JPS63210127A - Aromatic copolyester - Google Patents

Abstract

PURPOSE:To obtain a heat-resistant aromatic copolyester good in melt mold ability, high in flame retardancy and suitable for use at high temperatures, having aromatic phosphorus-containing diol residues, aromatic dicarboxylic acid residues and aromatic hydroxycarboxylic acid residues. CONSTITUTION:An aromatic copolyester comprising aromatic phosphorus- containing diol residues of formula I, aromatic dicarboxylic acid residues of formula II and aromatic hydroxycarboxylic acid residues of formula III (wherein Ar<1> is a trivalent aromatic group, and Ar<2> and Ar<3> are each a bivalent aromatic group which may be substituted in the aromatic ring), in which the molar ratio among these structural units is such that formula I and formula II are substantially equimolar, formula I and formula III are randomly arranged at a molar ratio of 95/5-5/95 and which has an intrinsic viscosity >=0.5. Examples of said phosphorus-containing aromatic diols which form structural units of formula I include compounds of formula IV and V. Examples of said aromatic dicarboxylic acids which form structural units of formula II include terephthalic acid and isophthalic acid, and examples of said aromatic hydroxycarboxylic acids which form structural units of formula III include 4-hydroxybenzoic acid.

Description

[Detailed description of the invention] (Industrial application field) The present invention mainly focuses on phosphorus-containing aromatic diol components.

The present invention relates to an aromatic copolyester with excellent heat resistance and flame retardancy obtained from an aromatic dicarboxylic acid component and an aromatic hydroxycarboxylic acid component.

(Prior Art) Aromatic polyesters have been well known as heat-resistant polymers. However, most aromatic polyesters are difficult to mold materials and have limited applications.

In addition, aromatic polyester is generally said to have excellent flame retardancy, but the limiting oxygen index described below is at most 4.
0, it is difficult to say that it has sufficient flame retardancy, and furthermore,
Because it has a very high melting point and high melt viscosity, it is extremely inconvenient that it must be molded at high temperature and pressure. On top of that.

Prolonged exposure to high temperatures is not a good idea from the standpoint of polyester decomposition, and is also economically disadvantageous.

Therefore, interest has been focused on the development of liquid crystalline polyesters with excellent flame retardancy and melt moldability, and many proposals have been made.

For example, Japanese Patent Publication No. 56-18016 proposes a thermotropic liquid crystalline copolyester consisting of polyalkylene terephthalate units and 4-hydroxybenzoic acid residue units, and this copolyester is relatively inexpensive and Melt moldability is also good, but heat resistance and flame retardance are insufficient.

On the other hand, U.S. Patent No. 4.161.470 states that 4
-Hydroxybenzoic acid residue unit and 2-hydroxy-6-
A thermotropic liquid crystalline copolyester consisting of naphthoic acid residue units has been proposed, and although this copolyester has good heat resistance, it is expensive, has poor melt moldability, and has poor flame retardancy. Not enough.

(Problems to be Solved by the Invention) As described above, it has been extremely difficult to obtain aromatic polyesters that are satisfactory in all aspects of heat resistance, flame retardancy, mechanical properties, and melt moldability. .

The present invention aims to provide a heat-resistant aromatic copolyester that has good melt moldability, high flame retardancy, and is suitable for use at high temperatures.

(Means for Solving the Problems) In order to achieve the above object, the present inventors conducted intensive research and found that a phosphorus-containing aromatic copolyester having a specific structure has extremely excellent properties. 1. The present invention has been achieved.

That is, the gist of the present invention is as follows.

It mainly consists of structural units represented by the following structural formulas [1] to [3], and the molar ratio of each structural unit is that [1] and [2] are substantially equal, and [1] and [3] are 9515~5/9
Aromatic -O-Ar'-0--OC-Ar''-Co-■ -0-Ar3-Co-■ (In the formula, Ar' represents a trivalent aromatic group, and Ar" and Ar" represent a divalent aromatic group. However, the aromatic ring may have a substituent.) The copolyester of the present invention , crystallinity, poor quality, or thermotropic liquid crystallinity, but thermotropic liquid crystallinity is preferable because it has very good heat resistance and melt moldability. It is preferable to select the copolymerization composition so that the temperature is below 330°C, preferably below 330°C.

