Fireproofed thermoplastic molding materials containing red phosphorus and based on polyesters or polyamides

Fireproofed thermoplastic molding materials which contain red phosphorus as a flame-proofing agent are obtainable by mixing PA1 (A) from 5 to 95% by weight of a polyamide or of a polyester or of a mixture of these, PA1 (B) from 5 to 95% by weight of an elastomer dispersion containing, as essential components, PA2 (b.sub.1) from 5 to 75% by weight of an elastomer prepared by emulsion polymerization, PA2 (b.sub.2) from 10 to 70% by weight of red phosphorus, p2 (b.sub.3) from 10 to 80% by weight of water and PA2 (b.sub.4) from 0.1 to 5% by weight of dispersant, and PA1 (C) from 0 to 60% by weight of fibrous or particulate fillers or a mixture of these, the total content of red phosphorus in the molding material being from 3 to 20% by weight, based on the total weight of the molding material, and the elastomer composition being introduced into a melt of the polyamide or of the polyester or of a mixture of these.

The present invention relates to fireproofed thermoplastic molding 
materials which contain red phosphorus as a flameproofing agent and are 
obtainable by mixing 
(A) from 5 to 95% by weight of a polyamide or of a polyester or of a 
mixture of these, 
(B) from 5 to 95% by weight of an elastomer dispersion containing, an 
essential components, 
(b.sub.1) from 5 to 75% by weight of an elastomer prepared by emulsion 
polymerization, 
(b.sub.2) from 10 to 70% by weight of red phosphorus, 
(b.sub.3) from 10 to 80% by weight of water and 
(b.sub.4) from 0.1 to 5% by weight of a dispersant, and 
(C) from 0 to 60% by weight of fibrous or particulate fillers or a mixture 
of these, 
the total content of red phosphorus in the molding material being from 3 to 
20% by weight, based on the total weight of the molding material, and the 
elastomer composition being introduced into a melt of the polyamide or of 
the polyester or of a mixture of these. 
The present invention furthermore relates to a process for the preparation 
of such molding materials, and their use for the production of moldings, 
and to moldings obtainable from the novel molding materials. 
Use of red phosphorus as the flameproofing agent in polyamides and 
polyesters has long been known. However, incorporation of red phosphorus 
in powder form into the polymer melt has some serious disadvantages. 
Since the phosphorus comes into contact with very hot surfaces during this 
procedure, there is a danger of phosphorus fires and phosphorus dust 
explosions. Moreover, phosphorus dusts are considered a health hazard. 
To improve the incorporation, in particular to reduce the dust, it has been 
proposed to coat or surround the red phosphorus with a polymer. For this 
purpose, GB-A-1 458 194 proposes styrene/butadiene copolymers and DE-A-26 
25 691 proposes polymers having a softening point about 90.degree. C. 
Furthermore, DE-A-32 15 750 describes a process for fireproofing 
polyamides and polyurethanes, in which the red phosphorus is used in a low 
molecular weight polyamide as the carrier. 
Although all these measures improve the dust problem, they cannot 
adequately overcome the danger of phosphorus fires and phosphorus dust 
explosions. 
It is an object of the present invention to provide fireproofed 
thermoplastic molding materials treated with red phosphorus and based on 
polyesters and polyamides, the said molding materials being capable of 
being prepared in a safe manner without health hazards and moreover having 
excellent mechanical properties. 
We have found that this object is achieved, according to the invention, by 
the fireproofed thermoplastic molding materials defined at the outset. 
The novel molding materials are obtainable by mixing from 5 to 95% by 
weight of a polyamide or of a polyester, or of a mixture of these, from 5 
to 95% by weight of an elastomer composition which contains, as essential 
components, an elastomer (component b.sub.1) prepared by emulsion 
polymerization, red phosphorus (b.sub.2), water (b.sub.3) and a dispersant 
(b.sub.4). 
