JP2002302579A - Molded article for food packaging use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded article for food packaging use, moldable under ordinary molding conditions, free from the troubles of the lowering of impact strength and the deterioration of the odor and taste of foods and keeping excellent odor, taste and impact strength. SOLUTION: The molded article for food packaging use is composed of a resin composition containing 100 pts. wt. of a polypropylene and 0.01-0.5 pt.wt. of a specific phosphorous acid ester. Preferably, the polypropylene is a polypropylene copolymer composed of a component obtained by the polymerization of monomers composed mainly of propylene and a component obtained by the copolymerization of propylene and ethylene. More preferably, the molded article for food packaging use is composed of a resin composition containing 100 pts.wt. of a polypropylene, 0.01-0.5 pts.wt. of a specific phosphorous acid ester and 0.01-1 pt.wt. of a specific acrylate compound or a phenolic antioxidant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a molded product for food packaging. More specifically, the present invention relates to a molded article for food packaging having excellent odor, taste, and impact strength.

[0002]

2. Description of the Related Art Polypropylene resins are widely used in the field of packaging such as food packaging and fiber packaging because of their excellent appearance, mechanical properties, and suitability for packaging. However, since the molding of the polypropylene resin is usually performed at 200 to 300 ° C., it may be decomposed by shearing force or high-temperature heat, resulting in deterioration of physical properties such as impact strength, or insufficient processing stability.

As a method for improving the processing stability of a polypropylene resin, for example, JP-A-10-273494 discloses a resin composition containing polypropylene and phosphites. Further, Japanese Unexamined Patent Publication No.
Japanese Patent No. 222493 discloses a resin composition containing polypropylene, phosphites and an antioxidant. However, when the resin composition described in the above publication is used for a molded product for food packaging, impact strength is reduced,
The taste and odor of the food may worsen,
Improvements have been demanded in terms of taste and impact strength.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a molded article for food packaging which is excellent in odor, taste and impact strength.

[0005]

Means for Solving the Problems In view of such circumstances, the present inventors have conducted intensive studies and as a result, have found that polypropylene containing a specific content and specific phosphites containing a specific range are contained. It has been found that a molded article for food packaging made of a resin composition that can solve the above-mentioned problems, and has completed the present invention.

That is, the present invention relates to a polypropylene 1
00 parts by weight and the following general formula (I) (Wherein R ¹ , R ² , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms,
Represents an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms or a phenyl group, and R ³ represents a hydrogen atom or 1 carbon atom.
To 8 alkyl groups. X is a sulfur atom or -CH
An R ⁶ -group (R ⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms),
n is 0 or 1. A represents an alkylene group having 2 to 8 carbon atoms or a * -CO (R ⁷ ) m- group (R ⁷ represents an alkylene group having 1 to 8 carbon atoms, and * represents a portion bonding to an oxygen atom; Represents 0 or 1.). Y and Z are
One of them represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Phosphites represented by)
The present invention relates to a molded product for food packaging comprising a resin composition containing 0.01 to 0.5 parts by weight. Hereinafter, the present invention will be described in detail.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene used in the present invention is a polymer or a copolymer obtained by polymerizing a monomer mainly composed of propylene, for example, a propylene homopolymer, a propylene random copolymer. Coalesce, a polypropylene-based copolymer comprising a component obtained by polymerizing a monomer mainly composed of propylene and a component obtained by copolymerizing propylene and ethylene (sometimes referred to as a propylene-ethylene block copolymer). And the like. As the propylene-based random copolymer, for example, propylene-ethylene random copolymer, propylene-α-olefin random copolymer, propylene-ethylene-α
-Olefin random copolymer and the like. Preferably, it is a polypropylene copolymer comprising a component obtained by polymerizing a monomer mainly composed of propylene and a component obtained by copolymerizing propylene and ethylene. These may be used alone or in combination of two or more.

