JP4097446B2 - Method for producing a veiled olefin elastomer - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for producing a bale-like olefin elastomer, and a bale-like olefin elastomer. More specifically, the present invention relates to a method and apparatus for producing a bale-like olefin elastomer that forms an olefin elastomer obtained by polymerizing ethylene and an α-olefin having 3 to 20 carbon atoms, and a bale-like olefin elastomer. About.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
Among the copolymers of ethylene and an α-olefin having 3 to 20 carbon atoms, a copolymer having an α-olefin content of 3 to 20 carbon atoms of 45 mol% or less is produced by copolymerization of raw materials, Generally, it is transported or stored in pellet form.
However, among these, a copolymer having a C3-C20 α-olefin content exceeding 15 mol% generally has a low crystallinity, and the copolymer pellets are relatively high in summer and the like. When transported or stored at a temperature, stored for a long time, or stored under pressure, fluidization occurs or pellets are integrated. And if the pellets are fluidized and integrated, it will be difficult to take out from the paper bag or plastic film bag, or gas and impurities present in the gaps between the pellets will be taken in, and a large amount of bubbles and impurities will contain the olefin elastomer mass This causes problems such as
[0003]
When kneading the olefin elastomer mass with various compounding agents such as a cross-linking agent and a filler using the olefin elastomer mass with integrated pellets in the same manner as when using the pellet, It is necessary to deaerate bubbles in the olefin elastomer mass to remove impurities. The deaeration of bubbles and the removal of impurities in the olefin elastomer mass need to be carried out by a dedicated process using a complicated and expensive machine, and have a lot of time and cost.
[0004]
For this reason, conventional olefin elastomer pellets have to be quality controlled at low temperatures so as not to be fluidized and integrated, or processed into a final product in a short period of time without being stored for a long time.
For this reason, it is a copolymer having a large content of α-olefin having 3 to 20 carbon atoms, and is easy to handle even when stored under general conditions, and is free of bubbles and impurities. Appearance of an elastomer was desired.
[0005]
The present inventor has intensively studied in view of such a situation, and is a specific olefin-based elastomer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms, and has a veil shape. However, the present inventors have found that the above problems can be solved and have completed the present invention.
As for the veil-shaped resin, bale of diene rubber such as styrene / butadiene rubber and butadiene rubber is known. Also proposed is a method of manufacturing ethylene-based rubber veils that use hard ethylene / propylene rubber crumbs that are not fluidized or integrated but may cause sticking, and that do not stick to each other by controlling the crumb temperature. (Japanese Patent Laid-Open No. 61-61810).
[0006]
As a result of intensive research in view of such a situation, the present inventors have found that a bale-like product composed of a relatively soft copolymer having a high content of α-olefin having 3 to 20 carbon atoms is fluidized or integrated. The present invention has been completed by discovering that there is no problem of conversion and that it can be transported and stored without introducing bubbles or impurities.
[0007]
OBJECT OF THE INVENTION
The present invention is a copolymer having a large content of α-olefin having 3 to 20 carbon atoms, and is easy to handle even when stored under general conditions, and bubbles and impurities are not taken in. It aims at providing the manufacturing method and manufacturing apparatus of a bale-like olefin system elastomer, and a bale-like olefin system elastomer.
[0008]
The method for producing the veiled olefin-based elastomer of the present invention includes:
Copolymerized ethylene and an α-olefin having 3 to 20 carbon atoms, having a density of 0.80 to 0.90 g / cm ³ and a crystallinity in the range of 0 to 10%. The structure derived from an α-olefin having 3 to 20 carbon atoms when the total of the structural unit (A1) to be obtained and the structural unit (A2) derived from the α-olefin having 3 to 20 carbon atoms is 100 mol% The olefin-based elastomer (A) containing 15 to 90 mol% of the unit (A2) and substantially free of a copolymer component derived from polyene is pelletized without containing a resin other than (A), Creating a pellet made of an olefin elastomer;
Pressure-molding the pellet;
It is characterized by having .
[0009]
In such a method for producing a veiled olefin-based elastomer of the present invention, the pellet temperature or baler temperature during pressure molding is preferably 10 to 80 ° C,
Pelletizing the olefinic elastomer (A) extruded from the extruder and creating pellets comprising the olefinic elastomer;
A step of pressure-molding the pellet of the olefin elastomer to create a pressure-molded product;
It is also preferable to have a step of cutting the pressure-formed product with an automatic cutting device .
