JP2000273163A - Continuous manufacturing apparatus for polyester composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing apparatus for a polyester compsn. in which minute particles are uniformly dispersed and substantially no coarse particles are included. SOLUTION: This apparatus comprises an addition inlet (5) through which inorg. and/or org. particles having an average diameter of 0.01-2.0 μm are added as a slurry of water and/or an org. compd. medium having a b.p. of not higher than 240 deg.C, one or two screw kneader extrudes with a vent (1) in which a polyester having not less than 70% of the repeating unit being the one selected from polyester groups consisting of ethylene terephthalate, butylene terephthalate, and ethylene naphthalate is kneaded adding the above-mentioned slurry, and a filtration measure (10) attached with a filter (11) through which the polyester compsn. supplied on the downstream side of the kneader extruder with the vent (1) is passed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a polyester composition, and more particularly, it is useful for fibers, films and other molding applications, and contains substantially no coarse particles having a large average particle diameter. Having an average particle size of 0.
The present invention relates to an apparatus for producing a polyester composition containing particles of 0.01 to 2.0 μm in a tightly dispersed state.

[0002]

2. Description of the Related Art Polyesters, especially polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate have been widely used as fibers, films and other molded articles because of their excellent physical and chemical properties. . However, in spite of its excellent characteristics, undesired troubles such as deterioration in workability due to poor workability due to poor slipperiness in handling the molded product itself and reduction in product value occur in the molding process for obtaining the molded product. It is also known to do.

[0003] In order to solve these problems, there have been proposed a number of methods for improving the surface smoothness of a molded article by imparting appropriate irregularities to the surface of the molded article by adding fine particles to polyester. Has been put to practical use. For example, a method of adding inert inorganic particles such as silicon oxide, titanium dioxide, calcium carbonate, talc, kaolinite, etc. to polyester (for example, JP-A-55-133431), or a method of adding silicon particles, polystyrene particles, etc. There is a method of adding heat-resistant polymer particles to polyester (for example, JP-A-3-115354).

However, the method of adding these particles is as follows.
Often, coarse particles are mixed. If such coarse particles are mixed in, for example, a film for a magnetic tape, it may cause a drop in electromagnetic conversion characteristics or cause dropout. Further, in the case of a film requiring transparency, such as for prepress printing or a microfilm, the film quality is impaired, for example, the transparency is significantly reduced. Further, in fiber applications, filter clogging at the time of spinning occurs, which lowers productivity and breaks single yarns, which is not preferable.

Therefore, in order to remove such coarse particles, when particles are added during the polyester synthesis reaction, a method of removing the coarse particles in advance by pulverization, classification, etc., and adding them in the form of a slurry or a solution is known. Proposals have been made (for example, Japanese Patent Publication No. 1-417170,
No. 105059). On the other hand, in the case of kneading and blending with a synthesized polyester, a method has been proposed in which powdery particles are added to a polymer and powdery particles while applying a shearing stress thereto by a single-screw or twin-screw extruder (for example, JP-A-2-34307, JP-B-7-6
No. 2076).

However, in the former case, crushing and classifying operations require a great deal of cost and operation time, and even after these purification operations are sufficiently performed, they are added to the polyester synthesis system or after the addition. At present, it is difficult to prevent the formation of coarse particles in the product polyester because the particles may re-aggregate. Further, if particles are added to a polyester synthetic system for producing a large amount of polyester every time, a large amount of brand switching loss occurs due to washing of the polyester synthetic system every time the brand of the polyester is changed.

In the latter case, even if the reagglomerated coarse particles present in the powdery particles are to be pulverized or crushed in a single-screw or twin-screw extruder, the agglomerated coarse particles are completely regenerated. Decentralization is extremely difficult in practice.

[0008] In order to solve these difficulties, a polyester having an average particle size of 0.01 to 10
A method of adding a slurry of 5 μm water of inorganic particles and / or an organic compound having a boiling point of 240 ° C. or lower (Japanese Patent Laid-Open No.
No. 15352) or a wet-type or dry-type classification treatment and / or a wet-type pulverization treatment to remove substantially 3 μm or more of particles. The titanium oxide having an average particle diameter of 0.1 to 0.5 μm and the polyester are co-rotated. (Japanese Patent Laid-Open Publication No. 1-173031) has been proposed. However, in these conventional methods, all of them give an extremely large shearing force in the extruder to achieve uniform dispersion, and if too much shearing stress is applied to uniformly redisperse the reagglomerated coarse particles. ,
There is a problem that the intrinsic viscosity of the polyester is remarkably reduced and the moldability or the quality of the product is deteriorated.

Heretofore, as far as the inventor knows, as a means for removing reagglomerated coarse particles from the product after passing through the extruder, the polyester composition exiting the kneading extruder is subsequently subjected to a filtration step. Is being done. However, in this method, the filtration device is almost clogged, and the pressure rise is remarkable. Therefore, the filter medium must be replaced in a very short period of time, and there are problems such as the cost of the filter medium, debris generated at the time of switching, and a large amount of labor required for the switching operation.

In general, as a technique for improving the filtration life, for example, a filter material having an extremely large filtration area such as a leaf shape (so-called “leaf filter”) or a candle shape (so-called “candle filter”) is used.
Techniques for removing foreign substances contained in polymers are commonly used. In such prior art, the reason why a filter medium having an extremely large filtration area is used is that, even if a large amount of polymer to be filtered is used, it is possible to use the filter over a long period of time, so that the frequency of replacing the filter medium can be complicated. Since it can be reduced as much as possible, maintenance and inspection of the filtration device can be facilitated, and production costs can be reduced. In addition, such prior art places an emphasis on removing and removing foreign matter, above all.

