U.S. patent application number 13/946824 was filed with the patent office on 2013-11-14 for chloro-substituted polyetherimides having improved relative thermal index.
This patent application is currently assigned to SABIC INNOVATIVE PLASTICS IP B.V.. The applicant listed for this patent is Hendrich Chiong, Miguel Angel Navarro de Castro, Thomas Link Guggenheim, Farid Fouad Khouri, Matthew L. Kuhlman, Roy Ray Odle, Brennan Alexander Smith. Invention is credited to Hendrich Chiong, Miguel Angel Navarro de Castro, Thomas Link Guggenheim, Farid Fouad Khouri, Matthew L. Kuhlman, Roy Ray Odle, Brennan Alexander Smith.
Application Number | 20130303698 13/946824 |
Document ID | / |
Family ID | 44816334 |
Filed Date | 2013-11-14 |
United States Patent
Application |
20130303698 |
Kind Code |
A1 |
Chiong; Hendrich ; et
al. |
November 14, 2013 |
CHLORO-SUBSTITUTED POLYETHERIMIDES HAVING IMPROVED RELATIVE THERMAL
INDEX
Abstract
A polyetherimide having an OH content that is greater than 0 and
equal or less than 100 ppm; and a chlorine content that is greater
than 0 ppm is disclosed herein. A method for preparing the
polyetherimide is also disclosed.
Inventors: |
Chiong; Hendrich; (Florence,
KY) ; Guggenheim; Thomas Link; (Mt. Vernon, IN)
; Khouri; Farid Fouad; (Clifton Park, NY) ;
Kuhlman; Matthew L.; (Evansville, IN) ; de Castro;
Miguel Angel Navarro; (Murcia, ES) ; Odle; Roy
Ray; (Mt. Vernon, IN) ; Smith; Brennan Alexander;
(Decatur, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chiong; Hendrich
Guggenheim; Thomas Link
Khouri; Farid Fouad
Kuhlman; Matthew L.
de Castro; Miguel Angel Navarro
Odle; Roy Ray
Smith; Brennan Alexander |
Florence
Mt. Vernon
Clifton Park
Evansville
Murcia
Mt. Vernon
Decatur |
KY
IN
NY
IN
IN
IL |
US
US
US
US
ES
US
US |
|
|
Assignee: |
SABIC INNOVATIVE PLASTICS IP
B.V.
Bergen op Zoom
NL
|
Family ID: |
44816334 |
Appl. No.: |
13/946824 |
Filed: |
July 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13059691 |
Jul 19, 2011 |
8524854 |
|
|
PCT/US2010/062191 |
Dec 28, 2010 |
|
|
|
13946824 |
|
|
|
|
61291605 |
Dec 31, 2009 |
|
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|
Current U.S.
Class: |
525/132 ;
525/425; 525/437; 525/439; 525/444; 528/170 |
Current CPC
Class: |
C08G 73/1071 20130101;
C08L 79/08 20130101; C08L 2666/20 20130101; C08L 2666/20 20130101;
C08G 73/1014 20130101; C08L 69/00 20130101; C08G 73/1046 20130101;
C08L 67/00 20130101; C08G 73/1003 20130101; C08L 69/00 20130101;
C08G 73/1067 20130101; C08G 73/1053 20130101; C08L 67/00
20130101 |
Class at
Publication: |
525/132 ;
528/170; 525/437; 525/439; 525/425; 525/444 |
International
Class: |
C08G 73/10 20060101
C08G073/10; C08L 79/08 20060101 C08L079/08 |
Claims
1. A polymer comprising a polyetherimide having an OH content that
is greater than 0 and less than or equal to 100 parts per million
by weight (ppm) and a chlorine content that is greater than 0
ppm.
2. The polyetherimide of claim 1, wherein the polyetherimide
comprises structural unit of Formula (I): ##STR00015## wherein R
and R' can be a linear or cyclic C.sub.2 to C.sub.20 alkyl group or
a substituted or unsubstituted C.sub.6 to C.sub.30 aryl group and n
has a value of 1 to 40.
3. The polyetherimide of claim 1, wherein chlorine content is
present in an amount greater than 0 to 4,000 ppm.
4. The polyetherimide of claim 1, wherein the polyetherimide has a
flame retardant rating of V0 at 1.5 mm.
5. The polyetherimide of claim 3, wherein the polyetherimide has a
flame retardant rating of V0 at 0.8 mm.
6. The polyetherimide of claim 1, having the structural unit of
Formula (III): ##STR00016## wherein n is an integer having a value
of 1 to 40.
7. A composition comprising the polyetherimide of claim 6, and an
additional polymer.
8. The composition of claim 7, wherein the polymer is selected from
the group consisting of polyesters, polycarbonates, polyolefins,
polysulfones, polyphenylene sulfides, polyetheretherketones,
polyethersulfones, polyamides, polyamideimides, polyimides other
than the polyetherimide of claim 1, and combinations thereof.
9. A composition comprising the polyetherimide of claim 1 and an
additional polymer.
10. The composition of claim 9, wherein the polymer is selected
from the group consisting of polyesters, polycarbonates,
polyolefins, polysulfones, polyphenylene sulfides,
polyetheretherketones, polyethersulfones, polyamides,
polyamideimides, polyimides other than the polyetherimide of claim
1, and combinations thereof.
11. A method for preparing the polyetherimide of claim 1, which
comprises contacting, in o-dichlorobenzene or anisole as diluent,
substantially equimolar amounts of a disodium salt of a dihydroxy
compound of formula HO--R'--OH, and a slurry of a bisimide, in the
presence of a catalytically active amount of a phase transfer
catalyst, thereby polymerizing the bisimide and the disodium salt;
wherein the bisimide and the disodium salt are polymerized in the
presence of a base selected from the group consisting of alkali
metal carbonates, alkyl hydrides, alkali metal hydroxides, alkali
metal phosphates, alkali metal bicarbonates, alkali metal acetates,
and combinations thereof; wherein said slurry of bisimide comprises
the reaction product of a mixture comprising a diamine of formula
H.sub.2N--R--NH.sub.2; chlorophthalic anhydride; and
o-dichlorobenzene or anisole; and an optional imidization catalyst,
said mixture having a solids content of greater than or equal to
about 5% by weight; wherein the base is added in an amount that is
sufficient to produce the polyetherimide of claim 1.
12. The method of claim 11, wherein the bisimide is made by
reacting chlorophthalic anhydride and excess amount of diamine or a
stoichoimetric amount of diamine.
13. The method of claim 11, wherein the method further comprises
adding a capping agent and capping amine groups.
14. The method of claim 13, wherein the capping agent is selected
from the group consisting of chlorophthalic anhydrides, phthalic
anhydrides, substituted phthalic anhydrides, alkyl anhydrides,
cyclic alkyl anhydrides, substituted aryl anhdrides, acyl alkyl
halides, acyl aryl halides, aldehydes, ketones, esters,
isocyanates, chloroformates, sulfonyl chlorides, and combinations
thereof.
15. The method of claim 11, wherein the disodium salt has excess
sodium hydroxide and is caustic rich.
16. The method of claim 11, wherein the base is
K.sub.3PO.sub.4.
17. The method of claim 16, wherein the K.sub.3PO.sub.4 is added in
the form of solid or an aqueous solution.
18. The method of claim 17, wherein the K.sub.3PO.sub.4 is added in
an aqueous solution and the K.sub.3PO.sub.4 is dried with bisphenol
A disodium salt or 1,3-bis[N-(4-chlorophthalimido)]benzene prior to
addition to the slurry.
19. The method of claim 17, wherein the K.sub.3PO.sub.4 is added as
a solid.
20. The method of claim 19, wherein the K.sub.3PO.sub.4 added has a
particle size of greater than 0 to 400 microns.
21. The method of claim 19, wherein the K.sub.3PO.sub.4 added has a
particle size ranging greater than 0 to less than 75 microns.
22. The method of claim 11, wherein the disodium salt is a
bisphenol A disodium salt, the bisimide slurry is a slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene, and the phase transfer
catalyst is hexaalkylguanidinium chloride wherein said slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene comprises the reaction
product of a mixture comprising m-phenylenediamine;
4-chlorophthalic anhydride; and o-dichlorobenzene or anisole; and
an optional imidization catalyst, said mixture having a solids
content of greater than or equal to about 5% by weight.
24. An article comprising the polyetherimide of claim 1.
Description
CROSS REFERENCED TO RELATED APPLICATION
[0001] This application is a continuation of U.S. Non-Provisional
application Ser. No. 13/059,691, filed Jul. 19, 2011 which is a 371
application of PCT Application Serial No. PCT/US2010/062191, filed
Dec. 28, 2010, which claims the benefit of U.S. Provisional Patent
Application Ser. No. 61/291,605 filed Dec. 31, 2009. These related
applications are incorporated herein by reference.
BACKGROUND
[0002] The invention relates to the field of polyetherimides.
Polyetherimides are engineering thermoplastics that are thermally
stable and find many applications under demanding elevated
temperatures. Polyetherimides made by chloro-displacement methods
are known.
[0003] Unfortunately, it has been discovered that
chloro-substituted polyetherimides made by chloro-displacement
methods exhibit diminished Relative Thermal Index properties that
do not meet some commercial applications. The Relative Thermal
Index is a known property that indicates how a polymer's properties
degrade after being subjected to heat aging. Materials are
investigated with respect to retention of certain critical
properties (e.g., dielectric strength, flammability, impact
strength, and tensile strength) as part of a long-term
thermal-aging program conducted in accordance with Underwriters
Laboratories, Inc. Standard for Polymeric Materials-Long Term
Property Evaluations (UL746B). The end-of-life of a material at
each test temperature in this program has been assumed to be the
time when the value of the critical property has decreased to 50%
of its original (as received) value.
[0004] For the foregoing reasons, there is an ongoing, unmet need
for chloro-substituted polyetherimides having improved Relative
Thermal Index properties, and methods of making such
chloro-substituted polyetherimides.
SUMMARY
[0005] Disclosed herein is a polyetherimide comprising a structural
unit of Formula (I):
##STR00001##
wherein R and R' can be a linear or cyclic C.sub.2 to C.sub.20
alkyl group or a substituted or unsubstituted C.sub.6 to C.sub.30
aryl group, n has a value of 1 to 40,
[0006] wherein the polyetherimide has an OH content that is greater
than 0 and less than or equal to 100 parts per million by weight
(ppm);
[0007] wherein the polyetherimide has a Relative Thermal Index that
is greater than or equal to 170.degree. C.; and
[0008] wherein the polyetherimide has an chlorine content that is
greater than 0 ppm.
[0009] Also disclosed herein is a polyetherimide comprising a
structural unit of Formula (III)
##STR00002##
[0010] wherein n is an integer having a value of 1 to 40;
[0011] wherein the polyetherimide has an OH content that is greater
than 0 and less than or equal to 100 parts per million by weight
(ppm);
[0012] wherein the polyetherimide has a Relative Thermal Index that
is greater than or equal to 170.degree. C.; and
[0013] wherein the polyetherimide has an chlorine content that is
greater than 0 ppm.
[0014] Also disclosed is a method for making a polyetherimide that
has a structural unit of Formula (I) that involves contacting, in
o-dichlorobenzene or anisole as diluent, substantially equimolar
amounts of a disodium salt of a dihydroxy compound of formula
HO--R'--OH, and a slurry of a bisimide, in the presence of a
catalytically active amount of a phase transfer catalyst, thereby
polymerizing the bisimide and the disodium salt;
[0015] wherein the bisimide and the disodium salt are polymerized
in the presence of a base selected from the group consisting of
alkali metal carbonates, alkyl hydrides, alkali metal hydroxides,
alkali metal phosphates, alkali metal bicarbonates, alkali metal
acetates, and combinations thereof;
[0016] wherein said slurry of bisimide comprises the reaction
product of a mixture comprising a diamine of formula
H.sub.2N--R--NH.sub.2; chlorophthalic anhydride; optional phthalic
anhydride; and o-dichlorobenzene or anisole; and an optional
imidization catalyst, said mixture having a solids content of
greater than or equal to about 5% by weight;
[0017] wherein the base is added in an amount that is sufficient to
produce the polyetherimide having the OH content specified
above.
