CA2189868C - Method of manufacturing polyolefin solutions - Google Patents
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- CA2189868C CA2189868C CA002189868A CA2189868A CA2189868C CA 2189868 C CA2189868 C CA 2189868C CA 002189868 A CA002189868 A CA 002189868A CA 2189868 A CA2189868 A CA 2189868A CA 2189868 C CA2189868 C CA 2189868C
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- polyolefin resin
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
- C08J3/09—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in organic liquids
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
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- Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
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Abstract
A method of manufacturing a polyolefin solution continuously and in a stable manner with a high yield which comprises kneading a polyolefin resin with a liquid being composed of a solvent for the polyolefin resin, and is characterized in that; (1) a continuous kneader having a self-cleaning action is used, and (2 ) a starving state is maintained in the internal sections of the kneader at a polyolefin resin feed section, a liquid feed section, and the section in which the kneading of the polyolefin resin and the liquid is initially carried out.
Description
SPECIFICATION
Method of Manufacturing Polyolefin Solutions Field of the Invention The present invention relates to a method ot' manufacturing a polyolefin solution used for manufactuririQ microporous polyolefin nienibranes, polyolefin fibers and the like. More particularly, it relates to a method for continuously manufacturing a solution of polyolefin havin, a wide molecular distribution range, irl a stable manner and with a high output.
Bac arou d of the Invem.tion A polyolefin resin has superior mechanical strength and physical characteristics; therefore, it has been used for various purposes. For example, microporous polyolefin niembranes and porous fibers have been used as a separator for batteries, a separation film for electrolytic capacitors, precision filters, air filters and the like. A polyolefin resin is generally manufactured using a polyolefin solution incorporating an advanced flow iniprover or solvent.
The polyolefin solution is conventionally manufactured by means of "batch" type kneading, continuous kneadin- and the like of a poiyolefin resin and a liquid such as mineral oil and the like. In the case of the batch kneading, the polyolefin and the liquid are put into an autoclave equippecl with a mixer, the temperature is increased while the mixture is mixed, and the polyolefin and the liquid are kneaded. However, with the batch kneading, the kneading time takes longer, which is a short-coming. In addition, with the batch kneading the residence time differs between a product taken out from the batch at the initial stage and that toward the end, when the kneaded solution is taken out for use. As a result, the quality within the batch or at the time of switc.hinb the batch is not stable, and furthermore, this method requires man power, which is another shortcoming. In addition, it is difficult to prepare a high viscosity solution and it is not possible to use higb molecular weight compositions in the 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 a polyolefin solution. However, in the prior art, the pressure in the kneader at the liquid feed section is high, and in additaon, the pressure 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 a liquid back-flow in the upstream direction is observed. As a result it is necessary to reduce the quantity of the supplied 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 polyolefin solution can be continuously obtained with a high yield and in a stable manner.
Disclosure of the Invention As a result of continuous research with the above purpose in mind, the present inventors 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 polyolefin solution having uniform quality can be continuously obtained in a stable manner with a high yield.
..J
Thus, the manufacturing method of a polyolefin solution according to the present invention, comprises kneadino a polyolefin i-esin with a liquid beina composed of a solvent, and is characterize(i by that (1) a continuous kneader having a self-cleatiinb action is used, and (2) a starving state is maintained in an intertial section of the kneader at a polyolefin resin feed section, a liquid feed section, and a section in which the kneading of the polyolefin resin and the liquid is initially carried out.
In addition, the manufacturing method of a polyolefin solution accordina to the present invention comprises kneading a polyolefin resin and a liquid composed of a solvent, and is characterized by that (1) a continuous kneadei- having a self-cleanino action is used, (2) at least one liquid feed section is placed downstream of a polyolefin resin feed section, and (3) the internal pressure in at least one section of the kneader between the polvolefin resin feed section and a liquid feed section located rnost upstream is set higher than the internal pressure of' the kneader in the liquid feed section located most upstream.
Brief DescriDtion of the Dra.wings The invention will be better understood with reference to the following description of a number of prefei-red ernbodirnerits thereof', biven in the context of the accompanying drawinos, in which:
Figure 1 is a schematic diagram showing a first arrangement of the location of a pressure meter in an extruder arld the location of the liquid feed section;
Figure 2 is a schematic diaorarn showing ~i second arranaement of the location of a pressure meter in an extrudet- and the location of the liquid feed section;
Figure 3 is a schematic diagram showing a third arrangement of the location of a presstire meter in an extruder and the location of the liquid feed section;
Figure 4 is a schematic dia(yram showin- a fourth arrangement of the location of a pressure meter in an extruder and the location of the liquid feed section;
Fiotire 5 is a schematic diagram showing a fifth arrangement of the location of a pressw-e meter in an extruder and the iocation of the liquicl feed section;
Fi~ure 6 is a schematic diaaram showing a sixth arrangement of the location of a pressure meter in an extruder and the location of the liquid feed section;
Figure 7 is a schematic diagranl showin~ a seventh arran-ement of the location of a pressure meter in an extruder and the location of the liquid feed section;
Fiaure 8 is a schematic dia-ram showin; an eiahth arranaement of the location of a pressure rneter in an extruder arid the, location of the licauid feed section;
Figure 9 is a schematic diagrani showing a ninth arrangement of the location of a pressure meter in an extruder arid the location of the liquid feed section; and Figure 10 is a schematic dia-ram showinr a tenth arrangement of the location of a pressure metei- in an extruder and the location of the liquid feed section;
S
In the drawings, the numerals I through 14 indicate a pressure meter, the numeral 20 indicates an extruder, the nurnei-al 21 indicates n laolyolefin feed section and the numeral 22 indicates a licluid feed section.
DETAILED DESCRIPq'ION OF PREFERREI) EMBC>DIIVIENTS
The present invention will be clescribed iti detail hereafter.
(1] Polyolefin resin The polyolefin resin can be -2 crvstalline homopolymer or copolymer obtained by polymerizing ethylene, propylene, 1-butene, 4-rnethyl-l-pentene or hexene or a blend thereof. The copolymer can be, for example, a block copolymer (rnulti-step polymer), obtained by introducino propylene and ethyiene sequentially to a i-eactor. Amona those above, polypropylene., l)olyethylene and a blend of them are preferable. The polyolefin inay be in powder or pellet form.
Among the polyolefin resins, preferi-ed is a polyolefin resin containing a component with a molecular weight of at least I x 106. Examples of polyolefin resins containing a component having a rnolecular wei-ht of at least I x 106 include crystalline homopolyrners and copolymers of ethylene, propylene, 1-butene, ~"T-nlethyl-l-pentene, 1-hexene and the like and blends thereof. Among them, preferred is an ultra high molecular weight polyethylene containin; at least 5% by weight of a component havin~ a molecular wei 2ht oY~ at least i x 10~>.
As for the polyolefin resin described above, it is desirable that it contains at least 5% by weight (according to the GPC tnethod), moi-e desirably 10% by weight to 90% by weight, of a component havinc a molecular weight of at least 1 x 106. In addition, it is desirable that the molecular wei;ht distribntion (weight avera~e molecular weight/number average molecular weight) of the polyolefir resin described above, is 5 to 300. Wllen the component having a molecular wei.ght of at least I x 106 is less than 5% by weight, the drawing property of a formed object made from the solution, cannot be improved, and it is not possible to obtain a formed object with sufficient strength. ln addition, i he afore-mentioned range of molecular weight distribution is desirable in order to easily prepare the solution.
Preferred is a polvolefin resin produced bv a reactor blend (multi.-step polymerized polyolefin), or a mixture of two oi- rnore of such polyolefins.
Foy-example, a mixture can be made by blending a polyolefin containing at least 5%
by weight of a component having a molecular wei~;ht of at least I x 106 with a polvolefin having a molecular weiaht of at least I x1(:34 but less than I x 106. A
mixture prepared by blending the polyethylene liaving an ultra high molecular weight described above with high density polyethylene having the molecular weight described above is especially desirable. For- example, a reactor blend containing at least 5% by weight of a component having a molecular weight of at least I x and a molecular weight dish~ibution (weight average molecular weightlnumber average molecular weight) of 5 to 300 can be produced bv rneans of multi-step polymerization. As for the multi-step polymerization rnethod, it is desirable to use a 2-step polymerization method to produce the high rnolecular weight polymer portion and the low molecular weight polymer portion.
In the manner described above, the polvolefin containing a component having a molecular weight of at least t~. 14~~,, niore desirably an ultra high molecular weight polyolefin containinb at least 5% by weight percent of a component having a molecular weight of at least 1 x 106, especially ultra hibh molecular weight polyethylene describeci previously, or a mixture of the ultra high molecular weight polyethylene anci high density polyethylene, is especially desirable as a solution for forminQ rnicroporous niembranes.
It is possible to add various additives, as tieeded, such as nucleation agent, anti-oxidant, ultra-violet ray absorbin; aoent, anti-blockin; aoent, pigment, dye, inorganic filler, anti-bacterial agent, deodorant, far-infrared radiation irradiation agent and the like.
[2] Liquid The liquid to be added to the polyolefin resin is a low volatile and good solvent for the polvolefin resin, and is for example, low volatile aliphatic or cyclic hydrocarbons such as nonane, decane, decalin, p-xylene, undeeane, dodecane, liquid paraffin and the like, or a fraction of mineral oil having a boiling point corresponding to the above.
As for the mixing ratio of the polyolefin resin and the liquid, the quantity of the liquid is 15 parts by weight to 2000 parts by weiaht, more desirably 20 parts by wei~ht to 1500 parts by wei~ht per 100 parts by wei~ht of the laolyolefin resin.
When the quantity of the liquid goes over 2000 parts by weight, kneading becomes difficult. On the other hand, when the quantity of the liquid is less than 15 parts by weight, the viscosity is hi-h and the quality deteriorates due to shearine, heat at the time of kneading.
131 Continuous kneader The continuous kneader used ior manufacturina the polyolefin solution has a self-cleaninIg action. In the case of the c.ontinZ ious kneader with the self-cleaning action, through aaroove section of 1_ screw, a thread ridqe o:r another screw or a protrudin~ section or the like of a cylinder passes, so that the mixture does not rotate with the screw, and it is possible to dii-ect the mixture in a direction in accordance with the thread ridge of the screw or a combination angle of a kneading disk. Therefore, in the case that there is a self-cleaning action, it is possible to keep a liquid feed section and a section in which the kneadin~ of the polvolefin resin and the iiquid is initially carried out in a starving state.
The self-cleaninlc, action of the kneader does not have to be effective in all sections of the kneader, but it is sufficient that the self-cleanino, action is effective in at least a section of the kneader in which the mixture described above exists, so that a liauid feed section and the section in which the kneadirrc, of the polyolefin resin and the liquid is initially carried out, are kept in the starved state.
In addition, the self-cleanin- action in the kneader cloes not have to be effective in all section of the kneader, but it is enouah that ttie self-cleanin- action is effective in at least one section of the sections in which the mixture described above exists, so that the pressure in the licluid feed section is tOko/cm2or below.
A twin-screw kneader or special single screw kneader is preferred as this type of continuous kneader described above. Specific examples of such kneader includes a co-rotating twin screw mixer (extruder), a counter-rotating twin screw mixter (extruder), or a special single-screw kneader such as a Bosco kneader and the like. The co-ratating twin-screw mixer is especially preferred.
