U.S. patent application number 13/856260 was filed with the patent office on 2013-09-05 for method of producing a fluororesin composition and electrical wire.
This patent application is currently assigned to Daikin Industries, Ltd.. The applicant listed for this patent is DAIKIN AMERICA, INC., DAIKIN INDUSTRIES, LTD.. Invention is credited to Ryouichi FUKAGAWA, Tadaharu ISAKA, Takahiro KITAHARA, Keizou SHIOTSUKI.
Application Number | 20130230645 13/856260 |
Document ID | / |
Family ID | 40957242 |
Filed Date | 2013-09-05 |
United States Patent
Application |
20130230645 |
Kind Code |
A1 |
KITAHARA; Takahiro ; et
al. |
September 5, 2013 |
METHOD OF PRODUCING A FLUORORESIN COMPOSITION AND ELECTRICAL
WIRE
Abstract
A method of producing a fluororesin composition includes
copolymerizing at least tetrafluoroethylene with
hexafluoropropylene so that a melt flow rate at 372 degree C. of
the copolymer formed in the copolymerization changes from 0.05-5.0
grams/10 minutes to 10-60 grams/10 minutes. The
tetrafluoroethylene/hexafluoropropylene copolymer can be used as a
coating on an electrical wire.
Inventors: |
KITAHARA; Takahiro;
(Settsu-shi, JP) ; ISAKA; Tadaharu; (Settsu-shi,
JP) ; FUKAGAWA; Ryouichi; (Settsu-shi, JP) ;
SHIOTSUKI; Keizou; (Orangeburg, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIKIN AMERICA, INC.
DAIKIN INDUSTRIES, LTD. |
Orangeburg
Osaka |
NY |
US
JP |
|
|
Assignee: |
Daikin Industries, Ltd.
Osaka
NY
Daikin America, Inc.
Orangeburg
|
Family ID: |
40957242 |
Appl. No.: |
13/856260 |
Filed: |
April 3, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12866135 |
Aug 4, 2010 |
|
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PCT/US2009/033555 |
Feb 9, 2009 |
|
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13856260 |
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61092212 |
Aug 27, 2008 |
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61146086 |
Jan 21, 2009 |
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Current U.S.
Class: |
427/117 ;
526/254 |
Current CPC
Class: |
B29B 9/16 20130101; C08F
214/262 20130101; C08F 14/26 20130101; H01B 3/307 20130101; C08F
214/28 20130101; C08F 14/26 20130101; C08F 214/26 20130101; C09D
127/18 20130101; C08F 214/28 20130101; C08F 214/262 20130101; B29B
9/12 20130101; C08F 216/1408 20130101; C08F 214/28 20130101; C08F
2/001 20130101; C08F 214/26 20130101 |
Class at
Publication: |
427/117 ;
526/254 |
International
Class: |
H01B 3/30 20060101
H01B003/30 |
Claims
1. A method of producing a fluororesin composition, the method
comprising: copolymerizing at least tetrafluoroethylene with
hexafluoropropylene so that a melt flow rate at 372 degree C. of
the copolymer formed in the copolymerization changes from 0.05-5.0
grams/10 minutes to 10-60 grams/10 minutes.
2. The method of producing the fluororesin composition according to
claim 1, wherein the copolymerizing at least tetrafluoroethylene
with hexafluoropropylene so that the copolymer formed in the
copolymerization with the melt flow rate at 372 degree C. of from
0.05-5.0 grams/10 minutes accounts for from 0.1-50 parts by weight
of the entire copolymer in the end of the copolymerization.
3. The method of producing the fluororesin composition according to
claim 2, wherein the fluororesin composition is obtained in a
process without a mixing process different from the
copolymerizing.
4. The method of producing the fluororesin composition according to
claim wherein the copolymerizing at least tetrafluoroethylene with
hexafluoropropylene so that the fluororesin composition in the end
of the copolymerization has a complex viscosity of from
2.0.times.10.sup.3 to 1.0.0.times.10.sup.3 Pa*s and a storage
modulus of from 0.2 to 3.5 Pa in melt viscoelasticity measurement
under a condition of atmosphere temperature of 310 degree C. and
angular frequency of 0.01 radian/second.
5. The method of producing the fluororesin composition according to
claim 2, wherein the copolymerizing at east tetrafluoroethylene
with hexafluoropropylene so that the fluororesin composition in the
end of the copolymerization has a melt tension at 372 degree C.
from 0.08 to 0.16 N.
6. The method of producing the fluororesin composition according to
claim 2, wherein the copolymerizing at least tetrafluoroethylene
with hexafluoropropylene so that the fluororesin composition in the
end of the copolymerization has a sum of a number of thermally
unstable end groups and the number of --CF.sub.2H end groups per
1.times.10.sup.6 carbon atoms fewer than or equal to 50.
7. The method of producing the fluororesin composition according to
claim 1, wherein the copolymerizing at least tetrafluoroethylene
with hexafluoropropylene so that the difference between the melting
point of the copolymer formed in the copolymerization with the melt
flow rate at 372 degree C. of from 0.05-5.0 grams/10 minutes and
the melting point of the entire copolymer in the end of the
copolymerization is less than 20 degree C.
8. The method of producing the fluororesin composition according to
claim 7, wherein the fluororesin composition is obtained in a
process without a mixing process different from the
copolymerizing.
9. The method of producing the fluororesin composition according to
claim 7, wherein the copolymerizing at least tetrafluoroethylene
with hexafluoropropylene so that the fluororesin composition in the
end of the copolymerization has a complex viscosity of from
2.0.times.10.sup.3 to 10.0.times.10.sup.3 Pa*s and a storage
modulus of from 0.2 to 3.5 Pa in melt viscoelasticity measurement
under a condition of atmosphere temperature of 310 degree C. and
angular frequency of 0.01 radian/second.
10. The method of producing the fluororesin composition according
to claim 1, wherein the copolymerizing at least tetrafluoroethylene
with hexafluoropropylene so that the difference between the melting
point of the copolymer formed in the copolymerization with the melt
flow rate at 372 degree C. of from 0.05-5.0 grams/10 minutes and
the melting point of the entire copolymer in the end of the
copolymerization is less than 10 degree C.
11. The method of producing the fluororesin composition according
to claim 1, wherein the fluororesin composition is obtained in a
process without a mixing process different from the
copolymerizing,
12. The method of producing the fluororesin composition according
to claim 1, wherein the copolymerizing at least tetrafluoroethylene
with hexafluoropropylene so that the fluororesin composition in the
end of the copolymerization has a complex viscosity of from
2.0.times.10.sup.3 to 10.0.times.10.sup.3 Pa*s and a storage
modulus of from 0.2 to 3.5 Pa in melt viscoelasticity measurement
under a condition of atmosphere temperature of 310 degree C. and
angular frequency of 0.01 radian/second.
13. The method of producing the fluororesin composition according
to claim 1, wherein the copolymerizing at east tetraftuoroethytene
with hexafluoropropylene so that the fluororesin composition in the
end of the copolymerization has a melt tension at 372 degree C.
from 0.08 to 0.16 N.
14. The method of producing the fluororesin composition according
to claim 1, wherein. the copolymerizing at east tetraftuoroethylene
with hexafluoropropylene so that the fluororesin composition in the
end of the copolymerization has a sum of a number of thermally
unstable end groups and the number of --CF.sub.2H end groups per
1.times.10.sup.6 carbon atoms fewer than or equal to 50.
15. The method of producing the fluororesin composition according
to claim 1, further comprising drying the fluororesin composition
to produce a powder.
16. The method of producing the fluororesin composition according
to claim 15, further comprising fluorination treating the powder
using fluorine gas.
17. The method of producing the fluororesin composition according
to claim 1, further comprising pelletizing the fluororesin
composition using melt extrusion to form at least one pellet.
18. The method of producing the fluororesin composition according
to claim 17, further comprising fluorination treating the pellet
using fluorine gas.
19. A method of producing an electrical wire using the method of
producing the fluororesin composition according to claim 1, further
comprising coating the electrical wire with the fluororesin
composition.
20. A method of producing an electrical wire using the method of
producing the fluororesin composition according to claim 1, further
comprising foam coating the electrical wire with the fluororesin
composition.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 12/866,135 filed on Aug. 4, 2010, which is a
National Stage application of International Patent Application No,
PCT/JP2009/033555 filed on Feb. 9, 2009, which claims the benefit
of U.S. provisional application Nos. 61/029,130, filed on Feb. 15,
2008, 61/092,212 filed on Aug. 27, 2008 and 61/146,086 filed on
Jan. 21, 2009,the entire contents of which are hereby incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is related to a
tetrafluoroethylenelhexafluoropropylene copolymer and the
production method thereof, and an electrical wire.
[0004] 2. Background Information
[0005] A fluororesin has excellent characteristics such as thermal
resistance, chemical resistance, solvent resistance, insulation
properties and the like. For this reason, the fluororesin is molded
into various products such as tubes, pipes, filaments, and the like
by melt extrusion molding and the like, and the products are
commercially available. particular, tetrafluoroethylene
(abbreviated to "TFE" in the following)/hexafluoropropylene
(abbreviated to "HFP" in the following) copolymer (abbreviated to
"FEP" in the following) has a lower dielectric constant, a lower
dielectric loss tangent and excellent insulation properties than
other fluororesins. Therefore, FEP is preferably used for coating
of an electrical wire such as arable, wire and the like.
[0006] By, the way, improvement of productivity and reduction of
cost and the like are currently required in the manufacturing
setting for coating the electrical wire and the like. Consequently,
various considerations to improve molding speed and to reduce
defects are proposed in the manufacturing setting. For instance,
polytetrafluoroethylene (abbreviated to "PTFE" in the following) is
added to FEP so that from 0.01 to 5 wt % of PTFE is contained in
the whole polymer to improve melt fracture phenomena and critical
extrusion speed (for example, refer to Japanese Published
Unexamined Patent Application No. S52-98761 (1977)), from 0.03 to 2
parts by weight of FIFE is added to 100 parts by weight of FEP or
the terpolymer consisting of TFE, HFP and perfluoroalkylvinylether
(abbreviated to "PAVE" in the following) to improve coating broken
during wire coating process (for example, refer to International
Patent Publication Nos. WO 03/22922 and WO 03/22923 pamphlets),
These techniques can reduce the size of a lump which is produced
between a coating resin and a conductive wire in some degree but
they can't reduce the occurrence frequency of the lump
substantially.
[0007] Moreover, a melt-processable fluororesin composition
containing from 0.01 to 3 parts by weight of PTFE with a standard
specific gravity of from 2.15 to 2.30 to 100 parts by weight of FEP
is prepared to improve moldability in melt extrusion molding,
especially to reduce defects significantly in high-speed extrusion
coating of an electrical wire (for example, refer to International
Patent Publication No. WO 06 123694 pamphlet). Furthermore, for
this melt-processable fluororesin composition, it is necessary to
mix PTFE in dispersion liquid with FEP in dispersion liquid.
[0008] Additionally, a melt-processable fluororesin composition
containing from 0.01 to 5 wt % of a perfluoropolymer to FEP with
high molecular weight and with a melting point of over 20 degree C.
higher than that of FEP is prepared (for example, refer to
Published Japanese translation of a PCT Application No.
2004-502853). Note that it is necessary to mix the
perfluoropolyrner in dispersion liquid with FEP in dispersion
liquid for the melt-processable fluororesin composition.
