Polyethylene and chlorinated polyethylene thereof
The polyethylene according to the present disclosure has a short relaxation time and a uniform particle size, thereby preparing a chlorinated polyethylene excellent in chlorination productivity and glass transition temperature by reacting with chlorine. And, a PVC composition with improved impact strength may also be prepared by including the same.
1. A polyethylene satisfying the following conditions 1) to 4):
1) a relaxation time is 2 seconds or less,
2) a melt index MI 5 (a melt index of the polyethylene measured at a temperature of 190° C. under a load of 5 kg in accordance with ASTM D 1238) is 0.75 g/10 min to 1.2 g/10 min,
3) a melt flow rate ratio (MFRR 21.6/5 , a value obtained by dividing the melt index measured at 190° C. under a load of 21.6 kg by the melt index measured at 190° C. under a load of 5 kg in accordance with ASTM D 1238) is 9.5 to 12.5, and
4) a density is 0.947 g/cm 3 to 0.954 g/cm 3 .
2. The polyethylene according to claim 1 , wherein the relaxation time is 0.5 seconds to 2 seconds.
3. The polyethylene according to claim 1 , wherein the polyethylene has a molecular weight distribution (Mw/Mn) of 4.4 or less.
4. The polyethylene according to claim 1 , wherein the polyethylene has a weight average molecular weight of 140000 g/mol to 200000 g/mol.
5. The polyethylene according to claim 1 , wherein an integral value in the region where log Mw is 4 or less in a GPC curve graph having an x-axis of log Mw and a y-axis of dw/d log Mw is 3% or less of a total integral value.
6. The polyethylene according to claim 1 , wherein an integral value in the region where log Mw is 5.5 or more in a GPC curve graph having an x-axis of log Mw and a y-axis of dw/d log Mw is 12% or more of a total integral value.
7. The polyethylene according to claim 1 , wherein the polyethylene has a particle size distribution (span) according to the following Equation 1 of 1.1 or less:
Span=( D 90 −D 10 )/ D 50 [Equation 1]
in Equation 1, D 90 , D 10 , and D 50 represent particle sizes (μm) corresponding to 90%, 10%, and 50% of a total volume of a polyethylene sample, respectively, in a cumulative particle size distribution on a volume basis measured by a particle size analyzer Tyler method.
8. The polyethylene according to claim 1 , wherein the polyethylene has a particle size (D 50 ) corresponding to 50% of a total volume of a polyethylene sample in a cumulative particle size distribution on a volume basis measured by a particle size analyzer Tyler method of 120 micrometers to 200 micrometers.
9. A method for preparing the polyethylene according to claim 1 , comprising a step of polymerizing ethylene in the presence of at least one first metallocene compound represented by the following Chemical Formula 1; and at least one second metallocene compound selected from the compounds represented by the following Chemical Formula 3:
in Chemical Formula 1,
Q 1 and Q 2 are the same as or different from each other, and are each independently hydrogen, halogen, C 1-20 alkyl, C 2-20 alkenyl, C 2-20 alkoxyalkyl, C 6-20 aryl, C 7-40 alkylaryl, or C 7-40 arylalkyl;
A 1 is carbon, silicon, or germanium;
M 1 is a Group 4 transition metal;
X 1 and X 2 are the same as or different from each other, and are each independently halogen, C 1-20 alkyl, C 2-20 alkenyl, C 6-20 aryl, a nitro group, an amido group, C 1-20 alkylsilyl, C 1-20 alkoxy, or a C 1-20 sulfonate group; and
one of C 1 and C 2 is represented by the following Chemical Formula 2a or 2b, and the other is represented by the following Chemical Formula 2c, 2d or 2e;
