Note: Descriptions are shown in the official language in which they were submitted.
201~999
o.z. 0050/40863
Thermoplastic moldin~ material~ of partly arom~tic and
amorphous copolyamides
The present invention relates to thermopla~tic
molding mnterial~ containing, as essential components,
A) from 20 to 98~ by weight of a partly aromatic co-
polyamide consisting essentially of
al) from 40 to 90% by weight of units which arederived from terephthalic acid and hexa-
methylenediamine,
a2) from 0 to 50% by weight of units which are
derived from ~-caprolactam and
a3) from 0 to 60% by -~eight of units which are
derived from adipic acid and hexamethylene-
diamine,
components a2) and/or a3) accounting in total for not
les~ than 10% by weight of the total number of
` units,
B) from 2 to 80~ by weight of an amorphous polyamide
~; which differs from A)
~ 20 and furthermore
-~ C) from 0 to 50% by weight of a toughened elastomer and
D) from 0 to 60~i by weight of fibrous or particulate
fillers or à mixture thereof.
The present invention furthermore relates ~o the
use of thes- molding materials for the produetion of
fibers,~films and other moldings, and to the moldings
obtainable u~ing these molding materials as essential
eomponent~s.
EP-A 70 001 diseloses polyamide blends based on
partly ery-talline and amorphous eopolyamides. However,
~the toughness properties of the moldings produeed there-
from are unsatisfaetory.
Furth-rmore, EP-A 73 036 diselose~ toughened
polyamide blends whieh eonsist of partly erystalline and
amorphous eopolyamides-
;`~ In these blends, toughening with olefin eopoly-
`~` mers has an adverse effeet on the rigidity and solvent
~` ,
.: ~-:'
` ~ 20~5~9
- 2 - O.Z. 0050/40863
resi~tance.
It is an ob~ect of the present invention to pro-
vide thermoplastic molding materials which have a good
overall spectrum of mechsnical properties, in particular
S good toughness.
We have found that this ob~ect i9 achieved,
according to the invention, by the thermoplastic molding
materials defined at the outset.
Preferred materials of this type and their use
are described in the subclaims.
The novel thermoplastic molding materials con-
tain, a~ component A), from 20 to 98, preferably from 40
to 95, in particular from 60 to 90, % by weight of a
partly aromatic copolyamide having the composition des-
cribed below.
The partly aromatic copolyamide~ A) contain, as
component al)~ fxom 40 to 90% by weight of units which
are derived from terephthalic acid and hexamethylene-
diamine. A small amount of the terephthalic scid, pre-
20ferably not more than 10% by weight, based on the total
~` aromatic dicarboxylic acids used, can be replaced by
isophthalic acid or other aromatic dicarboxylic acids,
preferably those in which the carboxyl groups are in the
para position.
25In addition to the units which are derived from
terephthalic acid and hexamethylenedi~mine, the partly
aro~atic copolyamide~ contain units which are derived
from ~-caprolactam (a2) and/or units which are derived
from adipic acid and hexamethylenediamine (a3). -~
30The amount of units which are derived from ~-
caprolactam is not more than 50, preferably from 20 to
50, in particulsr from 25 to 40, % by weight, while the
amount of units which are derived from adipic acid and
hexamethylenediamine is not more than 60, preferably from
~ 3530 to 60, in particolar from 35 to 55, % by weight.
w~ The copoIyamides may contain both units of
~ caprolactam and unitR of adipic acid and
. ~
,~
.
::;
~` .
~, ;~
- 2~ ~9~9
- 3 - O.Z. 0050t40863
hexamethylenediamine; in this ca~e, it ~hould be ensured
that the amount of units which are free of aromatic
groups is not leisis than 10, preferably not lesis than 2C,
% by weight. The ratio of units which are derived from
S~-caprolactam to those derived from adipic acid and hexa-
methylenediamine is not sub~ect to any special
restriction.
Preferred copolyamides are those whose composi-
tion is within the pentagon defined by apices X1 to X5 in
10the ternary diagram, points X1 to X5 being defined as
followss
X~ 40~ by weight of units al)
60~ by weight of units a3)
X2 60% by weight of units a1)
1540% by weight of units a3)
X3 80% by weight of units a1)
5% by weight of units a2)
15~ by weight of units a3)
X~ 80% by weight of units a,)
2020% by weight of units a2)
,~ ~ S5 '50% by weight of units a1)
j50% by weight of units a2)
\In the Figure, the pentagon defined by these
points is represented in a ternary diagram.
