JPH06145430A - Stabilized polyolefin composition - Google Patents

Abstract

PURPOSE:To provide a polyolefin composition excellent in processing stability and in improving effect for the coloration due to an antioxidant used. CONSTITUTION:The composition is obtained by incorporating (A) 100 pts.wt. of a polyolefin with (B) 0.005-0.05 pts.wt. of nordihydroguaiaretic acid and (C) 0.01-0.5 pts.wt. of an organophosphorus antioxidant.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to stabilized polyolefin compositions. More specifically, it relates to a polyolefin composition having excellent oxidative deterioration-preventing property of polyolefin during melt-kneading.

[0002]

2. Description of the Related Art Generally, polyolefin is relatively inexpensive and has excellent mechanical properties, and therefore it is used for producing various molded products such as injection molded products, hollow molded products, films, sheets and fibers. However, the polyolefin is molded and processed at a temperature equal to or higher than the melting point of the polyolefin, and is subjected to oxidative deterioration due to heat at the time of melt-kneading. There is a problem of discoloration and odor due to deterioration of properties and oxidative deterioration. In particular, since the propylene-based polymer has a tertiary carbon which is susceptible to oxidation in the polymer, it has a problem in heat-oxidative deterioration during melt-kneading (hereinafter referred to as processing stability).

Therefore, various antioxidants (processing stabilizers) have been widely used for the purpose of preventing thermal oxidative deterioration during melt-kneading of polyolefin. It is known to use tocopherols as these processing stabilizers, but tocopherols are viscous liquids and are complicated to handle, and when only tocopherols are added, sufficient processing stability is required unless a large amount is added. Is not obtained, and when a large amount is blended, there arises a problem that coloring due to tocopherols becomes remarkable. When nordihydroguaiaretic acid is used instead of tocopherols as a processing stabilizer, the processing stability is remarkably superior to tocopherols, but like tocopherols, the coloring caused by nordihydroguaiaretic acid becomes remarkable. Such a problem occurs. Further, in JP-A-62-39684, an antioxidant composition containing an antioxidant such as tocopherol, nordihydroguaiaretic acid, a condensed phosphate which is an inorganic phosphate and citric acid is a synthetic resin. It can be used for.

[0004]

However, in the above-mentioned JP-A-62-39684, the processing stability of a polyolefin composition in which nordihydroguaiaretic acid, condensed phosphate and citric acid are blended with polyolefin as a synthetic resin is disclosed. The anti-coloring property is similar to that of the polyolefin composition containing nordihydroguaiaretic acid alone, and almost no combined effect of condensed phosphate and citric acid on nordihydroguaiaretic acid is observed.
Further, the publication merely exemplifies an inorganic phosphate as the condensed phosphate to be used, and an organic phosphite-based compound, an organic phosphonite-based compound, an organic phosphinate-based compound, an organic phosphonate is used. There is no description or suggestion of organophosphorus antioxidants composed of nate compounds.

The present inventor has conducted extensive studies in order to solve the above-mentioned problems relating to the above-mentioned polyolefin composition, that is, the processing stability and the drawback of colorability due to the antioxidant used. As a result, the present inventor has found that a composition obtained by incorporating a specific amount of nordihydroguaiaretic acid and an organophosphorus antioxidant into a polyolefin can solve the above-mentioned drawbacks of the polyolefin composition. The present invention has been completed based on the findings. As is clear from the above description, an object of the present invention is to provide a polyolefin composition which is excellent in processing stability and the effect of improving the coloring property due to the antioxidant used.

[0006]

The present invention has the following constitution. A stabilized polyolefin composition comprising 0.005 to 0.05 part by weight of nordihydroguaiaretic acid and 0.01 to 0.5 part by weight of an organic phosphorus antioxidant, based on 100 parts by weight of the polyolefin.

The polyolefin used in the present invention is a crystalline homopolymer of α-olefin such as ethylene, propylene, butene-1, pentene-1, 4-methyl-pentene-1, hexene-1, octene-1, and the like. Polyolefin such as crystalline, low crystalline or amorphous random copolymer or crystalline block copolymer of two or more α-olefins, amorphous ethylene-propylene-nonconjugated diene terpolymer, etc. A copolymer of α-olefin with vinyl acetate or acrylic acid ester, a saponified product of the copolymer, a copolymer of these α-olefin and an unsaturated silane compound, an α-olefin and an unsaturated carboxylic acid or A copolymer of the anhydride, a reaction product of the copolymer and a metal ion compound, and a modification of the above-mentioned polyolefin with an unsaturated carboxylic acid or a derivative thereof. Examples of the polyolefin include olefin-modified polyolefins and silane-modified polyolefins obtained by modifying the above-mentioned polyolefins with unsaturated silane compounds. These polyolefins can be used alone or in combination of two or more kinds.

