KR101699869B1 - Preparation method of food container - Google Patents

Abstract

The present invention relates to a process for producing a polyolefin resin having a specific surface area of 160 m 2 / g or more by polymerizing an ethylene monomer alone or copolymerizing an ethylene monomer with an? -Olefin in the presence of a Ziegler-Natta catalyst having a porosity of 40% ; And molding the polyolefin resin.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing a food container,

More particularly, the present invention relates to a method of manufacturing a food container capable of minimizing a portion affecting the odor or flavor of foods, bottled water and beverages with a low volatile compound value and excellent sensory stability .

The recent trend of bottled water and beverages market is very sensitive to odor and taste. Accordingly, the inherent sensory evaluation of the resin has become important as an index of the possibility of polyethylene terephthalate, which is mainly used as a container, and polyethylene or polypropylene resin, which is mainly used as a bottle cap, .

Korean Patent Publication No. 2013-0029408 Korean Patent No. 0798744 U.S. Patent Publication No. 2014-0014656 Korean Patent No. 0362208 Korean Patent Publication No. 2014-0060871 Korean Patent Publication No. 2004-0089204 Korean Patent Publication No. 2001-0046400

The present invention is to provide a method of manufacturing a food container which has a low volatile compound value and is excellent in sensory stability and can minimize a portion affecting odor or flavor of food, bottled water and beverage.

In the present specification, the ethylene monomer is polymerized singly or in the presence of a Ziegler-Natta catalyst having a porosity of 40% or more or a copolymer of an ethylene monomer and an? -Olefin to prepare a polyolefin resin having a specific surface area of 160 m 2 / g or more step; And molding the polyolefin resin. A method of manufacturing a food container, comprising the steps of:

Hereinafter, a method of manufacturing a food container according to a specific embodiment of the present invention will be described in detail.

As described above, the method of manufacturing a food container according to an embodiment of the present invention comprises polymerizing an ethylene monomer alone or copolymerizing an ethylene monomer with an alpha -olefin in the presence of a Ziegler-Natta catalyst having a porosity of 40% / g; < / RTI > And molding the polyolefin resin.

The present inventors have found that a polyethylene resin produced using a Ziegler-Natta catalyst having a porosity of 40% or more, or 45% to 70% has a predetermined void in the interior thereof, and a process of manufacturing a food container using such a polyethylene resin The volatile compounds that generate odor and deteriorate the sensibility are easily removed, and the final product, the food container, has low volatile compound values and the excellent sensory stability can minimize the influence on the odor or taste of food, bottled water and beverage And the invention was completed through experiments.

Specifically, when the ethylene monomer is polymerized singly by using the Ziegler-Natta catalyst having the above porosity or when the ethylene monomer is copolymerized with the alpha -olefin, a ratio of 160 m 2 / g or more, or 190 m 2 / g to 300 m 2 / g Each of the polyolefin resin powders may have a surface area, and each of the polyolefin resin powders may be a three-dimensional phase containing fine pores, and thus may have the above-mentioned specific surface area. Since the polyolefin resin powder having the specific surface area has a specific three-dimensional shape, it is possible to easily remove volatile compounds that generate odor or deteriorate the functionality in the subsequent molding step or selectively applied drying and degassing processes have.

 When a Ziegler-Natta catalyst having a porosity of less than 40% or substantially no voids is used, a polyolefin resin having a low specific surface area or in which the above-described fine pores are not sufficiently distributed can be produced, The molded article or the food container provided from the resin may have a relatively high volatile compound content and may generate bad odor or deteriorate the functionality.

The porosity can be defined as the ratio of volume occupied by pores or voids in the total volume of the Ziegler-Natta catalyst, and can be measured using a BET meter.

The food container may be a food or beverage container or a stopper of a food and beverage container.

Specifically, the food container may include a polyolefin resin having a melt index of 0.8 to 15 g / 10 min measured at 190 占 폚 under a load of 2.16 kgf / cm2 according to ASTM D 1238, and the content of volatile compounds is 0.075 wt% % ≪ / RTI > When the melt index is less than 0.8 g / 10 min, it is not preferable for molding due to low flowability and high extrusion load, and when it exceeds 15 g / 10 min, physical properties such as environmental stress resistance are lowered.

