Methods and compositions for decolorizing thermoplastics and articles made using such decolorized thermoplastics
OwnerDaniel Connor, Keith Kellerinventors
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Abstract
The invention relates to the use of chemical compositions useful for decolorizing recycle thermoplastics such as oxidizing agents, reducing agents, or photo-initiators combined into thermoplastics such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonates (PC), polyethylene (PE), polylactic acid (PLA), nylon, PET copolymers, acrylics, Surlyn™, or other thermoplastics. In one example, a radical initiator of a peroxide-containing compound assists in achieving decolorization of thermoplastics. The decolorizing process may increase the value of plastics for purposes of recycling.
Claims52
A method of substantially decolorizing a colored thermoplastic, the method comprising the steps of:
- (a) providing a colored thermoplastic in solid form;
- (b) heating said colored thermoplastic, said thermoplastic having chromophores within the thermoplastic that exhibit color;
- (c) mixing said colored thermoplastic with an effective concentration of a decolorizing agent;
- (d) heating or exposing to light said decolorizing agent with said chromophores in said colored thermoplastic;
- (e) decolorizing at least some of said chromophores;
- and
- (f) thereby forming a substantially decolorized thermoplastic.
A method of lowering the color intensity level in a colored thermoplastic by employing a decolorization agent, the method comprising the steps of:
- (a) providing a colored thermoplastic in solid form;
- (b) heating a colored thermoplastic, said thermoplastic having chromophores within the thermoplastic that exhibit color;
- (c) mixing said colored thermoplastic with a decolorization agent;
- (d) heating or exposing to light said decolorizing agent with said chromophores in said colored thermoplastic;
- (e) decolorizing at least some of said chromophores;
- and
- (f) lowering the level of color exhibited by said thermoplastic.
A method of lowering the color intensity of a colored thermoplastic using an extruding mechanism, said method comprising the steps of:
- (a) heating a colored thermoplastic, said thermoplastic having chromophores within the thermoplastic that exhibit color;
- (b) mixing said colored thermoplastic with a decolorizing agent in an extruding mechanism;
- (c) decolorizing said chromophores, thereby forming a thermoplastic having reduced color intensity levels;
- and
- (d) extruding said thermoplastic.
A method of lowering the color level in a thermoplastic using methods of photochemical radical initiation, said method comprising the steps of:
- (a) heating a colored thermoplastic, said thermoplastic having chromophores therein that exhibit color;
- (b) mixing with said colored thermoplastic with at least one photochemical radical initiator;
- (c) exposing colored thermoplastic containing said photochemical radical initiator to light;
- (d) decolorizing at least some of said chromophores;
- and
- (e) lowering the level of color exhibited by said thermoplastic.
A method of substantially decolorizing a colored thermoplastic, the method comprising the steps of:
- (a) heating said colored thermoplastic, said thermoplastic having chromophores within the thermoplastic that exhibit color;
- (b) mixing said colored thermoplastic with a decolorizing agent for a period of time which is less than about two hours;
- (c) heating said decolorizing agent with said chromophores in said colored thermoplastic;
- (d) decolorizing said chromophores;
- and
- thereby forming a substantially decolorized thermoplastic.
A colored composition comprising:
- (a) a thermoplastic polymer;
- (b) a colorant;
- (c) a decolorizing agent, said decolorizing agent being adapted for reacting with at least one of said chromophores in reducing the color intensity level of said thermoplastic polymer.
A composition comprising a thermoplastic polymer and an inorganic peroxide.
Dependencies are inferred from the claim text.