5-aralkyl substituted 2H-benzotriazoles and stabilized compositions

5-alpha-Cumyl-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole and related 2H-benzotriazoles substituted on the benzo ring by at least one aralkyl group such as benzyl, alpha-methylbenzyl or alpha-cumyl exhibit outstanding efficacy in protecting organic substrates from light-induced deterioration as well as good resistance to loss by volatilization or exudation during the high temperature processing of stabilized compositions. The above-named compounds are surprisingly soluble in common organic solvents, and exhibit very high extinction coefficients.

BACKGROUND OF THE INVENTION 
The present invention relates to selected 2-aryl-2H-benzotriazoles which 
are useful in protecting light-sensitive organic materials from 
deterioration and to stabilized compositions containing said 
benzotriazoles. 
The UV absorbers of the o-hydroxyphenyl-2H-benzotriazole class have long 
been known as effective light stabilizers for organic materials and have 
enjoyed considerable commercial success. 
However, the hitherto known 2-aryl-2H-benzotriazoles of this group have in 
some circumstances exhibited limited compatibility in certain substrates, 
and excessive tendency to exude, sublime and/or volatilize during 
processing of stabilized compositions into sheets, films, fibers or other 
pellicles when processing must be done at elevated temperatures. Likewise 
such benzotriazoles may also suffer undue loss by volatilization or 
sublimation from fabricated structures, particularly thin films or 
coatings, especially when subjected to elevated temperatures during use. 
Attempts have been made to increase substrate compatibility or solubility 
and to reduce volatilization loss by modifying the structure of the 
benzotriazoles. 
In U.S. Pat. No. 3,230,194, a higher alkyl group was substituted for methyl 
and the compound 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole 
exhibited superior compatibility and performance in polyethylene. In U.S. 
Pat. No. 4,127,586, still other modifications to the 
2-aryl-2H-benzotriazole moiety were made to increase still further 
compatibility in substrates and resistance to volatilization. The compound 
2-[2-hydroxy-3-(1-phenylethyl)-5-methylphenyl]-2H-benzotriazole described 
therein exhibited better compatibility and better resistance to loss by 
volatilization during processing than did the earlier prior art 
benzotriazole compounds. 
In Japanese Kokai No. 158588/75, other benzotriazole light stabilizers such 
as 
2-(2-hydroxy-3-alpha,alpha-dimethylbenzyl-5-methylphenyl)-2H-benzotriazole 
are disclosed. 
However, still better resistance to loss from stabilized compositions 
during high temperature processing remained a practical objective and need 
in the art for the benzotriazole UV-absorbers. 
U.S. Pat. No. 4,226,763 describes attempts to increase the resistance of 
benzotriazole light absorbers to loss by volatilization. This patent 
describes 2-(2-hydroxy-3,5-di-alpha-cumylphenyl)-2H-benzotriazole which 
exhibits superior resistance to loss from stabilized compositions during 
high temperature processing or in end use applications where coatings or 
films of the stabilized compositions are exposed even to ambient 
weathering and light exposures compared to stabilized compositions 
containing the 2-aryl-2H-benzotriazoles of the prior art. This superior 
performance is attained at the cost of relatively low solubility in some 
substrates and processing solvents. 
U.S. Pat. No. 4,283,327 describes 
2-(2-hydroxy-3,5-di-tert-octylphenyl)-2H-benzotriazole which exhibits 
enhanced solubility in processing solvents and substrates, but which did 
not have outstanding resistance to loss by volatilization. 
U.S. Pat. No. 4,278,589 describes benzotriazoles having one alpha-cumyl 
group and one tert-octyl substituent on the 2-phenyl moiety in an attempt 
to achieve a balance of properties not obtained with two alpha-cumyl or 
with two tert-octyl groups. Benzotriazoles with a good balance of 
solubility and resistance to loss by volatilization were obtained, but not 
the outstanding levels of each required by an increasingly demanding 
market place for light stabilizers with truly exceptional properties. 
Although lower alkyl, lower alkoxy and halogen substitution on the benzo 
ring of 2H-benzotriazoles has long been known for example in U.S. Pat. No. 
4,127,586, the substitution of the benzo ring with benzyl, 
alpha-methylbenzyl, alpha,alpha-dimethylbenzyl or other phenylalkyl groups 
is not known. Japanese Sho No. 59/172,655 generically discloses such 
substitution, but specifically only describes aralkyl substitution on the 
2-phenyl ring of the 2-aryl-2H-benzotriazole stabilizers. 
Traditionally lacquers have been used in the automotive and other 
industries to produce high gloss coatings. Such lacquers typically consist 
of high molecular weight polymers dissolved in appropriate solvents. The 
solvents which usually constitute over 70% of the paint evaporate on 
baking to leave a polymer film. 
Energy and environmental considerations have more recently resulted in 
development of so called "high solids enamels" as alternate coating 
systems, which meet government mandated reduction in "volatile organic 
compounds (VOC)". High solids enamels typically consist of low molecular 
weight copolymers of methyl methacrylate, hydroxyethyl methacrylate, butyl 
acrylate and styrene. These copolymers which contain pendant hydroxyl 
groups are then blended with melamine crosslinking resins (ratios of about 
7:3). The final crosslinking reaction occurs when the painted article is 
subjected to baking. High solids enamels in contrast to lacquers contain 
usually less than 50% solvent. 
The bulk of these solvents are employed during the monomer polymerization 
process. Only a small quantity of solvent generally less than 10% of the 
total solvent is retained as "hold out" solvent to be added later to the 
final point The light stabilizing additives must be soluble enough in this 
hold out solvent to permit incorporation at this stage. The amount of 
solvent cannot be changed at will because paint viscosity is a critical 
parameter in avoiding defects such as runs and sags. To meet these demands 
for high solubility the instant stabilizers were developed. These products 
also meet and/or exceed the state of the art materials with respect to 
compatibility with the resin and lack of volatility. 
DETAILED DISCLOSURE 
This invention pertains to selected 2-aryl-2H-benzotriazole light absorbers 
and to organic materials stabilized thereby. 
