JPS638968B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyester having excellent transparency and slipperiness. More specifically, inert inorganic fine particles mainly composed of silicon oxide containing aluminum oxide produced by a specific production method are added in the polyester production process to have excellent particle dispersibility and good transparency. The present invention relates to a method for producing linear polyester that can be used to produce fibers or films with easy slipping properties. In general, polyester has excellent physical and chemical properties and is therefore widely used as textiles for clothing and industrial use, as well as for magnetic tapes, photographic films, and the like. However, when attempting to produce fibers or films that take full advantage of their brightness and transparency, poor process passability often occurs during the molding process and high-level processing of the fibers and films. The reason for this is often
This was due to the high coefficient of friction between fibers, between fibers, between films, between fibers and metals, and between films and metals. Many techniques have been proposed and implemented to lower the coefficient of friction of polyester and impart slipperiness to fibers and films. A method in which part or all of the particles are precipitated during the reaction process and exist as fine particles. (2) Method of adding titanium oxide. (3) A method of adding inert inorganic fine particles that have a small refractive index difference with polyester. and so on. The purpose of any of these methods is to make fine particles exist in polyester,
Fine irregularities are formed on the surface of the obtained fibers and films, and these irregularities lower the coefficient of friction between fibers and fibers, films and films, fibers and metals, and films and metals, ensuring excellent processability. It was something I wanted to do. However, since the method (1) involves generating particles due to a catalytic metal compound during the polyester synthesis reaction, it is difficult to control the particle amount and particle size, and to prevent the generation of coarse particles. Although method (2) can impart slipperiness to fibers or films, it has not been possible to apply it to applications requiring transparency due to the strong hiding power of titanium oxide. Furthermore, when titanium oxide is present in fibers or films to an extent that maintains transparency, there are problems such as insufficient slipperiness of the resulting fibers or films. On the other hand, in method (3), if the type and amount of inert inorganic fine particles added can be appropriately selected, it is possible to impart slipperiness while maintaining a certain degree of transparency. In other words, as a conventional method of adding inert inorganic fine particles having a small refractive index difference with the polyester to impart lubricity to the resulting fiber or film while maintaining transparency, (A) For the purpose of smooth transparency, fine particles (talc) mainly composed of silicon oxide and magnesium oxide are transesterified in the presence of tertiary amines, quaternary ammonium compounds, etc., and the particles are transesterified at any point in the polymerization reaction. Addition method (Japanese Patent Publication No. 43-23960). (B) A method of adding inorganic compounds such as kaolinite and talc (French Patent No. 1347696). (C) A method of adding silicon oxide with an average particle size of 20 mμ or less (Japanese Patent Publication No. 12150/1983). (D) Silicon oxide with an average primary particle diameter of 20 mμ to 100 mμ and a PH of 3.5 to 4.5 is treated with at least one basic compound selected from the group consisting of quaternary ammonium compounds, and the PH is 7.0
-10.5, and then added at any stage until the polymerization of polyester is completed (Japanese Unexamined Patent Publication No. 53-45396). etc. are known. Among these methods, (A) and (B) involve the addition of pulverized natural products, so the contamination of coarse particles is unavoidable, and the occurrence of yarn breakage and fuzz during fiber production due to the coarse particles. There were various problems such as frequent occurrence and coarse particles scattered on the film surface. In addition, method (C) uses fine silicon oxide as a raw material, so coarse particles from the raw material are not mixed in (A).
This can be avoided considerably compared to method (B). However, as described in Japanese Patent Publication No. 43-23960, because silicon oxide has extremely poor dispersibility in polyester, agglomeration occurs during the production of polyester, and when it is formed into a film, many coarse particles are formed on the surface of the film. They are scattered and not only reduce the transparency of the film, but also become a major hindrance in producing ultra-thin films. Furthermore, method (D) attempts to prevent agglomeration during the production of the polyester, which is a drawback of method (C), and certainly reduces the amount of coarse particles in the polymer compared to method (C). Although it is possible, it is still not sufficient. In view of the above-mentioned problems, the present inventors focused on the usefulness of (C) and (D) in particular, and as a result of intensive studies on preventing the agglomeration of silicon oxide, they arrived at the present invention. That is, the present invention provides terephthalic acid or its ester-formable derivative and ethylene glycol,
