GB2130196A

GB2130196A - Nitrated aryl ethers

Info

Publication number: GB2130196A
Application number: GB08119327A
Authority: GB
Inventors: Rainer Hagel; Klaus Redecker
Original assignee: Dynamit Nobel AG
Current assignee: Dynamit Nobel AG
Priority date: 1980-06-24
Filing date: 1981-06-24
Publication date: 1984-05-31
Also published as: GB2130196B; FR2538384A1; DE3023462A1; FR2538384B1; DE3023462C2

Abstract

Nitrated aryl ethers for use in explosive, propellant, ignition and intensifier charges are prepared by nucleophilic substitution of the halogen atoms in an aromatic halogenonitro compound by an aromatic hydroxy compound, generally in the presence of a base, the reactants being chosen such that at least one of the benzene rings in the reaction product obtained contains three nitro groups and the remainder contain(s) one or up to three nitro groups.

Description

SPECIFICATION Nitrated aryl ethers This invention relates to novel nuclearly nitrated aryl ethers and to a process for the production thereof.

The production of polynitroaryl ether compounds by reaction of dihydroxyaryl compounds with nitrochlorobenzenes in the presence of alkali is described for example in United States Patent Specification 3,944,575 or in C.A. 85,159665 (1976). The use of these lowly nitrated ethers as explosives is not disclosed.

The production of aryl ethers nitrated to a greater extent by reaction of 1,3-dichloro-4,6- dinitrobenzene with resorcinol or hydroquinone has been described hitherto. These ethers are cyclic ethers which can undergo subsequent nitration to yield a thermally stable octanitroether, which has been proposed for use as an explosive.

It is a disadvantage of these known processes that products are obtained thereby in which a maximum of only two nitro groups is present in each benzene ring. These nitro groups must yield an adequate amount of oxygen if complete conversion of an explosive material, especially when containing a binder, is to occur and the required explosive heat be obtained. Moreover, the introduction of further nitro groups by a subsequent nitration reaction is almost impossible. Hence, these known products contain too little oxygen for use as explosive material. It is considered that nitrated aromatic compounds for use as explosive materials should possess, if at all possible, three nitro groups per benzene ring.

Another facet of the problems which have existed hitherto has been the need to produce a thermally stable substance which can be employed alone as an explosive substance, or employed in the presence of binders, the hitherto used propellants such as nitrate esters of cellulose, or polyvinyl alcohol. These hitherto used propellants possess the disadvantage that they generally undergo selfignition at temperatures below 2000C and are therefore unsuitable for operation at the higher temperatures which can be experienced in particular in space travel or with weapons or high cadence.

According to one aspect of the invention, there is provided a nitrated arylether which either 1) possesses the general formula Ar'-O-Ar"-O-Ar' or 2) contains the repeating unit #Ar'-0-Ar"-O# wherein a) Ar' denotes a) the residue of a benzene, toluene or anisole molecule substituted by 1 to 3 nitro groups or p) a residue of the formula

in which A denotes oxygen or one of the groups

and m is O or 1 and one of the free valencies of the carbon atoms in the case of the compounds of formula I is saturated by a hydrogen atom, or y) the residue a fused ring aromatic hydrocarbon substituted by at least three nitro groups; and wherein b) Ar" stands for a) a phenyl residue when Ar' is the residue of a benzene, toluene or anisole molecule substituted by 3 nitro groups or p) i. the residue of a benzene, toluene or anisole molecule, ii. a residue of the formula

wherein A and m have the aforesaid meanings and at least one of the free valencies of the carbon atoms is saturated by a hydrogen atom, or iii. the residue of a fused ring aromatic hydrocarbon which residue is substituted by at least one nitro group; c) n has a value of from 4 to 20 and d) the positions of Ar' and Ar" can be exchanged with one another.

These ethers of this invention possess decomposition temperatures above 2000C and are suitable for use as such as explosives or propellants. They possess an adequate number of nitro groups per benzene ring.

