FR2487832A1 - Poly-hydroxyphenyl-2, 2H-benzotriazole - UV stabiliser for polymers and cellulosics - Google Patents

Abstract

Polyhydroxyphenyl-2, 2H-benzotriazoles of formula (I) are new (a is 3 or 4, b is zero or an integer, a+b is at most 5, R1 is H or halogen, R2 is H, halogen, opt.branched alkyl, OH, COOH or SO3H; R is H, opt. branched alkyl, cycloalkyl, halogen, NO2 or NH2. In (I) b is 0,1 or 2, R1 is H or Cl, R2 is H, Cl, 1-4C alkyl, cyclopentyl, cyclohexyl, Cl, NO2 or NH2. In partic. R1 is H or Cl, R2 is H, Cl, (m)ethyl, OH or COOH and R is (m)ethyl, Cl, NO2 or NH2. A pref. cpd. is of formula (II) (I) are claimed for use as anti-UV stabilisers e.g. for polyolefins, PVC, PVDC, polystyrene, polyesters and artificial or natural cellulosics.

Description

 POLYHYDROXYPHENYL-2, 2H-BENZOTRIAZOLES AND PROCESSES FOR OBTAINING THE SAME The present invention relates, as new industrial products, to polyhydroxyphenyl-2, 2H-benzotriazoles comprising at least three phenolic groups; the process for obtaining polyhydroxyphenyl-2, 9H-benzotriazoles further constitutes another object of the present invention.

 There are already known mono and dihydroxyphenyl-2, 2H-benzotriazoles, optionally substituted on the phenyl radical by various radicals such as alkyl, alkoxyls ... These various compounds have various uses and are used in particular as agents of optical brightening or UV stabilizers for plastics.

 The various hydroxyphenyl-2, 2H-benzotriazoles of the prior art generally all have a hydroxyl group in position 2 'while the position 6' on the phenyl group is not substituted. It can be 2-monohydroxy-2, 2H, 2H-benzotriazoles optionally comprising, in the 3 ', 4', or 5 'position and in general in the 5' position, various groups such as alkyl, cycloalkyl or alkoxy groups, alkoxycarbonyls, chlorine atoms. Such compounds are for example described in Swiss patent 517,105, in German patent applications 1,965,042, 2,063,861 in American patents 3,738,337 and 4,041,044, in Belgian patents 775,133, 813,882, in French patent applications 2,311,010, 2,311,011, 2,311,012, 2,311,013.

 It can also be optionally substituted 2,2-dihydroxyphenyl-2H-benzotriazoles, the two phenolic groups of which are in position 2 ', 3' or 2 ', 4', or 2 ', 5' on the phenyl ring. Such compounds are for example described in Belgian patent 790,629 and in German patent application 2,505,309.

 Finally, it is worth emphasizing that the various benzotriazoles of the prior art can also contain various substituents such as alkyl groups, halogen atoms, etc.

These substituents being carried by the benzene nucleus forming with the triazole nucleus a condensed polycyclic system.

 Furthermore, the literature and experience show that the properties of these various benzotriazoles and in particular their anti-UV properties (range of absorption frequencies amount of energy absorbed ...) are functions of nature. the number and position of the various substituents. On the other hand, one of the objectives of research in the field of anti-UV stabilizers consists in preparing compounds having anti-UV performances which are always improved, or better suited to certain types of use. The present invention meets precisely this goal.

dans laquelle les divers symboles ont la signification suivante - a : un nombre entier égal à 3 ou 4 - b : un nombre entier pouvant entre nul, la somme (a + b) étant au plus
égale à 5.It has now been determined and this is what makes an object of the present invention of new polyhydroxyphenyl-2, 2H-benzotriazoles, with anti-U "aciu effect and comprising at least three phenolic groups attached to the phenyl radical and having for formula (I):

in which the various symbols have the following meaning - a: an integer equal to 3 or 4 - b: an integer which can be between zero, the sum (a + b) being at most
equal to 5.

- R1: a hydrogen atom, or a halogen atom.

- R2: a hydrogen atom, a halogen atom, a straight or branched alkyl radical, a hydroxyl group, a carboxyl or sulfonic radical.

- R: a hydrogen atom, a straight or branched alkyl radical, a
cycloalkyl radical, a halogen atom, a nitro group, a
NH2 group.

