Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The present invention relates to ~-olefin copolymexs
containing pendant hindered amine groups which are useful as
light and heat stabilizers for organic materials and to
stabilized compositions containing said copolymers.
The hindered amine compounds having the 2,2,6,6-tetra-
substituted piperidinyl structure have long been known as
effective light stabilizers for organic materials and have
enjoyed considerable commercial success.
Such hindered aminé light stabilizers are described in
detail by H. J. Heller and H. R. Blattmann, Pure and Applied
Chemistry, 36, 141-161 (1973~.
It is known from U.S. Patent No. 3,705,166 that mono-
meric acrylic acid derivatives which contain at least one
piperidinyl group having a sterically hindered nitrogen atom
may be used as light stabilizers in organic polymers.
However, these acrylic acid derivatives tend to be too
volatile.
In U.S. Patent Nos 4,210,612 and 4,294,949 homopolymeric
and certain copolymeric compounds having pendant hindered
amine moieties are des~ribed as useful light stabilizers. The
'.
-- 2 --
~ ~ ~90~ ~
homopolymers are those made by the free radical polymeri~ation
of acryloyl or methacryloyl derivatives of compounds containing
hindered amine moieties. The copolymers are those made by the
free radical copolymerization of the acryloyl or methacry]oyl
substituted hindered amine monomers with o.her ethylenically
unsaturated monomers such as styrene, an alkyl acrylate, an
alkyl methacrylate, acrylonitrile, a maleimide or -
N-vinylpyrrolidone. Although ~-olefins are generically
disclosed as possible comonomers among a very wide variety of
ethylenically unsaturated monomers, ethylene copolymers
containing pendant hindered amine moieties are not described nor
are their particularly advantayeous properties contempla-ted.
Copolymers of acryloyl or methacryloyl substituted hindered
arnine monomers with acryloyl or methacryloyl monomers containino
light absorbing moieties such as the benzophenones,
benzotriazoles, a-cyanocinnam~tes or benzalmalonates are
described in US Patent No. 4,276,401 as being useful liyht
stabilizers for organic materials.
This lnvention pertains to ~-olefin copolymers containing
pendant hindered amine groups which are useful as light and heat
stabilizers for organic materials and to stabilized compositions
containing said copolymers.
-- 3 --
~ ~ 6~0~ ~
~ lore par~icularly, the ~-olefin copolymers of this
inverltion have recurring structural units, joined in essentially
a random fashion, of the formula I
~CH2C~} 2~ H2~ T (I)
wherein
T is hydrogen, alkyl of 1 to 18 carbon atoms or mixtbres
thereof,
Ll is hydrogen or methyl,
L2 is hydroxyl, -OCOCH3 or -COOL3,
L3 is hydrogen or alkyl of 1 to 6 carbon atoms,
E is -COO-, -OCO-, -O- or -CONR-,
R is hydrogen, alkyl of 1 to 12 carbon atoms, aralkyl of 7
to 12 carbon atoms, cyclohexyl, hydroxyalkyl of 1 to 6 carbon
atoms, alkoxyalkyl of 2 to 10 carbon atoms or dialkylaminoalkyl
~ . .
of 3 to 12 carbon atoms,
: ~ 4 -
; '
, ~ . ''
- , ,
. , .
~, - ,. .
~ :1 6~
G is a gro~p contai.nin~ an N-hetero,~yclic ring of t~e formula
Rlz R6. CH3
E~6 ~ ~ ~ CO~ NH ~ ~ CEl2R6
CH3 ~ ~ CH~ - Y.l ~~C ~ N - R5 (III)
: ~GCI'2 N C~12~'6
R5 . C~13 CH2R6
R6 CH3
.. ~6 -~ ~ .. . .CO - Nl~ ~ C~12R6
X CH 3~ CE13 Rll ~C ~ ~ N- X2
I . .C113 C~12R6
X;7 .
I^ -
NH- X1
N ~1
J~R6 R-i1 ~O~LR1
CE13 ~ ¦ CH3 ~ r
; R6CH2 ~ N CH2R6CH3 ~ ~ C113
~ ~5 R6C}~2 N CH2R6
: . R5
- 5 -
:;
, ,-
. ' ' ~ . ', :
~ ~ ~9~
R-N- Xl - C112CH2-
C}l3 ~ C63 ~rC~3 ~ ~ C~l3
R6CH2 N C~12R6 R6C112 N C112R6
R5
in which ~5 is hydrogen, oxyl, Cl-Clg alkyl, C3-Cg
alkenyl, C3-C6 alkynyl, C7-C12 aralkyl, -CH2CN,
C2-C2ï al~.oxyalXyl, an aliphatic acyl group having 1-~ C
atoms or one of the groups -CH2COOR7 or -COORg, in which
R7 is Cl-C12 alkyl, C3-Cg alkenyl, phenyl, C7-Cg
araIkyl or cyclohexyl and R8 is Cl-C12 alkyl, phenyl,
benzyl or cyclohexyl, and R6 is hydrogen or Cl-C4 alkyl,
and Xl is C3-C12 alkylene, -CH2CH20-CH2CH2- or a group of
the formula -CH(Rlo)-CH2-(VI), in which Rlo is hydrogen,
methyl, ethyl, phenoxymethyl or phenyl, and X2 is a grcup of
the formula VI, in which R~o is as c1efin2d above, or a group
of the forrnula -CH2-CH(OH)-CH2-(VII), R11 is C1-Clg
alkyl or is cyclohexyl, phenyl or benzyl which are unsubstituted
'
- . .
.
-
,. - : ; . .
. , :
? ~
l 1 B9()~1
.
or substituted by Cl-C~ alkyl or Cl-C4 alkoxy, Rl is
: alkoxy of 1 to 12 carhon atoms, phenoxv,
R-N-
C113 ~ C~l3 , piperidino or
R6C~l2 N C~2R6
R5
~R2R3 where R2 and R3 are hydrogen, alkyl of 1 to 12
carbon atoms, cyclohexyl or benzyl, R12 is hydrogen or hydroxy,
with the proviso that, when R12 is hydroxy, E is -OC0-,
a+b+c = 4 to 2600
~: a = 2 to 2400
b = 0 to 198
c - 2 to 200
a/(a+b~c)= 0.50 to 0.99
:
b~a+b+c~= 0 to 0.49, and
c~a-~b+c3= 0.01 to 0.50
,: ~
~ The ~-ole.~in copolymers of this invention have molecular
.
weight in:the .range of 500 to 500,000 as measured by gel
permeatlon chromdtography or by viscometl-y of p~lymer solutions
or poIymer mell:s.
,
::: : :
7 -
...... .. . ..
: . .. .
~, ' '
` ' ,
:. :
, .
~ 1 ~9~
The instant ~-olefin copolymers are made up of at least tw~
different rec~lrring structural units while additional different
str~ctural units may also be present.
The starting polymeric intermediate is an ~-Glefin
copolymer, preferably an ethyle~e copolymer, which may
additionally have a second ~olefin component. Preferably only
one ~olefin component is present.
In formula I, the first structural unit represents the
a ole~in component where T is hydrogen or alkyl of 1 to 18
carbon atoms or mixtures thereof when mixtures of a-olefi~s are
used. Preferably T is hydrogen where the ~-o]efin is ethylene.