In addition to the above-mentioned polyolefins, various synthetic rubbers (for example, polybutadiene, polyisoprene, polychloroprene, chlorinated polyethylene, chlorinated polypropylene, fluororubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, styrene-butadiene-).
Styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-
Styrene block copolymer, styrene-propylene-butylene-styrene block copolymer, etc.) or thermoplastic synthetic resin (eg polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, polyamide, polyethylene terephthalate, poly polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, fluorine resin, petroleum resin (e.g. C ₅ petroleum resins, hydrogenated C ₅ system Petroleum resin, C
_9- based petroleum resin, hydrogenated C _9- based petroleum resin, C ₅ -C ₉ copolymerized petroleum resin, hydrogenated C ₅ -C ₉ copolymerized petroleum resin, acid-modified C _9- based petroleum resin, etc., DCPD resin (eg cyclo Pentadiene petroleum resin, hydrogenated cyclopentadiene petroleum resin, cyclopentadiene-C ₅ copolymer petroleum resin, hydrogenated cyclopentadiene-C ₅ copolymer petroleum resin, cyclopentadiene-C ₉ copolymer petroleum resin, hydrogenated cyclopentadiene- C ₉ copolymerized petroleum resin, cyclopentadiene-C ₅ -C ₉ copolymerized petroleum resin, hydrogenated cyclopentadiene-C ₅ -C ₉ copolymerized petroleum resin, etc., having a softening point of 80 to 200 ° C. Can also be used. Crystalline propylene homopolymer, a crystalline propylene copolymer containing 70% by weight or more of a propylene component, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer,
Crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene-butene-1 terpolymer, crystalline propylene-hexene-butene-1 terpolymer and a mixture of two or more thereof. Particularly preferably used.

Nordihydroguaiaretic acid (hereinafter abbreviated as NDGA) used in the present invention, that is, 4,
4 '-(2,3-Dimethyl-tetramethylene) dipyrocatechol is a white crystalline powder substance with a melting point of 184-185 ° C. It is a guaiac fat extracted from creosote bush in the semi-desert region of the Southwestern United States. The main ingredients are oil, butter,
It is used as an antioxidant for cheese and is recognized as a food additive. The blending ratio of NDGA is 0.005 to 0.05 parts by weight, preferably 0.01 to 0.03 parts by weight, based on 100 parts by weight of polyolefin. When the amount is less than 0.005 parts by weight, the effect of improving the processing stability of the polyolefin composition is not sufficiently exhibited, and when it is more than 0.05 parts by weight, the coloring becomes remarkable.

The organophosphorus antioxidants used in the present invention include distearyl-pentaerythritol-diphosphite, diphenyl-pentaerythritol-diphosphite, bis (nonylphenyl) -pentaerythritol-diphosphite, catesyl- 2,6-di-t-butyl-4-
Methylphenyl phosphite, catesyl-2,4,6-tri-
t-Butylphenylphosphite, α-naphthylcatesylphosphite, 2,2'-methylenebis (4-methyl-6-t-
Butylphenyl) -2-naphthylphosphite, 4,4'-butylidene-bis (3-methyl-6-t-butylphenyl-di-tridecylphosphite), 1,1,3-tris (2-methyl-) Four-
Di-tridecylphosphite-5-t-butylphenyl) butane, trilauryltrithiophosphite, tricetyltrithiophosphite, di (laurylthio) pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10- Phosphaphenanthrene-10-oxide, 10
-Hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, triphenylphosphite, tris (nonylphenyl) phosphite, tris (2,4-di-nonylphenyl) phosphite Fight, tris (mono, dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2,6-di-t-butyl-4-methylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol-diphosphite, bis (2,6-di-t-butyl-4-
Methylphenyl) pentaerythritol-diphosphite, bis (2,6-di-t-butyl-4-s-butylphenyl) pentaerythritol-diphosphite, bis (2,4,6-
(Tri-t-butylphenyl) pentaerythritol-diphosphite, bis (2,6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) pentaerythritol-diphosphite, bis [2,6- Di-t-butyl-4-
(2 ', 4'-Di-t-butylphenyloxycarbonyl) -phenyl] pentaerythritol-diphosphite, bis (2,6-di-t-butyl-4-n-hexadecyloxycarbonyl
-Phenyl) pentaerythritol-diphosphite,