[0018] Also disclosed is a method for making a polyetherimide that
has a structural unit of Formula (III) that involves contacting, in
o-dichlorobenzene or anisole as diluent, substantially equimolar
amounts of bisphenol A disodium salt and a slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene, in the presence of a
catalytically active amount of a hexaalkylguanidinium chloride as a
phase transfer catalyst, thereby polymerizing the
1,3-bis[N-(4-chlorophthalimido)]benzene and the bisphenol A
disodium salt;
[0019] wherein the 1,3-bis[N-(4-chlorophthalimido)]benzene and the
bisphenol A disodium salt are polymerized in the presence of a base
selected from the group consisting of alkali metal carbonates,
alkyl hydrides, alkali metal hydroxides, alkali metal phosphates,
alkali metal bicarbonates, alkali metal acetates, and combinations
thereof;
[0020] wherein said slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene comprises the reaction
product of a mixture comprising m-phenylenediamine;
4-chlorophthalic anhydride; optional phthalic anhydride and
o-dichlorobenzene or anisole; and an optional imidization catalyst,
said mixture having a solids content of greater than or equal to
about 5% by weight;
[0021] wherein the base is added in an amount that is sufficient to
produce the polyetherimide having the OH content specified
above.
[0022] In another embodiment, the invention relates to a
polyetherimide having the structure of Formula (III):
##STR00003##
[0023] wherein n is an integer having a value of 1 to 40;
[0024] wherein the polyetherimide has an OH content that is greater
than 0 and less than or equal to 100 ppm;
[0025] wherein the polyetherimide has a Relative Thermal Index that
is greater than or equal to 170.degree. C.;
[0026] wherein the polyetherimide has an chlorine content that is
greater than 0 ppm;
[0027] wherein the polyetherimide is made by a method comprising
contacting, in o-dichlorobenzene or anisole as diluent,
substantially equimolar amounts of bisphenol A disodium salt and a
slurry of 1,3-bis[N-(4-chlorophthalimido)]benzene, in the presence
of a catalytically active amount of a hexaalkylguanidinium chloride
as a phase transfer catalyst, thereby polymerizing the
1,3-bis[N-(4-chlorophthalimido)]benzene and the bisphenol A
disodium salt;
[0028] wherein the 1,3-bis[N-(4-chlorophthalimido)]benzene and the
bisphenol A disodium salt are polymerized in the presence of a base
selected from the group consisting of alkali metal carbonates,
alkyl hydrides, alkali metal phosphates, alkali metal bicarbonates,
alkali metal hydroxides, alkali metal acetates, and combinations
thereof;
[0029] wherein said slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene comprises the reaction
product of a mixture comprising m-phenylenediamine;
4-chlorophthalic anhydride; optional phthalic anhydride; and
o-dichlorobenzene or anisole; and an imidization catalyst, said
mixture having a solids content of greater than or equal to about
5% by weight;
[0030] wherein the base is added in an amount that is sufficient to
produce the polyetherimide with less than or equal to 100 ppm
hydroxy endgroups.
[0031] These and other features, aspects, and advantages of the
present invention will become better understood with reference to
the following description and appended claims.
BRIEF DESCRIPTION OF THE FIGURES
[0032] FIG. 1 is a graphical representation of RTI aging results
for a control resin and a candidate resin.
[0033] FIG. 2 is a graphical representation of RTI
extrapolation.
[0034] FIG. 3 is a graphical representation of data from the
examples.
DESCRIPTION
[0035] The invention is based on the surprising discovery that it
is now possible to make polyetherimides having a Relative Thermal
Index (RTI) of 170.degree. C. or more by reducing the hydroxyl
group content in the polyetherimide to a range that is greater than
0 to less than or equal to 100 ppm by the use of a specific set of
bases and process conditions. Remarkably, it has been discovered
that when the polyetherimide has an OH group content that ranges
from greater than 0 to less than or equal to about 100 ppm, the
polyethermide exhibits an RTI of 170.degree. C. or more and when
the polyetherimide has an OH group content that is greater than
about 100 ppm, the polyetherimide exhibits an RTI that is less than
170.degree. C. Surprisingly, the use of stabilizers has not proven
to be a useful way to produce polyetherimides having RTI of
170.degree. C. or more.
[0036] Other than in the operating examples or where otherwise
indicated, all numbers or expressions referring to quantities of
ingredients, reaction conditions, and the like, used in the
specification and claims are to be understood as modified in all
instances by the term "about." Various numerical ranges are
disclosed in this patent application. Because these ranges are
continuous, they include every value between the minimum and
maximum values. Unless expressly indicated otherwise, the various
numerical ranges specified in this application are
approximations.
[0037] The polyetherimide has a structural unit of the Formula
(I)
##STR00004##
[0038] In one embodiment, the polyetherimide further comprises a
structural unit having the Formula (II)
##STR00005##
[0039] In Formulas (I) and (II) R can be a linear or cyclic alkyl
group of 2 carbons to 20 carbons wherein the valance of each carbon
is satisfied by being covalently bound to hydrogen or a combination
of hydrogen, halogen, oxygen, sulfur, and nitrogen. R can also be
an aryl substituted containing radical with the general Formula
of
##STR00006##
where Z can be a covalent bond between the two aryl rings, or one
of the following linkages:
##STR00007##
Y.sup.1 can be hydrogen, or an alkyl, halo or substituted aryl
group.
[0040] Most often R is substituted aryl benzene radical covalently
bonded at the meta or para position:
##STR00008##
W can be hydrogen, alkyl, halo, or a substituted aryl group.
Specifically R is a benzene radical covalently bonded at the meta
or para position.
[0041] In Formulas (I) and (II) R' can have the general
structure:
##STR00009##
where Q is a covalent bond or one of the following linkages:
##STR00010##
Y.sup.2 can be hydrogen, an alkyl group or substituted aryl group.
R'' and R''' can be an alkyl group containing only hydrogen or
hydrogen and a halogen, or a substituted aryl group.
[0042] R' can also have the structure:
##STR00011##
W can be hydrogen or an alkyl or substituted aryl group.
Specifically, W is hydrogen and the benzene is covalently bonded in
the meta or para position.
[0043] Specifically R' can be
##STR00012##
[0044] More particularly, in one embodiment, the polyetherimide has
the structural unit of Formula (III):
##STR00013##
[0045] wherein n is an integer ranging having a value of 1 to
40;
[0046] wherein the polyetherimide has an OH content that is greater
than 0 and less 100 ppm;
[0047] wherein the polyetherimide has a Relative Thermal Index that
is greater than or equal to 170.degree. C.; and
[0048] wherein the polyetherimide has a chlorine content that is
greater than 0 ppm.
[0049] The polyetherimide has a Relative Thermal Index (RTI) that
is greater than or equal to 170.degree. C., as determined by
Underwriting Laboratories (UL.RTM. protocol UL746B). The Relative
Thermal Index can be obtained directly by performing the extended
test in accordance with the UL746B protocol as described in the
Examples, or may be indirectly inferred with an accelerated heat
aging testing method also as described in the Examples. Briefly,
the RTI is inferred by comparing the peak molecular weight (Mp)
degradation (decrease) of an experimental sample with the peak (Mp)
degradation of a control sample that is a polyetherimide made by a
nitro-displacement method (a method in which the polyetherimide is
made from bisphenol-A dianhyride, phthalic anhydride and
metaphenylene diamine) that has been verified to have a Relative
Thermal Index of greater than or equal to 170.degree. C. by UL.RTM.
protocol UL746B. When the percent peak molecular weight degradation
of an experimental sample is within 10% of the percent peak
molecular weight degradation of the control sample, the Relative
Thermal Index of the experimental sample is said to have the same
Relative Thermal Index of the control sample, which is greater than
or equal to 170.degree. C. By contrast, when the percent peak
molecular weight degradation of an experimental sample is greater
than 10% of the percent peak molecular weight degradation of the
control sample that is a polyetherimide made by a
nitro-displacement method and made from a dianhydride and
metaphenylene diamine, the Relative Thermal Index of the
experimental sample is said to have a Relative Thermal Index of
less than 170.degree. C., e.g., 160.degree. C. For example, if the
peak molecular weight (Mp) drop of a control sample at 230.degree.
C. in 12 or 13 days is 8%, then a resin with less than or equal to
18% Mp drop would have the equivalent RTI rating as the control
sample. Indirectly determined RTI ratings are verifiable by the
UL.RTM. protocol UL746B. Due to the duration of the UL.RTM.
protocol UL746B (which can take months), it is not always practical
or possible to determine the Relative Thermal Index rating of a
candidate resin sample by UL.RTM. protocol UL746B. Relative Thermal
Index ratings indirectly obtained are preferably verified by the
UL.RTM. protocol UL746B whenever practical.
[0050] The chlorine content of the polyetherimide can vary,
depending on the application. The polyetherimide can have a
chlorine amount of greater than 0 to 10,000 ppm, or, more
specifically, greater than 0 to 4,000 ppm. In another embodiment,
the polymer has a chlorine content of greater than or equal to
2,000 to less than 3,000 ppm. In another embodiment, the polymer
has a chlorine content of greater than or equal to 1,000 to less
than 2,000 ppm. In another embodiment, the polymer has a chlorine
content of greater than 0 to less than 1,000 ppm.
[0051] In one embodiment, the polymer has advantageous flame
retardant properties. The polyetherimide, for instance, has a flame
retardant rating of V0 at 1.5 mm in one embodiment. In another
embodiment, the polyetherimide has a flame retardant rating of V0
at 0.8 mm.
[0052] The polyetherimide generally has an OH content that is
greater than 0 and less than or equal to 100 ppm. Advantageously,
when the OH content of the polyetherimide is within this range, the
polyetherimide exhibits a Relative Thermal Index that is greater
than or equal to 170.degree. C.
[0053] The polyetherimide of Formula (I), (II) or (III) is
generally made by a process that involves contacting, in
o-dichlorobenzene or anisole as diluent, substantially equimolar
amounts of a disodium salt of a dihydroxy compound of formula
HO--R'--OH, and a slurry of a bisimide, in the presence of a
catalytically active amount of a phase transfer catalyst, thereby
polymerizing the bisimide and the disodium salt;
[0054] wherein the bisimide and the disodium salt are polymerized
in the presence of a base selected from the group consisting of
alkali metal carbonates, alkyl hydrides, alkali metal hydroxides,
alkali metal phosphates, alkali metal bicarbonates, alkali metal
acetates, and combinations thereof;
[0055] wherein said slurry of bisimide comprises the reaction
product of a mixture comprising a diamine of formula
H.sub.2N--R--NH.sub.2; chlorophthalic anhydride; optionally
phthalic anhydride; and o-dichlorobenzene or anisole; and an
optional imidization catalyst, said mixture having a solids content
of greater than or equal to about 5% by weight;
[0056] wherein the base is added in an amount that is sufficient to
produce the polyetherimide.
[0057] The phase transfer catalyst can be any phase transfer
catalyst which, when added in accordance to the process, is
sufficiently thermally stable to produce the polyetherimide having
an OH group that is greater than 0 and less or equal to 100 ppm.
Suitable phase transfer catalysts are selected from the group
consisting of hexaalkylguanidium salts, tetralkyl or tetraaryl
phosphonium salts (phosphonium salts), phosphazenium salts, alkyl
pyridinium salts, bis alkyl pyridinium salts, biguanidiniium salts
(biguanide salts), alkylimidazolium salts, benzimidazolium salts,
N-alkyl-4-alkylaminopyridinium salts, and combinations thereof. The
foregoing salts include the indicated cationic component of the
salt as well as the anionic component of the salt, which can be
selected from the group of chlorides, bromides, iodides, sulfates,
phosphates, mesylates, tosylates, and the like, and combinations
thereof.
[0058] The amount of the phase transfer catalyst varies, depending
on the application. Generally, the amount of the phase transfer
catalyst is greater than or equal to 0.5 mole %, with respect to
the amount of bisphenol A disodium salt used in the polymerization
reaction. In another embodiment, the amount of the phase transfer
catalyst is 0.5 to 5 mole %, with respect to the amount of
bisphenol A disodium salt used in the polymerization reaction.
[0059] The optional imidization catalyst catalyzes the conversion
of amic acid functionality to cyclized imide functionality.
Suitable imidization catalysts are known in the art; they include
salts of organophosphorus acids, particularly phosphinates such as
sodium phenyl phosphinate and heterocyclic amines such as
4-diaminopyridine. In some embodiments the imidization catalyst
comprises sodium phenyl phosphinate. The amount of the imidization
catalyst can vary. Generally, when used, the imidization catalyst
is present in an amount that is greater than 0 and less than 2
weight percent, by weight of the polyetherimide.
[0060] The bisimide can be made by any suitable method. In one
embodiment, the bisimide is made by reacting chlorophthalic
anhydride and excess diamine or a stochoimetric amount of
diamine.
