JPH0291119A - Aromatic polyester and preparation thereof - Google Patents

Abstract

PURPOSE:To make it possible to perform melt-molding and to improve heat resistance, mechanical characteristics, etc., by reacting an arom. diol (or an ester-forming deriv. thereof), a dihydroxynaphthalene (or an ester-forming deriv. thereof) and an arom. dicarboxylic acid (or an ester-forming deriv. thereof). CONSTITUTION:A linear arom. polyester with an inherent viscosity of 5 or larger is obtd. by reacting x mol of an arom. diol (A) of formula I (wherein R is a hydrocarbon group) (or an ester-forming deriv. thereof), y mol of a dihydroxynaphthalene (B) of formula II (or an ester-forming deriv. thereof) and z mol of an arom. dicarboxylic acid (C) of formula III (wherein Ar is a para-orienting arom. group) (or an ester-forming deriv. thereof) at a ratio satisfying 40-60<=x/y<=85/15 and x+y>=z in the presence of a reaction catalyst (e.g., stannous acetate).

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a novel aromatic polyester, more specifically, it is melt moldable and has excellent heat resistance, mechanical properties, dimensional stability, and solvent resistance. This invention relates to a liquid crystal-forming aromatic polyester that has excellent oxidation properties during melting, has low water absorption, and is useful as engineering plastics.

<Prior art> Various liquid crystal-forming polyesters have been proposed as polyesters that can be melt-molded and have sufficiently high heat resistance and mechanical strength without using reinforcing materials such as glass fibers. ing.

As a type of such liquid crystal-forming polyesters, various aromatic polyesters composed of residues of aromatic dicarboxylic acids, mainly terephthalic acid, and residues of aromatic dihydroxy compounds, mainly substituted hydroquinone, have been proposed (
(Special Publication No. 58-45224, etc.). These aromatic polyesters have good heat resistance and excellent mechanical properties of molded products, so they are useful as molding materials and the like. However, upon investigation by the present inventors, it was found that molding is difficult due to the high melting temperature. Furthermore, in order to lower the melting point, we investigated adding a copolymer component described in Japanese Patent Publication No. 59-78232, etc., and found that although the melting point was lowered, problems remained in fluidity and fiber formation. Understood.

<Object of the Invention> The present inventors focused on this point and conducted various studies, and as a result, discovered that copolymerization of components with a specific structure significantly improves fluidity and fiber-forming property. has been reached.

<Structure and Effects of the Invention> That is, the present invention provides [where R is a hydrocarbon group]. ] [Here, Ar is a para-oriented aromatic group. ] is the main component, and the number of moles of units (A) and (B) are a and b, respectively, the following formula (I) 40, /60≦a
, /b≦85/15 ·(I>), and is an aromatic polyester characterized by having an intrinsic viscosity of 0.5 or more.

The present invention will be explained in detail below.

The diol component constituting the aromatic polyester of the present invention is mainly [where R is a hydrocarbon group]. ] and GO-Ar-CO-...(C)...(B).

In component (A), R is a hydrocarbon group, and specific examples include an alkyl group, an aralkyl group, and an aryl group. Preferably an alkyl group having 5 to 8 carbon atoms, 7 to 1 carbon atoms
5 aralkyl group, an aryl group having 6 to 12 carbon atoms, and more preferably -C-AI'' (where R1 and R2 are a hydrogen atom or a lower alkyl group, and Ar' is an aryl group having 6 to 12 carbon atoms). (3) is an aromatic group represented by () and an aryl group ((3) is an alkyl group).

Specific examples of component (A) include amylhydroquinone,
Hexylhydroquinone, heptylhydroquinone, octylhydroquinone, benzylhydroquinone, α-methylbenzylhydroquinone, α.

Examples include α-dimethylbenzylhydroquinone, phenylhydroquinone, tolylhydroquinone, and chlorphenylhydroquinone.

Specific examples of component (B) include 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2゜7-dihydroxynaphthalene, etc. In particular, 1
, 5-dihydroxynaphthalene is preferred.

