JP2512588B2 - Method for producing polyalkylene terephthalate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing polyalkylene terephthalate, which is preferably used for various molded articles, fibers, films, sheets, adhesives and the like.

(Prior Art) Polyalkylene terephthalate represented by polyethylene terephthalate and polybutylene terephthalate is
Excellent mechanical properties, electrical properties, flame resistance, weather resistance, chemical resistance, economy, etc. Especially, those reinforced with glass fiber are known to improve both mechanical properties and heat resistance. Used in products, fibers, films, sheets, adhesives, etc.

(Problems to be solved by the invention) However, small parts weighing about 10 mg to 10 g,
When molding a part having a thin part such that the wall thickness is 1 mm or less, a part having an acute angle part such as a gear, using a polyalkylene terephthalate composition containing glass fiber, the flow of the fiber Is insufficient in the thin-walled portion or the acute-angled portion of the component, the content of the glass fiber in the thin-walled portion or the acute-angled portion is smaller than that in the other portions, and as a result, a sufficient effect due to the glass fiber blending is obtained. However, the mechanical properties and the heat resistance are not uniform, and the heat resistance of the thin portion or the acute angle portion cannot be improved. Moreover, when a composition containing glass fibers is used, there is a drawback that anisotropy or warpage due to the orientation of the glass fibers is likely to occur, and precise molding is difficult.

Further, when not filled with glass fiber, the heat resistance is inferior as described above, for example, the heat distortion temperature of the product formed of polyethylene terephthalate is about 76 ° C, and the heat deformation temperature of the product formed of polybutylene terephthalate is The deformation temperature is very low at around 59 ℃, and there has been a long-awaited need for a more fundamental heat resistance method.

Furthermore, since polyethylene terephthalate is slow to crystallize, when injection molding is performed using a normal mold that is heated with hot water and used at a temperature of 100 ° C or less, the crystallization of the resin in the mold does not occur. It has the drawbacks that it does not proceed sufficiently, the dimensional stability of the resulting molded product is poor, and the surface condition of the molded product is poor.

When polyethylene terephthalate is molded at a mold temperature of 130 ° C or higher, the above-mentioned problem of slow crystallization is solved, but in this case it is necessary to use a high-temperature mold, which is economically difficult. It is a disadvantage.

Therefore, various methods have been tried so far in order to improve the crystallinity of polyethylene terephthalate.

For example, by adding a plasticizing component or copolymerizing it, a method of activating movement between polymer molecules to promote molecular orientation for crystallization, or a method of adding a crystal nucleating agent to facilitate crystallization. is there.

Regarding the method of the above, Japanese Patent Publication No. 47-3027 and Japanese Patent Publication No.
47-4140 and Japanese Patent Application Laid-Open No. 57-38849 disclose a technique of introducing a flexible chain such as polyether glycol into the molecular chain of an aromatic polyester. However, this method inevitably reduces the heat resistance and mechanical properties of the aromatic polyester.

Regarding the above method, JP-A-54-158452,
Japanese Patent Application Laid-Open No. 56-57825 and Japanese Patent Publication No. 54-38622 disclose a technique of adding a metal salt of an organic acid or a high melting point polyethylene terephthalate. However, the method of adding such an external nucleating agent has a limitation in promoting crystallization, and the crystallization cannot be said to be sufficiently fast.

Further, JP-A-55-82150 discloses a technique of adding specific liquid crystal molecules. However, with this method, the crystallization of polyalkylene terephthalate is slow. Further, Japanese Patent Application Laid-Open No. 56-104933 also discloses a method of binding a compound which gives a liquid crystal segment structure to a molecule, but even with this method, crystallization of polyalkylene terephthalate cannot be said to be sufficiently fast.

On the other hand, since polybutylene terephthalate crystallizes faster than polyethylene terephthalate, a good molded product can be obtained even with a mold of 100 ° C. or lower. However, this polybutylene terephthalate is disadvantageous in that it has lower heat resistance and lower mechanical properties than polyethylene terephthalate.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a method capable of producing a polyalkylene terephthalate having fast crystallization, heat resistance, and improved mechanical properties. To provide.

