JP2002363298A - Blow molded container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow-molded container excellent in rigidity and impact characteristics and not affecting odor, taste and the like to a dairy product when used as a dairy product container, and a polypropylene resin composition of the raw material thereof Offering things. SOLUTION: The polypropylene resin composition containing (a) a phenolic antioxidant and / or a hindered amine stabilizer and (b) a neutralizing agent is blow-molded,
(1) 300 ppm of volatile hydrocarbons having 6 to 10 carbon atoms
Hereinafter, (2) the oligomer component having 12 to 30 carbon atoms contains 60
A blow-molded container for dairy products, wherein the content is 0 ppm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-molded container for dairy products and a polypropylene resin composition for a blow-formed container for dairy products, and more particularly to a blow-molded dairy product having a low content of volatile hydrocarbons and oligomers. The present invention relates to a molded container and a polypropylene-based resin composition for a blow molded container for dairy products as a raw material thereof.

[0002]

2. Description of the Related Art The material of dairy containers such as milk drinks and yogurt has been standardized in accordance with Ordinance No. 52 of the Ministry of Health and Welfare (Showa 26, Standard for rigid resin packaging containers such as milk, raw materials). Currently approved raw materials are polyethylene,
It is limited to ethylene and 1-alkene copolymer. However, high-density polyethylene, which has poor transparency and whose contents cannot be confirmed, such as a dairy product container, has a factor disliked by consumers from the viewpoint of hygiene and safety. Further, in the case of low-density polyethylene and linear low-density polyethylene, which is a copolymer of ethylene and 1-alkene, the buckling strength of the bottle is relatively high compared to high-density polyethylene, but the rigidity of the material is low. And it is difficult to reduce the thickness. Further, in the case of dairy containers, high-temperature filling is necessary to sterilize the contents and increase the fluidity at the time of filling. However, the above polyethylene has a lower melting point than polypropylene, so that there is a problem that heat shrinks at the time of high-temperature filling. was there.

On the other hand, if a polypropylene resin is used,
A container having excellent rigidity, heat resistance and impact characteristics can be obtained. Polypropylene is higher in heat resistance than polyethylene, enables high-temperature filling of dairy products, improves sterilization, and is sanitary. Further, the production efficiency of the factory can be improved. Furthermore, it has excellent stretch blow moldability,
The thickness of the molded container can be reduced, which is convenient and economical. However, there is a problem that the polypropylene resin affects dairy products, and odor, taste and the like are easily changed.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to use a polypropylene resin,
It is an object of the present invention to provide a blow-molded container which is excellent in heat resistance and impact characteristics and does not affect odor, taste, etc. to a dairy product when used as a dairy product container, and a polypropylene resin composition as a raw material thereof.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, have found that a polypropylene resin composition containing an antioxidant and / or a hindered amine stabilizer and a neutralizing agent has been added. By making the contained volatile hydrocarbons and oligomer components less than a specified amount, a blow molded container for dairy beverages is obtained which has very little effect on odor and taste to milk products, and has excellent rigidity and impact characteristics. And found that the present invention has been completed.

That is, according to the first aspect of the present invention,
The polypropylene resin composition containing (a) a phenolic antioxidant and / or a hindered amine stabilizer and (b) a neutralizing agent is blow-molded, and (1) having 6 to 6 carbon atoms.
A blow molded container for dairy products is provided, wherein 10 volatile hydrocarbons are 300 ppm or less, and (2) an oligomer component having 12 to 30 carbon atoms is 600 ppm or less.

Further, according to the second aspect of the present invention, the first aspect
The blow-molded container for dairy products is provided, wherein the polypropylene-based resin composition according to the invention further comprises (c) a phosphorus-based antioxidant.

According to the third aspect of the present invention, the first aspect is provided.
Or (b) the neutralizing agent in the invention according to 2 or 3, wherein the metal salt of a fatty acid is
A blow molded container for dairy products is provided, which is any one selected from hydrotalcite and metal hydroxide salts.

According to a fourth aspect of the present invention,
A polypropylene resin composition containing (a) a phenolic antioxidant and / or a hindered amine stabilizer, and (b) a neutralizing agent, wherein (1) 300 ppm of volatile hydrocarbons having 6 to 10 carbon atoms. Hereinafter, (2) carbon number 12 to 3
A polypropylene resin composition for blow-molded containers for dairy products, wherein the content of the oligomer component 0 is 600 ppm or less.

According to the fifth aspect of the present invention, the fourth aspect
The polypropylene-based resin composition for blow-molded containers for dairy products, characterized in that the polypropylene-based resin composition according to the invention of (1) further comprises (c) a phosphorus-based antioxidant.

Further, according to the sixth aspect of the present invention, the fourth aspect
Or (b) the neutralizing agent according to the invention of 5, wherein the fatty acid metal salt is
A polypropylene-based resin composition for blow-molded containers for dairy products, characterized in that it is any one selected from hydrotalcite and metal hydroxide salts.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The dairy blow-molded container of the present invention comprises (a) a phenolic antioxidant and / or a hindered amine stabilizer, (b) a neutralizing agent, and if necessary,
(C) Blow molding a polypropylene-based resin composition containing a phosphorus-based antioxidant, and (1) 6 to 10 carbon atoms
Less than 300 ppm, preferably 20 ppm
0 ppm or less, more preferably 100 ppm or less, further preferably 50 ppm or less, particularly preferably 30 pp
m, and the lower limit thereof is preferably about 0.1 ppm. (2) The oligomer component having 12 to 30 carbon atoms has a content of 600 ppm or less, preferably 300 ppm or less, more preferably 150 ppm or less, and still more preferably 60 ppm or less.
pm or less, and the lower limit is preferably 0.1 pp
m.

[0013] Blown container for dairy products contains 6 to 1 carbon atoms
If the volatile hydrocarbon of 0 exceeds 300 ppm, the dairy product is undesirably easily smelled when heat-sterilized in a container, filled at a high temperature, or stored. Further, when the oligomer having 12 to 30 carbon atoms exceeds 600 ppm in the blow-molded container for dairy products, when heat-sterilizing the dairy product in the container, or at the time of filling at a high temperature, or during storage, the taste may be unfavorably changed. .

The polypropylene resin composition of the present invention comprises:
(A) a phenolic antioxidant and / or a hindered amine stabilizer, (b) a neutralizing agent, and if necessary,
(C) A polypropylene-based resin composition containing a phosphorus-based antioxidant, wherein (1) volatile hydrocarbons having 6 to 10 carbon atoms are 300 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less, and still more preferably Is 50 ppm or less, particularly preferably 30 ppm or less, the lower limit thereof is preferably about 0.1 ppm,
(2) The oligomer component having 12 to 30 carbon atoms is 600 pp
m, preferably 300 ppm or less, more preferably 150 ppm or less, even more preferably 60 ppm or less,
The lower limit is preferably about 0.1 ppm of the polypropylene resin composition. If the polypropylene resin composition satisfies the above conditions, the amount of the volatile hydrocarbon having 6 to 10 carbon atoms and the carbon number of 12
A blow molded container for dairy products can be obtained without increasing the amount of the oligomer components of ３０30.

As a method for obtaining the polypropylene resin composition of the present invention, (a)
(B) If necessary, the additive of (c) is added, and a volatile hydrocarbon having 6 to 10 carbon atoms and 12 to 12 carbon atoms are obtained by post-treatment.
A method of reducing the oligomer content of 30 to a predetermined amount or less, a method of reducing the content of volatile hydrocarbons having 6 to 10 carbon atoms and oligomers having 12 to 30 carbon atoms in a polypropylene resin to a predetermined amount or less by post-treatment (a), ( b) optionally adding the additive (c), the polypropylene resin having 6 to 6 carbon atoms
(A) after polymerizing the volatile hydrocarbon of 10 and the oligomer having 12 to 30 carbon atoms such that the content thereof is not more than a predetermined amount.
(B) There is a method of adding the additive of (c) as needed. The present invention may use any method. Hereinafter, the components of the polypropylene resin composition used in the present invention and the container comprising the same will be described in detail.

