JPS63218729A - Aromatic polyester of good fluidity - Google Patents

Abstract

PURPOSE:To obtain the titled melt-formable polyester outstanding in fluidity and heat resistance, capable of forming into fibers, films, three-dimensional molded articles, containers, etc., by copolymerization of each specific four kinds of aromatic compound. CONSTITUTION:A mixture of (A) p-hydroxybenzoic acid, (B) 2,6-dioxynaphtha lene, (C) 4,4'-dihydroxybiphenyl, (D) an aromatic dihydroxy compound such as hydroquinone, and (E) an aromatic dicarboxylic acid such as terephthalic acid is incorporated with, e.g., acetic anhydride followed by polycondensation through acetic acid elimination, thus obtaining the objective polyester with a molecular weight pref. 1,000-200,000, constituted of structural units of formu las I, II, III and IV (X is divalent aromatic group; Y is p- and/or m-residue of benzene) with such contents as follows: formula I ... 40-90mol.%, formulas II+III+IV ... 60-10mol.%, molar ratio: formula II/formula III ... 8/2-2/8, formula IV/(formulas II+III+IV) ... 1-40mol.%.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an aromatic polyester that can be melt-molded at 400° C. or lower and can provide molded articles having excellent fluidity and heat resistance.

<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.

Fully aromatic polyesters are widely known as such liquid crystal polymers, such as homopolymers of p-hydroxybenzoic acid and copolymers of biphenol and terephthalic acid. However, the melting points of these p-hydroxybenzoic acid homopolymers and copolymers are often too high, resulting in poor melt fluidity. For this reason, methods of copolymerizing various components to hydroxybenzoic acid to lower its melting point have been studied.
Method of copolymerizing hydroxybenzoic acid with phenylhydroquinone, terephthalic acid and/or 2,6-naphthalene dicarboxylic acid (Publication Patent Publication No. 55-500215)
No.), a method of copolymerizing p-hydroxybenzoic acid with 2,6-hydroxynaphthalene and terephthalic acid (Japanese Unexamined Patent Publication No. 5
4-50594) and a method of copolymerizing p-hydroxybenzoic acid with 2,6-hydroxyanthraquinone and terephthalic acid (US Pat. No. 4.224.433).
, A method of copolymerizing hydroxybenzoic acid with 4,4-dihydroxybiphenyl, terephthalic acid, and isophthalic acid (
Japanese Patent Publication Nos. 57-24407 and 60-25046), a method of copolymerizing p-hydroxybenzoic acid with phenylhydroquinone and aromatic dicarboxylic acid (US Patent No. 4.238.600), A method of copolymerizing nuclear-substituted phenylhydroquinone, hydroquinone, etc. (US Pat. No. 4,153.779) has been proposed.

<Problems to be solved by the invention> However, although many of the aromatic polyesters obtained by these methods have relatively low melting points of 400°C or less, they have insufficient fluidity or insufficient heat resistance. Therefore, better fluidity and higher heat resistance are desired.

Among these, polyester consisting of p-oxybenzoic acid, 2,6-di-droxynaphthalene, and terephthalic acid (Japanese Unexamined Patent Publication No. 54-50594) is characterized by good fluidity, but on the other hand, The glass transition temperature obtained from the dynamic loss peak temperature of Pyblon is as low as 96°C, and its heat resistance is poor. In addition, 2,6-cyoxynaphthalene or its derivatives are extremely easily sublimed during polymerization, making it difficult to obtain a uniform composition. It turned out that the polymer could not be obtained.

On the other hand, polyesters composed of p-oxybenzoic acid, 4,4°-dihydroxybiphenyl, terephthalic acid, and isophthalic acid have relatively good heat resistance, but have poor fluidity during polymerization. It was found that this method has the disadvantage that it is difficult to polymerize only by melt polymerization.

Therefore, an object of the present invention is to obtain a melt-moldable aromatic polyester that has both fluidity and heat resistance.

