JPS6139968B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyester, and more specifically, the present invention relates to a method for producing polyester.
The following is a method for producing polyester by adding an ethylene glycol slurry of inert inorganic particles preferably of 3 μ or less, and more specifically, it is produced as super bright fiber, micro film, or metal-deposited film with low turbidity and This invention relates to a method for producing polyester with excellent slip properties. Polyester in general, and polyethylene terephthalate in particular, has excellent mechanical and chemical properties and is widely used as textiles for clothing and industrial use, as well as films for magnetic tape, photography, capacitors, etc. However, contrary to its excellent properties, workability deteriorates due to poor slipperiness in terms of process passability in the molding process to obtain the above-mentioned molded product, post-processing processes such as surface treatment, and handling of the product itself. It is known that undesirable problems such as a decrease in product value occur. To solve these problems, it is common practice to incorporate fine particles into the polyester to give the surface of the molded product appropriate irregularities to improve the surface smoothness of the molded product. Such fine particles include metal compound catalysts used during polyester production,
For example, a method in which fine particles are formed in polyester using an alkali metal compound, an alkaline earth metal compound, or the like. A method is known in which particles of an insoluble, inert inorganic compound such as titanium oxide, silica, talc, kaolin, etc. are added to polyester. However, this method has the drawback that as the amount of metal compound added is increased in order to increase the amount of particles, coarse particles tend to be generated and it is extremely difficult to control the amount and diameter of the generated particles. have. Another method involves classifying inert inorganic particles in advance to remove coarse particles before use. In order to improve slipperiness by adding inert inorganic particles, methods have been proposed such as adding them during polymerization of polyester, mixing them with polyester chips during extrusion molding, and then molding them into fibers or films after melt extrusion. However, inert inorganic particles, especially silicon oxide, have extremely poor dispersibility, so they aggregate during polymerization or in the extruder, resulting in many coarse particles scattered on the surface of the molded product, which only reduces the transparency of film molded products. This was a major hindrance in producing ultra-thin films. Therefore, when adding inert inorganic particles to polyester, there is a method of uniformly dispersing the inert inorganic particles in a slurry. However, when ethylene glycol is used as a medium, another problem arises. Inert inorganic particles, particularly silicon oxide, generally do not have as good an affinity for ethylene glycol as they do for water, and primary particles agglomerate together in ethylene glycol to form secondary particles, which tend to form coarse particles. If such coagulated particles are present in the polyester, they cause clogging of filters, thread breakage, and tearing of the film in subsequent steps, as well as fixation of the film and drop-out of the magnetic tape. In view of the above circumstances, the present inventors have completed the present invention as a result of intensive studies on a method for producing polyester having good particle dispersibility by uniformly dispersing a slurry containing inert inorganic particles. That is, the present invention provides a method for producing a polyester containing polyethylene terephthalate as a main component by a transesterification or esterification reaction of terephthalic acid or its ester-forming derivative and glycol and a subsequent polycondensation reaction. A high-speed stirrer with shearing blades is used to
V (m/sec)] x [time T (sec)] is 4000 or more. Siloxane-polyoxyalkylene copolymer or diphenylpolysiloxane-polyoxyalkylene copolymer (particle
This is a polyester production method characterized by adding ethylene glycol slurry (0.01 to 20.0% by weight) to a polyester production reaction system. Next, the present invention will be explained in detail. The polyester in the present invention is mainly composed of polyethylene terephthalate, which can be formed into fibers, films, and other molded products, and can be formed by various conventional methods. It is manufactured by Of course, these polyesters may be homopolyesters or copolyesters, and examples of copolymerizable components include diethylene glycol, propylene glycol, neopentyl glycol, polyalkylene glycol, P-xylene glycol, 1. Diol components such as 4-cyclohexanedimethanol and 5-sodium sulforesorcin, adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,
Examples include dicarboxylic acid components such as 5-sodium isophthalic acid, polyfunctional dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxycarboxylic acid components such as P-oxyethoxybenzoic acid. When the dicarboxylic acid component is a dicarboxylic acid, after an esterification reaction with a glycol, and when a dicarboxylic acid ester is used, after an esterification reaction with a glycol, the obtained prepolymer is polycondensed at high temperature and under vacuum to obtain a polyester. It is also possible to polycondensate using the prepolymer itself as a starting material. The inert inorganic particles used in the present invention preferably have an average particle size of 3μ or less and have a sharp distribution on the fine side, and do not contain coarse particles of 10μ or more.