Here, in the above-mentioned conventional filtering apparatus, the filtering life of the filtering medium is determined based on the increase of the filtering pressure or the expiration of the expiration date, and the filtering medium is continuously replaced without stopping the production line. Generally, a plurality of filtration lines are provided in parallel. In this case, by stopping only the filtration line to be replaced without stopping other filtration lines, there is an advantage that the filtration operation can be continuously performed without stopping the production line. Because, in order to be able to replace the filter media without stopping the production line, the above-mentioned conventional filter device requires a complicated filter media mounting structure and a seal structure to prevent polymer leakage. This is because the filter medium cannot be replaced, and a plurality of parallel filtration lines are necessarily required.

However, such a conventional filtration system has the above-mentioned advantages, but also has disadvantages. That is, in such a conventional technique, since a filter medium having an extremely large filtration area is used, the speed of the polymer passing through the filter medium is also extremely low. In addition, during such a filtration operation, the polymer must be heated to a predetermined temperature so as not to solidify. For this reason, in the conventional filtration device, there is a problem that the polymer stays in the filtration device for a long time, and furthermore, the polymer is thermally degraded because it is continuously receiving heat during this time. Further, such a conventional filtration device has a large and complicated structure, and therefore, it is extremely difficult to eliminate a dead space where poor retention of a polymer is likely to occur. Has an aspect that the polymer is further accelerated by staying for a long time.

[0013] In addition, when restoring the filtration line that has been temporarily stopped to replace the filter medium, the supply of the polymer is restarted after cleaning the suspended filtration line, and the polymer is discharged for a certain period of time to release the residual polymer. Need to be wiped out,
It also has a very large problem of causing a great loss.

[0014]

The inventors of the present invention have made intensive studies to improve the above-mentioned drawbacks of the conventional method and to obtain a polyester having excellent moldability, and as a result, have reached the present invention. That is, an object of the present invention is to provide excellent dispersibility of the fine particles in the polyester and substantially no coarse particles having a particle size of 5 μm or more, and therefore, to provide excellent processability in producing a fiber, a film, and a resin molded product. In the case of fiber, there is little breakage of single yarn, in the case of film, it is excellent in slipperiness, uniformity of film surface and abrasion resistance, and in the case of resin molded product, dimensional stability and impact resistance It is an object of the present invention to provide a continuous production apparatus for a polyester composition which is excellent in water resistance.

[0015]

According to the present invention, there is provided (claim 1) an average particle diameter of 0.01 to 2.0 μm.
Water and / or a boiling point of 2
An addition port for adding as a slurry with an organic compound medium having a temperature of 40 ° C. or lower is provided, and a polyester selected from any one of polyester groups in which 70 mol% or more of repeating units is ethylene terephthalate, butylene terephthalate, or ethylene naphthalate A uniaxial or biaxial vented kneading extruder to which the slurry is added and kneaded,
A continuous production apparatus for the polyester composition, comprising: a filtration means provided with a filter medium for continuously passing the polyester composition supplied to the downstream side of the kneading extruder with a vent. 2) The continuous production apparatus for a polyester composition according to claim 1, wherein the screw of the vented kneading extruder is a biaxial full flight screw, and the slurry addition port is provided in a full flight portion of the screw. And a segment having a function of kneading and dispersing at least the fine particles and a segment having a function of disintegrating and dispersing the fine particles are provided in this order on the downstream side of the slurry addition port. An apparatus for continuously producing a polyester composition, wherein the apparatus for continuously producing a polyester composition according to claim 2 is: The “segment having a function of kneading and dispersing fine particles” is configured to include at least a propulsion rotor segment and a reverse propulsion rotor segment, and the “segment having a function of disintegrating and dispersing fine particles” is at least a knee. A continuous production apparatus for the polyester composition, wherein the continuous production apparatus for the polyester composition is configured to include a loading disk segment. (4) The continuous production apparatus for the polyester composition according to any one of (1) to (3), A vented kneading extruder is provided with a vent port at least on the upstream side of the slurry addition port and the "segment having a function of kneading and dispersing fine particles" in the polyester composition. The continuous production apparatus for a polyester composition according to claim 1, wherein The continuous production apparatus for a polyester composition, further comprising a metering / supplying unit which supplies the polyester composition supplied from the kneading extruder to the filtration unit while measuring the polyester composition, (Claim 6). In the continuous production apparatus for a polyester composition, the filter medium has a single fiber diameter of 2 to 30 μm.
A continuous non-woven fabric sintered body made of stainless steel monofilament, wherein the porosity of the filter medium is 50 to 80% and the average pore diameter is 20 to 80 μm. (Claim 7) In the continuous production apparatus for a polyester composition according to claim 1, the filtering means is a filtering means for substantially filtering and removing the coarse particles having an average particle diameter of 5 µm or more. The continuous production apparatus for a polyester composition according to claim 1, wherein the filter medium is provided in the middle of a polyester composition transfer line, and the transfer line is provided. The continuous production apparatus for a polyester composition, wherein the filter medium can be exchanged online without pausing, and (Claim 9). Wherein the filter medium is provided in a plurality of stages from the upstream side to the downstream side so as to be independently and freely exchangeable in series over a plurality of stages. Is provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below, but before that, definitions of terms used in the present invention will be described.

