JPS6337817B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyester containing fine particles, and in particular, by precipitating fine insoluble particles at a high concentration in the polymer during the polyester manufacturing process, fine irregularities are created on the surface of fibers and films as final products. The present invention relates to a method for producing polyester that can be formed with high density, has good transparency and slipperiness, and is free from defects such as knobs and fish eyes and is suitable as a raw material for producing fibers and films. Since polyester has excellent mechanical, electrical, and thermal properties, it is widely used as a raw material for various materials such as fibers and films. However, fibers and films obtained from polyester containing polyalkylene terephthalate as a main component generally have a large coefficient of friction and have poor passability during spinning or film forming processes. There is a strong desire to establish a method for producing polyester that provides the following properties. Generally, a method for improving the slipperiness of polyester fibers or films involves mixing insoluble fine particles with polyester to form fine irregularities on the surface of the fibers or films. Specifically, The so-called external particle method involves adding inert fine particles to polyester such as titanium dioxide, kaolinite, talc, and silica when producing polyester, and the addition of carboxylic acid components, oligomers, or phosphorus compounds during the polyester production reaction. There is a so-called internal particle method in which fine particles are formed by reacting the metal compound with a metal compound. When the external particle method and the internal particle method are compared, the internal particle method is said to be more advantageous for the following reasons. It is economically advantageous because it does not require equipment for particle refinement, classification, and dispersion. In the external particle method, it is necessary to use a dispersant in order to prevent knobs and eyes due to agglomeration of the added fine particles, but in the internal particle method, this is not necessary. Generally, dispersants impede the heat resistance and electrical properties of the product, so it is best not to add them. Particles produced by the internal particle method generally have low hardness, so products with excellent wear resistance can be obtained. Particles produced by the internal particle method have good compatibility with polyester, so no voids occur even when stretched, and since they have a refractive index close to that of polyester, the product has high transparency. By the way, in the internal particle method, fine particles are formed using catalyst residues of alkali metals, alkaline earth metals, etc. used as transesterification catalysts, and the amount and particle size of the fine particles formed are adjusted by adding a phosphorus compound. The method of doing so is the mainstream. However, this method has the following problems and cannot be said to satisfy market demands. Coarse particles tend to form, often resulting in products with low transparency. Moreover, coarse particles cause product defects such as fiber knobs and film fixing eyes. Scale tends to form inside the polymerization vessel, and this scale sometimes falls off and mixes into the polyester, causing defects such as knobs and fixing eyes. Polymerization conditions must be strictly controlled in order to keep the precipitated amount and particle size of fine particles constant at all times. Generally, under conditions where fine particles are precipitated, the concentration of precipitated particles tends to be low, and it is difficult to precipitate fine particles uniformly and at a high concentration. The present inventors focused on the above-mentioned circumstances, and by precipitating fine particles at a high concentration in the polymer during the polyester manufacturing process, the present inventors created a polyester that has excellent transparency and slipperiness, and has fewer product defects such as knobs and fitting eyes. It was completed as a result of intensive research to establish a method for producing terephthalate in the presence of at least one polycondensation catalyst selected from the group consisting of antimony compounds, titanium compounds, and germanium compounds. When producing a polyester from an acid or its ester-forming derivative (hereinafter referred to as the acid component) and alkylene glycol, from the start of the reaction until the intrinsic viscosity of the reactant reaches 0.2 as the polycondensation reaction progresses. The gist is that a zirconium compound and a phosphorus compound soluble in the reaction system are added to the produced polyester in an amount that satisfies the following formula. 80ppm≦[Zr]≦2500ppm 0.1≦Zr/P≦10 In the formula, [Zr] represents the content (ppm) in terms of Zr atoms relative to the acid component, and Zr/P represents the atomic ratio. The polyester of the present invention has 80 repeating units.