When producing polyester from glycol selected from 1,4-butanediol or its ester-forming derivative, aluminum halide is present in silicon halide at any stage until the polymerization of the polyester is completed, and dry process is performed. Polymerization is completed after adding 0.05 to 4% by weight of aluminum oxide-containing dry process silicon oxide containing 0.1 to 5% by weight of aluminum oxide produced by the method and having an average primary particle size of 100 mμ or less. This is a method for producing polyester with excellent particle dispersibility. The polyester in the present invention refers to a polyester containing terephthalic acid or an ester-forming derivative thereof as a dicarboxylic acid component and a glycol selected from ethylene glycol and 1,4-butanediol or an ester-forming derivative thereof as a glycol component. Note that a part of the terephthalic acid component may be, for example, 5-sodium sulfoisophthalic acid, 5,-potassium sulfoisophthalic acid, p-β-hydroxyethoxybenzoic acid, p-hydroxybenzoic acid, isophthalic acid, 4,4'-diphenyl sulfone. dicarboxylic acid,
4,4'-diphenylmethanedicarboxylic acid, 4,
4'-diphenyl ether dicarboxylic acid, 4,4'-
Difunctional carboxylic acids such as diphenyl dicarboxylic acid, 1,2'-diphenoxyethane-p,p'-dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, and sebacic acid, or their ester-forming derivatives. or replace a part of the glycol component with ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,4
-Substituted with aliphatic, alicyclic, aromatic dioxy compounds such as cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-bis-β-hydroxyethoxybenzene, bisphenol A, or their ester-forming derivatives It may be a copolymerized polyester in which 70 mol% or more of the repeating units in the main chain are ester units selected from ethylene terephthalate units and tetramethylene terephthalate units. Furthermore, it is also possible to use a small proportion of a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid, trimesic acid, etc., or a polymerization terminator such as monohydric polyalkylene oxide, phenylacetic acid, etc. To produce polyester from such raw materials,
For example, dimethyl terephthalate is transesterified with an aliphatic glycol, terephthalic acid is directly esterified with an aliphatic glycol, or terephthalic acid is subjected to an addition reaction with ethylene oxide. The most widely used method is to synthesize a cyclic glycol ester and/or a low polymer thereof, and then subject the product to a polymerization reaction by a conventional method. Further, in synthesizing the polyester for carrying out the present invention, catalysts, color inhibitors, matting agents, ether bond by-product inhibitors, antioxidants, flame retardants, etc. well known in the art can be appropriately used. The aluminum oxide-containing dry process silicon oxide in the present invention refers to the aluminum oxide content that is produced by making aluminum halide exist in silicon halide when silicon oxide is produced by a dry process.
0.1 to 5% by weight, preferably 0.3 to 2% by weight of silicon oxide. The dry method for manufacturing silicon oxide mentioned here is, for example, the method described on page 524 of "Practical Handbook of Additives for Plastics and Rubber" (Kagaku Kogyosha, published August 10, 1970). This is a method in which silicon halide is generally thermally decomposed together with moisture and oxygen in the gas phase. Here, the aluminum oxide content in the dry process silicon oxide needs to be 0.1 to 5% by weight. That is, if the aluminum oxide content is less than 0.1% by weight, severe aggregation occurs during the polyester polymerization reaction and coarse particles are generated. In addition, re-dispersion of aggregated particles during spinning or film formation becomes difficult to occur, and dispersion in the yarn or film becomes significantly worse. On the other hand, if the aluminum oxide content exceeds 5% by weight, the yellowing tendency of the resulting polymer increases (the b value increases), which is not preferable. Furthermore, unlike the aluminum oxide-containing silicon oxide produced by a dry process by making aluminum halide exist in silicon halide from the raw material stage as in the present invention, simply mixing aluminum oxide and silicon oxide does not allow the polymerization reaction of polyester. The disadvantage is that it tends to cause agglomeration. The average primary particle diameter of the dry process silicon oxide containing aluminum oxide in the present invention is 100 mμ or less, preferably 40 mμ or less. The average primary particle size is
When it exceeds 100 mμ, the transparency of the polyester obtained decreases. The amount of dry process silicon oxide containing aluminum oxide in the present invention is determined based on the polyester obtained.
The amount is 0.05 to 4% by weight, preferably 0.3 to 2% by weight. If it is less than 0.05% by weight, the resulting fiber or film will not have sufficient slipperiness, and if it exceeds 4% by weight, the transparency of the resulting fiber or film will decrease. In the present invention, the dry process silicon oxide containing aluminum oxide can be dispersed in aliphatic glycol, aliphatic alcohol, water, etc. by a known method and added as a dispersed slurry at any stage until the polymerization of polyester is completed. It is preferable to add it by dispersing it in glycol, which is a raw material for the polyester. Further, the concentration of the glycol slurry is preferably 1 to 20% by weight, particularly preferably 5 to 15% by weight, from the viewpoint of the number of coarse particles and the softening point of the resulting polyester chips. The dispersion slurry of dry-processed silicon oxide containing aluminum oxide in the present invention can be prepared by a conventionally known method. A method of dispersing in a high-speed stirrer having a plurality of parallel shearing blades and a method of using an ultrasonic dispersion method in combination with the dispersion method are preferred. The prepared slurry is preferably passed through a filter with 60 meshes or more in order to remove coarse particles in the slurry. Further, it is preferable to apply a dispersant for the purpose of preventing agglomeration of the aluminum oxide-containing dry method silicon oxide added before the completion of polyester polymerization. In particular, tetraalkylammonium compounds are suitable because they have a large aggregation prevention effect. An example of applying a tetraalkylammonium compound as a dispersant for silicon oxide is JP-A-53-45396, but compared to the agglomeration prevention effect on silicon oxide applied in that publication, the dry method containing aluminum oxide is The agglomeration prevention effect against silicon oxide is significantly better. Here, the tetraalkylammonium compounds include tetramethylammonium hydroxide, tetramethylammonium chloride, tetraethylammonium hydroxide, tetraethylammonium chloride,