On the other ha.nd, in the case of a kneader without a self-cleaninc, action, even if a thread rid;e of the screw is in the direction of feedin~, the coefficient of friction between a cylinder and the mixture of the polyolefin resin and the liquid in which the kneading has not been made sufficient, is extremely low, and the mixture described above only rotates with the screw, ~ind it tioes not have the capacity to feed the mixture toward the lower strearn. Therefore, in the case of a Icneader without self-cleaning action, it is not possible to keep the liquid feed section and the section in which the polyolefin resin and the liquid are initially kneaded in a starvina state. In addition, in order to move downstream the mixture rotating with this screw, an upstream pressure has to be increased. For that reason, the pressure is high in the case of the kneader without self-cleaning action.
At least one liquid feed section is placed. at a polyolefin resin feed sectiori or downstream thereof. The liquid is supplied en route to the kneader in which the polyolefin resin exists, and the solution of thc polyolefin resin of a uniform concentration is prepared by kneading.
[4] Kneading conditions (1) Conditions inside the kneader The nianufacturing method of a polyolefin solution according to the present invention, includes a case that a polyolefin i-esin and a liquid are supplied from the sanie feed section, and a case that the liquid feed section is placed downstream of the feed section of the polyolefin resin_ It is necessary to k-eep an internal section of the kneader at each feed section in a starvin(y state. In addition, it is necessary to keep the internal section of the kneader at a kneading section of an initial liquid and the polyolefin resin in a starving state. The starving state of the internal section of the kneader here means that there exists an air space between the cylinder and the screw where the polyolefin resiri or the mixture of' the liquid with the polyolefin resin does not exist. When such a starving state is realized, the pressure toward the direction of the screw length becomes 0.
In the manner described above, by making the pressure 0, it is possible to transport the mixture of the polyolefin resin and the liquid which has not been yet well kneaded toward the lower stream, without creating a backflow of the liquid even though there is a section where the polyolefin resin is not filled sufficientl_y upstrean-i of the liquid feed section. The fact that ttiere is no section being filled with only the polyolefin resin, means that the deterioration of the polyolefin resin does not take place due to the sheai-ing heat, even though the polyolefin resin with high viscosity is used.
In addition, in the case that the liquid feed section is placed at the polyolefin resin feed section and downstream thereof, it is preferred in the case that an extremely large quantity of the liquid is supplied, to keep at least one internal section of the kneader is filled with the polyole.fin resin, between the polyolefin resin feed section and the liquid feed section located most upstream. As described above, in the case that there is a section filled upstream, it is possible to reduce a 5 pressure in the section filled with only a polyolefin resin, and it is possible to prevent deterioration due to the heat at the section of the polyolefin resin alone.
This means that upstream from the liquid feed section located the most upstream in a starving state, a section is created of a greater pressure than the internal pressure at the said liquid feed section. A back flow toward upstream can 10 be prevented, by creating the pressure distribution in the manner described above, even when the quantity of the liquid is increased. As a result, an increase in yield can be achieved.
In addition, when two or more liquid feed sections are to be placed downstream of the polyolefin resin feed section, it is preferred for the same reason to set the internal pressure of at least one internal section of the kneader between the most upstream liquid feed section and the next downstream liquid feed section, at a higher value than the internal pressure of the liquid feed section of the kneader located most upstream. Furthermore, it is preferred to keep the internal pressure of at least one section of the kneader between the liquid feed section most upstream and the liquid feed section located next downstream, larger than the internal pressure in the kneader located in the consecutive two liquid feed sections immediately downstream of the polyolefin resin feed section. Doing so is advantageous since the quantity of supplied liquid and the yield can be increased.
The pressure distribution described above can be obtained by changing the shape of the screw of the kneader, the liquid feed location, operation conditions such as screw rotation number and the like.
(2) Internal pressure distribution in the kneader The method of manufacturing a polyolefin solution according to the present invention can be characterized by that a specific pressure distribution is maintained in the kneader. The pressure in the kneader here is an average value of the pressure in the internal section of the kneader over a coaistant time interval, and this constant time is a sufficiently long tinle to averaoe out the changes in pressure attributable a rotation of the screw of the kneader.
To achieve the desired pr-essure distribution, at least one section of the kneader located between the polyolefin resin feed section and the most upstream liquid feed, is kept at a liigher pressure than the pressure of the nlost upstream liquid feed. In other words, a section having g:reater pressure than the internal pressure of the liquid feed section is maintained upstream of the rnost upstream liquid feed. By establishiiig the pressure distribution in the manrrer described above, it is possible to prevent a backflow toward the upstreAun side of the kneader, even though the quantity of the added liquid is increased, and as a result, the yield can be increased.
In addition, when two or more liquid feed sections are to be placed, for the same reason, it is desirable to set the pressure in at least one section in the kneader between each of the liquid feed section and the feed section located immediately downstream, larger than the inner pressure of the iiqUid feed section located irnmediately downstream. Furthermore, it is clesirable to set the pressure in at least one section in the kneader between each of the liquid feed section and the feed section located immediately downstream, larger than the inner pressure of the two liquid feed sections described above. By doing so is an advantage that the liquid feed quantity and the yield can be increased.
In addition, it is desirable that the pressLu-e in the kneader at the liquid feed section located most upstream is set less than 10 kg/cm2 (gauge pressure).
Upstream of the most upstream liquid feed section, in order to provide-shearing to the section of the polyolefin resin along with high viscosity, the section filled with only the polyolefin is reduced to the minimum, by setting the pressure in the kneader within the range described above, and as a result, the shearing heat is controlled and the deterioration due to the heat can be prevented.
The pressure distribution described above can be obtained by changing the sbape of the screw of the kneader and the like.
(3)Kneading temperature It is desirable that the kneading temperature be set from the melting point of the polyolefin to 250 C, preferably from the melting point of the polyolefin + 10 C-to 220 C. If the kneading temperature is less than the melting point of a polyolefin-, sufficient kneading cannot be carried out, and if the kneading temperature is higher than 250 C, the deterioration of a polyolefin resin takes place.
Effects In the present invention, it is possible to make the pressure at the liquid feed section zero, by creating a starving state in the internal section of the Imeader at the polyolefin -resin feed section and the liquid feed section and the initial kneading section. As a result, it is possible to obtain a uniform polyolefin solution with a high yield, without creating the back flow of the liquid, even though there is no section filled with only the polyolefin resin upstream of the liquid feed section.
In addition, when there is a section filled with the polyolefin resin upstream of the most upstream liquid feed section, it is possible to reduce the pressure, and the deterioration due to the heat can be prevented at the section filled with the polyolefin resin alone, and at the same time, a large quantity of the liquid can be supplied.
In the present invention, it is possible to obtain a uniform polyolefin~
solution with a high yield, by creatitig a specific distribution of the internal pressure in the kneader.
Exa es The present invention will be described further in detail by way of the following Examples however, the present invention is not lirnited to the Examples.
Examples 1 through 16 Each of the polyolefin resins and the liquids, were kneaded in the mixing ratios, shown in Table 1, using a co-rotating twin screw rnixer(extruder), TEX-54, (manufactured by The Japan Steel Works, f,td. and the screw diameter = 58 mm, L/D ratio = 42). In addition, the screw shape of the extruder was selected so that a preferred pressure distribution could be obtained. F'ressure tr.eters were placed at 141ocations in the internal section of the krieader. p'i ;ure I through Figure 5 show the locations of the pressure meters in the internal section of the extruder and the liquid feed positions, and the relation of each Example and the Figures are shown in Table 1. However, the distance from the pressure meter i to left end of the extruder 20 was 236 mm, and the distance between each adjacent pressure meter was 94.5 mm. The die attached to the extruder, contains a slit having a thickness of 3 mm, and a width of 104 mm. Table I shows the hotyolefin resin and the liquid being used, and the quantity of supplied liquid for the polyolefin resin 100 parts by weight. In addition, the quantity (shown with parts by weight for the polyolefin of 100 parts by weight) of the liquid suppiied from each of' the liquid feed holes and the pressure in the internal section of the extruder and operation conditions are shown in Table 2. However, the pressut-e value shown in T able 2 was the value (kg/cm2, gage pressure) if the atmospheric pressure was set as zero. As shown in 'I'able 1, an extruder of a different structural type was used for each Example.
In addition, after the measurement of the nressure in the extruder, the pressure meters of the polyolefin feed section or the liquid feed section located most upstream and the pressure meter located at the place immediately downstream were removed, and several grains of the polyolefin resin (PE) pellet were dropped into the holes where the pressure rxietei-s had been rernoved. T'he PE pellets went into the internal section of the extruder irnmediately. Therefore, it was clear that the polyolefin feed section, the liquid feed section beinc, located most unstream and the location of the pressure meter located at the irnmediately downstream were in a starved state. In addition, the screw located in the space between the polyolefin feed section and the location of the first pressure meter locate.d at the immediate downstream, or in the space between the liqriid feed sectior- located most upstream and the location of the pressure meter located immediately downstream, was the kneading section to carry out the kneading of the polyolefin resin and the liquid. In addition, Examples 6 through 16 show that the pressure value (kg/cm2, gage pressure) at the location of the pressure meter located immediately upstream of the liquid feed section located most upstream, was over zero, so that the internal section of the extruder was in the filled state. The polyolefin solution, obtained in the above manner, was formed into a sheet of 2 rlim in thickness usitlg the press forrning die.
The sheet being obtained looked superior in its appearance. In addition, the sheet was drawn with a simultaneous two-axis, using a bLitch type rolling mill, and it became clear that it was possible to draw in the scale of more than 2 x 2 for all.
Comparative Examples 1 through 6 Each of the polyolefin resins and the liquids, shown in Table 1, were kneaded, using the co-rotating twin screw mixer (extruder), TEX-54, the same as that of Example 1. In addition, the screw shape of the extruder was selected so that the preferred pressure distribution could be obtained. The pressure meters were placed in the same manner with those of Example i.'T'lle location of the pressure meter and the location of the Iiquid feed section are shown in FFiQure 1, Figure 3, Figure 4, and Fi~ure 6, and the relation of each Cotnparative Exampie and the Figures are shown in Table 1.
Table 2 shows the internal pressure of the extruder and the operation conditions. As shown in Table 2, as for the Cornpa.rative Examples, the value of the pressure was over zero at the location of the imtnediately downstream of the polyolefin resin feed section, or the liquid feed section located rnost upstream, and at the location of the pressure meter irnrnediately downstream, it shows that the internal of the extruder was in the filled state, and it was not in a starvinc, state.
However, the pressure value shown in Table 2, was the value when the atmospheric pressure was zero (kglcm2, ga,e pressure). ~l,he operation conditions shown in Table 2 were the conditions when the stable production could be seen and when the maximum yield was realized.
In Comparative Example I throuoh Comparative Example 4, vvhen the yield was increased, the following phenomena were observed: its variation became big and the liquid not being kneaded jets out interniittently.
In addition, the polyolefin solution in Cornparative Example 5 and Comparative Example 6 was formed into a sheet of 2 ml-rl in thickness, using a press forminc, die. The color of the sheet was chanQed to yellow.
5ubsequently, this sheet was drawn with a simultaneous two-axis, using a batch type rolling mill, however, it was torri in all experimental coriditions.