According to a second aspect of this invention, there is provided a process for the production of a nitrated aryl ether, which comprises reacting an aromatic halogenonitro compound of formula: (Haliq Ar' wherein Hal denotes a halogen atom, Ar' has the aforesaid meaning and q is 1 when Ar' is a said residue a . or is 2 when Ar' is a said residue a .p or a 1 with a compound of formula (OH)r-Ar" wherein Ar" has the aforesaid meaning and r is 1 when Ar" is a said residue b.cy and 2 when Ar" is a said residue b.P. Reaction is preferably effected in the presence of basic media.It is preferred to use trinitrohalogeobenzenes ab initio to produce the required polynitropolyphenylene oxides although, especially if insufficient nitro groups/benzene ring are present, by subsequent nitration, a maximum of two further nitro groups can be introduced to each dihydroxybenzene structural unit.

It is important that one of the two reaction partners is substituted by two hydroxy groups or two halogen atoms. As well as employing a dihaiogeno-polynitrobenzene, a dihydroxynitrobenzene can also be used as one of the starting materials; the other reaction partner must then possess the necessary corresponding grouping for the required reaction to occur. Thus, for example, it is possible to react an aromatic dihydroxy compound with an aromatic monochloro compound employed usually in a molar ratio of 1:2.0 to 1:2.2 to obtain a compound of formula, for example

or an aromatic dichloro compound with a monohydroxy compound usually in a molar ratio of 1:2.0 to 1.1 to 2.0 to obtain a compound of formula, for example

p having a value of from 0 to 3, if only oligomeric compounds are to be obtained.At least one of the reaction partners should possess three nitro groups per benzene ring, and both will if especially energy rich compounds are to be obtained in the nucleophilic substitution reaction which occurs.

It is however also possible to react an aromatic nitrated dichloro compound with an aromatic, optionally nitrated, dihydroxy compound, generally in a molar ratio of 1:1.1. In this case long chain polynitropolyphenylene oxides with molecular weights between 450 and about 3,000 and containing for example the recurring unit of formula

wherein p has the aforesaid meaning, are obtained.

In general in carrying out the aforementioned reactions, the reaction components are employed in such molar ratios that an equivalent of monohydroxy compound or 0.5 equivalents of dihydroxy compound is preferably reacted per halogen atom. The hydroxy compound can also be employed in an excess of 5 to 10%: for example advantageously 2 mol of picryl chloride may be reacted with 1.1 mol of a dihydroxy benzene.

The reaction is preferably carried out in the presence of a base, for example an alkali metal hydroxide which can be dissolved in water. This quantity of the base corresponds to the OH-acid hydrogen content and is preferably employed in excess of about 10%.

In carrying out the reaction of a halogenopolynitroaromatic compound with a hydroxyaromatic compound, which can optionally be nitrated, the components are generally dissolved in a solvent and the base is added under cooling at ambient temperature or below the boiling point of the solvent.

Solvents miscible with water, for example ketones, for example acetone or DMF, DMSO and alcohols are suitable, as are also solvents of limited solubility in water, for example methyl acetate.

After the end of the reaction, water is added to precipitate a crude product which is filtered off, washed and dried or the reaction product is otherwise freed from solvent, as by solvent vaporisation. It can be used in this form directly as for example high temperature resistant propellant or subjected to a further nitration, for example with fuming nitric acid. This further nitration is preferably so carried out with polymers that the partially nitrated aryl ether is suspended in concentrated sulphuric acid. Fuming nitric acid is added slowly to this suspension. Too strong a heating of the reaction mixture is to be avoided by stirring it or by reducing the speed of the addition of fuming nitric acid. The reaction temperature should if possible not exceed 30"C.

The nucleophilic substitution reaction whereby the compounds of this invention are produced proceeds surprisingly smoothly, although the analogous reaction of for example picryl chloride to produce the corresponding nitrated diphenyl ethers only proceeds cleanly when employing the previously prepared metal salt of the phenol, for example an alkali metal or silver phenolate; frequently it is necessary to work in non-aqueous mediua when carrying out such reaction.