Furthermore, an example of the perfluoropolymer includes FEP with
from 2 to 20 wt % of a repeating unit derived from HFP. It is
reported that this melt-processable fluororesin composition can
remove a lump and can depress piling the lump up in extrusion
coating of an electrical wire. However, this melt-processable
fluororesin composition can't reduce the occurrence frequency of
the lump substantially as well as the melt-processable fluororesin
in which PTFE powder is mixed with FEP powder. Moreover,
fluctuation of capacitance is larger and the electrical properties
of the final products made from the melt-processable fluororesin
composition are worse when a smaller lump is produced.
[0009] Furthermore, FEP with a relatively high die swell of from 5
to 20% and with a melt flow rate within a specific range is
prepared to reduce nonuniformity of a diameter of electrical wire
in extrusion coating of the electrical wire (for example, refer to
International Patent Publication WO 01/36504 pamphlet). However, a
perfluoropolymer with high molecular weight, such as PTFE and the
like is not added to this FEP. Additionally, the technique for
reducing the occurrence frequency of the lump is not mentioned.
[0010] TFE/fluoroalkoxytrifluoroethylene copolymer (abbreviated to
"PFA" in the following) composition containing from 0.01 to 30 wt %
of PTFE with a crystallization temperature of more than or equal to
305 degree C. is prepared as a fluororesin that can be a raw
material for a molded body with an excellent surface flatness (for
example, refer to Japanese Published Unexamined Patent Application
No. H7-70397 (1995)). However, it is not clear that this PFA
composition can give an electrical wire without any defects in
high-speed extrusion coating of an electrical wire.
SUMMARY
[0011] In view of the above, the objective of the invention is to
give a tetrafluoroethylene/hexafluoropropylene copolymer with
improved moldability in melt extrusion molding, especially with
significant reduction of defects in high-speed extrusion coating of
an electrical wire and with manufacturability of an electrical wire
with smaller transmission loss (attenuation). A method of producing
a fluororesin composition includes copolymerizing at least
tetrafluoroethylene with hexafluoropropylene so that a melt flow
rate at 372 degree C. of the copolymer formed in the
copolymerization changes from 0.05-5.0 grams/10 minutes to 10-60
grams/1.0 minutes. The tetrafluoroethylene/hexafluoropropylene
copolymer can be used as a coating on an electrical wire.
[0012] FEP of this invention is FEP obtained from at least TFE and
HFP selected from the group consisting of TFE, HFP and a third
monomer (a monomer except TFE and HFP), and is melt-processable.
This FEP is FEP mainly constituted of TFE and HFP. The third
monomer may be copolymerized with TFE and HFP as long as the effect
of this invention is maintained.
[0013] Examples of the third monomer, without being limiting in any
particular way, include perfluorovinylether (abbreviated to "PFVE"
in the following), chlorotrifluoroethylene (abbreviated to "CTFE"
in the following), vinyl fluoride (abbreviated to "VF" in the
following), hexafluoroisobutene and the like.
[0014] An example of the PFVE, without being limiting in any
particular way, is an unsaturated perfluoro compound of general
formula: CF.sub.2=CF-ORf (wherein, Rf is an aliphatic perfluoro
hydrocarbon group). Note that in this application the aliphatic
perfluoro hydrocarbon group is an aliphatic hydrocarbon group in
which all hydrogen atoms bonded to carbon atoms are substituted by
fluorine atoms. Additionally, the aliphatic perfluoro hydrocarbon
group may have an ether oxygen. Furthermore, an example of PFVE is
PAVE. PAVE is the compound of general formula:
CF.sub.2=CFO(CF.sub.2).sub.nCF.sub.3 (wherein, n is an integer of
from 0 to 3 in this application). Examples of PAVE include
perfluoro (methylvinylether) (abbreviated to "PMVE" in the
following), perfluoro (ethylvinylether) (abbreviated to "PEVE" in
the following), perfluoro (propylvinylether) (abbreviated to "PPVE"
in the following), and perfluoro (butylvinylether) and the like.
Among these, from the perspective of crack resistance, PMVE, PEVE
and PPVE are preferred, and PPVE is more preferred.
[0015] Furthermore, FEP of this invention is preferably
perfluoropolymer, which includes, for example, the polymer
constituted of the TFE unit and HFP unit only, the polymer
constituted of the TFE unit, HFP unit and PFVE unit only. Among
these, from the perspective of improvement of defects, the polymer
constituted of the TEE unit, HFP unit and PFVE unit only is more
preferred. Note that the TEE unit, HFP unit and PFVE unit are
derived from TEE, HFP and PFVE respectively, and constitute TER For
example, TFE unit is expressed in --(CF.sub.2CF.sub.2)--.
[0016] In case FEP contains PFVE unit, only one kind of PFVE unit
can exist in the FEP, or two or more kinds of PFVE unit can exist
in the FEP. Moreover, in the FEP, the weight ratio of TEE unit and
HFP unit (total weight of both units is 100) is preferably (70 to
95):(5 to 30), is more preferably (85 to 95):(5 to 15).
Furthermore, in case FEP contains a third monomer unit, the
concentration of total of the third monomer unit is preferably less
than or equal to 10 wt % of the entire monomer unit in general.
Furthermore, in case this FEP is constituted of TEE unit, HEP unit
and PFVE unit only, the weight ratio of TFE unit, HFP unit and PFVE
unit (total weight of these units is 100) is preferably (70 to
95):(4 to 20):(0.1 to 10), is more preferably (75 to 95):(5 to
15):(0.3 to 3). Furthermore, in case PFVE unit contains two or more
kinds of units, for example, PMVE unit, PPVE unit and the like, the
weight of PFVE unit is based on the total weight of those units.
Moreover, in this application, this weight ratio is determined by
the measurement of content percentage of TFE unit, HFP unit, PPVE
unit and the like respectively with an NMR analyzer (AC300
manufactured by BRUKER BIOSPIN Co., Ltd, high temperature probe) or
an infrared spectrometer (type 1760 manufactured by PerkinElmer,
Inc.).
[0017] FEP of the invention is obtained without mixing with the
resin which has the melting point with difference of 20 degree C.
or more from the melting point of the FEP. Conversely, FEP of the
invention may be mixed with the resin which has the melting point
with difference of less than 20 degree C. from the melting point of
the FEP.
[0018] Furthermore, an example of the method for mixing an
arbitrary resin with the without being limiting in any particular
way, is method for mixing the resins in particle, method for mixing
the resins in aqueous suspension liquid or aqueous dispersion
liquid, method for melting the resins to mix them and the like.
[0019] Note that in case that the resins, which have different
melting point, are mixed together, it is possible to increase
generation of a small lump with increasing the difference between
melting points of a plurality of resins to be mixed because of
tunnelled resin with a higher melting point.
[0020] Moreover, a mixing process different from the polymerization
process is not necessary to produce the PEP of the invention. For
instance, the FEP of the invention can be obtained by multistage
polymerization in the polymerization process. For example, in order
to produce the FEP of the invention, TFE and HFP are polymerized in
a single system so that a melt flow rate (abbreviated to "MFR" in
the following) at 372 degree C. of the copolymer formed in the
polymerization changes from 0.05-5.0 grams/10 minutes to 10-60
grams/10 minutes to obtain an aqueous dispersion liquid of the FEP.
Note that a third monomer can be copolymerized at this time if
required. After this, the aqueous dispersion liquid prepared by the
above polymerization is dried to give dry powder, and the dry
powder is melt-extruded to give FEP of the invention. Note that the
aqueous dispersion liquid can be concentrated and the like if
required before dried. Thus, without the mixing process different
the polymerization process, for example, the advantage that the
production process can be simplified and another advantage are
obtained. In this polymerization the polymer having a relatively
low MFR is polymerized at an early stage, the polymer having a
relatively high MFR is polymerized at a late stage. On the
contrary, the polymer having a relatively high MFR may be
polymerized at the early stage, the polymer having a relatively low
MFR may be polymerized at the late stage. The MFR can be adjusted
by selecting the condition of the polymerization, such as a
polymerization temperature, a polymerization pressure, a
concentration of an initiator and the like.
[0021] Note that the production method in the production process
can be selected without any limitation. For example, an example of
the method is suspension polymerization method, solution
polymerization method, emulsion polymerization method,
supercritical polymerization method or the like. Note that in this
case, it is necessary to carry out polymerization so that the
component with a melt flow rate at 372 degree C. of from 0.05 to
5.0 g/10 minutes accounts for from 0.1 to 50 parts by weight of the
entire copolymer. Furthermore, note that in this case, it is
necessary to carry out polymerization so that the difference
between the melting point of the component having a melt flow rate
at 372 degree C. of from 0.05 to 5.0 grams/10 minutes and the
melting point of the polymer at the end of the polymerization is
less than 20 degree C. The more preferred difference between those
melting temperatures is within 10 degree C. The furthermore
preferred difference between those melting temperatures is within 7
degree C. The furthermore preferred difference between those
melting temperatures is within 5 degree C. The furthermore
preferred difference between those melting temperatures is within 3
degree C.
[0022] Note that, in general, a polymer having a lower melting
point has a relatively low thermal resistance. Thus, it is
preferred that the melting point of the component having a melt
flow rate from 0.05 to 5.0 grams/10 minutes is closer to the
melting point of the polymer at the end of the polymerization. In
other words, it is preferred that the composition distribution of
the polymer at the end of the polymerization is uniform.
[0023] As mentioned above, FEP of this invention has a melt flow
rate of from 10 to 60 g/10 minutes. FEP with this MFR range can
give the coated electrical wire with little nonuniformity of a
diameter even if an electrical wire is coated in high speed, and
can give the product with little fluctuation of capacitance
electrically. From the perspective of improvement in molding speed,
the more preferred lower limit for the MFR of FEP is 15 grams/10
minutes, the more preferred upper limit for that is 40 grams/10
minutes, the furthermore preferred lower limit for that is 20
grams/10 minutes, the furthermore preferred upper limit for that is
35 grams/10 minutes. In this application, MFR is measured by
applying load of 5 kg to approximately 6 grams of FEP at 372 degree
C. in a melt index tester conformable to ASTM D1238-98.
[0024] Furthermore, FEP of this invention prepared as above
exhibits a complex viscosity of from 2.0.times.10.sup.3 to
10.0.times.1.0.sup.s Pa*s and a storage modulus of from 0.1 to 3.5
Pa in melt viscoelasticity measurement under the condition of
atmosphere temperature of 310 degree C. and angular frequency of
0.01 radian/second. FEP with the range of these complex viscosity
and storage modulus has an excellent moldability, and has a
tendency to avoid a defect. Moreover, the more preferred lower
limit for the complex viscosity is 2.5.times.10.sup.3 Pa*s, the
furthermore preferred lower limit for that is 3.0.times.10.sup.3
Pa*s, the more preferred upper limit for that is 8.0.times.10.sup.3
Pa*s, the furthermore preferred upper limit for that is
7.0.times.10.sup.3 Pa*s. Still furthermore preferred upper limit
for that is 6.5.times.10.sup.3 Pa*s. The more preferred lower limit
for the storage modulus is 0.2 Pa, the more preferred upper limit
for that is 3.0 Pa. The complex viscosity and the storage modulus
are determined as the value in the angular frequency of 0.01
radian/second, which is obtained from frequency dispersion
measurement under the condition of an atmosphere temperature of 310
degree C., a diameter of parallel plate of 25 mm and a gap of 1.5
mm with amok viscoelasticity analyzer (MCR-500 manufactured by
Physica, Inc.).