More particularly, the 2-aryl-2H-benzotriazoles of this invention are 
represented by the formula I 
##STR1## 
wherein 
R.sub.1 and R.sub.2 are independently hydrogen, halogen, alkyl of 1 to 18 
carbon atoms or a group of formula II 
##STR2## 
wherein E.sub.1 and E.sub.2 are independently hydrogen or alkyl of 1 to 4 
carbon atoms and E.sub.3 is hydrogen, or alkyl of 1 to 4 carbon atoms, 
with the proviso that at least one of R.sub.1 and R.sub.2 must be a group 
of formula II; 
R.sub.3 is hydrogen, hydroxyl, alkyl of 1 to 12 carbon atoms, alkoxy of 1 
to 4 carbon atoms, phenyl, phenyl substituted by one, two or three alkyl 
groups having 1 to 8 carbon atoms, cycloalkyl of 5 to 6 carbon atoms, 
carboalkoxy of 2 to 9 carbon atoms, chlorine, carboxyethyl or a group of 
formula II, 
R.sub.4 is hydrogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 12 carbon 
atoms, chlorine or hydroxyl, and 
R.sub.5 is hydrogen, hydroxyl, alkyl of 1 to 12 carbon atoms, chlorine, 
cycloalkyl of 5 to 6 carbon atoms or a group of formula II. 
with the proviso that R.sub.3, R.sub.4 and R.sub.5 cannot each be hydrogen 
at the same time, and that only one of R.sub.3, R4 and R5 can be hydroxy 
at the same time. 
When R.sub.1, R.sub.2 or E.sub.3 is halogen, it may be fluorine, bromine, 
chlorine or iodine, preferably chlorine. 
When R.sub.1 or R.sub.2 is alkyl or 1 to 18 carbon atoms, it may be for 
example methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, 
tert-butyl, tert-amyl, 2-ethylhexyl, n-octyl, tert-octyl, n-dodecyl, 
tert-dodecyl or n-octadecyl. 
When E.sub.1, E.sub.2 or E.sub.3 is alkyl of 1 to 4 carbon atoms, it is for 
example methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl. 
When E.sub.3 is halogen, it may be fluorine, bromine, chlorine or iodine, 
preferably chlorine. 
R.sub.3 can be alkyl of 1 to 12 carbon atoms such as methyl, ethyl, 
sec-butyl, tert-butyl, tert-amyl, tert-octyl or n-dodecyl. R.sub.3 can 
also be alkoxy of 1 to 4 carbon atoms such as methoxy, ethoxy or n-butoxy. 
R.sub.3 is also phenyl substituted with one, two or three alkyl groups, 
said alkyl groups having 1 to 8 carbon atoms such as methyl, tert-butyl, 
tert-amyl or tert-octyl. R.sub.3 can also be cycloalkyl of 5 to 6 carbon 
atoms such as cyclopentyl or cyclohexyl. R.sub.3 is also carboalkoxy of 2 
to 9 carbon atoms such as carbomethoxy, carboethoxy, carbo-n-butoxy or 
carbo-n-octoxy. R.sub.3 is also a group of formula II such as benzyl, 
alpha-methylbenzyl or alpha,alpha-dimethylbenzyl(=alpha-cumyl). 
R.sub.4 can be lower alkyl of 1 to 4 carbon atoms such as methyl, ethyl or 
n-butyl. 
R.sub.4 can also be alkoxy of 1 to 12 carbon atoms such as methoxy, ethoxy, 
n-butyloxy, octyloxy or dodecyloxy. 
R.sub.5 can be alkyl or 1 to 12 carbon atoms such as methyl, sec-butyl, 
tert-butyl, tert-amyl, tert-octyl, n-dodecyl or tert-dodecyl. 
R.sub.5 can also be cycloalkyl or 5 to 6 carbon atoms such as cyclopentyl 
or cyclohexyl. R.sub.5 is also a group of formula II such as benzyl, 
alpha-methylbenxyl or alpha,alpha-dimethylbenzyl. 
Preferred compounds are those where only one of R.sub.1 and R.sub.2 is a 
group of formula II and most preferred are those where R.sub.1 is hydrogen 
and R.sub.2 is a group of formula II. 
Still more preferred are the compounds where R hd 1 is hydrogen, R.sub.2 is 
a group of formula II where at least one of E.sub.1 and E.sub.2 is methyl 
and where E.sub.3 is hydrogen or alkyl of 1 to 4 carbon atoms, especially 
hydrogen or p-methyl. R.sub.2 is most especially alpha, 
alpha-dimethylbenzyl. 
Preferably R.sub.3 is alkyl of 1 to 8 carbon atoms, or a group of formula 
II. 
Preferably R.sub.4 is hydrogen, hydroxyl, methyl or alkoxy of 1 to 8 carbon 
atoms. 
Preferably R.sub.5 is hydrogen, alkyl of 1 to 8 carbon atoms or a group of 
formula II. 
Most preferably R.sub.3 is methyl, tert-butyl, tert-amyl, tert-octyl, 
sec-butyl, benzyl, alpha-methylbenzyl or alpha,alpha-dimethylbenzyl. 
Most preferably R.sub.4 is hydrogen. 
Most preferably R.sub.5 is hydrogen, methyl, sec-butyl, tert-butyl, 
tert-amyl, tert-octyl, benzyl, alpha-benzyl, or 
alpha,alpha-dimethylbenzyl. 
SYNTHESIS OF COMPOUNDS 
The compounds of this invention are prepared the manner set forth in U.S. 
Pat. No. 4,226,763 wherein the substituted 2-nitroaniline is diazotized 
and then coupled, preferably in a strongly alkaline medium, with the 
appropriate phenol to give the intermediate o-nitroazobenzene. 
This o-nitroazobenzene intermediate is converted to the corresponding 
2-aryl-2H-benzotriazole by reductive cyclization using any number of 
conventional reducing systems including zinc and alkali, hydrazine, 
catalytic hydrogenation, and the like. 
Many of the various starting materials such as the substituted phenols, 
o-nitroaniline, alpha-methylstyrene, 5-chloro-2-nitroaniline, styrene, 
benzyl alcohol, and the like are items of commerce or can easily be 
prepared by known methods. 
The substituted phenols are conveniently made by the alkylation of phenol 
with an olefin in the presence of an acidic catalyst. The preparation of 
2,4-di(alpha,alpha-dimethylbenzyl)phenol, described in U.S. Pat. No. 
4,226,763, is a typical illustration. 
The substituted o-nitroanilines required to obtain the instant compounds 
substituted on the benzo ring with benzyl, alpha-methylbenzyl or 
alpha-cumyl (=alpha,alpha-dimethylbenzyl) groups can be prepared by the 
aralkylation of an o-nitroaniline using for example an olefin (such as 
styrene or alpha-methylstyrene), an alcohol (such as benzyl alcohol) or an 
ester such as alpha-cumyl acetate) in the presence of an acidic catalyst. 
