JPH0426330B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a novel aromatic polyester resin that is melt moldable and has excellent mechanical properties. <Conventional technology> In recent years, the demand for higher performance plastics has been increasing, and many polymers with various new performances have been developed and put on the market. Optically anisotropic liquid crystal polymers have attracted attention because of their excellent mechanical properties. (Special Publication No. 55-482). <Problems to be Solved by the Invention> However, although the mechanical properties of molded products made from these polymers are excellent in the flow direction, they are extremely poor in the direction perpendicular to the flow direction. It was found that the mechanical properties of molded products such as resins have a drawback of large anisotropy. On the other hand, aromatic polyester consisting of bisphenol A, terephthalic acid, and isophthalic acid is isotropic, and its mechanical properties are less anisotropic;
It was found that bisphenol A has a drawback of poor mechanical properties due to poor symmetry of the structure. Therefore, if we can obtain an aromatic polyester that has a molecular structure with relatively good symmetry and is isotropic, we can obtain molded products with less anisotropy and good mechanical properties. Considering this, we conducted research on various aromatic polyesters and discovered that aromatic polyesters with the following structure are specifically isotropic and can be melt-molded at temperatures below 400°C, resulting in the present invention. <Means for solving the problems> That is, the present invention uses repeating units represented by the following structural units (
It relates to a melt-moldable aromatic polyester resin having a concentration (measured in terms of concentration) of 0.40 to 20.0 dl/g. (However, in the formula, X and Y are X=Y=H, X=Y=Cl,
=Cl and Y=H, X=OCH ₃ and Y=H represents one or more groups selected from the combination) In the aromatic polyester resin of the present invention, the above structural unit () is tert-butylhydroquinone and 1,2 It means a structural unit of polyester produced from -bis(phenoxy)ethane-4,4'-dicarboxylic acid and/or nuclear-substituted 1,2-bis(phenoxy)ethane-4,4-dicarboxylic acid. The aromatic polyester resin of the present invention can be melt-molded at temperatures below 400°C, and molded products such as fibers, films, and resins having excellent mechanical properties can be easily obtained by ordinary melt-molding. Here, for example, the aromatic polyester obtained by using chlorohydroquinone instead of tert-butylhydroquinone becomes optically anisotropic under molding conditions, and 1,2-bis(phenoxy)ethane-4,
4′-dicarboxylic acid and/or nuclear substitution 1,2-
If terephthalic acid is used instead of bis(phenoxy)ethane-4,4'-dicarboxylic acid, the melting point will be higher than 500°C, making it impossible to achieve the object of the present invention. On the other hand, an aromatic polyester consisting of phenylhydroquinone and 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid has been filed with a patent application to show that it becomes liquid crystal only in a specific range. It was found that there is a problem in that the production cost of phenylhydroquinone is high. The nuclear substituted 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid in the present invention includes 1,2-bis(2,6-dichlorophenoxy)ethane-4,4'-dicarboxylic acid. , 1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylic acid, and 1,2-bis(2-methoxyphenoxy)ethane-4,4'-dicarboxylic acid. dicarboxylic acids, all of which give optically isotropic polyesters, but 1,
2-bis(2-chlorophenoxy)ethane-4,
4'-dicarboxylic acids are most preferred. In addition, if the proportion is small, terephthalic acid,
Dicarboxylic acid components such as 4,4-diphenyldicarboxylic acid, hydroquinone, methylhydroquinone, 4,4'-dihydroxybiphenyl, 2,6-
It is also possible to further copolymerize a diol component such as dihydroxynaphthalene and an oxycarboxylic acid such as p-oxybenzoic acid. Further, the logarithmic viscosity of the aromatic polyester of the present invention can be measured using pentafluorophenol as a solvent, and is 0.40 to 20.0 dl/g. Logarithmic viscosity
If it is less than 0.40 dl/g, the resulting molded product will have low strength, and if it is more than 20.0 dl/g, it will be difficult to melt mold. The aromatic polyester resin of the present invention can be manufactured according to the conventional polyester polycondensation method, and there are no particular restrictions on the manufacturing method, but typical manufacturing methods include the following methods (1) and (2). . (1) A method for producing a diester compound of an aromatic diol and an aromatic dicarboxylic acid by a demonocarboxylic acid polycondensation reaction. (2) A method of producing the diphenyl ester compound of the aromatic dicarboxylic acid and the aromatic diol by dephenol polycondensation reaction. In particular, method (1) is preferable because the polycondensation reaction proceeds without a catalyst, and in methods (1) and (2), stannous acetate, tetrabutyl tetanaate, lead acetate, and antimony trioxide are used as polycondensation reaction catalysts. Metal compounds such as cobalt acetate, sodium acetate, potassium acetate, etc. can also be used. The aromatic polyester resin of the present invention thus formed can be melt-molded at 400°C or lower, and can be melt-molded by extrusion molding,
It can be subjected to ordinary melt molding such as injection molding, compression molding, and blow molding, and can be processed into not only fibers but also films, three-dimensional molded products, containers, hoses, etc., and can be easily combined with other thermoplastic polymers. can be blended into. During molding, reinforcing agents such as glass fiber, carbon fiber, and asbestos, fillers, nucleating agents, pigments, antioxidants,
Additives such as stabilizers, plasticizers, lubricants, mold release agents, etc. can be added to impart desired properties to the molded article. The strength of the thus obtained molded article can be increased by heat treatment, and in many cases the elastic modulus can also be increased. This heat treatment can be carried out by heat treating the molded article in an inert atmosphere (eg nitrogen, argon, helium or water vapor) or in an oxygen-containing atmosphere (eg air) at a temperature below the melting point of the polymer. This heat treatment may or may not be under tension and can be carried out for a period of several minutes to several days. Molded articles obtained from the novel polyester resin of the present invention are characterized by being melt moldable at temperatures below 400°C and having excellent mechanical properties. <Example> The present invention will be further described below with reference to Examples. Example 1, Comparative Examples 1 and 2 50.0 g (0.2 mol) of tert-butylhydroquinone diacetate and 74.4 g (0.2 mol) of 1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylic acid were placed in a test tube for polymerization. mol) was charged, and acetic acid depolymerization was performed under the following conditions. First under a nitrogen atmosphere
After reacting at 250 to 280°C for 2 hours, the pressure was reduced to 0.6 mmHg, and the mixture was further heated for 3 hours to complete the polycondensation reaction, whereupon almost the theoretical amount of acetic acid was distilled out and a brown polymer was obtained. The theoretical structural formula of this polymer is as follows,
The elemental analysis results of the polyester showed good agreement with the theoretical values as shown in Table 1.