Tetrakis (2,4-di-t-butylphenyl)-
4,4'-biphenylene-di-phosphonite, tetrakis (2,6-di-t-butyl-4-methylphenyl) -4,4'-biphenylene-di-phosphonite, tetrakis (2,6- Di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) -4,4'-biphenylene-di-phosphonite, tetrakis [2,6-di-t-butyl-4- (2 ', 4) '-Di-t-butylphenyloxycarbonyl) -phenyl] -4,4'-biphenylene-
Di-phosphonite, tetrakis (2,6-di-t-butyl-4
-n-hexadecyloxycarbonyl-phenyl) -4,4'-biphenylene-di-phosphonite, tetrakis (2,4-di)
-t-Butylphenyl) -3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5]
Undecane-diphosphite, tetrakis (2,6-di-t-
Butyl-4-methylphenyl) -3,9-bis (1,1-dimethyl-2)
-Hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane-diphosphite, tetrakis (2,
6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) -3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [ 5.5] Undecane-diphosphite, tetrakis [2,6-di-t-butyl
-4- (2 ', 4'-di-t-butylphenyloxycarbonyl)-
Phenyl] -3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane-
Diphosphite, tetrakis (2,6-di-t-butyl-4-n-
Hexadecyloxycarbonyl-phenyl) -3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane-diphosphite,
Bis [2,2'-methylene-bis (4-methyl-6-t-butylphenyl)]-4,4'-biphenylene-di-phosphonite, bis [2,2'-methylene-bis (4, 6-di-t-butylphenyl)]-4,4'-biphenylene-di-phosphonite, bis [2,2'-ethylidene-bis (4-methyl-6-t-butylphenyl)]-4, 4'-biphenylene-di-phosphonite, bis [2,2'-ethylidene-bis (4,6-di-t-butylphenyl)]-4,4'-biphenylene-di-phosphonite, bis [ 2,2'-Methylene-bis (4-methyl-6-t-butylphenyl)]-3,9-bis (1,1-dimethyl-2-hydroxyethyl)
-2,4,8,10-Tetraoxaspiro [5.5] undecane-diphosphite, bis [2,2'-methylene-bis (4,6-di-t-
Butylphenyl)]-3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane-diphosphite, bis [2,2'- Ethylidene-
Bis (4-methyl-6-t-butylphenyl)]-3,9-bis (1,
1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane-diphosphite, bis [2,2'-ethylidene-bis (4,6-di-t-butyl) Phenyl)]-3,9-bis (1,1-dimethyl-2-hydroxyethyl)
-2,4,8,10-Tetraoxaspiro [5.5] undecane-diphosphite,

2,2'-bis (4,6-di-t-butylphenyl) octylphosphite, 2,2'-bis (4,6-di-t-butylphenyl) nonylphosphite, 2,2 '-Bis (4,6-di-t-
Butylphenyl) laurylphosphite, 2,2'-bis (4,6-di-t-butylphenyl) tridecylphosphite, 2,2'-bis (4,6-di-t-butylphenyl) myristylphosphite Fight, 2,2'-bis (4,6-di-t-butylphenyl) stearyl phosphite, 2,2'-bis (4,6-di-t-
Butylphenyl) (2,4-di-t-butylphenyl) phosphite, 2,2'-bis (4,6-di-t-butylphenyl) (2,
6-di-t-butyl-4-methylphenyl) phosphite, 2,
2'-bis (4,6-di-t-butylphenyl) (2,4,6-tri-t-
Butylphenyl) phosphite, 2,2'-bis (4,6-di-
t-butylphenyl) (2,6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) phosphite, 2,2'-bis (4,6-di-t-butylphenyl) [2 , 6-di-t
-Butyl-4- (2 ', 4'-di-t-butylphenyloxycarbonyl) -phenyl] phosphite, 2,2'-bis (4,6-di
-t-Butylphenyl) (2,6-di-t-butyl-4-n-hexadecyloxycarbonyl-phenyl) phosphite, 2,
2'-methylene-bis (4-methyl-6-t-butylphenyl) octyl phosphite, 2,2'-methylene-bis (4-methyl
-6-t-Butylphenyl) nonylphosphite, 2,2'-methylene-bis (4-methyl-6-t-butylphenyl) laurylphosphite, 2,2'-methylene-bis (4-methyl-6) -t-
Butylphenyl) tridecylphosphite, 2,2'-methylene-bis (4-methyl-6-t-butylphenyl) myristylphosphite, 2,2'-methylene-bis (4-methyl-6-t)
-Butylphenyl) stearyl phosphite, 2,2'-methylene-bis (4-methyl-6-t-butylphenyl) (2,4-diphenyl)
-t-Butylphenyl) phosphite, 2,2'-methylene-
Bis (4-methyl-6-t-butylphenyl) (2,6-di-t-butyl-4-methylphenyl) phosphite, 2,2'-methylene
-Bis (4-methyl-6-t-butylphenyl) (2,4,6-tri-t
-Butylphenyl) phosphite,

