Transparent formable polyurethane polycarbonate lamination

• US 4,045,269 A
• Filed: 12/22/1975
• Issued: 08/30/1977
• Est. Priority Date: 12/22/1975
• Status: Expired due to Term

• Current Assignee: Sierracin Corporation (Nouryon BV)
• Original Assignee: Sierracin Corporation (Nouryon BV)
• Inventors: Miller, William Albert, Hermansen, Ralph David, Voss, David Lehmann
• Primary Examiner(s): Simmons, David A.
• Application Number:
  US05/643,247
• Time in Patent Office: 617 Days
• Field of Search: 156/241, 156/306, 156/99, 156/102, 156/106, 156/221, 156/222, 156/196, 428/412, 428/423, 156/243, 156/246, 264/248, 264/1, 264/DIG. 57, 244/129 W
• US Class Current: 156/221
• CPC Class Codes: B29C 51/14 using multilayered preforms or sheets
• CPC Class Codes: B29C 53/04 of plates or sheets B29C63/04 takes precedence; bending or folding paper B31F1/0003; folding films B65H45/00
• CPC Class Codes: B29C 63/00 Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor B29C73/00 takes precedence; by blowing B29C49/00; by thermoforming B29C51/00
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/0026 Transparent
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 2305/72 Cured, e.g. vulcanised, cross-linked
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/536 Hardness
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 38/1866 conforming the layers or laminate to a convex or concave profile
• CPC Class Codes: Y10T 156/1043 Subsequent to assembly
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]

Abstract

A method for producing clear, cured transparent polycarbonate laminates comprises directly bonding a sheet of transparent thermosetting polyurethane sheet to a polycarbonate sheet to produce a laminate, heating the laminate above the softening point of the polycarbonate sheet, and forming the laminate to a desired curvature.

Claims

1. A method for producing a curved transparent polycarbonate laminate from a polycarbonate sheet comprising the steps of:

a. preparing a substantially completely cured, rigid, transparent thermoset polyurethane sheet having a Shore D hardness less than about 70 and a tear strength greater than about 50 pli at temperatures greater than the temperature T₁, the polycarbonate sheet heat deflection temperature, and less than the temperature T₂, the polycarbonate sheet chain scission temperature;

b. thereafter directly bonding the polyurethane sheet to the polycarbonate sheet to produce a laminate wherein the polyurethane sheet is an outer layer of the laminate;

c. heating the laminate to at least T₁ and less than T₂ ; and

d. forming the laminate to a desired curvature.

2. The method claimed in claim 1 wherein preparing the polyurethane sheet comprises reacting aliphatic diisocyanates with saturated polyalkylene ether polyols.

3. The method claimed in claim 1 wherein the step of preparing the polyurethane sheet comprises reacting a cycloaliphatic polyisocyanate with polyalkylene ether polyols.

4. The method claimed in claim 3 wherein the cycloaliphatic polyisocyanate is a cycloaliphatic diisocyanate.

5. The method claimed in claim 4 wherein the cycloaliphatic diisocyanate is 4,4'"'"'-methylene-bis (cyclohexyl isocyanate).

6. The method claimed in claim 1 wherein the step of directly bonding comprises fusion bonding the polyurethane sheet to the polycarbonate sheet.

7. A method as claimed in claim 1 wherein the polycarbonate sheet is fabricated from a polycarbonate based upon 2,2-bis(4-hydroxy-phenyl) propane.

8. A method as claimed in claim 1 wherein the step of preparing comprises preparing a polyurethane sheet at least about 0.01 inch thick.

9. A method for producing curved transparent polycarbonate laminates from polycarbonate sheet fabricated from a polycarbonate based upon 2,2-bis (4-hydroxy-phenyl) propane comprising the steps of:

a. preparing a substantially completely cured, rigid, transparent thermoset polyurethane sheet having a Shore D hardness less than about 70 and a tear strength greater than about 50 pli at a temperature of from about 270°

F to about 375°

F;

b. thereafter directly bonding the polyurethane sheet to the polycarbonate sheet to produce a laminate wherein the polyurethane sheet is an outer layer of the laminate;

c. heating the laminate to at least about 270°

F and less than about 375°

F; and

d. forming the laminate to a desired curvature.

10. The method claimed in claim 9 wherein the step of preparing the polyurethane sheet comprises reacting one or more aliphatic polyisocyanates with one or more saturated polyalkylene ether polyols.

