TRIM FOR MOTOR VEHICLE GLAZING SYSTEMS

Abstract

The invention relates to trims for motor vehicle glazing systems, comprising a base layer and a coating and having glass-like optical properties at least in some subsections, composites consisting of such trims for motor vehicle glazing systems, and car body parts, as well as preferred embodiments which comprise suitable combinations of materials. Said trims comprising, at least towards the front side thereof, an edge rounding having a variable radius which allows a more uniform layer thickness for the coating.

Claims

1.-15. (canceled)

16. A bezel for motor vehicle glazing systems, comprising a base layer based on a thermoplastic, with a front side and a reverse side, and also sides connecting the front side and the reverse side, wherein the bezel has a coating on the front side, wherein the edges between the sides connecting the front side and the reverse side of the base layer and the front side of the base layer have been rounded, wherein the rounding has a radius that is variable across the rounding and wherein the bezel has a coating in the rounded edge region of the front side.

17. The bezel as claimed in claim 16, wherein, in relation to the reverse side and the front side of the bezel, the bezel is U-shaped, O-shaped, double-O-shaped, T-shaped or I-shaped.

18. The bezel as claimed in claim 16, wherein the edges between the sides connecting the front side and the reverse side of the base layer and the reverse side of the base layer have been rounded.

19. The bezel as claimed in claim 18, wherein the bezel has a coating on the reverse side.

20. The bezel as claimed in claim 16, wherein at least the rounding of the edges between the sides connecting the front side and the reverse side of the base layer and the front side of the base layer has the shape of, or approximately the shape of, a Bezier curve.

21. The bezel as claimed in claim 20, wherein the Bezier curve is quadratic or cubic.

22. The bezel as claimed in claim 16, wherein the bezel is U-shaped, O-shaped, double-O-shaped or T-shaped, where at least one internal angle R1 situated between two legs of the bezel has been rounded, where the internal angle R1 describes, precisely or approximately, a quadrant.

23. The bezel as claimed in claim 22, wherein the radius of the quadrant is at least 10 mm.

24. The bezel as claimed in claim 16, wherein the width b of the region between the outermost point P at the rounded edge of the bezel and the point E at the transition between the rounded region and a surface without curvature is at least 2.5 mm.

25. The bezel as claimed in claim 16, wherein the wall thickness of the bezel is from 1.5 mm to 5 mm.

26. The bezel as claimed in claim 16, wherein the bezel comprises a plurality of layers of which one is a base layer comprising polycarbonate, optionally carbon black, and a mold-release agent based on a fatty acid ester, and where there is, on at least one side of the base layer, a polysiloxane-based scratch-resistant coating comprising at least one UV absorber.

27. The bezel as claimed in claim 26, wherein carbon black present comprises nanoscale carbon black with average primary particle size less than 100 nm, determined by scanning electron microscopy.

28. The bezel as claimed in claim 16, wherein the bezel has, on the reverse side, a rib which, in relation to the cross section of the bezel, is in the region of the edge rounding between the sides connecting the front side and the reverse side of the base layer and the front side of the base layer.

29. A compound-structure system comprising bodywork of a motor vehicle and comprising a bezel as claimed in claim 16.

30. A process for the production of a bezel as claimed in claim 16, comprising the following steps: closure of the injection mold, injection of a first polymer composition, preferably by way of injection-compression molding or cascade injection molding, then cooling to a maximal component temperature lower than the glass transition temperature of the first polymer composition, optionally moving of the cavity into the next position or use of a mold with a larger cavity for purposes of injection of a second polymer composition, in such a way that on closure of the mold in this position an intervening space is produced between the first hardened polymer composition and the mold wall, optional injection of the second polymer composition, then cooling to a maximal component temperature lower than the glass transition temperature of the second polymer composition, coating of the bezel.

Description

[0124] The invention is explained in more detail below with reference to some drawings depicting preferred embodiments.

