2,2,6,6-Tetramethyl-4-piperidyl carboxylic acid esters of butane or butene tri carboxylic acids as stabilizers for synthetic polymers

2,2,6,6-TETRAMETHYL-4-PIPERIDYL CARBOXYLIC ACID ESTERS OF BUTANE OR BUTENE TRICARBOXYLIC ACIDS ARE PROVIDED, USEFUL AS STABILIZERS FOR ORGANIC POLYMERIC MATERIALS, AND HAVING THE GENERAL FORMULA: ##STR1## wherein: R.sub.1 is selected from the group consisting of ##STR2## the R.sub.1 groups can be the same or different; R.sub.2 is selected from the group consisting of CH.sub.3 and CH.sub.2 ; and PA1 R.sub.3 is lower alkyl.

Hindered 2,2,6,6-tetraalkyl-4-carboxylic acid ester piperidine compounds 
have been proposed by Murayama et al U.S. Pat. No. 3,640,928 patented Feb. 
8, 1972 as light and heat stabilizers for synthetic polymers, such as 
polyolefins, polyvinyl chloride, polyvinylidene chloride, polyurethanes, 
and polyamides. These compounds have the general formula: 
##STR3## 
OR A SALT THEREOF. 
In the above Formula: 
R.sub.1 and R.sub.2 which may be the same or different, each are an alkyl 
group such as methyl, ethyl, isopropyl or dodecyl, or they form, together 
with the carbon atom to which they are attached, a saturated alicyclic 
group such as: 
##STR4## 
OR A GROUP OF THE FORMULA 
##STR5## 
n is an integer of 1 to 3 inclusive: and R.sub.3 is an acyl group. 
These compounds have proved to be particularly acceptable because they do 
not impart a discoloration of their own to the synthetic polymer. The 
compounds generally employed previously have either been highly colored, 
such as the nickel compounds (which are normally green) and the 
2-hydroxybenzophenones (which are varying shades and intensities of 
yellow). They also show very little tendency towards sublimation and 
exudation, and they have an excellent stabilizing action against both heat 
and light deterioration. 
Consequently, the Murayama et al patent has been followed by a large number 
of patent and literature disclosures by Murayama et al and others of 
compounds including a 2,2,6,6-tetrasubstituted-4-piperidyl group attached 
to a base molecule of varying structures. 
Murayama et al U.S. Pat. No. 3,893,303 patented Aug. 5, 1975 propose 
piperidino-spiro-hydantoin derivatives having the formula: 
##STR6## 
wherein 
R represents an alkyl group, an alkenyl group, an alkenoyl group which may 
be substituted with an aryl group, a hydroxyalkyl group, an alkoxyalkyl 
group, an alkoxycarbonylalkyl group, an acyloxyalkyl group, a cyanoalkyl 
group or nitroso group, and X and Y individually represent oxygen atom or 
sulfur atom. 
Murayama et al in U.S. Pat. No. 3,899,464 patented August 12, 1975 
disclose a variation of the piperidino spiro compounds having the formula: 
##STR7## 
wherein 
R.sub.1 represents hydrogen atom, an alkyl group, a substituted alkyl 
group, an alkenyl group, an alkynyl group, a substituted or unsubstituted 
aralkyl group, an aliphatic acyl group, an alkoxycarbonyl group or an 
aralkoxycarbonyl group, n is an integer of 1 to 4; 
When n is 1, R.sub.2 represents hydrogen atom, an aliphatic aromatic or 
heterocyclic monoacyl group, an alkyl group, an alkenyl group, an alkynyl 
group, an aralkyl group, an aryl group, an alkoxyalkyl group, an 
epoxyalkyl group, an alkoxysulfonylalkyl group, N-substituted carbamoyl 
group, a N-substituted thiocarbamoyl group, a monovalent group from an 
oxoacid or group 
##STR8## 
in which 
R.sub.3 represents hydrogen atom, a lower alkyl group or phenyl group and 
R.sub.4 represents an alkyl group; 
when n is 2, R.sub.2 represents carbonyl group, an aliphatic or aromatic 
diacyl group, an alkylene group, an alkenylene group, an alkynylene group, 
an aralkylene group, a N-substituted dicarbamoyl group or a divalent group 
from an oxoacid; 
when n is 3, R.sub.2 represents an aromatic triacyl group or a trivalent 
group from an oxoacid; and 
when n is 4, R.sub.2 represents an aromatic tetraacyl group, and A 
represents a group 
##STR9## 
in which 
R.sub.5 represents hydrogen atom or a lower alkyl group or, when n is 1, 
R.sub.5 may represent together with R.sub.2 a group 
##STR10## 
in which 
R.sub.6 represents the same group as defined in R.sub.1 and may be the same 
or different from R.sub.1, or a group 
##STR11## 
in which 
m is 1 or 2 and R.sub.7 represents hydrogen atom or, when n and m are 1, 
R.sub.7 represents methylene group together with R.sub.2. 
