JPH05193637A - Heat-resistant bottle of polyester - Google Patents

Abstract

PURPOSE:To obtain a heat-resistant bottle of polyester which has good mechanical strength and good heat resistance and is transparent and easily moldable. CONSTITUTION:A heat-resistant bottle is made of polyester consisting of a copolyester with a glass transition point above 80 deg.C which is composed of a dicarboxylic acid component mainly comprising terephthlalic acid or an ester- forming derivative thereof and a diol component containing 5-15mol% bis(4-beta- hydroxyethoxyphenyl) sulfone and which results from polymerization by the use of germanium oxide as catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to provide a transparent, tough, and easily heat-resistant heat-resistant bottle which can be filled at a high temperature of 80.degree.

[0002]

2. Description of the Related Art Bottles made of polyethylene terephthalate can be easily molded and have excellent transparency and mechanical properties, such as seasonings, edible oils, alcoholic drinks, carbonated drinks, beverages containing fruit juices, mineral water and other food products. It is widely used in a large amount for applications and non-food applications such as detergents, but is specially treated in the hot filling field where heat resistance is required, for example, as shown in JP-A-55-12031. It is necessary to heat the mouth of a polyethylene terephthalate bottle to whiten (crystallize) it to prevent deformation due to heat.

However, the heat resistance imparted by crystallization of the mouth is limited to the heat resistance of the mouth, and not only the heat resistance of the body and the bottom must be considered, but the crystallization of the mouth is not always uniform. In some cases, the shrinkage unevenness during crystallization causes a slight distortion of the shape, and the contents may leak even if the cap is used.

[0004]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a transparent, highly transparent, mechanical strength and heat resistant bottle that can be filled even at high temperatures.

[0005]

The above objects include a dicarboxylic acid based on terephthalic acid or an ester-forming derivative thereof, and 5 to 15 mol% of bis (4-β-hydroxyethoxyphenyl) sulfone. A polyester heat-resistant bottle made of a polyester copolymer containing a diol component and having a glass transition temperature of 80 ° C. or higher,
This is achieved by a polyester heat-resistant bottle in which the polyester copolymer is polymerized using germanium oxide as a catalyst.

The main component of the dicarboxylic acid component of the polyester copolymer is terephthalic acid or its ester-forming derivative (eg lower alkyl ester),
Other components include isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid,
Examples of the aromatic dicarboxylic acid such as 1,5-naphthalenedicarboxylic acid and 1,4-naphthalenedicarboxylic acid. Further, part of the dicarboxylic acid can be replaced with p-oxybenzoic acid or the like.

Examples of the diol component other than bis (4-β-hydroxyethoxyphenyl) sulfone include ethylene glycol, cyclohexanedimethanol, an ethylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol S, and the like. Most preferred is glycol.

Bis (4) contained in the polyester composition
The amount of -β-hydroxyethoxyphenyl) sulfone is
The diol component is 100 to 5 to 15 mol%, preferably 5 to 10 mol%. When it is less than 5 mol%, the glass transition temperature is largely lowered and the heat resistance is not sufficiently improved, and when it is more than 15 mol%, the crystallization rate becomes small and a tough bottle cannot be obtained by blow molding. The original properties of homopolyester are lost.

As the transesterification catalyst, an organic acid calcium salt is preferable because it is less colored than the titanium catalyst and the manganese catalyst and safer from the viewpoint of food hygiene. Further, for example, a method of directly polymerizing using terephthalic acid as a dicarboxylic acid component without undergoing a transesterification reaction is preferable because the process is simplified and the cost is advantageous.

The germanium oxide catalyst used as a polymerization catalyst in the present invention is preferable in that it is superior in color tone as compared with, for example, an antimony catalyst, and is safe from the viewpoint of food hygiene without fear of arsenic contamination.

The polyester heat-resistant bottle of the present invention can be manufactured as follows.

First, a low polymer is prepared by directly esterifying the above-mentioned dicarboxylic acid component and diol component by a conventional method or by transesterification in the presence of an organic acid calcium salt.

Next, a polycondensation reaction is performed at a temperature of 250 to 300 ° C. under reduced pressure using germanium oxide as a polycondensation catalyst to produce a polyester copolymer having a desired viscosity.

The intrinsic viscosity of the polyester copolymer is 0.7
It is preferably 0 to 0.90 dl / g, and 0.70 dl
If it is less than / g, the moldability is deteriorated in blow molding, while if it exceeds 0.90 dl / g, the melt fluidity is deteriorated, making it difficult to mold parison, for example.

The intrinsic viscosity is measured at 25 ° C. by using a solution prepared by melting 0.25 g of polymer in 100 ml of a mixture of 3 parts by weight of phenol and 2 parts by weight of 1,1,2,2 tetrachloroethane. did.

The above polyester copolymer is used in a water content of 100 p.
After drying to pm or less, preferably 50 ppm or less, a heat-resistant bottle can be molded by injection molding into a bottomed parison (preform) and blow molding the preform into a desired shape. Alternatively, a hollow pipe may be molded by extrusion molding, one end thereof is melt-sealed, and a neck portion to which a cap can be attached is formed at the other end, and then blow molding may be performed.