First, the definition of “average particle diameter of particles” used in the present invention is defined as “CP-50 type manufactured by Shimadzu Corporation”.
From the cumulative curves of the particles of each particle size and their abundance calculated based on the centrifugal sedimentation curve obtained when using the Centrifugal Particle Size Analyzer, 50 mass per
(A value obtained by reading the particle size corresponding to cent.) (Book “Particle Size Measurement Technology”, published by Nikkan Kogyo Shimbun, 1975)
Year, pp. 242-247).

Next, the above-mentioned "polyester" used for producing the polyester composition of the present invention, "inorganic and / or organic fine particles having an average particle diameter of 0.01 to 2.0 µm", and " Embodiments of the "slurry comprising water containing fine particles and / or an organic compound medium having a boiling point of 240 ° C. or lower" and their interrelation will be described below with reference to specific examples.

First, the polyester constituting the main component of the polyester composition produced using the apparatus of the present invention will be described. As the polyester, 70 mol% or more of the repeating unit is ethylene terephthalate, butylene terephthalate, or ethylene. It is any one type of polyester selected from a polyester group consisting of naphthalate. Specifically, it is a linear saturated polyester synthesized from a dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Here, as the dibasic acid or its ester-forming derivative, for example, terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, phthalic acid, phthalic anhydride , 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid, p-hydroxybenzoic acid, dimethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, 1,4
-Dimethyl cyclohexanedicarboxylate, dimethyl adipate, dimethyl sebacate, dimethyl phthalate, 5-
Examples thereof include sodium dimethyl sulfoisophthalate and dimethyl 5-tetrabutylphosphonium sulfoisophthalate. Of these, terephthalic acid, 2,6-naphthalenedicarboxylic acid, dimethyl terephthalate, and dimethyl 2,6-naphthalenedicarboxylate are preferred.

The diol and its ester-forming derivative include, for example, ethylene glycol, 1,4-
Butanediol, diethylene glycol, propylene glycol, 2,2-dimethyl-1,3-propanediol, dipropylene glycol, 1,6-hexanediol, 1,4-hexanedimethanol, dimethylolpropionic acid, poly (ethylene oxide) glycol And poly (tetramethylene oxide) glycol. Among them, ethylene glycol, 1,4-
Butanediol is preferred.

These dibasic acids or their ester-forming derivatives and diols or their ester-forming derivatives may be used alone or in combination of two or more.

Further, the polyester in the present invention includes:
Trimellitic acid, trimesic acid, trimellitic anhydride,
Pyromellitic acid, polyvalent carboxylic acids such as trimellitic acid monopotassium salt, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, polyvalent hydroxy compounds such as potassium dimethylolpropionate may be copolymerized in small amounts. .

The polyester can be obtained from the compounds exemplified above by a conventional method. That is, after the esterification reaction of the polyvalent carboxylic acid and the polyvalent hydroxy compound, polycondensation is performed at a high temperature under reduced pressure, or the ester-forming reaction between the ester-forming derivative of the polyvalent carboxylic acid and the polyvalent hydroxy compound, It can be produced by polycondensation at high temperature under reduced pressure.

In the present invention, the fine particles added to the polyester may be inorganic particles or organic particles. The average particle size is 0.01 to 2.0 μm (hereinafter, may be simply referred to as “fine particles”), and more preferably 0.03 to 1.8 μm. If the average particle diameter of the fine particles exceeds 3.0 μm, various problems associated with the incorporation of coarse particles as described in detail in the section of the prior art are caused, which is not preferable. Incidentally, the average particle diameter of the fine particles may be smaller than 0.01 μm, but there is little advantage in making the fine particles smaller than this in practice.
It does not need to be smaller than m.

Here, the inorganic particles include colloidal silica, wet silica, dry silica, etc., silicon oxide, titanium oxide, calcium carbonate, kaolinite, china clay, talc, alumina, zeolite, graphite, feldspar, molybdenum disulfide, Particles such as carbon black and barium sulfate can be exemplified. Examples of the organic particles include fine particles of polystyrene, polymethyl methacrylate, methyl methacrylate copolymer, methyl methacrylate copolymer crosslinked product, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, benzoguanamine resin, crosslinked silicone resin, and the like. Can be. These fine particles are, for example, disclosed in
As proposed in JP-A-247119, JP-A-4-7336, etc., even if the surface of the fine particles is coated with a compound different from the composition inside the particles, a silane coupling agent and / or a titanium coupling agent may be used. It does not matter even if it is processed in such as. Among them, fine particles of silicon oxide, titanium oxide, alumina, polystyrene, and a crosslinked silicone resin, or fine particles in which the surface of these fine particles is coated with another compound are preferable.

The amount of the fine particles to be added to the polyester is 0.1% in the polyester composition.
01-70% by weight, preferably 0.02-65% by weight,
More preferably, it is 0.05 to 60% by weight.

The polyester composition described above can be obtained by the following production method.

First, the above-mentioned fine particles are dispersed in a slurry. As a dispersion medium, "water and / or an organic compound having a boiling point of 240 ° C. or less" (hereinafter simply referred to as "water and / or organic compound medium") is used. May be abbreviated). Examples of the organic compound include alcohols such as methanol, ethanol, ethylene glycol and 1,4-butanediol, hydrocarbon compounds such as benzene, toluene and xylene, tetrahydrofuran, 1,3-dioxolan, and 2-methyl-1. , 3-dioxolane, ethers such as ethylene glycol ether, and esters, ketones, amines and the like. Among them, ethylene glycol, 1,4-butanediol,
Preferred are tetrahydrofuran, 1,3-dioxolan, 2-methyl-1,3-dioxolan, β-oxyethyl ether, and β-oxyethyl methyl ether. In addition, in making the particles into a slurry, these water and / or organic compound medium may be used alone,
Alternatively, two or more kinds may be used in combination.