Murayama et al U.S. Pat. No. 3,933,735 patented Jan. 20, 1976 propose 
4-piperidone derivatives having a structure similar to the 4-piperidyl 
derivatives, but with a keto oxygen at the 4-position of the piperidine 
ring. 
Murayama et al U.S. Pat. No. 3,941,744 patented Mar. 2, 1976, disclose 
another variation of the piperidino spiro derivatives having the formula: 
##STR12## 
wherein 
R' represents an alkyl group, a substituted alkyl group, an acyl group, an 
alkoxycarbonyl group, a substituted alkoxycarbonyl group, an amino group, 
a substituted amino group or nitroso group; 
X represents oxygen atom or sulfur atom; 
Y represents oxygen atom, sulfur atom or a group of the formula .dbd. N-R" 
in which R" is hydrogen atom, an alkyl group or a substituted alkyl group; 
Z represents oxygen atom or a group of the formula &gt;N-R'" is hydrogen atom, 
an alkyl group or a substituted alkyl group; 
n is an integer of 1 through 4 inclusive; and 
R represents, when n is 1, an alkyl group, a substituted alkyl group, an 
aryl group, a substituted aryl group, a cycloalkyl group, an 
alkoxycarbonyl group, a substituted alkoxycarbonyl group, a substituted 
phosphino group or a substituted phosphinyl group, when n is 2, an 
alkylene group, an alkenylene group, an arylene group, a substituted 
arylene group, an aralkylene group, an alkylenediphenylene group, a 
bis-(acyloxyalkylene) group, an alkylene-bis-(oxycarbonylalkyl) group, a 
dialkylene ether group or a diphenylene ether group, when n is 3, an 
alkanetriyl group, a tris(acyloxyalkylene) group, an 
alkane-tris-(oxycarbonylalkyl) group or a group of the group 
##STR13## 
in which 
p is an integer of 1 through 8 inclusive, and when n is 4, an alkane 
tetrayl group, a tetrakis-(acyloxyalkylene) group or an 
alkanetetrakis(oxycarbonylalkyl) group. 
Murayama et al U.S. Pat. No. 3,940,363 patented Feb. 24, 1976 disclose a 
further variation in which two 2,2,6,6-tetrasubstituted-4-piperidyl groups 
are linked together via the ring nitrogen atom to an R' alkylene linking 
group, which may be interrupted with an oxygen or sulfur atom, an 
alkenylene group, an alkynylene group, an aralkylene group, an aliphatic 
diacyl group, a group having the formula: 
##STR14## 
in which 
n is an integer of 1 or 2 and X is an alkylene group, or o-, m- or 
p-phenylene group or the carbon atoms of CO groups may be directly joined 
in the absence of X or a group of the formula: 
##STR15## 
in which 
Y is an alkylene group or o-, m- or p-phenylene group. 