Means for Solving the Problems〉 As a result of intensive study by the present inventors to solve the above problems,
Copolymerization of structural units consisting of an aromatic dihydroxy compound such as hydroquinone and an aromatic dicarboxylic acid such as terephthalic acid into an aromatic polyester consisting of p-hydroxybenzoic acid, 2,6-cyoxynaphthalene, and 4,4°-dihydroxybiphenyl. The inventors have found that the above-mentioned problems can be solved by applying the same method, and have arrived at the present invention.

That is, the present invention consists of the following structural units (I) to (IV), in which the structural unit (III) is 40 to 90 mol% of the total, and the structural unit [(II) + (III) ÷ (■) 1 is 60% of the total.
~10 mol%, structural unit (n)/(III)
The molar ratio of is 872 to 278, and the structural unit (IV)/
The present invention provides an aromatic polyester with good fluidity in which [(n)+(I[)+(IV)] is 11 to 40 moles.

60 + CO 廿 ... Beni) - fO (xΣ
02C-Q-COi, ・(III)-fo-x-o□c
-y-co廿...be■) (X in the formula is -Q-5-
Q-0-Q-11] One or more groups selected from 1, $, and p, and Y represents ÷ and/or χ:.

However, X is -ccr and/or <Σ(D-, and Y
is ÷)) In the aromatic polyester of the present invention, the structural unit (I
II) is a structural unit of a polyester produced from p-hydroxybenzoic acid, the above structural unit (■) is a structural unit of a polyester produced from 2,6-cyoxynaphthalene and terephthalic acid, (Ir> is 4.4 (III) is the structural unit of polyester produced from 4,4'-dihydroxybiphenyl and terephthalic acid, (IV) is hydroquinone, 4,4'- Polyesters produced from aromatic dihydroxy compounds such as dihydroxydiphenyl ether, 2.7-dihydroxynaphthalene, 2.6-dihydroxynaphthalene, and 4.4゛-dihydroxybiphenyl and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. indicates the structural unit of

It is essential that the above structural unit (III) accounts for 40 to 90 mol% of the total, and the structural unit (III) accounts for 90 to 90 mol% of the total.
~100 mol% or 0 to 40 mol% is not practical due to insufficient fluidity, and the most preferable composition is structural unit (I)
is 60 to 85 mol% of the total.

On the other hand, the molar ratio of the structural units (n)/(III) is 8/
2 to 2/8, preferably 6 no 4 to 2.5/7.5
It is. 1010-8/2 or 0710-2/8
However, it is not practical due to insufficient heat resistance or fluidity.

On the other hand, <IV)/[(II)+(III)+ (IV month) is 1 to 40 mol%, preferably 10 to 30 mol%. If it is more than 40 mol%, fluidity may be poor. In many cases, polyester with excellent heat resistance and fluidity can be obtained only by the composition of the present invention.

Preferred structural units (TV) are polyester structural units produced from hydroquinone and terephthalic acid.

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 methods (I) to (5). .

(I) Manufactured by deacetic acid polycondensation reaction from acylated products of oxycarboxylic acids such as acetoxybenzoic acid, acylated products of aromatic dihydroxy compounds such as 2,6-diacedoxynaphthalene, and aromatic dicarboxylic acids such as terephthalic acid. how to.

(2) A method for producing by deacetic acid polycondensation reaction from an aromatic dihydroxy compound such as p-oxybenzoic acid or 2,6-hydroxynaphthalene, an aromatic dicarboxylic acid such as terephthalic acid, and acetic anhydride.

(3) phenyl ester of Kano oxybenzoic acid and 2
．． A method for producing by dephenol polycondensation from an aromatic dihydroxy compound such as 6-dihydroxybiphenyl and a diphenyl ester of an aromatic dicarboxylic acid such as terephthalic acid.

(4) After reacting aromatic dicarboxylic acids such as Kanooxybenzoic acid and terephthalic acid with a desired amount of diphenyl carbonate to form diphenyl esters, 2,6
- A method of manufacturing by adding an aromatic dihydroxy compound such as hydroxynaphthalene and performing a dephenol polycondensation reaction.

(5) A method for producing only 2.6-hydroxynaphthalene among the above methods (2) to (4) using 2.6-diacedoxynaphthalene.

