Note: Descriptions are shown in the official language in which they were submitted.
WO 94/24344 PCT/IB94/00056
~~so~7~
_1_
Low Color Processing, Heat and Light Stabilizer System for Polypropylene Fiber
The instant invention pertains to stabilized polypropylene fiber, free or
essentially free of
any traditionally used phenolic antioxidant, and having enhanced light
stability, enhanced
long term heat stability and especially enhanced gas fade resistance. This
fiber formu-
lation is stabilized by an effective amount of a mixture of a selected
hindered amine, a se-
lected hydroxylamine and a selected phosphite.
Polypropylene fiber is traditionally stabilized with a blend of selected
phenolic antioxi-
dant, selected phosphite and selected hindered amine light stabilizer. This
formulation
generally provides adequate processing, heat and light stabilization
performance, but does
not provide adequate gas fade resistance which is needed to maintain color
properties
during storage and end-use application. There is a long-felt need in the
marketplace for a
stabilizer system which can prevent this gas fading and color formation
associated with
the use of phenolic antioxidants. Gas fading is known in the industry as a
discoloration re-
sulting from the exposure of plastic articles to an atmosphere containing
oxides of nitro-
gen.
The components of the instant stabilizer system for polypropylene fibers are
generically
well-known as stabilizers for a host of organic and polymeric substrates. The
components
of the instant stabilizer system for polypropylene fiber are a specific
combination of selec-
ted 2,2,6,6-tetramethylpiperidine hindered amines, phosphites or phosphonites
and N,N-
diallcylhydroxylamines, in the absence or essential absence of a phenolic
antioxidant. This
instant stabilizer formulation provides unexpectedly superior gas fade
resistance, and heat
and light stability performance properties to the polypropylene fibers which
are notorious-
ly difficult to stabilize effectively. The instant phenolic free antioxidant
stabilizer system
provides the best overall stabilization for polypropylene fiber. Discoloration
of polypropy-
lene fibers, when exposed to an atmosphere containing oxides of nitrogen, i.e.
gas fading
conditions, encountered with stabilizer systems containing phenolic
antioxidants, makes
such systems unacceptable in this important property even though in other
performance
criteria the phenolic antioxidants perform adequately.
WO 94/24344 PCT/IB94/00056
_7_
2160574
The hindered amines are a very important class of light and thermal
stabilizers based on
compounds having a 2,2,6,6-tetramethylpiperidine moiety somewhere in the
molecule.
These compounds have achieved great commercial success and are well-known in
the art.
Likewise, phosphonites or phosphites such as those described in US-A-4 360 617
have
also achieved great commercial success as stabilizers.
N,N-Dialkylhydroxylamines also are known in the art as seen in US-A-4 590 231,
US-A-4 782 105, US-A-4 876 300 and US-A-5 013 510. These compounds are useful
as
process stabilizers for polyolefins when used alone or in combination with
phenolic anti-
oxidants and/or other coadditives, particularly as taught in US-A-4 876 300.
Although
US-A-4 876 300 teaches generically that N,N-dialkylhydroxylamines can be used
in com-
bination with phenolic antioxidants, hindered amines, phosphites, UV absorbers
and other
additives, there is no specific disclosure that polypropylene fibers can be
beneficially sta-
bilized by specific combinations of selected hindered amines, phosphites or
phosphonites
and N,N-dialkylhydroxylamines. Thus the instant invention is essentially a
selection from
within the broad generic scope of US-A-4 876 300.
However, the instant composition is distinguished from the compositions of the
prior art in
several important aspects listed below:
1. Hindered phenolic antioxidants plus phosphites combinations have generally
poor gas
fade resistance;
2. Phosphites alone lack adequate process and thermal stabilization efficacy;
and
3. Phosphites plus hindered amines lack adequate process stabilization.
The instant combination of stabilizers provide all of the required mquisites
of gas fade
resistance and process and thermal stability.
The object of this invention is to provide a stabilizer system for
polypropylene fiber, in the
absence of any traditionally used phenolic antioxidant or in the presence of
only very low .
levels of phenolic antioxidant, which would allow the polypropylene fibers to
have en-
hanced light and long term heat stability and especially enhanced gas fade
resistance while
maintaining process stabilization comparable to any system using phenolic
antioxidants.
