JPH0796589B2 - Method for producing crosslinked propylene-based polymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a crosslinked propylene-based polymer. More specifically, a propylene-based polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of a catalyst residue does not have a specific amount of phenolic hydroxyl group, a hindered amine-based compound (hereinafter referred to as compound A), and phosphorus-based oxidation. Compounded with an inhibitor, radical generator and crosslinking aid,
The present invention relates to a method for producing a crosslinked propylene-based polymer, which comprises performing a melt-kneading treatment at a temperature of 150 ° C to 300 ° C.

[Prior Art] Generally, propylene-based polymers are relatively inexpensive and have excellent mechanical properties, and are therefore used in the production of various molded products such as injection molded products, hollow molded products, films, sheets and fibers. . However, the propylene-based polymer is molded and processed at a temperature equal to or higher than the melting point of the propylene-based polymer, but the propylene-based polymer is oxidatively deteriorated by heat at the time of melt kneading, and is processed by cutting the molecular chain of the propylene-based polymer And deterioration of mechanical strength and oxidative deterioration cause coloring and odor problems. In particular, a propylene-based polymer has a tertiary carbon that is easily oxidized in the polymer, and thus is easily subjected to thermal oxidative deterioration due to melt-kneading during molding and also has a thermal stability during practical use. Also has a problem. Therefore, for the purpose of preventing thermal oxidative deterioration during melt-kneading, 2,6-di-t has been conventionally used.
Low molecular weight phenolic antioxidants such as -butyl-p-cresol (BHT), and high molecular weight phenolic antioxidants are widely used to impart thermal stability during practical use.

However, when the propylene-based polymer containing the above-mentioned phenolic antioxidant is melt-kneaded, the phenol-based antioxidant used is oxidized during melt-kneading by the complex compound of titanium or vanadium which is the catalyst residue in the propylene-based polymer. As a result, a quinone compound is produced and the resulting propylene polymer is colored. In the process of studying the coloring property of a propylene-based polymer containing a large amount of titanium or vanadium as a catalyst residue, the present inventors have found that a propylene-based polymer containing a large amount of titanium or vanadium as a catalyst residue is added to the propylene-based polymer. Even if the above-mentioned phenolic antioxidant is blended and melt-kneaded, coloration does not occur which is a practical problem, but a propylene polymer blended with such a phenolic antioxidant is used with a crosslinking aid. It was found that the cross-linked propylene-based polymer obtained was markedly colored by melt-kneading treatment in the presence of a radical generator, and a polyol or a partial ester of a polyol and a fatty acid and a phenol-based antioxidant were first added to the propylene-based polymer. Cross-linked propylene polymer blended and melt-kneaded in the presence of a radical generator using a cross-linking aid Proposed a manufacturing method (Japanese Patent Application No. Sho 61-147581).

Further, for the purpose of improving the mechanical strength and heat resistance of the propylene-based polymer, a propylene-based polymer is cross-linked by a melt-kneading treatment in the presence of a radical generator using a crosslinking auxiliary agent such as a polyfunctional monomer. How to do it is well known.

[Problems to be Solved by the Invention] The present inventors were not satisfied with the method for producing a crosslinked propylene-based polymer previously proposed in Japanese Patent Application No. 61-147581, and the titanium or vanadium content as a catalyst residue was not satisfied. The present inventors have further earnestly studied a method for obtaining a crosslinked propylene-based polymer which is free from coloration even when a propylene-based polymer containing a large amount of the above is melt-kneaded in the presence of a radical generator using a crosslinking auxiliary. As a result, a specific amount of a hindered amine compound having no phenolic hydroxyl group (hereinafter referred to as compound A) in a propylene-based polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content in the catalyst residue, phosphorus-based oxidation. When the compound is mixed with an inhibitor, a radical generator and a cross-linking auxiliary agent and melt-kneaded, the cross-linked propylene polymer has no coloration and is practically satisfactory in preventing thermal oxidative deterioration during melt-kneading and in thermal stability during practical use. Based on this finding, the present invention has been completed.

As is apparent from the above description, the object of the present invention is to provide a propylene-based polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of a catalyst residue, with compound A, a phosphorus-based antioxidant, a radical generator and It is intended to provide a method for producing a crosslinked propylene-based polymer without coloring by blending a crosslinking aid and performing melt-kneading treatment.

[Means for Solving Problems] The present invention has the following configurations.

Titanium content of catalyst residue is 5 ppm or more or vanadium content is 0.
0.05 to 5 parts by weight of a hindered amine-based compound having no phenolic hydroxyl group (hereinafter referred to as compound A) and 0.01 to 1 part by weight of a phosphorus-based antioxidant based on 100 parts by weight of a propylene-based polymer containing 5 ppm or more. And 0.005 to 5 parts by weight of a radical generator and 0.1 to 20 parts by weight of a crosslinking aid, and melt-kneading at 150 to 300 ° C.

