U.S. patent application number 15/862715 was filed with the patent office on 2018-05-10 for copolymerized polyamide resin, method for preparing the same and molded article comprising the same.
The applicant listed for this patent is LOTTE ADVANCED MATERIALS CO., LTD.. Invention is credited to Young Sub JIN, Suk Min JUN, Jin Kyu KIM, Joon Sung KIM, So Young KWON, Ki Yon LEE.
Application Number | 20180127545 15/862715 |
Document ID | / |
Family ID | 55583739 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180127545 |
Kind Code |
A1 |
KWON; So Young ; et
al. |
May 10, 2018 |
Copolymerized Polyamide Resin, Method for Preparing the Same and
Molded Article Comprising the Same
Abstract
A copolymerized polyamide resin includes a polymer of a monomer
mixture comprising a dicarboxylic acid component comprising adipic
acid and a dicarboxylic acid represented by Formula 1, wherein each
R.sub.1 is independently a C.sub.1 to C.sub.5 alkyl group and a is
an integer from 0 to 4, and a diamine component comprising m-xylene
diamine and a diamine represented by Formula 2, wherein A is a
single bond or a C.sub.1 to C.sub.10 hydrocarbon group, R.sub.2 and
R.sub.3 are each independently a C.sub.1 to C.sub.5 alkyl group,
and b and c are each independently an integer from 0 to 4, wherein
the copolymerized polyamide resin has a difference between a
melting temperature (Tm) and a crystallization temperature (Tc) of
about 50.degree. C. or more. The copolymerized polyamide resin may
have excellent heat resistance and reduced or no gel generation and
yellowing phenomenon in a molding process. ##STR00001##
Inventors: |
KWON; So Young; (Uiwang-si,
KR) ; KIM; Jin Kyu; (Uiwang-si, KR) ; JIN;
Young Sub; (Uiwang-si, KR) ; KIM; Joon Sung;
(Uiwang-si, KR) ; LEE; Ki Yon; (Uiwang-si, KR)
; JUN; Suk Min; (Uiwang-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LOTTE ADVANCED MATERIALS CO., LTD. |
Yeosu-si |
|
KR |
|
|
Family ID: |
55583739 |
Appl. No.: |
15/862715 |
Filed: |
January 5, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14583429 |
Dec 26, 2014 |
9902808 |
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15862715 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 69/265 20130101;
C08G 69/30 20130101 |
International
Class: |
C08G 69/26 20060101
C08G069/26; C08G 69/30 20060101 C08G069/30 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2014 |
KR |
10-2014-0128684 |
Claims
1. A copolymerized polyamide resin including a polymer of a monomer
mixture comprising a dicarboxylic acid component comprising adipic
acid and a dicarboxylic acid represented by Formula 1, and a
diamine component comprising m-xylene diamine and a diamine
represented by Formula 2, wherein the copolymerized polyamide resin
has a difference between a melting temperature (Tm) and a
crystallization temperature (Tc) of about 50.degree. C. or more:
##STR00005## wherein, A is a single bond or a C.sub.1 to C.sub.10
hydrocarbon group, R.sub.1, R.sub.2 and R.sub.3 are the same or
different and are each independently a C.sub.1 to C.sub.5 alkyl
group, and a, b and c are the same or different and are each
independently an integer from 0 to 4, and wherein the copolymerized
polyamide resin has a Yellowness Index difference (.DELTA.YI) of
about 20 or less calculated according to Equation 3 below:
Yellowness Index difference(.DELTA.YI)=YI.sub.1-YI.sub.0 [Equation
3] wherein YI.sub.0 is a Yellowness Index (YI) value of the
copolymerized polyamide resin before a scorch test and YI.sub.1 is
a Yellowness Index value of the copolymerized polyamide resin after
a scorch test, as measured according to ASTM E313-73, wherein the
scorch test includes leaving about 1 to about 3 g of the
copolymerized polyamide resin at about 200.degree. C. for about 1
hour.
2. The copolymerized polyamide resin according to claim 1, wherein
the dicarboxylic acid component comprises adipic acid in an amount
from about 88 to about 95 mol % and the dicarboxylic acid
represented by Formula 1 in an amount from about 5 to about 12 mol
%, each based on 100 mol % of the dicarboxylic acid component, and
wherein the diamine component comprises m-xylene diamine in an
amount from about 80 to about 95 mol % and the diamine represented
the Formula 2 in an amount from about 5 to about 20 mol %, each
based on 100 mol % of the diamine component.
3. The copolymerized polyamide resin according to claim 1, wherein
the copolymerized polyamide resin has a mole ratio of the
dicarboxylic acid component and the diamine component (dicarboxylic
acid component:diamine component) from about 1:about 0.95 to about
1:about 1.15.
4. The copolymerized polyamide resin according to claim 1, wherein
the copolymerized polyamide resin has a terminal group encapsulated
with an end capping agent comprising an aliphatic carboxylic acid,
an aromatic carboxylic acid, or a mixture thereof.
5. The copolymerized polyamide resin according to claim 1, wherein
the copolymerized polyamide resin has a melting temperature (Tm)
from about 220 to about 250.degree. C., a crystallization
temperature (Tc) from about 170 to about 200.degree. C., and a
glass transition temperature (Tg) from about 90 to about
110.degree. C.