(Means for Solving the Problems) In the present invention, the p-terphenyl derivative represented by the formula [I] and the p-quaterphenyl derivative represented by the formula [II] have high crystallinity and are existing low molecular weight compounds. Among them, it has an extremely high melting point, and by introducing these compounds into the molecular chain of polyalkylene terephthalate by a transesterification reaction, crystallization is fast, and the finding that polyalkylene terephthalate excellent in heat resistance can be obtained. Was made based on.

That is, in the method for producing polyalkylene terephthalate of the present invention, a p-terphenyl derivative having a general formula represented by the following formula [I] and a p-terphenyl derivative having a general formula represented by the following formula [II] are used.
The above object is achieved by allowing at least one compound selected from the group consisting of quarterphenyl derivatives to act on polyalkylene terephthalate and introducing the compound into the molecular chain of polyalkylene terephthalate by transesterification.

(In the formula, R ¹ and R ² are each independently —H, —CH ₂ CH ₂
OH, -CH ₂ CH (CH ₃ ) OH, Represents) (In the formula, R ³ and R ⁴ are each independently -H, -CH ₂ CH ₂
OH, -CH ₂ CH (CH ₃ ) OH or Represents).

As the polyalkylene terephthalate used in the present invention, for example, polyethylene terephthalate or polybutylene terephthalate is preferably used.

Polyethylene terephthalate has the formula [III] The polyethylene terephthalate is a polycondensate containing a repeating unit represented by as a main constituent unit, and can be produced by a generally known method. For example, a method of polycondensing terephthalic acid or dimethyl terephthalate and ethylene glycol can be mentioned.

In addition, polybutylene terephthalate has the formula [IV] This polybutylene terephthalate is a polycondensate containing a repeating unit represented by as a main constituent unit, and can be produced by a generally known method. For example, a method of polycondensing terephthalic acid or dimethyl terephthalate and butylene glycol can be mentioned.

The p-terphenyl derivative used in the present invention includes:
4,4 "-dihydroxy-p-terphenyl, 4,4"
-Di (2-hydroxyethoxy) -p-terphenyl,
4,4 "-di (2-hydroxypropoxy) -p-terphenyl, 4,4" -di (2-acetoxypropoxy)
There are -p-terphenyl, 4,4 "-di (2-acetoxyethoxy) -p-terphenyl and 4,4" -diacetoxy-p-terphenyl. Moreover, 4,4-dihydroxy-p-quarterphenyl, 4,4-di (2-hydroxyethoxy) -p-quarterphenyl, 4,4-di (2-
Hydroxypropoxy) -p-quaterphenyl,
There is 4,4-di (2-acetoxypropoxy) -p-quaterphenyl. These compounds may be used alone or in combination of two or more kinds.

The liquid crystal transition temperature of these compounds is high, for example, 4,
The liquid crystal transition temperature of 4 ″ -dihydroxy-p-terphenyl from the crystalline state to the liquid crystal state is 336 ° C., 4,4 ″ -di (2
The liquid crystal transition temperature of -hydroxyethoxy) -p-terphenyl is 340 ° C, and the liquid crystal transition temperature of 4,4-dihydroxy-p-quaterphenyl is 336 ° C, 4,4-di (2
The liquid crystal transition temperature of -hydroxyethoxy) -p-quaterphenyl is 403 ° C. The liquid crystal state means a state in which the compound is in a molten state and the molecules maintain the alignment state. Liquid crystalline molecules generally have high crystallinity, and since the liquid crystal transition temperature of these compounds is high as described above, it is possible to introduce these compounds into the molecular chain of the polyalkylene terephthalate by transesterification reaction. It is possible to obtain a polyalkylene terephthalate that is rapidly crystallized and has excellent heat resistance.

The compounding amount of the p-terphenyl derivative and / or the p-quaterphenyl derivative is preferably 1 to 40 parts by weight with respect to 100 parts by weight of the polyalkylene terephthalate. When the amount is less than 1 part by weight, the heat resistance of the resulting polyalkylene terephthalate is not sufficiently improved. Further, when the compounding amount of the compound exceeds 40 parts by weight, a physically brittle product is obtained.