The polyamides used as component (A) are known per se. Partially 
crystalline or amorphous polyamides having a weight average molecular 
weight of not less than 5,000, as described in, for example, German 
Laid-Open applications DOS 2,071,250, DOS 2,071,251, DOS 2,130,523, DOS 
2,130,948, DOS 2,241,322, DOS 2,312,966, DOS 2,512,606 and DOS 3,393,210, 
are preferred. 
Examples of these are polyamides which are derived from lactams having 7 to 
13 ring members, such as polycaprolactam, polycapryllactam and 
polylaurolactam, and polyamides which are obtained by reacting 
dicarboxylic acids with diamines. Suitable dicarboxylic acids are 
alkanedicarboxylic acids of 4 to ;b 12, in particular 6 to 10, carbon 
atoms and aromatic dicarboxylic acids. Adipic acid, azelaic acid, sebacic 
acid, dodecanedioic acid, terephthalic acid and isophthalic acid may be 
mentioned here merely as examples. 
Particularly suitable diamines are alkanediamines of 4 to 14, in particular 
4 to 10, carbon atoms and m-xyllylenediamine, di-(4-aminophenyl)-methane, 
di-(4-aminocyclohexyl)-methane, 2,2-di-(4-aminophenyl)-propane and 
2,2-di-(4-aminocyclohexyl)-propane. Polyamides which are obtainable by 
copolymerization of two or more of the abovementioned monomers, or 
mixtures of a plurality of polyamides, are also suitable. 
Processes for the preparation of such polyamides, as well as such 
polyamides themselves, are known per se and are described in the 
literature, so that no further information is required here. 
The relative viscosity of the polyamides is in general from 2.2 to 4.5, 
measured in 96% strength by weight sulfuric acid (1 g/100 ml) at 
25.degree. C.). 
The polyesters which can be used as component (A) are also known per se and 
are described in the literature. Preferably used polyesters are those 
which contain an aromatic ring in the main chain. This may also be 
substituted, for example by halogens, such as chlorine or bromine, and by 
C.sub.1 -C.sub.4 -alkyl, eg. methyl, ethyl, isopropyl, n-propyl, isobutyl, 
n-butyl or tert-butyl. 
The polyesters can be prepared by reacting dicarboxylic acids, their esters 
or other ester-forming derivatives with dihydroxy compounds in a 
conventional manner. 
Examples of suitable dicarboxylic acids are aliphatic and aromatic 
dicarboxylic acids, which may also be used in the form of a mixture. 
Naphthalenedicarboxylic acids, terephthalic acid, isophthalic acid, adipic 
acid, azelaic acid, sebacic acid, dodecanedioic acid and 
cyclohexanedicarboxylic acids as well as mixtures of these carboxylic 
acids and their ester-forming derivatives may be mentioned here merely by 
way of example. 
Preferably used dihydroxy compounds are diols of 2 to 6 carbon atoms, 
particularly preferably ethylene glycol, butane-1,4-dio, butene-1,4-diol 
and hexane-1,6-diol; however, it is also possible to use hexane-1,4-diol, 
cyclohexane-1,4-diol, 1,4-di-(hydroxymethyl)-cyclohexane, bisphenol A, 
neopentylglycol, mixtures of these diols and ester-forming derivatives of 
these diols. 
Polyesters of terephthalic acid and a C.sub.2 -C.sub.6 -diol component, 
such as polyethylene terephthalate and polybutylene terephthalate, are 
particularly preferred. 
The relative viscosity, .eta. spec/c, of such polyesters, measured on a 
0.5% strength by weight solution in a phenol/ortho-dichlorobenzene mixture 
(weight ratio 3:2) at 25.degree. C., is in general from 1.2 to 1.8 dl/g. 
For the purposes of the present invention, polyesters include 
polycarbonates which are obtainable by polymerization of aromatic 
dihydroxy compounds with carbonic acid, or their derivatives. Products of 
this type are known per se and are described in the literature. 
Other polyesters are the liquid crystalline polyesters which exhibit 
pronounced anistropy of certain properties. The thermotropic wholly 
aromatic polyesters, as are known to the skilled worker from a large 
number of patent applications, may be mentioned here in particular. These 
form an anisotropic molten phase. 