More than mol% is composed of alkylene terephthalate, and other copolymerized components include isophthalic acid, P-β-oxyethoxybenzoic acid, 2,6-
Naphthalenedicarboxylic acid, 4,4'-dicarboxyldiphenyl, 4,4'-dicarboxybenzophenone, bis(4-carboxylphenyl)ethane, adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid or their Examples include dicarboxylic acid components such as alkyl ester derivatives. In addition, the glycol components include ethylene glycol,
Propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanedimethanol, an ethylene oxide adduct of bisphenol A, and the like can be arbitrarily selected and used. In addition, a small amount of amide bond, urethane bond, ether bond, carbonate bond, etc. may be included as a copolymerization component, in short, 80 mol%
All of the above polyalkylene terephthalates can function as a base resin as long as they have fiber-forming ability and film-forming ability. Next, the antimony compound, titanium compound, and germanium compound act as a polycondensation catalyst between the acid component and the alkylene glycol, and any compound can be used as long as it is soluble in the reaction system. For example, antimony compounds include antimony trioxide, antimony potassium tartrate, antimony glycolate, inorganic acid salts such as antimony trifluoride, and organic acid salts such as antimony acetate, and titanium compounds include tetraethyl titanate, tetrabutyl titanate, and titanium. partial hydrolysates of alkoxides, titanic oxalate, titanyl ammonium oxalate, potassium titanyl oxalate, titanium oxyacetylacetonate, titanic fluoride, etc. Germanium compounds include germanium oxide, germanium acetate, germanium ethoxide, germanium butoxide. etc.
Each of these polycondensation catalysts may be used alone, or two or more types may be used in an appropriate combination. The amount of these polycondensation catalysts added is not limited in some cases, but in the case of titanium compounds, the amount added is most commonly calculated based on the amount of titanium atoms relative to the acid component in the raw material.
0.0005-0.1 mol%, more preferably 0.002-0.03
mol%, in the case of antimony compounds and germanium compounds, 0.01 to 0.1 mol% in terms of antimony atoms and germanium atoms, more preferably
It ranges from 0.03 to 0.06 mol%. However, if the amount of polycondensation catalyst is too small, the reaction rate will be slow and it will take a long time to obtain a predetermined molecular weight, which is impractical, while if it is too large, the transparency and heat resistance of the resulting polymer will decrease. Further, the zirconium compound is essential as a particulate forming component for improving slipperiness in the internal particle method described above, and any zirconium compound can be used as long as it is soluble in the reaction system. Typical examples include zirconium alkoxides such as tetra-n-propionizirconate, tetraisopropiozirconate, tetra-n-butylzirconate, and tetra-n-amylzirconate, zirconyl acetate,
Organic acid zirconyl salts such as zirconyl formate, zirconyl tartrate, zirconyl oxalate, zirconyl stearate, zirconyl benzoate, zirconyl chloride,
Examples include inorganic acid zirconyl salts such as zirconyl bromide, zirconyl carbonate, and zirconyl ammonium carbonate. The amount of these zirconium compounds added is
In terms of zirconium atoms for the polyester produced
Must be set in the range of 80-2500ppm,
If it is less than 80 ppm, the amount of fine particles produced is small and the slipperiness of the final product cannot be sufficiently improved. on the other hand
If it exceeds 2,500 ppm, the slipperiness reaches a saturated state, and rather coarse particles are formed, which reduces transparency and worsens the polymer color, which is not preferable. A particularly preferable addition amount is 200 to 1300 ppm. Although the zirconium compound may be added in either solid or liquid form, it is most preferably added as an alkylene glycol solution in order to uniformly disperse the produced particles. If it is added in solid form, it is preferably sealed in a polyester container and added to the reaction system. The timing of addition of the zirconium compound should be set from the start of the esterification or transesterification reaction until the polycondensation reaction progresses and the intrinsic viscosity of the reaction product reaches 0.2. Because the viscosity is too high, the fine particles produced become unevenly mixed, making it impossible to obtain a homogeneous product. By the way, the initial polycondensation is almost complete when the intrinsic viscosity of the reactant reaches approximately 0.2, but since the molecular weight of the reaction product at this point is extremely small and the viscosity of the reaction solution is low, up to this point, the zirconium compound can be uniformly dispersed. The most preferable addition time confirmed by experiment was immediately after the completion of the esterification or transesterification reaction. The zirconium compound may be added at the same time as the titanium compound and the zirconium compound, which are polycondensation catalysts, or may be added separately. The phosphorus compound has the unique effect of making the insoluble particles formed finer and precipitating them at a high concentration due to the zirconium compound, and is the most characteristic component of the present invention along with the above-mentioned zirconium compound. Examples of such phosphorus compounds include phosphoric acid, phosphonic acid, and their derivatives. enyl ester,
Phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monoethyl ester, phosphoric acid diethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, methylphosphonic acid, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethyl ester , benzylphosphonic acid diethyl ester,
Examples include phenylphosphonic acid diethyl ester and phenylphosphonic acid diphenyl ester, and these may be used alone or in combination of two or more. These phosphorus compounds are used to refine the insoluble particles formed by the zirconium compound as mentioned above, so the amount of phosphorus added should be determined in consideration of the amount of zirconium added. By the way, the atomic ratio of Zr/P is
It was confirmed that the effect of adding the phosphorus compound was effectively exhibited by setting the addition amount within the range of 0.1 to 10. However, if the amount of the phosphorus compound is too small, the insoluble particles formed in the polymer cannot be made sufficiently fine, and the transparency of the final product decreases and knobs, fish eyes, etc. are likely to occur. On the other hand, if it is in excess, the polymerization rate will decrease and this will be industrially disadvantageous. Moreover, it is not preferable because it lowers the softening point and stability of the polymer. On the other hand, if the addition amount is set within the above-mentioned preferred range, insoluble fine particles with a diameter of about 1 μm or less will precipitate at a high concentration during the polyester manufacturing process, and these will form countless microscopic irregularities on the surface of the final product, such as fiber or film. , the slipperiness is significantly improved. Moreover, since the fine particles are uniformly dispersed, the transparency of the product is not impaired, and defects such as knobs and eyes are almost never generated. As with the case of zirconium compounds, the timing of addition of the phosphorus compound is determined from the start of the reaction until the intrinsic viscosity of the reactant increases.
Any time is fine until it reaches 0.2, but
When employing the transesterification method, it is preferable to add after the transesterification reaction is completed. This is because if the phosphorus compound is added before the transesterification reaction is completed, the transesterification catalyst may be deactivated and the reaction rate may be reduced. In addition, the phosphorus compound may be added at the same time as the zirconium compound,
They may be added separately. Note that when carrying out the present invention by transesterification, a transesterification catalyst must be used; however, the exchange catalyst in this case is not subject to particular restrictions, and conventionally known exchange catalysts such as alkali metals, alkali Compounds such as earth metals, zinc, and manganese can be arbitrarily selected and used. Among them, zinc and manganese compounds are recommended as the most preferred transesterification catalysts since they do not impede the transparency of the product. In addition, in the case of the direct weight method (method using free terephthalic acid), amines, ammonium compounds, alkali metal compounds, alkaline earth metal compounds are used as the third component to suppress the production of dialkylene glycol. It is also effective to add basic compounds such as, and all changes in their degree are within the scope of the present technology. Further, the method of the present invention can obtain similar effects when applied to either a batch polymerization method or a continuous polymerization method. The present invention is roughly constructed as described above, and the key point is to selectively use one or more of antimony compounds, titanium compounds, and germanium compounds as polycondensation catalysts, and to use a zirconium compound as an insoluble particle product and a zirconium compound as an insoluble particle product. By specifying the amount and timing of addition of the phosphorus compound as a micronization-promoting component, it is possible to uniformly generate fine insoluble particles in the polymer at high density. In addition to improving transparency and slipperiness, product defects such as knobs and fitting eyes can be prevented as much as possible. In particular, the polyester film obtained in the present invention has a smooth surface and excellent slipperiness, so it exhibits excellent performance as a base film for magnetic tapes, especially as a base film for video tapes. Next, Examples and Comparative Examples of the present invention will be shown. All parts in the examples mean parts by weight unless otherwise specified. The esterification reaction rate (esterification rate) was determined from the amount of carboxyl groups remaining in the reaction product and the saponification value of the reaction product. Intrinsic viscosity [η] is the polymer with phenol (6 parts by weight)
and tetrachloroethane (4 parts by weight) and measured at 30°C. The amount of diethylene glycol in the polymer was determined by decomposing the polymer with methanol and by gas chromatography as mole % relative to ethylene glycol. The precipitated particle diameter and particle concentration in the polymer were determined by observing a film formed by the method shown in the example using a reflective dark field microscope. The maximum surface roughness (R _T ), centerline average roughness (R _A ), and surface roughness density of the film were determined by Surfcom 300A.
