U.S. patent application number 16/503518 was filed with the patent office on 2019-10-24 for transparent polyester film with low visible light transmittance and high infrared-blocking rate.
The applicant listed for this patent is NAN YA PLASTICS CORPORATION. Invention is credited to TZAI-SHING CHEN, CHIA-HO CHENG, TE-CHAO LIAO, CHUN-CHE TSAO.
Application Number | 20190322824 16/503518 |
Document ID | / |
Family ID | 60048446 |
Filed Date | 2019-10-24 |
United States Patent
Application |
20190322824 |
Kind Code |
A1 |
LIAO; TE-CHAO ; et
al. |
October 24, 2019 |
TRANSPARENT POLYESTER FILM WITH LOW VISIBLE LIGHT TRANSMITTANCE AND
HIGH INFRARED-BLOCKING RATE
Abstract
A transparent polyester film has low visible light transmittance
of 5-50% by JIS K7705 testing standard and a high infrared-blocking
rate of at least 90% by JIS R3106 testing standard, which is
extruded from a kind of polyester resins obtained from 5-40 wt % of
nanoparticle-based thermal insulation slurry and/or 0.005-0.1 wt %
of nanoparticle-based black pigment slurry by weight of and to
react with the polymerization materials to completely perform an
esterification and a polycondensation, wherein the thermal
insulation nanoparticle has a chemical formula of
Cs.sub.XN.sub.YWO.sub.3-ZCl.sub.C with an average particle size of
10-90 nm and the nanoparticle-based black contains carbon black
particles having a particle size of 20-80 nm.
Inventors: |
LIAO; TE-CHAO; (TAIPEI,
TW) ; TSAO; CHUN-CHE; (TAIPEI, TW) ; CHENG;
CHIA-HO; (TAIPEI, TW) ; CHEN; TZAI-SHING;
(TAIPEI, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NAN YA PLASTICS CORPORATION |
Taipei |
|
TW |
|
|
Family ID: |
60048446 |
Appl. No.: |
16/503518 |
Filed: |
July 4, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15634037 |
Jun 27, 2017 |
|
|
|
16503518 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 48/08 20190201;
G02B 5/208 20130101; B29K 2105/162 20130101; B29C 48/022 20190201;
C08K 3/013 20180101; B29K 2995/0011 20130101; B29K 2067/00
20130101; B29K 2995/0026 20130101; C08K 3/04 20130101; C01D 17/003
20130101; B29K 2995/0027 20130101; B29K 2067/003 20130101; C08J
5/18 20130101; C08K 3/22 20130101; C08K 2201/011 20130101; C08L
67/02 20130101; C08K 3/04 20130101; C08J 2367/02 20130101; B29K
2995/0025 20130101; C08L 67/02 20130101; C08K 3/22 20130101; B29K
2995/0029 20130101; C08K 2201/005 20130101 |
International
Class: |
C08J 5/18 20060101
C08J005/18; G02B 5/20 20060101 G02B005/20; B29C 48/08 20060101
B29C048/08; B29C 48/00 20060101 B29C048/00; C08K 3/013 20060101
C08K003/013 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 4, 2016 |
TW |
105121074 |
Claims
1. A transparent polyester film comprising a low visible light
transmittance of 5-50% according to the JIS K7705 testing standard,
a high infrared-blocking rate of at least 90% according to the JIS
R3106 testing standard, and a haze level lower than 1.5% according
to the JIS K7705 testing standard.
2. The transparent polyester film according to claim 1, wherein the
transparent polyester film is a polyethylene terephthalate (PET)
film, a polyethylene naphthalate (PEN) film, a polyvinyl chloride
(PVC) film, a polycarbonate (PC) film, a polypropylene (PP) film, a
polyethylene (PE) film or a nylon film.
3. The transparent polyester film according to claim 1, wherein the
film thickness is from 12 to 75 .mu.m.
4. The transparent polyester film according to claim 1, wherein the
polyester film is obtained by a polyester resin including a thermal
insulation slurry 5-40wt % and a black pigment slurry 0.005-0.1wt
%.
5. The transparent polyester film according to claim 4, wherein the
thermal insulation slurry includes an nanoparticle-based thermal
insulation slurry, powdered tungsten-containing composite metal
oxychloride having a chemical formula of
Cs.sub.XN.sub.YWO.sub.3-zCL.sub.C, wherein Cs is cesium; N is tin
(Sn), antimony (Sb) or bismuth (Bi); W is tungsten; O is oxygen;
and X, Y, Z, and C are positive numbers satisfying the following
conditions: X.ltoreq.1.0; Y.ltoreq.1.0; Y/X.ltoreq.1.0;
Z.ltoreq.0.6, and C.ltoreq.0.1.
