Polycarbonates compact disks

Schmidt, L. B., et al., Injection Molding of Polycarbonate Compact Disks Relationship between Process Conditions, Birefringence, Block Error Rate, SPE-ANTEC, 1992. 

CD-ROM not erasablenot rewritable technology identical with audio compact disk (CD-DA) substrate and information layer from polycarbonate (PC)... 

Polycarbonates. Currently, all audio CDs (CD-AD), all CD-ROM, and the biggest fraction of substrate disks for WORM and EOD worldwide are manufactured from a modified bisphenol A—polycarbonate (BPA-PC) (3). In 1991, some 1.3 x 10 compact disks were produced, equivalent to an annual amount of about 35,000 t BPA-PC. WORM and EOD disks are manufactured mainly from BPA-PC for sizes of 5.25 in. and below, and glass for larger form factors (eg, 12 in.), partially also from BPA-PC, and in some cases from aluminum or from cross-linked polymers (epoxy resins) (190). 

Fig. 24. Birefringence (path difference) of a compact disk, made from CD-modified BPA polycarbonate (191). Q, max value Q, min value (—), mean value.

Other Polymers. Besides polycarbonates, poly(methyl methacrylate)s, cycfic polyolefins, and uv-curable cross-linked polymers, a host of other polymers have been examined for their suitabiUty as substrate materials for optical data storage, preferably compact disks, in the last years. These polymers have not gained commercial importance polystyrene (PS), poly(vinyl chloride) (PVC), cellulose acetobutyrate (CAB), bis(diallylpolycarbonate) (BDPC), poly(ethylene terephthalate) (PET), styrene—acrylonitrile copolymers (SAN), poly(vinyl acetate) (PVAC), and for substrates with high resistance to heat softening, polysulfones (PSU) and polyimides (PI). 

A total of 15,000—17,000 t of resin is used aimuaHy. Polycarbonate also has many technical uses in instmment panels and devices, especiaHy for membrane switches and insulators. Optical quaHty polycarbonate is the only suitable material for the compact disk market. Since their introduction in 1983, compact disks have shown explosive growth in the consumption of polycarbonate, with utiHty for audio, video, and computer appHcations. Consumption of optical quaHty resin more than doubled between 1988 and 1992, and as of 1995 accounted for about 20,000 t of annual production. 

Polycarbonate can be readily injection molded. Polycarbonates typically require only a short injection molding cycle time, because the polymer flows into the mold easily and solidifies rapidly. We injection mold polycarbonate to produce a wide variety of commercial goods, including compact disks, jewel cases, aircraft windows, kitchen utensils, and clear refrigerators drawers. Polycarbonates are also found in a wide range of disposable medical devices, such as the flow locks on intravenous tubes and the hard, disposable components of dialysis machines. Impact resistant polycarbonate is used to manufacture sports and other safety helmets. Glass fiber reinforced polycarbonate is used in the housings for power tools. 

Special polycarbonate grades have been developed for the optical information storage market e,g., compact disks. 

Polycarbonate compact discs have also been used as supports for microarray development [112]. The microarray is generated using an inkjet applicator that employs an electric current to dispense monodisperse droplets containing antibodies onto the disk. The sensing reaction is based on competitive inhibition immunoassays using fluorescent antibodies and final readout is accomplished using a fluorescence scanner. 

Polycarbonates are already commercially produced and have excellent properties including electrical insulation, transparency and heat resistance they have been applied in the manufacture of a range of products, from adhesives to compact disks, encapsulation of electrical and electronic parts, optical lenses and in packaging. Most of these polycarbonates have a poly(oxycarbonyloxy-l,4-phenylene... 

The other important family of polymers dependent on the phosgene building block is that of the polycarbonates (PCs). Their production (about 350 million lb) consumes approximately 6-7% of the phosgene demand. The high-performance characteristics of the PCs also promise continued growth albeit at a lower level than that of the PURs, because the PCs are not used to the same extent as the PUR in the manufacture of large objects. On the other hand, special grades of PCs are utilized in the manufacture of compact disks (CDs) and other popular electronic devices. 

Other applications for 4-/ i -octylphenol include chain termination of polycarbonates (54). The properties of low molecular weight polycarbonates used in injection-molding applications to form compact disks are enhanced when the polymer is terminated using 4-/< oct5iphenol. 

Since its release in 1982, the compact disk has taken the world by storm, and billions of CDs have been manufactured [5, 6]. Most of them are of the readonly memory (ROM) type, made from transparent polycarbonate (see Chart 12.1) and providing almost perfect resolution. 

Thermoplastics represent the most important group of plastics to be processed in injection molding. Typical injection-molded parts made from thermoplastics include automobile hubcaps and bumpers, gears in kitchen appliances, screw-on caps and Ms, bottle crates, printer cartridges, and bail-point pens. Even the Compact Disk (CD) is produced from polycarbonate (PC) by the injection molding method. 

Polycarbonate (PC), from which Compact Disks are molded, is amorphous... 

Ascorbic acid in pharmaceutical preparations has been determined using a gold electrode made from compact disks (CDs) modified with platinum. The CDs consisted of a polycarbonate base on which a thin layer of photosensitive organic dye had been deposited. On this layer a mirror-like film of gold was fixed. Due to the low price of the CDs, each sensor can be used as gold electrode. A slice of the CDs was modified by electrochemical deposition of Pt. 

FIGURE 5.2.1.3 Structure of Phenol. The primary use of phenol is in the synthesis of hisphenol-A, which is used to make polycarbonate substances such as compact disks (CDs) and CD-ROMs. 

Jacob Liedner An important challenge is to find innovative uses for collected plastics waste. For example, in the near future, compact disks could be a very good source of polycarbonate. However, the success will depend on finding good markets for the reprocessed polymer or its blends. 

Another example shows that two different inorganic building blocks, i.e. silicate and zir-conate structures, can also be linked by organic polymer units. A scratch-resistant coating material for polycarbonate (for instance, compact disks) ° ° for optical and microop-tical applications and transparent monoliths was developed by copolymerizing the methacrylate units of ( -PrO)3Zr(methacrylate) or ( -PrO)2Zr(methacrylate)2 and MEMO after sol-gel processing of the precursor mixture. 

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