JPH05186579A - Polyester resin for direct blow molding - Google Patents

Abstract

PURPOSE:To provide a polyester resin excellent in impact strength and moldability and suitable for direct blow molding. CONSTITUTION:The title resin is prepd. by reacting an acid component consisting mainly of terephthalic acid or its ester-forming deriv. with a glycol component contg. 10-50mol% (based on the glycol component) ethylene oxide adduct of bisphenol A, has an intrinsic viscosity of 0.65-1.4dl/g and a diethylene glycol content of 1wt.% or lower, and is suitable for direct blow molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin used for direct blow molding, and more particularly to a polyester resin containing a bisphenol A ethylene oxide adduct as a diol component and having excellent moldability and impact resistance. Is.

[0002]

2. Description of the Related Art Polyethylene terephthalate, polybutylene terephthalate and the like are generally used as polyester resins for molding materials for direct blow molding and the like. Further, modified polyester resins obtained by copolymerizing these polyesters with various monomers such as isophthalic acid and cyclohexanedimethanol, and polyethylene naphthalate containing naphthalenedicarboxylic acid as a main component as an acid component have been developed.

[0003]

However, in a modified polyester resin obtained by copolymerizing isophthalic acid, mechanical strength characteristics such as impact resistance deteriorate as the amount of isophthalic acid increases, and direct blow molding is performed. In this case, there is a problem that the resin has a low melt viscosity and is extremely difficult to mold, and the parison cannot be formed for a long time, so that a large container cannot be molded. In addition, the modified polyester resin copolymerized with cyclohexanedimethanol is not satisfactory although the moldability is improved as compared with the resin copolymerized with isophthalic acid, and the thermal stability of the resin is poor and There is a problem that the resin deteriorates significantly due to long-term retention. Further, although polyethylene naphthalate has a characteristic of having a higher melting point than conventional polyester resins, it is not satisfactory as a resin for molding material in terms of mechanical properties and moldability.

The present invention provides a polyester resin for direct blow, which has excellent moldability in direct blow molding and excellent impact resistance.

[0005]

In view of such circumstances, the inventors of the present invention have made earnest studies on a polyester resin for direct blowing, and as a result, as a result of copolymerizing a specific diol as a diol component, The inventors have found that the moldability during direct blow molding is significantly improved without impairing the excellent mechanical properties that they have, and have reached the present invention.

That is, the polyester resin for direct blowing of the present invention comprises an acid component containing terephthalic acid or its ester-forming derivative as a main component, and a diol component containing ethylene glycol and bisphenol A ethylene oxide adduct as a main component. , Bisphenol A ethylene oxide adduct is 10 with respect to all diol components
~ 50 mol% contained, intrinsic viscosity 0.65-1.4d
The content of l / g and diethylene glycol is 1% by weight or less.

In the present invention, the terephthalic acid or its ester-forming derivative used as the acid component is preferably contained in the total acid component in an amount of 80 mol% or more, more preferably 90 mol% or more. In the present invention, as the acid component, for example, isophthalic acid, naphthalene-1,4- or -2,6-dicarboxylic acid, glutaric acid, adipic acid, sebacic acid, oxalic acid, succinic acid,
Azelaic acid or the like or an ester-forming derivative thereof,
You may copolymerize in the range which does not impair the effect of this invention.
Examples of ester-forming derivatives of terephthalic acid or other acid components include dialkyl esters and diaryl esters.

The ethylene glycol and bisphenol A ethylene oxide adduct used as the diol component is preferably contained in the total diol component in an amount of 80 mol% or more, more preferably 90 mol% or more. As the diol component, diethylene glycol, triethylene glycol, neopentyl glycol, propylene glycol, polyoxytetramethylene glycol, polyethylene glycol, cyclohexanedimethanol, etc. may be copolymerized within the range not impairing the effects of the present invention.

In the polyester resin of the present invention, ethylene glycol as a diol component is preferably contained in the total diol component in an amount of 50 to 90 mol%, more preferably 55 to 90 mol%. . This has an ethylene glycol content of 90 mol%
If it exceeds, the moldability in direct blow molding is deteriorated and the mechanical strength and heat resistance are deteriorated. On the contrary, when the ethylene glycol content is less than 50 mol%,
This is because the mechanical properties of the homopolyester resin are impaired.