Another object of the instant invention is to provide a method to improve gas
fade re-
29276-677
CA 02160574 2001-04-23
-3-
sistance and to reduce color formation in polypropylene fibers by using the
instant stabili-
zer system free of phenolic antioxidant_
The instant invention pertains to stabilized polypropylene fiber, free or
essentially free of
any phenolic antioxidant, and having enhanced light stability, enhanced long
term heat
stability and enhanced gas fade resistance, which fiber is stabilized by a
mixture of
a) a hindered amine selected from the group consisting of
the polycondensation product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-6-tent-octylamino-s-triaxine;
the polycondensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4.-
hydroxy-
piperidine and succinic acid;
N,N' ,N" ,N' "-tetralas[4,6-bas(butyl-(2,2,6,6-tetramethylpipeiidin-4-
yl)amino)-s_
triazin-2-yl]-1,10-diamino-4,7-diazadecane;
the polycondensation product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-b-moipholino-s-triazine;
poly[methyl 3-{2,2,6,6-tetramethylpiperidin-4-yloxy)propyl]siloxane;
bas(2,2,6,6-tetramethylpiperidin-4-yl) cyclohexylenedioxydimethylmalonate;
1,3,5-tris { N-cyclohexyl-N-[2-(2,2,6,b-tetramethylpiperazin-3-on-4-
yl)ethyl]amino-s-
triazine;
the polycondensation product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-6-cyclohexylamino-s-triazine; and
poly { N-[4,6-bas(butyl-(2,2,6,6-tetramethyl-piperidin-4-yl)amino)-s-triazba-2-
yl]-
1,4,7-triazanonane }-tn-N"-[4,6-bas(butyl-(2,2,6,6-tett~methylpiperidin-4.-
yl)amino)-s-
triazin-2-yl]amine;
b) a phosphate or phosphonite selected from the group
consisting of
tris(2,4-di-tert-butylphenyl) phosphate;
3,9-di(2,4-di-tert-butylphenyl)-2,4,8,10-tetraoxa-3,9-diphospha[S.S] undecane;
2,2',2"-nittilo-tris[ethyl (3,3',S,S'-tetra-tert-butyl-1,1'-biphenyl-2,2'-
diyl) phosphate];
ethyl bas(2,4-di-tert-butyl-6-methylphenyl) phosphate; and
tetrakis(2,4-di-tert-butylphenyl)-4,4'-bis(diphenylene)phosphonite; and
c) a hydroxylamine selected from the group consisting of
CA 02160574 2001-04-23
29276-677
-4-
N,N-dioctadecylhydroxylamine;
N,N-dialkylhydroxylamine of the formula T1T2NOH where TI and TZ are the alkyl
mixture found in hydrogenated tallow amine; and
the N,N dialkylhydroxylamine product made by the direct oxidation of N,N-
di(liydro-
genated tallow)amine ;
wherein the weight ratio of components (a):(b):(c) is from 1:1:1 to 100:2:1;
preferably
10:1:1 to 10:2:1; aad most preferably 6:1:1 to 6:2:1.
T'he effective amount of the mixture of stabilizers is for example from 0 .
05%
to 5%, preferably 0.1 to 2%, most preferably 0.15 to 1%, by
weight based on the weight of the fiber.
Stabilized polypropylene fiber which are of particular interest are those
where the compo-
nent (a) is selected from the group consisting of
the polycondensation product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-6-tert-octylamino-s-t~aane;
the polycondensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-
hydroxy-
piperidine and succinic acid;
N,N',N",N' "-tetrakis[4,6-bis(butyl-(2,2,6,6-tetramethylpiperidin-4.-yi)amino)-
s-
triazin-2-yl]-1,10-diamino-4,7-diazadecane;
the polycondensation product of 4,4'-hezamethylene-bis(arnino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-6-morpholino-s-triazine;
poly[methyl 3-(2,2,6,6-tetcamethylpiperidin-4.-yloxy)propyl]siloxane;
bis(2,2,6,6-tetramethylpiperidin-4-yi) cyclohezylenedioxydimethylmalonate; and
1,3,5-Iris{N-cyclohexyl-N [2-(2,2,6,6-tetramethylpiperazin-3-on-4-
yl~thyl]amino-s-
triazine.
Stabilized polypropylene fiber which are also of particular interest are those
where the
component (b) is selected from the group consisting of
tris(2,4-di-tert-butylphenyl) phosphite;
3,9-di(2,4-di-tert-butylpheny1~2,4,8,10-tetraoxa-3,9-diphospha[5.5] undecane;
2,2',2"-nittilo-tiffs[ethyl (3,3',S,S'-tetra-ten-butyl-1,1'-biphenyl-2,2'-
diyl) phosphite];
and
29276-67? ~ 021.60574 2001-04-23
ethyl bis(2,4-di-cert butyl-6-methylphenyl) phosphite.
Stabilized polypropylene fiber which are particularly preferned are those
where the com-
;-- poneat (c) is the N,N-dialkyihYdroxY~ P~nct made by the direct oacidation
of N,N-
di(hydrogenated tallow)amine .