Tetraethylammonium bromide, tetrapropylammonium hydroxide, tetrapropylammonium chloride, tetraisopropylammonium hydroxide, tetraisopropylammonium chloride, tetrabutylammonium hydroxide, tetrabutylammonium chloride, etc. Among them, tetraethylammonium hydroxide is particularly preferred. The amount of the tetraalkylammonium compound added is preferably 0.5 to 30% by weight, particularly preferably 5 to 20% by weight, based on the aluminum oxide-containing silicon oxide in terms of the coarse particles and b value of the resulting polymer. In the present invention, the aluminum oxide-containing silicon oxide glycol slurry can be added at any stage until the polymerization of the polyester is completed, and it is particularly preferable to add the glycol slurry before the polymerization reaction of the polyester is started because uniform dispersibility is excellent. The intrinsic viscosity [η] of the polymer in the present invention is preferably 0.45 or more, more preferably 0.55 to 0.80, from the viewpoint of uniformity of particles in the obtained polymer. The present invention will be specifically explained below with reference to Examples. In addition, various measurement methods in the present invention are as follows. (b value) The polymer is molded into a cylindrical shape with a diameter of 2.5 to 3.5 mm and a height of 4.5 to 5.5 mm, and measured using a direct-reading color difference computer manufactured by Suga Test Instruments Co., Ltd. The larger the b value, the greater the yellowing tendency of the polymer. (Average primary particle diameter) Take a photograph of aluminum oxide-containing silicon oxide powder magnified 100,000 times using an electron microscope, measure the longest diameter of each primary particle from the obtained image, and calculate as the average of 1000 particles. It refers to the value given. (Transparency of Polymer) The polymer was molded into a cylindrical shape with a diameter of 2.5 to 3.5 mm and a height of 4.5 to 5.5 mm, and visually judged according to the following criteria. 1st grade: Very good 2nd grade: Fairly good 3rd grade: Fair 4th grade: Slightly poor 5th grade: Fairly poor (slippery of the film) Using a slip tester manufactured by Toyo Tester Co., Ltd.
The coefficient of static friction measured according to the ASTM-D-1894B method was used as a measure of slipperiness, and ranked as follows. [Static friction coefficient] [Slip property] Less than 1.2 ○ 1.2 to 1.5 △ 1.5 or more × (Number of coarse particles) Approximately 10 mg of the sample was sandwiched between 18 mm x 18 mm cover glasses and thermocompressed on a hot plate at 280°C to 300°C. Create a film with a diameter of approximately 10 mm. Observe this film with a phase contrast microscope (100x magnification), measure coarse particles with a maximum length of 10 μ or more, calculate the number of coarse particles per 10 mg of sample, and use the average value of 10 measurements per level. (Intrinsic viscosity [η]) Dissolve the polymer in O-chlorophenol and heat at 25°C.
This is the value measured at Example 1 Methanol is produced by charging 100 parts of dimethyl terephthalate, 64 parts of ethylene glycol, 0.1 part of calcium acetate monohydrate, and 0.03 parts of antimony trioxide into a transesterification tank, and raising the temperature to 150 to 230°C under a nitrogen atmosphere. The transesterification reaction was carried out while continuously distilling off from the system, and the reaction was completed 3 hours after the start of the reaction. Add trimethyl phosphate to the resulting product.
0.05 parts and further mixed with silicon chloride and aluminum chloride to produce aluminum oxide using a dry method.The aluminum oxide content is 1%, and the average primary particle size is
A mixture of silicon oxide containing 30 mμ of aluminum oxide and ethylene glycol in a weight ratio of 5:95 was prepared.
Janke & Kunkel Ultra Turrax T45DX
The slurry was dispersed for 30 minutes at 10,000 rpm and added at a concentration of 1.0% to the polyester obtained as dry method silicon oxide containing aluminum oxide. Next, the pressure of the polymerization reaction system was gradually reduced from 760 mmHg to 1 mmHg over 1 hour and 30 minutes, and at the same time the temperature was raised from 230°C to 280°C over 1 hour and 30 minutes. Under reduced pressure of 1 mmHg or less, polymerization temperature 280
Polymerization was continued for an additional 2 hours at ℃ for a total of 3 hours and 30 minutes. After the reaction was completed, the polymer was discharged into water in the form of a rod with a diameter of 3 mm, and cut into pieces of 5 mm in length to obtain polyester chips. [η] of the obtained polyester chip is
0.670, transparency was first grade, b value was 4.0, and the number of coarse particles was 24. The polyester chip is 180
After drying under reduced pressure at ℃ for 3 hours, it was formed into a sheet using an extruder set at 295℃, and then biaxially stretched at 95 to 130℃.
A 25μ biaxially stretched film was obtained. The static friction coefficient of the biaxially stretched film was 0.6, which was extremely good. Example 2 Polyester chips were obtained in the same manner as in Example 1 except that the slurry concentration of aluminum oxide-containing silicon oxide was changed as shown in Table 1. Table 1 shows the properties of each polyester. Table 1
It is clear from the results that when the slurry concentration is 1 to 20%, the melting point and number of coarse particles of the obtained polymer are particularly good.