[0008] The α-olefin is preferably a compound having 4 to 4 carbon atoms.
12-α-olefins, for example, 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-ethyl -1-butene, 2,3-dimethyl-1
-Butene, 2-methyl-1-pentene, 3-methyl-1
-Pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene,
Trimethyl-1-butene, methylethyl-1-butene,
1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-
Pentene, propyl-1-pentene, diethyl-1-
Butene, 1-nonene, 1-decene, 1-undecene, 1
-Dodecene and the like. Preferably, 1-butene,
1-pentene, 1-hexene, and 1-octene; more preferably, 1-pentene,
-Butene, 1-hexene.

Examples of the propylene-α-olefin random copolymer include a propylene-1-butene random copolymer and a propylene-1-hexene random copolymer. Examples of the polymer include a propylene-ethylene-1-butene random copolymer, a propylene-ethylene-1-hexene random copolymer, and the like.

The content of ethylene and / or α-olefin in the propylene random copolymer is not particularly limited, but is usually 0.1 to 20% by weight, preferably 1 to 10% by weight.

[0011] In a polypropylene copolymer comprising a component obtained by polymerizing a monomer mainly composed of propylene and a component obtained by copolymerizing propylene and ethylene, a component obtained by copolymerizing propylene and ethylene is used. The content is usually 5 to 40% by weight, and preferably 10 to 40% by weight from the viewpoint of impact resistance.

The content of ethylene in the component obtained by copolymerizing propylene and ethylene is usually 15 to 65.
% By weight, and preferably from 20 to 20% from the viewpoint of impact resistance.
60% by weight.

The intrinsic viscosity of the component obtained by copolymerizing propylene and ethylene is usually 1.0 to 5.0 dl.
/ G, from the viewpoint of impact resistance, preferably from 1.5 to
5.0 dl / g.

The method for producing the polypropylene used in the present invention is not particularly limited, and the polypropylene is produced by a known polymerization method using a known catalyst. Known catalysts include, for example, a Ti-Mg-based catalyst comprising a solid catalyst component obtained by complexing a Ti compound with a magnesium compound, an organic aluminum compound and an electron-donating compound if necessary. And a metallocene-based catalyst, and the like.
Preferred is a catalyst system comprising a solid catalyst component containing magnesium, titanium and halogen as essential components, an organoaluminum compound and an electron donating compound. For example, JP-A-61-218606 and JP-A-61-2790.
No. 4, JP-A-7-216017 and the like.

Known polymerization methods include, for example, a slurry polymerization method using an inert hydrocarbon solvent, a solvent polymerization method, a liquid phase polymerization method using no solvent, a gas phase polymerization method, and a liquid phase-gas method in which these are continuously performed. A phase polymerization method and the like are mentioned, and a gas phase polymerization method is preferable.

In the production of the polypropylene used in the present invention, if necessary, a residual solvent of the polypropylene,
Drying may be performed at a temperature equal to or lower than the temperature at which the polypropylene melts in order to remove ultra-low molecular weight oligomers and the like that are by-produced during the production. For example, examples of the drying method include the methods described in JP-A-55-75410 and JP-A-2565753.

The polypropylene 23 used in the present invention
Although the melt flow rate (MFR) measured at 0 ° C. is not particularly limited, it is preferably 0.1 to 50 g / 10 min, more preferably 1 to 50 g / 10 min, from the viewpoint of fluidity or film forming property. ２０20 g / 10 min.

The phosphite used in the present invention has the following general formula (I) (Wherein R ¹ , R ² , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms,
Represents an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms or a phenyl group, and R ³ represents a hydrogen atom or 1 carbon atom.
To 8 alkyl groups. X is a sulfur atom or -CH
An R ⁶ -group (R ⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms),
n is 0 or 1. A represents an alkylene group having 2 to 8 carbon atoms or a * -CO (R ⁷ ) m- group (R ⁷ represents an alkylene group having 1 to 8 carbon atoms, and * represents a portion bonding to an oxygen atom; Represents 0 or 1.). Y and Z are
One of them represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ).