6. The transparent polyester film according to claim 5, further
comprising an ethylene glycol 30-70 wt % and a dispersing aid
5-40wt %.
7. The transparent polyester film according to claim 4, wherein the
black pigment slurry includes a carbon black particles with an
average particle size of 20-80 nm
8. The transparent polyester film according to claim 4, wherein the
black pigment slurry includes includes a carbon black particles
5-25 wt %, an ethylene glycol 40-75 wt % and a dispersing aid at
10-50 wt %.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application is a divisional application of U.S.
application Ser. No. 15/634,037 filed on Jun. 27, 2017, and
entitled "TRANSPARENT POLYESTER FILM WITH LOW VISIBLE LIGHT
TRANSMITTANCE AND HIGH INFRARED-BLOCKING RATE AND METHOD FOR MAKING
THE SAME", now issued, the entire disclosures of which are
incorporated herein by reference.
[0002] Some references, which may include patents, patent
applications and various publications, may be cited and discussed
in the description of this disclosure. The citation and/or
discussion of such references is provided merely to clarify the
description of the present disclosure and is not an admission that
any such reference is "prior art" to the disclosure described
herein. All references cited and discussed in this specification
are incorporated herein by reference in their entireties and to the
same extent as if each reference was individually incorporated by
reference.
FIELD OF THE DISCLOSURE
[0003] The present invention relates to a transparent polyester
film and a method for making the same. More particularly, the
invention relates to a transparent heat-shielding polyester film
with low visible light transmittance and high infrared-blocking
rate, and to a method for making the same.
BACKGROUND OF THE DISCLOSURE
[0004] In order to save energy and reduce carbon dioxide emissions,
it is a common practice nowadays to carry out thermal insulation
with a layer of heat-shielding material adhered to the glass panels
of building and automobiles. A notable example of heat-shielding
materials is metal oxides, whose physical properties contribute to
effective thermal insulation and which have been widely used to
block infrared radiation.
[0005] Thermal insulation films for use on transparent windows
generally include a metallic reflective coating or an organic-dye
coating in order to provide thermal insulation. A metallic
reflective coating insulates heat by reflecting both infrared and
ultraviolet radiation and is therefore disadvantaged by an
undesirably high reflectivity. An organic-dye coating, on the other
hand, absorbs infrared radiation and hence insulates heat
ineffectively. The color of an organic-dye coating also tends to
fade over time.
[0006] Another thermal insulation films feature a multilayer film
structure made by electroplating or sputtering a dielectric
substrate with a thin layer of metal (e.g., silver). This
multilayer film structure can be configured to cause interference
that redistributes the intensity of light, thereby enhancing
penetration of the visible spectrum and reflection of the infrared
band to achieve thermal insulation. This type of thermal insulation
films, however, requires considerable investment in equipment and
expensive materials but only have a low product yield.
[0007] In regards to those known prior arts related to teach an
infrared-blocking material, U.S. Pat. No. 5,385,751 discloses a
fluorine-doped tungsten oxide as an infrared-blocking material.
This material is made by chemical vapor deposition and is hence
disadvantaged by a high manufacturing equipment cost and a high
production cost.
[0008] Japanese Published Patent Application No. 2003-121884
discloses a method for making a tungsten trioxide powder, whose
method includes the steps of: dissolving tungsten hexafluoride in
alcohol, separating a precipitate from the solution, and heating
the precipitate at 100-500.degree. C. to produce the tungsten
trioxide powder. The tungsten trioxide powder thus obtained is
applicable as an infrared-blocking material.
[0009] US Published Patent Application No. 2006/0178254 discloses a
method for preparing a tungsten oxide and a tungsten oxide
composite, wherein the tungsten oxide and tungsten oxide composite
obtained are optically effective in blocking infrared radiation.
Nevertheless, the heat treatment required is so complicated that,
during mass production, the optimal condition of each step of the
heat treatment must be individually adjusted; consequently,
difficulties in quality control result in unstable product
quality.
[0010] Japanese Published Patent Application No. H10-67881A
discloses a solution-dyed black polyester composition having an
excellent dispersion of specific carbon blacks, but the carbon
blacks after dispersed in the solution-dyed black polyester
composition are apt to agglomerate to coarse particles, leading to
the solution-dyed black polyester composition being difficulty in
quality control.
[0011] Other applicable prior art discloses a method for making a
black film by melting, extruding, and stretching a mixture of
polyester resins, a black polyester masterbatch, and an organic
carbon black dye. More specifically, the black film is made by,
among other steps, adding a certain percentage of black polyester
masterbatch in the film extrusion stage through a precision
metering device. As the method is subject to the precision and
stability of the metering device, a metering error often leads to a
difference in color and premature color fading.
