JPH0324493B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a polyester composition, and more particularly, to a method for producing a polyester composition with excellent slip properties in which inert inorganic particles are uniformly dispersed. Polyesters produced industrially today, such as polyethylene terephthalate, have excellent physical and chemical properties, and are used in fibers, films,
Widely used as other molded products. However, contrary to its excellent properties, its slipperiness is poor, so during the molding process to obtain the above-mentioned molded product, post-processing processes such as surface treatment, or during handling of the product itself,
It is known that undesirable troubles such as a decrease in product value due to deterioration in workability and handling properties are known to occur. For these troubles,
It is common practice to incorporate fine particles into polyester to impart appropriate irregularities to the surface of a molded article, thereby improving the surface smoothness of the molded article. Such fine particles include a method in which fine particles are formed in polyester using a metal compound catalyst used in polyester production, such as an alkali metal compound or an alkaline earth metal compound, and a method in which fine particles are formed in polyester such as titanium dioxide, silica, talc, and kaolin, which are insoluble in polyester. A method of adding particles of an active inorganic compound is known. However, in the method described above, 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. It has the following drawbacks. If coarse particles are contained in polyester, problems such as clogging of filters, thread breakage, and film tearing occur during the molding process of threads, films, etc., resulting in process interruption. Furthermore, when used as superprite yarn or a film for magnetic tape, the coarse particle portion causes uneven gloss in the yarn, and causes problems such as magnetic recording dropouts in the film for magnetic tape. To solve this problem, in the above method, there is a method in which inert inorganic fine particles are classified in advance to remove coarse particles before use. For example, a method is generally used in which a powder obtained by crushing natural raw stone or a powder obtained by synthesis is made into a slurry of water, methanol, alkylene glycol, etc., and is classified by natural sedimentation, centrifugation, etc., and coarse particles are removed. . However, even when using a slurry from which coarse particles have been removed by classification, the inert inorganic fine particles may aggregate to form secondary particles, which may not be uniformly dispersed in the polyester. If such agglomerated particles are present in the polyester, they will cause clogging of filters, thread breakage, and film tearing in the subsequent process, as well as coarse particles, and will also cause the threads and films to have a uniformly finely textured surface, resulting in poor quality of the product. This causes the value to decrease. To prevent agglomeration of inert inorganic fine particles,
Dispersion methods such as ultrasonic treatment, pH adjustment, and chemical dispersion methods using dispersants have been proposed, but although these methods can reduce aggregated particles at the stage of slurry of inert inorganic fine particles, When producing polyester, when a slurry is added to the reaction system, the inert inorganic fine particles agglomerate, resulting in the problem that a sufficiently uniform dispersion cannot be achieved. In view of these circumstances, the present inventors have developed a method for uniformly dispersing inert inorganic particles into polyester.
As a result of extensive studies, we found that by adjusting the concentration, average particle diameter, and viscosity of the dispersed slurry of inert inorganic particles to satisfy a specific relational expression, the inert inorganic particles can be uniformly dispersed in polyester. We have discovered that this can be done, and have arrived at the present invention. That is, the present invention provides an aromatic dicarboxylic acid and/or
Or, when producing a linear polyester by reacting its ester-forming derivative with glycol, at any stage of the production of the polyester, an inert inorganic particle slurry with an average particle size of 5 to 5000 mμ is added.
This is a method for producing a polyester composition, which is characterized in that it is added under the following conditions. 100≦C×/logD≦6000 [C: Concentration of inert inorganic particle dispersed slurry (wt%): Average particle diameter of inert inorganic particles (mμ): Inert inorganic particle dispersed slurry viscosity (centipoise)] In the present invention The polyester refers to a polyester containing an aromatic dicarboxylic acid as the main acid component and an alkylene glycol as the main glycol component. Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, and anthracene dicarboxylic acid. etc. are exemplified. Among these, terephthalic acid is particularly preferred. Examples of the alkylene glycol include alkylene glycols having 2 to 10 carbon atoms, such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol. Among these, ethylene glycol, tetramethylene glycol and the like are particularly preferred. In order to produce a polyester consisting of the above-mentioned aromatic dicarboxylic acid component and glycol component, the aromatic dicarboxylic acid and glycol may be directly polycondensed, or the aromatic dicarboxylic acid dialkyl ester and glycol may be transesterified. After
Polycondensation may also be performed. A small amount of a third component (usually 20 mol% or less and/or 20% by mole or less) is added to the above polyester for the purpose of various improvements.