[0125] FIG. 1: is a plan view of the front side of a U-shaped bezel, particular attention being drawn to the region of the internal angle between the legs of the bezel;

[0126] FIG. 2: is a plan view of the reverse side of the bezel of FIG. 1; the section A′-A′ is depicted in FIGS. 3a to 3f for various embodiments;

[0127] FIG. 3a: is a cross-sectional view along the line A′-A′ in FIG. 2 of the bezel shown in FIG. 2 in a first embodiment;

[0128] FIG. 3b: is a cross-sectional view along the line A′-A′ in FIG. 2 of the bezel shown in FIG. 2 in a second embodiment;

[0129] FIG. 3c: is a cross-sectional view along the line A′-A′ in FIG. 2 of the bezel shown in FIG. 2 in a third embodiment;

[0130] FIG. 3d: is a cross-sectional view along the line A′-A′ in FIG. 2 of the bezel shown in FIG. 2 in a fourth embodiment;

[0131] FIG. 3e: is a cross-sectional view along the line A′-A′ in FIG. 2 of the bezel shown in FIG. 2 in a fifth embodiment;

[0132] FIG. 3f: is a cross-sectional view along the line A′-A′ in FIG. 2 of the bezel shown in FIG. 2 in a sixth embodiment;

[0133] FIG. 4: is a plan view of the reverse side of the bezel of FIG. 1, particular attention being drawn to the region X which is the location of the internal angle between two legs;

[0134] FIG. 5a: is a perspective view of ribs attached in the internal angle region X shown in FIG. 4 in a first embodiment;

[0135] FIG. 5b: is a perspective view of ribs attached in the internal angle region X shown in FIG. 4 in a second embodiment;

[0136] FIG. 5c: is a perspective view of ribs attached in the internal angle region X shown in FIG. 4 in a third embodiment;

[0137] FIG. 6a: is a plan view of the front side of a U-bezel;

[0138] FIG. 6b: is a plan view of the front side of an O-bezel;

[0139] FIG. 6c: is a plan view of the front side of a double-O-bezel;

[0140] FIG. 6d: is a plan view of the front side of a T-bezel;

[0141] FIG. 6e: is a plan view of the front side of an I-bezel;

[0142] FIG. 7: is a cross-sectional view of the perimeter region of a bezel with rib in the perimeter region.

[0143] FIG. 1 shows a U-shaped bezel (abbreviated to: U-bezel) having a first and second exterior leg S1, S2 and a leg S3 connecting the legs S1 and S2, particular attention being drawn to region X of the internal angle R1 between the legs S2 and S3 of the bezel. The internal angle between the legs S3 and S1 is preferably the same as the internal angle between the legs S3 and S2, but it can also differ. The internal angle R1 describes approximately a quadrant. The radius of this quadrant is indicated by “Ri”. For easier understanding of the geometric relationships, the drawing moreover includes a coordinate system for orientation. It can be seen that the areas of the front side and of the reverse side of the bezel extend within the x/y-plane, and this also applies accordingly to the rounded transition region between the legs S3 and S1 with the internal angle R1. The feature, essential to the invention, of the edge rounding in z-direction is explained below.

[0144] FIG. 2 shows the rear view of the U-bezel of FIG. 1. The adhesive beads H can clearly be seen here. The sectional line A′-A′ runs through the rounded internal angle between the legs S1 and S3. The following FIGS. 3a to 3f show cross-sectional views of the bezel along this sectional line in various alternative embodiments. The upper rounded edge R.sub.o and the lower rounded edge R.sub.u can be seen. “P” indicates the outermost endpoint of the bezel at the rounded edge. An imaginary straight line A perpendicular to the front side and the reverse side of the bezel runs through said endpoint P. “E.sub.o” indicates the point of transition between the rounded region of the rounded edge and the actual front side of the bezel, i.e. generally a surface without curvature. “b” indicates the distance between the straight line A running through the point P and a perpendicular running through the point E.sub.o, where the perpendiculars run orthogonally with respect to the reverse side of the bezel.

[0145] In the embodiment shown in FIG. 3a, the upper edge rounding takes the form of a Bézier curve. Between the upper and lower rounded edge, R.sub.o and R.sub.u, there is no straight-line transition region present that is perpendicular to the front side and the reverse side. The endpoint P is therefore genuinely a point, whereas in the case of the embodiment shown in FIG. 3d the outermost endpoint P lies on a straight-line transition section on the straight line A perpendicular to the front side and reverse side of the bezel.

