JPS6239623A - Aromatic polyester - Google Patents

Abstract

PURPOSE:The titled novel melt moldable polyester, consisting of plural specific structural units, having improved mechanical properties and capable of giving molded articles exhibiting optical anisotropy. CONSTITUTION:A polyeter, obtained by polycondensing (A) p-acetoxybenzoic acid, etc., to be constituent units expressed by formula I with (B) chlorohydroquinone diacetate, etc., to be constituent units expressed by formula II (R is formula III, etc.), (C) 4,4'-diphenylcarboxylic acid and (D) terephthalic acid to be part of constituent units expressed by formula IV (R' is phenyl group, etc.) in the presence of a catalyst, e.g. stannous acetate, containing 10-90mol%, based on the total polyester, constituent units expressed by formula I and 90-10mol%, based on the total polyester, constituent units expressed by formulas (II and III at 100/0-30/70 molar ratio of the constituent units expressed by formula II to formula III and having >=0.35 inherent viscosity and 10-15,000 poises melt viscosity.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a novel aromatic polyester that is melt moldable and capable of providing molded articles with excellent mechanical properties and optical anisotropy. .

<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. 1. Liquid crystal polymers with optical anisotropy have attracted attention because of their excellent mechanical properties. (Tokuko Showa 55-
Publication No. 482)a (Problems to be Solved by the Invention) Aromatic polyesters are widely known as liquid crystal polymers. For example, homopolymers and copolymers of p-hydroxybenzoic acid are available under the trademark "L:KONOL". It is commercially available.

However, the melting point of this p-hydroxyben 1 homopolymer is too high to be melt-molded, and p-
A method of copolymerizing p-hydroxybenzoic acid with various components to lower its melting point was investigated. For example, p-hydroxybenzoic acid, phenylhydroquinone, terephthalic acid, and/or ? , a method of polymerizing 6-naphthalenedical with small auric acid (Japanese Patent Publication No. 55-500215), a method of copolymerizing p-hydroxybenzoic acid with 2,6-dihydroxynaphthalene and terephthalic acid (Japanese Patent Application Laid-open No. 54-1988) -5059
4) and a method of copolymerizing p-hydroxybenzoic acid with 2,6-dihyde, 1-xianthraquinone and terephthalic acid (U.S. Pat. No. 4,224,433). Although the aromatic polynisder produced by these methods (51) has a relatively low melting point of less than 400°C, the elastic modulus of the resulting yarn is still insufficient, and an even higher elastic modulus is desired. .

Therefore, the present inventors conducted extensive research with the aim of obtaining an aromatic polyester that can be melt-molded and has an excellent balance between mechanical properties such as a high modulus of elasticity and optical anisotropy.
First, some or all of the aromatic dicarboxylic acids of an aromatic polyester consisting of an aromatic dicarboxylic acid such as p-bitroxybenzoic acid, a specific aromatic compound such as p-bitroxybenzoic acid, and an aromatic dicarboxylic acid such as a terephthalic core are They have discovered that a novel aromatic polyester that satisfactorily meets the above objectives can be obtained by substituting and covering with 4'-diphenyldicarboxylic acid, and have filed an application (Japanese Unexamined Patent Publication No. 59-41328). It is also rigid even when using aromatic dihydroxy compounds such as chlorohydroquinone with small steric hindrance.
The present invention was accomplished by discovering that it has a good ability to form liquid crystals even though it is made of only one product.

Means for Solving the Problems> That is, the present invention consists of the following structural units (I> and (II> or (I>, (II) and (I[I)), in which the unit (I) accounts for 10 to 90 mol%, the structural unit (II
)+(I[I) accounts for 90 to 10 mol% of the total, and the molar ratio of units (II)/(III) is 10010 to 30/7
The present invention provides a melt-moldable aromatic polyester characterized by a

Indicates one or more groups that have been discovered. ) In the aromatic polyester of the present invention, the above structural unit (
i> is a structural unit of polyester produced from p-hydroxybenzoic acid, and the above structural unit (II) is a structural unit of an aromatic hx dihydroxy compound such as chlorohydroquinone and 4.4-
The structural unit of the polyester produced from diphenyldicarboxylic acid, and the above f'M unit (III) is obtained from an aromatic dioxy compound such as chlorohydroquinone and an aromatic dicarboxylic acid other than 4゜4-diphenyldicarboxylic acid such as terephthalic acid. It means each structural unit of the produced polyester.

