U.S. patent application number 13/163599 was filed with the patent office on 2012-12-20 for process for preparing amine-modified polyester resins with improved melt flow.
This patent application is currently assigned to Sabic Innovative Plastics. Invention is credited to Robert R. Gallucci.
Application Number | 20120322934 13/163599 |
Document ID | / |
Family ID | 47354188 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120322934 |
Kind Code |
A1 |
Gallucci; Robert R. |
December 20, 2012 |
Process for Preparing Amine-Modified Polyester Resins with Improved
Melt Flow
Abstract
The invention is directed to a process for preparing a linear or
branched amine-modified thermoplastic resin with high flowability
using as starting materials a linear or branched polyester and a
primary or secondary aliphatic amine. The process does not require
that the amine and polyester be combined in a liquid organic
solvent during the process, and can be performed readily at ambient
pressure. The amine-modified resins can be extruded and pelletized
using normal operating conditions, making this process a versatile
option for achieving a wide variety of viscosities in a simple, low
cost, continuous operation.
Inventors: |
Gallucci; Robert R.; (Mt.
Vernon, IN) |
Assignee: |
Sabic Innovative Plastics
|
Family ID: |
47354188 |
Appl. No.: |
13/163599 |
Filed: |
June 17, 2011 |
Current U.S.
Class: |
524/494 ;
264/176.1; 264/500; 524/605; 525/437 |
Current CPC
Class: |
B29C 48/2886 20190201;
C08G 63/6856 20130101; B29C 48/022 20190201; B29C 48/397 20190201;
B29C 48/76 20190201; B29C 48/04 20190201; B29C 48/919 20190201;
C08G 63/916 20130101; B29K 2105/16 20130101; B29C 48/405 20190201;
B29C 48/0022 20190201; B29C 48/40 20190201 |
Class at
Publication: |
524/494 ;
525/437; 524/605; 264/176.1; 264/500 |
International
Class: |
C08L 67/02 20060101
C08L067/02; B29C 49/00 20060101 B29C049/00; B29C 47/00 20060101
B29C047/00; C08G 63/91 20060101 C08G063/91; C08K 7/14 20060101
C08K007/14 |
Claims
1. A solvent-free process for preparing an amine-modified
thermoplastic polyester resin comprising: mixing a melted polyester
of Formula 1: ##STR00005## wherein: each T is independently a
divalent C.sub.6-10 aromatic group derived from a dicarboxylic acid
or a chemical equivalent thereof; each D is independently a
divalent C.sub.2-8 alkylene group derived from a dihydroxy compound
or a chemical equivalent thereof; and m is from 25 to 1000; and a
melted amine, having the formula NHR.sup.1R.sup.2, wherein: R.sup.1
is C.sub.6-36 alkyl, R.sup.2 is selected from the group consisting
of hydrogen, C.sub.1-C.sub.36 alkyl, C.sub.1-C.sub.36
alkylene-aryl, C.sub.1-C.sub.36 alkylene-heteroaryl,
C.sub.1-C.sub.36 alkylene-cycloalkyl, C.sub.1-C.sub.36
alkylene-heterocycloalkyl, and NHR.sup.1R.sup.2 contains at least
10 carbons; thereby forming an amine-modified thermoplastic
polyester resin characterized by one or both of the following
properties: (i) the resin comprises 0.01 to 5 weight percent of the
amine; and (ii) the ratio of the melt flow of the resin compared to
the unmodified polyester of Formula 1, as measured according to
ASTM D1238, is at least 1.05:1.
2. The process of claim 1, wherein the polyester is a linear
polyester having repeating structural units of Formula 1
##STR00006## and the resulting resin is a linear resin of Formula 2
##STR00007## wherein: each T is independently a divalent C.sub.6-10
aromatic group derived from a dicarboxylic acid or a chemical
equivalent thereof; each D is independently a divalent C.sub.2-8
alkylene group derived from a dihydroxy compound or a chemical
equivalent thereof; and m and n are each selected from 25 to 1000
and n is less than m.
3. The process of claim 2, wherein: each T in the resin of Formula
2 is independently phenyl or naphthyl; and each D in the resin of
Formula 2 is independently selected from the group consisting of
ethylene, propylene, butylene, and dimethylenecyclohexene.
4. The process of claim 2, wherein the polyester of Formula 1 is
selected from the group consisting of poly(ethylene terephthalate),
poly(1,4-butylene terephthalate), poly(ethylene naphthalate),
poly(butylene naphthalate), poly(1,3-propylene terephthalate),
poly(cyclohexylenedimethylene terephthalate) and combinations
thereof.
5. The process of claim 2, wherein the polyester of Formula 1 is a
post-consumer recycled polyester.
6. The process of claim 2, wherein the polyester of Formula 1
further comprises 10 to 500 ppm of one or more metal cations
selected from the group consisting of at least one of Ti, Sb, Sn,
Zn, Ge, Zr, and Co.
7. The process of claim 2, wherein the polyester resin of Formula 2
is characterized by a --COOH end group content of 10 meq/kg or
less.
8. The process of claim 2, wherein the amine has a boiling point
that is 200.degree. C. or higher at ambient pressure and a carbon
to nitrogen ratio of 10:1 to 36:1.
9. The process of claim 2, wherein the resin of Formula 2 comprises
0.05 to 2.5 weight percent of the reacted amine.
10. The process of claim 2, wherein the resin further comprises 1
to 60 weight percent of a filler selected from the group consisting
of fiber glass, carbon fibers, ceramic fibers, talc, clay, mica,
wollastonite, silica, quartz, alumina, barium sulfate, carbon,
graphite, metal oxides, glass beads, glass flakes, milled glass,
and any combination thereof.
11. The process of claim 10, comprising 10 to 40 weight percent
fiber glass with a diameter of 9 to 20 microns.
12. The process of claim 2, wherein 500 ppm or less of an organic
solvent is present.
13. The process of claim 2, wherein the process is a continuous
process and wherein the blend comprising the polyester of Formula A
and the amine NHR.sup.1R.sup.2 are mixed in a single screw or twin
screw extruder with no external vacuum applied.
14. The process of claim 2, wherein mixing occurs at a temperature
in the range of 200.degree. C. to 350.degree. C.
15. The process of claim 2, wherein the resin of Formula 2 has a
temperature of crystallization higher than the temperature of
crystallization of polyester of Formula 1.
16. The process of claim 2, the ratio of the melt flow of the resin
of Formula 2 compared to the unmodified polyester of Formula 1, as
measured according to ASTM D1238, is at least 1.1:1.
17. The process of claim 2, wherein the resin of Formula 2 has a
melt viscosity at 250.degree. C. of 20 to 100 cc/10 minute.