in Chemical Formulae 2a, 2b, 2c, 2d and 2e, R 1 to R 31 and R 1′ to R 13′ are the same as or different from each other, and are each independently hydrogen, halogen, C 1-20 alkyl, C 1-20 haloalkyl, C 2-20 alkenyl, C 1-20 alkylsilyl, C 1-20 silylalkyl, C 1-20 alkoxysilyl, C 1-20 alkoxy, C 6-20 aryl, C 7-40 alkylaryl, or C 7-40 arylalkyl, provided that at least one of R 9 to R 13 and R 1′ to R 13′ is C 1-20 haloalkyl, or
two or more R 14 to R 31 that are adjacent to each other are connected with each other to form a C 6-20 aliphatic or aromatic ring unsubstituted or substituted with a C 1-10 hydrocarbyl group;
• represents a site of binding to A 1 ; and
* represents a site of binding to M 1 ;
in Chemical Formula 3,
at least one of R 32 to R 39 is —(CH 2 ) n —OR, wherein R is C 1-6 linear or branched alkyl and n is an integer of 2 to 6;
the rest of R 32 to R 39 are the same as or different from each other, and are each independently selected from the group consisting of hydrogen, halogen, C 1-20 alkyl, C 2-20 alkenyl, C 6-20 aryl, C 7-40 alkylaryl, and C 7-40 arylalkyl, or two or more of R 32 to R 39 that are adjacent to each other are connected with each other to form a C 6-20 aliphatic or aromatic ring unsubstituted or substituted with a C 1-10 hydrocarbyl group;
Q 3 and Q 4 are the same as or different from each other, and are each independently hydrogen, halogen, C 1-20 alkyl, C 2-20 alkenyl, C 2-20 alkoxyalkyl, C 6-20 aryl, C 7-40 alkylaryl, or C 7-40 arylalkyl;
A 2 is carbon, silicon, or germanium;
M 2 is a Group 4 transition metal;
X 3 and X 4 are the same as or different from each other, and are each independently halogen, C 1-20 alkyl, C 2-20 alkenyl, C 6-20 aryl, a nitro group, an amido group, C 1-20 alkylsilyl, C 1-20 alkoxy, or a C 1-20 sulfonate group; and
m is an integer of 0 or 1.
10. The method for preparing the polyethylene according to claim 9 , wherein each of the Q 1 and Q 2 is independently C 1-3 alkyl, or C 2-12 alkoxyalkyl, each of the X 1 , X 2 , X 3 , and X 4 is independently halogen, A 1 is silicon, and each of the M 1 and M 2 is independently zirconium or hafnium.
11. The method for preparing the polyethylene according to claim 9 , wherein each of the R 9 to R 13 and R 9′ to R 13′ is independently hydrogen, or C 1-6 haloalkyl, provided that at least one of R 9 to R 13 and R 9′ to R 13′ is C 1-6 haloalkyl.
12. The method for preparing the polyethylene according to claim 9 , wherein the R 3 is C 1-6 linear or branched alkyl.
13. The method for preparing the polyethylene according to claim 9 , wherein each of the R 14 to R 21 is independently hydrogen or C 1-20 alkyl, or two or more of R 14 to R 21 that are adjacent to each other are connected with each other to form a C 6-20 aliphatic or aromatic ring substituted with C 1-3 alkyl.
14. The method for preparing the polyethylene according to claim 9 , wherein each of the R 34 and R 37 is independently unsubstituted C 1-6 alkyl or C 2-6 alkyl substituted with C 1-6 alkoxy.
15. The method for preparing the polyethylene according to claim 9 , wherein a weight ratio of the first metallocene compound and the second metallocene compound is 80:20 to 87:13.
16. The method for preparing the polyethylene according to claim 9 , wherein the polymerization is carried out while introducing 35 ppm or less of hydrogen gas based on ethylene content.
17. A chlorinated polyethylene prepared by reacting the polyethylene according to claim 1 with chlorine.
18. The chlorinated polyethylene according to claim 17 , wherein the chlorinated polyethylene has a Mooney viscosity measured at 121° C. of 85 or more to 140 or less.
19. A PVC composition, comprising the chlorinated polyethylene according to claim 17 And polyvinyl chloride (PVC).
20. The PVC composition according to claim 19 , wherein the PVC composition comprises 5 wt % to 20 wt % of the chlorinated polyethylene.