The aromatic polyester of the present invention often has a melting point of 4
00'C or less, and it is possible to easily mold fibers, films, various molded products, etc. with excellent mechanical properties by ordinary melt molding. Here, for example, the melting point of polyethylene terephthalene 1 is 256°C, and the melting point of polyethylene-4,4°-dinoenyl small xylene 1 is 355°C, and as the benzene angle in the structural unit increases, However, contrary to this prediction, the aromatic polyester of the present invention has a relatively low melting point of 400'C or less and has excellent melt moldability.

In the aromatic polyester of the present invention, the above structural unit (
i> accounts for 10 to 90 mol% of the total, especially 2
0 to 80 mol% is preferable, and if it exceeds 9Q mol%, the melting point of the aromatic polyester is high and melt molding becomes impossible, and if it is less than 10 mol%, melt fluidity often becomes poor, so it is preferable.・No one.

The proportion of the above R, S structural units (II) and (I[I) must be 90 to 10 mol%, especially 80 to 20 mol% of the total, and the - The ratio is 100/0 to 30/70. Especially 10010-5015
0 is preferable. If the ratio of unit (II) in unit (II) + (I[I) is less than 30 mol %, the mechanical properties of the resulting aromatic polyX sprue will deteriorate, which is not preferable.

In the aromatic polyester of the present invention, the above structural unit (
The aromatic dihydroxy components forming II) and (I) include chlorohydroquinone, methylhydroquinone, 4
, 4゛-dihydroxydiphenyl sulfide, 4,4°
-dihydroxybenzophenone, and chlorohydroquinone or methylhydroquinone is most preferred. In addition, the dicarboxylic acid component forming the structural unit (I[I) is terephthalic acid, 4,4"-
At least one member selected from diphenyl ether dicarboxylic acid, 4,4°-dicarboxylic acid, 1,2-bis(2-chlorophenoxy)ethane-4,4°-dicarboxylic acid, and 2,6-natutaledicarboxylic acid It is necessary. Of these, 1,2-bis(2-chlorophenoxy)ethane-4,4''-dicarboxylic acid is most desirable.

The aromatic polyester of the present invention can be produced according to the conventional polyester polycondensation method, and there are no particular restrictions on the production method, but typical production methods include the following (I) to (3).
) law.

(I) Diesters of p-acetoxybenzoic acid and aromatic dihydroxy compounds such as chlorohydroquinone diacetate and chlorohydroquinone dipropionate;
, 4"-Production method from aromatic dicarboxylic acids mainly composed of cyphenyl dicarboxylic acid by demonocarboxylic acid polycondensation reaction.

(2) Aromatic dihydroxy compounds such as phenyl ester of Kanooxybenzoic acid and chlorohydroquinone and 4
, 4"-Diphenyldicarboxylic acid as a main component, from diphenyl esters of aromatic dicarboxylic acids by dephenolization polycondensation.

(3) After reacting aromatic dicarboxylic acids mainly consisting of oxybenzoic acid and 4,4゛-diphenyldicarboxylic acid with a desired amount of diphenyl carbonate to form diphenyl esters, aromatic dihydroxy compounds such as chlorohydroquinone are added. A method of preparing by adding and removing phenol polycondensation reaction.

Typical catalysts used in the polycondensation reaction are metal compounds such as stannous acetate, tetrabutyl titanate lead acetate, sodium to lithium acetate, potassium acetate, and antimony trioxide. It is effective.

Many of the aromatic polyesters of the present invention can be measured for their logarithmic viscosity in pentafluorophenol;
The value measured at 60'C at a temperature of 0.1 (weight/volume)% is preferably 0.35 or more, particularly preferably 0.4 to 15.0.

Further, the heat of melting of the aromatic polyester of the present invention is from 10 to
15,000 voices is preferred, especially 20-5,000 voices.
Poise is more preferred.

a3, this melt viscosity is (liquid crystal starting temperature +40~90'
C) and a shear rate of 2,000 to 4,000 (I/sec).

In addition, when polycondensing the aromatic polyester of the present invention,
In addition to the components constituting the above structural units (I>, (II) and (III), isophthalic acid, 3,3'-diphenyldicarboxylic acid, 3,4'-diphenyldicarboxylic acid,
Aromatic dicarboxylic acids such as 2,2'-diphenyldicarboxylic acid, cycloaliphatic dicarboxylic acids such as l\kyly-hydroprephthalic acid, other aromatic diols such as hydroquinone a5 and m-oxybenzoic acid, 2,6 - Other aromatic oxycarboxylic acids such as oxynaphthoic acid can be roughly copolymerized in a small proportion that does not interfere with the purpose of the present invention.

