Lens molds with protective coatings for production of contact lenses and other ophthalmic products

A technology for ophthalmic products and contact lenses, applied in glasses/goggles, coatings, household appliances, etc., can solve the problems of high cost and expensive transparent resin, and achieve the effect of reducing mold cycle, increasing product output, and improving lens quality

Inactive Publication Date: 2002-06-26
BAUSCH & LOMB INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Also, in addition to being prone to chemical interactions, many transparent resins are more expensive than polypropylene and therefore too costly to discard

Method used

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  • Lens molds with protective coatings for production of contact lenses and other ophthalmic products
  • Lens molds with protective coatings for production of contact lenses and other ophthalmic products

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] This example illustrates the preparation of contact lens molds coated with silicon nitride using the plasma enhanced chemical vapor deposition (PECVD) method. The polystyrene mold was placed in a stainless steel chamber equipped with a capacitively coupled radio frequency (13.56 MHz) power supply, which was evacuated with a turbomolecular pump. When the pump pressure drops to base pressure 10 -4At Torr, the working gas allows the use of mass flow control (MFC). The desired pressure can be obtained using a throttle valve and a MKS baraton gauge. Process gases for the deposition of silicon nitride (where the silicon to nitrogen ratio is approximately 2.3) include silane and ammonia (SiH 4 / NH 3 ), the ratio is 1:4. The deposition pressure is 80-100 mTorr, and the temperature of the substrate during the deposition process is about 40-60°C. SiH 4 and NH 3 The flow rates are 10-20 sccm and 40-80 sccm respectively. The coating thickness is in the range of 60-120mm.

Embodiment 2

[0039] This example illustrates the preparation of contact lens molds coated with silicon oxide using plasma enhanced chemical vapor deposition (PECVD). Using an apparatus similar to that described in Example 1, contact lens molds were coated with silica. The working gas used to obtain the coating is trimethyldisiloxane and oxygen, and the ratio of trimethyldisiloxane to oxygen is 1:2. The coating thickness is in the range of 600-1000nm.

Embodiment 3

[0041] This example illustrates a chemically resistant plastic coating according to the invention. Flat plate samples of amorphous plastics (polystyrene, polycarbonate and polysulfone) were exposed to a mixture of monomers A and B used to make lenses. A and B are non-silicone soft lenses and silicone soft lenses, respectively. Monomer mixture A comprised the following components: 2-hydroxyethyl methacrylate (32 parts), n-vinylpyrrolidone or NVP (45 parts), 2-hydroxy-4-tert-butylcyclohexyl methacrylate (8 parts), Ethylene glycol dimethacrylate (0.1 part), methacryloyloxyethyl vinyl carbonate (0.5 part), glycerin (15 parts), a polymerizable blue body (150 ppm), and an initiator Darocur (0.2 parts). Monomer mixture B comprised the following components: a polyurethane-polysiloxane prepolymer derived from isophorone diisocyanate, diethylene glycol, α,ω- Hydroxybutyl polydimethylsiloxane and 2-hydroxyethyl acrylate are mixed in a molar ratio of 6:3:2:2 (50 parts), 3-methacryloylo...

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Abstract

This invention relates to the preparation of molds for the production of contact lenses and other ophthalmic articles. By using an inorganic material to coat the optical surfaces and sidewalls of mold parts made from clear-resin materials, manufacturers can produce lens molds with greater dimensional stability and chemical resistance. In addition to protecting the clear resin from interaction with otherwise reactive monomers from which the molded article is made, such coatings can also be used to achieve preferential release of the molded article. The resulting mold is especially useful for providing an economical way to improve manufacturing quality of contact lenses.

Description

technical field [0001] The present invention relates to improved lens molds for the production of contact lenses, intraocular lenses and other ophthalmic products. In particular, the invention relates to protective coatings using mold materials with improved dimensional stability and / or increased light transmission. The invention also relates to methods of making improved lens molds and their use in the production of contact lenses. Background of the invention [0002] Molds for the production of soft (hydrogel) contact lenses have been made from a variety of hard thermoplastic resins. For example, U.S. Patent 5,540,410 to Lust et al. and U.S. Patent 5,674,557 to Widman et al. disclose mold halves made of polystyrene, polyvinyl chloride, polyethylene, polypropylene, polystyrene and acrylonitrile and / or butanediene. Acrylic resins such as polymethyl methacrylate, polyacrylonitrile, polycarbonate, polyamides such as nylon, polyester, polyolefins such as polyethylene, polypro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G02C7/02B29C33/38B29C33/40B29C33/56B29C35/08B29C39/26B29C45/00B29L11/00
CPCB29D11/00548B29C2035/0827B29C2035/0833Y10S425/808B29C33/3842B29C35/0888B29L2011/0041B29C33/56
Inventor 李洪文多米尼克·V·鲁肖赖玉勤霍恩叶·黄
Owner BAUSCH & LOMB INC
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