JPH061835A - Production of aromatic polyester - Google Patents

Abstract

PURPOSE:To obtain the title polyester improved in heat resistance, mechanical properties and solvent resistance by polycondensing isophthalic acid or its esterifiable derivative with hydroquinone or its esterifiable derivative and a specified compound. CONSTITUTION:Isophthalic acid or its esterifiable derivative (A) is mixed with hydroquinone or its esterifiable derivative (B) and a compound of the formula, wherein X is methylene which may have a substituent; and n is 4 or 5 and/or its esterifiable derivative (C) in such amounts that the B/C molar ratio is 50/50-80/20, and the total of components B and C is 95-120mol% based on component A. The resulting mixture is polycondensed by melting at 300-400 deg.C in the presence of a catalyst to obtain an amorphous, wholly aromatic polyester having an intrinsic viscosity of 0.3-1.0 as measured in a phenol/tetrachloroethane solvent (weight ratio of 60/40) at 35 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an amorphous aromatic polyester, more specifically, an amorphous aromatic polyester which gives a molded article having excellent heat resistance, mechanical properties and solvent resistance by melt molding. The present invention relates to a method for producing polyester.

[0002]

2. Description of the Related Art Aromatic polyesters having various characteristics such as an amorphous polymer, a crystalline polymer or a liquid crystalline polymer can be obtained depending on the combination or composition of its constituent components. Among these, amorphous polymers are excellent in dimensional stability, transparency, mechanical properties, and heat resistance, and have been variously studied as so-called amorphous engineering plastics. Particularly, a polymer using terephthalic acid and isophthalic acid as an acid component and 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) as a diol component has a relatively balanced physical property. Development is being carried out by making use of this, but this polymer, like ordinary amorphous polymers, has insufficient solvent resistance, is easily dissolved or swelled in various organic solvents, and its use is limited. .

For the purpose of improving the solvent resistance, there has been proposed one in which hydroquinone is partially used as a diol component (JP-A-52-78999). The polymer containing the hydroquinone component is certainly more solvent resistant than the polymer using bisphenol A as the diol component,
Stress crack resistance is improved. However, as the production method thereof, the hydroquinone component is extremely susceptible to oxidation, the solubility of the polymer is insufficient, and the like. Therefore, the solution polymerization method or the interface used as the production method of bisphenol A alone is used. The polymerization method cannot be adopted.

Therefore, according to the above-mentioned Japanese Patent Laid-Open No. 52-78999, production by a melt polymerization method is tried as a production method of a polymer having a hydroquinone component introduced therein. However, in this method, as described in the example, after solidifying or crystallizing the polymer in the melt polymerization process, the solid-state polymerization of the polymer is subsequently carried out to produce the target aromatic polyester. This is 30
Since the melt viscosity of the polymer is high at a relatively low melt polymerization temperature of about 0 ° C. or less, it is difficult to obtain a polymer having a high degree of polymerization capable of expressing sufficient toughness, and further, the polymer obtained by the hydroquinone component is crystallized. It is considered that this is because the characteristics can be changed. However, this method of using solid-phase polymerization in combination has a problem that the manufacturing process is complicated, the productivity is low, and the cost is high.

According to the above-mentioned JP-A-52-78999, the polymer into which the hydroquinone component is introduced has a heat distortion temperature of 165 to 170 ° C., and terephthalic acid and isophthalic acid are used as the above-mentioned acid component, and as a diol component. There is a problem that the polymer using bisphenol A is slightly inferior in heat resistance as compared with 172 ° C.

[0006]

SUMMARY OF THE INVENTION Therefore, the present inventors have found that an amorphous aromatic polyester excellent in heat resistance, solvent resistance and stress crack resistance can be industrially produced by a melt polymerization method without using solid phase polymerization in combination. It is intended to provide a method of manufacturing at low cost.

[0007]

That is, the present invention provides (A) isophthalic acid and / or its ester-forming derivative, (B) hydroquinone and / or its ester-forming derivative, and (C) the following formula (I).