6. The copolymerized polyamide resin according to claim 1, wherein
the copolymerized polyamide resin has an intrinsic viscosity (IV)
difference (.DELTA.IV) of about 0.14 or less according to Equation
1: Intrinsic viscosity difference(.DELTA.IV)=IV.sub.1-IV.sub.0
[Equation 1] wherein, IV.sub.0 is an intrinsic viscosity of the
copolymerized polyamide resin, as measured at about 25.degree. C.,
and IV.sub.1 is an intrinsic viscosity, as measured by melting
about 10 g of the copolymerized polyamide resin at about
260.degree. C. and leaving the melted copolymerized polyamide resin
for about 30 minutes, followed by cooling the copolymerized
polyamide resin to about 25.degree. C.
7. The copolymerized polyamide resin according to claim 1, wherein
the copolymerized polyamide resin has a gel content of about 0.4%
or less, as measured by melting about 10 g of the copolymerized
polyamide resin at about 260.degree. C. and leaving the melted
copolymerized polyamide resin for about 30 minutes, followed by
cooling the copolymerized polyamide resin to an ambient
temperature.
8. A method for preparing a copolymerized polyamide resin
comprising: polymerizing a monomer mixture comprising a
dicarboxylic acid component comprising adipic acid and a
dicarboxylic acid represented by Formula 1, and a diamine component
comprising m-xylene diamine and a diamine represented by Formula 2,
wherein the copolymerized polyamide resin has a difference between
a melting temperature (Tm) and a crystallization temperature (Tc)
of about 50.degree. C. or more: ##STR00006## wherein, A is a single
bond or a C.sub.1 to C.sub.10 hydrocarbon group, R.sub.1, R.sub.2
and R.sub.3 are the same or different and are each independently a
C.sub.1 to C.sub.5 alkyl group, and a, b and c are the same or
different and are each independently an integer from 0 to 4, and
wherein the copolymerized polyamide resin has a Yellowness Index
difference (.DELTA.YI) of about 20 or less calculated according to
Equation 3 below: Yellowness Index
difference(.DELTA.YI)=YI.sub.1-YI.sub.0 [Equation 3] wherein
YI.sub.0 is a Yellowness Index (YI) value of the copolymerized
polyamide resin before a scorch test and YE is a Yellowness Index
value of the copolymerized polyamide resin after a scorch test, as
measured according to ASTM E313-73, wherein the scorch test
includes leaving about 1 to about 3 g of the copolymerized
polyamide resin at about 200.degree. C. for about 1 hour.
9. The method for preparing a copolymerized polyamide resin
according to claim 8, comprising polymerizing the monomer mixture
to obtain a prepolymer; and performing a solid state polymerization
of the prepolymer.
10. The method of preparing copolymerized polyamide resin according
to claim 8, the prepolymer has an intrinsic viscosity from about
0.1 to about 0.4 dL/g.
11. The method of preparing copolymerized polyamide resin according
to claim 8, wherein the solid state polymerization comprises
heating the prepolymer to a temperature of about 150 to about
220.degree. C.
12. A molded article formed from the copolymerized polyamide resin
according to claim 1.
13. The copolymerized polyamide resin according to claim 1, wherein
the copolymerized polyamide resin has a Yellowness Index change
(.DELTA.YI) of from about 10 to about 20.
14. The copolymerized polyamide resin according to claim 13,
wherein the copolymerized polyamide resin has a Yellowness Index
change (.DELTA.YI) of from about 10 to about 18.
15. The copolymerized polyamide resin according to claim 13,
wherein the dicarboxylic acid component comprises adipic acid and
1,4-cyclohexane dicarboxylic acid and the diamine component
comprises m-xylene diamine and bis(4-aminocyclohexyl)methane.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S.
application Ser. No. 14/583,429, pending, filed Dec. 26, 2014, in
the United States Patent and Trademark Office, and claims priority
under 35 USC Section 119 to and the benefit of Korean Patent
Application 10-2014-0128684, filed Sep. 25, 2014. The entire
disclosure of each of foregoing is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a copolymerized polyamide
resin, a method for preparing the same, and a molded article
comprising the same.
BACKGROUND
[0003] Among commercialized polyamide resins (nylons),
poly(m-xylene adipamide) (MXD6) has been used in a variety of
applications, such as film materials, injection molding materials,
and the like due to its excellent rigidity, gas-barrier property,
etc. MXD6 has an advantage over other nylons, because there are few
problems associated with the protrusion of inorganic fillers, for
example, glass fibers, from a surface of an article produced in an
injection molding process due to slowed crystallization rate. Thus,
MXD6 can provide molded products with a superior appearance due to
reduced surface roughness.
[0004] PET/MXD6/PET, PA6/MXD6/PA6, and the like have been used as
multilayer packaging films. Such multilayer films have been
primarily prepared by a coextrusion process. However, MXD6 can be
further polymerized by the heat generated during the extrusion of
MXD6 to increase its molecular weight and melt viscosity, thereby
making the extrusion process unstable. Furthermore, gel generation
during extrusion can result in a poor appearance of the film, such
as pin holes or fish eyes, etc. Gel generation can also reduce
workability. Generally, it is known that a benzyl methyl structure
included in MXD6 may form radicals under high temperature and
oxygen contact conditions, thereby resulting in an increase in the
molecular weight, gel forming, and the like.
[0005] Furthermore, MXD6 may have a reduced resistance to hot-humid
external environments, since it has a reduced heat resistance
compared with other high temperature resistant nylons.
