JPH0571610B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a highly rigid polyester that can form an anisotropic melt phase and has excellent heat resistance and fluidity. <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. An example of a polymer that forms an anisotropic melt phase is a liquid crystal polymer made by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate (Japanese Patent Application Laid-open No. 1989-1999).
72393), liquid crystal polymer copolymerized with p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (Japanese Unexamined Patent Publication No. 77691/1983), 4,4'-dihydroxybiphenyl in p-hydroxybenzoic acid Liquid crystal polymers (Japanese Patent Publication No. 57-24407, Japanese Patent Application Laid-Open No. 60-25046), which are copolymerized with terephthalic acid and isophthalic acid, are known. <Problems to be Solved by the Invention> These liquid crystal polymers have a higher modulus of elasticity than ordinary engineering plastics, but they have p-hydroxybenzoic acid as the main component, and have excellent heat resistance and It could not be said that the balance of moldability was necessarily excellent. In response to this, the
Although the publication discloses a polymer consisting of phenylhydroquinone and terephthalic acid, it has a problem of high melting point and poor fluidity. On the other hand, Japanese Patent Publication No. 63-35172 discloses a polymer consisting of phenylhydroquinone and 4,4'-diphenyldicarboxylic acid, but it has been found that it also has a high melting point and does not necessarily have good fluidity. <Means for Solving the Problems> As a result of intensive studies aimed at solving the above problems, the present inventors discovered that the following high-rigidity polyester specifically forms liquid crystals at low temperatures, and have achieved the present invention. Ivy. That is, the present invention provides the following structural units () to
Consisting of structural units selected from (), the structural unit () is 10 to 100 mol% of the whole, [() + ()] is 90 to 0 mol% of the whole, and the logarithmic viscosity is 0.5 to 100 mol%.
The present invention provides a highly rigid polyester characterized by a rigidity of 20 dl/g.

[ka]

[ka]

[ka] (However, X in the formula is

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[ka]

[ka] and

One or more selected from [formula] Indicates the above group, Y is

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[expression] and

One or more selected from [formula] Indicates the above group. Also, Z is

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Indicates one or more notations selected from [Formula]. Further, the logarithmic viscosity is a value measured at 60° C. in pentafluorophenol at a concentration of 0.1 g/dl. ) In the highly rigid polyester of the present invention, the structural unit () is essential, and the purpose of the present invention is achieved by the polymer consisting of the structural unit () specifically forming liquid crystals at low temperatures despite its rigid structure. considered to be a thing. In the highly rigid polyester of the present invention, the above structural unit () is a 2-(2-chlorophenyl) structural unit () is a structure of a polyester produced from 2-(2-chlorophenyl)hydroquinone and 4,4'-diphenyldicarboxylic acid. The structural units () are methylhydroquinone, chlorohydroquinone, phenylhydroquinone, t-butylhydroquinone, hydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, and 2,6-dihydroxynaphthalene. one or more dihydroxy compounds selected from ) Structure of polyester produced from one or more dicarboxylic acids selected from ethane-4,4'-dicarboxylic acid, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-diphenyl ether carboxylic acid Indicates the unit. In addition, the structural unit () has one or more aromatic acids selected from p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 3-chloro-4-hydroxybenzoic acid, and 3-phenyl-4-hydroxybenzoic acid. This figure shows the structural unit of polyester produced from group hydroxycarboxylic acids. In addition, in addition to the above structural units, a small amount of dioxy compound, dicarboxy compound, oxycarboxylic acid, p-phenylenediamine, etc. may be copolymerized. These structural units () account for 10 to 100 mol% of the total, preferably 15 to 100 mol%, and more preferably 50 to 100 mol%. The molar ratio of ()/() is preferably 10/0 to 5/5, more preferably 10/0 to 7/3. on the other hand,
The molar ratio of ()/() is preferably 10/0 to 1/9, more preferably 10/0 to 1.5/8.5. Further, the aromatic polyester capable of being anisotropically melt-formed used in the present invention can be produced according to the conventional polycondensation method for polyester, and although there is no particular restriction, typical production methods include the following (1) to (4). ) law. (1) Deacetic acid polycondensation from diacylated aromatic dihydroxy compounds such as 2-(2-chlorophenyl)hydroquinone, acylated aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acids such as 4,4'-diphenyldicarboxylic acid. A method of manufacturing by reaction. (2) From an aromatic dihydroxy compound such as 2-(2-chlorophenyl)hydroquinone, an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid such as 4,4'-diphenyldicarboxylic acid, and acetic anhydride to a deacetic acid polycondensation reaction. A method of manufacturing. (3) Dephenolation from aromatic dihydroxy compounds such as 2-(2-chlorophenyl)hydroquinone, diphenyl esters of aromatic dicarboxylic acids such as 4,4'-diphenyldicarboxylic acid, and phenyl esters of aromatic hydroxycarboxylic acids. A method of manufacturing by polycondensation. (4) Aromatic hydroxycarboxylic acids such as 2-(2-chlorophenyl)hydroquinone and 4,
A method in which an aromatic dicarboxylic acid such as 4'-diphenyl dicarboxylic acid is reacted with a desired amount of diphenyl carbonate to convert the carboxyl group into phenyl ester, and then an aromatic dihydroxy compound is added and a phenol-depleting polycondensation reaction is performed. . Acetic acid No. 1 is used as a catalyst for polycondensation reaction.
Metal compounds such as tin, tetrabutyl titanate, lead acetate, antimony trioxide, magnesium, sodium acetate, potassium acetate and trisodium phosphate are representative, and are particularly effective in dephenol polycondensation. Moreover, it is also possible to use melt polymerization and solid phase polymerization together for each of the above polycondensation methods. That is, a polymer that has been polycondensed by melt polymerization can be made to have a higher degree of polymerization by solid phase polymerization.
A wide variety of known methods can be used for solid phase polymerization. The aromatic polyester capable of forming an anisotropic melt phase used in the present invention has an anisotropic melt formation initiation temperature of 400
℃ or less, preferably the melting point measured by differential scanning calorimeter (DSC) is 200-450℃, 200-400℃
℃ is more preferable. Logarithmic viscosity of these polyesters ranges from 0.5 to 20.0
dl/g, preferably 1.0 to 10.0 dl/g. Furthermore, the melt viscosity of the aromatic polyester capable of forming an anisotropic melt phase used in the present invention is 10 ² to 2×10 ⁴
Poise is preferable, and 2×10 ² to 1×10 ⁴ poise is particularly preferable. The melt viscosity is a value measured using a Koka type flow tester at a liquid crystal start temperature of +40° C. and a shear rate of 1000 (1/sec). The aromatic polyester thus obtained can be made into a molded article by conventional extrusion, film forming, injection molding, etc. at a temperature of 450° C. or lower. The molded article of the present invention has extremely high rigidity due to its specific molecular structure. The present invention will be explained below with reference to Examples. Example 1 33.10 g (1.5 x 10 ^-1 mol) of 2-(2-chlorophenyl)hydroquinone and 4,4'- in a polymerization test tube
Diphenyldicarboxylic acid 36.33g (1.5×10 ^-1 mol)
and 33.69 g (3.3×10 ^-1 mol) of acetic anhydride, reacted at 130 to 150°C for 2 hours under a nitrogen stream, and then heated to 360°C.
The temperature was raised over 1 hour and 15 minutes until the temperature reached 1 hour and 15 minutes, and then the reaction was further carried out for 1 hour, the pressure was reduced to 0.8 mmHg, and the reaction was further carried out for 2 hours to complete the polycondensation. The liquid crystal initiation temperature of this polymer was 274°C, and it exhibited good optical anisotropy. The logarithmic viscosity of this polyester was 1.3 dl/g. Melt viscosity is 314℃,
The shear rate was 11,500 poise at a shear rate of 10 ³ (1/sec), indicating good fluidity. The theoretical structural formula of this polymer is as follows, and the elemental analysis values showed good agreement with the theoretical values. Further, when the thermal properties of this polymer were measured using a differential scanning calorimeter (Perkin-Elmer type), the melting point was 294°C.

