JPH05214089A - Method for separating sticky foreign matter from by-product produced in polymerization step for producing polymer - Google Patents

Abstract

PURPOSE:To prevent adverse influence of sticky matters, e.g. unreacted monomers or oligomers, accompanying by-products produced in e.g. the polycondensation step for producing a polyesterether copolymer, e.g. ethylene glycol and water, on an evacuation system and facilitate the separation of the sticky matters from the by-products. CONSTITUTION:By-products produced in the polymn. step for producing a polymer and accompanied by sticky matters, e.g. unreacted monomer or oligomers, are heated to a temp. higher than the m.p. of the sticky matters and discharged. During or after the discharge, the by-products are brought into contact with a treating liq. kept at a temp. lower than the m.p. of the sticky matters, and thus the matters are separated from the by-products.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, polycondensation reaction of a polyester ether copolymer
Not only does adhering foreign matter such as unreacted monomers and oligomers that accompany by-products such as ethylene glycol and steam produced as by-products in this process not adversely affect the vacuum suction system, but also by-products and adhesive foreign matter The present invention relates to a method for separating by-products by-produced in the course of a polymerization reaction of a polymer that can be easily separated and adherent foreign substances accompanying the by-products.

[0002]

2. Description of the Related Art Conventionally, when a polyester ether copolymer is produced, a polycondensation reactor and a vacuum means such as a vacuum pump and an ejector for keeping the inside of the polycondensation reactor in a nearly completely vacuum state are connected by vacuum piping. Using the polycondensation reactor, the inside of the polycondensation reactor containing the polymerization raw material is, for example, 0.
In a substantially complete vacuum state of about 5 to 1 mmHg · abs, heat the contents at a temperature of, for example, about 260 to 290 ° C.
It is polycondensed. By the way, in this polycondensation reaction process, it is known that by-products such as glycols and steam accompanied by adherent foreign substances such as unreacted monomers and oligomers are by-produced. Therefore, the polycondensation reactor and a vacuum pump for bringing the inside into a substantially complete vacuum state, a vacuum pipe connecting the vacuum means such as an ejector and the adhering foreign substances entrained in these by-products adhere inside the vacuum means, It grows and the vacuum suction capability of the vacuum means is reduced at an early stage.

For this reason, conventionally, as in the polycondensation reactor schematically shown in FIG. 2, the condenser shown as d in the figure is installed in the middle of the vacuum pipe c connecting the polycondensation reactor a and the vacuum means b. is doing. As shown in FIG. 3, the condenser d is an inlet pipe connected to the polycondensation reactor a side of the vacuum pipe c, with one end and the other end in the length direction inside the closed cylindrical main body e. f and an outlet pipe g connected to the vacuum means b side thereof are provided, and an inlet pipe f and an outlet pipe g inside the main body e are provided.
A pair of partition walls h, h are provided transversely to the central portion side from the opening end of the, and the adherent foreign substances entrained by by-products are selectively solidified between the pair of partition walls h, h, or condensed by-products Flow of by-products by arranging a plurality of processing pipes i, which are mixed or melted in a part and solidified or condensed and collected, with both ends in communication with the inlet pipe f and the outlet pipe g and spaced in parallel. A passage j is formed, and further, an inflow pipe k and an outflow pipe l for a treatment fluid such as water for condensing by-products are provided between the pair of partition walls h, h. In the figure, m is a discharge pipe for the condensed by-product, which is provided on the outlet pipe g side of the main body e and in which the by-product is condensed, and is connected to a receiving tank n provided below. or,
Reference numeral o is an exhaust pipe for gaseous by-products provided outside the vacuum means b. In addition, a heating socket for heating the inside of the polycondensation reactor a is externally mounted, but not shown.

[0004]

However, even when such a condenser is provided in the middle of the vacuum pipe connecting the polycondensation reactor and the vacuum means, unreacted monomers and polymers such as adherent foreign substances are entrained. The open end of the processing pipe that forms the flow path through which the by-product, which is cooled by the processing fluid such as water, flows when the high-temperature gaseous by-product flows into the main body through the inlet pipe. It is unavoidable that, in particular, adherent foreign matter adheres to and grows on this part by contacting with. In the condenser of such an aspect, since a plurality of processing pipes are arranged in parallel in the lengthwise direction inside the cylindrical main body, there is a degree of freedom to prevent the adhering foreign matter from being blocked transversely. However, there is still a problem that the vacuum suction capability of the vacuum means is lowered at an early stage. In addition, the adhering foreign substances entrained in the by-products selectively solidify as solids and adhere to the processing pipes, and are mixed or melted in a part of the condensed by-products and are installed in the receiving tank below the condenser. However, the condensed by-product containing the adherent foreign matter is environmentally problematic because of its high TOD (total oxygen demand).