Thermotropic liquid crystallinity refers to the property of copolyester molecules regularly arranging in one direction in the melt phase to produce a liquid crystal called nematic phase, and was confirmed by common polarization techniques using orthogonal polarizers. can.

The first structural unit constituting the copolyester of the present invention is
It is a residue of a phosphorus-containing aromatic diol represented by the above structural formula 〇.

Ar' in structural formula (2) is preferably a benzene ring or a naphthalene ring. Further, the hydrogen atom of the aromatic ring in structural formula (0) may be substituted with an alkyl group having 1 to 20 carbon atoms, an alkoxy group, an aryl group having 6 to 20 carbon atoms, an allyloxy group, or a halogen atom.

A specific example of the phosphorus-containing aromatic diol is the following formula (a):
Examples include compounds represented by (d), especially (al
or ('b) is preferred.

The second structural unit is a residue of an aromatic dicarboxylic acid represented by the above structural formula (2).

Ar2 in structural formula (2) is preferably a benzene ring, and may have the same substituent as in formula (8).

As aromatic dicarboxylic acid, terephthalic acid (TPA)
and isophthalic acid (IPA) are preferred, and the molar ratio of TPA and IP8 is 100/O to O/100. Preferably 100/0 to 50150. Optimally 100/O
It is appropriate to use a ratio of ~70/30.

In addition to TPA and IPA, 2,6-naphthalene dicarboxylic acid 2, etc. can also be used.

Further, the third structural unit is a residue of an aromatic hydroxycarboxylic acid represented by the above structural formula (2).

Ar3 in structural formula (0) is preferably a benzene ring or a naphthalene ring, and may have the same substituent as (2).

Specific examples of aromatic hydroxycarboxylic acids include:

Examples include 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, with 4-hydroxybenzoic acid being particularly preferred.

In addition, components other than the above may be copolymerized within a range that does not impair the heat resistance etc. of the copolyester, and such copolymerized components include 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 3
4.4'-dihydroxydiphenyl, naphthalic acid, 2,
2-bis(4'-carboxyphenyl)propane, bis(4-carboxyphenyl)methane, bis(4-carboxyphenyl)ether, ethylene glycol, 1,4
-butanediol, 2-butene-1,4-diol, cyclohexane dimetatool, pentaerythritol and the like.

It is necessary that the units of formula (1) and the units of (2) have substantially equimolar amounts, and unless this requirement is satisfied, a copolyester with a high degree of polymerization cannot be obtained.

Also, the ratio of the units of formula 1 and the units of formula ■ is 9 in terms of 1 molar ratio.
515-5/95. Preferably 80/20 to 10/9
0, 5015 for thermotropic liquid crystallinity
It is preferable to set it to 0 to 10/90. Outside these ranges, if the number of units of formula 1 increases, the strength and heat resistance will decrease, and if the number of units of 20 increases, the melting temperature will become too high and the flame retardance will become poor.

Furthermore, the copolyester of the present invention has an intrinsic viscosity [η]
is required to be 0.5 or more.

Preferably 0.6-10. The optimum value is 0.7 to 3.0. If [η] is less than 0.5, various physical, mechanical, and chemical properties including heat resistance will be poor, which is not preferable. However, if [η] is too large, the melt viscosity may become too high and melt moldability may be impaired, which is undesirable, and it is preferably 10 or less.

Next, as a preferable example in which the copolyester of the present invention can be produced economically, the first structural unit is diphenyl(2,5-dihydroxyphenyl)phosphine oxyto (PP), which is a compound represented by the formula (al). A detailed explanation of the manufacturing method for a copolyester in which the second structural unit is a TPA/IPA residue, and the third structural unit is a 4-hydroxybenzoic acid (411BA) residue. do.