In addition, the polyolefin resin may have an average density of 0.945 to 0.970 g / cm < 3 > according to ASTM D 1505. When the average density is less than 0.945, there may be a problem of low rigidity property and a cutting problem when forming the container stopper, and when the average density is more than 0.970, the impact property is significantly deteriorated.

In the step of molding the polyolefin resin, a known molding method can be used. However, injection and compression processes can be applied to manufacture a food or beverage container cap more easily. Specifically, the step of molding the polyolefin resin may include a step of performing the injection molding and compression processing of the polyolefin resin with a stopper of a food or beverage container or a food and beverage container.

When the process of drying and degassing the polyolefin resin in a process of forming the polyolefin resin to form a food container is further applied, the content of the volatile compound remaining in the polyolefin can be further reduced. Specifically, the step of molding the polyolefin resin comprises a step of drying and degassing the polyolefin resin having a specific surface area of 160 m 2 / g or more with a gas containing a water content of 1 ppmw or less and having a temperature of 50 ° C to 105 ° C As shown in FIG.

It is preferable that the gas used is a general air or nitrogen gas which controls moisture through a filter and contains moisture of 1 ppmw or less. The temperature of the drying and degassing ranges from 30 ° C or higher to a range that does not affect the physical properties of the polyethylene resin And preferably 50 ° C to 105 ° C to a temperature condition lower than the melting point of the polyethylene resin by 20 ° C. The flow rate of the gas is preferably as high as possible, and the time may last for 3 to 24 hours.

Meanwhile, the method of manufacturing a food container according to one embodiment may further include adding an amide-based lubricant when the ethylene monomer is polymerized singly or when the ethylene monomer is copolymerized with an alpha -olefin.

Specifically, the polyethylene resin powder is prepared by kneading 0 to 0.3 parts by weight of an amide-based lubricant such as an erucamide or behenamide compound for an appropriate torque for 100 parts by weight of a polyethylene resin using an extruder, 0.01 to 0.2 And 0.01 to 0.2 parts by weight of an antioxidant are uniformly dispersed and then melt extruded at a temperature of 150 to 220 캜 to prepare a pellet which is then stored in a silo and then degassed and dried to discharge a gas and discharge a volatile substance The process can be selectively performed to form a food container.

On the other hand, in the case of the homopolymerization of the ethylene monomer or the copolymerization between the ethylene monomer and the? -Olefin, the reaction conditions applied to the synthesis of the polyolefin may be used without limitation. For example, the homopolymerization of the ethylene monomer or the copolymerization between the ethylene monomer and the alpha -olefin can be carried out at a temperature of 60 DEG C to 90 DEG C and a pressure of 10 psi to 150 psi.

In the step of preparing the polyolefin resin, a Ziegler-Natta catalyst which is known to be usable for the synthesis of a polyolefin resin can be used without limitation, but the Ziegler-Natta catalyst can be a magnesium compound; An alkyl aluminum compound of formula (1); Transition metal compounds; It is preferable to include an internal electron donor including at least one compound selected from the group consisting of a compound represented by the following formula (2) and a compound represented by the following formula (3).

[Chemical Formula 1]

R ¹ AlX _{3 -l}

In Formula 1, R ¹ is a straight or branched alkyl group having 1 to 10 carbon atoms, 1 is an integer of 1 to 3, and X is halogen.

(2)

(3)

R ² , R ³ and R ⁴ may be the same or different and are each a hydrogen, a straight chain, branched or cyclic alkyl group (Alkyl) having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms An alkenyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, An alkylaryl group of 7 to 20 carbon atoms, or an alkyl group containing a hetero atom of 2 to 20 carbon atoms.

The magnesium compound may include at least one member selected from the group consisting of magnesium halide, alkoxy magnesium, alkyl magnesium halide, alkoxy halide magnesium, and allyloxy halide magnesium.

Specific examples of the magnesium compound include magnesium halides such as magnesium chloride, magnesium dichloride, magnesium bromide, magnesium fluoride, and magnesium iodide; Magnesium alkoxy halides such as magnesium methoxide chloride, magnesium ethoxy chloride, magnesium isopropoxy chloride, magnesium chloride butoxide, or magnesium octoxy chloride; Allyloxyhalogenated magnesium such as phenoxy magnesium chloride; And alkoxy magnesium such as ethoxy magnesium, isopropoxy magnesium, or butoxy magnesium; Etc., and it is preferable to use magnesium halide because it increases the activity of the catalyst. Among them, magnesium dichloride is preferably used because it exhibits stable and high activity in terms of structure and coordination with the transition metal compound, which is the main active metal.