Table 1 Quantity of Supplied No. Polyolefin Resin Liquid Liquid "I Types of the Extruder Examples 1 P E - 1 'Z' Liquid Parafin '8' 3 0 Figure 1 2 P E - 23' ii 3 0 Figure 1 3 P E - 1 ii 5 0 0 Figure 2 4 P E - 2 ii 5 0 0 Figure 2 PE-2 ~i 500 Figure 2 6 P E - 1 ~i 1 5 0 Figure 3 7 P E - 2 ~i 1 5 0 Figure 3 8 P E - 1 ri 5 0 0 Figure 4 9 PE-2 ii 500 Figure 4 PE-1 1 200 Figure 5 11 PE-2 ii 1 2 0 0 Figure 5 12 P E 31 4i n 5 0 0 Figure 5 = 13 P E - 4'5 ii 5 0 0 Figure 5 14 P E - 5"' ~i 5 0 0 Figure 4 p P ") ii 3 0 0 Figure 3 16 p p ir 1 2 0 0 Figure 4 co Comparative 00 Examples 00 i P E - 1 3 0 Figure 1 2 PE-2 i~ 3 0 Figure 1 3 PE-1 ii 1 50 Figure 6 4 PE-2 ii 1 5 0 Figure 6 5 PE-2 >i 500 Figure :l 6 P P 3 0 0 Figure 3 Note: (1) Quantity of supplied liquid:Parts by weight nf the liquid for the 100 parts by weight of the polyolefin resin (Z)PE-l:Weight average molecular weight 3.7X10' powder-form polyethylene(PE) (3)PE-2:Weight average molecular weight 2.OX106 powder-form polyethylene(PE)and Weight average molecular weight 3.7X10' powder-form polyethylene(PE)were blended using 3:14 ratio.(Component of the molecular weight of 1X10' and over according to the GPC method, 21.6% bv weight percent) (4)PE-3:Weight average molecular weight 3.7X105 pellet-form PE.
(5)PE 4:Weight average molecular weight 2.0X10' powder-form polyethylene(PE)and Weight average molecular weight 3.7X105 pellet-form polyethylene(PE),are blended using 3:14 ratio.(Component of the molecular weight of 1X10' and over according to the GPC method,21.6% by weight) (6)PE-5:Weight average molecular weight 2X106 powder-form polyethylene (7)PP:Weight average molecular weight 3.9X10' pellet-form polypropylene,to which sorbitol-based nucleation agent was added by lpart by weight.
(8)Liquid paraffin:Kinematic viscosity at 40'C is 64 cSt.
Table 2 Feed Quantity of the Liquid, Internal Pressure in the Extruder, and the Operation Conditions Position on the Extruder Cylinder Screw Rotation ! -r- Yield Polyolefin Tenm. Number Resin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Feed Hole 'C rpm kg/h Example Liquid Feed Quantity 30 - - - - - - - - - - - - - 150 100 80 1 Pressure in the Internal of the Extruder - 0.0 0.0 0. 0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ~ 200 Ex2~lG PrLiquid essuree~ Quantity of the Extruder - 0.0 0. 0 0. 0 0.0 0.0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -200 j----- -~ -~- -~ ------ -Example Liquid Feed Quantity _ 80 - - 180 - 240 - - - - - - - r 150 350 90 3 Pressure in the Internal of the Extruder 0. 0 0. 0 0. 0 0. 0 0,0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 ~ 200 Example Liquid Feed Quantity - 50 -;- 180 - 1 270 - -- - - - 150 350 100 = 4 Pressure in the Internal of the Extruder - ( 0.0 0. 0 1 2. 6 1.4 1.0 8.9 7.8 7.8 6. 0 5.1 4.0 2.1 0.2 0.0 ~-200 Example Liquid Feed Quantity - 80 - - 180 - - 240 - - - - - - -' 150 350 60 Fressure in the Internal of the Extruder - 0.0 0. 0 0.0 0.0 0.0 j 0. 0 0 ~ 0 0.0 0.0 0. 0 0. 0 0.0 0. 0 0.0 -200 Example Liquid Feed Quantity ~~-- - -! 150 - - ji--~j -- - - - 150 200 200 rv 6 Pressure in the Internal ef the Extruder 0. 0 Z. 1 0. 0 0. 0 U 0 l 0.0 0.0 0. U u. U 0. 0 1 0. 0 0. 0 0. 0 -200 00 Fxample Liquid Feed Quantity - - - 150 - - - - - - - - -- - 150 200 100 7 Pressure in the Internal of the Extruder - 0. 0 i. 4 0, 0 0. 0 O. 0 0, 0 0, 0 0. 0 0- 0 0. 0 0. 0 0, D 0. 0 ~200 0.0 t---- ;------ _ Examrle Liquid Feed Quantity - - -; 130 370 350 200 8 Pressure in the Internal of the Extruder 0.0 .9 0. 0; 0 0 0 0i0. i i~' 9. 6 8.6 4 a% o. 1 -200 3. 6 0.8 -~
~---~-Example Liquid Feed Quantity - - - 130 T- -! 370 - - - -!- ~- I - 15~ 350 100 o 9 Pressure in the Internal of the Extruder 0.9 0 0 0.0 11.2 10.2 9.8 9 5 8.2 7.4 6. 0 4.6 3. 6 1.8 ~-200 -- - - - - --- -- - -~
780 i- - - - 150 6po 200 N
4-~-p iluantity 140 - -'-- 280 , Pressure in the Internal of the Extruder 0.0 0.0 0,0 0.0 2.2 0.9 0.7 20.1 ~arrt~le iquid r 1! 15.315.0 14.211~.48.0 3.i 200 (.
, - -Example Liquid Feed Quantity - - 140 - - 280 780 - - - - 150 600 100 11 Pressure in the Internal of the Extruder - 0. 0 0.4 U. 0 0. 0 2 . 4 l . 1 U. 8 1 1 . 5 10.2 10. 0 8.9 3. 0 0. 200 ---~-------- ~--~--- - 100 Liquid Feed Quantity - - 200 - - 200 - - - - 'rJ 150 l~n ~ample ~ 1J f J~
12 Pressure in the Internal of the Extruder - 0.0 2 . 6 6.0 0.0 5. 3 2. 6 0.7 15- 3 10.2 10.0 9.5 8. 1 4.9 2.9 200 Fxarttple Liquid Feed Quantity - - 80 -- 180 - - 240 - - 150 13 Pressure in the Internal of the Extruder - 0. 0 1.4 0. 0 0. 0 2. 6 1. 8 0.7 5. 5 4.4 4. 3 4. 2 4. 0 3.6 2.9 200 ( 80 Fatample Liquid Feed Quantity _ - - 130 - - 370 - - - - - - - - 150 250 50 14 Pressure in the Internal of the Extruder 0.0 0.2 0.0 0.0 1. 1 0. 5 0. 3 0.2 0.1 0.0 0.0 0.0 0.0 0.0 ~-200 Example Liquid Feed Quantity - - - 300 - - - - - - - - - 150 150 200 Pressure in the Internal of the Extruder - 0. 0 1.4 0.0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0,0 14.0 13.6 12.9 ~-200 Example Liquid Feed Quantity - - - 230 - - !970 - - - - - - - - 150 600 200 6 Pressure in the Internal of the Extruder - 0.0 1.0 0.0 0.0 3.9 2. 3 2. 1 1.2 0.8 1. 3 9.8 5.6 4.3 3.1 ~-200 Table 2-2 Feed Quantity of the Liquid, Internal Pressure in the Fxtruder, and the Operation Conditions Position on the Extruder Cylinder Screw Rotation Yield Polyolefin Temp. Nwnber Resin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Feed Hole C rpm kg/h Comparative Liquid Feed Quantity 30 - - - - - - - - - - - - - - 150 100 4 Example 1 Pressure in the Internal of the Extruder - 6.8 6. 3 5. 3 4.9 3.3 2.5 0. 6 0.0 0.0 0.0 0.0 0.0 0.0 0. 0 -~200 Comparative Liquid Feed Quantity 30 - - - - - - - - - - - - - - 150 100 2 Example 2 Pressure in the Internal of the Fxtruder - 1.1 4. 5 8. 6 4.8 2.9 1.4 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0. 0 -200 Comparative Liquid Feed Quantit - 30 - - 0 - 45 - - 150 200 10 Exarnple 3 Pressure in the Internal of the Ext-ruder - 0.0 0.4 4.3 5.6 1.1 3 18. 10.6 6 1 167 17.5 1.5 0.7 34.3 29.7 ~-200 Gcmpa~at.ivz Liquid Feed Quantit.y 30 35 40~ 45 150 200 8 Ex.atr~ple 4 Pressure in the Internal of the Extruder 0. 0 1 0.0 2.4 4.1 0. 0 10. 3 15. 2 0. 4 13.2 14.1 0.2 2,.). 5 30.1 25.1 200 -----Comparative Liquid Feed Quantity - - - 130 - - 370 - - - - - - - - 150 350 100 Example 5 Pressure in the Internal of the Ext.ruder i.! II 11. 2 8. 5 40.6 31.2 30.1 25. 3 23. 5 20.1 16.7 13.1 10.1 6.7 ~-200 = -- r - ----- - I -Comparative L.tquid Feed Quantity 300 - - - - - - - - I - - - 150 150 200 N
Example 6 Pressure in the Internal of the Extruder - ) 6. 5 32.5 12.5 11. 3 9.9 8 5 1 7.3 b. 0 4.1 2.3 0. 8 j 5. 2 15.3 10. 3 -200 00 rn Examples 17 through 33 Each of the polyolefin resins and the 11quids, shown in "' able 3, were kneaded, usin; the co-rotatinb twin screw niixer(extruder),TEX-54, (manufactured by 'The Japan Steel Works Ltd., anci the screzx., diameter = 58 mm, L/D ratio = 42).
In addition, the screw shape of the extruder was selected so that a preferred pressure distribution could be obtained. The pressure ineters were placed at locations of the internal section of the kneader. 1-'ioure 7 through Figure 10 show the locations of the pressure meters in the internal section of the extruder and the liquid feed positions, and the relation of each Exatnple and the F'iQures are shown in Table 4 and 6. However, the distance frotn the pressure meter 1 to left end of the extruder 20 was 142 mm, and the distance between each pressure meter adjoining was 94.5 mm.
Table 4 and Table 6 show the operation conditions, and Table 5 and Table 7 show the pressure distribution being measured. However, the pressure values shown in Table 5 and Table 7 were the value (gauge pressure) at the time when the atmospheric pressure was set as zero. 1'he oDeration conditions shown in 'hable 4 and Table 6 were the conditions at the tirne of maximum yield when a stable yield was seen.
The polyolefin solution obtained in the above manner, is formed into a sheet of 2 mm in thickness using a p1-ess forming die. The sheet obtained looked superior in its appearance. In addition, the sheet was dt-awn irt simultaneous two-axis, using a batch type rolling mill, and it was clear that it was possible to draw in the scale of more than 2 x 2 for all.
Comparative Example 7 through Comparative Example 12 Each of the polyolefin resins and the liquids, shown in Table 3, were kneaded, usina co-rotating twin screw mixer (extruder), TEX--54, the same with Example 17. In addition, the screw shape of the extruder was selected so that a preferred pressure distribution could be obtained. The pressure meters were placed in the same manner with that of Example 17. "i,he locations of the pressure meters and the locations of the liquid feed sections are shown in Fioure 7 through Figure 10, and the relation of each Comparative, Example and the Figures are shown in Table 4 and Table 6.
Table 4 and Table 6 show the operation conditions, and Table 5 and Table 7 show the pressure distribution being rneastired. However, the operation conditions were the conditions at the time of maximum yield when the stable yield was observed.
In Comparative Examples 7, 8, 10 and 1 i, when the yield was increased, the following phenomena were observed: its variation becomes big and the liquid not being kneaded jetted out interrnittently.
in addition, the polyolefin solutions in the Comparative Example 9 and the Comparative Example 12 were formed i.nto a sheet of 2 mm in thickness, usin~
a press forming die, and these sheets were drawn in simultaneous two-axis, rising the batch type rolling mill, however, these sheets were torn in all experimental conditions.