The halogenonitro compounds employable in producing the ethers of this invention may be derived from single or polynuclear aromatic compounds. Examples of mononuclear aromatic compounds which may be used are mono- or dihalogenated di- and trinitro benzenes or the di- or trinitro toluenes, such as 2,4,6-trinitro-3,5-dichlorotoluene or chlorodinitro- and -trinitrobenzenes, or 2,4,6-trinitro-3,5-dichloroanisole. Examples of binuclear aromatic compounds which can be employed as starting materials for the new nitroethers, are dichloropolynitro derivatives of diphenyl, in which optionally the direct bond linking the rings of the diphenyl residue can be connected through bridging atoms of groups comprising hetero atoms for example by oxygen, nitrogen or a group from the list -NH-, -NH-CO-CO-NH- or -CH=CH-. These compounds can be characterised by the general formula

in which A stands for oxygen, nitrogen or for a group from the groups

Y for halogen and m for 0 or 1.

Examples of such diphenyl derivatives are 3,3'-dichloro-2,4,6,2',4',6'-hexanitrodiphenyl, dichlorohexanitrostilbene and dichlorohexanitrodiphenylamine. Other polynuclear starting compounds which may be used include the dihalogenopolynitro derivatives of fused aromatic hydrocarbons, for example naphthalene, anthracene or phenanthrene.

The aromatic hydroxy compounds which may be employed when producing the products of this invention are derived, like the chloronitro compounds, from mono- or polynuclear aromatic compounds which can be if necessary contain aromatic rings fused with one another. Examples of mononuclear aromatic hydroxy compounds which can be used include phenol, as well as nitrophenols and pyrocatechol, resorcinol and hydroquinone and their nitro derivatives. The corresponding derivatives of toluene or anisole may also be used. Polynuclear aromatic hydroxy compounds which may be used include, naphthols or dihydroxy diphenyls as well as their nitro derivatives, i.e. compounds whose ring system may be a polynuclear ring system of one of the types already postulated for the halogenonitro compound.

The nitrated aryl ethers according to the present invention possess a remarkably high thermal stability. Because of their higher energy content and their improved oxygen balance with respect to hitherto known nitrated aromatic compounds they may be used as propellants when high thermal requirements are set.

The production of the nitrated aryl ethers of this invention is described further in the following examples which commence with two preparatory examples relating to the preparation of starting compounds.

PREPARATIVE EXAMPLE A Picryl chloride 229 g of dry picric acid and, dropwise, without cooling, 100 ml of pyridine were added to 140 ml POCL3 with stirring. The temperature increased to 75 to 800C. After maintaining the reaction mixture for one half hour at 900C on an oil bath, the reaction solution obtained was cooled to about 400C and poured into 3 litres of water agitated with a Turrax stirrer. Picryl chloride was precipitated, washed until acid free and dried.

Yield 240 g (97% of theoretical) Melting point 79 to 81 0C.

PREPARATIVE EXAMPLE B Styphnic acid dichloride 730 g (1.81 mol) of dipyridinium styphnate were added with stirring (initially without cooling) in portions to 350 ml (3.82 mol) POCI3. The temperature increased and was limited to 700C. After completion of addition of the salt, the reaction mixture was warmed under continuous stirring for 30 minutes to 1000C, then cooled to 40O to 500C and the mixture was decomposed by addition in portions into 3 litres of water, accompanied by strong stirring. The water temperature was held at 300C by addition of ice. After filtering, the residue was washed acid free and dried in air.

Yield: 480 g (94.0% of theoretical) Melting point 122O to 1260C.