Note that other aromatic diols and/or aliphatic diols can also be used in a part of the components (^) and (8), for example, in a proportion of 30 mol% or less, more preferably 10 mol% or less. Other aromatic diols include hydroquinone and resorcinol.

Examples include bisphenol A, bisphenol S, bisphenol Z, 4,4°-dihydroxydiphenyl, 4.4°-dihydroxydiphenyl ether, butylhydroquinone, methylhydroquinone, chlorohydroquinone, and aliphatic diols include ethylene glycol, Neopentylene gellicol, cyclohexane dimethylol.

Bis-β-hydroxybisphenols (especially bis-β-hydroxybisphenols)
-hydroxybisphenol A, bis-β-hydroxybisphenol S, bis-β-hydroxybisphenol Z, etc.) or alicyclic glycols. Among these, other aromatic diols are more preferred.

The total number of moles of component (A) and component (8) in all diol components is 70 mol% or more, more preferably 80 mol%.
It is preferably at least 90 mol%, particularly at least 90 mol%.

The acid component constituting the aromatic polyester of the present invention is mainly -Go-Ar-Co---.(C) [Here, Ar is a para-oriented aromatic group. ] Consists of.

Here, Ar is a para-oriented aromatic group, and the para position refers to the 1st and 4th positions in the benzene nucleus, and the 2nd and 6th positions, the 2nd and 7th positions, or the 1st position in the naphthalene nucleus. and the 5th position, and the 4th and 4th positions in the diphenyl nucleus.
Represents the position in degrees.

Specific examples of component (C) include terephthalic acid, chlorterephthalic acid, bromoterephthalic acid, 25-dibromoterephthalic acid, methylterephthalic acid, 2゜6-natsuta lindicarbonylfi, 4,4'-diphenyldicarvone M , 3,3°-dibromo-4,4°-diphenyldicarboxylic acid, etc. Among these, terephthalic acids, particularly terephthalic acid, are preferred.

Further, in addition to the aromatic difunctional carboxylic acid, other difunctional carboxylic acids can also be used in small proportions. Examples of other difunctional carboxylic acids include isophthalic acid, succinic acid, adipic acid, and cyclohexanedicarboxylic acid.

The mole ratio of component (C) in all dicarboxylic acid components is 70 mol% or more, further 80 mol% or more, especially 9
It is preferably 0 mol% or more.

In the polymer of the present invention, when the number of moles of units (A) and (B) are a and b, respectively, the following formula (
I) 40/80≦a, /b≦85. /15...(I> is required, preferably 50.150≦a, /b≦75/25. a, /b <40/60. a /b >8
In the case of 5/15, both the melting points are too high and not only the fiber forming properties are not good, but also a liquid crystal polymer having good fluidity cannot be obtained, which is not preferable.

Moreover, the sum (molar ratio) of the component (A) and the component (B) and the component (C) (molar ratio) are theoretically 1/1.

The degree of polymerization of the aromatic polyester of the present invention needs to be 0.5 or more in terms of intrinsic viscosity, preferably 0.5 or more.
It is 8 or more, particularly preferably 1.0 or more.

Note that the intrinsic viscosity in the present invention is P-chlorophenol/
3 in a mixed solvent of tetrachloroethane = L/1 (weight ratio)
This value is calculated from the solution viscosity measured at 5°C.

The aromatic polyester of the present invention can be produced by the following method (Ao) [where R is a hydrocarbon group]. ] Aromatic diol and/or its ester-forming derivative represented by (Bo) Dihydroxynaphthalene and/or its ester-forming derivative represented by (Co) -CO-^r-CO-・-(C) [ Here, Ar is a para-oriented aromatic group. ] An aromatic dicarboxylic acid and/or an ester-forming derivative thereof represented by the above (A').

