JPH0774265B2 - Aromatic polyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aromatic polyester which is suitably used as a resin for paints, molded articles or fibers and has excellent heat resistance and moldability.

(Prior Art) Dibasic acids such as terephthalic acid, isophthalic acid, carbonic acid, and bisphenol A (2,2-propylidene-4,4'-biphenol), bisphenol S (4,4'-dihydroxydiphenyl sulfone), or Polycondensates with aromatic dihydroxy compounds such as 4,4′-dihydroxybiphenyl are referred to as polyarylate or wholly aromatic polyester,
It has already been put to practical use.

On the other hand, aromatic polyesters, which are homopolycondensates of aromatic hydroxycarboxylic acids, especially parahydroxybenzoic acid, have already been known to have extremely high heat resistance and mechanical strength, but they are difficult to mold. However, it has not been widely put into practical use.

However, recently, an aromatic polyester obtained by copolymerizing para-hydroxybenzoic acid and a component that lowers the melting point of the polycondensate in an appropriate ratio has anisotropy (thermotropic liquid crystal) when melted. It is found that not only the molding process is facilitated, but also the polymer chain is oriented in the flow direction, so that it has a high elastic modulus and mechanical strength.

The practical application of these melt-anisotropic aromatic polyesters has just begun, and future technological development is expected.

(Problems to be Solved by the Invention) The present invention has been made in view of such circumstances, and an object thereof is to have excellent heat resistance and mechanical strength,
Moreover, it is to provide an aromatic polyester having melt anisotropy and good moldability.

(Means for Solving the Problems) The aromatic polyester of the present invention comprises an aromatic dihydroxy compound and an aromatic dicarboxylic acid as two main constituents, or these two and an aromatic hydroxycarboxylic acid as main constituent components, and an orthochlorophenol An aromatic polyester having an intrinsic viscosity of 0.4 or more and 2.0 or less as measured by an Ubbelohde viscometer using a dilute solution at 30 ° C., wherein the main component of the aromatic dihydroxy compound is represented by the general formula (In the formula, n represents 2 or 4) The compound is characterized in that the above object can be achieved.

The aromatic dihydroxy compound represented by the general formula [I] of the present invention is specifically 1,2-bis (4'-hydroxy-3,
3'-diphenylbiphenyl-4-oxy) ethane and
It is 1,4-bis (4'-hydroxy-3,3'-diphenylbiphenyl-4-oxy) butane.

In the present invention, the compound represented by the general formula [I] is used as a main constituent component of the aromatic dihydroxy compound, and an aromatic dihydroxy compound other than this compound can be used in combination. Examples of other aromatic dihydroxy compounds include resorcin, hydroquinone, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone (2,5-dihydroxybiphenyl), methoxyhydroquinone, phenoxyhydroquinone, 4,4′-
Dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, 4,
4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, bisphenol A, 1,1'-di (4-hydroxyphenyl) cyclohexane, 1,2-bis (4-hydroxyphenoxy) ethane, 1,4-dihydroxynaphthalene , 2,6-dihydroxynaphthalene and the like.

Among these aromatic dihydroxy compounds, hydroquinone, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether and 4,4′-dihydroxydiphenyl sulfide are preferable for obtaining a highly crystalline polycondensate. used.

Examples of the aromatic dicarboxylic acid include metal salts of terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid,
4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, 4,4'-dicarboxydiphenyl sulfone, 4,4'-dicarboxybenzophenone, 1,2 -Bis (4-carboxyphenoxy) ethane, 1,4-dicarboxynaphthalene, 2,6-dicarboxynaphthalene and the like can be mentioned.

Among these aromatic dicarboxylic acids, terephthalic acid, 4,4′-dicarboxybiphenyl, 4,4′-dicarboxydiphenyl ether,
4,4'-dicarboxydiphenyl sulfide, 4,4'-
Dicarboxybenzophenone, 1,2-bis (4-carboxyphenoxy) ethane and 2,6-dicarboxynaphthalene are preferably used.

