Solar energy shielding window film laminates

• US 20070223097A1
• Filed: 07/31/2006
• Published: 09/27/2007
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: Garware Hi-Tech Films Ltd.
• Original Assignee: Garware Polyester Limited
• Inventors: Garware, Shashikant Bhalchandra, Adsul, Mohan Sitaram
• Granted Patent: US 7,883,777 B2
• Time in Patent Office: Days
• US Class Current: 359/586
• CPC Class Codes: B32B 2250/244 All polymers belonging to those covered by group B32B27/36
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/205 Metallic coating
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2264/105 Metal
• CPC Class Codes: B32B 2264/108 Carbon, e.g. graphite particles
• CPC Class Codes: B32B 2307/40 having particular optical properties light or UV resistant B32B2307/71
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/71 Resistive to light or to UV
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2839 with release or antistick coating
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31565 Next to polyester [polyethylene terephthalate, etc.]
• CPC Class Codes: Y10T 428/31605 Next to free metal
• CPC Class Codes: Y10T 428/31609 Particulate metal or metal compound-containing
• CPC Class Codes: Y10T 428/31678 : Of metal
• CPC Class Codes: Y10T 428/31681 : Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]

Abstract

The invention relates to solar energy shielding window film laminates exhibiting visual light transmittance in the range of 5 to 80% with minimum progressive fading or degradation of reflective quality wherein base polyester films have a layer of adhesive sandwiched there between, the adhesive layer containing dispersed mixed metal oxides as solar-energy-screen particles optionally in combination with rare earth hexaborides, antimony containing metal oxide, indium containing metal oxide, titanium nitride, or carbon particles either singly or in combinations thereof. The process for preparation of these laminates involves steps of selecting a polyester (PET) substrate; coating it with an adhesive formulation containing the dispersed mixed metal oxides as solar-energy-screen particles and other additives followed by lamination with a second PET film; applying a UV hard coat layer on one side of the PET film laminate and applying pressure sensitive adhesive on a side opposite the UV hard coat layer of the laminate followed by lamination with a release sheet.

Claims

1. (canceled)

2. A solar energy shielding window film laminate exhibiting visual light transmittance in the range of 5 to 80% with minimum progressive fading or degradation of reflective quality, which comprises:

at least two polyester films; and

at least one layer of adhesive contained between the polyester films, wherein the at least one adhesive layer comprises a laminating adhesive having solar-energy-screen particles dispersed therein, wherein the solar-energy-screen particles comprise complex metal oxides and optionally, one or more materials selected from the group of hexaborides, metal oxides, metals, titanium nitride, cobalt blue and carbon particles.

3. The solar energy shielding window film laminate of claim 2, wherein the metal oxides of the solar-energy-screen particles are selected from the group of antimony containing metal oxides, indium containing metal oxides, iron oxides, calcium oxides, titanium oxides, and combinations thereof.

4. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film is an optically clear, optionally ultraviolet stabilized, polyester film.

5. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film is a dyed, ultraviolet stabilized, polyester film.

6. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film is a metallized polyester film.

7. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film is a biaxially oriented polyester film, which demonstrates a thermal shrinkage of less than 10% in both the machine and transverse directions, and a tensile strength that is substantially similar in both the machine and transverse directions.

8. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film has a thickness ranging from about 12 to about 250 microns.

9. The solar energy shielding window film laminate of claim 8, wherein at least one polyester film has a thickness ranging from about 12 to about 75 microns.

10. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film is prepared from polymers having ester groups produced by either polymerization of dicarboxylic acids and diols, or by ester exchange polymerization of dimethyl terephthalate and monoethylene glycol.

11. The solar energy shielding window film laminate of claim 10, wherein the at least one polyester film is prepared from polymers having ester groups produced by polymerization of dicarboxylic acids and diols, wherein the dicarboxylic acids are selected from the group of terepthalic acid, isopthalic acid, 2,6-napthalene dicarboxylic acid and 1,4-cyclohexane dicarboxylic acid, and wherein the diols are selected from the group of monoethylene glycols, diethylene glycols, triethylene glycols, polyethylene glycols, and combinations thereof.

12. The solar energy shielding window film laminate of claim 2, wherein at least one polyester film is a film prepared from polyesters selected from the group of polyethylene terephthalate, polyethylene 2,6-naphthalate, and co-polyesters of 1,4-cyclohexane dicarboxylic acid.