[I] Polypropylene resin composition Additive Components The additive components added to the polypropylene resin composition of the present invention include (a) a phenolic antioxidant and / or a hindered amine stabilizer, (b) a neutralizing agent, and if necessary, ( c) It is a phosphorus antioxidant. When the polypropylene resin composition does not contain (a) a phenolic antioxidant and / or a hindered amine-based stabilizer, burns are likely to occur during molding of a dairy container, and problems are likely to occur.
Further, the odor may be transferred to dairy products, which is a problem. In addition, when a neutralizing agent is not contained, depending on the polymerization catalyst of propylene and the process, there is a concern that it may be affected by chlorine remaining as an impurity, and the neutralizing agent also functions as a dispersant to improve dispersibility of pigments and the like. Let it. Furthermore, the phosphorus-based antioxidant prevents deterioration of the resin composition at the time of molding processing, and is effective not only in suppressing burn and suppressing generation of odor, but also in suppressing discoloration. That is, dairy containers are often colored with a white pigment, but may change to yellow due to aging or the like. On the other hand, phosphorus-based antioxidants have an effect of suppressing discoloration and are useful.
(C) A lactone antioxidant or vitamin E can be substituted for the phosphorus antioxidant. Hereinafter, specific examples of the respective additives that can be used in the present invention and their preferable mixing ratios are shown.

(A-1) Phenolic antioxidant Specific examples of the phenolic antioxidant that can be used in the present invention include tris- (3,5-di-t-butyl-).
4-hydroxybenzyl) -isocyanurate, 1,
1,3-tris (2-methyl-4-hydroxy-5-t
-Butylphenyl) butane, octadecyl-3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 1,3,5-trimethyl-2,4,
6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- [3- (3-
t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,
4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid and the like can be mentioned. The amount of the phenolic antioxidant is 0.01 to 100 parts by weight of the propylene polymer.
To 0.5 part by weight, preferably 0.02 to 0.3 part by weight. If the amount is less than this, the heat aging resistance of the product is not sufficient. On the other hand, if the amount is excessive, it is not only uneconomical but also causes discoloration and bleeding, which is not preferable.

(A-2) Hindered amine light stabilizer Specific examples of the hindered amine light stabilizer that can be used in the present invention include dimethyl succinate and 1- (2
-Hydroxyethyl) -4-hydroxy-2,2,6
Polycondensate with 6-tetramethylpiperidine, poly [[6
-(1,1,3,3-tetramethylbutyl) imino-
1,3,5-triazine-2,4-diyl] [(2
2,6,6-tetramethyl-4-4piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t
Bis (1,2,2,6,6-pentamethyl-)-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid
4-piperidyl) ester, tetrakis (2,2,6)
6-tetramethyl-4-piperidyl) -1,2,3,4
-Butanetetracarboxylate, bis (2,2,6,
6-tetramethyl-4-piperidyl) sebagate, N,
Polycondensate of N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 1,2-dibromoethane, poly [(N, N'-bis (2,2,
6,6-tetramethyl-4-piperidyl) hexamethylenediamine)-(4-morpholino-1,3,5-triazine2,6-diyl)], 1,1 ′-(1,2-ethanediyl) -bis (3,3,5,5-tetramethylpiperazinone), tris (2,2,6,6-tetramethyl-4)
-Piperidyl) -dodecyl-1,2,3,4-butanetetracarboxylate, tris (1,2,2,6,6-
(Petanemethyl-4-piperidyl) -dodecyl-1,2,2
3,4-butanetetracarboxylate, bis (1,
2,2,6,6-pentanemethyl-4-piperidyl) sebagate and the like. These hindered amine antioxidants may be used alone or in combination of two or more. In particular, those having a molecular weight of 500 or more are preferred in terms of compatibility and excellent effect. The most suitable compound among these is a polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, poly [[6- (1 , 1,3
3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-4piperidyl) imino] hexamethylene [(2,2,6 6-tetramethyl-4-piperidyl)
Imino]], poly [(N, N'-bis (2,2,6,6
-Tetramethyl-4-piperidyl) hexamethylenediamine)-(4-morpholino-1,3,5-triazine2,6-diyl)]. The amount of the hindered amine component is 0.01 to 0.4 parts by weight, preferably 0.02 to 100 parts by weight per 100 parts by weight of the propylene polymer.
0.3 parts by weight. If the amount is less than this, the heat aging resistance of the product is not sufficient. On the other hand, if the amount is excessive, it is not only uneconomical but also causes discoloration and bleeding, which is not preferable.

(C) Phosphorus-based antioxidant In the present invention, the phosphorus-based antioxidant which can be used, if necessary, is selected from phosphorus-based antioxidants generally used as an oxidation stabilizer of a resin composition. They can be listed without any restrictions. Specifically, tris (mixed, mono and dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 4,4-butylidenebis (3-methyl-6-t-butyl) Phenyl-di-tridecyl) phosphate, 1,1,3-tris (2-methyl-4-di-tridecyl phosphite-5)
-T-butylphenyl) butane, bis (2,4-di-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-butylphenyl) -4
-4'-biphenylenephosphonite pentaerythritol-diphosphite, bis (2,6-di-butyl-4-methylphenyl) pentaerythritol-di-
Phosphite, 2,2'-ethylidenebis (4,6-
Di-tert-butylphenyl) fluorophosphite, methylenebis (4,6-di-tert-butylphenyl) -2-
Ethylhexyl-phosphite and the like. These may be used alone or in combination of two or more. Among these, tris (2,
4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-butylphenyl) -4-4'-biphenylenephosphonite pentaerythritol-di-
Phosphite, bis (2,6-di-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2′-ethylidenebis (4,6-di-t-butylphenyl) fluorophosphite and methylene bis A preferred example is a compound of (4,6-di-t-butylphenyl) -2-ethylhexyl-phosphite. The amount of the phosphorus antioxidant is 0.01 to 0.25 parts by weight, preferably 0.1 to 0.2 parts by weight, per 100 parts by weight of the propylene polymer.
02 to 0.2 parts by weight. If the amount is less than this, the heat aging resistance of the product is not sufficient. On the other hand, if the amount is excessive, it is not only uneconomical but also causes discoloration and bleeding, which is not preferable.

(B) Neutralizing Agent The neutralizing agent that can be used in the present invention is a fatty acid metal salt,
Examples thereof include hydrotalcite and metal hydroxide salts, which may be used alone or in combination of two or more. The amount of the neutralizing agent is 0.00.0 parts by weight per 100 parts by weight of the propylene polymer.
It is 1 to 0.2 part by weight, preferably 0.02 to 0.1 part by weight. If the amount is less than this, the effect of preventing corrosion of a mold, a molding machine or the like is not sufficient, while if it is excessive, it is not only uneconomical but also causes problems such as bleeding. Specific examples of the fatty acid metal salt, hydrotalcite and metal hydroxide salt are as follows.

(B-1) Fatty Acid Metal Salts Fatty acid metal salts that can be used in the present invention include calcium stearate, magnesium stearate, zinc stearate, aluminum stearate, lithium stearate, sodium stearate, and benzene. Calcium phosphate, magnesium behenate, zinc behenate, aluminum behenate, lithium behenate, similar metal salts of lauric acid, metal salts of montanic acid, metal salts of melicin acid, metal salts of cellotinic acid, lignocerin Acid metal salts, metal hydroxystearate salts and the like. Among these, metal soaps such as lithium stearate, magnesium stearate, zinc stearate, calcium stearate, aluminum stearate, magnesium behenate, zinc behenate, and calcium behenate are particularly preferred from the viewpoints of performance and easy availability. preferable. These metal salts must be prepared by a synthesis method in which a carboxylic acid compound is reacted with a metal hydroxide followed by washing, dehydration, and drying (reconstitution method), or a method of directly reacting without using water (direct method). Can be. In addition, instead of the fatty acid metal salt, calcium stearoyl lactate, sodium stearoyl lactate, magnesium stearoyl lactate,
Can also be used.

(B-2) Hydrotalcites Hydrotalcites that can be used in the present invention
Magnesium, calcium, zinc, aluminum
Containing water-based basic carbonates such as
And natural and synthetic products. As a natural product
Is Mg₆Al₂(OH)₁₆CO₃・ 4H₂O structure
One. In addition, as a synthetic product, Mg
_0.7Al_0.3(OH)₂(CO₃) 0.15.
54H₂O, Mg_4.5Al₂(OH)₁₃CO₃・
3.5H₂O, Mg_4.2Al₂(OH) ₁₂. 4CO
₃, Zn₆Al₂(OH)₁₆CO₃・ 4H₂O, Ca
₆Al₂(OH)₁₆CO₃・ 4H₂O, Mg₁₄Bi
₂(OH)_29.6・ 4.2H₂O and the like.