In the phosphites represented by the general formula (I), the substituents R ¹ , R ² , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, Represents a cycloalkyl group having 5 to 8 atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms or a phenyl group.

Here, representative examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec- A butyl group, a t-butyl group, a t-pentyl group, an i-octyl group, a t-octyl group, a 2-ethylhexyl group and the like are exemplified. As a typical example of a cycloalkyl group having 5 to 8 carbon atoms, for example, cyclopentyl Group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Representative examples of the alkylcycloalkyl group having 6 to 12 carbon atoms include 1-methylcyclopentyl group, 1-methylcyclohexyl group, 1-methyl -4
-I-propylcyclohexyl group and the like. Representative examples of the aralkyl group having 7 to 12 carbon atoms include a benzyl group, an α-methylbenzyl group and an α, α-dimethylbenzyl group.

R ¹ , R ² and R ⁴ are preferably an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, and an alkylcycloalkyl group having 6 to 12 carbon atoms. Among them, R ¹ and R ⁴ are more preferably a t-alkyl group such as a t-butyl group, a t-pentyl group, a t-octyl group, a cyclohexyl group, and a 1-methylcyclohexyl group.

R ² is more preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl,
An alkyl group having 1 to 5 carbon atoms such as a t-pentyl group, and more preferably a methyl group, a t-butyl group, and a t-pentyl group.

R ⁵ is preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, more preferably a hydrogen atom, a methyl group,
Alkyl groups having 1 to 5 carbon atoms such as ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group and t-pentyl group. .

The substituent R ³ is a hydrogen atom or a group having 1 carbon atom.
Represents an alkyl group having 1 to 8 carbon atoms, and examples of the alkyl group having 1 to 8 carbon atoms include the same alkyl groups as described above. It is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

The substituent X, when n is 0, indicates that two groups having a phenoxy group skeleton are directly bonded, and when n is 1, the substituent X is a sulfur atom or a group having 1 carbon atom.
Represents a methylene group which may be substituted by an alkyl group having from 8 to 8 or a cycloalkyl group having from 5 to 8 carbon atoms.
Here, examples of the alkyl group having 1 to 8 carbon atoms and the cycloalkyl group having 5 to 8 carbon atoms which are substituted on the methylene group include the same alkyl groups and cycloalkyl groups as described above. As the substituent X, n is preferably 0
Wherein two groups having a phenoxy group skeleton are directly bonded, or n is 1, and a methylene group or a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group , I-butyl group, t-butyl group and the like.

The substituent A is an alkylene group having 2 to 8 carbon atoms or a * -CO (R ⁷ ) m- group (where R ⁷ is
In the alkylene group of 8, * indicates that the moiety is bonded to an oxygen atom, and m is 0 or 1. ).

Here, representative examples of the alkylene group having 2 to 8 carbon atoms include ethylene group, propylene group,
Examples thereof include a butylene group, a pentamethylene group, a hexamethylene group, an octamethylene group, a 2,2-dimethyl-1,3-propylene group, and a propylene group is preferable. Further, * in the * -COR ⁷ -group indicates that the carbonyl group is a part bonded to the oxygen atom of the phosphite group. Representative examples of the alkylene group having 1 to 8 carbon atoms in R ⁷ include, for example, methylene group, ethylene group, propylene group, butylene group, pentamethylene group, hexamethylene group, octamethylene group, 2,2-dimethyl- 1,3
-Propylene groups and the like. * -CO (R ⁷⁾ m-
The group is preferably a * -CO- group in which m is 0, or a * -CO- group in which m is 1 and R ⁷ is ethylene.
(CH ₂ CH ₂ ) — group.

One of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Represents

Here, the alkyl group having 1 to 8 carbon atoms includes, for example, the same alkyl groups as described above. As the alkoxy group having 1 to 8 carbon atoms, for example, the alkyl moiety has the above-described alkyl group having 1 to 8 carbon atoms. As the aralkyloxy group having 7 to 12 carbon atoms, for example, an aralkyloxy group having the same aralkyl as the aralkyl having 7 to 12 carbon atoms can be used. .