[0061] In one embodiment, the process further comprises the
addition of a capping agent. The capping agent can be any compound
with greater than or equal to one substituent such that when the
capping agent is used, the substituent reacts with an amine group,
thereby "capping" the amine. Examples of suitable capping agents
can be selected from the group consisting of chloropthalic
anhydrides, phthalic anhydrides, substituted phthalic anhydrides,
alkyl anhydrides, cyclic alkyl anhydrides, substituted aryl
anhydrides, acyl alkyl halides, acyl aryl halides, aldehydes,
ketones, esters, isocyanates, chloroformates, sulfonyl chlorides,
and combinations thereof. The amount of the capping agent can vary.
In one embodiment, for instance, the amount can be 1 to 2 mole
equivalents, per mole equivalent of excess amine (e.g., reacted
m-phenylenediamine) present in the system. Other excess amounts are
possible.
[0062] The bases used in the method can be selected from the group
consisting of alkali metal carbonates, alkyl hydrides, alkali metal
hydroxides, alkali metal phosphates, alkali metal bicarbonates,
alkali metal acetates, and combinations thereof.
[0063] In one embodiment, the alkali metal phosphate base is
K.sub.3PO.sub.4. K.sub.3PO.sub.4 can be added in the form of solid
or an aqueous solution. In one embodiment, when K.sub.3PO.sub.4 is
added in an aqueous solution, the K.sub.3PO.sub.4 is dried with
bisphenol A disodium salt or
1,3-bis[N-(4-chlorophthalimido)]benzene prior to addition to the
slurry. Alternatively, aqueous K.sub.3PO.sub.4 can be added to a
slurry containing bisphenol A disodium salt in an organic solvent,
e.g., orthodichloro benzene, and dried. In another embodiment, when
the K.sub.3PO.sub.4 is added as a solid, the K.sub.3PO.sub.4 added
has a particle size of greater than 0 to 400 microns (micrometers).
In another embodiment, the K.sub.3PO.sub.4 added has a particle
size of greater than 0 to less than 75 microns.
[0064] The slurries/mixtures formed during polymerization are
generally anhydrous such that there can be less than 20 ppm water
present in the system, as measured in the distillate from the
polymerization vessel.
[0065] The amount of base used can vary. Generally, the amount of
the base is greater than 0 weight percent, based on the weight of
the polymer, and is present in a sufficient amount to enable the
production of a polyetherimide having an OH content that is greater
than 0 and less than or equal to 100 ppm and has an RTI rating that
is greater than or equal to 170.degree. C. Specific amounts will
vary, depending on the base that is actually used, equipment used,
how the base is introduced into the bisphenol A disodium salt, and
other factors. In one embodiment, the amount of the base used
during polymerization is greater than 0 to 2 weight percent, based
on the weight of the polymer. In another embodiment, the amount of
the base used during polymerization is greater than 0 to 1 weight
percent, based on the weight of the polymer. In another embodiment,
the amount of the base used during polymerization is 0.5 or more to
1.5 weight percent, based on the weight of the polymer.
[0066] The base is ordinarily added after the bisphenol A disodium
salt has been combined with the slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene in the presence of the
hexaalkylguanidinium chloride phase transfer catalyst.
[0067] Other methods of addition, however, are possible. The base,
for instance, can be added to the bisphenol A disodium salt before
the bisphenol A disodium salt is combined with the slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene in the presence of the
hexaalkylguanidinium chloride phase transfer catalyst. When the
alkali metal hydroxide is sodium hydroxide, the sodium hydroxide is
preferably added to the bisphenol A disodium salt in an aqueous
solution, then dried to provide a BPA (bisphenol-A) disodium salt
slurry in an organic solvent, where the amount of excess sodium
hydroxide is greater than 0 and less than 0.5 weight percent, based
on the weight of the polymer to be prepared from the use of the BPA
disodium salt, preferably at 0.1 to 0.2 weight percent. In one
embodiment, when sodium hydroxide is used, the bisphenol A disodium
salt has excess sodium hydroxide and is caustic rich. The skilled
artisan, however, will appreciate that other variations are
possible.
[0068] In one embodiment a polyetherimide having the structure of
Formula (II):
##STR00014##
[0069] wherein the polyetherimide has an OH content that is greater
than 0 and less than or equal to 100 ppm;
[0070] wherein the polyetherimide has a Relative Thermal Index that
is greater than or equal to 170.degree. C.; and
[0071] wherein the polyetherimide has an chlorine content that is
greater than 0 ppm;
[0072] wherein the polyetherimide is made by a method comprising
contacting, in o-dichlorobenzene or anisole as diluent,
substantially equimolar amounts of bisphenol A disodium salt and a
slurry of 1,3-bis[N-(4-chlorophthalimido)]benzene, in the presence
of a catalytically active amount of a hexaalkylguanidinium chloride
as a phase transfer catalyst, thereby polymerizing the
1,3-bis[N-(4-chlorophthalimido)]benzene and the bisphenol A
disodium salt; wherein the 1,3-bis[N-(4-chlorophthalimido)]benzene
and the bisphenol A disodium salt are polymerized in the presence
of a base selected from the group consisting of alkali metal
carbonates, alkyl hydrides, alkali metal phosphates, alkali metal
bicarbonates, alkali metal hydroxides, alkali metal acetates, and
combinations thereof;
[0073] wherein said slurry of
1,3-bis[N-(4-chlorophthalimido)]benzene comprises the reaction
product of a mixture comprising m-phenylenediamine;
4-chlorophthalic anhydride; optional phthalic anhydride; and
o-dichlorobenzene or anisole; and an optional imidization catalyst,
said mixture having a solids content of greater than or equal to
about 5% by weight;
[0074] wherein the base is added in an amount that is sufficient to
produce the polyetherimide having the OH content described
above.
[0075] Also disclosed herein are compositions comprising the
polyetherimde described herein having an RTI of 170.degree. C. or
more and a different polymer. Examples of polymers that can be
combined with the polyetherimide of Formula (I), (II), or (III) can
be selected from the group consisting of polyesters,
polycarbonates, polyolefins, polysulfones, polyphenylene sulfides,
polyetheretherketones, polyethersulfones, polyamides,
polyamideimides, polyimides other than the polyetherimide having an
OH group content of greater than 0 and less than or equal to 100
ppm, and combinations thereof.
[0076] The amounts of such additional polymers can vary, depending
on the application. Generally, the amount of the other polymer can
be 1 to 99 weight percent of the composition. For instance, a
composition can comprise 50 to 99 weight percent of the
polyetherimide having an OH content that is greater than 0 and less
than or equal to 100 ppm and 1 to 50 weight percent of the polymer,
wherein weight percent is based on the total weight of the
composition. In other embodiments, the amount can vary.
[0077] Compositions containing the polyetherimide having an OH
group content that is greater than 0 and less than or equal to 100
ppm and another polymer may further comprise an additive or
combination of additives. Exemplary additives include electrically
conductive fillers, reinforcing fillers, stabilizers, lubricants,
mold release agents, inorganic pigments, UV absorbers;
antioxidants, plasticizers; anti-static agents; foaming agents;
blowing agents; metal deactivators and combinations comprising one
or more of the foregoing. Examples of electrically conductive
fillers include conductive carbon black, carbon fibers, metal
fibers, metal powder, carbon nanotubes, and the like, and
combinations comprising any one of the foregoing electrically
conductive fillers. Examples of reinforcing fillers include glass
beads (hollow and/or solid), glass flake, milled glass, glass
fibers, talc, wollastonite, silica, mica, kaolin or montmorillonite
clay, silica, quartz, barite, and the like, and combinations
comprising any of the foregoing reinforcing fillers. Antioxidants
can be compounds such as phosphites, phosphonites and hindered
phenols or mixtures thereof. Phosphorus containing stabilizers
including triaryl phosphite and aryl phosphonates are of note as
useful additives. Difunctional or trifunctional phosphorus
containing stabilizers with one or two phosphorous atoms can also
be employed. Stabilizers may have a molecular weight greater than
or equal to 300 Daltons. In some embodiments, phosphorus containing
stabilizers with a molecular weight greater than or equal to 500
Daltons are useful. Phosphorus containing stabilizers are typically
present in the composition at 0.05 to 0.5% by weight of the
formulation. Flow aids and mold release compounds are also
contemplated.
[0078] The reinforcing filler may be present in an amount less than
or equal to 60 weight percent, based on the total weight of the
composition. Within this range the reinforcing filler may be
present in an amount greater than or equal to 10 weight percent, or
more specifically, greater than or equal to 20 weight percent. Also
within this range the reinforcing filler may be present in an
amount less than or equal to 50 weight percent, or, more
specifically, less than or equal to 40 weight percent.
[0079] Compositions comprising a polyetherimide having an RTI
rating of greater than or equal to 170.degree. C. and another
polymer may be made by blending the compositions in an extruder.
The polyetherimides described herein can also be formed, shaped, or
molded into articles using thermoplastic processes such as shaping,
film and sheet extrusion, injection molding, gas-assist injection
molding, extrusion molding, compression molding, blow molding, and
the like. The resulting articles may, for example, be in the form
of a film (e.g., a solvent cast film for an overmolded article),
sheet, molded object, or fiber.
[0080] The invention is further described in the following
illustrative examples in which all parts and percentages are by
weight unless otherwise indicated.
EXAMPLES
Examples 1-54
[0081] In the following examples the polyetherimide produced was
tested for the hydroxyl end group content by derivatization with a
phosphorylation reagent, followed by phosphorous 31, Nuclear
Magnetic Resonance (P31 NMR). The Relative Thermal Index (RTI)
rating of the polyetherimide was determined by the "Accelerated
Heat Aging Testing Method," or "Underwriter's Laboratory UL.RTM.
Relative Thermal Index Test Method UL746B, further described below.
Molecular weight of the polyetherimides produced in the examples
was determined by gel permeation chromatography (GPC) using a
Polymer Laboratory Mixed Bed C column, methylene chloride as
eluent, and polystyrene narrow standards to determine the Mp (Peak
Molecular Weight), Mn (Number Average Molecular Weight), and Mw
(Weight Average Molecular Weight of the material.
Techniques & Procedures
[0082] Underwriter's Laboratory (UL.RTM.) Relative Thermal Index
Test: Control polyetherimide and inventive polyetherimides
discussed in Example 19 and 20 were measured by the following
UL.RTM. RTI test. The Relative Thermal Index (RTI) rating of a
resin is a value certified by Underwriting Laboratories (UL.RTM.)
that relates to the long-term performance of materials employed at
high temperatures. The RTI rating is measured using the protocol
UL746B, and it is defined as the temperature at which a material
holds 50% of tensile strength after 100,000 hours.
[0083] Molded samples of a control material (a polyetherimide made
from bisphenol A dianhydride and metaphenylene diamine, commercial
grade ULTEM.TM. 1000/1000 (referred to as "NDU" mentioned in FIG.
1), with a previous RTI rating established by the above-described
UL protocol UL 746B and a sample of inventive polyetherimide
(referred to as "CDU" in the Figure) were placed in ovens at
controlled temperatures. Periodically, specimens were retrieved and
tested, plotting the retention of the following properties versus
time: (i) mechanical strength, (ii) impact, (iii) electrical, and
(iv) flammability. An example of the results can be seen in FIG. 1.
To obtain an RTI rating for a resin, a 4-point UL.RTM. program was
required, where specimens are aged at 4 different temperatures
until they lost 50% of the starting value of certain property.
[0084] Due to the long time scale of the UL test, the RTI rating
was obtained by extrapolation from property retention data obtained
at higher temperatures. For each temperature that was evaluated,
the 50% Property Retention (PR) time was obtained, and then the set
of data was plotted in a semi logarithmic graph. In the 4-point
UL.RTM. program, the RTI rating was calculated from the
extrapolation of the linearly regressed data to 100,000 hours, as
it can be seen in FIG. 2.
[0085] In order to correlate test results with existing materials,
all RTI candidate testing was performed side by side with a
previously RTI rated control sample that served as a reference to
compensate for variations in parameter calibrations and measuring
errors. The RTI rating for a candidate resin material was
determined based on the performance of the control material in the
side by side study, so the difference between the calculated RTI
temperatures of the candidate and the control was either added or
subtracted to the previously determined RTI rating of the control
material. The control material was validated by UL.RTM., verifying
that its Dynamic Scanning calorimetry (DSC), Thermogravimetric
Analysis (TGA) and Fourier-Transform Infrared Spectroscopy (FTIR)
responses match the ones from the material used to confer the RTI
rating for such grade.