The propylene-based polymer used in the production method of the present invention has a titanium content of the catalyst residue of 5 ppm or more or a vanadium content of 0.5 ppm.
A propylene-based polymer containing the above, for example, a solution polymerization method using a saturated hydrocarbon solvent, a bulk polymerization method, a gas phase polymerization method or a polymerization method by a combination of a bulk polymerization method and a gas phase polymerization method. is there. In the production method of the present invention, a propylene-based polymer having a titanium residue content of the catalyst residue of less than 5 ppm or a vanadium content of less than 0.5 ppm may be used. The propylene-based polymer used in the present invention has a titanium content of 5 p
A propylene-based polymer containing pm or more or 0.5 ppm or more of vanadium, which is a homopolymer of propylene, propylene and ethylene, butene-1, pentene-1, 4-methyl-pentene-1, hexene-1, octene. Of a crystalline random copolymer or a crystalline block copolymer with one or more α-olefins such as -1 and a copolymer of propylene and vinyl acetate, an acrylate ester or the like. Examples thereof include saponified products, copolymers of propylene and unsaturated carboxylic acids or their anhydrides, reaction products of the copolymers and metal ion compounds, etc. Of course, these propylene-based polymers may be used alone. That is, two or more kinds of propylene-based polymers can be mixed and used. Further, the above-mentioned propylene polymer and various synthetic rubbers (for example, ethylene-propylene copolymer rubber, ethylene-propylene-non-conjugated diene copolymer rubber, polybutadiene, polyisoprene, chlorinated polyethylene, chlorinated polypropylene, styrene-butadiene rubber) 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 resins (for example, polyolefins other than propylene-based polymers such as polyethylene, polybutene, poly-4-methylpentene-1), polystyrene, styrene-acrylonitrile copolymers, acrylonitrile-butadiene-styrene Polymers, polyamides, polyethylene terephthalate, polybutylene terephthalate, may also be used a mixture of polyvinyl chloride, etc.). Propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene-butene-1 ternary copolymer A propylene-based polymer which is a combination, a crystalline propylene-hexene-butene-1 terpolymer or a mixture of two or more thereof, and which contains 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of the catalyst residue is particularly preferable. Used.