[0008]

[Chemical 2]

The compound represented by the following formula and / or its ester-forming derivative have a molar ratio (B / C) of component (B) to component (C) of 50/50 to 80/20, and component (B) and component The total amount of (C) is in the range of 95 to 120 mol% with respect to the component (A), and these are added in the presence of a catalyst at a polymerization temperature of 300 to
Intrinsic viscosity (phenol / tetrachloroethane mixed solvent (weight ratio 60/40))
Medium, 35 ° C.) 0.3-1.0 polymer is obtained.

The present invention comprises isophthalic acid and / or its ester-forming derivative as component (A). Examples of the ester-forming derivative include alkyl ester, aryl ester, and acid chloride. As the component (A), isophthalic acid diaryl ester is preferable, and diphenyl isophthalate is particularly preferable.

Next, in the present invention, hydroquinone and / or its ester-forming derivative is used as the component (B). Examples of the ester-forming derivative include lower aliphatic carboxylic acid ester, and acetic acid ester is particularly preferable. Here, hydroquinone is preferable as the component (B).

Next, in the present invention, the following formula (I)

[0013]

[Chemical 3]

The compound represented by and / or its ester-forming derivative is used as the component (C). Here, X represents a methylene group which may have a substituent, and specific examples thereof include a methylene group, a methylmethylene group and a halogenated methylene group, and a methylene group is preferable.
n represents the length of a methylene chain which may have a substituent,
4 or 5 is shown. Of these, n = 5 is preferable. Examples of the ester-forming derivative include lower aliphatic carboxylic acid esters, and acetic acid ester is particularly preferable.
As the component (C), 1,1-bis (4-hydroxyphenyl) cyclohexane (hereinafter referred to as bisphenol Z) is preferable.

The molar ratio (B / C) of the component (B) and the component (C) is 50/50 to 80/20. When the mole fraction of the component (B) is less than 50%, the solvent resistance and stress crack resistance targeted by the present invention are still insufficient, and when it is more than 80 mol%, the obtained polymer becomes crystalline. And the transparency becomes insufficient. The molar ratio (B / C) of component (B) and component (C) is preferably 5
5/45 to 75/25, particularly preferably 60/40 to 7
It is 0/30. In the method for producing an aromatic polyester of the present invention, the total amount of the component (B) and the component (C) is in the range of 95 to 120 mol% with respect to the component (A), and this is subjected to polycondensation by heating. The total amount of the component (B) and the component (C) is preferably 97 to 115 mol%, and 99 to 11
The range of 0 mol% is particularly preferable.

In the present invention, the above-mentioned components are heated and melt-polycondensed in the presence of a catalyst. As the catalyst used here, conventionally known ones used in the production of polyester can be used. Examples thereof include antimony compounds such as antimony trioxide, tin compounds such as stannous acetate, titanium compounds such as titanium tetrabutoxide, and germanium oxide. And other germanium compounds. The amount of the catalyst used is not particularly limited, but is preferably about 0.1 mol% or less with respect to the above component (A).

The polymerization temperature during the heat polycondensation is 300 to 4
It is necessary to set the temperature to 00 ° C. Here, the polymerization temperature means the temperature at the latter stage of polymerization or at the end thereof. If the polymerization temperature is lower than 300 ° C., the melt viscosity of the polymer becomes high, and the polymer is crystallized, so that it is not possible to obtain a transparent polymer having a high degree of polymerization. Again 400
If the temperature is higher than ° C, the polymer is likely to deteriorate, which is not preferable.

In the production method of the present invention, it is preferable that the initial temperature of the polymerization reaction is relatively low, and the temperature is gradually raised to the above-mentioned polymerization temperature finally. The reaction temperature of the initial polymerization reaction at this time is preferably 150 to 280 ° C, more preferably 180 to 250 ° C. This polymerization reaction is carried out under normal pressure or under reduced pressure, but it is preferable that the initial polymerization reaction is carried out under normal pressure and gradually reduced. At atmospheric pressure, it is preferable to use an atmosphere of an inert gas such as nitrogen or argon. The polycondensation reaction time is not particularly limited, but is approximately 1
It is about 10 hours.

