JP5286477B2 - Stretch blow molded container - Google Patents

Description

  The present invention relates to a stretch blow molded container made of ethylene terephthalate-based polyester, and more specifically, heat resistance and appearance characteristics in which problems inherent to stretch blow molded containers made of silica-containing polyester resin are effectively solved. The present invention relates to a stretch blow molded container excellent in stretch moldability.

Stretch-molded containers of thermoplastic polyester resins such as polyethylene terephthalate have excellent transparency and surface gloss, as well as impact resistance, rigidity, and gas barrier properties required for containers such as bottles and cups. It is used as a container for beverages and foods.
However, stretch-molded containers made of polyester resin have the disadvantage of poor heat resistance and cause heat deformation and shrinkage deformation in volume when the contents are hot filled. (Heat setting) is being performed.
The heat resistance imparted to the stretch-molded container made of polyester resin by heat setting can withstand temperatures of about 90 ° C. such as hot filling, but heat sterilization or the like such as retort sterilization performed after filling the contents. Sterilization is performed for about 20 to 50 minutes in a high-temperature atmosphere of 100 ° C. or higher. As a result, it is difficult to obtain heat resistance sufficient to withstand heat sterilization only by heat setting after molding.

As a method for improving the heat resistance of a stretched polyester container, it has been proposed to use a polyester resin comprising 70 to 5% by weight of polyethylene terephthalate and 30 to 95% by weight of polybutylene terephthalate (Patent Document 1). Even when such a copolyester resin is used, the heat resistance obtained is only about 90 ° C. at most.
Further, when the stretch-molded container is molded by the one-stage blow molding method, the stretch-molded container having a small residual strain and excellent heat resistance is formed by heating and stretching the preform at a high temperature. Can be molded. For example, in a one-stage blow molding method, the preform temperature is set as high as possible, and heat generation due to internal friction or crystallization when stretching at a high speed is used, and the stretch molding and heat setting are simultaneously advanced to achieve heat resistance. A method for obtaining a stretch blow bottle made of a highly reactive polyester resin has been proposed (Patent Document 2).

However, when stretching at a high temperature, the strain is excessively relaxed and the strain hardening phenomenon does not easily occur. Therefore, unless the stretching speed is extremely high, stretching does not propagate to the entire molded product and has a uniform thickness. A molded container cannot be obtained. For this reason, conventionally, when the mechanical stretching speed is limited, the stretching temperature is lowered, and the stretching balance is obtained at the expense of the heat resistance that is the merit of high-temperature stretching.
The present inventors effectively strain-hardened even when a mechanical stretch speed is limited in the single-stage blow molding method, and has both excellent heat resistance by high-temperature stretch and stretch balance by strain-hardening. In order to provide a stretch-formed container, a polyester resin having a specific dispersion structure is used by using a polyester resin in which inorganic substances such as talc and mica are dispersed. It has been found that propagation can occur and the strain hardening phenomenon can be effectively generated, and it is possible to provide a stretch-molded container having excellent heat resistance (Patent Document 3).
Further, apart from the purpose of effectively generating the strain hardening phenomenon under the above-mentioned high-temperature stretching conditions, silica can be used as an inorganic dispersion to be dispersed in the polyester resin to suppress acetaldehyde in the resin (Patent Document 4). It has been proposed to improve the heat resistance and slip properties of a container made of a polyester resin composition in which an inorganic substance is dispersed (Patent Document 5).

JP-A-5-178338 Japanese Patent No. 1767894 International Publication No. 2006/115287 Japanese Patent Laid-Open No. 56-18646 Japanese Patent Publication No. 63-19330

When using the above-mentioned polyester resin in which inorganic substances are dispersed, the same strain-hardening phenomenon occurs as when stretched at high speed, even when stretched without increasing the stretch rate under high temperature conditions, and stretch moldability Although it becomes possible to produce a stretch-molded container well, the use of the inorganic material as described above has not yet been sufficiently satisfied in terms of appearance characteristics such as transparency and surface gloss.
Accordingly, an object of the present invention is to provide a stretch-molded container having excellent appearance characteristics such as transparency, excellent stretch-moldability, and excellent stretch balance such as thickness and shape uniformity.
Another object of the present invention is to provide a stretch-molded container having excellent appearance characteristics and excellent heat resistance.