Typical catalysts used in the polycondensation reaction are metal compounds such as stannous acetate, tetrabutyl titanate, lead acetate, antimony trioxide, magnesium, sodium acetate, potassium acetate, and trisodium phosphate, but they are not necessarily used. do not have to.

Logarithmic viscosity (o, if/d
(measured at 60°C in pentafluorophenol at 1 concentration)
is preferably 1.0 to 8.0, particularly preferably 3.0 to 6.0.

Further, the melt viscosity of the aromatic polyester of the present invention is 10 to
i s , ooo voices are preferred, especially 20 to 5,
000 voids is more preferred.

In addition, this melt viscosity is (liquid crystal starting temperature + 40 to 100℃
) at a rubbing speed of 1,000 to 3,000 (I/sec) using a Koka type flow tester.

The molecular weight of these aromatic polyesters is preferably 1,000 to 200,000, more preferably 3,000 to 100,000.

In the polymerization methods (I) and (2) above, this molecular weight can be determined by quantifying the amount of acetyl groups using an infrared spectrum of the hot-pressed film, or by measuring the amount of acetic acid produced after hydrolyzing the polymer by gas chromatography. It can be measured by graphography. Alternatively, it can be measured by a light scattering method after dissolving in a pentafluorophenol solution.

In addition, when polycondensing aromatic polyester, the above (I
II) to (IV) In addition to the constituent components, 4,4''-diphenyldicarboxylic acid, 3,3゛-diphenyldicarboxylic acid, 3,4゛-diphenyldicarboxylic acid, 2.2°-diphenyldicarboxylic acid, 1.2 - Aromatic dicarboxylic acids such as bis(phenoxy)ethane-4,4°-dicarboxylic acid, cycloaliphatic dicarboxylic acids such as hexahydroterephthalic acid, 3,3°, 5.5'-tetramethyl-4,4° - Aromatic dihydroxy compounds such as dihydroxybiphenyl, bisphenol A, bisphenol S, resorcinol, 4,4'-dihydroxydiphenyl sulfide, aromatic oxycarboxylic acids such as m-oxybenzoic acid, 2,6-oxynaphthoic acid, and p- Aminophenol, p-aminobenzoic acid, and the like may be further copolymerized in a small proportion that does not impair the object of the present invention.

The aromatic polyester of the present invention thus formed has a melting point of 40
The glass transition temperature is as low as 0℃, and in many cases is 140℃ or higher, so it can be used for ordinary melt molding such as extrusion molding, injection molding, compression molding, and blow molding, and can be used for fibers, films, and three-dimensional molded products. It can be processed into containers, hoses, etc.

In addition, during molding, for the aromatic polyester of the present invention,
Reinforcing agents, fillers, nucleating agents, raw materials, antioxidants, stabilizers, plasticizers, lubricants, etc. for glass fibers, carbon fibers, asbestos, etc.
Additives such as mold release agents and flame retardants, and other thermoplastic resins 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 steam) or under reduced pressure 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 several tens of 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 extremely excellent heat resistance and fluidity.

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

Example 1 P-acetoxybenzoic acid (I) 54,
O5g (30X10-2 mol), 2.6-diacedoxynaphthalene (If > 9.77g <4X10-
2 mol), 4,4'-diacetoxybiphenyl (I[
) 10.8br (4X10-2 mol), hydroquinone diacetate (TV) 3.88g (2X10-2
m) 'v> and Tf'-r'v phthalic acid 16.61 g
(IOXIO-2-E-le) (III)/[(I)
+(I[)+(III)+ (TV)] is 775 mol%
The molar ratio of (n)/(If) is 575, (IV)/[(I
I)+(II)+(IV)] was charged so as to be 25 mol %, and acetic acid depolymerization was performed under the following conditions.

First, a reaction was carried out at 250 to 340°C for 3 hours in a nitrogen gas atmosphere, then the temperature was raised to 350°C, the pressure was reduced to 1.5 mmHg, and the temperature was further heated for 1.0 hours to perform a polycondensation reaction and form a brown polymer. Obtained. Further, 5 batches of polymerization were carried out under the same conditions, and the polymer was recovered and pulverized using a pulverizer manufactured by Seisaku Co., Ltd.