[0025] Furthermore, a melt tension of EFT of this invention is
preferably from 0.08 to 0.16 N because the FEP with this range of
the melt tension can avoid formation of a lump produced from tiny
resin particles at an outlet in extrusion coating of an electrical
wire. The more preferred lower limit for the melt tension is 0.09
N.
[0026] In this application, the melt tension is determined by
measuring the strand extruded through an orifice with an inner
diameter of 2 mm and with a length of 20 ram under the condition of
a share rate of 36.5 (1/s) after approximately 50 g of resin is
added into a cylinder with an inner diameter of 15 mm maintained at
approximately 385 degree C. in a Capilograph.
[0027] In case FEP of the invention is obtained as aqueous
dispersion liquid, an aqueous media in the aqueous dispersion
liquid can be liquid containing water. It can be liquid containing
aqueous organic solvent, such as an aqueous alcohol and the like.
Of course, it can be liquid containing no aqueous organic
solvent.
[0028] Furthermore, melt extrusion can be generally carried out
under the desired condition as long as pelletization is possible.
FEP of this invention can be FEP with an end group, such as
--CF.sub.3, --CF.sub.2H and the like in at least a chain selected
from the group consisting of a main chain and a side chain of the
polymer. Additionally, it is preferred that there is few or no
thermally unstable end group, such as --COOH, --CH.sub.2OH, --COF,
--CF.dbd.CF--, CONH.sub.2, --COOCH.sub.3 and the like in the
chain.
[0029] The thermally unstable end group causes not only decrement
of thermal resistance of the resin but increment of attenuation of
the electrical wire obtained from the resin because the thermally
unstable end group is chemically unstable. Specifically, it is
preferred that the sum of the number of the thermally unstable end
group and the number of --CF.sub.2H end group is less than or equal
to 50 per 1.times.10.sup.6 carbon atoms. It is more preferred that
the number of the thermally unstable end group and -CF.sub.2H end
group is less than 20 per 1.times.10.sup.6 carbon atoms. And it is
furthermore preferred that the number of the thermally unstable end
group and --CF.sub.2H end group is less than or equal to 5. All of
the thermally unstable end group and --CF.sub.2H end group
described above can be replaced with --CF.sub.3, end group.
[0030] The thermally unstable end group and --CF.sub.2H end group
can be stabilized by converting to --CF.sub.3 end group in
fluorination treatment. An example of the fluorination treatment,
without being limiting in any particular way, is the method that a
polymer is exposed to a fluorine radical source which generates
fluorine radical under the condition of the fluorination treatment.
Examples of the fluorine radical source described above include
fluorine gas, CoF.sub.3, AgF.sub.2, UF.sub.6, OF.sub.2,
N.sub.2F.sub.2, CF.sub.3OF and halogen fluoride such as IF.sub.5,
ClF.sub.3 and the like, for example.
[0031] Among these, the method that fluorine gas is directly
contacted with the FEP of this invention is preferred. From the
perspective of controlling reaction, it is preferred that diluted
fluorine gas with a fluorine concentration of from 10 to 50 wt % is
used. The diluted fluorine gas can be obtained by diluting fluorine
gas with inert gas such as nitrogen gas, argon gas and the like.
The fluorine gas treatment can be generally carried out at
temperature of from 100 to 250 degree C. for example. Note that the
treatment temperature, without being limiting in the temperature
range above, can be determined depending on the situation.
[0032] The fluorine gas treatment is preferably carried out with
supplying the diluted fluorine gas into a reactor continuously or
intermittently. This fluorination treatment can be carried out to
dry powder after polymerization or melt-extruded pellet.
[0033] FEP of this invention has excellent moldability and gives
few defects. Additionally, the FEP has excellent thermal
resistance, chemical resistance, solvent resistance, insulation
properties, electrical characteristics and the like. Consequently,
this can be used as, for example, a coating material for electrical
wires, foamed wires, cables, wires and the like, and molding
material for tubes, films, sheets, filaments and the like.
[0034] Furthermore, FEP of this invention can significantly reduce
defects that have been a problem, such as coating broken, spark
out, generation of lumps, fluctuation of capacitance and the like
without slowing down the coating speed in extrusion coating of an
electrical wire. Therefore, this FEP is particularly used for
extrusion coating of an electrical wire. Conventional defects are
acknowledged as a problem in high speed coating at the coating
speed of from 1,000 feet/minute to 3,000 feet/minute. FEP of this
invention can be applied to the extrusion coating of an electrical
wire with few defects even in high speed molding. Furthermore, FEP
of this invention can carry tiny resin particles from an outlet of
an extruder before the tiny resin particles agglutinate to become a
lump even when the tiny resin particles generate around the outlet
in case the FEP is applied to the extrusion coating of an
electrical wire. Hence, employment of this FEP contributes to
manufacturing an electrical wire having significantly fewer lumps
than ever before. Moreover, FEP of this invention can be also
applied to extrusion molding for a foamed wire. In this case,
homogeneous foam formation (porosity) can be realized and foaming
rate can be improved. Furthermore, employment of this FEP
contributes to manufacturing a thinner foamed wire with excellent
molding stability in high speed. This is attributed to difficulty
to break foam by a core agent for foaming and difficulty to break
resin coating because of improvement of melt tension.
[0035] A conductive wire is coated with FEP of this invention to
obtain an electrical wire of this invention. Additionally, examples
of the electrical wire of this invention, without being limiting in
any particular way as long as the electrical wire is constituted
with a conductor (core wire) and FEP of this invention as coating
material, include cables, wires and the like. The electrical wire
like this can be preferably employed as an electrical insulated
wire for communication. An example of the electrical insulated wire
for communication is a cable for connecting a computer and a
peripheral device, such a cable for data transfer like LAN cable.
Such a cable is preferably used as a plenum cable wired under the
roof (plenum area) and the like. Examples of the electrical wire of
this invention include a high-frequency coaxial cable, a flat cable
and a cable with thermal resistance and the like. Among these, the
high-frequency coaxial cable is preferred. Examples of an outer
layer of the coaxial cable, without being limiting in any
particular way, include a conductive layer made of an external
conductor such as metal mesh, a resin layer (sheath layer) made
from a resin, for example, fluorine-containing copolymer having TFE
unit such as TFE/HFP copolymer, TFE/PAVE copolymer and the like,
polyvinyl chloride (abbreviated to "PVC" in the following),
polyethylene (abbreviated to "PE" in the following) and the
like.
[0036] The coaxial cable can have an outer conductive layer made
from a metal around the coated wire of this invention described
above and the resin layer (sheath layer) described above around the
outer conductive layer.
[0037] In the coated electrical wire of this invention, the coated
layer can be foamed. When the coated layer described above is
foamed, a coated electrical wire having smaller transmission loss
can be obtained. The foam body described above preferably has a
foaming rate of from 10 to 80%. The foam body described above
preferably has an average diameter of pore of from 5 to 100
.mu.m.
[0038] In this application, the foaming rate is defined as a
percentage of change of specific gravity before and after foaming,
and is the percentage of change between a specific gravity of a
material making a foamed body and an apparent specific gravity of
the fbamed body measured in water displacement method. The average
diameter of pore can be obtained from microscope photograph in
cross-section. The coating layer described above can be foamed in
well-known method. Examples of the method include, for example, (1)
method that a pellet, which is ready prepared from the FEP of this
invention added nucleating agent, is extrusion-molded with
introducing gas continually, (2) method that a chemical foaming
agent is degraded to generate gas to obtain a foamed body by
extrusion-molding the FEP of this invention which is mixed with the
chemical foaming agent while the FE of this invention is in melt
state. Examples of the nucleating agent in the method (1) described
above include well-known boron nitride (BN) and the like. Examples
of the gas described above include, for example,
chlorodifluoromethane, nitrogen, carbon dioxide, and the mixture of
these. Examples of the chemical foaming agent in the method (2)
described above include, for example, azodicarbonatnide,
4,4'-oxybis-benzenesulfortylhidradide. The conditions in each
method, such as the additive quantity of the nucleation agent and
the introduction quantity of the gas in the method (1) described
above, the additive quantity of the chemical foaming agent in the
method (2) described above and the like can be arbitrarily adjusted
depending upon kind of a resin and core cable used and a thickness
of desired coated layer.
[0039] Examples of the material for cable core for the electrical
wire of the invention, without being limiting in any particular
way, include metallic conductive material, such as copper, silver
and the like. The size of the core cable is preferably from AWG 10
to 50 in the electrical wire of this invention. The coating in the
electrical wire of this invention is FEP of the invention. This FEP
is preferably pertluoropolymer, is more preferably perfluoropolymer
constituted of TFE unit, HFP unit and PFVE unit. The thickness of
the coating is preferably from 1.0 to 40 mil in the electrical wire
of the invention.
[0040] Another coating layer can be formed on the coating layer of
FEP, another coating layer can be formed between a core cable and
the coating layer of FEP in this electrical wire of this invention.
Another coating layer can be a resin layer made from a resin, such
as TFE/PAVE copolymer, TFE/ethylene copolymer, vinylidene fluoride,
polyolefin such as PE, PVC and the like, without being limiting in
any particular way. Among these, PE and PVC are preferred from
perspective of cost. The thickness of the coating layer of FEP and
that of another coating layer can be, without being limiting in any
particular way, from 1 mil to 20 mil.
[0041] The electrical wire of this invention can be manufactured by
extrusion coating at coating speed of from 100 to 3,000
feet/minute. The FEP of this invention has little nonuniformity of
a diameter during the extrusion coating, and has the process
capability index (abbreviated to "Cp" in the following) of greater
than or equal to 1.0 in measurement of the nonuniformity of a
diameter even in the above range of extrusion coating speed.
Additionally, note that Cp measurement of the nonuniformity of a
diameter is analyzed with USYS 2000 (manufactured by Zumbach Inc.)
with a tolerance of from -0.5 mil to +0.5 mil after a core cable
with a diameter of 20.1 mil is coated with the FLP of this
invention with a single screw extruder (manufactured by Davis
Standard Inc.) for 2 hours so that the diameter of the final wire
is 34.5 mil and the outer diameter of the electrical wire is
measured with the outer diameter analyzer ODAC15XY (manufactured by
Zumbach Inc.)
[0042] The electrical wire of this invention has Cp of greater than
or equal to 1.0 in measurement of capacitance in case of a size of
core cable of from AWG 22 to 26 and a thickness of coating layer of
from 3.0 to 8.0 mil. Cp in measurement of capacitance is analyzed
with a tolerance of from -1.0 pf/inch +1.0 pf/inch after data
obtained by capacitance measurement with the capacitance analyzer
of Capac HS (Type: MR20.50HS, manufactured by Zumbach Inc.) for 2
hours are stored in USYS2000(manufactured by Zumbach Inc.).