; 25Poly~mideJ containinq from 50 to 80, in particu-
lar from 60 to 75, % by weight of units which are derived
from terephth~lic acid and hexamethylenediamine (units
; al)) and from 20 to 50, preferably from 25 to 40, % by
weight of units which are derived from e-caprolactam
30(units ~2) ) have proven particularly advantageous for many
~i iintended uses-
; In addition to the units al) to a3) described
above, the novel partly aromatic copolyamides may also
contain minor amounts, preferably not more than 15, in
35particular not more th~n 10, % by weight of further poly-
amide building blocks, as known for other poly~mides.
These building blocks may be derived from dicarboxylic
20~9~9
- 4 - O.Z. 0050/40863
acids of 4 to 16 carbon atoms and aliphatic or cyclo-
aliphatic diamines of 4 to 16 carbon atoms as well as
from aminocarboxylic acids or corresponding lactam~ of 7
to 12 carbon atoms. Suberic acid, azelaic acid, sebacic
5acid and isophthalic acid may be mentioned here as typ$-
cal dicarboxylic acids, 1,4-butanediamine, 1,5-pentane-
diamine, piperazine, 4,4'-diaminodicyclohexylmethane,
2,2-(4,4'-diaminodicyclohexyl)-propaneand3,3'-dimethyl-
4,4~-diaminodicyclohexylmethane may be mentioned as
10typical diamines, and capryllactam, enantholactam, omega-
aminoundecanoic acid and laurolactam may be mentioned as
typical lactams and aminocarboxylic acids, these being
merely some suitable monomers of this type.
The melting points of the partly aromatic copoly-
15amides A) are from 260 to more than 300C, this high
melting point also being associated with a high glass
~; transition temperature of, as a rule, more than ~5C, in
particular more than 85C.
Binary copolyamides based on terephthalic acid,
20hexamethylenediamine and ~-caprolactam have melting
points in the range of 300C and a glass transition
temperature of more than 100C with contents of about 70%
by w~ight of units which are derived from terephthalic
acid and hexamethylenediamine.
25Binary copolyamides based on terephthalic acid,
adipic acid and hexamethylenediamine (HMD), have melting
points of 300C or more even with lower contents of about
55% by weight of units derived from terephthalic acid and
~- hexamethylenediamine, the glass tran~ition temperature
30not being quite as high as in the case of binary copoly-
, ~amides whi¢h contain ~-caprolactam instead of adipic acid
or adipic acid/HMD.
The partly aromatic copolyamides A) can be prep-
ared, for example, by the process described in EP-A 129
35195 and EP-A 129 196.
In this proce~s, an aqueous 301ution of the mono-
mers, ie. in this case the monomers which form the units
,
.~ .
~ ~ .
~ ~ 2 ~
- 5 - O.Z. OOS0/40863
a,) to a3), i~ heated to 2s0-300C under superatmo~pheric
pres~ure with ~imultaneou~ evaporation of water and
formation of a prepolymer, the prepolymer and vapGrs are
then sepsrated continuou~ly, the vapors are rectified and
the entrained diamines are recycled. Finally, the pre-
polymer is passed into a polyconden~ation zone and i8
sub~ected to polycondensation under ~uperatmospheric
pres~ure of from 1 to 10 bar and at from 250 to 300C.
The essent$al feature of the process i~ that the aqueous
~alt so}ution i~ heated under superatmospheric pressure
of from 1 to 10 bar in the course of a residence time of
less than 60 seconds, the conversion advantageously being
not less than 93% and the water content of the prepolymer
not more than 7% by weight on emergence from the
evaporator zone.
Because of these short residence times, the
formation of triamines is substant$ally prevented, so
that the partly aromatic copolya~ides A) generally have
triamine contents of, preferably, less than 0.5, in par-
ticular less than 0.3, % by weight. High triamine con-
tents may lead to a deterioration in the product quality
and to problems with the continuous preparation of the
partly aromatic copolyamides. A particular example of a
triamine which may cause such problems is dihexa-
methylenetriamine, which is formed from the hexa-
methylenediamine used as a monomer.