[0086] Accelerated Heat Aging Testing Method:
[0087] The Accelerated Heat Aging Testing method involved heating
resin samples (parts, pellets or powder form) in a forced heated
air oven at 230.degree. C. for up to 24 days. The air used in the
oven was ambient air. The samples were pulled from the oven around
day 6, 12, 18, and 24. Commercially available ULTEM.TM. 1000/1000
grade samples with <10 ppm OH ends, made from bisphenol A
dianhydride and metaphenylene diamine and which has been verified
to have a RTI rating of 170.degree. C. by Underwriters
Laboratories, were heat aged at the same time as the experimental
resins. (ULTEM is a Trademark of SABIC Innovative Plastics IP
B.V.)
[0088] The heat aged samples were then analyzed by GPC to determine
the number average molecular weight (Mn), the weight average
molecular weight (Mw), and the peak molecular weight (Mp). The
samples that were heat aged in the UL RTI test were also analyzed
by GPC. The molecular weight degradation (as measured by Mp, Mn,
and Mw) of the inventive polyetherimide was compared with the
molecular weight degradation of the commercially available
ULTEM.TM. 1000/1000 grade samples.
[0089] A correlation was developed between the time a resin failed
the UL test (time the specimen lost 50% of its tensile strength)
and rate of Mp decline. If the percent peak molecular weight
degradation of an experimental sample was within 10% of the percent
peak molecular weight degradation of the control sample, then the
Relative Thermal Index of the experimental sample is said to have
the same Relative Thermal Index of the control sample. For example,
if the peak molecular weight (Mp) drop of a control sample is 8%,
then a resin with less than or equal to 18% Mp drop would have the
equivalent RTI rating as the control sample. Whenever practical and
possible, we verified results obtained from the Accelerated Heat
Aging Testing Method with the UL746B protocol.
Examples 1-9
[0090] Examples 1-9 explored the effect of the presence of
different bases during polymerization on the hydroxyl end group
content of the polyetherimide. The following examples involved
polymerization of bisphenol A disodium salt and
1,3-bis(N-(4-chlorophthalimido))benzene (ClPAMI) in the presence of
a hexaethylguanadinium chloride (HEGCl) catalyst. All
polymerization reactions were performed in orthodichlorobenzene
(ODCB). Reactions were performed on a laboratory scale.
[0091] The bisphenol A disodium salt was isolated and prepared as
follows. A 1 liter (L), round-bottomed flask was charged with a
slurry of bisphenol A disodium salt in orthodichlorobenzene (ODCB).
The ODCB was removed by means of a rotary evaporator (150.degree.
C., full (<10 mm) vacuum). After most of the ODCB had been
collected, the temperature of the oil bath was increased to
160.degree. C. and the salt allowed to dry further at full (<10
mm) vacuum for 3 hours. After cooling to room temperature, the
flask was filled with nitrogen gas (N.sub.2), detached from the
rotavap and placed in a vacuum oven for 3 days (130.degree. C.,
full (<10 mm) vacuum). The oven was cooled and the flask
immediately transferred to a glovebox inerted with nitrogen. The
solid disodium salt was stored under N.sub.2 inside the
glovebox.
[0092] The ClPAMI was isolated and prepared as follows. A sample of
ClPAMI slurry in ODCB was filtered using a Buchner funnel The
solids were sequentially washed with warm ODCB (3 times, 80.degree.
C.) and hexanes at room temperature (3 times). After allowing to
air dry for 1 hour, the solids were transferred to aluminum pans,
covered with aluminum foil and dried in an oven under full vacuum
(160.degree. C., 3 days). The dried ClPAMI was stored inside a
glovebox.
[0093] The polymerization was run and the polymer was isolated as
follows. Inside a glovebox an oven-dried, 250 milliliter (mL),
4-necked, round-bottomed flask equipped with a septa for nitrogen
inlet (other necks were capped with a stopper) was charged with a
base (150 milligrams [mg], 1% by weight with respect to the final
polymer), bisphenol A disodium salt (6.675 grams (g), 24.517
millimoles (mmol)), and 1,3-bis(N-(4-chlorophthalimido))benzene
(ClPAMI, 11.070 g, 25.318 mmol). To this mixture was added 150 g of
ODCB. The flask was taken out of the glovebox and assembled with a
Dean-Stark trap/condenser and mechanical stirrer. The mixture was
allowed to reflux with stirring (oil temp was kept at 200.degree.
C.). During this stage, ODCB started to collect in the Dean-Stark
trap. After removing approximately 75 milliliters (mL, 90 g) of
ODCB, HEGCl (330 mg of 20 weight percent in ODCB, 0.245 mmol of
HEGCl) was added. Nitrogen flow was increased to hasten the
overhead collection of ODCB until 30% solids was obtained. The
mixture was allowed to stir and sampled for GPC analysis every
hour. When the Mw standard deviation of the last three hourly
samples was <500 Daltons (Da) the mixture was diluted with ODCB
to 10% solids. The oil temperature was lowered to 165.degree. C.
followed by the addition of 5 drops of 85 weight percent aqueous
H.sub.3PO.sub.4. After 30 minutes, the mixture was allowed to cool
to room temperature and diluted with dichloromethane (75 mL) and
filtered through a Buchner funnel. The filtrate was slowly added to
a blender containing 250 mL hexanes. The precipitate was
homogenized, filtered, and rinsed with hexanes (2.times.100 mL).
The white solid was dried under vacuum (<10 mm, 165.degree. C.)
for greater than or equal to 12 hours.
[0094] The hydroxy end group content of the polymers produced with
the different bases is shown in Table 1. The "*" indicates a
comparative example.
TABLE-US-00001 TABLE 1 Hydroxy end group content RTI** Example Base
(ppm) (.degree. C.) 1* No base 302 160 2 K.sub.2CO.sub.3 8 170 3*
NaH 205 160 4 NaHCO.sub.3 25 170 5 K.sub.3PO.sub.4 13 170 6 K
Acetate 46 170 7* Na tent-BuO 329 160 8*
Na.sub.3PO.sub.4.cndot.12H.sub.2O 890 < or = 160 9* NaOH 265 160
**Determined by the Accelerated Heat Aging Testing Method
[0095] These examples show that not all bases result in the
reduction of the hydroxy end groups of the polymer. Surprisingly,
stronger bases, such as NaH and NaOH were unsuccessful in reducing
the hydroxyl end group content. Anhydrous Na.sub.3PO.sub.4 gave
similar results to those shown above for the hydrated version.
Examples 10-12
[0096] Examples 10-12 explored the effect of the point of addition
for the base on the hydroxyl end group content of the
polyetherimide. K.sub.3PO.sub.4 was used as the base. Base was
added to the bisphenol A disodium salt, to the ClPAMI slurry and
during polymerization.
[0097] The following examples involved polymerization of bisphenol
A disodium salt and 1,3-bis(N-(4-chlorophthalimido))benzene
(ClPAMI) in the presence of a hexaethylguanadinium chloride (HEGCl)
catalyst. The ClPAMI was rich in 4-monoamine. On stoich, and amine
rich ClPAMI perform equally well in the polymerization reaction
with bisphenol A disodium salt. All polymerization reactions were
performed in orthodichlorobenzene (ODCB). Reactions were performed
on a laboratory scale as described above.
[0098] The bisphenol A disodium salt was isolated and prepared as
described above in Examples 1-9.
[0099] The ClPAMI was rich in 4-monoamine (4-MA) was prepared as
follows. A 3-necked, round-bottomed flask was charged with
m-phenylene diamine (2.743 g, 25.365 mmol), 4-chlorophthalic
anhydride (4-ClPA) (9.225 g, 50.531 mmol), sodium phenylphosphinate
(12 mg, 0.0731 mmol) and ODCB (65 g). The flask was assembled with
a mechanical stirrer, a Dean-Stark trap, and a nitrogen inlet and
placed in pre-heated oil bath (170.degree. C.). The mixture was
stirred and the oil temperature was increased to 180.degree. C.
Nitrogen flow was gradually increased to allow a steady collection
of water/ODCB mixture in the Dean-Stark trap. Nitrogen flow was
decreased when approximately 10 ml of ODCB has been collected in
the trap. The mixture was allowed to stir until no further change
in residual 4-ClPA and 4-MA (final residual content: 0.4-0.7 mol %
4-MA and 0.00-0.02 mol % 4-ClPA, as determined by HPLC analysis).
The mixture was kept at 180.degree. C. under N.sub.2 and was ready
for polymerization.
[0100] The polymerizations were run as described above in Examples
1-9 with the following differences regarding the location of the
base addition. In example 10 powdered bisphenol A disodium salt was
combined with powdered K.sub.3PO.sub.4. The solids were
quantitatively transferred to the flask containing the ClPAMI
slurry. In Example 11 powdered K.sub.3PO.sub.4 was added to a flask
containing a ClPAMI slurry. The mixture was stirred for greater
than or equal to 1 hour at 180.degree. C. under nitrogen. Powdered
bisphenol A disodium salt was added to the mixture. Samples of the
reaction mixture were pulled hourly and analyzed by GPC.
[0101] In Example 12K.sub.3PO.sub.4 was added to the polymerization
reaction when the molecular weight standard deviation of the last
three hourly samples (last 3 hours) was <500 Daltons. When the
Mw standard deviation of the last three hourly samples (last 3
hours) was <500 Da, the mixture was diluted with ODCB to make
10% solids.
[0102] The hydroxy end group content of the polymers produced with
the different methods of K.sub.3PO.sub.4 base addition is shown in
Table 2 below. Molecular weight of the polymers and the time for
the polymer to achieve maximum molecular weight (time for the
reaction to "plateau") is also shown. The results show that the
location of the base addition does not have a significant impact on
the hydroxyl end group content.
Example 13
[0103] Example 13 explored the use of an aqueous solution of
K.sub.3PO.sub.4 instead of solid K.sub.3PO.sub.4. The bisphenol A
disodium salt was isolated and prepared as described above in
Examples 1-9.
[0104] The ClPAMI was rich in 4-monoamine was prepared as described
in Examples 10-12.
[0105] A 3-necked, round-bottomed flask equipped with a magnetic
stir bar and a means for N2 inlet was charged with bisphenol A
disodium salt (6.675 g, 24.518 mmol) and dry ODCB to make 20%
solids. The flask was assembled with a Dean-stark trap and heated
with stirring at 120.degree. C. To this mixture was slowly added
aqueous K.sub.3PO.sub.4 (375 mg, 40% aq). The slurry was mixed and
enough ODCB was slowly distilled until 25% solids are obtained. The
mixture was allowed to stir for greater than or equal to 12 hours.
The mixture was cooled but kept stirring under a slow N.sub.2 flow.
This slurry was ready for polymerization. The bisphenol slurry was
quantitatively transferred to the flask containing the ClPAMI
slurry. The mixture was heated to reflux and was stirred and
nitrogen flow was increased to hasten the overhead collection of
ODCB until 30% solids was obtained. At this stage,
hexaethylguanadinium chloride (HEGCl, 790 mg, 8.3% in ODCB) was
added and the reaction was allowed to proceed. The mixture was
stirred and sampled for GPC analysis every hour. When the weight
average molecular weight (Mw) standard deviation of the last three
hourly samples was <500 Daltons (Da) the mixture was diluted
with ODCB to make 10% solids. The polymer was quenched and isolated
as described in Examples 1-9.
[0106] The hydroxy end group content of the polymer produced is
shown in Table 2 below. Molecular weight of the polymer and the
time for the polymer to achieve maximum molecular weight (time for
the reaction to "plateau") is also shown. The results show that
aqueous K.sub.3PO.sub.4 can be used to make a polyetherimide with
low hydroxyl end group content.
TABLE-US-00002 TABLE 2 Hydroxy Time to end group Mode of addition
Mw final, plateau content RTI Example 1% K.sub.3PO.sub.4
kiloDaltons (hours) ppm (.degree. C.) 10 Powder, mixed 68.9 15 9
170** with salt 12 Powder, added 64.0 16 3 170** on plateau 11
Powder, added 66.2 10 10 170** to ClPAMI 13 40% aq, added 66.5 20
11 170** to salt, dried **Determined by the Accelerated Heat Aging
Testing Method
Examples 14-17
[0107] Examples 14-17 explored the effect of K.sub.3PO.sub.4
particle size on hydroxyl end group content of the polyetherimide
and the speed of the polymerization reaction.
[0108] The K.sub.3PO.sub.4 was fractionated into different particle
sizes as follows. A weighed amount of K.sub.3PO.sub.4 (100 g,
Acros) was placed in a 250 ml glass beaker and covered with an
aluminum foil. The beaker was then placed in preheated vacuum oven
(150.degree. C.) and subjected to full vacuum over 3 days. The oven
temperature was lowered to room temperature and the beaker taken
out and transferred to a dry box with a continuous N.sub.2 flow.