18. The process of claim 2, wherein 50 percent or more of the ester
linkages in Formula 1 are terephthalate ester linkages.
19. The process of claim 2, wherein the resin of Formula 2 is
essentially free of metal cations or metal oxides selected from the
group consisting of Pb, Hg, As, and Cd.
20. An amine-modified polyester resin of Formula 2 ##STR00008##
prepared by the process of mixing a linear or branched polyester
having repeating structural units of Formula 1 ##STR00009## and an
amine of formula NHR.sup.1R.sup.2 in an extruder, with no applied
vacuum and a temperature of 200 to 350.degree. C.; wherein: R.sup.1
is C.sub.6-36 alkyl R.sup.2 is selected from the group consisting
of hydrogen, C.sub.1-C.sub.36 alkyl, C.sub.1-C.sub.36
alkylene-aryl, C.sub.1-C.sub.36 alkylene-heteroaryl,
C.sub.1-C.sub.36 alkylene-cycloalkyl, C.sub.1-C.sub.36
alkylene-heterocycloalkyl, and NHR.sup.1R.sup.2 contains at least
10 carbons; each T is independently a divalent C.sub.6-10 aromatic
group derived from a dicarboxylic acid or a chemical equivalent
thereof; each D is independently a divalent C.sub.2-8 alkylene
group derived from a dihydroxy compound or a chemical equivalent
thereof; m and n vary from 25 to 1000 and n is less than m; and
wherein the resin is characterized by one or both of the following
properties: (i) the resin comprises 0.01 to 5 weight percent of the
amine; and (ii) the ratio of the melt flow of the resin compared to
the unmodified polyester of Formula 1, as measured according to
ASTM D1238, is at least 1.05:1.
21. The resin prepared by the process of claim 20, wherein the
mixture further comprises 1 to 60 weight percent of a filler
selected from the group consisting of fiber glass, carbon fibers,
ceramic fibers, talc, clay, mica, wollastonite, silica, quartz,
alumina, barium sulfate, carbon, graphite, metal oxides, glass
beads, glass flakes, milled glass, and any combination thereof.
22. The resin prepared by the process of claim 20, wherein the
filler is 10 to 40 weight percent of a 9 to 20 micron diameter
glass fiber.
23. An article comprising the composition prepared by the process
of claim 1.
24. The article of claim 23, wherein the article is an extruded
film or an injection molded article.
25. The article of claim 24 in the form of a component for an
electronic device.
26. A method for forming an article, comprising shaping, extruding,
blow molding, or injection molding a composition prepared by the
process of claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a process for preparing
amine-modified polyester resins with improved melt flow.
[0002] Polyesters and copolyesters, as well as their blends with
other thermoplastics, are used to make a range of products that
includes injection molded parts, films, blow-molded goods, and
pultruded sheets. These articles are used in automotive, electrical
and electronic applications. The mechanical strength, electrical
insulation and easy processability are some of the key
characteristics of polyesters which enable their use in these
applications. The current industrial trend is toward the
fabrication of parts, with complicated and fine designs, with small
flow cross-sectional areas where the fluidity of conventional
polyesters has been found inadequate.
[0003] To address the demanding requirements of high melt
flowability, a polyester resin can be replaced by another polyester
resin having lower viscosity. Thus there exists a need to prepare a
wide variety of high flow polyester resins in a simple, low cost
manner that can be applied to both large and small scale continuous
production. Further, the process should be environmentally friendly
using no solvent. Furthermore, the process should be accomplished
without the need for large scale chemical plant construction or
capital investment. In other instances there is a need to convert
high viscosity polyester compositions into lower viscosity
compositions through a simple low cost melt process.
[0004] U.S. Pat. Nos. 7,825,176, 7,405,250, and 7,405,249 disclose
polyester compositions with high flowability. The compositions
comprise a polyester and an alcohol that acts as a flow enhancer. A
need remains, however, for processes to make amide functionalized
polyester compositions with high flowability that rely on
non-alcoholic flow enhancers.
SUMMARY OF THE INVENTION
[0005] These and other needs are met by the present invention,
which is directed to a process for preparing amine-modified
polyester resins by a simple, inexpensive solvent-free process.
Specifically, the invention is directed to a solvent-free process
for preparing an amine-modified thermoplastic polyester resin by
mixing a melted polyester of Formula 1, shown below,
##STR00001##
with a melted amine, having the formula NHR.sup.1R.sup.2, thereby
forming an amine-modified thermoplastic polyester resin
characterized by one or both of the following properties:
[0006] (i) the resin comprises 0.01 to 5 weight percent of the
amine; and
[0007] (ii) the ratio of the melt flow of the resin compared to the
unmodified polyester of Formula, as measured according to ASTM
D1238, is at least 1.05:1.
[0008] For the polyester of Formula 1, each T is independently a
divalent C.sub.6-10 aromatic group derived from a dicarboxylic acid
or a chemical equivalent thereof. Also, each D is independently a
divalent C.sub.m alkylene group derived from a dihydroxy compound
or a chemical equivalent thereof. Additionally, m is from 25 to
1000.
[0009] For the amine of the present invention, R.sup.1 is
C.sub.6-C.sub.36 alkyl; R.sup.2 is selected from the group
consisting of hydrogen, C.sub.1-C.sub.36 alkyl, C.sub.1-C.sub.36
alkylene-aryl, C.sub.1-C.sub.36 alkylene-heteroaryl,
C.sub.1-C.sub.36 alkylene-cycloalkyl, C.sub.1-C.sub.36
alkylene-heterocycloalkyl; and NHR.sup.1R.sup.2 contains at least
10 carbons.
[0010] In another aspect, the invention is directed to compositions
comprising the resins described herein, as well as to articles
prepared by the process of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] All cited patents, patent applications, and other references
are incorporated herein by reference in their entirety. However, if
a term in the present application contradicts or conflicts with a
term in the incorporated reference, the term from the present
application takes precedence over the conflicting term from the
incorporated reference. All ranges disclosed herein are inclusive
of the endpoints, and the endpoints are independently combinable
with each other. The use of the terms "a" and "an" and "the" and
similar referents in the context of describing the invention
(especially in the context of claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. Further, it should further be
noted that the terms "first," "second," and the like herein do not
denote any order, quantity, or importance, but rather are used to
distinguish one element from another. The modifier "about" used in
connection with a quantity is inclusive of the stated value and has
the meaning dictated by the context (that is, it includes the
degree of error associated with measurement of the particular
quantity).
