JPH0653814B2 - 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 specific amount of a phenolic antioxidant, a polyol or a partial ester of the polyol and a fatty acid (hereinafter referred to as Compound A) is added to a propylene polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of a catalyst residue. ), A radical generator and a crosslinking aid, and melt-kneading at a temperature of 150 ° C. to 300 ° C. for producing a crosslinked propylene polymer.

[Conventional technology]

Generally, propylene-based polymers are relatively inexpensive and have excellent mechanical properties, and are therefore used for 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 phenol-based antioxidant is melt-kneaded, the phenol-based antioxidant used is melt-kneaded with a complex compound of titanium or vanadium which is a catalyst residue in the propylene-based polymer. A problem occurs when the propylene-based polymer obtained by being oxidized and forming a quinone compound is colored. Therefore, a propylene-based polymer is blended with pentaerythritol or a polyol, which is a reaction product of pentaerythritol and propylene oxide, in a propylene polymer composition (JP-A-58-213036), a polyol, a polyol and a fatty acid. Partial or complete ester,
Polypropylene composition containing one or more compounds of phosphite or thiophenite (Journal of
Applied Polymer Science, Volume 29, 4421-44
Page 26 (1984) [Journal of Applied Polymer Science
Vol.29, p.4421-4426 (1984)]) has been proposed.

Further, in order to improve the mechanical strength, heat resistance and rigidity 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 aid composed of a polyfunctional monomer. How to do it is well known.

[Problems to be solved by the invention]

The inventors of the present invention, in the process of studying the colorability of a prophylene-based polymer containing a large amount of titanium or vanadium as a catalyst residue, a propylene-based polymer containing a large amount of titanium or vanadium contained in the catalyst residue. Even if the above-mentioned phenolic antioxidant is blended and melt-kneaded, coloring that does not pose a practical problem does not occur, but a propylene polymer containing such a phenolic antioxidant is used with a crosslinking aid. It was found that the obtained crosslinked propylene-based polymer is markedly colored when melt-kneaded in the presence of a radical generator. This phenomenon is described in JP-A-58-213036 and Journal of Applied Polymer Science, 29, 4421-4426 (1984).
Year).

The inventors of the present invention, for the purpose of improving the mechanical strength and the like of a propylene-based polymer in which a phenol-based antioxidant is added to a propylene-based polymer containing a large amount of titanium or vanadium in the above-mentioned catalyst residue is crosslinked. The present inventors have earnestly studied a method for obtaining a crosslinked propylene-based polymer which is free from coloration even if it is melt-kneaded in the presence of a radical generator using an auxiliary agent.
As a result, a specific amount of a phenolic antioxidant, a polyol, or a partial ester of the polyol and a fatty acid (hereinafter referred to as compound A) is added to 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. ), A radical generator and a crosslinking aid are blended,
It was found that a cross-linked propylene-based polymer with no coloration was obtained by melt-kneading treatment, and the present invention was completed based on this finding.

As is clear from the above description, the object of the present invention is to make the titanium content of the catalyst residue 5 ppm or more or the vanadium content 0.5 p.
Provided is a method for producing a crosslinked propylene-based polymer having no color by blending a compound A, a phenol-based antioxidant, a radical generator and a crosslinking aid into a propylene-based polymer containing pm or more and melt-kneading the mixture. It is to be.

[Means for solving problems]

 The present invention has the following configurations.

100 parts by weight of a propylene polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of a catalyst residue, a polyol or a partial ester of the polyol and a fatty acid (hereinafter referred to as compound A), and a phenolic antioxidant. 0.01 to 1 part by weight, 0.005 to 5 parts by weight of a radical generator, and 0.1 to 2 of a crosslinking aid.
A method for producing a crosslinked propylene-based polymer, which comprises blending 0 part by weight and melt-kneading at 150 ° C to 300 ° C.