Table 3 Quantity of Supplied No. Polyolefin Resin Liquid Liguid'1' Examples 17 P E- 1'2 ' Liquid Parafin'$' 5 0 0 18 PE-l 500 20 PE-1 ~i 1 50 2 3 P E- 3'A' 5 0 0 24 PP "' 300 32 PE-4 cs ,~ 5 0 0 Comparative Examples 8 PE-1 i~ 150 = 9 PP '1 50 lI P E 2 " 1 5 0 12 PE-2 ~i 500 Note :(I)through(8) are the same as those of the Table 1.
Table 4 Feed Quantity of Liquid"" and the Operation Conditions of the Kneader ---Position on the Kneader 121 Cylinder Screw Rotation Yield Temp. Number C rpm kg/h _ __--------_- ---- -- - -Example 17 - - 220 - - J 140 - - J 140 - - J- J- - 150 ~-200 200 80 Example 18 - - 160 - - 170 - - 170 - - - - - 150 ~-200 350 100 I Example 19 - - 30 - ~ - - - - - - - - - - 1150 ~-200 100 100 ---- , Example 20 - - 150 150 ~-200 - - { - _ _-~ '~0 370 _ - - - - - - 150 ~-200 350 200 Example ..l - - 1 õ , - ---- - -- - !
Example 22 - - 140 ,- -~ 280 -;- 780 - - - - - 150 ~~200 600 200 { ao _- ! ~
Example 23 - - 60~ - - 130 -~- 310 - I-~-- J- - 150 ~-200 350 160 0, 300 150 ~-200 150 200 D
Exam le 24 P
- -i--'------- N
--~ - T , , rt Example 25 J - 230 - ! - 970 ! - - - ~ - - - ! - - 15 0 0 ~-20 600 200 - -- - _ __ __ -- ---_ - _ ~- - '-- j Comparative Example 7 - - 30 150 -200 100 - , , Comparative Example 8 30 40 ~- - 45 150 -200 200 10 ~ 200 Comparative Exampie 3 ~0 JJI 4r, 4,i 150 ~00 i3 ----- _ -_ -- -----'------ - ----- ~-_ Note:
(1) Feed quantity of liquid: Parts by weight of the liquid for the polyolefin resin 100 parts by weight.
(2) Position in the Kneader: The numericals 1 through 14 indicate the location positions of pressure meters shown in Figure 7 through Figure 10.
Table 5 Internal Pressure in the Kneader (kg/cm2) Position on the Kneader "' Example 17 0. 0 15. 2 10. 1 8. 6 2. 1 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Example 18 0. 0 5. 1 0. 0 0.0 0. 0-~~ 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Example 19 0.0 19.315.311.2 6 7.2 4.0 1.8 0.0 0.0 0.0 0.0 0.0 0.0 Example 20 0.0 10.9 8.6 8.4 8.2 8.0 7.51 6.7 5.2 3.9 2.41 0.8 0.0~ 0.0 Example 21 0.0 9. 1 4.8 2.2 20.1 15.4 15.0 14.2 13.5 12.1 11. 1 9.8 8.4 7.2 Example22 0.0 0.8 0.0 0.0 9.5 5.3 4.211 25.218.318.017.617.1 16.6 15.9 ao Example 23 0. 0 10. 3 6.3 2.425.61 20.3I 5.626.519.6 18.517.316.4115.012.4 --- _ 4 -j -i- _ 5.9 --~ 5. 5, 5.0 4.6 4.0 3.2 1.6 0. 2 D
Example 24 G. G 9. 4 6.8 6.8 6. 5 6. 3 - -~~ o Example2) 0.Or 3 1. 1 0.0113.39.3i 9.3 9.3; 9.2~ 9.29.0~ 7.8 6.8;
0.0 ~ 0.0 0.0 0.0 0.0 0.0 0.0 Comparative Example 7 0. 0 2. 5 8 21 11. 1 7 . 2 4 2 0 9 _ ~~~omparati~,e ExamPlP n U. U 0. 4 4, i h, h 1 . 1 17 i lts. 1 U.h 1 6 . 7 17.5 1 . ~ 30.7 34, s 1 29. 71 --a- --I-Comparative Example 9 0. 0 0. 0 3 . 1 4_ 3 3 10. 5 1 2 . 2 3. 1 2 . 3 14. ? G
~ ! 25. 3 28. ! 24. 3 Note:
(1) Position in the kneader: The nLmericals 1 throug.h 14 indicate location positions of press.:re meters shown in Figure 7 through Figure 10.
Table 6 Feed Quantity of Liquidand the Operation Conditions of the Kneader Position on the Kneader Cylinder Screw Rotation - - -- ---Temp. Number Yield 1 2 3 4 5 6 7 8 9 10 11 12 13 14 rpm kglh -- - - - --- - -Example 26 - - 220 - ! - 140I - - 140 - - - ! - - 150 ~-200 200 50 ; -_- _-- - f - ---__ i ~----- -----~ - -- ----- - -- -LExample 27 - - 160 - - 170 - - 170 - - - -~- 150 ~-200 350 70 70 Example 28 30 15 ~- - - - - -~- - 0 ~-200 100 Example 29 150 - + - - - - 150 ~-200 200 100 ~--- - - -- -------~- i ~--r-~ 17 -1---~---~ --- 350 Example 30 -!- 130 - - 0 - - - - - - - - 150 -200 35u 100 -------------- - - +--- { - - , _ ' Example 31 2 - ~ 140 - T fiQ~ r80 T- 150 - 20G 600 100 oo , - -- - - - ---- , -T--- ~
Example 32 - - 60 -~-~ 130 (- - 310 -~- - - - 150 -200 350 80 _---- -- - ~--~ 00 _ -' o - j- 150 ~ 200 250 50 o --- -- _ - _ ~
1 _ ------- -- ---Go parative Example 101 - - 1~~ -~ - ~70 - -~- - - - - -;150 -200 100 3 N
--- - -_i - - - _ = 1--- - { o -- ---- ---! ---! ---, _ ~ _ ---' - -i ~----- -- .-.-----' Ip Comparative Example 11 ! - 30 30 40 50 - 1 150 -200 200 8 -- -- -rt- ?
Comparative Example 121 - 130 - 1 370 150 -200 350 100 - -- -~ - ! - - ~ -~
Note:
(1) Feed quantity of liquid: Parts by weight of the liquid for the polyolefin resin 100 parts by weight.
(2) Position in the Kneader: The numericals 1 through 14 indicate the location positions of pressure meters shown in Figure 7 through Figure 10.
Table 7 Internal Pressure in the Kneader (kglcm2) Position on the Kneader --- - - - -Example 26 0.0 2.8 2.0 0.8 0. 0 0. 0 0.0 0 0 0.0 0.0 0.0 0.0 0.0 0.0 ---_ - -_._ __---- ---- -- _--~ { -i Example 27 0. 0 1.4 0.0 0.0 0.0 0.0 0.0 0.0 2. 0.0 0.0 L ~0.0 0.0 0.0 0 - .0~~
__ T - -----~ - ~-_ Example28 0.0 I 9 2.4i u.0 0.0i 0.0 0.01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ___ _ --- ~_----- - _~_--- __ -- - , , Example 29 0. 0 1 . 5 0. 5 0. 0 0. 0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 - --~
~ Example 30 0.0 l . 3 0.4 0.0 1 1 : 2 10 1 9. 8 1 11.4 9. : i 8. 1 ~: 3 5.9 ~. 3.44 _~
Lxample3l 0. 0 0. 4 0 0 u.~0 5 iL; ~.~10.1 9 8.6 0.93.1 ~.3 00 Example32 0.0I 1.3i 0.2 0.01 2.5 1.81 0.7 5.5 4.5 4.4 4.3 4.1 3.6 3.0 Example 33 0.0 0.3 0.0 0.0 1.3 0.61 0.51 0.3 0Ø0 0.0 0.01 0.0 O.Oi Comparative Example 10 0. 0 2.3 !. 5 i 10. 5 5. 7 1 2. 2' 0 c ~ " - - ~;--' ~,-~ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 o Comparat~:eExample~l, 0.0; 0.01 ~..4 4.11 0.01Q V ~15.2 0.4 13.2 14.11 0.2~22.530.11 25.1~
Comparative Example 1 2 1. 7 1 15. 2 11,2 8. 5 40. 6 31. 2 30.1 25.3 23.5 1 20. 1 I 16. 7 13.1 10.1 1 6.7 rote :
(1) Position in the kneader: The numericals 1 through 14 indicate location positions of pressure meters shown in Figure 7 through Figure 10.
Applicability in Industry-As described in detail above, with a riiethod accordiria to the present invention, by creating a straving state in an inter-nai section of the kneader at a polyolefin resin feed section and a licluid feed section, and an initial lcneadinc, section, it is possible to obtain a uniform polyolefin solution with a high yield, without creatinb a backflow of the liyuid. The polyolefin solution obtained by a method according to the present invention in the rnanner described above, can be used for manufacturing various types of polyolefin fornied objects.
In addition, a rnanufacturinb method acc.orclin- to the present invention can prevent a backflow of a liquid, and catl contirruously obtain a high yield of a uniform polyolefin solution, by means of a specific distribution of a pressure in the kneader. The polyolefin solution obtained by .: rnethod according to the present invention in the nianner described above, can be used for manufacturing various types of polyolefin formed objects, and is especially suitable for forming microporous mernbranes.
Method of Manufacturing Polyolefin Solutions Field of the Invention The present invention relates to a method ot' manufacturing a polyolefin solution used for manufactuririQ microporous polyolefin nienibranes, polyolefin fibers and the like. More particularly, it relates to a method for continuously manufacturing a solution of polyolefin havin, a wide molecular distribution range, irl a stable manner and with a high output.
Bac arou d of the Invem.tion A polyolefin resin has superior mechanical strength and physical characteristics; therefore, it has been used for various purposes. For example, microporous polyolefin niembranes and porous fibers have been used as a separator for batteries, a separation film for electrolytic capacitors, precision filters, air filters and the like. A polyolefin resin is generally manufactured using a polyolefin solution incorporating an advanced flow iniprover or solvent.
The polyolefin solution is conventionally manufactured by means of "batch" type kneading, continuous kneadin- and the like of a poiyolefin resin and a liquid such as mineral oil and the like. In the case of the batch kneading, the polyolefin and the liquid are put into an autoclave equippecl with a mixer, the temperature is increased while the mixture is mixed, and the polyolefin and the liquid are kneaded. However, with the batch kneading, the kneading time takes longer, which is a short-coming. In addition, with the batch kneading the residence time differs between a product taken out from the batch at the initial stage and that toward the end, when the kneaded solution is taken out for use. As a result, the quality within the batch or at the time of switc.hinb the batch is not stable, and furthermore, this method requires man power, which is another shortcoming. In addition, it is difficult to prepare a high viscosity solution and it is not possible to use higb molecular weight compositions in the 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 a polyolefin solution. However, in the prior art, the pressure in the kneader at the liquid feed section is high, and in additaon, the pressure 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 a liquid back-flow in the upstream direction is observed. As a result it is necessary to reduce the quantity of the supplied 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 polyolefin solution can be continuously obtained with a high yield and in a stable manner.
Disclosure of the Invention As a result of continuous research with the above purpose in mind, the present inventors 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 polyolefin solution having uniform quality can be continuously obtained in a stable manner with a high yield.
..J
Thus, the manufacturing method of a polyolefin solution according to the present invention, comprises kneadino a polyolefin i-esin with a liquid beina composed of a solvent, and is characterize(i by that (1) a continuous kneader having a self-cleatiinb action is used, and (2) a starving state is maintained in an intertial section of the kneader at a polyolefin resin feed section, a liquid feed section, and a section in which the kneading of the polyolefin resin and the liquid is initially carried out.