Here, the slurry of the fine particles and water and / or an organic compound medium can be prepared by an ordinary method. That is, the fine particles may be made into a slurry of water and / or an organic compound medium, and then pulverized or crushed, and further subjected to a classification treatment. Conversely, it may be pulverized or crushed after the classification process. Alternatively, the particles may be made into a slurry of water and / or an organic compound medium after a pulverization or pulverization and / or classification treatment is added in a dry system. Alternatively, a dry method and a wet method may be appropriately combined. For example, it may be pulverized by a dry method and then slurried and classified by a wet method, or may be pulverized and / or classified by a dry method and then pulverized by a wet method.

In order to obtain a uniform slurry, a dispersant may be added within a range not to impair the effects of the present invention.
Specific examples of the dispersant include sodium polystyrene sulfonate, sodium polyacrylate, carboxymethyl cellulose, polyvinyl alcohol, a salt of a copolymer of a vinyl compound and a carboxylic acid monomer, and a partial alkyl ester of polyacrylic acid. , Polyalkylene polyamine, ammonia, various ammonia salts, various kinds of soda salts such as sodium hydroxide, sodium hexametaphosphate, sodium pyrophosphate, tetraethylammonium chloride, tetramethylammonium hydroxide, tetramethylphosphonium bromide, tetrabutylphosphonium hydroxide and the like Onium compounds and the like can be mentioned.

Here, in the preparation of the slurry containing fine particles having an average particle diameter of 0.01 to 2.0 μm, which is added to the polyester, a slurry containing water and / or an organic compound medium containing fine particles is used. The concentration of
Although not particularly limited, after adding fine particles to the polyester,
From the viewpoint of operability in discharging water and / or an organic compound medium from a vent of a kneading extruder described later, the slurry concentration is preferably higher, and more preferably 20% by weight or more.

Hereinafter, an embodiment of a continuous production apparatus for a polyester composition of the present invention will be described in detail with reference to FIGS. 1 to 4, first, FIG. 1 is a side cross-sectional view schematically illustrating an embodiment of a polyester composition manufacturing apparatus of the present invention, and FIG. 2 is a kneading disperser attached to a screw of a kneading extruder of the present invention. FIG. 3 is an explanatory view (side view) schematically illustrating a disintegrating and dispersing segment portion, and FIG. 3 is a schematic view illustrating a preferred embodiment in which a screw having the disintegrating and disintegrating dispersion segments is mounted on a kneading extruder. FIG. FIG.
Describes an embodiment in which a continuous switching type filtration device capable of exchanging a filter medium online without stopping a transfer line of a polyester composition is provided in a plurality of stages (in the figure, a case of “two stages”) is provided over a plurality of stages. It is the side sectional view which illustrated typically.

With respect to the names of the respective symbols described in FIGS. 1 to 4, 1 is a single-screw or twin-screw kneading extruder with a vent, 2 is a barrel of the kneading extruder, 3 is a screw, and 4 is a polyester. A supply port 5 is a fine particle addition port, and 6 (61 to 61).
64) is a vent port, 7 is a screw driving device, 8 is a transfer line for the polyester composition, 9 is a metering means, and 10 is a continuous switching type filtration device. In addition,
As shown in FIG. 2, the screw 3 has a full flight section 31, a propulsion rotor segment 33 and a reverse propulsion rotor segment 34 as “segments having a function of kneading and dispersing fine particles”, and “crushing fine particles”. A kneading disk segment 32 as a "segment having a function of dispersing" is included. Further, the filtering device 10 is provided with a filtering medium 11. The "filtering means" referred to in the present invention is configured to include the continuous-switching-type filtration device 10 and the filter medium 11 attached to the filtration device. At this time, these "filtration means" are provided in the middle of the transfer line 8 of the polyester composition, and are a continuous switching type filtration device 10 in which the filter medium can be exchanged online without stopping the transfer line 8. Is preferred.

In the embodiment of the present invention described above, polyester is fed into the cylinder 2 from the supply port 4 as a chip into the kneading extruder 1 with vent, and the screw 3
Thus, the chips are melted while being transported downstream in the cylinder 3 heated by the heating means (not shown). At this time, the slurry containing the fine particles is added to the relatively low-temperature polyester still in a chip state from the addition port 5 into the cylinder-2, and thereby mixed with the polyester chip.

At this time, in the apparatus of the present invention, the kneading extruder 1
Screw 3 may be uniaxial or biaxial.
However, in the present invention, since it is important to add fine particles to the kneading extruder 1 and uniformly disperse them in the polyester, it is more preferable to use a twin screw having a high kneading function. In addition, at this time, the twin screw 3 is a full flight screw, and the full flight screw is provided with a “segment having a function of kneading and dispersing fine particles” and a “segment having a function of disintegrating and dispersing fine particles”. This is preferable because the fine particles can be more uniformly kneaded and dispersed in the polyester. Note that these “segment having a function of kneading and dispersing fine particles” and “segment having a function of disintegrating and dispersing fine particles” can be used alone, respectively. This is preferable because the functions of uniformly dispersing and kneading can be synergistically exhibited.

