Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-11-22
2003-08-12
Szekely, Peter (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C252S403000, C528S259000, C528S341000, C548S369400
Reexamination Certificate
active
06605658
ABSTRACT:
The present invention relates to stabilizing mixtures for organic polymers.
More specifically, the present invention relates to stabilizing mixtures for organic polymers comprising at least one compound belonging to the group of pyrazolones, at least one compound belonging to the group of organic phosphites or phosphonites, at least one compound belonging to the group of sterically hindered phenols and, optionally, at least one compound belonging to the group of sterically hindered amines and their use in the stabilization to degradation caused by oxygen, heat and/or light, of organic polymers.
The present invention also relates to the polymeric compositions stabilized with the above stabilizing mixtures and the end-products obtained by their processing.
Japanese patent application 50/155549 describes the use of derivatives of pyrazolone as stabilizers to degradation caused by heat of ethylene polymers.
Japanese patent application 51/045151 describes the use of derivatives of pyrazolone as stabilizers to degradation caused by heat of resins based on polyvinylchloride.
Organic phosphites, organic phosphonites and phosphoramides are known in the art as co-stabilizers, secondary anti-oxidants and process stabilizers for organic polymers among which polyolefins. Examples of these compounds can be found, for example, in R. Gachter/H. Muller (Ed.), “Plastic Additives Handbook” (1990), 3
rd
Ed., page 47, Hanser, Muinich.
U.S. Pat. No. 4,360,617 describes stabilizing mixtures comprising symmetrical triarylphosphites and phenolic anti-oxidants, particularly useful in the stabilization to degradation caused by oxygen, heat and/or light, of various organic polymers such as, polyurethanes, polyacrylonitrile, polyamide 12 or polystyrene.
Sterically hindered amines, in particular those carrying 2,2,6,6-tetramethylpiperidine groups in the molecule, are known as HALS.
The known stabilizers, however, are not capable of completely satisfying all the problems to be solved by a stabilizer such as, for example, storage life, water absorption, sensitivity to hydrolysis, stabilization during the polymer processing, colour properties of the stabilized polymer, volatility, migration within the stabilized polymer, compatibility with the polymer to be stabilized and improvement in light protection. There is consequently a continuous need of stabilizers for organic polymers capable of providing a better stabilization of the same.
The Applicant has now found that stabilizing mixtures comprising at least one compound belonging to the group of pyrazolones, at least one compound belonging to the group of organic phosphites or phosphonites, at least one compound belonging to the group of sterically hindered phenols and, optionally, at least one compound belonging to the group of sterically hindered amines, are capable of providing a better stabilization to degradation caused by oxygen, heat and/or light, of the organic polymers to which they are added.
An object of the present invention therefore relates to stabilizing mixtures for organic polymers comprising:
(a) at least one compound belonging to the group of pyrazolones;
(b) at least one compound belonging to the group of organic phosphites or phosphonites;
(c) at least one compound belonging to the group of sterically hindered phenols; and, optionally,
(d) at least one compound belonging to the group of sterically hindered amines.
Compounds belonging to the group of pyrazolones (a) useful for the purposes of the present invention are selected from those having general formula (I) or (II):
wherein:
R
1
represents a hydrogen atom; a linear or branched C
1
-C
18
alkyl group; a linear or branched C
2
-C
18
alkenyl group; a linear or branched C
2
-C
18
alkinyl group; a linear or branched C
2
-C
8
alkoxyalkyl group; a C
5
-C
8
cycloalkyl group, said cycloalkyl group optionally substituted; a heterocyclic group with 5 or 6 atoms containing at least one heteroatom selected from oxygen, nitrogen and sulfur, said heterocyclic group optionally substituted; a C
6
-C
20
aryl group, said aryl group optionally substituted; an amine group having general formula (III):
an acid or ester group having general formula (IV) or (V):
—COOR
9
(IV);
—CH
2
COOR
10
(V);
R
2
, R
3
, R
4
, R
5
and R
6
, the same or different, represent a hydrogen atom; a linear or branched C
1
-C
18
alkyl group; a linear or branched C
2
-C
18
alkinyl group; a linear or branched C
2
-C
18
alkenyl group; a C
5
-C
8
cycloalkyl group, said cycloalkyl group optionally substituted; a C
6
-C
20
aryl group optionally substituted;
or, R
2
and R
3
, considered jointly with the carbon atom to which they are bound, represent a C
5
-C
8
cycloalkyl group, said cycloalkyl group optionally substituted;
R
7
, R
8
, R
9
and R
10
, the same or different, represent a hydrogen atom; a linear or branched C
1
-C
18
alkyl group; a C
5
-C
8
cycloalkyl group, said cycloalkyl group optionally substituted; a C
6
-C
20
aryl group, said aryl group optionally substituted;
or, R
7
and R
8
, considered jointly with the nitrogen atom to which they are bound, represent a heterocyclic group with 5 or 6 atoms optionally containing another heteroatom selected from oxygen, nitrogen and sulfur, said heterocyclic group optionally substituted.