(a) PPQ diacetate (PP Rho A), TP
A/IPA and 4HBA acetate (4HBA-A
) in an amount that makes the hydroxyl residue and carboxyl residue equivalent, and preferably 0.05 to 0 of the hydroxyl residue.
．． Together with 25 times the equivalent of acetic anhydride (Δc20), or (b) PPQ and TPA/IPA in an amount such that the hydroxyl group and the carboxyl group are equivalent and at least the equivalent of the hydroxyl group, preferably 1.05 to 1.25 times. equivalent amount of A
C, 0 is charged into a reactor and subjected to an acid exchange reaction or an esterification reaction at a temperature of about 150°C under normal pressure for about 2 hours.

Thereafter, the temperature is raised sequentially, and if necessary, the pressure is reduced to distill off acetic acid while reacting.

Next, the temperature is increased and the pressure is reduced in sequence, and finally the temperature is 240-350℃.
A copolyester can be obtained by carrying out a polycondensation reaction in a melt phase or a solid phase for several tens of minutes to several tens of hours under a high reduced pressure of 1 torr or less.

1 usually for producing the copolyesters of the present invention.

Although a polycondensation catalyst is used, one or more compounds selected from various metal compounds and organic sulfonic acid compounds can be used as the double condensation catalyst.

As the metal compound, compounds such as antimony, titanium, germanium, tin, zinc, aluminum, magnesium, calcium, potassium, sodium, manganese, or cobalt are used.

Examples of organic sulfonic acid compounds include sulfosalicylic acid, 0
- Compounds such as sulfobenzoic anhydride are used;
Dimethyltin maleate and 0-sulfobenzoic anhydride are particularly preferably used.

The amount of catalyst added is usually 0.00% per mole of repeating units of polyester. 1X10-' to 100XIO-' mol, preferably 0.5X10-' to 50X10-' mol, optimally 1X10-' to 10XIO-' mol are suitable.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

In addition, the method of measuring the characteristic value is as follows.

It was determined from the solution viscosity measured at 20°C using a mixed solvent of equal weights of phenol and tetrachloroethane.

Using a 3P FF' (Tf) flow tester (CFT-500 model manufactured by Shimadzu Corporation), a diameter of 0.5 m and a length of 2. Using an Ofm die, the load was set at 100 kg/cJ, the temperature was raised from the initial temperature of 200°C at a heating rate of 10°C/min, and the temperature was determined as the temperature at which the polymer began to flow out from the goo.

lLimiting Oxygen Index (LOI) according to plagiarized JIS K7201 standard
was determined for a 1×16 inch thick sample.

Izot - Strong J” (IZ) ΔSTM 1/8 inch thick according to D256 standard.

Measured with a notch.

The thermotropic liquid crystallinity of the copolyester was confirmed using a Leitz polarizing microscope equipped with a hot stage.

Example 1 PPQ-A, 4HBA-A and TPA were charged into a reaction apparatus at a molar ratio of 25:75:25,
After setting the catalyst, dimethyltin maleate was added in an amount of 4 x 10-' mol per mol of polyester repeating unit under a nitrogen atmosphere.

The reaction was carried out under normal pressure at 150°C for 2 hours and then at 200°C for 2 hours with mixing.

Thereafter, the temperature was raised sequentially, and when it reached 280°C, pressure reduction was started, and the temperature was further raised, finally reaching 320°C.

Melt polymerization was carried out for 2 hours under reduced pressure of 1 torr or less.

The obtained copolyester was a thermotropic liquid crystalline copolyester with excellent color tone and having the characteristic values shown in Table 1.

The infrared absorption spectrum of this copolyester is shown in FIG.

Examples 2 to 24 Copolyesters were produced in substantially the same manner as in Example 1, except that the molar ratio of the raw materials was changed as shown in Table 1.

The obtained copolyesters were non-quality in Examples 22 to 24, crystalline in Examples 12 to 13, and thermotropic liquid crystal in the others.

The results of Examples 1 to 24 are shown in Table 1.

Comparative Examples 1 to 2 In Example 1, the charging molar ratio of PPQ-A and 4HBA-A was 1:99 (Comparative Example 1) or 99:1 (Comparative Example 2). ), the obtained copolyester was
In Comparative Example 1, the pigment began to decompose at an extremely high melting point of 450° C., making melt molding difficult. In Comparative Example 2, the melting point of the pigment was as high as 407° C. and was extremely brittle.