[Table] However, the oxygen content (%) is (100%-C%-H%
-Cl%). The melting point and optical anisotropy of this polyester were confirmed by placing it on a sample stage of a polarizing microscope and increasing the temperature. As a result, the melting point was 244°C, indicating that it was optically isotropic. When this polymer was measured with a differential scanning calorimeter (Perkin-Elmer type), the glass transition temperature was 141°C.
It had a melting point of 247°C, a cooling crystallization temperature of 204°C, and a heat of fusion of 6.8 cal/g. The logarithmic viscosity of this polymer was 3.0 dl/g in pentafluorophenol at 60°C and 0.1% concentration. This polymer was subjected to a Sumitomo-Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 280°C and a mold temperature of 30°C, 1/32″ x 1/2″ width x 5 For comparison, polybutylene terephthalate and polybutylene terephthalate containing 30% glass fiber were molded.This test piece was molded using Tensilon UTM-100 manufactured by Toyo Baldwin Co., Ltd. When a bending test (distance between spans 50 mm, strain rate 1 mm/min) was performed, as shown in Table 2, a surprisingly high modulus of elasticity, which is not normally obtained with isotropic polymers, was shown. When observed with a scanning electron microscope, it was found that almost no fibrils were observed, indicating that the molded product had little anisotropy.

[Table] Example 2 Same as Example 1, 12.5 g (5×10 ^-2 mol) of tert-butylhydroquinone diacetate and 1,
2-bis(2,6-dichlorophenoxy)ethane-4,4'-dicarboxylic acid 22.0g (5 x 10 ^-2 mol)
After reacting for 2 hours at 250 to 280 in a nitrogen atmosphere, the pressure was reduced to 1.0 mmHg, and the mixture was further heated for 3.5 hours.
When the polycondensation reaction was completed, almost a theoretical amount of acetic acid was distilled out and a brown colored polymer was obtained. The theoretical structural formula of this polymer is as follows,
The elemental analysis values of the polyester showed good agreement with the theoretical values as shown in Table 3.