[0043] Furthermore, there is not formation of greater than or equal
to 200 lumps with the height of from 10 to 50 mil on the electrical
wire while the electrical wire of this invention is manufactured by
extrusion coating at coating speed of from 1,000 to 3,000
feet/minute for 20 hours continuously. For example, the total
number of a lump generated is less than or equal to 20, or less
than or equal to 10 according in certain instances when a core
cable with a diameter of from 18.0 to 24.0 mil is extrusion-coated
with the FEP of this invention so that the diameter of the final
wire is from 30.0 to 40.0 mil at the speed in such range for 2
hours continuously. Note that, in this application, size (height)
and occurrence frequency of a lump are measured with the lump
detector of KW32TRIO (manufactured by Zumbach Inc,),
[0044] As mentioned above, the FEP of this invention can improve
moldability in melt extrusion molding, and can especially
significantly reduce defects in high-speed extrusion coating of an
electrical wire.
[0045] Furthermore, the FEP of this invention can realize
production of an electrical wire with smaller transmittance loss
(attenuation). Moreover, this FEP has excellent thermal resistance,
chemical resistance, solvent resistance, insulation properties,
electrical characteristics and the like. Furthermore, the coating
material of the electrical wire (including foamed wire) of this
invention is the FEP of this invention, For this reason, this
electrical wire gives few defects, and has excellent thermal
resistance, chemical resistance, solvent resistance, insulation
properties, electrical characteristics and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a cross-sectional view of an electrical wire in
accordance with the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0047] The invention is explained below in more detail with working
examples and comparative examples. Note that the invention is not
limited to these working examples only. Note that "part(s)"means
"part(s) by weight" in the following as long as there is no
definition about the word. The
tetrafluoroethylene/hexafluoropropylene copolymer(s) discussed
herein are useful in an electrical wire 1 as a coating 12 on a
conductive core 11, shown in FIG. 1, and discussed in examples
below. However, uses of the tetraftuoroethytene/hexafluoropropylene
copolymer(s) should not be limited by this disclosure. Moreover,
the specific examples of electrical wires disclosed herein should
not limit the present invention.
Working Example 1
Synthesis Example 1
[0048] 8163.5 lbs. of deionized water (including 3.5 lbs. of
ammonium .omega.-hydroxyfluorocarbonate) was added into a
glass-lined autoclave with an agitator (12,000 L volume), After
that, the autoclave was vacuumed and filled with nitrogen gas well.
After this, after the autoclave was vacuumed, 8459 lbs. of HFP was
added into the autoclave. While the deionized water and HFP were
agitated vigorously in the autoclave, the inner temperature was set
at 89.6 F and 950 lbs. of TFE and 92 lbs. of PPVE were added into
the autoclave. Next, the inner pressure of the autoclave was set at
150.6 psi, and 51.8 lbs. of 8 wt % di(w-hydroperfluorohexanoyl)
peroxide (abbreviated to "DHP" in the following) perfluorohexane
solution was added into the autoclave to initiate polymerization,
51.8 lbs. of 8 wt % DHP perfluorohexane solution was added into the
autoclave, and 1.7 psig of the inner pressure was reduced 2 hours
later and 4 hours later from the initiation of the polymerization.
Furthermore, 39.8 lbs. of 8wt % DHP perfluorohexane solution was
added into the autoclave, and 1.7 psig of the inner pressure was
reduced 6 hours later, 8 hours later and 10 hours later from the
initiation of the polymerization. Moreover, 2.5 psig of the inner
pressure was reduced respectively in ninth and twelfth addition of
DIP perfluorohexane solution counted from the addition of DHP
perfluorohexane solution at the initiation of polymerization. Note
that TFE was continuously charged into the autoclave during the
polymerization, 21.1 lbs. of PPVE was added into the autoclave
respectively at the time that the total quantity of TEE reached
1,6.40 lbs., 3,280 lbs. and .4,920 lbs. After a small quantity of
sample was collected from the autoclave at the time that the
further additional quantity of TFE reached 1,280 lbs., the sample
was dried to obtain 100 grams of dry powder, and the melt flow rate
at 372 degree C. of the dry powder was measured. The value of the
melt flow rate was 2.0 grams/10 minutes. Furthermore, the quantity
of polymer at this time corresponds to 16.8 wt % of the quantity of
the polymer at the end of the polymerization. Moreover, the melting
point of the dry powder was 256.2 degree C. After this, 85 lbs. of
methanol was added into the autoclave to adjust the molecular
weight.
[0049] Furthermore, after a small quantity of sample was collected
from the autoclave at the time that the further additional quantity
of TFE reached 4,100 lbs. and 5,740 lbs., the samples were dried to
obtain 100 grams of dry powder respectively, and the melting point
of the dry powders was measured. The melting point of the dry
powder at the time that the further additional quantity of TFE
reached 4,100 lbs. was 257.2 degree C. The melting point of the dry
powder at the time that the further additional quantity of TFE
reached 5,740 tbs. was 257.8 degree C. The polymerization was
terminated when the total quantity of TFE reached 7,600 lbs. After
the termination of the polymerization, unreacted TFE and HFP were
released from the autoclave to obtain wet powder. Water was added
to the wet powder to wash it in agitation. After this, the wet
powder was dried at 150 degree C. for 10 hours to obtain 8,800 lbs.
of dry powder. The melt flow rate at 372 degree C. of the dry
powder was 14.2 grams/10 minutes. Furthermore, the melting point of
the dry powder was 256.8 degree C. After this, after the dry powder
was pelletized at 370 degree C. with a twin screw extruder, the
&aeration of the pellet was carried out at 200 degree C. for 8
hours. The melt flow rate at 372 degree C. of the pellet was 22.9
grams/10 minutes. Measurement of properties
(1) Measurement of Basic Properties
[0050] Note that the basic properties of the FEP obtained from the
synthesis example 1 as above mentioned was measured by the method
described below.
(a) Melting Point
[0051] A melting point was determined from a peak of endothermic
curve obtained by thermal measurement at a temperature increase
rate of 10 degree Clminute with differential scanning calorimeter
of RDC220 (manufactured by Seiko Instruments Inc.) in conformity
with ASTM D-4591.
(b) Melt Flow Rate (MFR)
[0052] The melt flow rate is measured with a melt index tester
(manufactured by Toyo Seiki Seisaku-sho, Ltd) in conformity with
the ASTM D1238-98. First, approximately 6 g of a resin is inserted
into a cylinder maintained at 372 degree C. The cylinder is left
for 5 minutes to reach thermal equilibrium. After that, the resin
is extruded through an orifice with a diameter of 2 mm and a length
of 8 mm applying piston load of 5 kg to the cylinder to measure
quantity (gram) of the resin extruded per certain time (normally
from 10 to 60 seconds). The measurement is repeated three times
about the same samples, The extrusion quantity per 10 minutes
converted from the average of the measurement values (unit: g/10
minutes) is regarded as the final measurement value.
(c) Composition
[0053] The composition was determined from integration values at
each peak obtained from .sup.19F-NMR measurement at a temperature
of (melting point of polymer +20) degree C. with a nuclear magnetic
resonance apparatus of AC300 (manufactured by BRUKER-BIOSPIN Co.,
Ltd)
[0054] As a result, the composition of the FEP of the synthesis
example 1 described above was TFE 87.9: HFP 11.1: PPVE 1M in weight
ratio.
(d) Melt Tension
[0055] Approximately 50 grams of FEP of the synthesis example 1
described above was inserted into a cylinder with an inner diameter
of 15 mm maintained within 385 degree C. +/-0.5 degree C. The
cylinder was left for 10 minutes to even out the temperature in the
FEP. After that, a strand was obtained by extruding the FEP through
an orifice with an inner diameter of 2 mm (tolerance: less than or
equal to 0.002 mm) and a length of 20 min at share rate of 36.5
(1./sec) in a Capilograph (manufactured by ROSAND inc). Next, this
strand was passed to the pulley just under the outlet of the
orifice at a distance of 45 cm from the outlet of the orifice, and
was pulled obliquely upward at an angle of 60 degree, and was wound
on the roller approximately on a lewd. with the outlet of the
orifice. The melt tension was defined as the maximum value of the
values of tension measured under the condition that the take-up
speed of the roller was increased from 5 m/minute to 500 m/minute
for 5 minutes. As a result, the melt tension of the FEP of the
synthesis example 1 described above was 0.11 N.
(e) Complex Viscosity and Storage Modulus
[0056] First, the FEP of the synthesis example I was molded into a
cylindrical column with a diameter of 25 mm and a thickness of 1.5
mm (this molded body is called "sample" in the following). The
sample was placed on a parallel plate of a melt viscoelasticity
analyzer (MCR-500 manufactured by Physica, Inc.). Melt
viscoelasticity of the sample was measured at 310 degree C. by
frequency dispersion with the range of an angular frequency of 100
radian/second to 0.01 radian/second. The value of complex viscosity
and storage modulus was defined as the value at the angular
frequency of 0.01 radian/second. As a result, the complex viscosity
of the FEP of the synthesis example 1 described above was
3.35.times.10.sup.3 Pa*s, and the storage modulus was 0.38.
(2) Online Evaluation for Extrusion Coating
[0057] Next, extrusion coating an electrical wire was carried out
using the FEP of the synthesis example 1 described above as a
coating material. Some online measurements were performed as
described below during the extrusion coating of the electrical
wire.
[0058] The condition for the extrusion coating an electrical wire
is the following.
a) Conductive core: a low-carbon steel wire, AWG24 (American Wire
Gauge), diameter of the wire: 20.1 mil
[0059] b) Coating thickness: 7.2 mil
[0060] c) Diameter of a coated electrical wire: 34.5 mil
[0061] d) Take-over speed of an electrical wire: 1,800
feet/minute
[0062] e) Condition for melt molding (extrusion)
[0063] * Diameter of a shaft of cylinder=2 inches. Single screw
extruder with LID of 30
[0064] * Die (inner diameter)/tip (external shape)=8.71 nm/4.75
mm
[0065] * Preset temperature of the extruder: barrel part of Z1 (338
degree C.), barrel part of Z2 (360 degree C.), barrel part of Z3
(371 degree C.), barrel part of Z4 (382 degree C.), barrel part of
Z5 (399 degree C.), clamp part (404 degree C.), adapter part (404
degree C), crosshead part (404 degree c), die part (404 degree C.),
preheating temperature for a core cable (140 degree C.)
[0066] * length of a melt cone during the extrusion coating=from
3.7 to 4.0 mm
(a) Measurement of Spark Out
[0067] The number of occurrence of a spark on an uncoated part of
the extrusion coated wire chilled in an air cooling zone and a
water cooling zone with a length of approximately 6 meters was
measured with a Spark detector (Model HF-20-H manufactured by
CLINTON INSTRUMENT COMPANY) at a voltage of 2.0 kv for 2 hours
continually. As a result, the number of occurrence of a spark was 0
per 2 hours when the FEP of the synthesis example 1 described above
was used as a coating material.
(b) Measurement of Size (Height) and Frequency of Occurrence of a
Lump
[0068] Size (height) and frequency of occurrence of a lump were
measured with a lump detector of KW32TRIO (manufactured by Zumbach.
Inc.) for 2 hours continually. As a result, the generation status
of the lump in case that the FEP of the synthesis example 1
described above was used as a coating material shown in table
1.