The propylene-based polymer used in the production method of the present invention has a titanium content of 5 ppm or more or a vanadium content of 0.
A propylene polymer containing 5 ppm or more and obtained by, 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 the bulk polymerization method and the gas phase polymerization method. Is. In the production method of the present invention, the content of titanium in the catalyst residue is 5
There is no problem in using a propylene-based polymer having a content of less than ppm or a vanadium content of less than 0.5 ppm. In this case, the obtained crosslinked propylene-based polymer can be obtained without compounding the compound A. Does not cause coloring to a degree that poses a practical problem. The propylene-based polymer used in 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, which is a homopolymer of propylene, propylene and ethylene, butene-1. , Pentene-1, 4-methyl-pentene-1, hexene-1, octene-1, and the like, a crystalline random copolymer or crystalline block copolymer with one or more α-olefins, such as propylene, Copolymers with vinyl acetate, acrylic acid ester, etc. or saponified products of the copolymers, copolymers of propylene with unsaturated carboxylic acids or their anhydrides, reaction products of the copolymers with metal ion compounds And the like. Of course, these propylene-based polymers may be used alone or a mixture of two or more kinds of propylene-based polymers may be used. It is also possible to have. 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 resin (for example, polyethylene,
Polybutene, polyolefin other than proprylene-based polymers such as poly-4-methylpentene-1, polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, polyamide,
It is also possible to use a mixture with polyethylene terephthalate, polybutylene terephthalate, 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-
13-component copolymer, crystalline propylene-hexene-butene-1 3-component copolymer, wherein the titanium content of the catalyst residue was 5 pp
A propylene-based polymer containing m or more or vanadium content of 0.5 ppm or more is particularly preferable.

Examples of the compound A used in the present invention include glycerin, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol, dipentaerythritol,
Tripentaerythritol, xylitol, sorbitol, mannitol and other polyols, glycerin and fatty acid monoesters, diglycerin and fatty acid monoesters, sorbitan and fatty acid monoesters, sucrose and fatty acid monoesters, pentaerythritol and fatty acid monoesters or Partial esters of polyols and fatty acids such as diesters, trimethylolethane and fatty acid monoesters, trimethylolpropane and fatty acid monoesters, polyoxyethylene glycerin and fatty acid monoesters, polyoxyethylene sorbitan and fatty acid monoesters (as fatty acids Is lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, etc.)
Can be illustrated. Especially trimethylolethane,
Preference is given to monoesters of glycerin and fatty acids and mono- or diesters of pentaerythritol and fatty acids. Further, 2,6-di-t-as a phenol-based antioxidant
Butyl-p-cresol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,6-di-t-butyl-4-n-butylphenol 2,6-di-i-butyl-4-n-butylphenol, 2,6-di-cyclopentyl-4-methylphenol, 2- (α-methylcyclohexyl)-
4,6-Dimethylphenol, 2,6-di-octadecyl-4-methylphenol, 2,4,6-tri-cyclohexylphenol, 2,6-di-t-butyl-4-methoxymethylphenol, n-octathecil -Β- (4'-
Hydroxy-3 ', 5'-di-t-butylphenyl) propionate, 2,6-diphenyl-4-octadecyloxyphenol, 2,4,6-tris (3', 5'-di-t
-Butyl-4'-hydroxyhendylthio) -1,3,5-
Triazine, 2,6-di-t-butyl-4-methoxyphenol, 2,5-t-butylhydroquinone, 2,5
-Di-t-amylhydroquinone, 2,2'-thio-bis- (6-t-butyl-4-methylphenol), 2,
2'-thio-bis (4-octylphenol), 2,
2'-thio-bis- (6-t-butyl-3-methylphenol), 4,4'-thio-bis- (6-t-butyl-
2-methylphenol), 2,2'-methylene-bis-
(6-t-butyl-4-methylphenol), 2,2 '
-Methylene-bis- (6-t-butyl-4-ethylphenol), 2,2'-methylene-bis- [4-methyl-
6- (α-methylcyclohexyl) -phenol],
2,2'-methylene-bis- (4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis-
(6-nonyl-4-methylphenol), 2,2'-methylene-bis- [6- (α-methylbenzyl) -4-nonylphenol], 2,2'-methylene-bis- [6-
(Α, α-Dimethylbenzyl) -4-nonylphenol], 2,2′-methylene-bis- (4,6-di-t-
Butylphenol), 2,2'-ethylidene-bis-
(4,6-di-t-butylphenol), 2,2'-ethylidene-bis- (6-t-butyl-4-i-butylphenol), 4,4'-methylene-bis- (2,6) -Di-t-butylphenol), 4,4'-methylene-bis- (6-t-butyl-2-methylphenol), 4,
4'-butylidene-bis- (6-t-butyl-2-methylphenol), 4,4'-butylidene-bis- (6-
t-butyl-3-methylphenol), 4,4'-butylidene-bis- (2,6-di-t-butylphenol), 4,4'-butylidene-bis- (3,6-di-t).
-Butylphenol), 1,1-bis- (5-t-butyl-4-hydroxy-2-methylphenyl) -butane,
2,6-di- (3-t-butyl-5-methyl-2-hydroxybenzyl) -4-methylphenol, 1,1,3-tris- (5-t-butyl-4-hydroxy-2-methylphenyl) ) -Butane, bis [3,3-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] ethylene glycol ester, di- (3-t-butyl-4hydroxy-5-methylphenyl)- Dicyclopentadiene, di- [2- (3'-t-butyl-2'-hydroxy-5'-methylbenzyl) -6-t-butyl-
4-Methylphenyl] terephthalate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-
(Hydroxybenzyl) benzene, 1,3,5-tris-
(3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanurate, 1,3,5-Tris- (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 1,3,5-Tris-[(3,5-di-t- Examples include butyl-4-idroxyphenyl) propionyloxyethyl] isocyanurate or tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxykiphenyl) opionate] methane. The compounding ratio of the compound A and the phenol antioxidant is 0.0 with respect to 100 parts by weight of the propylene polymer.
It is 1 to 1 part by weight, preferably 0.05 to 0.5 part by weight. If the amount is less than 0.01 part by weight, the effect of preventing coloration of the resulting crosslinked propylene-based polymer is not sufficiently exhibited, and if it exceeds 1 part by weight, the effect of preventing coloration is further improved. Is not only unpredictable and impractical, but also uneconomical.

