Recording tapes

R = (CH2 )2) and terephthaUc acid (R = ) is familiar in the form of soda bottles, recording tape, and polyester fiber (see Fibers, polyester). 

Recording tape (electron-beam-curable coatings)... 

The principal uses of polyfethylene terephthalate) film are electrical, particularly in capacitors, as slot liners for motors and for recording tape. Its high strength and dimensional stability have led to a number of drawing office applications. The film is also a useful packaging material whilst metallised products have a number of uses as a decorative material. 

Geothite is produced by air oxidation of alkaline suspension of ferrous hydroxide (Sada etal., 1988). As a starting material for ferrous oxide, the preparation of fine particles with prescribed size, size distribution and shape is required in its application to magnetic materials for recording tapes and disks. With increasing oxidation rate, the crystal size decreases and the size distribution becomes sharper (Sada etal., 1988). The first step of the reaction. 

The most generally useful polyester is that made by reaction between dimethyl terephthalate (dimethyl 1,4-benzenedicarboxylate) and ethylene glycol (1,2-ethanediol). The product is used under the trade name Dacron to make clothing fiber and tire cord and under the name Mylar to make recording tape. The tensile strength of polyethylene terephthalate) film is nearly equal to that of steel. 

Magnetic recording tape, in addition to using plastic films as a support for the recording... 

Chromium metal is important in metallurgy, because it is used to make stainless steel and for chromium plating (Section 12.13). Chromium(IV) oxide, Cr02, is a ferromagnetic material that is used for coating chrome" recording tapes. 

A typical polyester molecule has 50 to 100 repeat units and a molar mass between 10,000 and 20,000 g/mol. PET can be formed into fibers (such as Dacron) or films (such as Mylar). Mylar films, which can be rolled into sheets 30 times thinner than a human hair, are used to make magnetic recording tape and packaging for frozen food. Dacron is best known for its use in clothing, but it has many other applications. For example, tubes of Dacron are used as synthetic blood vessels in heart bypass operations because Dacron is inert, nonallergenic, and noninflammatory. 

No part of this book may be reproduced or transmitted in any form or by any means—graphic, electronic, including photocopying, recording, taping, or information storage and retrieval systems—without written permission from the Royal Society of Chemistry... 

Because flexible films have excellent strength and good electrical and thermal properties, have low permeability to gases, water, oil, odour and could be sterilised so they are used in capacitors, cables, magnetic recording tapes, typewriter ribbons, food packaging, tracing film, book covers, etc. The film is coated with aluminium by vacuum disposition and used for decoration and in textiles. 

Polyesters are in widespread use in our modem life, ranging from bottles for carbonated soft drinks and water, to fibres for shirts and other apparel. Polyester also forms the base for photographic film and recording tape. Household tradenames, such as Dacron , Fortrel , Terylene and Mylar , demonstrate the ubiquitous nature of polyesters. 

A number of rather tenuous arguments suggest ozone damage to such materials as recording tape, asphalt, and dried milk. However, studies on such subjects are scattered and generally uncorroborated. Some studies even discuss beneficial effects of ozone, such as reduction of corrosion rates in steel and improvement in adhesion of ink to polyethylene films. 

Fibers—garments, permanent press and wash wear garments, felts, tire cord film—magnetic recording tape, high-grade film... 

Used in missile guidance systems in electronics as rectifiers, on memory or record tapes for permanent magnets also in radar, radio, television and computers... 

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