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BACKGROUND OF THE INVENTION
The present invention pertains to polyolefin compositions containing a
stabilizer or mixture of stabilizers selected from the group consisting of
the phenolic antioxidants, the hindered amine light stabilizers, the
alkylated hydroxybenzoate light stabilizers, the ultraviolet light
absorbers, the organic phosphorus compounds, the alkaline metal salts of
fatty acids and the thiosynergists, which are stabilized against
degradation and/or discoloration by an effective amount of a
polyhydroxylamine derivative; and to these polyhydroxylamine compounds
themselves.
Although phenolic antioxidants have long been known to be very effective
stabilizers for polyolefins and have enjoyed wide commercial success for
that use, polyolefin compositions stabilized with phenolic antioxidants
tend to discolor upon heating at elevated temperatures for prolonged
periods or upon exposure to the combustion products of natural gas.
While the concomitant addition of organic phosphites to such polyolefin
compositions mitigates the discoloration, it remains a serious practical
problem.
Likewise polyolefin compositions containing certain phenolic antioxidants
and hindered amine light stabilizers tend to discolor upon storage for
extended periods even at ambient temperatures.
The organic hydroxylamine compounds, such as N,N-dibenzylhydroxylamine, are
generally known and some are commercially available.
U.S. Pat. Nos. 3,644,278 and 3,778,464 describe the use of substituted
hydroxylamines of varying structures as antioxidant stabilizers for
hydrocarbons including polyolefins. The use of such substituted
hydroxylamines in polyolefins in combination with a phenolic antioxidant
or in combination with an organic phosphorus compound, an ultraviolet
light absorber, an alkylated hydroxybenzoate light stabilizer, a
thiosynergist or a hindered amine light stabilizer with the resulting
resistance to degradation and/or discoloration is not disclosed or
suggested.
U.S. Pat. No. 3,408,422 discloses the use of selected hydroxylamine
derivatives in unsaturated polyester compositions to prevent premature
gelation on storage.
U.S. Pat. No. 3,926,909 describes the use of substituted hydroxylamines as
stabilizers to prevent the discoloration of polyurethanes (Spandex) upon
exposure to light, smog or gas fumes.
U.S. Pat. No. 4,242,224 discloses that the pink discoloration which occurs
in the amine antioxidant and antiozonant emulsions used in the latex
industry at high pH values can be prevented or retarded by the use of
dialkylhydroxylamine or mercaptan stabilizers.
U.S. Pat. No. 4,316,996 pertains to a process of preparing phenolic
antioxidants in the presence of a hydroxylamine derivative and of a
substituted oxime to yield a phenolic antioxidant which itself exhibits
improved color and color stability. It is stated that, when such
antioxidants are incorporated into rubber, the amount and rate of
discoloration is reduced. The instant compositions are not disclosed or
suggested.
U.S. Pat. No. 3,432,578 relates to conjugated diene polymer compositions
stabilized against the adverse effects of ultraviolet light by use of
diaryl or diaralkyl hydroxylamine compounds including
N,N-dibenzylhydroxylamine. It is noted that the dialkylhydroxylamines are
completely ineffective in stabilizing such polymer compositions. This
patent mentions that other stabilizers may be used in conjunction with the
hydroxylamine derivative and in Table I discloses stabilized compositions
consisting of a conjugated diene polymer, phenolic antioxidants and
N,N-dibenzylhydroxylamine. Such compositions were resistant to
decomposition upon ultraviolet exposure.
U.S. Pat. No. 4,386,224 discloses the use of N,N-diethylhydroxylamine as a
color stabilizer for monoalkyl phenols such as nonyl or dodecyl phenol.
OBJECT OF THE INVENTION
The object of the instant invention is to provide new polyhydroxylamine
compounds.
These new polyhydroxylamines are effective in stabilizing polyolefins from
discoloration when the polyolefin contains one or more other stabilizers
selected from the group consisting of the phenolic antioxidants, the
hindered amine light stabilizers, the alkylated hydroxybenzoate light
stabilizers, the ultraviolet light absorbers, the organic phosphorus
compounds, the alkaline metal salts of fatty acids and the thiosynergists.