It is preferable to have a sharp distribution below μ. In detail, it is preferable that the value of ESD 10%, that is, the value of equivalent sphericity of particles at a point where the measured total particles are exactly 10% by weight, starting from the largest particle size, is 7 microns or less. If it contains coarse particles of 10μ or more or has an ESD10% value of 7μ or more, it is not preferable because coarse particles still exist even if the coarse particles caused by secondary agglomerated particles are eliminated. Specific examples of inert inorganic particles include silicon oxide, magnesia, alumina, talc, kaolin,
Examples include calcium carbonate, calcium sulfate, barium sulfate, and titanium oxide, with silicon oxide being particularly preferred. Examples of silicon oxide include dry-process or wet-process silicon dioxide represented by trade names such as "Aerosil" (manufactured by Nippon Aerosil Co., Ltd.) and "Thyroid" (Fuji Davison Co., Ltd.). The purpose of high-speed stirring in the present invention is to simultaneously shear, pulverize, and uniformly disperse inert inorganic particles in ethylene glycol. For mixing and stirring, please refer to the special issue of Chemical Industries, for example.
As described in VOL.11.No.3 (1967) pages 8-9, various types of stirring blades are known, but the present invention has essentially different shapes, so that the effects of the present invention can be improved. It is something that can be demonstrated. In other words, in Fig. 1, a high-speed agitator is used in which a plurality of stirring blades 2 are installed perpendicular to the blade axis 1, and a plurality of shear blades 3 are further installed on the stirring blades 2 parallel to the direction of rotation. It is. The shear blades may be deviated from the direction of rotation within a range that does not interfere with the torque of the blade axis, but preferably the shear blades are aligned with the circumferential direction of rotation or the shear blades are aligned with the normal direction of rotation. In order to achieve a shearing effect and a uniform dispersion effect, a plurality of shearing blades are installed, but they may be installed on one or both sides of the top or bottom of the stirring blade, or stirring blades with shearing blades can be installed in two or more stages. It may be installed in multiple stages. In the high-speed stirring, the circumferential speed V (m/sec) is expressed as V=2rπ・n/60 [where r is the radius (m) and n is the rotational speed (rpm)]; /second)]×[time T
(seconds)] must be 4000 or more. Although the dispersion effect differs depending on the type, particle size, and concentration of the inorganic particles,
If it is less than 4,000, it is difficult to achieve the desired dispersion effect, and micellar aggregated particles remain. When the number is 4000 or more, the difference in effectiveness becomes smaller, and conditions suitable for efficiency may be adopted. The effect of the present invention is exhibited when the ultrasonic wave as used in the present invention has a frequency of 20 kHz or more, but a frequency of 20 to 1000 kHz is practically satisfactory. If it is less than 20 kHz, it becomes difficult to exhibit the desired dispersion effect, and if it exceeds 1000 kHz, there is no difference in effectiveness, but it is not preferable in terms of efficiency. Ethylene glycol slurry of inert inorganic particles is finely dispersed by high-speed stirring and/or ultrasonic treatment, but in the case of high-speed stirring, dimethylpolysiloxane-polyoxyalkylene copolymer or diphenylpolysiloxane-polyoxyalkylene is formed after stirring treatment. It is preferable to add the copolymer, and in the case of ultrasonication, it can be added at any time. Dimethylpolysiloxane-polyoxyalkylene copolymer or diphenylpolysiloxane-
The amount of polyoxyalkylene copolymer added is preferably 0.01 to 20.0% by weight based on the inert inorganic particles.