Ramey et al U.S. Pat. Nos. 3,899,491, patented Aug. 12, 1975 and 3,920,659, 
patented Nov. 18, 1975, disclose alkyl alkanoate derivatives of 
substituted piperazines and substituted piperazinodiones. The substituted 
piperazines of U.S. Pat. No. 3,899,491 have the formula: 
##STR16## 
wherein 
R.sup.1 and R.sup.2 are methyl or together with the carbon to which they 
are bound form a mono-cyclic ring system having five or six carbon atoms; 
R.sup.3 is an alkyl group of from one to twenty atoms; 
R.sup.4 is hydrogen or methyl, and 
m is 0 or 1. 
The substituted piperazinodiones of U.S. Pat. No. 3,920,659 have the 
formula: 
##STR17## 
wherein 
R.sup.1 and R.sup.2 are independently of each other methyl or ethyl or 
together with the carbon to which they are bound form a cyclopentyl or 
cyclohexyl ring, which is unsubstituted or substituted with a methyl 
group; 
n is an integer of from 1 to 2; 
when n is 1, R.sup.3 is an alkyl group of from one to twenty carbon atoms; 
when n is 2, R.sup.3 is an alkylene group of from two to eight carbon 
atoms; and 
A is a straight or branched chain (lower) alkylene group containing from 
one to six carbon atoms with the limitation that the terminals of said 
alkylene group bear only hydrogen or one (lower) alkyl group. 
Ramey et al U.S. Pat. No. 3,920,661 patented November 18, 1975 disclose 
dicarboxylic acids and salts in which one carboxylic acid group is 
esterified with a 2,2,6,6-tetrasubstituted-4-hydroxy piperidine and having 
the formula: 
##STR18## 
wherein 
R.sub.1 and R.sub.2 independently of each other are straight- or 
branchedchain alkyl having from one to six carbon atoms, or together with 
the carbon to which they are bound form a cyclopentyl or cyclohexyl ring, 
which is unsubstituted or substituted with a methyl group; 
R.sub.3 is hydrogen, alkyl having one to twelve carbon atoms, 
.beta.-methoxyethyl, alkenyl having three or four carbon atoms, propargyl, 
benzyl or alkyl-substituted benzyl; 
R.sub.4 is straight or branched-chain alkylene having five to eight carbon 
atoms, or the group (CH.sub.2).sub.m Y(CH.sub.2).sub.n wherein Y is oxygen 
or sulfur and m and n independently of each other are an integer from 1 to 
3; 
M is hydrogen or a metal selected from the group consisting of barium, 
nickel, manganese, calcium, zinc, iron, sodium, cobalt, tin, and dialkyl 
tin, and 
z has a value of from 1 to 4, the value of z being the same as the 
available valence of M. 
Ramey et al U.S. Pat. No. 3,939,163 patented Feb. 17, 1976 disclose closely 
similar compounds in which R.sub.4 is alkylene having from one to four 
carbon atoms. 
Randell et al U.S. Pat. No. 3,939,170 patented Feb. 17, 1976 disclose 
dehydropyridinyl sulphides, sulphoxides and sulphones having the formula: 
##STR19## 
wherein 
X is S, SO or SO.sub.2 and Y and Y.sup.1 are the same or different and each 
is H, OH, O-- or a straight- or branched alkyl residue having from one to 
four carbon atoms, and salts thereof when Y and Y.sup.1 are other than O- 
Randell et al in published patent application No. B408,123 published Apr. 
13, 1976 disclose substituted piperidine-4-ols having the formula: 
##STR20## 
wherein 
R.sub.1 and R.sub.2 are the same or different and each is a straight- or 
branched alkyl residue having from one to twelve carbon atoms, or R.sub.1 
and R.sub.2, together with the carbon atom to which they are attached, 
form a cycloalkyl residue having from five to twelve carbon atoms or the 
group: 
##STR21## 
wherein 
R.sub.1 and R.sub.2 have their previous significance and Y is a straight- 
or branched alkyl residue having from one to twenty carbon atoms, an 
alkenyl or alkynyl residue having from three to twenty carbon atoms, an 
aralkyl residue having from seven to twelve carbon atoms or the group 
--CH.sub.2 X wherein X is the group 
##STR22## 
wherein 
R.sub.3 is hydrogen, a methyl or phenyl residue, the group 
##STR23## 
wherein 
R.sub.4 is an alkyl residue having from one to twenty carbon atoms. 