[0012]
Such a bale-like olefin elastomer of the present invention preferably has a volume filling rate of 75 to 95%, and is preferably formed by pressure-molding the olefin elastomer (A) pellets.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described.
(A) Olefin-based elastomer The olefin-based elastomer (A) according to the present invention is obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms.
[0014]
Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 4-methylpentene-1, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene. 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene, 9-methyldecene-1, 11-methyldodecene-1, 12 -Ethyltetradecene-1 and the like. Among these, propylene, 1-butene, 4-methylpentene-1, 1-hexene and 1-octene are preferable, and propylene is particularly preferable.
[0015]
The olefin elastomer (A) according to the present invention, which is obtained by copolymerizing ethylene and such an α-olefin, is derived from a structural unit (A1) derived from ethylene and an α-olefin having 3 to 20 carbon atoms. When the total amount of the structural unit (A2) is 100 mol%, the structural unit (A1) derived from ethylene is 10 to 85 mol%, preferably 40 to 85 mol%, particularly preferably 50 to 80 mol%. Containing 15 to 90 mol%, preferably 15 to 60 mol%, particularly preferably 20 to 50 mol% of a structural unit (A2) derived from an α-olefin having 3 to 20 carbon atoms, and a diene, It is substantially free of copolymer components derived from polyenes such as triene.
[0016]
The olefin elastomer (A) according to the present invention has a density of 0.80 to 0.90 g / cm ³ , preferably 0.84 to 0.90 g / cm ³ , more preferably 0.84 to 0.89 g. / Cm ³ .
Furthermore, it is desirable that the olefin elastomer (A) according to the present invention has a crystallinity of 50% or less, preferably 0 to 30%, more preferably 0 to 10%, and is measured in decalin at 135 ° C. The intrinsic viscosity [η] is 0.5 to 3.0 dl / g, preferably 0.8 to 2.4 dl / g, and the melting point is −50 to 120 ° C., preferably −50 to 90 ° C. More preferably, it is -50 to 50 ° C.
[0017]
The olefin elastomer (A) can be produced by appropriately adopting conventionally known methods.
Specifically, for example, a copolymer of ethylene and α-olefin having a desired composition is prepared by solution polymerization in the presence of ethylene, α-olefin, a solvent and a polymerization catalyst, and the polymer is used as a solvent. A dissolved polymer solution can be obtained, and then the solvent can be removed from the polymer solution to obtain the polymer.
[0018]
Such an olefin-based elastomer (A) is preferable because it is relatively soft and can produce a bale-like olefin-based elastomer having a high filling rate.
Method for producing bale olefin elastomer The method for producing a bale olefin elastomer of the present invention is to produce the above-mentioned olefin elastomer (A) by a method such as pressure molding or melt molding. In the present invention, it is preferable to produce by pressure molding. When the bale olefin-based elastomer is obtained by pressure molding, the olefin-based elastomer (A) as a raw material for pressure molding may be in any shape such as powder or pellet, Preferably there is.
[0019]
According to such a method for producing a bale-like olefin elastomer, it is possible to provide a bale-form olefin elastomer that does not cause bubbles or impurities to be taken in during transportation and storage without fluidization or integration problems.
In the present invention, the bale-like shape means an approximately rectangular parallelepiped lump of 1 to 200 kg, preferably 1 to 100 kg, and more preferably 10 to 50 kg.
[0020]
The method for producing a bale-like olefinic elastomer of the present invention is particularly preferably produced using only the olefinic elastomer (A) described above, but the olefinic elastomer (A) has the object of the present invention. Various additives may be contained as long as they are not impaired, and a small amount of resin other than the olefin-based elastomer (A) may be contained.
[0021]
Examples of the additive that may be contained include a softening agent, a stabilizer, and a coloring agent. The resin that may be contained is a thermoplastic resin, specifically, high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE). Ethylene / α composed of ethylene homopolymer (polyethylene), etc., ethylene having different density or structural unit amount from the olefin elastomer (A) and α-olefin having 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms. -Olefin copolymer: polypropylene such as propylene homopolymer, propylene block copolymer, propylene random copolymer; propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1- Examples thereof include crystalline homopolymers or copolymers of α-olefins having 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms such as octene. I can get lost.
