JPS6312894B2 - - 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, fibers or films containing aluminum oxide and silicon oxide-based inert inorganic fine particles produced by a specific method have excellent particle dispersibility, as well as good transparency and slipperiness. The present invention relates to a method for producing polyester that can produce polyester. In general, polyester has excellent physical and chemical properties and is therefore widely used as textiles for clothing and industrial purposes, as well as for films such as magnetic tapes and photographs. However, the brightness of polyester,
When attempting to manufacture fibers or films that take full advantage of their transparency, poor passability often occurs during the molding process and the high-level processing of the fibers or film. In most cases, this is due to the high coefficient of friction between fibers, between films, and between fibers and metals. In the past, many techniques have been proposed and implemented as methods for lowering the friction coefficient of such polyester and imparting slipperiness to fibers and films. (2) Adding titanium oxide (3) Adding inert inorganic fine particles having a small refractive index difference with polyester. 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. Method of adding (Japanese Patent Publication No. 43-23960) (B) Method of adding inorganic compounds such as kaolinite and talc (French Patent No. 1347696) (C) Method of adding silicon oxide with an average particle size of 20 mμ or less (Special Japanese Patent Publication No. 43-23960) Publication No. 37-12150) (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 combined with at least one basic compound selected from the group consisting of quaternary ammonium compounds. Treated with compound to lower pH to 7.0
A known method is to add the polyester at any stage until the polymerization of the polyester is completed after the polyester is prepared at a temperature of 10.5% (Japanese Patent Application Laid-Open No. 53-45396). 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 to
The problem was that the quaternary ammonium compound thermally decomposed and colored the polymer yellowish brown. In view of the above-mentioned problems, the present inventors particularly (C)
Focusing on the usefulness of (D), the present invention was arrived at as a result of intensive studies on methods for preventing agglomeration of silicon oxide. That is, the present invention provides terephthalic acid or its ester-forming derivative and ethylene glycol,
When producing polyester from a glycol selected from 1,4-butanediol or its ester-forming derivative, (a) aluminum halide is present in silicon halide at any stage until the polymerization of the polyester is completed; Dry process silicon oxide containing aluminum oxide containing 0.1 to 5% by weight of aluminum oxide produced by a dry process and having an average primary particle size of 100 mμ or less (b) Ethylene glycol or 1,4-butanediol (c) Sulfone A slurry consisting of an aromatic polyester having an acid base is processed by a dry process using an aluminum oxide synthesis method to reduce the content of silicon oxide in the resulting polyester.
This is a method for producing a polyester with excellent particle dispersibility, which is characterized in that the polymerization is completed after adding 0.05 to 4% by weight. 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. In addition, a part of the terephthalic acid component may be substituted with, for example, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, p-β
-Hydroxyethoxybenzoic acid, p-hydroxybenzoic acid, isophthalic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenyl etherdicarboxylic acid, 4, 4′-diphenyldicarboxylic acid,
1,2-diphenoxyethane-p,p'-dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, sebacic acid, or other difunctional carboxylic acids or ester-forming derivatives thereof, or glycols. Some of the ingredients are ethylene glycol,
trimethylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,
70 mol% or more of the repeating units in the main chain substituted with aliphatic, alicyclic, or aromatic dioxy compounds such as 4-bis-β-hydroxyethoxybenzene and bisphenol A or their ester-forming derivatives are ethylene terephthalate units. It may also be a copolymerized polyester having ester units selected from 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, aliphatic glycol esters of terephthalic acid and The most widely used method is to synthesize 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). Generally, this is a method in which silicon halide is thermally decomposed together with hydrogen 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, the aluminum oxide content is 5
Exceeding this percentage by weight is not preferable because the yellowing tendency of the resulting polymer increases (the b value increases). 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. The aluminum oxide-containing dry method silicon oxide in the present invention is prepared as a slurry in which aromatic polyester having a sulfonic acid group is used as a dispersant and is dispersed in ethylene glycol or 1,4-butanediol by a known method until the polymerization of the polyester is completed. It can be added at any stage of the process, but it is particularly preferable to add it by dispersing it in the glycol that is the raw material for the polyester. In addition, the concentration of dry process silicon oxide containing aluminum oxide in the glycol slurry is preferably 1 to 20% by weight from the viewpoint of the number of coarse particles and the softening point of the polyester obtained.
Particularly preferred is 5 to 15% by weight. In addition, in the present invention, in order to prevent the agglomeration of the aluminum oxide-containing dry process silicon oxide added before the completion of polyester polymerization, an aromatic polyester having a sulfonic acid group is used as a dispersant when preparing a glycol slurry of the dry process silicon oxide containing aluminum oxide. Characterized by its use. Such an aromatic polyester having a sulfonic acid group can be synthesized, for example, by the following conventionally known method. (a) A method of polymerizing an aromatic dicarboxylic acid having a sulfonic acid group or a derivative thereof and an alkylene glycol. (b) A method of polymerizing an alkylene glycol with a mixture of the above aromatic dicarboxylic acid or its derivative having a sulfonic acid group and an aromatic dicarboxylic acid or its derivative having no sulfonic acid group. (c) A method in which an aromatic polyester obtained by polymerizing an aromatic dicarboxylic acid or its derivative without a sulfonic acid group and an alkylene glycol is sulfonated by a conventionally known method and then neutralized. The aromatic dicarboxylic acid having a sulfonic acid group used in the above method includes, for example, 2,