Cook U.S. Pat. No. 3,929,804 patented Dec. 30, 1975 discloses 4-piperidine 
acetamide compounds having the formula: 
##STR24## 
wherein 
R.sub.1 and R.sub.2 are the same or different and each is a straight- or 
branched alkyl residue having from one to twelve carbon atoms, or R.sub.1 
and R.sub.2, together with the carbon atom to which they are attached form 
a cycloalkyl group having from five to twelve carbon atoms; 
R.sub.3 is hydrogen, a straight- or branched alkyl residue having from one 
to four carbon atoms, an aralkyl residue having from seven to nine carbon 
atoms or a cycloalkyl group having from five to six carbon atoms; 
R.sub.4 is a metal ion or a hydrocarbyl residue having from two to twenty 
carbon atoms and being either unsubstituted or substituted by halogen or 
interrupted by one or more oxygen or sulphur atoms; 
X is --O--, --S--, or &gt;NR.sub.5, wherein R.sub.5 has the same significance 
as R.sub.3 ; and 
n is 2, 3 or 4; as well as salts of the amine function of the compounds of 
formula I. 
Cook U.S. Pat. No. 3,939,168 patented Feb. 17, 1976 discloses closely 
similar compounds having a Y substituent on the piperidyl nitrogen atom, Y 
being alkyl, alkenyl, aralkyl or a group 
##STR25## 
wherein 
R.sub.7 is hydrogen, alkyl or phenyl. 
In accordance with the instant invention, 2,2,6,6-tetramethyl-4-piperidyl 
carboxylic acid esters of butane or butene tricarboxylic acids are 
provided, useful as stabilizers for organic polymeric materials, and 
having the general formula: 
##STR26## 
wherein 
R.sub.1 is selected from the group consisting of 
##STR27## 
the R.sub.1 groups can be the same or different; 
R.sub.2 is selected from the group consisting of CH.sub.3 and CH.sub.2 ; 
and 
R.sub.3 is lower alkyl. 
The R.sub.3 alkyl has from one to about six carbon atoms. Exemplary are 
methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, 
secondary butyl, n-amyl, isoamyl, tertiary amyl, n-hexyl, isohexyl, 
secondary hexyl and tertiary hexyl. 
The following compounds are exemplary: 
##STR28## 
The compounds in accordance with the invention are readily prepared using 
conventional procedures. The starting materials are either available or 
readily synthesized without difficulty. The corresponding 
2,2,6,6-tetra-substituted-4-hydroxy piperidine is used as a starting 
material for the 2,2,6,6-tetrasubstituted-4-piperidyl group R.sub.1. This 
is reacted with one or more carboxylic acid groups of the corresponding 
butane or butene tricarboxylic acid or lower alkyl ester in the presence 
of an organic solvent and a suitable esterification or transesterification 
catalyst. The hydroxy group of the piperidine becomes esterified or 
transesterified with the carboxylic acid groups of the acid or ester, 
forming the 4-piperidinyl carboxylic acid ester of the invention: 
##STR29## 
where 
R.sub.2 is CH.sub.3 or CH.sub.2 and R.sub.4 is H or lower alkyl such as 
methyl. 
