U.S. patent application number 12/512109 was filed with the patent office on 2010-02-04 for heat resistant molded or extruded thermoplastic articles.
This patent application is currently assigned to E. I. DU PONT DE NEMOURS AND COMPANY. Invention is credited to ROBERT J. PALMER, JUDITH ALISON PEACOCK, GEORGIOS TOPOULOS.
Application Number | 20100029819 12/512109 |
Document ID | / |
Family ID | 41095667 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100029819 |
Kind Code |
A1 |
PALMER; ROBERT J. ; et
al. |
February 4, 2010 |
HEAT RESISTANT MOLDED OR EXTRUDED THERMOPLASTIC ARTICLES
Abstract
Disclosed is a molded or extruded thermoplastic article having
high heat stability over at least 500 hours at least 170.degree. C.
including a thermoplastic composition including a thermoplastic
resin; one or more polyhydric alcohols having more than two
hydroxyl groups and a having a number average molecular weight
(M.sub.n) of less than 2000; one or more reinforcement agents; and
optionally, a polymeric toughener; wherein 4 mm test bars prepared
from said thermoplastic composition, and exposed at a test
temperature at 170.degree. C. for a test period of 500 hours, have,
on average, a retention of tensile strength of at least 50 percent,
as compared with that of an unexposed control of identical
composition and shape. Further disclosed is a molded or extruded
thermoplastic article, including a thermoplastic polyamide
composition, wherein 4 mm test bars of said thermoplastic polyamide
composition, when exposed at 210.degree. C. for a test period of
500 hours, have a retention of tensile strength of at least 70
percent.
Inventors: |
PALMER; ROBERT J.;
(Jonzier-Epagny, FR) ; PEACOCK; JUDITH ALISON;
(Commugny, CH) ; TOPOULOS; GEORGIOS; (Meyrin,
CH) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY;LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1122B, 4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Assignee: |
E. I. DU PONT DE NEMOURS AND
COMPANY
Wilmington
DE
|
Family ID: |
41095667 |
Appl. No.: |
12/512109 |
Filed: |
July 30, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61137345 |
Jul 30, 2008 |
|
|
|
Current U.S.
Class: |
524/387 |
Current CPC
Class: |
C08K 5/13 20130101; C08K
5/053 20130101; C08K 5/18 20130101; C08K 5/005 20130101; C08G
69/265 20130101; Y10T 428/139 20150115; C08L 77/06 20130101; C08L
77/00 20130101; C08K 5/005 20130101; C08K 5/053 20130101; C08G
69/36 20130101; C08K 5/06 20130101; C08K 5/06 20130101; C08L 77/00
20130101; C08L 77/00 20130101; C08L 77/00 20130101 |
Class at
Publication: |
524/387 |
International
Class: |
C08K 5/053 20060101
C08K005/053 |
Claims
1. A molded or extruded thermoplastic article comprising a
thermoplastic composition comprising (a) a thermoplastic resin
selected from the group consisting of polyamides, polyesters, and
mixtures thereof; (b) 0.25 to 15 weight percent of one or more
polyhydric alcohols having more than two hydroxyl groups and a
having a number average molecular weight (M.sub.n) of less than
2000; (c) 10 to about 60 weight percent of one or more
reinforcement agents; and (d) 0 to 50 weight percent of a polymeric
toughener comprising a reactive functional group and/or a metal
salt of a carboxylic acid; wherein all weight percentages are based
on the total weight of the thermoplastic composition and wherein 4
mm test bars prepared from said thermoplastic composition, and
exposed at a test temperature of 170.degree. C. for a test period
of 500 hours, in an atmosphere of air, and tested according to ISO
527-2/1A, have, on average, a retention of tensile strength of at
least 50 percent, as compared with that of an unexposed control of
identical composition and shape.
2. The molded or extruded thermoplastic article of claim 1 wherein
said thermoplastic resin is a polyamide resin comprising one or
more polyamides independently selected from the group consisting of
Group (I) polyamides having said melting point of less than
210.degree. C., comprising an aliphatic or semiaromatic polyamide
selected from the group poly(pentamethylene decanediamide) (PA510),
poly(pentamethylene dodecanediamide) (PA512),
poly(.epsilon.-caprolactam/hexamethylene hexanediamide) (PA6/66),
poly(.epsilon.-caprolactam/hexamethylene decanediamide) (PA6/610),
poly(.epsilon.-caprolactam/hexamethylene dodecanediamide)
(PA6/612), poly(hexamethylene tridecanediamide) (PA613),
poly(hexamethylene pentadecanediamide) (PA615),
poly(.epsilon.-caprolactam/tetramethylene terephthalamide)
(PA6/4T), poly(.epsilon.-caprolactam/hexamethylene terephthalamide)
(PA6/6T), poly(.epsilon.-caprolactam/decamethylene terephthalamide)
(PA6/10T), poly(.epsilon.-caprolactam/dodecamethylene
terephthalamide) (PA6/12T), poly(hexamethylene
decanediamide/hexamethylene terephthalamide) (PA6 10/6T),
poly(hexamethylene dodecanediamide/hexamethylene terephthalamide)
(PA612/6T), poly(hexamethylene tetradecanediamide/hexamethylene
terephthalamide) (PA614/6T),
poly(.epsilon.-caprolactam/hexamethylene
isophthalamide/hexamethylene terephthalamide) (PA6/6I/6T),
poly(.epsilon.-caprolactam/hexamethylene
hexanediamide/hexamethylene decanediamide) (PA6/66/610),
poly(.epsilon.-caprolactam/hexamethylene
hexanediamide/hexamethylene dodecanediamide) (PA6/66/612),
poly(.epsilon.-caprolactam/hexamethylene
hexanediamide/hexamethylene decanediamide/hexamethylene
dodecanediamide) (PA6/66/610/612), poly(2-methylpentamethylene
hexanediamide/hexamethylene hexanediamide/hexamethylene
terephthamide) (PA D6/66//6T), poly(2-methylpentamethylene
hexanediamide/hexamethylene hexanediamide/) (PA D6/66),
poly(decamethylene decanediamide) (PA1010), poly(decamethylene
dodecanediamide) (PA1012), poly(decamethylene
decanediamide/decamethylene terephthalamide) (PA1010/10T)
poly(decamethylene decanediamide/dodecamethylene
decanediamide/decamethylene terephthalamide/dodecamethylene
terephthalamide (PA1010/1210/10T/12T), poly(11-aminoundecanamide)
(PA11), poly(11-aminoundecanamide/tetramethylene terephthalamide)
(PA11/4T), poly(11-aminoundecanamide/hexamethylene terephthalamide)
(PA11/6T), poly(11-aminoundecanamide/decamethylene terephthalamide)
(PA11/10T), poly(11-aminoundecanamide/dodecamethylene
terephthalamide) (PA11/12T), poly(12-aminododecanamide) (PA12),
poly(12-aminododecanamide/tetramethylene terephthalamide)
(PA12/4T), poly(l 2-aminododecanamide/hexamethylene
terephthalamide) (PA12/6T), poly(12-aminododecanamide/decamethylene
terephthalamide) (PA12/10T) poly(dodecamethylene dodecanediamide)
(PA1212), and poly(dodecamethylene dodecanediamide/dodecamethylene
dodecanediamide/dodecamethylene terephthalamide)) (PA1212/12T);
Group (II) polyamides having said melting point of at least
210.degree. C., comprising an aliphatic polyamide selected from the
group consisting of poly(tetramethylene hexanediamide) (PA46),
poly(.epsilon.-caprolactam) (PA 6), poly(hexamethylene
hexanediamide/(.epsilon.-caprolactam/) (PA 66/6) poly(hexamethylene
hexanediamide) (PA 66), poly(hexamethylene
hexanediamide/hexamethylene decanediamide) (PA66/610),
poly(hexamethylene hexanediamide/hexamethylene dodecanediamide)
(PA66/612), poly(hexamethylene hexanediamide/decamethylene
decanediamide) (PA66/1010), poly(hexamethylene decanediamide)
(PA610), poly(hexamethylene dodecanediamide) (PA612),
poly(hexamethylene tetradecanediamide) (PA614), poly(hexamethylene
hexadecanediamide) (PA616), and poly(tetramethylene
hexanediamide/2-methylpentamethylene hexanediamide) (PA46/D6);
Group (III) polyamides having said melting point of at least
210.degree. C., comprising (aa) about 20 to about 35 mole percent
semiaromatic repeat units derived from monomers selected from one
or more of the group consisting of: (i) aromatic dicarboxylic acids
having 8 to 20 carbon atoms and aliphatic diamines having 4 to 20
carbon atoms; and (bb) about 65 to about 80 mole percent aliphatic
repeat units derived from monomers selected from one or more of the
group consisting of: (ii) an aliphatic dicarboxylic acid having 6
to 20 carbon atoms and said aliphatic diamine having 4 to 20 carbon
atoms; and (iii) a lactam and/or aminocarboxylic acid having 4 to
20 carbon atoms; and (iv) mixtures thereof; Group (IV) polyamides
comprising (cc) about 50 to about 95 mole percent semiaromatic
repeat units derived from monomers selected from one or more of the
group consisting of: (j) aromatic dicarboxylic acids having 8 to 20
carbon atoms and aliphatic diamines having 4 to 20 carbon atoms;
and (dd) about 5 to about 50 mole percent aliphatic repeat units
derived from monomers selected from one or more of the group
consisting of: (ii) an aliphatic dicarboxylic acid having 6 to 20
carbon atoms and said aliphatic diamine having 4 to 20 carbon
atoms; (iii) a lactam and/or aminocarboxylic acid having 4 to 20
carbon atoms; and (iv) mixtures thereof; Group (V) polyamides
having said melting point of at least 260.degree. C., comprising
(ee) greater than 95 mole percent semiaromatic repeat units derived
from monomers selected from one or more of the group consisting of:
(j) aromatic dicarboxylic acids having 8 to 20 carbon atoms and
aliphatic diamines having 4 to 20 carbon atoms; and (ff) less than
5 mole percent aliphatic repeat units derived from monomers
selected from one or more of the group consisting of: (ii) an
aliphatic dicarboxylic acid having 6 to 20 carbon atoms and said
aliphatic diamine having 4 to 20 carbon atoms; (iii) a lactam
and/or aminocarboxylic acid having 4 to 20 carbon atoms; and (iv)
mixtures thereof; and Group (VI) polyamides having no melting point
selected from the group consisting of poly(hexamethylene
isophthalamide/hexamethylene terephthalamide) (6I/6T) and
poly(hexamethylene isophthalamide/hexamethylene
terephthalamide/hexamethylene hexanediamide) (6I/6T/66).
3. The molded or extruded thermoplastic article of claim 2 wherein
said polyamide resin comprises a blend of two or more polyamides
selected from the group consisting of Group (I) and Group (II)
Polyamides; Group (I) and Group (III) Polyamide, Group (I) and
Group (VI) Polyamides, Group (II) and Group (III) Polyamides, Group
(II) and Group (IV) Polyamides, Group (II) and Group (V)
Polyamides, Group (II) and Group (VI) Polyamides, Group (III) and
Group (VI) Polyamides, and Group (IV) and Group (V) Polyamides.
