U.S. patent application number 15/338879 was filed with the patent office on 2017-02-16 for thermoplastic molding compounds.
The applicant listed for this patent is LANXESS Deutschland GmbH. Invention is credited to Tobias BENIGHAUS, Detlev JOACHIMI, Guenter MARGRAF, Christian RUTHARD, Holger SCHMIDT.
Application Number | 20170044351 15/338879 |
Document ID | / |
Family ID | 47891734 |
Filed Date | 2017-02-16 |
United States Patent
Application |
20170044351 |
Kind Code |
A1 |
BENIGHAUS; Tobias ; et
al. |
February 16, 2017 |
THERMOPLASTIC MOLDING COMPOUNDS
Abstract
Polymeric moulding compositions include iron oxalate as a
stabilizer system to improve the stability of the moulding
compositions with respect to adverse thermooxidative and/or
photooxidative effects.
Inventors: |
BENIGHAUS; Tobias;
(Duesseldorf, DE) ; JOACHIMI; Detlev; (Krefeld,
DE) ; MARGRAF; Guenter; (Dormagen, DE) ;
RUTHARD; Christian; (Mainz, DE) ; SCHMIDT;
Holger; (Dormagen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LANXESS Deutschland GmbH |
Cologne |
|
DE |
|
|
Family ID: |
47891734 |
Appl. No.: |
15/338879 |
Filed: |
October 31, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14386412 |
Sep 19, 2014 |
9481780 |
|
|
PCT/EP2013/055579 |
Mar 18, 2013 |
|
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15338879 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 77/02 20130101;
C08K 5/09 20130101; C08K 5/098 20130101; C08K 3/24 20130101 |
International
Class: |
C08K 5/098 20060101
C08K005/098 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 21, 2012 |
EP |
12160534.9 |
Claims
1. A polymeric moulding composition comprising: (1) 10 to 99.85% by
weight of polymer; (2) 0.05 to 10% by weight of iron oxalate; and
(3) 0.1 to 70% by weight of other ingredients different from
components (1) and (2), where the total of all of the percentages
by weight is always 100% by weight; and the polymer in the
composition consists of non-chlorinated polymer,
2. The moulding composition according to claim 1, wherein the iron
oxalate is iron(II) oxalate dihydrate.
3. The moulding composition according to claim 1, wherein the at
least one polymer is semicrystalline polyamide or semicrystalline
polyester.
4. The moulding composition according to claim 1, wherein the at
least one polymer is at least one aliphatic polyamide, or a blend
of at least one aliphatic polyamide and a polyalkylene, and the
aliphatic polyamide is a polyamide produced from one or more of the
monomers: adipic acid, 2,2,4-trimethyladipic acid,
2,4,4-trimethyladipic acid, azelaic acid, sebacic acid,
tetramethylenediamine, hexamethylenediamine,
2-methylpentane-1,5-diamine, 1,9-nonandiamine, 2,2,4- and
2,4,4-trimethylhexamethylenediamine, the isomers of
diaminodicyclohexylmethane, diaminodicyclohexylpropane,
bisaminomethylcyclohexane, and .epsilon.-caprolactam.
5. The moulding composition according to claim 1, wherein the at
least one polymer is a polyamide produced from one or more of the
following monomers: .epsilon.-caprolactam, adipic acid,
terephthalic acid, hexamethylenediamine, tetramethylenediamine, or
2-methylpentane-1,5-diamine.
6. The moulding composition according to claim 1, wherein the at
least one polymer is at least one of PA6, PA66, PA46, PA12, and
copolyamides thereof.
7. The moulding composition according to claim 1, wherein the other
ingredients comprise at least one additive from the group of heat
stabilizers different from component (2), UV stabilizers,
gamma-radiation stabilizers, hydrolysis stabilizers, antistatic
agents, emulsifiers, nucleating agents, plasticizers, processing
aids, impact modifiers, lubricants, mould-release agents, dyes or
pigments.