2,2'-methylene-bis (4-methyl-6-t-butylphenyl) (2,6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) phosphite, 2, 2'-
Methylene-bis (4-methyl-6-t-butylphenyl) [2,6-
Di-t-butyl-4- (2 ', 4'-di-t-butylphenyloxycarbonyl) -phenyl] phosphite, 2,2'-methylene
-Bis (4-methyl-6-t-butylphenyl) (2,6-di-t-butyl-4-n-hexadecyloxycarbonyl-phenyl) phosphite, 2,2'-methylene-bis (4, 6-di-t-butylphenyl) octylphosphite, 2,2'-methylene-bis (4,6-di-t-butylphenyl) nonylphosphite, 2,2'-methylene-bis (4,6- Di-t-butylphenyl)
Lauryl phosphite, 2,2'-methylene-bis (4,6-di
-t-Butylphenyl) tridecyl phosphite, 2,2'-
Methylene-bis (4,6-di-t-butylphenyl) myristyl phosphite, 2,2'-methylene-bis (4,6-di-t-butylphenyl) stearyl phosphite, 2,2'-methylene- Bis (4,6-di-t-butylphenyl) (2,4-di-t-butylphenyl) phosphite, 2,2'-methylene-bis (4,
6-di-t-butylphenyl) (2,6-di-t-butyl-4-methylphenyl) phosphite, 2,2'-methylene-bis (4,6-
Di-t-butylphenyl) (2,4,6-tri-t-butylphenyl) phosphite, 2,2'-methylene-bis (4,6-di-t-
Butylphenyl) (2,6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) phosphite,
2,2'-methylene-bis (4,6-di-t-butylphenyl) [2,6
-Di-t-butyl-4- (2 ', 4'-di-t-butylphenyloxycarbonyl) -phenyl] phosphite, 2,2'-methylene
-Bis (4,6-di-t-butylphenyl) (2,6-di-t-butyl-
4-n-hexadecyloxycarbonyl-phenyl) phosphite, 2,2'-ethylidene-bis (4-methyl-6-t-butylphenyl) octylphosphite, 2,2'-ethylidene-bis (4-methyl) -6-t-Butylphenyl) nonylphosphite, 2,2'-ethylidene-bis (4-methyl-6-t-butylphenyl) laurylphosphite, 2,2'-ethylidene-bis (4-methyl-6) -t-Butylphenyl) tridecylphosphite, 2,2'-ethylidene-bis (4-methyl-6-t-
Butylphenyl) myristylphosphite, 2,2'-ethylidene-bis (4-methyl-6-t-butylphenyl) stearylphosphite, 2,2'-ethylidene-bis (4-methyl)
-6-t-Butylphenyl) (2,4-di-t-butylphenyl) phosphite, 2,2'-ethylidene-bis (4-methyl-6-t-
Butylphenyl) (2,6-di-t-butyl-4-methylphenyl) phosphite, 2,2'-ethylidene-bis (4-methyl)
-6-t-butylphenyl) (2,4,6-tri-t-butylphenyl) phosphite, 2,2'-ethylidene-bis (4-methyl)
-6-t-Butylphenyl) (2,6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) phosphite, 2,2'-ethylidene-bis (4-methyl-6-t- Butylphenyl) [2,6-di-t-butyl-4- (2 ', 4'-di-t-butylphenyloxycarbonyl) -phenyl] phosphite, 2,2'-ethylidene-bis (4-methyl) -6-t-butylphenyl) (2,6-di-t-butyl-4-n-hexadecyloxycarbonyl-phenyl) phosphite,