[0006] Therefore, there is a need for a MXD6 based copolymerized
polyamide resin that can reduce or prevent gel generation and can
have improved heat resistance to expand the uses for MXD6 based
polyamide resin.
SUMMARY
[0007] The present invention provides a MXD6 based copolymerized
polyamide resin that can have excellent heat resistance, reduced or
no gel generation, and reduced yellowing phenomenon in a molding
process by including an alicyclic dicarboxylic acid and an
alicyclic diamine comprising two or more cyclohexyl groups, a
method for preparing the same, and a molded article comprising the
same.
[0008] The copolymerized polyamide resin is a polymer of a monomer
mixture comprising a dicarboxylic acid component comprising adipic
acid and a dicarboxylic acid represented by Formula 1, and a
diamine component comprising m-xylene diamine and a diamine
represented by Formula 2, wherein the copolymerized polyamide resin
has a difference between a melting temperature (Tm) and a
crystallization temperature (Tc) of about 50.degree. C. or
more:
##STR00002##
[0009] wherein, A is a single bond or a C.sub.1 to C.sub.10
hydrocarbon group, R.sub.1, R.sub.2 and R.sub.3 are the same or
different and are each independently a C.sub.1 to C.sub.5 alkyl
group, and a, b and c are the same or different and are each
independently an integer from 0 to 4.
[0010] In exemplary embodiments, the adipic acid may be present in
an amount from about 88 to about 95 mol % in the dicarboxylic acid
component, the dicarboxylic acid represented by Formula 1 may be
present in an amount from about 5 to about 12 mol % in the
dicarboxylic acid component, the m-xylene diamine may be present in
an amount from about 80 to about 95 mol % in the diamine component,
and the diamine represented by Formula 2 may be present in an
amount from about 5 to about 20 mol % in the diamine component.
[0011] In exemplary embodiments, the copolymerized polyamide resin
may have a mole ratio of the dicarboxylic acid component and the
diamine component (dicarboxylic acid component:diamine component)
from about 1:about 0.95 to about 1:about 1.15.
[0012] In exemplary embodiments, the copolymerized polyamide resin
may have a terminal group encapsulated with an end capping agent
comprising at least one of an aliphatic carboxylic acid and an
aromatic carboxylic acid.
[0013] In exemplary embodiments, the copolymerized polyamide resin
may have a melting temperature (Tm) from about 220 to about
250.degree. C., a crystallization temperature (Tc) from about 170
to about 200.degree. C., and a glass transition temperature (Tg)
from about 90 to about 110.degree. C.
[0014] In exemplary embodiments, the copolymerized polyamide resin
may have an intrinsic viscosity (IV) difference (.DELTA.IV) of
about 0.14 or less according to Equation 1 as below:
Intrinsic viscosity difference(.DELTA.IV)=IV.sub.1-IV.sub.0
[Equation 1]
[0015] wherein IV.sub.0 is an intrinsic viscosity of the
copolymerized polyamide resin, as measured at about 25.degree. C.,
and IV.sub.1 is an intrinsic viscosity, as measured by melting
about 10 g of the copolymerized polyamide resin at about
260.degree. C. and leaving the melted copolymerized polyamide resin
for about 30 minutes, followed by cooling it to about 25.degree.
C.
[0016] In exemplary embodiments, the copolymerized polyamide resin
may have a gel content of about 0.4% or less for a sample of about
10 g, as measured by melting about 10 g of the sample at about
260.degree. C. and leaving the melted sample for about 30 minutes,
followed by cooling it to an ambient temperature.
[0017] In exemplary embodiments, the copolymerized polyamide resin
may have a Yellowness Index difference (.DELTA.YI) of about 20 or
less, wherein the .DELTA.YI is determined by measuring the YI of a
copolymerized polyamide resin sample before and after a scorch
test, wherein the scorch test includes leaving about 1 to about 3 g
of the resin at about 200.degree. C. for about 1 hour.
[0018] The present invention also relates to a method for preparing
the copolymerized polyamide resin. The method includes polymerizing
a monomer mixture comprising a dicarboxylic acid component
comprising adipic acid and a dicarboxylic acid represented by
Formula 1, and a diamine component comprising m-xylene diamine and
a diamine represented by Formula 2, wherein the copolymerized
polyamide resin has a difference between a melting temperature (Tm)
and a crystallization temperature (Tc) of about 50.degree. C. or
more.
[0019] In exemplary embodiments, the method may comprise
polymerizing the monomer mixture to obtain a prepolymer; and
performing a solid state polymerization of the prepolymer.
[0020] In exemplary embodiments, the prepolymer may have an
intrinsic viscosity from about 0.1 to about 0.4 dL/g.
[0021] In exemplary embodiments, the solid state polymerization may
comprise heating the prepolymer to a temperature of about 150 to
about 220.degree. C.
[0022] The present invention further relates to a molded article
formed from the copolymerized polyamide resin.
DETAILED DESCRIPTION
[0023] Exemplary embodiments now will be described more fully
hereinafter in the following detailed description, in which some,
but not all embodiments of the invention are described. Indeed,
this invention may be embodied in many different forms and should
not be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements.