8. The moulding composition according to claim 1, further
comprising (4) 5 to 70% by weight of fillers or reinforcing
materials, where the proportions of components (1) to (3) are
reduced in such a way that the total of all of the percentages by
weight is 100.
9. The thermoplastic moulding composition according to claim 1,
wherein: the non-chlorinated polymer is PA6, PA66, or a copolyamide
of PA6 or PA66; the iron oxalate is iron(II) oxalate dihydrate; and
the other ingredients include at least one non-chlorine containing
additive selected from the group consisting of heat stabilizers
different from component (2), UV stabilizers, gamma-radiation
stabilizers, hydrolysis stabilizers, antistatic agents,
emulsifiers, nucleating agents, plasticizers, processing aids,
impact modifiers, lubricants, mould-release agents, dyes, and
pigments.
10. A method for stabilizing polymers and/or products produced from
the polymers against thermo-oxidative and/or photo-oxidative
degradation, the method comprising including 0.05 to 10% by weight
of iron oxalate into the polymer during production of the
polymer.
11. The method of claim 10, wherein the products produced from the
polymers include foils, fibres or mouldings of items for the
electrical industry, electronics industry,
telecommunications-industry, information technology industry, solar
industry, or computer industry, for the household, for sports, for
medical applications, for the consumer electronics industry, or for
motor vehicles.
12. Fibres, foils or mouldings having improved resistance to
thermo-oxidative and/or photo-oxidative degradation, wherein the
fibres, foils or mouldings are obtained via injection moulding,
extrusion or blow moulding of the moulding composition according to
claim 1.
13. A process for the production of the moulding composition
according to claim 1, the process comprising mixing components (1)
to (3) in the designated parts by weight, at a reaction temperature
sufficient for the reaction of the iron oxalate, and sufficient to
melt the polymer.
14. The process according to claim 13, comprising: premixing the
iron oxalate with the at least one polymer to form a first mixture;
heating the first mixture to a temperature of at least the reaction
temperature to form a heated mixture; and mixing the other
ingredients into the heated mixture.
15. The process according to claim 14, wherein the reaction
temperature is 100.degree. C. to 450.degree. C.
16. The process according to claim 14, wherein the reaction
temperature is 220.degree. C. to 400.degree. C., and the mixing
comprises at least one of combining, mixing, kneading, compounding,
extrusion or rolling.
Description
[0001] This application is a divisional of pending U.S. patent
application Ser. No. 14/386,412 filed Sep. 19, 2014, entitled
"Thermoplastic Molding Compounds", which claims the right of
priority under 35 U.S.C. .sctn.119 (a)-(d) and 35 U.S.C. .sctn.365
of International Application No. PCT/EP2013/055579, filed Mar. 18,
2013, which is entitled to the right of priority of European Patent
Application No. 12160534.9 filed Mar. 21, 2012, the contents of
which are hereby incorporated by reference in their entirety
[0002] The present invention relates to thermoplastic moulding
compositions comprising iron oxalate as stabilizer with respect to
adverse thermooxidative effects. The invention further relates to
the use of this stabilizer to improve the stability of
thermoplastic moulding compositions with respect to adverse
thermooxidative and/or photooxidative effects, and also to
processes for the production of the said moulding compositions.
[0003] Thermoplastic polymers, preferably polyamides or polyesters,
in particular semicrystalline polyamides or polyesters, are often
used as materials for mouldings which during their lifetime have
exposure to elevated temperatures for a prolonged period. For a
wide variety of applications here, in particular for applications
in the engine compartment of vehicles, a requirement is that the
materials have sufficient stability with respect to the adverse
thermooxidative effects that arise under these conditions.