According to the present invention, there is provided a stretch blow molded container formed from a resin composition comprising an ethylene terephthalate-based polyester resin and dry hydrophobic silica particles whose surface is covered with a hydrophobic organic functional group, The following formula δT (° C.) = TC1 (2nd) −TC1 (1st)
In the formula, TC1 (1st) is the crystallization exothermic peak temperature of the unstretched portion of the container by a differential scanning calorimeter (DSC), and TC1 (2nd) is a differential scanning calorimeter (after melting and quenching the unstretched portion of the container) DSC) represents the crystallization exothermic peak temperature, respectively.
Range δT Ri larger and 14 der less value than 0 (° C.), the dry hydrophobic silica particles, average primary particle size of the specific surface area by the 7~20μm and the BET method of 100-150 ² / g expressed by in there, stretch blow molded container, characterized that you have been contained in an amount of 0.25 to 1.0 wt% in the resin composition is provided.
Oite the stretch blow molded container of the present invention, dry-type hydrophobic silica particles, due to the hydrophobic organic functional groups of the silica particle surface is trimethylsilyl group, or thermal mechanical analysis of the container body (TMA) measurement 200 It is preferable that the shrinkage rate at 10 ° C. is 10% or less.

Although the stretch blow molded container of the present invention contains an inorganic substance, the excellent transparency and surface gloss inherent in the polyester resin are not impaired and have excellent appearance characteristics.
Further, in the stretch blow molded container of the present invention, by using specific dry hydrophobic silica particles, a good stretch balance due to strain hardening is obtained without causing a drop in stretch moldability, which is a disadvantage when silica particles are blended. It is possible to provide a stretch blow-molded container comprising
Furthermore, the stretch blow molded container of the present invention effectively utilizes the strain hardening phenomenon regardless of the stretching speed even under high temperature conditions, and has excellent heat resistance due to the reduction of residual strain, which is the effect of high temperature stretching. And has excellent heat resistance with a shrinkage rate at 200 ° C. of 10% or less by thermomechanical analysis (TMA) measurement of the container body.

The stretch blow molded container of the present invention contains dry hydrophobic silica particles whose surface is covered with a hydrophobic organic functional group in an ethylene terephthalate polyester resin, and the value of δT (° C.) represented by the above formula (1). It is an important feature that is greater than 0 and less than or equal to 14.
As described above, the present inventors proposed that by adding an inorganic substance to a polyester resin, a strain hardening phenomenon similar to that at the time of stretching at a high speed is generated to impart heat resistance to the stretch blow molded container. In addition, it is possible to suppress acetaldehyde in the polyester resin by dispersing silica in the polyester resin, and to improve heat resistance and slipping properties of a container made of a composition of an inorganic substance such as silica and the polyester resin. Although proposed, polyester resin compositions containing silica particles, among inorganic substances, increase the crystallization rate because silica particles function as crystal nucleating agents, and crystallize during high-temperature heating before stretching. As a result, the stretch moldability is inferior, and as a result, the thickness and shape are not uniform and the stretch balance is inferior, and at the same time, whitening occurs due to thermal crystallization. We had the problem of poor sex.

  In contrast, the stretch blow molded container of the present invention having the above characteristics has excellent heat resistance and appearance characteristics, and an excellent stretch balance has been found by the inventors' diligent research. The reason for this is not clear, but is thought to be due to the following reason. That is, dry hydrophobic silica particles whose surface is covered with hydrophobic organic functional groups change the aggregation structure depending on the shear rate, so the shear rate (molding rate) of the resin composition is controlled during molding. By forming dry hydrophobic silica particles in a resin to form a three-dimensional network structure with few crystal nuclei, it is possible to control the crystallization speed of the resin composition, and before the biaxial stretch blow molding is performed. Crystallization at the time of heating the reform at a high temperature is prevented and stretching inhibition due to crystallization is reduced, and it becomes possible to mold with good stretch moldability. Moreover, since whitening by thermal crystallization is suppressed, it is thought that it is excellent also in transparency.