Examples of the aromatic hydroxycarboxylic acid include meta-hydroxybenzoic acid, para-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 3-bromo-4-hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid, 3-phenyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 4-hydroxy-4 '
-Carboxybiphenyl, 2-hydroxy-6-carboxynaphthalene and the like.

Among these aromatic dihydroxycarboxylic acids, parahydroxybenzoic acid and 4-hydroxy-4′-carboxybiphenyl are preferably used to obtain a highly crystalline polycondensate.

In addition, in order to adjust the physical properties, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, butane-1,3-diol, hexamethylene glycol, diethylene glycol, cyclohexane-1,4-diol, etc. Group glycols can also be used.

The aromatic polyester is a polycondensate obtained by polycondensing an aromatic dicarboxylic acid and an aromatic dihydroxy compound, and obtained by adding and reacting an aromatic hydroxycarboxylic acid as necessary.

Of the constituents of the polycondensate, the aromatic dihydroxy compound and the aromatic dicarboxylic acid are preferably composed in a substantially equimolar ratio, and the aromatic hydroxycarboxylic acid is composed in any amount. This is because the hydroxyl group and the carboxyl group undergo a binding reaction in equimolar amounts to polymerize,
When either one of the hydroxyl group and the carboxyl group is large, it becomes difficult to obtain a high molecular weight polycondensate.

Any method may be adopted as the method for producing the aromatic polyester of the present invention. Usually, it is preferable to acetylate the hydroxyl group of the constituents and to carry out the polycondensation reaction while removing acetic acid from the acetylated aromatic diacetoxy compound and aromatic acetoxycarboxylic acid and aromatic dicarboxylic acid. Acetylation proceeds easily only by heating an aromatic dihydroxy compound or aromatic hydroxycarboxylic acid and acetic anhydride, and the hydroxyl group is changed to an acetoxy group. The polycondensation reaction can usually be carried out at temperatures of 200 ° C to 350 ° C. The polycondensation reaction often does not particularly require a reaction catalyst, but if necessary, a metal oxide, a metal hydroxide or a metal salt is used. Good results are obtained when the acetic acid produced by the polycondensation reaction is first taken out from the reaction system under normal pressure and finally under reduced pressure.

When the reaction system is particularly crystalline and heterogeneous, acetic acid is taken out under pressure and finally depressurized to obtain a more uniform system, which is a good result. The molecular weight of the polycondensate can be adjusted by adjusting the molar ratio of the aromatic dihydroxy compound and the aromatic dicarboxylic acid among the constituents, but this method is a relatively low molecular weight polycondensate. Is effective when getting. In order to obtain a polycondensate having a relatively high molecular weight, a method of controlling the size of the molecular weight by carrying out a reaction while using the melt viscosity of the polycondensate as a guide is adopted. Furthermore, when a high molecular weight polycondensate is required, more polyfunctional components can be used, as long as the polycondensate does not gel.

When the above-mentioned highly crystalline component is incorporated into the constituent components of the aromatic polyester of the present invention, the polycondensate often exhibits melt anisotropy. Melt anisotropy can be confirmed by a polarization technique using an ordinary polarization microscope. Specifically, on the heating stage
A test piece prepared to have a thickness of 1 mm or less is placed, and the test piece is heated at a temperature rising rate of 5 ° C./min in a nitrogen atmosphere,
40 times with a polarizing microscope with the polarizers orthogonal, or
It can be easily confirmed by observing at a magnification of 100 times.

The aromatic polyester of the present invention thus obtained is used at 30 ° C. using a dilute solution of orthochlorophenol.
Intrinsic viscosity of 0.4 or more measured by Ubbelohde viscometer
It is 2.0 or less. The liquid crystal transition temperature of the aromatic polyester is preferably 220 ° C. or higher and 300 ° C. or lower, and the heat distortion temperature is
120 ℃ or more and 200 ℃ or less is preferable, and the melt viscosity is 1.00
0 to 10,000 poise is preferred.

(Example) Next, the present invention will be described in detail based on examples.

<Synthesis of Aromatic Dihydroxy Compound> An aromatic dihydroxy compound was synthesized by the method shown below. The obtained compound had white crystals. NiCl ₂ bis (diphenylphosphino) propane (dpp
p) is Kumada et al., Bulletion of the Chemical Society of
The one synthesized according to JAPAN (1976) was used.