[0004] Thermoplastic moulding compositions generally exhibit
impairment of their mechanical properties when they are exposed to
elevated temperatures for a prolonged period. This effect derives
mainly from adverse oxidative effects on the polymers at elevated
temperatures (adverse thermooxidative effects). For the purposes of
the present invention, the expression "a prolonged period" means
more than 100 hours, and for the purposes of the present invention
the expression "elevated temperatures" means temperatures higher
than 80.degree. C.
[0005] The stability of thermoplastic moulding compositions with
respect to adverse thermooxidative effects is usually assessed via
comparison of mechanical properties, in particular of impact
resistance, of tensile stress at break and tensile strain at break
measured in the ISO 527 tensile test, and also of the modulus of
elasticity, at a defined temperature over a defined period.
[0006] Numerous systems for the stabilization of thermoplastic
polymers, also termed thermoplastics, with respect to adverse
thermooxidative effects and to the resultant molecular degradation
are known and have been described in the literature. A summary is
found in "Plastic Additives Handbook" (5th Edition, edited by: Hans
Zweifel, Carl Hanser Verlag, Munich, 2001) on pages 10 to 19 and 40
to 92. In engineering thermoplastics, in particular polyamides, it
is usual to use antioxidants based on sterically hindered phenols
or based on aromatic amines, as organic stabilizers, or systems
based on copper compounds, as inorganic stabilizers. The organic
stabilizers mentioned are generally used for temperatures up to
about 120.degree. C., and some are also still effective at high
temperatures.
[0007] Effective stabilization at higher temperatures up to about
140.degree. C. is usually achieved via stabilizer systems based on
mixtures of copper halides and alkali metal halides.
[0008] In recent years there has been a marked rise in the
requirements placed upon the service temperatures at which
thermoplastic polymers, such as polyamides, retain sufficient
stability. Many applications demand longer-term thermal
stabilization with respect to thermooxidative degradation at
160.degree. C. or even from 180 to 200.degree. C.
[0009] DE-4305166 A1 describes an improvement of copper-based
thermal stabilization systems via addition of strong reducing
agents which leads to in-situ formation of finely divided elemental
copper. DE-4305166 A1 also reveals that colloidal, elemental copper
which is not produced in-situ has markedly less activity in respect
of thermal stabilization.
[0010] U.S. Pat. No. 4,347,175 describes a process for the
stabilization of polymers via mixing of the polymers with formates
of multivalent metals and heating of the mixture to a temperature
above the decomposition temperature of the formates of the
multivalent metals.
[0011] In general, stabilizing systems can only delay, rather than
prevent, the thermooxidative degradation of thermoplastic moulding
compositions at elevated temperatures over a prolonged period. The
requirements placed upon thermoplastic moulding compositions or
upon mouldings to be produced therefrom in high-temperature
applications are not yet sufficiently met by the systems known from
the prior art: by way of example, long-term ageing in case of
storage after .about.1000 hours at from 180 to 200.degree. C.
causes a very marked reduction of impact resistance or tensile
stress at break, mostly to less than 50% of the initial value.
[0012] It is therefore an object of the present invention to
provide a stabilizer system and thermoplastic moulding compositions
comprising this stabilizer system, and thus to permit a further
marked improvement of stabilization with respect to adverse
thermooxidative effects when comparison is made with the systems
known from the prior art.
[0013] Surprisingly, it has now been found that a marked
improvement of the stability of thermoplastics, mouldings to be
produced therefrom, with respect to adverse thermooxidative effects
can be achieved with iron oxalate.
[0014] The object is achieved by, and the present invention
therefore provides, the use of iron oxalate for the stabilization
of thermoplastic polymers, or of moulding compositions based on
thermoplastic polymers, and of fibres, foils or mouldings to be
produced therefrom, with respect to adverse thermooxidative effects
and/or with respect to adverse photooxidative effects.
[0015] For clarity, it should be noted that the scope of the
invention comprises any desired combinations of all of the
definitions and parameters mentioned in general terms or in
preferred ranges below.