There is always some of this unit in the copolymer as seen ~y
molar ratio values for a/(a+b+c)being a positive number from 0.50
to O.99. On a molar basis at least half of each copolymer of
; this inventio~ is ~-olefin.
The sacond structural unit of formula I represents the
polar comonomer with wh1ch the ~~olefin, preferably ethylene,
was first polymerized before the pendant hindered amine group i9
attached to the olefin copolymer chain. Such copolymers are
olefin, preferably ethylene, copolymers with acrylic acid, lower
alkyl acrylates, m.ethacrylic acid, lower alkyl
methacrylates and vinyl acetate. When the vlnyl acetate
-- 8 --
. . .
~ ~ 69~ ~
copolymer is hydrolyzed, the corresponding vinyl alcohol
copolymer is obtained. Thus Ll is hydrogen or methyl, and
since acrylic acid and lower alkyl acrylates are preferred, L
is preferably hydrogen.
~ y like token L2 can ~e hydroxy, -OCOCH3 or ~COOL3
where L3 is hydrogen or al~yl of 1 to 6 carbon atoms.
Preferably L2 is -COOL3 where L3 is alkyl of 1 to 6 carbon
atoms .
These pendant polar functional groups represen-ted by L2
provide the sites on which, after appropriate esterification,
transesterification, amidation or other chemical reaction, a
pendant hindered amine moiety may be attached. Preferably
essentially all of the existing polar groups in the a-olefin
copolymer are r~acted so that very little if any of the original
polar groups remain in the final copolymer product containing
pendant hindered amine moieties. This is se`en by the molar
ratio of b~a-~b+c)which may be and i5 preferably zero.
However, by the judicious choice of amounts of reactants,
it is possible to react any desired proportion of -the polar
groups L2 to tailor the position and number of pendant
hindered amin~ warheads along the polymer chain in the final
copolymer product. This allows the preparation of copolymers of
:
_
~ .,
:
.
specific chemical and physical properties ~or individual end us~
applications. In such cases the molar ratio o~ b/~a+b+c~ is a
positive value above zero ranging up to 0.49.
The third structural unit in formula I represents the units
to which a hindered amine moiety has been attached. The group 1'
i6 -COO-r -OcO-, -0~ or -CONR- which relates directly to the
value~ of L2. Preferably E is -COO- or -CONR-.
~ en an alcohol, an amine or an acid cont~ining a hindered
amine moiety is r~acted with an olefin copolymer containing
pendant L2 groups by standard esterification, transesterifica-
tion or amidation procedures, all or a portion of said L2
groups are replaced with groups having the pendant E-G
moieties. The exact nature of G is not critical except that it
contains a hindered amine group. Such groups contain an
~I-heterocyclic ring of the formula
Rl2 R6 CH3
~6 ~ CO- ~H ~ ~ CH2R6
C~3 ~ ~ CH3 ~ X~N _ R~ (III~
CH2 N CI12R6 ~
C113 CH2Ro
'
P`6 C~13
~6 ~ CO - ~H ~ ~ CE12~6
C } i 2 n 6 ~ v )
CH3 2 ~
- 10 -
. ~ I
'
'
~ ~9~1
NH - Xl -
"~ .
O Xl - , ~ I
~ R6 N
R6CH2 ~ N ~ CH R ~ ~
: R5 R6CH2 N CH2R6
. R5
R-N- Xl - C112C112-
C113 \ ~ C~13 or Cll3 ~ ~ C~13
R6CH2 N CH2R6 R6CH2 N C112R6
: R5
Rs
:
'
ln which R is hydrogen, alkyl of 1 to 12 carbon atoms, aralkyl
of 7 to 12 carbon atoms, cyclohexyl, hydroxyalkyl of 1 to 6
carbon atoms, alkoxyalkyl of 2 to 10 carbon atoms or
dialkylaminoalkyl of 3 to:12 carbon atoms, preferably hydrogen,
~ . ~
~ Rl is alkoxy o 1 to 12 carbon atoms, phenoxy
: .~ .
;~ ;
: ~ :
:
. :
:,
~ l l. --
':
~' :
..... . . .
.
:, ', :
~ ~ :
6 1
R~
R 6
Cl-i3 ~ 1 Cll3 , piperidino
R6Cl~2 N Cll2R6
R5
or NR2R3 where R2 and R3 are hydrogen, alkyl of 1 to 12
carbon atoms, cyclohexyl or benzyl, Rs is hydrogen, oxyl,
Cl Cl~, C3-Cg alkerlyl, C3-C6 alkynyl, C7-CI2
aralkyl, CH2CN, C2-C21 alkoxyalkyl, an aliphatic acyl group
having 1-4 C atoms or one of the groups -CH2COOR7 or -COOR~
in which R7 is Cl-Cl~ alkyl, C3-C8 alkenyl, ~hen~l
C7-C8 aralkyl or cyclohexyl and R8 is Cl-C12 alkyl,
phenyl, benzyl or cyclohexyl, and R6 is hydrogen or Cl-C4
alkyl, and Xl is C3-C12 alkylene, CH2CH20CH2CH2- or a
group of the ~ormula -CH(Rlo)-CH2-(VI), in which Rlo is
hydrogen, metllyl, ethyl, phenoxymethyl or phenyl, and X2 is a
group of the :Eormula VI, in which Rlo is as defined above, or
a group of ~he formula -CH2-CH(OH)-CH2- (VII), Rll is
Cl-Clg alkyl or is cyclohexyl, phenyl or benzyl which are
unsubstitllted or substituted by Cl-C4 alkyl or Cl-C4
alkoxy, and ~12 is hydrogen or hydroxy.
1 2 -
: : ,
: :.
.'
G can be preferably a group of the formulae II, III, IV
or V. Most preferably G is a group of the formulae II of IV
where R12 i5 hydrogen.
As Cl-C18 alkyl, R5 is, for example, m~thyl, ethyl,
n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl or
octadecyl. Preferred alkyl groups are those having 1-12 C
atoms, also those having 1-8 C atoms and especially those
having 1-4 C atoms and in particular methyl.
As C3-CB alkenyl, R5 is, for example, allyl,
3-methyl-2-butenyl, 2-butenyl, 2-hexenyl or 2-octenyl,
especially allyl.
As C3-C6 alkynyl, R5 is, for example propargyl.
As C7-C12 aralkyl, R5 is, for example, benzyl,
~-phenylethyl or 4-tert-butyl-benzyl.
If R5 i5 C2-C21 alkoxyalkyl, the alkyl part can contain
1-3 C atoms and the alkoxy part can consist of 1-18 C atoms,
as, for example, in methoxymethyl, ethoxymethyl, 2-methoxy-
ethyl, 2-ethoxyethyl 2-n-butoxyethyl, 3-n-butoxypropyl,
2-octoxyethyl or ~-octadecyloxyethyl,
.
- 13 -
'., ~ ~, .
1 :?6906:1
preferred compounds are those in which R5 is an alkoxyalkyl
group havlng 2-6 C atoms.
As an aliphatic acyl group having 1-4 C atoms, R5 i5,
for example, formyl, acetyl, acryloyl or cro~onoyl, e~pecial-
ly acetyl.
As Cl-C4 alkyl, R6 is branched or, especially, non-
branched alkyl, such as ethyl, n-propyl or n-butyl, but in
particu]ar methyl. R6 is preferably hydrogen.