4. The molded or extruded thermoplastic article of claim 2 wherein
said polyamide resin comprises a blend of Group (II) and (V)
Polyamides.
5. The molded or extruded thermoplastic article of claim 2 wherein
said polyamide resin comprises a blend of (II) and Group (III)
Polyamides.
6. The molded or extruded thermoplastic article of claim 1 wherein
the thermoplastic material is a polyester selected from the group
consisting of poly(ethylene terephthalate), poly(trimethylene
terephthalate), poly(1,4-butylene terephthalate), poly(ethylene
2,6-naphthoate), and poly(1,4-cyclohexyldimethylene terephthalate),
and copolymers and blends of the same.
7. The molded or extruded thermoplastic article of claim 1 wherein
the polyhydric alcohol is selected fro the group consisting of
pentaerythritol, dipentaerythritol, tripentaerythritol,
di-trimethylolpropane, D-mannitol, D-sorbitol and xylitol.
8. The molded or extruded thermoplastic article of claim 1 wherein
said thermoplastic resin is a polyamide and said thermoplastic
composition comprises less than 25 ppm copper as determined with
atomic absorption spectroscopy.
9. The molded or extruded thermoplastic article of claim 1 selected
from the group consisting of charge air coolers; cylinder head
covers; oil pans; engine cooling systems, thermostat and heater
housings, coolant pumps, mufflers, housings for catalytic
converters; air intake manifolds; and timing chain belt front
covers.
10. A molded or extruded thermoplastic article comprising a
thermoplastic polyamide comprising (a) a polyamide resin; (b) 0.25
to 15 weight percent of one or more polyhydric alcohols having more
than two hydroxyl groups and a having a number average molecular
weight (M.sub.n) of less than 2000; (c) 10 to about 60 weight
percent of one or more reinforcement agents; and (d) 0 to 50 weight
percent of a polymeric toughener comprising a reactive functional
group and/or a metal salt of a carboxylic acid; wherein all weight
percentages are based on the total weight of the thermoplastic
composition and wherein 4 mm test bars prepared from said
thermoplastic composition, and exposed at a test temperature at
210.degree. C. for a test period of 500 hours, in an atmosphere of
air, and tested according to ISO 527-2/1A, have, on average, a
retention of tensile strength of at least 70 percent, as compared
with that of an unexposed control of identical composition and
shape.
11. The molded or extruded thermoplastic article of claim 10
wherein said thermoplastic resin is a polyamide resin comprising
one or more polyamides independently selected from the group
consisting of Group (II) polyamides having a melting point of at
least 210.degree. C., and comprising an aliphatic polyamide
selected from the group consisting of poly(tetramethylene
hexanediamide) (PA46), poly(.epsilon.-caprolactam) (PA 6),
poly(hexamethylene hexanediamide/(.epsilon.-caprolactam/) (PA 66/6)
poly(hexamethylene hexanediamide) (PA 66), poly(hexamethylene
hexanediamide/hexamethylene decanediamide) (PA66/610),
poly(hexamethylene hexanediamide/hexamethylene dodecanediamide)
(PA66/612), poly(hexamethylene hexanediamide/decamethylene
decanediamide) (PA66/1010), poly(hexamethylene decanediamide)
(PA610), poly(hexamethylene dodecanediamide) (PA612),
poly(hexamethylene tetradecanediamide) (PA614), poly(hexamethylene
hexadecanediamide) (PA616), and poly(tetramethylene
hexanediamide/2-methylpentamethylene hexanediamide) (PA46/D6);
Group (III) polyamides having a melting point of at least
210.degree. C., and comprising (aa) about 20 to about 35 mole
percent semiaromatic repeat units derived from monomers selected
from one or more of the group consisting of: (i) aromatic
dicarboxylic acids having 8 to 20 carbon atoms and aliphatic
diamines having 4 to 20 carbon atoms; and (bb) about 65 to about 80
mole percent aliphatic repeat units derived from monomers selected
from one or more of the group consisting of: (ii) an aliphatic
dicarboxylic acid having 6 to 20 carbon atoms and said aliphatic
diamine having 4 to 20 carbon atoms; and (iii) a lactam and/or
aminocarboxylic acid having 4 to 20 carbon atoms; Group (IV)
polyamides comprising (cc) about 50 to about 95 mole percent
semiaromatic repeat units derived from monomers selected from one
or more of the group consisting of: (i) aromatic dicarboxylic acids
having 8 to 20 carbon atoms and aliphatic diamines having 4 to 20
carbon atoms; and (dd) about 5 to about 50 mole percent aliphatic
repeat units derived from monomers selected from one or more of the
group consisting of: (ii) an aliphatic dicarboxylic acid having 6
to 20 carbon atoms and said aliphatic diamine having 4 to 20 carbon
atoms; (iii) a lactam and/or aminocarboxylic acid having 4 to 20
carbon atoms; and (iv) mixtures thereof; Group (V) polyamides
having a melting point of at least 260.degree. C., and comprising
(ee) greater than 95 mole percent semiaromatic repeat units derived
from monomers selected from one or more of the group consisting of:
(i) aromatic dicarboxylic acids having 8 to 20 carbon atoms and
aliphatic diamines having 4 to 20 carbon atoms; and (ff) less than
5 mole percent aliphatic repeat units derived from monomers
selected from one or more of the group consisting of: (ii) an
aliphatic dicarboxylic acid having 6 to 20 carbon atoms and said
aliphatic diamine having 4 to 20 carbon atoms; (iii) a lactam
and/or aminocarboxylic acid having 4 to 20 carbon atoms; and Group
(VI) polyamides having no melting point, and selected from the
group consisting of poly(hexamethylene isophthalamide/hexamethylene
terephthalamide) (6I/6T) and poly(hexamethylene
isophthalamide/hexamethylene terephthalamide/hexamethylene
hexanediamide) (6I/6T/66).
12. The molded or extruded thermoplastic article of claim 11
wherein said polyamide resin comprises a blend of two or more
polyamides selected from the group consisting of Group (II) and
Group (III) Polyamides, Group (II) and Group (IV) Polyamides, Group
(II) and Group (V) Polyamides, Group (II) and Group (VI)
Polyamides, Group (III) and Group (VI) Polyamides, and Group (IV)
and Group (V) Polyamides.
13. The molded or extruded thermoplastic article of claim 10
wherein the polyhydric alcohol is selected fro the group consisting
of pentaerythritol, dipentaerythritol, tripentaerythritol,
di-trimethylolpropane, D-mannitol, D-sorbitol and xylitol.
14. The molded or extruded thermoplastic article of claim 10
wherein said thermoplastic resin is a polyamide and said
thermoplastic composition comprises less than 25 ppm copper as
determined with atomic absorption spectroscopy.
15. The molded or extruded thermoplastic article of claim 10
selected from the group consisting of charge air coolers; cylinder
head covers; oil pans; engine cooling systems, thermostat and
heater housings, coolant pumps, mufflers, housings for catalytic
converters; air intake manifolds; and timing chain belt front
covers.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority of U.S.
Provisional Application No. 61/137,345, filed on 30 Jul. 2008 and
currently pending.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of molded and
extruded thermoplastic articles having improved long-term high
temperature aging characteristics.
BACKGROUND OF THE INVENTION
[0003] High temperature resins based on polyamides and polyesters
possess desirable chemical resistance, processability and heat
resistance. This makes them particularly well suited for demanding
high performance automotive and electrical/electronics
applications. There is a current and general desire in the
automotive field to have high temperature resistant structures
since temperatures higher than 150.degree. C., even higher than
200.degree. C., are often reached in underhood areas of
automobiles. When plastic parts are exposed to such high
temperatures for a prolonged period, such as in automotive
under-the-hood applications or in electrical/electronics
applications, the mechanical properties generally tend to decrease
due to the thermo-oxidation of the polymer. This phenomenon is
called heat aging.
[0004] In an attempt to improve heat aging characteristics, it has
been the conventional practice to add heat stabilizers (also
referred as antioxidants) to thermoplastic compositions comprising
polyester or polyamide resins. Examples of such heat stabilizers
include hindered phenol antioxidants, amine antioxidants and
phosphorus-based antioxidants. For polyester compositions, phenolic
antioxidants optionally combined with phosphorus based synergist
are conventionally used. For polyamide compositions, three types of
heat stabilizers are conventionally used to retain the mechanical
properties of the composition upon exposure to high temperatures.
One is the use of phenolic antioxidants optionally combined with a
phosphorus based synergist as previously mentioned, the use of
aromatic amines optionally combined with a phosphorus based
synergist and the third one is the use of copper salts and
derivatives. Phenolic antioxidants are known to improve the
mechanical/physical properties of the thermoplastic composition up
to an aging temperature of 120.degree. C.
[0005] U.S. Pat. No. 5,965,652 discloses a thermally stable
polyamide molding composition containing colloidal copper formed in
situ. However, the disclosed compositions exhibit retention of
impact strength only for a heat aging at 140.degree. C.
[0006] GB patent 839,067 discloses a polyamide composition
comprising a copper salt and a halide of a strong organic base.
However, the disclosed compositions exhibit improved bending heat
stability performance only for a heat aging at 170.degree. C.
[0007] Existing technologies lead not only to a poor improvement of
long-term heat aging resistance, but also the improved heat aging
characteristics are insufficient for more demanding applications
involving exposure to higher temperatures such as for example in
automotive under-the-hood applications and in
electrical/electronics applications.
[0008] US 2006/0155034 and US 2008/0146718 patent publications
disclose polyamide compositions comprising a metal powder as
thermal stabilizer with a fibrous reinforcing agent. Disclosed
compositions exhibit improved mechanical properties such as tensile
strength and elongation at break upon long-term heat aging at
215.degree. C. However, such metal powders are not only expensive
but they are also highly unstable because they are prone to
spontaneous combustion.
[0009] EP 1041109 discloses a polyamide composition comprising a
polyamide resin, a polyhydric alcohol having a melting point of 150
to 280.degree. C., that has good fluidity and mechanical strength
and is useful in injection welding techniques.
[0010] Unfortunately, with the existing technologies, molded
articles based on polyamide or polyester compositions either suffer
from an unacceptable deterioration of their mechanical properties
upon long-term high temperature exposure or they are very expensive
due to the use of high-cost heat stabilizers.
[0011] There remains a need for low-cost polyamide and polyester
compositions that are suitable for manufacturing articles and that
exhibit good mechanical properties after long-term high temperature
exposure.
SUMMARY OF THE INVENTION
[0012] There is disclosed and claimed herein a molded or extruded
thermoplastic article comprising a thermoplastic composition
comprising: [0013] (a) a thermoplastic resin selected from the
group consisting of polyamides, polyesters, and mixtures thereof;
[0014] (b) 0.25 to 15 weight percent of one or more polyhydric
alcohols having more than two hydroxyl groups and a having a number
average molecular weight (M.sub.n) of less than 2000; [0015] (c) 10
to about 60 weight percent of one or more reinforcement agents; and
[0016] (d) 0 to 50 weight percent of a polymeric toughener
comprising a reactive functional group and/or a metal salt of a
carboxylic acid; wherein all weight percentages are based on the
total weight of the thermoplastic composition and wherein 4 mm test
bars prepared from said thermoplastic composition, and exposed at a
test temperature of 170.degree. C. for a test period of 500 hours,
in an atmosphere of air, and tested according to ISO 527-2/1A,
have, on average, a retention of tensile strength of at least 50
percent, as compared with that of an unexposed control of identical
composition and shape.