The aqueous solutions used have, as a rule, a
monomer content of from 30 to 70, in particular from 40
to 65, % by weight.
The aqueous salt solution is advantageously
; passed from 50 to 100C continuously into an evaporator
zone, where the aqueous salt solution is heated to 250 to
330C under superatmospheric pressure of from 1 to 10,
preferably from 2 to 6, bar. Of course, the temperature
used is above the melting point of the particular poly-
amide to be prepared.
AS stated above, it is essential that the
l~., . . , - . . . ~ . .
~a~ 5~9
- 6 - O.Z. 0050/40863
residence time in the evaporator zone i8 not more than
60, preferably from 10 to 55, in particular from 10 ~o
40, seconds.
The conversion on emergence from the evaporator
zone i8 advantageously not less than 93, preferably from
95 to 98% and the water content is preferably from 2 to
5, in particular from 1 to 3, ~ by weight.
The evaporator zone i9 advantageously in the form
of a tube bundle. Tube bundles in which the cross-
section of the individual tubes i8 alternately tubular
and slot-like have proven particularly useful.
Furthermore, it has proven advantageous if the
mixture of prepolymer and vapor is passed through a
tubular mass transfer zone provided with baffles, im-
mediately after the evaporator zone, before separation of
the phase~. The temperatures and pres~ure conditions
used in the evaporator zone are maintained here. The
baffles, for example packing, such as Raschig rings,
metal rings or, in particular, wire mesh packing, create
~ 20 a large surface area. The pha~es, ie. prepolymer and
-~ vapor, are brought into intimate contact as a resul~.
,,
- ~ Consequently, the amount of diamine liberated with steam
is considerably reduced. As a rule, a residence time of
from 1 to 15 minutes is maintained in the mass transfer
~; 25 zone, which i8 advantageously in the form of a tube
bundle.
The two-phase mixture of vapor and prepolymer
emerging from the evaporator zone or mass transfer zone
is separated. As a rule, separation take~ place auto-
matically on the bas$s of the physical differences in a
; vessel, the lower part of the vessel advantageously being
in the form of a polymerization zone. The vapors libera-
ted essentially consist of steam and diamines, which have
been liberated during vaporization of the water. $hese
`~ 35 vapors are passed into a column and rectified. Bxamples
of ~uitable columns are packed columns, bubble tray
columns or sieve tray columns having from S to 15
.
`~
:~;- ' ` ' . ~:
2 ~
- 7 - O.Z. 0050/40863
theoretical plates. The column i8 advantageously operat-
ed under pre~ure conditions identical to those in the
evaporator zone. The diamines present in the vapo~s are
iseparated off here and are recycled to the evaporator
zone. It ii~ also possible to feed the diamines to the
downstream polymerization zone. The rectified steam ob-
tained is taken off at the top of the column.
The resulting prepolymer, which, depending on it~
conversion, consi~t~ essentially of low molecular weight
polyamide and may contain residual amounts of unconverted
salts and as a rule has a relative viscosity of from 1.2
to 1.7, is pas~ed into a polymerization zone. In the
polymerization zone, the melt obtained is sub~ected to
polycondensation st from 250 to 330C, in particular from
270 to 310C, and under superatmo3pheric pre~ure of from
1 to 10, in particular from 2 to 6, bar. Advantageously,
the vapors liberated here are rectified toge~her with the
abovementioned vapor~ in the column; preferably, a resid-
ence time of from 5 to 30 minutes is maintained in the
polycondensation zone. The resulting polyamide, which as
a N le has a relative viscosity of from 1.2 to 2.3, is
~ removed continuously from the condensation zone.
-~ In a preferred procedure, the polyamide thus ob-
tained i~ passed in the form of a melt through a di~-
charge zone with simultaneous removal of the residual
~;~; water present in the melt. Suitable discharge zones are,
` for example, devolatilization extruders. The melt freed
fro~ water in this manner is then extruded and the ex-
trudate~ are granulated. The resulting granule- are
advantageou~ly sub~ected to solid phase condensation
~i using superhei~ted steam at below the melting point, for
example from 170 to 240C, until a desired viscosity i9
obtained. The steam obtained at the top of the column is
advantageously used for this purpose.