EXAMPLES 1-3 Bis-(trinitroxy)-benzene 495 g (2 mol) of picrylchloride and 121 g (1.1 mol) of a dihydroxybenezeneras follows: Example 1: pyrocatechol Example 2: resorcinol Example 3: hydroquinone were treated, in 1 litre acetone with 88 g (2.2 mol) NaOH in water (1:1) added dropwise while the reaction mixture underwent strong stirring. In Example 3, the hydroquinone was added dissolved in 1.3 litres acetone and reaction was effected at 200C with cooling. In Example 2 reaction was effected at boiling temperature. Stirring was continued for a further 1 5 minutes and then 4 litres of water were added drop by drop. The solid phase was separated off by filtration, washed with water and then with ethanol and dried.

Yield: 1 ,2-bis-(2',4',6'-trinitroxy)-benzene 346 g (65% of theoretical) (Example 1) 1 ,3-bis-(2',4',6'-trinitrophenoxy)-benzene 479 g (90 /O of theoretical) (Example 2) 1 ,4-bis-(2',4',6'-trinitrophenoxy)-benzene 480 g (90% of theoretical) (Example 3) The compounds obtained possessed the following properties:

Properties Friction Impact M.p. Ep sensitivity EH Compound (C) ('C) (N) (J) (JIg) 1,2-Bis 235-238 320 > 350 8 2850 1,3-Bis 188-190 320 > 350 8 2970 1,3-Bis 350 320 > 350 8 2850 M.p.Melting point Ep = Explosion point EH = Explosion heat EXAMPLES 4 TO 6 282 g (1 mol) of styphnic acid dichloride and 278 g (2 mol) of a nitrophenol as follows: Example 4: 2-nitrophenol Example 5: 3-nitrophenol Example 6: 4-nitrophenol were dissolved in 1 litre acetone and treated at 200C under cooling with 80 g (2 mol) NaOH in water (1:1) added dropwise under strong stirring. The procedure as described in Examples 1 to 3 was then carried out.

Yields: 1 ,3-bis-(2'-nitrophenoxy)-2,4,6-trinitrobenzene 404 g (83% of theoretical) Melting point 2650 to 268"C (Example 4) 1 ,3-bis-(3'-nitrophenoxy)-2,4,6-trinitrobenzene 141 g (29% of theoretical) Melting point 1800 to 182 C (Example 5) 1 ,3-bis(4'-nitrophenoxy)-2,4,6-trinitrobenzene 405 g (83% of theoretical) Melting point 2230 to 227 0C (Example 6) EXAMPLE 7 The procedure of Example 3 was repeated, but using 1.3 litre dimethylformamide instead of the acetone as solvent. A 480 g yield was obtained (90% of theoretical).

EXAMPLE 8 The reaction of Example 3 was repeated but using 1 70 ml pyridine. The product yield was 420 g (79% of theoretical).

EXAMPLE 9 The reaction of Example 3 was repeated, but using 240 ml triethylamine as base, instead of the sodium hydroxide. A 480 g yield (90% of theoretical) was obtained.

EXAMPLE 10 495 picrylchloride and 1 21 g hydroquinone were dissolved in 3 litres of methyl acetate and treated under cooling with 240 ml triethylamine while undergoing vigorous stirring and at a maximum of 300 C. After distilling off the solvent in vacuum, the residue was first washed with warm ethanol, then with water. The yield of 1 ,4-(2',4',6'-trinitrophenoxy)-benzene was 400 g (75% of theoretical) EXAMPLE 11 (nitration) 10 g of each of the reaction products from Examples 4 to 6 were dissolved in a 50 ml sample of fuming nitric acid and stirred for one hour at ambient temperature. Then the reaction mixture was poured into 0.5 litre water and the precipitate which formed was filtered, washed and dried.

Yield: 11 g (93% of theoretical) The reaction products produced possessed the following properties.

s Properties Friction Impact M.p. M.p. Ep sensitivity EH Compound \ ('c) (C) (N) (J) (J/9) From Example 4 and 6 277-279 283 > 350 5 3120 From Example 5 277-279 315 > 350 5 ~L 3200

EXAMPLE 1 2 (nitration) Three experiments were carried out, using respectively 50 g samples of the products of each of Examples 1 to 3. In each case 250 ml fuming nitric acid were added to 250 ml concentrated sulphuric acid under stirring and the reaction products was introduced into the warm acid mixture and the suspension was gently boiled for, 1 to 6 hours. After cooling, the solid phase was filtered off, and the residue was washed acid free with water and aliowed to stand for 12 hours in 2.5% NaHCO3 solution.