[0012] Conventionally, to manufacture a thermal insulation film
features highly effective thermal insulation and low visible light
transmittance at least involves providing a substrate with a
thermal insulation layer to insulate heat, and further providing
the substrate with a colored layer to reduce transmittance by
blocking visible light. If a plastic substrate is used, however,
the foregoing steps tend to cause significant thermal contraction
of the substrate, and the different layers will undergo prolonged
thermal hysteresis that compromises adhesion between the layers,
thus giving rise to unstable product quality, a low product yield,
and lack of competitiveness in terms of manufacturing cost.
SUMMARY OF THE DISCLOSURE
[0013] In the prior art, a polyester film made by biaxial
stretching, also known as biaxial orientation, cannot achieve low
transmittance and high infrared-blocking rate at the same time.
Moreover, adding functional particles into the raw materials at a
certain percentage tends to have adverse effects on the optical
properties of the resulting polyester film (e.g., increasing the
haze level of the film), thus imposing limitations on the
application of the film as a transparent window insulation
film.
[0014] To solve the aforesaid problems of the prior art, the
present invention provides a transparent polyester film having the
following physical properties: a low visible light transmittance of
5-50% according to the JIS K7705 testing standard, a high
infrared-blocking rate of at least 90% according to the JIS R3106
testing standard, and a haze level lower than 1.5% according to the
JIS K7705 testing standard.
[0015] The transparent polyester film of the present invention has
a common film thickness ranged from 12 to 75 .mu.m, especially from
23 to 50 .mu.m. And, the transparent polyester film may be a
polyethylene terephthalate (PET) film, a polyethylene naphthalate
(PEN) film, a polyvinyl chloride (PVC) film, a polycarbonate (PC)
film, a polypropylene (PP) film, a polyethylene (PE) film, or a
nylon film, preferably a PET film.
[0016] The ingredients of the transparent polyester film of the
present invention include a thermal insulation slurry whose
particle sizes range from 10 to 90 nm and/or a black pigment slurry
containing carbon black particles whose particle sizes range from
20 to 80 nm. These slurries help the resulting transparent
polyester film achieve transparency as well as infrared rejection.
In particular, the thermal insulation slurry is composed
essentially of Cs.sub.XN.sub.YWO.sub.3-ZCl.sub.C, which provides a
significant improvement in infrared-blocking performance over
common transparent thermal insulation materials made with
antimony-doped tin oxide (ATO) or indium tin oxide (ITO).
[0017] To solve the aforesaid problems of the prior art, the
present invention also provides a method for making a transparent
heat-shielding polyester film having the following physical
properties: a low visible light transmittance of 5-50% according to
the JIS K7705 testing standard, a high infrared-blocking rate of at
least 90% according to the JIS R3106 testing standard, and a haze
level lower than 1.5% according to the JIS K7705 testing standard.
The method for making the transparent heat-shielding polyester film
of the present invention includes the steps of: [0018] 1) preparing
a nanoparticle-based thermal insulation slurry with a viscosity
ranging from 50 to 200 cps; [0019] 2) preparing a
nanoparticle-based black pigment slurry with a viscosity ranging
from 30 to 120 cps; [0020] 3) providing ethylene glycol monomers
and terephthalic acid (or dimethyl terephthalate) as polymerization
materials, by weight of the polymerization materials reacting the
prepared nanoparticle-based thermal insulation slurry in an amount
of 5-40 wt % and/or the prepared nanoparticle-based black pigment
slurry in an amount of 0.005-0.1 wt % with the polymerization
materials, and performing esterification and polycondensation to
obtain polyester resins; and 4) extruding the polyester resins at
270-290.degree. C. to form a transparent polyester film.
[0021] These and other aspects of the present disclosure will
become apparent from the following description of the embodiment
taken in conjunction with the following drawings and their
captions, although variations and modifications therein may be
affected without departing from the spirit and scope of the novel
concepts of the disclosure.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0022] The present disclosure is more particularly described in the
following examples that are intended as illustrative only since
numerous modifications and variations therein will be apparent to
those skilled in the art. Like numbers in the drawings indicate
like components throughout the views. As used in the description
herein and throughout the claims that follow, unless the context
clearly dictates otherwise, the meaning of "a", "an", and "the"
includes plural reference, and the meaning of "in" includes "in"
and "on". Titles or subtitles can be used herein for the
convenience of a reader, which shall have no influence on the scope
of the present disclosure.