 The object of the present invention therefore relates in particular to trihydroxyphenyl-2, 2H-benzotriazoles of formula (I) subsequently designated as compounds (I1) as well as tetrahydroxyphenyl-2, 2H-benzotriazoles subsequently designated as compounds ( I2).

 The subject of the invention relates, preferably, to the compounds of formula (I1) and (I2) in which the various symbols have the following meaning - b: an integer zero or equal to 1 or 2 - R1: an atom of hydrogen or a chlorine atom.

- R2: a hydrogen atom, a chlorine atom, a straight or branched alkyl radical having from 1 to 4 carbon atoms, a hydroxyl group, a carboxyl radical.

- R: a hydrogen atom, a straight or branched alkyl radical having from 1 to 4 carbon atoms, a cyclopentyl or cyclohexyl radical, a chlorine atom, a nitro group, an NH2 group.

 Finally, among the compounds of formula (here) and (I2), mention will be made very particularly of the compounds in which the various symbols R1, R2, R have the following meaning - R1: a hydrogen atom, a chlorine atom - R2: a hydrogen atom, chlorine atom, methyl or ethyl radical, hydroxyl or carboxyl group.

- R: a methyl or ethyl radical, a chlorine atom, a nitrated group, an NH2 group.

 It should be understood that the hydroxyl groups carried by the phenyl radical can occupy on the latter all the positions available there. It may in particular be trihydroxy-2 ', 4', 6 'phenyl-2, 2H-benzotriazoles, trihydroxy-2', 3 ', 4' phenyl-2, 2H-benzotriazoles, trihydroxy-3 ' , 4 ', 5' phenyl-2, 2H-benzotriazoles or 2-trihydroxy, 4 ', 5' phenyl-2, 2H-benzotriazoles or even tetrahydroxy-2 ', 3', 5 ', 6' (or 2 ', 4', 5 ', 6') or also (3 ', 4', 5 ', 6') phenyl-2,2H-benzotriazoles.

constituent un objet préférentiel selon l'invention. Parmi ces composés on peut citer à titre illustratif - le (trihydroxy-2', 4', 6' phényl)-2, 2H benzotriazole - le chloro-5 (trihydroxy-2', 4', 6' phényl)-2, 2H-benzotriazole - le dichloro-5,6 (trihydroxy-2', 4', 6' phényl)-2, 2H-benzotriazole - 1'hydroxy-5, (trihydroxy-2', 4', 6' phénylj-2, 2H-benzotriazole - le méthyl-5 (trihydroxy-2', 4', 6' phényl)-2, 2H-benzotriazole - le carboxy-5, (trihydroxy-2', 4', 6' phényl)-2, 2H-benzotriazole - le (trihydroxy-2', 4', 6' mêthyl-3' phényl)-2, 2H-benzotriazole - le (trihydroxy-2', 4', 6' diméthyl-3', 5' phényî)-2, 2H-benzotriazole - le (trihydroxy-2', 4', 6' chlore5' phényl)-2, 2H-benzotriazole - le (trihydroxy-2', 4', 6' nitro-5' phényl)-2, 2H-benzotriazole - le (trihydroxy-2', 4', 6' amino-5' phényl)-2, 2H-benzotriazole
D'autres trihydroxyphényl -2, 2H-benzotriazoles, non symétriques comme les (trihydroxy-2', 4', 6', phényl)-2, 2H-benzotriazoles, et qui contiennent les mêmes susbstituants que ceux qui viennent d'être cités dans le cadre des trihydroxy-2', 4', 6' phényl-2, 2H-benzotriazoles, peuvent être cités à titre illustratif des composés de la présente invention.The trihydroxy-2 ', 4', 6 ', phenyl-2, 2H-benzotriazoles and which have the formula