[0024] The copolymerized polyamide resin according to the present
invention is a polymer of a monomer mixture comprising (A) a
dicarboxylic acid component comprising (a1) adipic acid and (a2) an
alicyclic dicarboxylic acid, and (B) a diamine component comprising
(b1) m-xylene diamine and (b2) an alicyclic diamine comprising two
or more cyclohexyl groups, wherein the copolymerized polyamide
resin has a difference between a melting temperature (Tm) and a
crystallization temperature (Tc) of about 50.degree. C. or
more.
[0025] As used herein, the term "dicarboxylic acid (component)"
refers to dicarboxylic acids, alkyl esters thereof (C.sub.1 to
C.sub.4 lower alkyl esters, such as monomethyl, monoethyl,
dimethyl, diethyl, dibutyl esters, and the like), acid anhydrides
thereof, and the like, and mixtures thereof, and forms the
dicarboxylic acid moieties through a reaction with a diamine
(component). In addition, as used herein, the dicarboxylic acid
moieties and the diamine moieties mean residues remaining after
removal of hydrogen atoms, hydroxyl groups and/or alkoxy groups
upon polymerization of the dicarboxylic acid component and the
diamine component.
[0026] (A) Dicarboxylic Acid Component
[0027] The dicarboxylic acid component (A) used in the present
invention may comprise (al) adipic acid and (a2) an alicyclic
dicarboxylic acid, for example, a dicarboxylic acid represented by
Formula 1:
##STR00003##
[0028] wherein, each R.sub.1 is the same or different and each is
independently a C.sub.1 to C.sub.5 alkyl group, for example a
methyl group, an ethyl group, a propyl group, a butyl group, and
the like, and a is an integer from 0 to 4.
[0029] Examples of the dicarboxylic acids represented by Formula 1
may include, without limitation, 1,4-cyclohexane dicarboxylic acid,
2-methylcyclohexane-1,4-dicarboxylic acid,
2,5-dimethylcyclohexane-1,4-dicarboxylic acid, and the like, and
mixtures thereof.
[0030] In exemplary embodiments, the dicarboxylic acid component
may include adipic acid in an amount from about 88 to about 95 mol
%, for example, about 90 to about 95 mol %, based on about 100 mol
% of the dicarboxylic acid component. In some embodiments, the
dicarboxylic acid component may include adipic acid in an amount of
about 88, 89, 90, 91, 92, 93, 94, or 95 mol %. Further, according
to some embodiments of the present invention, the amount of adipic
acid can be in a range from about any of the foregoing amounts to
about any other of the foregoing amounts.
[0031] In exemplary embodiments, the dicarboxylic acid component
may include the dicarboxylic acid represented by Formula 1 in an
amount from about 5 to about 12 mol %, for example, about 5 to
about 10 mol %, based on about 100 mol % of the dicarboxylic acid
component. In some embodiments, the dicarboxylic acid component may
include the dicarboxylic acid represented by Formula 1 in an amount
of about 5, 6, 7, 8, 9, 10, 11, or 12 mol %. Further, according to
some embodiments of the present invention, the amount of the
dicarboxylic acid represented by Formula 1 can be in a range from
about any of the foregoing amounts to about any other of the
foregoing amounts.
[0032] Within these ranges, the obtained copolymerized polyamide
resin may have a reduced crystallization rate and an increased
glass transition temperature (Tg) over existing resins, and thus
may have excellent thermal stability, and further may exhibit
reduced or no gel generation and/or yellowing phenomenon in a
molding process.
[0033] (B) Diamine Component
[0034] The diamine component (B) used in the present invention may
comprise (b1) m-xylene diamine and (b2) an alicyclic diamine
comprising two or more cyclohexyl groups, for example, the diamine
represented by Formula 2:
##STR00004##
[0035] wherein, A is a single bond or a C.sub.1 to C.sub.10
hydrocarbon group, for example, a linear or branched C.sub.1 to
C.sub.10 aliphatic hydrocarbon group, C.sub.6 to C.sub.10 alicyclic
hydrocarbon group, and the like, and as another example a single
bond, a methylene group, an ethylene group, a propylene group, a
cyclohexylene group, and the like, R.sub.2 and R.sub.3 are the same
or different and may be each independently a C.sub.1 to C.sub.5
alkyl group, for example, a methyl group, an ethyl group, a propyl
group, a butyl group, and the like, and b and c are the same or
different and are each independently an integer from 0 to 4.
[0036] Examples of the diamine represented by Formula 2 may
include, without limitation, bis(p-aminocyclohexyl)methane (PACM),
bis-(p-amino-3-methyl-cyclohexyl)methane (MACM), and the like, and
mixtures thereof.
[0037] In exemplary embodiments, the diamine component may include
m-xylene diamine in an amount from about 80 to about 95 mol %, for
example, about 85 to about 95 mol %, based on about 100 mol % of
the diamine component. In some embodiments, the diamine component
may include m-xylene diamine in an amount of about 80, 81, 82, 83,
84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, or 95 mol %. Further,
according to some embodiments of the present invention, the amount
of m-xylene diamine can be in a range from about any of the
foregoing amounts to about any other of the foregoing amounts.
[0038] In exemplary embodiments, the diamine component may include
the diamine represented by Formula 2 in an amount from about 5 to
about 20 mol %, for example, about 5 to about 15 mol %, based on
about 100 mol % of the diamine component. In some embodiments, the
diamine component may include the diamine represented by Formula 2
in an amount of about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, or 20 mol %. Further, according to some embodiments of
the present invention, the amount of the diamine represented by
Formula 2 can be in a range from about any of the foregoing amounts
to about any other of the foregoing amounts.