The number of moles of (B') and (C') are a' and b', respectively.
, c' when closed, the following formulas (II) and <III) 40/60≦a', /b'≦85/15
-(n)a'+b'≧C...(III) An aromatic compound characterized by reacting at a rate that satisfies the following simultaneously and forming a substantially linear polymer having an intrinsic viscosity of 0.5 or more. This is a method for producing polyester. Here (A
As the ester-forming derivatives of o) and (Bo),
Preferably, lower fatty acid esters are mentioned, and specific examples include acetic acid diester, propionic acid diester, chloroacetic acid diester, etc. Among them, acetic acid diester is preferable.

Preferably, the ester-forming derivative of (Co) includes esters of aromatic hydroxy compounds, and specific examples thereof include phenyl ester, tolyl ester, naphthyl ester, etc. Among them, phenyl ester is preferred.

Examples of preferred manufacturing methods include (1) a method in which an aromatic diol diacetyl ester and a dicarboxylic acid are subjected to a heat reaction, (2) a method in which an aromatic diol and a dicarboxylic acid diphenyl ester are caused to undergo a heat reaction.

The ratio of each component is component (A')/(B') (molar ratio)
40/60 to 85/15, preferably 50150 to 7
5/25, and (component A'10B')/C' (molar ratio) is 1 or more, preferably 1.05 to 1.2.

The reaction is carried out by mixing the above components (^'), (B'), and (C') in predetermined amounts in a molten state. The reaction temperature is generally 180°C or higher, preferably 200°C or higher, particularly preferably 250°C or higher and 350°C or lower. Although any reaction pressure can be used, it is preferable to reduce the pressure as the reaction progresses.

In the reaction, the order of addition of each component is arbitrary. Moreover, what is generally known as a polyester polymerization catalyst can be used as a reaction catalyst. Examples of such reaction catalysts include sodium, potassium, calcium, and magnesium.

Zinc, manganese, cobalt, titanium, tin, lead.

Simple substances such as antimony and germanium and their compounds (e.g. oxides, hydrides, hydrogen oxides).

halides, alcoholades, phenolates, organic acid salts, inorganic acid salts, complex salts, double salts, etc.).

In the present invention, various additives such as antioxidants, stabilizers such as ultraviolet absorbers, and pigments are used.

A fluorescent whitening agent or the like may be added.

Effects of the present invention> The aromatic polyester according to the present invention not only has liquid crystal properties and is excellent in melt moldability, chemical resistance, mechanical properties, and heat resistance.

It also has extremely excellent performance in terms of fluidity and i-fiber formation.

Therefore, these properties can be utilized in a wide range of applications, and it is particularly suitable for use as engineering plastic fibers.

<Examples> The present invention will be described in detail with reference to Examples below. Note that "parts" in the examples mean parts by weight.

Further, the melting point is a value measured using DSC at a heating rate of 10° C./min.

Moreover, the flow start temperature is a pressure of 60 kg-cm-i! This is the temperature at which discharge begins when the temperature is raised at a rate of about 10° C./min from a cylindrical discharge hole with a radius of 0.5 mm and a length of 5 mm.

Examples 1 and 2 and Comparative Examples 1 and 2 α-methylbenzylhydroquinone, 1,5
- dihydroxynaphthalene in the amounts shown in Table 1, 31.8 parts of diphenyl terephthalate, and 0 parts of stannous acetate.
．． After adding 0.003 parts of triphenylphosphine and sufficiently replacing the inside of the system with nitrogen gas, the mixture was heated to 265° C. and stirred while slowly flowing nitrogen gas. After about 30 minutes, the reaction temperature was increased to 280°C, and then after about 1 hour to 300°C.
℃, then raised to 330℃ after about 1 hour, and then gradually reduced the pressure to 0.5mm absolute pressure over about 70 minutes.
Hg, and the reaction was continued with stirring for an additional 90 minutes.

The obtained polymer exhibited melt anisotropy. Table 1 shows its intrinsic viscosity. Furthermore, the melting point and flow start point measured by DSC under the above conditions are also listed in Table 1.

