JPH11310218A - Hollow molded container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow container made of a polycarbonate resin which is excellent in thermal stability and has improved resistance to deterioration resulting from moist and heat. SOLUTION: The hollow molded container comprises a polycarbonate resin whose structural viscosity index is 1.2 to 1.35 and an amount of divalent phenol remaining in the polycarbonate resin is 10 ppm or less, wherein the hollow molded container is a bottle for dairy products, beverage or water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a hollow molded container. More specifically, the structural viscosity index is relatively small,
Excellent heat stability obtained by molding a polycarbonate resin with an extremely small amount of dihydric phenol remaining in the resin by a method such as blow molding, extrusion molding, compression molding, or foam molding, and improved resistance to wet heat deterioration. And a hollow molded container made of polycarbonate resin.

[0002]

2. Description of the Related Art Conventionally, polycarbonate resins widely used as engineering plastics are excellent in transparency, dimensional stability, and impact resistance. It is used as a container.

However, when such a polycarbonate resin is molded into a hollow molded container by a method such as extrusion blow molding or stretch blow molding, the color of the hollow molded container may become yellow due to heat history. Further, in order to collect and reuse the hollow molded container, the container is washed with water or an alkaline aqueous solution having an alkali concentration of 1 to 4% by weight at a temperature of 60 to 80 ° C and a cleaning time of 2 hours.
Although washing is performed for up to 7 minutes, the hollow molded container that has been washed is filled with the contents, and there is a problem that the container is damaged when it is subjected to a strong impact due to dropping or the like in handling the container.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hollow molded container made of a polycarbonate resin having excellent heat stability and improved resistance to deterioration due to heat and humidity. The present inventor has conducted intensive research to achieve this purpose,
The hollow molded container formed from a polycarbonate resin with the amount of the dihydric phenol remaining in the polycarbonate resin being a specific amount or less has been found to have significantly improved thermal stability and resistance to moist heat deterioration, and has reached the present invention. .

[0005]

According to the present invention, there is provided a polycarbonate resin having a structural viscosity index of 1.2 to 1.35, wherein the amount of dihydric phenol remaining in the polycarbonate resin is 10 ppm. A hollow molded container formed from the following polycarbonate resin is provided.

The melting properties of polycarbonate resins are given by the formula
= K · P ^N [wherein Q is the flow rate of the molten resin (mL / sec)
c) and K are constants, P is pressure (kg / cm ² ), and N is structural viscosity index]. When N = 1, it indicates Newtonian fluidity, and as N increases, non-Newtonian fluidity increases. In the polycarbonate resin of the present invention, N has a value of 1.2 to 1.35.

[0007] The polycarbonate resin used in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor by a solution method or a melting method. Representative examples of the dihydric phenol used here include, for example, hydroquinone, resorcinol, 4,4′-biphenol, 1,1-bis (4-hydroxyphenyl) ethane,
2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-
Hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-
Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxyphenyl) pentane, 4,4 ′-(p-phenylenediisopropylidene) diphenol, 4,4 ′ -(M-phenylenediisopropylidene) diphenol, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, bis (4-hydroxyphenyl) oxide,
Bis (4-hydroxyphenyl) sulfide, bis (4
-Hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ester, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) Propane, bis (3,5-dibromo-4-hydroxyphenyl) sulfone, bis (4-hydroxy-
3-methylphenyl) sulfide, 9,9-bis (4-
(Hydroxyphenyl) fluorene, 9,9-bis (4-
(Hydroxy-3-methylphenyl) fluorene and the like. These may be used alone or in combination of two or more. Among them, 2,2-bis (4-hydroxyphenyl) propane is preferred.

As the carbonate precursor, carbonyl halide, carbonate ester or haloformate is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol and the like.

In producing the polycarbonate resin by reacting the dihydric phenol with the carbonate precursor by a solution method or a melting method, a catalyst, a terminal terminator, an antioxidant for the dihydric phenol and the like may be used, if necessary. May be used. The polycarbonate resin may be a polyester carbonate resin obtained by copolymerizing an aromatic or aliphatic bifunctional carboxylic acid, or a mixture of two or more of the obtained polycarbonate resins.

The reaction by the solution method is generally a reaction between dihydric phenol and phosgene, and is carried out in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. In order to promote the reaction, for example, a catalyst such as a tertiary amine such as triethylamine, tetra-n-butylammonium bromide, or tetra-n-butylphosphonium bromide, a quaternary ammonium compound, or a quaternary phosphonium compound may be used. As a terminal stopper, for example, phenol, p-te
Monofunctional phenols such as rt-butylphenol, p-cumylphenol and isooctylphenol can be used. At that time, the reaction temperature is usually 0 to 40.
° C, the reaction time is about 10 minutes to 5 hours, and the pH during the reaction is 9
It is preferable to keep the above.

