Poly(arylene ether) compression molding
View Patent ↗A method for compression molding of poly(arylene ether) powder comprises introducing a powder comprising unheated poly(arylene ether) powder to compaction equipment comprising a compression mold and subjecting the powder in the compression mold to a pressure sufficient to produce an article having a density greater than the unheated poly(arylene ether) powder wherein the pressure is applied at a temperature less than the glass transition temperature of the poly(arylene ether) powder.
1. A method for compression molding of poly(arylene ether) powder, comprising:
introducing a powder comprising unheated poly(arylene ether) powder to compaction equipment comprising a compression mold; and
subjecting the powder in the compression mold to a pressure of 1 to 50 tons per square centimeter to produce an article having a density of about 0.6 to about 1.2 grams per cubic centimeter, a compressive strength of greater than or equal to about 25 kg, and a diameter to height ratio of 1.6 to 2.1, wherein said pressure is applied at a temperature of 0 to 65° C.
2. The method of claim 1 wherein the temperature is 0 to about 60° C. and the pressure is applied for about 0.1 to about 100 seconds.
3. The method of claim 2 , wherein the article has a compressive strength of about 25 to about 3000 kilograms.
4. The method of claim 1 wherein the pressure is 1 to about 20 tons per square centimeter, the pressure is applied for about 300 to about 2000 second and the temperature is sufficient to at least soften the poly(arylene ether) powder and/or a binder when present.
5. The method of claim 4 wherein the article has a compressive strength greater than about 4000 kilograms and a density of greater than or equal to about 0.95 grams per cubic centimeter.
6. The method of claim 4 wherein the poly(arylene ether) is processed to remove or reduce gas trapped between the particles.
7. The method of claim 1 , wherein the powder further comprises a binder, a flame retardant, an additive, a modifying agent or a combination of two or more of the foregoing.
8. The method of claim 7 , wherein the binder is crystalline and has a melt temperature less than the glass transition temperature of the poly(arylene ether) powder.
9. The method of claim 7 , wherein the binder is amorphous and has a glass transition temperature less than the glass transition temperature of the poly(arylene ether) powder.
10. The method of claim 7 , wherein the binder is a reactive binder.
11. The method of claim 7 , wherein the binder is a non-reactive binder.
12. The method of claim 7 , wherein the additive is selected from the group consisting of antioxidants, mold release agents, ultra violet absorbers, stabilizers, lubricants, plasticizers, pigments, dyes, colorants, antistatic agents, blowing agents, and mixtures thereof.
13. The method of claim 7 , wherein the binder is present in an amount of about 0.01 to about 40 weight percent, based on the total weight of the mixture.
14. The method of claim 1 , wherein the compression mold is unheated upon introduction of the powder.
15. The method of claim 1 , wherein the compression mold is heated after introduction of the powder.
16. The method of claim 15 , wherein the compression mold is not heated during compressing.
17. The method of claim 1 , wherein the compression mold is heated prior to introduction of the powder.
18. The method of claim 17 , wherein the compression mold is heated after introduction of the powder.
19. The method of claim 17 , wherein the compression mold is not heated during the application of pressure.
20. The method of claim 1 , wherein the compression mold is a die of an extruder.
21. The method of claim 1 , wherein the article is a single phase compact.
22. The method of claim 1 , wherein the article is a multi phase compact.
23. The method of claim 1 , wherein the poly(arylene ether) powder comprises about 5 to about 70 volume percent, based on the total volume of poly(arylene ether) powder, of particles having a particle size less than about 100 micrometers.
24. The method of claim 1 wherein the poly(arylene ether) powder has an average particle size of about 50 to about 1500 micrometer.
25. The method of claim 1 wherein the compaction equipment is a confined pressure device.
26. The method of claim 1 wherein the compaction equipment is an extrusion device.
27. The method of claim 1 , wherein the poly(arylene ether) has an intrinsic viscosity of 0.08 to 0.60 deciliters per gram as measured in chloroform at 25° C.
28. The method of claim 1 , wherein the poly(arylene ether) has an average particle size of 90 to 1000 micrometers and 15 to 60 volume percent of the particles have a particle size less than about 100 micrometers, based on the total volume of poly(arylene ether).
29. A method for compression molding of poly(arylene ether) powder, comprising:
introducing an unheated poly(arylene ether) powder to compaction equipment comprising a compression mold, wherein the poly(arylene ether) has an intrinsic viscosity of about 0.29 to about 0.48 dl/g, as measured in chloroform at 25° C.;
subjecting the unheated poly(arylene ether) powder in the compression mold to a pressure of 1 to 50 tons per square centimeter to produce an article having a density of about 0.6 to about 1.2 grams per cubic centimeter, a compressive strength of greater than or equal to about 25 kg, and a diameter to height ratio of 1.6 to 2.1, wherein said pressure is applied at a temperature of 0 to 65° C.