Flexplay
Encyclopedia
Flexplay is a trademark for a DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

-compatible optical video disc format with a time-limited (usually 48-hour) playback time. They are often described as "self-destructing
Self-destruct
A self-destruct is a mechanism which causes a device to destroy itself under a predefined set of circumstances.Self-destruct mechanisms are also found on devices and systems where malfunction could endanger large numbers of people...

" although the disc merely turns black and does not physically disintegrate. The same technology was used by Disney
The Walt Disney Company
The Walt Disney Company is the largest media conglomerate in the world in terms of revenue. Founded on October 16, 1923, by Walt and Roy Disney as the Disney Brothers Cartoon Studio, Walt Disney Productions established itself as a leader in the American animation industry before diversifying into...

's Buena Vista Home Entertainment under the name ez-D. The Flexplay concept was invented by two professors, Yannis Bakos
Yannis Bakos
Yannis Bakos is a professor at the Leonard N. Stern School of Business at New York University. His primary area of expertise is the economic and business implications of information technology, the Internet, and online media. He is the co-founder of the , and the co-inventor of Flexplay...

 and Erik Brynjolfsson
Erik Brynjolfsson
Erik Brynjolfsson is the Schussel Family Professor of Management at the MIT Sloan School of Management, the Director of the MIT Center for Digital Business and a Research Associate at the National Bureau of Economic Research...

, who founded Flexplay Technologies in 1999. The technology was developed by Flexplay Technologies and General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

.

Overview

The technology was originally intended as an alternative means for the short-term rental of newly released movies. Since the disc is capable of being used in any standard DVD player, the manufacturers hoped it would succeed where other time-limited DVD technologies, such as DIVX
DIVX
DIVX was an unsuccessful attempt by Circuit City and the entertainment law firm Ziffren, Brittenham, Branca and Fischer to create an alternative to video rental in the United States.-Format:...

, failed. Test marketing of EZ-D discs began on August 2003 but was canceled early when consumers rejected the concept (partly due to environmental issues). Due to fears of cannibalizing DVD sales, movies were made available on eZ-D between 2 months and several years after being released on DVD and were priced at US$6.99, both factors that significantly limited consumer demand.

SpectraDisc was another such technology, and on January 13, 2003 Flexplay Technologies acquired all of the SpectraDisc Corporation assets. SpectraDisc discs worked in a similar way as Flexplay discs, only not starting as red and turning blue instead of black. The addition of the red layer to Flexplay discs may be in order to protect the expired discs from being read in next-generation players using blue lasers, for which the oxidized blue-color layer is essentially transparent.

In 2004 Flexplay was sold to The Convex Group which also owned the Lidrock and HowStuffWorks
HowStuffWorks
HowStuffWorks is a commercial edutainment website that was founded by Marshall Brain with the goal of giving its target audience an insight into the way in which many things work. The site uses various media in its effort to explain complex concepts, terminology and mechanisms, including...

 brands. As of 2008, Flexplay discs were priced at around US$4.99, a price comparable to that of a two-day DVD rental.

Specifications

Flexplay discs do not bear the DVD logo. When asked whether Flexplay discs do or do not comply with DVD forum standards, a company spokesperson replied that "Flexplay DVDs are produced to be readable in DVD players adhering to DVD Forum specifications."

A Flexplay disc is shipped in a vacuum-sealed package. There is a clear dye inside the disc, contained within the bonding resin of the disc, which reacts with oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

. When the seal is broken on the vacuum-packed disc, the layer changes from clear to black in about 48 hours, rendering the disc unplayable. If unopened, the shelf life of the sealed package is said to be "about a year". The DVD plastic also has a red dye in it, which prevents penetration of the disc by blue lasers, which would go straight through the oxygen-reactive dye.