[0023] The terms used herein generally have their ordinary meanings
in the art. In the case of conflict, the present document,
including any definitions given herein, will prevail. The same
thing can be expressed in more than one way. Alternative language
and synonyms can be used for any term(s) discussed herein, and no
special significance is to be placed upon whether a term is
elaborated or discussed herein. A recital of one or more synonyms
does not exclude the use of other synonyms. The use of examples
anywhere in this specification including examples of any terms is
illustrative only, and in no way limits the scope and meaning of
the present disclosure or of any exemplified term. Likewise, the
present disclosure is not limited to various embodiments given
herein. Numbering terms such as "first", "second" or "third" can be
used to describe various components, signals or the like, which are
for distinguishing one component/signal from another one only, and
are not intended to, nor should be construed to impose any
substantive limitations on the components, signals or the like.
[0024] The present invention provides a polyester film made by
reacting at least one dicarboxylic acid and at least one diol,
preferably taking terephthalic acid and ethylene glycol as
materials, with one or both of a nanoparticle-based thermal
insulation slurry and a nanoparticle-based black pigment slurry,
subjecting the reaction to have reactants preformed an
esterification and a polycondensation to obtain final produced
polyester resins, and then performing extrusion and biaxial
orientation on the polyester resins to form a biaxially oriented
polyester film.
[0025] As the polyester film of the present invention is made with
the nanoparticle-based thermal insulation slurry and/or the
nanoparticle-based black pigment slurry, the film not only provides
thermal insulation, but also has a uniform hue that does not fade
easily. More specifically, the film has a visible light
transmittance ranged between 5% and 50%, an infrared-blocking rate
of at least 90%, and a haze level lower than 1.5%.
[0026] The present invention also provides a method for making a
polyester film, and the method is carried out as follows: [0027] a)
Prepare a nanoparticle-based thermal insulation slurry:
[0028] The nanoparticle-based thermal insulation slurry includes
the following ingredients, whose respective percentages by weight
are based on the total weight of the ingredients of the thermal
insulation slurry and add up to 100%: [0029] a1) thermal insulation
particles having a chemical formula of
Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C, and added at 10-50 wt %,
commercially available from Nan Ya Plastics Corporation, Taiwan;
[0030] a2) ethylene glycol, added at 30-70 wt %; and [0031] a3) a
dispersing aid, added at 5-40wt %. [0032] b) Prepare a
nanoparticle-based black pigment slurry:
[0033] The nanoparticle-based black pigment slurry includes the
following ingredients, whose respective percentages are based on
the total weight of the ingredients of the pigment slurry and add
up to 100%: [0034] b1) carbon black particles, added at 5-25 wt %;
[0035] b2) ethylene glycol, added at 40-75 wt %; and [0036] b3) a
dispersing aid, added at 10-50 wt %. [0037] c) Prepare polyester
resins:
[0038] The nanoparticle-based thermal insulation slurry prepared at
step a) and/or the nanoparticle-based black pigment slurry prepared
at step b) is/are added to polymerization material monomers or a
mixture of polymerization material monomers. Then, esterification
or ester interchange is carried out to produce polyester resins.
[0039] d) Subject the polyester resins prepared at step c) to a
polyester film forming process to obtain a transparent
heat-shielding polyester film.
[0040] In the method described above for making a polyester film,
the step of preparing a nanoparticle-based thermal insulation
slurry includes the following sub-steps: [0041] A1) Providing
thermal insulation particles formed from a powdered
tungsten-containing composite metal oxychloride having a chemical
formula of
[0042] Cs.sub.XN.sub.YWO.sub.3-ZCl.sub.C, wherein Cs is cesium; N
is tin (Sn), antimony (Sb) or bismuth (Bi); W is tungsten; O is
oxygen; and X, Y, Z, and C are positive numbers satisfying the
following conditions: [0043] X.ltoreq.1.0; Y.ltoreq.1.0;
Y/X.ltoreq.1.0; Z.ltoreq.0.6, and C.ltoreq.0.1;
[0044] A2) Dispersing the thermal insulation particles
(Cs.sub.XN.sub.YWO.sub.3-zCL.sub.C) of sub-step a1) in ethylene
glycol to produce a thermal insulation particle solution.
[0045] More specifically, the thermal insulation particles are
added into an ethylene glycol solvent, stirred thoroughly, and set
aside to moisten the particles.
[0046] To achieve uniform dispersion of the thermal insulation
particles, a dispersing aid may be added into the thermal
insulation particle solution in an appropriate amount, wherein the
dispersing aid may be one or more selected from the group
consisting of an anionic dispersant, a non-ionic dispersant and
a
[0047] The polymeric dispersant, preferably a polymeric
dispersant.The polymeric dispersant is a copolymer with multiple
anchor groups and may be one or more selected from the group
consisting of a polycarboxylate, a sulfonic acid-based polyester
polyol, polyphosphoric ester, polyurethane, and a
modified-polyacrylate-based polymer.