The phosphites used in the present invention are preferably the following compounds (compounds 1 to 13). The structures of Compounds 1 to 13 are shown in Formulas 1 to 13. Compound 1: 2,4,8,10-tetra-t-butyl-6- [3-
(3-Methyl-4-hydroxy-5-t-butylphenyl) propoxy] dibenzo [d, f] [1,3,2] dioxaphosphepin

Embedded image

Compound 2: 2,10-dimethyl-4,8-di-tert-butyl-6
[3- (3,5-Di-t-butyl-4-hydroxyphenyl) propoxy] -12H-dibenzo [d, g] [1,
3,2] dioxaphosphosine,

Embedded image

Compound 3: 2,4,8,10-tetra-t-butyl-6- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propoxy] dibenzo [d, f] [1,3,2] dioxaphosphepin,

Embedded image

Compound 4: 2,4,8,10-tetra-t-pentyl-6- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propoxy] -12-methyl-12H-dibenzo [d,
g] [1,3,2] dioxaphosphosine,

Embedded image

Compound 5: 2,10-dimethyl-4,8-di-tert-butyl-6
[3- (3,5-Di-t-butyl-4-hydroxyphenyl) propionyloxy] -12H-dibenzo [d,
g] [1,3,2] dioxaphosphosine,

Embedded image

Compound 6: 2,4,8,10-tetra-t-pentyl-6- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] -12-methyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphine,

Embedded image

Compound 7: 2,4,8,10-tetra-t-butyl-6- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] -dibenzo [d, f] [1,3,2]
Dioxaphosphepin,

Embedded image

Compound 8: 2,10-dimethyl-4,8-di-tert-butyl-6-
(3,5-di-t-butyl-4-hydroxybenzoyloxy) -12H-dibenzo [d, g] [1,3,2] dioxaphosphine,

Embedded image

Compound 9: 2,4,8,10-tetra-t-butyl-6- (3,5
-Di-t-butyl-4-hydroxybenzoyloxy)
-12-methyl-12H-dibenzo [d, g] [1,3
2] dioxaphosphosine,

Embedded image

Compound 10: 2,10-dimethyl-4,8-di-tert-butyl-6 [3
-(3-Methyl-4-hydroxy-5-t-butylphenyl) propoxy] -12H-dibenzo [d, g] [1,
3,2] dioxaphosphosine,

Embedded image

Compound 11: 2,4,8,10-tetra-t-butyl-6- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propoxy] -12H-dibenzo [d, g] [1,3,2]
Dioxaphosphosine,

Embedded image

Compound 12: 2,10-diethyl-4,8-di-t-butyl-6 [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -12H-dibenzo [d, g] [1,3
2] dioxaphosphosine,

Embedded image

Compound 13: 2,4,8,10-tetra-t-butyl-6- [2,2
-Dimethyl-3- (3-t-butyl-4-hydroxy-
5-methylphenyl) propoxy] -dibenzo [d, f]
[1,3,2] dioxaphosphepin.

Embedded image

The content of the phosphite used in the present invention is 0.1 to 100 parts by weight of polypropylene.
0.01 to 0.5 part by weight, preferably 0.01 to 0.5 part by weight.
3 parts by weight. If the content of the phosphite is less than 0.01 part by weight with respect to 100 parts by weight of polypropylene, the odor and taste may be deteriorated, and if it exceeds 0.5 part by weight, the effect is saturated. Not economical.

Polypropylene 100 used in the present invention
The resin composition containing 0.1 parts by weight and 0.01 to 0.5 parts by weight of phosphites contains an acrylate compound or a phenolic antioxidant represented by the following formula (II).
You may add 01-1 weight part. (In the formula (II), R ⁶ is an alkyl group having 1 to 5 carbon atoms, R ⁷ is an alkyl group having 1 to 8 carbon atoms, R ⁸ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, ⁹ represents a hydrogen atom or a methyl group.)