The solid material was then filtered off, washed and dried.

Yield: 35 to 40 g (6068.4% of theoretical).

The nitration products possessed the following properties:

Properties Friction Impact M.p. Ep sensitivity EH Compound (0C) (C) (N) (J) (J/g) From Example 1 325 300-305 > 350 3 3560 From Example 2 284--286 270-278 > 350 3 3350 From Example 3 > 350 313-325 > 350 4 3300 EXAMPLE 13 The procedures of Examples 2 and 3 were repeated but employing 1,3-dichloro-2,4,6trinitrobenzene, (styphnic acid dichloride) in place of picryl chloride, using a molar ratio of dichloride/dihydroxy benzene of 1:1.1. Polymers were obtained.These were nitrated in the manner of Example 11 for 30 minutes and yielded reactive polynitropolyphenylene ethers. The m-linked product possessed an explosion point of 1 780C, the p-linked an explosion point of 21 30C and an explosion heat of 2793 J/g. The mean molecular weight amounted to 2400. The nitration reaction can take place with greater solids and/or with poorer mixing of the components to obtain a product which may undergo self ignition with powerful combustion. Accordingly, it is preferred to proceed according to Example 12 in the nitration.

EXAMPLE 14 (nitration) 50 g of the polymer from the reaction of 1 ,3-dichloro-2,4,6-trinitrobenzene with hydroquinone by the procedure described in Example 9 were suspended in 400 ml conc. sulphuric acid and treated at a maximum of 300C with 250 ml fuming nitric acid initially added dropwise while vigorous stirring was effected. Reaction was continued for one half hour, the product was poured into 5 litre water and the precipitated solid was filtered off, washed with water and dried.

Yield: 50 g; explosion point 2440 C, explosion heat 2738 J/g.

EXAMPLE 1 5 The reaction of Example 3 was repeated, however with use of 312 g 2,4,6-trinitro-, 3,5dichloroanisole instead of the styphnic acid dichloride in a molar ratio of 1:1.1 with respect to hydroquinone. 310 g of a polymer of explosion point 21 00C were obtained.

EXAMPLE 16 50 g of the polymer of Example 1 5 were nitrated according to the procedure of Example 1 4. 50 g of a substance with an explosion point of 2400C were obtained.

EXAMPLE 17 8 Ml Pyridine were added dropwise to a solution of 10 g 3,3'-dichloro-2,4,6,2',4',6'- hexanitrodiphenyl and 1 5 g 4-nitrophenol in 200 ml acetone at 200C undergoing stirring. The reaction product obtained was poured into 2 litre water and the precipitate which formed was separated off and washed with water and ethanol. 18 g of a substance which softened at from 1 080C were obtained.

EXAMPLE 18 The nitration of 50 g of the product of Example 1 7 by the procedure of Example 1 2 yielded 40 g of a substance with a softening point of 1 700C and an explosion point of 2520C.

Claims

1. A nitrated arylether which either 1) possesses the general formula Ar'-Ar"-Ar' or contains the repeating unit Ar'-O-Ar"-O# wherein a) Ar' denotes a) the residue of a benzene, toluene or anisole molecule substituted by 1 to 3 nitro groups or p) a residue of the formula

in which A denotes oxygen or one of the groups

and mis O or 1 and one of the free valencies of the carbon atoms in the case of the compounds of formula I is saturated by a hydrogen atom, or y) the residue a fused ring aromatic hydrocarbon substituted by at least three nitro groups; and wherein b) Ar" stands for a) a phenyl residue when Ar' is the residue of a benzene, toluene or anisole molecule substituted by 3 nitro groups or the i. the residue of a benzene, toluene or anisole molecule, ii. a residue of the formula

2. A nitrated arylether according to claim 1, which possesses the formula

in which p has a value of 1,2or3.