Process of the Invention
[0012] As provided above, the invention is directed to a process
for preparing a linear or branched amine-modified polyester resin
using a linear or branched polyester and an amine,
NHR.sup.1R.sup.2, as starting materials. In the process of the
present invention, melted polyester is mixed with melted amine to
form an amine-modified polyester resin. The polyester can be
melted, by heating to a temperature at or above its melting point,
before mixing with the amine, concurrent with mixing with the
amine, after initially mixing with the amine, or a combination
thereof.
[0013] The term "melted amine" means an amine that is in its liquid
state at room temperature or which requires heating to melt. In the
present invention, the amine can be melted before mixing with the
polyester, concurrent with mixing with the polyester, after
initially mixing with the polyester, or a combination thereof.
[0014] However, to form the amine-modified polyester, of the
present invention, mixing of melted polyester and melted amine must
occur.
[0015] "Solvent-free" as used herein, means free of a liquid that
solubilizes the polyester, the amine, or both polyester and amine,
prior to, during, or subsequent to the process of mixing the
components to form the amine-modified resin. Solvent-free means
that organic or aqueous solvents, if present at all, are present
only in trace or residual quantities. If an organic liquid solvent
is present in the mixture, it is typically a residual solvent, such
as chlorobenzene, dichlorobenzene, toluene, cresol, phenol,
chloroethylenes or the like, that was used in an earlier processing
or manufacturing steps, and is at a concentration of 1000 ppm or
less and more preferably of 500 ppm or less. Typically, such
residual solvents have a molecular weight of less than 200 and a
boiling point at ambient pressure of 200.degree. C. or lower.
"Ambient pressure" means the atmospheric pressure where the resin
is being manufactured, which is typically measured as barometric
pressure.
[0016] In addition, both the mixing and melting steps of the resin
process are readily performed at ambient pressure with no vacuum
applied to prevent the amine from volatilizing before reacting.
[0017] The materials used in the process of the present invention
include polyesters, a primary or a secondary aliphatic amine or
mixture thereof, and optional additives.
[0018] In one embodiment, the polyester is a linear polyester
having repeating structural units of Formula 1:
##STR00002##
wherein, for a single repeating unit, the value of m is 1. Further,
the amine is NHR.sup.1R.sup.2, wherein at least one of R.sup.1 and
R.sup.2 is C.sub.10-36 alkyl and the other of R.sup.1 and R.sup.2
is selected from the group consisting of hydrogen, C.sub.1-C.sub.36
alkyl, C.sub.1-C.sub.36 alkylene-aryl, C.sub.1-C.sub.36
alkylene-heteroaryl, C.sub.1-C.sub.36 alkylene-cycloalkyl,
C.sub.1-C.sub.36 alkylene-heterocycloalkyl; and the resulting resin
is a linear resin of Formula 2:
##STR00003##
wherein:
[0019] each T is independently a divalent C.sub.6-10 aromatic group
derived from a dicarboxylic acid or a chemical equivalent
thereof;
[0020] each D is independently a divalent C.sub.2-8 alkylene group
derived from a dihydroxy compound or a chemical equivalent
thereof;
[0021] R.sup.1 is C.sub.6-36 alky and R.sup.2 is selected from the
group consisting of hydrogen, C.sub.1-C.sub.36 alkyl,
C.sub.1-C.sub.36 alkylene-aryl, C.sub.1-C.sub.36
alkylene-heteroaryl, C.sub.1-C.sub.36 alkylene-cycloalkyl, and
C.sub.1-C.sub.36 alkylene-heterocycloalkyl;
[0022] m and n vary from 25 to 1000; and
[0023] n is less than m.
[0024] In other embodiments, the ingredients of the composition of
the present invention may additionally optionally comprise fillers,
reinforcement, colorants additives, or combinations thereof.
[0025] The composition ingredients of these and other embodiments
are described in greater detail in the following paragraphs.
Polyester
[0026] The polyesters used in the process and composition disclosed
herein are linear or branched thermoplastic polyesters having
repeating structural units of Formula 1.
[0027] In one embodiment, each T group is the same and each D group
is the same.
[0028] Alternately, copolyesters containing a combination of
different T and/or D groups can also be used.
[0029] Chemical equivalents of diacids include the corresponding
esters, alkyl esters, e.g., C.sub.1-3 dialkyl esters, diaryl
esters, anhydrides, salts, acid chlorides, acid bromides, and the
like.
[0030] Chemical equivalents of dihydroxy compounds include the
corresponding esters, such as C.sub.1-3 dialkyl esters, diaryl
esters, and the like. The polyesters can be branched or linear.
[0031] Examples of C.sub.6-14 aromatic dicarboxylic acids that can
be used to prepare the polyesters include isophthalic acid,
terephthalic acid, 1,2-di(p-carboxyphenyl)ethane,
4,4'-dicarboxydiphenyl ether, 4,4'-bisbenzoic acid, and the like,
and 1,4- or 1,5-naphthalene dicarboxylic acids and the like. A
combination of isophthalic acid and terephthalic acid can be used,
wherein the weight ratio of isophthalic acid to terephthalic acid
is 91:9 to 2:98, specifically 25:75 to 2:98. In some instances 50
percent or more of the ester linkages in Formula 1 are
terephthalate ester linkages.
[0032] Exemplary diols useful in the preparation of the polyesters
include C.sub.24 aliphatic diols such as ethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butane diol,
1,2-butylene diol, 1,4-but-2-ene diol, diethylene glycol,
cyclohexane dimethanol, and the like. In one embodiment, the diol
is ethylene and/or 1,4-butylene diol. In another embodiment, the
diol is 1,4-butylene diol. In still another embodiment, the diol is
ethylene glycol with small amounts (0.5 to 5.0 percent) of
diethylene glycol.
[0033] In some embodiments, each T in the resin of Formula 1 is
independently phenyl or naphthyl, and each D in the resin of
Formula 1 is independently selected from the group consisting of
ethylene, propylene, butylene, and dimethylene cyclohexene.
[0034] Specific exemplary polyesters include poly(ethylene
terephthalate) (PET), poly(1,4-butylene terephthalate) (PBT),
poly(ethylene naphthalate) (PEN), poly(butylene naphthalate) (PBN),
and poly(1,3-propylene terephthalate) (PPT),
poly(cyclohexylenedimethylene terephthalate) (PCT) or blends
thereof. In one embodiment, the polyester is PET, PBT or a mixture
thereof.
[0035] In some embodiments, the polyester of Formula 1 is a
post-consumer (recycled) polyester, such as recycled PET or similar
recycled resins. Such recycled resins are commercially available
from a variety of sources such as bottles, films, and fibers. In
one instance post consumer PET bottles with a diethylene glycol
(DEG) content of 0.5 to 2.5 mole percent and 10 to 500 ppm of a
metal selected from the group consisting of Ti, Sb, Sn, Zn, Ge, Zr,
Co or mixtures thereof are preferred.