The radical generator used in the present invention preferably has a decomposition temperature not too low in order 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-ethylketone peroxide, cyclohexanone peroxide, di-t
-Butyl peroxide, diquimyl peroxide,
2,5-di-methyl-2,5-di- (t-butylperoxy) hexane, 2,5-di-methyl-2,5-di-
(T-Butylperoxy) hexyne-3,1,3-bis- (t-butylperoxyisopropyl) benzene, t
-Butyl quimmyl peroxide, 1,1-bis- (t
-Butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis- (t-butylperoxy) cyclohexane, 2,2-bis- (t-butylperoxy) butane, p-menthane hydroper Oxide, di-isopropylbenzene hydroperoxide, quinene hydroperoxide, t-butyl hydroperoxide, p-cymen hydroperoxide, 1,1,3,3
Examples thereof include organic peroxides such as tetra-methylbutyl hydroperoxide or 2,5-di-methyl-2,5-di- (hydroperoxy) hexane. In particular, 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 0.00 with respect to 100 parts by weight of the propylene polymer.
It is 5 to 5 parts by weight, preferably 0.01 to 1 part by weight.
Further, the method of the melt kneading treatment is carried out at 150 ° C. to 300 ° C., preferably 180 ° C. to 270 by a customer type melt kneading device described later.
Perform at a temperature of ° 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, which is not preferable.