constitute a preferred object according to the invention. Mention may be made, among these compounds, by way of illustration - (2-trihydroxy, 4 ', 6', phenyl) -2, 2H benzotriazole - 5-chloro (2-trihydroxy, 4 ', 6', phenyl) -2, 2H-benzotriazole - dichloro-5,6 (trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole - 1-hydroxy-5, (trihydroxy-2', 4 ', 6' phenylj-2 , 2H-benzotriazole - methyl-5 (trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole - carboxy-5, (trihydroxy-2', 4 ', 6' phenyl) -2, 2H-benzotriazole - le (trihydroxy-2 ', 4', 6 'methyl-3' phenyl) -2, 2H-benzotriazole - le (trihydroxy-2 ', 4', 6 'dimethyl-3', 5 'phenyl) -2, 2H-benzotriazole - le (trihydroxy-2 ', 4', 6 'chlorine5' phenyl) -2, 2H-benzotriazole - le (trihydroxy-2 ', 4', 6 'nitro-5' phenyl) -2 , 2H-benzotriazole - (trihydroxy-2 ', 4', 6 'amino-5' phenyl) -2, 2H-benzotriazole
Other non-symmetrical trihydroxyphenyl -2, 2H-benzotriazoles such as (trihydroxy-2 ', 4', 6 ', phenyl) -2, 2H-benzotriazoles, and which contain the same substances as those which have just been mentioned in the context of trihydroxy-2 ', 4', 6 'phenyl-2, 2H-benzotriazoles, may be cited by way of illustration of the compounds of the present invention.

 Finally, one could also cite the / tetrahydroxy-2 ', 3', 5 ', 6' (or 2 ', 4', 5 ', 6') or also (3 ', 4', 5 ', 6') phenyl / -2, 2H-benzotriazoles optionally substituted in position 5 with a chlorine atom or a methyl group.

 The 2,2-polyhydroxyphenyl-2H-benzotriazoles of formula (I) can be obtained according to known methods and in particular by cyclizing reduction reaction of the corresponding 2-nitro-polyhydroxyazobenzenes. However, it has been found that this cyclizing reduction reaction is carried out poorly or in some cases not at all, if the phenolic functions are not wholly or partly etherified.

 Another object of the present invention is then constituted by a process for preparing the 2,2-polyhydroxyphenyl, 2H-benzotriazoles of formula (I) characterized in that the splitting is carried out by any known means of the polyhydroxyphenyl-2,2H - corresponding benzotriazoles. By this synthetic route, the compounds (I) can be obtained under satisfactory conditions.

dans laquelle les divers radicaux ont la signification suivante - les radicaux R'1 et R'2 sont tels que l'un d'entre eux représente un atome d'hydrogène, ou un atome d'halogène, l'autre radical représentant un atome d'hydrogène, un atome d'halogène un radical alkyle droit ou ramifié, un radical alkoxyle, un radical alkoxycarbonyle, un radical carboxyle.More precisely, another object of the present invention consists of a process for the preparation of polyhydroxyphenyl-2,2H-benzotriazoles of formula (I), characterized in that the ether bond of the etheroxides is cut by any known means of 2,2-phenyl-2H-benzotriazoles of formula (

in which the various radicals have the following meaning - the radicals R'1 and R'2 are such that one of them represents a hydrogen atom, or a halogen atom, the other radical representing an atom hydrogen, a halogen atom, a straight or branched alkyl radical, an alkoxyl radical, an alkoxycarbonyl radical, a carboxyl radical.

- R and b have the same meaning as that previously given for the compounds of formula (I) - Y represents an alkyl or cycloalkyl radical - Y 'has the same meaning as Y or represents a hydrogen atom.

- al is a non-zero whole number at most equal to 4.

- a2 is an integer possibly zero, the sum (al + a2) being equal to 3 or 4.

 According to a preferred procedure, the etheroxide bonds of the phenyl-2, 2H-benzotriazoles etheroxides of formula (II) are cleaved in which the various radicals have the following meaning - the radicals R'1 and R'2 are such that l '' one of them represents a hydrogen atom, a chlorine atom, the other a hydrogen atom, a chlorine atom, a straight or branched alkyl radical having from 1 to 4 carbon atoms, an alkoxyl radical having from q to 4 carbon atoms, an aikoxycarbonyl radical having from 2 to 5 carbon atoms, a carboxyl radical.

 - R: a straight or branched alkyl radical having this carbon zatonatonies, a cyclopentyl or cyolohexyl radical a chlorine atom; a nitro group; an NH2 group.

- Y: an alkyl radical having from 1 to 4 carbon atoms.

- Y ': an alkyl radical having e 1 to 4 carbon atoms or even a hydrogen atom.

