JPS5845224A - Aromatic polyester having melt anisotropy and its preparation - Google Patents

Abstract

PURPOSE:To obtain the titled polyester having high Young's modulus and strength, and formable easily by melt processing, by reacting an acid component composed of a specific aromatic difunctional carboxylic acid with a diol component composed of a specific substituted hydroquinone. CONSTITUTION:The objective polyester is prepared by the polycondensation reaction of (A) an aromatic difunctional carboxylic acid selected from (i) aromatic dicarboxylic acids (e.g. diphenyl terephthalate) and (ii) aromatic oxycarboxylic acid (e.g. p-hydroxybenzoic acid) with (B) a diol component containing (iii) a hydroquinone derivative >=70mol% of which is nucleus-substituted with a 9-15C tertiary aralkyl group (e.g. dimethylbenzylhydroquinone) and (iv) other diol component (e.g. hydroquinone). The amount of the ester unit containing the component (iii) is >=10mol% of the whole recurring ester unit.

Description

[Detailed description of the invention]

The present invention relates to a melt anisotropic aromatic polyester and a method for producing the same. More specifically, the present invention uses a substituted hehydroquinone that is nuclear-substituted with a tertiary 7-ralkyl group having 9 to 15 carbon atoms as the main diol component, and forms a melt-molded product that is easy to melt-mold and has a high Young's modulus. The present invention relates to a melt anisotropic aromatic polynisnal obtained and a method for producing the same. Polyethylene terephthalate has long been used as a material for fibers and films due to its excellent mechanical strength, heat resistance, and chemical resistance. Widely used as a material for plastics, etc. However, polyethylene terephthalate fibers, for example, are still not sufficient for industrial applications (eg, tire cords, etc.) that require high strength and high Young's modulus. On the other hand, aromatic polyamides such as polyP-phenylene terephthalamide and polyP-benzamide are known as fiber materials that provide extremely high Young's modulus 1 strength. However, unlike polyethylene terephthalate, which can be easily made into fibers by melt spinning, these aromatic polyamides are difficult to melt-spun, and are usually solution-spun (dry or wet-spun).
1 is made into fiber

[There is. Therefore, it is essential to recover the solvent, and the shape of the product obtained is also limited by the molding method, for example, it is limited to fibers, etc., and it still has many disadvantages from an industrial perspective. . In order to improve these drawbacks, P-oxybenzoic acid,
Aromatic copolyesters made of aromatic compound components such as hyde p-quinone, ten-7-thalic acid, and inphthalic acid-1, and fibers thereof have been proposed (@Open and Close Publication No. 50-43223). However, even in this case, the aromatic polyester using terephthalic acid as the dicarboxylic acid component has an extremely high melting point, and even if a polymer with a high degree of polymerization is produced, it cannot be melt-molded, for example, by melt-spinning, to achieve high strength. It is difficult to industrially and efficiently produce molded articles such as fibers having a high Young's modulus. In addition, aromatic polyesters using isophthalic acid as the dicarboxylic acid component can be melt-molded, and have the advantage that the melt viscosity is significantly lower than that of terephthalic acid-based aromatic polyesters, but they also have melt anisotropy. Therefore, it has the disadvantage that fibers with a high Young's modulus, whose appearance is particularly awaited, cannot be produced by spinning alone. As a result of extensive research into aromatic polyester that is easy to melt mold and can be used to form molded products such as fibers and films with high Young's modulus and high strength only by melt molding, the inventor found that the main diol component is carbon # ! It consists of a substituted hydroquinone that is nuclear-substituted with 19 to 15 tertiary aralkyl groups, and the main acid component has two ester-forming functional groups (
It has been discovered that an aromatic polyester made of an aromatic difunctional carboxylic acid in which a carboxyl group or a hydroxyl group (for example, a carboxyl group, a hydroxyl group, etc.) is bonded to the para position has the above-mentioned properties, and the present invention has been achieved based on this finding. That is, the present invention provides an aromatic bifunctional carboxyl group in which two ester-forming functional groups are bonded to the para position, an acid component mainly consisting of an acid, and a tertiary aralkyl group having 9 to 15 carbon atoms to substitute the nucleus. It consists essentially of a diol component mainly consisting of tIIt-converted hydroquinone, and replaces 1 with the aromatic dicarboxylic acid component in the aromatic bifunctional carbonic acid component.