In view of such conventional problems, a method of separating the by-product by-produced in the polymerization reaction process of the polymer according to the present invention and the adhering foreign substance accompanied with the by-product, for example, polyester ether Adhesive foreign substances such as unreacted monomers and oligomers that accompany by-products such as ethylene glycol and steam that are by-produced in this process during the polycondensation reaction of the copolymer adversely affect the vacuum suction system. It is intended that the by-products and adherent foreign substances can be easily separated from each other.

[0006]

In order to achieve these objects, according to claim 1 of the present invention, when a polymer is produced by a polymerization reaction, unreacted monomers and oligomers by-produced in this process are attached. By-products with entrained foreign substances are heated to a temperature above the melting point of the adherent foreign substances and induced to be discharged. The gist is a method for separating a by-product by-produced in a polymerization reaction process of a polymer and an adhering foreign substance entrained in the by-product, which is characterized in that the by-product is brought into contact with the treated liquid to separate the adhering foreign substance. or,
Claim 2 exemplifies that the treated liquid is of the same type as the condensed by-product. Further, the third aspect exemplifies that the by-product accompanied by the adhering foreign matter such as unreacted monomer or oligomer is heated to a temperature equal to or higher than the melting point of the adhering foreign matter and induced to be discharged.

[0007]

According to such a separation method, when the by-product accompanied by the unreacted adhesive foreign matter such as monomer or oligomer is brought into contact with the processing liquid whose melting point is lower than that of the adhesive foreign matter, the adhesive foreign matter is removed. Is deposited as a solid matter, and the by-product and adherent foreign matter can be separated.

[0008]

EXAMPLES The details of the method for separating by-products by-produced in the course of the polymerization reaction of the polymer according to the present invention and the adhering foreign substances entrained therein will be described with reference to the accompanying drawings.

The illustrated embodiment is described based on the continuous polycondensation reaction apparatus proposed by the present applicant for the purpose of producing a polyester ether copolymer continuously and with a short reaction time. is doing.

And in this continuous polycondensation reactor,
After the polyester and the polyethers are melt-mixed, or while being melt-mixed, they are continuously supplied to carry out the polycondensation reaction.

FIG. 1 shows an outline of such a continuous polycondensation reaction apparatus. A continuous horizontal polycondensation reactor is shown as 1 in the figure, and a vacuum pump for making the inside of this a substantially complete vacuum state of about 0.5 to 1.0 mmHg · abs is shown as 2 in the figure. A vacuum means using a Nash pump that uses a kind of sealing liquid, and further shown as 3 in the figure is a vacuum pipe connecting the polycondensation reactor 1 and the vacuum means 2.

Two mechanical boosters 4 and 5 are provided in series in the vacuum pipe 3.
By the way, with the vacuum means 2 using a Nash pump that uses a sealing liquid, the achieved decompression degree is limited to about 15 mmHg · abs,
It is not possible to reach the required almost complete vacuum state of about 0.5 to 1.0 mmHg · abs. Therefore, here, mechanical boosters 4, 5 are provided in the middle of the vacuum pipe 3.
Is provided so that a desired degree of reduced pressure can be achieved.
In addition, in the portion of the vacuum pipe 3 between the polycondensation reactor 1 and the mechanical booster 4 on the side thereof, by-products accompanied by adhering foreign substances such as unreacted monomers and oligomers flowing inside the reactor are provided. A heating socket 6 is provided for heating within a range of 100 to 250 ° C., preferably 100 to 120 ° C., at its own temperature of 100 ° C. or higher which is the melting point of the adherent foreign substance. By heating the by-product accompanied by the adherent foreign matter to such 100 ° C. or higher, the meltable viscosity of the adherent foreign matter becomes small, and when the internal pressure of the polycondensation reactor 1 is set within the above range, Usually 3 to 500
At an exhaust rate of about m ³ / min, the problem of adhesion of the vacuum pipe 3 to the pipe wall is eliminated. Also, the heating temperature of this is 25
The reason why the temperature is 0 ° C. or lower is due to the restriction and economic effect of using silicone oil as a heating medium.