Additionally, the instant invention also pertains to a binary stab~izer System
where the stn-
b~i~ed polypropylene fiber, free or essentially free of any phenolic
antioxidant, and
having enhanced light stability, enhanced song term heat stability
and.enhanced gas fade
resistance, which fiber is stabilized by a miztare of
I) a hindered amine selected from the group consisting of
the polycondensation product of 4,4'-hexamethylene-his
(amino-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-
tert-octylamino-s-triazine;
the polycondensation product of 1-(2-hydro~cyethyl)-2,2,6,6-teaamethyl-4-
hydrozy
piperidine and succinic acid;
N,N' ,N",N'"-oetralds[4,6-his(butyl-(2,2,6,6-tetramethyipiperidin-4-yi)amino)-
s_
t<i,a~in-2-yl]-1,10-diamino-4,7 ;
the polycondensation product of 4,4'-heaamethylene-bis(amino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-6-morpholino-s-ttia~i~ne;
posy[methyl 3-(2,2.6,6-tetramethylpiperidin-4-ylozy)ProPYi]siloxane;
his(2,2,6,6-tetramethylpiperidin-4-yl) cyciohezylenedioxydimethylmalonate;
1,3,5-tds{N-cyclohe~rl-N-{2-(2,2,6,6-tetramethylniperazin 3-on-4-
yl~ethyl]amino-
s-t<iaane; and
the poiycondensation product of 4,4'-hexamethyiene-bis(amino-2,2,6,6-
tetramethyi
piperidine) and 2,4-~iichloro-6-cycloheicyiamino-s-triazine; and
In a hydro~cylamine selected from the group consisting of
the N,N-dialkylhydroxylamine product made by the direct
oxidation of N,N-di(hydrogenated tallow)amine;
WO 94/24344 PCT/IB94/00056
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wherein the weight ratio of components (I):(II) is from 100:1 to 1:2;
preferably 10:1 to
1:l; and most preferably S:1 to 3:1.
Binary stabilized polypropylene fiber which are of particular interest are
those where the
component (I) is selected from the group consisting of
the polycondensadon product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
tetramethyl-
piperidine) and 2,4-dichloro-6-tent-octylamino-s-triazine;
the polycondensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-
hydroxy-
piperidine and succinic acid; and
N,N',N",N"'-tetrakis[4,6-bis(butyl-(2,2,6,6-tetramethylpiperidin-4-yl)amino)-s-
triazin-2-yl]-1,10-diamino-4,7-diazadecane.
Binary stabilized polypropylene fiber which are of particular interest are
those where the
component (II) is the N,N-dialkylhydroxylamine product made by the direct
oxidation of
N,N-di(hydrogenated tallow)amine by the process of US-A-S 013 510 or US-A-4
898 901.
'The effective amount of the mixture of stabilizers is from 0.05 to 5 %,
preferably 0.1 to 2 %,
most preferably 0.15 to 1 %, by weight based on the weight of the fiber.
The instant invention involves a selected mixture of stabilizers which are
.free or essentially
free of any phenolic antioxidants. Some manufacturers of polypropylene add
tiny amounts,
usually <0.01 °!o by weight of phenolic antioxidant, to aid in the
initial manufacture of the
polypropylene resin. The amount of phenolic antioxidant remaining in the resin
used to prepare
polypropylene fiber is far less than the 0.05°ro by weight of phenolic
antioxidant used in the
working examples of US-A-4 876 300. As the phrase free or essentially free of
phenolic anti-
oxidant as used in the context of the instant invention means 0 to 0.01
°k by weight of phenolic
antioxidant may be present in the instant compositions. No phenolic
antioxidant is deliberately
added to the instant compositions in order to achieve the stabilization
efficacies described.
Another most important aspect of the instant invention is to a method for
improving gas
fade resistance and reducing color formation in stabilized polypropylene fiber
by incorpo-
rating therein an effective stabilizing amount of the mixture of stabilizers
described above
without the loss of any other stabilization property.
Still another aspect of the instant invention is to a method for enhancing the
resistance to
WO 94/24344 PCT/IB94/00056
~1605'~4
degradation of polypropylene fiber, due to exposure to UV radiation over that
which can
be achieved by the use of conventional stabilizers alone, by incorporating
therein an effec-
tive stabilizing amount of the mixture of stabilizers described above.
Yet another aspect of the instant invention is to a method for enhancing the
thermal stabi-
lity of polypropylene fiber, over that which can be achieved by the use of
conventional
stabilizers alone, by incorporating therein an effective stabilizing amount of
the mixture of
stabilizers described above.
The cited hindered amines and phosphites are generally commercially available
or can be
made by published methods.
The N,N-dialkylhydroxylamines are prepared by methods disclosed in US-A-4 782
105;
US-A-4 898 901 and particularly US-A-5 013 510 by the direct oxidation of N,N-
di-
(hydrogenated tallow)amine by hydrogen peroxide.
The polypropylene fiber may also contain other additives such as fillers and
reinforcing
agents such as calcium carbonate, silicates, glass fibers, asbestos, talc,
kaolin, mica,
barium sulfate, metal oxides and hydroxides, carbon black, graphite and other
additives,
for example, plasticizers, lubricants, emulsifiers, pigments, optical
brighteners, flame-
proofing agents and anti-static agents.
Conventional stabilization systems, such as phenolic antioxidant with
phosphite and
hindered amine stabilizer, or phosphite with hindered amine stabilizer, can
provide excel-
lent stabilization to polypropylene fibers in selected performance areas, but
it is only
through the use of the instant ternary combination of a selected hindered
amine, selected
hydroxylamine and selected phosphite that all important performance properties
for sta-
bilized polypropylene fibers can be optimized.
