FR2487831A1 - Poly-hydroxyphenyl-2, 2H-benzotriazole ether - UV stabiliser for natural and synthetic polymers - Google Patents

Abstract

Novel polyhydroxyphenyl-2, 2H-benzotriazole ether are of formula (I) (R1 is H or halogen; R2 is H, halogen, opt.branched alkyl, alkoxy, alkoxycarbonyl or carboxy; R3 is opt.branched alkyl, cycloalkyl, halogen, nitro or NH2; each of R, R' and R" is H or (cyclo)alkyl at least one not being H; a is 1 or 2, b is 0,1 or 2 and a+b is not more than 3. In (I) R1 is H or Cl; R2 is H, Cl, 1-4C alkyl, OH or COOH; R3 is 1-4C alkyl, cyclopentyl or cyclohexyl, Cl, NO2 or NH2; R, R' and R" are H, 1-4C alkyl, cyclopentyl or cyclohexyl at least one not being H. The use of (I) as stabilisers against UV is claimed (I) is used in natural and synthetic polymers (e.g. polyethylene, PVC, PVDC, polyesters, cellulosics) in amt. of 0.001-5, pref. 0.01-1 wt.% to avoid or reduce photodegradation reactions.

Description

POLYHYDROXYPHENYL-2,2H-BENZOTRIAZOLES ETHEROXIDES
AND THEIR PROCESS FOR OBTAINING
The present invention relates, as new industrial products, polyhydroxyphenyl-2,2H-benzotriazoles etheroxides, the benzene nucleus of which is connected directly to the benzotriazolyl group, comprises on each position ortho to the benzotriazolyl group a phenolic group and / or an alkoxyl group. The process for obtaining the etheroxides of these polyhydroxy-phenyl-2, 2H-benzotriazoles also constitutes an object of the present invention.

 Polyhydroxyphenyl-2, 2H-benzotriazoles etheroxides are already known, optionally substituted on the phenyl radical by various radicals such as alkyl radicals ... These various compounds are intermediate products for coloring matters, optical brighteners and UV stabilizers.

 The various etheroxides of hydroxyphenyl-2, 2H-benzotriazoles and which appear in the prior art generally all contain a hydroxyl or alkoxyl group in position 2 '(first position ortho) while position 6' (second position ortho opposite of the benzotriazolyl group) is not occupied.

 It can be, for example, 2-monohydroxy-phenyi-2, 2H-benzotriazoles comprising in position 3 ', 4' or 5 'and in general in position 5' various groups such as alkoxy groups or hydroxyl groups , alkyls, cycloalkyls, alkoxycarbonyls, chlorine atoms, etc. Such compounds are for example described in Swiss patent 517,105, in German patent applications 1,965,042; 2,063,861 in US patents 3,738,837 and 4,041,044 in Belgian patents 775,133, 813,882, and finally in French patent applications 2,311,010, 2,311,011, 2,311,012, 2,311,013.

 Finally, it is good to emphasize that the various benzotriazoles of the prior art can also contain various substituents such as alkyl groups, halogen atoms, these substituents being carried by the benzene ring forming with the triazolylic heterocycle a polycyclic system condensed.

 The literature also teaches that benzotriazoles are sought-after products as anti-UV stabilizers and it is also known that the properties of these various benzotriazoles and in particular their anti-UV properties (range of absorption frequencies, quantity of energy absorbed ...) are a function of the nature, number and position of the various substituents. This is why we continue to look for anti-UV compounds with increased efficiency or better suited. certain types of use. The present invention precedes this goal.

dans laquelle les divers symboles représentent : - R1 : un atome d'hydrogène, un atome d'halogène - R2 un atome d'hydrogène, un atome d'halogène, un radical alkyle
droit ou ramifié, un radical alkoxyle, alkoxycarbonyle,
carboxyle.I1 has now been found and this is what constitutes an object of the present invention of new polyhydroxyphenyl-2, 2H-benzotriazoles etheroxides in which the two ortho positions of the benzotriazolyl group are occupied by hydroxyl and / or alkoxy groups and having an anti-UV effect improves. More specifically, an object of the present invention consists of polyhydroxyphenyl-2,2H-benzotriaole etheroxides and having the formula (I)

in which the various symbols represent: - R1: a hydrogen atom, a halogen atom - R2 a hydrogen atom, a halogen atom, an alkyl radical
straight or branched, an alkoxyl, alkoxycarbonyl radical,
carboxyl.

