Patent Application
20080063828
The present invention provides an optical disc, and more particularly, the substrate used on the optical disc is biodegradable with a sufficient length of life guaranteed for use. The preferred embodiments are disclosed as below.
Please refer to
The substrate 11 is formed of a biodegradable material mixed with an additive. The reflective layer 13 is formed over the substrate 11; the recording layer 15 is formed over the reflective layer 13; and the cover layer 17 is formed over the recording layer 15.
In an embodiment, the biodegradable material can be Polylactic Acid (PLA), starch, Polycaprolactone (PCL), Poly Vinyl Alcohol (PVA), Dihydroxy Acid Dibastic Alcohol, Aromatic Hydrocarbon Copolyester, Poly-3-Hydroxybutyrate-co-3-Polyhydroxyvalerate (PHBV), or other suitable materials. However, the transparency of the substrate formed by biodegradable material is lower. Therefore, the structure of the optical disc 1 based on the first preferred embodiment of the invention is more suitable for the specification that does not require a transparent substrate, such as dummy discs complied with a Blu-ray disc (BD) specification, a DVD+R specification, a DVD−R specification, a DVD+RW specification, a DVD−RW specification, and a High Density DVD (HD-DVD) specification. For example, the optical disc of the invention can be a dummy disc complied with the HD-DVD specification.
Please refer to
In another embodiment, the substrate 31 is formed of the biodegradable material with the additive as described above. However, in another embodiment, the substrate 31 is formed of the biodegradable material with the microcapsules 311 and the additive as described above.
In practice, the additive can include at least one anti-oxidant, and/or at least one antiseptic, and/or at least one antibiotic. The anti-oxidants under the category of additives can be, sodium metabisulfite, sodium thiosulfate, acetyl cystine, Butylated Hydroxy Anisole (BHA), Butyl Hydroxy Toluene, Tertiary-Butylhydroxyquinone (TBHQ), Dibutyl Hydroxy-Toluene (BHT), Butyl Hydroxy Anisole (BHA), L-Ascorbic Acid, Sodium L-Ascorbate, L-Ascorbyl Stearate, L-Ascorbyl Palmitate, Erythorbic Acid, Sodium Erythorbate, dl-α-Tocopherol, Propyl Gallate, Guaiac Resin, L-Cysteine Monohydro-chloride, Tertiary-Butyl Hydro-quinone, Calcium L-Ascorbate, Tocopherols Concentrate Mixed, d-α-Tocopherol Concentrate, EDTA Na2 or EDTA CaNa2, Potassium Sulfite, Sodium Sulfite, Sodium Sulfite (Anhydrous), Sodium Bisulfite, Sodium Hydrosulfite, Potassium Metabisulfite, Potassium Bisulfite, Sodium Metabisulfite, et al. Furthermore, the antiseptics under the category of additives can include Benzalkonium chloride, Butylene chlorohydrin, Thimerosal, Phenylmercuric acetate, Phenylmercuric nitrate, Sorbic acid, Potassium Sorbate, Sodium Sorbate, Calcium Propionate, Sodium Propionate, Dehydroacetic Acid, Benzoic Acid, Sodium Benzoate, Ethyl p-Hydroxy-benzoate, Propyl p-Hydroxy-benzoate, Butyl p-Hydroxy-benzoate, Isopropyl p-Hydroxybenzoate, Isobutyl p-Hydroxy-benzoate, Biphenyl, Sodium Iacetate, Calcium Sorbate, Potassium Benzoate, Nisin, Thiamine Dilauryl-sulfate, Propionic Acid, Natamycin, et al. Moreover, the antibiotics under the category of the additives can include Oxazolidone, iso-Oxazoline, Chitin, Nitric oxide, Aminoglycoside, et al.
It should be noted that the usage and the amount of the anti-oxidant, antiseptic, and antibiotic as described above can be optionally adjusted to fit the requirement, such as the additive release frequency of the microcapsules, to postpone the beginning of biodegradation of the optical disc to meet the general guaranteed time of usage for optical discs, such as around 15 to 20 years.
Please refer to
As shown in
In an embodiment, the coating layer 59 includes a plurality of microcapsules 591. As shown in
Similarly, the structure of the optical disc 5 based on the second preferred embodiment of the invention is more suitable for the specification that does not require a transparent substrate, such as the dummy discs complied with the BD specification, the DVD+R specification, the DVD−R specification, the DVD+RW specification, the DVD−RW specification, and the HD-DVD specification.
Similarly, the usage and amount of the anti-oxidant, antiseptic, and antibiotic as described above can be optionally adjusted to fit the requirement, such as the additive release frequency of the microcapsules, to postpone the beginning of biodegradation of the optical disc to meet the general guaranteed time of usage for optical discs, such as around 15 to 20 years.
Because the substrate of the optical disc of the invention is formed of biodegradable material, it can be degraded by microbes, and further reduces the hazardous impact on the environment. Furthermore, the optical disc of the invention includes additives, such as anti-oxidant, antiseptic, and antibiotic, to reduce the biodegradation effect. Furthermore, the biodegradation of the optical disc can be postponed to the desired expiration date thereof by adjusting the types and the amounts of the additive and the release frequency of the microcapsules.
With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 095133367 | Sep 2006 | TW | national |