The transition metal compound may include a transition metal compound represented by the following formula (4). The transition metal compound means a transition metal of Group IVB, VB, or VIB or an organic compound containing such a transition metal. Specific examples of the transition metal include Ti, Zr, Hf, Rf, V, Nb, Ta , Db, Cr, Mo, W, and Sg.

[Chemical Formula 4]

MX _n (OR ⁵ ) _4-n

In the formula (4), M is selected from the group consisting of transition metal elements of Group IVB, VB and VIB of the periodic table, X is halogen, R ⁵ is an alkyl group having 1 to 10 carbon atoms, and n is 0 to 4 as an oxidation number of metal.

The Ziegler-Natta catalyst may be prepared by reacting a magnesium compound with an alcohol to prepare a magnesium compound solution; And an inner electron donor including the alkyl magnesium compound, the transition metal compound, and the compound represented by Chemical Formulas 2 to 3, wherein the magnesium compound solution includes the compound represented by Chemical Formula 1.

In the production of the polyolefin synthesis catalyst, a magnesium compound solution can be prepared by reacting a magnesium compound with an alcohol.

The alcohol can be used without limitation as long as it is an alcohol known to be used in the production of a Ziegler-Natta catalyst for synthesizing polyolefins. Specific examples of the solvent include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, neopentanol, cyclopentanol, n- Aliphatic or alicyclic alcohols such as dodecanol, 2-methylpentanol, 2-ethylbutanol and 2-ethylhexanol; Aryl cyclic alcohols such as cyclohexanol and methylcyclohexanol; Or aromatic alcohols such as benzyl alcohol, methylbenzyl alcohol, isopropylbenzyl alcohol and? -Methylbenzyl alcohol; Among them, it is preferable to use an aliphatic or alicyclic alcohol. Since the alcohol having a cyclic or benzene ring has a large molecular size, the reactivity is poor and the reaction proceeds slowly, so ethanol having a relatively short chain length is used .

The alcohol may react with the magnesium compound to dissolve the magnesium compound, The compound swells to expand the surface area. Further, by adding the above alcohol, The compound can be swollen and there is no need to prepare a homogeneous solution at a high temperature. The solution is sufficiently stirred at a temperature of 0 to 40 ° C for about 30 minutes to 2 hours, and a magnesium compound is reacted with an alcohol to prepare a highly active catalyst .

The reaction molar ratio of the magnesium compound and the alcohol may be 1: 0.5 to 1:10, preferably 1: 2 to 1: 8. When the reaction molar ratio of the alcohol is more than 10 moles relative to the magnesium compound, the amount of the transition metal compound to be reacted with the magnesium compound must be increased in order to exhibit high activity, which is not preferable from the economical point of view. The yield may be small, which is undesirable.

The magnesium solution may be prepared by reacting the magnesium compound with an alcohol in the presence of a hydrocarbon solvent. When the reaction is carried out in the presence of a hydrocarbon solvent as described above, a homogeneous solution of a magnesium compound and an alcohol can be obtained while using a small amount of alcohol.

Specific examples of the hydrocarbon solvent include aliphatic or alicyclic hydrocarbons having 5 to 20 carbon atoms, and aliphatic or alicyclic hydrocarbon solvents having 8 to 17 carbon atoms are most preferred. More specific examples include aliphatic hydrocarbons such as hexane, heptane, octane, decane, dodecane, tetradecane, and mineral oil; Alicyclic hydrocarbons such as cyclic hexane, cyclic octane, methyl cyclic pentane and methyl cyclic hexane; And aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene.

The hydrocarbon solvent is preferably reacted at a rate of 5 to 20 mol per 1 mol of the magnesium compound. If the amount of the hydrocarbon solvent is less than the above range, it is difficult to obtain a homogeneous solution of the magnesium halide compound at a low temperature. If the amount is larger than the above range, the reactor capacity may increase in the process and the temperature may be difficult to control.

