Transparent polyester film with low visible light transmittance and high infrared-blocking rate and method for making the same

Patent metadata

Field	Value
Publication number	US-10435526-B2
Application number	US-201715634037-A
Country	US
Kind code	B2
Filing date	Jun 27, 2017
Priority date	Jul 4, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

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 X N Y WO 3-Z Cl 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.

First claim

What is claimed is:

1. A method for making a transparent polyester film with low visible light transmittance and a high infrared-blocking rate as well as a common film thickness ranged from 12 to 75 μm, comprising the steps of:
a) preparing a nanoparticle-based thermal insulation slurry with a viscosity of 50-200 cps, wherein the thermal insulation slurry comprises the following ingredients a1)-a3) to add up to 100%:
a1) 10-50 wt % of thermal insulation particles, based on the total weight of the thermal insulation slurry; and the thermal insulation particles having a chemical formula of Cs X N Y WO 3-Z Cl C with an average particle size of 10-90 nm,
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≤1.0; Y≤1.0; Y/X≤1.0; Z≤0.6, and C≤0.1;

a2) 30-70 wt % of ethylene glycol, based on the total weight of the thermal insulation slurry; and
a3) 5-40 wt % of a dispersing aid, based on the total weight of the thermal insulation slurry; wherein the dispersing aid is one or more selected from the group consisting of an anionic dispersant, a non-ionic dispersant and a polymeric dispersant;

b) preparing a nanoparticle-based black pigment slurry with a viscosity of 30-120 cps, wherein the pigment slurry comprises the following ingredients b1)-b3) to add up to 100%:
b1) 5-25 wt % of carbon black particles with an average particle size of 20-80 nm, based on the total weight of the pigment slurry;
b2) 40-75 wt % of ethylene glycol, based on the total weight of the pigment slurry; and
b3) 10-50 wt % of a dispersing aid, based on the total weight of the pigment slurry; wherein the dispersing aid is one or more selected from the group consisting of an anionic dispersant, a non-ionic dispersant and a polymeric dispersant;

c) making polyester resins by steps of:
c1) providing ethylene glycol monomers and terephthalic acid or dimethyl terephthalate as polymerization materials, and reacting 5-40 wt % of the prepared nanoparticle-based thermal insulation slurry of step a) and/or 0.005-0.1 wt % of the prepared nanoparticle-based black pigment slurry of step b) with the polymerization materials, by weight of the polymerization materials respectively;
c2) performing esterification at 250-285° C. for 100-140 min, and effecting pressure reduction for 30-45 min after the esterification is completed; and
c3) performing polycondensation at about 260° C. for 160-240 min in the presence of an antimony or titanium catalyst to produce a molten mass of polyester and a byproduct, removing the byproduct by refinery distillation, cooling the molten mass of polyester, and cutting the cooled molten mass of polyester into polyester resins; and

d) extruding the polyester resins at 270-290° C. to form a transparent polyester film whose physical properties feature 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 method for making a transparent polyester film as defined in claim 1 , wherein at step c1) the prepared nanoparticle-based thermal insulation slurry is used in an amount of 5-30 wt %, by weight of the polymerization materials, to react with the polymerization materials.

3. The method for making a transparent polyester film as defined in claim 1 , wherein at step c1) the prepared nanoparticle-based thermal insulation slurry is used in an amount of 25-30 wt %, by weight of the polymerization materials, to react with the polymerization materials.

4. The method for making a transparent polyester film as defined in claim 1 , wherein at step a3) or b3) the polymeric dispersant is 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.

5. The method for making a transparent polyester film as defined in claim 1 , wherein at step a3) or b3) the anionic dispersant is one or more selected from the group consisting of a polyacrylamide (co)polymer, a sodium polyacrylate (co)polymer, a styrene-acrylic acid (co)polymer and a sodium carboxylate copolymer.

6. The method for making a transparent polyester film as defined in claim 1 , wherein at step a3) or b3) the non-ionic dispersant is selected from the group consisting of fatty alcohol ethoxylate and polyoxyethylenealkylether.

Assignees

• Nanya Plastics Corp

Inventors

• Liao Te-Chao
• Tsao Chun-Che
• Cheng Chia-Ho
• Chen Tzai-Shing

Classifications

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• B29K2105/162

  Nanoparticles · CPC title

• B29K2995/0027

  for light outside the visible spectrum · CPC title

• C08K2003/2258

  of tungsten · CPC title

• C08K3/22 Primary

  of metals · CPC title