(B-3) Metal hydroxide salt Examples of the metal hydroxide salt that can be used in the present invention include magnesium hydroxide, aluminum hydroxide, and lithium aluminum composite hydroxide salt.

2. Polypropylene resin Examples of the polypropylene resin used in the present invention include a homopolymer of propylene and a copolymer of propylene and an α-olefin. Examples of the α-olefin include ethylene, butene-1, pentene-1, and hexene. -1,4-methyl-pentene-1, octene-1 and the like. Among these, a propylene homopolymer, a propylene-ethylene random copolymer, and a propylene-ethylene block copolymer are preferred.

The polypropylene resin used in the present invention is:
Although used in the blow molding method described below, the blow molding method includes
There are a direct blow molding method, an injection blow molding method, a hot stretch blow method, and a cold stretch blow method, and there is a preferable MFR in each of the mold methods.

In the direct blow method, the MFR of the polypropylene resin is preferably from 0.1 to 10 g / 10 minutes, more preferably from 0.2 to 5 g / 10 minutes,
More preferably, it is 0.5 to 2 g / 10 minutes. MFR
If the content is less than 0.1 g / 10 minutes, the flowability of the resin deteriorates, the resin pressure increases, and the surface of the product becomes rough.
If the MFR exceeds 10 g / 10 min, the resin will sag during blow molding and cannot be molded.

In the injection blow method, the MFR of the polypropylene resin is 0.1 to 50 g / 10
Is preferably 0.2 to 30 g / 10 min, and more preferably 0.5 to 20 g / 10 min. If the MFR is less than 0.1 g / 10 minutes, the flowability is poor during injection, the resin is not sufficiently filled in the mold, and molding is difficult. If the MFR exceeds 50 g / 10 minutes, molding becomes easy. The impact strength of the product is significantly reduced, and the commercial value is lost.

In the hot stretch blow method, the MFR of the polypropylene resin is preferably from 0.1 to 20 g / 10 minutes, more preferably from 0.2 to 10 g / 10 minutes, and still more preferably from 0.5 to 5 g. / 10 minutes. M
If the FR is less than 0.1 g / 10 minutes, the flowability at the time of injection is poor, the resin is not sufficiently filled in the mold, and molding is difficult.
If the MFR exceeds 20 g / 10 minutes, it becomes difficult to remove the molten preform from the injection mold.

In the cold stretching blow method, the MFR of the polypropylene resin is preferably 0.5 to 80 g / 10 min, more preferably 1 to 60 g / 10 min,
More preferably, it is 2 to 40 g / 10 minutes. When the MFR is less than 0.5 g / 10 minutes, the flowability is poor at the time of injection, the resin is not sufficiently filled in the mold, and molding is difficult.
If it exceeds 80 g / 10 minutes, the impact strength of the product will be remarkably reduced and the commercial value will be lost.

The polypropylene resin used in the polypropylene resin composition used in the present invention is a resin capable of reducing the amount of the volatile hydrocarbon and the oligomer to a predetermined amount in the presence or absence of an additive as described above. Alternatively, any of volatile hydrocarbons and oligomers at a predetermined amount or less from the time of polymerization may be used.

A propylene polymer using a Ziegler-based Mg-supported catalyst can be obtained by a usual polymerization method using a combination catalyst of an organic aluminum compound and a solid catalyst component containing magnesium, titanium halogen, and an electron donor compound as essential components. Can be. In order to enhance the crystallinity of the propylene polymer, a method of adding a third component during polymerization is preferably used. As the electron donor compound in the solid catalyst component, an organic acid ester, an organic silicon compound and the like are preferably used. As the third component at the time of polymerization, an organic silicon compound is preferably used. For example, JP-A-61
-7803, JP-A-62-1705, JP-A-62-1605
The method described in each publication of JP-A-11706 can be adopted. The propylene polymer used in the present invention is preferably a crystalline propylene polymer produced using the stereoregular catalyst, and the polymerization may be a continuous system or a batch system, and a slurry polymerization method using an inert hydrocarbon solvent, A bulk polymerization method using propylene itself as a solvent or a gas phase polymerization method can be employed. The temperature during polymerization is from room temperature to 200 ° C.
Preferably, the temperature is from normal temperature to 150 ° C, and the pressure is from normal pressure to 100 ° C.
kg / cm ² G, preferably normal pressure to 45 kg / cm ² G
It is. Adjustment of the MFR for polymerization is carried out by using hydrogen as a molecular weight regulator.

More specifically, magnesium, titanium,
A solid catalyst component containing a halogen and an electron donor compound as essential components is synthesized as follows. It is general that magnesium and titanium are introduced into the solid catalyst component from the following magnesium compounds and titanium compounds, and halogen is introduced from any of these compounds.

As the magnesium compound, magnesium halides such as magnesium chloride, magnesium bromide, and magnesium iodide, diethoxymagnesium, magnesium carbonate, butylmagnesium chloride, dibutylmagnesium, magnesium oxide, metallic magnesium and the like can be used. . Among them, it is preferable to use magnesium chloride. In particular, it is desirable to use a substantially anhydrous one.

As the titanium compound, a halogen compound of trivalent or tetravalent titanium is representative. Preferred titanium halide compounds have the general formula Ti (OR ¹ ) _n X
_4-n (R ¹ is a C ₁ -C ₁₀ hydrocarbon residue, X is a halogen), n = 0, 1 or 2
Is a tetravalent titanium halide compound. Specifically, T
_{iC1 4, Ti (OBu) C1} 3, Ti (OBu) 2 C
Can be exemplified 1 _2, etc., particularly preferred is T
_{iC1 4, Ti (OBu) C1} 3 ( "OBu 'in the formula have butoxy group) titanium tetrahalides or monoalkoxy tri titanium halide compound such. Note that in the above general formula, Ti (OBu) ₄ where n = 4 can also be used.