It was measured using a mold surface roughness meter under the conditions of a needle diameter of 1 μm, a load of 0.07 g, a measurement reference length of 0.8 mm, and a cutoff of 0.08 mm, and the average value of 10 points was displayed. Film haze was measured using a direct reading haze meter (manufactured by Toyo Seiki Co., Ltd.). The coefficient of dynamic friction of the film is ASTM-D-1894-
Measurement was conducted in accordance with 63T under the conditions of 23°C, 65% RH, and a tensile speed of 200 m/min. Example 1 50 parts of terephthalic acid and 28 parts of ethylene glycol were subjected to an esterification reaction using 0.022 part of antimony trioxide (318 ppm in terms of antimony atoms based on the polyester produced). Esterification rate 95%
The product of terephthalic acid 100% is added to this as a reservoir fraction.
parts, 56 parts of ethylene glycol, antimony trioxide
Add a slurry consisting of 0.044 parts (318 ppm in terms of antimony atoms based on the polyester produced),
Under nitrogen atmosphere, pressure 2.5Kg/cm ² , reaction temperature 240
The esterification reaction was carried out at a temperature of 95%. Next, the esterification reaction product equivalent to 100 parts of terephthalic acid was transferred to a polycondensation reactor at 240°C, and 0.1
Add 3.81 parts by volume of an ethylene glycol solution of zirconyl acetate at a molar concentration (300 ppm in terms of zirconium atoms based on the polyester produced), stir for 15 minutes at the same temperature and normal pressure, and add trimethyl phosphate at a concentration of 100 g/molar. Add 1.07 parts by volume of ethylene glycol solution (204 ppm in terms of phosphorus atoms based on the polyester produced, Zr/P = 0.5), stir for 10 minutes at the same temperature under normal pressure, and then 275
Gradually lower the pressure of the reaction system while increasing the temperature to ℃.
The polycondensation reaction was carried out at the same temperature and pressure for about 80 minutes at 0.05 mmHg. [η] of the obtained polyethylene terephthalate is 0.630, and diethylene glycol is
It was 2.2% and highly transparent. This polymer was melt-extruded at 290°C, stretched 3.5 times in the longitudinal direction at 90°C and 3.5 times in the transverse direction at 130°C, and then heat-treated at 220°C to obtain a film with a thickness of 15 μm. The coefficient of dynamic friction of this film is 0.50, the film haze is 0.4%, and the maximum surface roughness ( _RT ) is 0.09μ.