The present invention relates to a fiber-forming or film-forming melt anisotropic aromatic IJ ester containing at least 10 moles of total repeat units of ester units with an hydroquinone component, and a method for producing the same. The cylindrical component constituting the melting anisotropic aromatic polynickel of the present invention is a substituted hydroquinone (hereinafter referred to as Iit-substituted) whose nucleus is mainly substituted with a tertiary aralkyl group having 9 to 15 carbon atoms. It consists of ido-quinone (sometimes called ido-quinone). This third one? I & aralkyl group is -C(CH
2) An aralkyl group represented by tAr (where Ar is an aromatic group having 6 to 12 carbon atoms) is preferred,
Preferred specific examples of Ar include the following (in the formula, R is a C1-C3 lower alkyl group, preferably containing no tertiary hydrogen). In addition to the tertiary aralkyl group, the substituted hydroquinone may be substituted with a halogen, particularly chromium, or 7'-me. For example, in order to impart more -l- flame retardancy to aromatic polynisder, it is preferable to use a substituted hydroquinone whose nucleus is replaced by a tertiary alkyl group and a halogen. Preferred specific examples of the substituted hydroquinone include the following compounds. and so on. In addition to the substituted hydroquinone, a small proportion of other aromatic diols and/or aliphatic diols can also be used. Other aromatic diols include hydroquinone,
Resorcinol, bisphenol A, bisphenol S, bisphenol Z, 4,4'-dihydroxydiphenyl,
4.4'-dihydro, xydiphenyl ether, tertiary amyl hydroquinone, tertiary amyl hydroquinone,
Tertiary octylhydroquinone, tertiary nonylhydroquinone, methylhydroquinone. Talol hydroquinone, tertiary butyl hydroquinone,
Examples include 4-tertiary butyl resorcinol, etc.
In addition, aliphatic diols include ethylene glycol, neobenzene gelicol, cyclohexane dimethylol,
Bis-β-hydroxybisphenols (especially bis-β-hydroxybisphenols)
Examples include lower alkylene glycols or alicyclic glycols such as -hydroxybisphenol A, bis-β-hydroxybisphenol S, bis-β-hydroxybisphenol 2, etc.). Of these,
Other aromatic diols are more preferred. The proportion of the substituted hydroquinone in the total diol component is 70 molti or more, more 80 molti or more, especially 9
It is preferable that it is 0 molti or more. The acid component constituting the melt anisotropic aromatic polyester is mainly composed of an aromatic difunctional carboxylic acid having two ester-forming functional groups bonded to the para position. Here, the para position refers to the 1st and 4th positions in a benzene nucleus, the 2nd and 6th or 1st and 5th positions in a naphthalene nucleus, and the 4th and 4th positions in a diphenyl nucleus. ′
Represents the position of the digit. Furthermore, two ester-forming functional groups represent two carboxyl groups, or one carboxyl group and one hydroxyl group. Therefore, aromatic difunctional carboxylic acid means an aromatic dicarboxylic acid or an aromatic oxycarboxylic acid or a mixture thereof. Examples of the aromatic dicarboxylic acid include prephthalic acid, chlorterephthalic acid, plumtyrephthalic acid 12.5-
Dibromterephthall! ! ! , methylterentalic acid, 2
．． 6-naphthalene dicarboxylic acid, 4,4'-phenyl dicarboxylic acid, 3,3'-dinorom-4,4'-diphenyl dicarboxylic acid M, etc. can be used. Among these, terephthalic acids, particularly terephthalic acid, are preferred. Furthermore, examples of aromatic oxycarboxylic acids include P-oxybenzoic acid, 3-chloro-4-oxybenzoic acid, and 3-boom-4-oxybenzoic acid. Examples include 3.5-dichloro-4-oxybenzoic acid and 3-tertiary butyl-4-oxybenzoic acid. Among these, P-oxybenzoic acid is particularly preferred. In addition to the aromatic difunctional carboxylic acid, other difunctional carboxylic acids can also be used in small proportions. Other difunctional carboxylic acids include, for example, isophthalic acid, 1.