Polypropylene is used extensively for the manufacture of fiber for
residential, commercial
and automotive carpeting. White and light-colored fiber can suffer from
discoloration due
to gas fade discoloration. Polypropylene resin as it is originally
manufactured may contain
very low levels of phenolic antioxidant for stability till said resin is later
fabricated into
fiber. In each case some additional stabilizer package must be added to the
propylene resin
before fabrication into fiber is possible. Hindered phenolic antioxidants are
well-known as
a potential source of such discoloration by the formation of quinone type
chromophores as
WO 94/24344 PCTlIB94/00056
216057 4
oxidation products or as the result of environmental exposure to the oxides of
nitrogen
(known as "gas fade" discoloration).
It is therefore desirable to remove the phenolic antioxidant component from
the polypro-
pylene fiber. Unfortunately when this has been done in the past, other
properties related to
polymer stability are adversely effected. Phenolic antioxidants protect the
polymer during
high temperature melt processing, extrusion and spinning operations. Phenolic
antioxi-
dants further protect the polymer pellets and resultant fiber during storage
and final end-
use applications.
Surprisingly, it was found that the phenolic antioxidant could be replaced in
the instant
stabilizer system which is a ternary combination of a selected hindered amine,
a selected
hydroxylamine and a selected phosphite or a binary combination of a selected
hindered
amine and a selected hydroxylamine. Said system provides stability in excess
of that ob-
tained with conventional stabilizer systems having a phenolic antioxidant
component
without the discoloration associated with the phenolic antioxidant when the
stabilized
polypropylene fiber is exposed to gas fading conditions, i.e. in an atmosphere
containing
the oxides of nitrogen.
The following examples are presented for the purpose of illustration only and
are not to be
construed to limit the nature or scope of the instant invention in any manner
whatsoever.
Test Compounds:
AO A - 1,3,5-tris{3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate;
HALS 1 - the polycondensation product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
tetramethylpiperidine) and 2,4-dichloro-6-tert-octylamino-s-triazine;
HALS 2 - the polycondensation product of 1-(2-hydroxyethyl)-2,2,6,6-
tetramethyl-
4-hydroxypiperidine and succinic acid;
DIALS 3 - N,N',N",N"'-tetrakis[4,6-bis(butyl-(2,2,6,6-tetramethylpiperidin-4-
yl)
amino)-s-triazin-2-yl]-1,10-diamino-4,7-diazadecane;
HALS 4 - the polycondensation product of 4,4'-hexamethylene-bis(amino-2,2,6,6-
WO 94/24344 PCT/IB94/00056
-9-
tetramethylpiperidine) and 2,4-dichloro-6-morpholino-s-triazine;
HALS 5 - poly[methyl 3-(2,2,6,6-tetramethylpiperidin-4-yloxy)propyl]siloxane;
HALS 6 - bis(2,2,6,6-tetramethylpiperidin-4-yl) cyclohexylenedioxydimethyl-
malonate;
HALS 7 - 1,3,5-Iris{N-cyclohexyl-N-[2-(2,2,6,6-tetramethylpiperazin-3-on-4-yl)-
ethyl] amino-s-triazine;
Phos I - tris(2,4-di-tert-butylphenyl) phosphite;
Phos II - 3,9-di(2,4-di-tert-butylphenyl)-2,4,8,10-tetraoxa-3,9-
diphospha[5.5]unde-
cane;
Phos III - 2,2',2"-nitrilo[triethyl-tris-(3,3',5,5'-tetra-tert-butyl-1,1'-
biphenyl-2,2'-
diyl) phosphite];
Phos IV - ethyl bis(2,4-di-tert-butyl-6-methylphenyl) phosphite; and
HA A - the N,N-dialkylhydroxylamine product made by the direct oxidation of
N,N-di(hydrogenated tallow)amine by the process of US-A-5 013 510 or
US-A-4 898 901.
All additives are designated in % by weight based on the polypropylene. All
formulations
also contain 0.05% by weight of calcium stearate.
Example 1: Process Stabilization of Polypropylene Fiber.
Fiber grade polypropylene, containing 0.05 °lo by weight of calcium
stearate, is dry blen-
ded with the test additives and then melt compounded at 246°C into
pellets. The pelletized
fully formulated resin is then spun at 274°C into fiber using a Hills
laboratory model fiber
extruder. The spun tow of 41 filaments is stretched at a ratio of 1: 3.2 to
give a final denier
of 615/41.
The melt flow rates of the formulated pellets before spinning and of the spun
fiber tow
WO 94/24344 2 ~ 6 0 5 7 4 PCT/IB94100056
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after spinning are determined by ASTM 1238-86. The closer are the melt flow
rates before
and after spinning, the more effective is the process stabilization efficacy
of the stabilizer
system. The processing stability data are given in Tables 1, 2, 3 and 4 below.