[0048] The anionic dispersant may be selected from the group
consisting of acrylic acid-based anionic dispersants, including a
polyacrylamide (co)polymer, a sodium polyacrylate (co)polymer, a
styrene-acrylic acid (co)polymer, and a sodium carboxylate
copolymer.
[0049] The non-ionic dispersant may be selected from the group
consisting of fatty alcohol ethoxylate and
polyoxyethylenealkylether. [0050] A3) Using a wet-grinding machine,
grind the thermal insulation particle solution prepared at sub-step
a2) to further disperse the particles. Once the average particle
size of the thermal insulation particles reaches 10-90 nm and the
viscosity of the thermal insulation particle solution is between 50
and 200 cps, the desired nanoparticle-based thermal insulation
slurry is obtained.
[0051] In the method described above for making a polyester film,
the step of preparing a nanoparticle-based black pigment slurry
includes the following sub-steps: [0052] B1) Providing carbon black
particles (commercially available from Orion, Cabot, Mitsubishi,
and so on) as the black particles in the slurry. [0053] B2)
Dispersing the carbon black particles of sub-step bl) in ethylene
glycol to produce a black-particle solution.
[0054] More specifically, the carbon black particles are added into
an ethylene glycol solvent, stirred thoroughly, and set aside to
moisten the particles. To achieve uniform dispersion of carbon
black particles, a dispersing aid may be added into the
black-particle solution in an appropriate amount, wherein the
dispersing aid may be one or more selected from the group
consisting of an anionic dispersant, a non-ionic dispersant, and a
polymeric dispersant, preferably a polymeric dispersant.
[0055] The anionic dispersant, non-ionic dispersant, and polymeric
dispersant are the same as those for use in preparing the
nanoparticle-based thermal insulation slurry. [0056] B3) Using a
wet-grinding machine, grind the black-particle solution of sub-step
b2) to further disperse the particles. Once the average particle
size of the carbon black particles reaches 20-80 nm and the
viscosity of the black-particle solution is between 30 and 120 cps,
the desired nanoparticle-based black pigment slurry is
obtained.
[0057] In the method described above for making a polyester film,
the step of preparing polyester resins includes the following
sub-steps: [0058] C1) provide ethylene glycol monomers and
terephthalic acid (or dimethyl terephthalate) as polymerization
materials; [0059] C2) by weight of the polymerization materials of
sub-step cl), measure out the prepared nanoparticle-based thermal
insulation slurry in an amount of 5-40 wt % and/or the prepared
nanoparticle-based black pigment slurry in an amount of 0.005-0.1
wt %; wherein the nanoparticle-based thermal insulation slurry is
preferably used at 5-30 wt %, more preferably 25-30 wt %, by weight
of the polymerization materials; [0060] C3) Add the
nanoparticle-based thermal insulation slurry and/or
nanoparticle-based black pigment slurry prepared at sub-step c2)
sequentially into the ethylene glycol monomers while stirring the
ethylene glycol monomers, and then, add in the terephthalic acid or
dimethyl terephthalate. After that, perform esterification at
250-285.degree. C. for 100-140 min. Once esterification is
completed, lower the pressure for 30-45 min; and [0061] C4) Next,
perform polycondensation in the presence of an antimony or titanium
catalyst while the temperature is lowered from 280.degree. C. to
about 260.degree. C. The polycondensation reaction takes 160-240
min, producing a molten mass of polyester and a byproduct. Remove
the byproduct by refinery distillation, and cool the molten mass of
polyester. Then, cut the cooled molten mass of polyester into the
desired polyester resins.
[0062] In the method described above for making a polyester film,
the process for producing a transparent heat-shielding polyester
film whose physical properties including both a lower visible light
transmittance and a higher infrared-blocking rate comprises the
following sub-steps: [0063] D1) Use the prepared polyester resins
as raw materials; [0064] D2) Extrude the polyester resins formed as
an extrudate product at 270-290.degree. C., and biaxially stretch
the extrudate to form a polyester film; and [0065] D3) Once the
film is set, a transparent polyester film with a lower visible
light transmittance and a higher infrared-blocking rate is
obtained.
[0066] The polyester film of the present invention is advantageous
in that it can block infrared radiation effectively, has a low haze
level, and is weather-resistant as well as aging-resistant,
featuring a low visible light transmittance of 5-50% according to
the JIS K7705 testing standard, a high infrared-blocking rate of at
least 90% according to the JIS R3106 testing standard, and a haze
level lower than 1.5% according to the JIS K7705 testing
standard.
