Abstract:
The present invention provides thermoplastic ophthalmic lens blocking compositions that have many advantages over traditional metal alloy materials. Preferred compositions comprise a blend of a homopolymer or copolymer of epsilon-caprolactone with a modifier selected from the group consisting of carboxylic; straight chain monohydric alcohols; branched chain monohydric alcohols; polyethylene glycols; and polyethylene glycol ethers. The composition may also comprise one or more fillers or heat absorbing materials. In one embodiment, the composition is used to fill the cavity between a preformed lens block and a lens. In another embodiment the composition is used to form a lens block. Methods of holding a lens blank are taught. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.
Abstract:
The present invention provides thermoplastic ophthalmic lens blocking compositions that have many advantages over traditional metal alloy materials. Preferred compositions comprise a homopolymer or copolymer of epsilon-caprolactone, have a number average molecular weight between 3,000 and 100,000, and a polydispersity less than 10. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one embodiment, the composition is used to fill the cavity between a preformed lens block and a lens. In another embodiment the composition is used to form a lens block. Methods of holding a lens blank are taught. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.
Abstract:
An article comprising substrate having a surface and a coating on the surface of the substrate, the coating comprising a fluoropolymer and a fluorochemical surfactant. The fluoropolymer and the fluorochemical surfactant are selected such that the article is anti-reflective, abrasion resistant and anti-fogging. Methods of making the same are also described.
Abstract:
The present invention provides thermoplastic ophthalmic lens blocking compositions that have many advantages over traditional metal alloy materials. Preferred compositions comprise a homopolymer or copolymer of epsilon-caprolactone, have a number average molecular weight between 3,000 and 100,000, and a polydispersity less than 10. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one embodiment, the composition is used to fill the cavity between a preformed lens block and a lens. In another embodiment the composition is used to form a lens block. Methods of holding a lens blank are taught. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.
Abstract:
Tearable security laminates. More specifically, the present invention relates to a security card, comprising: a plastic card having edges; and a tearable security laminate attached to the plastic card by an adhesive layer, where the security laminate is tearable along an edge of the plastic card. In addition, the invention relates to methods of making security cards.
Abstract:
Multilayered film and film based assembly which are environmentally-compatible, and which exhibit one or more desirable characteristics of polyvinyl chloride (PVC) film and film based assemblies, such as clarity, flexibility and toughness, but without the environmental and health hazards associated with PVC materials, are provided. Also provided is a method of preparing such film and film based assembly.
Abstract:
Multilayered tubing which exhibits one or more desirable characteristics of polyvinyl chloride (PVC) tubings, such as clarity, flexibility and toughness, but without the environmental and health hazards associated with PVC materials, is provided. Also provided is a method of preparing such tubing.
Abstract:
The present invention provides methods of holding ophthalmic lens blanks using thermoplastic lens blocking compositions. Preferred compositions either comprise a homopolymer or copolymer of epsilon-caprolactone, have a number average molecular weight between 3,000 and 100,000, or have a polydispersity less than 10. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one method, the composition is injected into the cavity between a preformed lens block and a lens. In another method, the surface of a lens block comprising the thermoplastic lens blocking composition is heated and formed against the lens blank. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.
Abstract:
The present invention provides thermoplastic ophthalmic lens blocking compositions that have many advantages over traditional metal alloy materials. Preferred compositions comprise a homopolymer or copolymer of epsiloncaprolactone, have a number average molecular weight between 3,000 and 100,000, and a polydispersity less than 10. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one embodiment, the composition is used to fill the cavity between a preformed lens block and a lens. In another embodiment the composition is used to form a lens block. Methods of holding a lens blank are taught. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.
Abstract:
The present invention provides a block assembly for mounting an optical lens blank onto a lens processing machine, comprising a compliant lens block with a relatively thin double-sided adhesive tape having differential adhesion. This assembly affords a very cost efficient system for attaching a lens blank to a lens processing machine. In contrast to traditional thick adhesive pads, the tapes of the present invention do not suffer from shear displacements which may cause processing errors or inaccuracies. In addition, the double-sided adhesive tapes of the present invention achieve greater adhesion to the lens block than to the lens. This feature promotes and ensures a "clean" removal of the tape from the lens when the block is deblocked. The present invention also provides a method for mounting an optical lens blank onto a lens processing machine. This method comprises the steps of: disposing a compliant block assembly in close proximity to an optical lens blank (the block assembly comprising a base structure having a compliant receiving surface adapted to conform to a surface on an optical lens blank to be processed in a lens processing machine and a mounting means for mounting the block onto a chuck of a lens processing machine, wherein at least a portion of said compliant receiving surface is covered with a thin double-sided adhesive tape having differential adhesion); adhesively attaching the optical lens blank to the compliant block by applying the block to the optical lens blank with sufficient pressure to conform the receiving surface to the surface of the optical lens blank while the adhesive tape joins the block and optical lens blank together; and mounting the block and the adhesive tape joined optical lens blank onto the lens processing machine.