The reaction by the melting method is usually a transesterification reaction between a dihydric phenol and a carbonate ester,
The method is carried out by a method in which a dihydric phenol and a carbonate ester are mixed while heating in the presence of an inert gas to distill off the produced alcohol or phenol. The reaction temperature varies depending on the boiling point of the produced alcohol or phenol, but is usually in the range of 120 to 350 ° C.
In the latter stage of the reaction, the pressure of the system is reduced to about 10 to 0.1 Torr to facilitate the distillation of the alcohol or phenol produced. The reaction time is usually about 1 to 4 hours. Further, in order to increase the polymerization rate, a polymerization catalyst usually used for an esterification reaction and a transesterification reaction can be used.

Examples of the carbonate ester include an optionally substituted ester such as an aryl group having 6 to 10 carbon atoms, an aralkyl group or an alkyl group having 1 to 4 carbon atoms. Specific examples include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and the like. Is preferred.

The molecular weight of the polycarbonate resin of the present invention is 15,000 to 50,000 in terms of viscosity average molecular weight (M).
0 is preferable, 18,000 to 45,000 is more preferable, and 20,000 to 40,000 is further preferable.
The polycarbonate resin referred to in the present invention has a molecular weight of 0.7 g of polycarbonate resin in 100 mL of methylene chloride.
This is the viscosity average molecular weight determined by inserting the specific viscosity (η _sp ) determined from the solution dissolved at 0 ° C. into the following equation. η _sp /c=[η]+0.45×[η] ² c (where [η]
Is the intrinsic viscosity) [η] = 1.23 × 10 ⁻⁴ M ^0.83 c = 0.7

In the present invention, the amount of the dihydric phenol remaining in the polycarbonate resin is 10 ppm or less, more preferably 8 ppm or less. If the residual amount of the dihydric phenol exceeds 10 ppm, the thermal stability is poor, the wet heat resistance is not sufficient, and the mechanical strength of the hollow molded container is undesirably reduced.

In the present invention, the amount of the dihydric phenol remaining in the polycarbonate resin is adjusted to 10 ppm or less by mixing an organic solvent solution of the polycarbonate resin and an aqueous alkali solution, stirring the mixture and stirring the dihydric phenol in the organic solvent solution. Can be preferably employed to extract the compound into an aqueous alkali solution.

In the solution method, the solution of the polycarbonate resin in the organic solvent can be used as it is or after adjusting the organic phase to an appropriate concentration after the completion of the reaction.
In the melting method, the obtained polycarbonate resin can be used by dissolving it in an organic solvent. The concentration of the polycarbonate resin in the organic solvent solution is preferably from 5 to 35% by weight, more preferably from 5 to 20% by weight. When using an organic solvent solution of a polycarbonate resin in this concentration range,
It is preferable because the extraction of dihydric phenol is performed efficiently and a polycarbonate resin having a reduced amount of dihydric phenol can be easily obtained. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are preferable, and methylene chloride is particularly preferably used.

As the alkaline aqueous solution, an aqueous sodium hydroxide solution is preferably used, and preferably 0.1% aqueous solution.
An aqueous solution of sodium hydroxide having a concentration of -5% by weight, more preferably 0.3-4% by weight is used. The use of an aqueous solution of sodium hydroxide in such a concentration range is preferable because the extraction of dihydric phenol is performed efficiently and a polycarbonate resin with a reduced amount of dihydric phenol can be easily obtained. Further, the ratio of the aqueous sodium hydroxide solution and the organic solvent solution used is preferably in the range of 0.1 to 10 in terms of aqueous sodium hydroxide solution / organic solvent solution (volume ratio),
The range of 0.2 to 2 is more preferable. Mixing and stirring an organic solvent solution of a polycarbonate resin and an aqueous alkali solution at such a volume ratio is preferable because a dihydric phenol can be efficiently extracted and a polycarbonate resin having a reduced amount of the dihydric phenol can be easily obtained.