In the step of reacting the magnesium compound solution with the internal electron donor comprising the alkyl aluminum, the transition metal compound and the compound represented by the above formulas 2 to 3 containing the compound represented by the formula 1, The sequence or order of insertion is not limited. For example, the magnesium compound solution, the alkyl aluminum, the transition metal compound, and the internal electron donor may be reacted simultaneously, or the components may be sequentially added to react.

However, in order to increase the activity of the catalyst, an inner electron donor including the magnesium compound solution, the alkylaluminum including the compound represented by the formula (1), the transition metal compound, and the compound represented by the formula (2) Reacting the magnesium compound solution with an alkylaluminum compound including the compound represented by Formula 1, and reacting the magnesium compound solution and the reaction product of the alkylaluminum with a transition metal compound represented by Formula 2 to Formula 3 With an internal electron donor comprising a compound of formula < RTI ID = 0.0 > (I) < / RTI >

More specifically, alcohol and magnesia In the reaction of the compound, it is possible to generate a large amount of active sites by allowing alcohol to sparse and expand the magnesium compound to secure a space in which a large number of active sites can be generated, and then reacting with the alkyl aluminum to remove the alcohol attached to the magnesium compound have. That is, the alkylaluminum compound is reacted with the magnesium compound solution to increase the activity of the finally prepared polyolefin polymerization catalyst. When the polyolefin is polymerized using such a catalyst, a polyolefin having a broad molecular weight distribution can be obtained.

The alkyl aluminum may include at least one compound represented by the formula (1), and specific examples of the compound represented by the formula (1) include triethyl aluminum, trimethyl aluminum, triisopropyl aluminum, trioctyl aluminum, diethyl aluminum chloride , Diethylaluminum bromide, diethylaluminum iodide, diethylaluminum fluoride, ethylaluminum dichloride, dimethylaluminum chloride, methylaluminum dichloride, and the like.

The magnesium compound and the alkylaluminum can be reacted at a molar ratio of 1: 0.01 to 1: 5, preferably at a molar ratio of 1: 0.5 to 1:10. When the amount of the alkyl aluminum compound used is less than 0.01 mol per 1 mol of the magnesium compound, the molecular weight distribution of the produced polyolefin may not increase, and when it exceeds 50 mol, the catalytic activity may drop sharply.

The reaction temperature of the magnesium compound solution and the alkylaluminum compound is preferably -50 to 150 ° C, more preferably 0 to 100 ° C. If the temperature is out of the above range, the reactants do not sufficiently react to deteriorate the activity or the side reaction increases, which is not preferable. In addition, the reaction time is preferably sufficiently performed for 0.5 to 24 hours from the start of the reaction.

Then, a solution obtained by reacting the magnesium compound solution with alkyl aluminum may be sequentially reacted with a transition metal compound and an internal electron donor including the compounds represented by the above formulas 2 to 3, thereby preparing a polyolefin synthesis catalyst.

The magnesium compound and the transition metal compound may be reacted at a molar ratio of 1: 0.1 to 1:50, preferably at a molar ratio of 1: 1 to 1:10. When the amount of the transition metal compound to be used is less than 0.1 mole per 1 mole of the magnesium compound, the activity of the catalyst to be produced deteriorates or the stereoregularity of the synthesized polyolefin may be lowered, which is not preferable.

The temperature at which the transition metal compound is added to the solution obtained by reacting the magnesium compound solution with the alkylaluminum may be -50 ° C to 150 ° C, preferably -20 ° C to 100 ° C. The reaction process can be carried out by stirring the magnesium compound solution and the reaction product of the alkylaluminum in the reactor and adding a certain amount of the transition metal compound to the reaction product for about 2 hours. The slow administration of the transition metal compound is preferable because the transition metal compound can prevent the side reaction that may occur due to rapid reaction with other compounds.

Then, the reaction can be carried out by administering a transition metal compound, raising the temperature of the reaction product, and administering an internal electron donor.

