Method for producing a laminated pane

Abstract

A method for producing a laminated pane, wherein a first laminating film, a carrier film, and a second laminating film are provided and joined to form a pre-laminate, wherein the first laminating film, the carrier film, and the second laminating film have the same film thickness, a compensating film and the pre-laminate are arranged to form a layer stack between a first pane and a second pane, wherein, parallel to two side edges of the layer stack, in each case a strip-shaped peripheral film is arranged and the compensating film is provided to compensate an offset between the pre-laminate and the peripheral films, and the layer stack including the first pane, the pre-laminate, the compensating film with peripheral films, and the second pane is laminated to form a laminated pane, wherein the first laminating film and the second laminating film have a plasticizer content of less than 15 wt.-%.

Claims

1. A method for producing a laminated pane, the method comprising: providing and joining a first laminating film, a carrier film, and a second laminating film to form a pre-laminate, wherein the first laminating film, the carrier film, and the second laminating film have the same film thickness, to form a pre-laminate, arranging a compensating film, the pre-laminate and strip-shaped peripheral films adjacent and parallel to side-edges of the pre-laminate, the strip-shaped peripheral films forming a frame on four sides of the pre-laminate, to form a layer stack between a first pane and a second pane, wherein the compensating film is provided to compensate an offset between the pre-laminate and the strip-shaped peripheral films, and laminating the layer stack comprising the first pane, the pre-laminate, the strip-shaped peripheral films, the compensating film, and the second pane to form a laminated pane, wherein the first laminating film and the second laminating film have a plasticizer content of less than 15 wt.-%, and wherein a stiffness of the first and second laminating films is lower than a stiffness of the carrier film but stiffer than a stiffness of the compensating film, wherein a first thermoplastic bonding film is arranged between the compensating film and the first pane and a second thermoplastic bonding film is arranged between the pre-laminate and the second pane.

2. The method according to claim 1, wherein one of the strip-shaped peripheral films is arranged parallel to a longitudinal edge extending in the longitudinal direction of the pre-laminate.

3. The method according to claim 1, wherein the first laminating film and the second laminating film have a thickness of 25 μm to 250 μm.

4. The method according to claim 1, wherein the carrier film has a thickness of 25 μm to 250 μm.

5. The method according to claim 1, wherein the first thermoplastic bonding film and/or the second thermoplastic bonding film have a thickness of 0.1 mm to 0.8 mm.

6. The method according to claim 2, wherein the strip-shaped peripheral films have a thickness of 0.38 mm.

7. The method according to claim 1, wherein before lamination, the pre-laminate is provided with an incision in a peripheral region, wherein a depth of the incision is greater than the thickness of the first laminating film and the carrier film.

8. The method according to claim 1, wherein before lamination, the compensating film is joined to the first laminating film, the carrier film, and the second laminating film to form the pre-laminate.

9. The method according to claim 2, wherein the pre-laminate is produced at a temperature of up to 100° C.

10. The method according to claim 2, wherein the pre-laminate has an infrared-reflecting, electrochromic, or an electroluminescent functional layer.

11. A method comprising utilizing a laminated pane produced according to claim 1 as a vehicle pane, a watercraft pane, or an aircraft pane, as construction glazing or architectural glazing.

12. A laminated pane obtained by a method according to claim 1, comprising, arranged flat one above another: an outer pane, a first laminating film, a carrier film, a second laminating film, a compensating film with peripheral films, and a second pane, wherein the first laminating film, the second laminating film, and the carrier film have the same film thickness.

13. The method according to claim 1, wherein the plasticizer content is less than 5 wt.-%.

14. The method according to claim 13, wherein the first laminating film and the second laminating film are plasticizer-free.

15. The method according to claim 3, wherein the first laminating film and the second laminating film have a thickness of 50 μm.

16. The method according to claim 4, wherein the carrier film has a thickness of 50 μm.

17. The method according to claim 5, wherein the first thermoplastic bonding film and/or the second thermoplastic bonding film have a thickness of 0.38 mm.

18. The method according to claim 11, wherein the laminated pane is a side window, windshield, roof panel, or rear window.

Description

(1) In the following, the invention is explained in detail with reference to drawings and exemplary embodiments. The drawings are purely schematic and not to scale. The drawings in no way restrict the invention.

(2) They depict:

(3) FIG. 1 a cross-section of a structure of a laminated pane according to the invention before a lamination process,

(4) FIG. 2 a laminated pane according to the invention with a peripheral region,

(5) FIG. 3 a cross-section through another embodiment of a structure of a laminated pane according to the invention before a lamination process,

(6) FIG. 4 a cross-section through another embodiment of a structure of a laminated pane according to the invention before a lamination process, and

(7) FIG. 5 a flow chart of a method according to the invention for producing a laminated pane.

(8) FIG. 1 depicts a cross-section of a structure of a laminated pane 1 according to the invention, here, before the lamination process. The laminated pane 1 consists of a first pane 2 made of soda lime glass with a thickness of 1.4 mm and a second pane 3 made of soda lime glass with a thickness of 2.1 mm. Arranged between the first pane 2 and the second pane 3 is a first laminating film 4, a carrier film 5 with an infrared-reflecting coating, a second laminating film 6, and a compensating film 7. The laminating films 4 and 6 are essentially plasticizer-free PVB films with a very low thickness of approx. 50 μm. The laminating films 4 and 6 as well as the carrier film 5 have roughly the same film thickness. The carrier film 5 can, for example, be a PET film with a thickness of 50 μm. Two strip-shaped peripheral films 9 run in each case at two opposite longitudinal edges of the first and the second panes 2 and 3.