The o-nitroazobenzene intermediates of formula III 
##STR3## 
where R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are defined above are 
also new compounds and are part of this invention. 
The compounds of this invention are effective light stabilizers in a wide 
range of organic polymers. Polymers which can be stabilized include: 
1. Polymers which are derived from mono- or diolefins, e.g., polyethylene 
which can optionally be crosslinked, polypropylene, polyisobutylene, 
polymethylbutene-1, polymethylpentene-1, polyisoprene, polybutadiene. 
2. Mixtures of the homopolymers cited under (1), for example mixtures of 
polyropylene and polyethylene , polypropylene and polybutene-1, 
polypropylene and polyisobutylene. 
3. Copolymers of the monomers based on the homopolymers cited under (1), 
for example ethylene/propylene compolymers, propylene/butene-1copolymers, 
propylene/isobutylene copolymers thylene/butene-1 copolymers as well as 
terpolymers of ethylene and propylene with a diene, for example hexadiene, 
dicyclopentadiene or ethylidene norbornene, and copolymers of 
.alpha.-olefins, e.g., ethylene with acrylic or methacrylic acid. 
4. Polystyrene. 
5. Copolymers of styrene and of .alpha.-methylstyrene, for example 
styrene/butadiene copolymers, styrene/acrylonitrile copolymers, 
styrene/acrylonitrile/methacrylate copolymers, styrene/acrylonitrile 
copolymers modified with acrylic ester polymers to provide impact strength 
as well as block copolymers, e.g., styrene/butadiene/styrene block 
copolymers. 
6. Graft copolymers of styrene, for example the graft polymer of styrene to 
polybutadiene, the graft polymer of styrene with acrylonitrile to 
polybutadiene as well as mixtures thereof with the copolymers cited under 
(5), commonly referred to as acrylonitrile/butadiene/styrene or ABS 
plastics. 
7. Halogen-containing vinyl polymers, for example polyvinyl chloride, 
polyvinylidene chloride, polyvinyl fluoride, polychloroprene, chlorinated 
rubbers, vinyl chloride/vinylidene chloride copolymers, vinyl 
chloride/vinyl acetate copolymers, vinylidene chloride/vinyl acetate 
copolymers. 
8. Polymers which are derived from .alpha..beta.-unsaturated acids and 
derivatives thereof, polyacrylates and polymethacrylates, polyacrylic 
acids and polyacrylonitrile. The instant compounds are advantageously used 
in heat-curable acrylic resin acquers which are composed of a copolymer of 
acrylic acid and one or more of its derivatives, and a 
melamine-formaldehyde. 
9. Polymers which are derived fron unsaturated alcohols and amines and from 
the acyl derivatives thereof or acetals, for example polyvinyl alcohol, 
polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl 
maleate, polyvinyl butyral, polyallyl phthalate, poly-allyl melamine and 
copolymers thereof with other vinyl compounds, for example ethylene/vinyl 
acetate copolymers. 
10. Homopolymers and copolymers which are derived from epoxides, for 
example polyethylene oxide or the polymers which are derived from 
bis-glycidyl ethers. 
11. Polyacetals, for example polyoxymethylene, as well as polyoxymethylenes 
which contain ethylene oxide as comonomer. 
12. Polyalkylene oxides, for example polyoxyethylene, polypropylene oxide 
or polyisobutylene oxide. 
13. Polyphenylene oxides. 
14. Polyurethanes and polyureas, such as in urethane coatings. 
15. Polycarbonates. 
16. Polysulfones. 
17. Polyamides and copolyamides which are derived from diamines and 
dicarboxylic acids and/or from aminocarboxylic acids or the corresponding 
lactams, for example polyamide 6, polyamide 6/6, polyamide 6/10, polyamide 
11, polyamide 12, poly-m-phenylene-isophthalamide. 
18. Polyesters which are derived from dicarboxylic acids and dialcohols 
and/or from hydroxycarboxylic acids or the corresponding lactones, for 
example polyethylene glycol terephthalate, poly-1,4-dimethylol-cyclohexane 
terephthalate. 
19. Cross-linked polymers which are derived from aldehydes on the one hand 
and from phenols, ureas and melamine on the other, for example 
phenol/formaldehyde, urea/formaldehyde and melamine/formaldehyde resins. 
20. Alkyd resins, for example glycerol/phthalic acid resins and mixtures 
thereof with melamine/formaldehyde resins. 
21. Unsaturated polyesters resins which are derived from copolyesters of 
saturated and unsaturated dicarboxylic acids with polyhydric alcohols as 
well as from vinyl compounds as cross-linking agents and also the 
halogen-containing, flame-resistant modifications thereof. 
22. Natural polymers, for example cellulose, rubber, as well as the 
chemically modified homologous derivatives thereof, for example cellulose 
acetates, cellulose propionates and cellulose butyrates and the cellulose 
ethers, for example methyl cellulose. 
While compounds of this invention are very effective stabilizers for a host 
of organic substrates subject to light induced deterioration, as are the 2 
aryl-2H-benzotriazole light absorbers in general, the instant compounds 
with their surprising resistance to loss from a stabilized composition 
during high temperature processing due to volatilization, exudation or 
sublimation have particular value in stabilizing polymeric substrated 
which are perforce processed at elevated temperatures. 
Thus, the compounds of this invention are particularly useful as 
stabilizers for the protection of polyesters, for instance poly(ethylene 
terephthalte), poly(butylene terephthalate) or copolymers thereof; of 
polycarbonates, for example polycarbonate derived from bisphenol A and 
phosgene, or copolymers thereof; of polysulfones; of polyamides such as 
nylon-6, nylon-6,6, nylon 6,10 and the like as well as copolyamides; of 
thermoset acrylic resins; of thermoplastic acrylic resins; of polyolefins 
such as polyethylene, polypropylene, copolyolefins and the like; and of 
any polymer system requiring high temperature processing and fabrication. 
Although the compounds of the invention may be used above to provide a 
light stabilizing function, the compounds of this invention are often 
combined with other stabilizers, even other light stabilizers, in the 
preparation of stabilized compositions. The stabilizers may be used with 
phenolic antioxidants, pigments, colorants or dyes, light stabilizers such 
as hindered amines, metal deactivators, etc. 
In general, the stabilizers of this invention are employed from about 0.1 
to about 5% by weight of the stabilized composition, although this will 
vary with the particular substrate and application. An advantageous range 
is from about 0.5 to about 3%. 