- R3: a straight or branched alkyl radical; a cycloalkyl radical; a
halogen atom; a nitro group; an NH2 group.

- Each of the radicals R, R ', R ": a hydrogen atom or an alkyl or cycloalkyl radical, at least one of these three radicals being different from a hydrogen atom.

- a: an integer equal to 1 or 2.

- b: an integer equal to 0, 1 or 2, the sum (a + b) being at most equal to 3.

The subject of the invention relates preferably to the etheroxides of polyhydroxyphenyl-2, 2H-benzotriazoles according to formula (I) in which the various symbols have the following meanings - R1: a hydrogen atom, a chlorine atom - R2: a hydrogen atom, a chlorine atom, an alkyl radical
straight or branched having from 1 to 4 carbon atoms, a group
hydroxyl, a carboxyl radical.

- R3: a straight or branched alkyl radical having from 1 to 4 atoms of
carbon, a cyclopentyl or cyclohexyl radical; an atom of
chlorine; a nitro group; an NH2 group.

- R, R ', R ": a hydrogen atom, a straight or branched alkyl radical
having from 1 to 4 carbon atoms, a cyclopentyl radical or
cyclohexyl, at least one of these three radicals being different
of a hydrogen atom.

Finally, advantageously, mention will be made very particularly of the compounds according to formula (I) in which the various symbols have the following meaning - R1: a hydrogen atom, a chlorine atom - R2: a hydrogen atom, an atom chlorine, a methyl radical or
ethyl, a hydroxyl or carboxyl group.

- R3: a methyl or ethyl radical; a chlorine atom; a
nitro group; an NH2 - R, R ', R "group: a hydrogen atom, a straight or branched alkyl radical
having at most 4 carbon atoms, at least one of these radicals
being different from a hydrogen atom.

 As can be seen, the polyhydroxyphenyl-2, 2H-benzotriazoles etheroxides can be derived from trihydroxyphenyl-2, 2H-benzotriazoles or from tetrahydroxy-phenyl-2, 2H-benzotriazoles in which the hydroxyl groups have been partially or completely etherified. I1 must also be specified that the groups OR "and R3 can occupy on the phenyl radical all the positions which are available there. I1 can in particular be etheroxides" partial or total corresponding to trihydroxy-2 ', 4' , 6 'phenyl-2, 2H-benzotriazoles or with tetrahydroxy-2', 4 ', 5', 6 'phenyl-2, 2H-benzotriazoles.

According to a variant of the invention, the etheroxides derived from trihydroxy-2 ', 4', 6 'phenyl-2, 2H-benzotriazoles and which are then represented by the formula: (II).

also constitute a preferred object according to the invention. It should also be understood that the compounds of formula (II) in which the symbols have the restricted meanings and as previously exposed constitute particularly interesting compounds.

 Finally, according to another preferred variant, the object of the present invention is contained by the polyhydroxyphenyl-2, 2H-benzotriazole etheroxides of formula I and which contain one or more free phenolic groups.

Among the various etheroxides of polyhydroxyphenyl-2, 2H-benzotriazoles, there will be mentioned by way of illustration - (dimethoxy-2 ', 4' hydroxy-6 ') phenyl-2, 2H-benzotriazole - ((trimethoxy-2', 4 ') 6 'phenyl) -2, 2H-benzotriazole - le (triethoxy-2', 4 ', 6' phenyl) -2, 2H-benzotriazole - le (dimethoxy-2 ', 6', hydroxy-4 'phenyl) -2 , 2H-benzotriazole - le (dihydroxy-2 ', 6', 4-methoxy-phenyl) -2, 2H-benzotriazole - le (dihydroxy-2 ', 4', methoxy-6 ', phenyl) -2, 2H- benzotriazole - (2 ', 6' diethoxy, 4 'hydroxy-4' phenyl) -2, 2H -benzotriazole - (2 'dimethoxy, 6' hydroxy-4 ', chloro-5' phenyl) -2, 2H- benzotriazole - le (trimethoxy-2 ', 4', 6 'nitro-5' phenyl) -2, 2H-benzotriazole - le (trimethoxy-2 ', 4', 6 ', amino 5' phenyl) -2, 2H- benzotriazole - chlorine5, (trimethoxy-2 ', 4', 6 'phenyl) -2, 2H-benzotriazole - dichloro-5.6, (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 - ((dimethoxy-2 ', 6', methyl-3 ', hydroxy-4' phenyl) -2 , 2H-benzotriazole - le (dimethoxy-2 ', 6' dimethyl-3 ', 51 hydroxy-4' phenyl) -2,
2H-benzotriazole.