[0022]
When the veiled olefin-based elastomer contains various additives or resins other than the olefin-based elastomer (A), the olefin-based elastomer (A) and other components are mixed in advance by a method such as melt kneading. It is desirable to keep it, and it is more preferable to keep it in a pellet form.
The pellet is preferably obtained by melt-kneading the olefin-based elastomer (A) and various additives as necessary in an extruder as necessary, and extruding from the extruder.
[0023]
The shape of the pellet made of the olefin elastomer (A) is not particularly limited, but it is desirable that the thickness is about 0.5 to 10 mm, preferably about 1 to 5 mm.
The pressure molding condition is not particularly limited, but the pressure is 0.1 to 200 kg / cm ² , preferably 0.1 to 150 kg / cm ² , more preferably 2.5 to 150 kg / cm. ² is desirable, and the pressurization time is usually 1 to 20 seconds, preferably about 1 to 5 seconds, although it depends on the pressurization pressure.
[0024]
Moreover, the temperature conditions at the time of pressure molding are not particularly limited, and the temperature of pellets or the temperature of the baler that is usually pressure-molded is 10 to 80 ° C, preferably 10 to 70 ° C, particularly preferably 10 to 55 ° C. It is desirable to be in ° C. Under such pressure molding conditions, pellets that are pressure molding raw materials are molded into a substantially rectangular parallelepiped bale shape.
[0025]
By pressure-molding under the above conditions, a bale-like olefin-based elastomer that does not cause bubbles or impurities to be taken in during transportation and storage and without fluidization or integration problems can be produced.
In the production method of the present invention, pellets made of the olefin elastomer (A) are pressure-molded to produce a bale-like olefin-based elastomer, but the pressure-molded product obtained by pressure molding is cut. May produce a veiled olefin-based elastomer having a desired size and shape. Thus, when producing a bale-like olefin system elastomer, since a plurality of bale-form olefin system elastomers can be manufactured by one press molding, it is efficient and preferred.
[0026]
Bale olefin elastomer production apparatus The bale olefin elastomer production apparatus of the present invention includes an extruder for extruding the olefin elastomer (A) described above, and an olefin elastomer (A) extruded from the extruder. ) And a pressure forming means for pressure forming the pellet.
[0027]
According to such a veiled olefin-based elastomer production apparatus, a bale-shaped olefin-based elastomer that does not cause bubbles or impurities to be taken in during transportation and storage and without fluidization or integration can be produced.
Such a production apparatus preferably has a polymerization means for copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms upstream of the extruder. As the polymerization means, any polymerization reactor that normally performs polymerization of ethylene and α-olefin can be used.
[0028]
In the apparatus for producing a veiled olefin elastomer of the present invention, the extruder may be any one that extrudes the olefin elastomer (A). For example, the olefin elastomer (A) such as a powder produced by a polymerization apparatus is used. It is preferable to have a kneading part for melting and kneading the resin made of the above, and it is preferable to have a foreign matter removing means such as a screen. When the target bale-like olefin elastomer contains other components other than the olefin elastomer (A), the olefin elastomer (A) and other components are melt-kneaded in the kneading part. Is desirable.
[0029]
Any pelletizing means may be used as long as it pellets the resin composed of the olefin-based elastomer (A) extruded from the extruder, and any conventionally known pelletizer can be used, but water or water is sprayed. Therefore, it is preferable to use a so-called underwater cut type pelletizer that cuts the resin with a rotary blade or the like.
[0030]
The hole diameter of the die in the pelletizer is preferably set to a diameter of 2 mm to 10 mm, preferably 2 to 9 mm, more preferably about 2 to 6 mm. Further, the thickness of the pellet can be arbitrarily controlled by controlling the rotary blade of the pelletizer.
By such pelletizing means, the resin made of the olefin elastomer (A) is formed into granular pellets.
[0031]
The pressure molding means is capable of pressure molding the pellets made of the olefin-based elastomer (A) formed by the pelletizing means under the condition of forming a bale shape.
Specifically, it is desirable to introduce pellets made of the olefin-based elastomer (A), press the pellets at a pressure of about 150 kg / cm ² , and form the pellets into a substantially rectangular parallelepiped shape.