Table 1:
Melt Flow
Rate
A
Stabilizer mount
Pellets Fiber
HALS 1 0.30
Phos I 0.09 % 15.4 20.7
HA A 0.01 %
HALS 1 0.30 %
Phos I 0.05 % 14.9 19.6
HA A 0.05 %
HALS 1 0.05 %
Phos I 0.09 % 13.6 17.7
HA A 0.01 %
HALS 1 0.05
Phos I 0.05 % 13.6 18.8
HA A 0.05 %
AO A 0.05
HALS 1 0.05 % 14.3 19
3
Phos I 0.05 % .
HA A 0.05 %
WO 94/24344 PCT/IB94100056
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Table 2:
elt Flow
Rate
bili A
S
ta mount
zer
Pellets Fiber
HALS 2 0.30 %
Phos I 0.09 % 13.7 18.6
HA A 0.01 %
HALS 2 0.30 %
Phos I 0.05 % 13.8 18.3
HA A 0.05 %
HALS 2 0.05 %
Phos I 0.09 % 13.4 17.8
HA A 0.01 %
HALS 2 0.05 %
Phos I 0.05 % 14.4 18.7
HA A 0.05 %
AO A 0.05
HALS 2 0.05 % 12.9 18.1
Phos I 0.05 %
HA A 0.05
Table 3:
i A Melt Flow
Rate
lizer mount
Stab
Pellets Fiber
HALS 3 0.30 %
Phos I 0.09 % 13.3 19.3
HA A 0.01 %
HALS 3 0.30 %
Phos I 0.05 % 14.2 17.5
HA A 0.05 %
HALS 3 0.05 %
Phos I 0.09 % 14.3 18.6
HA A 0.01 %
HALS 3 0.05 %
Phos I 0.05 % 13.7 18.4
HA A 0.05
AO A 0.05 %
HALS 3 0.05 % 12.8 17.5
Phos I 0.05 %
HA A 0.05 %
WO 94/24344 PCT/IB94100056
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Table 4:
Melt Flow
Rate
StabilizerAmount
Pellets Fiber
HALS 2 0.05 %
Phos II 0.05 % 12.7 16.9
HA A 0.05 %
AO A 0.05 %a
HALS 2 0.05 % 12 16.2
9
Phos II 0.05 .
HA A 0.05 %
Inspection of the data given above shows that the instant formulations
containing selected
hindered amines, phosphites and hydroxylamines provide excellent process
stabilization to
polypropylene fully comparable to stabilizer systems containing phenolic
antioxidants.
Example 2: Process Stabilization of Polypropylene Fiber
Melt flow differences resulting from insufficient processing stability can be
even more evident
when the polypropylene is spun under more severe processing conditions. In
Example 1 the
polypropylene is spun at 274°C. However, it is not unusual for
polypropylene to be spun at
much higher temperature at 302°C. The melt flow values of polypropylene
spun at such tempe-
ratures are shown in the Tables 5, 6, 7 or 8 below.
WO 94/24344 PCT/IB94/00056
21GQ~~,~
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Table S:
Melt Flow
Rate
Stabilizer Amount Fiber Spun Fiber Spun
at 274C at 302C
Phos I 0.15 % 14.6 26.9
Phos I 0.10 % 13 15.5
3
AO A 0.05 % .
Phos I 0.05 % 12.7 16
1
AO A 0.05 % .
Phos I 0.10 % 13.5 16
2
HA A 0.05 % .
HALS 2 0.05 % 15 31
7 9
Phos I 0.10 . .
HALS 2 0.05 %
Phos I 0.10 % 14.3 16.3
AO A 0.05 %
HALS 2 0.05
Phos I 0.05 % 13.7 17.4
HA A 0.05
HALS 2 0.05 %
Phos I 0.10 % 13.6 16.1
HA A 0.05 %
WO 94124344 PCT/IB94/00056
2160574
- 14-
Table 6:
Melt Flow Rate
Stabilizer Amount Fiber Spun Fiber Spun
at 274C at 302C
Phos II 0.15 % 13.7 20.1
Phos II 0.10 % 13.0 16.5
AO A 0.05 %
HALS 2 0.05 % 15.2 22.2
Phos II 0.10
HALS 2 0.05 %
Phos II 0.10 % 12.2 15.5
AO A 0.05
HALS 2 0.05 %
Phos II 0.05 % 12.4 15.5
HA A 0.05 %
HALS 2 0.05 %
Phos II 0.10 % 12.7 15.6
HA A 0.05 %
WO 94/24344 .