The stabilizers of Formula I may readily be incorporated into the organic 
polymers by conventional techniques, at any convenient stage prior to the 
manufacture of shaped articles therefrom. For example, the stabilizer may 
be mixed with the polymer in dry powder form, or a suspension or emulsion 
of the stabilizer may be mixed with a solution, suspension, or emulsion of 
the polymer. The stabilized polymer compositions of the invention may 
optionally also contain from about 0.1 to about 5%, preferably from about 
0.5 to about 3% by weight of various conventional additives, such as the 
following, particularly phenolic antioxidants or light-stabilizers, or 
mixtures thereof: 
1. Antioxidants 
1.1 Simple 2,6-dialkylphenols, such as, for example, 
2,6-di-tert.-butyl-4-methylphenol, 2-tert.-butyl-4,6-dimethylphenol, 
2,6-di-tert.-butyl-4-methoxymethylphenol and 
2,6-dioctadecyl-4-methylphenol. 
1.2 Derivatives of alkylated hydropuinones, such as for example, 
2,5-di-tert.-butyl-hydroquinone, 2,5-di-tert.-amyl-hydroquinone, 
2,6-di-tert.-butyl-hydroquinone, 2,5-di-tert.-butyl-4-hydroxy-anisole, 
3,5-di-tert.-butyl-4-hydroxy-anisole, 3,5-di-tert.-butyl-4-hydroxyphenyl 
stearate and bis-(3,5-di-tert.-butyl-4-hydroxyphenyl) adipate. 
1.3 Hydroxylated thiodiphenyl ethers, such as for example, 
2,2'-thio-bis-(6-tert.-butyl-4-methylphenol), 
2,2'-thio-bis-(4-octylphenol), 
4,4'-thio-bis-(64,4'-thio-bis-(3,6-di-sec.-amylphenol), 
4,4'-thio-bis-(6-tert-butyl-2-methylphenol) and 
4,4'-bis-(2,6-dimethyl-14-hydroxyphenyl) disulfide. 
1.4 Alkylidene-bisphenols, such as, for example, 
2,2'-methylene-bis-(6-tert.-butyl-4-methylphenol), 
2,2'-methylene-bis-(6-tert.-butyl-4-ethylphenol), 
4,4'-methylene-bis-(-butyl-2-methylphenol, 
4,4'-methylene-bis-(2,6-di-tert.-butylphenol), 
2,6-di(3-tert.-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 
2,2'-methylene-bis-[4-methyl-6-(.alpha.-methylcyclo-hexyl)-phenol], 
1,1-bis(3,5-dimethyl- 
1,1-bis-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-butane, 2,2 
-bis-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propane, 
1,1,3-tris-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-butane, 2,2-bis 
-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercapto-butane, 
1,1,5,5-tetra-(5-tert.-butyl-4-hydroxy-2-methylphenyl)pentane and ethylene 
glycol bis-[3,3-bis-(3-tert.-butyl-4-hydroxyphenyl)-butyrate]. 
1.5 O-, N- and S-benzyl compounds, such as for example, 
3,5,3'5'-tetra-tert.-butyl-4,4'-dihydroxydibenzyl ether, octadecyl 
4-hydroxy-3,5-dimethylbenzyl-mercaptoacetate, 
tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-amine and bis-(4-tert.-bu 
-hydroxy-2,6-dimethylbenzyl) dithioterephthalate. 
1.6 Hydroxybenzylated malonates, such as for example, dioctadecyl 
2,2-bis-(3,5-di-tert.-butyl-2-hydroxybenzyl)-malonate, dioctadecyl 
2-(3-tert.-butyl-4-hydroxy-5-methylbenzyl)-malonate, 
di-dodecylmercapto-ethyl 
2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate and 
di-[4-(1,1,3,3-tetramethylbuty)-phenyl]2,2-bis-(3,5-di-tert.-butyl-4 
-hydroxybenzyl)-malonate. 
1.7 Hydroxybenzyl-aromatic compounds, such as, for example, 
1,3,5-tri-(3,5-di-tert.-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 
1,4-di-(3,5-di-tert.butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene and 
2,4,6-tri-(3,5-di-tert -butyl-4-hydroxybenzyl)-phenol. 
1.8 s-Triazine compounds, such as, for example 2,4-bis-octylmercapto 
-6-(3,5-di-tert.-butyl-4-hydroxy-anilino)-2-octylmercapto-4,6-bis-(3,5-di- 
tert.butyl-4-hydroxy anilino)-s-triazine, 
2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-s-triazine, 
2,4,6-tris-(3,5-di-tert.butyl- 4-hydroxyphenoxy)-s-triazine, 
2,4,6-tris-(3,5-di-tert -butyl-4-hydroxyphenylethyl)-s-triazine and 
1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)isocyanurate. 
1.9 Amides of .beta.-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionic acid, 
such as, for example, 
1,3,5-tris-(3,5,-di-tert.-butyl-4-hydroxyphenyl-propionyl)-hexahydro-s-tri 
azine and 
N,N'-di-3,-di-tert.-butyl-4-hydroxyphenyl-propionyl)-hexamethylenediamine, 
N,N'-bis-.beta.-(3,5-di-t-butyl-4-hydroxyphenyl)-propionyl-hydrazine. 
1.10 Esters of .beta.-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionic acid 
with monohydric or polyhydric alcohols, such as for example, with 
methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene 
glycol, 1,2-propanediol, diethylene glycol, thio-diethylene glycol, 
neopentylglycol, pentaerythritol, 3-thia-undecanol, 3-thia-pentadecanol, 
trimethylhexnediol, trimethylolethane, trimethylolpropane, 
tris-hydroxyethyl isocyanurate and 
4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-2.2.2]octane. 
1.11 Esters of .beta.-(5-tert.-butyl-4-hydroxy-3-methylphenyl-propionic 
acid with monohydric or polyhydric alcohols, such as for example, with 
methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene 
glycol, 1,2-propanediol, diethylene glycol, thiodiethylene glycol, 
neopentylglycol, pentaerythritol, 3-thia-undecanol, 3-thia-pentadecanol, 
trimethylhexanediol, trimethylolethane, trimethylolpropane, 
tris-hydroxyethyl isocyanurate and 
4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. 
1.12 Esters of 3,5-di-tert.-butyl-4-hydroxyphenylacetic acid with 
monohydric or polyhydric alcohols, such as for example, with methanol, 
ethanol, octadecanol, 1,6-hexandiol, 1,9-nonanediol, ethylene glycol, 
1,2-propenediol, diethylene glycol, thio-diethylene glycol, 
neopentylglycol, pentaerythritol, 3-thia-undecanol, 3-thia-pentadecanol, 
trimethylhexanediol, trimethylolethane, trimethylolpropane, 
tris-hydroxyethyl isocyanurate and 
4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-octane especially the 
tetrakis ester of pentaerythritol. 