Electron donation to be contained in the supported solid catalyst component
Compounds include alcohols, carboxylic esters,
Organic silicon compounds, ethers, etc.
However, preferably, alcohols having 1 to 10 carbon atoms,
Ester of aliphatic carboxylic acid having 1 to 10 carbon atoms, 2 carbon atoms
To 14 esters of aliphatic dicarboxylic acids, having 7 to 2 carbon atoms
An organic acid ester such as an ester of an aromatic carboxylic acid of 0;
General formula R¹R² _3-nSi (OR³)_n(Where R¹
Represents a branched chain hydrocarbon group, R²Is R¹Same as or
Different hydrocarbon groups are represented by R³Represents a hydrocarbon group, and n represents 2 ≦ n
≦ 3) organic silicon compound represented by the formula:
And 2 to 20 ethers. concrete
Include (a) methyl alcohol, ethyl alcohol,
Alcohols such as propyl alcohol and butyl alcohol
, (B) methyl acrylate, ethyl acrylate,
Propyl acrylate, butyl acrylate, methyl methacrylate
, Ethyl methacrylate, propyl methacrylate, meth
Aliphatic carboxylic acid esters such as butyl acrylate,
(C) ethyl oxalate, methyl malonate, diethyl succinate,
Dibutyl succinate, diethyl methyl succinate, α-methyl succinate
Diisobutyl rutherate, diethyl malonate, methyl malo
Dibutyl phosphate, diethyl ethylmalonate, isopropyl
Diethyl malonate, diethyl butylmalonate, phenyl
Diethyl malonate, diethyl malonate, allyl
Diethyl malonate, diethyl diisobutylmalonate, di
Diethyl normal butylmalonate, Dimethyl maleate
Monooctyl maleate, dioctyl maleate,
Dibutyl maleate, Dibutyl butyl maleate, Buty
Diethyl lumalate, diisotope β-methylglutarate
Ropyl, diallyl ethyl succinate, di-2-fumarate
Ethylhexyl, diethyl itaconate, dib itaconate
Chill, dioctyl citraconic acid, dimethic acid citraconic acid
Toluene, diethyl 1,2-cyclohexanecarboxylate,
Diisobutyl 2-cyclohexanecarboxylate
Aliphatic such as diethyl drophthalate and diethyl nadic
Polycarboxylic acid ester, (d) methyl benzoate, benzoate
Ethyl benzoate, propyl benzoate, butyl benzoate, tolu
Methyl ylate, ethyl toluate, methyl anisate,
Aromatic monocarboxylic acids such as ethyl nisnate and methyl cinnamate
Esters, (e) monoethyl phthalate, dimethyphthalate
Chill, methyl ethyl phthalate, monoisobutyl phthalate
, Mono-n-butyl phthalate, diethyl phthalate,
Ethyl isobutyl phthalate, ethyl normal phthalate
Chill, di-n-propyl phthalate, diisopropyl phthalate
Di-n-butyl phthalate, diisobutyl phthalate,
Di-n-heptyl talate, di-2-ethylhexyl phthalate
, Di-n-octyl phthalate, dineopent phthalate
, Didecyl phthalate, benzyl butyl phthalate, lid
Aromatic dicarboxylic esters such as diphenyl luate,
(To) (CH₃)₃CSi (CH₃) (OCH₃)₂,
(CH₃)₃CSi (CH (CH₃)₂(OC
H₃)₂, (CH₃)₃CSi (CH₃) (OC
₂H₅)₂, (C₂H₅)₃CSi (CH₃) (OCH
₃)₂, ((CH₃)₂) CH)₂Si (OC
H₃)₂, (CH₃) (C₂H₅) CHSi (CH₃)
(OCH₃)₂, ((CH₃)₂) CHCH₂)₂Si
(OCH₃)₂, (C₂H₅) (CH₃)₂CSi (C
H₃) (OCH ₃)₂, (C₂H₅) (CH₃)₂CS
i (CH₃) (OC₂H₅)₂, (CH ₃)₃CSi
(OCH₃)₃, (CH₃)₃CSi (OC
₂H₅)₃, (C₂H ₅)₃CSi (OC₂H₅)₃,
(CH₃)₂(C₂H₅) CHSi (OCH₃)₃,
(C₂H₅) (CH₃)₂CSi (OC₂H₅)₃No
Silicon compounds, (g) ethyl ether, butyl ether
, Tetrahydrofuran, 2,2'-dimethoxy-1,
1'-binaphthalene, 1,3-dimethoxypropane,
2,2'-dimethyl-1,3'-dimethoxypropane,
2,2'-diisopropyl-1,3'-dimethoxypro
Bread, 2-isopropyl-2-isobutyl-1,3-di
Ethers such as methoxypropane;
You. Among them, organic acid esters, especially aromatic
Carboxylic acid esters, especially benzoic acid esters
It is preferred to use

In preparing the supported solid catalyst component,
Magnesium halide is pre-treated
Is desirable. The pretreatment is performed by various known methods.
More specifically, the following (a) to (h)
Can be exemplified. (A) Magnesium dihalide or dihalogen
Magnesium and halo of titanium, silicon or aluminum
Pulverized with benzene compounds or halogenated hydrocarbon compounds
I do. Grinding is performed using a ball mill or vibration mill.
I can. (B) Hydrocarbon as a solvent using magnesium dihalide
Using hydrogen or a halogenated hydrocarbon, and
Using coal, phosphate or titanium alkoxide
To dissolve. Next, the poor solvent, inorganic halo
Electron donors such as genides and esters or methyl hydride
Add a polymer silicon compound such as rosien polysiloxane
And dissolve the dissolved magnesium dihalide in the solution.
More precipitation. (C) Magnesium mono or dial
Cholate or magnesium carboxylate and halo
A contact reaction is made with a genating agent. (D) Magnesium oxide
And chlorine or AlC1₃And a contact reaction. (E) Mg
X₂・ NH₂O (where X is a halogen) and halogen
Agent or TiC1₄And a contact reaction. (F) Mg
X₂-NROH (wherein X is a halogen, R is an alkyl group
And a halogenating agent or TiC1₄And the contact reacted
Let (G) Grignard reagent, MgR₂Compound (wherein
R is an alkyl group) or MgR₂Compound
Complexes with trialkylaluminum compounds are converted to halogen
Agent such as AlX₃, AlR_mX_{3 -M}(X in the formula is
Halogen, R is an alkyl group), SiC1₄Or S
iC1 ₃And contact reaction. (H) Grignard reagent
Silanol or polysiloxane, H₂O or shira
With a halogenating agent or Ti
C1₄And contact reaction.

The contact between the pretreated magnesium chloride, the titanium halide and the electron donating compound can also be carried out by forming a complex between the titanium halide and the electron donating compound and then contacting the complex with magnesium chloride. Alternatively, magnesium chloride may be brought into contact with a titanium halide and then contacted with an electron donating compound, or magnesium chloride may be brought into contact with an electron donating compound and then brought into contact with a titanium halide.
The contact may be carried out by pulverizing contact with a ball mill, vibration mill or the like, or by adding magnesium chloride or an electron-donating compound treated with magnesium chloride to the liquid phase of titanium halide. Washing with an inert solvent may be performed after the three or four components as the catalyst components are brought into contact, or at an intermediate stage of contacting each component. The titanium-containing supported solid catalyst component thus produced has a titanium halide content of 1 to 20% by weight, a magnesium halide content of 50 to 98% by weight, and a molar ratio of the electron donating compound to the titanium halide. It is about 0.05 to 2.0.

As the organoaluminum compound used as a cocatalyst with the solid catalyst component obtained above, the general formula AlR
_n X _3-n (wherein, R represents a hydrocarbon residue having 1 to 12 carbon atoms, X is halogen or alkoxy radical, n denotes an 0 <n ≦ 3) are preferred those represented by. Specific examples of such an organoaluminum compound include, for example, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, triisohexylaluminum, Octylaluminum, diethylaluminum hydride, diisobutylaluminum hydride, diethylaluminum monochloride, diethylaluminum sesquichloride, diethylaluminum monoethoxyside and the like. Of course, two or more of these organoaluminum compounds can be used in combination. The use ratio of the organoaluminum compound and the supported solid catalyst component can vary widely, but in general,
1 to 1 per titanium atom contained in the supported solid catalyst component
The organoaluminum compound can be used in a ratio of 1,000, preferably 10 to 500 (molar ratio).

The above solid catalyst component and organoaluminum catalyst
If necessary, add an electron donating compound to the system.
Can also. As the electron donating compound, the supported solid
Similar to the electron donating compound contained in the catalyst component
Among these electron donating compounds,
Also, in particular, of the general formula R¹R² _3-nSi (OR₃)_n(here
And R¹Represents a branched chain hydrocarbon group, R²Is R¹Is the same as
Or a different hydrocarbon group³Represents a hydrocarbon group, n
Is a number satisfying 2 ≦ n ≦ 3).
It is preferable to use Specific examples of these organosilicon compounds
For example, (CH₃)₃CSi (CH₃) (OC
H₃)₂, (CH₃)₃CSi (CH (CH₃)₂(O
CH₃)₂, (CH₃)₃CSi (CH₃) (OC₂H
₅)₂, (C₂H₅)₃CSi (CH₃) (OCH₃)
₂, ((CH₃)₂) CH)₂Si (OCH₃)₂,
(CH₃) (C₂H₅) CHSi (CH₃) (OC
H₃)₂, ((CH₃)₂) CHCH₂)₂Si (OC
H₃)₂, (C₂H₅) (CH₃)₂CSi (CH₃)
(OCH₃)₂, (C₂H₅) (CH₃)₂CSi (C
H₃) (OC₂H₅)₂, (CH₃)₃CSi (OCH
₃)₃, (CH₃)₃CSi (OC₂H₅)₃, (C₂
H₅)₃CSi (OC₂H₅)₃, (CH₃)₂(C₂
H ₅) CHSi (OCH₃)₃, (C₂H₅) (C
H₃)₂CSi (OC₂H₅) ₃, Etc.
Wear. These organic silicon compounds may be used alone or
Two or more can be used in combination. Add electron donor compound
The amount added at the time of
The ratio is usually 0.01 to 1, preferably 0.02 to 0.1.
5

For the homopolymerization of propylene (homopolymerization) using the above-mentioned catalyst, any method can be employed as long as the catalyst component and each monomer come into contact efficiently. Specifically, a slurry method using an inert solvent, a bulk method using propylene as a solvent without substantially using an inert solvent, a solution method, or substantially converting each monomer into a substantially gaseous state without using a substantially liquid solvent A keeping gas phase method can be employed. Either continuous polymerization or batch polymerization may be used. The polymerization reaction temperature is from room temperature to 200 ° C, preferably 30 to 150 ° C, more preferably 50 to 90 ° C,
The polymerization reaction pressure is from normal pressure to 50 kg / cm ² G.