PCTlIB94100056
-15-
Table 7:
Melt Flow
Rate
Stabilizer Aifridu~.t~ Fiber Spun Fiber Spun
at 274C at 302C
Phos I 0.15 % 14.6 26.9
Phos I 0.10 % 13.3 15.5
AO A 0.05
HALS 3 0.05 % 14.8 31.4
Phos I 0.10 %
HALS 3 0.05 %
Phos I 0.10 % 13.5 15.1
AO A 0.05 %
HALS 3 0.05 %
Phos I 0.05 % 12.4 16.9
HA A 0.05 %
HALS 3 0.05
Phos I 0.10 % 12.9 16.7
HA A 0.05 %
WO 94/24344 PCT/IB94/00056
16-
Table 8:
Melt Flow
Rate
Stabilizer Amount Fiber Spun Fiber Spun
at 274C at 302C
Phos II 0.15 % 13.7 20.1
Phos II 0.10 % 13.0 16.5
AO A 0.05 %
HALS 3 0.05 % 14.1 22.8
Phos II 0.10 %
HALS 3 0.05 %
Phos II 0.05 % 13.1 14.9
HA A 0.05 %
HALS 3 0.05
Phos II 0.10 % 12.5 15.4
HA A 0.05 %
The data in Tables 5, 6, 7 and 8 clearly show that in a conventional
stabilizer system a
combination of phenolic antioxidant and phosphite provide good processing
stability. The
removal of the phenolic antioxidant in the presence or absence of a hindered
amine results
in a significant loss in process stabilization. However, the substitution of a
hydroxylamine
in place of the phenolic antioxidant yields process stabilization fully
comparable to that
provided by the phenolic antioxidant-phosphite system.
As is seen in Example S, however, the presence of phenolic antioxidant in
stabilizer
systems has a detrimental effect on gas fade resistance.
Example 3: Light Stabilization of Polypropylene Fiber.
The fibers are also exposed to UV light and to long teen thermal aging under
standard
conditions.
Socks knitted from the stabilized polypropylene fibers are exposed in an Atlas
Xenon-
Arc-WeatherOmeter using the SAE J1885 Interior Automotive conditions at
89°C, 0.55
kW/cm2 at 340 nm with no spray cycle. Failure in this test is determined by
the observa-
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tion of the physical failure of the sock when it is "scratched" with a blunt
glass rod. The
longer it takes for this catastrophic failure to occur, the more effective is
the stabilizer
system. The days to failure are given in Tables 9, 10, 11 and 12 below for
each of the sta-
bilization systems.
Table 9:
StabilizerAmount Days to Failure
in
the WeatherOmeter
HALS 1 0.30 %
Phos I 0.09 % 34
HA A 0.01 %
HALS 1 0.30 %
Phos I 0.05 % 38
HA A 0.05
HALS 1 0.30 %
AO A 0.05 % 38
Phos I 0.05 %
HA A 0.05 %
HALS 1 0.30 %
AO A 0.05 % 28
Phos I 0.10 %
Table 10:
StabilizerAmount Days to Failure
in
the WeatherOmeter
HALS 2 0.30
Phos I 0.09 % 23
HA A 0.01 %
HALS 2 0.30 %
Phos I 0.05 % 30
HA A 0.05 %
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Table 11:
Days to Failure
in
StabilizerAmount the WeatherOmeter
HALS 3 0.30 %
Phos I 0.09 % 38
HA A 0.01 %
HALS 3 0.30 %
Phos I 0.05 % 37
Hp A 0.05
Table 12:
Days to Failure
in
Stabilizer Amount the WeatherOmeter
HALS 2 0.05 %
Phos II 0.05 % 9
HA A 0.05 %
Ex~le 4: Long Term Heat Stability of Polypropylene Fiber.
In the long term heat aging at 120°C, other knitted socks of the
stabilized polypropylene
fiber are exposed in a forced draft oven equipped with a rotating carousel.
Again, failure is
determined as described above. The longer it takes for such catastrophic
failure to occur,
the more efficacious is the stabilizer system. The test data are given in
Tables 13, 14 and
15 below.
Table 13:
Days to Failure
Stabilizer Amount
at 120C
HALS 1 0.30 %
Phos I 0.09 % 65
HA A 0.01
HALS 1 0.30 %
Phos I 0.05 % 61
HA A 0.05 %
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Table 14:
StabilizerAmount Days to Failure
at 120C
HALS 2 0.30 %
Phos I 0.09 % 40
HA A 0.01 %
HALS 2 0.30 %
Phos I 0.05 % 72
HA A 0.05 %
Table 15:
Days to Failure
StabilizerAmount
at 120C
HALS 3 0.30 %
Phos I 0.09 % 68
HA A 0.01 %
HALS 3 0.30 %
Phos I 0.05 % 75
HA A 0.05 %
Examples 5-6 show that, in regards to gas fade resistance, the instant
stabilization mixtum
is far superior as measured by Delta E values where low numbers indicate less
color. The
numerical differences shown are significant, and the samples can be easily
differentiated
visually.
Example 5: Gas Fade Resistance or Color Stability of Polypropylene Fiber.
Other knitted socks of the stabilized polypropylene fiber are exposed to
oxides of nitrogen
in an Exposure Chamber using the AATCC Test Method 23-1988, "Colorfastness to
Burnt
Gas Fumes" for 3 and 7 "cycles". Test specimens are removed from the chamber
and
assessed for change in color (Delta E color scale) on an Applied Color Systems
Model
CS-5 colorimeter (D65 illuminant, 2° observer). Low Delta E values
indicate less color
and better stabilization. The test data are given in Tables 16, 17, 18, 19,
20, 21 and 22
below.