TABLE-US-00001 TABLE 1 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 5 than 20 mil More
than or equal to 20 mil, less 1 than 30 mil More than or equal to
30 mil, less 1 than 40 mil More than or equal to 40 mil, less 1
than 50 mil
(c) Measurement of Nonuniformity of a Diameter of Extrusion Coated
Wire
[0069] The outer diameter (OD) of the extrusion coated wire was
measured with an outer diameter measuring instrument of ODAC 15XY
(manufactured by Zumbach Inc.) for 2 hours continually. The
stability of the diameter of the extrusion coated wire was defined
as a process capability index (abbreviated to "Cp" in the
following). Note that Cp was analyzed with USYS 2000 (manufactured
by Zumbach Inc.) from data of the outer diameter measured under the
condition that an upper limit for a diameter of a wire (USL) was
set 0.5 mil higher than the extrusion coated wire described above
with a diameter of 34.5 mil and a lower limit for the diameter of
the wire (LSL) was set 0.5 mil lower than the extrusion coated wire
described above. As a result, the stability of the diameter of the
extrusion coated wire (Cp) in case that the VET of the synthesis
example 1 described above was used as a coating material was
1.3.
(d) Measurement of Nonuniformity of a Capacitance
[0070] The capacitance of the extrusion coated wire was measured
with a capacitance measuring instrument of Capac HS (Type:
MR20.50HS manufactured by Zumbach Inc.) for 2 hours continually.
The stability of the capacitance of the extrusion coated wire was
defined as a process capability index (Cp). Note that Cp was
analyzed under the condition that an upper limit (LSI) was set +1.0
pf/inch and a lower limit (LSL) was set -1.0 pf/inch after data was
stored into USYS 2000 (manufactured by Zumbach Inc.) sequentially.
As a result, the stability of the capacitance of the extrusion
coated wire (Cp) in case that the FIT of the synthesis example 1
described above was used as a coating material was 1.6.
(e) Generation Quantity of Die-Drool
[0071] Generation quantity of Die-Drool was determined by visual
observation for 2 hours continually. As a result, generation of
Die-Drool was very few while the FEP of the synthesis example 1
described above was used as a coating material.
Working Example 2
Synthesis Example 2
[0072] After the pellet obtained in the synthesis example 1 was
inserted into a vacuum vibration type reactor of VVD-30
(manufactured by OKAWARA MFG.CO., LTD.), the pellet was heated to
200 degree C. After the reactor was vacuumed, F.sub.2 gas diluted
by 20 wt % with N.sub.2 gas was introduced into the reactor up to
the atmospheric pressure. F.sub.2 gas was introduced again after
the reactor was vacuumed three hours later from the first
introduction of F.sub.2 gas. The operation of the F.sub.2 gas
introduction described above and vacuuming was carried out 6 times.
After the reaction was completed, F.sub.7 gas in the reactor was
replaced with N.sub.2 gas and deaeration of the pellet was carried
out at 180 degree C. for 8 hours. The composition of the pellet
after the reaction was TFE 87.9: HFP 11.1: PPVE 1.0 in weight. The
melting point was 256.8 degree C. The MFR at 372 degree C. was 23.5
g/10 minutes. The sum of the number of thermally unstable end group
and the number of --CF.sub.2H end group per 1.times.10.sup.6 carbon
atoms was 0. The dielectric constant was 2.00. The dielectric
tangent was 3.8.times.10.sup.-4.
[0073] Moreover, the melt tension was 0.11 N, the complex viscosity
was 3.30.times.10.sup.3 Pa*s, and the storage modulus was 0.36.
Production Example 1
[0074] Wire coating was carried out using the FEP of the synthesis
example 2 described above as an insulating coating material (core
material). After this, a single braid was formed onto the FEP and
then the FEP of the synthesis example 2 as a protective coating
(sheath material) was coated onto the single braid to prepare a
coaxial cable of RF113.
[0075] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, LP.). As a result, the attenuation was 5.1 dB/meter at 6
GHz.
[0076] The condition for the extrusion coating an electrical wire
(core material) is the following.
[0077] a) Conductive core: copper coated with silver (7/0.08 mm
twisted conductive wire)
[0078] b) Coating thickness: 0.23 mm
[0079] c) Diameter of an insulated electrical wire: 0.7 mm
[0080] d) Take-over speed of an electrical wire: 60
meters/minute
[0081] e) Condition for melt molding (extrusion)
[0082] * Diameter of shaft of cylinder=2 inches
[0083] * rotational speed of screw: 10 rpm
[0084] * Preset temperature of the extruder: barrel part of Z1 (325
degree C.), barrel part of Z2 (340 degree C.), barrel part of Z3
(350 degree C.), barrel part of Z4 (365 degree C.), barrel part of
Z5 (370 degree C.), clamp part (380 degree C.), adapter part (380
degree C.), crosshead part (380 degree C.), die part (370 degree
C.), preheating temperature for a core cable (140 degree C.)
Measuring Method for the Number of the Thermally Unstable End
Group
[0085] A film with a thickness of approximately 0.3 mm was prepared
by extending the pellet by applying pressure with a hydraulic
press. The film was analyzed with the FT-IR Spectrometer 1760X
(manufactured by Perkin-Elmer Inc.),
[0086] A differential spectrum between a reference (a sample
fluorinated enough until any substantial difference of spectrums
between samples was not able to be seen) and a sample was obtained.
Absorbance of each peak was read and then the number of thermally
unstable end group per 1.times.10.sup.6 carbon atoms was calculated
from the following formula. The number of thermally unstable end
group per 1.times.10.sup.6 carbon atoms.times.1.times.K)/t (I;
absorbance, K; correction coefficient, t; thickness of film
(unit:mm))
[0087] The correction coefficient (K) for each thermally unstable
end group is described below.
TABLE-US-00002 --COF (1,884 cm.sup.-1) 405 --COOH (1,813 cm.sup.-1,
1,775 cm.sup.-1) 455 --COOCH.sub.3 (1,795 cm.sup.-1) 355
--CONH.sub.2 (3,438 cm.sup.-1) 480 --CH.sub.2OH (3,648 cm.sup.-1)
2,325
Measuring Method for the Number of the --CF.sub.2H End Group
[0088] The number of the --CF.sub.2H end group was determined from
the integration value at the peak derived from the --CF.sub.2H end
group and the integration value at another peak obtained from
.sup.19F-NMR. measurement at a temperature of (melting point of
polymer+20) degree C. with a nuclear magnetic resonance apparatus
of AC300 (manufactured by BRUKER-BIOSPIN Co., Ltd)
Measuring Method for Dielectric Constant and Dielectric Tangent
[0089] A cylindrical test piece with a diameter of 2.3 mm and a
length of 80 mm was prepared by melt extrusion at 280 degree C. The
electrical characteristics at 6.0 GHz of the test piece was
measured with a network analyzer (manufactured by Kantoh
Electronics Application and Development Inc.) in the cavity
resonance perturbation method (test temperature: 25 degree C.).
WORKING EXAMPLE 3
Synthesis Example 3
[0090] The FEP was synthesized in the same manner as in the
synthesis example 1. Then, in the same manner as in the synthesis
example 1, the melt flow rate at 372 degree C. of the dry powder
was measured at the time that the further additional quantity of
TFE reached 1,280 lbs. The value of the melt flow rate was 2.2
grams/10 minutes. Moreover, the melting point of the dry powder was
255.7 degree C. After this, 105 lbs. of methanol was added into the
autoclave to adjust the molecular weight.
[0091] Furthermore, in the same manner as in the synthesis example
1, after a small quantity of sample was collected from the
autoclave at the time that the further additional quantity of TEE
reached 4,100 lbs. and 5,740 lbs., the samples were dried to obtain
100 grams of dry powder respectively, and the melting point of the
dry powders was measured. The melting point of the dry powder at
the time that the further additional quantity of TFE reached 4,100
lbs. was 255.4 degree C. The melting point of the dry powder at the
time that the further additional quantity of TFE reached 5,740 lbs.
was 256.8 degree C.
[0092] Additionally, dry power was obtained at the end of the
polymerization in the same manner as in the synthesis example 1,
and the melt flow rate at 372 degree C. of the dry powder was
measured to be 24.0 grams/10 minutes. Furthermore, the melting
point of the dry powder was 256.4 degree C.
[0093] After this, after the dry powder was pelletized at 396
degree C. with a single screw extruder, and the deaeration of the
pellet was carried out at 200 degree C. for 8 hours. The melt flow
rate at 372 degree C. of the pellet was 26.7 grams11.0 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0094] Note that the basic properties of the FEP obtained from the
synthesis example 3 was measured by the measuring method shown in
the working example 1.The composition of the FEP of the synthesis
example 3 was TFE 87.9: HFP 11.1: PPVE 1.0 in weight ratio as is
the same as the composition of the FEP of the synthesis
example.
[0095] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the synthesis example 3
were also determined in the same manner as in the working example
1. As a result, the melt tension was 0.13N, the complex viscosity
was 4.78.times.10.sup.3 Pa*s, and the storage modulus was 1.12.
(2) Online Evaluation for Extrusion Coating
[0096] Extrusion coating an electrical wire was carried out using
the FEP of the synthesis example 3 in the same manner as in the
working example 1. After this, evaluation for the extrusion coating
was carried out in the same manner as in the working example 1. As
a result, the frequency of occurrence of a lump was shown in table
2. The stability of the diameter of the extrusion coated wire (Cp)
was 1.2. The stability of the capacitance of the extrusion coated
wire (Cp) was 1.3. Generation of Die-Drool was very few.
TABLE-US-00003 TABLE 2 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 4 than 20 mil More
than or equal to 20 mil, less 0 than 30 mil More than or equal to
30 mil, less 1 than 40 mil More than or equal to 40 mil, less 1
than 50 mil
WORKING EXAMPLE 4
[0097] Synthesis Example 4
[0098] The pellet was treated in the same as in the synthesis
example 2 except that the pellet obtained in the synthesis example
1 was replaced with the pellet obtained in the synthesis example
3.
[0099] The composition of the pellet after the reaction was TFE
87.9: HFP 11.1: PPVE 1.0 in weight. The melting point was 255.8
degree C. The MFR at 372 degree C. was 27.5 g/10 minutes. The sum
of the number of thermally unstable end group and the number of
--CF.sub.2H end group per 1.times.10.sup.6 carbon atoms was 0. The
dielectric constant was 2.02. The dielectric tangent was
3.8.times.10.sup.-4.
[0100] Moreover, the melt tension was 0.13 N, the complex viscosity
was 4.63.times.10.sup.3 Pa*s, and the storage modulus was 1.08.
[0101] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example 1.
Production Example 2
[0102] A coaxial cable of RF113 was prepared in the same manner as
in the production example 1 except that the FEP of the synthesis
example 2 was replaced with the FEP of the synthesis example 4.
[0103] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, L.P.). As a result, the attenuation was 5.2 dB/meter at 6
GHz.
WORKING EXAMPLE 5
Synthesis Example 5
[0104] The FEP was synthesized in the same manner as in the
synthesis example 1. Then, in the same manner as in the synthesis
example 1, the melt flow rate at 372 degree C. of the dry powder
was measured at the time that the further additional quantity of
TFE reached 1,280 lbs. The value of the melt flow rate was 2.8
grams/10 minutes. Moreover, the melting point of the dry powder was
255.6 degree C. After this, 90 lbs. of methanol was added into the
autoclave to adjust the molecular weight.
[0105] Furthermore, in the. same manner as in the synthesis example
1, after a small quantity of sample was collected from the
autoclave at the time that the further additional quantity of TEE
reached 4,100 lbs. and 5,740 lbs., the samples were dried to obtain
100 grams of dry powder respectively, and the melting point of the
dry powders was measured, The melting point of the dry powder at
the time that the further additional quantity of TFE reached 4,100
lbs. was 258.4 degree C. The melting point of the dry powder at the
time that the further additional quantity of TFE reached 5,740 lbs.
was 257.8 degree C.