m, the center line average roughness (R _A ) was 0.010 μm, and the surface roughness density was about 110 pieces/mm. When the particles in this film were observed using reflective dark field microscopy, countless extremely fine particles of 0.3 to 0.6 μm were observed, and coarse particles of 3 μm or more were observed at 36 locations under 200x magnification. It didn't exist. Next, using the polymer obtained above, at 285℃
When high-speed spinning was carried out at a discharge rate of g/min and a speed of 6000 m/min, the yarn could be taken off smoothly without any breakage. The obtained yarn had excellent gloss and extremely high transparency. Comparative Example 1 A polycondensation reaction was carried out under the same conditions as in Example 1, except that zirconyl acetate and trimethyl phosphate were not added. [η] of the obtained polymer
was 0.632, and diethylene glycol was 2.2%, making it highly transparent. This polymer was melt-extruded at 290°C, stretched 3.5 times in the longitudinal direction at 90°C and 3.5 times in the transverse direction at 130°C, and then heat-treated at 220°C to obtain a film with a thickness of 15 μm. The slipperiness of the obtained film was extremely poor and a uniform film could not be obtained. Furthermore, the coefficient of dynamic friction of this film could not be measured due to scale over, and the film haze was 0.2%.
When the particles in this film were observed by reflection dark field microscopy, no particles were observed at all. Next, using the polymer obtained above, at 285℃
When high-speed spinning was carried out at a discharge rate of g/min and a speed of 6,000 m/min, yarn breakage occurred approximately once every 5 minutes, and the yarn could not be taken off smoothly. Comparative Example 2 When polycondensation was carried out under the same conditions as in Example 1 except that antimony trioxide was not added, the [η] of the obtained polymer was as low as 0.378, indicating that satisfactory film formation and fiberization were not achieved. It was possible. Comparative Example 3 A polycondensation reaction was carried out under the same conditions as in Example 1 except that trimethyl phosphate was not added.
The obtained polymer had [η] of 0.638, diethylene glycol content of 2.2%, and was highly transparent. This polymer was made into a film with a thickness of 15 μm under the same conditions as in Example 1. The coefficient of dynamic friction of this film is 0.45, the film haze is 0.7, the maximum surface roughness (R _T ) is 0.21 μm, and the center line average roughness (R _A ) is 0.029 μm.
m, and the surface roughness density was approximately 70 pieces/mm. Further, when the particles in this film were observed by reflection dark field microscopy, countless particles of 1 to 2 μm in size were observed. Although the slipperiness is satisfactory, it is inferior to Example 1 in that the surface roughness is rougher and the surface roughness density is lower. Further, the transparency of the film was also slightly lower than that of Example 1. Examples 2 to 9 and Comparative Examples 4 to 5 Polyesters were obtained in exactly the same manner as in Example 1, except that the zirconium compounds and phosphorus compounds to be added and their amounts added were changed, and then films were formed. Table 1 shows the film properties of the obtained film and the evaluation results of spinning operability in high-speed spinning evaluated in the same manner as in Example 1.

[Table] Example 10 519 parts of terephthalic acid, 431 parts of ethylene glycol
After stirring, 0.16 parts of triethylamine and 0.23 parts of antimony trioxide were charged into a stainless steel autoclave equipped with a distillation column and a pressure regulator, and after purging with nitrogen, pressurized and maintained at a gauge pressure of 2.5 Kg/cm ² at 240°C.
The esterification reaction was carried out while continuously removing the water produced from the top of the distillation column. After starting the reaction
After 120 minutes, the pressure is released and the esterification rate is 95%.
of product was obtained. 0.90 parts of tetra-n-butyl zirconate/n-butyl alcohol salt (300 ppm in terms of zirconium atoms based on the produced polyester) was added to this esterification product, and the mixture was heated at normal pressure and 240°C.
Heat and stir for 15 minutes, then add an ethylene glycol solution of trimethyl phosphate at a concentration of 100 g
Add 5.55 parts by volume (204 ppm in terms of phosphorus atoms to the polyester produced, Zr/P = 0.5) and at normal pressure.