- (2-hydroxy-4 ', trimethoxy-4', 5 ', 6' phenyl) -2, 2H-benzotriazole - (tetramethoxy-2 ', 3', 4 ', 6' (or-2 ', 3 ', 5', 6 ') phenyl) -2,
2H-benzotriazole.

The polyhydroxyphenyl-2, 2H-benzotriazoles etheroxides of formula (I) can be obtained according to conventional methods and in particular by cyclizing reduction reaction by means of any known technique, of 2-nitro polyhydroxyazobenzene etheroxides and having the formula ( III)

 The various symbols R1, R2, R3, R, R ', R ", a, b having the meanings previously given. Such a process also constitutes an object of the present invention.

 The cyclizing reduction reaction of the substituted 2-nitro-azobenzenes of formula (III) can be carried out by chemical or electrochemical reduction.

 The chemical reduction 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 with 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 the American patents. 3,072,585, 3 23n 194, 4,041,044 and in French bevets 2,311,010.2 311,011, 2,311,012, 2,311,013.

 It has been observed elsewhere ', that it was impossible according to the known techniques to carry out the cyclizing reduction reaction on the 2-nitro polyhydroxyaroben @ enes whose two phenolic functions placed ortho vis-à-vis the future benzotriazolyl group does are not etherified. On the other hand, it has been found, unexpectedly, that the cyclizing reduction reaction takes place satisfactorily if one of the hydroxyl groups intended to be placed ortho to the benzotriazolyl group is etherified. Using this possibility then demethylating partially and selectively and according to any technique known from the prior art, polyhydroxyphenyl-2,2H-benzotriazole etheroxides can be obtained, the two ortho positions of the benzotriazolyl group being occupied by free hydroxyl groups.

soit avec les etheroxydes de polyhydroxybenzène de formule (V)

soit avec le polyhydroxybenzène correspondant. Cette dernière réaction étant ensuite suivie par une réaction d'alkylation par tout moyen connu des groupements phénoliques libres.Finally, the etheroxides of the 2-nitro polyhydroxy azobenzenes of formula (III) can be prepared by any known method, for example by reaction of the diazonium salt of the corresponding o-nitroaniline of formula (IV)

either with the polyhydroxybenzene etheroxides of formula (V)

either with the corresponding polyhydroxybenzene. This latter reaction is then followed by an alkylation reaction by any known means of the free phenolic groups.

 Finally, it will be indicated that certain polyhydroxy-2,2-2H-benzotriazole etheroxides can also be obtained according to known methods by first carrying out a reaction for the cyclizing reduction of 2-nitro, polyhydroxyazobenzene etheroxides and then by introducing during an additional step various substituents such as for example NO2, CH3, C2H5 groups, etc. In addition, it is obviously possible to alkylate certain hydroxyl groups of the polyhydroxyphenyl-2, 2H-benzotriazole, or alternatively to alkylate hydroxyl groups of the partial etheroxides of the polyhydroxyphenyl- 2,2H-benzotriazoles. It is also possible to carry out partial demethylations of various etheroxides of the abovementioned benzotriazoles.

 The present invention further relates to the use of the polyhydroxyphenyl-2,2H-benzotriazole etheroxides of formula (I) as anti-UV stabilizing agents. Among these various etheroxides, mention will be made more particularly of those which contain one or more free hydroxyl groups whose anti-UV efficacy is most marked. These various compounds have a significant anti-UV power and in general much higher than that of analogous compounds and the chemical formulas of which differ only in the position of the etheroxide and hydroxyl groups. It will be noted that the anti-UV compounds of the invention can be incorporated into various polymeric, synthetic, artificial or natural materials, in general at a rate of 0.001 to 5% and preferably from 0.01 to 1% in order to avoid or reduce photodegradation reactions. We can thus stabilize polyolefins (polyethylene, polypropylene ...), polyvinylchloride or vinylidene chlorides, polyesters (polyethylene terephtaitate of ethylene glycol or butylene glycol ...), cellulosic materials natural or artificial ...