It is 0.1-5.0% by weight. Dimethylpolysiloxane-polyoxyalkylene copolymer or diphenylpolysiloxane-
If the amount of the polyoxyalkylene copolymer added to the inert inorganic particles is less than 0.01% by weight, sufficient fine dispersibility of the particles in the polymer cannot be obtained, and if it exceeds 20% by weight, it may cause problems in the polyester polycondensation reaction. During the operation of gradually increasing the degree of vacuum, there is a risk that the reactants will foam and overflow, resulting in a drawback that productivity will be extremely poor. The dimethylpolysiloxane-polyoxyalkylene copolymer and diphenylpolysiloxane-polyoxyalkylene copolymer used in the present invention include dimethylpolysiloxane-polyoxyalkylene copolymer, dimethylpolysiloxane-polyoxypropylene copolymer, Dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer, diphenylpolysiloxane-polyoxyethylene copolymer, diphenylpolysiloxane-polyoxypropylene copolymer, diphenylpolysiloxane-polyoxyethylene-polyoxy Examples include propylene copolymers, among which dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymers are particularly preferred because they do not deteriorate the color tone or lower the softening point of polyesters. Further, two or more of these copolymers may be used in combination. Ethylene glycol, which is a slurry medium for inert inorganic particles, may of course contain small amounts of other components, such as water, organic solvents such as methanol, etc.
A small amount of PH adjuster such as acid or alkali may be used in combination depending on the purpose. Further, the slurry may be a mixed system of inert inorganic particles having two or more types of particle size distribution, and in addition to the inert inorganic particles, a catalyst, a heat stabilizer, an antioxidant, an ultraviolet absorber, etc. are used in combination. Good too. The thus obtained ethylene glycol slurry of uniformly dispersed inert inorganic particles can be added at any stage during the production of polyester, but it can be added from the early stage of the esterification or transesterification reaction between the dicarboxylic acid component and glycol. It is preferable to add it at the stage up to the prepolymer obtained after completion of the process, or at the initial stage of polycondensation of the prepolymer. As explained above, inert inorganic particles having an average particle size of 7 μm or less, preferably 3 μm or less and dimethylpolysiloxane particles uniformly dispersed according to the present invention.
By adding an ethylene glycol slurry of polyoxyalkylene copolymer or diphenylpolysiloxane-polyoxyalkylene copolymer to polyester, it does not contain coarse agglomerated particles that could not be obtained conventionally and contains a large number of uniform fine particles. Polyester is obtained, which not only reduces clogging, eliminates thread breakage, and film tearing in the manufacturing process of molded products, but also allows molded products with extremely uniform and finely refined surface irregularities to be obtained. The present invention is effective in the fields of polyethylene terephthalate fibers, films, and other molded products, and can be particularly preferably used in the fields of magnetic tapes, microfilms, and vapor-deposited films, which require high slipperiness and fine surface irregularities. . The present invention will be specifically explained below with reference to Examples. In addition, the particle dispersibility in the ethylene glycol slurry was determined by naturally filtering the adjusted slurry using a 25μ microfilter (manufactured by Dainippon Screen).
The degree of particle dispersibility was expressed by evaluating the ratio of the residue on the filter (weight) to the amount (weight) of inorganic particles in the ethylene glycol slurry. Grade 1: The amount of residue on the filter is less than 100 ppm. 2nd class: The amount of residue on the filter is 100ppm or more
Present at less than 200ppm. Grade 3: The amount of residue on the filter is 200ppm or more
Present at less than 500ppm. Grade 4: The amount of residue on the filter is 500 ppm or more. Particle dispersibility in a polymer is determined by sandwiching a small amount of polymer between two cover glasses, melting it at 280℃, pressing it, rapidly cooling it, and observing it under a microscope. The roughened portion was determined to be coarse particles. 1mm for particle dispersibility
Coarse particles of 7μ or more present in ^{No. 3} are observed and displayed with the following judgment. First grade: 0 to 10 coarse particles with a diameter exceeding 7μ/mm ³ Second grade: 10 to 20 coarse particles with a diameter exceeding 7μ/mm ³ . Tertiary grade: 20 to 50 coarse particles/ ^mm3 larger than 7μ exist. Grade 4: Coarse particles exceeding 7μ are present in an amount exceeding 50 pieces/mm ³ . Grades up to grade 2 can be put to practical use. In addition, the intrinsic viscosity of a polymer is a value measured at 25°C using 0-chlorophenol as a solvent, and the softening point is a value measured at 25°C using 0-chlorophenol as a solvent. 5mm inside the chip
This is the measured value of the temperature at which the water penetrates. Example 1 Ethylene glycol (hereinafter abbreviated as EG) 95
5% by weight of dry process silicon oxide ("Aerosil", with an average primary particle diameter of 40 mμ) was added to the high-speed stirrer of the present invention (6 shear blades each).