The relative viscosity, measured in 1~ strength
solution (1 g/100 ml) in 96~ strength by weight H2S0~ at
23C, is generally from 2.2 to 5.0, preferably from 2.3 ;~
~ ~ -
~--s; , ^, -,,-,~ - " ~ " ~ ~ ~
- 2 ~
.
- 8 - O.Z. 0050/40863
to 4.5, after the solid pha~e po~tconden~ation.
In another preferred procedure, the polyamide
melt discharged from the polyconden~ation zone i9 pa~ed
into a further polycondensation zone, where it i~ sub-
S~ected to condensation with continuous formation of new
surfaces at from 285 to 310C, advantageously under
reduced pressure, for example from 1 to 500 mbar, until
the desired viscosity is obtained. Suitable apparatuses
are known a~ finisher~.
10Another process, which resembles that described
above, is described in EP-A 129 196, which may be refer-
red to for further details of the process.
The novel molding materials contain, as component
B), amorphous, partly aromatic copolyamides in an amount
15of from 2 to 80, preferably from 5 to 60, % by weight.
The~e preferably contain, as essential building
blocks,
b1) from 40 to 100, preferably from 50 to 99, % by
weight of units which are derived from hexa-
20methylenediamine and isophthalic acid and
b2) from O to 60, preferably from 1 to 50, % by weight
of units which are derived from hexamethylenediamine
and terephthalic acid.
Suitable aromatic dicarboxylic acid~ for the
~.~
25preparation of component B) of the novel molding mater-
ials are in general those of 7 to 20, preferably 8 to 14,
carbon atom~. Mononuclear dicarboxylic acids carrying
earboxyl groups in the meta or para position, e~pecially
isophth~lic acid and terephthalic acid, are part~cularly
suitable.
Other aromatic dicarboxylic acids are, for exam-
ple, 2,6-pyridinedicarboxylic acid, 1,4-naphthalenedicar-
boxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-
~;naphthalenedicarboxylic acid and 4,4-diphenylsulfone-
dicarboxylic acid. It is also possible to use mixtures
;~ of two or more aromatic dicarboxylic acids, mixtures of
~ isophthalic acid with terephthalic acid being preferred.
~,' ~ ' '''`
~- 2~ 5~
- 9 - O.Z. 0050/40863
Suitable straight-chain or branched aliphatic or
cycloaliphatic diamines are in general those of 4 to 20,
preferably 6 to 12, carbon atoms. Hexamethylenediamine
and its alkyl-substituted derivatives, such as 2,2,4-
trimethylhexamethylenediamine, 2,2,5-trimethylhexa-
methylenediamine and tetramethyl-substituted hexa-
methylenediamines are particularly preferred.
Other suitable diamines are tetramethylenedi-
amine, pentamethylenediamine, 2-methylpentamethylene-
diamine, 2-methylhexamethylenediamine, 3-methylhexameth-
ylenediamine, 3,4-dimethylhexamethylenediamine, 2,4,4-
trimethylhexamethylenediamine, 2-methyl-4-ethylhepta-
methylenediamine, octamethylenediamine, nonamethylenedi-
amine, decamethylenediamine, undecamethylenediamine and
dodecamethylenediamine, as well as diamines of the
general formula
Rl
H 2N{;}~NH 2
R 2 R I R ~
where Rl is hydrogen or methyl and R2 and R3 are each
hydrogen or C1-C~-alkyl. Preferred alkyl groups are ethyl -~
;` and especially methyl.
It is also possible to use mixtures of two or
more diamines.
The amorphous copolyamides B) have a relative -~
viscosity of from 1.4 to 3.4, preferably from 1.5 to 2.8,
measured in a 1% strength by volume solution in 96%
. ~. " ,
strength by weight sulfuric acid at 23C.
The polyamides 8) are generally prepared batch-
wise or continuously, but preferably by continuous poly-
condensation processes, a~ described in ~P-A 129 195 and
~ 129 196.