As the transesterification method, any conventionally known method can be adopted. Further, a catalyst may be used to carry out the transesterification reaction more efficiently.

As the catalyst used, metals such as lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium and manganese. These metal oxides; and organic metal compounds such as organic acid salts and metal alkoxides.

Particularly preferred catalysts are calcium acetate, diacyl stannous, tetraacyl stannic acid, dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate, tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyltitanate, germanium dioxide and trioxide. It is antimony. You may use 2 or more types of these catalysts together. In addition, a small amount of heat stabilizer may be added to the reaction system in order to carry out the transesterification reaction stably. As the heat stabilizer used, hindered phenol type, phosphorus type and sulfur type are suitable.

(Example) Hereinafter, the present invention will be described based on examples.

<Synthesis of p-terphenyl derivative> (a) Synthesis of 4,4 "-dihydroxy-p-terphenyl 4-methoxy-4" -bromobiphenyl was reacted with magnesium in tetrahydrone to prepare a Grignard reagent. . The Grignard reagent and 4-bromoanisole were capped with NiCl ₂ (dppp) as a catalyst to give 4,4 ″ -dimethoxy-p-terphenyl. the p- terphenyl, treated with PBr ₃ in methylene chloride 4,4 "
-Dihydroxy-p-terphenyl was synthesized.

(B) 4,4 "-di (2-hydroxyethoxy) -p-
Synthesis of terphenyl and 4,4 ″ -di (2-hydroxypropoxy) -p-terphenyl 4,4 ″ -dihydroxy-p-terphenyl synthesized in (a) was reacted with ethylene carbonate and propylene carbonate, respectively. By doing so, 4,4 ″ -di (2-hydroxyethoxy) -p-terphenyl and 4,4 ″ -di (2-hydroxypropoxy) -p-terphenyl were synthesized.

(C) Synthesis of 4,4 ″ -diacetoxy-p-terphenyl The molar ratio of 4,4 ″ -dihydroxy-p-terphenyl synthesized in (a) and acetic anhydride is 1: 1 to 1: 1.2. The above ingredients were mixed and reacted in a sulfolane solvent at 160 ° C. for 3 hours to synthesize 4,4 ″ -diacetoxy-p-terphenyl.

(D) 4,4 "-di (2-acetoxyethoxy) -p-
Synthesis of terphenyl and 4,4 ″ -di (2-acetoxypropoxy) -p-terphenyl 4,4 ″ -di (2-hydroxyethoxy) instead of 4,4 ″ -dihydroxy-p-terphenyl, respectively -P-
4,4 ″ -di (2-acetoxyethoxy) was prepared in the same manner as in the item (c) except that terphenyl and 4,4 ″ -di (2-hydroxypropoxy) -p-terphenyl were used.
-P-terphenyl and 4,4 "-di (2-acetoxypropoxy) -p-terphenyl were synthesized.

<Synthesis of p-quaterphenyl derivative> (e) Synthesis of 4,4-dihydroxy-p-quaterphenyl derivative Journal of Chemical Society, pp. 1379-1385 (1940)
, 4,4-dihydroxy-p according to the method described in
-Quaterphenyl was synthesized.

(F) 4,4-di (2-hydroxyethoxy) -p-
Synthesis of quarterphenyl and 4,4-di (2-hydroxypropoxy) -p-quaterphenyl 4,4-dihydroxy-p-quaterphenyl was reacted with ethylene carbonate and propylene carbonate to give 4,4-di (2 -Hydroxyethoxy) -p-quaterphenyl and 4,4
-Di (2-hydroxypropoxy) -p-quaterphenyl was synthesized.

(G) 4,4-di (2-acetoxypropoxy) -p
-Synthesis of quarter phenyl 4,4-di (2-hydroxypropoxy) -p-quaterphenyl and acetic anhydride in a molar ratio of 1: 1 to 1: 1.2.
And mix in sulfolane solvent at 160 ℃ 3
After reacting for a period of time, 4,4-di (2-acetoxypropoxy) -p-quaterphenyl was synthesized.

