JPS6146495B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester blow molded article with good transparency. More specifically, the present invention relates to a polyester hollow molded product 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 a resin for plastic blow-molded products, but in recent years it has come to be restricted, especially in the field of blow-molded containers for food products, due to the problem of elution of vinyl chloride monomers. Although polyethylene terephthalate has various excellent properties as mentioned above, it has not been sufficiently penetrated into the field of blow molding. The reason for this was that the viscosity of the polymer when melted was low and crystallization was extremely rapid, resulting in the product being susceptible to whitening. To address this problem, various improvements have been made in the molding industry to a certain extent, and it has come to function as a substitute for polyvinyl chloride, but polyethylene terephthalate is still extremely susceptible to electrostatic charge, and during molding and processing. Whitening due to crystallization and major problems during use,
Issues such as impact resistance remain. On the other hand, examples of using sulfonate derivatives and polyalkylene glycol to improve these problems are JP-B No. 44-31828, JP-A No. 52-47069,
JP-A-52-47072, JP-A-52-134662, JP-A-52
-151365 etc. Japanese Patent Publication No. 44-31828 describes an example using a high molecular weight polyalkylene glycol which is substantially insoluble in polyester. Although the antistatic property of the polyester obtained in this case has been improved to some extent, it is cloudy and has poor transparency, so it cannot be used. 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 antistatic property can be imparted, but the material 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 the present invention as a result of extensive studies in order to simultaneously solve the various drawbacks of blow molding materials as described above and provide polyester molded products with excellent antistatic properties, transparency, and impact resistance. This invention has been achieved. 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.
0.01-5.0% by weight (B) 0.2-5.0% by weight of polyethylene glycol having a molecular weight of 600-8000 (C) 1.3-3.0% by weight of diethylene glycol component (D) 3-20ppm of Ti compound and/or Ge compound as Ti metal, Ge It is a polyester blow-molded article containing 10 to 100 ppm of metal (the above components (B) and (C) are co-condensed) and has good transparency. 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 and diethyl terephthalate, 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. Further, the diol component is mainly an ethylene glycol component, but a small amount of other glycols may also be used in combination. An example of this is propylene glycol,
Examples include trimethylene glycol, tetramethylene glycol, and cyclohexanedimethanol components. Component (A) used in the present invention, that is, an 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 such as a slimy feeling in the polyester molded product and deterioration in transparency occur, which is not preferable. The polyethylene glycol used in the present invention has a molecular weight of 600 to 8000, and the amount added is 0.2 to 5.0% by weight, preferably 0.3 to 2.5% by weight. Here, polyethylene glycol means 40 mol% of other polyalkylene glycol units.
Copolymerized products are also included below. If the molecular weight of polyethylene glycol is less than 600, it is undesirable because the impact resistance and elasticity are lowered probably because the blocking properties are lowered, and the softening point is extremely lowered and the dimensional stability is deteriorated, which is one of the objects of the present invention. The antistatic properties are not exhibited. If it exceeds 8,000, the polyethylene glycol component gradually becomes insoluble in the polyester, which is not preferable because not only the polymer but also the molded product will turn white despite rapid cooling during molding. In addition, if the amount of polyethylene glycol added is less than 0.2% by weight, the antistatic property will not be sufficient, and the amount of polyethylene glycol added will be 5.0% by weight.
If it exceeds this value, the heat resistance of the polymer will deteriorate and the color will be too yellowish to be of practical use. The conventional polymer thus obtained has improved antistatic properties compared to ordinary polyethylene terephthalate, but is inferior in transparency. The polymer color has a yellowish tinge. Impact resistance is not sufficiently improved. Such shortcomings appear. Therefore, the diethylene glycol component should be 1.3 to 3.0.
wt% and Ti compound and/or as polymerization catalyst
Or 3-20ppm Ge as Ti metal with Ge compound
By containing 10 to 100 ppm of the metal, the above-mentioned drawbacks can be solved at once, and even better antistatic properties can be obtained. If the diethylene glycol component is less than 1.3% by weight, it will not be possible to sufficiently improve the transparency of the blow molded product, and if it exceeds 3.0% by weight, the molded product will not have practical dimensional stability due to a decrease in the softening point. do not have. A more preferable addition amount of diethylene glycol is 1.5 to 2.5% by weight. In addition, if the amount of Ti compound and/or Ge compound added as a polymerization catalyst is less than 3 ppm and 10 ppm as metal, it is not practical because the polymerization rate is slow, and if it exceeds 20 ppm and 100 ppm, the polymer will become colored. In addition, the resulting polymer tends to crystallize during the cooling process during melt molding, resulting in the drawback that the hollow molded product is susceptible to whitening. Also, preferred Ti compounds and/or Ge
The amount of each compound added is 5 to 5 as metal.