"~ 30 The novel thermopla~tic molding matsrials may
contain, as a further component C), a rubber impact
modifier (elastomer) in amounts of not more than 50,
prefer~bly from 2 to 40, in particular from 5 to 30, % by
~x ~
- 2 0 ~ 9
- 10 - O.Z. 0050/40863
weight.
Ela~tomers based on ethylene, propylene, buta-
diene or acrylate~ or mixtures of these monomer~ may be
mentioned merely as example~ of rubber impact modifiers.
Polymers of this type are described in, for exam-
ple, Houben-Weyl, Methoden der organischen Chemie, Vol.
14/1 (Georg-Thieme-Verlag, Stuttgart, 1961), pages 392-
406, and in the monograph by C.B. Bucknall, Toughened
Plastics (Applied Science Publishers, London, 1977).
Some preferred types of such elastomers are des-
cribed below.
A first preferred group comprises the ethylene/
propylene (EP) and ethylene/propylene/diene (EPDM) rub-
bers, which preferably have a ratio of ethylene radicals
lS to propylene radicals of from 40 : 60 to 65 s 35.
The Mooney viscosities (MLI+4/100C) of such un-
crosslinked EP or EPDM rubbers (gel contents generally
below 1% by weight) are preferably from 25 to 100, in
~ particular from 35 to 90 (measured using the large rotor
- 20 after a running time of 4 minutes at 100C according to
DIN 53 523).
`~ EP rubbers generally have virtually no double
bonds, whereas EPDM rubbers may have from 1 to 20 double
bonds per 100 carbon atoms.
Examples of diene monomers for EPDM rubbers are
con~ugated dienes, such as 130prene and butadiene, non-
con~ugat-d dienes of 5 to 25 carbon atoms, such as 1,4-
butadiene, 1,4-hexadiene, l,S-hexadiene, 2,5-dimethyl-
1,5-hexadiene and 1,4-octadiene, cyclic dienes, such as
- 30 cyclopentadiene, cyclohexadiene, cyclooctadiene and di-
cyclopentadiene, and alkenylnorbornenes, such as 5-
ethylidene_2-norbornene, 5-butylidene-2-norbornene, 2-
methallyl-5-norbornene or 2-isopropenyl-S-norbornene and
tricyclodienes, such as 3-methyltricyclotS.2.1Ø2.6]-
3,8-decadiene, or mixtures thereof. l,S-Hexadiene, 5-
ethylidenenorbornene and dicyclopentadiene are preferred.
The diene content of the EPDM rubbers is prefer~bly from
',, " ~; ' 1 `
',:' , ;' :
.
~`` 20~L~$~9
- 11 - O.Z. 0050/40863
0.5 to 10, in particular from 1 to 8, ~ by weLght, based
on the total weiqht of the rubber.
EP and EPDM rubbers may also be grafted with
reactive csrboxylic acids or their derivatives. Acrylic
acid, methacrylLc acid and their derivatives and maleic
anhydride may be mentioned here merely as typical
examples.
Another group of preferred rubber~ comprises co-
polymers of ethylene with acrylic acid and/or meth-
acrylates, in particular those which additionally contain
epoxy group~. These epoxy groups are preferably ineor-
porated in the rubber by adding monomers which contain
epoxy groups and are of the general formula II or III
CHR3=CH--~CH2) ~ ~CHRl)--CH--CHR~
~ m n
CHR~=CRS--coo-(cH2)p-c\7 HR6 (III)
where Rl, R2, R3, R~, R5 and R6 are each hydrogen or alkyl
of 1 to 6 carbon atoms, m is an integer of from 0 to 20,
n i9 an inteqer of from 0 to 10 and p i~ an integer of
from 0 to 5.
Rl, RZ and R3 are eaeh preferably hydrogen, m is
preferably 0 or 1 and n is preferably 1. The correspond-
ing compounds are alkyl glyeidyl ethers or vinyl glycidyl
ethers.
Preferr~ed examples of compounds of the formula
III~re es~era of aerylic aeid and/or methacrylie aeid
which contain epoxy groups, of whieh esters glyeidyl
aerylate and glyeidyl methaerylate are partieulsrly
preferred.
, ~ .
The ethylene eontent of the copolymers is in
general from 50 to 98% by weight, the content of monomers
`~ eontaining epoxy groups and the content of aerylates
nd/or meth~crylates are eaeh from 1 to 49% by weight.