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

1/m/n/o =75/10/10/5
Table 1: However, 0 (%) = 100 (X) -〇 (%) - H (%)
Calculated from.

Also, place this polyester on the sample stage of a polarizing microscope,
When the temperature was raised and the optical anisotropy was confirmed, the temperature was 268℃.
The above results showed good optical anisotropy.

The logarithmic viscosity of this polyester was measured with pentafluorophenol (0.1 t/dj! concentration at 60° C.) and found to be 3.1 dρ/g.

This polyester was subjected to a Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.),
Under the conditions of cylinder temperature 320℃ and mold temperature 120℃,
A test piece measuring 1/8" thick x 1/2° wide x 5" long and a mold notch impact test piece measuring 1/8" thick x 2.1/2" long were prepared. The flexural modulus of this test piece was measured using Tensilon UTH-100 manufactured by Toyo Baldwin Co., Ltd. at a strain rate of 1 mm/min and a span distance of 50 m, and found to be 13 GPa. The isot impact value (mold notch) was as high as 15 kg-■/am. In addition, using Toyo Seiki's thermal deformation measuring device,
When the heat distortion temperature of a 78° thick test piece was measured, it was 24
It had excellent heat resistance of 1°C (I8, 56 kg/J).

The melt viscosity of this polymer was measured using a Koka type flow tester manufactured by Shimabara Seisakusho at 320° C. and a sliding speed of 3000 (I/sec), and found to be 1300 voids, indicating good fluidity. Using the spun yarn obtained at this time, a frequency of 1i0H was obtained using Reopybron DDV-II-EA manufactured by Toyo Baldwin Co., Ltd.
2. The glass transition temperature was determined from the peak temperature of dynamic loss at a heating rate of 2°C/min and a distance between chucks of 40 m.23
It was found that it has a high heat resistance of 4°C.

Examples 2 to 5, Comparative Examples 1 to 3 p-acetoxybenzoic acid (K) and 2.6-diacedoxynaphthalene (II), 4.4'-diacetoxybiphenyl (■), hydroquinone diacetate (IV- 1
> , 4.4'-diacetoxydiphenyl ether (I
V-2), 2,7-diacedoxynaphthalene (IV-
3) diacetate component and terephthalic acid (V>,
The dicarboxylic acid components consisting of isophthalic acid (Vl) were combined as shown in Table 2 and charged into a polymerization tube so that the number of moles of the diacetate component was equal to the number of moles of the dicarboxylic acid component, and the mixture was prepared in the same manner as in Example 1. A polycondensation reaction was carried out, and the liquid crystal initiation temperature, logarithmic viscosity, melt viscosity, and glass transition temperature of the obtained polymer were measured in the same manner as in Example 1. As is clear from Table 2, the polymer of the present invention has good fluidity and high heat resistance (Examples 2 to 5), but with compositions other than the present invention, the polymer solidifies during polymerization and has poor fluidity. There is (
It can be seen that Comparative Example 2.3) and heat resistance are poor (Comparative Example 1).

<Effects of the Invention> The aromatic polyester of the present invention can be melt-molded at 400° C. or lower and has good fluidity and heat resistance, so it can be used for various thin-walled and precision molded products.

Patent application Daitoshi Co., Ltd.

Claims (1)

[Claims] Consisting of the following structural units (I) to (IV), the structural unit (I
) is 40 to 90 mol% of the total, and the structural unit [(II) + (
III) + (IV)] consists of 60 to 10 mol% of the total,
The molar ratio of structural units (II) / (III) is 8/2 to 2/8, and the structural units (IV) / [(II) + (III) + (IV)]
is 1 to 40 mol%, and has good fluidity. ▲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) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・...(IV) (X in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas, tables, etc. There are ▼, ▲ etc.
There are mathematical formulas, chemical formulas, tables, etc. ▼ Y indicates ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and/or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼. However, X is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ and/or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Y is ▲
There are mathematical formulas, chemical formulas, tables, etc. (excluding combinations that are ▼)