[C] This polymer was subjected to a flow tester to determine the spinning temperature.
Spinning was carried out at 380°C with a spinneret hole diameter of 0.3 mmφ to obtain a spun yarn with a diameter of 0.08 mmφ. When this spun yarn was measured using a Rheoviblon DDV--EA manufactured by Toyo Baldwin Co., Ltd. at a frequency of 110 Hz, a heating rate of 2°C/min, and a distance between chucks of 40 mm, the α dispersion was as high as 172°C, and the elastic modulus was at 30℃
It was 32.3 GPa. Examples 2 to 23 2-(2-chlorophenyl)hydroquinone diacetate (), chlorohydroquinone diacetate (), methylhydroquinone diacetate (), phenylhydroquinone diacetate (), t-butylhydroquinone diacetate (), hydroquinone Diacetate (), 4,
A diacetoxy compound selected from 4'-diacetoxybiphenyl (), 44'-diacetoxydiphenyl ether (), 2,6-diacetoxynaphthalene () and 4,4'-diphenyldicarboxylic acid (), 1 ,2-bis(phenoxy)ethane-4,
4'-dicarboxylic acid (XI), 1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylic acid (XII), terephthalic acid (), isophthalic acid (
), 2,6-naphthalene dicarboxylic acid (),
4,4'-dicarboxydiphenyl ether (
) and p-hydroxybenzoic acid (), 2,6-hydroxynaphthoic acid (), 3-chloro-4-hydroxybenzoic acid (), 3-phenyl-4-hydroxybenzoic acid () Hydroxycarboxylic acids consisting of the following were charged into a reaction vessel in the proportions shown in Table 1, and acetic acid depolymerization was carried out in the same manner as in Example 1.

【table】

[Table] Examples 1 to 23 of the present invention formed liquid crystals at temperatures below 400°C, and produced strong polymers with good fluidity. <Effects of the Invention> The high-rigidity polyester of the present invention is melt moldable and has excellent mechanical and thermal properties, and can be used for various purposes such as engineering plastics.

Claims (1)

[Claims] 1 Consists of structural units selected from the following structural units () to (), in which the structural units () constitute 10 to 10 of the total
100 mol%, [()+()] is 90 to 0 mol% of the whole
A highly rigid polyester characterized by having a logarithmic viscosity of 0.5 to 20 dl/g. [Chemical] [Chemical] [Chemical] (However, X in the formula is one or more groups selected from [Formula] [Formula] [Formula] [Formula] [Formula] [Chemical] [Chemical] and [Formula] and Y represents one or more groups selected from [Formula] [Formula] [Formula] and [Formula]. Z is [Formula] [Formula] [Formula] and [Formula]. The logarithmic viscosity is the value measured at 60°C in pentafluorophenol at a concentration of 0.1 g/dl.)