The Flexplay discs are dual-layer DVD-9 discs. The change against standard DVDs is the composition of the resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...

 adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

 holding the inner and outer layer together, which is sensitive to oxygen and darkens within a pre-set time, usually 48 hours, when exposed to air. The replacement of the adhesive results in only minimal altering to the DVD manufacturing process. The time of the darkening can be influenced by varying the exact composition of the resin. For the DVD-5 discs, where there is no layer of bonding resin in the optical path, surface coating can be used.

According to the vendor, "Flexplay discs are fully recyclable and conform to all applicable EPA environmental standards." Some environmental groups have endorsed the product due to Flexplay's recycling plans and partnership with environmental industry leaders such as GreenDisk, leading to the creation of the first DVD recycling operation. Others such as the Grass Roots Recycling Network nevertheless have objected to the creation of a short-lived "disposable" version of a traditionally durable product.

Chemistry

The reactive layer comprises a polymer resin that acts as a carrier for a suitable leuco dye
Leuco dye
A leuco dye is a dye whose molecules can acquire two forms, one of which is colorless.For example, the spiro form of an oxazine is a colorless leuco dye; the conjugated system of the oxazine and another aromatic part of the molecule is separated by an sp3-hybridized "spiro" carbon...

, which, upon contact with atmospheric oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

, oxidizes to form an opaque or semi-opaque material.

Some of the dyes used are methylene blue
Methylene blue
Methylene blue is a heterocyclic aromatic chemical compound with the molecular formula C16H18N3SCl. It has many uses in a range of different fields, such as biology and chemistry. At room temperature it appears as a solid, odorless, dark green powder, that yields a blue solution when dissolved in...

, prussian blue
Prussian blue
Prussian blue is a dark blue pigment with the idealized formula Fe718. Another name for the color Prussian blue is Berlin blue or, in painting, Parisian blue. Turnbull's blue is the same substance but is made from different reagents....

, brilliant cresyl blue
Brilliant cresyl blue
Brilliant cresyl blue is a compound with formula ZnC34H40Cl4N6O2. It is a dye.- Reference :...

, Toluidine Blue O, Basic Blue 3, Methylene Green
Methylene green
Methylene green is a heterocyclic aromatic chemical compound similar to methylene blue. It is used as a dye.- External links :*...

, Taylor's Blue, Janus Green B, Meldola's Blue, Thionin
Thionin
Thionine, also known as thionine acetate or Lauth's violet, is a strongly staining metachromatic dye that are widely used for biological staining. Thionine can also be used in place of Schiff reagent in quantitative Feulgen staining of DNA. It can also be used to mediate electron transfer in...

, Nile Blue
Nile blue
Nile blue is a stain used in biology and histology. It may be used with live or fixed cells, and imparts a blue colour to cell nuclei....

, and Celestine Blue. The leuco dye is prepared by chemical reduction
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....

 using a suitable reducing agent
Reducing agent
A reducing agent is the element or compound in a reduction-oxidation reaction that donates an electron to another species; however, since the reducer loses an electron we say it is "oxidized"...

. The method commercially used by Flexplay and SpectraDisc employs methylene blue reduced by sodium dithionite
Sodium dithionite
Sodium dithionite is a white crystalline powder with a weak sulfurous odor. It is a sodium salt of dithionous acid. Although it is stable under most conditions, it will decompose in hot water and in acid solutions...

.

In order to prevent the oxidation being triggered during manufacture of the discs, and in order to avoid the need for operating in inert atmosphere, the leuco dyes are further chemically modified to their blocked forms. Such blocked leuco dyes are the leuco dye precursors that form the leuco dye by a slow, controlled chemical reaction. Leucomethylene blue can be reacted with triisopropylsilyl trifluoromethanesulfonate, forming triisopropylsilyloxycarbonylleucomethylene blue (TIPSOCLMB), which is stable in presence of air oxygen. In presence of nucleophile reagents, e.g. water, the blocked leuco dye compound undergoes hydrolysis, releasing the unblocked leuco dye. This reaction is slow (several days to a week), and the hydrolytic compound is supplied either as atmospheric moisture, or in the formulation of the resin.

