METHOD FOR PRODUCING RIGID LAMINATES FOR OPTICAL APPLICATIONS

• US 20090029100A1
• Filed: 07/23/2007
• Published: 01/29/2009
• Est. Priority Date: 07/23/2007
• Status: Abandoned Application

• Current Assignee: Adhesives Research Inc.
• Original Assignee: Adhesives Research Inc.
• Inventors: WIGDORSKI, Robert Michael, McKINNEY, Kevin James
• Application Number:
  US11/781,354
• Publication Number:
  US 20090029100A1
• Time in Patent Office: Days
• US Class Current: 428/98
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/14 using wave energy , i.e. electromagnetic radiation, or particle radiation using mechanical waves B29C65/06; using ultrasonic waves B29C65/08; pressing means transparent to electromagnetic radiation B29C66/81267
• CPC Class Codes: B29C 65/1406 Ultraviolet [UV] radiation
• CPC Class Codes: B29C 65/1425 Microwave radiation
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/4825 Pressure sensitive adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/4845 Radiation curing adhesives, e.g. UV light curing adhesives
• CPC Class Codes: B29C 65/4865 containing additives C09J11/00 and subgroups take precedence
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/342 Preventing air-inclusions
• CPC Class Codes: B29C 66/345 Progressively making the joint, e.g. starting from the middle B29C66/8341, B29C65/12, B29C65/14, B29C65/16 take precedence
• CPC Class Codes: B29C 66/45 Joining of substantially the whole surface of the articles methods or apparatus for laminating B32B37/00
• CPC Class Codes: B29C 66/73366 both parts to be joined being transparent or translucent to visible light
• CPC Class Codes: B29C 66/81611 by resilient material
• CPC Class Codes: B29C 66/8221 Scissor or lever mechanisms, i.e. involving a pivot point
• CPC Class Codes: B29C 66/8324 Joining or pressing tools pivoting around one axis scissor or lever transmission mechanisms B29C66/8221; tools self-aligning to the joining plane B29C66/8163
• CPC Class Codes: B29C 66/9241 by controlling or regulating the pressure, the force or the mechanical power
• CPC Class Codes: B29L 2011/00 Optical elements, e.g. lenses, prisms
• CPC Class Codes: B30B 15/061 : Cushion plates
• CPC Class Codes: B32B 2309/02 : Temperature
• CPC Class Codes: B32B 2309/105 : Thickness
• CPC Class Codes: B32B 2310/0831 : using UV radiation
• CPC Class Codes: B32B 37/003 : to avoid air inclusion
• CPC Class Codes: B32B 37/10 : characterised by the pressing technique, e.g. using action of vacuum or fluid pressure
• CPC Class Codes: B32B 37/1207 : Heat-activated adhesive B32B37/04 takes precedence
• CPC Class Codes: C09J 5/06 : involving heating of the applied adhesive
• CPC Class Codes: Y10T 428/24 : Structurally defined web or sheet [e.g., overall dimension, etc.]

Abstract

A method for fabricating a rigid lamination. The method includes providing a first rigid substrate, disposing an adhesive on a surface of the first rigid substrate and disposing a second rigid substrate on at least a portion of the adhesive. The second rigid substrate has a first end and a second end. The second rigid substrate is heated to a substantially uniform temperature, where the temperature is sufficient to melt the adhesive. A non-uniform pressure is applied to a surface of the second rigid substrate. The non-uniform pressure includes a lesser pressure and a greater pressure, where the greater pressure is applied at the first end of the second rigid substrate and is sufficient to impart adhesive flow in a direction toward the second end. The pressure is controllably increased along at least a portion of the surface between the first end and the second end, where the increase is controlled to drive the adhesive flow in the direction toward the second end until the pressure applied is substantially uniform across the surface and the adhesive between the first rigid substrate and the second rigid substrate is substantially free of entrained gas bubbles. The adhesive is cooled to form a rigid lamination having adhesive substantially free of entrained gas bubbles.

