Polycarbonate lenses

Monomer used in the manufacture of some polycarbonate lenses used as a chemical intermediate for numerous compounds. 

There are now new high index lenses, made from a variety of polymers that are thinner than CR-39 and polycarbonate lenses. 

These polycarbonate lenses attach to the outside of the respirator s eye lens usuaUy by elastic... 

T. Wydeven developed a plasma process that significantly improves the hardness of optical lenses and, consequently, leads to greater scratch resistance (7. Vinyl-trimethoxysilane films were deposited on transparent polycarbonate lenses by plasma polymerization. The adherent, clear films protect the substrate from abrasion and also serve as antireflection coatings. Post-treatment of the vinyltrimethoxysilane films in an oxygen glow discharge fui ther improved the abrasion resistance. 

The polycarbonate lenses in these protective glasses are lightweight, yet shatterproof. 

Figure 6-32. This streamlined headlamp by Ford and GE provides contoured, flush-mounted polycarbonate lenses that reduce air drag and some degree of weight.

If eye or face protection is needed for a specific job, a clean face shield can offer the same protection as safety glasses or goggles. Face shields are not intended to take the impact like that of polycarbonate lenses but can offer protection from dust, chemical splashes, wires, and banding. As with any exposure, seek out professional advice to ensure the proper protection is being offered. 

Regular, standard street-wear safety glasses do not provide the same protection as industrial eyewear, especially the full benefits gained from polycarbonate lenses. 

Company literature from several adhesive suppliers is currently available that lists UV curable and visible light curing acrylic adhesives as part of their product package. This type of acrylic adhesive is being used successfully in polycarbonate lens bonding. 

With a nylon plastic visor, polycarbonate lens, polypropylene chin guard and cotton shroud, Allegro s new Supplied Air Shield is perfect for use with grinding, chipping, spray painting and auto body repair. The Full Mask Supplied Air Respirator is made of silicone rubber for durability. Allegro Industries, (800) 622-3530, www.allegrosafety.com. 

Figure 1. Thermograph of polycarbonate lens cooled in 15 Btu steel mold and 60 Btu copper mold.

Eyeglass frames made of cellulose acetate plasticized with diglycerol esters do not exhibit opaqueness at the frame-lens junction with polycarbonate plastic lenses (146,147). 

In the photographic field polycarbonates now complete with ABS for projector housings, whilst in cameras polycarbonates are now used in the shutter assembly, film drive, flash-cube sockets and lens holders. One popular low-cost camera recently introduced into the UK market had at least eight parts moulded from polycarbonate. Polycarbonate film is also used for photographic purposes, e.g. for quality colour fine engravings. 

Optical immunosensors, 3 803, 813 Optical industry, indium in, 14 195 Optical information storage markets, polycarbonate grades for, 19 809-810 Optical isomers, 6 72-73 Optical lens systems, in photography,... 

Fig. 5. Optical sectioning of rhodamine phalloidin-stained F-actin in a neutrophil migrating through a 5-pm pore of a polycarbonate membrane. The neutrophil migration is stimulated in response to 10 M Af-formytmethionyl-leucy 1-phenylalanine. (A), (B), and (C) correspond to O.S-pm optical sections indicated as sections A, B, and C, respectively, in Fig. 4. The bar represents 10 pm. The images were collected with a Nikon Microphot FX microscope (x60 Plan-apochromat lens, numerical aperture, 1.6) connected to a Bio-Rad MRC600 laser-scanning confocal system.

J.F. Hoover, J.-P. Lens, and B. Mullen, Polycarbonate-polysiloxane copolymers, method of making, and articles formed therefrom, US Patent 7 524 919, assigned to SABIC Innovative Plastics IP B.V. (Bergen op Zoom, NL), April 28, 2009. 

Figure 3-5 Modification of polycarbonate spectacle lenses to facilitate drop instillation. After a hole is drilled through the center of each lens, the patient inserts the dropper tip into the hole, gazes superiorly, and squeezes the bottle.

As examples of new, fast-growing applications of reactive silicones, polycarbonate headlight lens coatings [3] and microelectronics applications can be cited. 

Glass window assembly Lens bonding Polycarbonate shield assembly... 

Legend XT is now prescription ready with a hassle-free prescription insert. With a polycarbonate, anti-fog lens, and low-profile design the Legend XT is compatible with hard hats and face shields. The breathable, hypoallergenic foam seal makes the Legend XT the 1 choice and meets all ANSI Z87.1 high impact requirements. U.S. Safety, www.ussafety. com. Booth 120. Circle 310... 

PC alone is widely used as vacuum cleaner housings, household appliance housings, and power tools. It is also used in safety helmets, riot shields, aircraft canopies, traffic light lens housings and automotive battery cases. In addition to standard grades of polycarbonates, a special film grade exists for high-performance capacitors. 

Plastic headlamp lenses have only recently become legal in Europe, and their use is now incorporated in ECE R20. However, plastic headlamp lenses have been legal in Japan for many years, and in the USA since 1979. The appropriate standard there is FMVSS 108, whose heat distortion and scratch requirements are met only by polycarbonate, with a silicone hard coating. A plastic lens only weighs half as much as glass the main incentives however are the lower assembly costs represented by plastics and the much greater design freedom, especially for flat low aspect ratio lenses, suitable for low-front aerodynamic bodies. 

In this chapter, we will cover the various lens fabrication techniques. The lens materials range from polymers to glass and include polycarbonates, ultraviolet (UV)-curable epoxies, polyimides, and polystyrenes. These techniques can produce lenses with numerical apertures (NAs) less than 0.6, typically 0.1 to 0.3 [7]. Low NA values are attributable to the surface profiles and refractive indices of microlenses. 

An in-sample compartment reflection accessory was also used in determining the optical constants (n, real refractive index, and k, absorption coefficient) for polymer films PET [318], polycarbonate [319], and PAN [320]. Many polymers are used as lens or window materials, because of their transparency, in the far-IR (10 00 cm" ) as well as in the visible. The optical constants of polymers such as TPX (poly-4-methylpent-l-ene) [321] and PET [322] have... 

Frameless/mono lens glasses that use the same polycarbonate material for the lens and temples and offer an unrestricted field of vision. (See photo SG-18.)... 

Heat and impact resistant, the Legend XT goggle has a clear polycarbonate frame that provides 180-degree protection and unobstructed vision and protects the wearer from dust, debris and impact. The Legend XT also has anti-fog lens, breathable foam seal and an available prescription insert. U.S. Safey, www.ussafety.com, (800)821-5218. Circle 266... 

Carbonate-modified unsaturated polyesters have received some attention.Where hydroxy-substituted bisarylcarbonates were used as intermediates,polyesters with improved properties were claimed. Combinations of polycarbonates and unsaturated polyesters have recently been patented as ophthalmic lens materials. 

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