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, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, 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, glycerose diacrylate, glycerol dimethacrylate, glycerol triacrylate, glycerol trimethacrylate, glycerol allyloxydiacrylate, glycerol allyloxydimethacrylate, trimethylolethane triacrylate, tri Methylolethane trimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,2,3-propanetriol triacrylate, 1,2,3-propanetriol trimethacrylate, 1,4-butanediol diacrylate, 1, 4-butanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimetha Relate, 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-trishydroxymethylethane dimethacrylate, 1,1,1-trishydroxymethylethane 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) dimethacrylate, triary Ludianurate, triallyl isocyanurate, triallyl trimellitate, diallyl phthalate, diallyl terephthalate, trimellitic acid triallyl ester, trimesic acid triallyl ester, pyromellitic acid triallyl ester, styrene monomer, vinyltoluene, ethyl vinylbenzene, divinylbenzene , Diisopropenylbenzene, divinylpyridine,
p, p'-dibenzoylquinone dioxime, p-nitrosophenol, m-phenylene bismaleimide, 4-methyl-m-phenylene bismaleimide, 4,4'-methylene-diphenyl bismaleimide, 4,4 ' -Ethylene-diphenyl bismaleimide, p-phenylene bismaleimide, 4,4'-vinylene-diphenyl bismaleimide, 4,4'-sulfonyl-diphenyl bismaleimide, 2,2'-dithio-diphenyl bismaleimide ,
Examples include 4,4'-ethylene-bisoxyphenyl bismaleimide, hexamethylene bismaleimide, 3,3'-dichloro-4,4'-biphenyl bismaleimide and the like. Particularly, trimethylolpropane triacrylate is preferable. The mixing ratio of the crosslinking aid is usually 0.1 to 20 parts by weight with respect to 100 parts by weight of the propylene-based polymer.
Parts by weight, preferably 0.5 to 2 parts by weight. If the amount is less than 0.1 part by weight, the effect of improving the mechanical strength of the resulting cross-linked propylene-based polymer will not be sufficiently exerted.
Even if it exceeds 0 parts by weight, the improvement effect of the mechanical strength and the like is little improved, and the amount of the unreacted crosslinking aid remaining in the crosslinked propylene-based polymer is increased, and the hue of the obtained molded product is increased. It is not preferable because it causes defects such as deterioration and generation of bubbles.

In the production method of the present invention, various additives which are usually added to a propylene-based polymer, such as a thioether-based polymer, 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. , Phosphorus-based antioxidants, light stabilizers, clarifying agents, nucleating agents, lubricants,
Antistatic agent, anti-fog agent, anti-blocking agent, non-dripping agent,
Pigments, heavy metal deactivators (copper damage inhibitors), dispersants or neutralizers for metallic soaps, inorganic fillers (eg talc, mica, clay, wollastonite, zeolite,
Asbestos, calcium carbonate, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium silicate,
The above-mentioned inorganic filler or organic filler surface-treated with a surface treating agent such as glass fiber, carbonic acid fiber) or a coupling agent (for example, silane type, titanate type, boron type, aluminate type, zircoaluminate type). (For example, wood powder, pulp, waste paper, synthetic fiber, natural fiber, etc.) can be used by mixing within a range that does not impair the object of the present invention. In particular, the combined use of a phosphorus-based antioxidant exhibits a synergistic color-preventing effect, so that it is preferably used in combination. Preferred phosphorus antioxidants are 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 and tris (2,4-di-t-butylphenyl)
A phosphite can be illustrated.

In the production method of the present invention, the compound A, the phenolic antioxidant, and the above-mentioned compound A are added to the propylene-based polymer containing 5 ppm or more of titanium content or 0.5 ppm or more of vanadium content of the catalyst residue.
Radical generators, cross-linking aids, and the prescribed amounts of the above-mentioned various additives that are usually added to propylene-based polymers are mixed using a conventional mixing device such as a Henschel mixer (trade name), a super mixer, a ribbon blender, or a Banbury mixer. And mix at a temperature at which the compounded radical generator is not decomposed, and melt kneading temperature 150 ° C. to 30 ° C. with a normal single-screw extruder, twin-screw extruder, Brabender or roll.
It is carried out by melt-kneading at 0 ° C, preferably 180 ° C to 270 ° C.

[Work]

In the present invention, the phenol-based antioxidant is a radical chain inhibitor, and the radical-generating agent is a melt-kneading process, that is, a radical is generated by heating, and a radical of the propylene-based polymer is extracted by abstracting hydrogen atoms of the propylene-based polymer. It is well known that the produced crosslinking agent reacts with the radicals of the propylene-based polymer to crosslink the propylene-based polymer and improve the mechanical strength.

In the production method of the present invention, when the compound A is crosslinked by melt-kneading a propylene polymer stabilized by a phenolic antioxidant in the presence of a radical generator with a crosslinking aid. It is not clear what kind of action it has on the complex compound of titanium or vanadium, but its action mechanism itself is not clear, but when the complete ester of polyol and fatty acid is used, the effect of the present invention is not exhibited. It is presumed that the alcoholic hydroxyl group of A acts on the complex compound of titanium or vanadium to form a stable chelate compound.