4-naphthalene dicarboxylic acid, 1,6-naphthalene dicarboxylic acid, succinic acid, adipic acid 1m-oxybenzoic acid, p-(/-human-oxyethoxy)benzoic acid, m-
(β-kl-″loxethoxy)synzoic acid, p-(4-
(human-oxyethoxy) benzoic acid, m-(4-hydroxyphenoxy)benzoic acid, p-(3-hydroxyphenoxy)benzoic acid, m-(3-hydroxyphenoxy)benzoic acid, 4-human, dixy-l -naphthoic acid, 6
Mention may be made of dicarboxylic acids and oxycarboxylic acids such as -hydroxy-1-naphthoic acid, 8-oxy-2-naphthoic acid and the like. The proportion of aromatic difunctional carboxylic acid in which two ester-forming functional groups are trap-bonded at the para position in the total acid component is:
It is preferably 70 molti or more, more preferably 80 molti or more, especially 90 molti or more. , molar ratio 90:
10~to;so, and even 75:25~25:75
It is preferable that In the present invention, it is necessary that the number of ester units derived from the aromatic dicarboxylic acid and the substituted hydroquinone be as small as 10 moles per total repeating unit of the aromatic polyester. When using a mixture of oxycarboxylic acid and oxycarboxylic acid, it is also necessary to consider the proportion of aromatic dicarboxylic acid in the total acid component.When producing the melt anisotropic aromatic polyester of the present invention, the diol component It is preferable to use the dicarboxylic acid component and the dicarboxylic acid component in an approximately equimolar ratio or more.Then, it is preferable that the diol component and the dicarboxylic acid component in the aromatic polyester be used in an approximately equimolar ratio.For example, terephthalic acid In the case of an aromatic polyniskel consisting of a p-oxybenzoic acid-containing component and a dimethylbenzyl ti1m hydride p-quinone component, when the molar ratio of the terephthalic acid component and the p-oxybenzoic acid-containing component is 1=1, it is tertiary. The 7-mil monoconverted hydrocarbon component and the prephthalic acid component may be in an approximately equimolar ratio; in other words, the diol component may be in an amount of approximately 1/2 mole based on the total acid component. Melt anisotropic aromatic polyesters have fiber-forming properties or film-forming properties.The term "fiber-forming properties" or "film-forming properties" does not refer to fiber or film applications, but rather to melt-forming properties. Therefore, the aromatic polyester of the present invention can be used not only as fibers and films, but also as plastics. The aromatic polyester is preferably a polymer with a viscosity of 08 or more, more preferably 1 or more, especially 15 or more.By using this polymer, a molded article having a high Young's modulus and high strength can be obtained. The melt anisotropic aromatic polyester of the present invention can be obtained industrially efficiently and easily.
It is mainly composed of a substituted hydroquinone component whose nucleus is substituted with 15 tertiary alano-1-kyl groups and an aromatic bifunctional carboxylic acid component in which two ester-forming groups are bonded to the rose position. A mature woman with excellent linearity (symmetry) of polymer molecules (molecular structure) and excellent quality. It has low melting temperature, low flow start temperature, etc. Furthermore, the melt anisotropic aromatic polynisder has the characteristics of having a relatively low specific gravity and excellent hydrolysis resistance. Conventionally, it has been said that when the linearity of a polymer molecule increases, the melting temperature, flow start temperature, etc. become significantly higher, and fully aromatic polyesters with such characteristics are known, but the aromatic varnish of the present invention exhibits characteristics completely different from those described above. For this, use the above-mentioned substituted hydroquinone.