Using the above catalyst, the polymerization of the propylene / α-olefin random copolymer is carried out by the polymerization of propylene and α-olefin.
It is performed by mixing and contacting with an olefin. As the polymerization mode, any method can be adopted as long as the catalyst component and each monomer are in efficient contact. Specifically, a slurry method using an inert solvent, a bulk method using propylene as a solvent without substantially using an inert solvent, a solution method, or substantially converting each monomer into a substantially gaseous state without using a substantially liquid solvent A keeping gas phase method can be employed. Either continuous polymerization or batch polymerization may be used. As polymerization conditions, the polymerization reaction temperature is from room temperature to 200
° C, preferably 30 to 150 ° C, more preferably 50 ° C.
９０90 ° C., polymerization reaction pressure is normal pressure ５０50 kg / cm ² G
Is performed under the following conditions.

Using the above catalyst, the propylene / ethylene block copolymer is converted to a propylene / ethylene block copolymer produced in producing a propylene / ethylene block copolymer containing a crystalline polypropylene part and an ethylene / propylene random copolymer part. The homopolymerization and the random copolymerization of ethylene and propylene are carried out using a Ziegler-type catalyst having high activity and high stereoregularity using the above-mentioned supported solid catalyst component and organoaluminum compound component. Except for performing the polymerization, a slurry polymerization method performed in an inert solvent such as hexane or heptane, a bulk polymerization method performed in liquid propylene, or a gas phase polymerization method can be used. The mode of homopolymerization of propylene or the random copolymerization of ethylene and propylene may be either a batch system or a continuous system.

The first stage polymerization is a step of producing a propylene homopolymer having high crystallinity and high MFR.
In the second stage polymerization, it is necessary to increase the concentration of hydrogen, which is a molecular weight regulator, to obtain a propylene homopolymer having a high MFR. The polymerization temperature in the first stage is from room temperature to 200 ° C, preferably 30 to 150 ° C, more preferably 50 to 90 ° C.
C., the polymerization reaction pressure is from normal pressure to 50 kg / cm ² G.

The second stage polymerization is a process for producing a low MFR ethylene / propylene random copolymer,
Conversely, in the second stage polymerization, it is necessary to keep the hydrogen concentration extremely low or to obtain a substantially hydrogen-free state in order to obtain a low MFR ethylene / propylene random copolymer. The polymerization reaction temperature in the second stage is 30 to 100.
° C, preferably 50 to 90 ° C, and the polymerization reaction pressure is from normal pressure to
It is performed under the condition of 50 kg / cm ² G. Hydrogen is preferably used for adjusting the molecular weight of the block copolymer.

The above-mentioned propylene / ethylene block copolymer is obtained by copolymerizing propylene with ethylene and other α-olefins (for example, butene, pentene, hexene, heptene, etc.) or an unsaturated organic compound. Acids and anhydrides thereof (for example, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, etc.) or unsweetened esters (for example, vinyl acetate, acrylic acid ester, methyl methacrylate, etc.), vinyl silane or aromatic It may be modified with aromatic vinyl silane. Furthermore,
Mixtures of these polymers can be used.

The Ziegler-based Mg described in detail above
In the method for producing a propylene-based resin by using a supported catalyst, a volatile hydrocarbon having 6 to 10 carbon atoms is contained in the resin.
Since an amount exceeding 0 ppm is contained and an oligomer component having 12 to 30 carbon atoms is contained in an amount exceeding 600 ppm in many cases, it is necessary to reduce these volatile hydrocarbons and oligomers. As a method for reducing the amount, the following method can be used. In this case, the above additives may be added, or the post-reduction additives may be added.

1) A method in which oligomer components are removed by slurry polymerization, and drying is enhanced by a dryer to reduce solvents and volatile hydrocarbons. 2) A method in which a washing step with propylene is provided in the course of bulk polymerization to reduce oligomers, and drying is enhanced by a dryer to reduce volatile hydrocarbons. 3) In each of the slurry, bulk, and gas phase polymerization methods, use of an electron donor or the like having high stereoregularity in the Mg-supported catalyst to suppress the production of oligomer components and enhance drying with a dryer to increase the volatile hydrocarbon content. How to reduce. 4) A method of shortening the homo / random polymerization residence time in each of the slurry, bulk, and gas phase polymerization methods to suppress the production of oligomer components, and enhancing drying with a dryer to reduce volatile hydrocarbons.

As a method of enhancing the drying using the resin powder, the drying temperature is 60 to 100 ° C., the drying time is 1 to 4 hours.
You may combine the processing methods of the hot air drying of a pellet.

Here, the amount of the volatile hydrocarbon having 6 to 10 carbon atoms refers to the constant temperature and humidity condition (temperature of 23 ± 2) after molding the container.
(C ° C, humidity 50 ± 5%) for 24 hours as a sample, and a gas obtained by pyrolyzing this as a sample.
The amount of the oligomer component of 2 to 30 is an amount determined by gas chromatography / mass spectrometry.

[II] Blow Molded Container The blow molded container of the present invention is obtained by blow molding the above-described polypropylene resin composition with a blow molding machine. Blow molding can be performed by a known method, a direct blow method, an injection blow method,
It is formed by a hot stretch blow method, a cold stretch blow method, or the like.

The direct blow molding is a method in which a mold is closed after extruding a cylindrical molten resin, expanded by air pressure, and cooled and solidified. As the blow molding conditions, the molding temperature is 170 to 250 ° C., the blowing pressure is 2 to 10 kg / c.
m ² and a blow ratio of 1.2 to 5.0 are preferred. In addition, these moldings can be widely used not only in single-layer extrusion but also in multilayer extrusion molding with various resins.

The stretch blow molding method includes a hot stretch blow molding method and a cold stretch blow molding method. The hot stretch blow molding method is a method generally used in polyethylene terephthalate container molding and the like, and is a biaxial stretch blow method by a hot parison method, which is a single stage in which an injection molding machine and a blow molding machine are integrated. The cold stretching blow method is a method of completely cooling an injection-molded preform (also referred to as a cold parison) and then stretching and blowing the same, that is, two-stage biaxial stretching blow by the cold parison method, and injection molding. This is a method in which the process and the stretch blow molding process are independent.

As a specific mechanism of the stretch blow method, there is a step of forming a test tubular bottomed preform by injection molding, adjusting the temperature to a temperature close to the melting point of the resin or lower, and then performing stretch blow molding. It is a thing. Injection molding is 1
It is molded by a general-purpose molding machine equipped with individual or plural preform dies. Specifically, the injection temperature is 150
It is sufficient that the injection pressure is 100 kg / cm ² or more and the mold clamping pressure satisfies 50 ton or more.

The stretch blow molding machine comprises a preform heating section and a blow mold section provided with a stretching rod. The hot parison heating section employs a method of controlling the temperature of the preform with a heating mold or the like. In this case, it is usually used. On the other hand, the heating section of the cold parison method generally heats the preform with an infrared lamp heater or the like.

The shape of the preform is a test tube shape having a mouth, and the mouth generally has a screw portion that can be fitted with a cap, but the mouth generally does not stretch blow. The thickness of the stretch blown portion of the preform is preferably 0.5 to 6 mm. If the wall thickness is small, there is a problem from the viewpoint of deformation during conveyance of the preform and shape retention during heating. On the other hand, when the thickness is large, in the case of a crystalline resin such as polyolefin, heat is difficult to be transmitted, so that the temperature distribution becomes large in the thickness direction. Undesirably occurs.

The size of the preform and the final molded product is generally about 1.5 to 5 times in the longitudinal (axial) direction and about 1.5 to 5 times in the transverse (circumferential) direction of the preform. In this case, the longitudinal stretching is by extruding a stretching rod from the mouth to the bottom,
In the transverse stretching, stretch blow is performed by applying one-stage or multi-stage pressure with high-pressure air of ^{2 to} 50 kg / cm ² . The stretching may be performed vertically and horizontally separately, but it is preferable that the stretching is performed simultaneously. The temperature at the time of stretch blowing differs depending on the material, but in the case of polyolefin, the temperature is preferably not higher than the melting point and not lower than the crystallization temperature.
１５０150 ° C.

