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High refractive index polysiloxane prepolymers

a polysiloxane and high refractive index technology, applied in the field of high refractive index polysiloxane prepolymers, can solve the problems of increasing the incidence of postoperative complications, less popularity of more rigid iol implants in the market, and difficulty in incorporating a quantitative amount of all-aromatic cyclics into the growing polymer molecule, etc., to achieve high refractive index, easy removal, and high elongation

Inactive Publication Date: 2005-08-11
LAI YU CHIN +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0007] Soft, foldable, high refractive index, high elongation, polymeric compositions or silicone elastomers are prepared in accordance with the present invention through a copolymerization process using polysiloxane prepolymers of the present invention. An advantage of using polysiloxane prepolymers of the present invention in the manufacture of medical devices is that the prepolymer compositions produced therefrom may contain pure methylphenylsiloxane cyclics (bp=160-190° C. at 5 mmHg), which can be removed easily under high vacuum application. This improved production process of the present invention using the polysiloxane prepolymers of the present invention eliminates difficulties formerly encountered in the purification of materials useful in the manufacture of medical devices. Following preparation of the polysiloxane prepolymers using the process of the present invention, the prepolymers are copolymerized to form desirable polymeric compositions useful in the manufacture of biocompatible medical devices such as ophthalmic devices. Such desirable polymeric compositions are transparent, relatively high in strength for durability during surgical manipulation, relatively high in elongation, relatively high in refractive index and particularly well suited for use in the manufacture of ophthalmic devices such as intraocular lens (IOL) implants, contact lenses, keratoprostheses, corneal rings, corneal inlays and the like. Medical devices fabricated from the polymeric compositions or silicone elastomers produced using polysiloxane prepolymers prepared in accordance with the present invention are of improved product quality and reliability.
[0009] Accordingly, it is an object of the present invention to provide a process for the production of transparent, biocompatible polymeric compositions having desirable physical characteristics and relatively high refractive indices.
[0010] Another object of the present invention is to provide a process for the production of polymeric compositions having relatively high refractive indices and good clarity.
[0013] Still another object of the present invention is to provide a process for the production of polymeric compositions that are economical to produce.

Problems solved by technology

Accordingly, more rigid IOL implants have become less popular in the market since larger incisions have been found to be associated with an increased incidence of postoperative complications, such as induced astigmatism.
Because of the poor solubility of the aromatic cyclics, incorporating a quantitative amount of the all-aromatic cyclics into the growing polymer molecule proved difficult.
Likewise, due to high melting points (octaphenylcyclosiloxane has melting point of 197-199° C.; boiling point of 332° C. / 1 mmHg), the aromatic cyclics have no vapor pressures and can not be removed effectively using a thin film evaporator even at extremely high temperature (200° C.).
The presence of aromatic cyclics as contaminants in the final silicone elastomer product creates the potential for defects and possible failures in products produced therefrom.

Method used

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  • High refractive index polysiloxane prepolymers
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  • High refractive index polysiloxane prepolymers

Examples

Experimental program
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Effect test

example 1

Preparation of Viny-Terminated Polydimethylsiloxane of Low Molecular Weight

[0027] A 3-neck, 500 mL round bottom flask connected with a reflux condenser and nitrogen inlet tube, was charged with 1,1,3,3,5,5,7,7-octamethyltetrasiloxane (43.73 g), 1,3-divinyltetramethyldisiloxane (1.39 g) and aminosilanoate (0.48 g), all from Gelest, Inc., Tullytown, Pa. The contents were stirred under nitrogen and heated with an oil bath at 80 to 90° C. After 16 hours, the contents were heated to 140° C. to decompose the amine catalyst. Yielded 23.9 g of product. SEC gave Mn of 8,600 Da and Mw of 13,300 Da.

example 2

Preparation of Viny-Terminated Polydimethylsiloxane-co-Methylphenylsiloxane with a Total of 10 Percent Phenyl

[0028] A 3-neck 500 mL round bottom flask connected with a reflux condenser and nitrogen inlet tube, was charged with 1,1,3,3,5,5,7,7-octamethyltetrasiloxane (29.98 g, 0.1043 mole), vinyl-terminated polydimethylsiloxane from Example 1 (4.51 g), 1,3,5,7-tetramethyl-1,3,5,7-tetraphenyltetrasiloxane (15.48 g, 0.0285 mole) and 40 mL of toluene. The contents were heated under nitrogen at 90° C. to distill off 12 mL of azeotrope with any water contaminant. Then 0.42 g of amine silanoate was added and the contents were heated for three hours under nitrogen blanket. After the heating, the reaction product mixture was added to 200 mL of ether and extracted twice with 30 mL of 0.05 N HCl, and then extracted twice with 20 mL of 0.05 N sodium bicarbonate. After removal of solvent, the product (45 g) was found to have Mn of 28,000 Da, Mw of 74,400 Da by SEC. The product had 26 percent by...

example 3

Preparation of Viny-Terminated Polydimethylsiloxane-co-Methylphenylsiloxane with a Total of 10 Percent Phenyl

[0029] The preparation was repeated using the same procedure as that described above in Example 2 except that the contents were refluxed for 16 hours instead of three hours. The final product had an Mn of 30,100 Da, Mw of 96,300 Da and had 21.5 percent of cyclics.

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Abstract

A process for producing polysiloxane prepolymers of improved homogeneity for use in the production of relatively high refractive index polymeric compositions is described herein. Polymeric compositions so produced are useful in the production of ophthalmic devices such as for example intraocular lenses and corneal inlays.

Description

FIELD OF THE INVENTION [0001] The present invention relates to high refractive index polysiloxane prepolymers useful in the manufacture of biocompatible medical devices such as intraocular lenses. More particularly, the present invention relates to high refractive index polysiloxane prepolymers having both alkylaromatic siloxane and dialkylsiloxane units, useful in the manufacuture of ophthalmic devices. BACKGROUND OF THE INVENTION [0002] Since the 1940's optical devices in the form of intraocular lens (IOL) implants have been utilized as replacements for diseased or damaged natural ocular lenses. In most cases, an intraocular lens is implanted within an eye at the time of surgically removing the diseased or damaged natural lens, such as for example, in the case of cataracts. For decades, the preferred material for fabricating such intraocular lens implants was poly(methyl methacrylate), which is a rigid, glassy polymer. [0003] Softer, more flexible IOL implants have gained in popul...

Claims

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Application Information

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IPC IPC(8): C08G77/20C08G77/44C08L83/04G02B1/04
CPCC08G77/045C08G77/20C08G77/44C08G77/50C08G77/70C08L83/04G02B1/043C08L83/00C08G77/06C08G77/14
Inventor LAI, YU-CHINQUINN, EDMOND T.LIU, XIAOJUN MICHAELMAZIARZ, EDMUND P. III
Owner LAI YU CHIN
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