[0017] Further disclosed is a molded or extruded thermoplastic
article, as disclosed above, wherein said thermoplastic resin
comprises a polyamide resin and wherein molded 4 mm test bars
prepared from said thermoplastic composition, and exposed at a test
temperature at 210.degree. C. for a test period of 500 hours, in an
atmosphere of air, and tested according to ISO 527-2/1A, have, on
average, a retention of tensile strength of at least 70 percent, as
compared with that of an unexposed control of identical composition
and shape.
DETAILED DESCRIPTION OF THE INVENTION
[0018] For the purposes of the description, unless otherwise
specified, "high-temperature" means a temperature at or higher than
170.degree. C., preferably at or higher than 210 .degree. C., and
most preferably at or higher than 230.degree. C.
[0019] In the present invention, unless otherwise specified,
"long-term" refers to an aging period equal or longer than 500 hrs,
preferably equal or longer than 1000 hrs.
[0020] As used herein, the term "high heat stability", as applied
to the thermoplastic composition disclosed herein or to an article
made from the composition, refers to the retention of physical
properties (for instance, tensile strength) of 4 mm thick molded
test bars consisting of the polyamide composition that are exposed
to air oven aging (AOA) conditions at a test temperature at
170.degree. C. for a test period of at least 500 h, in an
atmosphere of air, and then tested according to ISO 527-2/1A
method. The physical properties of the test bars are compared to
that of unexposed controls that have identical composition and
shape, and are expressed in terms of "% retention". In another
preferred embodiment the test temperature is at 210.degree. C., the
test period is at 500 hours and the exposed test bars have a %
retention of tensile strength of at least 70%. Herein "high heat
stability" means that said molded test bars, on average, meet or
exceed a retention for tensile strength of 50% when exposed at a
test temperature at 170.degree. C. for a test period of at least
500 h. Compositions exhibiting a higher retention of physical
properties for a given exposure temperature and time period have
better heat stability.
[0021] The terms "at 170.degree. C." and "at 210.degree. C." refer
to the nominal temperature of the environment to which the test
bars are exposed; with the understanding that the actual
temperature may vary by .+-.2.degree. C. from the nominal test
temperature.
[0022] The term "(meth)acrylate" is meant to include acrylate
esters and methacrylate esters.
[0023] Herein melting points and glass transitions are as
determined with differential scanning calorimetry (DSC) at a scan
rate of 10.degree. C./min in the first heating scan, wherein the
melting point is taken at the maximum of the endothermic peak and
the glass transition, if evident, is considered the mid-point of
the change in enthalpy.
[0024] The resin composition used in the present invention
comprises a thermoplastic resin selected from the group consisting
of polyamides, polyesters, and mixtures thereof. A preferred
thermoplastic resin is a polyamide resin. Another preferred
thermoplastic resin is a polyester resin.
[0025] Polyamides are condensation products of one or more
dicarboxylic acids and one or more diamines, and/or one or more
aminocarboxylic acids, and/or ring-opening polymerization products
of one or more cyclic lactams. Suitable cyclic lactams are
caprolactam and laurolactam. Polyamides may be fully aliphatic or
semi-aromatic.
[0026] Fully aliphatic polyamides used in the resin composition of
the present invention are formed from aliphatic and alicyclic
monomers such as diamines, dicarboxylic acids, lactams,
aminocarboxylic acids, and their reactive equivalents. A suitable
aminocarboxylic acid is 11-aminododecanoic acid. Suitable lactams
are caprolactam and laurolactam. In the context of this invention,
the term "fully aliphatic polyamide" also refers to copolymers
derived from two or more such monomers and blends of two or more
fully aliphatic polyamides. Linear, branched, and cyclic monomers
may be used.
[0027] Carboxylic acid monomers comprised in the fully aliphatic
polyamides include, but are not limited to aliphatic carboxylic
acids, such as for example adipic acid (C6), pimelic acid (C7),
suberic acid (C8), azelaic acid (C9), decanedioic acid (C10),
dodecanedioic acid (C12), tridecanedioic acid (C13),
tetradecanedioic acid (C14), and pentadecanedioic acid (C15).
Diamines can be chosen among diamines having four or more carbon
atoms, including, but not limited to tetramethylene diamine,
hexamethylene diamine, octamethylene diamine, decamethylene
diamine, dodecamethylene diamine, 2-methylpentamethylene diamine,
2-ethyltetramethylene diamine, 2-methyloctamethylenediamine;
trimethylhexamethylenediamine, meta-xylylene diamine, and/or
mixtures thereof.
[0028] The semi-aromatic polyamide is a homopolymer, a copolymer, a
terpolymer or more advanced polymers formed from monomers
containing aromatic groups. One or more aromatic carboxylic acids
may be terephthalate or a mixture of terephthalate with one or more
other carboxylic acids, such as isophthalic acid, phthalic acid,
2-methyl terephthalic acid and naphthalic acid. In addition, the
one or more aromatic carboxylic acids may be mixed with one or more
aliphatic dicarboxylic acids, as disclosed above. Alternatively, an
aromatic diamine such as meta-xylylene diamine (MXD) can be used to
provide a semi-aromatic polyamide, an example of which is MXD6, a
homopolymer comprising MXD and adipic acid.
[0029] Preferred polyamides disclosed herein are homopolymers or
copolymers wherein the term copolymer refers to polyamides that
have two or more amide and/or diamide molecular repeat units. The
homopolymers and copolymers are identified by their respective
repeat units. For copolymers disclosed herein, the repeat units are
listed in decreasing order of mole % repeat units present in the
copolymer. The following list exemplifies the abbreviations used to
identify monomers and repeat units in the homopolymer and copolymer
polyamides (PA): [0030] HMD hexamethylene diamine (or 6 when used
in combination with a diacid) [0031] T Terephthalic acid [0032] AA
Adipic acid [0033] DMD Decamethylenediamine [0034] 6 .di-elect
cons.-Caprolactam [0035] DDA Decanedioic acid [0036] DDDA
Dodecanedioic acid [0037] I Isophthalic acid [0038] MXD
meta-xylylene diamine [0039] TMD 1,4-tetramethylene diamine [0040]
4T polymer repeat unit formed from TMD and T [0041] 6T polymer
repeat un it formed from HMD and T [0042] DT polymer repeat unit
formed from 2-MPMD and T [0043] MXD6 polymer repeat unit formed
from MXD and AA [0044] 66 polymer repeat unit formed from HMD and
AA [0045] 10T polymer repeat unit formed from DMD and T [0046] 410
polymer repeat unit formed from TMD and DDA [0047] 510 polymer
repeat unit formed from 1,5-pentanediamine and DDA [0048] 610
polymer repeat unit formed from HMD and DDA [0049] 612 polymer
repeat unit formed from HMD and DDDA [0050] 6 polymer repeat unit
formed from .di-elect cons.-caprolactam [0051] 11 polymer repeat
unit formed from 11-aminoundecanoic acid [0052] 12 polymer repeat
unit formed from 12-aminododecanoic acid
[0053] Note that in the art the term "6" when used alone designates
a polymer repeat unit formed from .di-elect cons.-caprolactam.
Alternatively "6" when used in combination with a diacid such as T,
for instance 6T, the "6" refers to HMD. In repeat units comprising
a diamine and diacid, the diamine is designated first. Furthermore,
when "6" is used in combination with a diamine, for instance 66,
the first "6" refers to the diamine HMD, and the second "6" refers
to adipic acid. Likewise, repeat units derived from other amino
acids or lactams are designated as single numbers designating the
number of carbon atoms. In one embodiment the polyamide composition
comprises a one or more polyamides selected from the group
consisting of [0054] Group (I) polyamides having a melting point of
less than 210.degree. C., and comprising an aliphatic or
semiaromatic polyamide selected from the group consisting of
poly(pentamethylene decanediamide) (PA510), poly(pentamethylene
dodecanediamide) (PA512), poly(.epsilon.-caprolactam/hexamethylene
hexanediamide) (PA6/66), poly(.epsilon.-caprolactam/hexamethylene
decanediamide) (PA6/610), poly(.epsilon.-caprolactam/hexamethylene
dodecanediamide) (PA6/612), poly(hexamethylene tridecanediamide)
(PA613), poly(hexamethylene pentadecanediamide) (PA615),
poly(.epsilon.-caprolactam/tetramethylene terephthalamide)
(PA6/4T), poly(.epsilon.-caprolactam/hexamethylene terephthalamide)
(PA6/6T), poly(.epsilon.-caprolactam/decamethylene terephthalamide)
(PA6/10T), poly(.epsilon.-caprolactam/dodecamethylene
terephthalamide) (PA6/12T), poly(hexamethylene
decanediamide/hexamethylene terephthalamide) (PA610/6T),
poly(hexamethylene dodecanediamide/hexamethylene terephthalamide)
(PA612/6T), poly(hexamethylene tetradecanediamide/hexamethylene
terephthalamide) (PA614/6T),
poly(.epsilon.-caprolactam/hexamethylene
isophthalamide/hexamethylene terephthalamide) (PA6/61/6T),
poly(.epsilon.-caprolactam/hexamethylene
hexanediamide/hexamethylene decanediamide) (PA6/66/610),
poly(.epsilon.-caprolactam/hexamethylene
hexanediamide/hexamethylene dodecanediamide) (PA6/66/612),
poly(.epsilon.-caprolactam/hexamethylene
hexanediamide/hexamethylene decanediamide/hexamethylene
dodecanediamide) (PA6/66/610/612), poly(2-methylpentamethylene
hexanediamide/hexamethylene hexanediamide/hexamethylene
terephthamide) (PA D6/66//6T), poly(2-methylpentamethylene
hexanediamide/hexamethylene hexanediamide/) (PA D6/66),
poly(decamethylene decanediamide) (PA1010), poly(decamethylene
dodecanediamide) (PA1012), poly(decamethylene
decanediamide/decamethylene terephthalamide) (PA1010/10T)
poly(decamethylene decanediamide/dodecamethylene
decanediamide/decamethylene terephthalamide/dodecamethylene
terephthalamide (PA1010/1210/10T/12T), poly(11-aminoundecanamide)
(PA11), poly(11-aminoundecanamide/tetramethylene terephthalamide)
(PA11/4T), poly(11-aminoundecanamide/hexamethylene terephthalamide)
(PA11/6T), poly(11-aminoundecanamide/decamethylene terephthalamide)