The internal electron donor serves to form an active site of the catalyst by donating electrons to the transition metal compound within the polymerization catalyst for polyolefin synthesis, thereby increasing the catalytic activity and synthesizing a polyolefin having improved stereoregularity . Specifically, the ethylbenzoate or diisobutylphthalate has one or two acyl groups in the benzene ring, and has a structure in which the above-mentioned specific functional groups of R ² to R ⁴ are bonded at specific positions. That is, this chemical structure can strongly bind to the catalytic active site and can act as a nucleating agent for increasing the degree of crystallization. Accordingly, the internal electron donor including the compounds represented by Chemical Formulas 2 to 3 can more effectively increase the activity of the catalyst, and can reduce the amount of the internal electron donor through the role of the nucleating agent.

The internal electron donor may be reacted with 0.1 to 5 moles, preferably 0.1 to 1 mole, per mole of the magnesium compound. When the internal electron donor is reacted outside the above range, the uniformity of the active sites of the polyolefin synthesis catalyst finally obtained may be lowered, which is not preferable.

The process in which the product obtained by reacting the internal electron donor is washed with a hydrocarbon solvent and only the catalyst particles are precipitated and then the supernatant is removed are repeated several times and the catalyst particles having the transition metal compound removed therefrom under nitrogen And then the catalyst for polymerization of the final polyolefin can be prepared.

On the other hand, in order to secure a high environmental stress cracking property and a high melt tension while having excellent mechanical properties such as excellent bending strength and impact strength and the like, and to improve resin moldability or resin processability, The halogenated compound may include particles having various sizes, or may have a broad particle size distribution.

Specifically, the Ziegler-Natta catalyst comprises 2 wt% to 40 wt% of particles having a maximum diameter of more than 500 탆; 10 wt% to 35 wt% of particles having a maximum diameter of less than 120 탆; And particles having a maximum diameter of 120 [mu] m to 500 [mu] m of the remaining amount. Further, the halogenated compound of the transition metal bonded on the carrier may contain 2 to 40 wt% of particles having a maximum diameter of 500 탆 to 1000 탆 and 10 wt% to 35 wt% of particles having a maximum diameter of 50 탆 to less than 120 탆; And particles having a maximum diameter of 120 [mu] m to 500 [mu] m of the remaining amount.

Examples of the? -Olefin which can be used in the step of preparing the polyolefin resin include 1-butene, 1-pentene, 1-hexene, 4-methyl, 1-pentene, And the like.

According to the present invention, there is provided a method of manufacturing a food container capable of minimizing a portion affecting odor or taste of foods, bottled water and beverages with a low volatile compound value and excellent sensory stability, and a food container provided from such a manufacturing method .

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Manufacturing example : Ziegler - Appear  Preparation of Catalyst]

Production Example 1

A 300 ml pressure-resistant glass reactor equipped with a stirrer and an oil circulating heater was sufficiently evacuated with nitrogen and 110 ml of hexane was charged into the reactor under a nitrogen atmosphere. 5.71 g of anhydrous magnesium dichloride was added to the reactor and stirred at room temperature. 17.8 ml of ethanol was slowly added thereto over 1 hour and stirred at 300 rpm for 1 hour or more to sufficiently react the anhydrous magnesium dichloride and ethanol.

16 ml of diethylaluminum chloride and 16 ml of hexane were mixed and the alkylaluminum compound diluted to 50% was slowly added to the mixture of magnesium anhydrous magnesium dichloride and ethanol at 25 ° C at a rotation speed of 400 rpm for 4 hours Respectively. After completion of the addition, the stirring speed was increased to 500 rpm and reacted for 2 hours.

Then, 20 ml of titanium tetrachloride was gradually added to the thus prepared heterogeneous mixed solution at 25 占 폚, held for 30 minutes, and then slowly heated. At 73 ° C, 0.26 ml of ethyl benzoate was injected as an internal electron donor and reacted for 3 hours. When the reaction was completed, the temperature was lowered to 50 ° C, stirring was stopped, the catalyst was precipitated, the supernatant was removed, 200 ml of hexane was added, and the mixture was thoroughly rinsed. This process was repeated 6 times or more to prepare a catalyst for synthesizing polyethylene.

Production Example 2

1) except that 21 ml of ethanol was used instead of 17.8 ml of ethanol and 2) 16 ml of diethylaluminum chloride was mixed with 16 ml of hexane, and 20 ml of diethylaluminum chloride was mixed with 20 ml of hexane. A catalyst for synthesizing polyethylene was prepared in the same manner.