In principle, polyamides, or polyesters alone or any mixtures of these may 
be used as component (A). The amount of component (A) in the novel molding 
materials is from 10 to 90, preferably from 20 to 80, in particular from 
30 to 75, % weight, based on the total weight of the molding material. 
The aqueous elastomer compositions (B) which, when mixed with a melt of the 
component (A), give the novel molding materials contain, as essential 
components, the components (b.sub.1) to (b.sub.4) stated in claim 1. 
Component (b.sub.1) is an elastomer which is prepared by emulsion 
polymerization and accounts for from 5 to 75, preferably from 15 to 65, 
and in particular from 20 to 60, % by weight of the elastomer composition. 
The elastomers can be prepared by emulsion polymerization in a conventional 
manner, as described in, for example, Houben-Weyl, Methoden der 
organischen Chemie, volume XII. I (1961), and by Blackley in the monograph 
entitled Emulsion Polymerization. The emulsifiers and catalysts which can 
be used are known per se. 
In principle, homogeneous elastomers or those having a shell structure can 
be used. The shell-like structure is determined by the order of addition 
of the individual monomers; the morphology of the polymers is also 
influenced by this order of addition. 
Acrylates, eg. n-butyl acrylate and 2-ethylhexyl acrylate, the 
corresponding methacrylates, butadiene and isoprene as well as mixtures of 
these may be mentioned here merely as typical monomers for the preparation 
of the rubber part of the elastomers. These monomers can be copolymerized 
with further monomers, eg. styrene, acrylonitrile, vinyl ethers and 
further acrylates and methacrylates, such as methyl methacrylate, methyl 
acrylate, ethyl acrylate and propyl acrylate. 
The soft or rubber phase (having a glass transition temperature of less 
than 0.degree. C.), of the elastomers may constitute the core, the outer 
shell or a middle shell (in the case of elastomers having a structure 
consisting of more than two shells); in the case of multi-shell 
elastomers, it is also possible for a plurality of shells to consist of 
one rubber phase. 
If, in addition to the rubber phase, one or more hard components (having 
glass transition temperatures of more than 20.degree. C.), are present in 
the elastomer, these hard components are generally prepared by 
polymerization of styrene, acrylonitrile, methacrylonitrile, 
.alpha.-methylstyrene p-methylstyrene, acrylates and methacrylates, such 
as methyl acrylate, ethyl acrylate and methyl methacrylate, as principal 
monomers. In addition, smaller amounts of other comonomers may also be 
used here. 
In some cases, it has proven advantageous to use emulsion polymers which 
have reactive groups on the surface. Examples of such groups are epoxy, 
carboxyl, latent carboxyl, amino and amide groups as well as functional 
groups which can be introduced by the concomitant use of monomers of the 
general formula 
##STR1## 
where R.sup.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl, 
R.sup.2 is hydrogen, C.sub.1 -C.sub.8 -alkyl or aryl, in particular phenyl, 
R.sup.3 is hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.12 -aryl or 
--OR.sup.4, 
R.sup.4 is C.sub.1 -C.sub.8 -alkyl or C.sub.6 -C.sub.12 -alkyl which can be 
unsubstituted or substituted by O--or N-containing groups, 
X is a chemical bond, C.sub.1 -C.sub.10 -alkylene or C.sub.6 -C.sub.12 
-arylene or 
##STR2## 
Y is O--Z-- or NH--Z and Z is C.sub.1 -C.sub.10 -alkylene or C.sub.6 
-C.sub.12 -arylene. 
Furthermore, the graft monomers described in EP-A 208 187 are suitable for 
the introduction of reactive groups at the surface. 
Examples of monomers by means of which the stated functional groups can be 
introduced are glycidyl methacrylate, glycidyl acrylate, allyl glycidyl 
ether, vinyl glycidyl ether, glycidyl itaconate, acrylic acid, methacrylic 
acid and their metal salts, in particular alkali metal salts, and ammonium 
salts, maleic acid, fumaric acid, itaconic acid, vinylbenzoic acid, 
vinylphthalic acid, and monoesters of these acids with alcohols ROH, where 
R has not more than 29 carbon atoms and, for example, is methyl, ethyl, 
propyl, isopropyl, n-butyl, isobutyl, hexyl, cyclohexyl, octyl, 
2-ethylhexyl, decyl, stearyl, methoxyethyl, ethoxyethyl or hydroxyethyl. 