 Finally, the process of the present invention is advantageously carried out by carrying out the cleavage of the etheroxide bonds of the phenyl-2, 2H-benzotriazoles of formula (II) in which the various radicals have the following meanings: - the radicals R'1 and R'2 are such that one of them represents a hydrogen atom, or a chlorine atom the other a hydrogen atom, a chlorine atom, a methyl or ethyl radical, a methoxyl or ethoxyl group, a group methoxycerbonyle.

ethoxycarbonyl or carboxyl.

- R: a methyl or ethyl radical, a chlorine atom, a nitrated group, an NH2 group - Y: a methyl or ethyl group - Y ': a methyl or ethyl radical, a hydrogen atom.

 By way of illustration, various etheroxides of (trihydroxy-2 ', 4', o ') phenyl-2, 2H-benzotriazoles that may be used will be mentioned.

- (trimethoxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole - ((triethoxy-2', 4 ', 6' phenyl) -2, 2H-benzotriazole - ((dimethoxy-2 ', 6 ', hydroxy-4' phenyl) -2, 2H-benzotriazole - le (dihydroxy-2 ', 6', methoxy-4 'phenyl) -2, 2H-benzotriazole - le (dihydroxy-2', 4 ', methoxy -6 ', phenyl) -2, 2H-benzotriazole - le (diethoxy-2', 6 ', hydroxy-4' phenyl) -2, 2H-benzotriazole - chloro-5, (trimethoxy-2 ', 4', 6 'phenyl) -2.2H-benzotriazole - 5,6-dichloro (trimethoxy-2', 4 ', 6' phenyl) -2,2H-benzotriazole - methoxy-5 (trimethoxy-2 ', 4 ', 6' phenyl) -2, 2H-benzotriazole - dichloro-5,6 (dimethoxy-2 ', 6', hydroxy-4 'phenyl) -2,
2H-benzotriazole - methyl-5 (trimethoxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole - ethoxycarbonyl-5 (triethoxy-2', 4 ', 6' phenyl) -2, 2H -benzotriazole - (trimethoxy-2 ', 4', 6 'methyl-3' phenyl) -2, 2H-benzotriazole - le (dimethoxy-2 ', 6', dimethyl-3 ', 5' hydroxy-4 'phenyl ) -2, 2H-benzotriazole.

- (trimethoxy-2 ', 4', 6 'chloro-5' phenyl) -2, 2H-benzotriazole - ((trimethoxy-2 ', 4', 6 'nitro-5' phenyl) -2, 2H-benzotriazole
Other non-symmetrical 2,2-trihydroxyphenyl-2H-benzotriazoles etheroxides or tetrahydroxy-phenyl-2, 2H-benzotriazoles and containing the same substituents as those which have just been mentioned in the context of the trihydroxy phenyl-2,2H etheroxides -benzotriazoles "symmetrical" constitute examples of compounds which can be used in the context of the process of the present invention.

 Mention may also be made, among the etheroxides of tetrahydroxyphenyl-2, 2H-benzotriazoles, of the following compounds - trimethoxy-2 ', 3', 4 ', hydroxy-6' phenyl-2, 2H-benzotriazole - tetramethoxy-2 ', 3 ', 4', 6 '(or -2', 3 ', 5', 6 ') phenyl-2,2H-benzotriazole.

As already indicated, any known technique can be used to cut the etheroxide bonds. The methods for cutting etheroxide bonds are for example described in the Houben-weyl treaty: Methoden der organischen
Chemie-phenole-teil 1 Seite 313-416 (1976). According to this teaching, the split can be carried out using strong mineral acids (H2S04,
HBr, HC1, HI) in an aqueous medium or in a solvent medium (alcohol, phenol, acetic acid, etc.). The cleavage can also be carried out by means of metal halides (ale13, AlBr3, BC13, BBr3 ...) in an organic medium (benzene, dioxane, dichloroethane, nitrobenzene ...). The cleavage can also be carried out using nucleophilic reagents such as mineral or organic bases in an aqueous or alcoholic medium.

 In general, the etheroxide groups are cut off advantageously in an aqueous or hydroalcoholic medium in the presence of halogenated hydracids such as hydrobromic acid or hydroiodic acid (cf. for example synthesis 10 771/1978).

 The reaction being completed, the medium is made alkaline and the 2-polyhydroxyphenyl benzotriazole is separated by any known means; this is generally present in the form of a precipitate which can be recrystallized from any suitable solvent such as, for example, organic esters.