Production Example 3

1) except that 28 ml of ethanol was used instead of 17.8 ml of ethanol and 2) 16 ml of diethylaluminum chloride was mixed with 20 ml of hexylic acid instead of 20 ml of diethylaluminum chloride instead of 16 ml of hexane. A catalyst for synthesizing polyethylene was prepared in the same manner.

[ Example  1 to 2 and Comparative Example 1 : Polyolefin  Preparation of resin]

Comparative Example 1

In the presence of the Ziegler-Natta catalyst and hydrogen prepared in Preparation Example 1, the ethylene monomer was polymerized at a temperature of 80 ° C and a pressure of 70 psi for about 2 hours to prepare a polyethylene resin. At this time, the Ziegler-Natta catalyst contained anhydrous magnesium dichloride, ethanol, diethylaluminum chloride and titanium tetrachloride in a molar ratio of 1: 5.1: 2.1: 3.

Example 1

In the presence of the Ziegler-Natta catalyst and hydrogen prepared in Preparation Example 2, the ethylene monomer was polymerized at a temperature of 80 ° C and a pressure of 70 psi for about 2 hours to prepare a polyethylene resin. At this time, the Ziegler-Natta catalyst contained anhydrous magnesium dichloride, ethanol, diethylaluminum chloride and titanium tetrachloride in a molar ratio of 1: 6: 2.6: 3.

Example 2

In the presence of the Ziegler-Natta catalyst and hydrogen prepared in Preparation Example 2, the ethylene monomer was polymerized at a temperature of 80 ° C and a pressure of 70 psi for about 2 hours to prepare a polyethylene resin. At this time, the Ziegler-Natta catalyst contained anhydrous magnesium dichloride, ethanol, diethylaluminum chloride and titanium tetrachloride in a molar ratio of 1: 8: 2.6: 3.

The specific surface area of the polyethylene resin powder prepared in Comparative Example 1 and Examples 1 and 2 was calculated by the BET equation by measuring the amount of adsorbed nitrogen gas by adsorbing nitrogen in the powder.

[Manufacturing of food and beverage container stopper]

Using the polyethylene resin prepared in Comparative Example 1 and Examples 1 and 2, a container cap was manufactured under the conditions of injection molding at 230 캜 using an injection molding machine having 48 cavities of 30 mm size.

The content of the volatile compounds contained in the above-mentioned container stopper was determined by measuring the resin weight loss ratio when heat was applied at 105 DEG C for 1 hour.

Example 1 Example 2 Comparative Example 1 Catalyst porosity 0.49 0.65 0.35 Polyethylene powder Specific surface area (m 2 / g) 200 270 150 In the container cap
Volatile compounds (wt%) 0.073 0.049 0.080

As shown in Table 1, the polyethylene resin prepared using the Ziegler-Natta catalyst having a porosity of 49% and 65% had a specific surface area of 200 and 270 m 2 / g, respectively. It has been found that the container closure contains less than 0.080 wt% volatile compounds.

[ Example  3 to 6: Polyolefin  Preparation of resin]

A polyethylene resin was prepared in the same manner as in Example 1.

The specific surface area of the prepared polyethylene resin powder was calculated by BET equation by measuring the amount of nitrogen gas adsorbed by adsorbing nitrogen in the powder, and the volatile compound content was calculated by subtracting the weight of the resin when heat was applied at 105 DEG C for 1 hour The ratio was measured.

The melt flow index of the polyethylene resin powder thus prepared was measured under a load of 2.16 kgf / cm 3 at 190 캜 according to ASTM D 1238, and the density was measured according to ASTM D 1505.

The GC / MS was subjected to qualitative and quantitative analysis by collecting volatile components by headspace method at 200 ° C for 20 minutes, then heating the mixture to three stages, and qualitatively and quantitatively analyzing it. [Step 1: : The temperature was raised to 250 ° C at a rate of 10 ° C / minute and maintained for 5 minutes, the third stage: the temperature was raised to 320 ° C at a rate of 10 ° C / minute and then maintained for 5 minutes]

division
(Pellets) Example
3 Example
4 Example
5 Example
6 Dry (80 ° C) 3hr 6hr 12hr 24hr Suzy
Properties Melt Index (g / 10 min) 4.0 4.0 4.0 4.0 density
(g / cm3) 0.954 0.954 0.954 0.954 Volatile compounds (wt%) 0.070 0.047 0.030 0.025 GC / MS ratio 0.83 0.66 0.36 0.21

As shown in the above Table 2, it was confirmed that the content of residual volatile compounds and the content of hydrocarbons gradually decreased as the polyethylene produced in Example 1 was dried while being exposed to nitrogen gas at 80 ° C. In addition, the polyolefin resin to be produced has a melt index of 4.0 g / 10 min under the conditions of 190 ° C and 2.16 kgf / cm 3, and has excellent moldability.