P~rtieularly preferred eopolymers are those eon~
; si~ting of
,~:
~ ~.
,~. ' .
-` 2015~9
- 12 - O.Z. 0050/40863
from 50 to 98.9, in particular from 60 to 95, % by weight
of ethylene,
from 0.1 to 40, in particular from 2 to 20, ~ by weight
of glycidyl acrylate, glycidyl methacrylate, acrylic acld
and/or maleic anhydride, and
from 1 to 4S, in particular from 10 to 35, % by weight of
n-butyl acrylate and/or 2-ethylhexyl acrylate.
Other preferred ester~ of acrylic and/or meth-
acrylic acid are the methyl, ethyl, propyl, isobutyl and
tert-butyl esters.
Vinyl ester~ and vinyl ethers can also be used as
copolymers.
The ethylene copolymers described above can be
prepared by conventional processes, preferably by random
copolymerization under superatmospheric pressure at
elevated temperatures. Appropriate processe~ are des-
cribed in the literature.
~; The melt flow index of the ethylene copolymers is
in general from 1 to 80 g/10 min (measured at 190C and
under a load of 2.16 kg).
Other preferred elastomers C) (rubbers) are graft
; copolymers with butadiene, butadiene/styrene, butadiene/
acrylonitrile and acrylates, as described in, for ex-
ample, DE-A-16 94 173 and DE-A-23 48 377.
Particular examples of these are the ABS poly-
mers, as described in DE-A-20 35 390, DE-A-22 48 242 and
EP-A-22 216, the latter being particularly preferred.
Graft polymers of
from 25 to 98% by weight of an acrylate rubber having a
glass transition temperature of less than -20C, as the
~ ~ grafting base,
;~ and
~ from 2 to 75% by weight of a copolymerizable ethylen-
`~ ically unsaturated monomer who~e homopolymers or co-
polymers have a glass transition temperature of more than
25C, as the graft,
may also be used as rubber C).
.. ,:.. ,. .: :.... ~ , - ,
' ~i ~ . '. .... - - : .'
2~ ~9~
- 13 - O.Z. 0050/40863
The grafting bases are acrylate or methacrylate
rubbers, and up to 40% by weight of further comonomers
may be present. The Cl-C~-esters of acrylic acid or
methacrylic acid and their halogenated derivative~ as
well as aromatic acrylates and mixtures thereof are
preferred. Acrylonitrile, methacrylonitrile, styrene, ~-
methylstyrene, acrylamides, methacrylamides and vinyl-Cl-
C6-alkyl ethers may be mentioned a~ comonomers in the
graftinq base.
The grafting base may be noncrosslinked or par-
tially or completely crosslinked. Crosslinkinq is
achieved by copolymerization of, preferably, from Q.02 to
5, in particular from 0.05 to 2, % by weight of a cross-
linking monomer having more than one double bond. Suit-
able crosslinking monomers are described in, for example,
DE-A-27 26 256 and EP-A-50 265.
Preferred crosslinking monomers are triallyl
cyanurate, triallyl isocyanurate, triacryloylhexahydro-
s-triazine and trialkylbenzenes.
If the crosslinking monomers have more than 2
polymerizable double bonds, it is advantageous to limit
their amount to not more than 1% by weight, based on the
;~ grafting base.
Particularly preferred grafting bases are emul-
sion polymers having a gel content of more than 60% by
weight (determined in dimethylformamide at 25C according
to M. Hoffmann, H. gr~mer and R. Ruhn, Polymeranalytik,
Georg-Thi _ -Verlag, Stuttgart, 1977).
`~ Other suitable grafting baffes are acrylate rub-
bers having a diene core, as described in, for example,
EP-A-50 262.
Particularly suitable graft monomer~ are styrene,
-methylstyrene, w rylonitrile, methacrylonitrile and
methyl methacrylate or mixtures thereof, in particular
those of styrene and acrylonitrile in a weight ratio of
from 90 s 10 to 50 s 50.
The grafting yield, ie. the quotient of the
2 ~
- 14 - o.Z~ 0050/40863
amount of grafted monomer and the amount of graft monomer
used is in general from 20 to 80~.