1.13 Benzylphosphonates, such as, for example, dimethyl 3,5 
di-tert.-butyl-4-hydroxybenzylphosphonate, diethyl 
3,5-di-tert.-butyl-4-hydroxybenzylphosphonate, dioctadecyl 
3,5-di-tert.-butyl-4-hydroxybenzylphosphonate and dioctadecyl 
5-tert.-butyl-4-hydroxy-3-methylbenzylphosphonate. 
2. Light-stabilizers 
2.1 Esters of optionally substituted benzoic acids, e.g., 
3,5-di-tert.-butyl-4-hydroxybenzoic acid, 2,4-di-tert.butylphenyl ester or 
-octadecyl ester or 2-methyl-4,6-di-tert.-butylphenyl ester. 
2.2 Sterically hindered amines, e.g., 
4-benzoyl-2,2,6,6-tetramethylpiperidine, 
4-stearyloxy-2,2,6,6-tetramethylpiperidine, 
bis-(2,2,6,6-tetramethylpiperidyl) sebacate, 
bis-(1,2,2,6,6-pentamethylpiperidyl) 
2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate or 
3-n-octyl-7,7,9,9-trimethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione. 
2.3 Oxalic acid diamides, e.g., 4,4'-di-octyloxy-oxanilide, 
2,2'-di-octyloxy-5,5'-di-tert.-butyl-oxanilide, 
2,2'-di-dode-cyloxy-5,5'-di-tert.-butyl-oxanilide, 
2-N,N'-bis-(3-dimethyl-aminopropyl)-oxalamide, 
2-ethoxy-5-tert.-butyl-2'-ethyl-oxanilide and the mixture thereof with 
2-ethoxy2'-ethyl-5,4'-di-tert.-butyl-oxanilide, or mixtures of ortho-and 
para-methoxy- as well as of o- and p-ethoxy-disubstituted oxanilides. 
3. Metal deactivators, e.g. oxanilide, isophthalic acid dihydrazide, 
sebacic acid-bis-phenylhydrazide, bis-benzylideneoxalic acid dihydrazide, 
N,N'-diacetal-adipic acid dihydrazide, N,N'-bis-salicyloyl-oxalic acid 
dihydrazide, N,N'-bis-salicyloylhydrazine, 
N,N'-bis-(3,5-di-tert.-butyl-4-hydroxyphenylpropionyl)-hydrazine, 
N-salicyloyl-N'-salicylalhydrazine, 3-salicyloyl-amino-1,2-4-triazole or 
N,N'-bis-salicyloyl-thio-propionic acid dihydrazide. 
4. Basic co-stabilizers, e.g., alkali metal salts and alkaline-earth metal 
salts of higher fatty acids, for example Ca-stearate, Zn-stearate, 
Mg-behenate, Na ricinoleate or K-palmitate. 
5. Nucleation agents, e.g., 4 tert.-butylbenzoic acid, adipic acid or 
diphenylacetic acid. 
6. Phosphites and phosphonites, such as, for example, tri-phenyl phosphite, 
diphenylalkyl phosphites, phenyldialkyl phosphites, tri-(nonyl-phenyl) 
phosphite, trilauryl phosphite, trioctadecyl phosphite and 
3,9-isodecyloxy-2,4,8,10-tetraoxa-3,9-diphospha-[5.5]-undecane and 
tetra(2,4-di-tert-butylphenyl) diphenylene-4,4'bis(phosphonite). 
Other additives that can be incorporated in the stabilized compositions are 
thiosynergists such as dilauryl thiodiproprionate, lubricants such as 
stearyl alcohol, fillers, asbestos, kaolin, talc, glass fibers, pigments, 
optical brighteners, flameproofing agents and antistatic agents 
The following examples are presented for the purpose of illustration only 
and are not to be construed to limit the nature or scope of the instant 
invention in any manner whatsoever.

EXAMPLE 1 
4-alpha-Cumyl-2-nitroaniline 
In a 12-liter reaction flask fitted with a condenser, nitrogen inlet, 
stirrer, thermometer and addition funnel is placed 187.4 grams (1.375 
moles) of anhydrous zinc chloride. The flask is placed under a nitrogen 
atmosphere and 459 ml (5.5 moles) of concentrated (12N) hydrochloric acid 
is added over a 10-minute period with the temperature rising from 
22.degree. to 40.degree. C. To this is then added 760 grams (5.5 moles) of 
o-nitroaniline over a 15-minute period to avoid the formation of lumps. 
The resulting thick red slurry is heated to 60.degree. C. and then 858 ml 
(6.6 moles) of alpha-methylstyrene is added gradually over a 110-minute 
period with the temperature rising during this period from 60.degree. to 
90.degree. C. The deep red fluid reaction mixture is heated for another 
200 minutes at 90.degree.-105.degree. C. till only a trace of 
o-nitroaniline is observed by thin layer chromatography. 
The hot reaction mixture is diluted with 3 liters of toluene and stirred. 
The aqueous phase is separated at 60.degree. C. and the toluene phase is 
washed with 4.times.700 ml of water. The toluene phase is filtered and the 
filtrate is dried over anhydrous sodium sulfate. The dry toluene solution 
is heated to 70.degree. C. and 4 liters of heptane are added in 1-liter 
portions keeping the temperature above 55.degree. C. The mixture is then 
cooled to give 4-alpha-cumyl-2-nitroaniline as red-orange crystals in a 
yield of 976 grams (69.2%), melting at 92.degree.-94.degree. C. 
EXAMPLE 2 
4-alpha-Methylbenzyl-2-nitroaniline 
When an equivalent amount of styrene is substituted for alpha-methylstyrene 
in the procedure of Example 1, 4-alpha-methylbenzyl-2-nitroaniline is 
obtained as crystals, melting at 95.5.degree.-97.degree. C. 
EXAMPLE 3 
4-Benzyl-2-nitroaniline 
When an equivalent amount of benzyl alcohol is substituted for 
alpha-methylstyrene in the procedure of Example 1, 4-benzyl-2-nitroaniline 
is obtained. 