DETAILED DISCLOSURES
This invention also pertains to a composition, stabilized against
degradation, which comprises
(a) a saturated polyolefin or mixture thereof,
(b) a stabilizing amount of a stabilizer or mixture of stabilizers selected
from the group consisting of the phenolic antioxidants, the hindered amine
light stabilizers, the alkylated hydroxybenzoate light stabilizers, the
ultraviolet light absorbers, the organic phosphorus compounds, the
alkaline metal salts of fatty acids and the thiosynergists, and
(c) a stabilizing amount of a hydroxylamine derivative, or a mixture
thereof, containing the group
##STR1##
The instant composition is stabilized against degradation and/or
discoloration upon exposure to heating at elevated temperatures, to the
combustion products of natural gas, to gamma irradiation or to prolonged
storage at ambient temperature.
More particularly, the instant invention relates to a hydroxylamine
derivative of formula I
##STR2##
wherein T.sub.1 is hydrogen, alkyl of 1 to 36 carbon atoms, cycloalkyl of
5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, or said aralkyl
substituted by alkyl of 1 to 36 carbon atoms or by one or two halogen
atoms,
g is 2, 3 or 4,
when g is 2,
T.sub.2 is alkylene of 2 to 12 carbon atoms, cycloalkylene of 6 to 10
carbon atoms, arylene of 6 to 10 carbon atoms, alkylenearylenealkylene of
8 to 10 carbon atoms, or
##STR3##
when g is 3, T.sub.2 is alkanetriyl of 3 to 6 carbon atoms, or
##STR4##
or when g is 4,
T.sub.2 is alkanetetrayl of 4 to 6 carbon atoms.
T.sub.1 may be straight or branched chain alkyl of 1 to 36 carbon atoms
such as methyl, ethyl, isopropyl, isobutyl, tert-butyl, n-octyl,
2-ethylhexyl, nonyl, n-dodecyl, n-octadecyl, eicosyl, tetracosyl,
tricontyl or hexatricontyl. Preferably T.sub.1 is alkyl of 4 to 18 carbon
atoms.
T.sub.1 may also be cycloalkyl of 5 to 12 carbon atoms such as cyclopentyl,
cyclohexyl, cyclooctyl or cyclododecyl. Preferably T.sub.1 is cyclohexyl
or cyclododecyl.
T.sub.1 is also aralkyl of 7 to 9 carbon atoms such as benzyl,
alpha-methylbenzyl, or alpha, alpha-dimethylbenzyl where the benzyl group
may additionally be substituted by alkyl, preferably methyl, or by one or
two halogen groups, preferably chloro or bromo.
Preferably T.sub.1 is benzyl.
In formula I, g is 2, 3 or 4. Preferably g is 2 or 3.
When g is 2, T.sub.2 is alkylene of 2 to 12 carbon atoms such as ethylene,
1,2-propylene, trimethylene, tetramethylene, hexamethylene, octamethylene
or dodecamethylene. Preferably T.sub.2 is alkylene of 2 to 8 carbon atoms.
T.sub.2 is also cycloalkylene of 6 to 10 carbon atoms such as
cyclohexylene, preferably, 1,4-cyclohexylene, or decahydronaphthylene.
T.sub.2 can also be arylene of 6 to 10 carbon atoms such as o-, m- or
p-phenylene, preferably m- or p-phenylene, or 1,4-naphthylene.
T.sub.2 is also alkylenearylenealkylene of 8 to 10 carbon atoms, such as
p-xylylene or ethylene-p-phenylene-ethylene. Preferably T.sub.2 is
p-xylylene or
##STR5##
When g is 3, T.sub.2 is alkanetriyl of 3 to 6 carbon atoms such as
glyceryl; or preferably
##STR6##
When g is 4, T.sub.2 is alkanetetrayl of 4 to 6 carbon atoms, such as
(--CH.sub.2).sub.2 C(CH.sub.2 --).sub.2 or 1,2,3,4-butanetetrayl.
The instant hydroxylamine may generally be prepared by reacting
hydroxylamine or a substituted hydroxylamine with an activated halogen
compound in the presence of an acid acceptor; or by the oxidizing of an
amine with a peroxy compound such as benzoyl peroxide followed by
saponification of the intermediate formed to the desired hydroxylamine
derivative.