As a method of mixing and stirring an organic solvent solution of a polycarbonate resin and an alkali aqueous solution, for example, a method of stirring by rotating a stirring blade (a method in which the center axis of the tank is aligned with the stirring axis, a stirring method). A method in which the shaft is inclined, a method in which a stirring shaft is provided on the side wall of the tank, a method in which stirring is performed by swinging the tank, a method in which the liquid in the tank is circulated by a pump, and the like are used. After mixing and stirring,
The organic solvent solution phase and the alkaline aqueous solution phase are separated by standing, and the organic solvent phase can be taken out.

As another method of mixing and stirring an organic solvent solution of a polycarbonate resin and an aqueous alkali solution and extracting the organic solvent solution phase from which dihydric phenol has been extracted, a method using a centrifugal extraction device has been adopted. You. Among such centrifugal extraction devices, an AC centrifugal extraction device capable of continuously forming a dispersed phase and performing a centrifugal separation process using the same device is preferable. Specifically, Ultrex E manufactured by Hitachi, Ltd. is preferred.
A centrifugal extractor with a perforated plate such as P-02 or KCC centrifugal extractor manufactured by Kawasaki Engineering Co., Ltd. may be used. Further, it is preferable that the centrifugal extraction process is performed with a centrifugal force of preferably 300 G or more, more preferably 700 G or more.

The organic solvent solution of the polycarbonate resin treated with the alkali aqueous solution is then mixed and stirred with hydrochloric acid, and then repeatedly washed with water to remove water-soluble impurities. The organic solvent solution of the polycarbonate resin thus obtained is usually pulverized and granulated.

In the present invention, in particular, it is preferable that methylene chloride, which is suitably used as a solvent in the solution method, does not remain in the obtained polycarbonate resin. Specifically, the amount of methylene chloride remaining in the polycarbonate resin is preferably It is preferably at most 5 ppm, more preferably at most 1 ppm. When the amount of methylene chloride is within this range, it is preferable that the mirror surface of the molding die is not corroded when the hollow molded container of the present invention is continuously molded.

As a method for reducing the amount of methylene chloride, in the step of pulverizing a methylene chloride solution of a polycarbonate resin, for example, a methylene chloride solution of a polycarbonate resin and a solidifying solvent are stirred under a shearing force imparting action. A method of supplying and heating and stirring to obtain a polycarbonate resin powder, a premixed solution of a methylene chloride solution of a polycarbonate resin and a solidification solvent, or a method of separately preparing a methylene chloride solution of a polycarbonate resin and a solidification solvent separately. A pulverization method is used in which the organic solvent is removed by supplying hot water in a granulation tank. Separately the methylene chloride solution of the polycarbonate resin and the solidified solvent, respectively,
The granulation method of removing the organic solvent by supplying to hot water in a granulation tank is easy to control the specific surface area of the obtained polycarbonate resin granules within a predetermined range. A mixing device with a chlorinated solvent is not required and is preferably employed. When supplying the methylene chloride solution of the polycarbonate resin to the granulation tank, the solution may be dropped or sprayed.

Examples of such a solidifying solvent include heptane, hexane, cyclohexane, ethyl acetate, benzene, toluene, acetone and the like. Heptane, hexane and ethyl acetate are preferred, and heptane is particularly preferred. The amount of the solidifying solvent used is preferably in the range of 0.5 to 1.3, more preferably 0.7 to 1.2, by weight ratio to the polycarbonate resin. In this range, the obtained polycarbonate resin particles are less likely to form clumps that are small in stickiness and hardly adhere to each other, and that the crushing strength is high and the powder is less likely to become fine powder.

The temperature of the hot water during granulation is preferably from 40 to 70 ° C, more preferably from 42 to 50 ° C. In addition, the amount of warm water is 1.0 to 1.0 by weight with respect to the polycarbonate resin.
A range of 20 is preferred.

Stirring in the granulation tank is preferably carried out in a heating atmosphere while maintaining the above-mentioned temperature and having a shearing force in order to reduce the particle size. Paddle blades, helical stirring blades, etc. Examples thereof include a blade and a kneader, and specifically, a stirring blade having high stirring efficiency such as a full zone manufactured by Shinko Pantech Co., Ltd. and a Max Blend manufactured by Sumitomo Heavy Industries, Ltd. is preferably used. The obtained polycarbonate resin particles are then usually ground and dried. For the pulverization, a wet pulverizer is preferably used, and a super clean mill, a hammer mill, a glow mill, a homomic line mill or the like is preferably used. Hot air dryers, steam dryers and the like are preferably used for drying, but explosion-proof types are preferred. The polycarbonate resin particles thus obtained are preferably melt-kneaded and pelletized using an extruder having at least one vent port. The extruder may be single-screw or twin-screw, but a twin-screw extruder is preferred.

