Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Patent
1997-10-28
2000-08-29
Wu, David W.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
526154, C08F 1014, C08F11014
Patent
active
061110477
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION
This invention relates to copolymerization. It relates in particular to a copolymer of propylene and 1-pentene, to a process for producing such a copolymer, and to a polymer composition which includes such a copolymer.
SUMMARY OF INVENTION
According to a first aspect of the invention, there is provided, broadly, a copolymer of propylene and 1-pentene.
The copolymer may, more particularly, have a random arrangement of propylene and 1-pentene, ie it may be a random copolymer of propylene and 1-pentene. The copolymer may be thermoplastic, and may have crystalline and amorphous sequences.
The copolymer may further be characterized by the substantial absence of monomer sequences other than propylene and 1-pentene.
About 0.05% to 20% by mass of the copolymer may be derived from 1-pentene, with the balance thus being derived from propylene.
The melt flow index of the copolymer may be in the range of about 0.01 to about 200 g/10 minutes, preferably in the range 0.5 to about 60 g/10 minutes.
The copolymer may comply with the formula the weight percent of 1-pentene in the copolymer. The copolymer may also have a haze value lower than 7.5% when measured according to ASTM 1003-92, on a film of 100 .mu.m.
The copolymer may be that obtained by reacting propylene and 1-pentene in a reaction zone, while maintaining a pressure between 1 and 60 kg/cm.sup.2 in the zone, at a reaction temperature between 0.degree. C. and 100.degree. C., and for a reaction time between 20 minutes and 8 hours, in the presence of a suitable Ziegler-Natta catalyst or catalyst system. Still more particularly, the copolymer may be that obtained by continuously varying, during the reaction of the propylene and the 1-pentene, the ratio of the concentration of the propylene to that of the 1-pentene.
Thus, according to a second aspect of the invention, there is provided a process for producing a copolymer, which process comprises reacting propylene and 1-pentene in a reaction zone, while maintaining a pressure between 1 and 60 kg/cm.sup.2 in the zone, at a reaction temperature between 0.degree. C. and 100.degree. C., and for a reaction time between 20 minutes and 8 hours, in the presence of a suitable Ziegler-Natta catalyst or catalyst system.
The process may include continuously varying the ratio of the concentration of the propylene to that of the 1-pentene in the reaction zone, so that the copolymer has a random arrangement of propylene and 1-pentene. In other words, the copolymer is then a random copolymer of propylene and 1-pentene, which can also be referred to as `n-pentene-1`.
While the reaction temperature can be in the range of 0.degree. C. to 100.degree. C. as stated hereinbefore, it is preferably in the range of 20.degree. C.-80.degree. C., still more preferably in the range 40.degree. C.-70.degree. C.
Since propylene is a gas at atmospheric pressure, the reaction zone is thus provided by a closed reaction vessel, with the zone pressure being in said range of 1-60 kg/cm.sup.2. Preferably, the pressure is in the range 3-30 kg/cm.sup.2, more preferably in the range 6-14 kg/cm.sup.2.
The reaction will thus be continued for a sufficient period of time to obtain a desired degree of conversion of the monomers. Typically, the conversion can be in the range 10%-95%. Thus, the reaction time will normally be between said 20 minutes and 8 hours, preferably between 40 minutes and 2 hours.
The reaction is preferably carried out in a single reaction zone, ie a single stage reactor vessel is preferably used. The reaction can be effected in a batch fashion, with all the monomers, ie the propylene and 1-pentene, being added simultaneously at the start of the reaction to the reaction zone, and no product being removed therefrom during the course of the reaction. Thus, the continuous variation in the ratio of the concentration of the propylene to that of the 1-pentene during the reaction is achieved by virtue of the monomers being consumed at unequal rates during the reaction, ie the monomers have different reaction rates. Instead, the
REFERENCES:
patent: 3859386 (1975-01-01), Mainord
patent: 3974236 (1976-08-01), Koga et al.
patent: 4367322 (1983-01-01), Shiga et al.
Patent Abstract of Japan vol. 014, No. 260 (P-1056), Jun. 5, 1990 & JP,A,02 072311 (Mitsui Petrochem Ind Ltd), Mar. 12, 1990.
Joubert Dawid Johannes
Potgieter Antonie Hermanus
Potgieter Ignatius Hendrik
Tincul Ioan
(Sasol Technology (Proprietary) Limited)
Harlan R.
Wu David W.
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