As Cl-C12 alkyl, Rg is, for example, methyl, ethyl,
n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl or n dodecyl;
preferably, however, Rg is Cl-C4 alkyl.
As C7-C12 aralkyl, Rg is especially phenylethyl or in
particular ~enzyl.
Rlo is phenyl or phenoxymethyl, preferably methyl or
ethyl and especially hydrogen.
A~ Cl-C18 alkyl, Rll is, for example, meth~l ethyl r
propyl, butyl, hexyl, octyl, dod~cyl or octadecyl. Preferred
alkyl groups are those having 1-12 C atoms.
-- 1~ --
Rll can also be benzyl, cyclohexyl or phenyl and these
can be substituted in the nucle~s by Cl-C4 alkyl, such as
methyl, ethyl, propyl or a butyl, or by Cl-C~ alkoxy, such
as methoxy, ethoxy, propoxy or n~butoxy.
If R5 is the group -CH2COOR7 or -COOR8, R7 and R8 as
Cl-C12 al~yl, are, for example, methyl, ethyl~ isopropyl,
n-butyl, isobutyl, t-butyl, isopentyl, n-octyl or n-dodecyl.
Preferably, R7 and R8 are Cl-C~ alkyl. As C3~C8 alkenyl,
R7 is, for exampl~, allyl, 2-butenyl or 2-hexenyl. As C7-C8
aralkyl, R7 is, for example, benzyl or ~-phenylethyl~
Prefexably the copolymers of formula I are those where
G is a group of the formulae II, III, IV or V, in which R5
is hydrogen, Cl-C12 alkyl~ C3-C5 alkenyl, propargyl, C7-C8
aralkyl, acetyl, or C2-C10 alkoxy-alkyl and
R6 is hydrogen or methyl and E is -COO- or -CONR- in which
R ~s hydrog~n, Cl-C12 alkyl or benzyl, and Xl is a group of
the formula VI, in which Rlo is hydrogen or methyl, and X2
is a group of the foxmulae VI or VII, in which Rlo is as
defined above, and Rll is Cl-C12 alkyl or benzyl, and R12
is hydrogen.
:;:
~ 15 -
,~
.
.
~' .
~ 3~06~
Most preEerred copolymers of for~ula I are those where G is
a group of the formulae II or IV, in ~Jhich R5 is hydrogen,
C1-C8 alkyl, benzyl or acetyl and R6 is hydrogen or mcthyl
and E is -COO- or -CONR-
in which R is hydrogen or Cl-Cg alkyl, and X~ is a group
of the formulae VI or VII, in which Rlo is hydrogen, methyl or
ethyl, and R12 is hydrogen.
Further preferred copolymers of t~e formula I are where G
is a group of the formulae II or IV, in which Rs is hydrogen,
Cl--C~ alkyl, benzyl or acetyl and R6 is hydrogen and E is
-COO- or -CONR-
in which R is hydrogen or Cl-C4 alkyl, and X2 i5 a group
of the formulae VI or VII, in which Rlo is hydrogen or methyl,
and R12 is hydrogen.
Particularly preferred compounds are ethylene copolymers cf
the formula I in which ~ is a group of the formulae II or IV, in
which Rs is hydrogen, methyl or acetyl, R~ is hydrogen and E
is -COO- or -CONR-
in which R is hydrogen or~Cl-C4 alkyl, and X~ is a group
of the formulae VI or VII, in which Rlo is hydrogen, and R12
~,
j i5 hydrogen.
- lG -
.
. ~ .
There is always sorne of this third structural uni~ in the
copolymer of tllis i~vention as seen by the molar ratio values
for c/~a-~b-~c~being a positive number from 0.01 to 0.50.
Especially prererred are the copolymers where -E-G is
-COO
CH3 ~ ~ CH3
CH3 ~ CH3
The molecular weight of the instant olefin copolymers range
from about 500 to about 500,000. ~alues of a~b+c = 4 to 2600.
While the instant a-olefin copolymers containing pendant
hindered amine groups may range in molecular weight from
essentially oligomeric structures wi~h a molecular weight of
about 500 to high polymer materials with a molecular weight up
to 500,000, the preferred molecular weight range is 5,000 to
100,000 and most preferably is 10,000 to 50,000. These ranges
essentially correspond to values of a~b~-c of 40 to 520 and 80 to
260 respectively.
. .
The ~-olefin copolymers such as ethylene/e-thyl acrylate,
ethylene/methyl acrylate, ethylene/methyl acry]ate/acrylic acia,
ethylene/viny7 acetate, ethyl.ene/vinyl alcohol and the like are
- 17 ~
~, . . .
: ' . ' . ~
:
- '
I :I B9(~ 1
items of commerce with copo].ymers having various molecular
weights (melt indices) and weight percents of ethyl acrylate or
other comonomers being available.
The free radical polymerization of ethylene or other olefin
monomers with various polar comonomers is known in the art and
an appropriate diversity of starting olefin copolymer
intermediates is thus availableO
Examples of hindered amine alcohols and amines which can be
used in the instant invention include 1-(2-hydroxyethyl)-
2,2,6,6--tetramethylpiperidine, 1,2,2,6,6-pentamethyl-4-amino-
piperidine, l-acetyl-2,2,6,6-tetramethyl-4-aminopiperidine,
l-benzyl-2,2,6,6-tetramethyl.-4-aminoplperidine, 1,3,8-triaza-
2,4-dioxo-3-(2-hydroxyethyl)-7,7,8,g,9--pentamethylspiro[4.5]-
decane, 1,3,8 triaza-2,4-dioxo 3-n-dodecyl-7,7,9,9-tetramethyl-
B-(2-hydroxyethyl)-spiro[4.5~decane, 1,3,B-triaza-2,4-dioxo~3-
(2-hydroxyethyl)-7,7,g,9-tetramethyl-8-benzylspiro[4.5]decane
1,3,8-triaza-2,4-dioxo-3~n-butyl-7,7,9,9-tetramethyl-8-(2-hy-
droxyethyl)spiro~4.5]decane, 1-benzyl-2,2,6,6~tetramethyl-4-
(N~n~butyl)aminopiperidine, 1,2,2,6,6~pentamethyl-4-(N-benzyl~-
aminopiperidine, 1,2,2,6,6-pentamethyl-4-(N-n-propyl)amino-
piperidine, l-allyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and
2,3-dihydroxypropyl)-2,2,6,6-tetramethylpiperidine.
- 18 -
:
" :
~.
o ~ ~
A typical acid containing a hindered amine aroup is
R ~12 COO- lower alkyl
C~
3~ ~ J ~ CEI3
R6CH2 I CH2R6
~5
Sueh an aeid ean be attached to an olefin/vinyl alcohol or an
olefin/vinyl aeetate eopolymer by standard esterifieation or
transesterifieation teehniques.
The aleohols, amines and aeids containing the hindered
amine groups are well known in the art.
The piperidinyl derivatives used as reactants are also
known eompounds. The preparation o t~le eompounds of the
Pormula XI
R6 ~ ~
CE~3 ~ ~ c~3 (XI)
R6CH2 N C112~6
~5
- 19 -
~ 7B~061
where Y is -O- or -NR- has ~een describecl, for example, in V.S.
Patent No. 4,(114,887 (4-hydroxypiperidines) or in U.S. Patent
No. 3,684,765~4-aminopiperidines).