[0036] In still another specific embodiment, the polyester is PBT
with a weight average molecular weight (Mw) of 10,000 to 50,000. It
is to be understood that such terephthalate-based polyesters can
include amounts of aliphatic diacids or isophthalate esters as
well. Mixtures of polyesters of different type and/or different
molecular weights can also be employed. In some embodiments, 50
percent or more of the ester linkages in formula A are
terephthalate ester linkages.
[0037] Typically, the polyester will further contain 10 to 500 ppm
of a metal catalyst residue wherein the metal is selected from the
group consisting of at least one: Ti, Sb, Sn, Zn, Ge, Zr, and Co.
The polyester may further comprise 10 to 200 ppm of a phosphorous
containing compound such as acidic phosphorus species used as a
catalyst quencher.
[0038] The polyesters of formula 1 can have any end group
configuration. In most instances the end groups will be hydroxy,
carboxylic acid or ester end groups. In some instances, the
polyester will have a carboxylic acid (COOH) end group content of
from 15 to 40 meq/Kg.
Amine
[0039] The amine used in the process and composition disclosed and
claimed herein is a primary or secondary aliphatic amine or any
mixture thereof, thermally stable at polyester melt processing
temperatures, above about 200.degree. C. and more specifically
above about 250.degree. C. The amine of the process and composition
disclosed herein typically has a boiling point that is 200.degree.
C. or higher at ambient pressure and a carbon to nitrogen ratio of
10:1 to 36:1, and thus a total number of carbons in R.sup.1 and
R.sup.2 combined is from 10 to 36 carbons.
[0040] Exemplary amines are primary alkyl amine such as stearyl
amine, decyl amine, dodecyl amine, tetradecyl amine,
3-methyl-1-octyl amine, 3-ethyl-hexyl amine, 4-phenyl butyl amine,
2,7-diphenyl heptyl amine, 1 methyl-3-phenyl amine and the like. In
some instances the primary amine will be a C.sub.10-C.sub.20 alkyl
amine.
[0041] The primary or secondary aliphatic amine can be combined in
the melt with polyester resins at from 0.01 to 5 weight percent of
the mixture. Preferably, the composition will employ the amine in
an amount of from 0.05 to about 2.5 weight percent and more
preferably, in an amount of from 0.1 to about 1.0 weight percent of
the amine. In some instances the amine will be a low color amine,
for instance with a yellowness index of less than 10.
Filler
[0042] A filler or reinforcement agent may also be added to the
amine modified polyester resin disclosed herein. In some
embodiments, the filler is selected from the group consisting of
fiber glass, carbon fibers, ceramic fibers, talc, clay, mica,
wollastonite, silica, quartz, alumina, barium sulfate, carbon,
graphite, metal oxides, glass beads, glass flakes, milled glass and
any combination thereof. Fillers can also be nano fillers such as
nano clay and carbon nanotubes. Effective amounts of the filler
vary widely, but they are usually present in an amount of less than
or equal to 1 to 60 weight percent, based on the total weight of
the composition.
[0043] In some embodiments, the filler is glass fiber. In one
embodiment, the glass fibers that are used are relatively soda
free. Fibrous glass filaments comprised of borosilicate glass, also
known as "E" glass, are often preferred. Glass fiber is added to
the composition to increase the flexural modulus and strength. The
glass filaments can be made by standard processes, e.g., by steam
or air blowing, flame blowing and mechanical pulling. The preferred
filaments for plastic reinforcement are made by mechanical pulling
in various diameters. The fibers can also be bundled and chopped
for easier handling. The fibers can be further treated with
coupling agents and sizing. Exemplary coupling agents are amine or
epoxy functional alkoxy silanes. In some embodiments the glass
fiber of a 9 to 20 micron diameter is present at 10 to 40 weight
percent.
[0044] The glass fibers may be blended first with the other
ingredients and then fed to an extruder and the extrudate cut into
pellets, or, in a preferred embodiment, they may be separately fed
to the feed hopper of an extruder. The glass fibers may be fed
downstream in the extruder to minimize attrition of the glass. The
pellets so prepared when cutting the extrudate may be one-fourth
inch long or less. Such pellets contain finely divided uniformly
dispersed glass fibers in the composition. The dispersed glass
fibers are reduced in length as a result of the shearing action on
the chopped glass strands in the extruder barrel. This process can
also be used to make long glass reinforced modified compositions
wherein the glass fiber in essentially continuous in the pellet,
sometimes as long as 0.5 to 1.0 inches.
[0045] The amine compounds can be feed into the melt processing
equipment, for instance an extruder, along with the additive, for
instance glass fiber, to form the modified polyester composition
while mixing in the additive. In other instances the additive or
fiber can be pre-compounded into the polyester and then melt
processed with the amine compound to prepare the improved flow
composition.
Additives
[0046] The resin disclosed herein can also include various other
additives ordinarily incorporated with compositions of this type,
with the proviso that the additives are selected so as not to
significantly adversely affect the desired properties of the
composition. Combinations of additives can be used. Exemplary
additives include anti-oxidants, dyes, pigments, colorants, heat
stabilizers, flame retardants, drip retardants, crystallization
nucleators, metal salts, antistatic agents, plasticizers,
lubricants, UV stabilizers, and combinations comprising two or more
of the foregoing additives. These additives are known in the art as
are their effective levels and methods of incorporation. Effective
amounts of the additives vary widely, but they are usually present
in an amount of less than or equal to 10 weight percent, based on
the total weight of the composition. Amounts of these additives are
generally 0.25 weight percent to 2 weight percent, based upon the
total weight of the composition.
[0047] Exemplary antioxidant and heat stabilizer additives include,
for example, organophosphites such as tris(nonyl phenyl)phosphite,
tris(2,4-di-t-butylphenyl)phosphite,
bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, distearyl
pentaerythritol diphosphite or the like; alkylated monophenols or
polyphenols; alkylated reaction products of polyphenols with
dienes, such as
tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane,
or the like; butylated reaction products of para-cresol or
dicyclopentadiene; alkylated hydroquinones; hydroxylated
thiodiphenyl ethers; alkylidene-bisphenols; benzyl compounds;
esters of beta-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid
with monohydric or polyhydric alcohols; esters of
beta-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid with
monohydric or polyhydric alcohols; esters of thioalkyl or thioaryl
compounds such as distearylthiopropionate, dilaurylthiopropionate,
ditridecylthiodipropionate,
octadecyl-3-[3,5-di-tert-butyl-4-hydroxyphenyl)propionate,
pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate
or the like; amides of
beta-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid or the
like, or combinations comprising at least one of the foregoing
antioxidants. Antioxidants can be used in amounts of 0.001 to 1
weight percent, based on the total weight of the composition.