15ppm, 20-80ppm. Specific Ti compounds include tetrabutyl titanate, tetramethyl titanate, titanium tetrachloride, titanium oxalate, titanium oxalate, titanium acetate, titanium trimellitate, and hydrolysates or derivatives thereof. Examples of the Ge compound include germanium oxide, germanium alkoxide, germanic acid metal salts, and the like. Antimony compounds, silicon compounds, zirconium compounds, and the like are known as polycondensation catalysts other than Ti and/or Ge compounds, but these are not preferred in terms of dullness, coloration, and heat resistance of the resulting polymer. Furthermore, coexisting phosphorus compounds such as phosphorous acid, phosphoric acid, and esterified products thereof in these compositions as phosphorus atoms at least 0.1 times by mole based on the total metal atom components in the polymer is important for improving the quality of the polymer. More suitable for heat resistance and color tone. 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 blow molded products, but it can also be used in combination with vacuum forming, blow molding, and uniaxial or biaxial stretch molding. . For example, a series of 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, and (8) ejecting steps. The polyester blow molded product thus obtained is
It has excellent antistatic properties, transparency, and impact resistance, making it particularly suitable for filling and packaging materials such as food, cosmetics, and miscellaneous goods.It does not attract dust when left in a store, and is more resistant to drop impact than ordinary polyethylene terephthalate. However, it is extremely excellent. Hereinafter, the present invention will be explained with reference to Examples. still,
Prior to explaining the examples, a method for measuring characteristic values will be explained. (1) Surface specific resistance A 0.2 mm thick sheet sample was left for 1 hour at a room temperature of 20° C. and a humidity of 65% and was measured using a MMA-15 type ultra-micro ammeter manufactured by Kawaguchi Electric Seisakusho. (2) Dust adhesion test We applied silica sand to the sheet or molded product and examined the adhesion state. (3) Haze thickness 0.2mm according to ASTM-D-1003-59T
Measurements were made on sheets of ±0.01 mm. (4) Intrinsic viscosity Intrinsic viscosity of the polymer is a value measured at 25°C using 0-chlorophenol solvent. (5) Dimensional stability Cylindrical bottomed parison weighing 26g (inner volume 27g)
cc) in an atmosphere of 105℃ in two axial directions,
Obtain a bolt with an internal volume of approximately 400 c.c. this bolt
Determine the volumetric shrinkage rate when left in an atmosphere of 40℃ x 90% RH for 14 days. Shrinkage rate 0.5% or less Excellent ◎ 0.5-2% Good 〇 2%-4% Slightly poor △ 4% or more Poor × Values I made a judgment. (6) Drop impact strength Cylindrical bottomed parison weighing 26 g (inner volume 27
cc) in an atmosphere of 105℃ in two axial directions,
Obtain a bolt with an internal volume of approximately 400 c.c. This bolt was filled with water and dropped onto a concrete floor from a height of 2.5 m, and the number of drops and the state of damage when the bolt broke were determined. (7) Impact strength This is the value determined using a Charpy impact strength tester using a 5 mm wide sample of an unstretched sheet with a thickness of 0.2 mm. Judgment 2.2-2.5Kg-cm/mm ² or more Excellent ◎ 1.8-2.2Kg-cm/mm ² Good 〇 1.3-1.8Kg-cm/mm ² Slightly poor △ 1.3 Kg-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. while TPA 158 parts by weight and ethylene glycol 71 parts by weight
The parts by weight were mixed well, and the resulting slurry was continuously added to the reactor at a constant rate, and heated at 250°C under normal pressure.