Here, the “segment having a kneading function” is generally a propulsion rotor segment 33.
It is preferable to use the rotor propulsion rotor segment 34 and the reverse propulsion rotor segment 34 in this order toward the downstream side. This is because a part of the molten polymer conveyed in the propulsion direction by the propulsion rotor segment 33 can always be recirculated in the reverse propulsion direction by the reverse propulsion rotor segment 34. By this action, the molten polymer can be exchanged between the two types of rotor segments 33, 34, thereby giving the effect of kneading and dispersing the fine particles inside the molten polymer.
Moreover, these two types of rotor segments 33, 34
Can exert its function even under the high pressure of the cylinder 2 of the kneading extruder 1.
It functions very effectively in kneading and dispersing the fine particles inside the polyester. In this case, since the clearance between the two types of rotor segments 33 and 34 and the cylinder 2 is generally large, the shearing force acting on the polyester passing through the clearance is relatively small.
For this reason, unlike the prior art, the polymer is not deteriorated by receiving a high shearing force at this portion. However,
On the other hand, since a high shearing force cannot be obtained, the structure is such that the fine particles cannot be sufficiently crushed.

Therefore, in the apparatus of the present invention, for example, a kneading disk segment 32 is employed as the “segment having a function of crushing and dispersing fine particles”. As a result, when the reagglomerated and coarse particles pass through the kneading disk segment 32, a high shear force is applied to break the reagglomerated and coarse particles. At this time, in the conventional technology, since the gap between the cylinder and the screw of the kneading extruder is reduced and a high shearing force is applied to the polyester for a long time, undesirable phenomena such as a decrease in the intrinsic viscosity of the polyester occur. Occur. On the other hand, according to the apparatus of the present invention, since only a portion of the kneading disk segment 32 is particularly subjected to a high shearing force, the polymer passing through this portion is subjected to the high shearing force only for a short time. Not exposed to Therefore, the quality of the polyester does not deteriorate as in the prior art.

The "segment having a function of disintegrating and dispersing fine particles" is a kneading disk segment 3 which functions as a "segment having a function of kneading fine particles".
2 are provided immediately upstream and downstream of the rotor segments 33 and 34, thereby sufficiently crushing the fine particles due to insufficient shear force caused by a large clearance between the rotor segments 33 and 34 and the cylinder 2. It is preferable to disintegrate the remaining portion again. In other words, it is preferable that the kneading disk segment 32 is additionally provided just upstream of the propulsion rotor segment 33 as shown in FIG. In this way, the fine particles that are agglomerated and coarse before entering the “segment having the kneading and dispersing function” can be sufficiently crushed in advance by the “segment having the crushing and dispersing function”, and the crushed fine particles can be removed. Furthermore, kneading and dispersion can be performed by two types of rotor segments 33 and 34.

When the slurry is added to the kneading extruder as a “slurry in which fine particles are dissolved in water or a suitable organic compound medium”, the above-described structure allows a relatively low temperature and a relatively low pressure. Since it is possible to add a slurry containing fine particles to the polyester, water and the organic compound medium accompanying the addition of the slurry evaporate rapidly, which causes the fine particles in the slurry to aggregate and promote the generation of coarse particles. The problem can be solved. Also, since the temperature of the polyester is still relatively low temperature, by adding the slurry by raising the temperature to an appropriate temperature in advance, the temperature difference between each other can be reduced, so even if the slurry is added, The problem that the temperature of the polyester is suddenly lowered can be avoided.

At this time, as shown in FIG. 3, the kneading extruder with vent 1 includes at least an upstream side of the slurry addition port 5 and a “segment having a function of kneading and dispersing fine particles”. It is preferable from the viewpoint of kneading effect and deaeration efficiency to provide a vent port at the segment where the propulsion rotor 33 and the reverse propulsion rotor 34 are provided.

In the continuous production apparatus for a polyester composition of the present invention, the kneading extruder 1 is used as described above,
By adding the fine particles to the polyester and kneading and dispersing or disintegrating and dispersing, it is possible to extremely efficiently suppress aggregation of the fine particles contained therein and generation of coarse particles.

However, even with such an apparatus, it is possible to completely prevent the fine particles from aggregating and forming coarse particles, or to reduce the once agglomerated fine particles by the shear kneading effect of the screw 3 of the kneading extruder 1. It cannot be completely disintegrated. Therefore, coarse particles are inevitably mixed in the obtained polyester composition.

Therefore, in order to avoid such a problem, in the apparatus for producing a polyester composition of the present invention, a filter medium for continuously passing the polyester composition supplied to the downstream side of the vented kneading extruder 1 is used. The filtration means 10 provided with is provided. However, this filtering means 10
Is provided for the purpose of microfiltration in which coarse particles, particularly coarse particles having an average particle diameter of 5 μm or more, contained in the polyester composition are not substantially leaked downstream of the filtration means 10. However, when such fine filtration is required, it is inevitable that the filtration pressure on the filter medium increases. For this reason, the polyester composition containing the coarse particles may leak from the sealing portion of the filter medium, which may cause a deterioration in the quality of the finally obtained polyester composition.