(9) The compensating film 7 is placed centrally on one side of the first pane 2. The shape of the compensating film 5 corresponds roughly to the shape of the first pane 2, wherein at two opposite sides, a strip-shaped peripheral region A of the first pane 2 is not covered by the compensating film. The peripheral region A represents the maximum distance between the pane edge and the compensating film 7 at the edge of the pane.

(10) A so-called trilayer 8 is arranged on the compensating film 7. The trilayer 8 contains at least the first laminating film 4, the carrier film 5, and the second laminating film 6, with the carrier film 5 having previously been bonded to the first and second laminating film (4 and 6) at a temperature of up to 100° C. to form the trilayer 9. In this processing step, the carrier film 5 is embedded between the two laminating films (4 and 6) such that it is protected against environmental influences and is particularly easy to handle during further processing. The shape and size of the trilayer 8 correspond roughly to the shape and size of the compensating film 7 such that a layer stack comprising the compensating film 7 and the trilayer 8 is formed. Parallel to the two side edges of the layer stack, the strip-shaped peripheral film 9 is arranged in each case on the first pane 2; it thus completely fills the free peripheral region A between the first pane 2 and the second pane 3.

(11) The trilayer 8 is thinner than the peripheral films 9, as a result of which an offset would develop at the transition from the peripheral film 9 to the trilayer 8. The compensating film 7 has a thickness that fills this empty space. Ideally, the peripheral films and the layer stack consisting of the compensating film 7 and trilayer 8 should have the same thickness. The compensating film 7 and the peripheral films 9 are, for example, PVB films, with the peripheral films 9 having a thickness of 0.38 mm.

(12) The first pane 2 is bent together with the second pane 3 before a lamination process such that the first pane 2 and the second pane 3 are spherical. The first pane 2 and the second pane 3 can be bent spherically with any complexity, e.g., conically or parabolically. The curvatures of the panes 2 and 3 can, for example, have a cylindrical curvature with a bending radius R1 and/or a second curvature with a radius R2, where R1 is not equal to R2.

(13) Additionally, the laminated pane 1 can contain a first thermoplastic bonding film 10 between the compensating film 7 and the first pane 2 (FIG. 3). Analogously, a second thermoplastic bonding film 11 can be arranged between the pre-laminate and the second pane (FIG. 4). Both the first and the second thermoplastic bonding film 10 and 11 can be PVB films with a film thickness of 0.38 mm and completely cover the first or the second pane 2 or 3. The first and second thermoplastic bonding film 10 and 11 serve as adhesive layers and constitute the bond to the first or second pane 2 and 3.

(14) The laminated pane 1 can, for example, be provided as a roof panel of a motor vehicle.

(15) FIG. 2 depicts a plan view of the laminated pane 1 according to the invention having peripheral films 9 in the peripheral region A, before lamination. Here, the laminated pane 1 has two additional peripheral films 9 in peripheral regions B and C of the laminated pane 1 such that the pre-laminate 8 is surrounded in a frame-like manner by the peripheral films 9.

(16) FIG. 3 depicts a cross-section through a second embodiment of the layer stack according to the invention. Here, the laminated pane 1 includes a first thermoplastic bonding film 10, which is arranged between the first pane 2 and the compensating film 7 or the peripheral film 9, before lamination.

(17) FIG. 4 depicts another embodiment of the layer stack according to the invention. Here, the laminated pane 1 additionally includes a second thermoplastic bonding film 11, which is arranged between the second pane 3 and the first laminating film 4 or the peripheral film 9, before lamination.

(18) FIG. 5 depicts a flow chart of a preferred embodiment of the method according to the invention for producing a laminated pane 1. The steps depicted in FIG. 3 are as follows: I Providing a first laminating film 4, a carrier film 5, and a second laminating film 6; and joining the first laminating film 4, the carrier film 5, and a second laminating film 6 to form a pre-laminate (trilayer), II Providing the pre-laminate and a compensating film corresponding to the size of the first pane 2, III Placing a compensating film 7 on a first pane, with the compensating film 7 arranged centrally on the first pane 2 such that two free peripheral regions A are created on two longitudinal edges of the first pane IV Arranging the compensating film 7 and the pre-laminate 8 to form a layer stack, wherein a strip-shaped peripheral film 9, whose width corresponds to the peripheral region A, is in each case arranged parallel to two side edges of the layer stack V Placing a second pane 3 on the pre-laminate, wherein one side of the second pane 3 lies flat on the trilayer 8 and peripheral films 9 and covers them completely VI Laminating the stack comprising the first pane 2, the compensating film 7, the pre-laminate with peripheral films 9, and the second pane 3 in the autoclave to form a laminated pane 1.

(19) Optionally, in step I, the pre-laminate (quadrolayer) can consist of the first laminating film 4, the carrier film 5, the second laminating film 6, and the compensating film 7. In addition, the pre-laminate can have embossing that improves the adhesion of the pre-laminate. In another embodiment, the layer stack consisting of the laminating film, the carrier film, the second laminating film, and the compensating film can be pre-fixed at points in its peripheral regions by spot welding with a soldering iron.

(20) The pre-laminate is subjected to severe deformations in the autoclave. Despite the effect of heat and tensile forces on the pre-laminate, a wrinkle-free laminated pane can be ensured. Since, in a first step, the very thin carrier film 5 is embedded between two equally thin laminating films 4 and 6 with very low plasticizer content, its stiffness does not interfere with subsequent manufacturing processes and wrinkling defects in the laminated pane 1 can thus be reduced considerably.

LIST OF REFERENCE CHARACTERS

(21) (1) laminated pane (2) first pane (3) second pane (4) first laminating film (5) carrier film (6) second laminating film (7) compensating film (8) pre-laminate (9) peripheral film (10) first thermoplastic bonding film (11) second thermoplastic bonding film (A) longitudinal peripheral region (B) transverse peripheral region (C) transverse peripheral region