After stirring for 10 minutes, it was transferred to a polycondensation reactor at 240°C, and the temperature was raised to 275°C over 30 minutes, while the pressure of the reaction system was gradually lowered to 0.05 mmHg, and then kept at the same temperature and pressure for about 80 minutes. A polycondensation reaction was carried out. [η] of the obtained polymer is 0.639, diethylene glycol is 2.1
%, and had high transparency. When this polymer was formed into a film in the same manner as in Example 1, a film of almost the same high quality as in Example 1 was obtained. Further, when high-speed spinning was carried out in the same manner as in Example 1, the yarn could be spun smoothly without any breakage, and a yarn with high gloss and transparency was obtained. Example 11 519 parts of terephthalic acid, 431 parts of ethylene glycol
part, triethylamine 0.16 part and antimony trioxide 0.23 part, tetra-n-butylzirconate.n
-Pour 0.90 parts of butyl alcohol salt into a stainless steel autoclave equipped with a stirrer, a distillation column, and a pressure regulator, and after purging with nitrogen, pressurize to 2.5 gauge pressure.
The esterification reaction was carried out while maintaining the ^temperature at 240°C and continuously removing water produced from the top of the distillation column. After 120 minutes had passed from the start of the reaction, the pressure was released to obtain a product with an esterification rate of 95%. This esterification product was added to 5.55 parts by volume of an ethylene glycol solution of trimethyl phosphate at a concentration of 100 g (204 ppm in terms of phosphorus atoms based on the polyester produced).
After adding Zr/P=0.5) and heating and stirring at 240°C for 10 minutes at normal pressure, the mixture was transferred to a polycondensation reactor at 240°C and polycondensation was carried out under the same conditions as in Example 10. When the obtained polymer was formed into a film in the same manner as in Example 10,
A high quality film almost the same as in Example 10 was obtained. Further, when high-speed spinning was carried out in the same manner as in Example 1, yarn breakage did not occur and smooth spinning was possible, resulting in a yarn with high optical selectivity and transparency. Example 12 Dimethyl terephthalate 1000 g in polycondensation reactor
800 parts of ethylene glycol and 0.226 parts of zinc acetate (dihydrate), and heated to 2.5 parts at 195℃ under nitrogen atmosphere.
Transesterification was carried out by heating for a period of time. This transesterification product contains 0.38 parts of antimony trioxide, 1.45 parts of tetra-n-propiozirconate/2n-propionate salt (300 ppm in terms of zirconium atoms based on the polyester produced), and 1.37 parts of trimethyl phosphate (based on the polyester produced). 306 ppm (calculated as a phosphorus atom, Zr/P=0.33) was added, heated and stirred at the same temperature for 15 minutes, and then 275
Gradually lower the pressure of the reaction system while increasing the temperature to ℃.
The pressure was adjusted to 0.05 mmHg, and polycondensation was further carried out at the same temperature and pressure for about 80 minutes. When the obtained polymer was formed into a film in the same manner as in Example 1, a film of almost the same high quality as in Example 1 was obtained. Further, when high-speed spinning was carried out under the same conditions as in Example 1, the yarn could be taken up smoothly without breakage during spinning, and the gloss and transparency of the yarn obtained were extremely good.

Claims (1)

[Claims] 1. Polyester is produced from terephthalic acid or its ester-forming derivative and alkylene glycol in the presence of at least one polycondensation catalyst selected from the group consisting of antimony compounds, titanium compounds, and germanium compounds. During the period from the start of the reaction until the intrinsic viscosity of the reactant reaches 0.2 as the polycondensation reaction progresses, zirconium compounds and phosphorus compounds soluble in the reaction system are added in an amount that satisfies the following formula for the polyester produced. A method for producing a polyester containing fine particles, characterized by adding. 80ppm≦[Zr]≦2500ppm 0.1≦Zr/P≦10 In the formula, [Zr] represents the content (ppm) in terms of Zr atoms in terephthalic acid or its polyester-forming derivative, and Zr/P represents the atomic ratio.