In addition, the manufacturing method of a polyolefin solution accordina to the present invention comprises kneading a polyolefin resin and a liquid composed of a solvent, and is characterized by that (1) a continuous kneadei- having a self-cleanino action is used, (2) at least one liquid feed section is placed downstream of a polyolefin resin feed section, and (3) the internal pressure in at least one section of the kneader between the polvolefin resin feed section and a liquid feed section located rnost upstream is set higher than the internal pressure of' the kneader in the liquid feed section located most upstream.
Brief DescriDtion of the Dra.wings The invention will be better understood with reference to the following description of a number of prefei-red ernbodirnerits thereof', biven in the context of the accompanying drawinos, in which:
Figure 1 is a schematic diagram showing a first arrangement of the location of a pressure meter in an extruder arld the location of the liquid feed section;
Figure 2 is a schematic diaorarn showing ~i second arranaement of the location of a pressure meter in an extrudet- and the location of the liquid feed section;
Figure 3 is a schematic diagram showing a third arrangement of the location of a presstire meter in an extruder and the location of the liquid feed section;
Figure 4 is a schematic dia(yram showin- a fourth arrangement of the location of a pressure meter in an extruder and the location of the liquid feed section;
Fiotire 5 is a schematic diagram showing a fifth arrangement of the location of a pressw-e meter in an extruder and the iocation of the liquicl feed section;
Fi~ure 6 is a schematic diaaram showing a sixth arrangement of the location of a pressure meter in an extruder and the location of the liquid feed section;
Figure 7 is a schematic diagranl showin~ a seventh arran-ement of the location of a pressure meter in an extruder and the location of the liquid feed section;
Fiaure 8 is a schematic dia-ram showin; an eiahth arranaement of the location of a pressure rneter in an extruder arid the, location of the licauid feed section;
Figure 9 is a schematic diagrani showing a ninth arrangement of the location of a pressure meter in an extruder arid the location of the liquid feed section; and Figure 10 is a schematic dia-ram showinr a tenth arrangement of the location of a pressure metei- in an extruder and the location of the liquid feed section;
S
In the drawings, the numerals I through 14 indicate a pressure meter, the numeral 20 indicates an extruder, the nurnei-al 21 indicates n laolyolefin feed section and the numeral 22 indicates a licluid feed section.
DETAILED DESCRIPq'ION OF PREFERREI) EMBC>DIIVIENTS
The present invention will be clescribed iti detail hereafter.
(1] Polyolefin resin The polyolefin resin can be -2 crvstalline homopolymer or copolymer obtained by polymerizing ethylene, propylene, 1-butene, 4-rnethyl-l-pentene or hexene or a blend thereof. The copolymer can be, for example, a block copolymer (rnulti-step polymer), obtained by introducino propylene and ethyiene sequentially to a i-eactor. Amona those above, polypropylene., l)olyethylene and a blend of them are preferable. The polyolefin inay be in powder or pellet form.
Among the polyolefin resins, preferi-ed is a polyolefin resin containing a component with a molecular weight of at least I x 106. Examples of polyolefin resins containing a component having a rnolecular wei-ht of at least I x 106 include crystalline homopolyrners and copolymers of ethylene, propylene, 1-butene, ~"T-nlethyl-l-pentene, 1-hexene and the like and blends thereof. Among them, preferred is an ultra high molecular weight polyethylene containin; at least 5% by weight of a component havin~ a molecular wei 2ht oY~ at least i x 10~>.
As for the polyolefin resin described above, it is desirable that it contains at least 5% by weight (according to the GPC tnethod), moi-e desirably 10% by weight to 90% by weight, of a component havinc a molecular weight of at least 1 x 106. In addition, it is desirable that the molecular wei;ht distribntion (weight avera~e molecular weight/number average molecular weight) of the polyolefir resin described above, is 5 to 300. Wllen the component having a molecular wei.ght of at least I x 106 is less than 5% by weight, the drawing property of a formed object made from the solution, cannot be improved, and it is not possible to obtain a formed object with sufficient strength. ln addition, i he afore-mentioned range of molecular weight distribution is desirable in order to easily prepare the solution.
Preferred is a polvolefin resin produced bv a reactor blend (multi.-step polymerized polyolefin), or a mixture of two oi- rnore of such polyolefins.
Foy-example, a mixture can be made by blending a polyolefin containing at least 5%
by weight of a component having a molecular wei~;ht of at least I x 106 with a polvolefin having a molecular weiaht of at least I x1(:34 but less than I x 106. A
mixture prepared by blending the polyethylene liaving an ultra high molecular weight described above with high density polyethylene having the molecular weight described above is especially desirable. For- example, a reactor blend containing at least 5% by weight of a component having a molecular weight of at least I x and a molecular weight dish~ibution (weight average molecular weightlnumber average molecular weight) of 5 to 300 can be produced bv rneans of multi-step polymerization. As for the multi-step polymerization rnethod, it is desirable to use a 2-step polymerization method to produce the high rnolecular weight polymer portion and the low molecular weight polymer portion.
In the manner described above, the polvolefin containing a component having a molecular weight of at least t~. 14~~,, niore desirably an ultra high molecular weight polyolefin containinb at least 5% by weight percent of a component having a molecular weight of at least 1 x 106, especially ultra hibh molecular weight polyethylene describeci previously, or a mixture of the ultra high molecular weight polyethylene anci high density polyethylene, is especially desirable as a solution for forminQ rnicroporous niembranes.
It is possible to add various additives, as tieeded, such as nucleation agent, anti-oxidant, ultra-violet ray absorbin; aoent, anti-blockin; aoent, pigment, dye, inorganic filler, anti-bacterial agent, deodorant, far-infrared radiation irradiation agent and the like.
[2] Liquid The liquid to be added to the polyolefin resin is a low volatile and good solvent for the polvolefin resin, and is for example, low volatile aliphatic or cyclic hydrocarbons such as nonane, decane, decalin, p-xylene, undeeane, dodecane, liquid paraffin and the like, or a fraction of mineral oil having a boiling point corresponding to the above.
As for the mixing ratio of the polyolefin resin and the liquid, the quantity of the liquid is 15 parts by weight to 2000 parts by weiaht, more desirably 20 parts by wei~ht to 1500 parts by wei~ht per 100 parts by wei~ht of the laolyolefin resin.
When the quantity of the liquid goes over 2000 parts by weight, kneading becomes difficult. On the other hand, when the quantity of the liquid is less than 15 parts by weight, the viscosity is hi-h and the quality deteriorates due to shearine, heat at the time of kneading.
131 Continuous kneader The continuous kneader used ior manufacturina the polyolefin solution has a self-cleaninIg action. In the case of the c.ontinZ ious kneader with the self-cleaning action, through aaroove section of 1_ screw, a thread ridqe o:r another screw or a protrudin~ section or the like of a cylinder passes, so that the mixture does not rotate with the screw, and it is possible to dii-ect the mixture in a direction in accordance with the thread ridge of the screw or a combination angle of a kneading disk. Therefore, in the case that there is a self-cleaning action, it is possible to keep a liquid feed section and a section in which the kneadin~ of the polvolefin resin and the iiquid is initially carried out in a starving state.
The self-cleaninlc, action of the kneader does not have to be effective in all sections of the kneader, but it is sufficient that the self-cleanino, action is effective in at least a section of the kneader in which the mixture described above exists, so that a liauid feed section and the section in which the kneadirrc, of the polyolefin resin and the liquid is initially carried out, are kept in the starved state.
In addition, the self-cleanin- action in the kneader cloes not have to be effective in all section of the kneader, but it is enouah that ttie self-cleanin- action is effective in at least one section of the sections in which the mixture described above exists, so that the pressure in the licluid feed section is tOko/cm2or below.
A twin-screw kneader or special single screw kneader is preferred as this type of continuous kneader described above. Specific examples of such kneader includes a co-rotating twin screw mixer (extruder), a counter-rotating twin screw mixter (extruder), or a special single-screw kneader such as a Bosco kneader and the like. The co-ratating twin-screw mixer is especially preferred.
On the other ha.nd, in the case of a kneader without a self-cleaninc, action, even if a thread rid;e of the screw is in the direction of feedin~, the coefficient of friction between a cylinder and the mixture of the polyolefin resin and the liquid in which the kneading has not been made sufficient, is extremely low, and the mixture described above only rotates with the screw, ~ind it tioes not have the capacity to feed the mixture toward the lower strearn. Therefore, in the case of a Icneader without self-cleaning action, it is not possible to keep the liquid feed section and the section in which the polyolefin resin and the liquid are initially kneaded in a starvina state. In addition, in order to move downstream the mixture rotating with this screw, an upstream pressure has to be increased. For that reason, the pressure is high in the case of the kneader without self-cleaning action.
At least one liquid feed section is placed. at a polyolefin resin feed sectiori or downstream thereof. The liquid is supplied en route to the kneader in which the polyolefin resin exists, and the solution of thc polyolefin resin of a uniform concentration is prepared by kneading.
[4] Kneading conditions (1) Conditions inside the kneader The nianufacturing method of a polyolefin solution according to the present invention, includes a case that a polyolefin i-esin and a liquid are supplied from the sanie feed section, and a case that the liquid feed section is placed downstream of the feed section of the polyolefin resin_ It is necessary to k-eep an internal section of the kneader at each feed section in a starvin(y state. In addition, it is necessary to keep the internal section of the kneader at a kneading section of an initial liquid and the polyolefin resin in a starving state. The starving state of the internal section of the kneader here means that there exists an air space between the cylinder and the screw where the polyolefin resiri or the mixture of' the liquid with the polyolefin resin does not exist. When such a starving state is realized, the pressure toward the direction of the screw length becomes 0.
In the manner described above, by making the pressure 0, it is possible to transport the mixture of the polyolefin resin and the liquid which has not been yet well kneaded toward the lower stream, without creating a backflow of the liquid even though there is a section where the polyolefin resin is not filled sufficientl_y upstrean-i of the liquid feed section. The fact that ttiere is no section being filled with only the polyolefin resin, means that the deterioration of the polyolefin resin does not take place due to the sheai-ing heat, even though the polyolefin resin with high viscosity is used.
In addition, in the case that the liquid feed section is placed at the polyolefin resin feed section and downstream thereof, it is preferred in the case that an extremely large quantity of the liquid is supplied, to keep at least one internal section of the kneader is filled with the polyole.fin resin, between the polyolefin resin feed section and the liquid feed section located most upstream. As described above, in the case that there is a section filled upstream, it is possible to reduce a 5 pressure in the section filled with only a polyolefin resin, and it is possible to prevent deterioration due to the heat at the section of the polyolefin resin alone.
This means that upstream from the liquid feed section located the most upstream in a starving state, a section is created of a greater pressure than the internal pressure at the said liquid feed section. A back flow toward upstream can 10 be prevented, by creating the pressure distribution in the manner described above, even when the quantity of the liquid is increased. As a result, an increase in yield can be achieved.
In addition, when two or more liquid feed sections are to be placed downstream of the polyolefin resin feed section, it is preferred for the same reason to set the internal pressure of at least one internal section of the kneader between the most upstream liquid feed section and the next downstream liquid feed section, at a higher value than the internal pressure of the liquid feed section of the kneader located most upstream. Furthermore, it is preferred to keep the internal pressure of at least one section of the kneader between the liquid feed section most upstream and the liquid feed section located next downstream, larger than the internal pressure in the kneader located in the consecutive two liquid feed sections immediately downstream of the polyolefin resin feed section. Doing so is advantageous since the quantity of supplied liquid and the yield can be increased.