13. The solar energy shielding window film laminate of claim 2, wherein the at least one adhesive layer contains from about 1 to about 30% by dry weight, based on the total dry weight of laminating adhesive, of dispersed complex metal oxides.

14. The solar energy shielding window film laminate of claim 13, wherein combinations of main metals in the complex metal oxides are selected from the group of Cu—

Cr, Cu—

Fe—

Mn, Cu—

Mn, Cu—

Cr—

Mn, Cu—

Cr—

Mn—

Ni, Co—

Cr—

Fe and combinations thereof.

15. The solar energy shielding window film laminate of claim 13, wherein the at least one adhesive layer further contains from about 1 to about 8% by dry weight, based on the total dry weight of the laminating adhesive, of at least one hexaboride selected from the group of hexaborides of cesium, neodymium, holmium, erbium, lanthanum, ytterbium, chromium and calcium, and combinations thereof.

16. The solar energy shielding window film laminate of claim 13, wherein the at least one adhesive layer further contains from about 10 to about 70% by dry weight, based on the total dry weight of the laminating adhesive, of at least one metal oxide selected from the group of antimony containing metal oxides, indium containing metal oxides, and combinations thereof.

17. The solar energy shielding window film laminate of claim 16, wherein the at least one metal oxide is present in an amount ranging from about 40 to about 60% by dry weight, based on the total dry weight of the laminating adhesive.

18. The solar energy shielding window film laminate of claim 16, wherein the at least one metal oxide is antimony tin oxide.

19. The solar energy shielding window film laminate of claim 16, wherein the at least one metal oxide is indium tin oxide.

20. The solar energy shielding window film laminate of claim 2, wherein the solar-energy-screen particles have an average particle size ranging from about 1 to about 100 nanometers.

21. The solar energy shielding window film laminate of claim 20, wherein the solar-energy-screen particles have an average particle size ranging from about 8 to about 40 nanometers.

22. The solar energy shielding window film laminate of claim 2, wherein the laminating adhesive is a polyurethane laminating adhesive prepared from a polyol and at least one NCO-terminated co-reactant.

23. The solar energy shielding window film laminate of claim 2, wherein the laminating adhesive is an optionally ultraviolet curable, acrylic laminating adhesive.

24. The solar energy shielding window film laminate of claim 2, wherein one or more organic solvents are used to disperse the solar-energy-screen particles in the laminating adhesive, the one or more organic solvents being selected from the group of aromatic hydrocarbons, esters, alcohols, and mixtures thereof.

25. The solar energy shielding window film laminate of claim 2, wherein the at least one adhesive layer is prepared from an adhesive formulation comprising:

a laminating adhesive;

solar-energy-screen particles; and

from about 10 to about 90% by weight, based on the total dry weight of the laminating adhesive and solar-energy-screen particles, of one or more organic solvents.

26. The solar energy shielding window film laminate of claim 25, wherein the one or more organic solvents is present in the adhesive formulation in an amount ranging from about 40 to about 85% by weight, based on the total dry weight of the laminating adhesive and solar-energy-screen particles.

27. The solar energy shielding window film laminate of claim 2, wherein the at least one adhesive layer has a thickness ranging from about 2 microns to about 10 microns.

28. The solar energy shielding window film laminate of claim 2, which comprises:

(a) a first polyester film having opposing upper and lower surfaces;

(b) a second polyester film having opposing upper and lower surfaces and metal deposited on its upper surface;

(c) an adhesive layer having a thickness ranging from about 2 to about 10 microns that is contained between and that adheres together the lower surface of the first polyester film and the upper metallized surface of the second polyester film, wherein the adhesive layer comprises a laminating adhesive having solar-energy-screen particles dispersed therein, wherein the solar-energy-screen particles comprise Cu—

Fe—

Mn complex metal oxides in combination with one or more materials selected from the group of hexaborides, antimony containing metal oxides, indium containing metal oxides, and combinations thereof;

(d) a hard coat layer formed by an ultraviolet curable resin that is located on the upper surface of the first polyester film;

(e) a pressure sensitive adhesive layer located on the lower surface of the second polyester film; and

(f) a release sheet located on the pressure sensitive adhesive layer.