Koyoru. Therefore, the aromatic polyester of the present invention can be melt-molded at lower temperatures, and deterioration during molding, especially oxidative deterioration under heating and temperature rise, is suppressed to a low level, forming molded products of excellent quality. It has the feature of being able to Furthermore, since the production temperature of the aromatic polyester can be kept low, it also has the advantage of being able to produce monopolymerized polyesters by melt polymerization, which has been difficult with conventional polymers. Furthermore, since the aromatic polyester exhibits melt anisotropy, it has the advantage that a molded article with a high Young's modulus and high strength can be formed just by melt molding. In addition, 1 melt anisotropy 2 in the present invention means that the polymer exhibits optical anisotropy even in a molten state,
For example, the characteristics are described in detail in Japanese Patent Laid-Open No. 53-109598. The aromatic polyester of the present invention contains terephthalic acid as an aromatic dicarboxylic acid residue, dimethylbenzylhydroquinone as a tertiary aralkyl tMm hydroquinone residue, and an aromatic oxycarboxylic acid residue. Taking p-oxybenzoic acid as an example, it can be produced, for example, by the following method. That is, l) a method of adding terephthalic acid and an aryl carbonate such as p-oxybenzoic acid-containing IC diphenyl carbonate, heating and esterification reaction, and then adding dimethylbenzylhydroquinone to carry out υl thermal condensation; 2) terephthalic acid A method of carrying out polycondensation according to the method of 1) above, except that an esterification product of terephthalic acid and phenol and/or dimethylbenzylhydroquinone is used instead of the acid; 3) p-Oxobenzoic H phenyl, arephthalic acid 4) A method in which a mixture of diphenyl and dimethylbenzylhydrquinone diacetate is subjected to 9-polycondensation by heating; 4) A method in which a mixture of p-7'' setoxybenzoic acid, terephthalic acid and dimethylbenzylhydrquinone diacetate is subjected to 1-polycondensation by heating.Produced by method W. In the method 1) above, examples of the aryl carbonate include diphenyl carbonate, ditolyl carbonate, di-chlorophenyl carbonate, phenyltolyl carbonate, and polycarbonates such as matapolydimethylbenzylphenylene carbonate. Among these, diphenyl carbonate is preferably used from the viewpoint of quality stability, purity, 2 reactivity, etc. When using this 7-aryl carbonate, 1 equivalent of the free carboxyl group of terephthalic acid and p-oxybenzoic acid is used. 09 to 1.1 in terms of aryl carbonate bond
Preferably, it is two times equivalent, especially Vl1 times equivalent. The reaction is usually 200~a o o ”c, preferably 20
The reaction is carried out at a temperature of 0 to 280° C. until the generation of carbon dioxide gas produced by the reaction substantially stops. This reaction is suitable for 1 to 6 hours and is preferably carried out in the presence of a catalyst. Examples of the catalyst include titanium compounds such as titanium detrabutoxide, titanyl oxalate, titanium acetate, etc.; tin compounds such as stannous acetate; and zinc carbonate. Lead oxide, antimony trioxide, antimony pentoxide. Bismuth trioxide, cerium acetate, lanthanum oxide. Lithium oxide, potassium benzoate, calcium acetate. Magnesium oxide, magnesium acetate, etc., antimono, bismuth, cerium, lanthanum, lithium,
Sodium, potassium! II! m. Magnesium: Compounds containing metals such as calcium can be exemplified. Among these, compounds containing titanium, tin, and antimony are preferred because they can be used in common with the following polycondensation reaction. The amount of catalyst used is 0.005 to 0.05 mole per terephthalic acid, and 0.01 to 0.01 for history.
01 molti is preferred. When the reaction between terephthalic acid and aryl carbonate is completed in this way, the temperature in the reaction system is reduced to 200 to 280°C.