EXAMPLE 4 
2,4-Di-(alpha,alpha-dimethylbenzyl)phenol 
This intermediate is made by reacting a mixture of 705.8 grams (7.5 moles) 
of phenol with 1772.7 grams (15 moles) of alpha-methylstyrene in the 
presence of 25.7 grams (0.135 moles) of p-toluenesulfonic acid monohydrate 
catalyst. This mixture is heated under nitrogen at 140.degree. C. for 2.5 
hours. The reaction mixture is cooled to 110.degree. C. and 1125 ml of 
toluene is added. After washing the resulting solution at 80.degree. C. 
with 750 ml of an aqueous solution of 37.5 grams of sodium carbonate and 
75 grams of sodium chloride, the organic phase is washed thrice with 1000 
ml of aqueous sodium chloride solution; then dried over anhydrous sodium 
sulfate; filtered and vacuum distilled. The above-named product is 
obtained as the main fraction boiling at 172.degree.-175.degree. 
C./0.15-0.18 mm Hg in a yield of 1229.8 grams (49.6% of theory). The 
product melts at 63.degree.-65.degree. C. 
EXAMPLE 5 
4-alpha,alpha-Dimethylbenzyl-2-nitrobenzene Diazonium Chloride 
In a 500-ml flask fitted with a stirrer and thermometer, 76.9 grams (0.3 
mole) of 4-alpha,alpha-dimethylbenzyl-2 -nitroaniline is suspended in 200 
ml of xylene. To this is added at 25.degree. C. 86.4 grams (0.9 mole) of 
concentrated hydrochloric acid. The suspension is stirred at 38.degree. C. 
for 1 hour followed by the addition of 60 ml of water. The mixture is 
cooled to 20.degree. C. and seeded upon which the corresponding 
hydrochloride salt crystallized as a granular precipitate. The mixture is 
cooled to -5.degree. C. and diazotized by the addition over a period of 30 
minutes of 21.4 grams (0.31 mole) of solid sodium nitrite keeping the 
temperature at -5.degree. C. to -2.degree. C. The mixture is stirred at 
-2.degree. C. for 1 hour. Two phases occur and are separated. The lower 
aqueous phase contains the desired diazonium chloride and has a weight of 
244.1 grams and corresponds to 0.3 mole of diazonium chloride solution. 
EXAMPLE 6 
4-alpha,alpha-Dimethylbenzyl-2-nitro-2'-hydroxy-3',5'-di-tert-butylazobenz 
ene 
In a 1-liter flask, 54 grams (1.35 moles) of sodium hydroxide pellets are 
dissolved in 500 ml of methanol. To this is added 51.6 grams (0.25 mole) 
of 2,4-di-tert-butylphenol and 50 ml of xylene. The resulting solution is 
cooled to -8.degree. C. Over a period of 6 hours is added 244 grams (0.3 
mole) of the diazonium chloride solution, prepared in Example 5, keeping 
the temperature at -8.degree. C. After stirring overnight, the pH of the 
reaction mixture is brought to 9 by the addition of 55 ml (0.68 mole) of 
concentrated hydrochloric acid. 
The supernatant liquid is removed from the semisolid residue which is the 
crude azobenzene product which is thrice slurried with 100 ml portions of 
methanol and then thrice with 100 ml portions of water to remove inorganic 
salts. The resulting solid precipitate is treated with 300 ml of methanol 
causing it to crystallize. After filtration at 15.degree. C., the 
azobenzene product is obtained in a yield of 82.8 grams (69.9%) as a 
brick-red solid. The product after recrystallization from ethanol melts at 
105.degree.-107.degree. C. 
EXAMPLE 7 
5-alpha,alpha-Dimethylbenzyl-2-(2-hydroxy-3,5-di-tert-butyl 
phenyl)-2H-benzotriazole 
To a 1-liter 3-necked flask fitted with a stirrer, thermometer, reflux 
condenser and nitrogen inlet is charged 101.5 grams (0.214 mol) of the 
o-nitroazobenzene intermediate of Example 6 and 430 ml of toluene. To the 
resulting solution is added 64.2 ml of isopropanol and 64.2 ml of water. A 
nitrogen atmosphere is imposed and 34.2 grams (0.43 mole) of 50% aqueous 
sodium hydroxide is added. A flask containing 49.2 grams (0.75 gram-atoms) 
of zinc is connected to the reaction flask by Gooch rubber tubing and the 
zinc dust is added portionwise to the reaction mixture in seven (7) equal 
portions with 30 minute intervals between additions. After all the zinc is 
added, the mixture is stirred at 50.degree. C. overnight and then heated 
to 75.degree.-80.degree. C. for two hours. The mixture is then cooled to 
45.degree. C. and acidified with 214 grams of 50% aqueous sulfuric acid. 
The zinc sludge is removed by filtration. The product is contained in the 
organic layer, which is washed with five 30 ml portions of 70% sulfuric 
acid, and then dried over anhydrous magnesium sulfate. The toluene 
solution is concentrated to 150 grams and then diluted with 200 ml of 
ethanol and seeded to give the above-named product as a white solid in a 
yield of 52.5 grams (55.6%) melting at 93.degree.-95.degree. C. 
Analysis: Calcd for C.sub.29 H.sub.35 N.sub.30 : C,78.87; H, 7.99; N, 9.52. 
Found: C, 78.5; H, 8.2; N, 9.4. 
EXAMPLES 8-9 
When in the general procedure of Example 5, an equivalent amount of 
4-alpha-methylbenzyl-2-nitroaniline (Example 8) or 4-benzyl-2-nitroaniline 
(Example 9) is substituted for 
4-alpha,alpha-dimethylbenzyl-2-nitroaniline, the corresponding diazonium 
chloride solution is prepared. 
EXAMPLES 10-20 
o-Nitroazobenzene Intermediates 
Using the general procedure of Example 6, the following o-nitroazobenzene 
intermediates are prepared by selecting the appropriate diazonium chloride 
solution and the appropriate phenol. 
##STR4## 
______________________________________ 
Example 
R.sub.2 R.sub.3 R.sub.5 
______________________________________ 
10 alpha-cumyl* alpha-cumyl alpha-cumyl 
11 alpha-cumyl* tert-octyl alpha-cumyl 
12 alpha-cumyl* tert-amyl tert-amyl 
13 alpha-cumyl* tert-octyl tert-octyl 
14 alpha-methylbenzyl** 
alpha-cumyl alpha-cumyl 
15 benzyl*** alpha-cumyl alpha-cumyl 
16 alpha-cumyl* methyl hydrogen 
17 alpha-cumyl* tert-octyl hydrogen 
18 alpha-cumyl* alpha-cumyl tert-octyl 
19 alpha-cumyl* methyl tert-butyl 
20 alpha-cumyl* tert-butyl hydrogen 
______________________________________ 
*from diazonium chloride of Example 5 
**from diazonium chloride of Example 8 
***from diazonium chloride of Example 9 
EXAMPLE 21 
5-alpha,alpha-Dimethylbenzyl-2-[2-hydroxy-3,5-di (alpha, 
alpha-dimethylbenzyl)phenyl]-2H-benzotriazole 
Using the general procedure of Example 7 and the o-ntrioazobenzene 
intermediate of Example 10, the above-named product is obtained in a yoeld 
of 59.9% as a white solid melting at 141.degree.-142.degree. C. 