Claims

1. A method for fabricating a rigid lamination comprising:

providing a first rigid substrate;

disposing an adhesive on a surface of the first rigid substrate;

disposing a second rigid substrate on at least a portion of the adhesive, the second rigid substrate having a first end and a second end;

heating the second rigid substrate to a substantially uniform temperature, the temperature being sufficient to melt the adhesive;

applying a non-uniform pressure to a surface of the second rigid substrate, the non-uniform pressure including a lesser pressure and a greater pressure, the greater pressure being applied at the first end of the second rigid substrate and being sufficient to impart adhesive flow in a direction toward the second end;

controllably increasing the pressure along at least a portion of the surface between the first end and the second end, the pressure increase being controlled to drive the adhesive flow in the direction toward the second end until the pressure applied is substantially uniform across the surface and the adhesive between the first rigid substrate and the second rigid substrate is substantially free of entrained gas bubbles; and

cooling the adhesive to form a rigid lamination having adhesive substantially free of entrained gas bubbles.

2. The method of claim 1, further comprising removing excess adhesive from the lamination, the excess adhesive containing entrained gas bubbles.

3. The method of claim 1, wherein a perimeter step is applied to the first rigid substrate and at least a portion of the adhesive is disposed within the perimeter step.

4. The method of claim 1, wherein the adhesive comprises a plurality of layers.

5. The method of claim 4, wherein at least one of the plurality of layers is a release layer.

6. The method of claim 5, wherein at least one of the plurality of layers is a pressure sensitive adhesive.

7. The method of claim 1, wherein the adhesive layer is subsequently cured.

8. The method of claim 7, wherein the adhesive layer is exposed to visible light to cure at least a portion of the adhesive layer.

9. The method of claim 7, wherein the adhesive layer is exposed to ultraviolet wavelength radiation to cure at least a portion of the adhesive layer.

10. The method of claim 7, wherein the adhesive layer is tacky after curing.

11. The method of claim 7, wherein the adhesive layer is tack free after curing.

12. The method of claim 1, wherein the adhesive layer comprises an ionomeric adhesive.

13. The method of claim 1, wherein adhesive layer has sufficient volume to create a material flow to expel entrained gas bubbles air in the adhesive layer subsequent to application of non-uniform pressure.

14. The method of claim 1, wherein the adhesive layer includes at least twice the mass required to fill an area between the first rigid substrate and the second rigid substrate.

15. The method of claim 1, wherein the viscosity of the adhesive layer is greater than about 37,500 cP at the substantially uniform temperature.

16. The method of claim 1, wherein the viscosity of the adhesive layer is greater than about 50,000 cP at the substantially uniform temperature.

17. An apparatus for forming a rigid lamination comprising:

a first platen arranged and disposed to receive a lamination assembly, the lamination including a plurality of rigid substrates with an adhesive disposed between at least two of the rigid substrates;

a second platen operably disposed with respect to the first platen in order to apply a force and apply heat to the lamination assembly,

wherein the second platen is configured to heat a surface of the lamination assembly to a substantially uniform temperature, the temperature being sufficient to melt the adhesive; and

to apply a non-uniform pressure to the surface of the lamination assembly, the non-uniform pressure including a lesser pressure and a greater pressure, the greater pressure being applied to a first end of the surface and being sufficient to impart adhesive flow in a direction toward a second end;

wherein the second platen is further capable of controllably increasing the pressure along at least a portion of the surface between the first end and the second end, the increase being controlled to continue adhesive flow in the direction toward the second end until the pressure applied is substantially uniform across the surface.

18. The apparatus of claim 17, wherein a perimeter step is applied to the first rigid substrate and at least a portion of the adhesive is disposed within the perimeter step.

19. The apparatus of claim 17, wherein adhesive layer has sufficient volume to create a material flow to expel entrained gas bubbles air in the adhesive layer subsequent to application of non-uniform pressure.

20. The apparatus of claim 17, wherein the adhesive layer includes at least twice the mass required to fill an area between the first rigid substrate and the second rigid substrate.

21. A rigid lamination comprising:

a first rigid substrate having an adhesive disposed on at least a portion of the surface of the first rigid substrate;

a second rigid substrate in contact with the adhesive; and

wherein the adhesive includes a first portion and a second portion, the first portion being substantially free of entrained bubbles of gas and the second portion being removable and including entrained bubbles of gas.

22. The lamination of claim 21, wherein the rigid substrates are substantially aligned.

23. The lamination of claim 21, wherein the rigid substrates include an internal cavity.

24. The lamination of claim 21, wherein the internal cavity is bound by a perimeter step.

25. The lamination of claim 21, wherein the second portion is recyclable.

26. The lamination of claim 21, wherein the adhesive layer is cured.

27. The lamination of claim 26, wherein the adhesive layer is tacky after curing.

28. The lamination of claim 26, wherein the adhesive layer is tack free after curing.