Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2022096
POLYAMIDE COMPOSITION
BACXG~OUND OF THE INVENTION
This invention relates to a polyamide composition,
and more particularly to a composition for making high
strength black nylon 6,6 fibre. ~-~
The term "high-strength" as used herein refers to ~ -~
nylon 6,6 fibre which has been drawn to a draw ratio of
between about 4.6 and 5.2, and which has a minimum tenacity
of 7.0 gra~s per denier.
To make black nylon 6,6 fibre, a concentrate of
carbon black in a nylon 6 carrier or the like may be
blended with molten nylon 6,6. It has been found by
applicant that when nylon 6,6 polymer is blended with
carbon black concentrate, the maximum draw ratio obtainable
with filaments formed from the polymer is generally about
4.3, which i8 unacceptably low for high-strength
applications.
It is desired to provide high strength, black nylon
6,6 fibre.
SUMMARY OF THE INVENTION
~ ~
Accordingly, the invention provides a polyamide
composition for use in making high strength black nylon 6,6
fibre, said composition comprising:
a) nylon 6,6 polymer;
b) at least 0.4 wt% of carbon black based on the
weight of said composition;
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c) in the range of about 0.006 to 0.1 wt% based on
the welght of fiaid composition of an organic pigment ~aving
a particle ~ize in the range o~ about 0.05 to 0.2 microns, :~
said pigment being heat ~table at the melting polnt of sald
nylon and being lnsoluble in sald nylon; ::~
wherein (a) (b) and ~c) are blended together at a
temperature at or above the melting polnt of said polymer
to provide an even dispersion of (b) and (c) in (a).
In another one of its aspects, the invention :~
provides high strength black nylon 6,6 fibre, said fibre
being made from a polyamide composition which is spun lnto
filaments and drawn to a draw ratio of about 4.6 to 5.2, .
said composition comprising:
a) nylon 6,6 polymer; ~ :~
b) at least 0.4 wt% of carbon black based on the
weight of said composition; :~
c) in the range of about 0.006 to 0.1 wt% based on . :
the weight of said composition of an organic pigment having
a particle size in the range of about 0-05 to 0.2 microns,
6aid pigment being heat stable at the melting point of said -~;:
nylon and being insoluble in said nylon;
wherein (a) (b) and (c) are blended together at a
temperature at or above the melting point of said polymer
to provide an even dispersion of (b) and (c) in (a).
In still another one of its aspects, the invention
provides a process for making high strèngth, blacX nylon
6,6 fibre, said process comprising the steps of: ~ -
blending together at a temperature at or above the
melting point of nylon 6,6 to provide a polyamide
composition, the following components~
a) nylon 6,6 polymer;
b) at least 0.~ wt% carbon black;
c) in the range of about 0.006 to 0.1 wt% based on ~
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the weiqht of said compositlon of an organic pigment having
a particle size in the r~nge of about 0.05 to 0.2 microns,
said plqment belng heat stable at the melting point of said
nylon and belng insoluble in sald nylon;
spinning sald composltion to form filaments;
drawing said filaments to a draw ratio ~n the range
of about 4.6 to 5.2.
It has been found by applicant that when carbon
black is added to nylon 6,6, the maximum draw ratio
obtainable in fibre prepared from nylon 6,6 is unacceptably
low for high-strength applications. With the present
invention, the draw rat~o of fila~ents made of nylon 6,6
containing carbon black can be raised to the acceptable
ranqe for making high-strength nylon 6,6 fibre.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
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The draw ratlo of filaments made from the
compo~ition of the present invention is preferably in the
range of about 4.6 to 5.2 and most preferably is in the
range of 4.75 to 5.2. Fibres that can only be drawn to a
ratio below thi~ range will generally be too physically
weak for high-strength fibre applications.