Reference numeral 7 is a liquid sealing pipe of the vacuum means 2 using a Nash pump. In the middle of this, a sealing liquid storage tank 8
A cooling machine 9 for cooling the sealing liquid is provided. still,
Reference numeral 10 in the figure denotes a filter provided at the end of the pipe, which is filled with the liquid in the liquid-sealing liquid storage tank 8 and looked into the liquid. Further, 11 is an overflow pipe provided in the liquid storage tank 8 and 12 is an exhaust pipe. Further, reference numeral 13 in the figure is an inflow pipe for flowing cooling water into the cooler 9,
Reference numeral 14 is an outflow pipe for outflowing the cooling water from the cooler 9.
This cooler 9 has the same configuration as that shown in FIG. 3 which is conventionally used as a condenser in such a polycondensation reactor. Here, an ethylene glycol liquid is used as the sealing liquid. This is 100 which is the melting point of the adherent foreign matter.
The temperature is adjusted to be within the range of 5 to 50 ° C., preferably 10 to 30 ° C. at its own temperature of about 0 ° C. or less.

Next, 15 and 16 show the inlet pipe and the outlet pipe of the polycondensation reactor 1. Also, in the figure, 17 are these inlet pipes.
15 and a valve provided in the outlet pipe 16. Further, 18 is a sight glass, and 19 is a stirring blade for mixing and stirring the contents. In addition to this, the polycondensation reactor 1 is also provided with a heating socket for heating the inside to, for example, 260 to 290 ° C. at the content temperature, but it is not shown here.

Thus, in such a continuous polycondensation reactor, a polyester ether copolymer is produced as follows.

First, polyester and polyether are melt-mixed through the inlet pipe 15 of the continuous horizontal polycondensation reactor 1 or are continuously supplied while being melt-mixed. Specifically, here, 70% by weight of a 100-mer polyester and 30% by weight of polyethers are melt mixed and used. At this time, the pressure inside the polycondensation reactor 1 is 0.1
~ 2.0mmHg ・ abs, preferably 0.5 ~ 1.0mmHg ・
It is maintained under a near-complete vacuum state within the range of abs, and the temperature is heated to about 260 to 290 ° C. at the content temperature. Further, these contents are adjusted so as to undergo a polycondensation reaction within the inside for about 30 to 120 minutes. In this way, a 100-mer polyester ether copolymer is produced, which flows out through the outlet pipe 16.

On the other hand, by-products such as ethylene glycol and steam that are by-produced in the polycondensation reaction process in the polycondensation reactor 1 are accompanied by unreacted adhering foreign matters such as monomers and oligomers, and are then transferred to the vacuum means 2. It is sucked and guided and discharged from the polycondensation reactor 1 to the outside through the vacuum pipe 3. At this time, the by-product accompanied by the adherent foreign matter flowing in the vacuum pipe 3 is heated by the heating socket 6 at its own temperature of 100 to 250 ° C.,
Since it is preferably heated within the range of about 100 to 120 ° C., the melt viscosity of the adherent foreign matter becomes small, and when the internal stress of the polycondensation reactor 1 is set within the above range,
At an evacuation speed of usually about ^{3 to} 500 m ³ / min, there is no problem of adhesion of the vacuum pipe 3 to the pipe wall. The by-product accompanied by the adherent foreign matter that has passed through the two mechanical boosters 4 and 5 has its own temperature in the liquid storage tank 8 provided behind the vacuum means 2 of 5 to 50 ° C., preferably Contact with the ethylene glycol solution adjusted to within the range of 10 to 30 ° C during induction discharge causes adherent foreign substances to be deposited as solid matter, and by-products such as ethylene glycol and steam are contained in the ethylene glycol solution. The condensed or vaporized state is exhausted to the outside through the exhaust pipe 12.

The polyester used in the present invention includes aromatic dicarboxylic acids or alkyl esters thereof, such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-dicarboxylicdiphenyl,
4,4'-dicarboxylbenzophenone, bis (4-
(Carboxylphenyl) ethane and the like, or these alkyl esters such as methyl, ethyl and propyl, alone or in combination of two or more, while as the glycol, ethylene glycol, propylene glycol, 1,4-butanediol,
Examples include homopolymers or copolymers of neopentyl glycol, cyclohexanedimethanol and the like, or homopolymers or copolymers synthesized from two or more thereof, or a mixture thereof. Of these, polyethylene terephthalate having heat resistance is preferable.

Further, as the polyethers, general formulas (I) and (I) are used.