The compc,unds of the formulae XII and XIV
R6. CH3
CO--Nf~ CH2R6
HY Xl_~ ~C ~ - R5 (XII)
~ . . C~13 C~2R6
':
and
~ R6CI~ C~13~ ~XIV)
: 12
Ytt
.
can be prepared analogously to the methods described in U.S.
; Patent N~. 3,942i744.
- 20 -
, . .
0 6 1
The preparation of compounds of the formula XIII
R6 CH3
CO - Nl~ ~ ~ C~l2R6
R~ 7<N- X 2^ Y 1-
C1~3 C~12R6
'
is known, for example, from U.S. Patent No. 3,975,357.
The compounds of the formula XI, XII, XIII and XIV which
have different substituent.s in the 2-position and the 6-position
of the piperidyl ring can be prepared hy reacting a ketone o~
the formula CH3-CO-CH2-R6 with ammonia. The pyrimidine
formed is hydrolysed to an aminoketone of the formula XV, as
descrlbed in Helv. Chim. ~cta 30, 114 (1947).
`:
CH2-R6
:~ , CE13-C--CH2-cO~cH2 ~6 (XV)
NH2
:
~ - 21 -
: .
~, ,
,
In a second process s~ep, the compounds of the formulaXV
are reacted with ammonia and ke~one CH3-CO-CH2 R6~ as has
been described for example,in ~.onatsh. Chemie, B8, (1957) 464
(in ~he indicated formulae, R6 is as defined above). The
compounds of the formulae XI and XII in which R5 is hydrogen
can be obtained by hydrolysis from the pyrimidine obtained
in this way.
The compounds which carry substituents other than
hydrogen in the l-position and/or the 4-position are prepared
analogouslv to the metho~s described in the literature refer-
ences cited above.
While copolymers of this invention are very effective
stabilizers for a host of organic substrates subject to light
induced detexioration, as are the hindered amines in general,
the instant compounds with their surprising resistance to
loss from a s abilized composition during high te~perature
processing due to volatilization, exudation or sublimation
have particular value in stabilizing polymeric substrates
which are perforce processed at elevated temperatures.
Th~ copolymers of this invention are particularly useful
as stabilizers for the pro~ection of polyolefins, particular-
ly polyethylene, polypropylene and polypxopylene fibers.
- 22 -
~ ~ ~906 1
The reasons for this are not certain, but may be related to
the high compatibility of the instant olefi.n, particularly
ethylene, copolymers in the polyolefin substrates coupled with
an enhanced or more efficient utilizat..on of the polar hindered
amine stabilizing warheads.
Indeed, it is contemplated that t~,e structure of the
inskant ethylene copolymers provides ar, optimum balance between
ethylene units for compatibility and separated polar units with
pendant hindered amine groups for stabilization efficacy. It
appears that the instant copolymers containing a majority of
ethylene units along the copolymer bac~.bone with a lesser
number of structural units containi.ng pendant hindered amine
groups interspersed thereamong allows.for a more effective use
of the hindered ami.ne moieties, prevents their undesired
agglomeration in the polyolefin substrate and leads to
stabilization protection far beyond what would be expected from
the same total concentration of stabili.zer having no ethylene
components. Indeed, the instant copolymers even with less than
10 mol percent of units having pendant hindered amine groups are
very effective light stabilizers in po].yolefin substrates.
::
: :~ The copolymers of this invention are effective light
`
stabilizers in a wide range of organic polymers. Polymers which
:~
~ can be stabilized include:
'
'
23 -
- . - ....
.; ~ .
'.-
: .
O S 1
1. Polymers which are derived ~rom mono- or diolefins,
e.g., polyethylene which can optionally be crosslinked,
polypropylene, polyisobutylene, polyme~hylbutene-l, poly-
methyl-pentene-l, polyisoprene, polybutadiene~
2. Mixtures of ~he homopolymers cited under 1), for
example mixtures of polypropylene and polyethylene, poly-
propylene and polybutene-1, polypropylene and polyisobuty-
lene.
3. Copolymers of the monomers based on the homopolymers
cited under 1), for example ethylene/propylene copolymers,
propylene/butene-l copolymers, propylene/isobutylene copoly-
mers, ethylene~butene-l copolymers as well as terpolymers of
ethylene and propylene with a diene, for example hexadiene,
dicyclopentadiene or ethylidene norbornene, and copolymers
of ~-olefins, e.g., ethylene with acrylic or methacrylic
acid.
4. Polystyrene.
5. Copolymers of styrene and of ~-methylstyrene, for
example styrene/butadiene copolymers, styrene/acrylonitrile
copolymers, styrene/acrylonitrile~methacrylate copolymers,
styrene/acrylonitrile copolymers modified with acrylic ester
polymers to provide lmpact strength as well as block
copolymerss e.g., styrene/butadiene/styrene block copolymers.
~ ~,
:
~ _ ~4 _
. g~
`.`:..1
- . ,
'
n O 6 1
6. Graft copolymers of styrene, for example the graf~
polymer of styrene ~o polybutadiene, the graft polymer oX
styrene with acrylonitrile to polybutadiene as well as mix-
tures thereof with the copolymers cited under 5), commonly
referr4d 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 copoly-
mers.
8. Polymers which are derived from a,~-unsaturated acids
and derivatives thereof, such as polyacrylates and polymetha-
crylates, polyacrylic amides and polyacrylonitrile.
9. Polymers which are derived from 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, polyallyl melamine and co-
polymers thereof with other vinyl compounds, for example
ethylene/vinyl acetate copolymers.
- 25 -
-:
lO. 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 polybutylene oxide.
13. Polyphenylene oxides.
14. Polyurethane~ 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/lO, polyamide ll, polyamide 12,
poly-m-phenylene-isophthalamide.
- ~6 -
~'
,. " ,
: '
' '
, -
~
'
o ~ ~
18. Polyesters which are derived from dicarboxylic acidsand dialcohols and/or from hydroxycarboxylic acids or the
corresponding lactones, for example polyethylene glycol
th~rephthalate, poly-1,4-dimethylol-cyclohexane terephthalate.
19. Cross-linked polymers which are derived from
aldehydes on the one han~ and from phenols, ureas and melamine
on the other, for example phenol/formaldehyde, urea/form-
aldehyde 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 modiied homologous d~rivatives
~ thereof, for example cellulose acetates, cellulose propionates
; and cellulose butyrates and the cellulose ethers, for example
methyl cellulose.
,
- 27 -
,.
: : j
- :
-
.
~. . . ' :
I ~ 6nO~ 1
The stabilizing of polyolefins, styrene polymers andpolyamides and of polyurethanes is o particular importance,
and the instant copolymers are outstandingly suitable for
this. Examples of such polymers are high densi~y and low
density polyethylene, polypropylene, ethylene/propylene
copolymers, polystyrene, styrene/butadiene/acrylonitrile ter-
polymers, mixtures of polyolefins or of styrene polymers, and
polyurethanes based on polyethers or polyesters, in the form
of lacquers, filaments, films, sheets, films, elastomers or
foams.
The copolymeric stabilizers are added to the plastics in
a concentration of 0.05 to 5% by weight, calculated relative
to the material to be stabilized. Preferably, 0.1 to 2.5% by
weight of the copolymers calculated relative to the material
to be stabilized, ~rP incorporated into the latter.
