United States Patent O?ce
3,491,042
Patented Jan. 20, 1970
2
lised without the above mentioned disadvantages by us
ing as stabiliser a combination of a copper compound
3,491,042
with a salt of hydrocyanic acid. Examples of such salts
of hydrocyanic acid are: Alkali metal cyanides, alkaline
earth cyanides, substituted or unsubstituted ammonium
STABILIZED POLYAMIDE COMPOSITION CON
TAINING COPPER SALTS IAN
METAL
CYANIDES
-
?
cyanides, Zn(CN)2, Cd(CN)2, Ph(CN)2, TlCN and
Karl Heinz Hermann, Krefeld-Bockum, Germany, as
signor to Farbenfabriken Bayer ‘Aktiengesellschaft,
Leverkusen, Germany, a corporation _’of Germany
No Drawing. Filed Mar. 3, 1967', Ser. No. 620,276
Claims priority, application Germany, Mar. 12, 1966,
48
-
double salts such as K2Cd(CN),, and K2Zn (CN)4. Exam
ples of copper compounds which may be used are salts
of inorganic acids such as Cu(II)‘Cl2, Cu(I)Cl, Cu(II)Br2,
10 Cu(I)Br, Cu(I)I, Cu(I)CN, Cu(II)SO4 etc., salts of or
ganic carboxylic acids, e.g., Cu-acetate, Cu-stearate, Cu
Int. Cl. C08g 51/56, 51/52
U.S. Cl. 260—18
benzoate etc., salts of monofunctional of polyfunctional
7 Claims
ABSTRACT OF THE DISCLOSURE
15
phenols, and furthermore, complex compounds of these
copper salts with ammonia, amines, amides, lactams,
phosphites, phosphines etc. The cyanides may be added
in such quantity that the molar ratio of CNzCu is from
1:10 to 50:1, preferably from 1:2 to 20:1.
The copper compounds are advantageously added in
such a quantity that the polyamide contains 0.0001-0.2
salt of hydrocyanic acid and optionally in addition there
20 and preferably 0.001—0.02% by weight of copper. The
to, an iodine compound or a phosphorous compound.
stabiliser effect can be increased by the addition of halo
A polyamide composition stabilizedagainst degrada
tive effects of heat and oxygen, containing as stabilizers
a combination of inorganic or organicicopper salt and a
gen compounds, preferably iodine compounds, and/or
phosphorus compounds, e.g. by the addition 'of alkali
The present invention relates to polyamides which are
stabilized by means of a combination of copper com
pounds and salts of hydrocyanic acid. Shaped articles,
metal iodides or alkaline earth iodides, iodides of strong
25 organic bases, polyiodides, iodine, aromatic iodine com
pounds, phosphites and phosphines. The iodine com
pound or the phosphorus compound may be added in
amounts of between 0.01 to 5% by weight based on the
total weight of the polyamide composition.
their lactams show a reduction in theirrelative viscosities
The stabilisers may be added to the polyamide form—
and an impairment of their mechanical strength and elon 30 ing starting mixture before polymerisation, and polym
gation properties, when subjected to the action of air and
erisation may then be carried out in known manner, either
oxygen especially at elevated temperatures. At the same
such as ?laments, bristles, foils etc. made of polyamides
which have been obtained by polymerisation of diamines
and dicarboxylic acids, or of aminocarboxylic acids of
continuously or batchwise; alternatively, the stabiliser
time, the polyamide undergoes increasing brown dis
combination, either all the components together or sepa
rately and if desired in the form of a concentrate in poly
It is already known that polyamides may be protected 35 amide,
may be mixed to the polyamide melt during or
against the damaging effects of air and oxygen at ele
after polymerisation. The usual mixing devices, such as
vated temperatures by the addition of stabilisers. Exam
extruders, kneaders, stirrers etc., may be used for this
ples of compounds which have already been proposed for
coloration.