As another method for reducing the amount of methylene chloride, when the polycarbonate resin particles are pelletized by an extruder, the polycarbonate resin particles are passed through a vent portion using a vented twin-screw extruder. And an inert substance is degassed at the vent. As the extruder with a vent, an extruder with a multi-stage vent having two or more vent portions is preferable, and an extruder having two or more vents and two or more inert substance injection locations is preferable. Examples of the inert substance include water, nitrogen, carbon dioxide, and low-boiling hydrocarbons such as heptane, hexane, and cyclohexane. Among them, water, nitrogen, carbon dioxide, and heptane are preferable, and water is particularly preferable. The amount of the inert substance added is 0.2 to 4% by weight based on the polycarbonate resin powder.
Is preferable, and when an amount of the inert substance in this range is added,
The deaeration effect is excellent, and methylene chloride is easily reduced, which is preferable.

In the present invention, the obtained polycarbonate resin pellets are molded into a hollow molded container. For molding the hollow molded container, first, a preform is injection-molded in a first mold, and then blow molded using air or an inert gas while heating to a predetermined temperature in a second mold. It is preferably adopted. The heating temperature of the preform is 30 ° C. or more higher than the secondary transition temperature of the polycarbonate resin, and is preferably in a range up to the melting point of the polycarbonate resin. The blowing pressure of the air or the inert gas may be any pressure that can uniformly mold the hollow container without uneven thickness.
It is preferably about gf / cm ^{2 to} 8 kgf / cm ² .

The hollow molded container obtained by the present invention includes:
Examples include dairy products, soft drinks, water bottles, cups and the like, preferably dairy product bottles, soft drink bottles, and water bottles, and particularly preferably water bottles. The thickness of such a hollow molded container is 0.07 to 10 mm, preferably 0.07 to 5 mm, and more preferably 0.1 to 5 mm.
1 to 2 mm. A thickness in this range is suitable and preferable because it is not easily deformed by external pressure and the weight of the whole product does not become too heavy. The thickness referred to here is the thickness of the trunk portion, and is generally thicker at the plug portion and the bottom corner than the thickness of the trunk portion.

The hollow molded container of the present invention has a polyester resin such as polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, acrylic resin, polyethylene resin, polypropylene A thermoplastic resin layer such as a polyolefin resin such as a resin or a polyamide resin may be provided, and a hard coat layer for preventing abrasion and a printing layer may be provided outside the layer.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described below with reference to examples. Parts in Examples are parts by weight, and% is% by weight. The evaluation was based on the following method.

(1) Viscosity average molecular weight: 0.7 g of a polycarbonate resin is dissolved in 100 ml of methylene chloride,
Measured at ° C.

(2) MFR: MFR was measured at a temperature of 280 ° C. and a load of 2.16 kgf according to JIS K7210.

(3) Structural viscosity index: The structural viscosity index N is
Put the polycarbonate resin pellets into the cylinder of the Koka type flow tester (manufactured by Shimadzu Corporation) and set the temperature to 2
The pressure P (100 to 180 k
g / cm ² ) and the flow rate Q (mL / mL) of each molten resin.
sec) was measured, and each value was determined from the slope of a regression line obtained by plotting the values on a log-log graph.

(4) Residual amount of dihydric phenol (bisphenol A): 3 g of polycarbonate resin was dissolved in 30 ml of methylene chloride, and 270 ml of acetonitrile was stirred.
Was added dropwise, the mixture was concentrated to 30 ml, and the precipitate was filtered. Acetonitrile was added to make the volume constant to 50 ml, and 270 n by HPLC using a water / acetonitrile gradient eluent.
It was measured at a wavelength of m.

(5) Residual amount of methylene chloride: Measured by FID-GC by a head space method (250 ° C., 2 hours).

(6) Thermal stability: The sample pellet was heated at 120 ° C.
After drying for 5 hours with an injection molding machine (SG manufactured by Sumitomo Heavy Industries, Ltd.)
-150), a test piece (70 mm long,
(Width 50 mm, thickness 2 mm), respectively, and the change in hue (ΔE) thereof was measured. Hue changes are based on JIS Z
Color difference meter (Model Z manufactured by Nippon Denshoku Co., Ltd.)
-100DP), the respective L, a, and b values were measured and calculated by the following equation.