Further, in the stretch blow molded container of the present invention having excellent appearance characteristics and stretch balance, it is specified by the property that the value of δT (° C.) represented by the above formula (1) is greater than 0 and 14 or less. it can.
That is, in a stretch blow molded container comprising a resin composition containing dry hydrophobic silica particles having the above-described characteristics, the crystallization exothermic peak temperature TC1 (1st) of the unstretched portion of the container by a differential scanning calorimeter (DSC) is , It is close to the crystallization exothermic peak temperature TC1 (2nd) by the differential scanning calorimeter (DSC) after melting and quenching the unstretched portion of the container, that is, the crystallization rate is lowered. It has been found that stretch blow molded containers having various characteristics are not hindered by stretching due to crystallization, are formed with good stretch moldability, and can provide stretch blow molded containers with excellent stretch balance (thickness uniformity) and transparency. It was.

Note that the measurement of the crystallization exothermic peak temperature TC1 is performed at an unstretched portion (the center of the bottom or the mouth in an aseptic container or the like where the mouth is not crystallized) in order to eliminate the influence of oriented crystals due to stretching. In addition, the melting treatment in the measurement of the crystallization exothermic peak temperature TC1 (2nd) is performed at a temperature T equal to or higher than the melting point of the polyester resin to be used, specifically Tm + 10 ≦ T ≦ Tm + 40. Specifically, it is carried out at a temperature lowering rate of 40 ° C./min or higher up to 20 ° C.
The value of δT (° C.) represented by the above formula (1) is preferably greater than 0 and 14 or less, and particularly preferably in the range of 3 to 7, and in the case where it is greater than 14 ° C., examples described later As is clear from the results, the crystallization speed becomes excessively high and there is a possibility of whitening by heating.

It is clear from the results of Examples described later that the stretch blow molded container of the present invention having such characteristics has excellent heat resistance, stretch balance and appearance characteristics.
That is, the present invention comprises a polyethylene terephthalate resin composition containing dry hydrophobic silica particles whose surface is covered with a hydrophobic organic functional group, and the value of δT represented by the above formula (1) is 14 ° C. or less. It is clear that the stretch blow molded container has uniform thickness and container shape, excellent stretch moldability, low haze value and high gloss value, and remarkably excellent transparency and gloss. (Example).

(Ethylene terephthalate polyester resin)
In the ethylene terephthalate-based polyester resin used in the stretch blow molded container of the present invention, the dicarboxylic acid component is 50 mol% or more of the dicarboxylic acid component, particularly 80 mol% or more is terephthalic acid, and the diol component is 50 of the diol component. A polyester resin having an ethylene glycol content of at least mol, particularly at least 80 mol%, is used. Such an ethylene terephthalate-based polyester resin satisfies mechanical properties, thermal properties, and molding processability in a well-balanced manner among polyester resins.

Of course, it can also contain carboxylic acid components other than terephthalic acid. Examples of carboxylic acid components other than terephthalic acid include isophthalic acid, naphthalenedicarboxylic acid, p-β-oxyethoxybenzoic acid, and biphenyl-4,4′-dicarboxylic acid. , Diphenoxyethane-4,4′-dicarboxylic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, adipic acid, sebacic acid and the like.
As the diol component, 50 mol% or more, particularly 80 mol% or more of the diol component is preferably ethylene glycol in view of mechanical properties and thermal properties. As the diol component other than ethylene glycol, 1,4-butane is preferable. Examples thereof include diol, propylene glycol, neopentyl glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, cyclohexane dimethanol, ethylene oxide adduct of bisphenol A, glycerol, trimethylolpropane, and the like.

  Further, the dicarboxylic acid component and the diol component may contain a tribasic or higher polybasic acid and a polyhydric alcohol. For example, trimellitic acid, pyromellitic acid, hemimellitic acid, 1,1,2,2 -Ethanetetracarboxylic acid, 1,1,2-ethanetricarboxylic acid, 1,3,5-pentanetricarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, biphenyl-3,4,3 ', 4 Polybasic acids such as' -tetracarboxylic acid and polyvalent acids such as pentaerythritol, glycerol, trimethylolpropane, 1,2,6-hexanetriol, sorbitol, 1,1,4,4-tetrakis (hydroxymethyl) cyclohexane Mention may be made of alcohol.

Since the stretch blow molded container of the present invention can be stretch blow molded without increasing the crystallization speed by using a specific dry hydrophobic silica, it is advantageous even when a polyester resin having a high crystallization speed is used. Of course, by using a copolyester resin having a low crystallization rate, by reducing the crystallization rate, it is possible to obtain a better stretch balance, appearance characteristics, and the like.
The polyester resin used is not limited to this, but preferably has an intrinsic viscosity in the range of 0.72 to 0.90 dL / g.