The compound A used in the present invention includes 4-hydroxy-2,2,6,6-tetramethylpiperidine and 1-allyl-4.
-Hydroxy-2,2,6,6-tetramethylpiperidine, 1
-Benzyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1- (4-t-butyl-2-butenyl)-
4-hydroxy-2,2,6,6-tetramethylpiperidine,
4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine, 1-benzyl-2,2,6,6-tetramethyl -4-piperidyl maleate, bis (2,2,6,6
-Tetramethyl-4-piperidyl) adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl)
Fumarate, bis (1,2,3,6-tetramethyl-2,6-diethyl-4-piperidyl) sebacate, bis (1-allyl-2,2,6,6-tetramethyl-4-piperidyl) phthalate, Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1-propargyl-4-β-cyanoethyloxy-2,2,6,6-tetramethylpiperidine, 1-acetyl-2,2 , 6,6-Tetramethyl-4-piperidyl-acetate, trimellitic acid-tri- (2,2,6,6-tetramethyl-4-piperidyl) ester, 1-acryloyl-4-benzyloxy-2,2 , 6,6-Tetramethylpiperidine, bis (1,2,2,6,6-pentamethyl-4-piperidyl) dibutylmalonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) dibenzyl -Malonate, bis (1,2,3,6-tetramethyl-2,6-diethyl-4-piperidyl Dibenzyl - malonate, hexane-1 ', 6'
Bis-4-carbamoyloxy-1-n-butyl-2,2,
6,6-tetramethylpiperidine), toluene-2 ', 4'
-Bis- (4-carbamoyloxy-1-n-butyl-
2,2,6,6-tetramethylpiperidine), dimethyl-bis (2,2,6,6-tetramethylpiperidine-4-oxy)-
Silane, phenyl-tris- (2,2,6,6-tetramethylpiperidine-4-oxy) -silane, tris- (1-propyl-2,2,6,6-tetramethyl-4-piperidyl)-
Phosphite, tris- (1-propyl-2,2,6,6-
Tetramethyl-4-piperidyl) -phosphate, phenyl- [bis- (1,2,2,6,6-pentamethyl-4-piperidyl)]-phosphonate, tetrakis (2,2,6,
6-Tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetra Carboxylate, di (tridecyl) bis (2,2,6,6-
Tetramethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, di (tridecyl) bis (1,2,2,
6,6-Pentamethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, 2,2,4,4-tetramethyl-7
-Oxa-3,20-diazadisspiro [5,1,11,2] heneicosan-21-one, 3,9-bis [1,1-dimethyl-2-
{Tris (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl]-
2,4,8,10-Tetraoxaspiro [5,5] undecane, 3,9
-Bis [1,1-dimethyl-2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] Undecane, dimethyl succinate-2
-(4-hydroxy-2,2,6,6-tetramethylpiperidyl) ethanol condensate, poly [hexamethylene [(2,2,
6,6-Tetramethyl-4-piperidyl) imino]], poly [ethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetra Methyl-4-piperidyl) imino]], poly [[6-
[(1,1,3,3-Tetramethylbutyl) amino] -1,3,5-
Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,
6-Tetramethyl-4-piperidyl) imino]], poly [[6-morpholino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl ) Imino] hexamethylene [(2,2,6,6-tetramethyl-4
-Piperidyl) imino]], poly [[6-[(ethylacetyl) amino] -1,3,5-triazine-2,4-diyl]
[(2,2,6,6-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-Tetramethyl-4-
Piperidyl) imino]] and poly [[6-[(2,2,6,
6-Tetramethyl-4-piperidyl) butylamino]-
1,3,5-Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4- Piperidyl) imino]]. Especially tetrakiquis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, 3,9-bis [1,1-dimethyl-2-
{Tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl]
-2,4,8,10-tetraoxaspiro [5,5] undecane,
Poly [[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2,4-diyl] [(2,2,6,6
-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], poly [[6-morpholino-1,3,5-triazine-2, 4-diyl] [(2,2,6,6-tetramethyl-4-
Piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] or mixtures of two or more thereof are preferred. Further, as the phosphorus-based antioxidant, distearyl-pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite,
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-
n-octadecyloxycarbonylethyl-phenyl)
-Pentaerythritol diphosphite, Tris (2,
4-di-t-butylphenyl) phosphite and a mixture of two or more thereof can be exemplified. The compounding ratio of the compound A is 0.05 to 100 parts by weight of the propylene-based polymer.
It is 5 parts by weight, preferably 0.1 to 1 part by weight. When the amount is less than 0.05 part by weight, the thermal stability of the crosslinked propylene polymer in practical use is insufficient, and it may be more than 5 parts by weight, but further improvement in thermal stability in practical use. Is not only unpredictable and impractical, but also uneconomical. The compounding ratio of the phosphorus-based antioxidant is 100% by weight of the propylene-based polymer.
0.01 to 1 part by weight, preferably 0.05 to 0.5, relative to parts by weight
Parts by weight. When the amount is less than 0.01 part by weight, the effect of preventing thermal oxidative deterioration during melt-kneading of the crosslinked propylene-based polymer is not sufficiently exerted, and when it is more than 1 part by weight, further prevention of thermal oxidative deterioration is prevented. It is not only impractical because the effect cannot be expected to be improved, but it is also uneconomical.

As the radical generator used in the present invention, the decomposition temperature is preferably not too low to obtain a uniform composition, and the temperature for obtaining a half-life of 10 hours is 70 ° C or higher, preferably 100 ° C or higher. Benzoyl peroxide, t-butyl perbenzoate, t-butyl peracetate, t-butyl peroxyisopropyl carbonate, 2,5-di-methyl-2,5-di- (benzoylperoxy) hexane, 2, 5-di-methyl-2,5-di- (benzoylperoxy) hexyne-3, t-butyl-di-peradipate, t-butylperoxy-3,5,5-trimethylhexanoate, methyl-ethyl Ketone peroxide, cyclohexanone peroxide, di-t-butyl peroxide, dicumyl peroxide, 2,5-di-methyl-2,5-di- (t-butylperoxide) Xy) hexane, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexyne-3,1,3-bis- (t-butylperoxyisopropyl) benzene, t-butylcumyl Peroxide, 1,1-bis- (t-butylperoxy) -3,
3,5-Trimethylcyclohexane, 1,1-bis- (t-butylperoxy) cyclohexane, 2,2-bis- (t-
Butylperoxy) butane, p-menthane hydroperoxide, di-isopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-cymen hydroperoxide, 1,1,3,3-tetra- Methylbutyl hydroperoxide or 2,5-di-methyl-2,5-di-
An organic peroxide such as (hydroperoxy) hexane can be exemplified. Especially 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexyne-3 or 1 , 3-
Bis- (t-butylperoxyisopropyl) benzene is preferred. The mixing ratio of the radical generator is usually 0.005 to 5 parts by weight with respect to 100 parts by weight of the propylene-based polymer,
It is preferably 0.01 to 1 part by weight. Further, the method of melt kneading treatment, 150 ° C. ~ 300 ° C. by various melt kneading equipment described later,
It is preferably carried out at a temperature of 180 ° C to 270 ° C. If the melt-kneading temperature is lower than 150 ° C, sufficient crosslinking will not be carried out, and if it exceeds 300 ° C, the oxidative deterioration of the propylene-based polymer will be promoted and the propylene-based polymer will be markedly colored, such being undesirable.