(PA11/10T), poly(11-aminoundecanamide/dodecamethylene
terephthalamide) (PA11/12T), poly(12-aminododecanamide) (PA12),
poly(12-aminododecanamide/tetramethylene terephthalamide)
(PA12/4T), poly(12-aminododecanamide/hexamethylene terephthalamide)
(PA12/6T), poly(12-aminododecanamide/decamethylene terephthalamide)
(PA12/10T) poly(dodecamethylene dodecanediamide) (PA1212), and
poly(dodecamethylene dodecanediamide/dodecamethylene
dodecanediamide/dodecamethylene terephthalamide)) (PA1212/12T);
[0055] Group (II) polyamides having a melting point of at least
210.degree. C., and comprising an aliphatic polyamide selected from
the group consisting of poly(tetramethylene hexanediamide) (PA46),
poly(.epsilon.-caprolactam) (PA 6), poly(hexamethylene
hexanediamide/(.epsilon.-caprolactam/) (PA 66/6) poly(hexamethylene
hexanediamide) (PA 66), poly(hexamethylene
hexanediamide/hexamethylene decanediamide) (PA66/610),
poly(hexamethylene hexanediamide/hexamethylene dodecanediamide)
(PA66/612), poly(hexamethylene hexanediamide/decamethylene
decanediamide) (PA66/1010), poly(hexamethylene decanediamide)
(PA610), poly(hexamethylene dodecanediamide) (PA612),
poly(hexamethylene tetradecanediamide) (PA614), poly(hexamethylene
hexadecanediamide) (PA616), and poly(tetramethylene
hexanediamide/2-methylpentamethylene hexanediamide) (PA46/D6);
[0056] Group (III) polyamides having a melting point of at least
210.degree. C., and comprising [0057] (aa) about 20 to about 35
mole percent semiaromatic repeat units derived from monomers
selected from one or more of the group consisting of: [0058] (i)
aromatic dicarboxylic acids having 8 to 20 carbon atoms and
aliphatic diamines having 4 to 20 carbon atoms; and [0059] (bb)
about 65 to about 80 mole percent aliphatic repeat units derived
from monomers selected from one or more of the group consisting of:
[0060] (ii) an aliphatic dicarboxylic acid having 6 to 20 carbon
atoms and said aliphatic diamine having 4 to 20 carbon atoms; and
[0061] (iii) a lactam and/or aminocarboxylic acid having 4 to 20
carbon atoms; [0062] Group (IV) polyamides comprising [0063] (cc)
about 50 to about 95 mole percent semiaromatic repeat units derived
from monomers selected from one or more of the group consisting of:
[0064] (i) aromatic dicarboxylic acids having 8 to 20 carbon atoms
and aliphatic diamines having 4 to 20 carbon atoms; and [0065] (dd)
about 5 to about 50 mole percent aliphatic repeat units derived
from monomers selected from one or more of the group consisting of:
[0066] (ii) an aliphatic dicarboxylic acid having 6 to 20 carbon
atoms and said aliphatic diamine having 4 to 20 carbon atoms; and
[0067] (iii) a lactam and/or aminocarboxylic acid having 4 to 20
carbon atoms; [0068] Group (V) polyamides having a melting point of
at least 260.degree. C., comprising [0069] (ee) greater than 95
mole percent semiaromatic repeat units derived from monomers
selected from one or more of the group consisting of: [0070] (i)
aromatic dicarboxylic acids having 8 to 20 carbon atoms and
aliphatic diamines having 4 to 20 carbon atoms; and [0071] (ff)
less than 5 mole percent aliphatic repeat units derived from
monomers selected from one or more of the group consisting of:
[0072] (ii) an aliphatic dicarboxylic acid having 6 to 20 carbon
atoms and said aliphatic diamine having 4 to 20 carbon atoms;
[0073] (iii) a lactam and/or aminocarboxylic acid having 4 to 20
carbon atoms; and [0074] Group (VI) polyamides having no melting
point, and selected from the group consisting of poly(hexamethylene
isophthalamide/hexamethylene terephthalamide) (61/6T) and
poly(hexamethylene isophthalamide/hexamethylene
terephthalamide/hexamethylene hexanediamide) (6I/6T/66).
[0075] Group (I) polyamides may have semiaromatic repeat units to
the extent that the melting point is less than 210.degree. C. and
generally the semiaromatic polyamides of the group have less than
40 mole percent semiaromatic repeat units. Semiaromatic repeat
units are defined as those derived from monomers selected from one
or more of the group consisting of: aromatic dicarboxylic acids
having 8 to 20 carbon atoms and aliphatic diamines having 4 to 20
carbon atoms.
[0076] Another embodiment is a molded or extruded thermoplastic
article wherein said polyamide resin is selected from Group (III)
polyamides selected from the group consisting of
poly(tetramethylene hexanediamide/tetramethylene terephthalamide)
(PA46/4T), poly(tetramethylene hexanediamide/hexamethylene
terephthalamide) (PA46/6T), poly(tetramethylene
hexanediamide/2-methylpentamethylene hexanediamide/decamethylene
terephthalamide)_PA46/D6/10T), poly(hexamethylene
hexanediamide/hexamethylene terephthalamide) (PA66/6T),
poly(hexamethylene hexanediamide/hexamethylene
isophthalamide/hexamethylene terephthalamide PA66/6I/6T, and
poly(hexamethylene hexanediamide/2-methylpentamethylene
hexanediamide /hexamethylene terephthalamide (PA66/D6/6T); and a
most preferred Group (III) polyamide is PA 66/6T.
[0077] Another embodiment is a molded or extruded thermoplastic
article wherein said polyamide resin is selected from Group (IV)
polyamides selected from the group consisting of
poly(tetramethylene terephthalamide/hexamethylene hexanediamide)
(PA4T/66), poly(tetramethylene
terephthalamide/.epsilon.-caprolactam) (PA4T/6),
poly(tetramethylene terephthalamide/hexamethylene dodecanediamide)
(PA4T/612), poly(tetramethylene
terephthalamide/2-methylpentamethylene hexanediamide/hexamethylene
hexanediamide) (PA4T/D6/66), poly(hexaamethylene
terephthalamide/2-methylpentamethylene
terephthalamide/hexamethylene hexanediamide) (PA6T/DT/66),
poly(hexamethylene terephthalamide/hexamethylene hexanediamide)
PA6T/66, poly(hexaamethylene terephthalamide/hexamethylene
decanediamide) (PA6T/610), poly(hexamethylene
terephthalamide/hexamethylene tetradecanediamide) (PA6T/614),
poly(nonamethylene terephthalamide/nonamethylene decanediamide)
(PA9T/910), poly(nonamethylene terephthalamide/nonamethylene
dodecanediamide) (PA9T/912), poly(nonamethylene
terephthalamide/11-aminoundecanamide) (PA9T/11), poly(nonamethylene
terephthalamide/12-aminododecanamide) (PA9T/12), poly(decamethylene
terephthalamide/11-aminoundecanamide) (PA 10T/11),
poly(decamethylene terephthalamide/12-aminododecanamide) (PA10T/12)
poly(decamethylene terephthalamide/decamethylene decanediamide)
(PA10T/1010), poly(decamethylene terephthalamide/decamethylene
dodecanediamide) (PA10T/1012), poly(decamethylene
terephthalamide/tetramethylene hexanediamide) (PA10T/46),
poly(decamethylene terephthalamide/.epsilon.-caprolactam)
(PA10T/6), poly(decamethylene terephthalamide/hexamethylene
hexanediamide) (PA10T/66), poly(dodecamethylene
terephthalamide/dodecamethylene dodecanediamide) (PA12T/1212),
poly(dodecamethylene terephthalamide/.epsilon.-caprolactam)
(PA12T/6), and poly(dodecamethylene terephthalamide/hexamethylene
hexanediamide) (PA12T/66); and a most preferred Group (IV)
polyamide is PA6T/66.
[0078] Another embodiment is a molded or extruded thermoplastic
article wherein said polyamide resin is selected from Group (V)
polyamides selected from the group consisting of
poly(tetramethylene terephthalamide/2-methylpentamethylene
terephthalamide) PA4T/DT, poly(tetramethylene terephthalamide/
hexamethylene terephthalamide) PA4T/6T, poly(tetramethylene
terephthalamide/decamethylene terephthalamide) PA4T/10T,
poly(tetramethylene terephthalamide/dodecamethylene
terephthalamide)PA4T/12T, poly(tetramethylene
terephthalamide/2-methylpentamethylene
terephthalamide/hexamethylene terephthalamide) (PA4T/DT/6T),
poly(tetramethylene terephthalamide/hexamethylene
terephthalamide/2-methylpentamethylene terephthalamide)
(PA4T/6T/DT), poly(hexamethylene
terephthalamide/2-methylpentamethylene terephthalamide) (PA6T/DT),
poly(hexamethylene hexanediamide/hexamethylene isophthalamide) (PA
6T/61), poly(hexamethylene terephthalamide/decamethylene
terephthalamide) PA6T/10T, poly(hexamethylene
terephthalamide/dodecamethylene terephthalamide) (PA6T/12T),
poly(hexamethylene terephthalamide/2-methylpentamethylene
terephthalamide/poly(decamethylene terephthalamide) (PA6T/DT/10T),
poly(hexamethylene terephthalamide/decamethylene terephthalamide/
dodecamethylene terephthalamide) (PA6T/10T/12T), poly(decamethylene
terephthalamide) (PA10T), poly(decamethylene
terephthalamide/tetramethylene terephthalamide) (PA10T/4T),
poly(decamethylene terephthalamide/2-methylpentamethylene
terephthalamide) (PA10T/DT), poly(decamethylene
terephthalamide/dodecamethylene terephthalamide) (PA10T/12T),
poly(decamethylene terephthalamide/2-methylpentamethylene
terephthalamide/(decamethylene terephthalamide) (PA10T/DT/12T).
poly(dodecamethylene terephthalamide) (PA12T), poly(dodecamethylene
terephthalamide)/tetramethylene terephthalamide) (PA12T/4T),
poly(dodecamethylene terephthalamide)/hexamethylene
terephthalamide) PA12T/6T, poly(dodecamethylene
terephthalamide)/decamethylene terephthalamide) (PA12T/10T), and
poly(dodecamethylene terephthalamide)/2-methylpentamethylene
terephthalamide) (PA12T/DT); and a most preferred_Group (V)
Polyamide is PA6T/DT.
[0079] In various embodiments the polyamide is a Group (I)
Polyamide, Group (II) Polyamide, Group (III) Polyamide, Group (IV)
Polyamide, Group (V) Polyamide or Group (VI) Polyamide,
respectively.
[0080] The polyamides may also be blends of two or more polyamides.
Preferred blends include those selected from the group consisting
of Group (I) and Group (II) Polyamides; Group (I) and Group (III)
Polyamide, Group (I) and Group (VI) Polyamides, Group (II) and
Group (III) Polyamides, Group (II) and Group (IV) Polyamides, Group
(II) and Group (V) Polyamides, Group (II) and Group (VI)
Polyamides, Group (III) and Group (VI) Polyamides, and Group (IV)
and Group (V) Polyamides.
[0081] A preferred blend includes Group (II) and (V) Polyamides,
and a specific preferred blend includes poly(hexamethylene
hexanediamide) (PA 66) and poly(hexamethylene
terephthalamide/2-methylpentamethylene terephthalamide) (PA
6T/DT).
[0082] Another preferred blend includes Group (II) and Group (III)
Polyamides and a specific preferred blend includes
poly(.epsilon.-caprolactam) (PA6) and poly(hexamethylene
hexanediamide/hexamethylene terephthalamide (PA66/6T).