Further, in the polyester resin of the present invention,
As a diol component, a bisphenol A ethylene oxide adduct represented by the following general formula (1) is contained together with ethylene glycol. In the present invention, with bisphenol A ethylene oxide

[0011]

[Chemical 1]

(In the formula, n and m are integers satisfying the formula: 2 ≦ n + m ≦ 6.) Additive is 10 in all diol components.
It is contained in the range of 50 mol%. This is because the content of bisphenol A ethylene oxide adduct is 10 mol%.
This is because if it is less than 1, the moldability in direct blow molding is deteriorated, and the mechanical strength and heat resistance are deteriorated. On the contrary, when the content of the bisphenol A ethylene oxide adduct exceeds 50 mol%, the mechanical properties of the homopolyester resin are deteriorated and the preferable properties as a molded product are impaired. In particular, the range of 10 to 40 mol% is preferable from the viewpoint of impact resistance.

The polyester resin of the present invention comprising the above components is dissolved in a solvent in which phenol and 1,1,2,2-tetrachloroethane are mixed at a weight ratio of 1: 1 and then at 25 ° C. It is necessary that the intrinsic viscosity measured by an Ubbelohde viscometer is 0.5 to 1.4 dl / g, preferably 0.67 to 1.3 dl / g. This is because if the intrinsic viscosity is less than 0.65 dl / g, the fluidity of the resin becomes large, making it unsuitable for direct blow molding, and conversely, if it exceeds 1.4 dl / g, a high molding pressure is required. At the same time, it is difficult to realize the shape. Further, as the polyester resin for direct blowing of the present invention, it is important that the content of diethylene glycol is 1% by weight or less. This is because when the content of diethylene glycol exceeds 1% by weight, the moldability in direct blow molding is deteriorated, and the mechanical strength and heat resistance are deteriorated. The content of diethylene glycol is preferably in the range of 0.9% by weight or less. In the present invention, an antioxidant, a heat stabilizer, an ultraviolet absorber, within a range that does not impair the characteristics thereof.
You may add additives, such as a dye.

The polyester resin of the present invention is produced by a known polymerization method such as a transesterification method or an esterification method. In the transesterification method, terephthalic acid or its ester-forming derivative, bisphenol A ethylene oxide adduct and ethylene glycol are added such that the total diol component is 2.0 to 2.4 times the total acid component in molar ratio. Was charged into a reaction vessel, heated to a temperature of 150 to 250 ° C. in the presence of a transesterification catalyst to carry out a sufficient transesterification reaction, then added a polymerization catalyst and heated to 250 to 300 ° C. under a reduced pressure of 5 mmHg or less. Then, the resin of the present invention can be obtained by reacting for 2 to 5 hours.

In the direct polymerization method, terephthalic acid, bisphenol A ethylene oxide adduct and ethylene glycol are mixed so that the total diol component is 1.2 to 2.0 times the total acid component in molar ratio. After charging in a reaction vessel and heating to 150 to 250 ° C. under pressure with nitrogen to sufficiently esterify, a polymerization catalyst was added to 5 mmH.
The resin of the present invention can be obtained by heating at 250 to 300 ° C. under reduced pressure of g or less and reacting for 2 to 5 hours.

As the transesterification catalyst used in producing the modified polyester resin of the present invention, zinc acetate,
Manganese acetate, magnesium acetate, titanium tetrabutoxide, etc. may be mentioned, and as the polymerization catalyst, antimony trioxide, titanium tetrabutoxide, dibutyltin oxide, germanium dioxide, etc. may be mentioned, in the range of 100 to 1000 ppm with respect to the acid component. Is added.

[0017]

EXAMPLES The present invention will be specifically described below with reference to examples. Intrinsic viscosities in the examples are phenol, 1,
1,2,2-Tetrachloroethane was dissolved in a solvent mixed at a weight ratio of 1: 1 and measured with an Ubbelohde viscometer at 25 ° C. The glass transition point (Tg) and melting point (Tm) are
28 with a differential scanning calorimeter (DT-41 manufactured by Shimadzu Corporation)
A sample melt-quenched in a nitrogen stream at 0 ° C. was heated to 280 ° C. at a heating rate of 5 ° C./minute, and measured. Tg was a shoulder value and Tm was a peak value.