Inside the dry box was placed a prearranged stainless sieving pans
(arranged from top to bottom in microns: 850, 425, 250, 150, 75).
The K.sub.3PO.sub.4 was poured on top and sieving pans shaken until
no further materials are passing through (.about.5 hours). The
powders were collected and kept inside the glove box.
[0109] The fractionated K.sub.3PO.sub.4 was used in polymerizations
conducted according to Example 10 or 12. The hydroxy end group
content of the polymer produced is shown in Table 3.
TABLE-US-00003 TABLE 3 Particle size Hydroxy distribution of
K.sub.3PO.sub.4 Time to end group (microns), added at Mw final,
plateau content RTI** Example 1% kiloDaltons (hours) ppm (.degree.
C.) 14 <75, added as 50.0 8 23 170 described in Example 10 15
<75, added as 50.4 10 30 170 described in Example 12 16 150-250,
added as 49.1 17 0*** 170 described in Example 12 17 75-150, added
as 50.1 15 16 170 described in Example 12 **Determined by the
Accelerated Heat Aging Testing Method ***not detectable-less than
10 ppm
[0110] The data shows that the particle size of the K.sub.3PO.sub.4
affects the speed of the polymerization reaction with smaller
particle sizes correlating to faster polymerization reactions.
Examples 18-21
[0111] Examples 18-21 explored the use of K.sub.3PO.sub.4 during
polymerization in large scale reactions (pilot plant scale) to
reduce the quantity of hydroxy end groups on the polyetherimide. In
Example 18, the importance of particle size when using
K.sub.3PO.sub.4 was evaluated. Examples 19-20 illustrate successful
trials using finely divided K.sub.3PO.sub.4. Example 21 illustrates
the use of aqueous K.sub.3PO.sub.4, utilizing amine-rich ClPAMI and
capping of amine groups, thereby resulting in low OH material. The
RTI rating for the control material and the polyetherimides used in
Example 19 and 20 was determined in accordance to the UL.RTM.
Relative Thermal Index test method UL746B. The results of Examples
18-21 are summarized below. Examples 18 to 21 demonstrate the
preference to run the polymerization reaction under strict
anhydrous conditions and with finely divided base and/or finely
divided bisphenol A disodium salt.
[0112] The bisphenol A disodium salt was prepared as follows. A
350-gallon (the first vessel), baffled, steam-jacketed stainless
steel reactor, equipped with an agitator, a steam jacket,
temperature indication, appropriate fittings for charging
materials, a nitrogen inerting system, and an overhead line with
condenser, was charged with 474 kilograms (1045 pounds) of water,
and 191 kilograms (422 pounds, 839 moles) of bisphenol A (BPA). The
mixture was stirred and inerted with nitrogen for 1 hour. The
mixture was heated to 50.degree. C. centigrade over a 1-hour
period. The vessel was then charged with 134 kilograms (295.9
pounds, 1678 mol) of 50% sodium hydroxide (NaOH) with stirring. The
mixture was then heated to 90 to 92.degree. C. over one hour to
effect dissolution of the bisphenol A as disodium salt. The
solution was stirred for 1 hour at this temperature and then
sampled. The material was stoichiometrically balanced (less than or
equal to 0.1 mol % rich in NaOH).
[0113] A 500-gallon, baffled, insulated stainless steel reactor
(also referred to as the salt dryer or the second vessel), equipped
with temperature indication, means to maintain a strict nitrogen
atmosphere, a pump around loop that included a variable speed pump
and an oil-jacketed spiral heat exchanger, and an overheads line
with a condenser, was charged with 977 kilograms (2150 pounds) of
ODCB. The recirculation loop was equipped with a back-pressure
control valve on the discharge of the reboiler. The ODCB was
brought to 150.degree. C. under nitrogen using hot oil on the heat
exchanger. The aqueous mixture of bisphenol A disodium salt was
sprayed into the ODCB at 1.8-3.1 kilograms per minute (4 to 7
pounds per minute) with 22 psig back-pressure maintained on the
reboiler. This prevented boiling in the reboiler itself. The motive
force to transfer the aqueous salt in the first vessel to the salt
dryer was nitrogen pressure. The pump was set to provide 250 grams
per minute (gpm) of flow through the recirculation loop. The oil
was maintained at 218.degree. C. Water and ODCB distilled,
condensed, and collected in a decanter. The water was drawn off the
decanter, and the ODCB was recirculated back to the salt dryer. The
overheads stream of the reactor (prior to the condenser) was
periodically collected and analyzed for moisture. This was
accomplished by opening a valve on the overheads line to allow the
vapor to enter an externally cooled coil. The condensed vapor was
collected in a dry jar at the end of the coil, and then analyzed
for water by Karl Fischer titration. After 680 kilograms (1500
pounds) of ODCB had been collected the moisture content in the
overheads was <20 ppm water. An additional 227 kilograms (500
pounds) of ODCB was distilled off the second reactor and the oil
was then valved out of the reboiler to afford a dry slurry of
bisphenol A disodium salt in ODCB at 24.0% solids. The salt was
cooled to ambient temperature with cold oil on the reboiler.
[0114] A portion of the dry bisphenol A disodium salt slurry (29.2
kg of 24% solids slurry, 7.18 kg, 26.37 mol of dry weight bisphenol
A disodium salt) was charged to a third vessel. The third vessel
was a 50-gallon oil-jacked stainless steel reactor equipped with an
agitator, baffles, means for maintaining a nitrogen atmosphere, and
an overheads line equipped with a condenser. The slurry was diluted
with enough ODCB to provide a 10% solids slurry. Hot oil was
circulated on the jacket of the vessel to distill a small amount of
ODCB overhead in an attempt to dry the system. Where a base was
added, potassium phosphate (finely ground) was used. The slurry was
refluxed gently for 10 hours with stirring under nitrogen.
[0115] The ClPAMI was prepared as follows. In a fourth vessel,
namely a 50-gallon, glass-lined, oil-jacketed, baffled reactor,
equipped with a mechanical agitator, means for maintaining a
nitrogen atmosphere, appropriate fittings for charging raw
materials, and an over-head line equipped with a condenser, was
charged with 9.5227 kilograms (kg, 52.16 mol) of purified
4-chlorophthalic anhydride (4ClPA), containing 5% by weight
3-chlorophthalic anhydride, 100.8 g of phthalic anhydride (0.68
mol), 3.000 kg (27.74 mol) of metaphenylene diamine (mPD), 0.0110
kg (0.067 mol) of sodium phenylphosphinate, and 60 kg of
orthodichlorobenzene (ODCB) at ambient temperature. The mixture was
stirred and inerted with nitrogen for 1 hour. The mixture was then
heated to an internal temperature of 140.degree. C. over three
hours and held at that temperature for 30 minutes. Water generated
by the imidization and some solvent was distilled from the vessel
and condensed. The reaction mixture was then heated to 180.degree.
C. over 2 hours and held at that temperature for one hour. The
mixture was sampled to determine the purity of the ClPAMI monomer
by HPLC (high pressure liquid chromatography) analysis. It was
determined that the material was deficient in ClPA, and 9.8 grams
(0.054 mol) of 4-chlorophthalic anhydride was then added to the
reactor. The reaction was heated for another hour and re-sampled.
The material was judged to be `on stoichiometry`, 0.19 mol %
residual ClPA, 0.002 mol % residual monoamine (MA). The material
was then concentrated to 23% solids by distilling ODCB from the
vessel (% solids is defined as the weight of the ClPAMI monomer
divided by the sum of the ClPAMI monomer and solvent). The
distillate was analyzed for moisture by Karl Fischer titration and
found to be <20 ppm when 23% solids was achieved in the vessel.
A sample was taken of the reaction mixture and analyzed by HPLC to
determine the amount of monoamide-acid (MAA) present. The reaction
was judged complete as <0.1 mol % of MAA (mono amide acid) was
observed.
[0116] The polymerization was run and the polymer isolated as
follows. The bisphenol A disodium salt slurry in the third vessel
was cooled and transferred to the fourth vessel (the 50-gallon
reactor containing the ClPAMI slurry described above). The
bisphenol A disodium salt and ClPAMI mixture were dried over the
course of 10 hours by distilling ODCB overhead with the use of the
hot oil jacket on the vessel to provide a slurry that was
approximately 25% solids. The catalyst (HEGCl, 73.19 grams, 0.28
mol, dissolved in 292 grams of ODCB, moisture content of the
catalyst solution was 20 ppm as determined by Karl Fischer
titration) was then added to the slurry and the mixture was brought
to reflux (180 to 185.degree. C.) with the use of the hot oil
jacket on the vessel.
[0117] When the polymer had attained the desired molecular weight
as determined by GPC, the reaction mixture was cooled to
165.degree. C. and treated with 85% aqueous H.sub.3PO.sub.4 (193 g,
1 weight percent with respect to the amount of polymer present) for
1 hour with stirring. The reaction mixture was then diluted with
ODCB to provide a 10% by weight solution of polymer in ODCB and
cooled to 120 to 135.degree. C. The material was then filtered
through a 2 microns sintered metal filter to remove the
precipitated sodium chloride and phosphate salts to provide a clear
amber solution of polymer in ODCB. The filtrate was collected in an
oil-jacketed stainless vessel equipped with an agitator.
[0118] The polymer solution was then contacted with 329 kg of water
at 90.degree. C. The pH of the water had been adjusted to 4 to 5
with the addition of a small amount of H.sub.3PO.sub.4 prior to
transfer to the vessel. The two-phase system was mixed for 5
minutes at 160 rpm, and then allowed to settle for two hours. The
organic phase was drawn off to a separate identical vessel. The
aqueous phase was discarded. The organic phase was again washed
with 149 kilograms (329 pounds) of slightly acidic water as just
described. The organic phase was then concentrated to 30% solids
solution through the distillation of ODCB. The concentrated
solution was then feed at 33 kilograms per hour (72 pounds per
hour) to a devolatilizing vacuum extruder. The screw speed of the
extruder was 525 rpm, the vacuum ports on the extruder barrel was
maintained at 3 mm Hg, the melt temperature of the polymer was
430.degree. C. The strands of polymer were cooled in a water bath,
conveyed to a device to blow surface water from the strands, and
then feed to a chopper to produce resin pellets. Specific
conditions of the Examples 18-21 are discussed below.
Example 18
[0119] In Example 18 the K.sub.3PO.sub.4 was crushed and added to
the bisphenol A disodium salt slurry and heated with mixing for ten
hours at reflux (180.degree. C.). When the bisphenol A disodium
salt slurry with the K.sub.3PO.sub.4 was added to the ClPAMI slurry
large particles (approximately 1 to 5 mm in size) were present in
the resulting mixture that consisted primarily of K.sub.3PO.sub.4.
The fact that the K.sub.3PO.sub.4 was not finally divided resulted
in the isolation of polymer with 309 ppm OH end groups. It was
later discovered that a small amount of water had entered the
reactor where the bisphenol A disodium salt and the K.sub.3PO.sub.4
were heated, and agglomerated the K.sub.3PO.sub.4. The presence of
the water is believed to have reduced the effectiveness of the
K.sub.3PO.sub.4 (by agglomeration).
Example 19
[0120] In Example 19 the K.sub.3PO.sub.4 was used as received and
contained water in an amount of 1% by weight and the introduction
of moisture in the system during K.sub.3PO.sub.4 addition was
avoided. The bisphenol A disodium salt and K.sub.3PO.sub.4 were
heated and stirred at 180 C for 12 hours resulting in a finely
divided slurry. Use of this material in the polymerization reaction
resulted in low OH containing material (63 ppm OH).
Example 20
[0121] In Example 20 the K.sub.3PO.sub.4 was dried prior to use to
achieve a water content of less than 100 ppm water. The bisphenol A
disodium salt and K.sub.3PO.sub.4 were heated and stirred at 180 C
for 12 hours resulting in a finely divided slurry. Use of this
material in the polymermization reaction resulted in low OH
containing material (25 ppm OH).
Example 21
[0122] Example 21 explored the use of aqueous K.sub.3PO.sub.4 in
place of solid K.sub.3PO.sub.4 and the use of a capping agent to
cap amine endgroups.