The aromatic polyester of the present invention obtained by the above-mentioned production method has an intrinsic viscosity of 0.3 to 1.0 measured at 35 ° C. in a phenol / tetrachloroethane mixed solvent (weight ratio 60/40). It is necessary to be Heat resistance of the polymer obtained when the intrinsic viscosity is lower than 0.3,
The toughness is insufficient, and if it is higher than 1.0, the fluidity at the time of melt molding decreases, which is not preferable. The intrinsic viscosity is
0.4 to 0.8 is preferable.

In a preferred embodiment of the present invention, diphenyl isophthalate is used as the component (A), hydroquinone is used as the component (B), and bisphenol Z is used as the component (C).
A method of advancing polycondensation by gradually melting the temperature of the reaction system from normal pressure to gradually reducing it by gradually heating the reaction system to a reduced pressure is used. Furthermore, since the aromatic polyester obtained by the present invention has a relatively high melt viscosity, it can be preferably polymerized in an extruder type reaction apparatus in order to obtain a high degree of polymerization.

The aromatic polyester of the present invention obtained by the above-mentioned production method is an amorphous polymer, and a transparent molded article can be obtained by a melt molding method such as injection molding. Further, the fact that the polymer of the present invention is amorphous can be confirmed, for example, by its melting point not being observed by DSC.

During the production of the aromatic polyester of the present invention, various stabilizers such as oxidation stabilizers and anti-coloring agents, and various additives such as colorants, pigments and lubricants may be added if necessary.

[0023]

According to the production method of the present invention, an amorphous wholly aromatic polyester having good heat resistance, toughness, solvent resistance, and stress crack resistance can be produced by an inexpensive melt polymerization process. You can

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples. In the examples, “parts” means “parts by weight”. The intrinsic viscosity is phenol / tetrachloroethane mixed solvent (weight ratio 60 /
40), the concentration was 1.2 g / dl, and the temperature was 35 ° C. For the thermal properties of polymers, use a deflection temperature measuring device under load.
It was measured at a temperature rising rate of ° C / min.

[0025]

Examples 1 to 3 and Comparative Example 1 318 parts of diphenyl isophthalate, a predetermined amount of hydroquinone and bisphenol Z, 0.09 part of antimony trioxide (catalyst) and 0.33 part of triphenyl phosphate (stabilizer) were stirred. The reactor was placed in a reaction vessel having a vacuum distillation system equipped with an apparatus and a nitrogen inlet, reacted at 240 ° C. for 30 minutes in a nitrogen stream under normal pressure, and then heated to 340 ° C. over 1.5 hours. Next, the pressure was gradually reduced at the same temperature, and after 30 minutes, the pressure was adjusted to about 1 mmHg.

During this period, phenol was generated and distilled off. Polymerization was performed for about 90 minutes under the same conditions to obtain a polymer. The obtained polymer was light brown and transparent.

Next, this polymer was injection molded using an injection molding machine (Nippon Steel Co., N40A type) under the conditions of a cylinder temperature of 340 ° C., a mold temperature of 100 ° C. and a molding cycle of about 80 seconds. Table 1 shows the physical properties of the obtained molded product.

In Table 1, for comparison, an amorphous aromatic polyester resin (U Polymer U-100 manufactured by Unitika Ltd.)
As described above, it is understood that the aromatic polyester of the present invention has good heat resistance and extremely excellent solvent resistance.

[0029]

[Table 1]

Claims (1)

[Claims] 1. (A) isophthalic acid and / or its ester-forming derivative, (B) hydroquinone and / or its ester-forming derivative, and (C) the following formula (I): The compound represented by and / or its ester-forming derivative has a molar ratio (B / C) of component (B) and component (C) of 5
0/50 to 80/20, the total amount of the component (B) and the component (C) is set to 95 to 120 mol% with respect to the component (A), and these are added in the presence of a catalyst at a polymerization temperature of 300 to 400 ° C. Heat melt polycondensation, intrinsic viscosity (phenol / tetrachloroethane mixed solvent (weight ratio 60/40), 35
C.) 0.3 to 1.0 polymer is obtained, and a method for producing an amorphous wholly aromatic polyester.