In the formula (II), R ⁶ has 1 carbon atom.
And 5 alkyl groups, such as a methyl group, an ethyl group, a propyl group, a t-butyl group, and a 2,2-dimethylpropyl group. It is preferably a methyl group or an ethyl group, and more preferably an ethyl group.

In the formula (II), R ⁷ has 1 carbon atom.
And 8 alkyl groups, for example, a methyl group, an ethyl group, a propyl group, a t-butyl group, a t-pentyl group,
t-octyl group and the like. Preferably a methyl group,
It is a t-butyl group or a t-pentyl group, and more preferably a t-pentyl group.

In the formula (II), R ⁸ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, such as a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an octyl group and the like. Is mentioned. It is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.

In the formula (II), R ⁹ is a hydrogen atom or a methyl group. Preferably it is a hydrogen atom.

The acrylate compound used in the present invention includes, for example, 2,4-di-t-amyl-6- [1-
(3,5-di-t-amyl-2-hydroxyphenyl)
Ethyl] phenyl acrylate, 2,4-di-t-amyl-6- [1- (3,5-di-t-amyl-2-hydroxyphenyl) butyl] phenyl acrylate, 2,4
-Di-t-amyl-6- [1- (3,5-di-t-amyl-2-hydroxyphenyl) propyl] phenyl acrylate, 2-tert-butyl-6- (3-tert-butyl-2)
-Hydroxy-5-methylbenzyl) -4-methylphenyl acrylate and the like.

Preferably, 2,4-di-t-amyl-6 is used.
-[1- (3,5-di-tert-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate and 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl)- 4-methylphenyl acrylate.

The acrylate compound used in the present invention can be appropriately selected from commercially available ones. For example, 2-t-butyl-6- (3-t-butyl-
SUMILIZER GM (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., which is 2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6
Sumilizer GS (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., which is-[1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate.

The phenolic antioxidant used in the present invention is, for example, a hindered phenolic antioxidant or a single hindered phenolic antioxidant.
2,6-di-t-butyl-4-methylphenol, tetrakis [methylene-3 (3 ′, 5′-di-t-butyl-
4-hydroxyphenyl) propionate] methane, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 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 2 [3 (3,5-
Di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl isocyanate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-
4-hydroxybenzyl) benzene,

Tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate Pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-N-bis-3- (3-t-butyl-5-methyl-4) -Hydroxyphenyl) propionate, 1,6
-Hexanediol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,
2-thiobis-diethylenebis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate], 2,2'-methylene-bis- (4-methyl-6-
t-butylphenol), 2,2'-methylene-bis-
(4-ethyl-6-t-butylphenol), 2,2 ′
-Methylene-bis- (4,6-di-t-butylphenol), 2,2'-ethylidene-bis- (4,6-di-t
-Butylphenol) (Cheminox 1129), 2,
2′-butylidene-bis- (4-methyl-6-t-butylphenol), 4,4′-butylidenebis (3-methyl-6-t-butylphenol), 2-t-butyl-6
-(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6- (1- (3,5-di-t-amyl-
2-hydroxyphenyl) ethyl] phenyl acrylate and the like.

Among the phenolic antioxidants described above, a phenolic antioxidant having at least one group represented by the following general formula (III) or 1,3,5-tris (3,5- It comprises at least one member selected from di-t-butyl-4-hydroxybenzyl) isocyanurate. (In the formula (III), R ¹⁰ and R ¹¹ represent a hydrogen atom, a methyl group or a t-butyl group, which may be the same or different.)

Examples of the phenolic antioxidant having at least one group represented by the general formula (III) include tetrakis [methylene-3 (3 ′, 5′di-tert-butyl-4-hydroxyphenyl). ) Propionate] methane, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 3,
9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,
1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol-N-bis-3- (3-t-butyl-5-methyl-4-
Hydroxyphenyl) propionate, 1,6-hexanediol bis [3- (3,5-di-t-butyl-4-)
Hydroxyphenyl) propionate] and 2,2-thiobis-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate].

