GB2343288A

GB2343288A - Reconditioning of digital recording discs

Info

Publication number: GB2343288A
Application number: GB9823713A
Authority: GB
Inventors: Stanley Irwin Grossman; Howard Ira Miller
Original assignee: Rocky Mountain Traders Ltd
Current assignee: Rocky Mountain Traders Ltd
Priority date: 1998-10-29
Filing date: 1998-10-29
Publication date: 2000-05-03
Also published as: DE29823012U1; GB9823713D0; CA2272980A1

Abstract

The surface of a digital recording disc may be reconditioned by application of a first composition including a filler and then a second composition including a sealant. Any scratches or imperfections in the protective coating are filled by the first composition. The second composition then seals the first composition in place and preferably also provides a protective layer to help reduce the risk of future damage to the disc surface. Preferably, the first composition comprises wax or a blend of waxes in amount of 5% by weight or less and further comprises one or more of (a) an inert polish media in an amount of 10% by weight or more, (b) a solvent in an amount of 30% by weight or more, (c) an emulsifier in an amount of 10% by weight or more, and (d) water in an amount of 30% by weight or less, and the second composition comprises wax or a blend of waxes in an amount of 10% by weight or more and further comprises one or more of (a) a silicone or a blend of silicones in an amount of 5% by weight or more and (b) a solvent in an amount of 30% by weight or more where the percentages are based on the total weight of the first composition. The compositions may conveniently be provided in the form of a repair kit.

Description

METHOD FOR RECONDITIONING DIGITAL RECORDING DISCS The present invention relates to the repair of digital recording discs, in particular, to the removal of imperfections on the protective coating.

Digital recording discs, including compact discs (CDs), laser discs, and the like, are widely used to store large amounts of different types of information. Modern digital discs may be formatted for use with audio, video or computer equipment that reads the data recorded on the discs. The technology associated with digital discs and digital playback equipment is well known to those skilled in the art. Basically, digital information is encoded as a sequence of pits within a disc, beneath an optically transparent protective layer of plastic, such as polycarbonate. A laser beam reads the digital information during playback, and the information is then processed and presented to the user in the form of sound or visual images. A significant drawback to polycarbonate in use as a protective layer, however, is that the exterior surface of the polycarbonate layer is prone to scratching.

If the exterior surface becomes too scratched or dirty, it can interfere with the passage of the laser beam. When this happens, the optical read-out system will backtrack until it reads an unaffected sequence of pits and then continue. Often this leads to a"skip" or a constant"skipping", as the optical read-out system gets stuck on one sequence and the compact disc stops playing. Although modern optical read-out systems include error correction techniques, some scratches on the protective coating of a disc may still cause problems during playback. If such imperfections cause the optical read-out system to consistently malfunction, then the disc itself may be unusable. Due to the high cost of digital discs, it is desirable to repair such damaged discs rather than replace them.

Consequently, various methods for treating the surface of a CD have been developed, however, these prior art methods suffer from severa!disadvantages * if One known method for repairing scratches on a digital disc involves sanding or grinding the protective coating until the imperfections are no longer present, for example, as described in EP 0342359 to Schmid. Typically, this process involves several sequential, time consuming steps using grinding elements or polishing compounds having varying grades. While this method may effectively repair the protective coating of a single digital disc, it has a major drawback in that each time a disc is repaired, more of the protective coating is removed. This enhances the risk of a scratch actually damaging the data stored on the disc.

Another process for repairing damaged digital discs involves the localised removal of scratches or imperfections from the protective layer of the disc. This process may have limited use because the spot removal of imperfections inherently creates an unbalanced disc. An unbalanced CD (which can spin at rotational speeds of up to 500 RPM) may cause focusing problems, vibrations, and signal distortion during playback.

Against this background, the present invention aims to provide a method of reconditioning the protective coating of a digital recording disc that restores the playback quality of the disc. In particular, it provides a method of reconditioning the coating of discs which is quick, easy, inexpensive and does not require specialist expertise to carry out the method. The present invention also aims to provide a kit for reconditioning such discs.

More especially, the present invention avoids the use of complicated machinery and may be carried out by the ordinary person in the home or office, with minimal expense and time.

From a first aspect, the invention comprises a method for reconditioning digital recording discs comprising the steps of i) filling, and ii) sealing, in particular, to removing imperfections on the protective coating which cause malfunctioning of the optical read-out system.

From a further aspect, the invention encompasses a two part kit for reconditioning digital recording discs comprising two compositions to be used sequentially, namely a first composition, which includes a filler, and a second composition, which includes a sealant.