Incorporation can be effected after polymerization, for
example by mixing the compounds and, if desired, further
addltives into the melt by the methods customary in the art,
before or during shaping, or by applying the dissolvea or
dispersed compounds ~o the polymer, with subsequent evapor-
atlon of the solvent if necessary.
- 28 -
. ~
I ~ 6n~6 1
The novel copolymers can also be added to the plastics to
be stabilized in the form of a master batch which contains these
copolymers, for exa~ple in a concentration of 2.5 to 25% by
i weight.
Althou~h the compounds of the invention may be used all
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 deactivato s, etc.
In general, the stabilizers of this invention are employed
from about O.C5 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
:
0.1 to about 2.5~.
.
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
; ~thereErom. 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
.~ . '
~ 29 -
,
~ :~
, . :
: - . . :: : , -
: , : . -
.~ . .
~ ,. '' : ' ' "
' ~:'-. . ,~ .
,
.
,
~ 3 ~
of the polymer. The stabili~ed polymer compositions of the
invention may optionally also contain from about 0.05 to about
5~, preferably from ahout 0.1 to about 2.5~ by weight of various
conventional ac1ditives, 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-dimethyl-
phenol, 2,6-di-tert.-butyl-4-methoxymethylphenol and 2,6-diocta--
decyl-4-methylphenol.
1.2 Derivatives o alkylated hydroquinones, such as for
example, 2,5-di-tert.-butyl-hydroquinone, 2,5-di-tert.-amyl-
hydroquinone, 2,6-di-tert.-butyl-hydrocluinone, 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. Hydro~yated 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-(*ert.-butyl-3-methylphenol),
4,4'-thio-bis-(3,6-di-sec.-amylphenol), 4,4'-thio~bis-(6-tert.-
; - 30 -
:
:~ ,
,
:
.
:'
~ 1 690~ ~
butyl-2-me-thylphenol) ~n~ 4,4'-bis-(2,6-dimethyl-4-hydroxy-
phenyl) disulfide.
1.4 _k~ e-bis~enols, 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-methylpheno~, 4,4'-methylene-bis-(2,6-di-tert.-butyl-
phenol), 2,G-di-(3-tert.-butyl-5-methyl-2-hydroxybenzyl)-
4-methylphenol, 2,2'-methylene-bis-[4-methyl-6-(~-methylcyclo-
hexyl)-phenol], 1,1-bis(3,5-dimethyl-2~hydroxyphenyl)-butane,
1,l~bis~(5-tert.~buty]~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-~odecyl-
mercapto-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 etiher, octa-
decyl 4~hydroxy-3,5~dimethylbenzyl-mercaptoacetate, tris-(3,5-
di-tert.-butyl-4-hydroxybellzyl)-amine and bis-(4-tert.~buty]-3-
_
~ hydroxy-2,6-dimethylbenzyl) dithioterephthalate.
:~`:
- 31 -
~,
:
.
: ' ` . .
: :
1.6 Hydrox~D nzy]ated malonates, such as for example,
dioctadecyl 2,2-bis-(3,5-di-tert.-butyl-2-hydroxybenzyl)-malo-
nate, dioctadecyl 2-(3-tert.-butyl-4-hydroxy-5-methy]benzyl)-
malonate, di-dodecylmercapto-ethyl 2,2-bis-(3,5-di-tert.-butyl-
4-hydroxybenzyl)-malonate and di-[4-(1,1,3,3-te-tramethylbutyl)-
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-trimethyl-benzene, 1,4-di-(3,5-di-tert-butyl-4 hydroxy-
benzyl)-2,3,5,6-tetramethylberlzene and 2,4,6-tri-(3,5-di-tert.-
butyl-4-hydroxy-benzyl)-phenol.
1.8 s-Triazi.ne 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,~,6-tris-(3,5-di-tert.-
butyl-4-hydroxyphenoxy)-s-triazine, 2,4,6-tris-(3,5-di-tert.-
butyl-4-hydroxphenylethyl)-s-triazine and 1,3,5-tris-(3,5-di-
tert.-butyl-4-hydroxybenzyl) isocyanurate.
1.9 A~mides of ~-~3,5-di-tert.-butyl-4-hydroxyphenyl)-pro-
pionic acids, such as, for example 1,3,5--tris-(3,5 -di-ter!.-
butyl-4 hydroxyphenyl-propionyl)-hexahydro-s-triazine and
- 32 -
~ ~ ~9~ ~
N,N'-di-~,5-di-ter-t.-butyl-4-hydroxyph~nyl-propionyl)-hexa-
methylenediamine, N,N'-bis-~-(3,5-di-t-butyl-4-hydroxy~henyl)-
propionyl-hydrazine.
1.10 Esters of ~-(3,5-di-tert.-bu1yl-4-hyclroxy~_nyl)-pro-
pionic acid with monohydric or polyhydric alcohols, such as Eor
example, with methanol, ethanol, oc-tadecanol, 1,6-hexanediol;.
l,9-nonanediol, ethylene glycol, 1,2-propane-diol, diethylene
glycol, thiodiethylene glycol t neopentylglycol, pentaerythritol,
3-thiaundecanol, 3-thia-pentadecanol, trimethylhexanediol,
trimethylolethane, trimethylolpropane, tris-hydroxyethyl
isocyanurate and 4-hydroxymethyl-1-phospha-
~,6,7-trioxabicyclo-~2.2.2]octane.
1.11 Esters o~ ~-(5-tert.-butyl-4-~y~droxy-3-methylphenyl)-
propionic acid with monohydric or polyhydric alcohols, such as
for example, with methanol, ethanol, octadecanol, 1,6-
hexanediol, 1-9-nonanediol, ethylene g]ycol, 1,2-propanediol,
di~ ethylene glycol, thiodiethylene glycol, neopentylglycol,
pentaerythritol, 3-thia-undecanol, 3-thia-pentadecanol,
trimethylhexanediol, trimethylolethane, trimethylolpropane,
tr s-hydroxyethvl isocyanurate and 4-hydroxymethyl-1-phospha-
2,6,7-trioxabicyclo[2.2.2.~octane.
.~
~ - 33 -
;:
~,' .
,
1.12 ~sters of 3,5-cli-tert.-buty]-4-hy~droxy~henylacetic
acid with monohydric or polyhydric alcohols, such as for
exarnple, with ~ethanol, eth~nol, octadecanol, 1,6-hexancliol,
l,9-nonanediol, ethylene glycol, 1,2-propanediol, diethy]ene
g]ycol, thiodiethylene glycol, neopentylglycol, pentaerythri-
tol, 3-thia-undecanol, 3-thia-pentadecanol, trimethylhexanediol,
trimethylolethane~ trimethylolpropane, tris-hydroxyethyl
.isocyanurate and 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-
C2.2.2]-octane, especially the tetrakis ester of
pentaerythritolO
1.13 Ben~y_ph sphonates, such as, for example, dimethyl 3,5
di-tert.-butyl-4-hydroxybenzylphosphonate, diethyl
3,5-di-tert.-bu~yl-4-hydroxybenzylphosphonate, dioc~adecyl
3,5-di-tert.-butyl-4-hydroxybenzylphosphonate and dioctadecyl 5-
tert.-butyl-4-hydroxy-3-methylbenzylphosphonate.