(Dry hydrophobic silica particles)
In the present invention, it is important to use dry hydrophobic silica particles whose surface is covered with a hydrophobic organic functional group.
It is important in terms of appearance characteristics to use dry hydrophobic silica particles having an average primary particle size of 20 nm or less, particularly in the range of 7 to 12 nm. That is, when the dry hydrophobic silica particles are larger than 20 nm, the dispersibility is inferior, so that the haze value is high and the gloss value is low, and satisfactory transparency cannot be achieved.
The specific surface area of the dry hydrophobic silica particles by the BET method is preferably 300 m ² / g or less, particularly preferably in the range of 100 to 150 m ² / g. Silica particles having a specific surface area larger than 300 m ² / g tend not to exhibit the above-described aggregated structure change phenomenon as compared with the case of being in the above range.

The dry hydrophobic silica used in the present invention is obtained by hydrophobizing the silica surface by reacting silica powder with a reaction treatment agent. Silica powder is composed of dry silica particles. By using the dry hydrophobic silica particles, the above-mentioned aggregated structure change phenomenon can be effectively expressed. By making it contain in resin, it becomes easy to make haze value of a stretch blow molding container low, and to make gloss value high.
The dry hydrophobic silica may be hydrophobized by any treatment agent conventionally used in hydrophobization treatment, such as a silylating agent and a silicone oil-based treatment agent. From the viewpoint of fluidity, those having a trimethylsilyl group on the surface of silica particles surface-treated with a trimethylsilylating agent can be suitably used.
The dry hydrophobic silica particles are preferably contained in the resin composition in an amount of 0.01 to 1% by weight, particularly 0.25 to 0.75% by weight. When the content is high, the crystallization speed is faster than when the content is in the above range, while when the content of dry hydrophobic silica particles is less than the above range, the dry hydrophobic silica particles are used. The effect obtained by blending cannot be sufficiently obtained.

(Layer structure)
The stretch-molded container of the present invention only needs to have at least one layer composed of the above-described resin composition, and can be a container having a single layer structure composed of a resin composition, or a layer composed of a resin composition. In addition, a container having a multilayer structure in which other thermoplastic resin layers are combined can also be used.
In the case of a container having a multilayer structure, it is particularly preferable that the layer made of the resin composition constitutes an inner / outer layer. The thickness of the layer composed of the resin composition and the layer provided if necessary cannot be generally defined by the layer structure or the like, but can be set in the same manner as a conventionally known polyester stretch-molded container.

  As the thermoplastic resin other than the above-mentioned polyester resin, any resin that can be stretch blow molded can be used, and is not limited thereto, but is not limited to this, and olefin resins such as ethylene-vinyl alcohol copolymer and cyclic olefin polymer. And a polyamide resin such as a xylylene group-containing polyamide. Also, an oxygen-absorbing gas barrier resin composition in which a xylene group-containing polyamide is mixed with a diene compound and a transition metal catalyst, recycled polyester (PCR (resin that recycles used bottles), SCR (resin generated in a production plant) ) Or a mixture thereof) or the like. These recycled polyester resins preferably have an intrinsic viscosity (IV) in the range of 0.65 to 0.75 dL / g.

Moreover, in order to adhere | attach an inner layer or an outer layer, and an intermediate | middle layer, adhesive resin can also be interposed. As the adhesive resin, an acid-modified olefin resin or polyester resin obtained by graft polymerization of maleic acid or the like, or an amorphous polyester resin or polyamide resin can be used.
The polyester resin or thermoplastic resin other than the polyester resin used in the present invention has various additives such as a colorant and an ultraviolet absorber as long as the quality of the biaxially stretched container as the final molded product is not impaired. , Mold release agents, lubricants, nucleating agents, inorganic layered compounds for increasing gas barrier properties, and the like.