[0146] In FIG. 3b, the upper edge R.sub.o has been rounded in the shape of a Bézier curve. The lower edge R.sub.u has been non-specifically rounded. The point E.sub.o is the point at which the Bëzier curve ends. There is a straight-line transition section present, perpendicular to the front side and the reverse side of the bezel, between the two rounded edges at the sides connecting the front side and the reverse side of the bezel.

[0147] In the embodiment in FIG. 3c, the upper edge R.sub.o has been rounded in the shape of a Bézier curve. The lower edge R.sub.u has likewise been rounded in the shape of a Bézier curve, and specifically in the shape of a quadratic Bézier curve. There is no straight-line transition section present, perpendicular to the front side and the reverse side of the bezel, between the two rounded edges at the sides connecting the front side and the reverse side of the bezel.

[0148] In the embodiment shown in FIG. 3e, only the upper edge R.sub.o has been rounded, whereas the lower edge R.sub.u is a conventional “angular edge”, where an “angular edge” can certainly have minimal rounding caused by a manufacturing process. The upper edge R.sub.o has been rounded with radius varying across the rounding, and specifically in the shape of a Bézier curve. There is a direct transition between the rounding of the upper edge R.sub.o and the lower angular edge R.sub.u, and the vertical dimension of the outermost end point P is therefore equal to 0.

[0149] In contrast to this, the dimension of the section P in the embodiment shown in FIG. 3f is greater than 0, i.e. a portion of the cross section of the side connecting the front side and the reverse side of the bezel comprises a straight line.

[0150] FIG. 4 again shows, as in FIG. 2a, the reverse side of the U-bezel, inclusive of the region indicated by “X” at the point of intersection between two legs. This region “X” is depicted in enlarged form for certain embodiments in FIGS. 5a to 5c, there being ribs here placed perpendicularly onto the area of the reverse side of the bezel. These ribs can, as shown in FIG. 5a, form a rib structure interrupted by cutouts L or, as shown in FIG. 5b, can form a coherent rib line G. Another possibility is a coherent rib line G which has indentations F, as shown in FIG. 5c. It can moreover be seen in FIG. 4 that the adhesive beads are not continuous, but instead have gaps.

[0151] Cutouts L between two ribs are usually provided for, by way of example, water management. However, it is preferable in the invention to avoid cutouts between the individual ribs, or else if necessary that these take the form of indentations F. The cutouts imply local differences in stiffness which lead to concentrations of stress and therefore to higher expansion values.

[0152] FIGS. 6a to 6e show various preferred bezel shapes, and specifically a U-bezel (FIG. 6a), an O-bezel (FIG. 6b), a double-O-bezel (FIG. 6c), a T-bezel (6d) and an I-bezel (FIG. 6e).

[0153] FIG. 7 shows a cross section of the perimeter region of a bezel of the invention where a rib B is present in the perimeter region. The drawing does not include the depression in the front side of the base layer of the bezel, because although this is present its extent is minimal. The upper edge R.sub.o has been rounded in the shape of a Bézier curve. The location of the rib is in front of the point E.sub.o, i.e. in front of the point of transition between the rounded region of the rounded edge and the actual front side of the bezel, i.e. a surface without curvature.

KEY

[0154] R1 internal angle (rounded region between two legs) [0155] X region shown enlarged around the internal angle R1 [0156] P outermost endpoint of the bezel in the case of the rounded edge, optionally in the form of straight-line transition section between the upper and lower rounded edge [0157] A straight line through P, perpendicular to the plane of the front side and the reverse side [0158] r radius of an imaginary circle on which the respective point of the rounded edge lies [0159] E.sub.o point of transition between the rounded region of the rounded edge and the actual front side of the bezel, i.e. generally a surface without curvature [0160] b width of the region between A and E [0161] L cutout in a rib structure [0162] G rib [0163] F indentation in a rib [0164] H adhesive bead [0165] S leg [0166] R.sub.o upper rounded edge [0167] R.sub.u lower rounded edge [0168] Ri radius of the rounded region of the internal angle between two legs (x/y-plane) [0169] B rib