25 years ago the album “The Visitors” was the world’s first CD made from Makrolon®

It all started with ABBA
Philips and Bayer revolutionized data storage / The future lies in holography.

Leverkusen – It is small and round, provides enjoyable, crackle-free, crystal-clear sound, and it set off an acoustic revolution 25 years ago: the first pop CD to be made from Bayer’s high-tech material Makrolon® was ABBA’s album “The Visitors” in 1982. The compact disc produced the songs of the Swedish cult band in a sound quality that was totally new at the time, so that this shiny object totally changed the international music industry. It also changed the way people listened to music – for ever. What is more, it heralded the global conquest of optical data storage.

The era of the compact disc had begun: over the next few years this technology gradually ousted all analog recordings on records and magnetic tape. In 1996 it was followed by the DVD. Today the first HD-DVD and Blu-ray discs have reached the shelves, offering up to 80 times the capacity of a CD and producing razor-sharp images on the widescreen TV monitors of our sitting rooms, in a quality that is totally unprecedented. Better and better materials and technologies are permitting the use of increasingly larger data volumes. The future belongs to holographic media, with the storage of several hundreds of gigabytes. As before, materials from Bayer MaterialScience are well to the fore.

The audio CD: the initial spark that set off optical data storage
For the last quarter of a century the basic material for the storage of digital data on CDs and suchlike has been the high-tech plastic Makrolon® from Bayer. Working together with Philips and PolyGram, Bayer developed compact disc technology in the early eighties. The production of these discs was based on a specially tailored type of polycarbonate which still serves as the material for many optical recording media, although it has undergone a number of modifications since the early days. “I still remember the guys from Philips approaching us with a gleaming metal disc and announcing: ‘We’re going to put music on this thing soon’. We soon understood that we were helping to create a totally new technology. However, we didn’t have the slightest idea that this small disc would actually change the world one day,” says Dr. Hartmut Löwer, now head of Global Innovations in the Polycarbonates Business Unit (PCS) at Bayer MaterialScience.

The Bayer researchers set to work on Makrolon® and succeeded in modifying it for the special requirements of manufacturing processes in the music industry. The aim was to achieve the highest possible optical quality and transparency in the substrate, so that a laser head could read the digital code of a CD without any errors. Dr. Dieter Freitag was among the early pioneers. The former head of Central Materials Research at Bayer had already developed polycarbonates with an extraordinary level of flowability. This is vital for the production of CDs, because the plastic has to spread quickly and evenly within the mold. “What I didn’t know, however, was that, with this product, we would be able to split a Beethoven symphony into four billion pits and then press them onto a disc with a diameter of 12 centimeters.” Now he knows that with Makrolon® Bayer MaterialScience gave the industry a specially tailored material that would meet – and indeed still meets – the highest requirements with respect to storage capacity, data readability and stability. “The cradle for the mass production of CDs,” says Freitag with a smile, “was the Bayer facility in Krefeld-Uerdingen. And we were the midwives of this digital baby.”

Herbert von Karajan sets the tone
“What, you mean you can turn them over and then play the other side?!” says junior with amazement as dad nostalgically gets out the old record player to listen to one of those vinyls. Should be put in a museum. But before the soot-blackened vinyl material was replaced by the crystal-clear Makrolon® and started a digital revolution in music, the “industry giants” first had to agree on common standards for CDs. How many minutes of recording time and thus storage capacity should the new medium have? What should its diameter be ? We might think it was clearly a job for engineers to decide, but it wasn’t. We owe the final decision to Herbert von Karajan, the star conductor and classical music genius. Having correctly understood the digital opportunities of the compact disc at this early stage, von Karajan showed an amazing amount of foresight. He realized that it might be possible to store his music and therefore his life’s work for all eternity, and so he clearly defined the parameters for this new sound medium by insisting that it should have enough capacity to store his favorite piece, Beethoven’s 9th Symphony. The maestro had spoken. Michael Lang, CEO of Deutsche Grammophon, commented: “So you see from this example how classical music actually did influence the birth of the compact disc. But of course, classical music benefited greatly from the compact disc with its brilliant sound, ease of handling, ease of storage, no scrapes, no warps. And perhaps for maestro Karajan one of the benefits was not having to get up and turn the LP over every 15 minutes.”

Other sources say that it was the wife of the former Sony Chairman, Ako Morita, who decided on today’s storage capacity. One thing is certain now: a CD has a diameter of 12 centimeters and provides enough space for 74 minutes of musical pleasure. When it came to the circular hole in the middle, it was the Dutch who made the final decision. The 15-millimeter diameter of a CD, which we now take for granted, was exactly the size of the smallest coin in the world at the time: a Dutch ten-cent piece.

Rapid development
The outstanding sound quality and excellent durability of the new audio CD marked a paradigm shift in the technical recording of music and led to an amazing boom from the very first day of its market launch. The digitization of sound and music suddenly brought perfect musical enjoyment into our living rooms. Over 900,000 metric tonnes of polycarbonate are currently used for the production of optical recording media. Löwer comments that “the large volumes, coupled with a steady increase in data density, necessitate shorter production times and are therefore making increasingly higher demands on the raw material. Whereas in 1982 it took 27 seconds to produce a CD, this has now been reduced to less than three seconds.”

ata printing: increasing density, increasing speed
Optical data storage has been developing at a steady pace over the last 25 years. One partner of Bayer MaterialScience has been Sony. The first CD-ROM (ROM = read only memory) was launched in 1992, with a storage volume of over 450 floppy discs. It was suddenly possible to store entire reference works and to call them up whenever required. Only two years later computer users could simply “burn” and archive their documents to recordable or rewritable CDs (CD-Rs or CD-RWs).

The next logical step was the DVD (digital versatile disc), an optical recording medium that can hold several times as much data as a CD (4.7 gigabytes): in 1996, fourteen years after the launch of the compact disc, it took the world by storm. Like the CD, it was followed a few years later, by a “burnable” version.

Today, we are in a position to achieve even greater data densities on discs through the use of blue lasers which have shorter wavelengths than red ones. The new optical engineering technique is used in HD-DVDs and Blu-ray discs with storage capacities of 15 to 100 gigabytes, as these are the only ones that can fully satisfy the digital data requirements of high-definition TV.

But researchers at Bayer MaterialScience are already working with partners such as InPhase Technologies in the USA on holographic storage media (manufacturing partner: Maxell) which are set to continue the revolution in digital data discs. The new disc type – called TapestryTM – has a capacity of 300 gigabytes and is currently in its test phase. Unlike a conventional CD or DVD, data is no longer written and read bit by bit, but stored in the form of holograms, i.e. in entire data blocks all at once. This means that the read/write process can be accelerated many times over.

Makrolon® - a multiple talent
Thanks to a number of further properties and formula modifications, Makrolon® now has a world market share of 30 percent and is one of the best-selling products of the Bayer Group. Between its launch in 1982 and the year 2006, over 90 billion optical data media were made from this material. Music, images, videos, games and software – nearly everything is burnt onto CDs, DVDs, etc. these days.

As if this wasn’t enough, the multitalented plastic not only serves as material for recording media, but is also used in the electronics, construction and automotive industries as well as in sports, leisure and medical engineering – thanks to numerous insights that have been gained from the use of Makrolon® in CD manufacturing and which were subsequently applied to other areas. “The example of the CD shows that not only developmental stages, but also revolutions, are possible if the right partners work together,” says Löwer: Philips replaced analog with digital technology, Bayer replaced vinyl with Makrolon®. A vision became reality. And we’re continuing to work hard on many other small revolutions.”