[Effect]

The cross-linked propylene-based polymer obtained by the production method of the present invention is a radical generator and a cross-linking aid using a propylene-based polymer obtained by blending a conventionally known phosphorus-based antioxidant or a complete ester of a polyol and a fatty acid. The cross-linked propylene-based polymer obtained by the cross-linking method has no coloration compared to the cross-linked propylene-based polymer, and the mechanical strength is improved, so the desired molding is performed by various molding methods such as injection molding method, extrusion molding method and blow molding method. It can be suitably used for the production of products.

[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 based on the value of this YI. The smaller this number is,
Indicates that there is no coloring.

Examples 1 to 16 and Comparative Examples 1 to 3 As a propylene-based polymer, MFR (amount of molten resin discharged for 10 minutes when a load of 2.16 kg at 230 ° C. for 10 minutes) 2.0 g / 10 minutes of powdered propylene To 100 parts by weight of a homopolymer (titanium content 30 ppm), trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate as compound A, and 2,6-di- as a phenol-based antioxidant t-butyl-p-cresol, tetrakis [methylene-3- (3 ', 5'-di-t
-Butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)
Benzene, 1,3,5-tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate or n
-Octadecyl-β- (4'-hydroxy-3 ', 5'
-Di-t-butylphenyl) propionate, 2,5-di-methyl-2,5-di- (t- as a radical generator
Butyl peroxy) hexane or 1,3-bis-
(T-Butylperoxyisopropyl) benzene, trimethylolpropane triacrylate as a cross-linking aid, and other additives were added in predetermined amounts in a Henschel mixer (trade name) at the mixing ratios shown in Table 1 below, Three
After stirring and mixing for 1 minute, 200 ° C with a single screw extruder with a diameter of 40 mm
Was melt-kneaded, cross-linked and pelletized. Also,
As Comparative Examples 1 to 3, powdery propylene homopolymer having a MFR of 2.0 g / 10 min (titanium content 30 ppm) 100
Predetermined amounts of the additives shown in Table 1 below were mixed in parts by weight, and melt-kneaded in accordance with Examples 1 to 16 to obtain crosslinked pellets.

Using the pellets thus obtained, the colorability was evaluated by the test method described above. The results are shown in Table 1.

Examples 17 to 32, Comparative Examples 4 to 6 As a propylene-based polymer, a powdery crystalline ethylene-propylene random copolymer having an MFR of 7.0 g / 10 min (ethylene content 2.5% by weight, titanium content 33 pp).
m) 100 parts by weight, as compound A, trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate, 2,6- as a phenol-based antioxidant
Di-t-butyl-p-cresol, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2, 4,6-Tris (3,5-di-t-butyl-4)
-Hydroxybenzyl) benzene, 1,3,5-tris-
(3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanurate or n-ostadecyl-β- (4 '
-Hydroxy-3 ', 5'-di-t-butylphenyl)
Propionate, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl) benzene as a radical generator, and trisulfate as a crosslinking aid. Predetermined amounts of methylolpropane triacrylate and ground additives were added to the Henschel mixer (trade name) at the compounding ratios shown in Table 2 below, and the mixture was stirred and mixed for 3 minutes, and then the caliber was 40 mm.
Melt kneading at 200 ° C with a single-screw extruder
Pelletized. Further, as Comparative Examples 4 to 6, 100 parts by weight of a powdery crystalline ethylene-propylene random copolymer (ethylene content 2.5% by weight, titanium content 33 ppm) having an MFR of 7.0 g / 10 min. Each of the additives shown in Table 2 was blended in a predetermined amount, and Examples 17 to 32 were added.
A melt-kneading process was carried out in accordance with to obtain a crosslinked pellet.

Using the pellets thus obtained, the colorability was evaluated by the test method described above. The results are shown in Table 2.