[0037]

(Equation 1)

(7) Deterioration by wet heat: The sample pellet was 120
After drying at 5 ° C for 5 hours, the injection molding machine (Sumitomo Heavy Industries, Ltd. S
G-150) to form a test piece (70 mm long, 50 mm wide, 2 mm thick) at a cylinder temperature of 300 ° C.
After being immersed in hot water at 5 ° C. for 24 hours, 10 test pieces taken out were observed with a microscope, and the number of voids generated was measured for test piece 1.
The number was shown per sheet.

(8) Hollow container drop test: A 5-gallon water bottle having a thickness of 1.3 mm is injection-stretched blow-molded at 210 ° C., immersed in hot water at 95 ° C. for 24 hours, filled with water and filled with 6 m water. It was dropped from the height to the ground and the state of destruction was observed. The case where the sample was completely broken was evaluated as X, the degree of cracking was evaluated as Δ, and the case where no crack occurred was evaluated as 割 れ.

Example 1 A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 219.4 parts of ion-exchanged water, 40.2 parts of a 48% aqueous sodium hydroxide solution and 0.12 parts of hydrosulfite, and stirred. Bisphenol A 57.
After dissolving 5 parts, 181 parts of methylene chloride are added to give 2 parts.
28.3 parts of phosgene was blown in at 0 to 25 ° C. for about 40 minutes to obtain a polycarbonate oligomer. The temperature of the reaction mixture was adjusted to 30 ° C., and 1.24 parts of p-tert-butylphenol and 7.2 parts of a 48% aqueous sodium hydroxide solution were added to emulsify the mixture.
The reaction was completed by adding 64 parts and stirring for 1 hour. After the completion of the reaction, 246 parts of methylene chloride was added to dilute the solution to obtain a methylene chloride solution having a concentration of 14% by weight of the polycarbonate resin. A 0.5% aqueous sodium hydroxide solution was supplied at a flow rate of 1000 ml / min, and the organic phase was supplied at a flow rate of 1000 ml / min.
After treatment under pm conditions, the organic phase was acidified with hydrochloric acid, and then washed repeatedly with water. When the conductivity of the aqueous phase became almost the same as that of ion-exchanged water, methylene chloride was evaporated to obtain a polycarbonate resin powder. After drying this powder,
300 ppm of tris (2,4-di-tert-butylphenyl) phosphite and 450 ppm of monoglyceride stearate were added, and 1 part was added to the polycarbonate resin by a twin-screw extruder provided with a hydrogenation part and a vent immediately after the hydrogenation part. It was extruded into pellets by suction at a reduced pressure of 10 mmHg from the vent port while adding ion-exchanged water of weight%. The viscosity average molecular weight of the obtained pellet is 23,000.
(Specific viscosity is 0.418), MFR is 9.5 g / 10 mi
n, the structural viscosity index was 1.28. Bisphenol A in this pellet was 5 ppm, and methylene chloride was 0.8 ppm.
ppm. A test piece was prepared by injection molding of the obtained pellet, and the thermal stability and wet heat deterioration were evaluated. Further, the water bottle was subjected to injection stretch blow molding, and the obtained water bottle was subjected to a wet heat treatment and subjected to a drop test. The results are shown in Table 1. In addition, 300 bottles of water for about one month
After the 000 shot molding, the rust condition of the mold surface was observed. As a result, no fogging occurred on the mirror surface.

Example 2 A 14% by weight methylene chloride solution of a polycarbonate resin synthesized in the same manner as in Example 1 was passed through a centrifugal extractor with a perforated plate as in Example 1 at a flow rate of 1%.
A 1.0% aqueous sodium hydroxide solution was supplied at a flow rate of 500 ml / min at a rate of
After treatment under the condition of 500 rpm, washing was performed in the same manner as in Example 1 to obtain a methylene chloride solution of the polycarbonate resin. Next, a full-zone stirring blade (manufactured by Shinko Pantech Co., Ltd.) equipped with a plate-shaped baffle was attached to a 100-L stirring tank equipped with a jacket provided with a dripping nozzle, discharge port, and devolatilization port. 5 kg of polycarbonate resin powder obtained from bisphenol A having a particle size of 0.6 mm
While maintaining the internal temperature at 45 ° C. with uniform stirring, 3.5 kg / min of a methylene chloride solution of the obtained polycarbonate resin, 490 g / min of heptane,
A fixed amount of hot water of 45 ° C. was supplied at a rate of 2.5 kg / min to perform granulation. The obtained slurry of the polycarbonate resin particles was quantitatively taken out from the outlet through overflow. The discharged powder slurry is wet-pulverized, and 145 ° C.
, And extruded into pellets while adding ion-exchanged water in the same manner as in Example 1. Bisphenol A in this pellet was 4 ppm, and methylene chloride was 0.1 ppm.
It was 5 ppm. This was injection molded and evaluated for thermal stability and wet heat deterioration. Further, the water bottle was subjected to injection stretch blow molding, and the obtained water bottle was subjected to a wet heat treatment and subjected to a drop test. The results are shown in Table 1. After forming the water bottle for 300,000 shots in about one month, the rust condition of the mold surface was observed. As a result, no fogging occurred on the mirror surface.