It could not be put to practical use.

Examples 25 to 27 The above formula (b), (C) or (d
A copolyester was produced in the same manner as in Example 1, except that the diacetate of the phosphorous diol compound of ) was used.

The characteristic values of the obtained copolyester are shown in Table 1.

In addition, (bl, (C) and (d) in Table 2 represent the diacetates of the compounds of the formulas (b), fc) and (d), respectively.

Table 2 Example 28 PPQ, 4HBA, TPA and Ac in the reactor
, O were charged in a molar ratio of 25:75:25:100, and dimethyltin maleate was added as a catalyst in an amount of 4X10-' per mole of repeating units of polyester.
mol was added, and an esterification reaction was carried out at 150° C. under nitrogen atmosphere at normal pressure for 2 hours.

Thereafter, the mixture was incubated at 200° C. for 2 hours and then at 280”C for 2 hours.

After that, the reaction was carried out by sequentially raising the temperature and reducing the pressure, and finally 32
Melt polymerization was carried out for 2 hours at 0° C. and under reduced pressure of 1 torr or less.

The obtained copolyester has [η) 1.89. T
t258℃, IZ 14.1 kgf-cm/a
It was an excellent thermotropic liquid crystalline copolyester with an LOI of 61 and 8 cycles per color.

Example 29 PPQ, 4HBA, TPA, and Ac20 were charged in a reactor at a molar ratio of 25:75:25:150, and dimethyltin maleate was added as a catalyst by 4×10−' mole per mole of polyester repeating unit. , under nitrogen atmosphere, normal pressure, and 150° C. for 2 hours.

Thereafter, the reaction was carried out at 200° C. for 2 hours at normal pressure, and then for 2 hours at 280° C. under reduced pressure of 50 torr.

After solidifying and pulverizing the obtained reaction product, the reaction was started at 150°C under the reduced pressure of an Il-ru, and the temperature was gradually increased until the temperature reached 280°C.
The temperature was raised to .degree. C., and solid phase polymerization was carried out for a total of 24 hours.

The obtained copolyester has [η) 1.56. T
f258℃, I Z 14.1 kgf1cm/
cm, LOI of 61, and an excellent thermotropic liquid crystalline copolyester with 8 color tones.

(Effects of the Invention) According to the present invention, a novel copolyester having excellent properties as a heat-resistant and flame-retardant polymer as shown in order 9 is provided. It is useful as a material for films, fibers, and molding materials used in applications that require oxidation, or as a modifier for flame retardants and the like.

(1) Since it has a specific phosphorus-containing structural unit in its side chain,
Not only does it not decompose even when used at high temperatures, but it also has a high degree of flame retardancy when molded.

(2) Since the main chain is mainly composed of specific aromatic groups, it is easy to form thermotropic liquid crystal properties.

It has excellent mechanical properties, exhibits a favorable flow initiation temperature, and has excellent heat resistance and moldability.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an infrared absorption spectrum of the copolyester obtained in Example 1.

Claims (4)

[Claims] (1) Mainly consists of structural units represented by the following structural formulas [1] to [3], and the molar ratio of each structural unit is [1] and [2].
] are substantially equal, and [1] and [3] are 95/5~
An aromatic copolyester having an intrinsic viscosity of 0.5 or more and randomly arranged in a molar ratio of 5/95. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[1] -OC-Ar^2-CO-[2] -O-Ar^3-CO-[3] (In the formula, Ar^1 is a trivalent aromatic The groups Ar^2 and Ar^3 represent divalent aromatic groups.However, the aromatic ring may have a substituent.) (2) The copolyester according to claim 1, wherein the copolyester is a thermotropic liquid crystalline polyester. (3) The copolyester according to claim 1 or 2, wherein the copolyester consists of a structural unit represented by the following formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (4) The copolyester according to claim 1 or 2, wherein the copolyester consists of a structural unit represented by the following formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