‘
g
use as stabilisers are as follows: Manganese salts of in
organic and organic acids, copper salts of inorganic and
organic acids, derivatives of oxyacids of phosphorus, aro
matic amines and phenols. The use of combinations of
these groups of compounds with each other or with com
operation. The usual additives, such as pigments, dyes,
40
light stabilisers, optical brightening agents, ?llers such
as glass ?bres or asbestos ?bres, lubricants and mould
parting agent, plasticisers, crystallising agents, ?llers such
as the polyamides in addition to stabilisers. The poly
amides which have been stabilised according to the inven
pounds such as alkali metal halides, alkaline earth halides, 45 tion, especially against damage by oxidation at elevated
iodine, arylsulphonic acids, mercaptobenzimidazole etc.
temperatures, are particularly suitable for use in produc
which when used alone have no stabiliser effect, has been
tion of arti?cial silk for ?shing nets, drive belts, conveyor
found to be preferable.
belts, conveyor bands etc., tyre cords and moulded arti
The stabilisers hitherto used have the disadvantage that
cles which are exposed to heat within the presence of air
either their stabilising effect is not sufficient, as in the 50 or oxygen.
case of manganese salts, phosphorus compounds and phe
The following examples illustrate more particularly the
nols, or that they are sensitive to light and therefore cause
invention.
discoloration of the polyamide in theicourse of time, e.g.
EXAMPLE 1
aromatic amines and phenols.
1 kg. of a colourless polycaprolactam of relative viscos
The addition of copper salts, which are highly effective 55
ity 3.12 (measured on a 1% by weight solution in m
stabilisers, leads to discoloration of the polyamide. In
cresol at 25° C. in an Ubbelohde Viscosimeter) which
addition, when polyamidesv stabilised with the copper
has been prepared in the usual way is melted in a con
stabilisers hitherto known are coloured with pigments
ventional screw extruded and is at the same time homoge
containing sulphur or selenium, e.g. cadmium sulphide;
cadmium selenide, ultramarine, etc., it is not possible to 60 neously mixed with various stabilisers. The polycap
rolactam which contains stabiliser is spun to form a
obtain pure colour tones but only discolored yellow, red,
‘bristle of about 3 mm. diameter, which is then chopped up
blue and mixed colour tones owing to the small quanti
to form a granulate and dried. The granulate is then
ties of sulphides or selenides of monovalent or divalent
copper formed as a result of reaction between copper
stored in a drying cupboard at 150° C. with free access
compounds and pigment. The stabilising effect diminishes 65 of air, and its relative viscosity is measured after 144,
in proportion to this discoloration.
It has now been found that polyamides can be stabi
500 and 1,000 hours.
The results of the tests are shown in Table I.
3,491,042
TABLE I
Relative viscosity after—
.
Percent
Serial
No.
Copper compound
Molar
Cu in Further
polyamide additives
G.
G. Percent Cyanide
ratio Colour of
G. CuzCN polyamide
0 012 ________________________ .. KCN
0 012 ________________________ ._ KCN
0.012 KI
2.0
0.2 KCN
0 012 KI
2.0
0.2 Zn(CN)2
0.46
0.92
0.92
0 012 KI
0.012 KI
0.66
0.92
2.0
2.0
0.83
Colourless... 3.24
__'...do....... 3.22
_-_-. 0.
_. .22
-..__ 0___ 3.18
1:16 .....do1:8 .____d0_
3. 19
3.15
4.12
4.05
1, 000
hours
3.01
2.94
3. 84
3.80
2.68
2.60
3.62
3.52
___ 3.20
.._ 3.19
4.01
3.96
3.75
3.69
3.47
3. 34
___0.012 KI
2.0
0.2 KCN
0 84
1:16 _..._ O. 8.16
______________________________________________________________________________________________________________________ -. 3.09
3. 92
2.73
3.65
2.36
3.32
2.18
EXAMPLE 2
0.2 Zn(CN)2
0.2 KCN
1:4
1:8
1:8
: 1:8
Mix144
500
ing hours hours
15 of hydrocyanic acid being selected from the group con
sisting of KCN and Zn(CN)2.
