Polyolefin mixture containing poly(1-butene)

Details Polyolefin mixture containing poly(1-butene) Polyolefin mixture containing poly(1-butene)

1999-01-28

2001-01-30

Nutter, Nathan M. (Department: 1711)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Mixing of two or more solid polymers; mixing of solid...

C525S240000

Reexamination Certificate

active

06180720

ABSTRACT:

This invention concerns an elastomeric and thermoplastic polyolefin mixture. More particularly, it concerns a mixture comprising a heterophasic polyolefin composition and some crystalline or partially crystalline poly(1-butene), and the articles produced with said mixture.
The mixture of this invention can be used in many sectors, for example in the production of laminates, roofing materials, and articles manufactured by way of coinjection and injection molding, as well as blow molding, such as biomedical articles.
At the present time the main disadvantage of the heterophasic compositions with good flexibility and softness characteristics that are used in the above mentioned sectors, such as the ones described in published European patent application EP-A-472946 (Himont Inc.), is the tendency of being tacky. Said property is undesirable for some applications, for example, because it has a negative effect on the aesthetic aspect of the article, and does not ensure a good welding seal due to the presence of low molecular weights that rise to the surface of the sides to be welded. Moreover, highly tacky materials make storing difficult and the use of laminates more troublesome.
Also known are heterophasic compositions comprising crystalline poly(1-butene), crystalline propylene, and EPR or EPDM rubber. Examples of said mixtures are described in U.S. Pat. No. 4,078,020 in the name of Ciba Geigy Corporation. Said compositions present good flexibility and low hardness values.
Now a mixture of the above mentioned composition has been found which is very flexible, and displays very low hardness as well as low tackiness values.
In addition, the above mentioned mixture presents good tensile strength. As shown by the stress-strain curve, the specimen prepared with the above mentioned mixture shows greater strain resistance compared to the mixture without poly(1-butene). Said improvement does not have an adverse effect on other properties, particularly on flexibility. Therefore, the balance of the other mechanical properties is not significantly different from that of the mixture without poly(1 -butene).
Considering said properties, the mixture of this invention is specifically adequate for use in the production of geomembranes, for example. In fact, among the properties that are most desirable for geomembranes are good flexibility and good strain resistance. Flexibility is important because it makes it easier to handle the membranes during their transport and laying, and because the membranes can conform as much as possible to the undulations and roughness of the ground.
Moreover, as mentioned above, said mixtures also present the additional advantage of having reduced and delayed surface tackiness. The gradual increase in surface tackiness of an arcicle manufactured from elastomeric polymers is an undesired phenomenon that inevitably manifests itself after a period of time. The mixtures of the present invention, on the other hand, allow the manufacture of articles with satisfactory optical properties, such as gloss for example, as well as articles with strong welds. Moreover, low tackiness, for example, avoids the difficulties related with the storage and use of the laminates.
Therefore, object of the present invention is a thermoplastic and elastomeric polyolefin mixture comprising the following fractions (weight percentage):
I. from 3 to 25%, preferably 5-20%, of crystalline or partially crystalline isotactic poly(1-butene); and
II. from 75 to 97%, preferably from 80 to 95%, of a heterophasic polyolefin composition comprising:
A. 4-40%, preferably 8-38%, of a crystalline propylene homopolymer, or a crystalline copolymer of propylene with ethylene or a CH
2
═CHR &agr;-olefin, where R is a C
2
-C
8
alkyl radical, or a crystalline copolymer of propylene with ethylene and said CH
2
═CHR &agr;-olefin, said copolymers containing over 85% of propylene, and having a fraction insoluble in xylene greater than 80%;
B. 0-20%, preferably 0-15%, of a crystalline copolymer of ethylene with propylene or a CH
2
═CHR &agr;-olefin, where R is a C
2
-C
8
alkyl radical, or a crystalline copolymer of ethylene with propylene and said &agr;-olefin, said copolymers being insoluble in xylene at ambient temperature; and
C. 40-96%, preferably 50-75%, of an elastomeric copolymer of ethylene with propylene or a CH
2
═CHR &agr;-olefin, where R is a C
2
-C
8
alkyl radical, and optionally minor quantities of a diene, or a copolymer of ethylene with propylene and said &agr;-olefin, and optionally minor quantities of a diene, said copolymers containing ethylene in a quantity lower than 40%, preferably from 20 to 38%, and being soluble in xylene at ambient temperature.


REFERENCES:
patent: 4078020 (1978-03-01), Rose et al.
patent: 5143978 (1992-09-01), Berta
patent: 5286564 (1994-02-01), Cecchin et al.
patent: 5552482 (1996-09-01), Berta
patent: 0 472 956 B1 (1992-03-01), None

Affiliated with

Also associated with

Rating

Polyolefin mixture containing poly(1-butene) does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Polyolefin mixture containing poly(1-butene), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyolefin mixture containing poly(1-butene) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2546404