Rubbers based on acrylates, which may be used
according to the invention, are described in, for ex-
5ample, DE-A-24 44 584 and DE-A-27 26 256.
The rubbers C) preferably have a glass transition
temperature of less than -30C, in particular less than
-40C, which leads to good impact strength even at low
temperatures.
10Of course, it is also possible to use mixtures of
the abovementioned toughened elastomers.
The novel molding materials may contain, as com-
ponent D), not more than 60, preferably from 5 to 50, ~
by weight of fibrous or particulate fillers or mixtures
15thereof. Examples of fillers are asbestos, carbon fibers
or gla~s fibers in the form of woven gla~s fabrics, glass
mats or glass rovings, and wollastonite.
In addition to the components A) to D), the novel
molding materials may contain conventional additives and
20processing assistants. The amount of these i~ in general
not more than 20, preferably not more than 10, % by
weiqht, ba~ed on the total weight of components A) to D)~
Conventional additives are, for example, stabil-
izers and sntioxidants, heat stabilizers and W stsbil-
; 25izers, lubricants and mold release agents, colorants,
~such a8 dyes and pigments, plasticizers and flameproofing
~ agents.
`-~ Antioxidants and heat ~tabilizers which may be
added to the thermoplastic materials according to the
invention, are, for example, halides of metal~ of group
~I of the Periodic Table, for example sodium halides,
potassium halides or lithium halides, if necessary in
con~unction with copper(I) halides, eg. chlorides, brom-
ides or iodides. Sterically hindered phenols, hydro-
quinones, substituted members of this group and mixturesthereof can also be used, preferably in concentrations of
not more than 1% by weight, based on the weight of the
.
.
9 ~J,~
i;' '' `` ' ' ' i,
2 ~ 9
- 15 - O.Z. 0050/40863
molding material.
Examples of W stabilizers are various sub-
stituted resorcinols/ salicylate3, benzotriazol6s and
benzophenones, which are used in general in amounts of
5not more than 2.0S by weight.
Lubricants and mold release agents which as a
rule are added to the thermopla~tic molding material in
amount~ of not more than 1% by weight, are stearic acids,
stearyl alcohol, alkyl stearate~ and stearamides, a~ well
10as esters of pentaerythritol with long-chain fatty acids.
Red phosphoru~ and the other flameproofing agents
known in prineiple for partially crystalline polyamides
may be mentioned here merely as examples of flameproofing 5-~
agents.
15The novel molding materials can be prepared by
eonventional proeesses, by mixing the starting components
in a eonventional mixing apparatus, such as an extruder,
; a Brabender mill or a Banbury mill, and then extruding
the mixture. After extrusion, the extrudate is eooled ~ ~
20and comminuted. The mixing temperatures are in general -~ -
from 280 to 350C. -;~
It is also possible in prineiple, and ~ometimes
~, . ...
advantageou~, first to mix the low moleeular weight
eompone~nts A)~and B) and then to sub~eet the mixture to
25~ ~solid phase posteondensation.
;s;~The novel molding material~ possess a good over~
all peetrum of properties, in partieular good rigidity,
and are therefore~suitable for the produetion of moldings ~ -
of any type,~flbers and films.
EXAMPLES
`~ The following components were useds
Component A)
The preparation was carried out aeeording to
EP 129 195.
An aqueous solution, eonsisting of 35 kg of
c-eaprolaetam, 55 kg of terephthalie aeid, 38.5 kg of
hexamethrlenedlamine and 128.5 kg of water, was eonveyed
~.
.