Maleic anhydride and metal salts (in particular alkali metal and alkaline 
earth metal salts) of polymerizable carboxylic acids and esters of acrylic 
acid or methacrylic acid with tertiary alcohols, eg. tert-butyl acrylate, 
do not contain any free carboxyl groups but show similar behavior to the 
free acids and are therefore regarded as monomers having latent carboxyl 
groups. 
Other examples are acrylamide, methacrylamide and substituted esters of 
acrylic acid or methacrylic acid, such as N-tert-butylaminoethyl 
methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminomethyl 
acrylate and N,N-diethylaminoethyl acrylate. 
The particles of the rubber phase may furthermore be crosslinked. Examples 
of monomers which act as crosslinking agents are buta-1,3-diene, 
divinylbenzene, diallyl phthalate and dihydrodicyclopentadienyl acrylate, 
as well as the compounds described in EP-A 50 265. 
It is also possible to use graft-linking monomers, ie. monomers which 
possess two or more polymerizable double bonds which react at different 
rates during the polymerization. Preferably used compounds are those in 
which one or more reactive groups polymerize at about the same rate as the 
other monomers while the other reactive group (or reactive groups) 
polymerizes (or polymerize), for example, substantially more slowly. The 
different polymerization rates result in a certain proportion of 
unsaturated double bonds in the rubber. If a further phase is then grafted 
onto such a rubber, some or all of the double bonds present in the rubber 
react with the graft monomers with the formation of chemical bonds, ie. 
some or all of the grafted phase is bonded to the grafting base via 
chemical bonds. 
Examples of such graft-linking monomers are allyl-containing monomers, in 
particular allyl esters of ethylenically unsaturated carboxylic acids, 
such as allyl acrylate, allyl methacrylate, diallyl maleate, diallyl 
fumarate, diallyl itaconate and the corresponding monoallyl compounds of 
these dicarboxylic acids. In addition, there is a large number of other 
suitable graft-linking monomers; for further details, reference may be 
made to, for example, U.S. Pat. No. 4,148,846. 
In general, the amount of these crosslinking monomers in the component (A) 
is not more than 5, preferably not more than 3, % by weight, based on (A). 
A few preferred emulsion polymers are listed below. First, graft polymers 
which have a core and one or more outer shells and the following structure 
may be mentioned here: 
______________________________________ 
Type Monomers for the core 
Monomers for the shell 
______________________________________ 
A Buta-1,3-diene, isoprene, 
Styrene, acrylonitrile, 
n-butyl acrylate, ethyl- 
methyl methacrylate 
hexyl acrylate or a mix- 
ture of these 
B As for A but with the con- 
As for A 
comitant use of crosslink- 
ing agents 
C As for A or B n-Butyl acrylate, ethyl 
acrylate, methyl acrylate, 
buta-1,3-diene, isoprene, 
ethylhexyl acrylate 
D As for A or B As for A or C but with 
the concomitant use of 
monomers having reactive 
groups as described 
herein 
E Styrene, acrylonitrile, 
First shell of monomers 
methyl methacrylate or a 
as described under A and 
mixture of these B for the core 
Second shell as described 
under A or C for the shell 
______________________________________ 
Instead of graft polymers having a multi-shell structure, it is also 
possible to use homogeneous, ie. single-shell, elastomers, of 
buta-1,3-diene, isoprene and n-butyl acrylate or copolymers or these. 
These products too can be prepared with the concomitant use of 
cross-linking monomers or monomers having reactive groups. 
Examples of preferred emulsion polymers are n-butyl acrylate/(meth)acrylic 
acid copolymers, n-butyl acrylate/glycidyl acrylate or n-butyl 
acrylate/glycidyl methacrylate copolymers, graft polymers having an inner 
core of n-butyl acrylate or based on butadiene and an outer shell of the 
abovementioned copolymers and copolymers of ethylene with comonomers which 
provide reactive groups. 
