Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1998-11-05
2001-02-27
Hoke, Veronica P. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S126000, C524S139000
Reexamination Certificate
active
06194496
ABSTRACT:
The present invention relates to flame-retardant thermoplastic molding materials having improved processing behavior, the use of the novel thermoplastic molding materials for the production of fibers, films and moldings, and the fibers, films and moldings produced using these molding materials.
Polymer blends comprising polyphenylene ether (PPE) and styrene polymers are disclosed, for example, in U.S. Pat. Nos. 3,383,435; 4,128,602 and 4,128,603. Such molding materials are suitable for 15 the production of shaped articles which have better heat distortion resistance than high-impact polystyrenes (HIPS) which are not mixed with polyphenylene ethers. A detailed description of the properties of these polymer blends also appears in L.Bottenbruch, “Technische Polymer-Blends”, Kunststoff Handbuch 20 3/2, Hanser Verlag, Munich, 1993.
An important advantage of the polymer blends comprising polyphenylene ethers and styrene polymers is that, by adding halogen-free flameproofing agents, in particular phosphorus-containing compounds, it is possible to prepare molding materials which are flame-retardant and are therefore used for many electrical applications. In particular, testing of the flame-retardance according to UL 94 (in J.Troitzsch, “International Plastics Flammability Handbook”, page 346 et seq., Hanser Verlag, Munich, 1990) is decisive for use in the electrical sector. In this test, a flame is applied several times to vertically fastened test specimens. The test specimen heats up to a very great extent, leading in many cases to the dripping of flaming polymer material which ignites the cotton wool positioned under the rod. This undesirable behavior is observed in particular when large amounts of flameproofing agent have to be used to achieve short combustion times.
There is therefore a need for novel, highly effective flameproofing combinations which permit a reduction in the amount of flameproofing agent.
The literature discloses a number of examples where mixtures of different flameproofing agents have led to improvements in the properties of thermoplastic molding materials. For example, JP 57207641 describes PPE/HIPS blends, in which a mixture of resorcinol diphenyl phosphate (RDP) and triphenyl phosphate (TPPA) was used. German Laid-Open Application DE-OS 32 34 033 discloses PPE/HIPS blends which contains synergistic mixtures of phosphine oxides and monophosphates as flameproofing agents. This flameproofing combination permits a reduction in the amount of flameproofing agent, having an advantageous effect on the mechanical properties of the molding materials produced therefrom. However, these molding materials have disadvantages with regard to the processing behavior.
Furthermore, mixtures of phosphorus-containing compounds with nitrogen compounds have been described as flameproofing combinations. For example, JP 05025341 describes a phosphate/melamine mixture which comprises red phosphorus as a further component. Combinations of phosphorus-containing compounds with nitrogen and sulfur compounds are described, for example, in EP 0 496 120. Whereas the first combination leads to an improvement of the fire behavior, the second mixture claimed in EP 0 496 120 also has advantages with regard to coating of the mold. However, such mixtures have disadvantages with respect to toughness.
EP 0 090 523 describes polphenylene ether resins which contain a hydroxyl- and carboxyl-substituted ethylene polymer for improving the toughness of the molding materials. Unsubstituted or substituted triphenyl phosphate is mentioned as a possible flameproofing agent.
EP 0 538 950 describes polymer compositions having improved flameproof properties, the composition comprising, in addition to a copolymer grafted onto rubber, a polymer having hydroxystyrene units. Mono-, di- and oligomeric polyphosphates and metal and metalloid salts of organic phosphoric acid derivatives are mentioned as possible flameproofing agents.
It is an object of the present invention to provide an effective flameproofing combination for thermoplastic molding materials,in particular for thermoplastic molding materials based on polyphenylene ethers and vinyl aromatic polymers, such as HIPS, which combination permits optimization of the properties of the molding material with regard to fire behavior, mechanical properties and processing behavior.
We have found, surprisingly, that this object is achieved with the use of a combination of oligophosphorus compounds and phosphine oxides.