% by weight or less) may be copolymerized or blended. Such third components include, in addition to the aromatic dicarboxylic acids and alkylene glycols, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dioxy compounds, alicyclic glycols, aliphatic glycols containing aromatic nuclei, and polyalkylene glycols. , aliphatic oxyacids, aromatic oxyacids, and functional derivatives thereof; examples include polyethers, polyamides, polycarbonates, polyolefins, and the like. Furthermore, the above-mentioned polyester may contain a trifunctional compound or a monofunctional compound as long as it is considered to be substantially linear. Further, it may contain a catalyst and a stabilizer, and may also contain an antioxidant, a plasticizer, a dispersant, etc. as necessary. Examples of inert inorganic substances added to the polyester include magnesium oxide, zinc oxide,
Magnesium carbonate, calcium carbonate, calcium sulfate, alumina, silica, titanium dioxide, calcium, magnesium terephthalates, kaolin, china clay, diatomaceous earth, aluminosilicates and their hydrates, carbon black, calcium phosphate, etc. The average particle size is 5~5000mμ
Use the one. A major feature of the present invention is to prevent particle aggregation during polyester production by optimizing the concentration and viscosity of the slurry in accordance with the particle size of inert inorganic particles added during polyester production. It is in the point of doing. Average particle size of inert inorganic particles [(unit: mμ)]
The slurry concentration [C (unit: weight %)] and slurry viscosity [(unit: centipoise)] are very important factors in preventing particle agglomeration and have a close relationship. We calculated the average particle size (), slurry concentration
(C), As a result of repeating a large number of experiments in which the slurry viscosity () was changed, it was found that slurry can be added during polyester production as long as the value of C It is good with no agglomeration, but if it exceeds 6000, even if there is no aggregation of particles in the slurry, coarse particles will be generated due to aggregation during the production of polyester, and the quality of the product obtained will be poor. He discovered an extremely new fact. On the other hand, C×/log
For example, lowering the slurry concentration unnecessarily and lowering the value of C×/log() will result in a large amount of slurry medium for dispersing inert inorganic particles, which may lead to equipment constraints and burdens. grow bigger,
Since industrial productivity deteriorates, 100 or more is practically preferable. Here, the average particle size is 50% by weight of all measured particles.
means the "equivalent spherical diameter" of the particle at the point.
"Equivalent spherical diameter" (E, S, D, Equivalent
Spherical Diameter means the diameter of an imaginary sphere with the same volume as the particle, and can be calculated from an electron micrograph of the particle or measurement by a conventional sedimentation method. The slurry viscosity in the present invention refers to the viscosity of inorganic inert particles dispersed in a slurry medium,
This is a value measured using a rotational viscometer. The slurry medium used in the present invention may be any liquid medium as long as it can form a uniform dispersion system of inorganic particles and does not inhibit the esterification, transesterification, or polycondensation reaction. Glycol, which is a raw material for polyester, is preferred from the viewpoint of ease of production and polyester production efficiency. In addition, the slurry medium may of course contain small amounts of other components such as water or organic solvents such as methanol, and may also contain small amounts of surfactants, PH adjusters such as acids, alkalis, etc. depending on the purpose. It's okay. Further, the slurry may be a mixed slurry of two or more types of inert inorganic particles. The inorganic inert particle slurry may be added at any stage during the production of polyester, but it may be added at any stage from the beginning of the esterification or transesterification reaction between the aromatic dicarboxylic acid component and glycol until the end of the reaction. It is preferable to add As explained above, according to the present invention, a polyester containing no coarse agglomerated particles and containing uniform fine particles can be obtained, thereby reducing clogging, thread breakage, and film tearing in the manufacturing process of molded products. Needless to say, it is possible to obtain a molded product with extremely uniform and finely refined surface irregularities, especially in the fields of superprite yarn and magnetic tape films, which require easy slippage and the elimination of coarse protrusions. can be preferably used. The present invention will be specifically described below with reference to Examples. In addition, "parts" in the examples mean parts by weight, and the particle dispersibility in the slurry and the particle dispersibility in the polymer were measured as follows. Particle dispersibility in slurry: A small amount of the prepared slurry was sandwiched between two cover glasses, and the number of aggregated particles of 10 μ or more per 1 mm ² was counted using a microscope.
The smaller the number of aggregated particles, the better the particle dispersibility. Particle dispersibility in polymer: a small amount of polymer
Sandwiched between two cover glasses and melted at 280℃.