29. The solar energy shielding window film laminate of claim 2, which comprises:

(a) a first polyester film having opposing upper and lower surfaces and a stoichiometric mixture of metal and its oxides deposited on its upper lower surface;

(b) a hard coat layer located on the upper surface of the first polyester film;

(c) a second Polyester film having opposing upper and lower surfaces;

(d) an adhesive layer having a thickness ranging from about 2 to about 10 microns that is contained between and that adheres together the upper metallized lower surface of the first polyester film and the upper surface of the second polyester film, wherein the adhesive layer comprises a polyurethane laminating adhesive having solar-energy-screen particles dispersed therein, wherein the solar-energy-screen particles comprise complex metal oxides in combination with one or more materials selected from the group of hexaborides, antimony containing metal oxides, indium containing metal oxides, and combinations thereof;

(e) a pressure sensitive adhesive layer formed on the adhesive layer lower surface of the second polyester film; and

(f) a release sheet located on the pressure sensitive adhesive layer.

30. The solar energy shielding window film laminate of claim 2, which comprises:

(a) an optically clear polyester film having opposing upper and lower surfaces;

(b) a hard coat layer formed by an ultraviolet curable resin that is located on the upper surface of the optically clear polyester film;

(c) an ultraviolet stabilized polyester film having opposing upper and lower surfaces;

(d) an adhesive layer that is contained between and that adheres together the lower surface of the optically clear polyester film and the upper surface of the ultraviolet stabilized polyester film, wherein the adhesive layer comprises a laminating adhesive having solar-energy-screen particles dispersed therein, wherein the solar-energy-screen particles comprise complex metal oxides and optionally, one or more materials selected from the group of hexaborides, metal oxides, metals, titanium nitride, cobalt blue and carbon particles;

(e) a pressure sensitive adhesive layer located on the lower surface of the ultraviolet stabilized polyester film; and

(f) a release sheet located on the pressure sensitive adhesive layer.

31. The solar energy shielding window film laminate of claim 2, which comprises:

(a) a first polyester film in the form of an optically clear film having opposing upper and lower surfaces;

(b) a hard coat layer formed by an ultraviolet curable resin that is located on the upper surface of the first polyester film;

(c) a second polyester film having opposing upper and lower surfaces, wherein the upper surface of the second polyester film is adhered to the lower surface of the first polyester film;

(d) a third polyester film having opposing upper and lower surfaces and metal deposited on its upper surface, wherein the upper metallized surface of the third polyester film is adhered to the lower surface of the second polyester film;

(e) a fourth polyester film having opposing upper and lower surfaces, wherein the upper surface of the fourth polyester film is adhered to the lower surface of the third polyester film;

(f) a pressure sensitive adhesive layer formed on the lower surface of the fourth polyester film; and

(g) a release layer or sheet located on the pressure sensitive adhesive layer, wherein, adhesive layers are contained between and adhere together the polyester films, wherein each adhesive layer comprises a laminating adhesive having solar-energy-screen particles dispersed therein, wherein the solar-energy-screen particles comprise complex metal oxides and optionally, one or more materials selected from the group of hexaborides, metal oxides, metals, titanium nitride, cobalt blue and carbon particles.

32. A process for preparing a solar energy shielding window film laminate, wherein the film laminate comprises:

at least two polyester films; and

at least one layer of adhesive contained between the polyester films, wherein the at least one adhesive layer comprises a laminating adhesive having solar-energy-screen particles dispersed therein, wherein the solar-energy-screen particles comprise complex metal oxides and optionally, one or more materials selected from the group of hexaborides, metal oxides, metals, titanium nitride, cobalt blue and carbon particles, and wherein the process comprises;

(a) selecting a first and a second polyester film, each film having an upper and lower surface;

(b) coating the lower surface of the first polyester film with an adhesive formulation comprising the laminating adhesive, the solar-energy-screen particles, and a solvent;

(c) applying the upper surface of the second polyester film to the coated lower surface of the first polyester film;

(d) laminating together the first and the second polyester films;

(e) applying an ultraviolet curable resin to the upper surface of the first polyester film to form a hard coat layer;

(f) applying a pressure sensitive adhesive to the lower surface of the second polyester film; and

(g) applying a release sheet to the pressure sensitive adhesive contained on the lower surface of the second polyester film.