The intermediate hydroxylamines, halogen compounds and amines are largely
items of commerce or can be prepared by known methods.
The saturated polyolefins useful in the instant compositions are the
polymers, derived from monoolefins, such as polyethylene, which can
optionally be crosslinked, polypropylene, polyisobutylene, polybutene-1,
poly-3-methylbutene-1 and polymethylpentene-1. Polyethylene may be for
example medium density, high density or linear low density polyethylene.
Mixtures of the homopolymers cited above, for example mixtures of
polypropylene and polyethylene, polypropylene and polybutene-1, or
polypropylene and polyisobutylene and the like, may also be used.
Copolymers of monoolefins may also be used in the instant compositions, for
example ethylene/propylene copolymers, propylene/butene-1 copolymers,
propylene/octene-1 copolymers, ethylene/butene-1 copolymers,
ethylene/octene-1 copolymers as well as ethylene/vinyl acetate copolymers.
The instant compositions particularly employ as the polyolefin component
polyethylene, polypropylene, polyisobutylene, poly(butene-1),
poly(pentene-1), poly(3-methylbutene-1), poly(4-methyl-pentene-1) and
various ethylene or propylene copolymers.
Especially preferred polyolefin substrates are polypropylene, low density
polyethylene, medium density polyethylene, high density polyethylene,
linear low density polyethylene, poly(butane-1), ethylene/vinyl acetate
copolymer, ethylene/propylene copolymer and copolymers of ethylene or of
propylene with other alpha olefins.
The most preferred polyolefin substrate is polypropylene, high density
polyethylene, ethylene/propylene copolymer or a copolymer of ethylene or
of propylene with another alpha olefin.
The phenolic antioxidants useful in the instant compositions embrace a
large family of compounds examples of which are given below.
ANTIOXIDANTS
Simple 2,6-dialkylphenol, such as, for example,
2,6-di-tert.-butyl-4-methylphenol, 2-tert.-butyl-4,6-di-methylphenol,
2,6-di-tert.-butyl-4-methoxymethylphenol 2,6-dioctadecyl-4-methylphenol
and 2,6-di-tert-butylphenol.
Derivatives of alkylated hydroquinones, such as for example
2,5-di-tert.-butyl-hydroquinone, 2,5-di-tert.-amylhydroquinone,
2,6-di-tert.-butyl-hydroquinone, 2,5-di-tert.-butyl-4-hydroxy-anisole,
3,5-di-tert.-butyl-4-hydroxy-anisole,
tris-(3,5-di-tert.-butyl-4-hydroxyphenyl)phosphite,
3,5-di-tert.-butyl-4-hydroxyphenyl stearate and
bis-(3,5-di-tert.-butyl-4-hydroxyphenyl)adipate.
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-(6-tert.-butyl-3-methylphenol),
4,4'-thio-bis-(3,6-di-sec.-amylphenol),
4,4'-thio-bis-(6-tert.-butyl-2-methylphenol) and
4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl)disulfide.
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-(6-tert.-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.-methylcyclohexyl)-phenol],
1,1-bis(3,5-dimethyl-2-hydroxyphenyl)-butane,
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-dodecylmercaptobutane
, 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].
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.-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate.
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-tetramethylbutyl)phenyl]
2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate.
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.
s-Triazine compounds, such as, for example,
2,4-bis-octylmercapto-6-(3,5-di-tert.-butyl-4-hydroxy-anilino)-s-triazine,
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,
1,3,5-tris-(2,6-di-methyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate and
1,3,-5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)isocyanurate.
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-tria
zine and
N,N'-di(3,5-di-tert.-butyl-4-hydroxyphenyl-propionyl)-hexamethylenediamine
. N,N'-bis-.beta.-(3,5-di-t-butyl-4-hydroxyphenyl)-propionylhydrazine.
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, thiodiethylene glycol, triethylene
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.
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, di-ethylene glycol, triethylene 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.
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.
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.