The pressure distribution described above can be obtained by changing the shape of the screw of the kneader, the liquid feed location, operation conditions such as screw rotation number and the like.
(2) Internal pressure distribution in the kneader The method of manufacturing a polyolefin solution according to the present invention can be characterized by that a specific pressure distribution is maintained in the kneader. The pressure in the kneader here is an average value of the pressure in the internal section of the kneader over a coaistant time interval, and this constant time is a sufficiently long tinle to averaoe out the changes in pressure attributable a rotation of the screw of the kneader.
To achieve the desired pr-essure distribution, at least one section of the kneader located between the polyolefin resin feed section and the most upstream liquid feed, is kept at a liigher pressure than the pressure of the nlost upstream liquid feed. In other words, a section having g:reater pressure than the internal pressure of the liquid feed section is maintained upstream of the rnost upstream liquid feed. By establishiiig the pressure distribution in the manrrer described above, it is possible to prevent a backflow toward the upstreAun side of the kneader, even though the quantity of the added liquid is increased, and as a result, the yield can be increased.
In addition, when two or more liquid feed sections are to be placed, for the same reason, it is desirable to set the pressure in at least one section in the kneader between each of the liquid feed section and the feed section located immediately downstream, larger than the inner pressure of the iiqUid feed section located irnmediately downstream. Furthermore, it is clesirable to set the pressure in at least one section in the kneader between each of the liquid feed section and the feed section located immediately downstream, larger than the inner pressure of the two liquid feed sections described above. By doing so is an advantage that the liquid feed quantity and the yield can be increased.
In addition, it is desirable that the pressLu-e in the kneader at the liquid feed section located most upstream is set less than 10 kg/cm2 (gauge pressure).
Upstream of the most upstream liquid feed section, in order to provide-shearing to the section of the polyolefin resin along with high viscosity, the section filled with only the polyolefin is reduced to the minimum, by setting the pressure in the kneader within the range described above, and as a result, the shearing heat is controlled and the deterioration due to the heat can be prevented.
The pressure distribution described above can be obtained by changing the sbape of the screw of the kneader and the like.
(3)Kneading temperature It is desirable that the kneading temperature be set from the melting point of the polyolefin to 250 C, preferably from the melting point of the polyolefin + 10 C-to 220 C. If the kneading temperature is less than the melting point of a polyolefin-, sufficient kneading cannot be carried out, and if the kneading temperature is higher than 250 C, the deterioration of a polyolefin resin takes place.
Effects In the present invention, it is possible to make the pressure at the liquid feed section zero, by creating a starving state in the internal section of the Imeader at the polyolefin -resin feed section and the liquid feed section and the initial kneading section. As a result, it is possible to obtain a uniform polyolefin solution with a high yield, without creating the back flow of the liquid, even though there is no section filled with only the polyolefin resin upstream of the liquid feed section.
In addition, when there is a section filled with the polyolefin resin upstream of the most upstream liquid feed section, it is possible to reduce the pressure, and the deterioration due to the heat can be prevented at the section filled with the polyolefin resin alone, and at the same time, a large quantity of the liquid can be supplied.
In the present invention, it is possible to obtain a uniform polyolefin~
solution with a high yield, by creatitig a specific distribution of the internal pressure in the kneader.
Exa es The present invention will be described further in detail by way of the following Examples however, the present invention is not lirnited to the Examples.
Examples 1 through 16 Each of the polyolefin resins and the liquids, were kneaded in the mixing ratios, shown in Table 1, using a co-rotating twin screw rnixer(extruder), TEX-54, (manufactured by The Japan Steel Works, f,td. and the screw diameter = 58 mm, L/D ratio = 42). In addition, the screw shape of the extruder was selected so that a preferred pressure distribution could be obtained. F'ressure tr.eters were placed at 141ocations in the internal section of the krieader. p'i ;ure I through Figure 5 show the locations of the pressure meters in the internal section of the extruder and the liquid feed positions, and the relation of each Example and the Figures are shown in Table 1. However, the distance from the pressure meter i to left end of the extruder 20 was 236 mm, and the distance between each adjacent pressure meter was 94.5 mm. The die attached to the extruder, contains a slit having a thickness of 3 mm, and a width of 104 mm. Table I shows the hotyolefin resin and the liquid being used, and the quantity of supplied liquid for the polyolefin resin 100 parts by weight. In addition, the quantity (shown with parts by weight for the polyolefin of 100 parts by weight) of the liquid suppiied from each of' the liquid feed holes and the pressure in the internal section of the extruder and operation conditions are shown in Table 2. However, the pressut-e value shown in T able 2 was the value (kg/cm2, gage pressure) if the atmospheric pressure was set as zero. As shown in 'I'able 1, an extruder of a different structural type was used for each Example.
In addition, after the measurement of the nressure in the extruder, the pressure meters of the polyolefin feed section or the liquid feed section located most upstream and the pressure meter located at the place immediately downstream were removed, and several grains of the polyolefin resin (PE) pellet were dropped into the holes where the pressure rxietei-s had been rernoved. T'he PE pellets went into the internal section of the extruder irnmediately. Therefore, it was clear that the polyolefin feed section, the liquid feed section beinc, located most unstream and the location of the pressure meter located at the irnmediately downstream were in a starved state. In addition, the screw located in the space between the polyolefin feed section and the location of the first pressure meter locate.d at the immediate downstream, or in the space between the liqriid feed sectior- located most upstream and the location of the pressure meter located immediately downstream, was the kneading section to carry out the kneading of the polyolefin resin and the liquid. In addition, Examples 6 through 16 show that the pressure value (kg/cm2, gage pressure) at the location of the pressure meter located immediately upstream of the liquid feed section located most upstream, was over zero, so that the internal section of the extruder was in the filled state. The polyolefin solution, obtained in the above manner, was formed into a sheet of 2 rlim in thickness usitlg the press forrning die.
The sheet being obtained looked superior in its appearance. In addition, the sheet was drawn with a simultaneous two-axis, using a bLitch type rolling mill, and it became clear that it was possible to draw in the scale of more than 2 x 2 for all.
Comparative Examples 1 through 6 Each of the polyolefin resins and the liquids, shown in Table 1, were kneaded, using the co-rotating twin screw mixer (extruder), TEX-54, the same as that of Example 1. In addition, the screw shape of the extruder was selected so that the preferred pressure distribution could be obtained. The pressure meters were placed in the same manner with those of Example i.'T'lle location of the pressure meter and the location of the Iiquid feed section are shown in FFiQure 1, Figure 3, Figure 4, and Fi~ure 6, and the relation of each Cotnparative Exampie and the Figures are shown in Table 1.
Table 2 shows the internal pressure of the extruder and the operation conditions. As shown in Table 2, as for the Cornpa.rative Examples, the value of the pressure was over zero at the location of the imtnediately downstream of the polyolefin resin feed section, or the liquid feed section located rnost upstream, and at the location of the pressure meter irnrnediately downstream, it shows that the internal of the extruder was in the filled state, and it was not in a starvinc, state.
However, the pressure value shown in Table 2, was the value when the atmospheric pressure was zero (kglcm2, ga,e pressure). ~l,he operation conditions shown in Table 2 were the conditions when the stable production could be seen and when the maximum yield was realized.
In Comparative Example I throuoh Comparative Example 4, vvhen the yield was increased, the following phenomena were observed: its variation became big and the liquid not being kneaded jets out interniittently.
In addition, the polyolefin solution in Cornparative Example 5 and Comparative Example 6 was formed into a sheet of 2 ml-rl in thickness, using a press forminc, die. The color of the sheet was chanQed to yellow.
5ubsequently, this sheet was drawn with a simultaneous two-axis, using a batch type rolling mill, however, it was torri in all experimental coriditions.
Table 1 Quantity of Supplied No. Polyolefin Resin Liquid Liquid "I Types of the Extruder Examples 1 P E - 1 'Z' Liquid Parafin '8' 3 0 Figure 1 2 P E - 23' ii 3 0 Figure 1 3 P E - 1 ii 5 0 0 Figure 2 4 P E - 2 ii 5 0 0 Figure 2 PE-2 ~i 500 Figure 2 6 P E - 1 ~i 1 5 0 Figure 3 7 P E - 2 ~i 1 5 0 Figure 3 8 P E - 1 ri 5 0 0 Figure 4 9 PE-2 ii 500 Figure 4 PE-1 1 200 Figure 5 11 PE-2 ii 1 2 0 0 Figure 5 12 P E 31 4i n 5 0 0 Figure 5 = 13 P E - 4'5 ii 5 0 0 Figure 5 14 P E - 5"' ~i 5 0 0 Figure 4 p P ") ii 3 0 0 Figure 3 16 p p ir 1 2 0 0 Figure 4 co Comparative 00 Examples 00 i P E - 1 3 0 Figure 1 2 PE-2 i~ 3 0 Figure 1 3 PE-1 ii 1 50 Figure 6 4 PE-2 ii 1 5 0 Figure 6 5 PE-2 >i 500 Figure :l 6 P P 3 0 0 Figure 3 Note: (1) Quantity of supplied liquid:Parts by weight nf the liquid for the 100 parts by weight of the polyolefin resin (Z)PE-l:Weight average molecular weight 3.7X10' powder-form polyethylene(PE) (3)PE-2:Weight average molecular weight 2.OX106 powder-form polyethylene(PE)and Weight average molecular weight 3.7X10' powder-form polyethylene(PE)were blended using 3:14 ratio.(Component of the molecular weight of 1X10' and over according to the GPC method, 21.6% bv weight percent) (4)PE-3:Weight average molecular weight 3.7X105 pellet-form PE.
(5)PE 4:Weight average molecular weight 2.0X10' powder-form polyethylene(PE)and Weight average molecular weight 3.7X105 pellet-form polyethylene(PE),are blended using 3:14 ratio.(Component of the molecular weight of 1X10' and over according to the GPC method,21.6% by weight) (6)PE-5:Weight average molecular weight 2X106 powder-form polyethylene (7)PP:Weight average molecular weight 3.9X10' pellet-form polypropylene,to which sorbitol-based nucleation agent was added by lpart by weight.
(8)Liquid paraffin:Kinematic viscosity at 40'C is 64 cSt.