3. A nitrated arylether according to claim 1, which possesses the formula,

wherein p has the value of 0, 1, 2, or 3.

4. A nitrated arylether according to claim 1, which comprises from 4 to 20 repeating units of the formula

in which p has a value of 1,2or3.

5. A nitrated arylether, substantially as described in any one of the foregoing Examples.

6. A process for the production of a nitrated aryl ether as claimed in any one of the preceding claims, which comprises reacting an aromatic halogenonitro compound of formula: (HaI)-qAr' wherein Hal denotes a halogen atom, Ar' has the aforesaid meaning and q is 1 when Ar' is a said residue a. a or is 2 when Ar' is a said residue α.ss or α. p. with a compound of formula (OH)r-Ar" wherein Ar" has the aforesaid meaning and r is 1 when Ar" is a said residue b. α and 2 when Ar" is a said residue b.ss.

7. A process for the production of a nitrated aryl ether having the general formula Ar'-O-Ar' '-0-Ar' wherein Ar' and Ar" have the aforesaid meanings, which comprises reacting an aroamtic dihalogenonitro containing the residue a.a, a.p ora.yofclaim 1 and an aromatic optionally nitrated monohydroxy compound containing the residue b.a of claim 1 in a molar ratio of 1:2.0 to 1 :2.2.

8. A process according to claim 7, which is carried out to produce a compound according to claim 3.

9. A process for the production of a nitrated aryl ether having the general formula Ar'OAr"OAr' wherein Ar' and Ar" have the aforesaid meanings, which comprises reacting an aromatic monohalogeno-trinitro compound containing a residue a,B of claim 1 with an aromatic optionally nitrated dihydroxy compound containing a residue b.P of claim 1 in a molar ratio of 2:1 to 2:1.1.

10. A process according to claim 9, which is carried out to produce a compound according to claim 2.

11. A process for the production of a polymeric nitrated aryl ether having the recurring unit: #Ar'-O-Ar' 'O wherein Ar', Ar" and n have the aforesaid meanings, which comprises reacting an aromatic dihalogenonitro compound containing the residue a. a, a .p or a p set out in claim 1 with an optionally nitrated dihydroxy compound containing the residue ba or b . set out in claim 1, in a molar ratio of 1:1.1.

12. A process according to claim 11, which is carried out to produce a polymer according to claim 4.

13. A process according to any one of claims 6 to 12, which is carried out in the presence of base in a reaction medium in which the reaction product is precipitated by addition of water or which is removed by evaporation to yield the reaction product.

14. A process according to any one of claims 6 to 13, wherein the reaction product obtained is subjected to nitration.

15. A process according to claim 14, wherein the nitration is effected by suspending the reaction product in concentrated sulphuric acid and adding fuming nitric acid thereto at a temperature of up to 300 C.

1 6. A process for the production of a nitrated aryl ether as claimed in claim 6, substantially as described in any one of the foregoing Examples.

1 7. A nitrated aryl ether, whenever produced by the process claimed in any one of claims 6 to 1 6.

1 8. A propellant charge powder which comprises a nitrated aryl ether as claimed in any one of claims 1 to 5 and 17.

19. An intensifying charge or an ignition charge which comprises a nitrated aryl ether as claimed in any one of claims 1 to 5 and 17.

20. An explosive composition which comprises a nitrated aryl ether as claimed in any one of claims 1 to 5 and 17.

New claims or amendments to claims filed on 24th June 1981.

Superseded claims, All.