(Production method)
The stretch blow molded container of the present invention is not limited to this method, but is a resin comprising an ethylene terephthalate polyester resin and dry hydrophobic silica particles whose surface is covered with a hydrophobic organic functional group. A preform formed from the composition and having a value of δT (° C.) represented by the above formula (1) of greater than 0 and not greater than 14 ° C. is stretch blow molded at a stretching temperature of 110 to 120 ° C. By heat-setting at a temperature of 230 ° C., molding can be performed regardless of the stretching speed.
As described above, under high-temperature stretching conditions that can impart excellent heat resistance to the stretched molded product, the stretching balance deteriorates unless high-speed stretching is performed, but there is a limit to increasing the stretching speed, Conventionally, stretch molding is performed at a low temperature (95 to 105 ° C.) at the expense of the merit of high-temperature stretching such as low residual strain. On the other hand, when producing the stretch blow molded container of the present invention, by using the preform having the above-described characteristics, even when stretching under a high temperature condition of 110 to 120 ° C., the stretching speed can be made as much as possible. Therefore, it is possible to obtain a stretch-formed container having an excellent stretch balance by using a conventional stretch molding apparatus without increasing the height.

The preform can be formed by a conventionally known method such as injection molding or compression molding using the above-described resin composition. To form a preform having the above-described characteristics, It is important to control the crystallization rate of the resin composition.
The method for controlling the crystallization rate of the resin composition is not limited to this, but the dry hydrophobic silica particles used as described above are those having a specific surface area of 300 m ² / g or less. When an ethylene terephthalate polyester resin blended with a slow copolymerization component is used, or when a preform is formed by injection molding, it is possible to control injection speed or the like.

Further, in the molding of the stretch blow molded container of the present invention, the molded preform is subjected to stretch blow molding depending on the composition of the polyester resin used and the use of the container, but it is 110 to 120 ° C., particularly 115 to 120 ° C. It is preferable that the film is stretch-molded by heating to the stretching temperature, and the stretching temperature is in a high temperature range such as the above range, so that residual strain can be reduced and high heat resistance can be imparted. Become. For example, in forming an aseptic filling container that does not require high heat resistance, such as a container for heat resistance, the stretching temperature can be in the range of 95 to 105 ° C.
Here, the heating temperature of the preform, that is, the stretching temperature is the outer surface temperature of the preform immediately before the stretch blow molding, and can be measured by a radiation thermometer, a thermal image measuring instrument, or the like.
In order to heat the preform uniformly and at high speed to the above temperature, it is necessary to heat the preform from inside and outside of the preform by means such as hot air, infrared heater, high frequency induction heated iron core internal insertion, etc. preferable.

The preform is supplied into a publicly known stretch blow molding machine, set in a mold, stretched and stretched in the axial direction by pushing a stretch rod, and stretched and molded in the circumferential direction by blowing blow air. In order to efficiently perform stretch molding at a high temperature in the method of the present invention, it is preferable to blow hot air at 100 to 150 ° C. as blow air.
In the present invention, regardless of the stretching speed, it is possible to obtain the same stretching balance as when stretching at a higher speed than the set speed.

Further, in the present invention, since stretch blow molding is performed at a temperature higher than usual, there is a risk of oligomer precipitation due to high temperature stretching. Therefore, in order to prevent this, it is preferable to use a surface-treated mold. Further, in order to increase the releasability and suppress deformation after molding, it is preferable to circulate room temperature or cooling air in the blow bottle as cooling air at the time of releasing to reliably cool the molded product.
The stretch ratio in the biaxially stretched container is suitably 1.5 to 25 times in terms of area ratio. Among these, the axial stretch ratio is 1.2 to 6 times, and the circumferential stretch ratio is 1.2 to 4.5. It is preferable to double.

In addition, the effect of achieving both the low residual strain and the stretch balance obtained in the present invention can be obtained regardless of the heat setting conditions. However, heat sterilization exceeding 100 ° C. such as boil and retort treatment is performed. In order to obtain high heat resistance in use, it is preferable to heat-set at a temperature of 150 to 230 ° C., preferably 150 to 180 ° C. after stretching. The heat setting can be performed by means known per se, and can also be performed by a one-mold method performed in a blow mold, or a two-mold performed in a heat mold separate from the blow mold. It can also be done by law.
From the viewpoint of handling properties, it is desirable to cool with cold air when taking out from the mold after heat setting.