[0048] Exemplary heat stabilizer additives include, for example,
organophosphites such as triphenyl phosphite,
tris-(2,6-dimethylphenyl)phosphite, tris-(mixed mono- and
di-nonylphenyl)phosphite or the like; phosphonates such as
dimethylbenzene phosphonate or the like, phosphates such as
trimethyl phosphate, or the like, or combinations comprising at
least one of the foregoing heat stabilizers.
[0049] Exemplary lubricants and mold release agents include alkyl
esters for example, pentaerythritol tetrastearate (PETS), alkyl
carboxylic acid salts, alkyl amides, such as ethylene
bis-stearamide, and polyolefins, such as polyethylene.
[0050] Exemplary flame-retardant additives are present in an amount
at least sufficient to reduce the flammability of the polyester
resin, preferably to a UL94 V-0 rating. The amount will vary with
the nature of the resin and with the efficiency of the additive. In
general, however, the amount of additive will be from 2 to 30
percent by weight. A preferred range will be from about 10 to 20
percent by weight. Typical flame-retardants include halogenated
flame retardants such as polybromophenyl ether, brominated
polystyrene, brominated BPA polyepoxide, brominated imides, or
mixtures thereof. It is strongly preferred that the flame retardant
additive not chemically react with the amine additive of the
invention.
[0051] Examples of other suitable flame retardants are brominated
polystyrenes such as polydibromostyrene and polytribromostyrene,
decabromobiphenyl ethane, tetrabromobiphenyl, brominated alpha,
omega-alkylene-bis-phthalimides, e.g.
N,N'-ethylene-bis-tetrabromophthalimide, or brominated epoxy
resins.
[0052] The halogenated flame retardants are typically used with a
synergist, particularly inorganic antimony compounds. Such
compounds are widely available or can be made in known ways.
Typical, inorganic synergist compounds include Sb.sub.2O.sub.5,
Sb.sub.2S.sub.3, sodium antimonate and the like. Especially
preferred is antimony trioxide (Sb.sub.2O.sub.3). Synergists, such
as antimony oxides, are typically used at about 0.5 to 15 by weight
based on the weight percent of resin in the final composition.
[0053] In place of halogenated flame retardants, the use of
phosphorous based flame retardants can also be envisaged. Typical
phosphorous based flame retardants include organophosphates, for
example triaryl phosphates, metal salts of hypophosphorous acid,
metal salts of organophosphinic acid and the like. Synergists to
these phosphorous based flame retardants, such as melamine
cyanurates, melamine pyrophosphates and like can also be included
in the composition.
[0054] Exemplary drip retardants include fluoropolymers. The
fluoropolymer may be a fibril forming or non-fibril forming
fluoropolymer. Preferably the fluoropolymer is a fibril forming
polymer. In some embodiments polytetrafluoroethylene is the
preferred fluoropolymer. In some embodiments it is preferred to
employ an encapsulated fluoropolymer i.e. a fluoropolymer
encapsulated in a polymer as the anti-drip agent. An encapsulated
fluoropolymer can be made by polymerizing the polymer in the
presence of the fluoropolymer. Alternatively, the fluoropolymer can
be pre-blended in some manner with a second polymer, such as for
example, an aromatic polycarbonate resin or a styrene-acrylonitrile
resin as in, for example, U.S. Pat. Nos. 5,521,230 and 4,579,906,
to form an agglomerated material for use as an anti-drip agent.
Either method can be used to produce an encapsulated
fluoropolymer.
[0055] The anti-drip agent, when present, comprises greater than or
equal to about 0.5 weight percent, preferably greater than or equal
to about 0.1 weight percent, based on the total weight of the
composition. The anti-drip agent, when present, comprises less than
or equal to about 5 weight percent, preferably less than or equal
to about 2.5 weight percent, and more preferably less than or equal
to about 1 weight percent, based on the total weight of the
composition.
[0056] The amine modified resins prepared by the melt reaction of
the amine thermoplastic polyesters may be further melt compounded
with other polymers such as non-amine modified polyesters,
polystyrene, styrene acrylonitrile (SAN), polycarbonate,
polyetherimides, polyolefins and mixtures thereof. Rubber
modifiers, alone or in combination with the aforementioned resins,
may also be used. Exemplary rubber modifiers are methacrylate
butadiene styrene (MBS), butadiene grafted with SAN, styrene
butadiene block copolymers (SBS) hydrogenated styrene butadiene
block copolymers (SEBS) as well as acrylic rubber, and acrylate
styrene acrylonitrile (ASA) rubber.
Process Conditions and Resin Properties
[0057] While being held to no specific mechanism or mode of action,
it is thought that the reaction that gives rise to the resins
described herein is depicted in Scheme 1, wherein polybutylene
terephthalate (PBT) is the polyester (although other polyesters can
be employed).
##STR00004##
[0058] As shown in Scheme 1, PBT B, where "P" represents a linear
or branched polymer, is susceptible to amine attack at each ester
linkage of the polymer chain. Condensation of polyester B with the
amine 3 under suitable conditions gives rise to the resin 4, which
is characterized by a chemically bound amide end group attached to
a fragment of the original polyester polymer P, designated as
P.sub.1, as well as to the lower molecular weight polyester 5
designated as polymer P.sub.2. Both P.sub.1 and P.sub.2 (4 and 5)
are lower molecular weight than the initial polyester P. The
condensation reaction of the amine 3 with any of polyesters B, 4,
or 5 will continue until the amine has been substantially consumed.
It is surprising that this high temperature reaction of a low
melting or liquid amine, which will be a very low viscosity liquid,
is capable of mixing with the relatively high viscosity polyester
melt. Further it is very surprising that the reaction is quick
enough to be substantially accomplished in the very short contact
time (0.5 to 3 minutes) in a normal melt extrusion process. Under
most conditions, especially the short contact time in an extruder,
the initially formed amide will not react further.
[0059] In the process of the present invention, the polyester is at
least partially melted; that is, the polyester is at least 80
percent melted. More preferably, the polyester is at least 90
percent melted. More preferably, the polyester is at least 99
percent melted, and most preferably, the polyester is completely
melted.
[0060] As indicated, the polyester, amine, and other optional
components are mixed together. The process of mixing can be
achieved using a mixer such as a HENSCHEL-Mixer.RTM. high speed
mixer or the like. Other low shear processes such as a drum
tumbler, paint shaker, vee-blender or hand mixing can also
accomplish this mixing. Optionally some of the ingredients can be
pre-extruded with the polyester prior to amine addition.