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Table 16:
Delta E
Color
after
Cycle
StabilizerAmount
3 7
HALS 1 0.30 %
Phos I 0.09 % 2.4 2.8
HA A 0.01 %
HALS 1 0.30 %
Phos I 0.05 % 2.3 2.9
HA A 0.05 %
HALS 1 0.30 %
AO A 0.05 % 5.7 6.7
Phos I 0.09 %
HA A 0.01 %
HALS 1 0.30 %
AO A 0.05 % 4 6.1
3
Phos I 0.05 % .
HA A 0.05 %
Table 17:
Delta E
Color
after
Cycle
A
Stabilizermount
3 7
HALS 1 0.05 %
Phos I 0.09 % 1.9 1.5
HA A 0.01 %
HALS 1 0.05 %
Phos I 0.05 % 1.8 1.9
HA A 0.05 %
HALS 1 0.05 %
AO A 0.05 % 3,g 5.2
Phos I 0.09 %
HA A 0.01 %
HALS 1 0.05 %
AO A 0.05 %
2 5.0
3
Phos I 0.05 % .
HA A 0.05 %
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Table 18:
Delta
E Color
after
Cycle
St A
bili t
zer moun
a
3 7
HALS 2 0.30
Phos I 0.09 % 1.6 1.5
HA A 0.01 %
HALS 2 0.30 %
Phos I 0.05 % 1.5 1.9
HA A 0.05 %
HALS 2 0.30 %
AO A 0.05 % 3 5
9 3
Phos I 0.09 % . .
HA A 0.01 %
HALS 2 0.30
AO A 0.05 % 1 3.7
9
Phos I 0.05 % .
HA A 0.05 %
Table 19:
Delta E
Color
after
Cycle
bili A
S t
zer moun
ta
3 7
HALS 2 0.05 %
Phos I 0.09 % 1.6 1.5
HA A 0.01
HALS 2 0.05 %
Phos I 0.05 % 1.0 1.3
HA A 0.05 %
HALS 2 0.05 %
AO A 0.05 % 3,g 4.9
Phos I 0.09 %
HA A 0.01 %
HALS 2 0.05 %
AO A 0.05 %
2 3.9
0
Phos I 0.05 % .
HA A 0.05 %
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Table 20:
Delta E
A Color
after
Cycle
Stabilizer mount
3 7
HALS 3 0.30 %
Phos I 0.09 % 2.4 2.3
HA A 0.01 %
HALS 3 0.30
Phos I 0.05 % 1.7 1.9
HA A 0.05
HALS 3 0.30 %
AO A 0.05 % 4.g 6.7
Phos I 0.09 %
HA A 0.01 %
HALS 3 0.30 %
AO A 0.05 %
1 5.3
3
Phos I 0.05 % .
HA A 0.05 %
Table 21:
Delta E
A Color
after
Cycle
Stabilizer mount
3 7
HALS 3 0.05 %
Phos I 0.09 % 1.9 1.6
HA A 0.01 %
HALS 3 0.05 %
Phos I 0.05 % 1.2 1.3
HA A 0.05 %
HALS 3 0.05 %
AO A 0.05 % 4.0 5.3
Phos I 0.09 %
HA A 0.01 %
HALS 3 0.05 %
AO A 0.05 %
2 4.6
3
Phos I 0.05 % ~
HA A 0.05 %
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Table 22:
Delta E
Color
after
Cycle
St nt
bili A
o
zer m
a u
3 7
HALS 2 0.05 %
Phos II 0.05 % 1.5 1.8
HA A 0.05 %
HALS 2 0.05
AO A 0.05 % 1.9 1
3
Phos II 0.05 % .
HA A 0.05 %
Example 6: Gas Fade Resistance or Color Stability of Polypropylene Fiber
Other knitted socks of the stabilized polypropylene fiber are exposed to
oxides of nitrogen
in an Exposure Chamber using the AATCC Test Method 23-1988, "Colorfastness to
Burnt
Gas Fumes" for 3 "cycles". Test specimens are removed from the chamber and
assessed
for change in color (Delta E color scale) on an Applied Color Systems Model CS-
5
colorimeter (D65 illuminant, 2° observer). The test data are given in
Tables 23, 24 and 25
below. Low Delta E values indicate less color and better stabilization.