[0106] Additionally, at the end of the polymerization, dry powder
was obtained in the same manner as in the synthesis example 1. The
melt flow rate at 372 degree C. of the dry powder was 15.1 grams/10
minutes. Furthermore, the melting point of the dry powder was 258.7
degree C.
[0107] After this, after the dry powder was pelletized at 380
degree C. with a twin screw extruder, and the deaeration of the
pellet was carried out at 200 degree C. for 8 hours. The melt flow
rate at 372 degree C. of the pellet was 29.6 grams/1.0 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0108] Note that the basic properties of the FEP obtained from the
synthesis example 5 was measured by the measuring method shown in
the working example 1. The composition of the FEP of the synthesis
example 5 was TFE 88.0: HFP 11.0: PPVE 1.0 in weight ratio.
[0109] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the synthesis example 5
were also determined as in the same manner as in the working
example 1. As a result, the melt tension was 0.09N, the complex
viscosity was 3.14.times.10.sup.3 Pa*s, and the storage modulus was
0.15.
(2) Online Evaluation for Extrusion Coating
[0110] Extrusion coating an electrical wire was carried out using
the FEP of the synthesis example 5 in the same manner as in the
working example 1. After this, evaluation for the extrusion coating
was carried out in the same manner as in the working example 1. As
a result, the frequency of occurrence of a lump was shown in table
3. The stability of the diameter of the extrusion coated wire (Cp)
was 1,4. The stability of the capacitance of the extrusion coated
wire (Cp) was 1.5. Generation of Die-Drool was very few.
TABLE-US-00004 TABLE 3 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 10 than 20 mil More
than or equal to 20 mil, less 2 than 30 mil More than or equal to
30 mil, less 1 than 40 mil More than or equal to 40 mil, less 1
than 50 mil
Working Example 6
Synthesis Example 6
[0111] The pellet was treated in the same as in the synthesis
example 2 except that the pellet obtained in the synthesis example
1 was replaced with the pellet obtained in the synthesis example
5.
[0112] The composition of the pellet after the reaction was TEE
88.0: HEP 11.0: PPVE 1.0 in weight. The melting point was 257.8
degree C. The MFR at 372 degree C. was 29.9 g/10 minutes. The sum
of the number of thermally unstable end group and the number of
--CF.sub.2H end group per 1.times.10.sup.6 carbon atoms was 0. The
dielectric constant was 2.03. The dielectric tangent was
3.9.times.10.sup.-4.
[0113] Moreover, the melt tension was 0.09 N, the complex viscosity
was 3.08.times.10.sup.3 Pa*s, and the storage modulus was 0.14.
[0114] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example 1.
Production Example 3
[0115] A coaxial cable of RF113 was prepared in the same manner as
in the production example 1 except that the FEP of the synthesis
example 6 was used as an insulating coating material (core
material) and the FEP of the synthesis example 6 was used as a
protective coating (sheath material).
[0116] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewitt-Packard Development
Company, L.P.). As a result, the attenuation was 5.2 dB/meter at 6
GHz.
Working Example 7
Synthesis Example 7
[0117] The FEP was synthesized in the same manner as in the
synthesis example 1 except that the inner pressure of the autoclave
before 51.8 lbs, of 8 wt % DHP perfluorohexane solution was added
thereinto was set at 152.1 psi. Then, in the same manner as in the
synthesis example 1, the melt flow rate at 372 degree C. of the
powder was measured at the time that the further additional
quantity of TFE reached 1,280 lbs. The value of the melt flow rate
was 1.0 grams/10 minutes. Moreover, the melting point of the dry
powder was 258.5 degree C. After this, 115 lbs. of methanol was
added into the autoclave to adjust the molecular weight.
[0118] Furthermore, after a small quantity of sample was collected
from the autoclave at the time that the further additional quantity
of TFE reached 4,100 lbs. and 5,740 lbs., the samples were dried to
obtain 100 grams of dry powder respectively, and the melting point
of the dry powders was measured. The melting point of the dry
powder at the time that the further additional quantity of TFE
reached 4,100 lbs. was 256.4 degree C. The melting point of the dry
powder at the time that the further additional quantity of TFE
reached 5,740 lbs. was 255.8 degree C.
[0119] Additionally, dry power was obtained at the end of the
polymerization in the same manner as in the synthesis example 1,
and the melt flow rate at 372 degree C. of the dry powder was
measured to be 27,1 grams/1.0 minutes. Furthermore, the melting
point of the dry powder was 255.6 degree C.
[0120] After this, in the same manner as in the synthesis example
1, after the dry powder was pelletized at 370 degree C. with a twin
screw extruder, and the deaeration of the pellet was carried out at
200 degree C. for 8 hours. The melt flow rate at 372 degree C. of
the pellet was 35.0 grams/10 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0121] Note that the basic properties of the FEP obtained from the
synthesis example 7 was measured by the measuring method shown in
the working example 1. The composition of the FEP of the synthesis
example 7 was TFE 87.8: HFP 11.2: PPVE 1.0 in weight ratio,
[0122] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the synthesis example 7
were also determined in the same manner as in the working example
1. As a result, the melt tension was 0.12N, the complex viscosity
was 3.01.times.10.sup.3 Pa*s, and the storage modulus was 0.45.
(2) Online Evaluation for Extrusion Coating
[0123] Extrusion coating an electrical wire was carried out using
the FEP of the synthesis example 7 in the same manner as in the
working example 1. After this, evaluation for the extrusion coating
was carried out in the same manner as in the working example 1. As
a result, the frequency of occurrence of a lump was shown in table
4. The stability of the diameter of the extrusion coated wire (Cp)
was 1.1. The stability of the capacitance of the extrusion coated
wire (CP) was 1.1, Generation of Die-Drool was very few.
TABLE-US-00005 TABLE 4 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 7 than 20 mil More
than or equal to 20 mil, less 3 than 30 mil More than or equal to
30 mil, less 2 than 40 mil More than or equal to 40 mil, less 1
than 50 mil
Working Example 8
Synthesis Example 8
[0124] The pellet was treated in the same as in the synthesis
example 2 except that the pellet obtained in the synthesis example
1 was replaced with the pellet obtained in the synthesis example
7.
[0125] The composition of the pellet after the reaction was TFE
87.8: HFP 11.2: PPVE 1.0 in weight. The melting point was 255.0
degree C. The MFR at 372 degree C. was 36.1 g/10 minutes. The sum
of the number of thermally unstable end group and the number of
--CF.sub.2H end group per 1.times.10.sup.6 carbon atoms was 0. The
dielectric constant was 2.03. The dielectric tangent was
3.9.times.10.sup.-1.
[0126] Moreover, the melt tension was 0.12 N, the complex viscosity
was 2.89.times.10.sup.3 Pa*s, and the storage modulus was 0.43.
[0127] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example 1.
Production Example 4
[0128] A coaxial cable of RF113 was prepared in the same manner as
in the production example 1 except that the FEP of the synthesis
example 2 was replaced with the FEP of the synthesis example 8.
[0129] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, L.P.). As a result, the attenuation was 5.2 dB/meter at 6
GHz.
Working Example 9
Synthesis Example 9
[0130] The FEP was synthesized in the same manner as in the
synthesis example 1. Then, in the same manner as in the synthesis
example 1, the melt flow rate at 372 degree C. of the dry powder
was measured at the time that the further additional quantity of
TFE reached 1,280 lbs. The value of the melt flow rate was 2.3
grams/10 minutes. Moreover, the melting point of the dry powder was
257.8 degree C. After this, 90 lbs. of methanol was added into the
autoclave to adjust the molecular weight.
[0131] Furthermore, in the same manner as in the synthesis example
1, after a small quantity of sample was collected from the
autoclave at the time that the further additional quantity of TEE
reached 4,100 lbs. and 5,740 lbs., the samples were dried to obtain
100 grams of dry powder respectively, and the melting point of the
dry powders was measured. The melting point of the dry powder at
the time that the further additional quantity of TFE reached 4,100
lbs. was 256.5 degree C. The melting point of the dry powder at the
time that the further additional quantity of TEE reached 5,740 lbs.
was 255.0 degree C.
[0132] Additionally, dry power was obtained at the end of the
polymerization in the same manner as in the synthesis example it,
and the melt flow rate at 372 degree C. of the dry powder was
measured to be 15.5 grams/10 minutes. Furthermore, the melting
point of the dry powder was 254.9 degree C.
[0133] After this, after the dry powder was pelletized at 404
degree C. with a single screw extruder, and the deaeration of the
pellet was carried out at 200 degree C. for 8 hours. The melt flow
rate at 372 degree C. of the pellet was 20.0 grams/10 minutes.
Measurement of Properties
Measurement of Basic Properties
[0134] Note that the basic properties of the EH) obtained from the
synthesis example 9 was measured by the measuring method shown in
the working example 1.The composition of the FEP of the synthesis
example 9 was TFE 87.8: REP 11.2: PPVE 1.0 in weight ratio.
[0135] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the synthesis example 9
were also determined in the same manner as in the working example
1. As a result, the melt tension was 0.13N, the complex viscosity
was 5.98.times.10.sup.3 Pa*s, and the storage modulus was 1.01.
(2) Online Evaluation for Extrusion Coating
[0136] Extrusion coating an electrical wire was carried out using
the FEP of the synthesis example 9 in the same manner as in the
working example 1. After this, evaluation for the extrusion coating
was carried out in the same manner as in the working example 1. As
a result, the frequency of occurrence of a lump was shown in table
5. The stability of the diameter of the extrusion coated wire (Cp)
was 1.1. The stability of the capacitance of the extrusion coated
wire (Cp) was 2. Generation of Die-Drool was very few.
TABLE-US-00006 TABLE 5 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 6 than 20 mil More
than or equal to 20 mil, less 0 than 30 mil More than or equal to
30 mil, less 0 than 40 mil More than or equal to 40 mil, less 2
than 50 mil
Working Example 10
Synthesis Example 10
[0137] The pellet was treated in the same as in the synthesis
example 2 except that the pellet obtained in the synthesis example
1 was replaced with the pellet obtained in the synthesis example
9.
[0138] The composition of the pellet after the reaction was TFE
87.8: HFP 11.2: PPVE 1.0 in weight. The melting point was 255.0
degree C. The MFR at 372 degree C. was 20.6 g/10 minutes. The sum
of the number of thermally unstable end group and the number of
--CF.sub.2H end group per 1.times.10.sup.6 carbon atoms was 0. The
dielectric constant was 2.00. The dielectric tangent was
3.8.times.10.sup.-4.
[0139] Moreover, the melt tension was 0.13 N, the complex viscosity
was 5.71.times.10.sup.3 Pa*s, and the storage modulus was 0.95.
[0140] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example 1.
Production Example 5
[0141] A coaxial cable of RF113 was prepared in the same manner as
in the production example I except that the FEP of the synthesis
example 2 was replaced with the FEP of the synthesis example
10.
[0142] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, L.P.). As a result, the attenuation was 5.1 dB/meter at 6
GHz.
