Reaction injection molding as a process to prepare contact lenses

• US 5,656,210 A
• Filed: 03/31/1995
• Issued: 08/12/1997
• Est. Priority Date: 03/31/1995
• Status: Expired due to Term

• Current Assignee: Johnson & Johnson Vision Products, Inc.
• Original Assignee: Johnson & Johnson Vision Products, Inc.
• Inventors: Wong, Shaio-Wen, Hill, Gregory A., Frisch, Kurt C., Sendijarevic, Vahid
• Primary Examiner(s): Vargot, Mathieu D.
• Application Number:
  US08/415,000
• Time in Patent Office: 865 Days
• Field of Search: 264/2.6, 264/1.7, 264/328.6, 523/106, 525/903
• US Class Current: 264/2.6
• CPC Class Codes: B29D 11/00125 Auxiliary operations, e.g. removing oxygen from the mould, conveying moulds from a storage to the production line in an inert atmosphere
• CPC Class Codes: B29L 2011/0041 Contact lenses
• CPC Class Codes: C08G 18/5024 containing primary and/or secondary amino groups
• CPC Class Codes: C08G 18/637 characterised by the in situ polymerisation of the compounds having carbon-to-carbon double bonds in a reaction mixture of saturated polymers and isocyanates
• CPC Class Codes: C08G 18/6685 with compounds of group C08G18/3225 or polyamines of C08G18/38
• CPC Class Codes: C08G 2120/00 Compositions for reaction injection moulding processes
• CPC Class Codes: C08G 2270/00 Compositions for creating interpenetrating networks
• CPC Class Codes: C08L 2205/04 containing interpenetrating networks
• CPC Class Codes: C08L 33/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 75/02 Polyureas
• CPC Class Codes: G02B 1/043 Contact lenses
• CPC Class Codes: Y10S 525/903 Interpenetrating network

Abstract

The present process is directed to using a reaction injection molding process to make contact lenses made up of an interpenetrating polymer network of polyurea and polyacrylic by the reaction injection molding process.

Claims

1. A process for the preparation of a reaction injection molded contact lens comprising

(a) mixing components in a reactive mixture in a RIM machine under sufficient conditions to form precursors for a polyurea network and a polyacrylic network, which upon curing forms on a interpenetrating polymer network, said reactive mixture comprising:

(i) an amine terminated chain extender comprising a mixture of amines A and B, said amines being present in said reactive mixture in about 20-60% by weight, wherein A is ##STR21## wherein f₁ is independently an integer from 1-75, R is an alkylene containing 3 carbon atoms and each R is the same,

f is an integer between 1 and 150;

R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ are independently hydrogen or lower alkyl;

Z₁ and Z₂ are independently a chemical bond or lower alkylene,

with A and B being present in relative weight ratios ranging from about 60/40 to about 100% A;

(ii) an organic di-or poly-isocyanate present in sufficient quantity to react with said amine terminated chain extender of (i) to form therefrom a polyurea network;

(iii) an acrylic ester of the formula;

##STR22## wherein R₃ is hydrogen or lower alkyl;

m is an integer from 0 to 150;

Z₃ and Z₅ are independently alkylene;

Z₄ and Z₆ are independently a chemical bond or alkylene;

R₄ is hydrogen, lower alkyl or ##STR23## R₅ is hydrogen or lower alkyl;

R₆ and R₈ are independently hydrogen or lower alkyl;

R₇ is lower alkylene, a chemical bond or --CH₂ (OCH₂ CH₂)_q --;

q is an integer between 0 and 200, inclusive;

p is an integer of 1-3.

said acrylic ester being present in said reactive mixture in about 10-50% by weight;

(iv) a free radical initiator being present in said reactive mixture in sufficient quantity to polymerize the acrylic ester of (iii) forming therefrom a polyacrylic network; and

(v) a triamine present in sufficient quantity to crosslink said amine terminated chain extender of (i) wherein the ratio of polyurea to polyacrylic ranges from about 90;

10 to about 50;

50, and the sum of the weights of the components in the reactive mixture adds to 100%;

(b) injecting said reactive mixture of (a) into a closed mold in fluid communication with the RIM machine and having a cavity in the shape of a contact lens under conditions sufficient to gel and harden said liquid into an interpenetrating polymer network;

(c) removing the product of (b) from the mold;

(d) optionally post-curing the product of (c) and

(e) immersing the product of (d) in a water or an aqueous medium to form a hydrogel.

2. The process according to claim 1 wherein B is a polyoxypropylene diamine of the formula:

##STR24##

3. The process according to claim 1 wherein the triamine is present in an amount ranging from 30 to 50% total amine equivalents present in said mixture.

4. The process according to claim 3 wherein the triamine is diethylene triamine or poly(oxypropylene)triamine.

5. The process according to claim 1 wherein the isocyanate is methylene-bis (4,4'"'"'-cyclohexylisocyanate) or isophorone diisocyanate.

6. The process according to claim 1 wherein the free radical initiator is 2,5-dimethyl-2,5-di-(2-ethylhexanoyl peroxy) hexane, benzoyl peroxide, t-butyl hydroperoxide, t-butyl peroxide or lauryl peroxide.