The procedure carried out is the same as that of Ex
3. A polyamide'composition containing
ample 1, except that 3.5 g. of a cadmium sulphide pigment
(a) a copper compound selected from the group con
(Yellow 6G) are mixed in with the polyamide at the
same time as the stabilisers. The colours of the products
obtained are indicated in Table II.
29
sisting of CuCl2, CuCl, CuBr2, CuBr, CuI, CuCN,
CuSO4, copper acetate, copper stearate and copper
TABLE II
Percent
Serial
No.
Copper compound
G.
Molar
Cu in
_
polyamide Other additives
ratio
G. Percent Cyanide
_
G. Cu: CN Colour of polyamide
____________________________________________________________________________________________________________________________ .. Pure yellow.
0. 012
. KCN
0 46
0. 012
................ -- KCN
0. 92
1:8
D0.
0 92
1:8
D0.
0 83
1 66
0 92
1:8
1:16
1:8
D0.
D0.
Do.
1:8
D0.
0. 012
2. 0
0. 012
0. 012 KI
0. 012 Triphenylphosp
2. 0
2. 0
0.5
0. 012 Tridecylphosphite.-..
0. 012
KI ______________ .-
.-
_
.
.
Cu(I)I. ..
_______ ..
Cu(II;aeetate'HzO_.
.. C11(II C12 _________ _-
0. 2 Zn(CN)2 '
0. 2 Zn(G~N)2 '
0.05
CN
0. 1 KCN
0 92
2. 0
0. 2
KCN
1 84
1:16
D0.
2.0
0.2 KCN
1 84
1:16
D0.
............_....__-_..._. ....................... ._ Dirty, yellow-brown.
2. 0
0.
D0.
0. 012 Triphenylphosphine-_
0.5
.
Do.
0. 012
K
1. 0
D0,
2.0
Do,
Tridecylphosphite- -. -
0.012 KI __________________ -_
25
1. 0
0. 2 KCN
1.4 Pure yellow, like 1.
0. 012
KI __________________ .-
2. 0
D0,
benzoate in an amoun of 0.0001 to 0.2 0 based on
EXAMPLE 3
40
.
t
.
'7
. .
the total’ weight
of
the
polyamide
composition
of
acid and a stabilser combination is polycondensed in an
autoclave in the usual manner at a temperature of 270°
C. The colour of the polyamide obtained is indicated in 4,
(b) a salt of hydrocyanic acid selected from the group
consisting of an alkali metal ‘cyanide, an alkaline
A mixture of 1.0 kg. caprolactam, 35 g. e-aminocaproic
copper.
earth metal cyanide, Zn(CN)2, Cd(CN)2, Pb(CN)2,
Table III.
TlCN, K2Cd(CN)4, and K2Zn(CN)4, in an amount
TABLE III
Percent
Serial
Cu in
No.
Copper compound
1 ________ .. Cu
G.
Molar
_ _
polyamide Other additives
Per-
G.
ratio
cent Cyanide
__________ -_ 0.27
.92
1:8
2-.
-- Cu(II)aoetate 1120.- 0 34
.66
1:
3-
-- ClJ(II)Clz-H2O .... -_
.
1:16
4.
..
5.
6.
7--
._ Cu(II)acetate-Hz0_. 0.34
.. Cl1(II)C12-2H2O...-- .32
.- Cu(II)Cl2-2H2O_---- 0.32
8..
.. Cu(II)acetate-Hz0.. 0.34
.32
u(I)Br __________ .. 0. 27
pound selected from the group consisting of CuCl2,
CuCl, CuBrz, CuBr, CuI, CuCN, CuSO4, copper acetate,
copper stearate, and copper benzoate, in an amount of 65
0.0001 to 0.2% based on the total weight of the poly
amide composition of copper and a salt of hydrocyanic
acid selected from the group consisting of alkali metal
cyanide, an alkaline earth metal cyanide, Zn(CN)2,
Colourless.
