Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1996-11-07
1998-04-21
Weber, Thomas R.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C08J 311
Patent
active
057418489
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a method of manufacturing a polyolefin solution used for manufacturing microporous polyolefin membranes, polyolefin fibers and the like. More particularly, it relates to a method for continuously manufacturing a solution of polyolefin having a wide molecular distribution range, in a stable manner and with a high output.
BACKGROUND OF THE INVENTION
Polyolefin resins have superior mechanical strength and physical characteristics; therefore, they have been used for various purposes. For example, microporous polyolefin membranes and porous fibers have been used as a separators for batteries, separation films for electrolytic capacitors, precision filters, air filters and the like polyolefin resins are generally manufactured using a polyolefin solution incorporating an advanced flow improver or solvent.
Polyolefin solutions are conventionally manufactured by "batch" type heading, continuous kneading of a polyolefin resin and a liquid, such as mineral oil. In the case of batch type kneading, the polyolefin and the liquid are put into an autoclave equipped with a mixer, the temperature is increased while the mixture is mixed, and the polyolefin and the liquid are kneaded. However, with batch type kneading, kneading takes a rather long, which is a short-coming. In addition, with batch type kneading the residence time differs between the product taken out from the batch at the initial stage and that toward the end. Moreover, the quality within the batch or at the time of switching the batch is not stable. Furthermore, this method is labor intensive, which is another shortcoming. In addition, it is difficult to prepare highly viscous solutions and it is not possible to use high molecular weight compositions in pellet form. This is a further shortcoming.
Therefore, in recent years, a continuous type kneader equipped with a liquid feed section downstream of a resin feed section has been used for manufacturing polyolefin solutions. However, as seen in continous type kneaders of the prior art, the pressure in the kneader at the liquid feed section is higher than the pressure downstream. For that reason, when the quantity of supplied liquid is increased, the kneading of polyolefin cannot be carried out sufficiently, and an upstream liquid back-flow is observed. As a result it is necessary to reduce the feed quantity of liquid. In addition, the amount of shearing exothermic energy is large within the kneader area in which only the polymer exists, and this often results in deterioration of the polymer due to heat.
In view of the above, an object of the present invention is to provide a manufacturing method in which a high yield of polyolefin solution can be continuously obtained in a stable manner.
DISCLOSURE OF THE INVENTION
As a result of continuous research with the above purpose in mind, the present inventors have made the present invention, using a continuous kneader having a self-cleaning effect, and by maintaining a starving state within an internal section of the kneader at a polyolefin resin feed section, a liquid feed section and a kneading section. The present inventors discovered that in this way, a high yield of polyolefin solution having uniform quality can be continuously obtained in a stable manner.
Thus, a method of manufacturing a polyolefin solution according to the present invention comprises kneading a polyolefin resin with a liquid composed of a solvent, and is characterized in that: a polyolefin resin feed section, a liquid feed section, and a section in which kneading of the polyolefin resin and the liquid is initially carried out.
In addition, a method of manufacturing a polyolefin solution according to the present invention comprises kneading a polyolefin resin and a liquid composed of a solvent, and is characterized in that: resin feed section, and the polyolefin resin feed section and a liquid feed section located most upstream is set higher than the internal pressure of the kneader in the liquid feed section located most upstream.
REFERENCES:
patent: 3923947 (1975-12-01), Cook
patent: 4320041 (1982-03-01), Mitsubishi
patent: 4668717 (1987-05-01), Stamicarbon
International Search Report, Japanese Patent Office, May 14, 1996.
Kono Koichi
Miyasaka Kenji
Nogata Tetsuro
Takita Kotaro
Tonen Chemical Corporation
Weber Thomas R.
LandOfFree
Method of manufacturing polyolefin solutions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing polyolefin solutions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing polyolefin solutions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2058257