[Measurement]
1. Measurement of crystallization rate change [δT (° C.) = TC1 (2nd) −TC1 (1st)] (1) Measurement of crystallization exothermic peak temperature (Tc1) by DSC About 5 to 10 mg from center of bottom of molded stretch blow bottle The crystallization exothermic peak temperature was measured using a differential scanning calorimeter (EXSTAR6000DSC 6220: Seiko Instruments Inc.). The measurement temperature profile is as follows.
[1] Temperature rise from 20 ° C. to 290 ° C. at 10 ° C./min [2] Hold at 290 ° C. for 5 minutes [3] Temperature drop from 290 ° C. to 20 ° C. at 150 ° C./min [4] 20 ° C. to 290 ° C. Temperature rise at 10 ° C./min [5] Hold at 290 ° C. for 5 minutes [6] Temperature drop from 290 ° C. to 20 ° C. at 10 ° C./min Of these, the crystallization exothermic peak temperature measured in [1] is TC1 ( 1st), the crystallization exothermic peak temperature measured in [4] is defined as TC1 (2nd).

[Evaluation]
1. Determination of presence or absence of whitening after heating of preform Presence or absence of whitening (thermal crystallization) due to heating of an infrared heater immediately before stretch blow molding of the preform was confirmed.

2. Determination of presence or absence of stretch inhibition due to crystallization In advance, biaxial stretch blow molding was performed by marking at an interval of 10 mm with an oil-based magic from the neck ring under the mouth toward the bottom of the body of the preform. In this stretch blow bottle, it was determined that bottles with the same marking interval were not obstructed, and non-uniform bottles were obstructed.

3. Measurement of Haze of Stretched Blow Bottle Body The prepared bottles were visually observed and evaluated as ○ for bottles with excellent transparency, Δ for bottles with slightly poor transparency, and × for opaque (whitened) bottles.

4). Measurement of Gloss of Stretched Blow Bottle Body The prepared bottles were visually observed and evaluated as ◯ for bottles with excellent gloss, Δ for bottles with slightly poor gloss, and x for bottles with poor gloss.

5. 200 ° C. Shrinkage in Thermomechanical Analysis (TMA) Measurement A test piece 10 mm × 30 mm larger from the bottle body is cut so that the long side direction is the bottle height direction, and a viscoelastic spectrometer (EXSTAR6000DMS: Seiko Instruments Inc.) )). The measurement conditions are shown below.
Measurement mode: F control mode, distance between test specimen initial marks: 20 mm, stress profile: unweighted, temperature rising profile: from shrinkage curve obtained by heating from 25 ° C. to 210 ° C. at 2 ° C./min, The shrinkage rate curve was calculated using the following equation.
S (shrinkage rate:%) = X / L × 100,
X: Shrinkage amount at each temperature (mm), L: Initial gauge distance (mm) = 20 mm
The amount of shrinkage at the start of measurement was 0, and the shrinkage rate when the temperature reached 200 ° C. was derived from the calculated shrinkage rate curve.
Regarding the shrinkage rate at 200 ° C. by thermomechanical analysis (TMA) measurement, no whitening or stretching inhibition occurs after heating the preform, and the appearance characteristics are excellent (Examples 1 to 9 and Comparative Example 10). No. was used when the shrinkage rate at 200 ° C. was 10% or less.

[Example 1]
The main material ethylene terephthalate polyester resin [isophthalic acid (IA) 2 mol% copolymerized PET] (BK6180B: Nippon Unipet Co., Ltd.) and dry silica particles consisting of hydrophobic silica A shown in Table 1 are set in a heating cylinder. Amorphous masterbatch resin pellets are prepared by blending with a twin screw extruder with granulation equipment (KZW: Techno Novell Co., Ltd.) at a temperature of 280 ° C., and the pellets are heated at 150 ° C. under vacuum for 4 hours. Then, crystallization and drying treatment were performed.
Next, the master batch resin pellets and the resin pellets composed of the main material are dry blended and supplied to an injection molding machine hopper, and injection molding is performed under the conditions of a heating temperature of 115 ° C. and a filling time of 2.8 seconds. A preform having a weight of 14 g and a silica concentration of 1% was obtained.
This preform was heated to 115 ° C. with an infrared heater, biaxially stretched using a blow mold having a stretching ratio of 3 times, 3 times, area 9 times, and a mold temperature of 25 ° C. A stretch blow bottle was formed.
Table 2 shows the results of the above measurement, and whitening after heating the preform, inhibition of stretching due to crystallization, and evaluation of haze and gloss of the stretch blow bottle body.

[Example 2]
A stretch blow bottle was prepared in the same manner as in Example 1 except that the silica particles were dry hydrophobic silica B shown in Table 1, and the above measurements and evaluations were performed.

[Example 3]
A stretch blow bottle was prepared in the same manner as in Example 1 except that the silica particles were dry hydrophobic silica C shown in Table 1, and the above measurements and evaluations were performed.