Table 2 Feed Quantity of the Liquid, Internal Pressure in the Extruder, and the Operation Conditions Position on the Extruder Cylinder Screw Rotation ! -r- Yield Polyolefin Tenm. Number Resin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Feed Hole 'C rpm kg/h Example Liquid Feed Quantity 30 - - - - - - - - - - - - - 150 100 80 1 Pressure in the Internal of the Extruder - 0.0 0.0 0. 0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ~ 200 Ex2~lG PrLiquid essuree~ Quantity of the Extruder - 0.0 0. 0 0. 0 0.0 0.0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -200 j----- -~ -~- -~ ------ -Example Liquid Feed Quantity _ 80 - - 180 - 240 - - - - - - - r 150 350 90 3 Pressure in the Internal of the Extruder 0. 0 0. 0 0. 0 0. 0 0,0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 ~ 200 Example Liquid Feed Quantity - 50 -;- 180 - 1 270 - -- - - - 150 350 100 = 4 Pressure in the Internal of the Extruder - ( 0.0 0. 0 1 2. 6 1.4 1.0 8.9 7.8 7.8 6. 0 5.1 4.0 2.1 0.2 0.0 ~-200 Example Liquid Feed Quantity - 80 - - 180 - - 240 - - - - - - -' 150 350 60 Fressure in the Internal of the Extruder - 0.0 0. 0 0.0 0.0 0.0 j 0. 0 0 ~ 0 0.0 0.0 0. 0 0. 0 0.0 0. 0 0.0 -200 Example Liquid Feed Quantity ~~-- - -! 150 - - ji--~j -- - - - 150 200 200 rv 6 Pressure in the Internal ef the Extruder 0. 0 Z. 1 0. 0 0. 0 U 0 l 0.0 0.0 0. U u. U 0. 0 1 0. 0 0. 0 0. 0 -200 00 Fxample Liquid Feed Quantity - - - 150 - - - - - - - - -- - 150 200 100 7 Pressure in the Internal of the Extruder - 0. 0 i. 4 0, 0 0. 0 O. 0 0, 0 0, 0 0. 0 0- 0 0. 0 0. 0 0, D 0. 0 ~200 0.0 t---- ;------ _ Examrle Liquid Feed Quantity - - -; 130 370 350 200 8 Pressure in the Internal of the Extruder 0.0 .9 0. 0; 0 0 0 0i0. i i~' 9. 6 8.6 4 a% o. 1 -200 3. 6 0.8 -~
~---~-Example Liquid Feed Quantity - - - 130 T- -! 370 - - - -!- ~- I - 15~ 350 100 o 9 Pressure in the Internal of the Extruder 0.9 0 0 0.0 11.2 10.2 9.8 9 5 8.2 7.4 6. 0 4.6 3. 6 1.8 ~-200 -- - - - - --- -- - -~
780 i- - - - 150 6po 200 N
4-~-p iluantity 140 - -'-- 280 , Pressure in the Internal of the Extruder 0.0 0.0 0,0 0.0 2.2 0.9 0.7 20.1 ~arrt~le iquid r 1! 15.315.0 14.211~.48.0 3.i 200 (.
, - -Example Liquid Feed Quantity - - 140 - - 280 780 - - - - 150 600 100 11 Pressure in the Internal of the Extruder - 0. 0 0.4 U. 0 0. 0 2 . 4 l . 1 U. 8 1 1 . 5 10.2 10. 0 8.9 3. 0 0. 200 ---~-------- ~--~--- - 100 Liquid Feed Quantity - - 200 - - 200 - - - - 'rJ 150 l~n ~ample ~ 1J f J~
12 Pressure in the Internal of the Extruder - 0.0 2 . 6 6.0 0.0 5. 3 2. 6 0.7 15- 3 10.2 10.0 9.5 8. 1 4.9 2.9 200 Fxarttple Liquid Feed Quantity - - 80 -- 180 - - 240 - - 150 13 Pressure in the Internal of the Extruder - 0. 0 1.4 0. 0 0. 0 2. 6 1. 8 0.7 5. 5 4.4 4. 3 4. 2 4. 0 3.6 2.9 200 ( 80 Fatample Liquid Feed Quantity _ - - 130 - - 370 - - - - - - - - 150 250 50 14 Pressure in the Internal of the Extruder 0.0 0.2 0.0 0.0 1. 1 0. 5 0. 3 0.2 0.1 0.0 0.0 0.0 0.0 0.0 ~-200 Example Liquid Feed Quantity - - - 300 - - - - - - - - - 150 150 200 Pressure in the Internal of the Extruder - 0. 0 1.4 0.0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0,0 14.0 13.6 12.9 ~-200 Example Liquid Feed Quantity - - - 230 - - !970 - - - - - - - - 150 600 200 6 Pressure in the Internal of the Extruder - 0.0 1.0 0.0 0.0 3.9 2. 3 2. 1 1.2 0.8 1. 3 9.8 5.6 4.3 3.1 ~-200 Table 2-2 Feed Quantity of the Liquid, Internal Pressure in the Fxtruder, and the Operation Conditions Position on the Extruder Cylinder Screw Rotation Yield Polyolefin Temp. Nwnber Resin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Feed Hole C rpm kg/h Comparative Liquid Feed Quantity 30 - - - - - - - - - - - - - - 150 100 4 Example 1 Pressure in the Internal of the Extruder - 6.8 6. 3 5. 3 4.9 3.3 2.5 0. 6 0.0 0.0 0.0 0.0 0.0 0.0 0. 0 -~200 Comparative Liquid Feed Quantity 30 - - - - - - - - - - - - - - 150 100 2 Example 2 Pressure in the Internal of the Fxtruder - 1.1 4. 5 8. 6 4.8 2.9 1.4 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0. 0 -200 Comparative Liquid Feed Quantit - 30 - - 0 - 45 - - 150 200 10 Exarnple 3 Pressure in the Internal of the Ext-ruder - 0.0 0.4 4.3 5.6 1.1 3 18. 10.6 6 1 167 17.5 1.5 0.7 34.3 29.7 ~-200 Gcmpa~at.ivz Liquid Feed Quantit.y 30 35 40~ 45 150 200 8 Ex.atr~ple 4 Pressure in the Internal of the Extruder 0. 0 1 0.0 2.4 4.1 0. 0 10. 3 15. 2 0. 4 13.2 14.1 0.2 2,.). 5 30.1 25.1 200 -----Comparative Liquid Feed Quantity - - - 130 - - 370 - - - - - - - - 150 350 100 Example 5 Pressure in the Internal of the Ext.ruder i.! II 11. 2 8. 5 40.6 31.2 30.1 25. 3 23. 5 20.1 16.7 13.1 10.1 6.7 ~-200 = -- r - ----- - I -Comparative L.tquid Feed Quantity 300 - - - - - - - - I - - - 150 150 200 N
Example 6 Pressure in the Internal of the Extruder - ) 6. 5 32.5 12.5 11. 3 9.9 8 5 1 7.3 b. 0 4.1 2.3 0. 8 j 5. 2 15.3 10. 3 -200 00 rn Examples 17 through 33 Each of the polyolefin resins and the 11quids, shown in "' able 3, were kneaded, usin; the co-rotatinb twin screw niixer(extruder),TEX-54, (manufactured by 'The Japan Steel Works Ltd., anci the screzx., diameter = 58 mm, L/D ratio = 42).
In addition, the screw shape of the extruder was selected so that a preferred pressure distribution could be obtained. The pressure ineters were placed at locations of the internal section of the kneader. 1-'ioure 7 through Figure 10 show the locations of the pressure meters in the internal section of the extruder and the liquid feed positions, and the relation of each Exatnple and the F'iQures are shown in Table 4 and 6. However, the distance frotn the pressure meter 1 to left end of the extruder 20 was 142 mm, and the distance between each pressure meter adjoining was 94.5 mm.
Table 4 and Table 6 show the operation conditions, and Table 5 and Table 7 show the pressure distribution being measured. However, the pressure values shown in Table 5 and Table 7 were the value (gauge pressure) at the time when the atmospheric pressure was set as zero. 1'he oDeration conditions shown in 'hable 4 and Table 6 were the conditions at the tirne of maximum yield when a stable yield was seen.
The polyolefin solution obtained in the above manner, is formed into a sheet of 2 mm in thickness using a p1-ess forming die. The sheet obtained looked superior in its appearance. In addition, the sheet was dt-awn irt simultaneous two-axis, using a batch type rolling mill, and it was clear that it was possible to draw in the scale of more than 2 x 2 for all.
Comparative Example 7 through Comparative Example 12 Each of the polyolefin resins and the liquids, shown in Table 3, were kneaded, usina co-rotating twin screw mixer (extruder), TEX--54, the same with Example 17. In addition, the screw shape of the extruder was selected so that a preferred pressure distribution could be obtained. The pressure meters were placed in the same manner with that of Example 17. "i,he locations of the pressure meters and the locations of the liquid feed sections are shown in Fioure 7 through Figure 10, and the relation of each Comparative, Example and the Figures are shown in Table 4 and Table 6.
Table 4 and Table 6 show the operation conditions, and Table 5 and Table 7 show the pressure distribution being rneastired. However, the operation conditions were the conditions at the time of maximum yield when the stable yield was observed.
In Comparative Examples 7, 8, 10 and 1 i, when the yield was increased, the following phenomena were observed: its variation becomes big and the liquid not being kneaded jetted out interrnittently.
in addition, the polyolefin solutions in the Comparative Example 9 and the Comparative Example 12 were formed i.nto a sheet of 2 mm in thickness, usin~
a press forming die, and these sheets were drawn in simultaneous two-axis, rising the batch type rolling mill, however, these sheets were torn in all experimental conditions.
Table 3 Quantity of Supplied No. Polyolefin Resin Liquid Liguid'1' Examples 17 P E- 1'2 ' Liquid Parafin'$' 5 0 0 18 PE-l 500 20 PE-1 ~i 1 50 2 3 P E- 3'A' 5 0 0 24 PP "' 300 32 PE-4 cs ,~ 5 0 0 Comparative Examples 8 PE-1 i~ 150 = 9 PP '1 50 lI P E 2 " 1 5 0 12 PE-2 ~i 500 Note :(I)through(8) are the same as those of the Table 1.
Table 4 Feed Quantity of Liquid"" and the Operation Conditions of the Kneader ---Position on the Kneader 121 Cylinder Screw Rotation Yield Temp. Number C rpm kg/h _ __--------_- ---- -- - -Example 17 - - 220 - - J 140 - - J 140 - - J- J- - 150 ~-200 200 80 Example 18 - - 160 - - 170 - - 170 - - - - - 150 ~-200 350 100 I Example 19 - - 30 - ~ - - - - - - - - - - 1150 ~-200 100 100 ---- , Example 20 - - 150 150 ~-200 - - { - _ _-~ '~0 370 _ - - - - - - 150 ~-200 350 200 Example ..l - - 1 õ , - ---- - -- - !
Example 22 - - 140 ,- -~ 280 -;- 780 - - - - - 150 ~~200 600 200 { ao _- ! ~
Example 23 - - 60~ - - 130 -~- 310 - I-~-- J- - 150 ~-200 350 160 0, 300 150 ~-200 150 200 D
Exam le 24 P
- -i--'------- N
--~ - T , , rt Example 25 J - 230 - ! - 970 ! - - - ~ - - - ! - - 15 0 0 ~-20 600 200 - -- - _ __ __ -- ---_ - _ ~- - '-- j Comparative Example 7 - - 30 150 -200 100 - , , Comparative Example 8 30 40 ~- - 45 150 -200 200 10 ~ 200 Comparative Exampie 3 ~0 JJI 4r, 4,i 150 ~00 i3 ----- _ -_ -- -----'------ - ----- ~-_ Note:
(1) Feed quantity of liquid: Parts by weight of the liquid for the polyolefin resin 100 parts by weight.
(2) Position in the Kneader: The numericals 1 through 14 indicate the location positions of pressure meters shown in Figure 7 through Figure 10.