The content of the acrylate compound or the phenolic antioxidant used in the present invention depends on the odor, taste, stain resistance to processing machine, color tone of the resin composition and the molded article made of the same, and the surface appearance of the film when formed into a film. From the viewpoint of, usually, 100 parts by weight of the polypropylene resin,
0.01 to 0.5 parts by weight, preferably 0.01 to 0.5 parts by weight.
0.3 parts by weight.

Other additives and other resins may be added to the resin composition used in the present invention as long as the objects and effects of the present invention are not impaired. For example, phosphorus antioxidants, sulfur antioxidants, ultraviolet absorbers, light stabilizers, hydroxylamine, lubricants, adhesives, antifogging agents, plasticizers, flame retardants, nucleating agents, metal deactivators, Examples include an antistatic agent, a pigment, an antiblocking agent, a surfactant, a processing aid, a foaming agent, an emulsifier, a brightener, a coloring improver, and an auxiliary stabilizer.

Other resins include various olefin resins such as polyethylene and polybutene, and ethylene and α-
Examples thereof include olefin copolymer elastomers, which may be those produced with a heterogeneous catalyst or those produced with a homogeneous catalyst such as a metallocene catalyst. Further, a styrene-based copolymer rubber obtained by hydrogenating a styrene-butadiene-styrene copolymer or a styrene-isoprene-styrene copolymer may, for example, be mentioned.

The method for producing the resin composition used in the present invention is not particularly limited, and includes a known heat-melt mixing method. For example, polypropylene, phosphites, and, if necessary, acrylate compounds, phenolic antioxidants, other additives, and other resins are directly mixed using a mixing device such as a Henschel mixer, and then heat-mixed. A method in which phosphites, other additives and other resins are blended with polypropylene in the form of a polypropylene masterbatch having a high concentration thereof, and then heated and melt-mixed, a meltable additive In a molten state, and added to the extruder in a liquid state, followed by melting and heat mixing.

Here, the acrylate compound, phenolic antioxidant, other additives and other resins added as necessary may be added simultaneously with the phosphites, or may be added at another stage. May be.

The apparatus used for the heating and melting mixing includes:
For example, an extruder, a Banbury mixer, a batch type kneader and the like can be mentioned. The conditions of the heat-melt mixing method are preferably in the presence of an inert gas (nitrogen, argon, etc.), and the temperature of the heat-melt mixing is usually lower than 300 ° C, preferably 180 to 250 ° C. .

The molded article for food packaging of the present invention is not particularly limited, and examples thereof include a film, a sheet, and a blow molded article. Further, the molded product for food packaging of the present invention may be a single-layer molded product, or may be a laminated molded product including at least one layer that is the molded product for food packaging of the present invention. The other layers used are not particularly limited.

As a method for producing a film or sheet which is a molded product for food packaging of the present invention, a method for producing a single-layer film or sheet using a usual inflation method, a T-die method, a calendar method, or the like, Alternatively, a method of producing a film or a sheet as at least one layer of a laminate formed with a different resin may be used. Examples of the manufacturing method of the laminated molded body include a usual extrusion laminating method, a heat laminating method, a dry laminating method, and the like.

Examples of the method for producing the film include a method for producing a film by stretching the obtained film or sheet. Examples of the stretching method include a roll stretching method, a tenter stretching method, and a tubular stretching method. And a method of stretching uniaxially or biaxially.

Examples of uses of the molded article for food packaging of the present invention include packaging bags and pouches obtained by using films, trays and containers obtained by using sheets, and blow containers. Examples of the manufacturing method of the packaging bag include a method of heat sealing and fusing the film, and examples of the manufacturing method of the tray and the container include a secondary forming method such as pressure forming or vacuum forming. Examples of the method for producing the container include a direct blow molding method and a stretch blow molding method.