The water produced by the esterification reaction was continuously distilled out of the system from the rectification column. 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, 0.002 parts by weight of phosphoric acid, 1.0 parts by weight of diethylene glycol, and 0.0075 parts by weight of tetrabutyl titanate were added, and after another 5 minutes, 1.0 parts by weight of sodium dodecylbenzenesulfonate was added. 2.0 parts by weight of polyethylene glycol having a molecular weight of 4000 and 0.01 parts by weight of methylphenyl polysiloxane were added, and the final temperature was 280°C and the degree of vacuum was 0.5 using a conventional method.
Polycondensation reaction is carried out under mmHg, and the intrinsic viscosity is
A polymer of 0.643 was obtained. The diethylene glycol content of the polymer was 1.92% by weight, about 2.1% by weight of polyethylene glycol, 1.06% by weight of sodium dodecylbenzenesulfonate, and 11 ppm of titanium metal. After vacuum drying the polymer at 170° C. for 3 hours, an injection molding machine with a cylinder temperature of 280° C. is used to obtain a cylindrical bottomed parison (inner volume 27 c.c.) weighing 26 g. then
After being left in an atmosphere at 105°C for 5 minutes, it was stretched biaxially to obtain a bottle with an internal volume of 400 c.c. When we conducted a dust adhesion test on the bottle, we found that there was very little adhesion of silica sand, it had excellent anti-static properties, the impact resistance was 10 times or more, and the bottle had good transparency and color, and the appearance was good. It was glass-like. Example 2 Polymers (Experiments Nos. 1 to 25) were obtained in the same manner as in Example 1, with different composition ratios of sodium dodecylbenzenesulfonate, polyethylene glycol, and diethylene glycol components. However, germanium dioxide was used as the polymerization catalyst, and the amount of germanium metal in the polymer was 60 ppm. The results are shown in Table 1.

[Table] Experiment No. 1, 2, 8, 9, 14, 15, 18-20 and
No. 25 is a comparative experimental example outside the scope of the present invention. As shown in Table 1, sodium alkylbenzenesulfonate component 0.01-5.0% by weight, molecular weight 600-
Polyethylene glycol with 8000% by weight, diethylene glycol component 1.3-3.0% by weight
It was confirmed that the polymer having the composition range has excellent antistatic properties, transparency, impact resistance, and dimensional stability. Comparative Example 1 A polymer was produced in exactly the same manner as in Example 1, except that 0.03 parts by weight of antimony trioxide was added as a polycondensation catalyst. It was found that the obtained polymer had a much darker tinge than ordinary polyethylene terephthalate using this catalyst, and the injection-molded cylindrical bottomed parison was also opaque, making it undesirable as a blow-molded product. 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 while distilling off methanol at 140 to 220°C under a nitrogen stream. Subsequently, the reactants were transferred to a polymerization vessel, and 0.025 parts by weight of trimethyl phosphate, 0.01 parts by weight of germanium dioxide as a polymerization catalyst, 0.005 parts by weight of titanate oxalate, and 2.25 parts by weight of sodium dodecylbenzenesulfonate, polyethylene glycol having a molecular weight of 2000 were added. Add 3.0 parts by weight and 0.02 parts by weight of methylphenylpolysiloxane, reduce the pressure in the system and raise the temperature.
Finally, polycondensation was performed at 282℃ and 0.2mmHg for 4 hours to create a polymer with an intrinsic viscosity of 0.691, excellent transparency, and extremely little yellowing (diethylene glycol component in the polymer was 2.1% by weight, and residual Ge metal content).
23ppm, residual amount of titanium metal 6ppm). An unstretched sheet (thickness 250 microns) of the polymer was heated at 90°C.
Rice crackers were placed in a vacuum deep-drawn box-shaped tray under these conditions and left in an atmosphere of 40°C and 65% RH, but there was very little dust adhesion and no loss of transparency was observed.

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;
0.01-5.0% by weight (B) Polyethylene with a molecular weight of 600-8000 0.2
~5.0% by weight (C) Diethylene glycol component 1.3~3.0% by weight (D) Ti compound and/or Ge compound 3~20ppm as Ti metal, 10~20ppm as Ge metal
A polyester blow-molded article with good transparency, containing 100 ppm [However, the above components (B) and (C) are co-condensed].