[0039] Within these ranges, the obtained copolymerized polyamide
resin may have excellent workability, superior heat resistance, and
the like, and may exhibit reduced or no gel generation and
yellowing phenomenon in a molding process.
[0040] The copolymerized polyamide resin according to the present
invention may have a mole ratio of the dicarboxylic acid component
(A) and the diamine component (B) ((A):(B)) from about 1:about 0.95
to about 1:about 1.15, for example, from about 1:about 0.95 to
about 1:about 1.10. Within these ranges, the copolymerized
polyamide resin may have an excellent terminal reactivity, and thus
may be prepared within the proper polymerization periods.
[0041] The copolymerized polyamide resin according to the present
invention may have a terminal group encapsulated with an end
capping agent. The end capping agent may include at least one of an
aliphatic carboxylic acid and/or an aromatic carboxylic acid, for
example, without limitation, acetic acid, propionic acid, butyric
acid, valeric acid, caproic acid, caprylic acid, lauric acid,
tridecanoic acid, myristic acid, palmitic acid, stearic acid,
pivalic acid, isobutyric acid, benzoic acid, toluic acid,
.alpha.-naphthalene carboxylic acid, .beta.-naphthalene carboxylic
acid, methylnaphthalene carboxylic acid, and the like and mixtures
thereof.
[0042] The copolymerized polyamide resin may include an end capping
agent in an amount, without limitation, from about 0.01 to about 5
parts by mole, for example, about 0.1 to about 3 parts by mole,
based on about 100 parts by mole of the dicarboxylic acid (A) and
the diamine (B). Within these ranges, the molecular weight of the
copolymerized polyamide resin may be easily adjusted.
[0043] The copolymerized polyamide resin of the present invention
may be prepared according to the conventional process for preparing
polyamide, for example, by polymerizing the monomer mixture
comprising the dicarboxylic acid component (A) and the diamine
component (B).
[0044] The polymerization may be performed by the conventional
polymerization method, for example, a melt polymerization method,
wherein the polymerization temperature may range from about 80 to
about 280.degree. C., for example, from about 90 to about
270.degree. C., and the polymerization pressure may range from
about 10 to about 40 kgf/cm.sup.2, without being limited
thereto.
[0045] In exemplary embodiments, the copolymerized polyamide resin
may be prepared by polymerizing the monomer mixture to obtain a
prepolymer; and performing a solid state polymerization of the
prepolymer. For example, the copolymerized polyamide resin may be
obtained by a process including: placing the monomer mixture, a
catalyst and water in a reactor, stirring the mixture at about 80
to about 150.degree. C. for about 0.5 to about 2 hours, maintaining
the mixture at about 200 to about 220.degree. C. under a pressure
of about 20 to about 40 kgf/cm.sup.2 for about 1 to about 4 hours
and lowering the pressure to about 10 to about 30 kgf/cm.sup.2,
followed by performing the reaction (copolymerization) for about 1
to about 3 hours to obtain a polyamide prepolymer, and performing a
solid state polymerization (SSP) of the prepolymer at a temperature
between a glass transition temperature (Tg) and a melting
temperature (Tm) in a vacuum for about 2 to about 20 hours.
[0046] The prepolymer may have an intrinsic viscosity [.eta.],
without limitation, from about 0.1 dL/g to about 0.4 dL/g, for
example, from about 0.1 dL/g to about 0.3 dL/g, as measured in
about 98% sulfuric acid solution at 25.degree. C. using an
Ubbelohde viscometer. Within these ranges, the copolymerized
polyamide resin may be easily withdrawn from the reactor.
[0047] In exemplary embodiments, the solid state polymerization may
comprise heating the prepolymer to a temperature of about 150 to
about 220.degree. C., for example, about 180 to about 210.degree.
C. in a vacuum or in the presence of an inert gas, such as
nitrogen, argon, etc. Within these ranges, the copolymerized
polyamide resin may have a weight average molecular weight from
about 5,000 to about 50,000 g/mol.
[0048] A catalyst may be used in the copolymerization reaction. The
catalyst may be a phosphorus catalyst, for example, phosphoric
acid, phosphorous acid, hypophosphorous acid, salts thereof,
derivatives thereof, and the like, and mixtures thereof. In
exemplary embodiments, the catalyst may include phosphoric acid,
phosphorous acid, hypophosphorous acid, sodium hypophosphate,
sodium hypophosphinate, and the like, and mixtures thereof.
[0049] The catalyst may be present in an amount of about 3 parts by
weight or less, for example, from about 0.001 parts by weight to
about 1 part by weight, and as another example from about 0.01
parts by weight to about 0.5 parts by weight, based on about 100
parts by weight of the total monomer mixture, without being limited
thereto.
[0050] Furthermore, in the process for preparing the polyamide
resin, the end capping agent may be used in an amount as described
above, and the viscosity of the prepared copolymerized polyamide
resin may be adjusted by adjusting the amount of the end capping
agent.
[0051] The copolymerized polyamide resin of the present invention
may be characterized as having a difference between a melting
temperature (Tm) and a crystallization temperature (Tc) of about
50.degree. C. or more, for example, from about 50 to about
70.degree. C., and as another example from about 55 to about
65.degree. C. If the difference between the melting temperature
(Tm) and the crystallization temperature (Tc) of the copolymerized
polyamide resin is less than about 50.degree. C., then a
deteriorated appearance quality such as the projection or
protrusion of inorganics from a surface of a molded product
produced using the resin can occur after melt processing since the
crystallization rate becomes faster.