[Table] Example 3 Chips were obtained in the same manner as in Example 1 except that the ethylene glycol slurry of silicon oxide containing aluminum oxide was passed through the filter shown in Table 2. Table 2 shows the characteristics of the chips obtained. From Table 2, it can be seen that when a slurry filter with 60 meshes or more is used, the number of coarse particles in the polymer is particularly small and good.

[Table] Example 4 Polymerization and chipping were carried out in the same manner as in Example 1 except that the type of dry process silicon oxide containing aluminum oxide and the content of aluminum oxide were changed as shown in Table 3. Then, a film was formed. Table 3 shows the properties of the chips and films obtained. Table 3 shows that when the content of aluminum oxide in the dry method silicon oxide containing aluminum oxide is within the range of 0.1 to 5% and the average primary particle size of the silicon dioxide is 100 mμ or less, the obtained The polyester chip has good transparency, a small number of coarse particles, and a low b value. Furthermore, it is clear that the film formed using this polyester chip has extremely good slipperiness. Experiment Nos. 12, 13, 18, 23, and 24 are comparative experimental examples to further clarify the effects of the present invention.

[Table] Example 5 Polyester chips having different intrinsic viscosities were obtained by changing the polymerization time in Example 1 as shown in Table 4.
Table 4 shows the characteristics of the chips obtained. From Table 4, it can be seen that when [η] is 0.45 or more, the number of coarse particles in the obtained polyester chips is particularly small and good.

