Transparent laminated glass and use thereof

Abstract

A transparent laminated glass is described. The transparent laminated glass can comprise a transparent outer pane, at least one polymer layer, and a transparent inner pane. Uses of the transparent laminated glass are also described.

Claims

1. A method to fabricate a transparent laminated glass for motor vehicle glazings as a windshield with high stone impact resistance, the method comprising bonding a transparent outer pane, made of silicate glass with a thickness of 1.6 mm to 1.8 mm, to at least one polymer layer with a thickness of 0.76 mm or 0.86 mm, and bonding a transparent inner pane, made of silicate glass with a thickness of 1.2 mm to 1.4 mm, to the at least one polymer layer, wherein the at least one polymer layer contains plasticized polyvinyl butyrals and the ratio of the thickness of the transparent outer pane to the sum of the thickness of the transparent outer pane and the transparent inner pane is from 0.552 to 0.571.

2. The method to fabricate a transparent laminated glass of claim 1, wherein the thickness of the transparent outer pane is 1.70 mm to 1.80 mm.

3. The method to fabricate a transparent laminated glass of claim 1, further comprising bending the transparent laminated glass two-dimensionally and/or three-dimensionally in a longitudinal direction and/or a transverse direction of the transparent laminated glass.

4. The method to fabricate a transparent laminated glass of claim 1, further comprising completely or partially coating the transparent inner pane or the transparent outer pane on a side facing the at least one polymer layer with at least one infrared radiation shielding layer with a thickness of 1 nm to 1000 nm.

5. The method to fabricate a transparent laminated glass of claim 1, further comprising coating the at least one polymer layer with a layer that absorbs or reflects infrared radiation.

6. The method to fabricate a transparent laminated glass of claim 1, further comprising partially coating with an opaque layer the transparent outer pane on the side facing the at least one polymer layer, and wherein the transparent outer pane is in the shape of a frame with a width of 10 mm to 300 mm and the opaque layer has a thickness of 1 m to 500 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) One embodiment of the invention is depicted in the drawings and is described in greater detail in the following. FIG. 1 through 3 are schematic depictions that illustrate the principle of the invention. The schematic depictions do not have to be to scale.

(2) They depict

(3) FIG. 1 a cross-section through a symmetrical transparent laminated glass according to the prior art,

(4) FIG. 2 a cross-section through an unsymmetrical transparent laminated glass according to the invention with reduced glass thicknesses, and

(5) FIG. 3 a cross-section through the unsymmetrical transparent laminated glass according to the invention with further reduced glass thicknesses and an increased distance between the inner pane and the outer pane.

(6) In FIG. 1 through 3, the reference characters have the following meaning: (1) Transparent outer pane (2) PVB bonding film (3) Transparent inner pane (1) Transparent outer pane with reduced thickness (2) PVB bonding film with increased layer thickness (3) Transparent inner pane with reduced thickness (A) Distance between outer pane and inner pane (A) Increased distance between outer pane and inner pane (1) Transparent outer pane with further reduced thickness (3) Transparent inner pane with further reduced thickness

EXAMPLES

(7) A comparative example according to the prior art is depicted in FIG. 1. The laminated glass was produced symmetrically with an outer pane (1) of the thickness 2.1 mm and an inner pane (3) with a thickness of 2.1 mm in an autoclave process. A conventional bonding film (2) with a thickness of 0.76 mm was used. The distance (A) between the inner pane (3) and the outer pane (1) was accordingly roughly 0.76 mm.

(8) An exemplary embodiment according to the invention is depicted in FIG. 2. The laminated glass was produced unsymmetrically with a bent outer pane (1) of a thickness of 1.8 mm and a bent inner pane (3) with a thickness of 1.4 mm in an autoclave process. A conventional PVB bonding film (2) with a thickness of 0.76 mm was used. The distance (A) between the inner pane (3) and the outer pane (1) was accordingly roughly 0.76 mm. The value of the mechanical tensile stresses of the transparent outer pane (1) was measured as less than 7 MPa and was reduced compared to the comparative example. The stone impact resistance of the substrate according to the invention increased compared to the comparative example. The kinetic threshold energy E_t of a projectile at which a 50% fracture probability of the laminated glass was measured increased by 25% compared to the comparative example. The value of the mechanical compressive stresses of the laminated glass was measured as greater than 10 MPa. The optical distortion in zone A was in the range of less than 1 arc minute. The weight of the pane was reduced.

(9) FIG. 3 depicts a variation of the transparent laminated glass according to the invention. The laminated glass was produced unsymmetrically with an outer pane of a thickness of 1.7 mm (1) and an inner pane (3) with a thickness of 1.3 mm in an autoclave process. A multilayer polymer layer containing PVB bonding film (2) with a thickness of 0.86 mm was used. The distance (A) between the inner pane (3) and the outer pane (1) was accordingly roughly 0.86 mm. The kinetic threshold energy E_t of a projectile at which a 50% fracture probability of the laminated glass was measured increased by 25% compared to the comparative example. The value of the mechanical compressive stresses of the laminated glass was measured as greater than 10 MPa. The optical distortion in zone A was in the range of less than 1 arc minute. The weight of the pane was further reduced compared to the previous exemplary embodiment.

(10) The results from the comparative example (FIG. 1) and the exemplary embodiments (FIG. 2 and FIG. 3) are depicted in Table 2.

(11) TABLE-US-00002 TABLE 2 PVB Outer pane bonding film Inner pane Stone Thickness Thickness Thickness impact Example Reference [mm] Reference [mm] Reference [mm] resistance Weight FIG. 1 (1) 2.1 (2) 0.76 (3) 2.1 FIG. 2 (1) 1.8 (2) 0.76 (3) 1.4 Improved Reduction FIG. 3 (1) 1.7 (2) 0.86 (3) 1.3 Improved Greater reduction

(12) Surprisingly and unexpectedly, the laminated glass according to the invention has improved stone impact resistance.