The crosslinking aid used in the present invention is a polyfunctional monomer, a monofunctional monomer, a quinone dioxime compound, a nitroso compound or a maleimide compound, and ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol diethylene. Methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, 1,
3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, glycerol triacrylate, glycerol trimethacrylate, glycerol allyloxydiacrylate, glycerol allyloxydimethacrylate, trimethylolethane triacrylate, Trimethylolethane trimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,2,3-propanetriol triacrylate, 1,2,3-propanetriol methacrylate, 1,4-butanediol diacrylate, 1, 4-butanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,6 Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tris (2-
Acryloyloxyethyl) cyanurate, Tris (2
-Methacryloyloxyethyl) cyanurate, tris (2-acryloyloxyethyl) isocyanurate,
Tris (2-methacryloyloxyethyl) isocyanurate, 1,3,5-triacryloylhexahydro-s-
Triazine, 1,3,5-trimethacryloylhexahydro-s-triazine, 1,1,1-trishydroxymethylethanediacrylate, 1,1,1-trishydroxymethylethanedimethacrylate, 1,1,1-tris Hydroxymethylethane triacrylate, 1,1,1-Trishydroxymethylethane trimethacrylate, 1,1,1-Trishydroxymethylpropane diacrylate, 1,1,1-Trishydroxymethylpropane dimethacrylate, 1,1,1
-Trishydroxymethylpropane triacrylate,
1,1,1-trishydroxymethylpropane trimethacrylate, 2,2'-methylene-bis- (6-t-butyl-
4-methylphenol) diacrylate, 2,2'-methylene-bis- (6-t-butyl-4-methylphenol) dimethacrylate, 2,2'-methylene-bis- (6
-T-butyl-4-ethylphenol) diacrylate, 2,2'-methylene-bis- (6-t-butyl-4-
Ethylphenol) dimethacrylate, 2,2'-methylene-bis- (4,6-di-t-butylphenol) diacrylate, 2,2'-methylene-bis- (4,6-di-t-butylphenol) di Methacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl phthalate, diallyl terephthalate, trimellitic acid triallyl ester, trimesic acid triallyl ester, pyromellitic acid triallyl ester, styrene monomer, vinyltoluene, Ethyl vinyl benzene, divinyl benzene, diisopropenyl benzene, divinyl pyridine, p, p'-dibenzoylquinone dioxime, p-nitrosophenol, N, N '-(m-
Phenylene) bismaleimide, N, N '-(p-phenylene) bismaleimide, N, N'-(4-methyl-m-phenylene) bismaleimide, N, N '-(4,4'-methylene-
Diphenyl) bismaleimide, N, N- (4,4'-ethylene-diphenyl) bismaleimide, N, N '-(3,3'-dichloro-4,4'-biphenyl) bismaleimide, N, N'-
(3,3'-dichloro-4,4'-methylene-diphenyl) bismaleimide, N, N '-(3,3'-dichloro-4,4'-ethylene-diphenyl) bismaleimide, N, N- ( 3,3′−
Dimethyl-4,4'-methylene-diphenyl) bismaleimide, N, N- (3,3'-dimethyl-4,4'-ethylene-diphenyl) bismaleimide, N, N '-(4,4'-vinylene -Diphenyl) bismaleimide, N, N '-(4,4'-sulfonyl-diphenyl) bismaleimide, N, N'-(2,2 '
-Dithio-diphenyl) bismaleimide, N, N '-(4,
4'-ethylene-bisoxyphenyl) bismaleimide, N, N '-(hexamethylene) bismaleimide, N, N'
-(4,4'-trimethylene glycol-dibenzoate) bismaleimide, N, N '-(3,3'-dichloro-4,
Examples include 4'-trimethylene glycol-dibenzoate) bismaleimide, N, N '-(3,3'-dimethyl-4,4'-trimethylene glycol-dibenzoate) bismaleimide, and mixtures of two or more thereof. it can. Particularly preferred is trimethylolpropane triacrylate, trimethylolpropane trimethacrylate or a mixture thereof. The blending ratio of the crosslinking aid is usually 0.1 to 20 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the propylene polymer. When the amount is less than 0.1 part by weight, the effect of improving the mechanical strength of the crosslinked propylene-based polymer is not sufficiently exhibited, and even when it exceeds 20 parts by weight, the degree of improvement in the mechanical strength and the like is small, and The amount of unreacted crosslinking aid remaining in the system polymer becomes large, which causes defects such as deterioration of the hue of the obtained molded product and generation of bubbles.