[0016] The present invention therefore also provides thermoplastic
moulding compositions comprising [0017] (1) from 10 to 99.85% by
weight of a thermoplastic polymer or a combination of different
thermoplastic polymers, [0018] (2) from 0.05 to 10% by weight of
iron oxalate, and [0019] (3) from 0.1 to 70% by weight of other
ingredients, where the total of the percentages by weight is always
100% by weight.
[0020] In one preferred embodiment, the thermoplastic moulding
compositions according to the invention also comprise, in addition
to components (1) to (3), (4) from 5 to 70% by weight of fillers or
reinforcing materials, preferably glass fibres or carbon fibres,
particularly preferably glass fibres, where the proportions of
components (1) to (3) are reduced in such a way that the total of
all of the percentages by weight is 100.
[0021] According to the invention, preference is given to
thermoplastic moulding compositions comprising [0022] (1) from 10
to 99.75% by weight of a thermoplastic polymer or a combination of
different thermoplastic polymers, [0023] (2) from 0.05 to 8% by
weight, preferably from 0.1 to 5% by weight, particularly
preferably from 0.2 to 3% by weight of iron oxalate, and [0024] (3)
from 0.1 to 70% by weight of other ingredients, where the total of
the percentages by weight is always 100% by weight.
[0025] The present invention further provides the use of the
thermoplastic moulding compositions according to the invention for
the production of fibres, foils or mouldings of any type.
[0026] However, the present invention also provides a process for
the thermal stabilization of thermoplastic polymers and of fibres,
foils or mouldings to be produced therefrom, by using a stabilizer
system comprising at least iron oxalate.
[0027] However, the present application also provides a process for
the mitigation on all adverse photo-oxidative and/or
thermooxidative effects on thermoplastic polymers, or on foils,
fibres or mouldings to be produced therefrom, by adding at least
iron oxalate.
[0028] The thermoplastic polymers to be used as component (1) are
preferably amorphous polymers, thermoplastic elastomers or
semicrystalline polymers. It is particularly preferable to use the
stabilizer system according to the invention for polymers which are
used in high-temperature applications, and it is very particularly
preferable to use the stabilizer system according to the invention
in semicrystalline polymers having a melting point of at least
180.degree. C. or in amorphous polymers having a glass transition
temperature of at least 150.degree. C.
[0029] Particularly preferred amorphous polymers to be used as
component (1) are amorphous polyamides, amorphous polyimides,
amorphous polyetherimides, amorphous polysulphones or amorphous
polyacrylates.
[0030] Particularly preferred semicrystalline polymers to be used
as component (1) are semicrystalline polyphenylene sulphides,
semicrystalline polyesters, semicrystalline polyether ketones or
semicrystalline polyamides, in particular semicrystalline
polyesters or semicrystalline polyamides, particular preference
being given more particularly to semicrystalline polyamides.
[0031] In one preferred embodiment, a blend of different
thermoplastic polymers is also used as component (1).
[0032] Very particular preference is more particularly given to
using aliphatic or semiaromatic polyamide as component (1), i.e. as
semicrystalline polyamide, and particularly to using nylon-6 or
nylon-6,6 with relative solution viscosities in m-cresol of from
2.0 to 4.0, and very particular preference is more particularly
given to using nylon-6 with a relative solution viscosity in
m-cresol of from 2.3 to 3.2.
[0033] In methods for the determination of relative solution
viscosity, the flow times of a polymer solution are measured
through an Ubbelohde viscometer, the aim then being to determine
the viscosity difference between a polymer solution and its
solvent, in this case m-cresol (1% solution). Standards that can be
used are DIN 51562; DIN ISO 1628 or corresponding standards.
[0034] The blends to be used in one preferred embodiment preferably
comprise, as component (1), nylon-6, nylon-6,6, nylon-4,6, nylon-12
or copolyamides. In an embodiment to which alternative preference
is given the blends comprise at least one of the polyamides
mentioned and at least one other thermoplastic polymer from the
group of polyphenylene oxide, polyethylene or polypropylene.