2,2'-ethylidene-bis (4,6-di-t-butylphenyl) octyl phosphite, 2,2'-ethylidene-
Bis (4,6-di-t-butylphenyl) nonylphosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) laurylphosphite, 2,2'-ethylidene-bis ( 4,6-Di-t-butylphenyl) tridecylphosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) myristylphosphite, 2,2'-ethylidene-bis (4 , 6-Di-t-butylphenyl) stearyl phosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) (2,4-di-t-butylphenyl) phosphite, 2 ,
2'-ethylidene-bis (4,6-di-t-butylphenyl) (2,6
-Di-t-butyl-4-methylphenyl) phosphite, 2,
2'-ethylidene-bis (4,6-di-t-butylphenyl) (2,
4,6-Tri-t-butylphenyl) phosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) (2,6-di-t
-Butyl-4-n-octadecyloxycarbonylethyl-phenyl) phosphite, 2,2'-ethylidene-bis (4,6-
Di-t-butylphenyl) [2,6-di-t-butyl-4- (2 ', 4'-
Di-t-butylphenyloxycarbonyl) -phenyl] phosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) (2,6-di-t-butyl-4-n- Hexadecyloxycarbonyl-phenyl) phosphite, 2,2'-thio-
Bis (4-methyl-6-t-butylphenyl) octylphosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl) nonylphosphite, 2,2'-thio-bis ( 4-methyl-6-t-butylphenyl) lauryl phosphite, 2,
2'-thio-bis (4-methyl-6-t-butylphenyl) tridecyl phosphite, 2,2'-thio-bis (4-methyl-6-t-
Butylphenyl) myristylphosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl) stearylphosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl) ) (2,4-Di-t-butylphenyl) phosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl)
(2,6-di-t-butyl-4-methylphenyl) phosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl)
(2,4,6-tri-t-butylphenyl) phosphite, 2,
2'-thio-bis (4-methyl-6-t-butylphenyl) (2,6-
Di-t-butyl-4-n-octadecyloxycarbonylethyl
-Phenyl) phosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl) [2,6-di-t-butyl-4- (2 ', 4'
-Di-t-butylphenyloxycarbonyl) -phenyl]
Phosphite, 2,2'-thio-bis (4-methyl-6-t-butylphenyl) (2,6-di-t-butyl-4-n-hexadecyloxycarbonyl-phenyl) phosphite,

2,2'-bis (4,6-di-t-butylphenyl) fluorophosphite, 2,2'-bis (4-methyl-6-t-butylphenyl) fluorophosphite, 2,2 '-Bis (4-t
-Amyl-6-methylphenyl) fluorophosphite,
2,2'-bis (4-s-eicosylphenyl) fluorophosphite, 2,2'-methylene-bis (4-methyl-6-t-butylphenyl) fluorophosphite, 2,2'-methylene- Bis (4-ethyl-6-t-butylphenyl) fluorophosphite, 2,2'-methylene-bis (4-methyl-6-nonylphenyl) fluorophosphite, 2,2'-methylene-bis (4, 6-dinonylphenyl) fluorophosphite, 2,
2'-methylene-bis (4-methyl-6-cyclohexylphenyl) fluorophosphite, 2,2'-methylene-bis (4-
Methyl-6- (1'-methylcyclohexyl) phenyl) fluorophosphite, 2,2'-i-propylidene-bis (4-nonylphenyl) fluorophosphite, 2,2'-butylidene-bis (4,6-) Dimethylphenyl) fluorophosphite, 2,2'-methylene-bis (4,6-di-t-butylphenyl) fluorophosphite, 2,2'-methylene-bis (4,
6-di-t-amylphenyl) fluorophosphite, 2,
2'-ethylidene-bis (4-methyl-6-t-butylphenyl)
Fluorophosphite, 2,2'-ethylidene-bis (4-ethyl-6-t-butylphenyl) fluorophosphite,
2,2'-ethylidene-bis (4-s-butyl-6-t-butylphenyl) fluorophosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) fluorophosphite, 2,2'-Ethylidene-bis (4,6-di-t-amylphenyl) fluorophosphite, 2,2'-methylene-bis (4-
Methyl-6-t-octylphenyl) fluorophosphite, 2,2'-butylidene-bis (4-methyl-6- (1'-methylcyclohexyl) phenyl) fluorophosphite, 2,
2'-methylene-bis (4,6-dimethylphenyl) fluorophosphite, 2,2'-thio-bis (4-t-octylphenyl) fluorophosphite, 2,2'-thio-bis (4,6 -J
-s-Amylphenyl) fluorophosphite, 2,2'-thio-bis (4,6-di-i-octylphenyl) fluorophosphite, 2,2'-thio-bis (5-t-butylphenyl) Fluorophosphite, 2,2'-thio-bis (4-methyl-6-t-
Butylphenyl) fluorophosphite, 2,2'-thio-
Bis (4-methyl-6-α-methylbenzylphenyl) fluorophosphite, 2,2'-thio-bis (3-methyl-4,6-di-
t-Butylphenyl) fluorophosphite and 2,2 '
Examples thereof include -thio-bis (4-t-amylphenyl) fluorophosphite.

