Polyethylene with controlled wax content, chlorinated polyethylene thereof and molded article produced from the chlorinated polyethylene
Disclosed are polyethylene, chlorinated polyethylene thereof and a molded article produced from the chlorinated polyethylene. More specifically, disclosed are polyethylene for preparation of chlorinated polyethylene, the polyethylene having a molecular weight distribution (MWD) of 5 or less, a melting index (5.0 kg) of 0.1 to 10 dg/min, a weight average molecular weight of 50,000 to 300,000 g/mol, a melting temperature of 125 to 135° C., a wax content of 0.0001 to 3% by weight or 0.01 to 0.3% by weight and a density of 0.94 g/cm 3 or more, chlorinated polyethylene thereof and a molded article produced from the chlorinated polyethylene.
1. Polyethylene for preparation of chlorinated polyethylene, the polyethylene having a molecular weight distribution (MWD) of 5 or less, a melting index (5.0 kg) of 0.1 to 10 dg/min, a weight average molecular weight of 50,000 to 300,000 g/mol, a melting temperature of 125 to 140° C., a density of 0.94 g/cm 3 or more and a wax content of 0.01 to 0.3% by weight.
2. The polyethylene according to claim 1 , wherein the polyethylene has a low molecular weight (≦5,000 g/mol) content of 0.01 to 5% by weight.
3. The polyethylene according to claim 1 , wherein the molecular weight distribution (MWD) is 2.1 to 3.4.
4. The polyethylene according to claim 1 , wherein the melting index (5.0 kg) is 0.3 to 7 dg/min.
5. The polyethylene according to claim 1 , wherein the melting temperature is 125 to 135° C.
6. The polyethylene according to claim 1 , wherein the density is 0.945 to 0.955 g/cm 3 .
7. The polyethylene according to claim 1 , wherein the polyethylene has a wax content of 0.05 to 0.2% by weight.
8. The polyethylene according to claim 1 , wherein the polyethylene has an average particle size of 30 to 400 μm.
9. The polyethylene according to claim 1 , wherein the polyethylene is prepared in the presence of a metallocene catalyst.
10. Chlorinated polyethylene prepared by reacting the polyethylene according to claim 1 with chlorine.
11. The chlorinated polyethylene according to claim 10 , wherein the chlorinated polyethylene has a chlorine content of 20 to 45% by weight.
12. The chlorinated polyethylene according to claim 10 , wherein the chlorinated polyethylene has a Mooney viscosity of 70 to 110.
13. The chlorinated polyethylene according to claim 10 , wherein the chlorinated polyethylene has a volume resistance of 10 13 to 10 17 Ωcm and thermal stability of 150 to 180° C.
14. An extrusion-molded article produced from the chlorinated polyethylene according to claim 10 .
15. The extrusion-molded article according to claim 14 , wherein the extrusion-molded article is cross-linked using a peroxide cross-linking agent.
16. The extrusion-molded article according to claim 15 , wherein the extrusion-molded article has a volume resistance of 1×10 14 Ωcm to 200×10 14 Ωcm.
17. The extrusion-molded article according to claim 14 , wherein the extrusion-molded article is a wire cable or a hose.
18. A method for preparing chlorinated polyethylene comprising:
dispersing 100 parts by weight of the polyethylene according to claim 1 , 0.1 to 0.2 parts by weight of an emulsifier, and 1 to 5 parts by weight of a dispersant in water; and
reacting the resulting dispersion with 80 to 200 parts by weight of chlorine in the presence of 0.01 to 1.0 parts by weight of a catalyst.
19. A method for producing an extrusion-molded article comprising:
a) roll-mill compounding the chlorinated polyethylene according to claim 10 with a cross-linking agent;
b) extruding the compounded chlorinated polyethylene;
c) allowing the extrudate to stand at 100 to 180° C. for 3 to 60 minutes; and
d) cross-linking (curing) the extrudate.