The etheroxides of the polyhydroxyphenyl-2, 2H-benzotriazoles of formula (II) can be obtained in general directly by a cyclizing reduction reaction of the etheroxides of 2-nitro polyhydroxy, azobenzene, the phenol etheroxide groups all being carried by the benzene nucleus not comprising not the NO2 group. These various substituted azobenzene derivatives then have the formula (III)

 The various symbols R'1, R'2, Y, Y ', al, a2; R, b having the meanings previously given.

 Finally, it will be indicated that certain etheroxides of polyhydroxyphenyl-2, 2H-benzotriazoles can be obtained according to known methods, by first carrying out a reaction of cyclizing reduction of etheroxides of nitro-2, polyhydroxyazobenzenes then by introducing or transforming during an additional step various substituents such as for example No2 groups ...

avec les etheroxydes de polyhydroxybenzène de formule (V)

The etheroxides of formula (III) can themselves be prepared by any known method, for example by reaction of the diazonium salt of the corresponding o-nitroaniline of formula (IV)

with polyhydroxybenzene etheroxides of formula (V)

 O-nitroaniline (IV) can optionally be reacted with the polyhydroxybenzene corresponding to formula (V), this latter reaction then being followed by an alkylation reaction by any known means of the free phenolic groups. Polyhydroxybenzenes and their ethers are well known compounds such as, for example, described in Methoden der Organischen Chemie Band VI / 1C phenole teil 1 und 2 Houben-Weyl (1976).

 The cyclizing reduction reaction of the substituted nitroazobenzenes of formula (III) can be carried out by any known means and in particular by chemical or electrolytic reduction.

 Finally, the chemical reduction of the corresponding substituted nitro azobenzenes can be carried out by means of zinc in alcoholic solution, of alkali hydroxide or by means of alkali sulfides or ammonium sulfides. The reduction can also be carried out by hydrogen in an alkaline aqueous medium or in an organic solvent medium, in the presence of usual hydrogenation catalysts such as nickel, palladium, etc. These various reactions are described in particular in American patents 3 072 585, 3 230 194, 4 041 044 and in French patents 2 311 010, 2 311 011, 2 311 012, 2 311 013.

 It will be indicated that it is also possible to introduce, by means of known methods, various substituents such as NH2, NO2, CH3, C2H5 groups, in various (polyhydroxyphenyl) -2, 2H-benzotriazoles.

 The (polyhydroxyphenyl) -2, 2H-benzotriazoles of formula (I) can be used in many applications.

 These compounds are of great interest in diazo reproduction methods (one-component or two-component diazotypy methods, thermal diazotypy methods) in which reproductions stable under ultraviolet radiation are obtained after formation of azo dyes by reaction of coupling between any diazonium salt known and recommended for this purpose in the diazo reproduction industry (cf. for example the work by D. KOSAR "light sensitive systems") and a polyhydroxyphenyl-2, 2H-benzotriazole of formula ( Ij. There is no discoloration of the dyes formed after accelerated aging tests. In addition, these products in regions where the d-.azonium salt was destroyed by ultraviolet light before the coupling reaction allow these regions. to keep their original white appearance, without any background rise. We also note that these products are colorless or little colored, rifles allow the obtaining of materials having a p high covering workpiece, i.e. a material whose colored parts have a high opacity in the ultraviolet and the near visible range of 20G at 500 nm). Opens each dye molecule being partially formed by a product molecule ultraviolet absorber, the so-called dyes are extremely resistant to daylight.

 The present invention also relates to the use of the polyhydroxyphenyl-2, 2H-benzotriazoles of formula (I) as stabilizers.

 The (polyhydroxyphenylj-2,2H-benzotriazoles of the invention and in particular the (trihydroxy-2,4,4 ', 6' phenyl) -2,2H-benzotriazoles indeed have a very important anti-UV stabilizing power, which is in general clearly superior to that of the corresponding mono or dihydroxyphenyl-2 benzotriazoles. The polyhydroxyphenyl-2, 2H-benzotriazoles can be incorporated in various synthetic or artificial or natural polymeric materials and in general at a rate of 0.001 to 5 X and preferably of 0 , 01 to 1% in order to avoid photodegradation reactions.