[0067] The polyester film of the present invention is therefore
perfect for use on the glazing of buildings, on the glass panels of
vehicles, and in agricultural applications to protect crops from
overexposure to the sun, providing outstanding thermal insulation
while also overcoming the drawbacks of the conventional thermal
insulation films made by sputtering or wet coating, namely a
complicated manufacturing process, high cost, and unsatisfactory
quality.
[0068] The physical properties of the polyester film of the present
invention were evaluated by the following measuring/testing
methods: [0069] 1. Particle Size Measurement:
[0070] Dynamic Light-Scattering Particle Size Distribution Analyzer
LB-500 of HORIBA, Japan, was used to measure the sizes of the
ground and dispersed particles in the nanoparticle-based thermal
insulation slurry and nanoparticle-based black pigment slurry.
[0071] 2. Visible light transmittance (VLT %) test:
[0072] The transmittance and haze of a transparent heat-shielding
polyester film are tested with the TC-H III Haze Meter produced by
Tokyo Denshoku Co., Ltd. of Japan, and the test is conducted
according to the JIS K7705 testing standard.
[0073] The higher the visible light transmittance, the more
transparent the transparent heat-shielding film. [0074] 3.
Infrared-Blocking Rate (IR Cut %) Test:
[0075] The infrared-blocking rate of a polyester film is tested
with the LT-3000 infrared cut rate tester produced by HOYA of
Japan, and the test is conducted according to the JIS R3106 testing
standard.
[0076] The higher the infrared-blocking rate, the more effective
the polyester film is in thermal insulation. [0077] 4. Haze (Hz %)
Test:
[0078] The transmittance and haze of a transparent heat-shielding
polyester film are tested with the TC-H III Haze Meter produced by
Tokyo Denshoku Co., Ltd. of Japan, and the test is conducted
according to the JIS K7705 testing standard.
[0079] The smaller the haze (Hz %) value, the more clarity the
transparent heat-shielding polyester film. [0080] 5. Quick
Ultra-Violet (QUV) Weathering Test:
[0081] The ATLAS UV TEST weatherometer of Atlas Technology Co. was
used for the test, and the parameters of the test are as follows:
wavelength of the UVB light tubes: 313 nm; testing temperature:
50-60.degree. C.; irradiation cycle: 4 hours of irradiation
followed by 4 hour of steaming, per cycle; test duration:
[0082] 1000 hours; and irradiation power: 71 w/m.sup.2. The
colorimetric value DE was detected with a spectroscope. The lower
the DE value, the higher the weather-resistance.
[0083] The physical properties of the polyester film of the present
invention are demonstrated by and compared between the following
examples 1-8 and comparative examples 1-12. Please note that the
scope of the present invention is not limited by the examples or
comparative examples.
Example 1
[0084] A 38 .mu.m-thick polyester film was made in the following
manner. Ethylene glycol monomers and terephthalic acid (or dimethyl
terephthalate) were used as the polymerization materials. A
nanoparticle-based thermal insulation slurry is prepared to contain
thermal insulation particles (Cs.sub.XN.sub.YWO.sub.3-zCL.sub.C)
each having a particle size of 10 nm, and a black pigment slurry is
prepared to contain carbon black particles each having a particle
size of 20 nm.
[0085] Based on the total weight of the polymerization materials,
the prepared nanoparticle-based thermal insulation slurry and the
black pigment slurry were added at 30 wt % and 0.005 wt %
respectively.
[0086] Esterification and polycondensation were subsequently
performed to produce polyester resins, which were extruded and
stretched at 270-290.degree. C. via a conventional polyester film
forming process until a 38 .mu.m-thick transparent polyester film
was formed.
[0087] The physical properties of the resulting polyester film are
shown in Table 1
Example 2
[0088] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that the particle size of the thermal
insulation particles (Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.3) was
changed to 65 nm, and that the black pigment slurry was added at
0.01 wt %.
[0089] The physical properties of the resulting polyester film are
shown in Table 1
Example 3
[0090] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that the particle size of the thermal
insulation particles (Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C) was
changed to 90 nm, and that the black pigment slurry was added at
0.05 wt %.
[0091] The physical properties of the resulting polyester film are
shown in Table 1.
Example 4
[0092] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that the thermal insulation slurry was added
at 25 wt %, that the particle size of the thermal insulation
particles (Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C) was changed to 10 nm,
that the black pigment slurry was added at 0.05 wt %, and that the
particle size of the carbon black particles was changed to 50
nm.
[0093] The physical properties of the resulting polyester film are
shown in Table 1.
Example 5
[0094] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that the thermal insulation slurry was added
at 25 wt %, that the particle size of the thermal insulation
particles (Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C) was changed to 65 nm,
that the black pigment slurry was added at 0.07 wt %, and that the
particle size of the carbon black particles was changed to 50
nm.