[0061] In one embodiment the polyester, amine, and optional
additives are mixed and melted using an extruder or other melt
mixing apparatus. In one instance the mixture is fed into the
throat of an extruder via a hopper or loss in weight feeder.
Alternatively, one or more of the components can be incorporated
into the composition by feeding directly into the extruder at the
throat and or downstream through a side feeder. Alternatively, any
desired additives can also be compounded into a masterbatch and
then combined with the remaining polymeric components at any point
in the process. The extruder is generally operated at a temperature
higher than that necessary to cause the composition to flow.
Usually this is 20 to 50.degree. C. above the polyester crystalline
melting point (Tm) The extrudate is quenched in a water batch and
pelletized. Such pellets can be used for subsequent molding,
shaping, or forming.
[0062] The extruder may be a twin screw extruder such as a Werner
Pfleiderer twin screw extruder set at approximately 300 rpm using a
2 or 4-hole die. The barrel temperature is typically set in the
range of 200 to 350.degree. C., and more typically in the range of
230 to 270.degree. C. The co-rotating twin screw extruder is run at
ambient pressure without vacuum applied to the vent. The absence of
applied vacuum aids in the retention of the amine in the molten
polymer of formula A allowing for a better opportunity to
chemically react to form a grafted amide functionality (3). In one
instance the extrudate may then be cooled in a water bath, blown
dry with air and chopped into pellets approximately 1/8 inch long.
The continuous melt reaction may also be accomplished in single
screw extruders under similar conditions.
[0063] In other instances the amine modification of the polyester
resin may be accomplished in an injection molding machine to tailor
melt viscosity of the polyesters or polyester blends to the
requirements of a specific part or mold. In yet other instances the
amine modification may be accomplished in an extruder to make
sheet, film or fibers.
[0064] The resulting resin of Formula 1 typically has a number
average molecular weight of 10,000 to 30,000 and is characterized
by a carboxylic acid (COOH) end group content of 10 meq/Kg or less.
The resin is essentially free of metal cations or metal oxides
selected from the group consisting of Pb, Hg, As, and Cd and thus
contains 50 ppm or less and more preferably 10 ppm or less of
contaminants. In other instances these harmful metals are not
detectable.
[0065] Another surprising benefits of some of the high flow resins
made by the amine reaction is an improvement in the temperature at
which they begin to form crystals when cooled from the melt
(Tc=temperature of crystallization). The amine modified resins of
Formula 2 have a Tc hat is higher than the Tc of the polyesters of
Formula 1. In some instances the Tc of the modified resin is 1 to
10.degree. C. greater than the Tc of the unmodified resin of
Formula 1. A higher crystallization temperature is a benefit as it
allows faster solidification of the molten polymer often leading to
faster cycle time when molding parts, especially in an injection
molding processes. The resins of Formula 2 typically also have a
higher heat of crystallization (dHc) as compared to the polyesters
of Formula 1. This may indicate a higher crystalline content which
may improve stiffness and barrier properties of formed the
polyester article.
[0066] The resin of Formula 2 typically has an increased melt flow
according to ASTM D1238 that is at least 10 percent or higher
compared to that of the polyester of Formula 1. In other instances
melt flow will be improved by 50 percent over the starting resin.
In other instances the amine modified polyester will have a melt
flow at 250.degree. C. of from 20 to 100 cc/10 min.
[0067] In other instances in addition to high melt flow the amine
modified polyester resins also have good stability in the melt
(melt dwell) showing less than a 20% change in the initial melt
viscosity after being held at 250.degree. C. for 30 minutes at
constant shear. In yet other instances the amine modified resin
will show a change in melt viscosity (melt dwell) after 30 minutes
of less than 15 percent of the initial value. With more than 0.5 wt
% added amine the modified polyester shows a change in initial melt
dwell viscosity of less than 10% of the initial value. This melt
dwell stability is very significant in that it shows that after the
initial reaction of amine with the polyester of formula 1 the
reaction to form the higher flow polyester of formula 2 is
complete. The small change in the melt dwell of the amine modified
polyesters of formula 2 shows that there is no further reaction or
degradation of the modified polyester. With higher amine content
the resin show that in addition to higher flow (a higher melt flow)
there is also better melt stability (less change in melt dwell)
than the starting polyester of formula 1.
Articles
[0068] The polyester composition of the invention may be formed by
techniques known in the art. The ingredients are typically in
powder or granular form, and extruded as a blend, and/or comminuted
into pellets or other suitable shapes. The ingredients may be
combined in any manner, e.g., by dry mixing or by mixing in the
melted state in an extruder, or in other mixers. For example, one
embodiment comprises melt mixing the ingredients in powder or
granular form, extruding the mixture and comminuting into pellets
or other suitable shapes. Also included is dry mixing the
ingredients, followed by mixing in the melted state in an
extruder.
[0069] The blends of the invention may be formed into shaped
articles by a variety of common processes for shaping molten
polymers such as injection molding, compression molding, film or
fiber extrusion and gas assist injection molding. Examples of such
articles include electrical connectors, enclosures for electrical
equipment, automotive engine parts, lighting sockets and
reflectors, electric motor parts, power distribution equipment,
communication equipment, wire coatings and the like including
devices that have molded in snap fit connectors. The modified
polyester resins can also be made into fibers, films, and
sheets.
[0070] The following examples illustrate, but do not limit the
invention. Any references cited herein are incorporated by
reference in their entirety.
EXAMPLES
[0071] The materials used to prepare the amine-modified polyester
resins are summarized in Table 1.
TABLE-US-00001 TABLE 1 Materials PBT 315 Poly(1,4-butylene
terephthalate), intrinsic viscosity (IV) = 1.10 dl/g, VALOX 315
from SABIC Innovative Plastics, 38 meq/Kg COOH PBT 195
Poly(1,4-butylene terephthalate), intrinsic viscosity (IV) = 0.66
dl/g, VALOX 195 from SABIC Innovative Plastics, 17 meq/Kg COOH PET
Poly(1,2-ethylene terephthalate), intrinsic viscosity 0.535 dl/g
IV, 0.8% diethylene glycol (DEG), 20 meq/Kg COOH Glass Fiber Owens
Corning 183F, 13 micron diameter E glass C.sub.18H.sub.37NH.sub.2
Octadecyl amine (also called stearyl amine) was AREEM 18D from Akzo
Nobel, a distilled grade, approximately 98.5% primary amine, Mw =
269.5, amine number approximately 208 mg KOH/g.