In order to cope with such a problem, regarding the filter medium provided in the filter means 10, pores (voids) having a specific range of average pore diameter are formed therein, so that the polyester composition is formed. It is preferable to impart a function of breaking the aggregated coarse particles by the action of the shearing force applied to the polyester composition when the polyester composition is passed through the pores. In this case, if the filter medium is further made to have a high porosity, since the filter medium itself has a high porosity, a large amount of coarse particles that could not be disintegrated even when passing through the pores are captured and retained in these pores in a large amount. Can be. In addition, by providing the filter medium with a property of high porosity, the passage resistance when the polyester composition passes through the filter medium can be extremely reduced, and the pressure loss in the filter medium can be suppressed low. In addition, because of the high porosity, even if coarse particles are trapped therein, the filtration pressure does not increase so much and the life of the filter medium itself is prolonged.

However, it is inevitable that a high filtration pressure acts as described above in a filter medium that is destined to be subjected to microfiltration. In such a case, the filter medium itself undergoes compression deformation. When the porosity and the average pore diameter are easily changed, coarse particles easily pass through the filter medium. Therefore, even if a large filtration pressure acts on the filter medium, it is important that the porosity and the average pore diameter of the filter medium do not change. Then, by clearing such elements, the polyester composition after passing through the filtration means 10 is 5 μm
The above coarse particles can be substantially not included.

In order to embody the above-described filter medium, the present invention provides a method of producing a nonwoven fabric sintered body made of stainless steel single fiber having a single fiber diameter of 2 to 30 μm, wherein the porosity is 50 to 80%. It is preferable to use a filter medium having an average pore diameter of 20 to 80 μm, preferably 60 to 70%. Such a filter medium has a porosity of 40 to 60% as a limit and is usually used at a porosity of about 40%, and is compared with a metal mesh filter having a porosity of 20 to 50%. Has a very high porosity. Moreover, the use of fibers increases the fiber length relative to the fiber diameter.
Because the so-called “aspect ratio” increases, the number of bonding points between fibers increases, and the shape stability increases. As a result, even when a large filtration pressure is applied, the porosity and the average pore diameter easily change. Disappears. Moreover, the pressure loss at the time of filtration can be reduced as compared with a conventional filter medium made of a sintered metal powder or a wire mesh.

Incidentally, such a filter medium is, for example, an air-laid filter described in US Pat. No. 28,478.
The single fiber diameter is 2 to 2 by the air-laid web method.
It can be obtained by forming a non-woven fabric made of a 30 μm stainless steel single fiber, compression-molding, and then subjecting the compression-molded non-woven fabric to a known sintering process in powder metal treatment. In this case, the filter medium can be obtained by sintering a web in which monofilaments having a substantially constant fiber diameter are uniformly dispersed by the airlaid web method. For this reason, when compared with a filter medium made of a metal powder sintered body using a metal powder in which it is extremely difficult to make the constituent particle diameters all the same,
Fine and uniformly distributed pores can be obtained. Also,
By variously combining monofilaments having different thicknesses, it is possible to easily provide a gradient in the pore diameter distribution with respect to the flow direction of the polyester composition.

Next, in the apparatus of the present invention, when the polyester composition is supplied to the filtration means 10 having such a filtering material, the polyester composition supplied from the kneading extruder 1 with a vent is measured while measuring the polyester composition. It is preferable to provide a metering / supplying means 9 for supplying to 10. because,
Generally, since the filtration pressure and the filtration performance are in a substantially proportional relationship, it is necessary to secure an appropriate filtration pressure,
For this purpose, it is necessary to control the filtration pressure acting on the filter medium within an appropriate range by always controlling the amount of the polyester composition passing through the filter medium to a constant value. If the polyester composition supplied from the kneading extruder 1 is supplied to the filtering means 10 as it is, the fluctuation of the discharge pressure of the kneading extruder 1 acts on the filter medium as it is, and the filtering pressure constantly fluctuates. In addition, the polymer discharge balance is temporarily lost, and the kneading extruder 1
The discharge pressure may increase for some reason even if it is temporary.

On the other hand, by using the metering / supplying means 9, it is possible to always keep the use conditions of the filter medium in an appropriate range, and to appropriately maintain the quality of the polyester composition to be filtered. Further, the service life of the filter medium can be extended, and the life of the filter medium can be easily predicted. In addition, as such a metering / supplying unit 9, for example, a gear pump that can supply the polyester composition without large pulsation can be preferably used.

However, although the service life of the filter medium can be extended, since coarse particles are trapped in the filter medium, clogging due to these coarse particles cannot be avoided. Is required. Such a replacement of the filter medium may be performed by constantly monitoring the filtration pressure and performing the replacement when the filtration pressure exceeds a predetermined value. After the period, the replacement may be performed forcibly in consideration of safety.

As described above, the filtering means 10 is generally installed on the downstream side of the kneading extruder 1 and is used on-line. For this reason, when the filter medium is exchanged, the production of the polyester composition is performed. The point is to perform continuously without stopping the line. Moreover, in this case, it is necessary to reduce the frequency of replacement of the filter medium as much as possible because the production cost can be reduced and the work of switching the filter medium can be reduced. However, as a conventional filtration device for achieving such an object, a candle type filtration device having a large filtration area and a small flow rate of a polymer is generally used. As described in detail in the section of “Technique”, various problems caused by this are also caused as described above.