The mixture was mixed and stirred in a cylindrical container with an inner diameter of 360 mm using four individual blades each with a diameter of 150 mm. After this, the stirring speed was set to 400r.pm, respectively.
After treatment at 900 rpm and 1200 rpm for a predetermined time, a 30% by weight ethylene glycol solution of dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer was uniformly added at 0.16% by weight. Next, 100% by weight of dimethyl terephthalate and 70% by weight of ethylene glycol were transesterified in a conventional manner using 0.035% by weight of manganese acetate tetrahydrate as a catalyst. A 20% by weight glycol slurry (sio ₂ concentration, 1% by weight to polymer) was added under stirring. Thereafter, a polycondensation reaction was carried out at high temperature and under vacuum at normal pressure. Table 1 shows the particle dispersibility of the ethylene glycol slurry and the polymer to which the ethylene glycol slurry was added. As shown in Table 1, when [peripheral speed V (m/sec)] x [time T (sec)] becomes 4000 or more and the dimelpolysiloxane-polyoxyethylene-polyoxypropylene copolymer is added, The slurry has good particle dispersibility and is uniformly sheared and dispersed.
Furthermore, the state of particles in the polymer to which the slurry was added corresponded to the state in the ethylene glycol slurry, with no coarse particles observed and uniform fine particles.

[Table] Comparative Example 1 Instead of high-speed stirring using the device of the present invention, a homo mixer (manufactured by Tokushu Kikako Co., Ltd.) was used to prepare Aerosil EG.
Aerosil EG slurry and polymer were obtained in the same manner as in Example 1 except for adjusting the slurry. When the stirring time of the homomixer was set to 1 hour, a large number of micellar secondary agglomerated particles were observed in the EG slurry, so the stirring time was then extended, but the micellar secondary agglomerated particles still remained. Furthermore, the polymer obtained by adding the slurry contained a large number of aggregated coarse particles, and it is thought that the micellar secondary aggregated particles remained unbroken at the EG slurry stage. Example 2 To 95% by weight of EG, 5% by weight of dry process silicon oxide ("Aerosil" having an average primary particle diameter of 40 mμ) was added, and treated using the same homomixer as in Comparative Example 1 for 15 minutes. Then, the slurry was passed through an ultrasonic device manufactured by Ultrasonic Industry Co., Ltd. (model USV-400F28S, output
28 KHZ) for 1 hour, and then 3% by weight of dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer was added to the particles. Using this slurry, polyethylene terephthalate (intrinsic viscosity 0.621: softening point 260.1°C) was obtained in the same manner as in Example 1. No coarse particles of 7μ or more were observed in the polymer. Example 3 95% by weight of EG and 5% by weight of dry process silicon oxide (“Aerosil” primary particles with an average particle size of 40 mμ)
and the rotation speed using the high-speed stirrer used in Example 1.