Example 3 50 parts of 2,2-bis (4-hydroxyphenyl) propane, 49.2 parts of diphenyl carbonate and 0.00001 part of sodium hydroxide as a catalyst were placed in a reactor equipped with a stirrer and a distillation column. And 0.0016 parts of tetramethylammonium hydroxide,
It was replaced with nitrogen. This mixture was heated to 150 ° C. and dissolved with stirring. Next, while heating to 200 ° C. at a reduced pressure of 30 Torr, most of the phenol was distilled off in 1 hour, and the temperature was further increased to 270 ° C.
A polymerization reaction was carried out for 3 hours as Torr to obtain a polycarbonate resin. This polycarbonate resin was dissolved in methylene chloride to form a methylene chloride solution having a concentration of 10% by weight of the polycarbonate resin, and the solution was treated with a centrifugal extractor in the same manner as in Example 1 to form a powder. The additives were added and extruded into pellets in the same manner as in Example 1. The molecular weight of the obtained pellet was 24,1.
00 (specific viscosity 0.437), MFR 6.0 g / 10
min, the structural viscosity index was 1.30. Bisphenol A in this pellet was 6 ppm, and methylene chloride was 0.7 ppm. A test piece was prepared by injection molding of the obtained pellet, and the thermal stability and wet heat deterioration were evaluated. Further, the water bottle was subjected to injection stretch blow molding, and the obtained water bottle was subjected to a wet heat treatment and subjected to a drop test. The results are shown in Table 1. In addition, 3 bottles of water for about one month
After the 000 shot molding, the rust condition of the mold surface was observed, and no fogging occurred on the mirror surface portion.

[Comparative Example 1] In Example 1, the methylene chloride solution of the polycarbonate resin after the completion of the reaction was not treated with a centrifugal extractor using sodium hydroxide, but was made acidic with hydrochloric acid and then washed with water. Pellets were obtained in the same manner as in Example 1 except that a single screw extruder was used instead of the screw extruder, and only degassing from the vent was performed without adding ion-exchanged water. Bisphenol A in this pellet is 27p
pm and methylene chloride were 35 ppm. This was injection molded and evaluated for thermal stability and wet heat deterioration. Further, the water bottle was subjected to injection stretch blow molding, and the obtained water bottle was subjected to a wet heat treatment and subjected to a drop test. The results are shown in Table 1. In addition, 300 bottles of water for about one month
After forming the 000 shots, the rust condition of the mold surface was observed, and it was found that the mirror surface portion was slightly fogged.

Comparative Example 2 In Example 1, 0.5%
The aqueous sodium hydroxide solution was replaced with a 6% aqueous sodium hydroxide solution, and the flow rate of the 6% aqueous sodium hydroxide solution was 500 m.
Pellets were obtained in the same manner as in Example 1 except that L / min was used. Bisphenol A in this pellet is 25pp
m and methylene chloride were 0.9 ppm. This was injection molded and evaluated for thermal stability and wet heat deterioration. Further, the water bottle was subjected to injection stretch blow molding, and the obtained water bottle was subjected to a wet heat treatment and subjected to a drop test. The results are shown in Table 1. In addition, 300 bottles of water for about one month
After the 000 shot molding, the rust condition of the mold surface was observed. As a result, no fogging occurred on the mirror surface.

[0045]

[Table 1]

[0046]

The polycarbonate resin hollow container of the present invention has extremely low residual dihydric phenol, is excellent in heat stability, and is excellent in wet heat deterioration. Its industrial effect is exceptional. There is.

Claims (2)

[Claims] 1. A hollow molded container formed of a polycarbonate resin having a structural viscosity index of 1.2 to 1.35, wherein the amount of dihydric phenol remaining in the polycarbonate resin is 10 ppm or less. . 2. The hollow molded container according to claim 1, wherein the hollow molded container is a dairy product bottle, a soft drink bottle or a water bottle.