Additive manufacturing for transparent ophthalmic lens

Patent metadata

Field	Value
Publication number	US-9969135-B2
Application number	US-201314908653-A
Country	US
Kind code	B2
Filing date	Jul 31, 2013
Priority date	Jul 31, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A method using additive manufacturing technologies and processes to manufacture a three-dimensional ophthalmic lens with a high management level of the homogeneity during the construction of the ophthalmic lens, through a control of two technical characteristics of voxel: the ability to modify their viscosity, and the ability to inter-diffuse together to provide a final homogeneous element. These two technical characteristics are managed by the choice of component(s) used to manufacture each voxel and by the kind of physical and/or chemical treatment apply to each of them.

First claim

What is claimed:

1. A method of manufacturing a three-dimensional transparent ophthalmic lens comprising the following steps:
/1/ constituting at least a voxel of a liquid composition (A) in a state 1a;
/2/ constituting at least a voxel of a liquid composition (B) in a state 1b;
/3/ increasing viscosity of at least a said constituted voxel to reach it from a state 1 to a state 2;
/4/ inter-diffusing through a physical and/or a chemical treatment, at least a voxel wherein viscosity is increased, either of a composition (A) to a state 2a or a composition (B) to a state 2b, with another voxel either of a composition (A) in a state 1a or 2a, or of a composition (B) in a state 1b or 2b, to create an intermediate element (n); and
/5/ repeating, (X) times, with (X) being an integer, at least one of the step selected from /1/, /2/, /3/ and /4/ to form an intermediate element (n+(X)) until a three-dimensional transparent ophthalmic lens is obtained, and when at least two steps from said steps are repeated, said at least two steps are repeated in the same order as cited or in a different order according to chemical compound(s) involved to said liquid composition (A) and said liquid composition (B).

2. The method according to claim 1 comprising the following steps:
/1/ constituting a first voxel of a liquid composition (A) in a state 1a;
/2/ constituting a new voxel, adjacent to said first voxel, of a liquid composition (B) to a state 1b;
/3/ increasing viscosity of said first voxel and said new voxel to reach them respectively to a state 2a and to a state 2b;
/4/ inter-diffusing said first voxel and said new voxel, by submitting them to a physical and/or chemical treatment, to create an intermediate element (n) in a state 3 by merging the two voxels; and
/5/ repeating, (X) times, with (X) being an integer, steps /2/ to /4/ respectively by applying said steps “increasing viscosity” and “inter-diffusing” to each new voxel and to intermediate element to form a intermediate element (n+(X)) until a three-dimensional transparent ophthalmic lens is obtained.

3. The method of claim 1 , wherein:
step /3/ is performed between steps /1/ and /2/ and is then applied to the first voxel of a liquid composition (A) in a state 1a; and
comprising further a step /3A/ increasing viscosity after step /4/ and applying to intermediate element which is the result of step /4/.

4. The method of claim 1 , wherein liquid composition (A) and liquid composition (B) are identical.

5. The method of claim 1 , wherein liquid composition (A) and liquid composition (B) are different.

6. The method of claim 1 , wherein each new voxel comprises the liquid composition (A) or liquid composition (B), or the liquid composition (A) then a liquid composition (B).

7. The method of claim 1 , wherein during step /5/, each new voxel comprises liquid composition (A) and a liquid composition (B), and wherein liquid composition (A) and liquid composition (B) are different.

8. The method of claim 1 , wherein during step /5/ each new voxel comprises a liquid composition (A), and wherein liquid composition (A) in the step /1/ and liquid composition (B) in the step /2/ are identical.

9. The method of claim 1 , wherein the step(s) of increasing viscosity are selected from the group consisting of:
a crosslinking process, which could be initiate by cationic reaction, by free radical reaction or by condensation reaction by applying activating light or thermal treatment to liquid composition;
an evaporation process, and more particularly evaporation of solvent comprised into liquid composition; and
a process consisting to submit liquid composition to a temperature which is below the temperature used at the deposition step of the voxel.

10. The method according to claim 9 , wherein each step of increasing viscosity is identical or different.

11. The method of claim 1 , wherein the inter-diffusing step(s) are selected from:
spontaneous inter-diffusion; and
induced inter-diffusion, which represent a process selected from the group consisting of exposure to radiation, mechanical agitation, decrease of molecular mass of voxel, and exposure to a solvent.

12. The method according to claim 11 wherein each step of inter-diffusing is identical or different.

13. The method of claim 1 , further comprising:
post-treatment step(s) selected from the group consisting of:
a crosslinking process, which is initiated by cationic reaction, by free radical reaction or by condensation reaction by applying activating light or thermal treatment to the liquid composition;
an annealing process; and
a drying process by thermal treatment or solvent extraction.

14. The method according to claim 13 wherein each step of post-treatment is identical or different.

15. The method according claim 1 , wherein:
the step of increasing the viscosity increases the initial viscosity of the liquid composition from 5 times to 20 times, the final viscosity of the ophthalmic lens manufactured by said method being more than 50 000 cPs at 25° C.

16. The method of claim 1 , wherein the step of increasing viscosity is by a cross-linking process that represents a photo-polymerization or a thermal-polymerization process wherein the liquid composition comprises:
at least a monomer and/or oligomer comprising at least a reactive group selected from epoxy, thioepoxy, epoxysilane, (meth)acrylate, vinyl, urethane, thiourethane, isocyanate, mercapto, and alcohol; and
at least an initiator activated by activating light or activating temperature, said initiator being selected from cationic initiator and free-radical initiator; and
wherein activated initiator initiates activation of at least one reactive group from monomer and/or oligomer to generate their polymerization reaction via propagation process.

17. The method of claim 1 , wherein the liquid composition (A) and (B) comprises:
at least a mixture of two monomers and/or oligomers each comprising different reactive groups wherein at least a reactive group of the first monomer and/or oligomer increases viscosity by a photo-polymerization process and a reactive group of the second monomer increases viscosity by a photo-polymerization process or by a thermal-polymerization process; and
at least a mixture of two initiators, the first initiator activating the at least a reactive group of said first monomer by treatment of activating light, the second initiator activating the at least a reactive group of said second monomer by thermal treatment or by activating light treatment which is different than previous activating light.

18. The method of claim 1 , wherein steps of constituting voxels comprises a step of constituting alternatively voxels based of two different liquid compositions (A) and (B):
a liquid composition (A) comprising at least a monomer and/or oligomer with two families of reactive groups, one family being activated by photo-polymerization in the presence of a photo-initiator;
a liquid composition (B) comprising at least same monomer and/or oligomer of said first composition and an initiator which is different than said first photo-initiator and is activated by photo-polymerization or by thermal-polymerization.

19. The method according to claim 18 , wherein said liquid composition (B) comprises a photo-initiator activated by photo-polymerization said photo-initiator being:
either a cationic initiator which is activatable by irradiation to a different wavelength and/or intensity of activating light than activating light used to activate the initiator of the

Assignees

• Essilor Int

Inventors

• Valeri Robert A
• Weber Steven
• Biteau John

Classifications

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B29D11/00432 Primary

  Auxiliary operations, e.g. machines for filling the moulds (B29D11/00125 takes precedence) · CPC title

• B29D11/00009

  Production of simple or compound lenses · CPC title

• B29L2011/0016

  Lenses · CPC title