The phenolic antioxidant of particular interest is selected from the group
consisting of n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate,
neopentanetetrayl tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),
di-n-octadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate,
1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, thiodiethylene
bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),
1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,
3,6-dioxaoctamethylene bis(3-methyl-5-tert-butyl-4-hydroxyhydrocinnamate),
2,6-di-tert-butyl-p-cresol, 2,2'-ethylidene-bis(4,6-di-tert-butylphenol),
1,3,5-tris(2,6-dimethyl4-tert-butyl-3-hydroxybenzyl)isocyanurate,
1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,
1,3,5-tris[2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy)ethyl]isocyanur
ate, 3,5-di-(3,5-di-tert-butyl-4-hydroxybenzyl)mesitol, hexamethylene
bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),
1-(3,5-di-tert-butyl-4-hydroxyanilino)-3,5-di(octylthio)-s-triazine,
N,N'-hexamethylene-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide),
calcium bis(ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate), ethylene
bis[3,3-di(3-tert-butyl-4-hydroxyphenyl)butyrate], octyl
3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate,
bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazide, and
N,N'-bis-[2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy)ethyl]oxamide.
A most preferred embodiment has as the phenolic antioxidant,
neopentanetetrayl tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),
n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate,
1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,
1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,
2,6-di-tert-butyl-p-cresol or
2,2'-ethylidene-bis(4,6-di-tert-butylphenol).
When the instant compositions contain an organic phosphorus compound, such
compounds may be for example, triphenyl phosphite, diphenylalkyl
phosphites, phenyldialkyl phosphites, tri-(nonylphenyl)phosphite,
trilauryl phosphite, trioctadecyl phosphite,
di(isodecyloxy)-2,4,8,10-tetraoxa-3,9-diphospha-[5.5]-undecane and
tri-(4-hydroxy-3,5-di-tert.butylphenyl)phosphite or similar phosphonites.
The organic phosphorus compound of particular interest is selected from the
group consisting of tris(2,4-di-tert-butylphenyl)phosphite,
3,9-di(2,4-di-tert-butylphenoxy)2,4,8,10-tetraoxa-3,9-diphospha[5.5]undeca
ne, tris(p-nonylphenyl)phosphite,
3,9-distearyloxy-2,4,8,10-tetraoxa-3,9-diphospha[5.5]undecane, dilauryl
phosphite,
3,9-di[2,6-di-tert-butyl-4-(2-(n-octadecyloxycarbonyl)ethyl)-phenoxy]-2,4,
8,10-tetraoxa-3,9-diphospha[5.5]undecane and
tetrakis(2,4-di-tert-butylphenyl) 4,4'-bis(diphenylene)phosphonite.
Tris(2,4-di-tert-butylphenyl)phosphite is especially preferred.
When the instant compositions contain a thiosynergist, such thiosynergists
may be for example dilauryl thiodipropionate, distearyl thiodipropionate
or neopentanetetrayl tetrakis(3-dodecylthiopropionate). Distearyl
thiodipropionate or dilauryl thiodipropionate is particularly preferred.
When the instant compositions contain an alkaline metal salt of a fatty
acid, such salts are the alkali metal, alkaline earth metal, zinc, cadmium
or aluminum salts of the higher fatty acids for example calcium stearate,
zinc stearate, magnesium behenate, sodium ricinoleate or potassium
palmitate. Calcium stearate is particularly preferred.
When the instant compositions contain a hindered amine light stabilizer,
such hindered amines may for example be
4-benzoyl-2,2,6,6-tetramethylpiperidine,
4-stearyloxy-2,2,6,6-tetramethylpiperidine,
bis-(2,2,6,6-tetramethylpiperidyl)sebacate or
3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triaza-spiro[4.5]decane-2,4-dione.