[0123] The bisphenol A disodium salt with K.sub.3PO.sub.4 was
prepared as follows. The bisphenol A disodium salt was prepared as
described in Examples 18-20. A 50-gallon oil-jacketed stainless
steel reactor was charged with a slurry of bisphenol A disodium
salt in ODCB where the % solids of the salt in the ODCB was 15% by
weight (7.822 kg of bisphenol A disodium salt was present). The
slurry was sparged with nitrogen for 70 minutes and then heated to
170.degree. C. A 50 weight percent solution of potassium phosphate
(K.sub.3PO.sub.4, 420.8 g of solution, 210.4 g, 0.99 mole) in water
was sprayed into the hot ODCB mixture over 50 minutes. The spray
was a fine spray of droplets that had an average size of 40 u. The
spray was directed at surface of the material in the vessel. Water
and ODCB flashed overhead and was condensed. The vessel was
equipped with a bottom fitting plumbed to a centrifugal pump that
discharged back to the vessel. The contents of the vessel were
recirculated through the pump to effectively reduce the particle
size of bisphenol A disodium salt and K.sub.3PO.sub.4 solids. The
mixture was concentrated to .about.20% by distilling ODCB overhead.
The amount of moisture in the overheads as the material in the
vessel was at 19.5% solids was 16 ppm. The vessel was cooled to
120.degree. C. and stirred for 12 hours and then cooled to room
temperature.
[0124] The ClPAMI was prepared as described in Examples 18-20 using
following amounts: 4-ClPA (9.8769 kg, 54.10 mol), 3-ClPA (0.5045
kg, 2.76 mol), phthalic anhydride (PA, 4.9 grams, 0.033 mol),
meta-phenylene diamine (mPD, 3.000 kg, 27.74 mol), SPP (11 gr,
0.067 mol) and 68.7 kg of ODCB. The final product was concentrated
to 20% solids by distillation of ODCB. The final stoichiometry of
the product was 0.33 mol % excess 4-MA (0.184 mol) and
non-detectable amount of 4-ClPA. The mixture was cooled to ambient
temperature.
[0125] The polymerization proceeded by combining the bisphenol A
disodium salt slurry containing K.sub.3PO.sub.4 with the ClPAMI,
drying the combined mixture by the distillation of a small amount
of ODCB from the vessel, followed by addition of the polymerization
catalyst (HEGCl, 75.8 gr, 0.287 moles in 300 mL of dry ODCB). An
exothermic reaction ensued. The reaction ran at 180.degree. C. for
6 hours and analysis (gel permeation chromatography, GPC) showed
that the polymer had a Mw of 21,000 Daltons. An additional portion
of the K.sub.3PO.sub.4 treated bisphenol A disodium salt slurry was
then added to the vessel (387 gr, 1.42 mol) and the mixture was
heated for another 6 hours at which time the Mw was 34,350 Daltons.
An additional portion of the K.sub.3PO.sub.4 treated bisphenol A
disodium salt slurry was then added to the vessel (105 g, 0.386
mol) and the mixture was heated for another 12 hours at which time
the Mw was 46,930 Daltons. Phthalic anhydride (PA, 50 gram, 0.34
mol, 1.85 equiv with respect to the amount of 4-MA present in the
starting CIPAMI mixture) was then added to the vessel to cap the
free amine end-groups. The reaction was heated at 180.degree. C.
for another 3 hours. The polymer was then treated with phosphoric
acid and isolated as described in Examples 18-20.
[0126] The resulting polymer had a molecular weight of 46,700
Daltons with a hydroxy end group content of 57 ppm and an amine end
group content of 13 ppm, and an RTI rating of 170.degree. C., as
determined by the Accelerated Heat Aging Testing Method.
[0127] This example demonstrated the use of aqueous K.sub.3PO.sub.4
to treat the bisphenol A disodium salt, the use of a centrifugal
pump to reduce the particle size of the salt particles, the
importance of dryness of the polymerization reaction mixture, the
ability to run a polymerization reaction amine rich followed by
capping of the amines with PA, to ultimately provide a resin low in
OH and NH.sub.2 end content in a reasonable amount of time.
[0128] The results of Examples 18-21 are summarized below in Table
4.
TABLE-US-00004 TABLE 4 Peak Molecular Accelerated weight drop Heat
Aging UL Test OH Content of after 12 Testing Protocol Polymer (ppm
days at 230.degree. C. Method UL756B Example by weight) (% Mp Drop)
(.degree. C.) (.degree. C.) ULTEM .TM. <10 8.5 170 170 1000/1000
18 309 35.0 160 NM (Comparative) 19 63 12.8 170 170 20 25 12.5 170
170 21 57 12.6 170 NM NM: not measured
Example 22-49
[0129] Examples 22-40 explored the effect of the stoichiometry of
the bisphenol A disodium salt on the quantity of hydroxyl end
groups in the polyetherimide.
[0130] The bisphenol A disodium salts were prepared as follows. A
2-liter, 3-necked, round-bottomed flask was charged with the
requisite amount of bisphenol A to prepare approximately 0.5 moles
of aqueous disodium salt of the desired stoichiometry (see Table 5)
at roughly 15% solids. The bisphenol A was weighed into the flask
on a capable balance that was checked with standard weights just
prior to weighing. The bisphenol A generally contained less than
400 ppm of water and this error was neglected. The flask, along
with degassed water, and a 1N Anachemia Acculute (part number
83112-000, containing 0.998 to 1.002 moles of NaOH) was placed in a
glove box under nitrogen. A balance with a two decimal point
capability was also in the glove box.
TABLE-US-00005 TABLE 5 Delta moles Standard BPA from Weight. 1.0N
(Stoichiometry perfect Weight Total weight Weight solids NaOH
Acculute and EXAMPLE Error in Mole %) stoichiometry BPA (g) std (g)
(g) H.sub.2O (g) 22 On stoichiometry 0 114.1450 907.53 136.13
793.39 BPA rich stds 23 0.3 0.0015 114.4874 909.82 136.47 795.33 24
0.5 0.0025 114.7157 911.34 136.70 796.62 25 0.6 0.003 114.8299
912.10 136.81 797.27 26 1 0.005 115.2865 915.14 137.27 799.86 27 2
0.01 116.4279 922.75 138.41 806.32 28 3 0.015 117.5694 930.36
139.55 812.79 29 5 0.025 119.8523 945.58 141.84 825.73 30 8 0.04
123.2766 968.41 145.26 845.13 BPA deficient stds 31 -0.2 0.001
113.9167 906.25 135.94 792.33 32 -0.3 0.0015 113.8026 905.61 135.84
791.81 33 -0.5 0.0025 113.5743 904.33 135.65 790.75 34 -0.6 0.003
113.4601 903.69 135.55 790.23 35 -1 0.005 113.0036 901.12 135.17
788.12 36 -2 0.01 111.8621 894.72 134.21 782.85 37 -3 0.015
110.7207 888.31 133.25 777.59 38 -4 0.02 109.5792 881.90 132.28
772.32 39 -5 0.025 108.4378 875.49 131.32 767.05 40 -8 0.04
105.0134 856.26 128.44 751.25
[0131] The NaOH was carefully added to the flask and degassed water
was used to complete the transfer of the caustic from the Acculute
plastic bottle to the flask. The combined total weight of water and
the contents of the Acculute bottle was approximately 800 grams.
The flask was capped in the dry box and then transferred to a
laboratory hood.
[0132] The flask was fitted with a mechanical stirrer, and a Dean
and Stark receiver topped with a reflux condenser. The arm of the
Dean and Stark fitted to the flask was wrapped with electrically
heated tape. The third neck was fitted with a nitrogen adapter. A
gentle of flow of nitrogen was established. The flask was then
immersed in a temperature controlled oil bath that sat on a
laboratory jack. The set-up was such that the oil bath could be
lowered completely away from the bottom of the round-bottomed
flask.
[0133] The mixture was stirred at room temperature until the
bisphenol A dissolved. Bisphenol A rich salts periodically required
gentle heating to effect dissolution of the bisphenol A. Degassed
reagent grade toluene was added to the flask to the point that
there was about one inch of head-space between the liquid level and
the bottom of the side neck joint. The oil temperature was then
taken to 145.degree. C. Toluene and water distilled from the flask
and the water collected in the arm of the receiver. The water was
removed and not allowed to return to the flask. The bulk water was
removed in this manner over a course of about 6 hours. Fresh
degassed toluene was added after about two-thirds of the water had
been removed. Very little water distilled over after six hours of
reflux. Bisphenol A disodium salt agglomerated on the sides of the
vessel. The heat was removed and the material cooled to room
temperature overnight under nitrogen.
[0134] While maintaining nitrogen above the salt slurry, the sides
of the flask and the stir shaft were carefully scraped with a large
bent spatula. Once the caked-on salt was removed, the Dean and
Stark receiver and nitrogen adapter were replaced in the original
configuration. Degassed toluene was added to nearly fill the flask,
but enough head space was left for vapor to exit. The vessel was
placed back into the temperature controlled oil bath set at 145 to
150.degree. C., and toluene/water was distilled overhead with a
gentle nitrogen sweep, while allowing the toluene in the collection
arm return to the vessel and drawing off the water that collected
in the side arm. After 4 to 5 hours of reflux, the vast majority of
the water had been removed and the toluene in the collection arm of
the receiver was nearly clear. At this point, 1 liter of toluene
was distilled overhead and withdrawn from the side arm (no toluene
was allowed to flow back into the vessel). Approximately 500 mL of
degassed bottled reagent grade toluene was added to the flask and
distilled off until about 500 mL of slurry remained in the
vessel.
[0135] The oil bath was removed from the vessel while maintaining a
nitrogen sweep in the system. The material was allowed to cool. The
vessel was capped and transferred to a glove box maintained under
nitrogen. The slurry was then transferred to a 1-liter, 1-necked,
round-bottomed flask.
[0136] The flask was then quickly placed on a rotary evaporator and
vacuum was slowly established to 75 to 100 mm Hg. The flask was
lowered into a temperature controlled oil bath set at 50 to
60.degree. C. The bulk toluene was removed to afford dry salt. The
flask was removed from the oil bath and nitrogen back-added to the
evaporator. The flask was removed and shaken to break up any cake.
The vacuum traps and bulb receiver on the rotary evaporator were
emptied, rinsed with acetone, blown dry, and replaced. The flask
was again placed on the rotary evaporator and the flask placed
under full vacuum (<25 mm Hg). The flask was heated in the oil
bath set a 150.degree. C. for one hour to afford dry free flowing
solid bisphenol A disodium salt.
[0137] ClPAMI was synthesized as described in Examples 18-21. A
portion of ClPAMI/ODCB slurry (2 kg) was cooled to room
temperature. The slurry was vacuum filtered using a Whatman Number
1 filter paper on a large Buchner funnel to afford a wet cake. One
liter of warmed ODCB (90.degree. C.) was added to the cake in the
filter. Vacuum was applied to remove this ODCB rinse. The rinse was
repeated with another 1 liter of 90.degree. C. ODCB. The wet cake
in the funnel was then rinsed with 1 liter of room temperature
toluene to remove the bulk of the ODCB from the cake. The cake was
then placed in an aluminum pan. The pan was placed in a vacuum oven
(10 mm) for 12 hours at 150.degree. C. The pan was removed from the
oven and allowed to cool to afford dry ClPAMI monomer.
[0138] Polymerizations were performed as follows. All charges were
done in dry box with the glassware being assembled. A 250-mL,
three-necked, round-bottomed flask equipped with a stopper and a
gas valve were charged with 6.09 grams (0.0224 moles) of a
particular stoichiometry bisphenol A disodium salt, and 10 grams
(0.0228 moles) ClPAMI (prepared as described above). The flask was
charge with 65 grams of ODCB. The flask was then equipped with a
stir shaft and bearing. The flask was removed from the dry-box and
immediately fitted with a nitrogen adapter on a side neck. The
remaining stopper was allowed to float, venting any pressure. The
vessel was then fitted with a Dean and Stark receiver topped with a
reflux condenser. A gentle sweep of nitrogen was established
through the head-space of the vessel. The reaction was then heated
to 200.degree. C. with the use of an external oil bath, and a
gentle nitrogen sweep was established, to azeotropically dry the
ODCB mixture. ODCB was removed from the mixture until it reached 30
weight percent solids (.about.25 grams of ODCB). The mixture was
gently stirred to avoid splattering of the materials on the sides
of the flask or on the stir shaft. Once the overheads were dry by
Karl Fischer analysis, 90 mg (1 mole %) of HEGCl was charged to the
solution; within 30 minutes the solution was brownish and finally a
golden solution after 90 minutes. The mixture was sampled after 2
hours to measure Mw, and then every hour until the reaction had
plateaued (plateau=last 3 hourly samples had a standard deviation
of less than 500 Daltons). If the Mw was below 45K a correction of
140 mg of bisphenol A disodium salt was made to target a polymer Mw
of 55,000.