The rate of the deblocked leuco dye oxidation is dependent on the pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

 of the resin polymer matrix. By adding basic compounds (e.g. 1,4-diazabicyclo[2.2.2] octane (DABCO
DABCO
DABCO or 1,4-diazabicyclo[2.2.2]octane is a chemical compound. It is a polyurethane and Baylis-Hillman reaction catalyst, complexing ligand and Lewis base. It is used to regulate the reaction rate in Flexplay time-limited DVDs by adjusting pH. Antioxidants, like DABCO, are used to improve the...

), or other amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s), the pH is increased, and the reaction rate increases correspondingly. Correspondingly, by adding strong protic acids (e.g. camphorsulfonic acid
Camphorsulfonic acid
Camphorsulfonic acid, sometimes abbreviated CSA or 10-CSA is a organosulfur compound. Like typical sulfonic acids, it is a relatively strong acid that exists as a colourless solid that is soluble in organic solvents....

), the reaction rate can be decreased and the lifetime of the disc prolonged.

The residual oxygen can be removed from the substrates used for disc manufacture by storing them under vacuum or oxygen free atmosphere (e.g. pure nitrogen) for a period of time (hours to days). Alternatively, an oxygen scavenger (e.g. iron(II) salts, tin(II) salts, or organometallic compounds) can be added to the polymer formulation, reacting with the oxygen present in the polymer matrix in shorter timeframe than the hydrolysis of the blocked leuco dye takes.

The reaction timing can be further controlled by addition of other substances. As the diffusion rate of oxygen through the polymer layer is more or less constant, a supply of suitable antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

s (e.g. organometallic compounds) which react with the oxygen preferentially to the leuco dye leads to gradual depletion of the antioxidant compound. Only after the antioxidant is consumed, the leuco dye starts being oxidized, achieving the period of delay of the reaction onset, followed by a rapid reflectivity degradation. Stannous ethylhexanoate can be used here as the antioxidant organometallic. Various resin-soluble tin(II) and iron(II) compounds can be used, e.g. chelates and fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

 salts. Other usable compounds are e.g. hydroquinone
Hydroquinone
Hydroquinone, also benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, having the chemical formula C6H42. Its chemical structure, shown in the table at right, has two hydroxyl groups bonded to a benzene ring in a para position. It is a white granular solid...

s, alkylhydroxylamine
Hydroxylamine
Hydroxylamine is an inorganic compound with the formula NH2OH. The pure material is a white, unstable crystalline, hygroscopic compound. However, hydroxylamine is almost always provided and used as an aqueous solution. It is used to prepare oximes, an important functional group. It is also an...

s, dithionates, reducing saccharides (e.g. glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

), alpha-hydroxyketones (acetol), substituted boron hydrides and silicon hydrides.

The oxidized dyes in the expired discs absorb primarily at the wavelength of the current diode lasers (red, 650 nm) used in the DVD players. However, the new generation of DVDs is designed to use blue lasers at 450-460 or even 405 nm, for which the methylene blue is essentially transparent. While SpectraDisc did not take this in account, the Flexplay discs incorporate a layer of a color filter, blocking the blue lasers from reading the disc, expired or not. Acridine Yellow
Acridine yellow
Acridine yellow, also known as acridine yellow G, acridine yellow H107, basic yellow K, and 3,6-diamino-2,7-dimethylacridine, is a yellow dye with strong bluish-violet fluorescence. It is a derivate of acridine. In histology, it is used as a fluorescent stain, and as a fluorescent probe for...

 can be used for this purpose, together with 9,10-bis(phenylethynyl)anthracene
9,10-Bis(phenylethynyl)anthracene
9,10-Bisanthracene is an aromatic hydrocarbon with the chemical formula is C30H18. It displays strong fluorescence and is used as a chemiluminescent fluorophore with high quantum efficiency....