Claims (13)

In the presence of a Ziegler-Natta catalyst having a porosity of 45% to 70%, the ethylene monomer is polymerized singly or the ethylene monomer is copolymerized with an -olefin to obtain a polyolefin having a specific surface area of 190 m 2 / g to 300 m 2 / g Producing a resin; And
And molding the polyolefin resin by injection-molding the polyolefin resin into a food or beverage container or a stopper of a food and beverage container,
The Ziegler-Natta catalyst may be a magnesium compound; An alkyl aluminum compound of formula (1); Transition metal compounds; An internal electron donor comprising at least one compound selected from the group consisting of a compound represented by the following formula (2) and a compound represented by the following formula (3)
The Ziegler-Natta catalyst may be prepared by reacting a magnesium compound with an alcohol to prepare a magnesium compound solution; And an inner electron donor including the alkyl magnesium compound, the transition metal compound, and the compound represented by Chemical Formula 2 to 3, wherein the magnesium compound solution includes the compound represented by Chemical Formula 1,
The reaction mole ratio of the magnesium compound to the alcohol in the step of reacting the magnesium compound with the alcohol in the step of preparing the magnesium compound solution is 1: 6 to 8,
Wherein the content of the volatile compound is 0.075% by weight or less:
[Chemical Formula 1]
R ¹ AlX _3-l
Wherein R ¹ is a straight or branched alkyl group having 1 to 10 carbon atoms, 1 is an integer of 1 to 3, X is halogen,
(2)

(3)

In Formulas 2 and 3 above,
R ² , R ³ and R ⁴ may be the same or different and each represents hydrogen, a straight chain, branched or cyclic alkyl group (Alkyl) having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms (Alkenyl) A cycloalkyl group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms (Alkylaryl) group, or an alkyl group containing a hetero atom having 2 to 20 carbon atoms.
The method according to claim 1,
Wherein the food container is a food or beverage container or a food and beverage container.
The method according to claim 1,
Said food container comprising a polyolefin resin having a melt index of 0.8 to 15 g / 10 min measured at 190 占 폚 under a load of 2.16 kgf / cm2 according to ASTM D 1238,
A method of manufacturing a food container.
delete delete delete The method according to claim 1,
The step of molding the polyolefin resin further comprises a step of drying and degassing the polyolefin resin having a specific surface area of at least 160 m < 2 > / g using a gas containing not more than 1 ppmw of water and having a temperature of from 50 DEG C to 105 DEG C Wherein the method comprises the steps of:
The method according to claim 1,
The homopolymerization of the ethylene monomer or the copolymerization between the ethylene monomer and the? -Olefin is carried out at a temperature of 60 ° C to 90 ° C and a pressure of 10 psi to 150 psi.
A method of manufacturing a food container.
delete The method according to claim 1,
Wherein the magnesium compound comprises at least one member selected from the group consisting of magnesium halide, alkoxy magnesium, alkyl magnesium halide, magnesium alkoxy magnesium halide and magnesium allyloxy halide.
The method according to claim 1,
Wherein the transition metal compound comprises a transition metal compound represented by the following formula (4): < EMI ID =
[Chemical Formula 4]
MX _n (OR ⁵ ) _4-n
In the formula (4), M is selected from the group consisting of transition metal elements of Group IVB, VB and VIB of the periodic table, X is halogen, R ⁵ is an alkyl group having 1 to 10 carbon atoms, and n is 0 to 4 as an oxidation number of metal.
The method according to claim 1,
Wherein the? -Olefin comprises at least one monomer selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 4-methyl, 1-pentene, 1-heptene and 1-octene .
The method according to claim 1,
Further comprising the step of adding an amide-based lubricant when the ethylene monomer alone is polymerized or when the ethylene monomer is copolymerized with? -Olefins.