The first composition fills the imperfections and preferably also acts to remove dirt, dust and grease. In this way, the light refractivity is reduced so that the damage becomes substantially invisible to the laser beam.

The second composition, used after the first, acts to seal the first composition in place and preferably also provides a protective layer over the surface of the disc to protect the disc from further scratches, as well as dust and grease etc. The protective layer also adds an aesthetic shine to the disc.

In a preferred embodiment, the first, filler composition is applied to the exterior surface of the protective coating of the disc, and is rubbed onto the surface from the centre of the disc towards the outer edge. Rubbing is ideally carried out using a non-abrasive applicator, such as a soft cloth or sponge, and with sufficient force to treat substantially all the imperfections. The disc is rubbed for a relatively short period of time, before allowing the filler to dry.

Once the filler is dry, the second, sealing composition is applied to the same surface and rubbed with a second non-abrasive applicator to obtain an optically-and visuallydesirable finish.

For ease of application, the preferred filler for use in the filler composition is a wax or blend thereof. The wax or blend of waxes act to fill any scratches and/or imperfections and are preferably hard enough to have sufficient adhesion to the surface.

It is further preferred that the first, filler composition includes an inert ; medium, for example, in the form of a mild abrasive.

In this regard, it is desirable that the polishing medium is sufficiently abrasive to clean the scratches on the plastic surface, but not too abrasive, otherwise the surface may be further scratched instead of polished. In order to provide the desired consistency, the first composition advantageously also includes a solvent, as well as waxes and a polishing medium.

The solvent not only act as a carrier for the polish and a solvent for the wax, but furthermore, is believed to dissolve any grease and dirt on the disc thereby conditioning the protective coating of the disc.

Applicant has found that it is advantageous to use gum spirits of Turpentine as the solvent.

The first composition may additionally comprise an emulsifier and/or water.

The emulsifier is preferably included to hold the ingredients in suspension and prevent them from separating. It also ensures even dispersal of the polish within the liquid to prevent uneven polishing and unnecessary abrasion in selected areas.

Water may be added in an amount sufficient to provide the desired consistency, i. e. a consistency that is easily applicable to the surface.

A preferred embodiment of the first composition comprises waxes in amount of 5% or less.

In a further preferred embodiment, the first composition comprises waxes in amount of 5% or less and further comprises any or all of (a) an inert polish media in an amount of 10% or more, (b) a solvent in an amount of 30% or more, whereby the solvent is preferably gum spirits of Turpentine, (c) an emulsifier in an amount of 10% or more, and/or (d) water in an amount of 30% or less, where the weight percentages are based on the total weight of the first composition.

It is preferred that the sealant in the second composition is a wax or blend thereof, which provides a protective layer, for example, by sealing in the filling agent applied with the filler. The wax or blend of waxes also help restore any depth to the plastic coating which may be removed during the filling process.

It is advantageous if the second composition also includes a protective agent. For example, Applicant has found it beneficial to use silicones, which aid polishing and improve the scratch-resistance of the surface.

It is further preferred if the second composition additionally includes a solvent, for example, an aliphatic hydrocarbon solvent, as well as a wax or blend of waxes.

In a preferred embodiment, the second composition comprises waxes in an amount of 10% or more.

In a further preferred embodiment, the second composition comprises waxes in an amount of 10% or more and further comprises any or all of (a) silicones in an amount of 5% or more, and/or (b) a solvent in an amount of 30% or more, whereby the solvent is preferably an aliphatic hydrocarbon solvent, where the weight percentages are based on the total weight of the second composition.

It is preferred that the invention comprises a kit of parts comprising the first composition and the second composition and preferably including at least one nonabrasive applicator. Ideally two applicators are provided, one for each of the first and second compositions.

To prevent further scratching and/or the generation of dust and fluff, it is desirable that the or each non-abrasive applicators are made from a lint-free material.

In order to aid use the invention, the kit of parts advantageously also includes instructions for use.

