JPS6221021B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester hollow molded article with good transparency. More specifically, the present invention relates to a polyester hollow molded article having excellent transparency, antistatic properties, and impact resistance. Polyester, particularly polyethylene terephthalate, has excellent physical and chemical properties and is therefore widely used in the fields of fiber, film, and plastic molding. Conventionally, polyvinyl chloride has been mainly used as the resin for plastic hollow molded bodies, but
In recent years, the problem of elution of vinyl chloride monomers has led to restrictions, particularly in the field of blow-molded containers for food products. Although polyethylene terephthalate has various excellent properties as mentioned above, it has not been sufficiently advanced into the field of blow molding. This was due to the low viscosity of the polymer when melted and the extremely rapid crystallization and whitening of the product. To solve this problem, various improvements have been made in the molding industry to some extent, and it has come to function as a substitute for polyvinyl chloride, but polyethylene terephthalate is still extremely susceptible to electrostatic charges during molding, processing, and use. However, there still remain problems such as whitening due to crystallization and impact resistance, which can sometimes be a major hindrance. On the other hand, there are examples of using sulfonate derivatives and polyalkylene glycols to improve these problems.
47069, JP-A-52-47072, JP-A-52-134662, JP-A-52-151365, etc. Special Public Service 1977
-31828 describes an example using a high molecular weight polyalkylene glycol that is substantially insoluble in polyester, but the polyester obtained in this case has improved antistatic properties to some extent, but is cloudy and transparent. It cannot be used because it is bad. JP-A-52-47069 and JP-A-52-47072 exemplify films made from compositions of sulfonate derivatives and polyalkylene glycols having a molecular weight of 400 to 8,000. In this case, it is true that a certain degree of electrostatic property can be imparted, but it tends to whiten during the cooling process after melt molding, and glass-like transparency, which is essential for blow molding applications, cannot be obtained. In addition, in JP-A-52-134662, only sulfonate derivatives were added to polyester, and the temperature was 100℃ to 250℃.
An example is described in which antistatic properties are obtained by heat treatment at ℃. However, this method does not improve whitening during the cooling process after melt molding, nor does it improve impact resistance. The inventors of the present invention have made extensive studies to simultaneously solve the various drawbacks of blow molding materials as described above and to provide a polyester molded product with excellent antistatic properties, transparency, and impact resistance, and as a result, they have developed the present invention. has been reached. That is, the present invention is essentially polyethylene terephthalate obtained by the reaction of terephthalic acid or its lower alkyl ester with ethylene glycol, and (A) an alkali metal salt of alkylbenzenesulfonic acid.
0.01 to 5.0% by weight, (B) 2.0 to 4.5 mol% of diethylene glycol component based on the total diol component, and (C) General formula HOCH ₂ CH ₂ O-R-OCH ₂ CH ₂ OH (However, R is