Processed for 20 minutes under 900 rpm. Next, the slurry was treated for 1 hour using an ultrasonic generator (model USV4000F28S, output 28KHZ) manufactured by Ultrasound Kogyo Co., Ltd., and then dimethyl-polysiloxane-polyoxyethylene-polyoxypropylene copolymer was treated with 3 particles of dimethyl-polysiloxane-polyoxyethylene-polyoxypropylene. % by weight was added. Polyethylene terephthalate (intrinsic viscosity 0.625,
A softening point of 260.5°C was obtained. No coarse particles of 7μ or more were observed in the polymer. Example 4 5% by weight of alumina silicate (average primary particle size: 0.6μ) was added to 95% by weight of EG, and treated for 30 minutes at a rotation speed of 900 rpm using the high-speed stirrer used in Example 1. Thereafter, dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer was added in an amount of 2% by weight based on the particles. The slurry was processed using an ultrasonic generator manufactured by Ultrasonic Industry Co., Ltd. (model USV400F28S, output
28 KHZ) for 1 hour. Using this slurry, polyethylene terephthalate (intrinsic viscosity 0.631,
A softening point of 259.8°C was obtained. No coarse particles of 7μ or more were observed in the polymer, and the dispersibility was good. Example 5 5% by weight of dry process silicon oxide (average particle size of "Aerosil" primary particles 40 mμ) was added to 95% by weight of EG, and after treatment for 15 minutes using the same homomixer as in Comparative Example 1, dimethylpolymer Siloxane
A polyoxyethylene-polyoxypropylene copolymer was added in an amount of 3% by weight based on particles. The slurry was heated using an ultrasonic generator (USV-400F, 28S type, output 28KHZ) manufactured by Ultrasound Kogyo Co., Ltd.
Time processed. Using this slurry, polyethylene terephthalate (intrinsic viscosity 0.611, softening point 260.8°C) was obtained in the same manner as in Example 1. No coarse particles of 7μ or more were observed in the polymer. Example 6 5% by weight of dry process silicon oxide (“Aerosil” primary particles with an average particle size of 40 mμ) was added to 95% by weight of EG, and the mixture was stirred using the high-speed stirrer used in Example 1 at a rotation speed of 900 r.pm. After treatment for 20 minutes, dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer was added in an amount of 3% by weight based on the particles. The slurry was treated for 1 hour using an ultrasonic generator manufactured by Ultrasound Kogyo Co., Ltd. (USV400F, 28S type, output 28KHZ). Polyethylene terephthalate (intrinsic viscosity
0.618, softening point 261.0°C). 7 in the polymer
No coarse particles larger than μ were observed at all. Example 7 The stirring speed was 900 rpm, the treatment time was 600 seconds ([peripheral speed V] x [time T] = 4238), and dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer was replaced with dimethylpolysiloxane-polyoxyethylene-polyoxypropylene copolymer. Polyethylene terephthalate (intrinsic viscosity 0.642, softening point 260.3°C) was obtained in the same manner as in Example 1 except that the siloxane-polyoxyethylene copolymer was used. Particle dispersibility in the polymer was first class, with no coarse particles larger than 7 μm observed.

[Brief explanation of the drawing]

FIG. 1 shows a three-dimensional view of the high speed stirrer of the present invention. 1: Blade shaft, 2: Stirring blade, 3: Shear blade.

Claims (1)

[Scope of Claims] 1. When producing a polyester containing polyethylene terephthalate as a main component by transesterification or esterification reaction of terephthalic acid or its ester-forming derivative and glycol and subsequent polycondensation reaction, a plurality of polyesters parallel to the direction of rotation are produced. A high-speed stirrer with multiple shear blades [peripheral speed V (m/sec)] ×
High-speed stirring and dispersion treatment and/or ultrasonic treatment such that [time T (sec)] is 4000 or more,
Polyester is produced from an ethylene glycol slurry of inert inorganic particles with an average particle size of 7μ or less and dimethylpolysiloxane-polyoxyalkylene copolymer or diphenylpolysiloxane-polyoxyalkylene copolymer (0.01 to 20.0% by weight based on particles). A method for producing polyester, which comprises adding the polyester to a reaction system. 2. The method for producing polyester according to claim 1, wherein silicon oxide having an average particle size of 7 μm or less is used as the inert inorganic particles.