Examples 33 to 48, Comparative Examples 7 to 9 As a propylene-based polymer, a powdery crystalline ethylene-propylene block copolymer having an MFR of 4.0 g / 10 min (ethylene content 8.5% by weight, titanium content 33 pp).
m) 100 parts by weight, as compound A, trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate, 2,6- as a phenol-based antioxidant
Di-t-butyl-p-cresol, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2, 4,6-Tris (3,5-di-t-butyl-4)
-Hydroxybenzyl) benzene, 1,3,5-tris-
(3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanurate or n-octadecyl-β- (4 '
-Hydroxy-3 ', 5'-di-t-butylphenyl)
Propionate, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl) benzene as a radical generator, and trisulfate as a crosslinking aid. Methylol propane triacrylate and other additives were added to the Henschel mixer (trade name) at the specified proportions shown in Table 3 below, and the mixture was stirred and mixed for 3 minutes, and then the caliber was 40 mm.
Melt kneading at 200 ° C with a single-screw extruder
Pelletized. Further, as Comparative Examples 7 to 9, 100 parts by weight of a powdery crystalline ethylene-propylene block copolymer (ethylene content 8.5% by weight, titanium content 33 ppm) having an MFR of 4.0 g / 10 min. Each of the additives shown in Table 3 was added in a predetermined amount, and Examples 33 to 48 were added.
A melt-kneading process was carried out in accordance with to obtain a crosslinked pellet.

Using the pellets thus obtained, the colorability was evaluated by the test method described above. The results are shown in Table 3.

Examples 49 to 64, Comparative Examples 10 to 12 As a propylene-based polymer, powdery crystalline ethylene-propylene-butene-1 terpolymer (Methylene content 2.5% by weight, MFR 7.0 g / 10 min). Butene-1 content 4.5% by weight, titanium content 33 ppm) 100 parts by weight, compound A as trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate,
2,6-di-t-butyl-p-cresol, tetrakis [methylene-3-] as a phenolic antioxidant
(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-
2,4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris- (3,5-
Di-t-butyl-4-hydroxybenzyl) isocyanurate or n-octadecyl-β- (4'-hydroxy-3 ', 5'-di-t-butylphenyl) propionate, 2,5-di- as a radical generator Methyl-2,
5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl)
Predetermined amounts of benzene, trimethylolpropane triacrylate as a cross-linking aid, and other additives were added to a Henschel mixer (trade name) at the compounding ratios shown in Table 4 below, and the mixture was stirred and mixed for 3 minutes, and then the diameter was 40 mm. Was melt-kneaded at 200 ° C. with a single-screw extruder to crosslink and pelletize. Further, as Comparative Examples 10 to 12, the MFR was 7.0.
g / 10 minutes of powdery crystalline ethylene-propylene-butene-1 terpolymer (ethylene content 2.5% by weight,
Butene-1 content 4.5% by weight, titanium content 33 pp
m) 100 parts by weight of each of the additives shown in Table 4 described below were added in a predetermined amount, and the mixture was melt-kneaded in accordance with Examples 49 to 64 to obtain crosslinked pellets.

Using the pellets thus obtained, the colorability was evaluated by the test method described above. The results are shown in Table 4.

Examples 65 to 80, Comparative Examples 13 to 15 As a propylene-based polymer, a powdery crystalline ethylene-propylene block copolymer having an MFR of 4.0 g / 10 min (ethylene content: 16.0% by weight, vanadium content: 0). .6
ppm) 100 parts by weight, as compound A, trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate, 2,6 as a phenol-based antioxidant.
-Di-t-butyl-p-cresol, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2 , 4,6-Tris (3,5-di-t-butyl-
4-hydroxybenzyl) benzene, 1,3,5-tris-
(3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanurate or n-octadecyl-β- (4 '
-Hydroxy-3 ', 5'-di-t-butylphenyl)
Propionate, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane or 1,3-bis- (t-butylperoxyisopropyl) benzene as a radical generator, and trisulfate as a crosslinking aid. Predetermined amounts of methylolpropane triacrylate and other additives were added to the Henschel mixer (trade name) at the compounding ratios shown in Table 5 below, and the mixture was stirred and mixed for 3 minutes, and then the bore diameter was 40 mm.
Melt kneading at 200 ° C with a single-screw extruder
Pelletized. In addition, MFR as Comparative Examples 13 to 15
Of 4.0 g / 10 min powdery crystalline ethylene-propylene block copolymer (ethylene content 16.0% by weight,
100 parts by weight of vanadium content (0.6 ppm) was added with predetermined amounts of the additives described in Table 5 below, and melt-kneading was performed according to Examples 65 to 80 to obtain crosslinked pellets.