1.0 to 1.0% per mole of prephthalic acid component, while maintaining
3 moles, more preferably 10 to 2 moles of dimethylbenzylhydroquinone are added and the following polycondensation reaction is carried out. Although the polycondensation reaction actually proceeds without a catalyst, it is preferably carried out using a conventionally known transesterification catalyst. Calcium and magnesium are preferred as transesterification catalysts. Strontium, barium, lanthanum, cerium, manganese, cobalt, zinc, germanium. Examples include compounds containing metals such as tin, lead, antimony, and bismuth, and specific examples include magnesium acetate, calcium benzoate, strontium acetate, barium propionate, lanthanum carbonate, cerium oxide, manganese acetate, cobalt acetate, and zinc acetate. , germanium oxide, stannous acetate, lead oxide, antimony trioxide, bismuth trioxide, and the like. It is also preferable to use a stabilizer together with these transesterification (li polycondensation catalysts). Examples of preferable stabilizers include conventionally known trivalent or pentavalent phosphorus compounds or their esters, such as tinous acid, Phosphoric acid, phenylbosphonic acid, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, petite phosphonic acid, benzylbosphonic acid, trimethylphosphite, trinotylphosphate,
Triethyl phosphate, trinotyl phosphate, triphenyl phosphite. Triphenyl phosphate, diethyl phosphonate, dimethyl-(methyl)phosphonate, dimethyl-
(ethyl)phosphonate, dimethyl(benzyl)phosphonate, and the like. Such stabilizers improve the melt stability of the polymer and, depending on the type of catalyst, deactivate the polycondensation catalyst. Therefore, when the catalyst is to be inactivated, it is preferable to add the stabilizer after the polycondensation reaction is completed. Since polycondensation catalysts containing antimony or germanium are difficult to be inactivated by stabilizers, stabilizers can be added from the beginning of the polycondensation reaction when such catalysts are used. The lid for use of these catalysts is 0005 to 05 mole of the total number of moles of terephthalic acid and p-oxybenzoic acid, and furthermore, α
It is preferable that the amount is 01 to 01 mol, and the ratio (P) of the stabilizer is 08 <P/N< 1.5 with respect to the M (N mol) of the above-mentioned condensation catalyst (where P: mol of stabilizer). It is preferable to use After adding such an amount of catalyst, optionally a stabilizer, and dimethylbenzylhydroquinone to the reaction system, the reaction system is heated to, for example, 250 to 300°C and the reaction is carried out under normal pressure to produce phenol, that is, a monohydroxy aromatic compound. is distilled out of the system to allow polycondensation to proceed. The polycondensation reaction is first carried out under normal pressure and then under reduced pressure, and the resulting monohydroxy aromatic compound is distilled out of the system.
Let it proceed. In the reaction under normal pressure, it is preferable that the reaction temperature is gradually increased as the amount of aromatic monohydroxy compound distilled out. Such reaction under normal pressure is preferably carried out at a reaction temperature as low as possible so long as the aromatic monohydroxy compound can be distilled out. For example, at temperatures below 250'C, the condensation reaction proceeds slowly, but the aromatic monohydroxy compound produced does not bubble out of the reaction system, so the reaction soon reaches equilibrium. Therefore, in practice, starting from a reaction temperature of about 260°C [
It is preferable to gradually raise the temperature to reach a reaction temperature of about 290° C. at about 35 to 60 degrees of the distilled amount of the aromatic monohydroxy compound. If the reaction temperature is set at a high temperature of 290°C or higher from the beginning and the reaction is allowed to proceed, undesirable side reactions such as gelation may occur. When such an amount of aromatic monohydroxy compound is distilled out of the system, the pressure of the reaction thread is reduced to Vc L, and while the aromatic monohydroxy compound produced is further distilled out of the system, the degree of pressure reduction and the reaction are gradually increased. Regarding the temperature, it is preferable to finally carry out the reaction at a reaction temperature of 320 to 340° C. under a pressure of about 1 mH1/or lower to obtain a ribolimer with a predetermined degree of polymerization. In the method 2) above, the esterification reaction between terephthalic acid and phenol and/or tertiary amylhydroquinone can be carried out by a conventionally known method. In addition to phenol, phenols such as cresol, P-7' tylphenol, etc., or tertiary esters of the polyester
Although aralkyl-substituted hydrogines can also be used, the method of esterification with phenol is preferred from the viewpoint of operability. In the esterification reaction, the hydroxyl group of the phenol or tertiary amylhydroquinone is 1 mole or more, preferably 1.1 to 4 times the mole, particularly preferably 1.2 to 2 times the mole of the carboxy syl group of terephthalic acid. Use so that it becomes a mole, 2