Analysis: Calcd for C.sub.39 H.sub.39 N.sub.3 O: C, 82,79; H, 6.95; N, 
7.43. Found: C, 82.9; H, 7.2; N, 7.5. 
The product of Example 21 is obtained in two different crystalline 
modification forms one of which melts at 114.degree.-116.degree. C. and 
exhibits far greater solubility in many organic solvents, including xylene 
and methyl amyl ketone, than the other crystalline form. 
EXAMPLE 22 
5-alpha,alpha-Dimethylbenzyl-2-(2-hydroxy-3-alpha,alpha- 
dimethylbenzyl-5-tert-octylphenyl)-2H-benzotriazole 
Using the general procedure of Example 7 and the o-nitroazobenzene 
intermediate of Example 11, the above named product is obtained in a 34% 
yield as an amber glass which is recrystallized to a solid melting at 
99.degree.-100.degree. C. 
Analysis: Calcd for C.sub.38 H.sub.45 N.sub.3 O: C., 81.53; H, 8.10; N, 
7.51. Found: C, 81.3; H, 8.3; N, 7.5. 
EXAMPLE 23 
5-alpha,alpha-Dimethylbenzyl-2-(2-hydroxy-3,5-di-tert-amylphenyl-2H-benzotr 
iazole 
Using the general procedure of Example 7 and the o-nitroazobenzene 
intermediate of Example 12, the above-named product is obtained in a 34% 
yield as an amber glass. 
Analysis: Calcd for C.sub.31 H.sub.39 N.sub.3 O: C, 79.27; H, 8.37; N, 
8.95. Found: C, 80.2; H, 8.5; N, 8.9. 
EXAMPLE 24 
5-alpha,alpha-Dimethylbenzyl-2-(2-hydroxy-3,5-di-tert-octylphenyl)-2H-benzo 
triazole 
Using the general procedure of Example 7 and the o-nitroazobenzene 
intermediate of Example 13, the above-named product is obtained as a 
solid, recrystallized from isopropanol, melting at 120.degree.-122.degree. 
C. 
Analysis: Calcd for C.sub.37 H.sub.51 N.sub.3 O: C, 80.24; H, 9.28; N, 
7.59. Found: C, 80.3; H, 9.3; N, 7.7. 
EXAMPLE 25 
5-alpha-Methylbenzyl-2-[2-hydroxy-3,5-di-(alpha,alpha-dimethylbenzyl)phenyl 
]-2H-benzotriazole 
Using the general procedure of Example 7 and the o-nitroazobenzene 
intermediate of Example 14, the above-named compound is obtained in a 
yield of 44.4% as a solid melting at 123.degree.-125.degree. C. 
Analysis: Calcd for C.sub.38 H.sub.37 N.sub.3 O: C, 82.72; H, 6.76; N, 
7.62. Found: C, 82.6; H, 6.7; N, 7.6. 
EXAMPLE 26 
5-Benzyl-2-[2-hydroxy-3,5-di-(alpha,alpha-dimethylbenzyl) 
phenyl]-2H-benzotriazole 
Using the general procedure of Example 7 and the o-nitroazobenzene 
intermediate of Example 15, the above-named product is obtained in a yield 
of 44.6% as a white solid melting at 91.degree.-93.degree. C. 
Analysis: Calcd for C.sub.37 H.sub.35 N.sub.3 O: C, 82.65; H, 6.56; N, 
7.82. Found: C, 82.5; H, 6.4; N, 7.8. 
EXAMPLE 27 
5-alpha,alpha-Dimethylbenzyl-2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-b 
enzotriazole 
Using the general procedure of Example 7 and the o-nitroazobenzene 
intermediate of Example 19, the above-named compound is obtained as a 
solid melting at 87.degree.-89.degree. C. 
Analysis: Calcd for C.sub.26 H.sub.29 N.sub.3 O; C, 78.16; H, 7.32; N, 
10.52. Found: C, 77.9; H, 7.5; N, 10.3. 
EXAMPLES 28-31 
Using the general procedure of Example 7 and the appropriate 
o-nitroazobenzene intermediates of Examples 16-18, and 20, the following 
2H-benzotriazoles are prepared. 
______________________________________ 
##STR5## 
Example R.sub.2 R.sub.3 R.sub.5 
______________________________________ 
28 alpha-cumyl methyl hydrogen 
29 alpha-cumyl tert-octyl hydrogen 
30 alpha-cumyl alpha-cumyl 
tert-octyl 
31 alpha-cumyl tert-butyl hydrogen 
______________________________________ 
EXAMPLE 32 
Resistance to Loss of Benzotriazole Stablilizers 
A number of 2-aryl-2H-benzotriazole light stabilizers are subjected to 
thermal gravimetric analysis with a flow rate of 100 ml nitrogen/minute 
both isothermally at 280.degree. C. to indicate the time in minutes to 
reach 50% weight loss of the stabilizer as well as in a scanning mode at a 
heating rate of 10.degree. (C.) per minute to ascertain the temperature at 
which 10% and 50% weight loss of stabilizer are observed. 
Experimental data are given on the table which follows. 
These results correlate closely with the resistance of the indicated 
stabilizer to exudation or volatilization during any processing step with 
polymer formulations during the preparation of sheet, film, fiber or other 
fabricated pellicles. The absence or essential absence of exuded or 
volatilized stabilizer on processing equipment (i.e., rollers, guides, 
orifices, and the like) increases significantly the times between required 
shut-downs of continuously operated process equipment and represents 
enormous practical and economic savings related to the specific stabilizer 
used. 