[Table] Example 6 Polymerization and chipping were carried out in the same manner as in Example 1 except that the amount of dry process silicon oxide containing aluminum oxide added to the obtained polyester was changed as shown in Table 5. Next, a film was formed. Table 5 shows the properties of the chips and films obtained. Table 5 shows that when the amount of dry process silicon oxide containing aluminum oxide is within the range of 0.05 to 4%, the resulting polyester chips have good transparency, a small number of coarse particles, and a low b value. low. Furthermore, it is clear that the film formed using this polyester chip has extremely good slipperiness. Experiment Nos. 28, 29, and 36 are comparative experimental examples for further clarifying the effects of the present invention.

[Table] Example 7 In Example 1, the content of aluminum oxide in silicon oxide containing aluminum oxide was changed as shown in Table 6, and when preparing an ethylene glycol slurry of dry process silicon oxide containing aluminum oxide, Table 6 Transesterification and polymerization were carried out in the same manner as in Example 1 except that the dispersant shown in Example 1 was added. Table 6 shows the properties of the polyester chips obtained. Tetraethylammonium hydroxide is suitable as a dispersant, and the amount added is 0.5
It is clear that ~30% is preferred. Experiment
Nos. 50 and 55 are comparative examples to further clarify the effects of the present invention.

【table】

[Table] 1) Aluminum oxide content (%) in silicon oxide containing aluminum oxide
2) % of aluminum oxide content relative to silicon oxide
Example 8 100 parts of dimethyl terephthalate, 93 parts of 1,4-butanediol, and 0.03 parts of tetrabutyl titanate were charged into a transesterification tank and heated under a nitrogen gas atmosphere.
The transesterification reaction was carried out while the methanol, tetrahydrofuran and water produced by raising the temperature from 140°C to 225°C were continuously distilled out of the system, and the reaction was completed 4 hours after the start of the reaction. 0.03 part of tetrabutyl titanate was added to the obtained product, and silicon chloride and aluminum chloride were further mixed to produce a product using a dry process.The aluminum oxide content was 1%.
A 1,4-butanediol slurry containing 5% aluminum oxide-containing silicon oxide and 1% tetraethylammonium hydroxide with an average primary particle size of 30 mμ was added to the polyester obtained as aluminum oxide-containing silicon oxide so that the amount was 1.0%. added to. Next, the pressure of the system was gradually reduced from 760 mmHg to 1 mmHg over 1 hour, and at the same time the temperature was raised from 225°C to 250°C over 1 hour. 1mm
Under reduced pressure below Hg, at a polymerization temperature of 200℃ for an additional 2 hours,
Polymerization was carried out for a total of 3 hours. After the reaction was completed, the polymer was discharged into water to obtain a rod-shaped polymer having a diameter of 3 mm. Further, the polymer was cut to a length of 5 mm to obtain polyester chips. The resulting polyester chips had an intrinsic viscosity of 0.811, a b value of 8.0, and a coarse particle number of 25. After drying the polyester chips under reduced pressure at 160°C for 5 hours, they were formed into a sheet using an extruder set at 250°C.
Subsequently, the film was biaxially stretched at 100 to 110°C, and the static friction coefficient of the 25μ biaxially stretched film was 0.6.

Claims (1)

[Claims] 1. When producing polyester from terephthalic acid or its ester-forming derivative and a glycol selected from ethylene glycol and 1,4-butanediol or its ester-forming derivative, at any stage until the polymerization of the polyester is completed, A polyester containing 0.1 to 5% by weight of aluminum oxide produced by a dry method by making aluminum halide exist in silicon halide, and which can obtain aluminum oxide-containing dry method silicon oxide having an average primary particle size of 100 mμ or less. A method for producing a polyester with excellent particle dispersibility, characterized in that the polymerization is completed after adding 0.05 to 4% by weight.