2. Light-stabilizers
2.1 Esters of optionall~ substituted benzoic acids, e.g.,
3j5-di-tert.-butyl-4-hydroxybenzoic acid, 2,4-di-tert.-butyl-
phenyl ester or -octadecyl ester or 2-methyl-4,6-di-~ert.-butyl-
phenyl ester.
~, ' .
~ .
- 34
`
9 ~ ~ 1
2.2 Sterl _ ly hindered amines e.g., 4-benzoyl-2,2,6,6-
tetrame-thylpiEeridine, 4-stearyloxy-2,2,6,6-tetramethyl-
piperidine, bis-(2,2,6,6-tetramethylpiperidyl) sebacate, bis-
(1,2,2,6,6-pertamethylpiperidyl) sebacate, bis-(1,2,2,6,6-
pentamethylpiEeridyl) 2-n-butyl-2-(2-hydroxy-3,5-di-tert-butyl-
benzyl)malonate or 3-n-octyl-7,7,9,9-tetra-methyl-1,3,8-
triazaspiro[4.5]decane-2,4-dione.
2.3 Oxalic acid diamides, eOg., 4,4'-di-octyloxy-oxani-
lide, 2,2'-di-octyIoxy-5,5'-di-tert.butyl-oxanilide, 2,2'-di-
dodecycloxy-5,5'-di tert.-butyl-oxanilide, 2-ethoxy-2'-ethyl-
oxanilide, N,N'-bis-(3-dimethvl-amlnopropyl)-oxala~ide, 2-
ethoxy-5-tert.-butyl-2'-ethyl-oxanilide and the mixture thereof
with 2-ethoxy-2'-ethyl-5,4'-di-tert.-kutyl-oxanilide, or mixture
of ortho- and para-methoxy- as well as of o- and p-ethoxy-di-
substituted oxanilides.
~'
3. Metal deactivators, e.g., oxanilide, isophthalic acid
,
dihydrazide, sebacic acid-bis-phenylhydrazide, bis-benzyli-
dene-oxalic 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-hydroxy-
phenyIpropionyl)-hydxazine, N-salicyloyl-N'-salicylalhydrazine,
~:
3-salicyloyl-amino-1,2,4-triazole or N,N'-bis-salicyloyl-thio-
propionic acid dihydra2ide.
,~ .
~,
~ ~ ~9~ ~
4. Basic co-stabili.~ers, e.g., alkali metal salts and
alkali.ne-earth metal salts of hiaher fatty acids, for example
Ca-steara~e, Z~-stearate, Mg-behenate, Na-ricinoleate or
K-palmitate.
5. Nucleation agents, e.g., 4-tert.-butylbenzoic acid,
adipic acid or diphenylacetic acid.
6. Phos~hites and phosphonites, such as, for example,
triphenyl 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-butyl~henyl)
diphenylene-4,4'-bis(phosphonite).
Other additives that can be incorporated in the stabilized
compositions are thiosynergists such as dilauryl thiodiproprion-^~
ate, lubricants such as stearyl alcohol, fi].lers, asbestos,
kaolin, talc, glass fibers, pigments, optical brig~teners,
flameproofing agents and antistatic agents.
While the instant copolymers containing pendant hindered
a~ine moieties G are particularly useful as stabiliz~ers for
polymeric substrates, it is also contemplated that said
copolymers would provide dyesites for the subsequent dyeing of
~; .
- 36 -
: `''' ~
. ~ :
.
:
1 ~ ~90~ ~
.he stabilized polymer with acid dyes. This wou]d be rnost
beneficial in the dyeing of polyolefins such as poly~ropylene by
the inclusion of the hindered amine ba;ic s'te into polyo]efin
fiber.
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 a~.y manner
whatsoever.
EXAMPLE 1
:
Rthylene/2,2,6,6-Tetramethylp~e_~ yl Acrylate Copolymer
In a 500-ml 3-necked round-bottomed flask fitted with a
stirrer, reflux condenser, thermometer, nitrogen inlet tube and
an oil bath was placed a mixture of 14.5 grams of ethylene/ethyl
acrylate copolymer (77/23) with a number average molecular
weiyht of 28,000 with an ethyl acrylate content of 23% by weight
(= 0.033 mole of ethyl acrylate~, 15.7 grams (0.1 mole)
2,2,6,6-tetramethylpiperidin~4-ol and 0.3 gram o tetrabutyl
titanate. The mixture was heated at 175C under a nitrogen
atmosphere for 20 hours with gentle stirriny.
- 37 -
~ , .
.
: , ' ' '
- .
3 ~
A quan-titative amoullt (0.033 mole 1.52 grams) of ethano]
was liberated in the transesterificati()n reaction and ~1as
collected ln 2 suitable trap cooled by an acetone-dry ice bath.
The resulting copolymer product was then dissolved in 150
ml of anhydrous toluene. The toluene solution was then added
dropwise into an excess of anhydrous hexane to precipitate t~e
copolymer. The copolymer was isolated by filtra-tion and then
suspended in refluxing acetone to extrcct any unreacted 2,2,6,6-
tetramethylpiperidin-4-ol. The extracted and purified desired
copolymer was isolated by filtration and dried at 50C/0.2 mm
for 7 hours. The desired copolymer was obtained in a yield of
15.5 grams (95~).
Analysis:
Calculated (~) C: 79.02; H: 12.55; N: 2.57.
Found (%) C: 79~94; H: 12.01; N: 2.08.
EXAMPLE la
When the reaction of Example 1 was carried out using only
3.15 grams (0.02 mole) of 2,2,6,6-tetramethylpiperidin-4-ol,
that is an 0.6 molar equivalent of
2,2,6,6-tetramethylpiperidin-4-ol rather than a 3 molar
equivalent amount per pendant ester group in the ethylene/ethyl
- 38 -
.:
.
,
: ' . ' . . '
'~ ' ~ '' ' -'
7 1 ~
acrylate (77/23) copolymer, a product was obtained in ~hich
approximately half the pendant ethyl ester groups were replaced
by hindered amine moieties. The product con-tained l.12
nltrogen .
EXAMPLE 2
Ethylene/2,2,6,6 Tetramethylpiperidin-~-yl Acrylate Copolymer
The above-named copolymer was prepared using the general
procedure of Example 1 by the use of an equivalent amount of an
ethylene/ethyl acrylate (82/18) copolymer with a number average
molecular weight of 33,000 with an ethyl acrylate content of 18t;
by weight.
~ ~ .
Analysis:
Calculated (%) C: 80.10; H: 13.02; N: 2.10.
:~: Found (~ C: 80.38; H: 12.85; N: 1.78.
X~MPLE 3
~ .
Ethylene/2,2,6,6-Tetramethylpiperidin-4 yl Acrylate Copolymer
. ~ .
. The above-named copo]ymer was prepared using the ~eneral
: procedure of Example 1 by the use of an equivalent amount of an
~ ethylene/ethyl acrylate (61/39) copolymer with a n~mber average
: ~ :
~ 3g -
,
3 ~ 6 :~
molecular weicht of 28,000 with an ethyl acrylate content of 39%
by weight.
Analysis:
Calculated (%) C: 75.56; H: 11.86; N: 3.83.
Found (%) C: 74.84; H: 11.38; N: 3.22.