[0095] The physical properties of the resulting polyester film are
shown in Table 1.
Example 6
[0096] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that the thermal insulation slurry was added
at 25 wt %, that the particle size of the thermal insulation
particles (Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C) was changed to 90 nm,
that the black pigment slurry was added at 0.07 wt %, and that the
particle size of the carbon black particles was changed to 80
nm.
[0097] The physical properties of the resulting polyester film are
shown in Table 1.
Example 7
[0098] A 23 .mu.m-thick polyester film was made in the same way as
in example 2, wherein the particle size of the thermal insulation
particles (Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C) was 65 nm, the black
pigment slurry was added at 0.01 wt %, and the particle size of the
carbon black particles was 50 nm.
[0099] The physical properties of the resulting polyester film are
shown in Table 1.
Example 8
[0100] A 50 .mu.m-thick polyester film was made in the same way as
in example 2, wherein the particle size of the thermal insulation
particles (Cs.sub.XN.sub.YWO.sub.3-zCl.sub.C) was 65 nm, the black
pigment slurry was added at 0.01 wt %, and the particle size of the
carbon black particles was 50 nm.
[0101] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 1
[0102] A 38 .mu.m-thick polyester film was made, without adding any
thermal insulation slurry or black pigment slurry for
polyesterification.
[0103] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 2
[0104] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that the black pigment slurry was added at
0.15 wt %.
[0105] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 3
[0106] A 38 .mu.m-thick polyester film was made in the same way and
with the same amount of thermal insulation slurry added for
polyesterification as in example 1, except that the particle size
of the thermal insulation particles
(Cs.sub.XN.sub.YWO.sub.3-ZCL.sub.C) was changed to 120 nm, that the
weight percentage of the black pigment slurry was changed to 0.05
wt %, and that the particle size of the carbon black particles was
changed to 100 nm. The physical properties of the resulting
polyester film are shown in Table 1.
Comparative Example 4
[0107] A 38 .mu.m-thick polyester film was made, without adding any
black pigment slurry for polyesterification. In the course of
proceeding polyesterification, the thermal insulation slurry was
added at 5 wt % and the particle size of the thermal insulation
particles (Cs.sub.XN.sub.YWO.sub.3-ZC.sub.C) was 65 nm.
[0108] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 5
[0109] A 38 .mu.m-thick polyester film was made in the same way as
in Comparative Example 4 without using any black pigment slurry,
except that the amount of the thermal insulation slurry added for
polyesterification was changed to 10 wt %.
[0110] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 6
[0111] A 38 .mu.m-thick polyester film was made in the same way as
in Comparative Example 4 without using any black pigment slurry,
except that the amount of the thermal insulation slurry added for
polyesterification was changed to 15 wt %.
[0112] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 7
[0113] A 38 .mu.m-thick polyester film was made in the same way as
in Comparative Example 4 without using any black pigment slurry,
except that the amount of the thermal insulation slurry added for
polyesterification was changed to 20 wt %. The physical properties
of the resulting polyester film are shown in Table 1
Comparative Example 8
[0114] A 38 .mu.m-thick polyester film was made without using any
thermal insulation slurry for polyesterification. In the course of
proceeding polyesterification, the black pigment slurry was added
at 0.005 wt %, with the particle size of the carbon black particles
being 50 nm.
[0115] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 9
[0116] A 38 .mu.m-thick polyester film was made in the same way as
in Comparative
[0117] Example 8 without using any thermal insulation slurry,
except that the amount of the black pigment slurry added for
polyesterification was changed to 0.01 wt %.
[0118] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 10
[0119] A 38 .mu.m-thick polyester film was made in the same way as
in Comparative Example 8 without using any thermal insulation
slurry, except that the amount of the black pigment slurry added
for polyesterification was changed to 0.05 wt %.
[0120] The physical properties of the resulting polyester film are
shown in Table 1
Comparative Example 11
[0121] A 38 .mu.m-thick polyester film was made in the same way as
in Comparative Example 8 without using any thermal insulation
slurry, except that the amount of the black pigment slurry added
for polyesterification was changed to 0.1 wt %.
[0122] The physical properties of the resulting polyester film are
shown in Table 1.
Comparative Example 12
[0123] A 38 .mu.m-thick polyester film was made in the same way as
in example 1, except that polymerization was carried out without
any thermal insulation slurry or black pigment slurry, and that the
thermal insulation slurry and the black pigment slurry were mixed
with the polyester resins in the film forming (i.e., extrusion and
stretching) stage, before the mixture was heated and stretched into
a 38 .mu.m-thick polyester film, wherein the thermal insulation
slurry was added at 30 wt % and had a particle size of 65 nm and
the black pigment slurry was added at 0.01 wt % and had a particle
size of 50 nm. The physical properties of the resulting polyester
film are shown in Table 1.