We can thus stabilize polyolefins (polyethylene, polypropylene ...) polyvinyl chloride or vinylidene, polystyrene, polyesters (polyethylene terephthalate glycol or butylene glycol ...), natural or artificial cellulosic materials. .

 Finally, it should be noted that the 2,2-polyhydroxyphenyl, 2H-benzotriazoles according to the invention lead, after coupling, to azo dyes with a benzotriazolyl group, which are particularly stable in light and UV radiation.

The following examples illustrate the invention
EXAMPLE 1
Preparation of (trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole

 0.05 mol of (dimethoxy-2 ', 6' hydroxy-4 'phenyl) -2, 2H-benzotriazole (or 13.6 g) in 100 ml of 48% hydrobromic acid is heated to boiling for 4 hours. The methyl bromide release is carried out for 2 hours during which the composition corresponding to the azeotrope (48%) is maintained by removing the excess water.

 After cooling, the reaction medium is evaporated, the medium is taken up with 100 ml of water, the insoluble material is filtered and dried, then recrystallized from 100 ml of 50/50 cyclohexane / ethyl acetate mixture.

(lui-même obtenu par réaction de copulation en milieu hydroalcoolique acide entre le triméthoxy 1, 3, 5 benzène et le chlorhydrate de diazonium correspondant à I'o-nitraniline). On ajoute ensuite 50 g de poudre de zinc et 100 ml de soude (densité d = 1;33) puis agite le milieu durant 12 heures.11 g of (trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole are thus obtained, the physicochemical characteristics of which are as follows - melting point: 2380C - conforming infrared spectrum
OH free: band at 3600 cm 1 - OH linked intramolecularly: 3170 cm 1
-C = N- strip at 1,640 cm 1
aromatic bands: 1,610 - 1,520 - 1,500 cm:: 1,160 - 1,280 cm'l - UV spectrum: maximum absorption wavelength X = 279 - 284 nm
absorbance E at 279 - 284nm = 12,200 l / mole l / cm 1
The (2 'dimethoxy, 6' 4-hydroxy-4 'phenyl) -2, 2H-benzotriazole was obtained in the following manner
0.2 mole (ie: 60 g) of nitroazobenzene of formula is introduced into 500 ml of methanol

(itself obtained by coupling reaction in an acidic hydroalcoholic medium between trimethoxy 1, 3, 5 benzene and diazonium hydrochloride corresponding to o-nitraniline). 50 g of zinc powder and 100 ml of sodium hydroxide (density d = 1.33) are then added and the medium is stirred for 12 hours.

After complete evaporation in a rotary evaporator, the medium is taken up in 400 ml of water and acidified with hydrochloric acid (d = 1.19) until the excess zinc is dissolved; the insoluble material is filtered, washed with water, then purified by treatment with ethyl acetate.

- (polyhydroxyphényl)-2, 2H-benzotriazole obtenu

EXAMPLES 2 to 4
According to the procedure described in Example 1, various (polyhydroxyphenyl) -2.2H-benzotriazoles are prepared by cleavage using methanolic hydrobromic acid solution, corresponding (polyhydroxyphenyl) -2.2H-benzotriazole etheroxides. The results are as follows: a) Example 2
- committed etheroxide

- (polyhydroxyphenyl) -2, 2H-benzotriazole obtained

- (polyhydroxyphényl)-2, 2H-benzotriazole obtenu :

This compound obtained with a yield of 80 X has the following properties - Melting point: 2410 - UV spectrum, absorbance (measured at 292 nm = 8,600 1 / mole 1 / cm-1
measured at 353 nm = 10,000 1 / mole -1 / cm-1 b) Example 3
- committed etheroxide

- (polyhydroxyphenyl) -2, 2H-benzotriazole obtained:

- (polyhydroxyphényl )-2, 2H-benzotriazole obtenu

This compound obtained with a yield This 95% has the following properties: - Melting point - 2800 - UV spectrum, absorbance (# measured b 335 nm = 77 900 1 / mole-1 / cm-1 a? Example 4
- etheroxide used:

- (polyhydroxyphenyl) -2, 2H-benzotriazole obtained

This compound obtained with a yield of 50% has the following properties: - Melting point: 241 - UV spectrum, absorbance (measured at 304 nm = 9,300 1 / mole-1 / cm-1
e measured at 365 nm = 17,400 1 / mole-1 / cm-1
EXAMPLE 5
Preparation of (trihydroxy-2 ', 3', 4 'phenyl) -2, 2H-benzotriazole:

(lui-même obtenu par réaction de copulation en milieu hydroalcoolique acide entre le chlorhydrate de diazonium correspondant à l'o-nitroaniline et le diméthoxy 2,3 phénol).Are introduced into 500 ml of methanol: 0.2 mole (or 60 g) of nitroazobenzene of formula

(itself obtained by coupling reaction in an acidic hydroalcoholic medium between diazonium hydrochloride corresponding to o-nitroaniline and dimethoxy 2,3 phenol).

 70 g of zinc powder and 80 ml of sodium hydroxide (d = 1.33) are added and the mixture is stirred for 10 hours. After complete evaporation, the medium is taken up in 400 ~ ml of water and acidified with HCl (d = 1.19) until the zinc is dissolved. Extracted with 2 x 100 ml of ethyl acetate, eliminates the ethyl acetate and obtains 45 g of oil.

 Demethylated as in Example 1 and 38 g of a creamy white solid is obtained.

Yield: 78.5%
Melting point: 1970C
Absorbance C at 340nm = 22,700 l / mole l / cm 1
IR - mass spectra - NMR compliant
EXAMPLE 6
Preparation of trihydroxy-2 ', 4', 6 'methyl-3' phenyl) -2, 2H-benzotriazole

 - 0.03 mole (7.3 g) of (trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole - 70 ml of water - are loaded into a 250 ml stainless steel autoclave 3 ml of sodium hydroxide d = 1.33 (0.03 m) - 1.5 g of tricaprylmethylammonium chloride and - 2 g of methyl chloride in solution in 40 ml of toluene.

 The mixture is heated for 1 hour at 100, cooled and filtered the insoluble material which is washed with water and dried: 6.2 g of a yellow solid product corresponding to the expected product.

- yield: 80% - melting point: 2320 - UV absorbance spectrum (e at 354 nm) = 21,700 l / mole l / cm 1 -l - Compliant IR spectrum: two types of OH at 3,600 cm and 31,60 cm whose absorbance ratio remains constant with the dilutions - mass spectrum and NMR in conformity
EXAMPLE 7 (tetrahydroxy-2 ', 4', 5 ', 6' phenyl) -2, 2H benzotriazole:

(lui-même obtenu à partir de triméthoxy-3, 4, 5 phénol).The procedure is as described in Example 1, demethylating the following derivative:

(itself obtained from 3, 4, 5, 5-trimethoxyphenol).

The tetrahydroxy-2 ', 4', 5 ', 6' phenyl benzotriazole obtained is compliant (NMR analyzes, mass spectrometry, UV and IR).

EXAMPLE 8 (2'-trihydroxy, 3 ', 4' 5-nitro-phenyl) -2, 2H-benzotriazole

(lui-même obtenu comme décrit à l'exempte 5, suivi d'une nitration à 25 dans le mélange acide nitrique/acide acétique). The procedure is as described in Example 1 by demethylating the derivative

(itself obtained as described in example 5, followed by nitration at 25 in the nitric acid / acetic acid mixture).

The (trihydroxy-2'-, 3 ', 4' nitro-5'phenyl) -2, 2H-benzotriazole obtained complies with IR, UV, NMR and mass.

EXAMPLE 9
1,000 g of a powdered PVC resin are used, characterized by a viscosity index according to standard NF 51 013, of 80 in which is incorporated t52 g of dioctyl phthalete, 8 g of a stabilizing mixture (consisting of calcium stearate, zinc stearate and sorbitol in respective proportions of 58i3%, 29.2%, i2.5%) and, per 50 g of a mixture consisting of 71.4 X epoxidized soybean oil , with 14.3% of hydrogenated bisphenol A, and with 14.3% of nonylphenyl tris phosphite.

 A sheet is prepared from the above composition by calendering at 1700 for 4 minutes, then exposing the test pieces to UV radiation at 350 using the Xenotest 150.

 It is found that the test pieces become light brown after 700 hours of exposure. After 1000 h the coloring is dark brown.