The hindered amine light stabilizer of particular interest is selected from
the group consisting of bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate,
bis(1,2,2,6,6-pentamethylpiperidin-4-yl)sebacate,
di(1,2,2,6,6-pentamethylpiperidin-4-yl)
(3,5-di-tert-butyl-4-hydroxybenzyl)butylmalonate,
tris(2,2,6,6-tetramethylpiperidin-4-yl)nitrilotriacetate,
1,2-bis(2,2,6,6-tetramethyl-3-oxopiperazin-4-yl)ethane,
2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxodispiro[5.1.11.2]heneicosane,
polycondensation product of 2,4-dichloro-6-tert-octylamino-s-triazine and
4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine),
polycondensation product of
1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic
acid, polycondensation product of
4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) and
1,2-dibromoethane, polycondensation product of
2,4-dichloro-6-morpholino-s-triazine and
4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine),
N,N'N",N"'-tetrakis[(4,6-bis(butyl-(2,2,6,6-tetramethylpiperidin-4-yl)-ami
no-s-triazin-2-yl]-1,10-diamino-4,7-diazadecane, octamethylene
bis(2,2,6,6-tetramethylpiperidin-4-carboxylate) and
4,4'-ethylenebis(2,2,6,6-tetramethylpiperazin-3-one).
A most preferred embodiment has as the hindered amine light stabilizer
bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate, the polycondensation
product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and
succinic acid, the polycondensation product of
2,4-dichloro-6-tert-octylamino-s-triazine and
4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) or
N,N',N",N"'-tetrakis[(4,6-bis(butyl-(2,2,6,6-tetramethyl-piperidin-4-yl)am
ino)-s-triazine-2-yl]-1,10-diamino-4,7-diazadecane.
When the instant compositions contain an ultraviolet light absorber, such
light absorbers may include the 2H-benzotriazoles, the benzophenones, the
oxanilides, the alpha-cyanocinnamates the substituted benzoate esters or
the nickel salts of the O-alkyl hindered phenolic benzylphosphonates.
Examples of such ultraviolet light absorbers are seen below.
UV-ABSORBERS
2-(2'-Hydroxyphenyl)-benzotriazoles, e.g., the 5'-methyl-,
3',5'-di-tert.-butyl-, 5'-tert.-butyl-, 5'-(1,1,3,3-tetramethylbutyl)-,
5-chloro-3',5'-di-tert.-butyl-, 5-chloro-3'-tert.-butyl-5'-methyl-,
3'-sec.-butyl-5'-tert.-butyl-, 3'-.alpha.-methylbenzyl-5'-methyl,
3'-.alpha.-methylbenzyl-5'-methyl-5-chloro-, 4'-hydroxy-, 4'-methoxy-,
4'-octoxy-, 3',5'-di-tert.-amyl-, 3'-methyl-5'-carbomethoxyethyl- and
5-chloro-3',5'-di-tert.-amyl-derivative.
2,4-bis-(2'-Hydroxyphenyl)-6-alkyl-s-triazines, e.g., the 6-ethyl-,
6-heptadecyl- or 6-undecyl-derivative.
2-Hydroxybenzophenones e.g., the 4-hydroxy-, 4-methoxy-, 4-octoxy-,
4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy-, 4,2',4'-trihydroxy-,
2,2',4,4'-tetrahydroxy- or 2'-hydroxy-4,4'-dimethoxy-derivative.
1,3-bis-(2'-Hydroxybenzoyl)-benzenes, e.g.,
1,3-bis-(2'-hydroxy-4'-hexyloxy-benzoyl)-benzene,
1,3-bis-(2'-hydroxy-4'-octyloxy-benzoyl)-benzene or
1,3-bis-(2'-hydroxy-4'-dodecyloxybenzoyl)-benzene.
Esters of optionally substituted benzoic acids, e.g., phenylsalicylate,
octylphenylsalicylate, dibenzoylresorcin,
bis-(4-tert.-butylbenzoyl)-resorcin, benzoylresorcin,
3,5-di-tert.-butyl-4-hydroxybenzoic acid-2,4-di-tert.-butylphenyl ester or
-octadecyl ester or -2-methyl-4,6-di-tert.-butyl ester.
Acrylates, e.g., .alpha.-cyano-.beta.,.beta.-diphenylacrylic acid-ethyl
ester or isooctyl ester, .alpha.-carbomethoxy-cinnamic acid methyl ester,
.alpha.-cyano-.beta.-methyl-p-methoxy-cinnamic acid methyl ester or -butyl
ester or N(.beta.-carbomethoxyvinyl)-2-methyl-iodoline.