[0035] The polyamides to be used with preference in the
thermoplastic moulding compositions according to the invention can
be produced by various processes and synthesized from various
units. There are very many known procedures for the production of
polyamides, and as a function of desired final product these use
different monomer units, various chain regulators for adjustment to
a desired molecular weight, or else monomers having reactive groups
for post-treatments to be carried out subsequently.
[0036] The industrially relevant processes for the production of
the polyamides preferred according to the invention mostly proceed
by way of polycondensation in the melt. For the purposes of the
present invention, the hydrolytic polymerization of lactams is also
considered to be polycondensation.
[0037] Polyamides preferred according to the invention are
semicrystalline polyamides which are produced by starting from
diamines and dicarboxylic acids and/or lactams having at least 5
ring members, or from corresponding amino acids. Preferred starting
materials that can be used are aliphatic and/or aromatic
dicarboxylic acids, particularly adipic acid, 2,2,4-trimethyladipic
acid, 2,4,4-trimethyladipic acid, azelaic acid, sebacic acid,
isophthalic acid, terephthalic acid, aliphatic and/or aromatic
diamines, particularly tetramethylenediamine, hexamethylenediamine,
2-methylpentane-1,5-diamine, 1,9-nonandiamine, 2,2,4- and
2,4,4-trimethylhexamethylenediamine, the isomers of
diaminedicyclohexylmethane, diaminodicyclohexylpropane,
bisaminomethylcyclohexane, phenylenediamine, xylylenediamine,
aminocarboxylic acids, in particular amino caproic acid, or the
corresponding lactams. Copolyamides of a plurality of the monomers
mentioned are included.
[0038] Particularly preferred polyamides according to the invention
are produced from caprolactam, very particularly preferably from
.epsilon.-caprolactam.
[0039] Particular preference is moreover more particularly given to
most of the compounded materials that are based on PA6 and on PA66,
and to other compounded materials that are based on aliphatic
or/and aromatic polyamides and, respectively, copolyamides, and
that have from 3 to 11 methylene groups for each polyamide group in
the polymer chain.
[0040] Iron oxalate is used as component (2).
[0041] Oxalate here is the thermally activatable reducing anion
which at temperatures of from 100 to 450.degree.C., preferably from
150 to 400.degree. C., particularly preferably from 200 to
400.degree. C., undergoes reactions at an adequate reaction rate
with a standard potential, at 25.degree. C. relative to the
standard hydrogen electrode, or less than 0 V, preferably less than
-0.15 V, particularly preferably less than -0.3 V. For the purposes
of this invention, adequate reaction rates are considered to be
reaction rates which lead to at least 10 mol %, preferably at least
25 mol %, particularly preferably at least 50 mol %, conversion of
the substance used, in this case the thermally activatable reducing
anion, over a period of one hour.
[0042] More particularly, very particular preference is given to
iron(II) oxalate dihydrate as component (2).
[0043] Component (2) to be used according to the invention is
preferably used in the form of powder, paste or compactate.
Preferred powders of component (2) have an average particle size
d.sub.50 of at most 1000 .mu.m, preferably from 0.1 to 500 .mu.m,
particularly preferably from 0.5 to 250 .mu.m (in accordance with
ASTM D1921-89, Procedure A), thus ensuring fine dispersion within
the thermoplastic. If component (2) is used in the form of paste or
compactate, the binders usually used for the production of pastes
or compactates, preferably waxes, oils, polyglycols or similar
compounds, can be used, optionally also in combinations, in
suitable quantitative proportions.