Working Example 11
Synthesis Example 11
[0143] The FEP was synthesized in the same manner as in the
synthesis example 1. Then, in the same manner as in the synthesis
example 1, the melt flow rate at 372 degree C. of the dry powder
was measured at the time that the further additional quantity of
TFE reached 1,280 lbs. The value of the melt flow rate was 2.5
grams/10 minutes. Moreover, the melting point of the dry powder was
256.7 degree C. After this, 95 lbs. of methanol was added into the
autoclave to adjust the molecular weight.
[0144] Furthermore, in the same manner as in the synthesis example
1, after a small quantity of sample was collected from the
autoclave at the time that the further additional quantity of TFE
reached .4,100 lbs. and 5,740 lbs., the samples were dried to
obtain 100 grams of dry powder respectively, and the melting point
of the dry powders was measured. The melting point of the dry
powder at the time that the further additional quantity of T FE
reached 4,100 lbs. was 254.8 degree C. The melting point of the dry
powder at the time that the further additional quantity of TEE
reached 5,740 lbs. was 255.5 degree C.
[0145] Additionally, dry power was obtained at the end of the
polymerization in the same manner as in the synthesis example 1,
and the melt flow rate at 372 degree C. of the dry powder was
measured to be 16,1 grams/10 minutes. Furthermore, the melting
point of the dry powder was 256.9 degree C.
[0146] After this, after the dry powder was pelletized at 396
degree C. with a single screw extruder, and the deaeration of the
pellet was carried out at 200 degree C. for 8 hours. The melt flow
rate at 372 degree C. of the pellet was 18.2 grams/10 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0147] Note that the basic properties of the FEP obtained from the
synthesis example 11 was measured by the measuring method shown in
the working example 1,The composition of the FEP of the synthesis
example 11 was TFE 87.9: HEP 11.1: PPVE 1.0 in weight ratio.
[0148] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the synthesis example 11
were also determined in the same manner as in the working example
1. As a result, the melt tension was 0.14N, the complex viscosity
was 6.75.times.10.sup.3 Pa*s, and the storage modulus was 1.30.
(2) Online Evaluation for Extrusion Coating
[0149] Extrusion coating an electrical wire was carried out using
the FEP of the synthesis example 11 in the same manner as in the
working example 1. After this, evaluation for the extrusion coating
was carried out in the same manner as in the working example 1. As
a result, the frequency of occurrence of a lump was shown in table
6. The stability of the diameter of the extrusion coated wire (Cp)
was 1.1. The stability of the capacitance of the extrusion coated
wire (Cp) was 1.1. Generation of Die-Drool was very few.
TABLE-US-00007 TABLE 6 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 5 than 20 mil More
than or equal to 20 mil, less 2 than 30 mil More than or equal to
30 mil, less 1 than 40 mil More than or equal to 40 mil, less 2
than 50 mil
Working Example 12
[0150] Synthesis example 12
[0151] The pellet was treated in the same as in the synthesis
example 2 except that the pellet obtained in the synthesis example
1 was replaced with the pellet obtained in the synthesis example
11.
[0152] The composition of the pellet after the reaction was TEE
87.9: HFP 11.1: PPVE 1.0 in weight. The melting point was 255.1
degree C. The MFR at 372 degree C. was 18.5 g/10 minutes. The sum
of the number of thermally unstable end group and the number of
--CF.sub.2H end group per 1.times.10.sup.6 carbon atoms was 0. The
dielectric constant was 2.00. The dielectric tangent was
3.8.times.10.sup.-4.
[0153] Moreover, the melt tension was 0.14 N, the complex viscosity
as 6.50.times.10.sup.3 Pa*s, and the storage modulus was 1.21.
[0154] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example 1.
Production Example 6
[0155] A coaxial cable of RF113 was prepared in the same manner as
in the production example 1 except that the FEP of the synthesis
example 2 was replaced with the FEP of the synthesis example
12.
[0156] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, L.P.). As a result, the attenuation was 5.1 dB/meter at 6
GHz.
Working Example 13
[0157] Synthesis Example 13
[0158] The FEP was synthesized in the same manner as in the
synthesis example 1. Then, in the same manner as in the synthesis
example 1, the melt flow rate at 372 degree C. of the dry powder
was measured at the time that the further additional quantity of
TEE reached 1,280 lbs. The value of the melt flow rate was 1.9
grams/10 minutes. Moreover, the melting point of the dry powder was
256.1 degree C. After this, 95 lbs. of methanol was added into the
autoclave to adjust the molecular weight.
[0159] Furthermore, in the same manner as in the synthesis example
1, after a small quantity of sample was collected from the
autoclave at the time that the further additional quantity of TEE
reached 4,100 lbs. and 5,740 lbs., the samples were dried to obtain
100 grams of dry powder respectively, and the melting point of the
dry powders was measured. The melting point of the dry powder at
the time that the further additional quantity of TFE reached 4,100
lbs. was 255.7 degree C. The melting point of the dry powder at the
time that the further additional quantity of TFE reached 5,740 lbs.
was 254.8 degree C.
[0160] Additionally, dry power was obtained at the end of the
polymerization in the same manner as in the synthesis example 1,
and the melt flow rate at 372 degree C. of the dry powder was
measured to be 17,0 grams/10 minutes. Furthermore, the melting
point of the dry powder was 256.1 degree C.
[0161] After this, after the dry powder was pelletized at 370
degree C. with a twin screw extruder, and the deaeration of the
pellet was carried out at 200 degree C. for 8 hours. The melt flow
rate at 372 degree C. of the pellet was 24.5 grams/10 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0162] Note that the basic properties of the FEP obtained from the
synthesis example 13 was measured by the measuring method shown in
the working example 1. The composition of the FEP of the synthesis
example 13 was TFE 87.9: HFP 11.1: PPVE 1.0 in weight ratio.
[0163] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the synthesis example 13
were also determined in the same manner as in the working example
1. As a result, the melt tension was 0.12N, the complex viscosity
was 4.06.times.10.sup.3 Pa*s, and the storage modulus was 0.61.
(2) Online Evaluation for Extrusion Coating
[0164] Extrusion coating an electrical wire was carried out using
the FEP of the synthesis example 13 in the same manner as in the
working example 1. After this, evaluation for the extrusion coating
was carried out in the same manner as in the working example 1. As
a result, the frequency of occurrence of a lump was shown in table
7. The stability of the diameter of the extrusion coated wire (Cp)
was 1.2. The stability of the capacitance of the extrusion coated
wire (Cp) was 1.4. Generation of Die-Drool was very few.
TABLE-US-00008 TABLE 7 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 6 than 20 mil More
than or equal to 20 mil, less 1 than 30 mil More than or equal to
30 mil, less 2 than 40 mil More than or equal to 40 mil, less 0
than 50 mil
Working Example 14
Synthesis Example 14
[0165] The pellet was treated in the same as in the synthesis
example 2 except that the pellet obtained in the synthesis example
1 was replaced with the pellet obtained in the synthesis example
13.
[0166] The composition of the pellet after the reaction was TFE
87.9: HFP 11.1: PPVE 1.0 in weight. The melting point was 255.0
degree C. The MFR at 372 degree C. was 25.1 g/10 minutes. The sum
of the number of thermally unstable end group and the number of
--CF.sub.2H end group per 1.times.10.sup.6 carbon atoms was 0. The
dielectric constant was 2.01. The dielectric tangent was
3.8.times.10.sup.-4.
[0167] Moreover, the melt tension was 0.12 N. the complex viscosity
was 3.91.times.10.sup.3 Pa*s, and the storage modulus was 0.57.
[0168] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example
Production Example 7
[0169] A coaxial cable of RF113 was prepared in the same manner as
in the production example 1 except that the PEP of the synthesis
example 2 was replaced with the FEP of the synthesis example
14.
[0170] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, L.P.). As a result, the attenuation was 5.1 dB/meter at 6
GHz.
Working Example 15
[0171] Extrusion coating an electrical wire and evaluation for the
extrusion coating was carried out in the same manner as in the
working example 1 except that the pellet Obtained in the synthesis
example 1 was replaced with the pellet Obtained in the synthesis
example 14. As a result, the frequency of occurrence of a lump was
shown in table 8. The stability of the diameter of the extrusion
coated wire (Cp) was 1.2. The stability of the capacitance of the
extrusion coated wire (Cp) was 1.4. Generation of Die-Drool was
very few.
TABLE-US-00009 TABLE 8 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 5 than 20 mil More
than or equal to 20 mil, less 0 than 30 mil More than or equal to
30 mil, less 1 than 40 mil More than or equal to 40 mil, less 0
than 50 mil
Working Example 16
[0172] The master batch pellet was prepared by mixing the pellet
obtained in the synthesis example 14 and boron nitride (BN, Grade:
SHLP-325, average particle diameter: 10.3 .mu.m, manufactured by
CARBORUNDUM Company) so that the concentration of the boron nitride
can be 7.5 wt %. After this, the pellet obtained in the synthesis
example 14 and the master batch pellet were mixed together at the
ratio of 9 to 1. And coating an electrical wire with foamed FEP was
carried out under the condition described below.
The Condition for the Coating an Electrical Wire with the Foamed
FEP
[0173] a) Conductive core: soft copper wire, the diameter of the
wire: 0.7mm
[0174] b) Coating thickness: 0.2 mm
[0175] c) Diameter of an coated wire: 1.1 mm
[0176] d) Take-over speed of an electrical wire: 1,000
feet/minute
[0177] e) Pressure for introduction of nitrogen: 34.0 MPa
[0178] f) Condition for melt molding (extrusion)
[0179] * Diameter of shaft of cylinder=35 mm. A single screw
extruder with L/D=30
[0180] * Die (inner diameter)/chip (outer diameter)=4.7 mm/2.2
mm
[0181] * Preset temperature of the extruder: barrel part of Z1 (330
degree C.), barrel part of Z2 (350 degree C.), barrel part of Z3
(370 degree C.), barrel part of Z4 (370 degree C.), barrel part of
Z5 (370 degree C.), clamp part (375 degree C.), adapter part (370
degree C.), crosshead part (365 degree C.), die part (360 degree
C.), preheating temperature for a core cable (140 degree C.)
[0182] * length of a melt cone during the coating=2.0 mm
[0183] Note that the coating an electrical wire with foamed FEP was
carried out for an hour. The spark out, the stability of the
diameter of the coated wire and the stability of the capacitance of
the coated wire of the foamed wire were measured in the same manner
as in the working example 1. Moreover, the foaming rate and the
average pore diameter of the foamed coating were measured.
Furthermore, the surface state of the foamed wire was observed.
[0184] As a result, the spark out was 0 time/hour. The stability of
the diameter of the extrusion coated wire (Cp) was 1.1. The
stability of the capacitance of the extrusion coated wire (Cp) was
1.1. The foaming rate was 24%. The average pore diameter was 23
.mu.m. The surface state was excellent.
(1) Foaming Rate
[0185] After approximately 50 cm of the coating is peeled off from
the conductive core, the outer diameter, the inner diameter and the
length of the coating was measured to calculate the volume of the
coating. Next, the weight of the coating was measured. Then, the
weight was divided by the volume to obtain the density (d: g/cm3)
of the coating.
Forming rate (%)=(1-d/2.15).times.100
[0186] (2.15 in the formula above is the absolute specific gravity
of non-foamed FEP)
(2) Average Pore Diameter
[0187] After the photography of the cross sectional view of the
foamed wire was taken with a scanning electron microscope, the
diameter of each of the pores in the photograph was measured. Then,
the diameter of the pores is averaged to obtain the average pore
diameter.