Oxalic acid diamides, e.g., 4,4'-di-octyloxy-oxanilide,
2,2'-di-octyloxy-5,5'-di-tert.-butyl-oxanilide,
2,2'-di-dodecyloxy-5,5'-di-tert.-butyl-oxanilide,
2-ethoxy-2'-ethyl-oxanilide, N,N'-bis-(3-dimethyl-aminopropyl)-oxalamide,
2-ethoxy-5-tert.-butyl-2'-ethyloxanilide and the mixture thereof with
2-ethoxy-2'-ethyl-5,4'-di-tert.-butyl-oxanilide, or mixtures of ortho- and
para-methoxy- as well as of o- and p-ethoxy-disubstituted oxanilides.
Preferably the ultraviolet light absorber used in the instant compositions
is 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole,
2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole,
2-[2-hydroxy-3,5-di-(alpha,alpha-dimethylbenzyl)phenyl]-2H-benzotriazole,
2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole,
2-hydroxy-4-octyloxybenzophenone, nickel bis(O-ethyl
3,5-di-tert-butyl-4-hydroxybenzylphosphonate), 2,4-dihydroxybenzophenone,
2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-benzotriazole, nickel
butylamine complex 2,2'-thiobis(4-tert-butylphenol),
2-ethoxy-2'-ethyloxanilide or
2-ethoxy-2'-ethyl-5,5'-di-tert-butyloxanilide.
The stabilized polyolefin compositions of the instant invention may also
contain other additives such as the pigments, colorants or dyes, light
stabilizers such as metal deactivators, talc and other fillers, etc.
In general, the hydroxylamine stabilizers of this invention are employed
from about 0.01 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 0.025 to about 2%, and especially 0.05 to
about 1%.
The hydroxylamine compounds of this invention stabilize polyolefins
especially during high temperature processing with relatively little
change in color, even though the polymer may undergo a number of
extrusions.
The instant stabilizers may readily be incorporated into the polyolefins 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 polyolefin compositions of the invention may
optionally also contain from about 0.01 to about 5%, preferably from about
0.025 to about 2%, and especially from about 0.1% to about 0.05%, by
weight of various conventional additives, such as the following, or
mixtures thereof:
The following may be mentioned as examples of further additives that can be
used in the instant compositions.
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-thiopropionic acid dihydrazide.
Nucleation agents, e.g., 4-tert.-butylbenzoic acid, adipic acid,
diphenylacetic acid or substituted sorbitols such as 1,3;
2,4-dibenzylidenesorbitol.
Other additives that can be incorporated in the stabilized compositions are
antiblocking agents, clarifiers, antiozonants, lubricants such as stearyl
alcohol, fillers, carbon black, asbestos, kaolin, talc, glass fibers,
pigments, optical brighteners, flameproofing agents and antistatic agents.
While the stabilizers of this invention may be conveniently incorporated by
conventional techniques into polyolefins before the fabrication thereof
into shaped articles, it is also possible to apply the instant stabilizers
by a topical application to the finished articles. This is particularly
useful with fiber applications where the instant stabilizers are applied
topically to the fibers, for example, by way of a spin finish during the
melt spinning process.
The following examples are presented for the purpose of illustration only
and are not to be construed to limit the nature of scope of the instant
invention in any manner whatsoever.
EXAMPLE 1
N,N'-Dihydroxy-N,N'-di-tert-butyl-p-xylylenediamine
A suspension of 3.0 g tert-butylhydroxylamine hydrochloride, 5.0 g of
anhydrous sodium carbonate and 3.15 g of p-xylylene dibromide in 20 ml of
N,N-dimethylformamide is heated at 80.degree. C. under nitrogen for 3
hours. Dilution of the reaction mixture with water followed by
crystallization from heptane affords 2.1 g of product as a white solid;
m.p. 137.degree.-138.degree. C.
Analysis: Calculated for C.sub.16 H.sub.28 N.sub.2 O.sub.2 : C, 68.53; H,
10.06; N, 9.99. Found: C, 68.7; H, 9.8; N, 10.1.
EXAMPLE 2
N,N'-Dihydroxy-N,N'-dibenzyl-p-xylylenediamine
The procdure of Example 1 is repeated using 5.59 g of benzylhydroxylamine,
5.99 g of p-xylylene dibromide and 6.0 g of anhydrous sodium carbonate.