[0017]

The polyester heat-resistant bottle of the present invention is
It has excellent moldability, transparency, and toughness, and can be filled at high temperatures. Further, there is an advantage that a heat treatment after molding for imparting heat resistance is unnecessary. Furthermore, since germanium oxide is used as a polymerization catalyst, it has an excellent color tone and is safe in terms of food hygiene.

[0018]

The present invention will be described in more detail with reference to the following examples.

Example 1 1 mol of dimethyl terephthalate; 0.1 mol of bis (4-β-hydroxyethoxyphenyl) sulfone; 2.1 mol of ethylene glycol; 0.1 g of calcium acetate as an ester reaction catalyst, and a rectification column. After charging to the polymerization can,
The mixture was heated to 250 ° C. and stirred while flowing a slight amount of nitrogen.
During this period, the temperature of the rectification column was maintained at 60 to 70 ° C. to reflux ethylene glycol and distill only methanol out of the system.

Calculated from the amount of methanol collected, when the transesterification rate reached about 90%, 0.05 g of germanium oxide as a polymerization catalyst; 0.25 g of trimethyl phosphate as a heat stabilizer were added and heated. , The pressure was gradually reduced while continuing to stir, and the pressure in the can was reduced to 1 torr over about 1 hour.
The following high vacuum was used. During this time, the temperature was raised to 280 ° C. After continuing the polymerization for about 4 hours in this state, the pressure was returned to normal pressure and extruded in a gut shape, cooled with water, and then I
A pelletized polyester copolymer having V = 0.75 was obtained.

The lightness (L), hue (a), and saturation (b) of the obtained polyester copolymer were measured by Suga Test Instruments Co., Ltd.
When measured with a color meter, L / a / b = 83.
It was 7 / -1.1 / -1.9.

Table 1 shows the results of NMR analysis of the amount of bis (4-β-hydroxyethoxyphenyl) sulfone contained in the polyester copolymer.
The values in the table are mol% when the entire diol component in the polyester copolymer is 100.

[0023]

[Table 1]

This polyester copolymer was subjected to a reduced pressure of 150
Dry to 100ppm or less of water at ℃, Nissei ASB-5
Using a 0-type injection blow molding machine, the polymer temperature was 285 ° C, the internal volume was 1 L, the date was 40 g, and the cap diameter was 30 mmφ.
Molded into a bottle of book.

Table 1 shows the results obtained by filling each container with hot water of 80 ° C. and checking the deformation of the appearance of the container. The values in the table indicate the number of bottles with cap leakage in 10 bottles.

Further, the glass transition temperature (Tg) of the obtained bottle was measured by DSC (DSC-8230) manufactured by Rigaku Co., Ltd. and the results are shown in Table 1.

Example 2 Polymerization, bottle molding and measurement were carried out under the same conditions as in Example 1 except that bis (4-β-hydroxyethoxyphenyl) sulfone was 0.05 mol and ethylene glycol was 2.15 mol. went. The results are shown in Table 1.

Example 3 Bottle molding and measurement were carried out in the same manner as in Example 1 except that terephthalic acid was used instead of dimethyl terephthalate for direct polymerization. The results are shown in Table 1.

Comparative Example 1 Polymerization, bottle molding and measurement were carried out under the same conditions as in Example 1 except that bis (4-β-hydroxyethoxyphenyl) sulfone was 0.02 mol and ethylene glycol was 2.18 mol. It was The results are shown in Table 1.

Comparative Example 2 Polymerization, bottle molding and measurement were carried out under the same conditions as in Example 1, except that bis (4-β-hydroxyethoxyphenyl) sulfone was not used and ethylene glycol was 2.2 mol. .. The results are shown in Table 1.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 1 except that 0.08 g of antimony trioxide was added instead of 0.05 g of germanium oxide. The obtained polyester copolymer had a lightness (L) of 41.1, and was darker than the case where germanium oxide was used. Moreover, when antimony trioxide is used, there is a risk of arsenic contamination, which is a food hygiene problem.

Claims (4)

[Claims] 1. A glass transition temperature containing a dicarboxylic acid containing terephthalic acid or an ester-forming derivative thereof as a main component, and a diol component containing 5 to 15 mol% of bis (4-β-hydroxyethoxyphenyl) sulfone. 8
A polyester heat resistant bottle comprising a polyester copolymer at 0 ° C. or higher, wherein the polyester copolymer is polymerized using germanium oxide as a catalyst. 2. The polyester heat-resistant bottle according to claim 1, wherein the polyester copolymer is polymerized after transesterification using a calcium salt of an organic acid as a catalyst. 3. The heat-resistant polyester bottle according to claim 1, wherein the polyester copolymer is directly polymerized. 4. The polyester copolymer is 0.70 to 0.
The polyester heat-resistant bottle according to claim 1, which has an intrinsic viscosity of 90 dl / g.