Suitable reactor temperatures are from about 90.degree. to about 
210.degree. C. Transesterification catalysts can include alkaline 
materials such as an alkali or alkaline earth metal, which can be added in 
the form of the metal or in the form of an alkaline compound, such as an 
alkaline oxide or hydroxide, or alkaline salt, such as the carbonate or 
hydride, or as the alcoholate. Sodium is quite potassium carbonate, 
lithium hydroxide, potassium hydroxide, sodium hydride, lithium hydride, 
potassium hydride, calcium hydride, the oxides and hydroxides of calcium 
strontium and barium, and the alcoholates, usually of methyl, ethyl or 
isopropyl alcohol, or phenolates of all of these metals. Other metal 
alkoxides such as those of aluminum, titanium and zirconium can be used, 
as well as organotin compounds such as dibutyl tin oxide, dimethyl tin 
dilaurate, and dimethyl tin diacetate; and heavy metal salts such as 
cobalt naphthenate and lead 2-ethyl hexoate. Only a very small amount of 
the catalyst need be employed, for example, as little as from 0.01 to 2% 
by weight.

The following Examples illustrate the preparation of the compounds of the 
invention: 
EXAMPLE I 
##STR30## 
3.5 g of butane-1,2,3-tricarboxylic acid trimethyl ester, and 7.5 g of 
2,2,6,6-tetramethylpiperidine-4-ol were dissolved in 60 ml of xylene, and 
0.2 ml of titanium tetraisopropoxide added. 
The solution was heated and stirred for 5 hours up to 140.degree. C., while 
distilling off the methanol as it was liberated. After cooling, the 
solution was filtered, and 100 ml of ethyl ether was added to the 
filtrate. The resulting solution was washed with water, dried with K.sub.2 
CO.sub.3. A very pale yellow viscous liquid residue was obtained, after 
distilling off the solvent. White crystals m.p. 119.degree.-121.degree. C. 
were obtained by recrystallization of the viscous liquid from n-hexane. 
______________________________________ 
Elemental Analysis: 
C% H% N% 
______________________________________ 
Found: 67.85 9.93 6.70 
Calculated: 67.18 10.11 6.91 
IR Analysis: 
.gamma. NH: 3280 cm.sup.-1 
.gamma.C: 1730 cm.sup.-1, 
.delta.CH.sub.3 : 1380 cm.sup.-1 
______________________________________ 
The product was shown by the analytical results to have the formula shown 
above. 
EXAMPLE II 
##STR31## 
3-Butene-1,2,3-tricarboxylic acid trimethyl ester 4.6 g, and 9.9 g 
2,2,6,6-tetramethyl-4-hydroxy piperidine were dissolved in 80 ml of xylene 
and 0.2 ml tetraisopropyl titanate was added. The solution was reacted for 
5 hours at 140.degree. C., while distilling off the methanol produced. The 
reaction mixture was cooled, and 200 ml ethyl ether added. The mixture was 
washed with water, dried, and the solvent removed by distillation. A pale 
yellow viscous liquid was obtained. 
______________________________________ 
Elemental Analysis: 
C% H% N% 
______________________________________ 
Found: 68.14 9.65 6.73 
Calculated: 67.40 9.82 6.94 
IR Analysis: 
.gamma. NH: 3280 cm.sup.-1 
.gamma. C=O: 1725 cm.sup.-1 
.delta. CH.sub.3 : 1380 cm.sup.-1 
______________________________________ 
The product was shown by these analytical results to have the formula shown 
above. 
EXAMPLE III 
##STR32## 
3-Butene-1,2,3-tricarboxylic acid trimethyl ester 4.6 g and 
9-aza-3-ethyl-3-hydroxy methyl-8,8,10,10-tetramethyl 1.5-dioxaspiro [5.5] 
undecane 17.1 g were dissolved in 80 ml of xylene, 0.3 ml titanium tetra 
isopropoxide was added, and the reaction mixture was heated and stirred 
for six hours at 140.degree. C. while distilling off methanol as it was 
liberated. After cooling, 200 ml of ethyl ether was added to the solution 
and the resulting solution washed with water, dried with K.sub.2 CO.sub.3, 
and the ethyl ether removed by distillation, whereupon a pale yellow 
viscous liquid was obtained. 