Table 5 Internal Pressure in the Kneader (kg/cm2) Position on the Kneader "' Example 17 0. 0 15. 2 10. 1 8. 6 2. 1 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Example 18 0. 0 5. 1 0. 0 0.0 0. 0-~~ 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Example 19 0.0 19.315.311.2 6 7.2 4.0 1.8 0.0 0.0 0.0 0.0 0.0 0.0 Example 20 0.0 10.9 8.6 8.4 8.2 8.0 7.51 6.7 5.2 3.9 2.41 0.8 0.0~ 0.0 Example 21 0.0 9. 1 4.8 2.2 20.1 15.4 15.0 14.2 13.5 12.1 11. 1 9.8 8.4 7.2 Example22 0.0 0.8 0.0 0.0 9.5 5.3 4.211 25.218.318.017.617.1 16.6 15.9 ao Example 23 0. 0 10. 3 6.3 2.425.61 20.3I 5.626.519.6 18.517.316.4115.012.4 --- _ 4 -j -i- _ 5.9 --~ 5. 5, 5.0 4.6 4.0 3.2 1.6 0. 2 D
Example 24 G. G 9. 4 6.8 6.8 6. 5 6. 3 - -~~ o Example2) 0.Or 3 1. 1 0.0113.39.3i 9.3 9.3; 9.2~ 9.29.0~ 7.8 6.8;
0.0 ~ 0.0 0.0 0.0 0.0 0.0 0.0 Comparative Example 7 0. 0 2. 5 8 21 11. 1 7 . 2 4 2 0 9 _ ~~~omparati~,e ExamPlP n U. U 0. 4 4, i h, h 1 . 1 17 i lts. 1 U.h 1 6 . 7 17.5 1 . ~ 30.7 34, s 1 29. 71 --a- --I-Comparative Example 9 0. 0 0. 0 3 . 1 4_ 3 3 10. 5 1 2 . 2 3. 1 2 . 3 14. ? G
~ ! 25. 3 28. ! 24. 3 Note:
(1) Position in the kneader: The nLmericals 1 throug.h 14 indicate location positions of press.:re meters shown in Figure 7 through Figure 10.
Table 6 Feed Quantity of Liquidand the Operation Conditions of the Kneader Position on the Kneader Cylinder Screw Rotation - - -- ---Temp. Number Yield 1 2 3 4 5 6 7 8 9 10 11 12 13 14 rpm kglh -- - - - --- - -Example 26 - - 220 - ! - 140I - - 140 - - - ! - - 150 ~-200 200 50 ; -_- _-- - f - ---__ i ~----- -----~ - -- ----- - -- -LExample 27 - - 160 - - 170 - - 170 - - - -~- 150 ~-200 350 70 70 Example 28 30 15 ~- - - - - -~- - 0 ~-200 100 Example 29 150 - + - - - - 150 ~-200 200 100 ~--- - - -- -------~- i ~--r-~ 17 -1---~---~ --- 350 Example 30 -!- 130 - - 0 - - - - - - - - 150 -200 35u 100 -------------- - - +--- { - - , _ ' Example 31 2 - ~ 140 - T fiQ~ r80 T- 150 - 20G 600 100 oo , - -- - - - ---- , -T--- ~
Example 32 - - 60 -~-~ 130 (- - 310 -~- - - - 150 -200 350 80 _---- -- - ~--~ 00 _ -' o - j- 150 ~ 200 250 50 o --- -- _ - _ ~
1 _ ------- -- ---Go parative Example 101 - - 1~~ -~ - ~70 - -~- - - - - -;150 -200 100 3 N
--- - -_i - - - _ = 1--- - { o -- ---- ---! ---! ---, _ ~ _ ---' - -i ~----- -- .-.-----' Ip Comparative Example 11 ! - 30 30 40 50 - 1 150 -200 200 8 -- -- -rt- ?
Comparative Example 121 - 130 - 1 370 150 -200 350 100 - -- -~ - ! - - ~ -~
Note:
(1) Feed quantity of liquid: Parts by weight of the liquid for the polyolefin resin 100 parts by weight.
(2) Position in the Kneader: The numericals 1 through 14 indicate the location positions of pressure meters shown in Figure 7 through Figure 10.
Table 7 Internal Pressure in the Kneader (kglcm2) Position on the Kneader --- - - - -Example 26 0.0 2.8 2.0 0.8 0. 0 0. 0 0.0 0 0 0.0 0.0 0.0 0.0 0.0 0.0 ---_ - -_._ __---- ---- -- _--~ { -i Example 27 0. 0 1.4 0.0 0.0 0.0 0.0 0.0 0.0 2. 0.0 0.0 L ~0.0 0.0 0.0 0 - .0~~
__ T - -----~ - ~-_ Example28 0.0 I 9 2.4i u.0 0.0i 0.0 0.01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ___ _ --- ~_----- - _~_--- __ -- - , , Example 29 0. 0 1 . 5 0. 5 0. 0 0. 0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 - --~
~ Example 30 0.0 l . 3 0.4 0.0 1 1 : 2 10 1 9. 8 1 11.4 9. : i 8. 1 ~: 3 5.9 ~. 3.44 _~
Lxample3l 0. 0 0. 4 0 0 u.~0 5 iL; ~.~10.1 9 8.6 0.93.1 ~.3 00 Example32 0.0I 1.3i 0.2 0.01 2.5 1.81 0.7 5.5 4.5 4.4 4.3 4.1 3.6 3.0 Example 33 0.0 0.3 0.0 0.0 1.3 0.61 0.51 0.3 0Ø0 0.0 0.01 0.0 O.Oi Comparative Example 10 0. 0 2.3 !. 5 i 10. 5 5. 7 1 2. 2' 0 c ~ " - - ~;--' ~,-~ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 o Comparat~:eExample~l, 0.0; 0.01 ~..4 4.11 0.01Q V ~15.2 0.4 13.2 14.11 0.2~22.530.11 25.1~
Comparative Example 1 2 1. 7 1 15. 2 11,2 8. 5 40. 6 31. 2 30.1 25.3 23.5 1 20. 1 I 16. 7 13.1 10.1 1 6.7 rote :
(1) Position in the kneader: The numericals 1 through 14 indicate location positions of pressure meters shown in Figure 7 through Figure 10.
Applicability in Industry-As described in detail above, with a riiethod accordiria to the present invention, by creating a straving state in an inter-nai section of the kneader at a polyolefin resin feed section and a licluid feed section, and an initial lcneadinc, section, it is possible to obtain a uniform polyolefin solution with a high yield, without creatinb a backflow of the liyuid. The polyolefin solution obtained by a method according to the present invention in the rnanner described above, can be used for manufacturing various types of polyolefin fornied objects.
In addition, a rnanufacturinb method acc.orclin- to the present invention can prevent a backflow of a liquid, and catl contirruously obtain a high yield of a uniform polyolefin solution, by means of a specific distribution of a pressure in the kneader. The polyolefin solution obtained by .: rnethod according to the present invention in the nianner described above, can be used for manufacturing various types of polyolefin formed objects, and is especially suitable for forming microporous mernbranes.
Claims (12)
1. A method of manufacturing a solution of a polyolefin resin having a melting point in a solvent liquid, comprising the steps of:
providing a continuous kneader having a self-cleaning action, and having a plurality of internal sections including a polyolefin resin feed section, at least one solvent liquid feed section, and a section in which kneading of the polyolefin resin and the liquid is initially performed;
kneading the polyolefin resin with the solvent liquid using the kneader at a temperature in the range between the melting point of the polyolefin resin and 250°C;
and maintaining the polyolefin resin feed section, the solvent liquid feed section and the section in which kneading of the polyolefin resin and the solvent liquid is initially performed, in a starved condition.
providing a continuous kneader having a self-cleaning action, and having a plurality of internal sections including a polyolefin resin feed section, at least one solvent liquid feed section, and a section in which kneading of the polyolefin resin and the liquid is initially performed;
kneading the polyolefin resin with the solvent liquid using the kneader at a temperature in the range between the melting point of the polyolefin resin and 250°C;
and maintaining the polyolefin resin feed section, the solvent liquid feed section and the section in which kneading of the polyolefin resin and the solvent liquid is initially performed, in a starved condition.
2. The method according to claim 1, wherein:
(1) the polyolefin resin feed section is disposed and at least one liquid feed section is disposed downstream of the polyolefin resin feed section, and (2) the internal sections of the kneader at the polyolefin resin feed section and the liquid feed section located most upstream are maintained in the starved condition, and at the same time, the internal sections of the kneader in which the kneading of the solvent liquid supplied from the liquid feed section and the polyolefin resin is carried out initially is kept in the starved condition.
(1) the polyolefin resin feed section is disposed and at least one liquid feed section is disposed downstream of the polyolefin resin feed section, and (2) the internal sections of the kneader at the polyolefin resin feed section and the liquid feed section located most upstream are maintained in the starved condition, and at the same time, the internal sections of the kneader in which the kneading of the solvent liquid supplied from the liquid feed section and the polyolefin resin is carried out initially is kept in the starved condition.
3. The method according to claim 1 or 2, wherein a pressure in at least one internal section of the kneader between the polyolefin resin feed section and the liquid feed section being located most upstream is maintained higher than an internal pressure in the kneader at the liquid feed section located most upstream.
4. The method according to any one of claims 1 to 3, wherein:
(1) at least two liquid feed sections are placed downstream of the polyolefin resin feed section, and (2) a pressure in at least one internal section of the kneader between the liquid feed section located most upstream and the liquid feed section which follows downstream is maintained higher than a pressure in the kneader at the liquid feed section located most upstream.
(1) at least two liquid feed sections are placed downstream of the polyolefin resin feed section, and (2) a pressure in at least one internal section of the kneader between the liquid feed section located most upstream and the liquid feed section which follows downstream is maintained higher than a pressure in the kneader at the liquid feed section located most upstream.
5. The method according to claim 4, wherein a pressure in at least one internal section of the kneader between a liquid feed section located most upstream and the next downstream liquid feed section is maintained higher than a pressure in the kneader located at two liquid feed sections immediately downstream of the polyolefin resin feed section.
6. The method according to any one of claims 1 to 5, wherein the continuous kneader is a co-rotating twin screw mixer.
7. The method according to any one of claims 1 to 6, wherein the polyolefin resin contains more than 5% by weight of a component having a molecular weight of at least 1 × 10 6.
8. The method according to any one of claims 1 to 7, wherein the polyolefin resin is an ultra high molecular weight polyethylene containing more than 5% by weight of a component having a molecular weight of at least 1 × 10 6 or a composition of the ultra high molecular weight polyethylene and high density polyethylene.
9. The method according to any one of claims 1 to 8, wherein the liquid solvent is at least one member selected from the group consisting of an aliphatic hydrocarbon, a cyclic hydrocarbon and a mineral oil.
10. The method according to any one of claims 1 to 8, wherein the liquid solvent is a low volatile good solvent for the polyolefin resin, the solvent being at least one aliphatic or cyclic hydrocarbon selected from the group consisting of nonane, decane, decalin, p-xylene, undecane, dodecane liquid paraffin or a fraction of mineral oil having a boiling point corresponding to that of the aliphatic or cyclic hydrocarbon.
11. The method according to any one of claims 1 to 10, wherein the liquid solvent is used in an amount of 15 parts by weight to 2000 parts by weight per 100 parts by weight of the polyolefin resin.
12. The method according to any one of claims 1 to 11, wherein the polyolefin has a weight average molecular weight/number average molecular weight ratio of 5 to 300.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002552473A CA2552473C (en) | 1995-03-08 | 1996-03-07 | Method of manufacturing polyolefin solutions |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7077230A JPH08245799A (en) | 1995-03-08 | 1995-03-08 | Production of polyolefin solution |
| JP77230/1995 | 1995-03-08 | ||
| PCT/JP1996/000564 WO1996027631A1 (en) | 1995-03-08 | 1996-03-07 | Process for producing polyolefin solution |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002552473A Division CA2552473C (en) | 1995-03-08 | 1996-03-07 | Method of manufacturing polyolefin solutions |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2189868A1 CA2189868A1 (en) | 1996-09-12 |
| CA2189868C true CA2189868C (en) | 2007-04-03 |
Family
ID=37951694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002189868A Expired - Fee Related CA2189868C (en) | 1995-03-08 | 1996-03-07 | Method of manufacturing polyolefin solutions |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2189868C (en) |
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1996
- 1996-03-07 CA CA002189868A patent/CA2189868C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2189868A1 (en) | 1996-09-12 |
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