The amount of red phosphorus (b.sub.2) in the aqueous elastomer composition 
is from 10 to 70, preferably from 20 to 70, in particular from 25 to 65, % 
by weight, based on the total weight of the aqueous elastomer composition. 
The red phosphorus can be used directly in the commercial form. However, 
there are also commercial products in which the red phosphorus is coated 
on the surface with low molecular weight liquid substances, such as 
silicone oil, liquid paraffin or esters of phthalic acid or of adipic acid 
or polymers or oligomers. All these products can be used according to the 
invention. 
The median particle size d.sub.50 (number average) of the phosphorus 
particles distributed in the elastomer composition is preferably from 
0.0001 to 0.5, in particular from 0.001 to 0.2, mm. 
The elastomer compositions contain, as component b.sub.3, from 10 to 80, 
preferably from 12 to 70, and particularly preferably from 15 to 55, % by 
weight of water. Some or all of this originates from the preparation of 
the elastomers b.sub.1 by emulsion polymerization. 
The substances present as dispersants in the aqueous elastomer compositions 
B are known per se and are described in the literature. Alkali metal and 
ammonium salts of alkyl-, aryl-, alkaryl- and aralkylsulfonates, sulfates, 
polyethersulfates, fatty acids and hydroxy-substituted fatty acids or 
their esters, alcohols, amines and amides, alkylphenols and 
organophosphoric acids and their alkyl metal or ammonium salts, as listed 
in, for example, EP-A 82 020, may be mentioned here. 
The aqueous elastomer compositions can simply be prepared by mixing the red 
phosphorus into the dispersion obtained in the emulsion polymerization in 
a mixing apparatus, for example a stirred kettle or another apparatus 
known for this purpose. This is carried out, as a rule, from 10.degree. to 
70.degree. C., preferably at room temperature, in the course of from 1 
minutes to 5 hours, preferably not less than about 10 minutes. The 
dispersants (emulsifiers) are, as a rule, added before the emulsion 
polymerization, but may also be partially added before the addition of the 
red phosphorus. 
If the elastomer dispersion obtained in the emulsion polymerization has an 
excessively high or excessively low water content, the latter can be 
accordingly brought to the desired value by removing or adding water. 
The aqueous elastomer compositions prepared in this manner, in the form of 
suspensions or dispersions, are free-flowing and pumpable. The major part 
of the phosphorus particles does not separate out, as is observed, for 
example, when phosphorus is mixed into water. 
In addition to the components (A) and (B), the novel thermoplastic molding 
materials can also contain up to 60, preferably from 5 to 50, in 
particular from 10 to 40, % by weight of fibrous or particulate fillers or 
a mixture of these. Fibrous fillers, such as glass fibers, carbon fibers 
of fibrous silicates, such as wollastonite, are preferred. Glass spheres 
can also advantageously be used. 
Where glass fibers are used, they may be treated with a size and an 
adhesion promoter to improve compatibility with the polyamide or the 
polyester. In general, the glass fibers used have a diameter of from 6 to 
20 .mu.m. These glass fibers can be incorporated both in the form of 
ground glass fibers and in the form of continuous strands (rovings). In 
the finished injection-molded article, the mean length of the glass fibers 
is preferably from 0.08 to 0.5 mm. 
As stated above, the amount of fillers can be up to 60, preferably up to 
50, in particular from 5 to 45, % by weight, based on the total weight of 
the molding material. 
In addition to the essential components (A) to (C), the novel molding 
materials can contain conventional additives and processing assistants. 
The amount of these is in general not more than 60, preferably not more 
than 50, % by weight, based on the total weight of the components (A) to 
(C). 
Examples of conventional additives are stabilizers and antioxidants, heat 
stabilizers and UV stabilizers, lubricants and mold release agents, 
colorants, such as dyes and pigments, and elasticizers. 
