Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-10-02
2002-12-10
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...
C524S110000, C525S205000, C525S327600, C526S262000
Reexamination Certificate
active
06492442
ABSTRACT:
The present invention relates to a stabilizer composition and to its use to stabilize nonliving organic material against the effects of light, oxygen and heat.
The mechanical, chemical and/or aesthetic properties of nonliving organic material, especially plastics and coating materials, are known to be impaired by the effects of light, oxygen and heat. This impairment is normally manifested as yellowing, discoloration, cracking or embrittlement of the material. The purpose of stabilizers or stabilizer compositions is to afford satisfactory protection to counter the deterioration of organic material as a result of light, oxygen and heat.
Sterically hindered amines (Hindered Amine Light Stabilizers; HALS) are known stabilizers against photolytic and thermal decomposition of plastics. Particularly suitable compounds of this kind are oligomeric HALS. For instance, DE-A-4239437 discloses certain maleamide-&agr;-olefin copolymers having tetramethylpiperidyl side groups, which constitute effective stabilizers.
The oligomeric HALS comprise solids. It has been found that the incorporation and homogeneous distribution of these substances in, for example, polymer molding compounds are occasionally difficult.
DE-A-4440288 discloses the use of certain 3-arylacrylic esters as light stabilizers and stabilizers for nonliving organic material. The 3-arylacrylic esters may be used in combination with sterically hindered amines.
DE-A-4405670 relates to a stabilizer mixture comprising chroman derivatives, organic phosphites or phosphonites and amines for stabilizing organic material.
It is an object of the present invention to specify a new stabilizer composition based on oligomeric HALS which is in a form that is easy to incorporate into the material to be stabilized, may be distributed homogeneously and affords a high protective action against the effects of light, oxygen and heat. The stabilizer composition should be particularly effective in the stabilization of polyurethanes.
We have found that this object is achieved in accordance with the invention by means of a stabilizer composition comprising
A) at least one 3-arylacrylic ester of the formula I
where
Ar is an aryl radical which may carry 1, 2 or 3 substituents selected from C
1-4
alkyl, C
1-4
alkoxy, hydroxyl, phenoxy, amino, mono- or di(C
1-4
alkyl)amino, halogen or nitro or may carry a methylenedioxy group,
R
1
is C
1
to C
20
alkyl or C
2
to C
20
alkenyl, and
R
2
and R
3
are hydrogen or C
1
to C
4
alkyl,
B) a polymeric compound having a molecular weight of at least 2000 which carries, on a polymeric framework, side groups having secondary amine functions, all substituents positioned &agr; to the amine nitrogen being other than nitrogen,
C) at least one chroman derivative of the formula II
where R
4
is a group of the formula
and
D) at least one organic phosphite and/or phosphonite.
The stabilizer composition of the invention is generally a viscous liquid at room temperature and is therefore easy to incorporate into and disperse homogeneously in the material to be stabilized. The stabilizer composition of the invention preferably comprises a viscous liquid having a viscosity in the range from 2600 to 3000 mPas, in particular from 2700 to 2900 mPas, measured at 20° C. and 30 s
−1
using a Haake Rheowin RS 150 apparatus.
It has also been found that the protective action of the stabilizer composition of the invention against the effects of light, oxygen and heat is higher than to be expected from the contributions of the components of the stabilizer composition. The pronounced protective action of the stabilizer composition of the invention is therefore based on a synergistic effect of the components.
The stabilizer composition of the invention comprises as component A) a 3-arylacrylic ester of formula I.