______________________________________ 
TGA Data 
Isothermal Scanning 
at 280.degree. C. (at 10.degree.(C.) per minute 
Time (minutes) Temperature .degree.C. to 
to Indicated Weight Indicated Weight 
Loss of Stabilizer Loss of Stabilizer 
50% 10% 50% 
______________________________________ 
Stabilizer* 
A 0.75 182 215 
B 0.9 200 233 
C 1.0 210 247 
D 1.9 225 260 
E 3.0 250 290 
F 24 300 340 
G 7.4 267 307 
of Example 
7 19 295 338 
21 2040 365 412 
22 840 340 387 
23 33 285 325 
24 40 308 348 
26 3780 360 405 
______________________________________ 
A is 2(2-hydroxy-5-methylphenyl)-2H--benzotriazole. 
B is 2(2-hydroxy-3,5-di-tert-amylphenyl)-2H--benzotriazole. 
C is 2(2-hydroxy-3-tert-butyl-5-sec-butylphenyl)-2H--benzotriazole. 
D is 2(2-hydroxy-5-tert-octylphenyl)-2H--benzotriazole. 
E is 2[2-hydroxy-3-(1-phenylethyl)-5-methylphenyl]-2H--benzotriazole. 
F is 
2[2-hydroxy-3,5-di-(alpha,alpha-dimethylbenzyl)phenyl]-2H--benzotriazole. 
G is 
2[2-hydroxy-3-(alpha,alpha-dimethylbenzyl)-5-tert-octylphenyl]-2H--benzot 
iazole. 
D is 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole. 
E is 2-[2-hydroxy-3-(1-phenylethyl)-5-methylphenyl]-2H-benzotriazole. 
F is 2-[2-hydroxy-3,5-di-(alpha,alpha-dimethylbenzyl)phenyl]-2 
H-benzotriazole. 
G is 
2-[2-hydroxy-3-(alpha,alpha-dimethylbenzyl)-5-tert-octylphenyl]-2H-benzotr 
iazole. 
While prior art benzotriazole F exhibits thermogravimetric properties 
similar to the benzotriazole of Example 7, the benzotriazoles of Examples 
21-24 and 26, particularly Examples 21 and 26, are very much more 
resistant to thermogravimetric loss. This can be translated into enhanced 
resistance to sublimation and exudation (much less volatility) compared to 
the prior art benzotriazole. 
The instant compounds incorporated in a stabilized polymer composition 
would remain there during processing permitting excellent processability 
coupled with a final polymer pellicle with greater protection against 
subsequent light-induced deterioration. 
EXAMPLE 33 
Solubility of Benzotriazole Stabilizers 
The benzotriazole stabilizers are classically materials with relatively low 
solubility in common organic solvents. This is particularly the case where 
the benzotriazole is substituted in the 2-phenyl ring with aralkyl groups 
intended to decrease stabilizer volatility during processing and use. 
It has now been found that surprisingly substitution of the benzo ring of 
the benzotriazole stabilizer with an aralkyl group, such as alpha-cumyl, 
does not reduce solubility, but actually enhances solubility especially 
when the 2-phenyl ring is substituted with two alkyl groups. 
Solubility data are given in the table below. 
______________________________________ 
Solubility of Benzotriazole Stabilizer 
in grams per 100 grams solvent at 25.degree. C. 
Methyl Butyl 
Amyl Cellosolve 
Heptane Xylene Ketone Acetate 
______________________________________ 
Stabilizer* 
B 23 70 34 19 
F 1.5 16 6 14 
G 9.7 82 33 19 
of Example 
7 97 197 128 61 
23 &gt;100 &gt;100 &gt;100 &gt;100 
______________________________________ 
*The identities of stabilizers B, F and G are given in Example 32. 
The only difference between the benzotriazole stabilizer B and that of 
Example 23 is in the substitution of the instant compound by an 
alpha-cumyl group at the 5-position in the benzo ring of the 
2H-benzotriazole. 
EXAMPLE 34 
Absorbance at 340nm 
The compounds of this invention show unanticipated enhancement of 
absorbance at 340nm as can be seem from a comparison of molar extinction 
coefficients E compared to state of the art compund F which lacks an 
aralkyl-substituent in the 5-position. In many cases the enhanced 
absorbance is also seen when products are compared i.e. in terms of 
Specific Extinction Coefficients a on an equal weight rather than molar 
basis. 
______________________________________ 
Enhanced Absorbance E a 
______________________________________ 
Compound F 15100 34 
Compound of 
Example 7 19000 43 
Example 21 19500 28 
Example 22 18500 33 
Example 23 19100 41 
Example 24 17400 31 
Example 26 18500 35 
______________________________________ 
Molar Extinction Coefficient E = a .times. molecular weight 
##STR6## 
EXAMPLE 35 
A high solids thermosetting acrylic enamel consisting of 70 parts by weight 
of a copolymer prepared from methyl methacrylate, hydroxyethyl 
methacrylate, butyl acrylate and styrene and 30 parts by weight of 
hexakis-methoxymethyl melamine as crosslinker and 0.1 parts by weight of 
p-toluene sulfonic acid is formulated with two parts by weight of the 
following additives. The resulting clear enamel is then sprayed as a clear 
coat onto steel panels precoated with silver metallic paint. 
The panels after curing are then exposed outdoors in Florida for a period 
of 12 months. The retention of gloss is then determined: 
______________________________________ 
% Retention of Original Gloss 
______________________________________ 
Stabilizer 
Without Stabilizer 
30 
Compound F 79 
Compound of 
Example 22 73 
Example 23 76 
Example 24 82 
______________________________________ 
EXAMPLE 36 
Similar panels are those prepared in Example 35 are also exposed to 
ultraviolet light and humidity in the QUV apparatus for a period of 876 
hours. The retention of original gloss after exposure is determined. 
______________________________________ 
% Retention 
of Original Gloss 
______________________________________ 
Stabilizer 
Compound B 73 
Compound F 60 
Compound G 67 
Compound of 
Example 7 71 
Example 25 46 
Example 26 77 
______________________________________ 
The data obtained in Examples 35 and 36 clearly show that the instant 
2H-benzotriazole compounds, possessing the far superior solubility in most 
organic solvents, are essentially equally as effective as prior art 
benzotriazoles in terms of light stabilization efficacy. 
EXAMPLE 37 
Samples of light stabilizers are incorporated into polycarbonate resin by 
milling at 400.degree. F. (240.degree. C.) for a 15 minute period. During 
this milling period some light stabilizer is lost by sublimation depending 
on its volatility and compatibility. At the end of the milling period the 
percent stabilizer loss is determined spectrophotometrically. 
______________________________________ 
% loss (by weight) 
______________________________________ 
Stabilizer D 40 
Stabilizer F &lt;3 
Stabilizer of Example 7 
&lt;3 
Stabilizer of Example 21 
&lt;3 
______________________________________