11. The method claimed in claim 9 wherein the step of preparing the polyurethane sheet comprises reacting a cycloaliphatic diisocyanate with polyalkylene ether polyols.

12. The method claimed in claim 11 wherein the cycloaliphatic diisocyanate is 4,4'"'"'-methylene-bis (cyclohexyl isocyanate).

13. The method claimed in claim 9 wherein the step of directly bonding comprises fusion bonding the polyurethane sheet to the polycarbonate sheet.

14. A method for producing curved transparent polycarbonate laminates comprising the steps of:

a. preparing a substantially completely cured, rigid, transparent thermoset polyurethane sheet with a Shore D hardness less than about 70 and a tear strength greater than about 50 pli at a temperature of from about 270°

F to about 375°

F, and having a thickness of at least about 0.01 inch, by reacting 4,4'"'"'-methylene-bis (cyclohexyl isocyanate) with saturated polyalkylene ether polyols;

b. thereafter fusion bonding the polyurethane sheet to a polycarbonate sheet prepared from 2,2-bis (4-hydroxy-phenyl) propane to produce a laminate wherein the polyurethane sheet is an outer layer of the laminate;

c. heating the laminate to at least about 270°

F and less than about 375°

F; and

d. forming the laminate to a desired shape.

15. A method for producing a curved transparent polycarbonate laminate from a polycarbonate sheet comprising the steps of:

a. casting an uncured thermosetting polyurethane on the polycarbonate sheet;

b. substantially completely curing the cast polyurethane into a rigid sheet at least about 0.01 inch thick on the polycarbonate sheet to directly bond the polyurethane to the polycarbonate sheet to produce a laminate wherein the polyurethane sheet is an outer layer of the laminate, and wherein the cured polyurethane sheet has a Shore D hardness less than about 70 and a tear strength greater than about 50 pli at temperatures greater than the temperature T₁, the polycarbonate sheet heat deflection temperature, and less than the temperature T₂, the polycarbonate sheet chain scission temperature;

c. heating the laminate to at least T₁ and less than T₂ ; and

d. forming the laminate to a desired curvature.

16. The method of claim 15, comprising the additional step of fusion bonding the cured polyurethane sheet to the polycarbonate sheet.

17. The method claimed in claim 15 wherein the step of curing the polyurethane sheet comprises reacting aliphatic diisocyanates with saturated polyalkylene ether polyols.

18. The method claimed in claim 15 wherein the step of curing the polyurethane sheet comprises reacting a cycloaliphatic polyisocyanate with polyalkylene ether polyols.

19. The method claimed in claim 18 wherein the cycloaliphatic polyisocyanate is a cycloaliphatic diisocyanate.

20. The method claimed in claim 19 wherein the cycloaliphatic diisocyanate is 4,4'"'"'-methylene-bis (cyclohexyl isocyanate).

21. A method as claimed in claim 15 wherein the polycarbonate sheet is fabricated from a polycarbonate based upon 2,2-bis (4-hydroxy-phenyl) propane.

22. A method for producing curved transparent polycarbonate laminates from polycarbonate sheet fabricated from a polycarbonate based upon 2,2-bis (4-hydroxy-phenyl) propane comprising the steps of:

a. casting an uncured thermosetting polyurethane on the polycarbonate sheet;

b. substantially completely curing the cast polyurethane into a rigid sheet at least about 0.01 inch thick on the polycarbonate sheet to directly bond the polyurethane to the polycarbonate sheet to produce a laminate wherein the polyurethane sheet is an outer layer of the laminate, and wherein the cured polyurethane sheet has a Shore D hardness less than about 70 and a tear strength greater than about 50 pli at a temperatue of from about 270°

F to about 375°

F;

c. heating the laminate to at least about 270°

F and less than about 375°

F; and

d. forming the laminate to a desired curvature.

23. The method of claim 22 comprising the additional step of fusion bonding the cured polyurethane sheet to the polycarbonate sheet.

24. The method claimed in claim 22 wherein the step of curing the cast polyurethane comprises reacting one or more aliphatic polyisocyanates with one or more saturated polyalkylene ether polyols.

25. The method claimed in claim 22 wherein the step of curing the cast polyurethane comprises reacting a cycloaliphatic diisocyanate with polyalkylene ether polyols.

26. The method claimed in claim 25 wherein the cycloaliphatic diisocyanate is 4,4'"'"'-methylene-bis (cyclohexyl isocyanate).