The container obtained by blow molding as described above has an extremely small effect on the odor and taste of the dairy product, and has excellent rigidity and impact characteristics, and is therefore most suitable as a dairy product container. It is. Examples of the dairy products that can be stored in the container of the present invention include milk drinks, yogurt, and the like. Examples of the milk drinks include drinking milk, milk drinks, dairy products, lactic acid bacteria drinks, and milk-containing soft drinks. Include plain, hard, soft, and drinks.

[0058]

The present invention will be described more specifically with reference to the following examples. The evaluation methods and the test methods used in the examples and comparative examples are shown below.

(1) MFR: MFR was measured in accordance with JIS-K7210 at a condition temperature of 230 ° C. and an operating load of 2.16 kg.

(2) Method for measuring volatile hydrocarbons: A molded polypropylene article was cut into small pieces of several mm square, and 5 mg of a sample was subjected to pyrolysis under the following conditions and analyzed by gas chromatography. (I) Thermal decomposition conditions Thermal decomposition apparatus; PYR-1A manufactured by Shimadzu Corporation Thermal decomposition temperature; 210 ° C Pipe temperature; 100 ° C (ii) Conditions of gas chromatograph Equipment: G-C14B column manufactured by Shimadzu Corporation; -100 (40 m, composition;
(Methyl Silicone, polar; non-polar, film thickness: 1 μm) Column temperature: 60 ° C. → 150 ° C. Calibration curve: Performed in terms of n-heptane.

(3) Oligomer measurement method: Analysis was carried out by the following method based on the description in “Polymer Analysis Handbook” (Kinokuniya Publishing). 2.5 g of the freeze-crushed sample was subjected to heating and reflux extraction with 100 ml of hexane for 1 hour, filtered by cooling, desolvated by a rotary evaporator to dryness, added with 4 ml of hexane, and extracted with an ultrasonic washing machine. This was measured by gas chromatography / mass spectrometry (SIM) under the following conditions. Apparatus; HP-GCD column; HP-1 0.23 mm × 30 m Temperature; 100 ° C. → 5 ° C./min→300° C. Injection amount: 1 μl Splitless detection; SIM (m / Z = 43, 57 monitors m / Z =
Quantification at 43 ( _C18 converted absolute calibration curve method) The absolute calibration curve method was based on JIS K0123.

(4) Color tone measuring method: Toshiba injection molding machine IS9
0, the pellet sample was 2 × 80 × 120 m in a temperature of 230 ° C., a mold cooling water temperature of 40 ° C., and a molding cycle of 40 seconds.
m of a sheet-shaped test piece, and using the test piece, JI
The YI value was measured according to SK7103.

(5) Formability: The condition at the time of forming the hue measurement sheet was observed.

(6) Odor test method: A clean wide-mouthed glass bottle with a stopper (300 ml) having no odor is prepared, and about 80 g of a sample obtained by cutting a blow-molded container into a shape of about 20 × 20 mm is placed in the wide-mouth bottle. . The bottle is capped and placed in a Toyo Seiki gear oven heated to 80 ° C. for 2 hours and heated.
After heating, it was taken out and evaluated within 10 minutes according to the following odor criteria. Standard of smell 0 grade: not felt 1st grade: barely felt 2nd grade: felt 3rd grade: feel comfortable 4th grade: strong smell

(7) Taste test method: Blow molded wall thickness 1
After treating a 600 ml container with boiling water for 5 minutes or more, 200 ml of coffee milk was put in the container, and the mouth was sealed with aluminum foil for cooking. Then one in the refrigerator 24
Stored for hours. One was heated at 80 ° C. for 2 hours, allowed to cool at room temperature for 1 hour, and stored in a refrigerator for 24 hours. In addition, 300ml of a wide-mouthed glass bottle with a stopper that does not smell clean
200 ml of coffee milk was placed in the container for comparison. After each treatment, a sensory test was performed by comparing with a glass bottle (wide-mouthed bottle). The criterion was expressed by the number of people who felt the difference compared to coffee milk in a glass bottle. (1/1
0 = 1 in 10)

Example 1 A Ziegler-Natta catalyst was prepared by the following method. <Solid catalyst component 1> Remove into a flask sufficiently purged with nitrogen.
Introduce 4000 ml of water / deoxygenated n-heptane
And then MgCl₂8 mol, Ti (On-C
₄H₉)₄, And reacted at 95 ° C. for 2 hours.
Was. After completion of the reaction, the temperature was lowered to 40 ° C.
Hydropolysiloxane (of 20 centistokes)
Was introduced, and reacted for 3 hours. Generate
The solid component was washed with n-heptane. Then enough
In a flask purged with nitrogen, add n-f.
Introduced 1000 ml of butane and synthesized above
4.8 mol of a solid component was introduced in terms of Mg atoms. Next
In 500 ml of n-heptane,₄8
The mixture was introduced into the flask at 30 ° C. for 30 minutes.
The reaction was performed at 0 ° C. for 3 hours. After the reaction is completed, add n-heptane
Washed. Then, to 500 ml of n-heptane
0.48 mol of phthalic acid chloride was mixed at 70 ° C.
Introduce into the flask in 30 minutes and react at 90 ° C for 1 hour
Was. After the completion of the reaction, the resultant was washed with n-heptane. Then, S
iCl₄200 ml at 30 ° C for 30 minutes
The mixture was introduced into a sco and reacted at 80 ° C. for 6 hours. End of reaction
Thereafter, the solid was sufficiently washed with n-heptane to obtain a solid component. Next
Then, in a flask sufficiently purged with nitrogen,
1000 ml of the prepared n-heptane were introduced, and
100 g of the solid component synthesized above was introduced, and (t-C₄H
₉) Si (CH₃) (OCH₃)₂24 ml,
Al (C₂H ₅)₃34 g was contacted at 30 ° C. for 2 hours.
Was. After the contact is completed, the substrate is sufficiently washed with n-heptane, and MgC
l₂Was obtained as a solid catalyst component. This solid catalyst component
Content was 1.1% by weight.

<Polymerization method 1> The propylene-ethylene random copolymer powder obtained by the gas phase polymerization method was polymerized by using the above-mentioned Ziegler-Natta catalyst. Continuous production of a propylene-ethylene random copolymer was carried out using a stirring-type continuous gas phase polymerization reactor comprising a reactor having an inner volume of 10 L. First, after replacing the inside of the reactor with nitrogen that has been sufficiently purified,
2.2 kg of a sufficiently dehydrated and deoxygenated polymer carrier was charged, and then gas replacement was sufficiently performed with propylene. Hydrogen and ethylene used together were controlled by the hydrogen concentration and ethylene concentration in the gas phase. Further, triethylaluminum and the solid catalyst component were continuously introduced, and the polymerization temperature was reduced to 7%.
Propylene-ethylene random copolymerization was continuously performed at 5 ° C. and a total pressure of 14.5 kg / cm ² . The copolymerized powder was intermittently extracted. Thus, a powdery propylene-ethylene random copolymer was obtained.

The obtained propylene-ethylene random copolymer powder was washed at 80 ° C. with a small amount of nitrogen (about 1000 ml / min) at 80 ° C. using a gear oven manufactured by Toyo Seiki Co., Ltd.
The drying treatment was performed for 0 minutes.

With respect to 100 parts by weight of the dried powder, pentaerythyl-tetrakis [3- (3,5-t-butyl-4) was used as a phenolic antioxidant.
-Hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals Co., Ltd .; hereinafter abbreviated as RA1010), 0.1 part by weight, tris (2,4-di-t-butylphenyl) phosphate as a phosphorus-based antioxidant (Ciba Specialty Chemicals Co., Ltd .; RA
168. ) 0.1 parts by weight and 0.05 parts by weight of calcium stearate as a neutralizing agent were added, and the mixture was sealed with a super mixer with nitrogen and mixed for 3 minutes. Then 30m
While using a mD extruder to seal the hopper with nitrogen,
Granulated and pelletized at 30 ° C. The resulting propylene
The ethylene random copolymer has an MFR of 1.8 g / 10
Min, ethylene content = 3.2% by weight.