[Example 4]
Except that the silica concentration was 0.1%, a stretch blow bottle similar to that of Example 3 was prepared, and the above measurements and evaluations were performed.

[Example 5]
Except for the silica concentration of 0.25%, a stretch blow bottle similar to that in Example 3 was prepared, and the above measurements and evaluations were performed.

[Example 6]
Except for the silica concentration of 0.5%, a stretch blow bottle similar to that of Example 3 was prepared and subjected to the above measurements and evaluations.

[Example 7]
A stretch blow bottle similar to that in Example 3 was prepared except that ethylene terephthalate-based polyester resin was [Homo PET] (RT543CTHP: Nippon Unipet Co., Ltd.) and the silica concentration was 0.1%. Each evaluation was performed.

[Example 8]
Except for the silica concentration being 0.25%, a stretch blow bottle similar to Example 7 was prepared, and the above measurements and evaluations were made.

[Example 9]
Except for the silica concentration of 0.5%, a stretch blow bottle similar to that in Example 7 was prepared and subjected to the above measurements and evaluations.

[Comparative Example 1]
A stretch blow bottle similar to that of Example 1 was prepared except that the silica particles were dry hydrophilic silica E shown in Table 1, and the above measurements and evaluations were performed.

[Comparative Example 2]
A stretch blow bottle similar to Comparative Example 1 was prepared, except that the filling time at the injection molding of the preform was 0.6 seconds, and the above measurements and evaluations were performed.

[Comparative Example 3]
A stretch blow bottle similar to Comparative Example 1 was prepared except that the silica particles were dry hydrophilic silica F shown in Table 1, and the above measurements and evaluations were performed.

[Comparative Example 4]
A stretch blow bottle was prepared in the same manner as in Comparative Example 1 except that the dry hydrophilic silica G shown in Table 1 was used as the silica particles, and the above measurements and evaluations were performed.

[Comparative Example 5]
A stretch blow bottle was prepared in the same manner as in Comparative Example 1 except that the silica particles were changed to wet hydrophilic silica H shown in Table 1, and the above measurements and evaluations were performed.

[Comparative Example 6]
A stretch blow bottle was prepared in the same manner as in Comparative Example 1 except that the silica particles were changed to wet hydrophobic silica D shown in Table 1, and the above measurements and evaluations were performed.

[Comparative Example 7]
A stretch blow bottle was prepared in the same manner as in Comparative Example 1 except that the inorganic dispersion was Mica I shown in Table 1, and the above measurements and evaluations were performed.

[Comparative Example 8]
A stretch blow bottle similar to that of Example 4 was prepared, except that the filling time during injection molding of the preform was 0.6 seconds, and the above measurements and evaluations were performed.

[Comparative Example 9]
A stretch blow bottle similar to Comparative Example 8 was prepared except that the silica concentration was 0.25%, and the above measurements and evaluations were made.

[Comparative Example 10]
A stretch blow bottle similar to that of Example 1 was prepared except that the inorganic dispersion was not contained and the stretch temperature was 100 ° C., and the above measurements and evaluations were performed.

Claims (3)

A stretch blow molded container formed from a resin composition comprising an ethylene terephthalate-based polyester resin and dry hydrophobic silica particles whose surface is covered with a hydrophobic organic functional group, which has the following formula δT (° C) = TC1 (2nd) -TC1 (1st)
In the formula, TC1 (1st) is the crystallization exothermic peak temperature of the unstretched portion of the container by a differential scanning calorimeter (DSC), and TC1 (2nd) is a differential scanning calorimeter (after melting and quenching the unstretched portion of the container) DSC) represents the crystallization exothermic peak temperature, respectively.
Range δT Ri larger and 14 der less value than 0 (° C.), the dry hydrophobic silica particles, average primary particle size of the specific surface area by the 7~20μm and the BET method of 100-150 ² / g expressed by in there, stretch blow molded container, characterized that you have been contained in an amount of 0.25 to 1.0 wt% in the resin composition. The dry hydrophobic silica particles, stretch blow molded container of claim 1 Symbol placement hydrophobic organic functional groups of the silica particle surface is trimethylsilyl group. The stretch blow molded container according to claim 1 or 2, wherein the shrinkage ratio at 200 ° C by thermomechanical analysis (TMA) measurement of the container body is 10% or less.