EXAMPLE 4
Ethylene/1,2,2,6,6-Pentamethylpiperidin-4-yl Acrylate Copolymer
The above-named copoiymer was prepared by the general
procedure of Example 1 by sub~tituting for the 2,2,6,6-tetra-
methylpiperidin-4-ol an equivalent amoullt of
1,2,2,6,6-penta-methylpiperidin-4-ol, and reacting with an
~;~ ethylene/ethyl acrylate copolymer (77/23).
~ .
Analysis: .
Calculated (%) C: 79.06; H: 12.56; N: 2.550
Found (%) C: 79.07; H: 12.36; N: 2.32
',~
:
- 40 -
~ .
~ ~ ~9~
EXAMPLE 5_
Ethylene/1-(2-Acryloyloxyethyl)-3,3,5,5-tetramethyl-
~pera in -2,6-dione Copolymer
The above-named copolymer was prepared by the general
procedure of Example 1 by substituting for the
2,2,6,6-tetramethylpiperidin-4-ol an equivalent amount of
1-~2-hydro~yethyl)-3,3,5,5-tetramethylpiperazine-2,6-dione. The
reaction was run at 210C.
Analysis:
Calculated (%) C: 75.46; H: 11.86f N: 3.86.
Found (~) C: 75.43; H: 11.48; N: 3.50.
EXAMPLE 6
~'
Ethylene/1,2,2,6,6-Pentamethylpiperidin-4-yl Acrylate Copolymer
: ' :
To a 1000 ml round bottomed flasX fitted as was the flask
in Exal~ple 1 was charged 46.2 grams of 1,2,2,6,6-pentamethyl-
piperidin-4-ol and 50 grams of ethylene/ethyl acrylate (82/18)
copolymer havin~ a num~er average molecular weight of 33,000, an
ethyl acrylate content of 18% by weight, and a melt flow rate of
6g/10 min. (ASTM D1238, cond. E~.
- 41 -
I :~ 69~ ~
The mixt~re was heated under a nitrogen atmosphere at 180C
for 30 minutes till essentially all the polymer pellets were
melted. The hot melt was gently s-tirred to give a hot
homogeneous mix to which 1 gram of tetrabutyl titanate was
added.
The reaction temperature was raised to 210C and aliquot
samples of product were taken at 4-hour intervals. After 12
hours, the temperature was lowered to 120C and 500 ml of
toluene were added 610wly with stirring. The resulting toluene
solution was then added slowly into 2000 ml of methanol with
vigorous stirring to precipitate the desired product. The
precipitate was suspended in the methanol with stirring for
another five hours before isolating by filtration. The isolated
product was washed with methanol and dried at room
temperature/0.1 mm for 1 hour and then at 80C/0.1 mm for two
hours. The copolymer was obtained as free flowing wh~te
granules readily soluble in hot toluene or hot xylene.
Analysis:
Calculated (%) C: 80.22; H: 13.05; N: 2.05.
Found (%) C: 80.23, H: 13.07 N: 1.96.
- 42 -
:
: 1
o ~ ~
EXA~PLE 7
Ethylene/2,2,6,6-Tetramethylpiperidin~ _A~y~ate Copo_y~er
The above-named copolymer was prepared by the general
procedure of Example 6 by substitu-ting for 1,2,2,6,6-penta-
methylpiperidin-4-ol an equivalent amount of
2,2,6,6-tetra-methylpiperidin-4-ol. The product had a melt flow
rate of 8g/10 min. (ASTM D1238, cond. E).
Analysis:
Calculated (%) C: 80.10; H: 13.02 N: 2.15.
Found (%) C: 80.85; H: 12.53; N: 1.98.
Tbe copolymer was obtained as free flowing white granules which
were soluble in hot xylene or hot toluene.
~, .
` ~ EXAMPLE 8
. . .
Ethylene/2,2,6,6~Tetramethylpiperidin~4~yl- Acrylate Copolymer
~ Using the procedure of Example 7, but with an
;~ ethylene/ethyl acrylate copolymer having a number average
molecular weight of 33,600 and an ethyl acrylate content of 18
- 43 ~
::
~ ~ 6~
by weight, th~ above-na~,ed copolymer was obtained as whi~e
ruhhery granu~es. The co~olymer was readily soluble in hot
xylene or hot to]uene.
EXAMPLE 9
Ethylene/2,2,6,6-Tetramethylpiperidin-4-yl~crylate Copolymer
To a 500-ml resin kettle equipped with a stirrer and
thermometer was charged 86.1 grams of a granulated copolymer of
ethylene/methyl acrylate (80/20) havins a melt index of 2 (ASTM
method D 1238, cond. E). The copolymer contained 17.2 grams
(0.2 moles) of methyl acrylate. To the pclymer was added 80 ml
of xylene and 39.3 grams (0.25 moles) of
2,2,6,6-tetra~ethylpiperidin-4-ol. The reaction mixture was
heated for 30 minutes at 150C and then 0.23 gram (0.01 mole) of
lithium amide catalyst was added. The mixture was heated for a
further 8 hours at 145-150C with stirring while a slow nitrogen
sw~ep stream was passed through the systemO The catalyst was
then deactivated by the addition of one ml of acetic acid
followed by stirring for two hours at 145C.
,
The viscous liquid mass was poured onto aluminum sheets and
cooled. The now solidified product was cut into small pieces
and ground in a Wiley mill together with dry ice. The ground
4 -
.
. ., :
~ ~ ~9~6 ;~
product (160 gralns) was washed with a lotal of 1000 ml of
methanol in six portions and then driec at room temperature.
The procluc-t contained 2.02~ nitrogen (calculated, for complete
replacement of ~ethyl ester by hinderec amine, 2.52~ ni~rogen).
NMR spectra indicated 20~ residual methyl ester groups in
the product. Transesterification was thus 80~ complete.
Evaporation of the methanol washings resulted in a quantitative
recovery of the remaining unreacted 2,2,6,6-tetramethyl-
piperidin-4-ol (13.7 grams, 0.087 moles).
EXAMPLE 10
Copolymer with Pendant Amide Groups
A mixture of 15 grams of an ethylene/ethyl acrylate (82/18)
copolymer, 36 grams of 4-(y-aminopropylamino)-2,2,6,6-tetra-
methylpiperidine and 13 grams of ground potassium fluoride was
heated at 200C for 25 hours. The reaction mixture was then
diluted with 50 ml of xylene and poured .into 1000 ml of
methanol. The resulting precipitate was filtered, washed
thoroughly with ethanol and water, and then dried. The nitrogen
content o 2.29~ indicated that approximately 40~ of the pendant
ethyl ester groups had been converted into the hindered amine
amide groups.
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EXAMPLF.S 11-16
The follo~ing polymers were obtained by transesterification
of an ethylene/ethyl acrylate (82/18) copolymer using the
alcohols i.ndicated in the table below. The transesterification
reactions were carried out in the presence of tetrabutyl
titanate as catalyst at 150-200C.