[0139] The reaction was then heated at 160.degree. C., then treated
with 170 mg (1 weight % with respect to polymer) of 85% aqueous
H.sub.3PO.sub.4. Once the acid was added the mixture was purged
with nitrogen to remove any water (5 minutes). The reaction was
heated for another hour. The reaction was then cooled and diluted
to 10 weight percent with CH.sub.2Cl.sub.2 (approximately 70 mL).
The mixture was then filtered on Buchner funnel using a Whatman 1
micrometer GF (glass filter) disk. The filtrate solution was then
transferred to blender where an equal volume of hexane was added
and blended, where upon the polymer precipitated from solution. The
mixture was filtered and the isolated polymer was dried under
vacuum at 165.degree. C. for 24 hours to form a dry polymer
powder.
[0140] The resulting polymers were analyzed for OH end content by
P31 NMR. Results are shown in Table 6.
TABLE-US-00006 TABLE 6 ppm Amine ppm Salt Catalyst Mw at End OH End
Example source amt S/C ratio Plateau PDI Group Group RTI** 41* 1%
BPA 1.5 0.98/6.22 75402 2.97 55 1344 160 rich 42* on stoich 1.5
0.98/6.22 46884 2.33 71 570 160 43* 0.2% 1.5 0.98/6.22 60949 2.74
62 496 160 NaOH rich 44* 0.3% 1.5 0.98/6.22 55291 2.96 0 466 160
NaOH 45* 0.5% 1.5 0.98/6.22 52187 2.39 93 512 160 NaOH 46* 1% 1.5
0.98/6.2 75420 3.11 123 342 160 NaOH 47 2% 1.5 0.98/6.18 47410 2.9
111 55 170 NaOH 48 3% 1.5 0.98/6.22 45210 2.39 197 54 170 NaOH 49
4% 1.5 0.98/6.15 48830 2.17 89 62 170 NaOH *Comparative Example
**Determined by the Accelerated Heat Aging Testing Method
Discussion of Examples 41-49
[0141] The results show that only some polyetherimides had an OH
content that was greater than 0 and less than or equal to 100 parts
per million by weight (ppm); and a Relative Thermal Index that is
greater than or equal to 170.degree. C. The caustic rich salts that
were 2% to 4% NaOH excess resulted in polymer with .about.60 ppm OH
end group content. The amine endgroup composition was slightly
elevated. The isolated polymers were heat aged in the Accelerated
Heat Aging Testing Method and shown to heat age as well as resin
with very low OH end content. Greater than or equal to 2 mol %
excess NaOH rich bisphenol A disodium salt was necessary to lower
the amount of OH ends to a level that afforded polymer that heat
aged well. Further, the polymers made in Example 41-49 showed
elevated amine end groups.
Examples 50-52
[0142] Polymerizations were run as described above and were treated
with 4-ClPA in two different modes. In one mode, 1 weight percent
of 4-ClPA (with respect to the weight of polymer produced) was
added to the polymerization reaction mixture 1 hour after the Mw
build had ceased to build, at 180.degree. C. The mixture was heated
for 2 hours and then treated with phosphoric acid and isolated as
described above. In the other mode, the polymerization mixture was
quenched with phosphoric acid 1 hour after the Mw build had ceased
to build, and then 1 weight percent of 4-ClPA (with respect to the
weight of polymer produced) was added to the reaction mixture at
180.degree. C. and stirred for 2 hours at 180.degree. C. The
polymers were then heat aged in the Accelerated Heat Aging Testing
Method and the data is shown in Table 7.
TABLE-US-00007 TABLE 7 OH End ClPA Capping Content RTI Rating
Example Method (ppm) (.degree. C.) 50 before quenching 24 170 with
H.sub.3PO.sub.4 51 before quenching 47 170 with H.sub.3PO.sub.4 52
after quenching 64 170 with H.sub.3PO.sub.4
Examples 53-56
[0143] The synergy of added K.sub.3PO.sub.4 and caustic rich salt
to produce resin with <100 ppm OH was explored. Polymerizations
were run as described above. BPA disodium salt was prepared that
was 1 mole % rich in sodium hydroxide. This salt was rigorously
dried and then polymerized with ClPAMI in the presence of 0.25 to
1.0 weight percent solid K.sub.3PO.sub.4 (with respect to the
polymer weight produced) and a phase transfer catalyst
(hexaethylguanidinium chloride, 1 mole % with respect to the amount
of bisphenol A disodium salt). The amount of excess caustic used to
make the BPA disodium salt was 0.12 weight percent with respect of
the amount of polymer produced.
[0144] The results are shown in Table 8 below.
TABLE-US-00008 TABLE 8 Synergy of K.sub.3PO.sub.4 and 1 mol %
Caustic Rich Disodium Salt (1) Weight weight percent percent excess
OH End Example K.sub.3PO.sub.4 NaOH Content (ppm) RTI Rating** 53
0.25 0.13 459 160 54 0.35 0.13 177 160 55 0.50 0.13 54 170 56 1.00
0.13 28 170 (1) Weight percent K.sub.3PO.sub.4 is with respect to
the amount of polymer produced. Weight percent excess NaOH is with
respect to the amount of polymer produced and equates to 1 mole %
NaOH rich BPA disodium salt. The OH content was measured by P31
NMR. Studies have shown that polymer containing less than 100 ppm
OH has an RTI of 170.degree. C. **As determined by Accelerated
Heating Aging Testing Method
Alternative Examples
[0145] The purpose of these examples was to determine whether the
use of stabilizers would improve the RTI properties of
chloro-displaced polyetherimides. Inexplicably, as further
discussed below, the use of the stabilizers did not result in
chloro-displaced polyetherimides having an RTI of 170.degree. C. or
more.
[0146] More particularly, the use of stabilizers to address the
thermal stability issues of polyetherimide resins having a hydroxyl
end group content greater than 100 ppm was explored. These examples
are all comparative and are named "alternative examples" to
distinguish them from the preceding comparative examples.
[0147] Two different polyetherimide resins were used. One
polyetherimide resin made from a chloro displacement process had a
hydroxyl end group content of 350 ppm containing chlorine endgroups
(Resin III), which was isolated from the initial reaction of ClPAMI
and bisphenol A disodium salt in ODCB in the presence of a phase
transfer catalyst and had an RTI rating of 160.degree. C. The other
polyetherimide was commercial grade ULTEM.TM. 1000-1000 material
prepared from bisphenol A dianhydride, meta-phenylene diamine, and
phthalic anhydride as described in U.S. Pat. No. 4,417,044
(assigned to SABIC Innovative Plastics), and had a hydroxyl end
group content of <10 ppm, no chlorine end groups, and an RTI
rating of 170.degree. C.
Alternative Examples 1-15
[0148] The stabilizers listed in Table 9 were compounded into a
polymer of Formula (III) containing 350 ppm OH endgroup content in
the amounts shown. Amounts are in weight percent based on the total
weight of the composition.
TABLE-US-00009 TABLE 9 Alter- Amount native (weight Example
Stabilizer percent) CAS Supplier 1 Irgafos P-EPQ 0.15 119345-01-6
Ciba 2 Irganox 1010 0.30 98584-37-3 Ciba 3 Irgaphos 168 0.30
31570-04-4 Ciba 4 Doverphos S-9228 0.30 154862-43-8 Dover Chem 5
Irganox 1330 0.15 1709-70-2 Ciba 6 Irganox 1010 + 0.15/0.15 Ciba
Irgaphos 168 7 Irgaphos169 + 0.10 Phosphoric acid (2:1 mol) 8
Hycite 713 (DHT-4C) 0.05 11097-59-9 Ciba 9 DER 661 Epoxy 0.30
25036-25-3 Dow 10 Mono zinc phosphate 0.30 13598-37-3 N/A (MZP) 11
SAPP (Sodium 0.30 7758-16-9 N/A dihydrogen pyrophosphate) 12 Zinc
oxide 0.30 1314-13-2 N/A 13 Sodium phenyl 0.05 4297-95-4 Ferro
phosphenate (SPP) Corporation 14 Trisodium phosphate 0.05
10101-89-0 N/A 15 Phosphoric acid 0.30 68698-62-4 N/A dipentyl
ester sodium salt
Techniques & Procedures
[0149] The stabilizers were dry mixed with the polyetherimide
having a hydroxyl end group content of 350 ppm and extruded on a 18
millimeter (mm) Coperion ZSK-18 MegaLab twin screw extruder
(high-temperature version), with 12 barrels. The extruder had a
feed in barrel number 1, a twin screw side feeder in barrel number
2, a vacuum vent in barrel number 11, a length to diameter ratio
(L/D) of 48, and was fed by an adjustable rotatory screw feeder.
The extruder was run under the following conditions shown in Table
10.
TABLE-US-00010 TABLE 10 Extrusion Conditions Set/Read Zone 1 (Feed)
600.degree. C. Zone 2 620.degree. C. Zone 3 640.degree. C. Zone 4
650.degree. C. Zone 5 660.degree. C. Zone 6 (Vac. Vent) 670.degree.
C. Zone 7 680.degree. C. RPM 250
[0150] The isolated pellets were aged using the accelerated heat
aging test at 230.degree. C., using our previously described
Accelerated Heat Aging Test Method. The peak molecular weight of
the compounded pellets was measured before heat aging, after 6 days
of aging and after 13 days of aging by gel permeation
chromatography (GPC). The molecular weight of the polyetherimide
having a hydroxyl end group content of 350 ppm prior to aging,
after 6 days of aging and after 13 days of aging is shown for
comparison. Similarly, the molecular weight of the polyetherimide
having a hydroxyl end group content of <10 ppm prior to aging,
after 6 days of aging and after 13 days of aging is also shown. The
heat aging results are shown in Table 11.
TABLE-US-00011 TABLE 11 Peak Molecular Weight (Mp) of Compounded
Resins Observed in the Accelerated Heat Aging Testing Method.
Alternative days @ 230.degree. C. Example Stabilizer 0 6 13 RTI*
Resin with <10 ppm OH(ULTEM .TM. 1000-1000) 49959 50859 49987
Resin with 350 ppm OH (Resin III) 50609 46306 36771 160 1 Irgafos
P-EPQ 50136 46692 36899 160 2 Irganox 1010 50417 43513 34698 160 3
Irgaphos 168 50187 45998 36753 160 4 Doverphos S-9228 49336 43590
34833 160 5 Irganox 1330 50345 44278 34956 160 6 Irganox 1010 +
Irgaphos 168 50774 45796 38239 160 7 Irgaphos169 + Phosphoric acid
(2:1 mol) 51023 45859 39750 160 8 Hycite 713 (DHT-4C) 51746 43725
32615 160 9 DER 661 Epoxy 50053 43127 36087 160 10 Mono zinc
phosphate (MZP) 48811 45637 39569 160 11 SAPP (Sodium dihydrogen
pyrophosphate) 48886 42600 35537 160 12 Zinc oxide 50224 41670
34408 160 13 Sodium phenyl phosphinate (SPP) 48727 44618 38882 160
14 Trisodium phosphate 47650 42305 34654 160 15 Phosphoric acid
dipentyl ester sodium salt 47754 41932 34629 160 *Estimated RTI
rating based on the Mp retention.
[0151] No clear improvement was observed in the heat aging
performance of the resin containing 350 ppm OH endgroup content
containing various stabilizers; only MZP and SPP showed marginal
improvement in thermal stability as measured by the decrease in Mp
over time. However, the compounding of MZP and SPP into the polymer
resulted in a product with hazy appearance, precluding their use as
a stabilizer. None of the stabilizers resulted in the thermal
stability performance of the resin that contained <10 ppm OH
endgroup content.
Alternative Examples 16-51
[0152] An additional set of stabilizers were compounded into resin
of Formula (III) containing 350 ppm hydroxy endgroups as described
for examples 1-15, in the amounts shown in Table 12. The
compounding process provided resin in the form of pellets. The
amounts of stabilizer compounded into the resin are in weight
percent based on the total weight of the composition.