The organic pigment used in the present invention
may be any pigment that will allow processing of the
filaments of the polyamide composition at the acceptable
range of draw ratios for ma~ing high strength fibre. The
pigment is preferably indanthrone blue, alphaphthalocyanine
blue or phthalocyanine green. The amount of pigment used
is preferably between 0.010 and 0.067 wt% and is most
preferably between 0.010 and 0.040 wt% based on ths total ~;
weight of the composition.
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I~ too little pigment iB added, t~e draw ratio obtainable
wlll be too low and if too ~uch plgment iB added,
unacceptable tints in the fibre may develop, and the
strength obtalnable from the fibre composltion may be
limlted due the presence of excessive pigment. The mean
particle BiZQ of the pigment i8 preferably ln the range of
0.05 to 0.2 microns and is most preferably in the range of
o.OSS to 0.13 microns.
The amount of carbon black used should be sufficient
to impart a black colour to the yarn. Most preferably
about 0.4 to 1.3 wt% carbon black is used.
Preferably concentrates of both the organic pigment
and the carbon black are prepared by dispersing them in -
polymeric carriers before they are mixed with nylon 6,6
polymer, since it is difficult to mix powdered carbon black
and pigments directly with nylon 6,6 polymer. The
polymeric carriers are preferably nylon 6 and the like.
The carbon black concentrate may al60 contain other
additives including ionomer, lubricants and plasticizers
used to help provide good dispersion of the carbon black.
The amount of carrier used should be sufflcient to
facilitate the mixing of the nylon 6,6 polymer with the
pigment or with carbon black and all of the additives.
Alternatively, the pigment, the carbon blacX and all of the
additives may be combined with a single carrier to provide ~;
a pigment/carbon blacX concentrate.
The concentrates may be formed into pellets. These
pellets may then be added to nylon 6,6 flake and
subsequently extruded to form the polyamide composition.
Alternatively, the concentrates may be extruded separately ~- --
and then injected into an extruder containing molten nylon
~6,6. The method used to combine the pigment, carbon blacX
and nylon 6,6 i~ not essential to the invention, provided
that the carbon black and the pigment are evenly dispersed
in the polymer before it is spun into filaments.
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The lnventlon will be further de~cribed, by way of
illustration only, with referenc~ to the ~vllowlng
example~.
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EXAMPLe 1
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A dry blend of 300 grams of nylon 6,6 flake and 6
grams of black colour concentrate of the formula given in
Table 1 was extruded under nitrogen in a lab extruder at a
rate of 1 lb/hr at typical conditions for nylon 6,6 fibre
making processes. The resultant composition was spun into 7
filaments and attempts were made to draw the fibre with
rollers to a draw ratio of 4.79 and wind it up at 1082
meter6 per minute to make 44 dtex fibre.
It was found that it was impossible to run this
process as in all cases the fibre broke immediately as
attempts were made to string it up to the w~nder.
~ABLE 1
Black Colour Concentrate Formula
Nylon carrier resins 62.9 wt~
Hydrocarbon resin 4.8 wt%
Plasticizers and lubricants 5.2 wt~
Carbon 81ack 27.0 wt~
Soluble ~lue toner 0.3 wt%
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EX~LE 2
A dry blend of the same compo~ition as Example 1 wa~
prepared, except that about 1 gram of an organic pigment
concentrate comprising about 85 wt% nylon 6 and 15 wt~
indanthrone blue pigment of a mean particle size of about
o.l microns was also added to the blend. The blend wa~
extruded and spun into filaments and drawn a~ described in
Example 1 at draw ratios of 4.79 (Sample 1) and 5.12
(Sample 2).
No breakage of the fibre occurred and the fibre was
easily strung up to the winder. The physicals of the
resultant fibre are given in Table 2.
TA~LE 2 ~ -
Physical Properties
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Sample 1 Sample 2
Decitex: 44 42.0
Break Strength (N) 2.6 2.6
Elongation (%) 19.44 14.22
Tenacity (gram/denier) 6.7 7.03
Pigment in Fibre (wt%) 0.048 0.048
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These physical properties are acceptable from a ~ -
commercial viewpoint and, based on experiments with a broad
range of regular and coloured nylon 6,6 compositions, are
equivalent to a 7.5 gram per denier product at a draw ratio
of 4.8 when scaled up to a full commercial spinning
machine.