The impact strength is the Izod impact strength (JIS
According to K7110), the test piece was evaluated as No. 1-A with a notch. The content of diethylene glycol in the resin was measured by gas chromatography after decomposing the resin with hydrazine and filtering the decomposed solution. The moldability is as follows:
The shape of 10 molded products when extruded at a length of 00 mm and subjected to direct blow molding into a bottle shape was evaluated according to the following criteria.

Good: All 10 were good. Fair: 7-9 out of 10 were good. Poor: Good out of 10 was 6 or less. Bisphenol A used in the examples. The ethylene oxide adduct used was n + m = 2 in the general formula (1).

Example 1 100 parts by mole of terephthalic acid and 140 parts of ethylene glycol
Molar part and bisphenol A ethylene oxide adduct 1
Add 0 mol part to the reaction vessel and pressurize with nitrogen to 250
The temperature was gradually raised to 0 ° C. for esterification, and the esterification reaction was stopped when the amount of water distilled out reached 93% of the theoretical amount. Next, 350 ppm of trimethyl phosphate as a stabilizer was added to all acid components, and 450 ppm of antimony trioxide was added as a polymerization catalyst to all acid components, and the temperature was gradually raised to 285 ° C. so that the temperature became 5 mmHg or less. The reaction vessel was depressurized and reacted for 3 hours from the start of depressurization to obtain a polyester resin. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

Example 2 100 mol parts of dimethyl terephthalate, 180 mol parts of ethylene glycol and 30 mol parts of bisphenol A ethylene oxide adduct were placed in a reaction vessel, and manganese acetate was used as a transesterification catalyst at 400 ppm with respect to all acid components.
After the addition, the transesterification reaction was carried out while gradually raising the temperature to 240 ° C. The amount of methanol distilled is 97, which is the theoretical amount.
The transesterification reaction was stopped when the percentage reached. Next, trimethyl phosphate as a stabilizer was added in an amount of 300 ppm to all acid components, and germanium dioxide as a polymerization catalyst was added in an amount of 200 ppm to all acid components.
While gradually raising the temperature to 0 ° C., the pressure in the reaction vessel was reduced to 5 mmHg or less, and the polyester resin was obtained by reacting for 4 hours from the start of pressure reduction. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

Example 3 100 parts by mole of terephthalic acid, 140 parts of ethylene glycol
Molar part and bisphenol A ethylene oxide adduct 4
Add 7 parts by mole to the reaction vessel and pressurize with nitrogen to 250
The temperature was gradually raised to 0 ° C to carry out esterification, and the esterification reaction was stopped when the amount of water distilled out reached 95% of the theoretical amount. Next, 350 ppm of trimethyl phosphate as a stabilizer was added to all acid components, and 450 ppm of antimony trioxide was added as a polymerization catalyst to all acid components, and the temperature was gradually raised to 280 ° C. so that the temperature was 5 mmHg or less. The reaction vessel was depressurized and reacted for 4 hours from the start of depressurization to obtain a polyester resin. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

Example 4 100 mol parts of dimethyl terephthalate, 180 mol parts of ethylene glycol and 52 mol parts of bisphenol A ethylene oxide adduct were placed in a reaction vessel, and manganese acetate was used as a transesterification catalyst at 400 ppm with respect to all acid components.
After the addition, the transesterification reaction was carried out while gradually raising the temperature to 240 ° C. The amount of methanol distilled is 97, which is the theoretical amount.
The transesterification reaction was stopped when the percentage reached. Next, trimethyl phosphate as a stabilizer was added in an amount of 300 ppm to all acid components, and germanium dioxide as a polymerization catalyst was added in an amount of 200 ppm to all acid components.
While gradually raising the temperature to 0 ° C., the pressure in the reaction vessel was reduced to 5 mmHg or less, and the polyester resin was obtained by reacting for 3 hours from the start of pressure reduction. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