<Measurement of temperature rising crystallization temperature> The polyalkylene terephthalate to be measured is
It was dried in a vacuum oven at 110 ° C. After drying, the polyalkylene terephthalate was sandwiched between polytetrafluoroethylene-coated stainless steel plates and pressed at 280 ° C. under a pressure of 18 MPa to obtain a film having a thickness of 0.375 mm. Next, this film was pressed with a predetermined pressure for 2 minutes, and then the film was cooled in ice. About 10 mg of this film was heated with a DSC (differential calorimeter) at 16 ° C./min to record an exothermic curve. The exothermic peak temperature obtained from the obtained curve was defined as the temperature rising crystallization temperature.

<Isothermal crystallization half-life> The polyalkylene terephthalate to be measured is
It was melted at 270 ° C for 10 minutes and then rapidly cooled to 200 ° C. After the temperature of the thermometer of the device reached 200 ° C., the crystallization exothermic peak curve was recorded while maintaining the temperature. The time required to reach half the peak area was defined as the isothermal crystallization half-life.

Examples 1 to 8 With respect to 100 parts by weight of polyethylene terephthalate (manufactured by Toyobo Co., Ltd., Byron 200P), the amount (parts by weight) of the p-terphenyl derivative shown in Table 1 (part by weight), antimony trioxide and heat. Stabilizer (Ilgarnox 1010, manufactured by Ciba Geigy) was added. The amount of antimony trioxide added was 0.05 parts by weight in Examples 1, 2 and 4 to 8, and Example 3 was used.
Then, it was 0.1 part by weight. The amount of the heat stabilizer added was the same as in Example 1.
Was 0.25 parts by weight, and in Examples 2-8, it was 0.3 parts by weight.
This mixture was melt-kneaded under a reduced pressure of 0.1 mmHg or less to carry out a transesterification reaction. The reaction time was 1.
5 hours, 1 hour in Examples 1, 2 and 4-8. The reaction temperature was 340 ° C. in Examples 1 and 2 and 350 ° C. in Examples 3-8.

The obtained polyethylene terephthalate is press-molded at 300 ° C to obtain a sheet, and the sheet's heat distortion temperature (load
18.6 kg / cm ² ) was measured according to ASTM D648.

Moreover, the temperature rising crystallization temperature of each polyethylene terephthalate obtained in Examples 1, 2 and 4 to 8 was measured. No exothermic peak was observed for any of the polyethylene terephthalates. This indicates that the polyethylene terephthalate has already completed crystallization when cooled.

Also, the isothermal crystallization half-life of each polyethylene terephthalate obtained in Examples 1 and 3 to 8 was measured. Regarding the polyethylene terephthalate obtained in Example 3,
Crystallization was so fast that no clear exothermic peak could be observed and the isothermal crystallization half-life could not be determined.

 The results are shown in Table 1.

Comparative Example 1 The heat distortion temperature, elevated temperature crystallization temperature and isothermal crystallization half-life of polyethylene terephthalate used in Example 1 were measured in the same manner as in Example 1. The results are shown in Table 1.

Examples 9 to 16 With respect to 100 parts by weight of polybutylene terephthalate (manufactured by Engineering Plastics Co., Ltd., Barox 310), the amount (parts by weight) of the p-terphenyl derivative shown in Table 2 (part by weight), antimony trioxide and A heat stabilizer (Ilgarnox 1010, manufactured by Ciba Geigy) was added. The amount of antimony trioxide added was the same in Examples 9, 10 and 12-16.
0.05 parts by weight, and in Example 11 0.1 parts by weight. The amount of the heat stabilizer added was 0.25 parts by weight in Example 9 and 0.3 parts by weight in Examples 10 to 16. This mixture was melt-kneaded under a reduced pressure of 0.1 mmHg or less to carry out a transesterification reaction. The reaction time was 1.5 hours in Example 11 and 1 hour in Examples 9, 10 and 12-16. The reaction temperature was 34 in Examples 9 and 10.
0 ° C., and in Examples 11 to 16 350 ° C.

The heat distortion temperature of the obtained polybutylene terephthalate was measured by the same method as in Example 1. The results are shown in Table 2.

Comparative Example 2 The heat distortion temperature of only the polybutylene terephthalate used in Example 9 was measured by the same method as in Example 1. The results are shown in Table 2.