, and a scale of different azo dyes, aromatic hydrocarbon
Aromatic hydrocarbon
An aromatic hydrocarbon or arene is a hydrocarbon with alternating double and single bonds between carbon atoms. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent...

s, and other dyes. The dyes can be added directly to the polycarbonate resin the discs are made of.

Additionally, other methods of the disc degradation are proposed to be deployed together with the primary one; the concern of the technology developers here is that while the dye oxidation mechanism prevents the disc from being read by current consumer technologies, the information on the disc, recorded in the pattern of the pits in the reflective layer, remains intact and could be recovered. One of the methods is to make the two reflective layers in the DVD-9 disc of different metals (e.g. aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 and silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

), and separate them with an ionic conductor separator. The atmospheric oxygen then undergoes electrochemical reaction in such crude fuel cell
Fuel cell
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...

 with the silver as cathode
Cathode
A cathode is an electrode through which electric current flows out of a polarized electrical device. Mnemonic: CCD .Cathode polarity is not always negative...

 and aluminum as anode
Anode
An anode is an electrode through which electric current flows into a polarized electrical device. Mnemonic: ACID ....

, leading to growth of dendritic silver through the dielectric layer. When the silver reaches the aluminium, an electric short circuit forms, and galvanic corrosion then rapidly degrades the reflective layers. Many other mechanisms are proposed for this slower, less controlled "backup" method of data destruction, ranging from corrosion of the reflective layers to degradation of the polymer matrix of the disc itself.

Releases

The Disney organization announced in 2003 that it would issue some releases on Flexplay ez-D discs. Discs were test-marketed in Austin, Texas. One grocery chain dropped the discs in February, 2004, saying "It didn't turn out to be an item that our customers were looking for."

In 2004 Flexplay was purchased by The Convex Group who also own the Lidrock and HowStuffWorks
HowStuffWorks
HowStuffWorks is a commercial edutainment website that was founded by Marshall Brain with the goal of giving its target audience an insight into the way in which many things work. The site uses various media in its effort to explain complex concepts, terminology and mechanisms, including...

 brands. , Flexplay discs were priced at around US$4.99, a price comparable to that of a two-day DVD rental.

The first Flexplay disc to receive national consumer distribution in the U.S. was a 2004 Christmas movie entitled Noel
Noel (film)
Noel is a 2004 Christmas-themed drama film written by David Hubbard and directed by Chazz Palminteri. It stars Susan Sarandon, Penélope Cruz, Paul Walker, Alan Arkin, Daniel Sunjata and an uncredited Robin Williams.-Plot summary:...

, which was released "trimultaneously" to theatres, to cable TV, and to Flexplay disc. Reportedly theatres were angered at the simultaneous release, and as a result the movie actually received screenings in only a few dozen theatres.

, Flexplay discs appeared in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 under the 48dvd brand name, and were also used in 2006 for the Japanese release of Mission: Impossible 3.

In June 2008, Flexplay announced that Staples would be selling Flexplay discs in their retail stores.

See also

  • Planned obsolescence
    Planned obsolescence
    Planned obsolescence or built-in obsolescence in industrial design is a policy of deliberately planning or designing a product with a limited useful life, so it will become obsolete or nonfunctional after a certain period of time...

  • DIVX (Digital Video Express) and DVD-D
    DVD-D
    DVD-Ds, also referred to as disposable DVDs, are a type of digital video disc that is designed to be used for a maximum 48 hours after the containing package is opened. After this time, the DVDs become unreadable to DVD players because they contain a chemical that, after the set period of time,...

    , other disposable disc formats
  • Disc rot
    Disc rot
    Disc rot is a phrase describing the tendency of CD or DVD or other optical disks to become unreadable due to physical or chemical deterioration...

    , the unintended decay of optical discs due to physical or chemical deterioration

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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