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EXAMPL~ 3
Dry blends of the same composition A8 Example 2 were
prepared, except that in one sample (Sample 3) 2.02 grams
of a p~gment concentrate containing 20 wt%
alphapthalocyanine blue of a mean particle size of 0.1
~icrons in a nylon 6 carrier was substituted for the
indanthrone blue concentrate and in another sample (Sample
4) 2.0 gram of a pigment concentrate containing lS wt%
phthalocyanine green of a mean particle size of 0.1 microns
in a nylon 6 carrier was substituted for the indanthrone
blue concentrate.
These samples were extruded, spun and drawn as
outlined in Example 1 and processed read~ly into f~bre
without breakage.
The physical properties of these samples are reported
in Table 3 below.
TABLE 3
Physical Properties
SamDle 3 ~ample 4
Decitex: 46 45-5
Break Strength (N) 2.5 2.5
Elongation (%) 16.75 18.58
Tenac$ty (gram/den,er) 6.0 6.16
These phy~ical properties are acceptable from a
commercial viewpoint and would translate to a 7.0 gram per
denier product at full commercial ~cale.
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EXA~L~ 4
Dry blends of the same composition as Example 2 were
prepared, except that in one sample (Sample 5) 2 grams of a
concentrate Or 20 wt% monoazo blue dye (a polymer-soluble
colourant) in a nylon 6 carrier was substituted for the
indanthrone blue concentrate and in another sample (Sample
6), 1 gram o~ a concentrate of anthraquinone red of a mean
particle diameter of 0.5 ~icrons in a nylon 6 carrier was
substituted for the indanthrone blue concentrate. The
samples were then extruded, spun, and drawn as outlined in
Example 1.
It was found that the filaments produced using both
of these samples broke during drawing. `~ -
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EXAMPLE 5 ~ -
Dry blends of the same composition as Example 2 were
prepared, except that the amount of indanthrone blue
concentrate added was varied to provide three compositions
(Samples 7, 8 and 9) with different amounts of indanthrone
blue. A fourth cqmposition (Sample 10) was prepared by
making a concentrate of carbon black and indanthrone blue
by combining indanthrone blue with the carbon black and the
additives of Table 1 to provide a single dispersion in a
carrier resin and then combining the concentrate with nylon
6,6. The results obtained after extruding, spinning an~
drawing the compositions by the method outlined in Example
1 are reported in TABLE 4.
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TABLE 4
Sample 7 ~gm~Sample 9 Sample 10
Amount blue ln fibre
(wt ~): 0.097 0.034 0.015 0.006
Decitex: 45.6 44.0 44.3 4s.0
Break Strength (N): 2.5 2.6 2.6 2.4 -
Elongation (%3:18.16 18.4 15.62 lS.99
10 Tenacity(gpd) 6.3 6.7 6.5 6.12
Samples 7 to 10 all produced acceptable yarns.
~XAMPLe 6
A sample (Sample 11) comprising 98.2 wt% nylon 6, 6
flake and 1.8 wt% of black colour concentrate (see Table 1)
was preparsd. A second sample (Sample 12) comprising 98.1
wt% nylon 6,6 flake, 1.7 wt % blac~ colour concentrate (see -
Table 1) and 0.2 wt % pi~ment concentrate (85 wt~ nylon 6
carrier and 15 wt% indanthrone blue pigment, mean particle -~
size 0.0~ microns) was also prepared. These samples were
each separat~ly run on a full scale commercial spinning
machine operating at speeds above 2000 meters per minute
and capacity over several hundred pounds per hour. The
maximum draw ratio for each sample was determined by
modifying the draw roller speeds. The maximum draw ratio
for Sample 11 was found to be about 4.3 (product properties
unacceptable for high strength applications) and for Sample
12 was found to be about 5.0 (product acceptable for high
strength applications).
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