Therefore, in the apparatus for producing a polyester composition of the present invention, as in the conventional method, a plurality of filtration lines (transfer lines) are arranged in parallel in order to continuously exchange the filter medium without stopping the production line. And a line for replacing the filter medium is stopped without stopping these lines at the same time ". That is, in the present invention, "when replacing the filter medium, the filter medium is provided in the middle of the transfer line of the polyester composition,
The filter medium can be exchanged online without stopping the transfer line (filtration line). "

In order to achieve the above object, the filtering means 1
As 0, a "continuous screen changer (continuous filter medium changing device)" is used. Specifically, when the filter medium installed in the transfer line is gradually clogged by the captured foreign matter and reaches a specified pressure or a specified time, at least in a part of the filter medium replacement process, a new filter medium is added. A filtration device having a mechanism in which a filter medium clogged at the same speed as inserted into the transfer line is separated from the transfer line is used. According to this method, since the continuous fluidity of the process can be ensured, the variation in the polymer temperature, the decrease and the variation in the filtration pressure can be suppressed, and the sealing property of the filter medium can be maintained well. In addition, since continuous fluidity can be ensured, it is possible to prevent the occurrence of dead space due to the drift of the polymer and the deterioration of the polymer due to stagnation for a long time.

Examples of the “continuous screen changer” having such a filtering means 10 include, for example,
Commercially available filtration equipment manufactured by Gnois (SF, GSF, KSF,
And RSF type).

Incidentally, in the filtering means 10 of the present invention,
It is preferable that the filter medium 11 is provided in a plurality of stages (more preferably, two to three stages) from the upstream side to the downstream side so as to be independently exchangeable independently in series. In this case, in the filtration means 10 of the present invention, the kneading extruder 1 side, that is, the filter medium on the upstream side captures coarse particles having a large particle diameter, or forcibly feeds the coarse particles into pores of the filter medium, The purpose is to disintegrate the coarse particles by the shearing force applied to the coarse particles at that time. On the other hand, by using a high-density filter medium on the downstream side, by providing a role of a breakwater for substantially removing coarse particles having an average particle diameter of 5 μm or more, the minimum particle diameter of the average particle diameter is about 5 μm. Used for capturing particles. As described above, the stepwise filtration in accordance with the trapped particle size and its role makes it possible to reduce the clogging amount of particles in the filter medium and at the same time, reduce the filtration pressure acting on each filter medium. Therefore, the durability of the filter medium, the filtration performance, and the protection of the filtration means (filter medium) can be protected, and the life time can be extended with respect to the filter life, which is the most important factor.

In general, the filtration pressure and the filtration area of the filtration medium are inversely proportional to each other, so that it is necessary to secure an appropriate filtration pressure. However, the filtration medium of the present invention is independent of each other over a plurality of stages in series. The filtration area of the filter medium in each stage can be arbitrarily selected. For this reason, it is possible to secure an appropriate filtration pressure for each filter medium.
In addition, it is desirable to switch the filter media at the same time as much as possible. For that purpose, the filtration area of the first-stage filter medium is set to be larger than the filtration area of the second-stage filter medium, and the filter pressure reaches a specified filtration pressure. It is preferable to have a system that switches the filter media at the same time. For this,
In order to synchronize the time required for each filter medium to reach the replacement filtration pressure, it is necessary to set the filtration area of each filter medium in accordance with the particle diameter captured by each filter medium, and the filtering means 10 of the present invention makes this possible. I do.

As described above, according to the present invention, the fine particles can be dispersed and kneaded in the polyester by the kneading extruder 1 equipped with a vent, and the aggregated coarse particles can be disintegrated. Can uniformly be dispersed to produce a polyester composition. Furthermore,
Thereafter, it was passed through a filtration means while being weighed to remove coarse particles of 5.0 μm or more, whereby 5.0
Coarse particles larger than μm are substantially removed.

The polyester composition from which coarse particles of 5.0 μm or more have been removed in this manner can be directly sent to a fiberizing step, a thinning step, a three-dimensional object molding step, or the like. Pelletization (chip formation) can also be performed once in the granulation step.

According to the present invention described above, it is possible to obtain a good dispersion state of fine particles in the polyester in a wide concentration range and substantially free of coarse particles of 5.0 μm or more. Therefore, to produce a polyester composition containing a high concentration of particles, do not contain any separately produced particles,
Alternatively, even if it is contained, it can be adjusted to a desired particle concentration by diluting with a very small amount of polyester, and the obtained polyester composition is in a uniform dispersion state substantially not containing coarse particles of 5.0 μm or more. .

The polyester composition thus obtained does not substantially contain particles having a particle size of 5.0 μm or more and has two 2,000-mesh wire mesh filters having an inner diameter of 64 mmφ. Temperature, 33.3 g / m
The filtration pressure rise rate when filtering at a filtration rate of 1 in.
It has excellent particle dispersibility of 0 kg / cm ² / hr or less, particularly 5 kg / cm ² / hr or less.

[0061]

According to the apparatus for continuously producing the polyester composition of the present invention described above, the dispersibility of the fine particles in the polyester is excellent, and substantially no coarse particles of 5 μm or more are present. , Film, and excellent molding processability when made into a resin molded product, in the case of fibers, there are few single yarn breaks, and in the case of film, excellent in slipperiness and uniformity of the film surface and abrasion resistance, In the case of a resin molded product, a polyester composition having excellent dimensional stability and impact resistance can be continuously produced.

Even if these polyester compositions are used in a fiberizing step, a thinning step, and various three-dimensional molding steps, the polyester composition contains very few coarse or agglomerated particles. The amount of particles captured by the filter for removing foreign substances provided can be significantly reduced, and the replacement period of the filter due to an increase in filtration pressure can be extended, and the filter can be replaced over a long period of time. Thus, the filter can be used stably. Also, in the fiber forming step, clogging of the filter at the time of spinning does not occur, so that productivity does not decrease and single yarn breakage does not occur. Further, for example, in the case of a film for a magnetic tape, the electromagnetic conversion characteristics are reduced, or a dropout is caused. This has a remarkable effect of preventing generation and mixing of coarse particles that impair film quality such as deterioration.