Do.
D0.
Green grey.
Red grey.
Green.
Do.
.. Blue red.
9 ............. ._do ............. _. 0. 34
What I claim is:
1. A polyamide composition containing a copper com
Colour of
G. CuzCN polyamide
....... .. Grey black.
such that the molar ratio of CN to Cu is in the range
from 1:10 to 50:1, and
(c) 0.01 to 5% based on the total weight of the poly
amide composition of an iodine compound selected
from the group consisting of an alkali metal iodide,
an alkaline earth metal iodide and iodine.
4. The polyamide composition of claim 3, wherein
said copper compound is selected from the group consist
ing of CuCl2, CuBr, CuI and copper acetate, said salt
Cd(CN)2, Pb(CN)2, TlCN, K2Cd(CN)4 and K2Zn(CN)4, 70 of hydrocyanic acid is selected from the group consisting
of KCN and Zn(CN)2, and said iodine compound is
in an amount such that the molar ratio of CN to Cu is in
the range from 1:10 to 50:1.
2. The polyamide composition of claim 1, wherein
said copper compound is selected from'the group con
sisting of Cu'ClZ, CuBr, CuI and copper acetate, said salt 75
potassium iodide.
‘
5. A polyamide composition containing
(a) a copper compound selected from the group con
sisting of CuClZ, CuCl, CuBr2, CuBr, CuI, CuCN,
5
3,491,042
CuSO4, copper acetate, ‘copper stearate and copper
benzoate, in an amount of 0.0001 to 0.2% based on
the total weight of the polyamide composition of
is triphenylphosphine.
copper,
(b) a salt of hydrocyanic acid selected from the group
consisting of an alkali metal cyanide, an alkaline
References Cited
earth metal cyanide, Zn(CN)2, Cd(CN)2, Pb(CN)2,
UNITED STATES PATENTS
TICN, K2Cd(CN)4, and K2Zn(CN)4, in an amount
such that the molar ratio of CN to Cu is in the range
from 1:10 to 50:1, and
(c) 0.01 to 5% based on the total weight of the poly
amide composition of a phosphorus compound
selected from the group consisting of a phosphite and
a phosphine.
6. The polyamide composition of claim 5, wherein
said copper compound is selected from the group con
2,510,777
6/ 1950
2.705,227
3/1955
Stamato? ________ __ 260—4S.7
3.340227
9/1967
Krieger _________ __ 260——45.75
906,893
839,067
said copper compound is selected from the group con
sisting of CuClz, CuBr, CuI and copper acetate, said salt
of hydrocyanic acid is selected from the group consisting
of KCN and Zn(CN)2, and said phosphorous compound
is tridecylphosphite.
7. The polyamide ‘composition of claim 5, wherein
6
sisting of CuCl2, CuBr, CuI and copper acetate, said salt
of hydrocyanic acid is selected from the group consisting
of KCN and Zn(CN)2, and said phosphorous compound
Gray ____________ __ 260—4S.7
FOREIGN PATENTS
2/1946 France.
6/ 1960 Great Britain.
DONALD ‘E. CZAJA, Primary Examiner
V. P. HOKE, Assistant Examiner
20
US. Cl. X.R.
260—37, 45.7, 45.75, 45.9
UNITED STATES PATENT OFFICE
CERTIFICATE OF CORRECTION
Patent No.
Inventor(s)
Dated
January 20,
Karl Heinz Hermann
It is certified that error appears in the above-identified patent
and that said Letters Patent are hereby corrected as shown below:
EOEUIEM 215E
4
511505
Table I
Column G.
"0.66" should read —-——l.66-—-‘.
after Cyanide
3
42
"0.84" should read —-—l. 84~-~-.
4
16
"Zn (CN)2 should read --—Zn(ZN) 2
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