The pellet sample was supplied to a small direct blow molding machine JB105 blow molding machine manufactured by Japan Steel Works, Ltd.
Direct blow molding was performed at a resin temperature of 220 ° C. to form a container having a capacity of 500 mL, a wall thickness of 0.7 mm, and a weight of 40 g. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Example 2 The pellet sample of Example 1 was dried and deodorized at 80 ° C. for 24 hours using a gear oven manufactured by Toyo Seiki. In addition,
The pellets of the propylene-ethylene random copolymer after the deodorization treatment had an MFR of 1.9 g / 10 min and an ethylene content of 3.2% by weight. Thereafter, a test container was molded with a blow molding machine in the same manner as in Example 1, and the volatile hydrocarbon content, odor, and the taste of coffee milk using this container during storage and warming of the blow-molded container were evaluated. Table 1 shows the results
Shown in

Example 3 Using the solid catalyst of Example 1, a propylene-ethylene random copolymer powder was polymerized by the following slurry polymerization method. <Polymerization Method 2> A propylene-ethylene random copolymer was produced in a stirred polymerization tank having an internal volume of 200 liters. After sufficiently replacing the inside of the polymerization tank with propylene, 60 liters of dehydrated and deoxygenated n-heptane were introduced, and 15.0 g of triethylaluminum and 3.0 g of the solid catalyst component were introduced at 60 ° C. in a propylene atmosphere. After the temperature in the polymerization tank was raised to 65 ° C., propylene was added to 5.
9 kg / hour, ethylene was introduced at a feed rate of 0.04 kg / hour, and the hydrogen used together was controlled by the hydrogen concentration in the gas phase. Thereafter, the introduction of propylene and ethylene was stopped, and the temperature in the polymerization tank was kept at 65 ° C. for 90 minutes. The slurry thus obtained was filtered and dried under reduced pressure (80 ° C., 3 hours) to obtain 32.0 kg of a powdery propylene-ethylene random copolymer. The obtained propylene-ethylene random copolymer has an MFR =
1.8 g / 10 min, ethylene content = 3.2% by weight.

The powder thus obtained was subjected to a slight amount of nitrogen (about 100 / min.) Using a gear oven manufactured by Toyo Seiki.
(0 ml) while drying at 90 ° C. for 3 hours.
(Equivalent to enhanced drying)

Blow molding was performed in the same manner as in Example 1 except that the propylene-ethylene random copolymer powder obtained by the above slurry polymerization method was used instead of the propylene-ethylene random copolymer powder used in Example 1. A container was obtained. The pellets of the propylene-ethylene random copolymer after granulation had an MFR of 1.8 g / 10
Min, ethylene content = 3.2% by weight. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Example 4 Using the solid catalyst of Example 1, a propylene-ethylene random copolymer powder was polymerized by the following bulk polymerization method. <Polymerization method 3> Continuous production of a propylene-ethylene random copolymer by a process incorporating a liquid phase polymerization tank with an internal volume of 0.85 m3 with a stirrer and a degassing system consisting of a double tube heat exchanger and a flash tank. Was carried out.
Liquefied propylene was continuously supplied to the liquid phase polymerization tank at 115 kg / hour, and the amount of hydrogen and ethylene used together was controlled by the hydrogen concentration and ethylene concentration in the gas phase. Further, triethylaluminum, t-butylethyldimethoxysilane, and a solid catalyst component were continuously introduced. The polymerization temperature was 70 ° C. The slurry formed in this liquid phase polymerization tank was fed to a fluidized flash tank via a double tube heat exchanger using a slurry pump. In the fluidized flash tank, the temperature inside the tank was maintained at 70 ° C. while feeding propylene gas heated from the lower part. The powder thus obtained was placed at 70 ° C. under a nitrogen atmosphere at 4 ° C.
After drying for 0 minutes, a powdery propylene-ethylene random copolymer was obtained.

The powder thus obtained was subjected to a small amount of nitrogen (about 100 per minute) using a gear oven manufactured by Toyo Seiki.
(0 ml) while drying at 80 ° C. for 60 minutes. (Equivalent to enhanced drying)

The procedure of Example 1 was repeated except that the propylene-ethylene random copolymer powder obtained by the bulk polymerization method was used instead of the propylene-ethylene random copolymer powder obtained by the gas phase polymerization method used in Example 1. A blow-molded container was obtained in the same manner as in Example 1. Incidentally, pellets of the propylene-ethylene random copolymer after granulation,
MFR = 1.8 g / 10 min, ethylene content = 3.2% by weight. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Example 5 Using the solid catalyst of Example 1, a propylene homopolymer powder was polymerized by the following gas phase polymerization method. <Polymerization method 4> Continuous production of a propylene homopolymer was carried out using a stirring-type continuous gas-phase polymerization reactor comprising a reactor having an internal volume of 10 L. First, the inside of the reactor was replaced with nitrogen that had been sufficiently purified, and then 2.2 kg of a polymer carrier that had been sufficiently dehydrated and deoxygenated was charged, followed by sufficient gas replacement with propylene. The hydrogen used together was controlled by the hydrogen concentration in the gas phase. Further, triethylaluminum and the solid catalyst component were continuously introduced, and the polymerization temperature was 75 ° C. and the total pressure was 1
Propylene homopolymerization was continuously performed at 4.5 kg / cm ² . The polymerized powder was withdrawn intermittently.

The powder thus obtained was subjected to a small amount of nitrogen (about 100 per minute) using a gear oven manufactured by Toyo Seiki.
(0 ml) while drying at 80 ° C. for 60 minutes to obtain a powdery propylene homopolymer. (Enhance drying)

A blow-molded container was obtained in the same manner as in Example 1, except that the propylene-ethylene random copolymer powder obtained by the gas phase polymerization method used in Example 1 was replaced with a propylene homopolymer. After granulation, the obtained propylene homopolymer had an MFR of 1.4 g / 10 minutes. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Example 6 Using the solid catalyst of Example 1, propylene-ethylene block copolymer powder was polymerized by the following gas phase polymerization method.
Continuous production of a propylene-ethylene block copolymer was carried out using a stirred continuous gas phase polymerization reactor in which two reactors having an internal volume of 10 L were connected in series. First, the inside of the first-stage reactor was replaced with sufficiently purified nitrogen, and then 2.2 kg of a sufficiently dehydrated and deoxygenated polymer carrier was charged, followed by sufficient gas replacement with propylene. Triethyl aluminum, continuously introducing the solid catalyst component,
Propylene homopolymerization was continuously performed at a polymerization temperature of 75 ° C. and a total pressure of 14.5 kg / cm ² . The powder polymerized in the first-stage polymerization step is intermittently pumped to the second-stage reactor and newly supplies a mixed gas of ethylene and propylene,
Ethylene-propylene copolymerization was continuously performed at a polymerization temperature of 70 ° C. The powder copolymerized in the second polymerization step is
I pulled out intermittently. The hydrogen used in each polymerization step was controlled by the hydrogen concentration in the gas phase.

The powder thus obtained was subjected to a very small amount of nitrogen (about 100 per minute) using a gear oven manufactured by Toyo Seiki.
(0 ml) while drying at 80 ° C. for 60 minutes while flowing to obtain a powdery propylene-ethylene random copolymer. (Enhance drying)

A blow molding container was prepared in the same manner as in Example 1 except that the propylene-ethylene random copolymer powder obtained by the gas phase polymerization method used in Example 1 was replaced with a propylene-ethylene block copolymer powder. I got
After granulation, the obtained propylene-ethylene block copolymer had an MFR of 1.4 g / 10 minutes and an ethylene content of 11% by weight. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Comparative Example 1 After the same polymerization as in Example 1 was performed, the same granulation and pelletization as in Example 1 were performed using the resulting propylene-ethylene random copolymer powder without drying and strengthening. A blow molded container was obtained in the same manner as in Example 1. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Comparative Example 2 After the same polymerization as in Example 3 was carried out, the resulting propylene
A blow-molded container was obtained in the same manner as in Example 3 except that the ethylene random copolymer powder was not used and drying and strengthening were not performed. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Comparative Example 3 After the same polymerization as in Example 4 was carried out, the resulting propylene
A blow-molded container was obtained in the same manner as in Example 4, except that the ethylene block copolymer powder was not used and drying and strengthening were not performed. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Comparative Example 4 The same polymerization as in Example 6 was carried out, and the obtained propylene homopolymer powder was used.
A blow molded container was obtained in the same manner as in Example 6. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Comparative Example 5 After performing the same polymerization as in Example 7, the resulting propylene
A blow-molded container was obtained in the same manner as in Example 7, except that the ethylene random copolymer powder was not used and the drying and strengthening were not performed. Table 1 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of the coffee milk stored and heated when the container was stored.