The reaction is carried out while heating at 30 to 400°C, preferably 240 to 360°C, and distilling water produced as a result of the esterification reaction out of the reaction system. The esterification reaction usually takes 1 to 12 hours, and can be carried out under a pressure of 1 to 10 kg/- if necessary. At this time, the esterification rate is 50% or more, preferably 70% or more, particularly preferably 851% or more. Here, the esterification rate can be determined by the following formula. Varnishing Reaction Rate (%) Although a catalyst is not necessarily required in the esterification reaction, a catalyst is preferably used. Such a catalyst is titanium tetrabutoxide. Titanyl oxalate, stannous acetate, lead oxide, antimony trioxide, bismuth trioxide, vinegar), lanthanum oxide, lithium oxide, sodium metal, potassium benzoate Mention may be made of compounds containing metals such as titanium, tin, lead, ferrite, bismuth, cerium, lanthanum, lithium, sodium, potassium, zinc, etc., such as zinc carbonate. 0005 to 05 molti per terephthalate, preferably 0
．． 01 to O1 morch. The reaction between p-oxybenzoic acid and 1-lyl carbonate is
p-oxybenzoic acid is added to the reaction system after the completion of the esterification reaction according to method 1) above. The reaction may be carried out by adding 7 reel carbonate and a catalyst if necessary, or the reaction may be carried out in a separate reaction system. The latter method is preferable from the viewpoint of reaction operability, quality of the obtained polymer, etc. ◎ Phenyl ester of terephthalic acid obtained by baking, p
- Phenyl ester of oxybenzoic acid and dimethylpenzylhydroquinone are reacted in a polycondensation reaction system to obtain a polyester. The polycondensation reaction is carried out according to method 1) above. In the method 3) above, the polycondensation reaction is carried out in the same manner as in the step after the reaction of the aryl carbonate with terephthalic acid and p-oxybenzoic acid in the method 1). This yields polyester. In the method 3), since there is less impurity mixed into the raw material and the purity of the starting raw material can be increased, the quality of the obtained polyester is high, which is different from the preferred method. Furthermore, in the method 4) above, the raw material is heated under normal pressure, preferably in the presence of an inert gas such as nitrogen, with a catalyst of the type and amount described in the method 1) above, the temperature is raised, and the temperature is increased to a temperature of the theoretical lid. When more than 90 units of acetic acid are distilled out, the reaction is moved to vacuum. Reaction conditions such as temperature, heating rate, and system atmosphere. The pressure reduction rate ring can be based on the method 1). The aromatic polyester thus obtained can be made into a polyester molded article by melt extrusion molding at a temperature below its melting point or below its decomposition temperature, for example, 240 to 400°C. For example, polyester fiber is produced by melting aromatic polyester at 240 to 400°C and extruding it from a spinneret at a draft rate of 5 to 5000 and a winding speed of lO to 50.
It can be obtained by winding at 0rn/m. At that time, polyester fibers do not necessarily require heat treatment;
Just by melt spinning and winding, the strength is 5#/do or more, Young 4
A high strength Iff of zsookg/- or more and a high Young's modulus can be achieved. This fiber can be advantageously used for tire cords, rubber reinforcing materials, fillers, and other heat-resistant industrial precious materials. Also, polyester film is 240-400'C. It can be obtained by melt-extruding it through a die and winding it up on a drum. A conventionally known device can be used as the film forming machine, and the draft during extrusion is 1 to 50, preferably 1 to 10. At that time, the film extruded onto the drum can be left to cool at room temperature, or it can be rapidly cooled in water! ,&stomach. The polyester film thus obtained has sufficient Young's modulus (70 kg/- or more) and strength (30 kl/- or more) in the uniaxial direction compared to polyethylene terephthalate even as it is. This film can be advantageously used as an industrial material. Molded articles using the polyester of the present invention have sufficient strength even without heat treatment as described in JP-A No. 50-43223, but it is possible to further increase the strength by heat treatment. can. For example 200-300
When heat treated at ℃ for about 10 hours, the above properties are increased several times. The molded product using the aromatic polyester of the present invention has a high Young's modulus and also has excellent hydrolysis resistance.
Tire cord, rubber reinforcement. It can be advantageously used as industrial materials such as fillers and films. The present invention will be explained below with reference to Examples. In addition, in the example “
Everything that says "part" means "M ok part". In addition, the intrinsic viscosity in the present invention is 10
M mixed solvent (phenol/tetrachloroethane = 1
/ tyon / vol mixture) and heated to 50 °C.