 A new PVC composition is prepared in which 0.05% of (trihydroxy 2) 4 ', 6' methyl-3 'phenyl) -2, 2H-benzotriazole is introduced.

 The test pieces which are obtained from this new composition do not reveal any coloration after 1000 h of exposure.

EXAMPLE 10
A composition is prepared based on a powdered PVC resin, the latter being characterized by a viscosity index, according to the standard.
NF 51 013, of 95.

The composition is as follows - PVC resin: 65.4 g - dioctyl phthalate 33.06 g - calcium stearate 0.16 g - zinc stearate 0.07 g - sorbitol 0.03 g - epoxidized soybean oil 1, 00 g - nonylphenyl tris phosphite: 0.60 g - 2,2,4 trimethyl mercaptoacetate-1,3 pentanediol 0.28 g
The test pieces obtained using this composition turn brown after 300 hours of exposure. They are completely black after 600 hours.

 A composition similar to the previous one is prepared in which 0.2 g of (trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole is incorporated. After 1600 hours of exposure to Xenotest, the test pieces have not undergone any evolution.

 A third PVC composition similar to the preceding ones is also prepared, but into which 0.2 g of (2-hydroxyphenyl) -2,2H-benzotriazole is introduced.

 Upon exposure to Xenotest, brown spots appear after 800 hours. The test pieces are completely black after 1600 hours.

Claims (5)

1 / As new industrial products, polyhydroxyphenyl-2,  2H-benzotriazoles of formula (I)

 equal to 5.  - b: an integer that can be zero, the sum (a + b) being at most  - a: an integer equal to 3 or 4  in which the various symbols have the following meaning  - R1: a hydrogen atom, or a halogen atom.  sulfonic.  straight or branched, a hydroxyl group, a carboxyl radical or  - R2: a hydrogen atom, a halogen atom, an alkyl radical  NH2 group.  cycloalkyl radical, a halogen atom, a nitro group, a  - R: a hydrogen atom, a straight or branched alkyl radical; a 2 / Polyhydroxyphenyl-2, 2H-benzotriazoles of formula (I), according to  claim 1 in the formulas of which the various symbols have the  next meaning  - b: an integer zero or equal to 1 or 2  - R1: a hydrogen atom or a chlorine atom.  hydroxyl, a carboxyl radical.  straight or branched having from 1 to 4 carbon atoms, a group  - R2: a hydrogen atom, a chlorine atom, an alkyl radical  chlorine, a nitro group, an NH2 group.  with 4 carbon atoms, a cyclopentyl or cyclohexyl radical, an atom  - R: a hydrogen atom, a straight or branched alkyl radical having I 3 / Polyhydroxyphenyl-2, 2H-benzotriazoles of formula (I) according to one of  claims 1 or 2 in the formulas of which the various symbols  have the following meaning  - R1: a hydrogen atom, a chlorine atom  - R2: a hydrogen atom, a chlorine atom, a methyl radical  or ethyl, a hydroxyl or carboxyl group.  nitrated, an NH2 group.  - R: a methyl or ethyl radical, a chlorine atom, a group 4 / (Trihydroxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazoles according to one of  claims 1 to 3 and having the formula

 5 / Process for the preparation of polyhydroxyphenyl-2, 2H-benzotriazoles according to  one of claims 1 to 4 characterized in that one carries out by  any known means cutting the ether bond of the etheroxides of  2,2-phenyl-2H-benzotriazoles of formula (II)

 in which the various radicals have the following meaning - the radicals R'1 and R'2 are such that one of them represents a hydrogen atom, or a halogen atom the other radical represents a d atom hydrogen, a halogen atom, a straight or branched alkyl radical, an alkoxy radical, an alkoxycarbonyl radical, a carboxyl radical.  being at most equal to 5.  - b an integer which can be zero, the sum {b + al a2)  NH2 group,  cycloalkyl radical, a halogen atom, a nitro group, a - R: a hydrogen atom, a straight or branched alkyl radical, a  - Y 'has the same meaning as Y or represents a hydrogen atom.  - Y represents an aikyle ru cyoloalkyle radical  - al is a non-zero whole number at most equal to 4.  being equal to 3 or 4.  - a2 is an integer possibly zero, the sum val + a2)  Claims 1 to 4 as UV stabilizers  5 / Use of polyhydrophenyl, 2H-benzotriazoles according to one of