[0052] In exemplary embodiments, the copolymerized polyamide resin
may have a melting temperature (Tm) from about 220 to about
250.degree. C., for example, about 230 to about 250.degree. C., and
as another example from about 230 to about 245.degree. C., and a
crystallization temperature (Tc) from about 170 to about
200.degree. C., for example, from about 170 to about 190.degree. C.
Within these ranges, the copolymerized polyamide resin may have
excellent moldability when preparing a molded article requiring
heat resistance and good appearance properties.
[0053] Furthermore, the copolymerized polyamide resin may have a
glass transition temperature (Tg) from about 90 to about
110.degree. C., for example, about 95 to about 105.degree. C.
Within these ranges, the copolymerized polyamide resin may have
excellent heat resistance.
[0054] In exemplary embodiments, the copolymerized polyamide resin
may have an intrinsic viscosity from about 0.6 to about 1.4 dL/g,
for example, about 0.7 to about 1.3 dL/g, as measured at 25.degree.
C. after dissolving at a concentration of about 0.5 g/dL in a
concentrated sulfuric acid solution (about 98%), and an intrinsic
viscosity (IV) difference (.DELTA.IV) of about 0.14 or less, for
example, from about 0.01 to about 0.10 according to Equation 1
below. Within these ranges, when melt processing the copolymerized
polyamide resin, it is possible to reduce or prevent gel
generation.
Intrinsic viscosity difference(.DELTA.IV)=IV.sub.1-IV.sub.0
[Equation 1]
[0055] wherein, IV.sub.0 is an intrinsic viscosity of the
copolymerized polyamide resin, as measured at about 25.degree. C.,
and IV.sub.1 is an intrinsic viscosity, as measured by melting
about 10 g of the copolymerized polyamide resin at about
260.degree. C. and leaving the melted copolymerized polyamide resin
for about 30 minutes, followed by cooling it to about 25.degree.
C.
[0056] In exemplary embodiments, the copolymerized polyamide resin
may have a gel content of about 0.4% or less, for example, about
0.01 to about 0.30%, as measured by melting about 10 g of a sample
of the copolymerized polyamide resin at about 260.degree. C. and
leaving the melted copolymerized polyamide resin for about 30
minutes, followed by cooling it to an ambient temperature. The gel
content may be calculated according to Equation 2 as below.
Gel content(%)=[W.sub.1/W.sub.0].times.100 [Equation 2]
[0057] wherein, W.sub.0 is a mass of the sample (about 10 g), as
measured by melting about 10 g of the sample of the copolymerized
polyamide resin at about 260.degree. C. and leaving the melted
copolymerized polyamide resin for about 30 minutes, followed by
cooling it to an ambient temperature, and W.sub.1 is a mass of the
filtered material (gel), as measured by dissolving the sample in
about 100 mL of hexafluoroisopropanol (HFIP), pouring the solution
into a filter paper, subjecting the resulting filtered material at
about 80.degree. C. in a vacuum oven, and vacuum drying the
material at about 10 torr of degree of vacuum for about 5
hours.
[0058] In exemplary embodiments, the copolymerized polyamide resin
may have a Yellowness Index change (.DELTA.YI) of about 20 or less,
for example, from about 10 to about 20, and as another example from
about 13 to about 18, wherein the .DELTA.YI is determined by
measuring the YI of a copolymerized polyamide resin sample before
and after maintaining the sample at about 200.degree. C. for about
1 hour. The gel content may be calculated according to Equation 2
above.
[0059] In exemplary embodiments, the copolymerized polyamide resin
may have a Yellowness Index change (.DELTA.YI) of about 20 or less,
for example, from about 10 to about 20, and more particularly from
about 13 to about 18, wherein the .DELTA.YI is determined by
measuring the YI of a copolymerized polyamide resin sample before
and after a scorch test, wherein the scorch test includes leaving
about 1 to about 3 g of the resin at about 200.degree. C. for about
1 hour. The Yellowness Index difference (.DELTA.YI) may be
calculated according to Equation 3 as below.
Yellowness Index difference(.DELTA.YI)=YI.sub.1-YI.sub.0 [Equation
3]
[0060] wherein, YI.sub.0 is a Yellowness Index (YI) value of the
copolymerized polyamide resin before the scorch test, as measured
according to ASTM E313-73, and YI.sub.1 is a Yellowness Index value
of the copolymerized polyamide resin after the scorch test which
includes leaving about 1 to about 3 g of the copolymerized
polyamide resin at about 200.degree. C. for about 1 hour.
[0061] In exemplary embodiments, the copolymerized polyamide resin
may have a weight average molecular weight from about 5,000 to
about 50,000 g/mol as measured by a gel permeation chromatography
(GPC), without being limited thereto.
[0062] A molded article according to the present invention may be
prepared from the copolymerized polyamide resin. For example, the
copolymerized polyamide resin may be used for packing films,
barrier bottle applications, cases for electrical and electronic
devices, exterior materials of vehicles, and the like, without
being limited thereto, requiring heat resistance, melt workability,
discoloration resistance, and the like. The molded article can be
easily prepared by those skilled in the art.