Comparative Example 1 100 parts by mole of terephthalic acid and 180 of ethylene glycol
Put the molar part into the reaction vessel and pressurize with nitrogen at 250 ° C.
The temperature was gradually raised to esterification, and the esterification reaction was stopped when the amount of distilled water reached 93% of the theoretical amount. Then, as a stabilizer, trimethyl phosphate was added to the total acid component at 350 ppm, and as a polymerization catalyst, antimony trioxide was added to the total acid component at 450 ppm,
While gradually raising the temperature to 280 ° C., the pressure in the reaction vessel was reduced to 5 mmHg or less, and the polyester resin was obtained by reacting for 3 hours from the start of pressure reduction. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

Comparative Example 2 100 mol parts of dimethyl terephthalate, 220 mol parts of ethylene glycol and 1 mol part of bisphenol A ethylene oxide adduct were placed in a reaction vessel, and 400 ppm of manganese acetate was added to all acid components as an ester exchange catalyst. The transesterification reaction was performed while gradually raising the temperature to 240 ° C. The amount of methanol distilled is 97% of the theoretical amount
The transesterification reaction was stopped when the temperature reached to 0. Then
Add 300 ppm of trimethyl phosphate as a stabilizer to all the acid components and 200 ppm of germanium dioxide as a polymerization catalyst to all the acid components, and gradually raise the temperature to 280 ° C. so that the reaction vessel becomes 5 mmHg or less. The pressure was reduced, and the polyester resin was obtained by reacting for 4 hours from the start of the pressure reduction. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

Comparative Example 3 100 mol parts of dimethyl terephthalate, 130 mol parts of ethylene glycol and 100 mol parts of bisphenol A ethylene oxide adduct were placed in a reaction vessel, and manganese acetate was used as a transesterification catalyst at 400 pp for all acid components.
m was added, and the transesterification reaction was carried out while gradually raising the temperature to 240 ° C. The amount of methanol distilled is 9 which is the theoretical amount.
When the amount reached 7%, the transesterification reaction was stopped. Next, 300 ppm of trimethyl phosphate as a stabilizer was added to all the acid components, and 200 ppm of germanium dioxide was added as a polymerization catalyst to the acid components.
While gradually raising the temperature, the pressure in the reaction vessel was reduced to 5 mmHg or less, and the polyester resin was obtained by reacting for 3 hours from the start of pressure reduction. The resin composition and characteristics of the obtained polyester resin are shown in Table 1.

[0027]

[Table 1]

As is clear from Table 1, bisphenol A
The polyester resin of Comparative Example 1 containing no ethylene oxide adduct and Comparative Example 2 having a small content thereof had a very high content of diethylene glycol and were inferior in impact resistance,
In particular, it is inferior in the moldability of direct blow molding.
Further, in the polyester resin of Comparative Example 3 having a large content of bisphenol A ethylene oxide adduct, the content of diethylene glycol was relatively large, the moldability in direct blow molding was not sufficient, and the impact resistance was particularly poor. is there. On the other hand, in the polyester resins of Examples 1 to 4 which are the present invention, the content of diethylene glycol is small, the impact resistance is excellent, and the moldability of direct blow molding is also excellent.

[0029]

INDUSTRIAL APPLICABILITY According to the present invention, a resin containing a predetermined amount of a bisphenol A ethylene oxide adduct and limiting the content of diethylene glycol has excellent impact resistance and direct blow excellent in moldability. It is possible to provide a polyester resin suitable for molding.

[0030]

Front Page Continuation (72) Inventor Tomohiko Yoshida 2-1, Ushikawa-dori, Toyohashi-shi, Aichi Mitsubishi Rayon Co., Ltd. Toyohashi Plant

Claims (1)

[Claims] 1. An acid component containing terephthalic acid or an ester-forming derivative thereof as a main component, and a diol component containing ethylene glycol and a bisphenol A ethylene oxide adduct as a main component, wherein the bisphenol A ethylene oxide adduct is a total diol. 10 to component
Contains 50 mol% and has an intrinsic viscosity of 0.65 to 1.4 dl
/ G, the content of diethylene glycol is 1 wt% or less, a polyester resin for direct blowing.