Antioxidiants and heat stabilizers are, for example, halides of metals of 
group I of the periodic table, for example sodium halides, potassium 
halides and lithium halides, if necessary in combination with copper(I) 
halides, for example chlorides, bromides or iodides. Sterically hindered 
phenols, hydroquinones, substituted members of this group and mixtures of 
these compounds, preferably in concentrations of not more than 1% by 
weight, based on the weight of the mixture, can also be used. 
Examples of UV stabilizers are various substituted resorcinols, 
salicylates, benzotriazoles and benzophenones, which are generally used in 
amounts of not more than 2% by weight. 
Lubricants and mold release agents, which as a rule are added in amounts of 
not more than 2% by weight, based on the thermoplastic materials, are 
stearic acid, stearyl alcohol, alkyl stearates and stearamides as well as 
esters of pentaerythritol with long-chain fatty acids. 
The additives also include stabilizers which prevent the decomposition of 
the red phosphorus in the presence of moisture and atmospheric oxygen in 
the finished product. Examples of these are zinc oxide and cadmium oxide. 
In the novel process for the preparation of fireproofed thermoplastic 
molding materials which contain red phosphorus, an aqueous elastomer 
composition B of the composition stated in claim 1 is mixed into a melt of 
the polyester or polyamide or a mixture of these (component (A), the 
amount of the red phosphorus being from 3 to 20% by weight, based on the 
total weight of the molding material, and the relative amounts of 
component (A) and of component (B) each being from 10 to 90% by weight. 
Of course, the phosphorus content of from 3 to 20% by weight is influenced 
by appropriately selecting the amounts of components (A) and (B) and by 
the composition of the elastomer composition (B) itself, and can also be 
established in this manner. 
The amount of red phosphorus is preferably from 4 to 16% by weight, based 
on the total weight of the thermoplastic molding materials. 
It is possible to prepare a masterbatch of the elastomer composition in a 
small amount of a polyamide, to mix the elastomer composition into the 
melt of the polyamide or of the polyester or of a mixture of these, and to 
mix this mixture thoroughly and extrude it in an extruder and then, in a 
second operation, again to mix the product obtained in the first extrusion 
with further thermoplastic, i.e. polyester or polyamide, in an extruder. 
The water present in the aqueous elastomer composition is preferably 
removed during the extrusion in the extruder, by appropriate means, which 
are known per se. 
Any fillers C present are preferably added during the final mixing of the 
components in the extruder; however, it is in principle also possible to 
add some or all of the fillers during the preparation of the 
above-described masterbatch or polyamide or polyester and elastomer 
composition. 
However, it should be emphasized that the preparation of such a masterbatch 
is not absolutely essential; in many cases, it has even proven 
advantageous to mix all components directly in one operation in an 
extruder or an appropriate mixing apparatus, since this reduces the 
thermal load on the thermoplastic (since only a single melting process is 
required). 
Suitable mixing apparatuses are screw extruders, Brabender mills or Banbury 
mills, in which the components are usually mixed at from 220.degree. to 
300.degree. C. The mixing temperatures do of course depend on the type of 
thermoplastic used, i.e. on the type of polyester or type of polyamide. 
Novel molding materials can be converted, for example by injection molding, 
to moldings which have very low rubber contents and possess good 
mechanical properties, in particular good impact strength. The preparation 
as such is safer and much less of a health hazard than the incorporation 
of red phosphorus by mixing in a conventional manner. 
The molding materials according to the invention are suitable for the 
production of moldings, for example for the electrical sector, the 
building sector and the automotive sector. It is also possible to produce 
films, fibers and sheets from the novel molding materials.

EXAMPLES 
Preparation of the aqueous elastomer composition 
A dispersion of a core/shell polymer which had a core of n-butyl acrylate 
and dihydrodicyclopentadienyl acrylate (weight ratio 98:2) and a shell of 
n-butyl acrylate and methacrylic acid (weight ratio 98:1.5) and a 
core/shell weight ratio of 60:40 and which had been obtained by emulsion 
polymerization in a conventinal manner was mixed with red phosphorus and 
the sodium salt of a C.sub.12 -C.sub.18 -alkanesulfonic acid in a stirred 
kettle at room temperature. The mixing time was 30 minutes. 
