Window interlayer with sound attenuation properties
The present invention discloses a method for forming a laminated window. The method includes: a) assembling a mold between two plies that make up a laminated window; b) filling the mold with a reaction mixture having: (1) at least one chain extender; (2) at least one polyether polyol having a molecular weight of approximately 1,000; and (3) at least one aliphatic polyisocyanate; and c) curing the reaction mixture.
1. A method of making a polyurethane material comprising:
a) reacting the following components to form a reaction mixture:
(1) at least one chain extender;
(2) at least one polyether polyol having a molecular weight of approximately 1,000; and
(3) at least one aliphatic polyisocyanate
wherein the reaction mixture has an OH:NCO ratio that is between 0.89:1 to 0.94:1, and
b) curing the reaction mixture by exposing the reaction mixture to ultraviolet radiation having a wavelength between 220 and 450 nm, or heating the reaction mixture to a temperature ranging from 180° F. to 290° F.
2. The method according to claim 1 , wherein the chain extender is selected from ethylene glycol; 1,2-propanediol; 1,3-propanediol; 1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2-methylpropane diol; 1,2-pentanediol; 1,3-pentanediol; 1,4-pentanediol; and 1,5-pentanediol.
3. The method according to claim 1 , wherein the polyether polyol is selected from polyethers with caprolactones and organo functional polydimethyl siloxanes.
4. The method according to claim 1 , wherein the at least one aliphatic polyisocyanate is selected from an aliphatic diisocyanate and an aliphatic triisocyanate.
5. The method according to claim 4 , wherein the aliphatic diisocyanate is selected from bis(4-isocyanato-cyclohexyl)methane; hexamethylene diisocyanate; 4,4-bis(cyclohexyl)methane diisocyanate; isophorone diisocyanate; 1-methylcyclohexane-2,4-diisocyanate; and trimethyl hexamethylene diisocyanate (TMDI).
6. The method according to claim 4 , wherein the aliphatic triisocyanate is 4,4′,4″-tricyclohexy methane triisocyanate.
7. The method according to claim 1 , wherein the reaction mixture comprises between 0.5-1.0 equivalents of the at least one polyether polyol.
8. The method according to claim 1 , wherein the reaction mixture further comprises a polyester polyol having a molecular weight of approximately 300 in an amount ranging from greater than 0 to 0.5 equivalents.
9. The method according to claim 1 , wherein the reaction mixture further comprises a dye selected from nanopigments, organo tungsten dyes, and mixtures thereof.
10. The method according to claim 9 , wherein the dye is an organo tungsten dye prepared by reacting one mole of tungsten hexachloride with 3 or more moles of an alkyl ester of phosphoric acid.
11. The method according to claim 1 , wherein the reaction mixture further comprises 2% to 25% by weight of the reaction mixture of urethane acrylate, hydroxyethyl acrylate, and propyl acrylate.
12. The method according to claim 1 , wherein the reaction mixture comprises an ultraviolet light catalyst, a thermal catalyst, or both.
13. An interlayer formed by the method of claim 1 .
14. A method for increasing sound attenuation in a window comprising:
a) assembling a mold comprising two plies that make up a laminated window, the plies being a predetermined distance apart;
b) filling the mold with a reaction mixture comprising:
(1) at least one chain extender;
(2) at least one polyether polyol having a molecular weight of approximately 1,000; and
(3) 1.0 equivalents of at least one aliphatic polyisocyanate
wherein the reaction mixture has an OH:NCO ratio that is between 0.89:1 and 0.94:1, and
c) curing the reaction mixture by exposing the reaction mixture to ultraviolet radiation having a wavelength between 220 and 450 nm, or heating the reaction mixture to a temperature ranging from 180° F. to 290° F.
15. The method according to claim 14 , wherein the curing step comprises thermal curing, ultraviolet light curing, or both.
16. The method according to claim 14 , wherein the reaction mixture forms an interlayer being a sheet having a thickness ranging from 30 mils to 1 inch.
17. The method according to claim 14 , wherein the laminated window attenuates sound waves having a frequency of 1000 Hz and above.
18. The method according to claim 14 , wherein the laminated window exhibits a degree of adhesion ranging from 1 pound to 10 pounds per lineal inch (1.75×10 2 N/m to 1.75×10 3 N/m) as determined by a 90° Peel Test according to NASA TECH BRIEF 65-10173.
19. The method according to claim 14 , wherein the at least one aliphatic polyisocyanate is 4,4′,4″-tricyclohexy methane triisocyanate.
20. The method according to claim 14 , wherein the reaction mixture further comprises a polyester polyol having a molecular weight of approximately 300 in an amount ranging from greater than 0 to 0.5 equivalents.
21. The method according to claim 1 , wherein the reaction mixture further comprises an adhesion promoter.
22. The method according to claim 21 , wherein the adhesion promoter is an isocyanate functional silane.
23. The method according to claim 21 , wherein the reaction mixture further comprises a catalyst.
24. The method according to claim 23 , wherein the catalyst is dibutyltin dilaurate.
25. A method of making a polyurethane material comprising:
a) reacting at least one polyether polyol having a molecular weight of approximately 1,000 with at least one aliphatic polyisocyanate, thereby forming a prepolymer mixture;
b) reacting the prepolymer mixture with x equivalents of at least one chain extender, thereby forming a reaction mixture, and
c) curing the reaction mixture,
wherein the method comprising reacting a ratio of OH:NCO that is between 0.89:1 and 0.94:1.