【formula】

【formula】

Polyester blow molding made of a polyester containing 0.05 to 10.0 mol% of at least one compound component represented by the group [Formula] and in which at least the (B) component and (C) component are copolycondensed. It is the body. Substantially polyethylene terephthalate used in the present invention refers to bisbenzene obtained after esterification reaction with terephthalic acid and ethylene glycol, or after transesterification reaction between lower alkyl esters of dicarboxylic acids, such as dimethyl terephthalate, diethyl terephthalate, etc., and ethylene glycol. It is obtained by polycondensing diol ester and/or its low polymer in the presence of a specific polymerization catalyst at high temperature under vacuum, and contains a small amount of dicarboxylic acid residues other than terephthalic acid residues. Good too. Dicarboxylic acid residues other than terephthalic acid residues include residues such as isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, trimellitic acid, pyromellitic acid, adipic acid, and sebacic acid.
Oxyacid components such as oxycarboxylic acid components such as p-oxyethoxybenzoic acid can also be used. Furthermore, although the diol component is mainly an ethylene glycol component, small amounts of other glycols may also be used in combination. Examples include propylene glycol, trimethylene glycol, tetramethylene glycol, and cyclohexadimethanol components. The component (A) used in the present invention, that is, the alkali metal salt of alkylbenzenesulfonic acid, preferably has an alkyl group having 6 to 20 carbon atoms, and examples thereof include hexylbenzenesulfonic acid, octylbenzenesulfonic acid, and nonylbenzenesulfonic acid. , decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, stearylbenzenesulfonic acid, and other sodium, potassium, and lithium salts. Among these, sodium dodecylbenzenesulfonate is particularly effective in terms of antistatic properties and polymer color tone. The amount of alkali metal alkylbenzenesulfonic acid salt is from 0.01 to 5.0% by weight, preferably from 0.03 to 2.0% by weight. If it is less than 0.01% by weight, antistatic properties cannot be obtained, and if it exceeds 5.0% by weight, disadvantages arise such as a slimy feeling in the polyester hollow molded article and poor transparency, which is not preferable. The diethylene glycol component (B) used in the present invention is 2.0 to 4.5 mol% of the total diol components, and the general formula of the component (C) is HOCH ₂ CH ₂ O-R-OCH ₂ CH ₂ OH (wherein R is

