Method of preparing thick laminate wafers for wafer thermoforming and injection molding

Patent metadata

Field	Value
Publication number	US-12251897-B2
Application number	US-202117801548-A
Country	US
Kind code	B2
Filing date	Feb 25, 2021
Priority date	Feb 26, 2020
Publication date	Mar 18, 2025
Grant date	Mar 18, 2025

Abstract

A method of forming an ophthalmic laminate lens, includes: forming a planar laminate by adhering a first polycarbonate layer to a first side of a thermoplastic elastomer layer, and adhering a second polycarbonate layer to a second side of the thermoplastic elastomer layer, the first polycarbonate layer having a thickness greater than 250 μm, the second polycarbonate layer having a thickness greater than 250 μm, and the thermoplastic elastomer layer having a thickness in a range of 15 μm to 150 μm; thermoforming the planar laminate into a curved laminate, the curve laminate having a pre-molding curvature; arranging the curved laminate in a mold; and molding, via the mold set at a predetermined temperature and a predetermined pressure, the curved laminate with a polymer melt into a curved lens.

First claim

What is claimed is:

1. A method of forming an ophthalmic laminate lens, comprising:
forming a planar laminate by adhering a first polycarbonate layer to a first side of a thermoplastic elastomer layer, and adhering a second polycarbonate layer to a second side of the thermoplastic elastomer layer, the first polycarbonate layer having a thickness greater than 250 μm, the second polycarbonate layer having a thickness greater than 250 μm, and the thermoplastic elastomer layer having a thickness in a range of 15 μm to 150 μm;
thermoforming the planar laminate into a curved laminate, the curved laminate having a pre-molding curvature;
arranging the curved laminate in a mold; and
molding, via the mold set at a predetermined temperature and a predetermined pressure, the curved laminate with a polymer melt into a curved lens.

2. The method of claim 1 , wherein:
the mold includes a concave mold insert and a convex mold insert;
the curved laminate is arranged in the mold such that the second polycarbonate layer is adjacent to the concave mold insert; and
the polymer melt is injected between the first polycarbonate layer of the curved laminate and the convex mold insert.

3. The method of claim 2 , wherein:
a thickness of the first polycarbonate layer is equal to a thickness of the second polycarbonate layer; and
the first polycarbonate layer in contact with the polymer melt produces a concave surface of the curved lens.

4. The method of claim 3 , wherein the first thickness of the first polycarbonate layer and the second thickness of the second polycarbonate layer are each in a range of 380 μm to 800 μm.

5. The method of claim 2 , wherein:
a thickness of the first polycarbonate layer is greater than a thickness of the second polycarbonate layer; and
the first polycarbonate layer in contact with the polymer melt produces a concave surface of the curved lens.

6. The method of claim 5 , wherein:
the thickness of the first polycarbonate layer is in a range of 380 μm to 800 μm; and
the second thickness of the second polycarbonate layer is in a range of 250 μm to 600 μm.

7. The method of claim 2 , wherein a diameter of the first polycarbonate layer and a diameter of the thermoplastic elastomer layer are both smaller than a diameter of the second polycarbonate layer.

8. The method of claim 7 , wherein:
a thickness of the second polycarbonate layer is greater than a thickness of the first polycarbonate layer; and
the first polycarbonate layer in contact with the polymer melt produces a concave surface of the curved lens.

9. The method of claim 2 , wherein the thermoforming the planar laminate into the curved laminate is performed without any intermediate molding steps.

10. The method of claim 9 , wherein the thermoformed curved laminate has a base curve greater than 5.0 D.

11. The method of claim 2 , wherein a material of the thermoplastic elastomer layer is thermoplastic polyurethane.

12. The method of claim 2 , wherein a material of the thermoplastic elastomer layer is polyether-block-polyamides.

13. The method of claim 12 , wherein a thickness of the first polycarbonate layer is determined based on a temperature of the injected polymer melt such that the thickness of the first polycarbonate layer prevents heat transfer from the polymer melt to the thermoplastic elastomer layer above a predetermined threshold.

Assignees

• Essilor Int

Inventors

• Drammeh Ahmed
• Begg Eric
• Tokarski Zbigniew
• Jiang Peiqi

Classifications

• G02B1/041

  Lenses · CPC title

• B32B2551/00

  Optical elements · CPC title

• B32B2307/732

  Dimensional properties · CPC title

• B32B25/08

  of synthetic resin · CPC title

• B29K2075/00

  Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material · CPC title