[0083] Another embodiment is a molded or extruded thermoplastic
article comprising a thermoplastic polyamide composition as
disclosed above, wherein molded 4 mm test bars prepared from said
polyamide composition, and exposed at a test temperature at
210.degree. C. for a test period of 500 hours, in an atmosphere of
air, and tested according to ISO 527-2/1A, have, on average, a
retention of tensile strength of at least 70 percent, as compared
with that of an unexposed control of identical composition and
shape. Thermoplastic polyamide compositions meeting these test
requirements are referred to as "meeting the requirements of AOA
210.degree. C./500 hours testing."
[0084] The thermoplastic polyamide compositions meeting the
requirements of AOA 210.degree. C./500 hours testing comprise one
or more polyamide resins wherein said polyamide resin comprises a
one or more polyamides independently selected from the groups
consisting of Group (II) Polyamides, Group (III) Polyamides, Group
(IV) polyamides, Group (V) Polyamides and Group (VI) Polyamides, as
disclosed above.
[0085] In various embodiments thermoplastic polyamide compositions
meeting the requirements of AOA 210.degree. C./500 hours are Group
(II) Polyamides, Group (III) Polyamides, Group (IV) Polyamides,
Group (V) Polyamides and Group (VI) Polyamides, respectively.
[0086] A further preferred embodiment is the molded or extruded
thermoplastic article wherein said polyamide resin is selected from
Group (V) Polyamides and wherein said test temperature is at least
230.degree. C. for a test period of at least 500 hours and said
retention of tensile strength is at least 60%, and more preferably
at least 70%, 80% and 90%.
[0087] The molded or extruded thermoplastic article may comprise a
polyester as the thermoplastic resin. Polyesters that are useful
are typically derived from one or more dicarboxylic acids (where
herein the term "dicarboxylic acid" also refers to dicarboxylic
acid derivatives such as esters) and one or more diols. In
preferred polyesters the dicarboxylic acids comprise one or more of
terephthalic acid, isophthalic acid, and 2,6-naphthalene
dicarboxylic acid, and the diol component comprises one or more of
HO(CH.sub.2).sub.nOH (I); 1,4-cyclohexanedimethanol; and
HO(CH.sub.2CH.sub.2O).sub.mCH.sub.2CH.sub.2OH (II); wherein n is an
integer of 2 to 12, and m on average is 1 to 4. Other dicarboxylic
acids that may be used to form the thermoplastic polyester include
decandioic acid, dodecanedioic acid, and adipic acids.
Hydroxycarboxylic acids such as hydroxybenzoic acid may be used as
comonomers. Preferably, the polyester used in the resin composition
according to the present invention is selected from poly(ethylene
terephthalate) (PET), poly(trimethylene terephthalate) (PTT),
poly(1,4-butylene terephthalate) (PBT), poly(ethylene
2,6-naphthoate) (PEN), and poly(1,4-cyclohexyldimethylene
terephthalate) (PCT), and copolymers and blends of the same.
[0088] The molded or extruded thermoplastic article comprises 0.25
to 15 weight percent of one or more polyhydric alcohols having more
than two hydroxyl groups and a number average molecular weight
(M.sub.n) of less than 2000, as determined for polymeric materials
with gel permeation chromatography (GPC)
[0089] Polyhydric alcohols may be selected from aliphatic
hydroxylic compounds containing more than two hydroxyl groups,
aliphatic-cycloaliphatic compounds containing more than two
hydroxyl groups, cycloaliphatic compounds containing more than two
hydroxyl groups, aromatic and saccharides.
[0090] An aliphatic chain in the polyhydric alcohol can include not
only carbon atoms but also one or more hetero atoms which may be
selected, for example, from nitrogen, oxygen and sulphur atoms. A
cycloaliphatic ring present in the polyhydric alcohol can be
monocyclic or part of a bicyclic or polycyclic ring system and may
be carbocyclic or heterocyclic. A heterocyclic ring present in the
polyhydric alcohol can be monocyclic or part of a bicyclic or
polycyclic ring system and may include one or more hetero atoms
which may be selected, for example, from nitrogen, oxygen and
sulphur atoms. The one or more polyhydric alcohols may contain one
or more substituents, such as ether, carboxylic acid, carboxylic
acid amide or carboxylic acid ester groups.
[0091] Examples of polyhydric alcohol containing more than two
hydroxyl groups include, without limitation, triols, such as
glycerol, trimethylolpropane,
2,3-di-(2'-hydroxyethyl)-cyclohexan-1-ol, hexane-1,2,6-triol,
1,1,1-tris-(hydroxymethyl)ethane,
3-(2'-hydroxyethoxy)-propane-1,2-diol,
3-(2'-hydroxypropoxy)-propane-1,2-diol,
2-(2'-hydroxyethoxy)-hexane-1,2-diol,
6-(2'-hydroxypropoxy)-hexane-1,2-diol,
1,1,1-tris-[(2'-hydroxyethoxy)-methyl]-ethane,
1,1,1-tris-[(2'-hydroxypropoxy)-methyl]-propane,
1,1,1-tris-(4'-hydroxyphenyl)-ethane,
1,1,1-tris-(hydroxyphenyl)-propane,
1,1,3-tris-(dihydroxy-3-methylphenyl)-propane,
1,1,4-tris-(dihydroxyphenyl)-butane,
1,1,5-tris-(hydroxyphenyl)-3-methylpentane, di-trimethylopropane,
trimethylolpropane ethoxylates, or trimethylolpropane propoxylates;
polyols such as pentaerythritol, dipentaerythritol, and
tripentaerythritol; and saccharides, such as cyclodextrin,
D-mannose, glucose, galactose, sucrose, fructose, xylose,
arabinose, D-mannitol, D-sorbitol, D-or L-arabitol, xylitol,
iditol, talitol, allitol, altritol, guilitol, erythritol, threitol,
and D-gulonic-y-lactone; and the like.
[0092] Preferred polyhydric alcohols include those having a pair of
hydroxyl groups which are attached to respective carbon atoms which
are separated one from another by at least one atom. Especially
preferred polyhydric alcohols are those in which a pair of hydroxyl
groups is attached to respective carbon atoms which are separated
one from another by a single carbon atom.
[0093] Preferably, the polyhydric alcohol used in the thermoplastic
composition is pentaerythritol, dipentaerythritol,
tripentaerythritol, di-trimethylolpropane, D-mannitol, D-sorbitol
and xylitol. More preferably, the polyhydric alcohol used is
dipentaerythritol and/or tripentaerythritol. A most preferred
polyhydric alcohol is dipentaerythritol.
[0094] In various embodiments the content of said polyhydric
alcohol in the thermoplastic composition is 0.25-15 weight percent,
preferably 0.25-8 weight percent, more preferably 0.25-5 weight
percent. In polyamides, most preferably 1-4 weight percent; in
polyesters most preferably 0.25 to 1.5 weight percent, based on the
total weight of said thermoplastic composition.
[0095] The molded or extruded thermoplastic article comprises 10 to
about 60 weight percent, and preferably about 12.5 to 55 weight
percent and 15 to 50 weight percent, of one or more reinforcement
agents. The reinforcement agent may be any filler, but is
preferably selected from the group consisting calcium carbonate,
glass fibers with circular and noncircular cross-section, glass
flakes, glass beads, carbon fibers, talc, mica, wollastonite,
calcined clay, kaolin, diatomite, magnesium sulfate, magnesium
silicate, barium sulfate, titanium dioxide, sodium aluminum
carbonate, barium ferrite, potassium titanate and mixtures
thereof.
[0096] Glass fibers with noncircular cross-section refer to glass
fiber having a cross section having a major axis lying
perpendicular to a longitudinal direction of the glass fiber and
corresponding to the longest linear distance in the cross section.
The non-circular cross section has a minor axis corresponding to
the longest linear distance in the cross section in a direction
perpendicular to the major axis. The non-circular cross section of
the fiber may have a variety of shapes including a cocoon-type
(figure-eight) shape, a rectangular shape; an elliptical shape; a
roughly triangular shape; a polygonal shape; and an oblong shape.
As will be understood by those skilled in the art, the cross
section may have other shapes. The ratio of the length of the major
axis to that of the minor access is preferably between about 1.5:1
and about 6:1. The ratio is more preferably between about 2:1 and
5:1 and yet more preferably between about 3:1 to about 4:1.
Suitable glass fiber are disclosed in EP 0 190 001 and EP 0 196
194.
[0097] The molded or extruded thermoplastic article, optionally,
comprises 0 to 50 weight percent of a polymeric toughener
comprising a reactive functional group and/or a metal salt of a
carboxylic acid. In one embodiment the molded or extruded
thermoplastic article comprises 2 to 20 weight percent polymeric
toughener selected from the group consisting of: a copolymer of
ethylene, glycidyl (meth)acrylate, and optionally one or more
(meth)acrylate esters; an ethylenel.alpha.-olefin or
ethylene/.alpha.-olefin/diene copolymer grafted with an unsaturated
carboxylic anhydride; a copolymer of ethylene, 2-isocyanatoethyl
(meth)acrylate, and optionally one or more (meth)acrylate esters;
and a copolymer of ethylene and acrylic acid reacted with a Zn, Li,
Mg or Mn compound to form the corresponding ionomer.
[0098] In the present invention, the polymer composition of the
present invention may also comprise other additives commonly used
in the art, such other heat stabilizers or antioxidants referred to
as "co-stabilizers", antistatic agents, blowing agents, lubricants,
plasticizers, and colorant and pigments.
[0099] Co-stabilizers include copper stabilizers, secondary aryl
amines, hindered amine light stabilizers (HALS), hindered phenols,
and mixtures thereof.
[0100] A significant advantage of the molded or extruded
thermoplastic articles of the invention is that high thermal
stability is provided without the use of conventional copper heat
stabilizers. Copper heat stabilizers tend to act as corrosive
agents over long periods of time at elevated temperatures; and in
some environments actually cause degradation of semiaromatic
polymers. Thus, another embodiment is molded or extruded
thermoplastic article wherein said thermoplastic resin is a
polyamide and said thermoplastic composition comprises less than 25
ppm copper as determined with atomic absorption spectroscopy.
[0101] Herein the thermoplastic composition is a mixture by
melt-blending, in which all polymeric ingredients are adequately
mixed, and all non-polymeric ingredients are adequately dispersed
in a polymer matrix. Any melt-blending method may be used for
mixing polymeric ingredients and non-polymeric ingredients of the
present invention. For example, polymeric ingredients and
non-polymeric ingredients may be fed into a melt mixer, such as
single screw extruder or twin screw extruder, agitator, single
screw or twin screw kneader, or Banbury mixer, and the addition
step may be addition of all ingredients at once or gradual addition
in batches. When the polymeric ingredient and non-polymeric
ingredient are gradually added in batches, a part of the polymeric
ingredients and/or non-polymeric ingredients is first added, and
then is melt-mixed with the remaining polymeric ingredients and
non-polymeric ingredients that are subsequently added, until an
adequately mixed composition is obtained. If a reinforcing filler
presents a long physical shape (for example, a long glass fiber),
drawing extrusion molding may be used to prepare a reinforced
composition.
[0102] The thermoplastic composition having a polyhydric alcohol
having two or more hydroxyl groups, as disclosed above, is useful
in increasing long-term thermal stability at high temperatures of
molded or extruded articles made therefrom. The long-term heat
stability of the articles can be assessed by exposure (air oven
ageing) of 4 mm thick test samples at various test temperatures in
an oven for various test periods of time. The oven test
temperatures for the composition disclosed herein include
170.degree. C. and 500 hours test periods; 210.degree. C. and 500
hours test periods; and 230.degree. C. and 500 hours test periods.