1. A nitrated arylether which is: 1) a compound of the general formula Ar'-O-Ar"-O-Ar' or 2) a polymer which contains the repeating unit #Ar'-O-Ar"-O- wherein n is an integer of from 4 to 20, in which compound 1) the residue Ar" and the two residues Ar' and in which repeating unit of said polymer 2) at least one of said residue Ar' and said residue Ar" denotes: a) the residue of a benzene, toluene or anisole molecule substituted by three nitro groups; b) a residue of the formula

in which A denotes oxygen or one of the groups

and m is O or 1 and one of the free valencies of the carbon atoms in the case of the compounds of formula I is saturated by a hydrogen atom when said residue is terminally positioned; or c) the residue of a fused ring aromatic hydrocarbon substituted by at least three nitro groups, and in which compound or polymer any residue Ar' or Ar", when not possessing the meaning a), b) or c), denotes d) i. the residue of a benzene, toluene or anisole molecule substituted by 0, 1 or 2 nitro groups, ii. a residue of the formula

wherein A and m have the aforesaid meanings and a free valency is present in one or both benzene rings of said formula depending respectively on whether it is present at a terminal position or an intermediate position in said general formula or repeating unit, in which formula the benzene rings optionally are substituted by up to two nitro groups; or iii. the residue of a fused ring aromatic hydrocarbon optionally substituted by up to two nitro groups, or 3) the nitration production of a said compound or polymer.

2. A nitrated arylether according to claim 1, which possesses the formula

in which p has a value of O, 1, 2 or 3.

3. A nitrated arylether according to claim 1, which possesses the formula,

wherein p has a value of 0, 1, 2 or 3.

in which p has a value of 0, 1,2 or 3.

6. A process for the production of a nitrated aryl ether as claimed in any one of the preceding claims, which comprises reacting an aromatic halogenonitro compound of formula: (Hal)2-Ar' wherein Hal denotes a halogen atom and Ar' has the aforesaid meaning, with a dihydroxy compound of formula (OH)2-Ar" wherein Ar" has the aforesaid meaning, at least one of Ar' and Ar" possessing one of the meanings a), b) and c).

7. A process for the production of a nitrated aryl ether having the general formula Ar'-0-Ar' '-O-Ar' wherein Ar' and Ar" have the meanings set out in claim 1, which comprises reacting an aromatic dihalogenonitro compound of formula (Hal)2-Ar" with an aromatic monohydroxy compound of formula HO-Ar' in a molar ratio of 1:2 to 1 :2.2, at least one of Ar' and Ar" possessing one of the meanings a), b) and c) set out in claim 1 and Hal denoting a halogen atom.

9. A process for the production of a nitrated aryl ether having the general formula Ar'-0-Ar"-O-Ar' wherein Ar' and Ar" have the meanings set out in claim 1, which comprises reacting an aromatic monohalogeno compound of formula Hal-Ar' wherein Hal denotes a halogen atom and Ar' possesses one of the meanings a), b) and c) set out in claim 1 with a compound of formula (HO)2-Ar" wherein Ar" has one of the meanings a), b), c) and d) of claim 1, in a molar ratio of 2:1 to 2:1.1.

11. A process as claimed in claim 6 for the production of a polymeric nitrated aryl ether having the recurring unit: #Ar'-0-Ar"-0# wherein Ar', Ar" and n have the meanings set out in claim 1, which comprises reacting a said aromatic dihalogenonitro compound wherein Ar' possesses one of the meanings a), b) and c) set out in claim 1 with a said dihydroxy compound wherein Ar" possesses one of the meanings a), b), c) and d) set out in claim 1, in a molar ratio of 1:1.1.

1 5. A process according to claim 14, wherein the nitration is effected by suspending the reaction product in concentrated sulphuric acid and adding fuming nitric acid thereto at a temperature of up to 300C.

16. A process for the production of a nitrated aryl ether as claimed in claim 6, substantially as decribed in any one of the foregoing Examples.

17. A nitrated aryl ether, whenever produced by the process claimed in any one of claims 6 to 16.

1 8. A propellant charge powder which comprises a nitrated aryl ether as claimed in any one of claims 1 to 5 and 1 7.

1 9. An intensifying charge or an ignition charge which comprises a nitrated aryl ether as claimed in any one of claims 1 to 5 and 17.