[Brief description of the drawings]

FIG. 1 is a side sectional view schematically illustrating an embodiment of an apparatus for producing a polyester composition of the present invention.

FIG. 2 is an explanatory view (side view) schematically illustrating a kneading dispersion and crushing dispersion segment attached to a screw of the kneading extruder of the present invention.

FIG. 3 is a side sectional view schematically illustrating an embodiment in which a screw having a kneading dispersion and a crushing dispersion segment is mounted on a kneading extruder.

FIG. 4 is a side sectional view schematically illustrating an embodiment in which a continuous switching type filtration device is provided in a plurality of stages in series.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Kneading extruder 2 Cylinder 3 Screw 4 Polyester supply port 5 Slurry addition port 6 Vent port 8 Transfer line 9 Metering supply means 10 Filtration means 11 Filter material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B29D 7/01 B29D 7/01 C08L 67/02 C08L 67/02 // B29K 67:00 105: 08 F term (Reference) 4F201 AA24 AC04 AL03 AR12 BA01 BA04 BC02 BC13 BC33 BC37 BD05 BK25 BK26 BK36 BK40 BK49 BM06 BN18 BQ16 BQ44 BQ50 BQ54 4F207 AA24 AC04 AL03 AR12 KA01 KA17 KF03 KF12 KK12 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL13 KL01 AR12 WA06 WA33 WA97 WB02 WF02 WF41 WF46 WK03 4J002 BC032 BD132 BD152 BG062 BG102 CC132 CF011 CF041 CF051 CF061 CF071 CF081 CF101 CF141 CF181 CP002 DA026 DA036 DE136 DE146 DE236 DG026 DG046 DJ03 016 016 FB016 016 016 AC02 AE01 AE02 AE03 BA02 BA03 BA05 BA07 BA08 BD03A BD07A BF09 BF10 BF25 BH02 CA02 CA06 CB04A CB 05A CB06A CC06A CD03 CH03 CH06 EB05A FC03 FC05 FC16 FC35 FC36 HA01 HB01 HB03A HB06 JA013 JA093 JA123 JA183 JA203 JA283 JA293 JE053 JE063 JE093 JE143 JE182 JE223 JF143 JF163 JF223 JF323 JF513 KE02 KE03 KE03 KE03KE03KE05KE

Claims (9)

[Claims] 1. An inorganic and / or organic fine particle having an average particle size of 0.01 to 2.0 μm is prepared by adding water and / or a boiling point of 240
An addition port is provided for addition as a slurry with an organic compound medium at a temperature of not more than 0 ° C., and 70% by mole or more of the repeating unit is selected from a polyester selected from the group consisting of ethylene terephthalate, butylene terephthalate, and ethylene naphthalate. A uniaxial or biaxial vented kneading extruder for adding and kneading the slurry, and a filtering means provided with a filter medium for continuously passing the polyester composition supplied to the downstream side of the vented kneading extruder; The continuous production apparatus of the polyester composition characterized by being provided. 2. The continuous production apparatus for a polyester composition according to claim 1, wherein the screw of the kneading extruder with a vent is a biaxial full flight screw, and the slurry addition port is a full flight of the screw. And a segment having a function of kneading and dispersing at least the fine particles and a segment having a function of disintegrating and dispersing the fine particles are provided in this order on the downstream side of the slurry addition port. An apparatus for continuously producing a polyester composition, comprising: 3. The continuous production apparatus for a polyester composition according to claim 2, wherein the “segment having a function of kneading and dispersing the fine particles” includes at least a propulsion rotor segment and a reverse propulsion rotor segment. Wherein the “segment having a function of crushing and dispersing the fine particles” is constituted so as to include at least a kneading disk segment. 4. The continuous production apparatus for a polyester composition according to any one of claims 1 to 3, wherein the kneading extruder with a vent includes at least an upstream side of the slurry addition port and the “ A continuous production apparatus for a polyester composition, wherein a vent port is provided in a "segment having a function of kneading and dispersing fine particles". 5. The continuous production apparatus of a polyester composition according to claim 1, further comprising a metering / supplying unit that supplies the polyester composition supplied from the kneading extruder with vent to the filtration unit while measuring the polyester composition. An apparatus for continuously producing a polyester composition, comprising: 6. The continuous production apparatus of a polyester composition according to claim 1, wherein the filter medium is a nonwoven fabric sintered body made of stainless steel single fiber having a single fiber diameter of 2 to 30 μm,
The porosity of the filter medium is 50 to 80%, and the average pore diameter is 20 to 8
An apparatus for continuously producing a polyester composition, which has a thickness of 0 μm. 7. The continuous production apparatus for a polyester composition according to claim 1, wherein the filtration means is a filtration means for substantially filtering and removing the coarse particles having an average particle diameter of 5 μm or more. A continuous production apparatus for a polyester composition. 8. The continuous production apparatus for a polyester composition according to claim 1, wherein the filter medium is provided in the middle of a polyester composition transfer line, and the filter medium is exchanged online without stopping the transfer line. An apparatus for continuous production of a polyester composition, which is flexible. 9. The apparatus for continuously producing a polyester composition according to claim 8, wherein the filter medium is provided in a plurality of stages from the upstream side to the downstream side so as to be independently and independently exchangeable in series. Continuous production apparatus for a polyester composition.