Example 1 A 2-glass (1,2'-acetoxy-3,3'-) 1,2-bis (4'-acetoxy-3,3'- Diphenylbiphenyl-4-oxy) ethane 15.7384g (0.02mo
l), terephthalic acid 3.3226 g (0.02 mol) and paraacetoxybenzoic acid 3.6032 g (0.02 mol) were charged, the flask was put in a silicone oil bath, and the temperature of the bath was adjusted while blowing nitrogen gas into the flask from the gas inlet. I raised it. When the temperature of the bath increased and the temperature of the contents reached about 240 ° C, the polycondensation reaction started and the acetic acid produced began to distill from the distillation port. It takes about 3 hours to increase the temperature of the contents.
The temperature was raised to 300 ° C. After the temperature of the contents reached 300 ° C. and another hour passed, the distillation port was connected to a vacuum vessel, and the pressure inside the flask was gradually reduced to 1 Torr or less. When the content in the flask became 1 torr or less and further reacted for 1 hour, the content became an extremely viscous liquid, so the flask was pulled up from the bath and cooled. After the product cooled and solidified, the flask was broken and taken out. The resulting product was a pale brown, opaque aromatic polyester. The limiting viscosity of the obtained aromatic polyester measured by a Ubbelohde viscometer at 30 ° C. using a dilute solution of orthochlorophenol was 0.5. When the product was observed with a polarization microscope, it had melt anisotropy at 262 ° C. or higher. The heat distortion temperature was 158 ° C (JIS K7202 compliant, 18.5 kgf / cm ² ), and the melt viscosity at 220 ° C was 5100 poise.
The melt viscosity was measured with a flow tester under a load of 100 kgf.

Examples 2 and 3 As shown in Table 1, an aromatic polyester was synthesized in the same manner as in Example 1 except that the composition of each constituent component of the aromatic polyester was changed.

The intrinsic viscosity of the aromatic polyester obtained in Example 2 as measured by a Ubbelohde viscometer at 30 ° C. using a dilute solution of orthochlorophenol was 0.6. The intrinsic viscosity of the aromatic polyester obtained in Example 3 measured in the same manner as above was 0.6.

With respect to the obtained aromatic polyester, its liquid crystal transition temperature, heat distortion temperature (HDT) and melt viscosity were measured in the same manner as in Example 1. The results are summarized in Table 1.

Examples 4 to 6 As shown in Table 2, aromatic polyesters were synthesized in the same manner as in Example 1 except that the composition of each constituent component of the aromatic polyester was changed.

The aromatic polyester obtained in Example 4 had an intrinsic viscosity of 0.6 as measured by an Ubbelohde viscometer at 30 ° C. using a dilute solution of orthochlorophenol. Example 5
The intrinsic viscosity of the aromatic polyester obtained in 1. above was 0.6 in the same manner as above. The intrinsic viscosity of the aromatic polyester obtained in Example 6 measured in the same manner as above is
It was 0.7.

With respect to the obtained aromatic polyester, its liquid crystal transition temperature, heat distortion temperature (HDT) and melt viscosity were measured in the same manner as in Example 1. The results are summarized in Table 2.

(Effect of the Invention) As described above, the aromatic polyester of the present invention has
It has excellent mechanical strength and moldability, and can be suitably used in the fields of paints, adhesives, fibers, films, sheets, and molded products.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroki Kadomachi 7-20 Otemachi, Ibaraki City, Osaka Prefecture

Claims (1)

[Claims] 1. Ubbelohde measured at 30.degree. C. using an aromatic dihydroxy compound and an aromatic dicarboxylic acid as two main constituents, or these two and an aromatic hydroxycarboxylic acid as main constituents and using a dilute solution of orthochlorophenol. An aromatic polyester having an intrinsic viscosity of 0.4 or more and 2.0 or less as measured by a viscometer, wherein the main component of the aromatic dihydroxy compound is represented by the general formula [I] (In the formula, n represents 2 or 4) Aromatic polyesters characterized by being compounds.