TABLE-US-00001 TABLE 1 Physical Property Analysis of polyester
films thermal insulation black pigment slurry (wt %) slurry (wt %)
Particle Particle IR QUV size (nm) size (nm) VLT cut Haze 500 Hrs
10 65 90 120 20 50 80 100 (%) (%) (Hz %) (DE) Example 1 30 -- -- --
0.005 -- -- -- 50 90 1.06 2.7 2 -- 30 -- -- 0.01 -- 35 93 1.12 2.5
3 -- 30 -- 0.05 -- 23 95 1.38 2.0 4 25 -- 0.05 -- 23 91 1.22 2.4 5
25 0.07 9 94 1.30 2.1 6 25 0.07 5 97 1.42 2.0 7 30 -- -- 0.01 -- 38
92 1.12 2.6 8 30 -- -- 0.01 -- 30 94 1.12 2.4 Comparative 1 -- --
-- -- -- -- -- -- 92 12 0.14 4.5 Example 2 30 -- -- -- 0.15 -- --
-- 2 99 1.49 1.3 3 -- -- -- 30 -- -- -- 0.05 20 98 12.1 1.6 4 -- 5
-- -- -- -- 79 12 0.71 5.3 5 -- 10 -- -- -- -- 76 16 0.75 5.1 6 --
15 -- -- -- -- 73 19 0.82 4.8 7 -- 20 -- -- -- 71 22 0.88 4.5 8 --
-- -- -- 0.005 -- 52 15 0.87 2.9 9 -- -- -- -- 0.01 -- 37 18 0.92
2.6 10 -- -- -- -- 0.05 -- 26 22 1.03 2.4 11 -- -- -- -- 0.1 -- 6
47 1.14 2.0 12 -- 30* -- -- 0.01* -- 28-36 89-94 1.12-3.21
2.3-3.9
[0124] note: in comparative example 12 the thermal insulation
slurry and the black pigment slurry were mixed with polyester
resins in the film forming stage, i.e., added in extrusion and
stretching stage.
Results:
[0125] 1. According to Table 1, the polyester films in those
comparative examples 4-7 without carbon black particles had high
visible light transmittance values and therefore did not feature
low visible light transmittance. [0126] 2. According to Table 1,
the polyester films in those comparative examples 8-11 without
thermal insulation particles had low infrared-blocking rates and
were therefore ineffective in blocking infrared radiation. [0127]
3. According to Table 1, the polyester films in the examples 1-8
had low visible light transmittance and high infrared-blocking
rates thanks to the inclusion of both the thermal insulation
particles and the carbon black particles. [0128] 4. According to
Table 1, the polyester film in the comparative example 1, neither
having thermal insulation particles nor carbon black particles, had
much higher visible light transmittance and a far lower
infrared-blocking rate than that of the polyester film in the
example 2. [0129] 5. According to Table 1, the polyester film was
made in the comparative example 2 where both the nanoparticle-based
thermal insulation slurry and the nanoparticle-based carbon black
slurry were added at exceedingly large percentages, resulted in
that the polyester film of the comparative example 2 had a high
infrared-blocking rate but so low visible light transmittance that
the film was almost impermeable to light. [0130] 6. According to
Table 1, the polyester film was made in the comparative example 3
where both the nanoparticle-based thermal insulation slurry and the
nanoparticle-based carbon black slurry were added and contained
relatively large particles, resulted in that the polyester film of
the comparative example 3 had low visible light transmittance, a
high infrared-blocking rate, and a relatively high haze level that
compromised the clarity of the polyester film. [0131] 7. According
to Table 1, the polyester film was made in the comparative example
12 where the thermal insulation slurry and the black pigment slurry
were mixed with the polyester resins in the film forming stage,
i.e., added in extrusion and stretching stage, showed relatively
low uniformity in concentration such that the visible light
transmittance, infrared-blocking rate, haze level, and QUV
weather-resistance of the film were less uniform than that of the
polyester film in the example 2, which is an indication of unstable
quality.
[0132] The foregoing description of the exemplary embodiments of
the disclosure has been presented only for the purposes of
illustration and description and is not intended to be exhaustive
or to limit the disclosure to the precise forms disclosed. Many
modifications and variations are possible in light of the above
teaching.
[0133] The embodiments were chosen and described in order to
explain the principles of the disclosure and their practical
application so as to enable others skilled in the art to utilize
the disclosure and various embodiments and with various
modifications as are suited to the particular use contemplated.
Alternative embodiments will become apparent to those skilled in
the art to which the present disclosure pertains without departing
from its spirit and scope.
* * * * *