______________________________________ 
Elemental Analysis: 
C% H% N% 
______________________________________ 
Found: 66.03 9.69 4.31 
Calculated: 65.65 9.75 4.42 
IR Analysis: 
.gamma.NH: 3300 cm.sup.-1 
.gamma.C=0: 1720 cm.sup.-1 
.delta.CH.sub.3 : 1375 cm.sup.-1 
______________________________________ 
The product was shown by these analytical results to have the formula shown 
above. 
The 2,2,6,6-tetrasubstituted-4-piperidyl carboxylic acid esters of the 
invention are effective stabilizers to enhance the resistance to 
deterioration due to heat and/or light of synthetic polymeric materials 
which are susceptible to such degradation, including polyolefins such as 
low density polyethylene, high density polyethylene, polypropylene, 
polybutylene, polyisobutylene, polypentylene, and polyisopentylene, 
polystyrene; polydienes, such as polybutadiene and polyisoprene; and 
copolymers of olefins and dienes with other ethylenically and 
acetylenically unsaturated monomers, such as ethylene-propylene 
copolymers, ethylene-butene copolymers, ethylene-pentene copolymers, 
ethylene-vinyl acetate copolymers, styrene-butadiene copolymers, 
acrylonitrile-styrene-butadiene copolymers, synthetic rubbers of all 
types, such as polychloroprene; polyvinyl halides, including polyvinyl 
chloride homopolymer, polyvinylidene chloride; and copolymers of vinyl 
chloride and vinylidene chloride; vinyl chloride and vinyl acetate; 
vinylidene chloride and vinyl acetate; and other ethylenically unsaturated 
monomers; polyacetals such as polyoxymethylene and polyoxyethylene; 
polyesters such as polyethylene glycol-terephthalic acid ester polymers; 
polyamides such as polyepsiloncaprolactam; polyhexamethylene adipamide and 
polydecamethylene adipamide; polyurethanes; and epoxy resins. 
The synthetic polymer can be in any physical form, including (for example) 
filaments, yarns, films, sheets, molded articles, latex, and foam. 
The stabilizers of the invention can be employed as the sole stabilizer or, 
preferably, in combination with other conventional heat and light 
stabilizers for the particular synthetic polymer. 
Thus, for example, in the case of polyvinyl chloride resins, other 
polyvinyl chloride resin heat stabilizers can be included, including 
polyvalent metal fatty acid salts such as barium and cadmium salts of the 
higher fatty acids; organic triphosphites, organotin compounds; hindered 
phenols; and epoxy compounds. 
With polyolefin resins there can be employed fatty acid salts of polyvalent 
metals, organic phosphites, phenolic antioxidants, and the higher fatty 
acid esters of thiodipropionic acids, such as, for example, dilauryl 
thiodipropionate. 
With polyamide resin compositions, polyamide stabilizers such as copper 
salts in combination with iodides and/or phosphorus compounds and salts of 
divalent manganese can be used. 
With synthetic rubbers and acrylonitrile butadiene styrene terpolymers, 
antioxidants such as hindered phenols and bis-phenols, polyvalent metal 
salts of the higher fatty acids, and organic phosphites can be used. 
In addition, other conventional additives for synthetic polymers, such as 
plasticizers, lubricants, emulsifiers, antistatic agents, flameproofing 
agents, pigments and fillers, can be employed. 
The following Examples in the opinion of the inventors represent preferred 
embodiments of synthetic resin compositions in accordance with the 
invention. 
EXAMPLES 1 to 6 
Polypropylene compositions were prepared using stabilizers of the invention 
and three of the prior art, and having the following formulation: 
______________________________________ 
Ingredient Parts by Weight 
______________________________________ 
Polypropylene 100 
Dilauryl thiodipropionate 
0.3 
Stearyl .beta.-(3,5-di-t-butyl-4-hydroxyphenyl) 
0.1 
propionate 
Stabilizer as shown in Table I 
0.3 
______________________________________ 
The composition was thoroughly blended in a Brabender Plastograph, and then 
compression-molded to form sheets 0.5 mm thick. Pieces 2.5 cm square were 
cut off from the sheets and exposed to a carbon arc in a Weather-O-Meter 
until failure, to evaluate resistance to deterioration in the presence of 
ultraviolet light. The time in hours when degradation set in, as 
determined by a significant discoloration and/or embrittlement, was noted 
as hours to failure. 
Resistance to gas staining was evaluated using nitrogen oxide gas. The 
sheet was exposed to the gas at 25.degree. C. for 72 hours. Yellowness was 
measured by a Hunter colorimeter after this exposure. 
The results of both tests are given in Table I. 
TABLE I 
__________________________________________________________________________ 
Resistance 
Resistance to 
To Light Gas Staining 
Example No. 
Stabilizer Hours to Failure 
Yellowness 
__________________________________________________________________________ 
Control 1 
Bis-(2,2,6,6-tetramethyl-4- 
470 0.14 
piperidinyl)sebacate 
Control 2 
Tris-(2,2,6,6-tetramethyl-4- 
460 0.17 
piperidinyl)trimellitate 
Control 3 
Bis-(9-aza-3-methyl-8,8,10,10- 
440 0.15 
tetramethyl-1,5-diaxaspiro[5,5]- 
3-undecylmethyl)adipate 
##STR33## 750 0.10 
##STR34## 720 0.09 
##STR35## 740 0.10 
##STR36## 790 0.08 
##STR37## 780 0.09 
##STR38## 770 0.88 
__________________________________________________________________________ 
It is apparent from the above results that the compounds of the invention 
are superior stabilizers in enhancing the resistance of the polypropylene 
polymer composition to deterioration in the presence of ultraviolet light, 
and to gas staining. 
EXAMPLES 7 to 12 
High density polyethylene compositions were prepared using stabilizers of 
the invention and three of the prior art, and having the following 
formulation: 
______________________________________ 
Ingredient Parts by Weight 
______________________________________ 
High-density polyethylene 
100 
Ca-stearate 1.0 
Pentaerythritol tetrakis 
0.2 
(.beta.-lauryl mercaptopropionate) 
2,6-di-t-butyl-p-cresol 
0.1 
Stabilizer as shown in Table II 
0.2 
______________________________________ 
The stabilizer was blended with the polymer on a two-roll mill and sheets 
0.5 mm thick were prepared by compression molding of the blend. Pieces 2.5 
cm square were cut off from the sheets, and exposed in a Weather-O-Meter 
to ultraviolet light. The time in hours when degradation set in, as 
determined by a significant discoloration and/or embrittlement, was noted 
as hours to failure. 
Resistance to gas staining was determined using the same test procedure as 
in Examples 1 to 6. 
The results are reported in Table II: 
TABLE II 
__________________________________________________________________________ 
Resistance 
Resistance to 
To Light Gas Staining 
Example No. 
Stabilizer Hours to Failure 
Yellowness 
__________________________________________________________________________ 
Control 1 
2,2,6,6-tetramethyl-4- 630 0.18 
piperidinyl benzoate 
Control 2 
Bis-(9-aza-3-ethyl-8,8,10,10- 
810 0.16 
tetramethyl-1,5-dioxaspiro [5,5]- 
3-undecyl methyl) sebacate 
Control 3 
2-(2'-hydroxy-5'-methyl-phenyl) 
750 0.21 
benzotriazole 
##STR39## 1420 0.11 
##STR40## 1380 0.12 
##STR41## 1350 0.12 
10. 
##STR42## 1540 0.10 
##STR43## 1490 0.11 
##STR44## 1520 0.10 
__________________________________________________________________________ 
The stabilizers of the invention are clearly superior to the controls in 
enhancing resistance of the polyethylene to degradation under ultraviolet 
light, and to gas staining. 