[Table] However, the oxygen content (%) is (100%-C%-H%
−Cl%). This polyester was placed on a sample stage of a polarizing microscope and heated to confirm its optical anisotropy. As a result, it was found to be optically isotropic. When this polymer was measured with a differential scanning calorimeter (PerkinElmer type), the glass transition temperature was 133℃.
However, no melting peak could be detected. On the other hand, the logarithmic viscosity of this polymer in pentafluorophenol at 60°C and 0.1% concentration is 2.9 dl/
It was hot at g. Example 3 Same as Example 1, 12.5 g (5×10 ⁻² mol) of tert-butylhydroquinone diacetate and 1,
2-bis(2-methoxyphenoxy)ethane-
18.1 g (5 x 10 ^-2 mol) of 4,4'-dicarboxylic acid was charged and reacted in a nitrogen atmosphere at 250 to 280 ℃ for 2 hours, then the pressure was reduced to 0.9 mmHg and heated for an additional 3.5 hours to complete the polycondensation reaction. When this was carried out, almost the theoretical amount of acetic acid was distilled out and a brown polymer was obtained. The theoretical structural formula of this polymer is as follows,
The elemental analysis values of the polyester showed good agreement with the theoretical values as shown in Table 4.

[Table] However, the oxygen content (%) is (100%-C%-H%
−Cl%). This polyester was placed on the stage of a polarizing microscope and heated to confirm its optical anisotropy. As a result, it was found to be optically isotropic. When this polymer was measured with a differential scanning calorimeter (PerkinElmer type), the glass transition temperature was 121℃.
Melting point 170℃, cooling crystallization temperature 153℃, heat of fusion
It was 3.3 cal/g. On the other hand, the logarithmic viscosity of this polymer is 0.1% at 60°C in pentafluorophenol.
The concentration was 2.63 dl/g. Example 4 In a test tube for polymerization, 12.5 g (5 x 10 ^-2 mol) of tert-butyl hydroquinone diacetate and 1,2
-bis(phenoxy)ethane-4,4'-dicarboxylic acid (15.1 g (5 x 10 ^-2 mol)) was charged, and acetic acid depolymerization was carried out under the following conditions. First, the reaction was carried out at 250℃ for 1 hour in a nitrogen atmosphere, and then the temperature was raised to 310℃ in 1.5 hours, and at the same time 0.9mm
The pressure was reduced to Hg and the mixture was further heated for 1.5 hours to complete the polycondensation reaction, whereupon almost the theoretical amount of acetic acid was distilled out and a brown polymer was obtained. The theoretical structural formula of this polymer is as follows,
The elemental analysis results of the polyester showed good agreement with the theoretical values as shown in Table 5.

[Table] However, the oxygen content (%) is (100%-C%-H%
−Cl%). This polyester was placed on the sample stage of a polarizing microscope and heated to confirm its melting point and optical anisotropy. As a result, the melting point was 240℃ and it showed optical anisotropy, 316
It was found that it exhibits a peculiar behavior of becoming isotropic at ℃. Furthermore, when the polymer was measured with a differential scanning calorimeter (Perkin-Elmer type), the glass transition temperature was 146°C.
The melting points are 233℃ and 305℃, and the logarithmic viscosity is 3.4 dl/g in pentafluorophenol at 60℃ and 0.1% concentration.
It was hot. This polyester was subjected to a Koka-type flow tester and spun at 330°C with a nozzle hole diameter of 0.3 mmφ, and wound at 22 m/min to obtain a spun yarn with a diameter of 0.06 mmφ. The elastic modulus of this spun yarn was measured at a frequency of 110 Hz, a heating temperature of 2°C/min, and a distance between chucks of 40 mm using Toyo Baldwin Co., Ltd.'s Rheovibron DDV--EA, and it was 28 GPa. When the fractured surface of the polymer was observed using a scanning electron microscope, it was found that almost no fibrillar morphology was observed, indicating that the polymer had little anisotropy. <Effects of the present invention> The aromatic polyester resin of the present invention can be melt-molded at temperatures below 400°C, and molded products with low anisotropy and good mechanical properties can be obtained, making it suitable for engineering plastics and other uses. can be used.

Claims (1)

[Claims] 1 The main constituent is a repeating unit represented by the following structural unit (), and the logarithmic viscosity (measured in pentafluorophenol at 60°C at a concentration of 0.1%) is 0.40.
Melt moldable aromatic polyester resin with ~20.0 dl/g. (However, in the formula, X and Y are X=Y=H, X=Y=Cl,
=Cl and Y=H, X=OCH ₃ and Y=H).