After pressing and rapid cooling, the amount per 1 mm ² is measured using a microscope.
The number of aggregated particles of 10μ or more was counted. The fewer the number of aggregated particles of 10μ or more, the better the particle dispersibility, and unless this number is 20 particles/mm ² or less, satisfactory results cannot be obtained. Example 1 Ethylene glycol (hereinafter abbreviated as EG) 90
10 parts of silica (average particle size: 40 mμ) was added to the mixture, and the mixture was dispersed and classified using a disperser and a centrifuge. The particle dispersibility of this slurry was 3 aggregated particles/1 mm ² of 10 μ or more. Also, the viscosity of the slurry was 150 centipoise. Next, 100 parts of dimethyl terephthalate and 70 parts of EG were subjected to a transesterification reaction in the presence of 0.035 parts of manganese acetate tetrahydrate as a catalyst in a conventional manner while raising the temperature from 140°C to 230°C. 10 parts of the prepared slurry (silica concentration 1% by weight to polymer) were added with stirring. Furthermore, 0.03 part of antimony trioxide and 0.01 part of trimethyl phosphate were added as catalysts, and then a polycondensation reaction was carried out in a conventional manner under high temperature vacuum to obtain polyethylene terephthalate. As shown in Table 1, the particle dispersibility in the polymer was 5 aggregated particles of 10μ or more/ ^1mm2 , which was at a good level that could be used for superprite yarn and magnetic tape films. . Comparative Example 1 A polyester composition was produced in the same manner as in Example 1, except that 25 parts of silica (average particle size: 40 mμ) was dispersed in 75 parts of EG, and the slurry concentration was changed. The results are shown in Table 1. The dispersibility of the slurry is 5 particles/1mm ² of aggregated particles of 10μ or more, but the dispersibility in the polymer is poor with 81 particles/1mm ² of aggregates of 10μ or more. It was hot. Examples 2 to 5 and Comparative Examples 2 to 4 Using various inert inorganic particles, slurry concentration,
A polyester composition was obtained in the same manner as in Example 1 except that the viscosity was changed. The results are shown in Table 1. Examples 2 to 5, which satisfy the condition Cx/logD≦6000, have good particle dispersibility in the polymer, but Comparative Examples 2 to 4, which do not satisfy the above condition. The polymer contained many aggregated particles and had poor dispersibility.

[Table] Example 6 A polyester composition was produced in the same manner as in Example 1, except that the addition of the silica dispersion slurry was changed from after the end of the transesterification reaction to during the transesterification reaction (at the time when the internal temperature was 170°C). The results are shown in Table 2. The molecular dispersibility in the polymer was good as the number of aggregated particles of 10μ or more was 4/mm ² . Example 7 100 parts of dimethyl terephthalate and 70 parts of EG were subjected to a transesterification reaction in the presence of 0.035 parts of manganese acetate tetrahydrate as a catalyst, while raising the temperature from 140°C to 230°C in a conventional manner. 0.03 part of antimony trioxide as a catalyst and 0.01 part of trimethyl phosphate as a stabilizer were added to the reaction product, and then a polycondensation reaction was carried out in a conventional manner until the intrinsic viscosity was 0.2.
At that point, the reaction system was returned to normal pressure, 10 parts of the slurry prepared in Example 1 (silica concentration 1% by weight to polymer) was added, and then the reaction system was returned to vacuum again and then vacuumed at high temperature in the usual manner. A polycondensation reaction was carried out below to obtain polyethylene terephthalate. The results are shown in Table 2. Particle dispersibility in polymer is
The number of aggregated particles of 10μ or more was 7 pieces/mm ² , which was good. Example 8 100 parts of dimethyl terephthalate was mixed with dimethyl-2,
Polyethylene-2,6-naphthalate was obtained in the same manner as in Example 1 except that 125 parts of 6-naphthalate was used. The results are shown in Table 2. Particle dispersibility in the polymer is 6 aggregated particles of 10μ or more/mm ²
It was good.

【table】

Claims (1)

[Scope of Claims] 1. When producing a linear polyester by reacting an aromatic dicarboxylic acid and/or its ester-forming derivative with a glycol, at any stage of the production of the polyester, an average particle size of 5 to 5000 mμ
A method for producing a polyester composition, which comprises adding an inert inorganic particle slurry under the following conditions. 100≦ C