Particularly bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite, bis (2,6-di-
t-Butyl-4-methylphenyl) -pentaerythritol-
Diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene-
Di-phosphonite, tris (2,4-di-t-butylphenyl) phosphite, 2,2'-methylene-bis (4,6-di-t-
Butylphenyl) octylphosphite and 2,2'-
Ethylidene-bis (4,6-di-t-butylphenyl) fluorophosphite is preferred. These organic phosphorus antioxidants may be used alone or in combination of two or more. The mixing ratio of the organophosphorus antioxidant is 0.01 to 0.5 part by weight, preferably 0.03 to 0.1 part by weight, based on 100 parts by weight of the polyolefin. With a blending ratio of less than 0.01 part by weight, the effect of improving the processing stability and the anti-coloring property is not sufficiently exhibited, and it may be more than 0.5 part by weight,
Further improvement in processing stability and discoloration resistance cannot be expected, which is impractical and uneconomical.

In the composition of the present invention, various additives which are usually added to polyolefins, for example, antioxidants such as phenol type and thioether type, light stabilizers, heavy metal deactivators (copper damage inhibitors) , Clarifying agents, Nucleating agents, Lubricants, Antistatic agents, Antifogging agents, Antiblocking agents, Dropless agents, Radical generators such as peroxides, Flame retardants, Pigments, Halogen scavengers, Metal soaps, etc. Dispersant or neutralizing agent, organic or inorganic antibacterial agent, inorganic filler (for example, talc, mica, clay, wollastonite, zeolite, kaolin, bentonite, perlite, diatomaceous earth, asbestos, calcium carbonate, water) Aluminum oxide, magnesium hydroxide, silicon dioxide, titanium dioxide, zinc oxide, magnesium oxide, zinc sulfide, barium sulfate, calcium silicate, silica Surface treatment such as aluminum, glass fiber, potassium titanate, carbon fiber, carbon black, graphite and metal fiber), coupling agent (eg silane, titanate, boron, aluminate, zircoaluminate, etc.) The above-mentioned inorganic filler or organic filler (for example, wood flour, pulp, waste paper, synthetic fiber, natural fiber, etc.) surface-treated with the agent can be used together within the range not impairing the object of the present invention.

In the composition of the present invention, a predetermined mixing amount of each of the above-mentioned NDGA and organophosphorus antioxidant and the above-mentioned various additives which are usually added to polyolefin is added to a polyolefin in a conventional mixing apparatus such as Henschel mixer (trade name), Mix using a super mixer, ribbon blender, Banbury mixer, etc.
It can be obtained by melt-kneading pelletizing at a melt-kneading temperature of 150 ° C. to 320 ° C., preferably 180 ° C. to 290 ° C. with a shaft extruder, a Brabender or a roll. The obtained composition is used for producing a desired molded article by various molding methods such as an injection molding method, an extrusion molding method and a blow molding method.

[0019]

In the present invention, NDGA acts as a radical chain inhibitor, and the organophosphorus antioxidant acts as a peroxide decomposer to improve the NDGA's processing stability synergistic agent and anti-coloring property. It is considered to be a thing.

[0020]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods used in Examples and Comparative Examples were as follows. 1) Processing stability: The melt flow rate (MFR) of the obtained pellets is measured (in accordance with JIS K6758), and this is designated as the first MFR. Then, the pellets obtained were melt-kneaded again at a melt-kneading temperature of 280 ° C. and pelletized, and this was repeated twice. M of the obtained pellet
FR is again measured by the above-mentioned method each time melt kneading is performed, and these are designated as second MFR and third MFR, respectively. The processing stability was evaluated from the magnitude of ΔMFR defined by the following formula. ΔMFR = 3rd MFR−1st MFR (3rd MFR indicates the MFR after passing through the extruder three times.) The smaller the value of this ΔMFR, the better the processing stability during repeated extrusion, in other words during molding. Indicates that. 2) Color prevention: YI (Yellowness) of the obtained pellets
Index) is measured (according to JIS K 7103), and this is designated as the first YI. Then, the pellets obtained were melt-kneaded again at a melt-kneading temperature of 280 ° C. and pelletized, and this was repeated twice. The YI of the obtained pellets is again measured by the above-mentioned method each time it is melt-kneaded, and these are designated as the second YI and the third YI, respectively. The anti-coloring property was evaluated from the size of ΔYI defined by the following formula. ΔYI = third YI−first YI (third YI indicates YI after passing through the extruder three times.) The smaller the numerical value of ΔYI, the better the coloring prevention property.