【formula】

【formula】

The compound component represented by [Formula] group is 0.05 to 10.0 mol%. The diethylene glycol component is less than 2.0 mol% and the components (C) are 1,4-bis(hydroxyethoxy)benzene, 4,4'-bis(hydroxyethoxy)diphenylsulfone and 2,2-bis(4
-If the content of at least one type of (hydroxyethoxyphenyl)propane compound is less than 0.05 mol%, devitrification occurs in hollow molded bodies with a wall thickness of 3 mm or more, which is undesirable, and sufficient antistatic effect is not observed. It is not possible and practical. In addition, the diethylene glycol component is 4.5 mol%
and when the compound represented by component (C) exceeds
If it exceeds 10.0 mol%, it is not preferable because the dimensional stability and mechanical strength of the hollow molded product will drop significantly. This component improves the impact resistance of the polyester hollow molded body,
It has the characteristics of being transparent and capable of imparting a mutual effect of developing antistatic properties with the alkali metal salt of alkylbenzenesulfonate, and can exhibit this effect by using both components in combination. In particular, the maximum effect can be exhibited when the total mol% of the diethylene glycol component and the compound represented by component (C) is 2.5 to 8 mol%. Any method generally known as a polyester manufacturing method can be used to manufacture the polyester composition. For example, (1) a method in which a carboxylic acid, mainly terephthalic acid, and a diol component are esterified under normal pressure or pressure to form a bisdiol ester and/or a low polymer thereof, and then polycondensed. (2) A method in which a lower alkyl ester of a carboxylic acid, mainly terephthalic acid, and a diol component are transesterified into a bisdiol ester and/or a low polymer thereof, and then polycondensed. etc. can be used. alkylbenzenesulfonic acid alkali metal salts,
Diethylene glycol, 1 and 4 represented by the general formula
-bis(hydroxyethoxy)benzene, 4.
4'-bis(hydroxyethoxy)diphenylsulfone and 2,2-bis(4-hydroxyethoxyferol)propane can be added at any stage before the end of polycondensation. As the polycondensation catalyst, conventionally known catalysts such as antimony compounds, silicon compounds, germanium compounds, and titanium compounds can be used. Among these, titanium compounds and germanium compounds are particularly preferred in terms of transparency and color tone for polymers. Preferred Ti compounds include tetrabutyl titanate, tetramethyl titanate, titanium tetrachloride, titanium oxalate, titanium acetate, titanium trimellitate, and hydrolysates or derivatives thereof. Examples of the Ge compound include germanium oxide, germanium alkoxide, and metal germanate. Furthermore, in these compositions, coexisting phosphorous compounds such as phosphorous acid, phosphoric acid, and their esters as phosphorous atoms at least 0.1 times the total amount of metal atoms in the polymer is necessary. It is more suitable for heat-resistant color tones. In addition, in addition to antioxidants such as found phenol type antioxidants, polysiloxanes, pigments, dyes, inert inorganic fine particles, etc. may be used as appropriate. The blow molding material of the present invention is made of the polyester thus obtained. Extrusion blow molding, injection blow molding, or injection/extrusion combined blow molding is applied to the manufacturing method of the blow molded body, but it can be used in combination with vacuum forming, blow molding, and uniaxial or biaxial stretch molding. . For example, methods for producing stretch-oriented hollow bodies include (1) extrusion or injection molding of the parison, (2) reheating of the parison, (3) axial stretching, (4) blow mold closure, (5) ) Compressed air blowing, (6) cooling, (7) mold opening, (8)
Examples include the extraction process. The thus obtained polyester hollow molded product has excellent antistatic properties, transparency, and impact resistance, and is particularly suitable as a filling and packaging material for foods, cosmetics, miscellaneous goods, etc. Especially when left in a store, it does not attract dust and can be used normally. Compared to polyethylene terephthalate, it is extremely resistant to drop impact. The present invention will be specifically described below with reference to Examples. Note that, prior to explaining the examples, a method for measuring characteristic values will be explained. (1) Surface resistivity Measure a 0.2 mm thick sheet sample that has been left for 1 hour at a room temperature of 20°C and a humidity of 65% using a Kawaguchi Electric Seisakusho MMA-15 ultra-micro ammeter. (2) Dust adhesion test Apply silica sand to the sheet or molded product and check the adhesion condition. (3) Haze Measured on an injection plate with a thickness of 7 mm according to ASTM-D-1003-59T. (4) Intrinsic viscosity The intrinsic viscosity of the polymer is a value measured at 25°C using O-chlorophenol solvent. (5) Impact strength This is the value determined by taking a 5 mm wide sample of an unstretched sheet with a thickness of 0.2 mm and using a Charpy impact strength tester. Judgment 2.2-2.5Kg-cm/mm ² or more Excellent ◎ 1.8-2.2Kg-cm/mm ² Good 1.3-1.8Kg-cm/mm ² Slightly poor △ 1.3Kg-cm/mm ² or less Poor × Example 1 Terephthal 100 parts by weight of ethylene terephthalate low polymer obtained by esterification of acid and ethylene glycol (reaction rate 97.5%, molar ratio of EG unit/TPA unit 1.2) was stored at 250°C in a reactor. On the other hand, 158 parts by weight of TPA and 71 parts by weight of ethylene glycol
The slurry obtained by thoroughly mixing the parts by weight is continuously added to the reactor at a constant rate, the esterification reaction is carried out at 250°C under normal pressure, and the water produced is continuously distilled out of the system from the rectification column. I let it out. The slurry supply time was 3 hours and 40 minutes, and the esterification reaction was completed in 4 hours. 100 parts by weight of the obtained esterification reaction product was transferred to a polycondensation reactor, 1.0 parts by weight of diethylene glycol and 0.01 parts by weight of tetrabutyl titanate were added, and after another 5 minutes, 1.0 parts by weight of sodium dodecylbenzenesulfonate and 2.2 parts by weight of sodium dodecylbenzenesulfonate were added. - Add 6.5 parts by weight of bis(4-hydroxyethoxyphenyl)propane and 0.01 part by weight of methylphenyl polysiloxane, and use the usual method at a final temperature of 285°C and a degree of vacuum of 0.5 mmHg.
A polycondensation reaction was carried out under the following conditions to obtain a polymer with an intrinsic viscosity of 0.658. The composition of the polymer is such that the diethylene glycol content is
3.5 mol%, 2,2-bis(4-hydroxyethoxyphenylpropane) component is about 5.5 mol%,
Sodium dodecylbenzenesulfonate 1.06% by weight,
It contained 15 ppm of titanium metal. The polymer was vacuum dried at 170°C for 3 hours and then blow molded using an injection molding machine with a cylinder temperature of 275°C to obtain a bottle-shaped container weighing 30g and having an internal volume of 200cc. When the bottle was subjected to a dust adhesion test, it was found that there was very little adhesion of silica sand, and the bottle had excellent antistatic properties.The bottle also had good transparency and color tone, and had a glass-like appearance. In addition, the impact strength of a separately molded sheet with a thickness of 0.2 mm is 2.3 Kg-cm/mm ² , which is far superior to the impact strength of ordinary polyethylene terephthalate sheets other than the present invention, which is 1.8 Kg-cm/mm ² . I understood. Example 2 Intrinsic viscosity obtained by changing the component composition ratios of sodium dodecylbenzenesulfonate, the compound of the general formula, and diethylene glycol in the same manner as in Example 1
Polymers of 0.68 to 0.70 (Experiments Nos. 1 to 26) were obtained. Germanium dioxide was used as a polymerization catalyst, and the germanium metal salt in the polymer was 75 ppm. The results are shown in Table-1.