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Table 23:
StabilizerAmount Delta E Color after
Cycle 3
HALS 1 0.15 %
Phos I 0.08 % 6.9
AO A 0.04
HALS 1 0.15 %
Phos I 0.08 % 2.4
HA A 0.04 %
HALS 4 0.30 %
Phos I 0.10 %
AO A 0.05
HALS 4 0.30 %
Phos I 0.05 % 1.2
HA A 0.05 %
HALS 5 0.30 %
Phos I 0.10 % 3.2
AO A 0.05 %
HALS 5 0.30 %
Phos I 0.05 % 1.0
HA A 0.05 %
HALS 6 0.30 %
Phos I 0.10 % 2.1
AO A 0.05 %
HALS 6 0.30 %
Phos I 0.05 % 1.0
HA A 0.05 %
HALS 7 0.30
Phos I 0.10 % 2.2
AO A 0.05 %
HALS 7 0.30 %
Phos I 0.05 % 1.0
HA A 0.05 %
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Table 24:
StabilizerAmount Delta E Color after
Cycle 3
HALS 1 0.15
Phos III 0.08 % 5.6
AO A 0.04 %
HALS 1 0.15 %
Phos III 0.08 % 3.8
HA A 0.04 %
Table 25:
StabilizerAmount Delta E Color after
Cycle 3
HALS 1 0.15 %
Phos IV 0.08 % 4.8
AO A 0.04 %
HALS 1 0.15 %
Phos IV 0.08 % 2.3
HA A 0.04 %
Inspection of the data given above shows that the instant formulations
containing other se-
lected hindered amines, other phosphites and hydroxylamines provide excellent
gas fade
resistance and color stability to polypropylene far superior to the stabilizer
systems contai-
ning a phenolic antioxidant.
Example 7: Gas Fade Resistance or Color Stability of Polypropylene Fiber
Following the procedure of Example 6, the gas fade resistance or color
stability of poly-
propylene fiber is measured when said fiber is protected by a binary system of
stabilizers
comprising a hindered amine and a hydroxylamine without the presence of any
phosphite
compared to fiber with additionally contains a phenolic antioxidant. The test
data are
given in Tables 26, 27 and 28 below. Low Delta E values indicate less color
and better sta-
bilization.
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Table 26:
StabilizerAmount Delta E Color after
Cycle 3
HALS 1 0.05 %
Phos I 0.10 % 4.7
AO A 0.05 %
HALS 1 0.05 %
1
0
HA A 0.10 % .
HALS 1 0.05 %
2
1
HAA 0.05% .
Table 27:
StabilizerAmount Delta E Color after
Cycle 3
HALS 2 0.05 %
Phos I 0.10 % 4.1
AO A 0.05 %
HALS 2 0.05
9
0
HA A 0.10 % .
HALS 2 0.05 %
9
0
Hp A 0.05 % .
Table 28:
StabilizerAmount Delta E Color after
Cycle 3
HALS 3 0.05
Phos I 0.10 % 4.4
AO A 0.05 %
HALS 3 0.05 %
1
0
HA A 0.10 % .
HALS 3 0.05 %
9
0
HA A 0.05 % .
Inspection of the data given above shows that the instant binary formulations
containing
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selected hindered amines and hydroxylamines provide excellent gas fade
resistance and
color stability to polypropylene far superior to the stabilizer systems
containing a phenolic
antioxidant. '
Example 8: Process Stabilization of Polypropylene Fiber
Melt flow differences resulting from insufficient processing stability are
quite evident
when the polypropylene is spun under severe processing conditions. This is
particularly
evident when polypropylene is spun at 302°C. The lower the melt flow
rates are the more
effective is the process stabilization efficacy of the stabilizer system (see
also example 1).
The melt flow values of polypropylene spun at that temperature are shown in
the Tables
29, 30 and 31 below.
Table 29:
Melt Flow Rate
Stabilizer Amount
Fiber Spun at
302C
HALS 1 0.05 % 65
HALS 1 0.05 % 34
Phos I 0.10 %
HALS 1 0.05 %
Phos I 0.10 % 16
AO A 0.05 %
HALS 1 0.05 %
Phos I 0.05 % 18
HA A 0.05 %
HALS 1 0.05 % 1 g
HA A 0.05 %
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Table 30:
Melt Flow Rate
Stabilizer Amount Fiber Spun at
302C
HALS 2 0.05 % 56
HALS 2 0.05 % 24
Phos I 0.10
HALS 2 0.05 %
Phos I 0.10 % 15
AO A 0.05 %
HALS 2 0.05 %
Phos I 0.05 % 19
HA A 0.05 %
HALS 2 0.05 % 18
HA A 0.05 %
Table 31:
Melt Flow Rate
Stabilizer Amount Fiber Spun at
302C
HALS 3 0.05 % 28
HALS 3 0.05 % 31
Phos I 0.10 %
HALS 3 0.05 %
Phos I 0.10 % 16
AO A 0.05 %
HALS 3 0.05 %a
Phos I 0.05 % 1~
HA A 0.05 %
HALS 3 0.05 % 1~
HA A 0.05 %
The data in Tables 29, 30 and 31 clearly show that in a conventional
stabilizer system a
combination of phenolic antioxidant, hindered amine and phosphite provide good
processing stability. The removal of the phenolic antioxidant results in a
significant loss in
process stabilization. However, the substitution of a hydroxylamine in place
of the
phenolic antioxidant yields process stabilization fully comparable to that
provided by the
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phenolic antioxidant-phosphite system both in the presence or absence of the
phosphite
component. Thus the binary stabilizer system of hindered amine plus
hydroxylamine
provides excellent thermal process stabilization to the polypropylene fiber.