In the production method of the present invention, various additives usually added to a propylene-based polymer, such as thioether-based oxidation, are added to a propylene-based polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of the catalyst residue used. Inhibitors, light stabilizers, clarifiers, nucleating agents, lubricants, antistatic agents, antifogging agents, antiblocking agents, non-dripping agents, pigments, heavy metal deactivators (copper damage inhibitors), metal soaps Dispersant or neutralizing agent, inorganic filler (eg talc, mica, clay, wollastonite, zeolite, asbestos, calcium carbonate, aluminum hydroxide, magnesium hydroxide, silicon dioxide, titanium dioxide, zinc oxide, magnesium oxide) , Zinc sulfide, barium sulfate, calcium silicate, glass fiber, carbon fiber, potassium titanate, metal fiber, etc.) or coupling Inorganic or organic filler (eg, wood powder, pulp, waste paper, synthetic) surface-treated with a surface treating agent such as a silane-based agent, a titanate-based agent, a boron-based agent, an aluminate-based agent, a zircoaluminate-based agent, etc. (Fibers, natural fibers, etc.) can be used by blending within the range not impairing the object of the present invention.

The production method of the present invention is a propylene-based polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of a catalyst residue, the above-mentioned compound A, a phosphorus-based antioxidant, a radical generator, a cross-linking aid and usually propylene. The prescribed amount of the above-mentioned various additives to be added to the system polymer is not decomposed by using a conventional mixing device such as a Henschel mixer (trade name), a super mixer, a ribbon blender, or a Banbury mixer. Mix at about temperature,
Using a conventional single-screw extruder, twin-screw extruder, Brabender or roll, the melt-kneading temperature is 150 ° C to 300 ° C, preferably 18
It is carried out by melt-kneading at 0 ° C to 270 ° C.

[Operation] In the present invention, compound A is plastics, 35 volumes, 11
No., pages 44 to 58 (1984 edition), it mainly acts as a radical scavenger and has thermal stability during use (heat resistance).
Contribute to the improvement of. Phosphorus-based antioxidants are peroxide decomposers to prevent thermal oxidative deterioration during melt-kneading, and radical generators generate radicals by melt-kneading treatment, that is, heating to remove hydrogen atoms from the propylene-based polymer. As is well known, the radicals of the propylene polymer are generated, and the crosslinking aid reacts with the radicals of the propylene polymer to crosslink the propylene polymer and improve the mechanical strength and the like.

[Effects] The crosslinked propylene-based polymer obtained by the production method of the present invention is not more colored than the crosslinked propylene-based polymer according to the above-mentioned Japanese Patent Application No. 61-147581 filed by the present inventors, and is mechanically Injection molding method, because strength etc. is improved,
It can be suitably used for the production of a target molded article by various molding methods such as an extrusion molding method and a blow molding method.

[Examples] Hereinafter, the present invention will be specifically described 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.

Colorability: YI (Yellowness Index) of the obtained pellets was measured (in accordance with JIS K 7103), and the colorability was evaluated from the magnitude of this YI value. The smaller this value is, the less the coloring is.

Examples 1 to 16 and Comparative Examples 1 to 3 As a propylene-based polymer, MFR (load at 230 ° C. 2.
Discharge amount of molten resin for 10 minutes when 16 kg is added) 2.0 g / 1
Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) as compound A was added to 100 parts by weight of unstabilized powdery propylene homopolymer (titanium content 30 ppm) for 0 minutes.
1,2,3,4-butanetetracarboxylate, 3,9-bis [1,1-dimethyl-2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyl Oxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, poly [[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5 -Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl))
Imino]] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] or poly [[6-morpholino-1,3,5-triazine-2,4-diyl] [(2 ,
2,6,6-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], bis (2,4-
Di-t-butylphenyl) -pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite or tris (2,4-di- t-butylphenyl) phosphite, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl) as a radical generator
Benzene, trimethylolpropane triacrylate as a cross-linking aid, and other additives were added in the Henschel mixer (trade name) in the proportions shown in Table 1 below, and the mixture was stirred and mixed for 3 minutes. Was melt-kneaded at 200 ° C. with a single-screw extruder to crosslink and pelletize. Further, as Comparative Examples 1 to 3, 100 parts by weight of an unstabilized powdery propylene homopolymer having an MFR of 2.0 g / 10 minutes (titanium content of 30 ppm) was added to each of the additives described in Table 1 below. A fixed amount was compounded and melt-kneaded according to Examples 1 to 16 to obtain crosslinked pellets.

The obtained pellets were used to evaluate the colorability by the above-mentioned test method. The results are shown in Table 1.