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Po 1 ymer
Example Pol~nler %N ~N
No. Alcohol M~ calcd found
C~13
~3
~(CH2)6- NH- C NH 455()03.65 3.29
~CH3
C 3
o CH3
~ CH3
12HOCH2CH~- N NH 430003.86 3.32
7~CH3
CH3
CH3
13 HOCE-12CH2- N, ~ NH 440003.79 3.l9
~ H3
: CH3
CH3
/ CH
: 14 HOCH2CH20CH~CH2-NH ~ 450003.71 2.95
CH3
CH3
. CH3
: ~ CH3
15HOCH2CH2OCE~2cH2-~ ~ N-CH3 46500 3.58 3.08
CH3 ~ CH3
CH3
: :
CH3
~:~ ~ H3
16HOCH2C}l2- ~ ~ NH 45,500 3.65 3.05
C4Hg ~
~CH3
CH3
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EXAMPLE 17
Accelerated UV Li~ht Exposure Testi g
Polypropylene powder (Hercules Profax~ 6401) was
thoroughly blended with 0.2% by weight of the antioxidant, di(n-
octadecyl) 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, which
prevents oxidative degradation of polypropylene during processing
and with 0.5% of a light stabilizer being tested. The blended
materials were then milled on a two-roll mill at 182C for 5
minutes after which time the stabilized polypropylene was sheeted
~rom the mill and allowed to cool.
The milled polypropylene sheets were Cllt into pieces and
processed for 3 minutes on a hydraul,ic press at 220C and 175 psi
(12.3 Kg/cm ) pressure. The resulting sheet of 5 mil (0.127 mm)
thickness was water cooled in the press.
The 5 mil (0.127 mm) film was tested in a fluorescent
sunlight black light environment with the development of carbonyl
absorption in the in~rared spectrum at the 5.85 micron wavelength
being the measure of stabilization protection a~forded by the
stabilizers present in the polypropylene. Failure was taken as the
hours required to cause the carbonyl absorption to reach a value of
0.5. Such a value correlates with
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the reduction of physical properties of the polypropylene
pellicle to unacceptable ].evels and is proportional to the
amount of degradation caused by the ultraviolet light exposure.
The results are set out in Table A.
TABLE A
Polypropylene plus Fluorescent Sunlight
0.2% by weight anti- Black Light Test Hours
oxidant* plus O . 5~ to Failure
by weight light (0.5 Carbonyl Absorption)
stabilizer of Example No.
No light stabilizer 560
1 1170
2 1790
3 2200
16~0
970
6 1270
7 1250
* antioxidant is ditn-octadecyl) 3,5-di-tert-butyl-4-hydroxy-
benzyl~hosFhonate.
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EXAMPLE 18
Using the general procedure of Example 17, linear low
density polyethylene (Dowiex 2047, initial melt index 3.4g/10
min) which contained 0.015~ by weight o~ pentaerythrityl
tetrakis-(3,5-cli-tert-butyl-4-hydroxyhydrocinnamate) as
antioxidant was blended with the instant ethylene copolymer
light stabilizers and then compression molded into 5 mil (0.127
mm) film test samples.
These samples were tested in a carbon arc Weather-O-meter
with water spray attachment to simulate rainfall and in the
fluorescent sunlight black light apparatus with the develop-
ment of carbonyl absorption as measured at the 5.85 micron
wavelength in the infrared spectrum taken to indicate the degree
of stabilization protection afforded by said light stabilizers.
The results are set forth in Table B.
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TABL~ B
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Linear Polyethylene Ho;~rs to Failure
plus 0.015~ by weiaht (0.5 Carbon~_Absorption?
antioxidant* plus (% by ~luorescent
weight) light stabilizer Carbon Arc Sunlight BlacX
of Example No. WeatherOmeter Liaht
, .
~o light stabilizer 379 1089
7 (0.25) 1881 >4551
7 (0.50) 1961 >5122
7 (1.0~) 2036 >5122
6 (0.25) 1831 >5122
6 (0.50) 1~33 >5122
6 (1.00) 1814 >5122
* antioxidant is pentaerythrityl tetrakis (3,5-di-tert~butyl-4-
hydroxyhydrocinnamate)
These data show the outstanding e~fectiveness of the
instant ethylene copolymers as light stabilizers even at very
low concentrations (0.25~ by weight) in linear polyethylene.
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There was no exudation of the instant ethylene copolymer
light stabilizers from linear polyethylene after storage at ambient
temperatures for 1000 hours and for 3000 hours.
EXAMPLE 19
Polypropylene (Hercules Profax 6501~) containing 0.1% by
weight of calcium stearate, but no antioxidant, was blended with
the instant ethylene copolymer light s~abilizers. The mixture
was pelletized and extruded at 450F (232C) into 4 inch (10.2
cm) tape with a thickness of 5 mil (0.127 mm). The tape was cut
into 1/4 inch (6.4 mm) wide strips which were then stretched by
a 6:1 ratio over ~odet rolls at a temperature of 225F (107C)
to give a stretched film tape of 2 mil (o.o508 mm) thickness.
The tape was sub~ected to long term heat aging at 125C
by storing in an oven at 125C with the hours to failure being
taken as the time (hours) required for the elongation value to
; fall to 50% of the initial value.
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Separate samples were also subjected to the carbon arc
WeatherOmeter with the same measure of hours to failure being taken.
The results are given in Table C.
TABLE C
Polyethylene Hours -to ~lailure
plus 0.1% by weight (50% Retention of Elongation)
light stabilizer Carbon Arc Long Term Heat
of Example No. WeatherOmeter Aging (125C)
._
no light stabilizer 344 69
8 977 471
7 1043 443
6 901 462
These data show that the instant ethylene copolymers are
very effective light and heat stabilizers for polypropylene.
EXAMPLE ?
.
Using the general procedure of Example 19, polypropylene
2 mil (0.o508 mm) tape made with polypropylene (Hercules, Profax
6501~) containing 0.1% by weight of calcium stearate, 0.05% by
~; weight of the an-tioxidant, 2,6-di-tert-butyl-p-cresol, and 0.1%
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of an ethylene copolymer of this invention was subjected to lon3
term heat aging a~ 125C with hours to failure being recorded
when only 50 of the original elongation value of the tape was
reached. The results are given in Table D.
TABLE D
~: PolypropyleneHours to Failure
plus 0.05% by weight(SO~ Retention of Elongation
antioxidant* and 0.1% by Long Term Heat
weight light stabilizer_ Aging at 125C
of Example
no light stabilizer 43
8 54~
6 370
; * 2,6-di-tert-butyl-p-cresol
Again the instant ethylene copolymers exhibit excellent
heat stabilization effect~ for polypropylene.
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EXAMPLE 21
Using the general procedure of Ex~lmple 20, 0.1% of the
i.nstant stabilizer was incorporated in~:o polypropylene and
exposed in a carbon arc Weather-Ometer. The time required for
the elongation value to fall to 50% of the original ~alue was
determined. The results are given on ~'able E.
Table E
Polypropylene
plus 0.1% by ~ours to Fa;lure
weight of light (50~ Retention o~ Elongation)
Stabilizer of Example No. _Carbon Arc Weather-Ometer
no stabilizer 317
11 , 61 9
13 1185
14 1120
: 15 1190
16 . 1166
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Example 22 .
Ethylene/Viny]. 1,2,2,6,6-Pentamethylpiperidine-4-carboxylate
Copolym r
The above-named copolymer is prepared by the general
procedure of Example 1 by substituting for the
2,2,6,6-tetramethylpiperidin-4-ol an equivalent amount of methy:L
1,2,2,6,6-pentamethylpiperidine-4-carboxylate and reacting with
an ethylene/vinyl acetate copolymer t75/25~.
Example 23
The copolymer of Example 22 is an effe~tive light and heat
stabilizer for polypropylene.
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