In a preferred embodiment, the kit of parts comprises the first composition, the second composition and further comprises any or all of (a) packaging, (b) at least one nonabrasive applicator, and/or (c) instructions for use. It will be appreciated that the present invention may be embodied in other specific forms without departing from the essential attributes thereof

Claims

Claims : 1. A d*Hecording disc repair kit for reconditioning the surface of a disc, wherein the kit comprises first and second compositions to be used sequentially on the surface, the first composition including a filler and the second composition including a sealant.
2. A repair kit according to claim 1, wherein the filler in the first composition comprises a wax or blend thereof.
3. A repair kit according to claim 2, wherein the wax or blend of waxes in the first composition is of a consistency sufficient to adhere to the disc surface.
4. A repair kit according to any preceding claim, wherein the first composition further includes an inert polishing medium.
5. A repair kit according to claim 4, wherein the inert polishing medium is a mild abrasive.
6. A repair kit according to any preceding claim, wherein the first composition further includes a solvent.
7. A repair kit according to claim 6, wherein the solvent comprises gum spirits of Turpentine.
8. A repair kit according to any preceding claim, wherein the first composition further includes an emulsifier and/or water.
9. A repair kit according to any preceding claim, wherein the first composition comprises wax or a blend of waxes in amount of 5% by weight or less based on the total weight of the first composition.
10. A repair kit according to any preceding claim, wherein the first composition comprises wax or a blend of waxes in amount of 5% by weight or less and further comprises one or more of (a) an inert polish media in an amount of 10% by weight or more, (b) a solvent in an amount of 30% by weight or more, (c) an emulsifier in an amount of 10% by weight or more, and (d) water in an amount of 30% by weight or less, where the percentages are based on the total weight of the first composition.
11. A repair kit according to any preceding claim, wherein the sealant in the second composition comprises a wax or blend thereof.
12. A repair kit according to any preceding claim, wherein the second composition further includes a protective agent.
13. A repair kit according to claim 12, wherein the protective agent comprises a silicone or blend thereof.
14. A repair kit according to any preceding claim, wherein the second composition further includes a solvent.
15. A repair kit according to claim 14, wherein the solvent comprises an aliphatic hydrocarbon solvent.
16. A repair kit according to any preceding claim, wherein the second composition comprises wax or a blend of waxes in an amount of 10% by weight or more based on the total weight of the first composition.
17. A repair kit according to any preceding claim, wherein the second composition comprises wax or a blend of waxes in an amount of 10% by weight or more and further comprises one or more of (a) a silicone or a blend of silicones in an amount of 5% by weight or more and (b) a solvent in an amount of 30% by weight or more, where the percentages are based on the total weight of the second composition.
18. A repair kit according to any preceding claim, further comprising at least one nonabrasive applicator.
19. A repair kit according to claim 18, wherein two non-abrasive applicators are provided, one for each of the first and second compositions.
20. A repair kit according to claim 18 or claim 19, wherein the or each non-abrasive applicator is made from a lint-free material.
21 A method for reconditioning digital recording discs comprising the steps of : i) filling any imperfections on the protective coating surface of the disc with a first composition and ii) sealing the first composition with a second composition.
22. A method according to claim 21, wherein the first composition is applied to the protective coating surface of the disc, is rubbed onto the surface and is allowed to dry before the second composition is applied to the same surface.
23. A method according tb claim 21 or 22, wherein polishing of the protective coating surface is carried out simultaneously with the filling step.
24. A method according to any of claims 21 to 23, wherein the surface is filled with a first composition.
25. A method according to claim 24, wherein the first composition comprises a wax or blend thereof as filler.
26. A method according to claim 25, wherein the first composition further comprises an inert polishing medium.
27. A method according to any of claims 24 to 26, wherein the first composition comprises wax or a blend of waxes in amount of 5% by weight or less and further comprises one or more of (a) an inert polish media in an amount of 10% by weight more, (b) a solvent in an amount of 30% by weight or more, (c) an emulsifier in an amount of 10% by weight or more, and (d) water in an amount of 30% by weight or less, where the percentages are based on the total weight of the first composition.
28. A method according to any of claims 21 to 27, wherein the surface is sealed with a second composition.
29. A method according to claim 28, wherein the second composition comprises a wax or blend thereof as sealant.
30. A method according to claim 28 or 29, wherein the second composition further comprises a protective agent.
31. A method according to claim 30, wherein the protective agent comprises a silicone or blend thereof.
32. A method according to any of claims 28 to 31, wherein the second composition comprises wax or waxes in an amount of 10% by weight or more and further comprises one or more of (a) a protective agent in an amount of 5% by weight or more and (b) a solvent in an amount of 30% by weight or more, where the percentages are based on the total weight of the second composition.
33. A method according to any of claims 21 to 32, wherein the filling and sealing steps are carried out using first and second compositions as contained in the repair kit as claimed in any of claims 1 to 20.
34. A method for reconditioning digital recording discs according to any one of claims 21 to 33 substantially as hereinbefore described.
35. A repair kit for reconditioning digital recording discs according to any one of claims 1 to 20 substantially as hereinbefore described.