially insensitive to calcareous water in the vat, whereas the original bromine containing chlorinated indanthrone body is very sensitive to calcareous water and. cannotjbe satisfactorily dyed in hard water by the usual dyeing methods.

Example 5 100 parts of monobromo-monochloro-indanthrone as obtained by the procedure described in U. S. Patent 1,862,865 (containing about 15% bromine and 6.5% chlorine) is vatted with the addition of 10 parts of the condensation product of epichlorhydrin and ethylene diamine (described in U. S. Patent 1,977,253) 80 parts of sodium hydroxide and 100 parts of sodium hydrosulfite in 10,000 parts of ordinary tap water, while keeping the temperature below 35 C. After stirring the vat for two hours at 32 to 35 C., the dyestufi? is isolated by either of the methods described in Example 1. The product thus obtained is less sensitive towards hard water vats,

but equal in bleach iastness and brilliancy of shade in comparison with the starting material. It is lower in chlorine and slightly lower in bromine content than the unvatted starting material.

Example 6 30 parts of'athe tetrachloro-indanthrone obtained by chlorination of indanthrone in nitrobenzene according to the process disclosed in Example 2 of U. S. Patent 1,847,329 and which contains 23.21% chlorine, was acid pasted by dissolvingin 200 parts of sulfuric acid and drowning-in 2000 partsof cold water. The precipitate is filtered off, washed acid free and milled to a smooth paste. An amount of this paste equal to 15 parts of tetrachloro-indanthrone (100%) is suspended in 1200 parts of ordinary tap water of about 100 parts hardness per million, containing 1.5 parts of the condensation product of epichlorhydrin and ammonia, described in U. S. Patent 1,977,251. There are then added 15 parts of caustic soda and the temperature is adjusted to 30 to 32 C. 20 parts of sodium hydrosulfite are now added and the vat is stirred at a slow rate for two hours. It will be observed that the color of the vats may be varied within wide limits.

body remains in perfect solution during the entire course of the two hours stirring.

The reaction product may be isolated from this vat by the procedure outlined in Example 1. The resulting product is substantially a dichloro-indanthrone of 13.5-14.0% chlorine content, which dyes and prints in bright reddish-blue shades of fully equal fastness properties towards chlorine in comparison with the parent color paste consisting of tetrachloro-indanthrone.

When a similar amount of the tetrachloro-indanthrone above used is suspended in 1500 parts of distilled water at 50 C. and vatted with parts of caustic soda and parts of sodium hydrosulfite at temperatures of 50 to 55 C., it is found that after hour of vatting, precipitation of a greater amount of the dyestuff takes place, which cannot be brought back into solution by adding more caustic and hydrosulfite or by raising the temperature. After stirring the vat for 2 hours at this temperature, the product is isolated by the method indicated in Example 1. It is a chlorinated indanthrone of 12.4% chlorine content, which dyes cotton in somewhat more greenish and duller blue shades which are distinctly less fast to bleach in comparison with the dyeing obtained from the parent unvatted color paste.

It will be understood that the amounts of alkali and hydrosulfite as well as the degree of dilution As long as the color can be vatted under the conditions employed, a selective dehalogenation, which leaves that part of the halogen intact which is instrumental in imparting bleach fastness to the indanthrone molecule, can be effected according to this invention by maintaining the vatting temperature below 35 C. Experiments have shown that the vatting procedure according to this invention may be carried out successfully at temperatures as low as plus 5 C., provided that a vatting assistant is employed which is capable of holding the color in the vatted state in solution for about A; to 1 /2 hours at this low temperature.

It is not necessary to maintain mechanical agitation throughout the entire process, nor to maintain the temperature within narrow limits, when a complete vat has been obtained, except that the temperature should not be allowed to rise above about 35 C.

In all cases where it is desired to obtain halogenated indanthrone bodies having maximum fastness to bleach, the halogenated indanthrone to be treated must contain suflicient halogen so that the introduction of additional amounts of halogen does not increase its bleach fastness.

I claim:

1. The process for preparing dichloro-indanthrones from higher chlorinated bodies which comprises reacting such higher chlorinated indanthrone bodies in an alkaline hydrosulfite solution at temperatures not materially above 35 C., in the presence of a vatting assistant, until no further chlorine is removed.

2. The process for preparing dichloro-indanthrones from higher chlorinated bodies which comprises reacting such higher chlorinated indanthrone bodies in an alkaline hydrosulfite solution at temperatures not materially above 35 C., in the presence of a vatting assistant of the group consisting of water-soluble condensation products of ammonia or a water-soluble primary aliphatic amine with dichlorhydrin or epichlorhydrin, until no further chlorine is removed.

3. The process for preparing dihalogen-indanthrones from higher halogenated bodies which comprises reacting such higher halogenated indanthrone bodies in an alkaline hydrosulfite solution at temperatures not materially above 35 C., in the presence of a vatting assistant, until no further halogen is removed.

4. The process for preparing dichloro-indanthrones from higher chlorinated bodies which comprises reacting such higher chlorinated indanthrone bodies in an alkaline hydrosulfite solution at'temperatures not materially above 35 C. until no further chlorine is removed.

5. In the process for eliminating that halogen from the molecule of a halogen containing indanthrone compound which adds nothing to the bleach 'fastness of such compound by subjecting it to the action of an alkaline hydrosulfite solution, the step which comprises maintaining the solution at a temperature not materially above 35 C. until no further halogen is removed at that temperature.

6. In the process for eliminating that halogen from the molecule of a halogen containing indanthrone compound which adds nothing to the bleach fastness of the compound, the step which comprises subjecting the halogenated indanthrone to the action of an alkaline hydrosulfite solution maintained at a temperature not materially above 35 C., in the presence of a vatting assistant, and continuing the reaction until no further halogen is removed at that temperature.

7; The process which comprises vatting a chlorinated indanthrone compound containing more than two atoms of chlorine in an alkaline alkali metal hydrosulfite solution at a temperature not materially above 35 C.'in the presence of a vatting assistant.

8. The process which comprises vatting a halogenated indanthrone compound containing more than two atoms of halogen in an alkaline alkali metal hydrosulfite solution at a temperature not materially above 35 C. in the presence of a vatting assistant.

9. The process which comprises vatting a halogenated indanthrone compound which contains no substituents on the azine nitrogen atoms in an alkaline alkali metal hydrosulfite solution at a temperature not materially above 35 C.

O'I'I'O STALLMANN.