Examples 17 to 32, Comparative Examples 4 to 6 As a propylene-based polymer, MFR 7.0 g / 10 min unstabilized powdery crystalline ethylene-propylene random copolymer (ethylene content 2.5%, titanium content 33ppm) 10
To 0 parts by weight, as compound A, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, 3,9-bis [1,1-dimethyl- 2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl] -2,
4,8,10-Tetraoxaspiro- [5,5] undecane, poly [[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2,4 -Jail] [(2,2,6,6
-Tetramethyl-4-piperidyl) imino] hexamethylene-[(2,2,6,6-tetramethyl-4-piperidyl)
Imino]] or poly [[6-morpholino-1,3,5
-Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,
6,6-Tetramethyl-4-piperidyl) imino]], bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite as a phosphorus-based antioxidant, tetrakis (2,4-di- t-butylphenyl) -4,4'-biphenylene-di-phosphonite or tris (2,
4-di-t-butylphenyl) phosphite, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylper) as a radical generator (Oxyisopropyl) benzene, trimethylolpropane triacrylate as a cross-linking aid, and other additives in predetermined amounts were put in a Hensell mixer (trade name) at the mixing ratios shown in Table 2 below, and mixed by stirring for 3 minutes. A single-screw extruder having a rear diameter of 40 mm was melt-kneaded at 200 ° C., cross-linked and pelletized. Moreover, Comparative Examples 4 to 6
As shown in Table 2 below, 100 parts by weight of powdery crystalline ethylene-propylene random copolymer (Methylene content: 2.5% by weight, titanium content: 33 ppm) which is not stabilized and has an MFR of 7.0 g / 10 min. A predetermined amount of each additive was blended and melt-kneaded according to Examples 17 to 32 to obtain crosslinked pellets.

The obtained pellets were used to evaluate the colorability by the above-mentioned test method. The results are shown in Table 2.

Examples 33 to 48, Comparative Examples 7 to 9 As a propiene-based polymer, MFR 4.0 g / 10 min unstabilized powdery crystalline ethylene-propylene block copolymer (ethylene content 8.5% by weight, titanium content Amount 33pp
m) 100 parts by weight of tetrakis (2,2,6,6 as Compound A
-Tetramethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, 3,9-bis [1,1-dimethyl-2
-{Tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, poly [[ 6-[(1,1,3,3-tetramethylbutyl)
Amino] -1,3,5-triazine-2,4-diyl] [(2,2,
6,6-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] or poly [[6-morpholino-1,
3,5-Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) Imino]], and bis (2,4-di-t-
Butylphenyl) -pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl)
-4,4'-Biphenylene-di-phosphonite or tris (2,4-di-t-butylphenyl) phosphite, 2,5-di-methyl-2,5-di- as a radical generator
Predetermined amounts of (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl) benzene, trimethylolpropane triacrylate as a crosslinking aid and other additives are shown in Table 3 below. Put in the Henschel mixer (trade name) in the stated mixing ratio,
After stirring and mixing for 3 minutes, the mixture was melt-kneaded at 200 ° C. in a single-screw extruder having a diameter of 40 mm, crosslinked and pelletized. Further, as Comparative Examples 7 to 9, powdery crystalline ethylene-propylene block copolymer having an MFR of 4.0 g / 10 minutes and not stabilized (ethylene content 8.5% by weight, titanium content 33 ppm) 100
Predetermined amounts of the additives shown in Table 3 below were mixed in parts by weight, and melt-kneaded in accordance with Examples 33 to 48 to obtain crosslinked pellets.

The obtained pellets were used to evaluate the colorability by the above-mentioned test method. The results are shown in Table 3.

Examples 49-64, Comparative Examples 10-12 As a propylene-based polymer, MFR 7.0 g / 10 min unstabilized powdery crystalline ethylene-propylene-butene-
1 Tetrakis (2,2,6,6-tetramethyl-4) as compound A was added to 100 parts by weight of a terpolymer (ethylene content 2.5% by weight, butene-1 content 4.5% by weight, titanium content 33 ppm). -Piperidyl) 1,2,3,4-butanetetracarboxylate, 3,9-bis- [1,1-dimethyl-2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxy Carbonyl) butylcarbonyloxy} ethyl] -2,4,8,
10-tetraoxaspiro [5,5] undecane, poly [[6-[(1,1,3,3-tetramethylbutyl) amino]
-1,3,5-Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4 -Piperidyl) imino]] or poly [[6-morpholino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-
4-piperidyl) imino] hexamethylene [(2,2,6,6
-Tetramethyl-4-piperidyl) imino]], bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite as a phosphorus-based antioxidant, tetrakis (2,4-di-t-butyl) Phenyl) -4,4'-biphenylene-di-phosphonite or tris (2,4
-Di-t-butylphenyl) phosphite, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxy) as a radical generator Isopropyl) benzene, trimethylolpropane triacrylate as a cross-linking aid, and other additives in the respective prescribed amounts in the Henschel mixer (trade name) at the blending ratios shown in Table 4 below, and after stirring and mixing for 3 minutes It was melt-kneaded at 200 ° C. in a single-screw extruder with a diameter of 40 mm, cross-linked and pelletized. Further, as Comparative Examples 10 to 12, powdery crystalline ethylene-propylene-butene-1 terpolymer having an MFR of 7.0 g / 10 min and not stabilized (ethylene content 2.5% by weight, butene-1 content) 4.5% by weight,
Titanium content of 33 ppm) was mixed with 100 parts by weight of each of predetermined amounts of the additives shown in Table 4 described below, and melt-kneading treatment was carried out in accordance with Examples 49 to 64 to obtain crosslinked pellets.