[0066]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The measurement and evaluation of the physical properties of the polypropylene and the resin composition used in the examples and comparative examples were performed according to the following methods. (1) Ethylene Content of Polypropylene (Unit:% by Weight) The ethylene content was measured by IR spectroscopy, and described in Polymer Handbook (1995, published by Kinokuniya Bookstore).
It was determined in accordance with the method for (ii) block copolymer described on page. (2) Amount of xylene-soluble component of polypropylene at 20 ° C. (unit:% by weight) After completely dissolving 1 g of a sample in 100 ml of boiling xylene, the temperature was lowered to 20 ° C. and left for 4 hours. Thereafter, this was separated by filtration into a precipitate and a solution, and the filtrate was dried to 70 ° C. under reduced pressure.
And dried. The weight was measured to determine the amount of xylene-soluble components at 20 ° C. (3) Melt flow rate (MFR, unit: g / 10
Min) According to JIS K7210, temperature 230 ° C, load 2
1. Measured at 18N.

(4) Odor test Two 10.5 cm × 12 cm film samples were placed in a container having an inner volume of 200 ml, covered with aluminum foil, and adjusted in an air oven at 60 ° C. for 2 hours. Then, after leaving at room temperature for 30 minutes, a sensory test was performed. The odor was determined based on the following criteria. ：: Almost no smell. Δ: Smell was weak. X: Strong smell.

(5) Taste test 6.0 g of a film cut into 100 mm × 10 mm strips in a 300 ml container and 240 ml of mineral water
, And covered with aluminum foil and boiled for 30 minutes. After standing at room temperature overnight, 50 ml of water was poured into the cup, and a sensory test was performed. The taste was determined according to the following criteria. ：: Almost no taste. Δ: Slightly tasted. ×: Taste was clearly felt.

(6) Impact strength (-15 ° C., unit: kg-
(cm / mm) At −15 ° C., the impact strength of the film was measured using a hemispherical impact head having a diameter of 15 mm using a film impact tester manufactured by Toyo Seiki.

Example 1 0.01 part by weight of calcium hydroxide based on 100 parts by weight of polypropylene (propylene-ethylene block copolymer, ethylene content 5.2% by weight, xylene soluble component at 20 ° C. 11.7% by weight) And 0.10 part by weight of the following phosphite compound (1) (the compound 1 represented by the above-mentioned (Chemical Formula 1)) was added, and the mixture was mixed for 3 minutes with a nitrogen-substituted Henschel mixer. This mixture was supplied to a hopper purged with nitrogen, and melt-kneaded at a set temperature of 220 ° C. using a 40 mmφ single screw extruder to form pellets. MFR was 2.7 g / 10 minutes. After the obtained pellets were dried in an air oven at 100 ° C. for 24 hours, a φ equipped with a coat hanger type T die having a width of 400 mm was used.
Using a 50 mm extruder, resin temperature 300 ° C, discharge rate 1
The film was extruded at 2 kg / hr, cooled by a chill roll temperature of 50 ° C., a line speed of 20 m / min, and an air chamber cooling method to prepare a film having a thickness of 60 μm and evaluated.
The results are shown in Table 1.

Phosphite compound (1): 2,4
8,10-tetra-t-butyl-6- [3- (3-methyl-4-hydroxy-5-t-butylphenyl) propoxy] dibenzo [d, f] [1,3,2] dioxaphospho Pin (CAS No. 203255-81-6)
(Sumilyzer GP: manufactured by Sumitomo Chemical Co., Ltd.)

Example 2 Example 2 was carried out in the same manner as in Example 1, except that 0.10 part by weight of Irganox 1010 (manufactured by Ciba Specialty Chemicals) was further used. The MFR of the pellet was 2.7 g / 10 minutes. Using the obtained pellets, a film was prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

Example 3 In Example 1, the phosphite compound (1) was changed to 0.05 parts by weight, and Irganox 101 was further added.
0 (manufactured by Ciba Specialty Chemicals) 0.20
The procedure was performed in the same manner as in Example 1 except that parts by weight were used. The MFR of the pellet was 2.6 g / 10 minutes. Using the obtained pellets, a film was prepared in the same manner as in Example 1 and evaluated.