[0032]
The apparatus for producing a veiled olefin-based elastomer of the present invention preferably further has a cutting means for cutting the pressure-molded product downstream of the pressure-forming means for pressure-molding the pellets. In the case of having a cutting means for cutting the pressure-molded product, a plurality of desired products can be obtained by cutting a bale-shaped product larger than the desired bale shape as the pressure-molded product and then cutting it. This is desirable because it is possible to produce a veiled olefin-based elastomer.
[0033]
Bale olefin elastomer The bale olefin elastomer of the present invention is produced by the method or apparatus for producing the bale olefin elastomer of the present invention using the olefin elastomer (A) described above.
The veiled olefin-based elastomer of the present invention desirably has a volume filling ratio of 60 to 95%, preferably 65 to 95%, particularly preferably 75 to 95%.
[0034]
Such a bale-like olefin elastomer of the present invention can be used as a raw material for producing a final product without going through complicated steps such as degassing of bubbles and removal of impurities.
[0035]
【The invention's effect】
According to the present invention, it is possible to provide a method and apparatus for producing a bale-like olefin elastomer that does not cause bubbles or impurities to be taken in during transportation and storage without causing fluidization or integration problems. Furthermore, the bale-like olefin-based elastomer obtained by such a method can be used as a raw material for producing a final product without going through complicated steps such as degassing of bubbles and removal of impurities.
[0036]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
In Example 1 and Comparative Example 1, the following ethylene-based α-olefin copolymer resin was used.
[0037]
Ethylene-based α-olefin copolymer resin: 52 mol% of structural units derived from ethylene and 48 mol% of structural units derived from propylene
Density: 0.85 g / cm ³
・ Crystallinity: 0%
Intrinsic viscosity [η] (measured in 135 ° C. decalin); 1.6 dl / g
Melting point: -40 ° C
[0038]
[Example 1]
When the ethylene-based α-olefin copolymer resin is melt-kneaded and extruded from an extruder that continuously processes at 3500 kg / h, cooling water flowing at a rate of 90 m ³ / h is passed through and filled. In this state, it was extruded from a die (hole diameter: 3 mm) of an extruder, and immediately after that, cut and pelletized by a rotating device having a cutter blade, cooled and transported with cooling water. Additionally, after separation of the pellets with cooling water downstream of the centrifugal separator, the resulting pellet was 50kg weighed and filled in the compression molding apparatus (IMEX Co. Ltd.), applied pressure 150 kg / cm ^2, pressure Pressure molding was performed for 1.5 seconds at a temperature of pellets of 20 ° C. to obtain a bale-shaped resin lump. Furthermore, it cut | disconnected by the automatic cutting apparatus downstream. As a result, 25 kg of a regular resin lump was obtained. Since compression molding was performed, no bubbles were taken from the voids between the pellets. The volume filling rate of the bale-like resin mass was 90%.
[0039]
In addition, although this resin has a property of flowing even at room temperature, lapping with a polyolefin film for preventing flow can be easily performed because the veil is a regular lump. Overall, no problems were found in handling.
[0040]
[Comparative Example 1]
In the same equipment as in Example 1, an attempt was made to fill pellets directly into a paper bag. After filling, the resin flowed in the paper bag to form one resin lump. The voids between the pellets directly held the air bubbles, and it was not easy to remove from the bag, and a large problem was observed in quality and handling.

Claims (3)

Copolymerized ethylene and an α-olefin having 3 to 20 carbon atoms, having a density of 0.80 to 0.90 g / cm ³ and a crystallinity in the range of 0 to 10%. The structure derived from an α-olefin having 3 to 20 carbon atoms when the total of the structural unit (A1) to be obtained and the structural unit (A2) derived from the α-olefin having 3 to 20 carbon atoms is 100 mol% The olefin-based elastomer (A) containing 15 to 90 mol% of the unit (A2) and substantially free of a copolymer component derived from polyene is pelletized without containing a resin other than (A), Creating a pellet made of an olefin elastomer;
Pressure-molding the pellet;
A process for producing a veiled olefin-based elastomer, comprising:   The manufacturing method of the bale-like olefin elastomer of Claim 1 whose temperature of the pellet at the time of pressure molding or the temperature of a baler is 10-80 degreeC. Pelletizing the olefinic elastomer (A) extruded from the extruder and creating pellets comprising the olefinic elastomer;
A step of pressure-molding the pellet of the olefin elastomer to create a pressure-molded product;
The method for producing a bale-like olefin-based elastomer according to claim 1, further comprising a step of cutting the pressure-molded product with an automatic cutting device .