The relative viscosity M (vr) is determined using an Ostwald viscometer,
It was calculated using the following formula. Intrinsic viscosity - Inηr10.5 In addition, the flow start temperature is polyester diameter 05 shoulder,
Place it in a flow tester with a length 40mm nozzle,
The temperature was raised at a base temperature of about 2° C. under a pressure of 60°C &/cd, and the temperature was determined as the temperature at which the polyester started to flow out from the nozzle. Furthermore, the specific gravity was determined by heat-treating the polymer at 200° C. for 3 hours to crystallize it, and measuring it with a pycnometer using a mixed solvent of carbon tetrachloride g-n-hexane. Furthermore, hydrolysis resistance was determined by treating polymer 1.09 at a temperature of 240°C for 15 hours to crystallize it, sealing it with distilled water of 10117, and heat-treating it at a temperature of 120°C for 48 hours. The intrinsic viscosity (η+nh)a before treatment and the intrinsic viscosity (yinh) after treatment were determined using the following formula. Example 1 Diphenyl terephthalate 3189 dimethylpenzylhydroquine 250s antimony trioxide
0.1 part was heated at 260℃/3o minutes under normal pressure, 27
0℃/30 minutes. The reaction was carried out while distilling off phenol at 290°C for 30 minutes, and then the temperature was gradually raised and the lo
The polycondensation reaction was carried out by distilling off the phenol while increasing the degree of vacuum by OtmHI, and finally about 1118I! Hemming was performed by reacting for 20 minutes at 330°C above and below MA air. The resulting polyester had a flow initiation temperature of 305° C. and an intrinsic viscosity of 4.668. This polyester is 350
It was melted at 0.degree. C., extruded using a spinning machine with a diameter of 039, and wound up at a draft of 20 at a speed of 50 m/min. The fineness of the obtained fiber is 40 denier and the strength is 7.2 p/do.
, Young's modulus is 5200 Y/-2 and elongation is 24 qb). The specific gravity of the polyester was 1.203, and the resistance to soot water decomposition was 91 inches. Examples 2 to 4 Polyesters were produced in the same manner as in Example 1 using raw materials having the compositions shown in the following table, and then melt-spun. The flow initiation temperature, intrinsic viscosity, and physical properties of the yarn of the obtained polyester were as shown in the following table.

Claims (1)

[Claims] 1. Two ester-forming functional groups are attached to the para position. It consists essentially of an acid component mainly composed of an aromatic difunctional carboxylic acid and a diol component mainly composed of a substituted hydroquinone having 11% of its nuclei from 9 to ISO tertiary aralkyl groups; 1. A fiber-forming or film-forming melt anisotropic aromatic polyester containing at least 10 mol of ester units of an aromatic dicarboxylic acid component in a functional carboxylic acid component and the substituted hydroquinone component in a completely repeating manner. 2 % iFf[, characterized in that the substituted hydroquinone component is at least 70 moles of the total diol component.
1# Aromatic polyester according to desired range 1IIm. 1. The aromatic polyester according to claim 1, wherein the aromatic difunctional carboxylic acid is an aromatic dicarboxylic acid, or an aromatic dicarboxylic acid and an aromatic oxycarboxylic acid. 4. The aromatic polyester according to claim 1 or 3, wherein at least 70 moles of the aromatic dicarboxylic acid component is at least one type selected from terephthalic acids. The aromatic polyester according to claim m1 or claim 3, wherein at least 70 moles of the aromatic oxycarboxylic acid component is at least one type selected from P-oxybenzoic acids. The aromatic polyester according to claim 81 or 3, characterized in that the molar ratio of aromatic dicarboxylic acid to aromatic oxycarboxylic acid/acid is from 9:1 to 1:9. 7 Mainly 7-aryl esters of aromatic nocarboxylic acids in which a carboxyl group is bonded to the para position, or AIJ-11 esters of aromatic oxycarboxylic acids in which hydroxyl groups and carboxyl groups are bonded to para positions. A bifunctional cuff containing a 7-aryl ester of a carbonic acid and a carbon number of 9 to
15, substituted with a tertiary 7-ralkyl group,
A diol (Bl) mainly containing hydroquinone, or an aromatic dicarboxylic acid in which a carboxyl group is bonded to the para position, or an aromatic oxycarboxylic acid prisoner in which a hydroxyl group and a carboxyl group are bonded to the para position. A method for producing a melt anisotropic aromatic polynisnal having an intrinsic viscosity of 08 or more, the method comprising melt polymerizing the diol (B) and diaryl carbonate (Q).