7. The process according to claim 1 wherein the polyura/polyacrylic weight ratio is about 80:

20 to about 70;

30.

8. The process according to claim 1 wherein the polyurea/polyacrylic weight ratio is about 75:

25.

9. The process according to claim 1 wherein the mold contains a plurality of vents.

10. The process according to claim 1 wherein the isocyanate is present in the reactive mixture in amounts ranging from about 15% to about 50% by weight.

11. The process according to claim 10 wherein the isocyanate is present in the reactive mixture in amounts ranging from about 25% to about 40% by weight.

12. The process according to claim 1 wherein the free radical initiator is present in amounts ranging from about 0.01% to about 1% by weight.

13. The process according to claim 1 wherein

(a) the reactive mixture is mixed in a RIM machine at sufficient pressure to form precursors for a polyurea network and a polyacrylic network, which upon curing form an interpenetrating polymer network, said reactive mixture comprising

(i) an amine terminated chain extender comprising a mixture of amines A and B, said amines being present in said reactive mixture in about 20-60% by weight, wherein A is ##STR25## wherein f₁ is an integer from 1-75, R is an alkylene containing 3 carbon atoms and each R is the same;

R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ are hydrogen or lower alkyl;

f is an integer between 1 and 150, inclusive;

Z₁ and Z₂ are independently a chemical bond or lower alkylene;

with A and B being present in relative weight ratios ranging from about 60;

40 to about 100% A;

(ii) an organic di-or poly-isocyanate present in sufficient quantity to react with said amine terminated chain extender of (i) to form therefrom a polyurea network;

(iii) about 10-50% by weight in said reactive mixture of an acrylate ester component of a mixture of a first acrylate of the formula;

##STR26## and a second acrylate being a diacrylate of the formula;

##STR27## a triacrylate of the formula;

##STR28## or a mixture thereof, wherein R₃, R₄, R₅, R₉ and R₈ are independently hydrogen or lower alkyl;

R₆ is lower alkyl;

R₇ is a chemical bond or lower alkylene or --CH₂ (OCH₂ CH₂)_q --;

q is an integer between 0 to 200, inclusive;

m and n are independently integers of 0-150 and;

p is an integer of 1-3;

said ratio of the first acrylate to second acrylate ranges from about 80;

20 to about 95;

5;

(iv) a free radical initiator being present in said reactive mixture in sufficient quantity to polymerize the acrylic ester of (iii), forming therefrom a polyacrylic network,

(v) a triamine present in sufficient quantity to crosslink said amine terminated chain extender, wherein the ratio of polyurea to polyacrylate ranges from about 90;

10 to about 50;

50;

(b) injecting said mixture of (a) into a closed mold in fluid communication with the RIM machine and having a cavity in the shape of a contact lens under conditions sufficient to gel and harden said liquid into an interpenetrating polymer network;

(c) removing the product of (b) from the mold;

(d) optionally post-curing the product of (c) and

(e) immersing the material from (d) in a water or an aqueous medium to form a hydrogel.

14. The process of claim 13 wherein R₃, R₄, R₅ and R₉ are CH₃.

15. The process of claim 13 wherein R₃, R₅ and R₉ are CH₃, m is o, R₄ is hydrogen and n is 2.

16. The process of claim 13 wherein R₃, R₉ and R₅ are CH₃, m is 4, R₄ is hydrogen and n is 2.

17. The process of claim 13 wherein m is 4, R₄ is hydrogen, p is 3, R₆ is ethyl, R₇ is ethylene, and R₃ and R₈ are CH₃.

18. The process according to claim 13 wherein B is a polyoxypropylene diamine of the formula:

##STR29##

19. The processing according to claim 13 wherein a triamine is present in the reactive mixture ranging from 30% to 50% of total amine equivalents.

20. The process according to claim 19 wherein the triamine is diethylene triamine or poly(oxypropylene)triamine.

21. The process according to claim 13 wherein the isocyanate is methylene-bis (4,4'"'"'-cyclohexylisocyanate) or isophorone diisocyanate.

22. The process according to claim 13 wherein the free radical initiator is 2,5-dimethyl-2,5-di-(2-ethylhexanoyl peroxy) hexane, benzoyl peroxide, t-butyl hydroperoxide, t-butyl peroxide or lauryl peroxide.

23. The process according to claim 13 wherein the polyurea polyacrylic weight ratio is about 75:

25.

24. The process according to claim 13 wherein the mold contains a plurality of vents.

25. The process according to claim 13 wherein the isocyanate is present in the reactive mixture in amounts ranging from about 15% to about 50% by weight.

26. The process according to claim 13 wherein the isocyanate is present in the reactive mixture in amounts ranging from about 25% to about 40% by weight.

27. The process according to claim 13 wherein the free radical initiator is present in the reactive mixture in amounts ranging from about 0.01% to about 1% by weight.

28. The process according to claim 1 wherein water is additionally present in the reactive mixture.

29. The process according to claim 28 wherein water is present in a Concentration of about 3% to about 7% by weight.