【table】

[Table] Experiment No. 1-4, 8, 12, 13, 18, 19 and 23-
No. 26 is a comparative experimental example outside the scope of the present invention. As shown in Table 1, polymers having a composition range of 0.01 to 5.0% by weight of the sodium alkylbenzenesulfonate component, 0.05 to 10.0 mol% of the compound represented by the general formula, and 2.0 to 4.5 mol% of the diethylene glycol component have antistatic properties, transparency, It was confirmed that both impact resistance and dimensional stability are excellent. Example 3 150 parts by weight of dimethyl terephthalate, 87 parts by weight of ethylene glycol, 0.8 parts by weight of diethylene glycol
parts by weight and 0.06 parts by weight of manganese acetate tetrahydrate were mixed, and a transesterification reaction was carried out at 140 to 220°C under a nitrogen stream while distilling methanol off. Subsequently, the reactants were transferred to a polymerization reactor, and 0.045% by weight of trimethyl phosphate, 0.03 parts by weight of germanium dioxide as a polymerization catalyst, 2.25 parts by weight of sodium dodecylbenzenesulfonate, and 15 parts by weight of 4,4'-bis(hydroxyethoxy)diphenylsulfone were added. ,
Add 0.02 parts by weight of methylphenylpolysiloxane, reduce the pressure in the system, and raise the temperature until the final temperature is 286℃ and 0.2mmHg.
Polycondensation was carried out for 4 hours to obtain a polymer with an intrinsic viscosity of 0.672, excellent transparency, and extremely little yellowing. The polymer had a composition ratio of 5.6 mol% of 4,4'-bis(hydroxyethoxy)diphenylsulfone and 3.4 mol% of diethylene glycol component. Rice crackers were placed in a box-shaped tray made from an unstretched sheet (thickness 250 microns) of the polymer under vacuum deep drawing at 90°C and left in an atmosphere of 40°C x 65% RH, but there was very little dust adhesion. Transparency was not lost at all. Furthermore, the impact strength of the sheet was extremely excellent at 2.5 Kg-cm/mm ² .

Claims (1)

[Scope of Claims] 1. Substantially polyethylene terephthalate obtained by the reaction of terephthalic acid or its lower alkyl ester with ethylene glycol, (A) an alkali metal salt of alkylbenzenesulfonic acid;
0.01 to 5.0% by weight, (B) 2.0 to 4.5 mol% of diethylene glycol component based on the total diol component, and (C) General formula HOCH ₂ CH ₂ O-R-OCH ₂ CH ₂ OH (where R is [Formula] [Formula] [Formula] At least one compound component represented by the group
A polyester blow molded article comprising a polyester containing 0.05 to 10.0 mol% and in which at least the component (B) and the component (C) are copolycondensed.