[0044] As further ingredients of component (3) it is preferable to
use at least one substance of the group of thermal stabilizers
different from component (2), UV stabilizers, gamma-radiation
stabilizers, hydrolysis stabilizers, antistatic agents,
emulsifiers, nucleating agent, plasticizers, processing aids,
impact modifiers, lubricants, mould-release agents, dyes or
pigments. The additives mentioned, and other suitable additives,
are prior art and can be found by the person skilled in the art by
way of example in Plastics Additives Handbook, 5th Edition,
Hanser-Verlag, Munich, 2001, pages 80-84, 546-547, 688, 872-874,
938, 966. The ingredients to be used as component (3) can be used
alone or in a mixture, or in the form of masterbatches.
[0045] According to the invention, preferred additional thermal
stabilizers which are to be used as additive and which differ from
component (2) are copper compounds, in particular copper halides in
combination with alkali metal halides, or are alkali metal halides
and alkaline earth metal halides, preferably sodium chloride and
calcium chloride, manganese chloride, sterically hindered phenols
and/or phosphites, phosphates, preferably disodium
dihydrogendiphosphate, hydroquinones, aromatic secondary amines in
particular diphenylamines, substituted resorcinols, salicylates,
benzotriazoles or benzophenones, and also variously substituted
members of these groups and/or mixtures thereof. It is particularly
preferable to use, as thermal stabilizer, potassium bromide and/or
copper(I) iodide, and it is very particularly preferable to use
potassium bromide and copper(I) iodide.
[0046] According to the invention, preferred UV stabilizers to be
used as additive are substituted resorcinols, salicylates,
benzotriazoles or benzophenones.
[0047] According to the invention, if preferred impact modifiers or
elastomer modifiers are to be used as component (3) they very
generally involve copolymers preferably composed of at least two of
the following group of monomers: ethylene, propylene, butadiene,
isobutene, isoprene, chloroprene, vinyl acetate, styrene,
acrylonitrile and acrylate or methacrylate having from 1 to 8
carbon atoms in the alcohol component. The copolymers can comprise
compatibilizing groups, preferably maleic anhydride or epoxide.
[0048] According to the invention, preferred dyes or pigments to be
used as additive are inorganic pigments, particularly titanium
dioxide, ultramarine blue, iron oxide, zinc sulphide or carbon
black, or else organic pigments, particularly preferably
phthalocyanines, quinacridones, perylenes, and also dyes,
particularly nigrosine or anthraquinones as colourants, or else
other colorants.
[0049] According to the invention, preferred nucleating agents to
be used as additive are sodium phenylphosphinate or calcium
phenylphosphinate, aluminium oxide or silicon dioxide or talc
powder, particularly talc powder.
[0050] According to the invention, preferred lubricants and/or
mould-release agents to be used as additive are long-chain fatty
acids, in particular stearic acid, salts thereof, in particular Ca
stearate or Zn stearate, or else the ester or amide derivatives of
these, in particular ethylenebisstearylamide, glycerol tristearate,
stearyl stearate, montan waxes, in particular esters of montanic
acids with ethylene glycol, or else oxidized and non-oxidized forms
of low-molecular-weight polyethylene waxes and of
low-molecular-weight polypropylene waxes. According to the
invention, particularly preferred lubricants and/or mould-release
agents are those in the group of the esters or amides of saturated
or unsaturated aliphatic carboxylic acids having from 8 to 40
carbon atoms with saturated aliphatic alcohols or amines having
from 2 to 40 carbon atoms. In another preferred embodiment, these
moulding compositions according to the invention comprise mixtures
of the abovementioned lubricants and/or mould-release agents.
[0051] For the purposes of the present invention, fillers and
reinforcing materials as component (4) are fibrous, acicular or
particulate fillers and fibres, acicular or particulate reinforcing
materials. Preference is given to carbon fibres, glass beads,
amorphous silica, calcium silicate, calcium metasilicate, magnesium
carbonate, kaolin, calcined kaolin, chalk, powdered quartz, mica,
phlogopite, barium sulphate, feldspar, wollastonite,
montmorillonite or glass fibres, particularly glass fibres, in
particular glass fibres made of E glass. In one preferred
embodiment, in order to improve compatibility with thermoplastics,
the fibres or the particulate reinforcing materials have been
provided with suitable surface modifications, in particular surface
modifications comprising saline compounds.