[0063] Next, the present invention will be explained in more detail
with reference to the following examples. However, it should be
understood that these examples are provided for illustration only
and are not to be in any way construed as limiting the present
invention.
EXAMPLES
Example 1
[0064] A monomer mixture comprising 0.630 mol (92.07 g) of adipic
acid and 0.070 mol (12.05 g) of 1,4-cyclohexane dicarboxylic acid
as a dicarboxylic acid component (A), and 0.665 mol (90.57 g) of
m-xylene diamine and 0.035 mol (7.36 g) of bis
(4-aminocyclohexyl)methane (PACM) as a diamine component (B), 0.11
g of sodium hypophosphate as a catalyst and 28 ml of distilled
water are placed in a 1 L autoclave, which in turn is filled with
nitrogen. Next, after stirring the components at 130.degree. C. for
60 minutes, the mixture is heated to 210.degree. C. for 1 hour and
left for 1 hour at a pressure of 13 kgf/cm.sup.2. After flashing
the mixture, it is separated into water and a polyamide
pre-copolymer. The separated polyamide pre-copolymer (intrinsic
viscosity [.eta.]=0.21 dL/g) is put into a tumbler type reactor,
and is subject to solid state polymerization at 190.degree. C. for
5 hours. Then, the polyamide pre-copolymer is cooled slowly to an
ambient temperature to obtain a copolymerized polyamide resin.
Example 2
[0065] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.630 mol (85.81 g) of m-xylene
diamine and 0.070 mol (14.72 g) of bis (4-aminocyclohexyl)methane
instead of 0.665 mol (90.57 g) of m-xylene diamine and 0.035 mol
(7.36 g) of bis (4-aminocyclohexyl)methane as the diamine component
(B) are used.
Example 3
[0066] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.595 mol (81.04 g) of m-xylene
diamine and 0.105 mol (22.09 g) of bis (4-aminocyclohexyl)methane
instead of 0.665 mol (90.57 g) of m-xylene diamine and 0.035 mol
(7.36 g) of bis (4-aminocyclohexyl)methane as the diamine component
(B) are used.
Example 4
[0067] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.665 mol (97.18 g) of adipic
acid and 0.035 mol (6.03 g) of 1,4-cyclohexane dicarboxylic acid
instead of 0.630 mol (92.07 g) of adipic acid and 0.070 mol (12.05
g) of 1,4-cyclohexane dicarboxylic acid as the dicarboxylic acid
component (A), and 0.595 mol (81.04 g) of m-xylene diamine and
0.105 mol (22.09 g) of bis (4-aminocyclohexyl)methane instead of
0.665 mol (90.57 g) of m-xylene diamine and 0.035 mol (7.36 g) of
bis (4-aminocyclohexyl)methane as the diamine component (B) are
used.
Example 5
[0068] A copolymerized polyamide resin is prepared in the same
manner as in Example 2 except that the conditions in the solid
state polymerization are changed from 190.degree. C. and 5 hours to
200.degree. C. and 7 hours.
Comparative Example 1
[0069] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.70 mol (102.30 g) of adipic
acid only is used as the dicarboxylic acid component (A), and 0.70
mol (95.34 g) of m-xylene diamine only is used as the diamine
component (B).
Comparative Example 2
[0070] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.70 mol (102.30 g) of adipic
acid only is used as the dicarboxylic acid component (A).
Comparative Example 3
[0071] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.70 mol (95.33 g) of m-xylene
diamine only is used as the diamine component (B).
Comparative Example 4
[0072] A copolymerized polyamide resin is prepared in the same
manner as in Example 1 except that 0.595 mol (86.95 g) of adipic
acid and 0.105 mol (18.08 g) of 1,4-cyclohexane dicarboxylic acid
are used instead of 0.630 mol (92.07 g) of adipic acid and 0.070
mol (12.05 g) of 1,4-cyclohexane dicarboxylic acid as the
dicarboxylic acid component (A), and 0.70 mol (95.33 g) of m-xylene
diamine only is used as the diamine component (B).
Comparative Example 5
[0073] A copolymerized polyamide resin is prepared in the same
manner as in Example 2 except that 0.630 mol (85.81 g) of m-xylene
diamine and 0.070 mol (9.53 g) of p-xylene diamine instead of 0.630
mol (85.81 g) of m-xylene diamine and 0.070 mol (14.72 g) of bis
(4-aminocyclohexyl)methane as the diamine component (B) are
used.
Experimental Example
[0074] The polyamide resins prepared in Examples and Comparative
Examples are evaluated with respect to a melting temperature, a
crystallization temperature, a glass transition temperature, an
intrinsic viscosity, a fluidity, an absorption rate and a gas
generation amount by the following methods. Results are shown in
Table 1.
[0075] Physical Property Evaluation
[0076] (1) Melting temperature (Tm), crystallization temperature
(Tc) and glass transition temperature (Tg) (unit: .degree. C.):
Melting temperature, crystallization temperature and glass
transition temperature are measured on each of the polyamide resins
obtained after solid state polymerization in the Examples and
Comparative Examples using a differential scanning calorimeter
(DSC). The DSC is a Q20 instrument (TA Co., Ltd.). For measurement
of crystallization temperature, a 5 mg to 10 mg of specimen is
dried (to 3,000 ppm or less of moisture) at 80.degree. C. for 4
hours in a vacuum, heated from 30.degree. C. to 400.degree. C. at a
rate of 10.degree. C./min in a nitrogen atmosphere, and then left
at 400.degree. C. for 1 minute. Then, the specimen is cooled at a
rate of 10.degree. C./min to obtain an exothermic peak, from which
crystallization temperature is measured. Further, glass transition
temperature and melting temperature are measured from transition
temperature and a maximum point of an endothermic peak obtained
while the specimen is heated to 400.degree. C. at a rate of
10.degree. C./min (2nd scan) after the specimen is maintained at
30.degree. C. for 1 minute after measurement of the crystallization
temperature, respectively.