The test samples, after air oven ageing, are tested for tensile
strength and elongation to break, according to ISO 527-2/1A test
method; and compared with unexposed controls having identical
composition and shape, that are dry as molded (DAM). The comparison
with the DAM controls provides the retention of tensile strength
and/or retention of elongation to break, and thus the various
compositions can be assessed as to long-term heat stability
performance.
[0103] In various embodiments the thermoplastic composiiton
composition has an AOA 170.degree. C./500 hours retention of
tensile strength of at least 50% and preferably at least 60, 70,
80, and 90%, based upon comparison with DAM non-exposed
controls.
[0104] In various embodiments the thermoplastic polyamide
composition has an AOA 210.degree. C./500 hours retention of
tensile strength of at least 70% and preferably at least 70, 80,
and 90%, based upon comparison with DAM non-exposed controls.
[0105] In another aspect, the present invention relates a use of
the above disclosed thermoplastic compositions for high temperature
applications.
[0106] In another aspect, the present invention relates to a method
for manufacturing an article by shaping the thermoplastic
composition of the invention. Examples of articles are films or
laminates, automotive parts or engine parts or
electrical/electronics parts. By "shaping", it is meant any shaping
technique, such as for example extrusion, injection moulding,
thermoform moulding, compression moulding or blow moulding.
Preferably, the article is shaped by injection moulding or blow
moulding.
[0107] The molded or extruded thermoplastic articles disclosed
herein may have application in many vehicular components that meet
one or more of the following requirements: high impact
requirements; significant weight reduction (over conventional
metals, for instance); resistance to high temperature; resistance
to oil environment; resistance to chemical agents such as coolants;
and noise reduction allowing more compact and integrated design.
Specific molded or extruded thermoplastic articles are selected
from the group consisting of charge air coolers (CAC); cylinder
head covers (CHC); oil pans; engine cooling systems, including
thermostat and heater housings and coolant pumps; exhaust systems
including mufflers and housings for catalytic converters; air
intake manifolds (AIM); and timing chain belt front covers. As an
illustrative example of desired mechanical resistance against
long-term high temperature exposure, a charge air cooler can be
mentioned. A charge air cooler is a part of the radiator of a
vehicle that improves engine combustion efficiency. Charge air
coolers reduce the charge air temperature and increase the density
of the air after compression in the turbocharger thus allowing more
air to enter into the cylinders to improve engine efficiency. Since
the temperature of the incoming air can be more than 200.degree. C.
when it enters the charge air cooler, it is required that this part
be made out of a composition maintaining good mechanical properties
under high temperatures for an extended period of time.
[0108] The present invention is further illustrated by the
following examples. It should be understood that the following
examples are for illustration purposes only, and are not used to
limit the present invention thereto.
EXAMPLES
Materials
[0109] In the Examples and Comparative Examples:
[0110] PA66 refers to an aliphatic polyamide made of
1,6-hexanedioic acid and 1,6-hexamethylenediamine having an
relative viscosity in the range of 46-51 and a melting point of
about 263.degree. C., commercially available from E.I. DuPont de
Nemours and Company, Wilmington, Del., USA under the trademark
Zytel.RTM. 101NC010.
[0111] PA6-1 refers to Durethan B29 poly(.epsilon.-caprolactam)
available from Lanxess Germany.
[0112] PA6-2 refers to Ultramid.RTM. B27
poly(.epsilon.-caprolactam) available from BASF, USA.
[0113] PA6T/DT refers HTN501 NC010, a copolyamide of terephthalic
acid, hexamethylenediamine, and 2-methyl-pentamethylenediamine
having an inherent viscosity (IV), according to ASTM D2857 method,
in the range of 0.8 to 0.95 (typically 0.88) and a melting point of
about 300.degree. C., and available from E.l. DuPont de Nemours and
Company, Wilmington, Del., USA.
[0114] PA 6T/66 refers HTN502 NC010, a copolyamide made from
terephthalic acid, adipic acid, and hexamethylenediamine; wherein
the two acids are used in a 55:45 molar ratio; having a melting
point of ca. 310.degree. C., having an inherent viscosity (IV),
according to ASTM D2857 method, in the range of 0.9 to 1.0
(typically 0.96) available from E.I. DuPont de Nemours and Company,
Wilmington, Del., USA.
[0115] PBT refers to Crastin.RTM. 6003 poly(1,4-butylene
terephthalate) having a melt flow rate (MFR) from 77 to 97 g/10 min
(measured according to ISO1133, 250.degree. C., 2.16 kg) available
from E.l. DuPont de Nemours and Company, Wilmington, Del., USA
[0116] PE refers to pentaerythritol that was from Perstorp
Speciality Chemicals AB, Perstorp, Sweden.
[0117] DPE refers to dipentaerythritol that was from Perstorp
Speciality Chemicals AB, Perstorp, Sweden as Di-Penta 93.
[0118] TPE refers to tripentaerythritol that was from Sigma Aldrich
Co., Milwaukee Wis.
[0119] Sorbitol was from Sigma Aldrich Co., Milwaukee Wis.
[0120] DI-TMP refers to di-trimethylolpropane that was from
Perstorp Speciality Chemicals AB, Perstorp, Sweden.
[0121] Glass fibers A 4.5 mm length chopped glass fibers, refers to
OCV 983, available from Owens Corning Vetrotex, France.
[0122] Glass Fiber B refers to PPG 3660 chopped glass fiber
available fro PPG Industries, Pittsburgh, Pa.
[0123] Glass Fiber C refers to OCV 952 chopped glass fiber
available from Owens Corning Vetrotex, France.
[0124] Glass Fiber D refers to PPG 3540 chopped glass fiber
available from PPG Industries, Pittsburgh, Pa.
[0125] Black Pigment A refers to 40 wt % nigrosine black pigment
concentrate in a PA66 carrier.
[0126] Cu heat stabilizer refers to a mixture of 7 parts of
potassium iodide and 1 part of copper iodide in 0.5 part of a
stearate wax binder.
[0127] Vestowax A01535 was available from Evonik Industries,
Germany.
[0128] Irganox.RTM. 1010 stabilizer was available from Ciba
Speciality Chemicals Inc, Switzerland.
[0129] Irganox.RTM. 1098 stabilizer was available from Ciba
Speciality Chemicals Inc, Switzerland.
[0130] Irgafos.RTM. 12 stabilizer refers to phosphite heat
stabilizer Ciba Speciality Chemicals Inc, Switzerland.
[0131] Acrawax.RTM. C lubricant refers to N,Ni-ethylene
bisstearamide from Lonza Chemical Co.
[0132] SHP refers to sodium dihydrogen phosphate from Sigma-Aldrich
GmbH.
[0133] Fusabond.RTM. EP 1021 is a copolymer of ethylene and maleic
anhydride mono ester, available from E.I. DuPont de Nemours and
Company, Wilmington, Del., USA.
[0134] DER 732 Epoxy is a liquid epoxy resin available from Dow
Chemical, Midland, Mich.
[0135] Polyamide A refers to PA66/6T (75/25 molar ratio repeat
units) with amine ends approximately 50 meq/kg that was provided
according to the following procedure: Polyamide 66 salt solution
(3928 lbs. of a 51.7 percent by weight with a pH of 8.1) and 2926
lbs of a 25.2% by weight of polyamide 6T salt solution with a pH of
7.6 were charged into an autoclave with 100 g of a conventional
antifoam agent, 20g of sodium hypophosphite, 220g of sodium
bicarbonate, 2476 g of 80% HMD solution in water, and 1584 g of
glacial acetic. The solution was then heated while the pressure was
allowed to rise to 265 psia at which point, steam was vented to
maintain the pressure at 265 psia and heating was continued until
the temperature of the batch reached 250.degree. C. The pressure
was then reduced slowly to 6 psia, while the batch temperature was
allowed to further rise to 280-290.degree. C. The pressure was then
held at 6 psia and the temperature was held at 280-290.degree. C.
for 20 minutes. Finally, the polymer melt was extruded into
strands, cooled, and cut into pellets. The resulting polyamide
66/6T is referred to herein as Polyamide A having a melting point
of about 268.+-.1.degree. C., relative viscosity (according to ASTM
D-789 method) of 42.+-.2; NH2 ends of 43.+-.2 meg/kg and COOH ends
of 88.+-.5 meg/kg.
[0136] Polyamide B refers to PA66/6T (75/25 molar ratio repeat
units) with high amine ends, that is, at least 70 meq/kg, that was
provided according to the following procedure:
Polyamide 66/6T salt solution (214.25 lbs. of a 39.70 percent by
weight) was prepared from hexamethylenediamine, 1,6-adipic acid,
and terephthalic acid in water, where the molar ratio of 1,6-adipic
acid to terephthalic acid is 75:25. The salt solution had a pH of
8.20.+-.0.05 and was charged into an autoclave with 3.5 g of a 10
percent by weight solution of a conventional antifoam agent in
water, 0.7 g of sodium hypophosphite, 7.7 g of sodium bicarbonate,
237.5 g of 80% HMD solution in water, and 15 g of glacial acetic
acid. The solution was then heated while the pressure was allowed
to rise to 265 psia at which point, steam was vented to maintain
the pressure at 265 psia and heating was continued until the
temperature of the batch reached 255.degree. C. The pressure was
then reduced slowly to 10 psia, while the batch temperature was
allowed to further rise to 275-285.degree. C. The pressure was then
held at 10 psia and the temperature was held at 275-285.degree. C.
for 20 minutes. Finally, the polymer melt was extruded into
strands, cooled, and cut into pellets. The resulting polyamide
66/6T is referred to herein as Polyamide B having a melting point
of about 269.+-.1.degree. C.; relative viscosity (according to ASTM
D-789 method) of 44.+-.2, NH2 ends of 88.+-.2 meg/kg and COOH ends
of 51.+-.5 meg/kg.
Methods
[0137] Compounding Method A
[0138] Examples 1-14 and comparative examples C-1-C-7 were prepared
by melt blending the ingredients listed in the Tables in a 40 mm
twin screw extruder (Berstorff ZE40) operating at about 280.degree.
C. using a screw speed of about 300 rpm, a throughput of 110
kg/hour. The glass fibers were added to the melt through a screw
side feeder. Ingredient quantities shown in the Tables are given in
weight percent on the basis of the total weight of the
thermoplastic composition.
[0139] The compounded mixture was extruded in the form of laces or
strands, cooled in a water bath, chopped into granules and placed
into sealed aluminum lined bags in order to prevent moisture pick
up. The cooling and cutting conditions were adjusted to ensure that
the materials were kept below 0.15 wt % of moisture level.
[0140] Compounding Method B
[0141] Examples 15, 16 and Comparative Example C-8 were prepared by
melt blending the ingredients listed in the Table 9 in a 40 mm twin
screw extruder (Berstorff ZE40) operating at a processing set
temperature of barrel and die of 250.degree. C. and a melt
temperature of about 290.degree. C. Extrusion and chopping was as
described in Method A; with the exception that before molding, the
samples were pre-dried to less than 0.04 wt % moisture.