5-, 3,5- or 3,4-dicarboxybenzenesulfonic acid, 1,4- or 2,6-dicarboxynaphthalenesulfonic acid, 4,4-dicarboxydiphenylsulfonic acid, 4,4'-dicarboxybenzenesulfonic acid, Examples include alkali metal salts and ammonium salts such as carboxydiphenylmethanesulfonic acid and 4,4'-dicarboxydiphenylaminesulfonic acid. Among these, those which give the most favorable results are 3,5-dicarboxybenzenesulfonates and their derivatives. Examples of alkylene glycols to be reacted with the above compounds include ethylene glycol, propylene glycol, butylene glycol, pentamethylene glycol, hexamethylene glycol,
Diethylene glycol, dipropylene glycol and the like are preferred, with ethylene glycol being most preferred. Aromatic dicarboxylic acids without sulfonic acid groups used in methods (2) and (3) above include terephthalic acid, isophthalic acid, phthalic acid, 1,4
- or 2,6-naphthalene dicarboxylic acid, 4,
4'-dicarboxydiphenyl, 4,4'-dicarboxydiphenylmethane, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenylmethane, etc., and derivatives thereof. The amount of these dicarboxylic acids to be used is about 0.1 to 3 moles per mole of the dicarboxylic acid having a sulfonic acid group. Furthermore, an aliphatic dicarboxylic acid, p-oxybenzoic acid, p-β-hydroxyethoxybenzoic acid, or a derivative thereof can be appropriately copolymerized with the aromatic polyester having a sulfonic acid group, which is the dispersant of the present invention. be. The linear aromatic polyester having a sulfonic acid group and the like used as a dispersant in the present invention can be obtained by a conventionally known method as described above, and the one that gives the most favorable results in the present invention is 3,5- The reduced viscosity (ηsp/C) obtained by polycondensing sodium dicarbomethoxybenzenesulfonate and ethylene glycol after transesterification is 0.05 or more, preferably 0.1 or more, and the amount used depends on the melting point of the polymer and coarse particles. From the viewpoint of
Weight percent is preferred. The dispersion slurry of dry-processed silicon oxide containing aluminum oxide in the present invention is prepared by mixing dry-processed silicon oxide containing aluminum oxide, an aromatic polyester having a sulfonic acid group, and glycol using a conventional method such as a ball mill, homomixer, sand grinder, speed line mill, or roll mill. It can be obtained by mixing and grinding using a known dispersing machine, but it is
The method disclosed in Japanese Patent No. 125495, in which the material is dispersed in a high-speed stirrer having a plurality of shearing blades parallel to the rotating direction of the stirring blades, is preferred. 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 present invention will be specifically explained below with reference to Examples. In the present invention, "part" means part by weight, and "%" means % by weight. 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 Very poor (film slipperiness) 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 〇 1.2 or more and less than 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, and calculate the number of coarse particles per 10 mg of sample. Each level was measured 10 times, and the average value was taken as the number of coarse particles. (Intrinsic viscosity [η]) Dissolve the polymer in O-chlorophenol and heat at 25°C.
This is the value measured at (Melting point) Using Perkin-Elmer's DSC-1B, 10 mg of sample polymer was heated from room temperature at a rate of 16°C/min in a nitrogen gas atmosphere, and the minimum point (Tm) of the melting peak was measured. . (Reduced viscosity ηsp/C) Aromatic polyester with sulfonic acid group 2
This is the value measured at 25°C after dissolving 100ml of DMF. Example 1 100 parts of dimethyl terephthalate, 100 parts of sodium 3,5-dicarbomethoxybenzenesulfonate,
A low polymer was prepared by transesterifying 100 parts of ethylene glycol in the presence of 0.05 part of manganese acetate tetrahydrate as a transesterification catalyst, and then 0.04 parts of antimony trioxide as a polymerization catalyst.
The mixture was polymerized under reduced pressure to obtain an aromatic polyester having a sulfonic acid group as a dispersant and having an ηsp/C of 0.22. Charge 100 parts of dimethyl terephthalate, 64 parts of ethylene glycol, 0.1 part of calcium acetate monohydrate, and 0.03 part of antimony trioxide into a transesterification can.
The transesterification reaction was carried out while the temperature was raised to 150 to 230°C under a nitrogen atmosphere, and methanol produced was continuously distilled out of the system, and the reaction was completed 3 hours after the start of the reaction. Add trimethyl phosphate to the resulting product.
Adding 0.05 parts and further mixing silicon chloride and aluminum chloride to produce by dry method, the aluminum oxide content is 1%, and the average primary particle size is 30 m.
Janke&
Kunkel Ultra Turrax T45DX (10000rpm)
The slurry was dispersed for 30 minutes and added to the polyester obtained as a dry process silicon oxide containing aluminum oxide at a concentration of 1.0%. Then, 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 pressure was reduced to 1 mmHg.
The temperature was raised from 230°C to 280°C over 30 minutes. 1
Polymerization was carried out for an additional 2 hours at a polymerization temperature of 280°C under reduced pressure of less than mmHg, 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 was 0.672, transparency was first grade,
The b value was 4.1 and the number of coarse particles was 16. After drying the polyester chips at 180℃ for 3 hours under reduced pressure
Sheeting in an extruder set at 295°C followed by
Biaxial stretching was carried out at 95 to 130°C to obtain a 25μ biaxially stretched film. The static friction coefficient of the biaxially stretched film is 0.6
It was extremely good. Example 2 Polyester chips were obtained in the same manner as in Example 1, except that the composition ratio of the slurry consisting of dry method silicon oxide containing aluminum oxide, aromatic polyester having a sulfonic acid group, and ethylene glycol was changed. The properties of each polyester are shown in Table 1. Table 1 shows that when the concentration of aluminum oxide-containing dry process silicon oxide in the slurry and the ratio of the aromatic polyester having a sulfonic acid group to the dry process silicon oxide containing aluminum oxide within the range of the present invention, the melting point of the resulting polymer, It is clear that the number of coarse particles is particularly good.

