Polycarbonate composition to produce optical quality products with high quality and good processability
View Patent ↗The present disclosure relates to thermoplastic compositions, methods of making thermoplastic compositions, and articles made from thermoplastic compositions. The disclosed compositions comprise a polycarbonate polymer, a triacylglyceride release agent, and a monoacylglyceride release agent. In an embodiment, the thermoplastic composition comprises: greater than 90 weight percent based on the total weight of the composition of a melt polycarbonate polymer; a triacylglyceride release agent; and a monoacylglyceride release agent. The total amount of triacylglyceride release agent and the monoacylglyceride release agent is 0.01 to 0.5 weight percent based on the total weight of the composition.
1. An article formed from a composition, wherein the composition comprises:
glycerol tristearate, glycerol monostearate, and greater than 90 weight percent based on the total weight of the composition of a melt polycarbonate polymer, wherein the melt polycarbonate polymer is made by a melt polymerization process;
wherein a total amount of glycerol tristearate and the glycerol monostearate is 0.01 to 0.1 weight percent based on a total weight of the composition; wherein a ratio of the glycerol monostearate to the glycerol tristearate is 1:1.5 to 1:3.5; and
wherein the article has an article average static charge of −3 to 0 kV as determined by averaging the static charge of a 1500th to a 2500th article formed.
2. The article of claim 1 , wherein the glycerol tristearate is present in an amount of 0.01 to 0.05 weight percent relative to the total weight of the composition.
3. The article of claim 1 , wherein the ratio is 1:2 to 1:3.3.
4. The article of claim 1 , wherein the glycerol tristearate and the glycerol monostearate are the only two release agents.
5. The article of claim 1 , wherein the polycarbonate has a PDI of 1.9 to 2.6.
6. The article of claim 1 , wherein the polycarbonate includes branching structures, wherein the branching structures are present in an amount of greater than 0 to less than 2,000 ppm.
7. The article of claim 1 , wherein the article is an injection molded part.
8. The article of claim 1 , wherein the article is a media storage device.
9. The article of claim 8 , wherein the media storage device comprises CD-R, CD-RW, DVD-R, DVD-RW, BD-R, or BD-RW.
10. The article of claim 1 , wherein the article exhibits a reduction in deposits compared to that exhibited by an article formed from an identical reference composition in the absence of the glycerol tristearate.
11. The article of claim 10 , wherein the reduction in deposits comprises a decreased plate-out.
12. The article of claim 11 , wherein the plate-out is 2.5 mg to 6.0 mg.
13. A method for making an article; comprising
forming a composition;
extruding the composition to form an extruded composition; and
forming the article from the extruded composition;
wherein the composition comprises glycerol tristearate, glycerol monostearate, and greater than 90 weight percent based on the total weight of the composition of a melt polycarbonate polymer, wherein the melt polycarbonate polymer is made by a melt polymerization process;
wherein a total amount of the glycerol tristearate and the glycerol monostearate is 0.01 to 0.1 weight percent based on the total weight of the composition; wherein a ratio of the glycerol monostearate to the glycerol tristearate is 1:1.5 to 1:3.5; and
wherein the article has an article average static charge of −3 to 0 kV as determined by averaging the static charge of a 1500th to a 2500th article formed.