The reaction product is recrystallized from acetonitrile to give the
product as a white solid; m.p. 160.degree.-163.degree. C.
Analysis: Calculated for C.sub.22 H.sub.24 N.sub.2 O.sub.2 : C, 75.8; H,
6.9; N, 8.0. Found: C, 76.0; H, 7.1; N, 8.6.
EXAMPLE 3
N,N'-Dihydroxy-N,N'-dioctyl-p-xylylenediamine
To a suspension of 164.7 g of anhydrous dibasic sodium phosphate and 42.0 g
of N,N'-dioctyl-p-xylylenediamine in 700 ml of dry tetrahydrofuran is
added a solution of 62.0 g of benzoyl peroxide in 300 ml of
tetrahydrofuran over a 30 minute period. The resulting suspension is
heated under reflux for 17 hours and then cooled to room temperature. The
insoluble material is removed by filtration and the filtrate is
concentrated to a thick oil which upon flash chromatography (SiO.sub.2,
4:1 hexane:ethylacetate) affords 17.2 g of
N,N'-dioctyl-N,N'-dibenzoyloxy-p-xylylenediamine, m.p.
80.degree.-81.degree. C. Saponification of 6.8 g of the above with 2.23 g
of powdered potassium hydroxide in 50 ml of methanol yields 2.5 g of
product as a white solid; m.p. 101.degree.-103.degree. C.
Analysis: Calculated for C.sub.24 H.sub.44 N.sub.2 O.sub.2 : C, 73.4; H,
11.3; N, 7.1. Found: C, 73.7; H, 11.4; N, 7.1.
EXAMPLE 4
N,N'-Dihydroxy-N,N'-dioctadecyl-p-xylylenediamine
The procedure of Example 3 is repeated using 18.6 g of anhydrous dibasic
sodium phosphate, 8.4 g of N,N'-dioctadecyl-p-xylylenediamine and 7.02 g
of benzoyl peroxide to afford 5.5 g of
N,N'-dioctadecyl-N,N'-dibenzoyloxy-p-xylylenediamine. Saponification of
4.65 g of the above with 0.89 g of powdered potassium hydroxide in 50 ml
of methanol yields 2.0 g of product as a white solid; m.p.
118.degree.-120.degree. C.
Analysis: Calculated for C.sub.44 H.sub.84 N.sub.2 O.sub.2 : C, 78.5; H,
12.6; N, 4.2 Found: C, 78.5; H, 12.7; N, 4.4.
EXAMPLE 5
N,N'-Dihydroxy-N,N'-dibenzylhexamethylenediamine
The procedure of Example 3 is repeated using 29.6 g of
N,N-dibenzylhexamethylenediamine 142 g of dibasic sodium phosphate and
53.2 g of benzoyl peroxide to afford 20.6 g of
N,N'-dibenzyl-N,N'-dibenzoyloxyhexamethylenediamine. Saponification of
31.3 g of the above with 11.5 g of potassium hydroxide in 300 ml of
methanol gives 8.2 g of product as a white solid; m.p.
133.degree.-135.degree. C.
Analysis: Calculated for C.sub.20 H.sub.28 N.sub.2 O.sub.2 : C, 73.1; H,
8.6; N, 8.5. Found: C, 73.1; H, 8.4; N, 8.5.
EXAMPLE 6
N,N'-Dihydroxy-N,N'-dicyclohexyl-p-xylylenediamine
When an equivalent amount of cyclohexylhydroxylamine hydrochloride is
substituted for tert-butylhydroxylamine hydrochloride using the procedure
of Example 1, the above named compound is obtaned as a white solid, m.p.
195.degree.-196.degree. C.
EXAMPLE 7
2,4,6-Tris(N-benzylhydroxylaminomethyl)mesitylene
To a suspension of 3.87 g of sodium carbonate in 30 ml of dry
N,N-dimethylformamide is added 4.50 g of N-benzylhydroxylamine followed by
3.23 g of 2,4,6-tris(chloromethyl)mesitylene. After stirring at 80.degree.