[0077] (2) Intrinsic viscosity (IV, unit: dL/g): An intrinsic
viscosity is measured by dissolving the resin at a concentration of
0.5 g/dL in a 98% sulfuric acid solution at 25.degree. C. using an
Ubbelohde viscometer.
[0078] (3) Intrinsic viscosity difference (.DELTA.IV): An intrinsic
viscosity difference (.DELTA.IV) before and after melt processing
is measured according to Equation 1 as below.
Intrinsic viscosity difference(.DELTA.IV)=IV.sub.1-IV.sub.0
[Equation 1]
[0079] wherein, IV.sub.0 is an intrinsic viscosity of the
copolymerized polyamide resin, as measured at 25.degree. C., and
IV.sub.1 is an intrinsic viscosity, as measured by melting 10 g of
the copolymerized polyamide resin at 260.degree. C. and leaving the
melted copolymerized polyamide resin for 30 minutes, followed by
cooling it to 25.degree. C.
[0080] (4) Gel content (unit: %): A gel content after melt
processing is measured according to Equation 2 as below.
Gel content(%)=[W.sub.1/W.sub.0]'100 [Equation 2]
[0081] wherein, W.sub.0 is a mass of the sample (10 g), as measured
by melting 10 g of the sample of the copolymerized polyamide resin
at 260.degree. C. and leaving the sample for 30 minutes, followed
by cooling it to an ambient temperature, and W.sub.1 is a mass of
the filtered material (gel), as measured by dissolving the sample
in 100 mL of hexafluoroisopropanol (HFIP), pouring the solution
into a filter paper, subjecting the resulting filtered material at
80.degree. C. in a vacuum oven, and vacuum drying the material at
10 torr of degree of vacuum for 5 hours.
[0082] (5) Yellowness Index difference (.DELTA.YI): A yellowness
Index difference (.DELTA.YI) before and after a scorch test is
measured according to Equation 3 as below.
Yellowness Index difference(.DELTA.YI)=YI.sub.1-YI.sub.0 [Equation
3]
[0083] wherein, YI.sub.0 is a Yellowness Index (YI) value of the
copolymerized polyamide resin before the scorch test, as measured
according to ASTM E313-73, and YI.sub.1 is a Yellowness Index value
of the copolymerized polyamide resin after the scorch test, wherein
the scorch test includes leaving 1 to 3 g of the copolymerized
polyamide resin at 200.degree. C. for 1 hour.
TABLE-US-00001 TABLE 1 Comparative Examples Examples 1 2 3 4 5 1 2
3 4 5 (A) Adipic acid 90 90 90 95 90 100 100 90 85 90
1,4-Cyclohexane 10 10 10 5 10 -- -- 10 15 10 dicarboxylic acid (B)
m-Xylene diamine 95 90 85 85 90 100 95 100 100 90 Bis 5 10 15 15 10
-- 5 -- -- -- (4-aminocyclohexyl) methane p-Xylene diamine -- -- --
-- -- -- -- -- -- 10 Melting temperature (.degree. C.) 245 240 233
238 240 235 230 248 255 250 Crystallization 190 185 170 175 180 190
185 199 206 203 temperature (.degree. C.) Difference between
melting 55 55 63 63 60 45 45 49 49 47 temperature and
crystallization temperature Glass transition 95 100 103 100 102 84
89 90 103 106 temperature (.degree. C.) Intrinsic viscosity (dL/g)
0.85 0.88 0.86 0.85 1.20 0.84 0.88 0.84 0.88 0.86 Intrinsic
viscosity difference 0.10 0.07 0.04 0.05 0.08 0.20 0.17 0.19 0.21
0.18 (.DELTA.IV) between before and after melt processing Gel
content (%) after 0.30 0.22 0.10 0.26 0.25 0.50 0.48 0.48 0.51 0.49
melt processing Yellowness Index difference 18 15 10 14 16 30 27 28
25 28 (.DELTA.YI) between before and after scorch test
[0084] It can be seen that copolymerized polyamide resins according
to the present invention exhibit excellent heat resistance, and
reduced or no gel generation and yellowing phenomenon in a molding
process.
[0085] In contrast, for Comparative Examples 1 to 5, which did not
use the alicyclic dicarboxylic acid and/or the alicyclic diamine
comprising two or more cyclohexyl groups, it can be seen that the
polyamide resins have a difference between the melting temperature
and the crystallization temperature of less than 50.degree. C., an
increased intrinsic viscosity, an increased gel content, a
decreased heat discoloration resistance (Yellowness Index
difference), and the like in a melting process.
[0086] Many modifications and other embodiments of the invention
will come to mind to one skilled in the art to which this invention
pertains. Therefore, it is to be understood that the invention is
not to be limited to the specific embodiments disclosed and that
such modifications and other embodiments are intended to be
included within the scope of the appended claims.
* * * * *