JPH02151628A - Aromatic copolyester - Google Patents

Abstract

PURPOSE:To obtain an arom. copolyester having excellent heat resistance, flame retardance, moldability, etc., and being able to form easily a thermotropic liq. crystal by reacting a diacetate of a P-contg. arom. diol, a naphthalenedicarboxylic acid and a benzenedicarboxylic acid, thereby providing a specified mol. structure and physical properties. CONSTITUTION:A random arom. copolyester mainly consisting of structural units of formulae II-IV (wherein Ar<1> is a trivalent arom. group; Ar<2> is a divalent naphthalene ring group; Ar<3> is a divalent benzene ring group) wherein the molar number of formula II is substantially equal to the sum of the molar numbers of formulas III and IV and the ratio of the molar number of formula III to formula IV is 100/0-5/95 and having an intrinsic viscosity of 0.5 or larger is prepd. by reacting, e.g. a diacetate of a P-contg. arom. diol (e.g. a compd. of formula I), a naphthalenedicarboxylic acid (e.g. 2,6-naphthalenedicarboxylic acid) and a benzenedicarboxylic acid (e.g. terephthalic acid).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aromatic copolyester containing a phosphorus atom and having excellent heat resistance and flame retardancy.

(Prior Art) Aromatic polyesters have been 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 40.
Furthermore, since 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. Moreover.

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 heat resistance, flame retardance, and melt moldability, and many proposals have been made.

For example, in JP-A-62-174228, a thermotropic liquid crystalline polyester containing a phosphorus-containing aromatic diol component has been proposed as one that satisfies these requirements. It consists of hydroquinone terephthalate and parahydroxybenzoate units, and there is a significant difference in reactivity between the two (the reactivity of the component forming the parahydroxybenzoate unit is large), making it difficult to control the seven-mer sequence of the copolyester. Particularly in compositions containing a large number of parahydroxybenzoate units, there is a problem in that these units partially become homopolymerized, and as a result, the fluidity and crystallinity of the copolyester are impaired.

(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 retardance, mechanical properties, and melt moldability.

The present invention seeks to provide an aromatic copolyester that has good melt moldability, high flame retardancy, and heat resistance suitable for use at high temperatures.

(Means for Solving the Problems) In order to solve the above problems, the present inventors have conducted intensive research and found that phosphorus-containing aromatic copolyesters having a specific structure have extremely unique 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], the number of moles of [1] is substantially equal to the sum of the number of moles of [2] and [3], and [2] An aromatic copolyester which is a random copolyester in which the ratio of the number of moles of and [3] is 10,010 to 5/95, and has an intrinsic viscosity of 0.5 or more.

0-Ar'-〇- -OC-Ar2-Co-■ -QC-Ar'-Co-■ (In the formula, r Ar' is a trivalent aromatic group, Ar'' is a divalent naphthalene ring group, Ar' represents a divalent benzene ring group.However, the aromatic ring may have a substituent.

) The copolyester of the present invention is preferably a thermotropic liquid crystal copolyester since it has very good heat resistance and melt moldability. And the flow start temperature is 350℃ or less,
It is preferable to select a copolymerization composition so that the temperature is preferably 330°C or less.

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 copolyester of the present invention first has a residue of a phosphorus-containing aromatic diol represented by formula 5 as an essential structural unit.

Ar' in formula (2) is preferably a benzene ring group or a naphthalene ring group, and the aromatic ring is 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. may have a substituent.

Specific examples of this phosphorus-containing aromatic diol include:

Examples include compounds represented by the following formula (Jl) or (b).

In particular, compounds of (al) are preferred.

Moreover, the second structural unit of the copolyester of the present invention is a naphthalene dicarboxylic acid residue represented by 2.

A specific example of this naphthalene dicarboxylic acid is:

Examples include 2,6-naphthalene dicarboxylic acid and 1,4-naphthalene dicarboxylic acid, with the former being particularly preferred.

Furthermore, the third structural unit of the copolyester of the present invention is 2
It is a residue of benzenedicarboxylic acid represented by the formula (■).

As the benzenedicarboxylic acid, terephthalic acid and isophthalic acid are suitable, and the molar ratio of terephthalic acid and isophthalic acid is 100/O to 0/100°, preferably 100/O to 50,150°. Optimally 100/0-7
0/30. 10 to make thermodropink liquid crystalline
It is appropriate to use a ratio of 0.010 to 80/20.

In addition, components other than those mentioned above may be copolymerized within a range that does not impair the heat resistance etc. of the copolyester. Examples of such copolymerization components include 1, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, and 3-hydroxybenzoic acid.
Chloro-4-hydroxybenzoic acid, 3-phenyl-4-
Hydroxybenzoic acid.

2-Hydroxy-6-naphthoic acid, resorcinol.

Hydroquinone, phenylhydroquinone, methylhydroquinone, tert-butylhydroquinone.

Phenyl(2,5-dihydroxyphenyl)ethylidene, 9.10-dihydro-9-oxa-10-(2'.

5'-dihydroxyphenyl)phosphthiphenanthrene-10-oxide, 4,4'-dihydroxydiphenyl, ethylene glycol, ■+4-butanediol, 1
．． 4-Cyclohexane dimetatool, pentaerythritol, ■, 4-cyclohexanedicarboxylic acid, 2,2-
Bis(4'-carboxyphenyl)propane, bis(4'-carboxyphenyl)propane
-carboxyphenyl) ether, trimellitic acid, etc.

It is necessary that the number of moles of structural unit [1] and the sum of the number of moles of structural units [2] and [3] be substantially equal, and if this requirement is not met, a copolyester with a high degree of polymerization will not be obtained. I can't.

Also, the ratio of the number of moles of the structural unit (■) to the number of moles of (■) is 100
10-5/95. Preferably 50,150 to 5/95 is appropriate. Outside this range, the proportion of constituent units ■ is high (
As a result, heat resistance decreases slightly.

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

Preferably 0.6 to 10.0. Optimally 0.7-3.0
It is desirable that 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 10.0 or less.

The copolyester of the present invention can be produced according to a conventional method for producing wholly aromatic polyesters, for example, in the following manner.

(a) The diacetate of aromatic diol and the aromatic dicarboxylic acid in an amount such that the hydroxyl residue and the carboxyl group are equivalent, and preferably 0.05 of the hydroxyl residue.
with ~0.25 equivalents of acetic anhydride.

or (b) the aromatic diol and the aromatic dicarboxylic acid in an amount such that the hydroxyl group and the carboxyl group are equivalent, and the amount equivalent to the hydroxyl group or more.

Preferably, 1.05 to 1.25 equivalents of acetic anhydride are charged into a reactor, and the reaction is carried out at a temperature of about 140° C. for about 2 hours under normal pressure.

Perform acid exchange reaction or esterification reaction.

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℃.
The copolyester can be obtained by carrying out a polycondensation reaction in the melt phase or solid phase at a temperature of 1 Torr or less under high vacuum for several tens of minutes to several hours.

Although the copolyester of the present invention can be produced without a catalyst, a single polycondensation catalyst may also be used.

As the polycondensation catalyst, one or more compounds selected from various metal compounds and organic sulfonic acid compounds can be used.

As the metal compound, compounds such as antimony, titanium, germanium, tin, zinc 9 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, and 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. l×10−′ to 100×10−′ mol,
Preferably 0.5 X 10-' to 50X10-' moles, optimally 1x10-4 to 10XIO-' moles are suitable.

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

Note that the method for measuring the characteristic values is as follows.

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

Using DSCIZ type manufactured by PerkinElmer, the heating rate was 2.
Measured at 0°C/win.

Drag force, l-: @'fp '1' (Using a flow tester (Shimabara manufactured rupture CFT-500 type), with a goo with a diameter of 0.5 mm and a length of 2.0 mm, the load was 100 kg/aa, and the initial temperature was The temperature was increased from 200°C at a temperature increase rate of 10°C/lll1n, and the temperature was determined as the temperature at which the polymer began to flow out from the goo.

1.Limiting oxygen index (LOI) according to flammability JIS K7201 standard
was determined for a 1716 inch thick sample.

Measured under a heavy load at a thickness of 178 inches in accordance with the ASTM 0648 standard.

I'--IZ Measured according to ASTM 0256 standard with a thickness of 1 x 8 inches and a notch. (The unit is kg f cna /
cm ) The thermotropic liquid crystallinity of the copolyester was confirmed using a Leitz polarizing microscope with a hot stage.

Example 1 In a reactor, phosphorus-containing aromatic diol diacetate (PPQ-8) of the formula (13) + 2,6-naphthalene dicarboxylic acid (NDC) and terephthalic acid (TPA) were placed in a molar ratio of 100:40. : 60, and reacted under nitrogen atmosphere at normal pressure at 140°C for 2 hours and then at 200°C for 2 hours with mixing.

Thereafter, the temperature was raised sequentially, and when the temperature reached 280°C, pressure reduction was started, and the temperature was further raised to finally perform melt polymerization at 340°C for 2 hours under reduced pressure of 1 torr or less. (In addition.

The polymer solidified during the polymerization. ) The obtained copolyester has [η) 0.88°T...
372℃, 'rg 184℃, Tf 250℃
, with LOI 73.

It was a thermotropic liquid crystalline copolyester with excellent color tone.

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

Further, the above copolyester was molded at a temperature of 350°C.

It was molded into a test piece measuring 5 inches long x 1/2 inch wide x 1 x 8 inches thick at a mold temperature of 70°C, and IZ and HDT were measured, and IZ = 10.1. HDT=186℃
Met.

Furthermore, 30% by weight of glass fiber was added as a filler to the above copolyester, and the molding temperature was 350°C.

A similar test piece was molded at a mold temperature of 200°C, and IZ and HDT were measured. HDT 2
It became 43℃.

Addition of filler significantly improved HDT.

Examples 2 to 5 Copolyesters were produced in substantially the same manner as in Example 1, except that the molar ratio of raw materials was changed as shown in Table 1.

The characteristic values of the copolyesters obtained in Examples 1 to 5 were
Shown in the table.

Notes to Table 1: (1) HDT and IZ are values for a molded product filled with 30% by weight of glass fiber.

(2) Example 3.4 did not show a clear glass transition point.

Comparative Example 1 In Example 1, the molar ratio of NDC and TPA was 1:
99, the obtained copolyester was as follows.

Since the melting point exceeds 450℃, the
It began to decompose at 50°C, making melt molding difficult.

Example 6 A phosphorus-containing aromatic diol (PP) of the formula (a) was placed in a reactor.
), NDC, TPA and acetic anhydride in a molar ratio of 100
= 60: 40: 220, dimethyltin maleate was added as a catalyst in an amount of 4 x 10-' mol per mol of repeating unit of the polyester, and the mixture was heated under nitrogen atmosphere at normal pressure for 2 hours at 135°C and then at 280°C for 2 hours. The reaction was carried out in a timed manner.

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 5 hours at 0° C. and under reduced pressure of 1 torr or less. (
Note that the polymer solidified during the first polymerization. ) The obtained copolyester has a temperature of [η) 0.75°Tm367°C,
It was an excellent thermotropic liquid crystalline copolyester with a Tf of 249°C and Lot 72 of one color.

Moreover, a molded product made by filling this copolyester with 30% by weight of glass fiber has an IZ17.6. HDT 217℃
showed that.

Example 7 In a reactor, PPQ, NDC, TPA, isophthalic acid (
IPA) and acetic anhydride in a molar ratio of 100:55:
35: IO: Prepared so that it was 220, added 4 x 10-' mol of dimethyltin maleate as a catalyst per 1 mol of polyester repeating unit, and heated under nitrogen atmosphere at normal pressure for 2 hours at 135°C and then at 280°C for 2 hours. I reacted in parts.

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 5 hours at 0° C. and under reduced pressure of 1 torr or less.

The obtained copolyester has [η) 0.94゜'r
g 187℃, Tf 259℃, 8 at LOI To
It was an amorphous copolyester with excellent color tone.

In addition, 30 weight fJ% of glass fiber is added to this copolyester.
Filled molded product C, 1215.6. )IDT 20
It showed 5°C.

(Effects of the Invention) According to the present invention, a novel copolyester having excellent physical properties as a primary heat-resistant and flame-retardant polymer compound is provided, and this copolyester has a high degree of heat resistance and flame retardancy. It is useful as films, fibers, and other molded products used in applications requiring.

(i) 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 (it also has a high degree of flame retardancy when molded).

(ii) Since the main chain is mainly composed of specific aromatic groups, it is easy to form thermotropic liquid crystal properties and has excellent mechanical properties. At the same time, it exhibits a favorable flow start temperature and has excellent heat resistance and moldability. Are better.

(iii) Adding a reinforcing material such as glass fiber further improves heat resistance and mechanical properties.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an infrared absorption spectrum of the copolyester obtained in Example 1. PERCENT TRAN! 9MITTANCE Patent Applicant Nihon Ester Co., Ltd.

Claims (2)

[Claims] (1) It mainly consists of structural units represented by the following structural formulas [1] to [3], and the number of moles of [1] is substantially equal to the sum of the number of moles of [2] and [3], A random copolyester having a molar ratio of [2] and [3] of 100/0 to 5/95, and an aromatic copolyester having an intrinsic viscosity of 0.5 or more. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[1] -OC-Ar^2-CO-[2] -OC-Ar^3-CO-[3] (In the formula, Ar^1 is a trivalent aromatic group, Ar^2 represents a divalent naphthalene ring group, and Ar^3 represents a divalent benzene ring group.However, the aromatic ring may have a substituent.) (2) The aromatic copolyester according to claim 1, wherein the aromatic copolyester has a copolymer composition exhibiting thermotropic liquid crystallinity.