Shaped interplayer for heads-up display windshields and process for preparing same
AssigneeE. I. Du Pont de Nemours and Company
InventorsJimmy K Travis, Randall A Hollingsworth
Life of this patent
Estimating the term…
Abstract
A self-supporting adhesive web (10) having a uniform thickness profile across at least 20% of its width as shown by areas A and B and a wedge-shaped thickness profile in areas C and D. As shown in FIG. 2, a laminate comprises sheets of glass (12 and 14) having sandwiched therebetween adhesive interlayer (16). Interlayer (16) has a uniform thickness profile extending from edge (18) to point (20) and a wedge-shaped thickness profile from point (20) to edge (22).
Claims15
A continuous web (10) of self-supporting adhesive sheet useful for making a transparent adhesive interlayer (16) comprising:
- (a) an area of uniform thickness profile across at least 20% of its width starting the center of the web and continuing in both directions toward the outer edges of the web, and (b) two areas of variable thickness profile increasing in thickness from the outer edges of the web to the area of uniform thickness at the center of the web, such that by splitting the web in the region of uniform thickness, two pieces of sheet are obtained each having an area of at least 20% uniform thickness.
A vehicle windshield for a heads-up display (HUD) system comprising outboard (12) and inboard (14) sheets of glass having a transparent adhesive interlayer (16) sandwiched there between, characterized by further having a uniform thickness profile (18, 20) across at least 20% of the area beginning at a top edge of said interlayer and extending to an image area for said display, and having a predetermined wedge-shaped thickness profile (20, 22) extending through the image area to the bottom edge of said interlayer.
A process for preparing transparent adhesive interlayer (16), the process comprising the steps of:
- (a) extruding a plasticized polyvinyl butyral composition through an adjustable extrusion die to provide a web of adhesive sheeting material (10);
- (b) quenching the web (10);
- characterized by further comprising the steps of:
- (c) slitting said web (10) at or near its mid-point;
- and
- (d) winding said slit web onto separate rolls, and wherein said die provides a continuous web of self-supporting material having a uniform thickness profile across at least 20% of the area of the web extending along the center of the web and a wedge-shaped thickness profile decreasing in thickness from the area of uniform thickness to the edge of said web.
A continuous web of self-supporting adhesive sheet useful for making a transparent adhesive interlayer comprising (a) two areas of uniform thickness profile across at least 20% of its width extending from the edges of the web toward the center such that the web includes an area of non-uniform thickness whereby splitting the web in the area of non-uniform thickness provides two pieces of sheet, each having an area of at least 20% uniform thickness and (b) an area of non-uniform thickness profile wherein the thickness of the web is continuously increasing starting at or near the center of the web and increasing linearly in the direction of both edges to the areas of uniform thickness along the edges of the web, wherein a vertex is formed at each juncture where an area of uniform thickness meets an area of non-uniform thickness, and wherein the vertices maybe curved such that a sharp edge is not detectable by physical inspection of the vertex.
A continuous web of self-supporting adhesive sheet useful for making a transparent adhesive interlayer comprising (a) two areas of uniform thickness profile across at least 20% of its width extending from the edges of the web toward the center such that by splitting the web at or near its midpoint between the outer edges, two pieces of sheet are obtained each having an area of at least 20% uniform thickness and (b) an area of non-uniform thickness profile wherein the thickness of the web is continuously increasing in a non-linear manner, starting at or near the center of the web and increasing in the direction of both edges to the areas of uniform thickness, wherein a vertex is formed at each juncture where an area of uniform thickness meets an area of non-uniform thickness and also at the juncture where the web is thinnest, and wherein the vertices can be curved such that a sharp edge is not detectable by physical inspection of the vertex.
A continuous single cut web of self-supporting adhesive sheet useful for making a transparent adhesive interlayer comprising (a) an area of uniform thickness profile across at least 20% of its width extending from one edge of the web toward the center and (b) an area of non-uniform thickness profile increasing in thickness starting from the opposite edge of the web and increasing in the direction of the area of uniform thickness.
Dependencies are inferred from the claim text.