The obtained pellets were used to evaluate the colorability by the above-mentioned test method. The results are shown in Table 4.

Examples 65 to 80, Comparative Examples 13 to 15 As a propylene-based polymer, MFR 4.0 g / 10 min unstabilized powdery crystalline ethylene-propylene block copolymer (ethylene content 16.0 wt%, vanadium-containing) amount
0.6 ppm) to 100 parts by weight of tetrakis (2,
2,6,6-Tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, 3,9-bis [1,1-dimethyl-2- {tris (1,2,2,6 , 6-Pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, poly [[6-[(1,1,3,3 -Tetramethylbutynyl) amino] -1,3,5-triazine-2,4-diyl]
[(2,2,6,6-Tetramethyl-4-piperidyl) imino] hexamethylene-[(2,2,6,6-Tetramethyl-4
-Piperidyl) imino] or poly [[6-morpholino-1,3,5-triazine-2,4-diyl] [(2,2,6,6
-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], bis (2,6-di-t) as a phosphorus-based antioxidant
-Butyl-4-methylphenyl) -pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite or tris (2,4-diphenyl) -T-butylphenyl) phosphite, 2,5-di- as a radical generator
Methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl) benzene, trimethylolpropane triacrylate as a cross-linking agent and other additives, respectively. Put a fixed amount into the Henschel mixer (trade name) at the blending ratio shown in Table 5 below, stir and mix for 3 minutes, then melt knead at 200 ° C with a single screw extruder with a diameter of 40 mm to crosslink and pellet. Turned into Further, as Comparative Examples 13 to 15, MFR is 4.0 g / 10 minutes unstabilized powdery crystalline ethylene-propylene block copolymer (ethylene content 16.0 wt%, vanadium content 0.6 ppm) to 100 parts by weight. Predetermined amounts of the additives shown in Table 5 below were mixed and melt-kneaded according to Examples 65 to 80 to obtain crosslinked pellets.

The obtained pellets were used to evaluate the colorability by the above-mentioned test method. The results are shown in Table 5.

Various compounds and additives shown in Tables 1 to 5 are as follows.

Compound A [I]; Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate Compound A [II]; 3,9-bis [1,1 -Dimethyl-2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl] -2,
4,8,10-Tetraoxaspiro [5,5] undecane compound [III]; poly [[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine- 2,4-Diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene-[(2,2,6,6-tetramethyl-
4-piperidyl) imino]] compound A [IV]; poly [[6-morpholino-1,3,5-
Triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,
6-Tetramethyl-4-piperidyl) imino] phosphorus-based antioxidant [I]; bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite phosphorus-based antioxidant [II]; tetrakis (2,4-di-t-
Butylphenyl) -4,4'-biphenylene-di-phosphonite phosphorus-based antioxidant [III]; tris (2,4-di-t-butylphenyl) phosphite phosphorus-based antioxidant [IV]; bis (2,6-Di-t-butyl-4-methylphenyl) -pentaerythritol-diphosphite radical generator [I]; 2,5-di-methyl-2,5-di-
(T-Butylperoxy) hexane Radical generator [II]; 1,3-Bis- (t-butylperoxyisopropyl) benzene Crosslinking aid; Trimethylolpropane triacrylate Phenolic antioxidant 1; 2,6- Di-t-butyl-p-
Cresol phenolic antioxidant 2; tetrakis [methylene-3-
(3 ', 5'-Di-t-butyl-4'-hydroxyphenyl) propionate] methane polyol compound (partial ester of polyol and fatty acid); pentaerythritol monostearate HALS (hindered amine compound having phenolic hydroxyl group) 1 [2- [3- (3,5-di-t-butyl-4-
Hydroxyphenyl) propionyloxy] ethyl]-
4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine Ca-St; calcium stearate The examples and comparative examples shown in Table 1 are the cases where a propylene homopolymer was used as the propylene polymer.
As can be seen from Table 1, in Examples 1 to 16, compound A, a phosphorus-based antioxidant, a radical generator and a crosslinking aid were added to a propylene homopolymer containing 30 ppm of titanium in the catalyst residue according to the present invention. However, it is melt-kneaded and cross-linked. Examples 1 to 16 and Comparative Example 1 (Method for producing a crosslinked propylene-based polymer of Japanese Patent Application No. 61-147581 previously proposed by the present inventors, that is, a partial ester of a polyol and a fatty acid, a phenol-based polymer in a propylene-based polymer. In comparison with Comparative Example 1 in which an antioxidant, a radical generator and a cross-linking auxiliary agent are blended, melt-kneaded and cross-linked, Examples 1 to 16 are less colored than Comparative Example 1, and the anti-coloring property is improved. I understand. Comparative Example 2 and Example 1 in which a hindered amine compound having a phenolic hydroxyl group was used instead of the compound A
Compared with -16, Comparative Example 2 is markedly colored, and it can be understood that this coloring is caused by the formation of a quinone compound by the phenolic hydroxyl group of the hindered amine compound. Also, comparing Comparative Examples 3 and 1 to 16 in which the partial ester of the polyol and the fatty acid used in Comparative Example 1 is further added to Comparative Example 2, Comparative Example 3 is similar to Comparative Example 1 in that the coloring property is improved. It turns out that it is less than Examples 1-16.

