Method for removing coatings from compact discs
First Claim
1. A method for removing the lacquer and aluminum coatings from the polycarbonate substrate or a compact disc, comprising the steps of:
- (a) immersing a batch of compact discs comprising compact discs coated with a solvent based lacquer coating and/or compact discs coated with a UV-cured acrylic lacquer coating in an alkaline solution at a pH of about 13 or more;
(b) heating said alkaline solution;
(c) mechanically agitating said immersed discs by applying to said heated alkaline solution ultrasonic energy having a frequency in the range from about 20 to about 40 Khz with an energy density in the range from about 10 to about 200 watts per liter, the alkaline solution being at a sufficient concentration and temperature and in contact with the agitated discs for a time sufficient to dissolve the lacquer and aluminum coatings into solution and to leave behind stripped polycarbonate discs;
(d) washing the stripped polycarbonate discs to remove remanent alkaline solution therefrom; and
(e) drying the washed polycarbonate discs.
1 Assignment
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Accused Products
Abstract
A method for removing the lacquer and aluminum coatings from the polycarbonate substrate of scrap compact discs so as to reclaim the polycarbonate includes the steps of immersing the discs in a an alkaline solution, heating the solution to a predetermined temperature and mechanically agitating the immersed discs by applying ultrasonic energy to the solution at a sufficient energy density and for a sufficient time to dissolve the lacquer and the aluminum into the solution. The solution containing the dissolved lacquer and aluminum is decanted from the stripped polycarbonate discs, the discs are washed with water to remove remanent alkaline solution, and then dried.
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Citations
10 Claims
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1. A method for removing the lacquer and aluminum coatings from the polycarbonate substrate or a compact disc, comprising the steps of:
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(a) immersing a batch of compact discs comprising compact discs coated with a solvent based lacquer coating and/or compact discs coated with a UV-cured acrylic lacquer coating in an alkaline solution at a pH of about 13 or more; (b) heating said alkaline solution; (c) mechanically agitating said immersed discs by applying to said heated alkaline solution ultrasonic energy having a frequency in the range from about 20 to about 40 Khz with an energy density in the range from about 10 to about 200 watts per liter, the alkaline solution being at a sufficient concentration and temperature and in contact with the agitated discs for a time sufficient to dissolve the lacquer and aluminum coatings into solution and to leave behind stripped polycarbonate discs; (d) washing the stripped polycarbonate discs to remove remanent alkaline solution therefrom; and (e) drying the washed polycarbonate discs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification