JPH0645742B2 - Polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a polyester resin comprising a thermotropic liquid crystalline phosphorus-containing polyester and another thermoplastic resin, which is excellent in heat resistance, flame retardancy and moldability. It relates to a composition.

(Prior Art) A wholly aromatic polyester (polyarylate) is conventionally known as a heat-resistant polymer. In general, wholly aromatic polyester has extremely high melting point and high melt viscosity at the same time even though it has excellent physical properties, and therefore it is extremely inconvenient to process at high temperature and high pressure. However, long-term exposure to high temperature is not a good idea from the viewpoint of polyester decomposition and is economically disadvantageous.

Recently, thermotropic liquid crystalline polyester, which has excellent processability, has been attracting attention and is being actively studied.

However, the thermotropic liquid crystalline polyesters that have been proposed hitherto have insufficient melt processability, heat resistance, and flame retardancy.

On the other hand, thermoplastic resins such as polyethylene terephthalate, polybutylene terephthalate, and polycarbonate are widely used as engineering plastics with good moldability, but the required performance is increasing year by year, and the heat distortion resistance and flame retardancy are high. The problem of not being enough has arisen.

In addition, blending of another polymer has been attempted for the purpose of improving the moldability and mechanical properties of the thermotropic liquid crystalline polyester. For example, a thermotropic liquid crystalline polyester having a 2,6-naphthalene group has been used. It has been proposed to blend polyalkylene terephthalate, polycarbonate, etc. (JP-A-57-25234,
57-44551). However, although such a composition improves moldability and mechanical properties to some extent, it is not sufficient and flame retardancy is not improved at all.

(Problems to be Solved by the Invention) The present invention solves the drawbacks of conventional thermoplastic resins as thermotropic liquid crystalline polyesters and engineering plastics, and has excellent moldability, good heat resistance, and high difficulty. It is intended to provide a polyester resin composition which is also flammable.

(Means for Solving the Problems) As a result of earnest studies to achieve the above-mentioned object, the inventors of the present invention have found that the composition of a phosphocopolyester containing a thermotropic liquid crystallinity of a specific structure and another thermoplastic resin. The present invention has been accomplished by finding that it is effective to use the product.

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

5 to 95 mol% of the units constituting the main chain are represented by the following structural formula (I)
Is a unit represented by the following structural formula (I
The unit represented by I) is composed of a thermotropic liquid crystalline random copolyester having an intrinsic viscosity of 0.5 or more and a thermoplastic resin selected from polyethylene terephthalate, polybutylene terephthalate and polycarbonate. A polyester resin composition that accounts for 8 to 80% by weight.

[Ar ¹ represents a trivalent aromatic group, and Ar ² represents a divalent aromatic group. However, the aromatic ring may have a substituent. The copolyester in the present invention is a thermotropic liquid crystalline random copolyester containing 5 to 95 mol%, preferably 10 to 80 mol%, and more preferably 20 to 40 mol% of the unit represented by the structural formula (I). It has good melt moldability and usually has a melting point of 350 ° C or less, preferably 300
It is below ℃. If the number of units represented by the structural formula (I) is too large, the strength of the molded product will be reduced, while if it is too small, the melting point will be too high or the flame retardancy will be low.

As Ar ¹ in the structural formula (I), a benzene ring and a naphthalene ring are most preferable. Further, in the structural formula (I), the hydrogen atom of the aromatic ring may be substituted with an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group, an aryloxy group or a halogen atom.

The unit of structural formula (I) is derived from a phosphorus-containing aromatic diol component and an aromatic dicarboxylic acid component.

Specific examples of the phosphorus-containing aromatic diol include the following formulas (a) to
Those represented by (d) are mentioned, and particularly preferable ones are
It is represented by the formula (a) and the formula (b).

(a) (b) (c) (d) As the aromatic dicarboxylic acid, terephthalic acid (TPA) and isophthalic acid (IPA) are suitable, and the molar ratio of TPA and IPA is 100: 0 to 0: 100, preferably 100: 0 to 50:50, optimal It is suitable to use in a ratio of 100: 0 to 80:20.

The second unit forming the copolyester with the unit of structural formula (I) is a unit composed of an oxycarboxylic acid residue represented by structural formula (II).

As Ar ² in the structural formula (II), a benzene ring and a naphthalene ring are most preferable. Further, in the structural formula (II), the hydrogen atom of the aromatic ring may be substituted with an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group, an aryloxy group or a halogen atom.

Specific examples thereof include a 4-hydroxybenzoic acid residue and a 6-hydroxy-2-naphthoic acid residue, and the most preferred one is a 4-hydroxybenzoic acid residue.

In addition, components other than the above may be copolymerized within the range of forming a thermotropic liquid crystalline copolyester having good melt moldability.
Naphthohydroquinone, 2,6-naphthohydroquinone, 4,4'-dihydroxydiphenyl, naphthalic acid,
2,2-bis (4-carboxyphenyl) propane, bis (4-carboxyphenyl) methane, bis (4-carboxyphenyl) ether, ethylene glycol, cyclohexanedimethanol, pentaerythritol and the like can be mentioned.

As an example of the preferred copolyester in the present invention,
The unit represented by the structural formula (I) is 9,10-dihydro-9-oxa-10- (2 ′, 5 ′) represented by the above formula (a).
-Dihydroxyphenyl) phosphaphenanthrene-1
A process for producing a copolyester in which a unit derived from 0-oxide (PHQ) and TPA / IPA, and a unit represented by the structural formula (II) is a unit consisting of 4-hydroxybenzoic acid (4HBA) residue An example will be described.

(A) A hydroxyl group and a carboxyl group are formed between the acid component composed of TPA / IPA, the diol component composed of the PHQ diacetate body (PHQ-A), and the oxycarboxylic acid component composed of the 4HBA acetate body (4HBA-A). An equivalent amount (and preferably 0.01 to 0.25 times equivalent of acetic anhydride based on the amount of all hydroxyl groups) or (b) an acid component consisting of TPA / IPA and PH
A diol component consisting of Q and an oxycarboxylic acid component consisting of 4HBA were charged in an amount of 1.05 to 1.25 times as much acetic anhydride as the equivalent amount of hydroxyl groups and carboxyl groups and the amount of all hydroxyl groups in a reactor, and under normal pressure, The esterification reaction or acid exchange reaction is carried out at a temperature of about 150 ° C. for about 2 hours. After that, the temperature is raised sequentially and, if necessary, the acetic acid is distilled off under reduced pressure to carry out an acid exchange reaction. Then finally usually 25
A copolyester having melt moldability can be obtained by performing a polycondensation reaction in a melt phase or a solid phase at a temperature of 0 to 350 ° C. under a high reduced pressure of less than 1 torr for several tens of minutes to several hours.

Usually, a catalyst is used in the polycondensation reaction, but in the production of the copolyester in the present invention, one or more kinds of compounds selected from various metal compounds and organic sulfonic acid compounds are used.

Such metal compounds include antimony, titanium, germanium, tin, zinc, aluminum, magnesium,
A compound such as calcium, manganese, sodium or cobalt is used, while a compound such as sulfosalilic acid or o-sulfobenzoic anhydride is used as the organic sulfonic acid compound. Particularly preferred are dimethyltin maleate and o-sulfobenzoic anhydride.

The amount of the catalyst added is usually 0.1 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, preferably 0.5 × 10 ^{4 with} respect to 1 mol of the constitutional unit of polyester.
^-4 to 50 × 10 ^-4 mol, optimally 1 × 10 ^-4 to 10 × 10 ^-4 mol is suitable.

In the process of polycondensation reaction, depending on the type of the constituent units of the polyester, the polyester may be solidified to be in a solid state or may be polycondensed in a molten state.

The copolyester in the present invention must have an intrinsic viscosity [η] of 0.5 or more, preferably 1.0
˜10.0, optimally 3.0 to 6.0. If [η] is less than this range, various physical and mechanical special values such as heat resistance are inferior, while if [η] is more than this range, melt viscosity becomes too high and fluidity is impaired. Or
It is not preferable because the melting point becomes too high and the molding temperature must be remarkably increased.

Further, the thermal characteristic values of the copolyester in the present invention are as follows: melting point 350 ° C. or lower, heat distortion temperature 155 ° C. or higher, preferably melting point 330 ° C. or lower, heat distortion temperature 180 ° C. or higher, optimally melting point 28
A temperature of 0 to 300 ° C and a heat distortion temperature of 180 to 230 ° C are suitable in terms of achieving both heat resistance and various physical and mechanical property values.

Next, the thermoplastic resin to be blended with the thermotropic liquid crystalline copolyester may be any as long as it improves the moldability of the thermotropic liquid crystalline copolyester.
Either amorphous or thermotropic liquid crystallinity may be used, but normally, one having no thermotropic liquid crystallinity is used.

Specific examples of such a thermoplastic resin include polyarylates of bisphenol compounds and TPA / IPA dicarboxylic acid compounds, polyarylates of 4HBA oxycarboxylic acid compounds, polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate. , Polycarbonate, polyether ether ketone,
Examples thereof include polysulfone and polyether sulfone, and these may be used in combination of two or more kinds.

The most preferred thermoplastic resins are polyalkylene terephthalates selected from polyethylene terephthalate and polybutylene terephthalate (including copolymers containing them as a main component) and polycarbonates. As the polycarbonate, 4,4'-dioxydiallyl alkane-based polycarbonate is particularly preferable, and for example, bis (4-
Hydroxyphenyl) methane, bis (4-hydroxyphenyl) ethane, 2,2-bis (4'-hydroxyphenyl) propane, bis (4-hydroxy-3,5-dichlorophenyl) methane, 2,2-bis (4 ' 4, such as -hydroxy-3 ', 5'-dimethylphenyl) propane and bis (4-hydroxyphenyl) phenylmethane.
A polycarbonate obtained from 4'-dioxydiphenylalkane and phosgene or diphenyl carbonate is preferably used.

The ratio of the thermotropic liquid crystalline copolyester to the thermoplastic resin is 8 to 80% by weight of the composition, preferably
20-80% by weight, optimally 50-80% by weight is recommended. If the amount of copolyester is too large, the strength of the molded product will decrease, while if it is too small, the glass transition temperature will be low and the flame retardancy will be insufficient, which is not preferable.

To obtain a composition by mixing the thermotropic liquid crystalline copolyester and another thermoplastic resin, both components are uniformly mixed by a solution blending method or a mixing method using a two-roll, Banbury mixer, melt extruder or other mixer. Can be mixed with.

EXAMPLES Next, the present invention will be described in more detail with reference to examples.

[Η] was determined from the solution viscosity measured at 20 ° C using an equal weight mixed solvent of phenol and ethane tetrachloride.

The melting point was measured using a DSC-2 type differential scanning calorimeter manufactured by Perkin Elmer Co., Ltd., and the heat distortion temperature was measured under a large load in accordance with JIS K7207.

Izod impact strength is thickness 1 according to ASTM D256 standard
Measured at / 8 inch.

Flame retardance is based on UL-94 standard (HB, V-2, V-1, V-
0) and limit oxygen index (LOI) according to JIS K 7201 standard
It was judged by.

In addition, the thermotropic liquid crystal property is Le with hot stage.
It was confirmed with an itz polarization microscope.

Further, the formability was evaluated by using the J-100-S type molding machine manufactured by Japan Steel Works, to form a disc-shaped test piece of 100φ x 1/8 inch, and the following criteria according to the conditions at that time. .

A: Injection time is 10 seconds or less and molding temperature is 330 ° C
◯: Injection time is 10 to 15 seconds and molding temperature is less than 330 ° C △: Injection time is 15 to 30 seconds and molding temperature is less than 330 ° C ×: Injection time is 30 seconds or more or molding temperature is 330 C or higher Examples 1 to 9 PHQ-A, 4HBA-A and acetic anhydride were added to the reactor at a molar ratio of 2.
5: 7.5: 2 and PHQ-A and an equimolar amount of TPA were charged, and dimethyltin maleate as a catalyst was added in an amount of 4 × 10 ^-4 mol to 1 mol of the polyester constitutional unit. The reaction was carried out while mixing at 0 ° C for 2 hours. The reaction product was reacted under atmospheric pressure at 250 ° C. for 2 hours and then at 50 torr for 2 hours at 260 ° C. Next, this reaction product was reacted by gradually raising the temperature under a reduced pressure of 0.1 torr, and finally raising the temperature to 320 ° C. to perform melt polymerization for a total of 3 hours.

The obtained copolyester was [η] 5.41 and was a liquid crystalline copolyester having a good color tone.

This copolyester and polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PB
T) or polycarbonate resin (PC) at a ratio shown in Table 1 and then a screw-type extruder equipped with a die having a diameter of 4 mm (screw diameter 30 mm, L /
D20), a screw rotation speed of 30 rpm, a processing temperature corresponding to the composition, extruding in a strand shape, cooling, and then cutting into a length of 3 mm to obtain a granular material.

Table 1 shows the results of measuring the physical properties by molding 1/8 × 1/8 × 5 (inch) sample pieces using this granular material.

As Comparative Examples 1 to 4, the results of molding each of the above resins alone are shown in Table 1.

Example 10 In a reactor, PHQ, resorcin (RS), 4HBA and acetic anhydride were used in a molar ratio of 6: 1: 3: 15 and TPA in an equimolar amount to the sum of PHQ and RS.
Then, 4 × 10 ⁻⁴ mol of dimethyltin maleate as a catalyst was added to 1 mol of the polyester constitutional unit, and the mixture was reacted under a nitrogen atmosphere at atmospheric pressure and 150 ° C. for 2 hours while reacting. The reaction was reduced to 250 ° C. for 2 hours and then 50
The reaction was performed at 260 ° C. for 2 hours as a torr. Next, this reaction product was heated under a reduced pressure of 0.1 torr to carry out the reaction, and finally the temperature was raised to 310 ° C. to carry out melt polymerization for a total of 5 hours.

The obtained copolyester had an [η] of 2.99 and was a liquid crystalline copolyester having a good color tone.

This copolyester and PET were mixed at a weight ratio of 80/20, molded in the same manner as in Example 1, and the physical properties were evaluated. The results are shown in Table 2.

Example 11 A reactor was charged with PHQ, hydroquinone (HQ), 4HBA and acetic anhydride in a molar ratio of 6: 1: 3: 18 and TPA / IPA (molar ratio 60/40) in an equimolar amount to the sum of PHQ and HQ. As a catalyst, dimethyltin maleate was added in an amount of 4 × 10 ^-4 mol per 1 mol of the polyester constitutional unit, and the mixture was reacted under a nitrogen atmosphere at atmospheric pressure and 150 ° C. for 2 hours while reacting. Under normal pressure,
The reaction was carried out at 250 ° C. for 2 hours and then at 50 torr for 2 hours at 260 ° C. Next, this reaction product was reacted by gradually raising the temperature under a reduced pressure of 0.1 torr, finally raising the temperature to 320 ° C., and carrying out melt polymerization for a total of 4 hours.

The obtained copolyester was [η] 1.25 and was a liquid crystalline copolyester having a good color tone.

This copolyester and PET are mixed at a weight ratio of 80/20, molded in the same manner as in Example 1, and the physical properties are evaluated. The results are shown in Table 2.

Examples 12 to 18 Copolyesters were prepared in the same manner as in Example 1 using PHQ-A, 4HBA-A, HQ-A (HQ diacetate) and TPA / IPA in the molar ratios shown in Table 2. Obtained.

These copolyesters and PET were mixed at a weight ratio of 80/20 and molded in the same manner as in Example 1, and the results of evaluation of physical properties are shown in Table 2.

As Comparative Examples 5 to 7, an example in which an experiment was performed in the same manner as in Example 1 using a copolyester that did not exhibit thermotropic liquid crystallinity was added. (Comparative Example 5 could not be uniformly mixed with PET, and Comparative Examples 6 and 7 could not be molded by a general-purpose molding machine because the melting point and melt viscosity of the copolyester became too high.

Examples 19 to 21 Table 2 shows the physical properties of test pieces obtained in the same manner as in Example 1 except that other phosphorus compounds were used instead of PHQ-A in Example 1.

In Table 2, b, c and d before the numerical values in the PHQ column of Examples 19 to 21 are the structural formulas (b), (c) and
It shows that the diacetate body of the organic phosphorus compound of (d) was used.

(Effects of the Invention) According to the present invention, the high heat resistance and flame retardancy of the phosphorus-containing thermotropic liquid crystalline copolyester and the excellent moldability of the thermoplastic resin are exhibited in a well-balanced manner, and are useful as engineering plastics. Provided is a polyester resin composition having excellent heat resistance, flame retardancy, and good moldability.

Claims (4)

[Claims] 1. A unit represented by the following structural formula (I) accounts for 5 to 95 mol% of units constituting the main chain and a unit represented by the following structural formula (II) for 95 to 5 mol%. There is an intrinsic viscosity of 0.
A polyester resin composition comprising 5 or more thermotropic liquid crystalline random copolyester and a thermoplastic resin selected from polyethylene terephthalate, polybutylene terephthalate and polycarbonate, the former occupying 8 to 80% by weight of the composition. [Ar ¹ represents a trivalent aromatic group, and Ar ² represents a divalent aromatic group. However, the aromatic ring may have a substituent. ] 2. The polyester resin composition according to claim 1, wherein the unit represented by the structural formula (I) is represented by the following structural formula. 3. The polyester resin composition according to claim 1, wherein the unit represented by the structural formula (I) is represented by the following structural formula. 4. The polyester resin composition according to claim 1, 2, or 3, wherein the unit represented by the structural formula (II) is a 4-hydroxybenzoic acid residue.