The present invention therefore relates to flame-retardant thermoplastic molding materials based on
A) at least one polyphenylene ether and
B) at least one vinyl aromatic polymer, which comprises,
C) as a flameproofing agent, a mixture of
C
1
) at least one oligophosphorus compound of the general formula (I) and/or (II)
where
R
1
and R
4
, independently of one another, are each unsubstituted or substituted alkyl or aryl,
R
2
and R
3
, independently of one another, are each unsubstituted or substituted alkyl, aryl, alkoxy or aryloxy,
R
5
is alkylene, —SO
2
—, —CO—, —N═N— or —(R
6
)P(O)—, where R
6
is unsubstituted or substituted alkyl, aryl or alkylaryl, and
n and p, independently of one another, are each from 1.0 to 30, and
C
2
) at least one phosphine oxide of the general formula (III)
where R
7
, R
8
and R
9
, independently of one another, are each hydrogen or unsubstituted or substituted alkyl, aryl, alkylaryl or cycloalkyl of up to 40 carbon atoms.
Suitable substituents in compounds of the formulae (I), (II) and (III) are cyano, hydroxyl, C
1-14
-alkyl and halogen, such as F, Cl, Br and J.
Preferred alkyl radicals are C
1
-C
20
-alkyl, in particular C
1
-C
12
-alkyl, e.g. methyl, ethyl, n-propyl, n-butyl, neopentyl, n-hexyl, n-octyl, n-nonyl, n-dodecyl, 2-ethylhexyl, 3,5,5-trimethylhexyl and substituted alkyl radicals, e.g. 5 cyanoethyl.
Preferred aryl radicals are phenyl and naphthyl as well as mono- or polysubstituted radicals, such as tolyl, xylyl, mesityl and cresyl.
Preferred alkylaryl radicals are C
1
-C
20
-alkylaryl, in particular C
1
-C
12
-alkylaryl, radicals, the alkyl moiety and aryl moiety being as defined above.
Preferred cycloalkyl groups include C
3
-C
10
-cycloalkyl, such as cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.
Preferred alkoxy radicals are C
1
-C
20
-alkoxy radicals, the C
1
-C
20
-alkyl moiety being as defined above.
Preferred aryloxy radicals are those in which the aryl moiety is as defined above.
Preferred alkylene radicals are C
1
-C
6
-alkylene, such as methylene, ethylene, propylene and hexylene.
The novel molding materials contain the flameproofing combination, preferably in an amount of from about 1 to about 20% by weight, based on the total weight of the molding material.
If necessary, a polymeric hydroxy compound may additionally be present in an amount which improves the fire behavior.
According to a preferred embodiment of the invention, a molding material is provided, containing
A) from about 5 to about 98% by weight of polyphenylene ethers,
B) from about 1 to about 94% by weight of styrene polymers,
C) from about 1 to about 20% by weight of flameproofing combination which comprises
from about 5 to about 95% by weight of at least one phosphorus compound of the above general formula (I) and/or (II) as component C
1
and
from about 5 to about 95% by weight of a phosphine oxide of the above general formula (III) as component C
2
,
D) from about 0 to about 50% by weight of an impact modifier,
E) from about 0 to about 10% by weight of a hydroxyl-carrying polymer
and
F) from about 0 to about 60% by weight of conventional 10 additives.
Here, the stated contents of C
1
and C
2
are each based on the total weight of the flameproofing combination.
A flameproofing combination which contains a mixture of resorcinol diphenyl phosphate and/or hydroquinone diphenyl phosphate with triphenylphosphine oxide is particularly preferred.
Phosphate and phosphine oxide are preferably present in a molar ratio of from about 1:9 to about 9:1.
The polyphenylene ethers (component A) contained in the novel molding mate
Seibring Joachim
Weber Martin
BASF - Aktiengesellschaft
Hoke Veronica P.
Keil & Weinkauf
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