[0072] The blends were prepared by the extrusion of mixtures of
polybutylene terephthalate (PBT) or polyethylene terephthalate
(PET) with octadecyl amine and, in some instances, glass fiber (GF)
as shown in Tables 2 to 5. The ingredients were combined and mixed
for approximately 4 minutes using a paint shaker. The blends of
Tables 2 to 5 were compounded on a 30 mm Werner Pfleiderer twin
screw extruder at approximately 450 to 520.degree. F.
(approximately 232 to 271.degree. C.) barrel set temperature at
approximately 300 rpm using a 2 or 4-hole die. The blends were not
dried prior to extrusion. The co-rotating twin screw extruder was
run without vacuum applied to the vent. The melt was easy to strand
and pelletize, and there was no foaming, vent flow or surging. The
extrudate was cooled in a water bath, blown dry with air and then
chopped into pellets approximately 1/8 inch long.
[0073] The fiber glass filled blends of Table 5 were mixed in a
similar fashion adding the fiber glass after an initial mixing
period of 4 minutes and gently mixing on a drum tumbler to prevent
fuzzing of the glass fiber bundles. The blends were not dried prior
to extrusion. The mixtures were extruded on a 2.5 inch Prodex
single screw extruder at 450 to 530.degree. F. (approximately 232
to 277.degree. C.) at 80 rpm using a double wave screw. The
extruder had a 6 hole die. No vacuum was applied to the vent. The
melt was easy to strand and pelletize, and there was no foaming,
vent flow or surging. The extrudate was cooled in a water bath,
blown dry with air and then chopped into approximately 1/8 inch
long pellets. The blends were not dried prior to extrusion.
[0074] The pelletized extrudates were dried for at least 4 hours
(h) at 120.degree. C. and test parts were injection molded at a set
temperature of 240 to 260.degree. C. and mold temperature of
approximately 100.degree. C. using a 30 second cycle time.
Test Methods
[0075] Melt flow was run using a 1.26 or 2.16 Kg weight at 250 or
265.degree. C. The pellets had been dried for approximately 2 to 4
hours at 120.degree. C. The melt flow was measured after a 6 minute
melt equilibration period and is reported as cubic centimeters
(cc)/10 minutes according to ASTM D1238.
[0076] Weight average (Mw) and number average molecular weight (Mn)
were measured by gel permeation chromatography (GPC) in a similar
fashion according to ASTM D5296. GPC samples were prepared by
dissolving approximately 40 mg of sample in 1 mL
hexafluoro-2-propanol (HFIP) and 1 mL chloroform. After complete
dissolution, the polymer solution was diluted to 5% HFIP using
chloroform. The GPC was run using 5% HFIP in chloroform as the
eluent with a 295 nm UV detector. Polystyrene (PS) standards were
used for calibration.
[0077] Differential scanning calorimetry (DSC) was performed
according to ASTM D3418 with a 20.degree. C. per minute heating
rate to 250.degree. C. for the PBT examples and 290.degree. C. for
the PET examples and then cooled at -20.degree. C. per minute.
Temperature of crystallization (Tc) and heat of crystallization
(dHc) was measured on first cool. The heat of crystallization
(dHc), which is the energy released as crystals form from the
molten polyester, is reported as Joules/gram (J/g). Temperature of
melting (Tm) was measured on second heat and is the peak melting
point.
[0078] Melt dwell (time sweep) studies were performed according to
ASTM D4440 at 250.degree. C. for 30 minutes under nitrogen on a
rheometer with a sandwich, or parallel-plate/cone-plate, fixture.
Viscosity data (poise=P) was compared after 6 minutes (initial
value) and 30 minutes (final value). The pellets were dried for
approximately 2 to 4 hours at 120.degree. C. prior to testing.
[0079] Flexural properties were measured on 3.2 mm injection molded
bars according to ASTM method D790 with a 1.27 mm/min cross-head
speed. The molded samples were conditioned for at least 48 hours at
50 percent relative humidity prior to testing.
[0080] In the data tables provided below, letters designate
comparative examples while numbers designate examples of the
invention.
Data
[0081] The results for the high molecular weight PBT examples are
summarized in Table 2. From 0.1 to 1.0 weight percent of octadecyl
amine was extruded with a high molecular weight PBT (315) in a twin
screw extruder at 300 rpm set at 450 to 510.degree. F.
(approximately 232 to 266.degree. C.) with no vacuum. The melt flow
values at 250.degree. C. show that the addition of the amine vastly
improves melt flow, giving a much higher melt flow compared to
Control A, which contains no added amine. The flow improvement is
especially dramatic with 0.5 to 1.0 percent octadecyl amine, where
the melt flow increased from 26.3 to 111, representing
approximately a two-fold to five fold increase in melt flow
compared to Control A. Surprisingly, the octadecyl amine modified
polyesters of Table 2 showed good melt stability as measured by the
change in viscosity (measured in poise=P) between 6 and 30 minutes
at 250.degree. C. (melt dwell). With higher amine levels, the
percent change in viscosity decreased from 16.5 to 0.6 percent,
indicative of improved melt stability with higher amine
modification.
TABLE-US-00002 TABLE 2 High MW PBT Examples Example A [Control] 1 2
3 4 5 Weight Percent PBT 315 100.0% 99.9% 99.7% 99.5% 99.3% 99.0%
Weight Percent C.sub.18H.sub.37NH.sub.2 0.0% 0.1% 0.3% 0.5% 0.7%
1.0% Melt Flow 250.degree. C., 2.16 Kg, cc/10 min. 14.4 16.2 26.3
40.2 58.2 111.0 Mw (PS stds) 95801 95404 86958 82335 73618 67138 Mn
28042 28076 26467 25859 23974 22281 Melt dwell 250.degree. C. 6
min. (P) 6905 6114 3678 2428 1701 972 Melt dwell 250.degree. C. 30
min (P) 5930 5104 3101 2166 1613 966 Percent change 6 to 30 min.
-14.1% -16.5% -15.7% -10.8% -5.2% -0.6% T melting (Tm) .degree. C.
223.5 223.1 222.9 224.4 224.0 224.7 T crystallization (Tc) .degree.
C. 191.2 191.5 192.5 193.5 193.8 193.9 Heat of cryst. (dHc) J/g
54.5 52.9 56.8 56.7 56.0 55.3
[0082] The high melt flow and favorable melt stability of the
Examples in Table 2 are an advantage for end-uses involving filling
thin-walled molded parts with high flow lengths. Examples 1 to 5
also showed enhanced crystallization with increasing amine content
as indicated by a higher crystallization temperature (Tc) and a
higher heat of crystallization (dHc).