In formula I, Ar is, for example,
phenyl,
o-, m- or p-tolyl,
o-, m- or p-ethylphenyl,
o-, m- or p-propylphenyl,
m- or p-cumyl,
o-, m- or p-butylphenyl,
m- or p-iso-butylphenyl,
m- or p-sec-butylphenyl,
m- or p-tert-butylphenyl,
2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-dimethylphenyl, mesityl,
o-, m- or p-methoxyphenyl,
o-, m- or p-ethoxyphenyl,
o-, m- or p-propoxyphenyl,
m- or p-iso-propoxyphenyl,
o-, m- or p-butoxyphenyl,
m- or p-iso-butoxyphenyl,
m- or p-sec-butoxyphenyl,
m- or p-tert-butoxyphenyl,
2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-dimethoxyphenyl,
o-, m- or p-hydroxyphenyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-dihydroxyphenyl, 3-hydroxy-4-methoxyphenyl,
m- or p-phenoxyphenyl,
o-, m- or paminophenyl,
o-, m- or p-(N-methylamino)phenyl,
o-, m- or p-(N,N-dimethylamino)phenyl,
o-, m- or p-fluorophenyl,
o-, m- or p-chlorophenyl,
2,4-dichlorophenyl,
o-, m- or p-bromophenyl,
o-, m- or p-nitrophenyl,
2,3- or 3,4-methylenedioxyphenyl,
2-, 3
- or 4-biphenylyl, and
&agr;- or &bgr;-naphthyl.
Particular preference is given to (C
1
-C
4
alkoxy)phenyl radicals, especially those where the alkoxy radical is in p-position on the phenyl nucleus.
R
1
is a straight-chain or branched C
1
-C
20
alkyl or C
2
-C
20
alkenyl group, e.g., methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, sec-pentyl, tert-pentyl, neo-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, iso-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, iso-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, vinyl, allyl, methallyl, oleyl, linolyl and linolenyl. Of these, straight-chain or branched C
5
to C
16
alkyl groups, especially straight-chain or branched C
8
to C
12
alkyl groups, are preferred. Of particular interest are straight-chain or branched C
8
alkyl groups.
A particularly preferred 3-arylacrylic ester of the formula I is 2-ethylhexyl p-methoxycinnamate.
The stabilizer composition of the invention comprises as component B) a polymeric compound having a molecular weight of at least 2000, in particular from 2300 to 50,000, which on a polymeric framework carries side groups having secondary amine functions, all substituents positioned a to the amine nitrogen atom being other than hydrogen and being, for example, C
1
-C
4
alkyl radicals, especially methyl groups. The compound suitable as component B) is composed, accordingly, of successive repeating units, each repeating unit having a polymer framework moiety and at least one side group having at least one secondary amine function, all substituents positioned a to the amine nitrogen atom being other than hydrogen. The repeating unit may comprise further side groups which improve, for example, compatibility with the organic material to be stabilized. In general, component B) comprises from 5 to 100, preferably from 6 to 60, repeating units.
Components B) advantageously comprise maleic anhydride (co)polymers comprising, for example, from 0 to 90 mol % C
2
-C
30
&agr;-olefin units and from 10 to 100 mol % maleic anhydride units, some or all—for example, more than 92 mol %—of the maleic anhydride units being imidated with 4-amino-2,2,6,6-tetramethylpiperidine.
With particular preference, component B) comprises a maleic acid-&agr;-olefin copolymer comprising structural units of the formula III
where at least 92 mol % of the radicals R
5
are a tetramethylpiperidyl radical of the formula IV
and up to 8 mol % of the radicals R
5
are hydrogen, C
1
-C
22
alkyl or C
5
-C
8
cycloalkyl, and
R
6
is C
14
-C
28
alkyl, preferably C
16
-C
24
alkyl, especially C
18
-C
22
alkyl.
The radical R
6
is preferably a mixture of C
14
-C
2
8 alkyl groups, preferably C
16
-C
24
alkyl groups, especially C
18
-C
22
alkyl groups. The plot of the molar fraction of the alkyl groups having a given carbon number as a proportion of the total number of all radicals R
6
in the copolymer molecules of a sample against the carbon number comprises preferably at least two maxima, each accounting for at least 30, preferably at least 40 mol %, and the carbon numbers assigned to these maxima differing by one or, preferably two, carbon atoms. The mixtures in question are, in particular, mixtures of octadecyl, eicosyl and docosyl, of which two of these groups,
Appel Manfred
Aumüller Alexander
Krockenberger Jürgen
Trauth Hubert
BASF - Aktiengesellschaft
Szekely Peter
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