[0142] Compounding Method C
[0143] Examples 17-22 and Comparative Examples C-9-C-11 were
prepared by melt blending the ingredients listed in the Tables in a
30 mm twin screw extruder (ZSK 30 by Coperion) operating at about
310.degree. C. barrel setting using a screw speed of about 300 rpm,
a throughput of 13.6 kg/hour and a melt temperature measured by
hand of about 355.degree. C. The glass fibers were added to the
melt through a screw side feeder. Ingredient quantities shown in
the Tables are given in weight percent on the basis of the total
weight of the thermoplastic composition. Extrusion and chopping was
as described in Method A.
[0144] Physical Properties Measurement
[0145] Mechanical tensile properties, i.e. E-modulus, stress at
break (Tensile strength) and strain at break (elongation at break)
were measured according to ISO 527-2/1A. Measurements were made on
injection molded ISO tensile bar as listed:
[0146] Examples 1-14 and Comparative Examples C-1-C-7: mold
temperature was 100.degree. C., melt temperature was
295-300.degree. C.;
[0147] Examples 15-16 and C-8: PBT mold temperature was 80.degree.
C., melt temperature was about 250.degree. C.
[0148] Examples 17-22 and C-11: mold temperature for PA 6T/6D was
145-150.degree. C.; mold temperature for PA 6T/66 was
90-100.degree. C.; and melt temperature was 325-330.degree. C. for
both resins.
[0149] The thickness of the test specimens was 4 mm and a width of
10 mm according to ISO 527/1A at a testing speed of 5 mm/min
(tensile strength and elongation). Tensile Modulus was measured at
1 mm/min.
[0150] Air Oven Ageing (AOA)
[0151] The test specimens were heat aged in a re-circulating air
ovens (Heraeus type UT6060) according to the procedure detailed in
ISO 2578. At various heat aging times, the test specimens were
removed from the oven, allowed to cool to room temperature and
sealed into aluminum lined bags until ready for testing. The
tensile mechanical properties were then measured according to ISO
527 using a Zwick tensile instrument. The average values obtained
from 5 specimens are given in the Tables.
[0152] Retention of E-modulus, stress at break and strain at break
corresponds to the percentage of the E-modulus, stress at break and
strain at break after heat aging for 500 hours 1000 hours in
comparison with the value of the specimens non-heat-aged control
specimens considered as being 100%.
Example 1 and 2 and C-1
[0153] Compositions of Examples 1, 2 and Comparative Example C-1
are listed in Table 1 for PA66 compositions. Tensile properties
after AOA at 210.degree. C. at 500 h and 1000 h, and non-heat-aged
control are listed in Table 2. Table 3 lists the retention of
physical properties of the AOA samples as compared with the
non-aged controls. Higher values of mechanical tensile properties
(E-modulus, tensile strength, stress at yield) mean better
mechanical properties.
TABLE-US-00001 TABLE 1 Example No. Formulation C-1 1 2 PA66 69.7
68.2 66.7 Glass fiber A 30.0 30.0 30.0 Cu Heat stabilizer 0.3 0.3
0.3 DPE -- 1.5 3.0
TABLE-US-00002 TABLE 2 Example No. C-1 1 2 Tensile modulus at
23.degree. C. (MPa) non-heat-aged 9731 9881 10200 heat aging at
210.degree. C. for 500 hours 9543 10047 10322 heat aging at
210.degree. C. for 1000 hours 9360 9786 10002 Tensile Strength at
break at 23.degree. C. (MPa) non-heat-aged 206 214 213 heat aging
at 210.degree. C. for 500 hours 161 191 211 heat aging at
210.degree. C. for 1000 hours 121 165 202 Elongation at break at
23.degree. C. (MPa) DAM 3.5 3.6 3.1 heat aging at 210.degree. C.
for 500 hours 2.0 2.5 2.9 heat aging at 210.degree. C. for 1000
hours 1.5 2.1 2.7
TABLE-US-00003 TABLE 3 Example No. C-1 1 2 Retention of Tensile
modulus at 23.degree. C. non-heat-aged 100% 100% 100% (MPa) (9731)
(9881) (10200) heat aging at 210.degree. C. for 500 hours 98.1%
101.7% 101.2% heat aging at 210.degree. C. for 1000 hours 96.2%
99.0% 98.1% Retention of Tensile Strength at 23.degree. C.
non-heat-aged 100% 100% 100% (MPa) (206) (214) (213) heat aging at
210.degree. C. for 500 hours 78.2% 89.3% 99.1% heat aging at
210.degree. C. for 1000 hours 58.7% 77.1% 94.8% Retention of
Elongation at break at 23.degree. C. non-heat-aged 100% 100% 100%
(MPa) (3.5) (3.6) (3.1) heat aging at 210.degree. C. for 500 hours
57.1% 69.4% 93.5% heat aging at 210.degree. C. for 1000 hours 42.9%
58.3% 87.1%
[0154] As shown in Table 3, the comparative example comprising only
a conventional copper heat stabilizer (C-1) showed poor retention
of the mechanical properties, e.g. the retention of elongation at
break upon a 1000 hours heat aging value was only 42.9%. In
contrast, the Examples 1 and 2 according to the present invention
exhibited retention of elongation at break values of 58.3 and
87.1%. For example, the polyamide composition comprising 3 wt % of
a polyhydric alcohol (Example 2) exhibited a surprising and
unexpected 1.5 to 2 fold increase of the retention of tensile
strength and elongation at break upon a 1000 hours heat aging.
Examples 3-5 and Comparative Examples C-2-C-3
[0155] Compositions of Examples 3-5 and Comparative Example C-2 and
C-3 are listed in Table 4 for PA66 compositions. Tensile properties
after AOA at 210.degree. C. at 500 h and 1000 h, and non-heat-aged
control; and retention of physical properties; are listed in Table
4.
[0156] As shown in Table 4, the comparative examples containing no
copper stabilizer (C-2); or only copper stabilizer (C-3), showed
poor retention of tensile strength under AOA conditions. Example 4
containing, only DPE as a thermal stabilizer, showed much better
retention of tensile strength than the conventional copper
stabilized system (C-3).
TABLE-US-00004 TABLE 4 Example C-2 C-3 3 4 5 PA66 70.00 69.70 68.95
67.00 66.70 Glass fiber A 30.00 30.00 30.00 30.00 30.00 Cu Heat
stabilizer 0.30 0.30 0.30 DPE 0.75 3.00 3.00 Tensile properties DAM
Tensile Modulus [MPa] 9385.0 9502.0 9706.0 9872.0 9888.0 Tensile
Strength [MPa] 199.8 204.2 208.2 198.0 196.5 Elongation @ Break [%]
3.9 3.8 3.7 3.0 2.9 Tensile properties 500 h at 210.degree. C.
Tensile Modulus [MPa] 9810 10530 10618 10824 10930 Tensile Strength
[MPa] 94.2 155.8 179.6 212.2 207.2 retention Tensile Strength (%)
47.2 76.3 86.2 107.2 105.4 Elongation @ Break [%] 1.2 1.8 2.2 3.2
2.8 Tensile properties 1000 h at 210.degree. C. Tensile Modulus
[MPa] 5123 8837 10146 10645 10931 Tensile Strength [MPa] 12.8 74.4
115.7 168.1 178.1 % retention Tensile Strength 6.4% 36.4% 55.6%
84.9% 90.6% Elongation @ Break [%] 0.3 1.1 1.5 2.1 2.1
Examples 6-9
[0157] PA66 compositions of Examples 6-10 with a variety of
polyhydric alcohols and Comparative Example C-3 are listed in Table
5. Tensile properties after AOA at 210.degree. C. at 500 h and 1000
h, and tensile properties of non-heat-aged control; and retention
of physical properties; are listed in Table 5. All the examples
showed greater than 80% retention of tensile strength, after 500
hours AOA at 210.degree. C. These results are comparable to or
better than the conventional copper stabilizer (C-3).
Examples 10 and C-4
[0158] PA6 compositions of Examples 10 and Comparative Example C-4
are listed in Table 6. Tensile properties after AOA at 210.degree.
C. at 500 h and 1000 h; tensile properties of non-heat-aged
control; and retention of physical properties; are listed in Table
6. After 1000 hours AOA at 210.degree. C., Example 10 showed
greater than 100% retention of tensile strength, whereas C-4 with
copper stabilizer showed only about 52% retention of tensile
strength.
TABLE-US-00005 TABLE 5 Example C-3 6 7 8 9 PA66 69.70 66.70 66.70
66.70 66.70 Glass fiber A 30.00 30.00 30.00 30.00 30.00 Cu Heat
stabilizer 0.30 0.30 0.30 0.30 0.30 PE 3.0 TPE 3.00 Sorbitol 3.00
Di-TMP 3.00 Tensile properties DAM Tensile Modulus [MPa] 9502.0
9804.0 10058.0 9890.0 9522.0 Tensile Strength [MPa] 204.2 196.1
211.3 195.8 201.8 Elongation @ Break [%] 3.8 2.7 3.2 2.7 3.5
Tensile properties 500 h at 210.degree. C. Tensile Modulus [MPa]
10530 10749 10955 10856 10991 Tensile Strength [MPa] 155.8 190.8
200.2 167.8 191.6 retention Tensile Strength (%) 76.3 97.3 94.7
85.7 95.0 Elongation @ Break [%] 1.8 2.3 2.5 1.9 2.4 Tensile
properties 1000 h at 210.degree. C. Tensile Modulus 8837 10719
10810 10502 10844 [MPa] Tensile Strength 74.4 155.8 162.0 118.8
170.4 [MPa] retention Tensile Strength (%) 36.4 79.4 76.7 60.7 84.4
Elongation @ Break [%] 1.1 1.8 1.8 1.3 2.0
TABLE-US-00006 TABLE 6 Example C-4 10 PA6-1 69.70 66.70 Glass fiber
A 30.00 30.00 Cu Heat stabilizer 0.30 0.30 DPE 3.00 Tensile
properties DAM Tensile Modulus [MPa] 9286.0 9298.0 Tensile Strength
[MPa] 186.6 186.8 Elongation @ Break [%] 4.3 3.9 Tensile properties
500 h at 210.degree. C. Tensile Modulus [MPa] 11552 11364 Tensile
Strength [MPa] 158.3 206.9 Retention Tensile 84.8 110.8 Strength
(%) Elongation @ Break 1.7 3.0 [%] Tensile properties 1000 h at
210.degree. C. Tensile Modulus [MPa] 11030 11304 Tensile Strength
[MPa] 98.0 207.1 Retention Tensile 52.5 110.9 Strength (%)
Elongation @ Break 1.0 3.3 [%]
TABLE-US-00007 TABLE 7 Example C-5 11 C-6 12 C-7 13 PA66 68.85
67.80 Polyamide A (66/6T) 68.85 67.80 Polyamide B (66/6T) 68.85
67.80 Glass Fiber B 30.00 30.00 30.00 30.00 30.00 30.00 Black
Pigment A 0.70 0.70 0.70 0.70 0.70 0.70 Cu Heat stabilizer 0.45
0.45 0.45 DPE 1.50 1.50 1.50 Tensile properties DAM Tensile Modulus
[MPa] 9747.0 9811.0 8791.0 8848.0 9207.7 8631.0 Tensile Strength
[MPa] 207.8 205.2 198.6 189.1 196.1 187.2 Elongation @ Break [%]
3.8 3.4 3.7 3.2 5.5 3.4 Tensile properties 500 h at 210.degree. C.