[0083] The results for the low molecular weight PBT examples are
summarized in Table 3. In these runs, from 0.1 to 0.7 weight
percent of octadecyl amine was extruded with a low molecular weight
PBT 195 in a twin screw extruder at 300 rpm set at 450 to
510.degree. F. (approximately 230 to 265.degree. C.) with no
vacuum. As shown by the melt flow values at 250.degree. C., the
addition of the amine vastly improved melt flow, giving a much
higher melt flow compared to Example B which contains no added
amine. Even when a lower weight was used for the melt flow (1.26
versus 2.16 Kg), the modified polyesters of Examples 6 to 9 still
have exception flow. The flow improvement is especially dramatic
with 0.3 to 0.7 weight percent octadecyl amine, where 0.7 weight
percent of octadecyl amine represents a three-fold increase in melt
flow as compared to Control B. Also of note is the higher
crystallization temperature (Tc) and the increased crystallinity as
shown by a higher heat of crystallization (dHc) as compared to
Example B.
TABLE-US-00003 TABLE 3 Low Mw PBT Examples Example B [Control] 6 7
8 9 Weight Percent PBT 195 100.0% 99.9% 99.7% 99.5% 99.3% Weight
Percent C.sub.18H.sub.37NH.sub.2 0.0% 0.1% 0.3% 0.5% 0.7% Melt Flow
250.degree. C., 2.16 Kg, cc/10 min. 60.2 68.7 96.0 123.0 166.0 Mw
(PS std) 55060 54302 53150 52378 51377 Mn 20777 20506 20291 19922
19733 T melting (Tm) .degree. C. 223.6 224.2 223.8 223.8 223.8 T
crystallization (Tc) .degree. C. 195.4 197.6 198.8 197.6 196.9 Heat
of cryst. (dHc) J/g 57.7 57.9 58.4 60.8 62.0
[0084] Despite their relatively low molecular weights, the
amine-modified resins of Table 3 can still be extruded and
pelletized using normal operating conditions, making this a very
versatile process to achieve a wide variety of viscosities in a
simple, low cost, continuous, unit operation.
[0085] The results for the PET examples are summarized in Table 4.
With only 0.3 to 1.0 weight percent octadecyl amine (Examples 10 to
13), PET melt flow at 265.degree. C. was significantly increased
over control (Control C). In particular, Example 13 represents a
greater than four-fold increase in melt flow as compared to Control
C. The temperature of crystallization (Tc) was increased to 205 to
208.degree. C., and the heat of crystallization (dHc) was increased
from 44.5 J/g to as much as 53.9 J/g.
TABLE-US-00004 TABLE 4 PET Examples Examples C [Control] 10 11 12
13 Weight Percent PET 100.0% 99.9% 99.7% 99.5% 99.3% Weight Percent
C.sub.18H.sub.37NH.sub.2 0.0 0.3% 0.5% 0.7% 1.0% Melt Flow
265.degree. C., 1.2 Kg, cc/10 min. 50.8 94.3 101.2 137.5 210.0 Mw
45577 40536 38284 36884 33834 Mn 16001 14699 14211 13900 13169 T
melting (Tm) .degree. C. 258.4 257.5 257.9 257.1 257.7 T
crystallization (Tc) .degree. C. 199.6 205.3 207.2 207.5 208.1 Heat
of cryst. (dHc) J/g 44.5 49.4 51.0 53.9 53.1
[0086] The results for PBT examples that employed a glass fiber
filler are summarized in Table 5. These blends were prepared by
adding the fiber glass after an initial mixing period of
approximately 4 minutes and then gently mixing the mixture on a
drum tumbler to prevent fuzzing of the glass fiber bundles.
Examples 14 to 17 and Control D show the utility of octadecyl amine
modification of 30 weight percent glass fiber (GF) reinforced PBT.
With only 0.3 to 1.0 weight percent octadecyl amine, melt flow at
250.degree. C. was increased from 4.6 to as high as 50.4 cc/10
minute. The glass fiber and its chemical coating did not cause any
interference in the reaction. Examples 14 to 17 all extruded well
with no surging or foaming. The crystallization temperature (Tc)
was increased as was the heat of crystallization (dHc). The change
in melt viscosity on being held at 250.degree. C. for 30 minutes
was reduced with the added octadecyl amine compared to the 30
percent GF control (Control D) which contained no amine. This
finding indicates superior melt stability of the glass-reinforced
high flow amine-modified resins. The flexural modulus was also
increased in some instances to over 8000 MPa.
TABLE-US-00005 TABLE 5 Glass Filled High Mw PBT Examples Example D
[Control] 14 15 16 17 Weight Percent PBT 315 70.0% 69.7% 69.5%
69.3% 69.0% Weight Percent Glass Fiber 30.0% 30.0% 30.0% 30.0%
30.0% Weight Percent C.sub.18H.sub.37NH.sub.2 0.0% 0.3% 0.5% 0.7%
1.0% Melt Flow 250.degree. C., 2.16 Kg, cc/10 min 4.6 9.4 18.0 25.3
50.4 Mw (PS stds) 102200 84036 73638 65754 56692 Mn 29633 25933
23606 21886 19820 Melt Dwell 250.degree. C. 6 min. (P) 17992 9157
4577 3749 1722 Melt Dwell 250.degree. C. 30 min. (P) 11621 6519
3716 2971 1628 Percent change 6 to 30 min. -34.5% -28.8% -18.8%
-20.7% -5.5% T melting (Tm) .degree. C. 222.3 222.7 222.9 222.7
222.7 T crystallization (Tc) .degree. C. 189.3 191.6 192.4 192.9
194.0 Heat of cryst. (dHc) J/g 38.9 39.4 42.0 39.4 45.2 Flex
Modulus MPa 7830 7880 8090 8350 8130 Flex Strength MPa 188 187 191
188 183
[0087] The foregoing invention has been described in some detail by
way of illustration and example for purposes of clarity and
understanding. The invention has been described with reference to
various specific embodiments and techniques. However, it should be
understood that many variations and modifications may be made while
remaining within the spirit and scope of the invention. It will be
obvious to one of skill in the art that changes and modifications
may be practiced within the scope of the appended claims.
Therefore, it is to be understood that the above description is
intended to be illustrative and not restrictive. The scope of the
invention should, therefore, be determined not with reference to
the above description, but should instead be determined with
reference to the following appended claims, along with the full
scope of equivalents to which such claims are entitled. All
patents, patent applications, and publications cited in this
application are hereby incorporated by reference in their entirety
for all purposes to the same extent as if each individual patent,
patent application, or publication were so individually
denoted.
* * * * *