When in general formula (I), R
2
and/or R
3
represent a hydrogen atom and in general formula (II), R
6
represents a hydrogen atom, said compounds having general formula (I) and (II) can be present as such, or in tautomeric equilibrium.
When the C
5
-C
18
cycloalkyl groups, the C
6
-C
20
aryl groups and the heterocyclic groups with 5 or 6 atoms are defined as optionally substituted, said groups are intended as being substituted with: halogen atoms selected from chlorine and bromine, linear or branched C
1
-C
18
alkyl groups, linear or branched C
1
-C
18
alkoxyl groups, linear or branched C
2
-C
18
alkenyl groups, linear or branched C
2
-C
18
alkinyl groups, OH groups, NH
2
groups, SH groups.
Examples of C
1
-C
18
alkyl groups are: methyl, ethyl, propyl, isopropyl, butyl, octyl, etc.
Examples of C
2
-C
18
alkenyl groups are: vinyl, propylene, butylene, pentylene, hexylene, etc.
Examples of C
2
-C
18
alkinyl groups are: acetylene, propine, butine, 2-butine, etc.
Examples of C
2
-C
8
alkoxyalkyl groups are: methoxyethyl, butoxyethyl, ethoxyethyl, etc.
Examples of C
5
-C
8
cycloalkyl groups, optionally substituted are: cyclohexyl, cyclopentyl, methylcyclohexyl, etc.
Examples of heterocyclic groups with 5 or 6 atoms, optionally substituted, are: piperidine, morpholine, piperazine, tetramethylpiperidine, pentamethylpiperidine, etc.
Examples of C
6
-C
20
aryl groups, optionally substituted, are: phenyl, naphthyl, anthracenyl, 2-hydroxyphenyl, benzyl, 2-phenylethyl, 4-t-butylbenzyl, etc.
Compounds belonging to the group of pyrazolones (a) of particular interest for the purposes of the present invention, but which in no way limit its scope, are:
Compounds belonging to the group of pyrazolones (a) are known in the art: some are commercially available products, others prepared as described, for example, by R. H. Wiley and P. Wiley, in “The Chemistry of Heterocyclic Compound” (1964), in the volume relating to “Pyrazolones, pyrazolidones and derivatives”, Interscience Publisher, pages 13-19; or in Kirk-Othmer, “Encyclopedia of Chemical Technology” (1982), Vol. 19, 3
rd
Ed., pages 445-453; or in Houben-Weyl, “Methoden Der Organischen Chemie” (1964), Vol. 10/2, pages 614-640.
Compounds belonging to the group of organic phosphites or phosphonites (b) useful for the purposes of the present invention are selected from those having the following general formulae (VI)-(XII):
wherein:
n′ is 2, 3 or 4;
p′ is 1 or 2;
q′ is 2 or 3;
r′ is an integer ranging from 4 to 12, extremes included;
y′ is 1, 2 or 3;
z′ is an integer ranging from 1 to 6, extremes included;
when n′ is 2, A′ represents a C
2
-C
18
alkylene group; a C
2
-C
12
alkylene group containing an oxygen atom, a sulfur atom, or an —NR′
4
— gr
Broussard Fabio
Girelli Daniele
Malatesta Vincenzo
Neri Carlo
Wis Maria Lucia
Ferrell Michael W.
Great Lakes Chemical (Europe) GmbH
Szekely Peter
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