Examples 17 to 22 Polyethylene terephthalate was obtained in the same manner as in Example 1 except that the p-quaterphenyl derivative shown in Table 3 was used in place of the p-terphenyl derivative. The amount of p-quaterphenyl derivative added was the amount (parts by weight) shown in Table 3. The amount of antimony trioxide added was the same as in Example 1.
It was 0.05 parts by weight for 7, 18 and 20 to 22, and 0.1 parts by weight for Example 19. The amount of the heat stabilizer added was 0.25 parts by weight in Example 17 and 0.3 parts by weight in Examples 18 to 22. The reaction time was 1.5 hours in Example 19 and 1 hour in Examples 17, 18 and 20-22. The reaction temperature was 34 in Examples 17 and 18.
0 ° C., and in Examples 19 to 22, 350 ° C.

A sheet was obtained from the obtained polyethylene terephthalate in the same manner as in Example 1, and the heat distortion temperature was measured. Moreover, when the temperature rising crystallization temperature of the polyethylene terephthalate obtained in Examples 17, 18 and 20 to 22 was measured in the same manner as in Example 1, no exothermic peak was observed for any of the polyethylene terephthalates. . This indicates that the polyethylene terephthalate has already completed crystallization when cooled.

Furthermore, the isothermal crystallization half-life of the polyethylene terephthalate obtained in Examples 17, 18 and 20-22 was measured. Regarding the polyethylene terephthalate obtained in Example 18, the crystallization was too fast, a clear exothermic peak could not be observed, and the isothermal crystallization half-life could not be determined.

 The results are shown in Table 3.

Examples 23 to 28 Polybutylene terephthalate was obtained in the same manner as in Example 9 except that the p-quaterphenyl derivative shown in Table 4 was used in place of the p-terphenyl derivative. The amount of p-quaterphenyl derivative added was the amount (parts by weight) shown in Table 4. The amount of antimony trioxide added was the same as in Example 2.
In the case of 3, 24 and 26 to 28, the amount was 0.05 part by weight, and in Example 25, it was 0.1 part by weight. The amount of the heat stabilizer added was 0.25 parts by weight in Example 23 and 0.3 parts by weight in Examples 24 to 28. The reaction time is
1.5 hours for Example 25, 1 for Examples 23, 24 and 26-28
It was time. The reaction temperature was 340 in Examples 23 and 24.
C, and in Examples 25 to 28, it was 350C.

The heat distortion temperature of the obtained polybutylene terephthalate was measured by the same method as in Example 1. The results are shown in Table 4.

From the results of Tables 1 to 4, by introducing the above-mentioned p-terphenyl derivative or p-quaterphenyl derivative into the molecular chain of polyalkylene terephthalate, crystallization of the obtained polyalkylene terephthalate becomes faster,
It was also confirmed that the heat resistance was improved.

(Effects of the Invention) As described above, according to the present invention, it is possible to obtain a polyalkylene terephthalate which is rapidly crystallized and is excellent in heat resistance, and this polyalkylene terephthalate is also used in fields where mechanical and heat resistance are highly required. be able to.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Daishiro Kishimoto 2-11-20 Mishimaoka, Ibaraki City, Osaka Umeyama Mansion 102 (56) References JP-A-3-250021 (JP, A) JP-A 1-299822 (JP, A) JP 54-38622 (JP, A) JP 47-4140 (JP, B1) JP 47-3027 (JP, B1)

Claims (1)

(57) [Claims] 1. A p-terphenyl derivative having a general formula represented by the following formula [I] and a p-terphenyl derivative having a general formula represented by the following formula [II].
At least one compound selected from the group consisting of quaterphenyl derivatives is allowed to act on polyalkylene terephthalate, and the compound is introduced into the molecular chain of polyalkylene terephthalate by a transesterification reaction to produce polyalkylene terephthalate. Method: (In the formula, R ¹ and R ² are each independently —H, —CH ₂ CH ₂
OH, -CH ₂ CH (CH ₃ ) OH, Represents) (In the formula, R ³ and R ⁴ are each independently -H, -CH ₂ CH ₂
OH, -CH ₂ CH (CH ₃ ) OH or Represents).