EXAMPLES 13 to 18 
Polybutene-1, resin compositions were prepared using stabilizers of the 
invention and three of the prior art, and having the following 
formulation: 
______________________________________ 
Ingredient Parts by Weight 
______________________________________ 
Polybutene-1 100 
Tetrakis [methylene-3-(3,5-di-t-butyl-4- 
0.1 
hydroxyphenyl) propionate] methane 
Dilauryl thiodipropionate 
0.2 
Stabilizer as shown in Table III 
0.5 
______________________________________ 
The stabilizer was blended with the resin in a two-roll mill, and sheets 
0.5 mm thick were prepared by compression molding of the resulting blend. 
Pieces 2.5 cm square were cut off from the sheets, and subjected to 
ultraviolet light in a Weather-O-Meter. The time in hours when degradation 
set in, as determined by a significant discoloration and/or embrittlement, 
was noted as hours to failure. 
Resistance to gas staining was determined using the same test procedure as 
in Examples 1 to 6. 
The results are reported in Table III: 
TABLE III 
__________________________________________________________________________ 
Resistance 
Resistance to 
To Light Gas Staining 
Example No. 
Stabilizer Hours to Failure 
Yellowness 
__________________________________________________________________________ 
Control 1 
2-hydroxy-4-methoxy 610 0.18 
benzophenone 
Control 2 
Bis-(2,2,6,6-tetramethyl-4- 
830 0.14 
piperidinyl) sebacate 
Control 3 
Tris-(9-aza-3-ethyl-8,8,10,10- 
790 0.16 
tetramethyl-1,5-dioxaspiro [5,5]- 
3-undecylmethyl) trimellitate 
##STR45## 1340 0.10 
##STR46## 1320 0.11 
##STR47## 1280 0.10 
##STR48## 1470 0.08 
##STR49## 1450 0.09 
##STR50## 1470 0.09 
__________________________________________________________________________ 
It is apparent from the data that the stabilizers of the invention are 
superior to the stabilizers of the prior art in imparting resistance to 
deterioration under ultraviolet light and to gas staining. 
EXAMPLES 19 to 24 
A group of polyvinyl chloride resin compositions was prepared having the 
following formulation: 
______________________________________ 
Ingredient Parts by Weight 
______________________________________ 
Polyvinyl chloride 100 
Dioctylphthalate 48 
Epoxidized soybean oil 2.0 
Ca stearate 1.0 
Zn stearate 0.1 
Tris-nonylphenyl phosphite 
0.1 
Stabilizer as shown in Table IV 
0.1 
______________________________________ 
This formulation was blended and sheeted off on a two-roll mill to form 
sheets 1 mm thick. The light resistance of these sheets was then 
determined by placing strips 1 cm long in a Weather-O-Meter, and exposing 
them to ultraviolet light. The time in hours was then noted for the sheet 
to develop a noticeable discoloration and/or embrittlement, indicating 
deterioration due to oxidation in the presence of ultraviolet light. 
This test was repeated for a total of six stabilizers in accordance with 
the invention, having the formulae indicated in Table IV, in comparison 
with three controls. The following results were obtained: 
TABLE IV 
______________________________________ 
Hrs. 
to 
Ex. Fail- 
No. Stabilizer ure 
______________________________________ 
Con- 2-hydroxy-4-octoxybenzophenone 
380 
trol 1 
Con- Tris-(9-aza-3-ethyl-8,8,10,10- 
420 
trol 2 
tetramethyl-1,5-dioxaspiro[5,5]- 
3-undecylmethyl)trimellitate 
Con- 2,2,6,6-tetramethyl-4-piperidinyl 
330 
trol 3 
stearate 
##STR51## 650 
20. 
##STR52## 610 
##STR53## 620 
##STR54## 620 
##STR55## 600 
##STR56## 640 
______________________________________ 
It is apparent that each of the stabilizers in accordance with the 
invention is far superior to the controls, which are each conventional 
ultraviolet light stabilizers for polyvinyl chloride.