- 2 ~
- 16 - O.Z. OOS0/40863
from a heated stock vessel at about 80C at a rate corres-
ponding to an amount of polyamide of 5 kg/hour, by means
of a metering pump, into a tubular evaporator arranged
partly horizontally and partly vertically. The
evaporator was heated with a liquid heating medium which
was at 295C, with vigorous circulation. The evaporator
had a length of 3 m, a capacity of 180 ml and a heat-
transfer surface area of about 1300 cm2. The residence
time in the evaporator was 50 sec. The mixture emerging
from the evaporstor and consisting of prepolymer and
steam had a temperature of 290C and was separated in a
separator into steam and melt. The melt remained in the
separator for a further 10 minutes and was then extruded
in an extruder having a devolatilization zone, and the
extrudate was solidified in a water bath and then granu-
lated. The separator and the evaporator zone were kept
under a pressure of 5 bar by a pressure control means
arranged downstream of the column. The steam separated
off in the ~eparator was fed to a packed column which had
about 10 theoretical plates and in which about 1 } of
vapor condensate per hour was addad at the top to
~ generate a reflux. The resulting temperature at the top
-~ of the column was 152C. The steam emerging down~trea~
; of the let-down valve was condensed and contained le88
than 0.05% by weight of hexame~hylenediamine and less
than O.l~i by weight of ~-caprolactam. An aqueous solu-
~ tion of hex~methylenediamine, which contained 80% by
;~ weight of hexamethylenediamine and from 1 to 3% by weight
of ~-caprolact~m, based in each case on the polyamide
produced, was obtained as the bottom product of the
column. The solution was recycled to the ~tarting salt
solution before entry into the evaporator, by means of a
~`~ pump.
Downstream of the evaporator, the prepolymer had
a relative viscosity of 1.25, measured in 96% strength by
weight sulfuric acid at 20C, and a conversion of from 93
to 95% according to terminal group analysis. The content
~ 2~15~9
....
- 17 - O.Z. 0050/40863
of bishexamethylenetriamine wa~ from 0.1 to 0.15% by
weight, ba~ed on polyamide.
After the polymer melt had emerged from the
separator, the polyamide had a very pale color, dn
extremely low content of 0.17% of bishexamethylenetri~
amine and a relative viscosity of from 1.65 to 1.80.
The product had roughly equivalent amounts of
terminal carboxyl and amino groups. --~
The content of extractables (extraction with
methanol) was from 3.1 to 3.3% by weight.
In the extruder, the melt was then let down to
atmospheric pressure and underwent virtually no further
condensation during a residence time of less than 1
minute. The resulting granules were condensed by con- ~-
lS tinuous solid phase condensation with superheated steam
at 195C during a residence time of 30 hours to a final
viscosity ~ rel of 2.50. The content of extractables was
then 0.2% by weight (extraction with methanol).
Component A ) (for comparison)
~20 Polyhexamethyleneadipamide having a relative vis-
;~ cosity of ... , measured in 96% ~trength by weight ~ul- e
furic acid (1 g/100 ml) at 23C.
Component B)
An amorphous copolyamide of
60% by weight of an equimolar mixture of hexamethylene-
diamine and isophthalic acid and
40% by weight of an equimolar mixture of hexamethylene-
diamlne and terephthalic acid
was~prepared by batchwise condensation of the components
in an autociave at 320C. The relative viscosity q rel
~, was 1.~, moasured in 96% strength by weight sulfuric acid
(1 g/100 ml) at 23C; the copolyamide had a glass transi-
tion temperature of 140C.
Components A) or A ) and B) were melted in a twin-
~` 35 screw extruder at 320C, the melt was extruded and the
:
extrudate was granulated. The granules were converted by
in~ection }ding into moldings in order to determine the
~ .
~ .'
2 ~ 9
- 18 - O.Z. 0050/40863
modulu~ of el~sticity (according to DIN 53 452), the
tensile strength (according to DIN 53 455), the Izod
notched impact strength (according to ISO 180, Method A)
and the notched impact strength (according to DIN 53
s 453)-
The composition of the mixture~ and the resultsof the measurements are shown in the Table.
TABLE
Test No. 1* 2 3 4* S* 6* 7*
Component A) [X by wt.] 100 95 80
Component A~) [X by wt.] - - - 100 98 95 80
Component B) [X by wt.] - 5 20 - 2 5 20
Modulus of
elasticity [N/mm2]2940 29002760 3180 3040 3060 2890
Tensile
strength [N/mm2]80 72 72 80.6 70.8 67.8 53.3
Izod notched impact
strength 23C [kJ/m2l2.4 1316.7 3.1 3.5 4.6
;~ -40C 1.5 1.610.5 1.5 2.0 2.1 5.1
Notched impact
~tren&th 23C [kJ/m2]2.8 4.210.1 3.6 2.5 2.7 5.3.
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