Example 4 The procedure of Example 1 was repeated, except that 0.05 parts by weight of Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) was used. The MFR of the pellet is 2.8 g / 1.
It was 0 minutes. Using the obtained pellets, a film was prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

Example 5 The procedure of Example 1 was repeated except that 0.10 parts by weight of Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) was used. The MFR of the pellet is 2.8 g / 1.
It was 0 minutes. Using the obtained pellets, a film was prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

Comparative Example 1 Phosphite compound (1) used in Example 1
Example 1 was repeated, except that 10 parts by weight was changed to 0.20 part by weight of Irganox 1010 (manufactured by Ciba Specialty Chemicals). The MFR of the pellet was 3.4 g / 10 minutes. Using the obtained pellets, a film was prepared in the same manner as in Example 1 and evaluated.
The results are shown in Table 1.

Comparative Example 2 Phosphorous ester compound (1) used in Example 1
10 parts by weight of 0.20 parts by weight of Irganox 1010 (manufactured by Ciba Specialty Chemicals) and Irgafos 168 (manufactured by Ciba Specialty Chemicals)
The procedure was performed in the same manner as in Example 1 except that the amount was changed to 0.05 part by weight. The MFR of the pellet was 2.7 g / 10 minutes.
Using the obtained pellets, a film was prepared in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

[0078]

[Table 1]

Examples 1-4 satisfying the requirements of the present invention are as follows:
It turns out that it is excellent in odor, taste, and impact strength. On the other hand, it can be seen that Comparative Example 1, which did not use phosphites, which is a requirement of the present invention, had insufficient odor and impact strength, and Comparative Example 2 had insufficient taste.

[0080]

As described above, according to the present invention, it is possible to obtain a molded article for food packaging excellent in odor, taste and impact strength.

Continued on front page F term (reference) 3E086 AB01 BA02 BB15 BB85 CA01 DA08 4J002 BB121 BB141 BB151 BP021 EJ027 EJ037 EJ047 EJ067 ER007 EU197 EV077 EW066 FD077 GG01 GG02

Claims (4)

[Claims] (1) 100 parts by weight of polypropylene and the following general formula (I) (In the formula (I), R ¹ , R ² , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, and a carbon atom having 6 carbon atoms. Represents an alkylcycloalkyl group having 1 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms or a phenyl group, R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and X represents a sulfur atom or —CHR ⁶ —. A group (R ⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms), and n is 0 or 1. A is an alkylene having 2 to 8 carbon atoms. Group or * -CO (R ⁷ ) m- group (R ⁷ is
In the alkylene group of 8, * indicates that the moiety is bonded to an oxygen atom, and m is 0 or 1. ). Y,
Z is one of a hydroxyl group and 1 to 1 carbon atoms.
8 represents an alkoxy group or an aralkyloxy group having 7 to 12 carbon atoms, and the other represents a hydrogen atom or 1 carbon atom.
To 8 alkyl groups. A molded product for food packaging, comprising a resin composition containing 0.01 to 0.5 parts by weight of the phosphites represented by the formula (1). 2. A molded article for food packaging according to claim 1, comprising a resin composition containing 100 parts by weight of polypropylene and 0.01 to 0.3 parts by weight of phosphites. 3. A polypropylene copolymer comprising a component obtained by polymerizing a monomer mainly composed of propylene and a component obtained by copolymerizing propylene and ethylene. 2. The molded article for food packaging according to 1. 4. 100 parts by weight of polypropylene, 0.01 to 0.5 parts by weight of phosphites, and 0.01 to 0.5 parts by weight of an acrylate compound or a phenolic antioxidant represented by the following general formula (II): A molded article for food packaging, comprising a resin composition containing 1 part by weight. (In the formula (II), R ¹ is an alkyl group having 1 to 5 carbon atoms, R ² is an alkyl group having 1 to 8 carbon atoms, R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, ⁴ represents a hydrogen atom or a methyl group.)