C. for 8 hours, dimethylformamide is removed under reduced pressure and
the residue is partitioned between methylene chloride and water. The
combined organic layers are washed with water, brine, dried and evaporated
to give a crude product. Recrystallization from ethyl acetate-heptane
affords 4.0 g of white solid, mp 193.degree.-195.degree. C.
Analysis: Calculated for C.sub.33 H.sub.39 N.sub.3 O.sub.3 : C, 75.4; H,
7.5; N, 8.0. Found: C, 74.8; H, 7.4; N, 7.7.
EXAMPLE 8
2,4,6-Tris-(N-methylhydroxylaminomethyl)mesitylene
The procedure of Example 7 is repeated using 10.0 g of methylhydroxylamine
hydrochloride, 10.6 g of 2,4,6-tris(chloromethyl)mesitylene and 51.0 g of
sodium carbonate in 100 ml of dry dimethylformamide.
Preparative liquid chromatography separation affords the product as a white
solid, mp 170.degree.-172.degree. C.
Analysis: Calculated for C.sub.15 H.sub.27 N.sub.3 O.sub.3 : C, 60.6; H,
9.2; N, 14.1. Found: C, 60.4; H, 9.2; N, 13.7.
EXAMPLE 9
Processing Stability of Polypropylene at 500.degree. F. (260.degree. C.)
The base formulation comprises 100 parts of unstabilized polypropylene
(Profax 6501, Himont) with 0.10 parts of calcium stearate. The test
stabilizers are solvent blended onto the polypropylene from solutions in
methylene chloride. After removal of the solvent by evaporation under
reduced pressure, the stabilized resin formulation is extruded at 100 rpm
from a 1 inch (2.54 cm) diameter extruder under the following extruder
conditions:
______________________________________
Temperature
Extruder Location .degree.F.
.degree.C.
______________________________________
Cylinder #1 450 232
Cylinder #2 475 246
Cylinder #3 500 260
Die #1 500 260
Die #2 500 260
Die #3 500 260
______________________________________
After each of the first, third and fifth extrusions, resin pellets are
compression molded into 125 mil (3.2 mm) thick plaques at 380.degree. F.
(193.degree. C.) and specimen yellowness index (YI) is determined
according to ASTM D1925. Low YI values indicate less yellowing.
Results are seen in Table I.
It is clear from the data in Table I that the presence of the
N,N'-dihydroxy-N,N'-dioctyl-p-xylyleneamine in the polypropylene
composition containing a phenolic antioxidant essentially eliminates all
color formation associated with the presence of the phenolic antioxidant.
TABLE I
______________________________________
Processing Stability of Polypropylene at 500.degree. F. (260.degree. C.)
Yellowness Index
Conc. Color After
Stabilizer
Extrusion
Stabilizer* % by wt. 1 3 5
______________________________________
Base formulation
-- 2.9 3.3 3.5
Antioxidant A 0.1 3.1 6.3 8.1
Antioxidant A plus
0.1
Compound of 0.05 2.4 4.0 5.4
Example 3
______________________________________
*Antioxidant A = neopentanetetrayl
tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinnamate)
Compound of Example 3 = N,N'--dihydroxyN,N'--dioctylp-xylylenediamine
EXAMPLE 10
Processing Stability of Polypropylene at 500.degree. F. (260.degree. C.)
Following the exact procedure of Example 9, polypropylene compositions
containing, in addition to a phenolic antioxidant, an organic phosphorus
compound are tested for processing stability in respect to repeated
extrusions at 500.degree. F. (260.degree. C.) by measuring transducer
pressures and yellowness index values. The results are seen on Table II.
During extrusion, the internal extruder pressure is determined using a
pressure transducer.
If the transducer pressure after the fifth extrusion is nearly as high as
after the first extrusion, the polypropylene is being well stabilized by
the given stabilization formulation.
TABLE II
__________________________________________________________________________
Processing Stability of Polypropylene at 500.degree. F. (260.degree. C.)
Transducer Pressure
Conc.
after Extrusion
Yellowness Index
Stabilizer
psi/(Kg/cm.sup.2)
Color After Extrusion
Stabilizer*
% by wt.
1 3 5 1 3 5
__________________________________________________________________________
Base formulation
-- 630/44.1
555/38.9
540/37.8
3.3 3.4
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