Using the pellets thus obtained, the colorability was evaluated by the test method described above. The results are shown in Table 5.

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

Compound A [I]; trimethylolethane compound A [II]; glycerin monostearate compound A [III]; pentaerythritol monostearate compound A [IV]; pentaerythritol distearate phenolic antioxidant [I]; 2,6-di-t-butyl-p-cresolphenol-based antioxidant [II]; tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] Methanephenol antioxidant [III]; 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzylbenzenephenol antioxidant [IV]; 1,3,5-Tris-
(3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanurate phenol antioxidant [V]; n-octadecyl-β
-(4'-Hydroxy-3 ', 5'-di-t-butylphenyl) propionate 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 phosphorous antioxidant 1; tetrakis ( 2,4-Di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite Phosphorus antioxidant 2; Bis (2,4-t-butylphenyl) -pentaerythritol-diphosphite Polyol compound (polyol and fatty acid Complete ester); pentaerythritol tetrastearate 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 phenolic 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. Comparing Examples 1 to 16 and Comparative Examples 1 and 2, Examples 1 to 16 were less colored, and Comparative Examples 1 and 2 in which a phosphorus-based antioxidant was used instead of Compound A were significantly colored. I understand. Comparative Example 3 and Example 1 using a complete ester of a polyol and a fatty acid instead of the compound A
When compared with 16 or less, Comparative Example 3 is still not sufficiently satisfactory although the coloring property is improved to some extent. Further, in each Example, compound A according to the present invention, a phenol-based antioxidant, a radical generator, a crosslinking aid and a phosphorus-based antioxidant were blended, melt-kneaded, and cross-linked.
It can be seen that in No. 10, as compared with Example 5, the excellent anti-coloring effect of the compound A is not hindered, and a remarkable synergistic effect by the combined use of the phosphorus-based antioxidant is observed.

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

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 polyol or a partial ester of said polyol and a fatty acid (hereinafter referred to as compound A) is added to 100 parts by weight of 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. 0.01 to 1 part by weight of a phenolic antioxidant, 0.005 to 5 parts by weight of a radical generator, and 0.1 to 20 parts by weight of a cross-linking aid, and melt-kneaded at 150 to 300 ° C. A method for producing a crosslinked propylene-based polymer, comprising: 2. The method for producing a crosslinked propylene polymer according to claim 1, wherein trimethylolethane, glycerin and a fatty acid monoester or pentaerythritol and a fatty acid mono or diester are blended as the compound A. 3. As a phenolic antioxidant, 2,6-di-t-butyl-p-cresol and tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) are used. ) Propionate] methane, 1,3,5 trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris- (3,3)
Claims 1. Incorporating 5-di-t-butyl-4-hydroxybenzyl) isocyanurate or n-octadecyl-β- (4'-hydroxy-3 ', 5'-di-t-butylphenyl) propionate. The method for producing a crosslinked propylene-based polymer as described in the item. 4. A radical generator, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane,
Claim 2, wherein 2,5-di-methyl-2,5-di- (t-butylperoxy) hexyne-3 or 1,3-bis (t-butylperoxyisopropyl) benzene is blended. A method for producing the crosslinked propylene-based polymer as described. 5. A compound having a polyfunctional monomer, a monofunctional monomer, a quinonedioxime compound, a nitroso compound or a maleimide compound as a crosslinking aid.
The method for producing a crosslinked propylene-based polymer as described in the item. 6. A propylene homopolymer, a crystalline ethylene-propylene random copolymer, a crystalline ethylene-propylene block copolymer, a crystalline propylene-butene-1 random copolymer, a crystalline ethylene as the propylene-based polymer. -The propylene-butene-1 terpolymer or the crystalline propylene-hexene-butene-1 terpolymer is used to produce the crosslinked propylene polymer according to claim 1.