[Chemical 1] R: (. Wherein, l number of R need not be the same as) C ₂ -C ₉ alkylene group of general formula (II) (II)

[Chemical 2] R ¹ , R ² : C ₂ -C ₉ alkylene group (wherein (m + n) R ¹ , R ² need not be the same)

[Chemical 3] At least one kind or two kinds or more shown by is preferably used. In the general formulas (I) and (II), the terminal hydroxy group may be, for example, an esterified derivative. Further, in the general formula (II), the aromatic may have a substituent such as halogen.
Further, in the general formulas (I) and (II), R, R ¹ and R ² are preferably C _{2 to} C ₅ alkylene groups. Among these, those having an aromatic ring in the molecular chain, such as polyalkylene oxide adducts of bisphenol A, bisphenol S, etc., are particularly preferable because they can be melt-mixed at a relatively high temperature. The molecular weight of polyethers is 200 or more,
It is preferably 200 to 10,000. Where 200
If it is less than the above range, the melting point of the produced polymer is lowered, which is not preferable. On the other hand, if it exceeds 10,000, the compatibility is poor and it becomes difficult to obtain a product of uniform quality. The amount of polyether is 1-60
Parts by weight, preferably 5 to 35 parts by weight. If the amount of polyether is less than 1 part by weight, the desired physical properties of the polymer cannot be obtained, which is not preferable. On the other hand, if the amount exceeds 60 parts by weight, deterioration is severe and the quality is deteriorated, which is not preferable.

The viscosity of polyester is 0.3 [dl /
g] or more, preferably 0.5 [dl / g] or more is preferable because the flow at the time of molding becomes good and the mechanical strength of the molded product is improved.

Incidentally, as the sealing liquid, water, high-boiling alcohol, etc. can be used in addition to the ethylene glycol liquid.
Further, as this sealing liquid, one in which the by-product does not melt can be used.

Further, the inside and outside of the vacuum pipe 3 are thermally insulated, or the length thereof is relatively short, and the by-product entrained with the adhering foreign matter lowers below the melting point of the adhering foreign matter at its own temperature. If there is no fear, it is not always necessary to heat during the induction discharge from the polycondensation reactor 1.

Further, the by-product accompanied by the adherent foreign matter is induced and discharged from the polycondensation reactor 1 and once stored in, for example, a tank or the like, and then brought into contact with the treatment liquid, thereby separating the by-product and the adherent foreign matter. It is also possible to let.

The present invention, like the illustrated embodiment,
The present invention can be applied not only when the polyester ether copolymer is produced by the continuous system but also when it is produced by the batch system.

Further, in addition to the polyester ether copolymer, it can be applied to the case of producing a polymer resin such as polyamide, polycarbonate, polyester carbonate.

[0026]

INDUSTRIAL APPLICABILITY As described above, in the method for separating the by-product by-produced in the course of the polymerization reaction of the polymer according to the present invention and the adhering foreign matter entrained therein, for example, the polyester ether copolymer is subjected to a polycondensation reaction. When it is generated, adhering foreign substances such as unreacted monomers and oligomers that accompany by-products such as ethylene glycol and steam that are by-produced in this process do not adversely affect the vacuum suction system. Foreign matter can be easily separated.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of a continuous polycondensation reaction apparatus used in a method for separating a by-product by-produced in a polymerization reaction process of a polymer according to the present invention and an adhering foreign substance accompanying the by-product.

FIG. 2 is an explanatory view showing the outline of a conventional polycondensation reaction device.

FIG. 3 is a sectional view showing a condenser installed therein.

[Explanation of symbols]

 1 Continuous horizontal polycondensation reactor 2 Vacuum means 3 Vacuum piping 4 Mechanical booster 5 Mechanical booster 6 Heating socket 7 Sealing liquid piping 8 Sealing liquid storage tank 9 Cooling machine 10 Filter 11 Overflow piping 12 Exhaust piping 13 Inflow piping 14 Outflow Piping 15 Inlet piping 16 Outlet piping 17 Valve 18 Peephole 19 Stirrer

Claims (3)

[Claims] 1. When a polymer is produced by a polymerization reaction, by-products accompanied by adhering foreign substances such as unreacted monomers and oligomers produced as a by-product in this process are heated to a temperature above the melting point of the adhering foreign substances and then induced and discharged. During or after the induced discharge, by-products accompanied by adherent foreign substances such as unreacted monomers and oligomers are contacted with a treatment liquid whose melting point is lower than the melting point of the adherent foreign substances to separate the by-products from the adherent foreign substances. A method for separating by-products by-produced during the polymerization reaction process of the above-mentioned polymer and adherent foreign substances accompanying them. 2. The method for separating a by-product produced as a by-product in a polymerization reaction process of a polymer and an adhering foreign substance accompanied with the by-product according to claim 1, wherein the treated liquid is the same kind as the condensed by-product. 3. A by-product in the polymerization reaction process of the polymer according to claim 1 or 2, wherein by-products accompanied by unreacted adhering foreign substances such as monomers and oligomers are heated to a temperature not lower than the melting point of the adhering foreign substances and induced to be discharged. A method for separating the by-product that forms and the adhering foreign substances that accompany it.