Tensile Modulus [MPa] 9558.0 9028.0 8353.0 8549.0 8377.0 8355.0
Tensile Strength [MPa] 160.7 210.0 148.0 198.5 151.3 202.0
Retention Tensile 77.3% 102.3% 74.5% 105.0% 77.1% 107.9% Strength
[%] Elongation @ Break [%] 2.0 3.3 1.9 3.4 2.0 3.8 Tensile
properties 1000 h at 210.degree. C. Tensile Modulus [MPa] 7353 9700
9142 9392 9404 9310 Tensile Strength [MPa] 62.0 127.0 86.0 152.0
101.0 165 Retention Tensile 29.8% 61.9% 43.3% 80.4% 51.5% 88.1%
Strength [%] Elongation @ Break [%] 1.1 1.8 1.1 2.1 1.2 2.4
Examples 11-13 and C-5-C-7
[0159] Compositions of Examples 11-13 and C-5-C-7 are listed in
Table 7. Examples 12 and C-6 show the heat ageing performance of
PA66/6T (75/25 molar ratio) having a number of amine ends of about
45 meq/Kg. Examples 13 and C-7 show the heat ageing performance of
PA66/6T (75/25 molar ratio) having a number of amine ends of about
88 meq/Kg. Tensile properties after AOA at 210.degree. C. at 500 h
and 1000 h, and tensile properties of non-heat-aged control; and
retention of physical properties; are listed in Table 7. The
Examples show that the presence of DPE at 1.5 wt % level provides
significant improvement in retention of tensile strength, and
especially at 1000 h and 210.degree. C., as compared to the
comparative examples having the conventional copper stabilizer.
Furthermore Example 13, having amine ends at 88 meq/Kg exhibits
unexpectedly higher % retention of tensile strength in heat ageing
at 1000 h and 210.degree. C., than Example 12 (amine ends 45
meq/Kg) and Example 11 (PA66 having NH2 ends in the 45-50 meq/Kg
range).
Example 14
[0160] This Example illustrates the unexpected and surprising
results provided a blend of Group (II) polyamide (PA6) with Group
(III) polyamide (PA66/6T) having high amine ends (88 meq/Kg).
Example 14, listed in Table 8, contains PA66/6T and 5 wt % PA6, and
has a 98.6% retention of tensile strength after AOA at 1000 h and
210.degree. C., compared with Example 13 containing PA66/6T alone,
which shows 88.1% retention of tensile strength under the same
conditions. This indicates that blends of polyamides can have
significantly improved properties over that of the base polyamide
comprising the major fraction of the blend. The PA6 composition of
Example 10 shows 110.9% retention of tensile strength under the
same conditions.
TABLE-US-00008 TABLE 8 Example 14 Polyamide B (66/6T) 57.81 PA6-2
5.00 Glass Fiber A 35.00 Black Pigment A 0.69 DPE 1.50 Tensile
properties DAM Tensile Modulus [MPa] 11300 Tensile Strength [MPa]
208 Elongation @ Break [%] 3.4 Tensile properties 500 h at
210.degree. C. Tensile Modulus [MPa] 11425 Tensile Strength [MPa]
227 Retention Tensile Strength (%) 109.1 Elongation @ Break [%] 3.5
Tensile properties 1000 h at 210.degree. C. Tensile Modulus [MPa]
11418 Tensile Strength [MPa] 205 Retention Tensile Strength (%)
98.6 Elongation @ Break [%] 2.7
Example 15-16 and Comparative Example C-8
[0161] These Examples, listed in Table 9, illustrate the results
provided with poly(butylene terephthalate) (PBT) stabilized with
DPE. The Tensile properties after 1000 h AOA at 180.degree. C. show
93 and 104% retention of Tensile strength for Examples 15 and 16,
respectively, versus an 80% retention for the Comparative Example
C-8 lacking DPE.
Examples 17-21 and Comparative Examples C-9 and C-10
[0162] Examples 17-21 illustrate the use of a Group (V) Polyamide,
in the form of PA6T/DT, in combination with polyhdric alcohols in
heat ageing. Tensile properties after AOA at 210.degree. C. at 500
h and 1000 h; AOA at 230.degree. C. at 500 h and 1000 h; tensile
properties of non-heat-aged DAM control (0 hours); and retention of
physical properties; are listed in Table 10. The Examples show a
surprising and unexpected improvement in % retention of tensile
strength as compared to a composition with no thermal stabilizer
(C-9) or a composition with the conventional copper thermal
stabilizer (C-10) at both temperatures.
TABLE-US-00009 TABLE 9 Example C-8 15 16 Composition (wt %) PBT
69.20 68.70 67.70 Glass Fiber C 30.00 30.00 30.00 Irganox 1010 0.30
0.30 0.30 Vestowax AO 1535 0.50 0.50 0.50 DPE 0.50 1.50 Tensile
properties DAM Tensile Modulus [MPa] 9718.0 9858.0 10105.0 Tensile
Strength [MPa] 147.2 151.1 139.8 Elongation @ Break [%] 2.8 2.5 1.9
Tensile properties 500 h at 180.degree. C. Tensile Modulus [MPa]
9399.0 10296.0 10096.0 Tensile Strength [MPa] 157.6 158.8 158.8
Retention Tensile 107.1 105.1 113.6 Strength (%) Elongation @ Break
[%] 2.5 2.1 2.0 Tensile properties 1000 h at 180.degree. C. Tensile
Modulus [MPa] 9999.0 10065.0 10665.0 Tensile Strength [MPa] 118.2
140.9 145.3 Retention Tensile 80.3% 93.2% 103.9% Strength (%)
Elongation @ Break [%] 1.5 1.7 1.7
TABLE-US-00010 TABLE 10 Example C-9 C-10 17 18 19 20 21 PA6T/DT
64.75 64.05 63.25 61.75 62.75 63.75 61.75 DPE 1.5 3 TPE 2 1 3 Cu
heat stabilizer 0.7 Wax OP 0.25 0.25 0.25 0.25 0.25 0.25 0.25 Glass
Fiber D 35 35 35 35 35 35 35 AOA 210.degree. C. TS (MPa) 0 h 225
223 214 212 218 218 215 TS (MPa) 500 h 115 141 218 218 220 186 213
TS (MPa) 1000 h 98 130 210 208 210 152 207 500 h TS Retention (%)
51 63 102 103 101 85 99 1000 h TS Retention (%) 44 58 98 98 96 70
96 El (%) 0 h 2.3 2.4 2.2 2.2 2.2 2.2 2.2 El (%) 500 h 1.2 1.4 2.2
2.2 2.2 1.8 2.2 El (%) 1000 h 0.9 1.3 2.1 2.1 2.1 1.5 2.1 500 h El
Retention (%) 52 58 100 100 100 82 100 1000 h El Retention (%) 39
54 95 95 95 68 95 AOA 230.degree. C. TS (MPa) 0 h 225 223 214 212
218 218 215 TS (MPa) 500 h 75 125 135 172 158 135 177 TS (MPa) 1000
h 20 91 115 156 142 128 152 500 h TS Retention (%) 33 56 63 81 72
62 82 1000 h TS Retention (%) 9 41 54 74 65 59 71 El (%) 0 h 2.3
2.4 2.2 2.2 2.2 2.2 2.2 El (%) 500 h 0.8 1.1 1.3 1.8 1.7 1.2 1.7 El
(%) 1000 h 0.3 0.8 1.2 1.7 1.4 1.1 1.5 500 h El Retention (%) 35 46
59 82 77 55 77 1000 h El Retention (%) 13 33 55 77 64 50 68 TS =
tensile strength EL = elongation to break
Examples 22 and Comparative Examples C-11
[0163] Examples 22 and C-11 illustrate the use of a Group (IV)
Polyamide, in the form of PA6T/66, in combination with polyhydric
alcohols in heat ageing. AOA at 210.degree. C. 1000 h show 87%
retention of tensile strength for Example 22, versus a 62%
retention for a copper stabilized composition lacking DPE.
TABLE-US-00011 TABLE 11 Example C-11 22 Composition (wt %) PA 6T/66
64.35 62.75 DPE 2.00 Wax OP 0.25 0.25 Copper heat stabilizer 0.40
Glass Fiber D 35.00 35.00 AOA 210.degree. C. TS (MPa) 0 h 202 202
TS (MPa) 500 h 135 185 TS (MPa) 1000 h 126 176 500 hrs TS Retention
(%) 67 92 1000 hrs TS Retention (%) 62 87 EI (%) 0 h 2.2 2.1 EI (%)
500 h 1.4 1.9 EI (%) 1000 h 1.2 1.8 500 hrs EI Retention (%) 64 90
1000 hrs EI Retention (%) 55 86 AOA 230.degree. C. TS (MPa) 0 h 202
202 TS (MPa) 500 h 131 162 TS (MPa) 1000 h 100 148 500 hrs TS
Retention (%) 65 80 1000 hrs TS Retention (%) 50 73 EI (%) 0 h 2.2
2.1 EI (%) 500 h 1.4 1.8 EI (%) 1000 h 1.0 1.5 500 hrs EI Retention
(%) 64 86 1000 hrs EI Retention (%) 45 71 TS = tensile strength EL
= elongation to break
Examples 23 and Comparative Examples C-12
[0164] Examples 23 and C-12 illustrate a toughened blend of Group
(II) and Group (V) Polyamide, in the form of PA66 and PA6T/DT,
respectively, in combination with TPE polyhydric alcohol in heat
ageing. AOA at 220.degree. C. 1008 h show 110% retention of tensile
strength for Example 23, versus 63% retention for C-12 having no
TPE present.
TABLE-US-00012 TABLE 12 Example C-12 23 PA6T/DT 47.11 44.11 PA66 20
20 Fusabond.RTM. EP1021 13 13 Glass Fiber B 17.5 17.5 Black Pigment
B 1 1 DER 732 Epoxy 0.5 0.5 SHP 0.04 0.04 Irganox.RTM. 1010 0.25
0.25 Irganox.RTM. 1098 0.2 0.2 Irgafos 12 0.2 0.2 Acrawax 0.2 0.2
TPE 3 AOA 200.degree. C. TS (MPa) 0 h 121 124 TS (MPa) 504 h 77.36
122 TS (MPa) 1008 h 78.42 129.6 504 hrs TS Retention (%) 64.04
98.15 1008 hrs TS Retention (%) 64.92 104.26 AOA 220.degree. C. TS
(MPa) 0 h 121 124 TS (MPa) 504 h 88.65 133.4 TS (MPa) 1008 h 76.64
137.4 504 hrs TS Retention (%) 73.39 107.32 1008 hrs TS Retention
(%) 63.44 110.54
[0165] The Examples illustrate that polyhydric alcohols added to
polyamide and/or polyester compositions are an economically viable
solution to the current need of having articles that are highly
heat resistant upon long-term exposure in comparison with
conventional heat stabilizers that lead either to poor heat aging
resistant compositions or expensive ones.
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