Adhesives and Adhesive Tape
Adhesives are substances that hold materials together by surface attachment. Natural adhesives such as beeswax, resin, and bitumen have been used since earliest times. Ancient Egyptians used glue made from animal skin and bones for woodworking. Medieval monks used egg white to bind gold leaf to their illuminated manuscripts. The nineteenth century saw the advent of rubber and pyroxylin cements.
Although adhesive tape was first patented in 1848 by the American Henry Day, and an adhesive bandage was invented by a German pharmacist, Paul Beiersdorf, in 1882, the real advances in adhesive technology came in the twentieth century when synthetic materials were developed. While natural adhesives--such as glue made from animal and plant proteins, pastes of dextrin, starch or latex, and natural rubber, resin, and bitumen--remain in wide use, synthetics now dominate the industry. Synthetic resins are either thermoplastic (softened by heating) or thermosetting (hardened by heating).
The most familiar adhesive tape, Scotch tape, was the invention of Richard Drew of the Minnesota Mining and Manufacturing Company (3M). At the time, two-toned paint jobs were all the rage on automobiles. Painters at auto body shops used gummed tape to make a sharp edge between contrasting colors. When they removed the tape, paint often came with it. Drew, a 3M lab researcher then taking samples of waterproof sandpaper to auto body shops, responded to mechanics' complaints. He developed a pressure-sensitive masking tape in the mid-1920s that did not mar the paint. To make the two-inch wide tape more affordable, only the edges of the tape had adhesive applied. When the car painters used the lightly treated tape, it fell off. They told the 3M salesmen to take "this Scotch tape" back to their stingy bosses (or "this tape back to your Scotch bosses") and put adhesive all over it. Like the improved tape, the Scotch name stuck. In 1930 Drew invented a way to coat Du Pont's newly invented (1924) cellophane with adhesive. The resulting pressure-sensitive transparent tape was also given the Scotch name. Sales were slow, though, until a sales manager invented a dispenser for the tape. Scotch tape became a huge seller for 3M, with hundreds of varieties; it was largely supplanted in the 1960s by Magic Tape, which could be written on and did not yellow or become brittle with age. Removable, restickable transparent tape arrived in the 1980s.
Other modern adhesives include epoxy resins, developed in the 1950s, which allow bonding of previously difficult materials, such as glass and metal. Superglue is a cyanoacrylate ester--based adhesive that sets in seconds and works on many different materials--including (to the dismay of careless users) human skin.
Throughout history, a wide range of materials has been used to close deep cuts and other wounds, including cobwebs, the jaws of leaf-cutting insects and, in modern times, stitches and staples. But by 1997 another material was showing promise: surgical glue. Doctors found that instead of sewing patient's wounds and having to remove the stitches a week or so later, they could simply glue the edges together and send their patients home. The adhesive, Dermabond, is an octylcyanoacrylate polymer manufactured by Closure Medical Corporation of Raleigh, North Carolina. The reactive ingredient in Dermabond, 2-octyl acrylate, reacts with moisture on the skin's surface to form a strong plastic coating.
State-of-the-art adhesives continue to be widely used in industry—notably on aircraft--in place of such traditional fastening methods as rivets, bolts, and welding.
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