Examples 1 to 7 and Comparative Examples 1 to 5 MFR as polyolefin (load at 230 ° C. 2.16 k
Discharge amount of molten resin for 10 minutes when g is added) 6.0g / 10
100 parts by weight of non-stabilized powdery crystalline propylene homopolymer, NDGA, bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite as an organophosphorus antioxidant, Bis (2,6-di-t-butyl-4-
Methylphenyl) -pentaerythritol-diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-di-
t-Butylphenyl) -4,4'-biphenylene-di-phosphonite, 2,2'-methylene-bis (4,6-di-t-butylphenyl) octylphosphite, 2,2'-ethylidene- Bis (4,6-di-t-butylphenyl) fluorophosphite or tris (2,4-di-t-butylphenyl) phosphite and other additives are added in predetermined amounts, respectively, as described below.
Henschel mixer (trade name) in the mixing ratio shown in the table
After being stirred and mixed for 3 minutes, the mixture was melt-kneaded at 200 ° C. with a single screw extruder having a diameter of 40 mm to form pellets. Further, as Comparative Examples 1 to 5, 100 parts by weight of an unstabilized powdery crystalline propylene homopolymer having an MFR of 6.0 g / 10 min were added with respective predetermined amounts of the additives shown in Table 1 below. Melt-kneading processing was performed according to Examples 1 to 7 to obtain pellets. The pellets thus obtained were used to evaluate the processing stability and anti-coloring property according to the test method described above. The results are shown in Table 1.

Examples 8-14, Comparative Examples 6-10 100 parts by weight of unstabilized powdery crystalline ethylene-propylene block copolymer (ethylene content 8.5% by weight) as MFR 4.0 g / 10 min as polyolefin. To NDG
A, bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) -pentaerythritol as organic phosphorus antioxidant -Diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,
4'-biphenylene-di-phosphonite, 2,2'-methylene
-Bis (4,6-di-t-butylphenyl) octylphosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) fluorophosphite or tris (2,4-di- t
-Butylphenyl) phosphite and other additives in the prescribed amounts shown in Table 2 below in a Henschel mixer (trade name), and after stirring and mixing for 3 minutes, a single-screw extruder with a diameter of 40 mm The mixture was melt-kneaded at 200 ° C. and pelletized. Also, as Comparative Examples 6 to 10, MFR
Is 4.0 g / 10 minutes, and 100 parts by weight of an unstabilized powdery crystalline ethylene-propylene block copolymer (ethylene content: 8.5% by weight) is added with a predetermined amount of each of the additives described in Table 2 below. The ingredients were blended and melt-kneaded according to Examples 8 to 14 to obtain pellets. The pellets thus obtained were used to evaluate the processing stability and anti-coloring property according to the test method described above. The results are shown in Table 2.

Examples 15 to 21 and Comparative Examples 11 to 15 70% by weight of powdered crystalline propylene homopolymer having an MFR of 8.0 g / 10 min as a polyolefin and not stabilized, M
FR 7.0 g / 10 min unstabilized powdery crystalline ethylene-propylene-butene-1 terpolymer (ethylene content 2.5% by weight, butene-1 content 4.5% by weight) 5% by weight,
MI (amount of molten resin discharged at a load of 2.16 kg at 190 ° C for 10 minutes) 5.0 g / 10 minutes unstabilized powder Ziegler-Natta high density ethylene homopolymer
Unstabilized powdery amorphous ethylene-propylene random copolymer with 10% by weight and Mooney viscosity ML1 + 4 (100 ° C) of 25 (propylene content 25% by weight) 15% by weight in total 100 parts by weight NDGA, bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) -as organophosphorus antioxidant Pentaerythritol-diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene- The-
Phosphonite, 2,2'-methylene-bis (4,6-di-t-butylphenyl) octyl phosphite, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) fluorophosphite Fight or Tris (2,4-di-t-butylphenyl)
Put the specified amounts of phosphite and other additives into the Henschel mixer (trade name) at the compounding ratios shown in Table 3 below, stir and mix for 3 minutes, and then calibrate 40 mm.
Was melt-kneaded at 200 ° C. with a single-screw extruder to produce pellets. Further, as Comparative Examples 10 to 15, powdery crystalline propylene homopolymer 70 having an MFR of 8.0 g / 10 min, which is not stabilized.
Wt%, MFR 7.0 g / 10 min, powdered crystalline ethylene-propylene-butene-1 terpolymer not stabilized (ethylene content 2.5 wt%, butene-1 content 4.5 wt%) 5 Unstabilized powdered Ziegler-Natta high density ethylene homopolymer with wt% and MI of 5.0 g / 10 min
Unstabilized powdery amorphous ethylene-propylene random copolymer having a Mooney viscosity ML1 + 4 (100 ° C.) of 25 and 15% by weight, totaling 100% by weight Each part was blended with a predetermined amount of each of the additives shown in Table 3 below, and melt-kneaded according to Examples 15 to 21 to obtain pellets. The pellets thus obtained were used to evaluate the processing stability and anti-coloring property according to the test method described above. The results are shown in Table 3.