TABLE-US-00012 TABLE 12 Alternative Example CAS NAME AMOUNT SOURCE
16 119345-01-6 Irgafos .RTM. P-EPQ 0.60% Ciba 17 29690-82-2 Epoxy
Cresol Novolac (ECN 1299) 0.60% Ciba 18 82091-12-1 BMSC 0.60% Sabic
BoZ 19 Polycarbonate Grade 100 1.00% Sabic MtV 20 42955-03-3 Torlon
9000T 1.00% Solvay 21 34052-90-9 1,3-Phenylene-bis-oxazoline (BOX)
0.60% 22 Marlex Concentrate 10% Fine Grinds 6.00% Sabic MtV 23 PPS
Ryton S4 0.60% Phillips 24 71878-19-8 Chimassorb 944 LD 0.60% Ciba
25 84989-41-3 Aquapel 364 (Alkyl Ketene Dimer) 0.60% 26 7704-34-9
Elemental Sulfur 0.30% Aldrich 27 38103-06-9 BPADA 0.60% Sabic MtV
28 115-83-3 Pentaerythrityl tetrastearate 0.60% 29 Nylon 6-6 0.60%
30 PBT 195 Fine Grind 0.60% Sabic 31 29598-76-3 Seenox 412-S 0.60%
32 D9000 Siltem Fines 0.30% Sabic MtV 33 26061-90-5 Bondfast E
(Poly-ethylene-co-glycidyl 0.60% Sumitomo methacrylate) 34
13676-54-5 Bismaleimide 0.60% Aldrich 35 Irgafos 12 0.60% Ciba 36
Irganox 1098 0.60% Ciba 37 Irganox 1035 0.60% Ciba 38 2386-87-0
Joncryl ADR 0.60% Basf 39 Epocros RPS-1005 0.60% 40 108-30-5
Succinic Anhydride 0.60% Aldrich 41 941-69-5 Phenylmaleimide 0.60%
42 10081-67-1 Nauguard 445 0.60% Chemtura 43 89-32-7 Benzene
Tetracarboxylic Dianhydride 0.60% Aldrich 45 Irganox 1010 0.60%
Ciba 46 Irganox 1330 0.60% Ciba 47 5949-29-1 Citric Acid 0.60%
Aldrich 48 108-31-6 Maleic Anhydride 0.60% Aldrich 49 497-19-8
Sodium Carbonate 0.60% Aldrich 50 Irgafos 168 0.60% Ciba 51
10101-89-0 Trisodium Phosphate 0.60% Aldrich 52 Resin with 350 ppm
OH (Resin III) SABIC
[0153] The obtained compounded pellets were aged using the
accelerated heat aging test at 230.degree. C., using our previously
described Accelerated Heat Aging Test Method. The molecular weight
of the compounded pellets was measured before heat aging, after 6
days of aging and after 13 days of aging. The molecular weight of
the polyetherimide having a hydroxyl end group content of 350 ppm
prior to aging, after 6 days of aging and after 13 days of aging is
shown for comparison. The starting and heat aged pellets were
analyzed by gel permeation chromatography (GPC) to determine the
peak molecular weight (Mp). Results are shown in Table 13.
TABLE-US-00013 TABLE 13 Alternative days @ 230.degree. C. Example
Stabilizer 0 6 13 RTI 16 Irgafos .RTM. P-EPQ 48379 43727 38401 160
17 Epoxy Cresol Novolac (ECN 1299) 49933 41319 30642 160 18 BMSC
50609 45290 36835 160 19 Polycarbonate Grade 100 50593 46117 38416
160 20 Torlon 9000T 50406 46635 40629 160 21
1,3-Phenylene-bis-oxazoline (BOX) 47301 43197 37814 160 22 Marlex
Concentrate 10% Fine Grinds 50612 44570 41792 160 23 PPS Ryton S4
50181 47799 42156 160 24 Chimassorb 944 LD 47055 40125 32482 160 25
Aquapel 364 (Alkyl Ketene Dimer) 50493 39231 31272 160 26 Elemental
Sulfur 47070 42363 37404 160 27 BPADA 50460 41646 37415 160 28
Pentaerythrityl tetrastearate 51153 45445 31942 160 29 Nylon 6-6
48004 39959 37072 160 30 PBT 195 Fine Grind 50383 42491 34054 160
31 Seenox 412-S 51028 42013 36115 160 32 D9000 Siltem Fines 50534
42806 37697 160 33 Bondfast E (Poly-ethylene-co-glycidyl
methacrylate) 51294 45368 37219 160 34 Bismaleimide 50440 43813
36860 160 35 Irgafos 12 47619 44286 38954 160 36 Irganox 1098 48515
44772 33870 160 37 Irganox 1035 50680 42852 33520 160 38 Joncryl
ADR 50891 40876 28267 160 39 Epocros RPS-1005 50184 41739 35008 160
40 Succinic Anhydride 50332 44197 36289 160 41 Phenylmaleimide
49359 44273 37364 160 42 Nauguard 445 50430 45316 40595 160 43
Benzene Tetracarboxylic Dianhydride 50853 44618 36149 160 45
Irganox 1010 50649 40649 31722 160 46 Irganox 1330 50737 40260
30861 160 47 Citric Acid 50349 43539 35985 160 48 Maleic Anhydride
49951 42610 32493 160 49 Sodium Carbonate 47784 47223 39949 160 50
Irgafos 168 51074 44003 38923 160 51 Trisodium Phosphate 46474
45228 38362 160 starting resin 49944 46083 39342 160
[0154] Some improvement in the heat aging performance of the resin
was observed with the use of Irgafos 12, Naugard 445, and
polyphenylene sulfide. The inorganic bases sodium carbonate and
trisodium phoshate also showed improvement but the pellets were
hazy or opaque, precluding their use as a heat stabilizer. A useful
heat stabilizer can not affect the haze, opacity, or color of the
resin. The most favorable stabilizers from these examples 16 to 51
were studied further.
Alternative Examples 52-94
[0155] The stabilizers and combinations of stabilizers listed in
Tables 14 and 15 were compounded into resin with Formula (III)
containing 350 ppm of hydroxy endgroups as previously described for
alternative examples 1-15, in the amounts shown. Amounts are in
weight percent based on the total weight of the composition.
TABLE-US-00014 TABLE 14 Alternative Example CAS NAME AMOUNT 52 PPS
Ryton S4 0.30% 53 PPS Ceramer 0.30% 54 PPS F7100 site 0.50% 55 PPS
F7100 site 0.30% 56 PPS F7100 site 0.10% 57 Irgafos 12 0.50% 58
Irgafos 12 0.30% 59 Irgafos 12 0.10% 60 10081-67-1 Nauguard 445
0.30% 61 71878-19-8 Chimassorb 944LD 0.30% 62 Tinuvin 622 LD 0.30%
63 UVINUL 5050H (F2305) 0.30% 64 Na2CO3 0.01% 65 K2CO3 0.01% 66
10101-89-0 Trisodium Phosphate 0.50% 67 10101-89-0 Trisodium
Phosphate 0.10% 68 10101-89-0 Trisodium Phosphate 0.01% 69 CYASORB
UV 3638 (F6525) 0.30% 70 Irgafos 168 (F542) 0.30% 71 Ultranox 626
0.30% 72 Seenox 412-S 0.30% 73 Irganox 1024 0.30% 74 Naugard XL-1
0.30% 75 4297-95-4 Sodium phenyl phosphenate 0.05% 76 13598-37-3
Mono zinc phosphate 0.30% 77 Diaminodiphenylsulfone 0.30% 78 Copper
bromide 0.01% 79 CuAc (50 ppm) + KI (1500 ppm) 0.155% 80 Chimassorb
2020 0.30% 81 4-(Trifluoromethylthio)benzamide 0.30% 82
3-(Trifluoromethyl)phenyl thiourea 0.30% 83 Vanox PML 0.30% 84
Vanox MBM mpd bis-maleimide 0.30% 85 Agerate Stalite S 0.30% 86
Vanox 12 0.30%
TABLE-US-00015 TABLE 15 Alternative Example NAME AMOUNT NAME AMOUNT
87 PPS F7100 site 0.30% Irgafos 12 0.30% 88 PPS F7100 site 0.30%
Naugard 445 0.30% 89 PPS F7100 site 0.30% Na3PO4 0.10% 90 Irgafos
12 0.30% Naugard 445 0.30% 91 Irgafos 12 0.30% Na3PO4 0.10% 92
Naugard 445 0.30% Na3PO4 0.10% 93 Seenox 412-S 0.30% Irgafos 12
0.30% 94 Seenox 412-S 0.30% Irganox 1024 0.30%
[0156] The resulting compounded resin pellets were tested as
described above in Alternative Examples 1-15. Results are shown in
Table 16.
TABLE-US-00016 TABLE 16 Alternative days @ 230.degree. C. Example
Stabilizer 0 6 13 52 PPS Ryton S4 49741 47556 42753 53 PPS Ceramer
49767 46369 41847 54 PPS F7100 site 49784 47093 43241 55 PPS F7100
site 49987 47006 42535 56 PPS F7100 site 49799 46648 41663 57
Irgafos 12 47857 45759 42447 58 Irgafos 12 48064 46065 42307 59
Irgafos 12 48953 46008 41927 60 Nauguard 445 49720 46311 42409 61
Chimassorb 944LD 48566 45162 40278 CDU 49887 45441 40624 62 Tinuvin
622 LD 47954 44583 40369 63 UVINUL 5050H (F2305) 48875 44244 40391
64 Na.sub.2CO.sub.3 49590 45235 40389 65 K.sub.2CO.sub.3 46243
43163 38530 66 Trisodium Phosphate 47260 46346 42069 67 Trisodium
Phosphate 46629 44367 39573 68 Trisodium Phosphate 49397 44970 69
CYASORB UV 3638 (F6525) 49719 46306 41442 70 Irgafos 168 (F542)
49527 45750 41963 71 Ultranox 626 48777 46503 42588 72 Seenox 412-S
49697 43705 38841 73 Irganox 1024 49231 44047 39550 74 Naugard XL-1
49619 43609 38554 75 Sodium phenyl phosphenate 46435 45204 41217 76
Mono zinc phosphate 49389 46507 41312 77 Diaminodiphenylsulfone
49066 46793 42456 78 Copper bromide 49868 44251 39206 79 CuAc (50
ppm) + KI (1500 ppm) 49396 43245 37107 NDU 53196 51179 47921 80
Chimassorb 2020 48974 44590 40555 81
4-(Trifluoromethylthio)benzamide 49362 47168 42859 82
3-(Trifluoromethyl)phenyl thiourea 49499 47319 42124 83 Vanox PML
48836 46787 41871 84 Vanox MBM mpd bis-maleimide 49685 46365 41908
85 Agerate Stalite S 49650 46694 42715 86 Vanox 12 49862 46428
42762 87 PPS F7100 site/Irgafos 12 48360 46900 43098 88 PPS F7100
site/Naugard 445 49586 46170 42483 89 PPS F7100 site/ Na3PO4 46784
46045 40461 90 Irgafos 12/Naugard 445 48054 45558 41929 91 Irgafos
12/Na3PO4 48694 44720 40035 92 Naugard 445/Na3PO4 47116 45516 41573
93 Seenox 412-S/Irgafos 12 48067 42910 38158 94 Seenox
412-S/Irganox 1024 49602 43149 36982
[0157] The above screening in addition to evaluations based on
changes in glass transition point depression, polydispersity index,
resin color, resin color thermal stability, presence of haze or
opacity, odor upon compounding, phase separation, molding issues
and other factors led to the conclusion that Irgafos 12, Naugard
445 and Ultranox 626 showed the best improvement in heat aging
performance overall, and thus they were selected as formulations
for actual RTI testing. Unfortunately, the selected stabilizers did
not work as shown in Alternative Examples 95-100, further discussed
below
Alternative Examples 95-100
[0158] Resin of Formula (III) containing 350 ppm of hydroxy
endgroups was compounded with Irgafos 12, Naugard 445 and Ultranox
626 as previously described for alternative Examples 1-15 in the
amounts shown in Table 17. The compounded pellets along with
control materials were then tested by the Underwriters Laboratories
RTI test UL746B. After extensive testing including examination of
the extrusion conditions no improvement was seen in the RTI values
of the compositions containing stabilizers when compared to the
base polyetherimide (having a hydroxyl end group content of 350
ppm) without stabilizers. All the materials shown in Table 17 had
an RTI of 160.degree. C. or lower. The stabilizer approach to raise
the RTI of a resin with Formula (III) containing >100 ppm of
hydroxy end groups was abandoned.
TABLE-US-00017 TABLE 17 OH content of Stabilizer (wt % with respect
to Example Resin resin (ppm) weight of resin) 95 Formula III 350
Naugard 445 (0.3 wt %) 96 Formula III 350 Naugard 445 (0.3%)1
Irgafos 12 (0.1 wt %) 97 Formula III 350 Irgafos 12 (0.1 wt %) 98
Formula III 350 Irgafos 12 (0.2 wt %) 99 Formula III 350 Ultranox
626 (0.3 wt %)
[0159] Although the present invention has been described in detail
with reference to certain preferred versions thereof, other
variations are possible. Therefore, the spirit and scope of the
appended claims should not be limited to the description of the
versions contained therein.
* * * * *