[0052] The present invention further provides a process for the
production of the thermoplastic moulding compositions according to
the invention, characterized in that components (1) to (3), and
also optionally (4), are mixed in appropriate proportions by
weight. The mixing of components preferably takes place at
temperatures from 220 to 400.degree.C., by combining, mixing,
kneading, compounding, extruding, or rolling the components
together, with particular preference via compounding in a
co-rotating twin-screw extruder or Buss kneader. It can be
advantageous to premix individual components.
[0053] In one preferred embodiment, the moulding compositions
according to the invention are produced in a two-stage process. In
the first step, component (2) is mixed with a thermoplastic polymer
to give a premix, and heated to a temperature above the reaction
temperature of component (2). It is also possible that other
components of the thermoplastic moulding composition according to
the invention are mixed in this step with component (2) and with a
thermoplastic polymer. This step is preferably carried out in a
co-rotating twin-screw extruder, Buss kneader or planetary-roll
extruder.
[0054] It is preferable that component (2) is reacted in this first
step in a polyamide, preferably PA6 or PA66, with a relative
solution viscosity in m-cresol of from 2.8 to 5.0, preferably from
3.5 to 4.5.
[0055] It is preferable that, in this first step, the premix made
of thermoplastic polymer and component (2), and also optionally
other components is heated to a temperature of from 300 to
400.degree. C., particularly from 320 to 390.degree. C., very
particularly from 330 to 380.degree. C.
[0056] In one preferred embodiment, the premix in the first step
comprises not only the thermoplastic and components (2) but also at
least one processing stabilizer. Preferred processing, stabilizer
used comprises sterically hindered phenols and/or phosphites,
phosphates, hydroquinones, aromatic secondary amines, in particular
diphenylamines, substituted resorcinols, salicylates,
berizotriazoles or berizophenones, or else variously substituted
members of these groups and/or mixtures thereof.
[0057] The proportion of component (2) in the premix in the first
step is preferably from 1 to 60% by weight, particularly preferably
from 1 to 30% by weight, very particularly preferably from 2 to 20%
by weight.
[0058] The premix is preferably reacted in a twin-screw extruder,
Buss kneader or planetary-roll extruder equipped with a
devolatilizing function, in order to relief gaseous components
arising during the reaction of component (2).
[0059] As an alternative, component (2) can be reacted in a
suitable substance of components (3) in a twin-screw extruder, Buss
kneader or other apparatus suitable for heating the mixture to
temperatures above the reaction temperature of component (2). A
batch process can also be used in the first step, preferably in a
stirred autoclave.
[0060] In an alternative preferred embodiment, component (2) is
used in combination with one or more compounds which increase the
reaction rate of component (2). The reaction of component (2) is
thus possible at lower temperatures. Compounds of this type, are
also termed activators, are described by way of example in U.S.
Pat. No. 4,438,223, the entire content of which is concomitantly
comprised by the present invention. It is preferable to use, as
activator, at least one compound from the group of sodium
hydrogencarbonate or potassium hydrogencarbonate, sodium acetate or
potassium acetate, sodium carbonate or potassium carbonate, sodium
chloride or potassium chloride, sodium bromide or potassium
bromide, sodium iodide or potassium iodide, sodium rhodanide or
potassium rhodanide or sodium benzoate or potassium benzoate.
[0061] In the second step, the premix from the first step is mixed
with the remaining components of the thermoplastic moulding
composition according to the invention by the processes described
above.
[0062] The thermoplastic moulding compositions to be produced
according to the invention can be processed by processes known to
the person skilled in the art, in particular via injection
moulding, extrusion or blow moulding.