The various additives shown in Tables 1 to 3 are as follows. NDGA: nordihydroguaiaretic acid organophosphorus antioxidant [1]: bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite organophosphorus antioxidant [2]: bis ( 2,6-di-t-butyl-
4-Methylphenyl) pentaerythritol-diphosphite organophosphorus antioxidant [3]: bis (2,4,6-tri-t-butylphenyl) pentaerythritol-diphosphite organophosphorus antioxidant [4] ]: Tetrakis (2,4-di-t-
Butylphenyl) -4,4'-biphenylene-di-phosphonite Organic phosphorus antioxidant [5]: 2,2'-methylene-bis (4,
6-di-t-butylphenyl) octyl phosphite organophosphorus antioxidant [6]: 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) fluorophosphite organophosphorus antioxidant Agent [7]: Tris (2,4-di-t-butylphenyl) phosphite Condensed phosphate: Sodium pentapolyphosphate citric acid Ca-St: Calcium stearate

[Table 1]

[Table 2]

[Table 3]

The examples and comparative examples shown in Table 1 are the cases where a crystalline propylene homopolymer was used as the polyolefin. As can be seen from Table 1, Examples 1-7
Is a mixture of NDGA and an organic phosphorus-based antioxidant according to the present invention. Examples 1 to 7 and Comparative Examples 1 and 2
Compared with (NDGA alone combination system), Example 1
It can be seen that Nos. 7 to 7 are excellent in both processing stability and anti-coloring property. In particular, it can be seen that Comparative Example 2 in which the amount of NDGA compounded in Comparative Example 1 is increased has improved processing stability as compared with Comparative Example 1, but is markedly colored. Comparative Example 3 and Examples 1 to 7 in which an organophosphorus antioxidant is blended alone
In comparison with Comparative Example 3, it can be seen that the anti-coloring property of Comparative Example 3 is remarkably excellent, but the processing stability is considerably inferior. Also,
Comparing Examples 1 to 7 with Comparative Example 4 in which the blending amount of NDGA exceeds the upper limit value of the present invention in Examples 1 to 7,
It can be seen that the processing stability of Comparative Example 4 is remarkably excellent as in Examples 1 to 7, but the anti-coloring property is considerably inferior. Further, comparing Comparative Example 5 in which condensed phosphate and citric acid were used in combination with NDGA and Examples 1 to 7, Comparative Example 5 clearly shows that compared to Comparative Examples 1 and 2, condensed phosphorus was added to NDGA. Even if the acid salt and citric acid are used in combination, the processing stability and the anti-coloring property are hardly improved, and Examples 1 to 7 are remarkably excellent in the processing stability and the anti-coloring property, and the synergistic effect is remarkable in the composition of the present invention. It can be seen that the effect is recognized. Therefore, it is clear that the comparative examples that do not simultaneously satisfy the combination of the two components of NDGA and the organophosphorus antioxidant according to the present invention do not exhibit the effects of the present invention. That is, it can be said that the processing stability and anti-coloring property obtained in the present invention are unique effects that can be seen only when the NDGA and the organophosphorus antioxidant are blended in specific amounts in the present invention. Tables 2 to 3 show crystalline ethylene-propylene block copolymer or crystalline propylene homopolymer, crystalline ethylene-propylene-butene-1 terpolymer, and Ziegler-Natta high density as polyolefin, respectively. A mixture of an ethylene homopolymer and an amorphous ethylene-propylene random copolymer was used, and the effects similar to those described above were also confirmed for these.

[0026]

The composition of the present invention is remarkably excellent in processing stability and anti-coloring property as compared with the conventionally known polyolefin compositions relating to the NDGA blending system.

Claims (1)

[Claims] 1. A stabilized polyolefin composition comprising 0.005 to 0.05 parts by weight of nordihydroguaiaretic acid and 0.01 to 0.5 parts by weight of an organophosphorus antioxidant, relative to 100 parts by weight of a polyolefin.