Composition of the elastomer dispersion: 
52.3% by weight of elastomer 
47.2% by weight of water 
0.5% by weight of the sodium salt of a C.sub.12 -C.sub.18 -alkanesulfonic 
acid. 
0.9 g of the abovement emulsifier and 51.9 g of red phosphorus were added 
to 47.2 g of this dispersion. 
A stable, free-flowing and pumpable dispersin of the following composition 
was obtained: 
______________________________________ 
24.7% by weight of elastomer 
(b.sub.1) 
51.9% by weight of red phosphorus 
(b.sub.2) 
22.2% by weight of water (b.sub.3) 
1.2% by weight of emulsifier 
(b.sub.4) 
______________________________________ 
Preparation of the novel molding materials (Examples 1 to 3) 
The following components were used: 
Component A: 
Polyhexamethyleneadipamide (nylon 6,6) having a relative viscosity of 2.6, 
measured in 96% strength sulfuric acid (1 g/100 ml) at 25.degree. C. 
(Ultramid.RTM.A3 from BASF AG). 
Component B: 
Elastomer composition as described above. 
Component C: 
Glass fibers. 
64.5 kg of the polyamide (A) were melted in an extruder at 280.degree. C., 
and 13.6 kg of the elastomer dispersion (B) and 25 kg of glass fibers were 
mixed into this melt (Example 1). In the Examples 2 and 3, the amount of 
polyamide was reduced to 63.8 kg and in addition 0.7 kg of cadmium oxide 
or zinc oxide was added as the phosphorus stabilizer. 
In Comparative Examples 4 and 5, the red phosphorus was incorporated in 
powder form into the molding materials, a rubber whose composition 
corresponded to that of elastomer b.sub.1 of the elastomer composition 
additionally being added in Example 5. 
After mixing in the extruder, the molding materials were estruded, 
granulated, and processed to test specimens by injection molding. 
The water liberated in the novel molding materials during mixing was 
removed via an apparatus on the extruder. 
The results of the impact strength measurements according to DIN 53,453, of 
the damaging energy according to DIN 53,443, of the modulus of elasticity 
according to DIN 53,457 and of the tensile strength according to DIN 
53,455, as well as the results of the flame test according to UL 94, are 
reproduced in Table 1. 
The determination of soluble phosphorus was carried out after storage of 
standard small bars for 30 days in water at 80.degree. C. 
TABLE 1 
______________________________________ 
Example No. 1 2 3 4V* 5V* 
______________________________________ 
Component 
A (% by weight) 64.5 63.8 63.8 68.0 53.3 
b.sub.1 (% by weight) 
3.36 3.36 3.36 -- 14.0 
b.sub.2 (% by weight) 
7.0 7.0 7.0 7.0 7.0 
b.sub.4 (% by weight) 
0.14 0.14 0.14 -- -- 
C (% by weight) 25.0 25.0 25.0 25.0 25.0 
Further additives (% by weight) 
-- 0.7 0.7 -- 0.7 
CdO ZnO CdO 
Impact strength a.sub.n 
53 50 55 35 50 
kJ/m.sup.2 at 23.degree. C. 
Damaging energy W.sub.50 
10 11 11 -- 11 
Nm (23.degree. C.) 
Modulus of elasticity 
7200 7000 7100 9000 5800 
N/mm.sup.2 
Tensile strength 116 110 116 160 93 
N/mm.sup.2 
Rating according to UL 94 
V-0 V-0 V-0 V-0 V-0 
(3 mm flat bars) 
ppm of P after 30 d 
190 60 80 105 40 
______________________________________ 
*Comparative Examples 
The results in Table 1 show that the novel molding materials, with 
substantially lower rubber contents than in Comparative Example 5, possess 
good impact strength and, because of the lower rubber content, the modulus 
of elasticity and the tensile strength are substantially better than in 
the case of conventional toughened polyamides having a higher rubber 
content.