Method for producing a safety tempered vehicle glazing unit and safety tempered vehicle glazing unit
A method for producing a safety tempered vehicle glazing unit, includes a. tempering a glass pane at a tempering temperature; b. cooling the tempered glass pane to a first temperature T1 above room temperature; c. coating the tempered glass pane with a dispersion of an organic resin at the first temperature T1, and d. drying and cooling to room temperature Tr.
1 . A method for producing a safety tempered vehicle glazing unit formed of a single pane, comprising:
a. tempering a single glass pane at a tempering temperature, including bending the pane to have a concave inner surface;
b. cooling the tempered glass pane to a first temperature T1 above room temperature Tr;
c. coating over the concave inner surface of the tempered glass pane with a dispersion of an organic resin at the first temperature T1, and
d. drying and cooling to room temperature Tr, thus drying the dispersion to form a layer with anti-shatter properties,
wherein the glazing unit with said layer has a light transmission in the visible spectrum of T-ref±5%, where T-ref is a light transmission in the visible spectrum of a reference glazing unit, which is the same glazing unit without said layer,
wherein said layer has a thickness of 90 μm-200 μm.
2 . The method according to claim 1 , comprising a step a1 before step b:
a1. applying a further coating on the glass pane or tempered glass pane, the coating being on the concave inner surface.
3 . The method according to claim 2 , wherein the further coating comprises one or more of an IR-light reflective coating or enamel coating.
4 . The method according to claim 2 , wherein the further coating comprises an IR-light reflective coating,
wherein the dispersion is a polyurethane dispersion, and
wherein the light transmission of the glazing unit with said layer and the light transmission of the reference glazing unit are equal within a measurement tolerance.
5 . The method according to claim 1 , wherein the first temperature T1 is between 40° C. and 220° C.
6 . The method according to claim 5 , wherein the first temperature T1 is between 40° C. and 100° C.
7 . The method according to claim 6 , wherein the first temperature T1 is between 50° C. and 80° C.
8 . The method according to claim 1 , wherein the dispersion is a polyurethane dispersion.
9 . The method according to claim 1 , wherein said dispersion consists of an anionic aqueous solution of a polyurethanic compound including at least one aliphatic or aromatic polyurethanic compound.
10 . The method according to claim 1 , wherein the coating of step c is a curtain coating step or spray coating step.
11 . The method according to claim 10 , wherein the coating of step c is a curtain coating step.
12 . The method according to claim 1 , wherein the drying of step d comprises a heating to a temperature T2, the temperature T2 being higher than the first temperature T1, before the cooling to room temperature Tr.
13 . The method according to claim 1 , wherein said layer has a thickness of 90 μm-150 μm.
14 . The method according to claim 1 , wherein the light transmission of the glazing unit with said layer and the light transmission of the reference glazing unit are equal within a measurement tolerance.