 It will also be noted that the 2,2-2H-benzotriazole polyhydroxyphenyl etheroxides of formula (I) and which contain at least one free hydroxyl group are of great interest in diazo reproduction processes (diazotypic thermal processes) where reproductions stable to ultraviolet radiation and daylight, after formation of azo dyes by coupling reaction between any diazonium salt known and recommended for this purpose in the diazo reproduction industry (cf. for example the work from J. KOSAR "light sensitive systems" J and a compound of formula (I), containing at least one free hydroxyl group. There is no discoloration of the dyes formed after accelerated aging tests. Furthermore, these dyes appear to have a high covering power (the colored parts have a high opacity in the ultraviolet and the near visible from 200 to 500 nm).

 Finally, the polyhydroxyphenyl-2,2H-benzotriazoles etheroxides of formula <I) constitute intermediates for obtaining polyhydroxyphenyl-2,2H-benzotriazoles by cleavage of the etheroxide groups. The resulting tri or tetra-hydroxyphenyl-2,2H-benzotriazoles are excellent anti-UV stabilizers and provide azo dyes with benzotriazolyl groups which are particularly stable to light and to UV radiation.

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

0.2 mole (i.e. 60 g) of nitroazobenzene of formula is introduced into 500 ml of methanol

 (. itself obtained by coupling reaction in an acidic hydroxyalcoholic medium, between the diazonium hydrochloride of o-nitranilim and trimethoxybenzene).

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, 1 medium is taken up in 400 ml of water and acidified with hydrochloric acid (e = 1.79) until the excess zinc is dissolved; the insoluble material is filtered, washed with water, then purified by a treatment with ethyl acetate. This gives 32.5 g of (2 'dimethoxy, 6' 4-hydroxy-phenyl) - 2, 2H-benzotriazole whose physicochemical characteristics are
following t: - melting point: 2250 - conforming mass and NMR spectrum - UV spectrum: @ (absorbance) = 12 200 l / mole-ô / cm-
(Absorbance # is determined at a wavelength
= 279 - 284 min) - conforming IR spectrum: OH free at 3610 -
- C = N at 1640 cm
# 0-: 1160 - 1280 cm 1
EXAMPLE 2
Is prepared according to a procedure analogous to that of Example 1, the (dimethoxy-2 ', 6' hydroxy-4 'phenyl) -2 chloro-5, 2H-benzotriazole having the formula

 This compound has the following physicochemical characteristics - melting point: 173 - 1740 - UV spectrum: # (absorbance at 287 nm): 11 400 1 / mole- / cm- - conforming 1R spectrum: intermolecular OH at 3240 cm- disappearing by dilution effect - conforming mass and NMR spectra.

I1 is obtained by cyclizing reduction of the nitroazobenzene of formula

EXAMPLE 3
Preparation of (hydroxy-2 ', trimethoxy-4', 5 ', 6' phenyl) -2, 2H-benzotriazole

This compound is obtained according to a procedure analogous to that described in Example 1 from the nitro-azobenzene of formula

The physico-chemical properties of hydroxy-2 ', trimethoxy-4', 5 ', 6' phenyl) -2, 2H-benzotriazole are as follows - UV absorbance spectrum (at 284 nm) = 13,900 1 / mole / cm - - Compliant IR spectrum: intramolecular H bond at 3320 cm from OH, with N
-C = N at 1630 cm
# -0 to 1160 - 1280 cm - conforming mass and NMR spectra
EXAMPLE 4

 4.5 g (0.02 mole) of (trihydroxy 2 ', 4', 6 'phenyl) - 2, 2H-benzotriazole, 20 ml of water, 2 ml of sodium hydroxide (d = 1.33): 2 ml or 0.02 mole. The mixture is stirred and heated to 400. 4 ml of methyl sulphate (0.04 mol) are then poured in 2 hours, maintaining the pH at 10 by adding sodium hydroxide. It is left to stir for another hour at 400. It is neutralized, filtered, washed with water and dried. 4.6 g of beige solid are obtained which are purified by column chromatography. One obtains inter alia a fraction of 1 g of (dimethoxy-2 ', 4' hydroxy 6 'phenyl) -2, 2H = benzotriazole.