[0063] It can be advantageous to produce mouldings or semifinished
products directly from a physical mixture produced at room
temperature, preferably from 0 to 40.degree. C., this being know as
a dry blend, of premixed components and/or of individual
components.
[0064] The mouldings to be produced according to the invention from
the moulding compositions can preferably be used in the motor
vehicle industry, electrical industry, electronics industry,
telecommunications industry, solar industry, information technology
industry, or computer industry, in the household, in sports, in
medicine or in the consumer electronics industry. More
particularly, moulding compositions according to the invention can
be used for applications requiring high stability with respect to
heat-ageing. For applications of this type, preference is given to
the use for mouldings in vehicles, in particular in motor vehicles,
more particularly in the engine compartment of motor vehicles. The
present invention therefore also provides the use of thermoplastic
moulding compositions comprising the stabilizer system to be used
according to the invention for the production of mouldings and
items with increased stability with respect to adverse
thermooxidative effects and/or adverse photooxidative effects,
preferably of mouldings for motor vehicles, more particularly
preferably for the engine compartment of motor vehicles. The
thermoplastic moulding composition according to the invention are
moreover also suitable for applications or moulding compositions or
items where stability with respect to adverse photooxidative
effects is required in addition to thermooxidative stability,
preferably solar installations.
[0065] The invention further provides the use of the fibres, foils
or mouldings to be produced according to the invention for the
production of items for the electrical industry, electronics
industry, telecommunications industry, information technology
industry, solar industry, or computer industry, for the household,
for sports, for medical applications or for the consumer electronic
industry, particularly preferably for motor vehicles, very
particularly preferably for the engine compartment of motor
vehicles.
EXAMPLES
[0066] In order to demonstrate the advantages of the moulding
compositions according to the invention, a premix was first
produced with 5% of iron oxalate, and the thermoplastic moulding
compositions were then produced. Data in [%] are always percent by
weight.
[0067] Production of a Premix with 5% of Iron Oxalate
[0068] 5% by weight of iron oxalate were mixed with 95% by weight
of a PA6 A polyamide in a ZSK 26 Compounder twin-screw extruder
from Coperion Werner & Pfleiderer (Stuttgart, Germany) at a
temperature of about 370.degree. C., discharged in the form of
strand into a water bath, cooled until pelletizable and pelletized.
The pellets were dried for two days at 70.degree. C. in a vacuum
drying oven.
[0069] Production of the Thermoplastic Moulding Composition
[0070] The individual components were mixed in a ZSK 26 Compounder
twin-screw extruder from Coperion Werner & Pfleiderer
(Stuttgart, Germany) at a temperature of about 280.degree. C.,
discharged in the form of strand into a water bath, cooled until
pelletizable and pelletized. The pellets were dried for two days at
70.degree. C. in a vacuum drying oven.
TABLE-US-00001 TABLE 1 Compositions of the moulding compositions
(all data in % by weight). Comparative Inventive Ingredient Example
1 Example 1 Glass fibre 30.000 30.000 PA6 B 69.680 59.820 Microtalc
powder 0.020 0.020 Montan ester wax 0.160 0.160 Potassium bromide
0.100 Copper(I) iodide 0.040 Premix of 5% of iron oxalate in PA6 A
10.000
[0071] Materials Used: [0072] PA6 A: Nylon-6, linear with a
relative solution viscosity of 4.0 for a 1% solution in m-cresol
[0073] PA6 B: Nylon-6, linear with a relative solution viscosity of
2.9 for a 1% solution in m-cresol [0074] Montan ester wax, e.g.
Licowax.RTM. E from Clariant GmbH [0075] Glass fibres, e.g. CS7928
from Lanxess Deutschland GmbH [0076] Potassium bromide,
d.sub.99<70 .mu.m [0077] Copper(I) iodide, d.sub.99<70 .mu.m
[0078] Iron oxalate, for example iron(II) oxalate dihydrate from
VWR international GmbH
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