For comparison, a case was shown in which another aromatic diol was used instead of 1,5-dihydroxynaphthalene in Example 1, and the rest was reacted in the same manner. When 4,4'-dihydroxydiphenyl is used as a copolymerization component, the fluidity is inferior to that when 1,5-dihydroxynaphthalene is used, and 2,2'-bis(4-
When hydroxyphenyl)propane was used, it became isotropic under polymerization conditions and had a high melt viscosity, making stirring difficult and only a product with a low degree of polymerization could be obtained.

Example 3 In a reactor similar to Example 1, phenylhydroquinone 13
．． 96 parts, 1,5-dihydroxynaphthalene 4.80 parts, diphenyl terephthalate 31.8 parts and acetic acid 1st
0.003 parts of tin, 0.004 parts of triphenylphosphine
and reacted in the same manner as in Example 1.

The obtained polymer is a thermotropic liquid crystal with an intrinsic viscosity of 2.41. Although the melting point determined by DSC was not clear, the flow initiation temperature was 274°C, and the flow characteristics and fiber forming properties were very excellent.

Example 4 In a reactor similar to Example 1, 18.46 parts of benzylhydroquinone diacetate, 9.76 parts of 1,5-dihydroxynaphthalene diacetate, 16.6 parts of terephthalic acid,
Then, 0.003 part of stannous acetate and 0.004 part of triphenylphosphine were added, and the reaction was carried out in the same manner as in Example 1. The obtained polymer is a thermotropic liquid crystal with an intrinsic viscosity of 2.03. The melting point was 299°C and the flow start temperature was 255°C, and the flow characteristics and fiber forming properties were very excellent.

Example 5 In a reactor similar to Example 1, 20.28 parts of α,α-dimethylbenzylhydroquinone diacetate and 9.76 parts of 1,5-dihydroxynaphthalene diacetate were added.

2.6-naphthalenedicarbone 198.64 parts, stannous acetate 0.003 parts, triphenylphosphine 0
, 004 parts were charged and reacted in the same manner as in Example 1. The obtained polymer is a thermotropic liquid crystal with an intrinsic viscosity of 2.15. Melting point: 325℃, induction temperature: 2
The temperature was 82°C, and the flow characteristics and fiber forming properties were excellent.

Comparative Example 3 1.5-dihydroxynaphthalene diacetate 9.76
When the reaction was carried out in the same manner except that 7.76 parts of hydroquinone diacetate was used instead of 1 part, the polymer precipitated and solidified during the reaction under reduced pressure.

Examples 6 to 7 In a reaction vessel similar to Example 1, 17.55 parts of α-methylbenzylhydroquinone and 31 parts of diphenyl terephthalate were added.
．． 8 parts of stannous acetate, 0.003 parts of stannous acetate, and the substances shown in Table 2 in the amounts shown in Table 2 were charged, and the reaction was carried out in the same manner as in Example 1. The obtained polymer exhibited melt anisotropy. Table 2 also shows its intrinsic viscosity, melting point and flow start point measured by DSC under the above conditions, and flow characteristics.

Claims (2)

[Claims] (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(A) [Here, R is a hydrocarbon group. ] ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(B) and -CO-Ar-CO-...(C) [Here, Ar is a para-oriented aromatic group. ] is the main component, and when the number of moles of units (A) and (B) are a and b, respectively, it satisfies the following formula (I) and has an intrinsic viscosity of 0.5 or more. Aromatic polyester. (2) (A') ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(A) [Here, R is a hydrocarbon group. ] Aromatic diol and/or its ester-forming derivative, (B') ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(B) Dihydroxynaphthalene and/or its ester-forming derivative, and (C') ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (C) [Here, Ar is a para-oriented aromatic group. ] The aromatic dicarboxylic acid and/or its ester-forming derivative represented by (A'), (B'), (C'
), the following formulas (II) and (III) 40/60≦a'/b'≦85/15... (II) a'
+b'≧c'...(III) A method for producing an aromatic polyester, which is characterized by reacting at a ratio satisfying the following at the same time and producing a substantially linear polymer having an intrinsic viscosity of 0.5 or more.