The aromatic polyester of the present invention thus formed has a melting point of 40
It has a low temperature of 0'C or less, and can be used for ordinary melt molding such as extrusion molding, injection molding, compression molding, and blow molding, and can be processed into fibers, films, three-dimensional molded products, containers, hoses, etc. be.

/゛゛For the aromatic polyester of the present invention during molding,
Additives such as reinforcing agents such as glass fiber, carbon fiber, and asbestos, fillers, nucleating agents, pigments, antioxidants, stabilizers, plasticizers, lubricants, mold release agents, and flame retardants, as well as other thermoplastic resins. By doing so, desired characteristics can be imparted to the molded product.

It should be noted that the strength of the molded product thus made 1d can be increased by heat treatment, and the elastic modulus can also be increased in many cases.

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.

The molded article obtained from the novel aromatic polyester of the present invention has good optical anisotropy due to its parallel molecular arrangement, and has excellent mechanical properties.

<Example> The present invention will be further explained below with reference to Examples.

Example 1 5.4 g of acetoxybenzoic acid (3,0
x 10-2 mol), hydroquinone diacetate 16. OQ (7,0X10-2 mol), 4°4-diphenyldicarboxylic acid 17. OQ (7゜0×10-2
mol) was prepared, and deacetylation was carried out under the following conditions. First, the reaction was carried out at 200 to 330'C for 2.5 hours in a nitrogen gas atmosphere, then the pressure was reduced to 1°0IrIfrIHq at 330'C, and the polycondensation was completed by heating roughly for 0.5 hours. A nearly stoichiometric amount of acetic acid was distilled out to yield a brown polymer.

The theoretical structural formula of this polymer is as follows, and the elemental analysis results of this polyester showed good agreement with the theoretical values shown in Table 1.

(m/n molar ratio = 30/70) Table 1 In addition, this polyester was placed on the sample stage of a polarizing microscope and heated to confirm the melting point and optical anisotropy ((I).
The melting point was 238°C, and it showed good optical anisotropy.

Further, when this polymer was measured with a differential scanning calorimeter (PerkinElmer type ■), the glass transition temperature was 86°C, the melting point was 269°C, and the cooling crystallization temperature was 216°C.

This polyester was subjected to a Koka-type flow tester and spun at a spinning temperature of 310°C and a spinneret hole diameter of 0.3#φ.
The spun yarn of sφ is 17. Melt viscosity shear rate '3000
(I/sec) and 5000 voices.

This spun yarn was processed into a bullet 1 (I
When the modulus was measured, it was found to be 75 GPa at 30''C.

Examples 2 to 16 p-acetoxybenzoic acid (■), talolhydroquinone diarete-1 to (II), methylhydroquinone diacetate (III), 4.4°-diacetate-1 to xydiphenylsulnoid (IV), 4. /1''-Diace1-gisibenzono'■non (V), 4,4''-diphenyldicarboxylic acid (Vl),'-rshi)ri) L4 (Vl)
, 4.4'-dicarboxyphinyl ether (■)
, 1.2-bis(noenoxy)ethane-4,4-dicarboxylic acid (IX), 1.2-bis(2-chloronoenoxy)ethane-4,4°-dicarboxylic WL(X), 2.6
-dicarpoxynaphthalene (X'f) (j-(7)
Back (Ii) −□ (V) (7) Component (Vl)
The same number of moles of the (Xi) component was added to a polymerization test tube, and the same conditions as in Example 1 were added. The polycondensation reaction was carried out under 1.

The obtained polymer is 400' as shown in Tables 2 and 3.
It exhibited excellent optical anisotropy below C. Note that the melting point of some polymers was measured by differential scanning calorimetry h1.

Among these, experiment No. 6, polymer J: and experiment No.
Polymers No. 3 were spun at 340°C and 350°C in the same manner as in Example 1.
It was found that the fiber had an extremely high elastic modulus of 106 GPa at 7 GPa and 0.1 sφ.

Effects of the Present Invention The aromatic polyester of the present invention can be melt-molded and molded products with a high elastic modulus can be obtained, so it can be used in various applications such as engineering plastics as a fully bendable substitute plastic. .

Claims (1)

[Claims] The following structural units (I) and (II) or (I), (I
I) and (III), where the unit (I) is 10 of the total
~90 mol%, the structural units (II) + (III) account for 90 to 10 mol% of the total, and the molar ratio of units (II)/(III) is 100/0 to 30/70. Melt-formable aromatic polyester. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) (However R in the formula ▲ can be a mathematical formula, chemical formula, table, etc. ▼
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, R' is ▲ Mathematical formula, chemical formula There are , tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Indicates one or more groups selected from. )