(3) Evaluation of Surface State
[0188] Evaluation of the surface state of the foamed wire was
carried out by running fingers across the foamed wire. The
evaluation standard is below.
[0189] Excellent--Smooth
[0190] Good--A little Rough
[0191] Not Good--Very Rough
Comparative Example 1
Comparative Synthesis Example 1
[0192] 8163.5 lbs. of deionized water (including 3.5 lbs. of
ammonium .omega.-hydroxyfluorocarbonate) was added into a
glass-lined autoclave with an agitator (12,000L volume). After
that, the autoclave was vacuumed and filled with nitrogen gas well.
After this, after the autoclave was vacuumed, 8460 lbs. of HFP was
added into the autoclave. While the deionized water and HFP were
agitated vigorously in the autoclave, the inner temperature was set
at 93.2 F. Next, after 92 lbs. of PPVE were added into the
autoclave, TFE was continuously added until the inner pressure of
the autoclave reached 151.0 psi, additionally 99.2 lbs. of 8 wt %
di(.omega.-hydroperfluorohexanoyl) peroxide (abbreviated to "DHP"
in the following) perfluorohexane solution was added into the
autoclave to initiate polymerization. 99.2 lbs. of 8 wt %
perfluorohexane solution was added into the autoclave, and 0.3 psig
of the inner pressure was reduced 2 hours later and 4 hours later
from the initiation of the polymerization. Furthermore, 39.8 lbs.
of 8 wt % DI-IP perfluorohexane solution was added into the
autoclave, and 0.3 psig of the inner pressure was reduced 6 hours
later, 8 hours later and 10 hours later from the initiation of the
polymerization. Moreover, 1.0 psig of the inner pressure was
reduced respectively in ninth and twelfth addition of DIP
perfluorohexane solution counted from the addition of DHP
perfluorohexane solution at the initiation of polymerization. Note
that TFE was continuously charged into the autoclave during the
polymerization, 21.1 lbs. of PPVE was added into the autoclave
respectively at the time that the total quantity of TFE reached
1,640 lbs., 3,280 lbs. and 4,920 lbs. After a small quantity of
sample was collected from the autoclave at the time that the
further additional quantity of TFE reached 1,280 lbs., the sample
was dried to obtain 100 grams of dry powder, and the melt flow rate
at 372 degree C. of the dry powder was measured. The value of the
melt flow rate was 18.0 grams/10 minutes. Furthermore, the quantity
of polymer at this time corresponds to 15.6 wt % of the quantity of
the polymer at the end of the polymerization. Moreover, the melting
point of the dry powder was 249.7 degree C. After this, 85 lbs. of
methanol was added into the autoclave.
[0193] Furthermore, after a small quantity of sample was collected
from the autoclave at the time that the further additional quantity
of TEE reached 3,280 lbs., 4,100 lbs., 4,920 lbs., and 5,740 lbs.,
the samples were dried to obtain 100 grams of dry powder
respectively, and the melting point of the dry powders was
measured. The melt flow rate at 372 degree C. and the melting point
of the dry powder at the time that the further additional quantity
of TEE reached 3,280 lbs. were respectively 20.1 grams/10 minutes
and 251.5 degree C. The melt flow rate at 372 degree C. and the
melting point of the dry powder at the time that the further
additional quantity of TEE reached 4,100 lbs, were respectively
21.7 grams/10 minutes and 253.0 degree C. Furthermore, the quantity
of polymer at the time the further additional quantity of TEE
reached 4,100 lbs. corresponds to 50.0 wt % of the quantity of the
polymer at the end of the polymerization. The melt flow rate at 372
degree C. and the melting point of the dry powder at the time that
the further additional quantity of TEE reached 4,920 lbs, were
respectively 21.5 grams/10 minutes and 254.6 degree C. The melt
flow rate at 372 degree C. and the melting point of the dry powder
at the time that the further additional quantity of TEE reached
5,740 lbs. were respectively 20.3 grams/10 minutes and 256.0 degree
C. The polymerization was terminated when the total quantity of TEE
reached 8,200 lbs. After the termination of the polymerization,
unreacted TEE and RFP were released from the autoclave to obtain
wet powder. Water was added to the wet powder to wash it in
agitation. After this, the wet powder was dried at 150 degree C.
for 10 hours to obtain 9,500 lbs. of dry powder. The melt flow rate
at 372 degree C. of the dry powder was 18,3 grams/10 minutes.
Furthermore, the melting point of the dry powder was 257.7 degree
C. After this, after the dry powder was pelletized at 370 degree C.
with a twin screw extruder, the deaeration of the pellet was
carried out at 200 degree C. for 8 hours. The melt flow rate at 372
degree C. of the pellet was 24.0 grams/10 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0194] Note that the basic properties of the FEP obtained in the
comparative synthesis example 1 was measured by the measuring
method shown in the working example 1. The melting point of the FEP
obtained in the comparative synthesis example 1 (the FEP was
pelletized) was 257.1 degree C. The composition of the FEP of the
comparative synthesis example 1 was TEE 87.9: HFP 11.1: PPVE 1.0 in
weight ratio. The sum of the number of thermally unstable end group
and the number of --CF.sub.2H end group per 1.times.10.sup.6 carbon
atoms was 563. The dielectric constant was 2.03. The dielectric
tangent was 14.0.times.10.sup.-4.
[0195] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the comparative
synthesis example 1 were also determined as in the same manner as
in the working example 1. As a result, the melt tension was 0.07N,
the complex viscosity was 3.46.times.10.sup.3 Pa*s, and the storage
modulus was 0.05.
[0196] Note that the measuring method of the number of thermally
unstable end group, the measuring method of the number of
--CF.sub.2H end group, and the measuring method of the dielectric
constant and the dielectric tangent are as indicated in the
production example 1.
(2) Online Evaluation for Extrusion Coating
[0197] Extrusion coating an electrical wire was carried out using
the FEP of the comparative synthesis example 1 in the same manner
as in the working example 1. After this, evaluation for the
extrusion coating was carried out in the same manner as in the
working example 1. As a result, the frequency of occurrence of a
lump was shown in table 9. The stability of the diameter of the
extrusion coated Tire (Cp) was 1.0. The stability of the
capacitance of the extrusion coated wire (Cp) was 1.0. Generation
of Die-Drool vas few.
TABLE-US-00010 TABLE 9 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 13 than 20 mil More
than or equal to 20 mil, less 5 than 30 mil More than or equal to
30 mil, less 3 than 40 mil More than or equal to 40 mil, less 4
than 50 mil
Comparative Example 2
Comparative Production Example 1
[0198] A coaxial cable of RF1.1.3 was prepared in the same manner
as in the production example 1 except that the FEP of the synthesis
example 2 was replaced with the FEP of the comparative synthesis
example 1.
[0199] The attenuation of the coaxial cable obtained was measured
with a network analyzer of HP8510C (Hewlett-Packard Development
Company, L.R). As a result, the attenuation was 5.6 dB/meter at 6
GHz.
Comparative Example 3
Comparative Synthesis Example 2
[0200] 270.1 kg of deionized water (including 0.1 kg of ammonium
.omega.-hydroxyfluorocarbonate) was added into a glass-lined
autoclave with an agitator (1,000 L volume). After that, the
autoclave was vacuumed and filled with nitrogen gas w After this,
after the autoclave was vacuumed, 233 kg of HEP was added into the
autoclave. While the deionized water and HFP were agitated
vigorously in the autoclave, the inner temperature was set at 29.0
degree C. Next, after 2.6 kg of PPVE were added into the autoclave,
TFE was continuously added until the inner pressure of the
autoclave reached 0.9 MPa, additionally 3.8 kg of 8 wt %
di(.omega.-hydroperfluorohexanoyl) peroxide (abbreviated to "DHP"
in the following) perfluorohexane solution was added into the
autoclave to initiate polymerization. During the polymerization,
TEE was continuously charged into the autoclave to maintain the
inner pressure of the autoclave at 0.9 MPa, 3.8 kg of 8 wt % DHP
perfluorohexane solution was respectively added into the autoclave
3 hours later, 8 hours later and 13 hours later from the initiation
of the polymerization. Additionally, 1.9 kg of 8 wt % DHP
perfluorohexane solution was respectively added into the autoclave
18 hours later, 23 hours later, 28 hours later and 33 hours later
from the initiation of the polymerization. 0.7 kg of PPVE was added
into the autoclave respectively at the time that the total quantity
of TEE reached 61.6 kg, 123.3 kg and 185 kg, After a small quantity
of sample was collected from the autoclave 5 hours later from the
initiation of the polymerization, the sample was dried to obtain
100 grams of dry powder, and the melt flow rate at 372 degree C. of
the dry powder was measured. The value of the melt flow rate was
18.3 grams/10 minutes. After this, 1.7 kg of methanol was added
into the autoclave. The polymerization was terminated 37 hours
later from the initiation of the polymerization. At this time, the
total quantity of TEE reached 308 kg. After the termination of the
polymerization, unreacted TEE and HFP were released from the
autoclave to obtain wet powder. Water was added to the wet powder
to wash it in agitation. After this, the wet powder was dried at
150 degree C. for 24 hours to obtain322 kg of dry powder. The melt
flow rate at 372 degree C. of the dry powder was 17.5 grams/10
minutes. Furthermore, the melting point of the dry powder was 256.4
degree C. After this, after the dry powder was pelletized at 370
degree C. with a twin screw extruder, the deaeration of the pellet
was carried out at 200 degree C. for 8 hours. The melt flow rate at
372 degree C. of the pellet was 25.1 grams/10 minutes.
Measurement of Properties
(1) Measurement of Basic Properties
[0201] Note that the basic properties of the FEP obtained in the
comparative synthesis example 2 was measured by the measuring
method shown in the working example 1. The composition of the FEP
of the comparative synthesis example 2 was TEE 87.9: HFP 11.1: PPVE
1.0 in weight ratio.
[0202] Additionally, the melt tension, the complex viscosity, and
the storage modulus of the FEP obtained in the comparative
synthesis example 2 were also determined as in the same manner as
in the working example 1. As a result, the melt tension was 0.07N,
the complex viscosity was 3.32.times.10.sup.3 Pa*s, and the storage
modulus was 0.06.
(2) Online Evaluation for Extrusion Coating
[0203] Extrusion coating an electrical wire was carried out using
the FEP of the comparative synthesis example 2 in the same manner
as in the working example 1. After this, evaluation for the
extrusion coating was carried out in the same manner as in the
working example 1. As a result, the frequency of occurrence of a
lump was shown in table 10. The stability of the diameter of the
extrusion coated wire (Cp) was 1.0. The stability of the
capacitance of the extrusion coated wire (Cp) was 1.0. Generation
of Die-Drool was few.
TABLE-US-00011 TABLE 10 Number of occurrence Height of lump (mil)
(/2 hours) More than or equal to 10 mil, less 14 than 20 mil More
than or equal to 20 mil, less 5 than 30 mil More than or equal to
30 mil, less 3 than 40 mil More than or equal to 40 mil, less 3
than 50 mil
[0204] The FEP of this invention has features, such as capability
to improve moldability in melt extrusion molding, especially
significant reduction of defects in high-speed extrusion coating of
an electrical wire and capability to manufacture an electrical wire
with smaller transmission loss (attenuation), and highly
contributes to reduction of the cost for manufacturing an
electrical wire and improvement of performance of the electrical
wire.
* * * * *