- melting point: 1600 - UV absorbance spectrum (# at 284 nm): 12,000 l / mole - / cm- - Compliant IR spectrum: -OH intramolecular bond at 3310 cm
-C = N- at 1630 cm - # O- at 1160 - 1280 cm 1 - conforming mass and NMR spectra
EXAMPLE 5

 Charged (0.05 mole) 13.6 g of (2-dimethoxy, 6 '4-hydroxy-phenyl) -2, 2H-benzotriazole (obtained as in Example 2), 50 ml of water, 6 ml of soda (d = 1.33) or 0.06 mole. It is brought to 400 and poured in 2 hours, 6 ml (0.06 mole) of methyl sulfate. The mixture is left to stir for another hour at 400 and 2 ml of sodium hydroxide are added to basify. Cool, filter, wash with water and dry in vacuo to 500.

 13.5 g of yellow solid are obtained (yield 95 X) which is recrystallized from 100 ml of toluene to give 12 g of white solid.

- melting point: 174 - UV absorbance spectrum (E at 274 - 284 nm) = 14,000 1 / mole / cm - conforming IR spectrum: - OCH3: 2,840 cm 1
# -OC: 1205 - 1330 cm 1
aromatic, -C = N- 1600 - 1615 cm-

Claims (6)

 carboxyl.  straight or branched, an alkoxyl, alkoxycarbonyl radical,  - R2: a hydrogen atom, a halogen atom, an alkyl radical  - R1: a hydrogen atom, a halogen atom  in which the various symbols represent

 2,2-polyhydroxyphenyl-2H-benzotriazoles of formula (I)  CLAIMS 1 / As new industrial products the etheroxides of  a halogen atom; a nitro group; an NH2 group.  - R3: a straight or branched alkyl radical, a cycloalkyl radical;  different from a hydrogen atom.  alkyl or cycloalkyl, at least one of these three radicals being  - each of the radicals R, R ', R ": a hydrogen atom or a radical  - a: an integer equal to 1 or 2.  more equal to 3.  - b: an integer equal to 0, 1 or 2, the sum (a + b) being at 2 / Polyhydroxyphenyl-2, 2H-benzotriazole etheroxides according to the  claim 1.  hydroxyl group, a carboxyl radical.  straight or branched having 1 to 4 carbon atoms, one  - R2: a hydrogen atom, a chlorine atom, an alkyl radical  - R1: a hydrogen atom, a chlorine atom  in which the various symbols have the following meanings  chlorine; a nitro group; an NH2 group.  carbon, a cyclopentyl or cyclohexyl radical; an atom of  - R3: a straight or branched alkyl radical having from 1 to 4 atoms of  radicals being different from a hydrogen atom.  cyclopentyle or cyclohexyle, at least one of these three  branched having from 1 to 4 carbon atoms a radical  - R, R ', R ": a hydrogen atom, a straight alkyl radical or 3 / Polyhydroxyphenyl-2, 2H-benzotriazole etheroxides according to one of  claims 1 and 2.  or ethyl, a hydroxyl or carboxyl group.  - R2: a hydrogen atom, a chlorine atom, a methyl radical  - R1: a hydrogen atom, r chlorine atom  in which the various symbols have the following meaning:  nitro group; an NH2 group.  - R3: a methyl or chyle radical; a chlorine atom; a  radicals being different from a hydrogen atom.  having at most t carbon atoms, at least one of these  - R, R ', R ": a hydrogen atom, a straight or branched alkyl radical 4 / Polyhydroxyphenyl-2, 2H-benzotriazole etheroxides according to one of  claims 1 to 3 and having the formula (II)

 5 / Polyhydroxyphenyl-2, 2H-benzotriazole etheroxides according to one of  claims 1 to 4 and which include one or more groupings  free phenolics. 6 / A process for the preparation of polyhydroxyphenyl-2, 2H-benzotriazoles etheroxides according to one of claims 1 to 5 characterized in that a cyclizing reduction reaction is carried out by any known means of 2-nitro polyhydroxyazobenzene etheroxides formula (III)

 according to one of claims 1 to 5 as anti-UV stabilizer.  Claims 1 to 5 7 / Use of 2,2-2H-benzotriazole polyhydroxyphenyl etheroxides  the various symbols having the meanings given in the