[Table] Example 3 Polymerization and chipping were carried out after transesterification in the same manner as in Example 1 except that the type and amount of dry process silicon oxide containing aluminum oxide were changed as shown in Table 2. It was filmed. Table 2 shows the properties of the chips and films obtained. From Table 2, the content of aluminum oxide in dry method silicon oxide containing aluminum oxide is 0.1 to 5%.
and when the average primary particle diameter of the silicon dioxide is 100 mμ or less, the resulting polyester chips have good transparency, a small number of coarse particles, and a low b value. Furthermore, it is clear that the film produced using this polyester chip has extremely good slipperiness.

[Table] Example 4 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 3. Then, a film was formed. Table 3 shows the properties of the chips and films obtained. Table 3 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 produced using this polyester chip has extremely good slipperiness.

【table】

[Table] Example 5 By changing the polymerization time of the aromatic polyester having a sulfonic acid group as a dispersant in Example 1, polymerization times of aromatic polyesters having a sulfonic acid group as a dispersant having various ηps/C as listed in Table 4 were obtained. An aromatic polyester was obtained. Using this dispersant, polyester chips containing aluminum oxide and dry method silicon oxide were obtained in the same manner as in Example 1. The properties of each polyester are shown in Table 4, and the ηsp/
When C is 0.05 or more, the number of coarse particles of the obtained polymer is good.

[Table] Example 6 100 parts of dimethyl terephthalate, 93 parts of 1,4-butanediol, and 0.03 parts of tetrabutyl titanate were charged into a transesterification tank, and the mixture was 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 an aluminum oxide content of 1% by dry method.
and silicon oxide containing aluminum oxide with an average primary particle diameter of 30 mμ, an aromatic polyester having a sulfonic acid group with ηsp/C of 0.22 which is a dispersant synthesized in advance in Example 1, and butylene glycol at a weight ratio of 5. :0.5:94.5
JanKe & Kunkel UItra Turrax T45DX
The slurry was dispersed for 30 minutes at 10,000 rpm and added to the polyester obtained as a dry process silicon oxide containing aluminum oxide in an amount of 1.0%. Then, the system was gradually depressurized for 1 hour.
The pressure was reduced from 760 mmHg to 1 mmHg, and at the same time the temperature was raised from 225°C to 250°C over 1 hour. Polymerization was carried out for an additional 2 hours at a polymerization temperature of 200°C under reduced pressure of 1 mmHg or less, 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 polyester chips obtained had an intrinsic viscosity of 0.811, a b value of 7.5, and a coarse particle number of 19.
The polyester chips were dried under reduced pressure at 160°C for 5 hours, formed into a sheet using an extruder set at 250°C, and then biaxially stretched at 100 to 110°C, resulting in a 25μ biaxially stretched film with a static friction coefficient of 0.6. It was hot.

Claims (1)

[Claims] 1. When producing a 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, until the polymerization of the polyester is completed. (a) Containing aluminum oxide containing 0.1 to 5% by weight of aluminum oxide produced by a dry process by making aluminum halide exist in silicon halide, and having an average primary particle size of 100 mμ or less; Dry process silicon oxide (b) Ethylene glycol or 1,4-butanediol (c) A slurry consisting of an aromatic polyester having a sulfonic acid group is added to the dry process silicon oxide containing aluminum oxide in the resulting polyester.
A method for producing a polyester having excellent particle dispersibility, which comprises adding a polyester to a concentration of 0.05 to 4% by weight and then completing polymerization.