Method for producing a composite pane with a functional element

1. A method for producing a composite pane, comprising arranging a functional element in a recess of a thermoplastic frame film, arranging the thermoplastic frame film along with the functional element between a first glass pane and a second glass pane to form a layer stack, and subsequent joining of the layer stack to form a composite pane by lamination, wherein the thermoplastic frame film and the functional element have a different thickness and the different thickness is at least partially compensated by at least one thermoplastic compensating film, whose thickness is less than twice as large as a difference between the thicknesses of the thermoplastic frame film and the functional element such that a maximum offset in the layer stack is less than the difference between the thicknesses of the thermoplastic frame film and the functional element, wherein the thickness of the thermoplastic frame film is greater than the thickness of the functional element and wherein the thermoplastic compensating film is arranged on the functional element within the recess, wherein the functional element is a multilayer element which includes an active layer arranged between two transparent surface electrodes formed on insulating transparent polymeric carrier layers.

2. The method according to claim 1 , wherein the maximum offset in the layer stack is less than or equal to the thickness of the thermoplastic compensating film.

3. The method according to claim 1 , wherein the difference in thickness between the thermoplastic frame film and the functional element is more than 50 μm and wherein no offset of more than 50 μm occurs in the layer stack.

4. The method according to claim 1 , wherein the thermoplastic compensating film is suitable to constitute an adhesive bond to the thermoplastic frame film and adjacent glass panes or adjacent other thermoplastic layers.

5. The method according to claim 1 , wherein the thermoplastic compensating film includes a plasticizer content of less than 15 wt-%.

6. The method according to claim 5 , wherein the plasticizer content is less than 10 wt.-%.

7. The method according to claim 5 , wherein the plasticizer content is less than 5 wt.-%.

8. The method according to claim 7 , wherein the thermoplastic compensating film is substantially plasticizer-free.

9. The method according to claim 8 , wherein the thermoplastic compensating film has a thickness of 40 μm to 70 μm.

10. The method according to claim 1 , wherein the thermoplastic compensating film has a thickness of 25 μm to 100 μm.

11. The method according to claim 1 , wherein the functional element is a functional element with variable optical properties.

12. The method according to claim 11 , wherein the functional element is an SPD, a PDLC, an electrochromic, or an electroluminescent functional element.

13. The method according to claim 1 , wherein a first thermoplastic bonding film is arranged between the thermoplastic frame film and the first glass pane and a second thermoplastic bonding film is arranged between the thermoplastic frame film and the second glass pane.

14. The method according to claim 11 , wherein the functional element is a functional element with electrically switchable or controllable optical properties.