Tables 2 to 5 show crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline ethylene-as propylene-based polymer, respectively.
A propylene-butene-1 terpolymer, a crystalline ethylene-propylene block copolymer,
The effects similar to those described above were also confirmed for these.

Therefore, it can be seen that the crosslinked propylene-based polymer obtained by the production method of the present invention is not colored and its mechanical strength and heat resistance are improved.

From this, the cross-linked propylene-based polymer obtained by the production method of the present invention is melt-kneaded in the presence of a radical generator using a cross-linking auxiliary compounded with a compound having a conventionally known coloring preventing effect. It was found that the anti-coloring property was remarkably superior to that of the resin cross-linked by the above method, and the remarkable effect of the present invention was confirmed.

Claims (6)

[Claims] 1. A propylene-based polymer 100 containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content in a catalyst residue.
0.05 parts by weight of a hindered amine compound having no phenolic hydroxyl group (hereinafter referred to as compound A) is used with respect to parts by weight.
~ 5 parts by weight and 0.01 to 1 part by weight of phosphorus antioxidant,
0.005 to 5 parts by weight of radical generator, 0.1 to 20 of crosslinking aid
A method for producing a crosslinked propylene-based polymer, which comprises blending parts by weight and melt-kneading at 150 ° C to 300 ° C. 2. A tetrakis (2,2,6,6-
Tetramethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, 3,9-bis [1,1-dimethyl-2-
{Tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) butylcarbonyloxy} ethyl]
-2,4,8,10-tetraoxaspiro [5,5] undecane,
Poly [[6-[(1,1,3,3, -tetramethylbutyl) amino] -1,3,5-triazine-2,4-diyl] [(2,2,6,6
-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], poly [[6-morpholino-1,3,5-triazine-2, 4-diyl] [(2,2,6,6-tetramethyl-4-
Piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], or a mixture of two or more thereof.
The method for producing a crosslinked propylene-based polymer as described in the item. 3. Phosphorus antioxidants such as bis (2,4-di-t-butylphenyl) -pentaerythritol-diphosphite and bis (2,6-di-t-butyl-4-methylphenyl). -Pentaerythritol-diphosphite, tetrakis (2,4-di-t-butylphenyl) -4,
Crosslinked propylene according to claim (1), which contains 4'-biphenylene-di-phosphonite, tris (2,4-di-t-butylphenyl) phosphite or a mixture of two or more thereof. Of producing a base polymer. 4. As a radical generator, 2,5-di-methyll-2,5-di- (t-butylperoxy) hexane, 2,5
-Di-methyl-2,5-di- (t-butylperoxy) hexyne-3 or 1,3-bis- (t-butylperoxyisopropyl) benzene is included in the claim (1). A method for producing the crosslinked propylene-based polymer as described. 5. The method according to claim 1, wherein a polyfunctional monomer, a monofunctional monomer, a quinonedioxime compound, a nitroso compound, a maleimide compound or a mixture of two or more thereof is blended as a crosslinking aid. 1. A method for producing a crosslinked propylene-based polymer. 6. A propylene-based polymer, propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline propylene-butene-1 random copolymer, crystalline The crosslinked propylene-based polymer according to claim (1), wherein an ethylene-propylene-butene-13 copolymer, a crystalline propylene-hexene-butene-13 copolymer or a mixture of two or more thereof is used. Manufacturing method of coalescence.