Example 7 After the propylene-ethylene random copolymer powder used in Example 1 and the drying treatment were performed, a stabilizer was added as an antioxidant and RA10 was used as a phenolic antioxidant.
A blow-molded container was obtained in the same manner as in Example 1, except that 0.1 was used as 0.1 part by weight and 0.05% by weight of calcium stearate as a neutralizing agent. Table 2 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of coffee milk using the container during storage and heating.

Example 8 After the propylene-ethylene random copolymer powder used in Example 1 was dried and treated, a stabilizer was used as an antioxidant and RA10 was used as a phenolic antioxidant.
10 is replaced by 0.1 part by weight, a HARS stabilizer dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,2-teotramethylpepyridine polycondensate (Ciba Specialty Chemicals) Co., Ltd .; T
Abbreviated as NV622. ) A blow-molded container was obtained in the same manner as in Example 1 except that 0.1 part by weight was used. Table 2 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of coffee milk using the container during storage and heating.

Comparative Example 6 Example 1 was repeated except that no stabilizer was added.
A blow-molded container was obtained in the same manner as described above. Table 2 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of coffee milk using the container during storage and heating.

Comparative Example 7 The procedure of Example 1 was repeated except that the stabilizer was used as a phenolic antioxidant and RA1010 was used in only 0.1 part by weight.
A blow molded container was obtained in the same manner as in Example 1. Table 2 shows the results of evaluating the volatile hydrocarbon content and the odor of the blow-molded container, and the taste of coffee milk using the container during storage and heating.

Comparative Example 8 A blow-molded container was obtained in the same manner as in Example 1 except that the stabilizer in Example 1 was used as a neutralizing agent and only 0.05 parts by weight of calcium stearate was used. Table 2 shows the results of evaluating the volatile hydrocarbon content and odor of the blow-molded container, and the taste of the coffee milk when stored and heated when using this container.
Shown in

Example 9 A blow-molded container was obtained by hot stretch blow molding using the pellets formed in Example 1 after granulation.

Using a hot method stretch blow molding machine ASB50 manufactured by Nissei ASB Co., Ltd., the injection pressure was 90 kg / cm ² ,
Hot method stretch blow molding was performed under the conditions of a resin temperature of 230 ° C. and a blow temperature of 130 ° C., and a capacity of 500 cc and a wall thickness of 0.5
mm container was molded.

The amount of volatile hydrocarbons in the blow molded container,
Table 2 shows the results of evaluating the smell and the taste of coffee milk when stored using the container and when heated.

Example 10 Using the solid polymerization catalyst component prepared in Example 1, a propylene-ethylene random copolymer powder was produced and dried by the following methods. Continuous production of a propylene-ethylene random copolymer was carried out using a stirring-type continuous gas phase polymerization reactor comprising a reactor having an inner volume of 10 L. First, the inside of the reactor was replaced with nitrogen that had been sufficiently purified, and then 2.2 kg of a polymer carrier that had been sufficiently dehydrated and deoxygenated was charged, followed by sufficient gas replacement with propylene. Hydrogen and ethylene used together were controlled by the hydrogen concentration and ethylene concentration in the gas phase. Further, triethyl aluminum and the solid catalyst component were continuously introduced, and the polymerization temperature was 75 ° C.
Propylene-ethylene random copolymerization was continuously performed at a total pressure of 14.5 kg / cm ² . The copolymerized powder was intermittently extracted. Thus, a powdery propylene-ethylene random copolymer was obtained.

The obtained propylene-ethylene random copolymer powder was washed at 80 ° C. with a small amount of nitrogen (about 1000 ml / min) at 80 ° C. using a gear oven manufactured by Toyo Seiki Co., Ltd.
The drying treatment was performed for 0 minutes.

After the same additive formulation as in Example 1 was applied and granulated, the obtained propylene-ethylene random copolymer had an MFR of 30 g / 10 min and an ethylene content of 2.5.
% By weight. Using the pellets after granulation, a blow molded container was obtained by cold stretch blow molding.

Using an injection molding machine IS150 manufactured by Toshiba Machine Co., Ltd., injection pressure 100 kg / cm ² , resin temperature 210 ° C., weight 2
One gram of the preform was injection molded. Thereafter, the preform was subjected to cold stretch blow molding using a cold stretch blow blow molding machine EFB1000ET manufactured by Frontier under the conditions of an outer surface temperature of the preform of 130 ° C. and a blow pressure of 30 kg / cm ² , and a capacity of 500 cc and a thickness of 500 cm. A 0.3 mm container was molded.

Table 2 shows the results of evaluation of the volatile hydrocarbon content and odor of the cold stretch blow-molded container, and the taste of coffee milk using the container during storage and heating.

[0102]

[Table 1]

[0103]

[Table 2]

[0104]

The polypropylene resin composition of the present invention has excellent rigidity and impact properties, and when used as a dairy container,
Does not affect odor, taste, etc. for dairy products. Furthermore, conventional polyethylene and polystyrene containers could not be filled at high temperature, but by using the container made of the polypropylene resin composition of the present invention, they can be filled at high temperature and are excellent in color tone. It is most suitable as a container for beverages, lactic acid bacteria drinks, milk drinks such as milk-containing soft drinks, and dairy products such as yogurt.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/13 C08K 5/17 5/17 5/524 5/524 C08L 23/10 C08L 23/10 B65D 1 / 00 A (72) Inventor Tatsuo Kobayashi No. 1 Toho-cho, Yokkaichi-shi, Mie Japan Polychem Co., Ltd. Material Development Center (72) Inventor Shigenobu Kawai No. 1 Toho-cho, Yokkaichi-shi, Mie Pref. Japan Material Development Center ( 72) Inventor Koichiro Ishii 1st Toho-cho, Yokkaichi-shi, Mie Japan Polychem Co., Ltd. Catalyst Development Center F-term (reference) 3E033 AA08 BA16 BB04 CA03 CA07 CA20 FA03 GA02 4F071 AA20 AB18 AB21 AC09 AC11 AC12 AC15 AE05 AE22 AF14 AF23 AF45 AH05 BA01 BB13 4J002 BB121 BB141 DE049 DE289 EG029 EG039 EJ016 EU077 EW068 FD047 FD076 FD078 FD209 GG01

Claims (6)

[Claims] 1. A blow molding of a polypropylene resin composition containing (a) a phenolic antioxidant and / or a hindered amine stabilizer, and (b) a neutralizing agent,
(1) 300 ppm of volatile hydrocarbons having 6 to 10 carbon atoms
Hereinafter, (2) the oligomer component having 12 to 30 carbon atoms contains 60
A blow-molded container for dairy products, which is not more than 0 ppm. 2. The blow-molded container for dairy products according to claim 1, wherein the polypropylene resin composition further contains (c) a phosphorus-based antioxidant. 3. The dairy product according to claim 1, wherein (b) the neutralizing agent is any one selected from fatty acid metal salts, hydrotalcite, and metal hydroxide salts. For blow molded containers. 4. A phenolic antioxidant, and / or
Or a hindered amine stabilizer and (b) a polypropylene resin composition containing a neutralizing agent, wherein (1) volatile hydrocarbons having 6 to 10 carbon atoms are 300 ppm or less, (2)
A polypropylene resin composition for blow-molded containers for dairy products, wherein the content of the oligomer component having 12 to 30 carbon atoms is 600 ppm or less. 5. The polypropylene resin composition for blow molded containers for dairy products according to claim 4, wherein the polypropylene resin composition further comprises (c) a phosphorus antioxidant. 6. The dairy product blow according to claim 4, wherein (b) the neutralizing agent is any one selected from fatty acid metal salts, hydrotalcite, and metal hydroxide salts. Polypropylene resin composition for molded containers.