JPS63309544A - Production of crosslinked propylene polymer - Google Patents

Abstract

PURPOSE:To obtain the title noncolored polymer excellent in strength etc., by mixing a propylene polymer containing a catalyst residue with a zinc carboxylate, a phenolic antioxidant, a radical generator and a crosslinking aid, and melt-kneading the mixture. CONSTITUTION:100pts.wt. propylene polymer (A) containing at least 5ppm titanium component as a catalyst residue or at least 0.5ppm vanadium component as a catalyst residue is mixed with 0.01-1pt.wt. zinc salt (B) of a carboxylic acid (e.g., zinc stearate), 0.01-1pt.wt. phenolic antioxidant (C) (e.g., 2,6-di-t-butyl- p-cresol), 0.005-5pts.wt. radical generator (D) [e.g., 2,5-dimethyl-2,5-di-(t- butylperoxy)hexane] and 0.1-20pts.wt. crosslinking aid (E). This mixture is melt-kneaded at 150-300 deg.C to obtain a crosslinked propylene polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a crosslinked propylene polymer. In more detail, (1) the titanium content of the catalyst residue is 5 p.
A propylene polymer containing 0.5 ppm or more of vanadium or 0.5 ppm or more of vanadium is blended with specific amounts of a phenolic antioxidant, a zinc salt of carboxylic acid (hereinafter referred to as compound A), a radical generator, and a crosslinking aid. and (2) blending specific amounts of a phenolic antioxidant, a radical generator, and a crosslinking aid into the propylene polymer, and then melt-kneading the propylene polymer at a temperature of 150°C to 300°C. A specific amount of zinc salt of carboxylic acid (hereinafter referred to as compound A) was blended into the crosslinked propylene polymer that had been melt-kneaded again at 300°C.
The present invention relates to a method for producing a crosslinked propylene polymer, which is characterized by carrying out a melt-kneading treatment at a temperature of .degree. C. to 300.degree.

[Prior Art] In general, propylene polymers are relatively inexpensive and have excellent mechanical properties, so they are used to manufacture various molded products such as injection molded products, blow molded products, films, sheets, and fibers. . However, propylene-based polymers are molded at temperatures above the melting point of the propylene-based polymer, but are subject to oxidative deterioration due to the heat during melt-kneading, and are processed by cutting the molecular chains of the propylene-based polymer. Problems of coloration and odor caused by a decrease in properties and mechanical strength as well as oxidative deterioration occur. In particular, propylene-based polymers contain tertiary carbon that is easily susceptible to oxidation, so they are susceptible to thermal oxidative deterioration due to melt kneading during molding, and their thermal stability during practical use. There is also a problem. For this reason, in order to prevent thermal oxidative deterioration during melt-kneading, 2,6-di-
Low molecular weight phenolic antioxidants such as t-butyl-p-cresol (8HT) are widely used, and high molecular weight phenolic antioxidants are widely used to provide thermal stability in practical use.

However, when the propylene polymer containing the above-mentioned phenolic antioxidant is melt-kneaded, the phenolic antioxidant used forms a phenoxy coordination complex due to the titanium or vanadium complex compound that is the catalyst residue in the propylene polymer. or the phenolic antioxidant is oxidized to produce a quinone compound, causing problems such as coloring of the resulting propylene polymer. For this reason,
Polyolefin composition containing polyolefin and zinc salt of organic acid (Plastics Age, Vol. 33, No. 1,
Pages 152-159 (1987 edition) [Plast
ics age.

Vol, 33. Na 1. p, 152-159
(1987) ) and a zinc salt of a carboxylic acid with the aim of obtaining greater resistance to yellowing and a higher stabilizing effect at concentrations consisting of phenolic antioxidants. A stabilizer system and a stabilized polymer composition containing this stabilizer system (JP-A-62-43437) have been proposed.

In addition, in order to improve the mechanical strength, heat-resistant rigidity, etc. of propylene-based polymers, propylene-based polymers are cross-linked by melt-kneading in the presence of a radical generator using a cross-linking aid consisting of a polyfunctional monomer. The method to do this is well known.

In the process of researching the coloring properties of propylene-based polymers containing a large amount of titanium or vanadium as catalyst residues, the present inventors discovered that Even if the above-mentioned phenolic antioxidant is blended and melt-kneaded, coloration to a degree that poses a practical problem does not occur. It has been found that when crosslinked by melt-kneading in the presence of a radical generator, the resulting crosslinked propylene polymer becomes significantly colored. This phenomenon is described in the aforementioned Plastic Swage, Vol. 33, No. 1, 152-1.
59 pages (1987 edition) and JP-A-62-43437
There is no description in the publication, and there is no description that even suggests the above phenomenon. In view of the above-mentioned problem, the present inventors first attempted to obtain a crosslinked propylene polymer without coloration. The purpose is to provide a method for producing a crosslinked propylene polymer by blending a polyol or a partial ester of a polyol with a fatty acid, a phenolic antioxidant, and a crosslinking aid into a propylene polymer, and melt-kneading the mixture in the presence of a radical generator ( Patent Application No. 147581/1981) was proposed.

[Problems to be Solved by the Invention] The present inventors were not satisfied with the method for producing a crosslinked propylene polymer previously proposed in Japanese Patent Application No. 147581/1982, and so they removed the titanium or vanadium content of the catalyst residue. In order to improve the mechanical strength of a propylene polymer containing a large amount of propylene polymer and a phenolic antioxidant, it is melt-kneaded in the presence of a radical generator using a crosslinking aid. Further intensive research was conducted on a method for obtaining crosslinked propylene polymers that do not become colored even when crosslinked.

As a result, (1) specific amounts of a phenolic antioxidant and a zinc salt of carboxylic acid (hereinafter referred to as compound A ),
Formulated with radical generators and crosslinking aids, the temperature! 50℃
melt-kneading treatment at ~300°C, and (2) blending specific amounts of a phenolic antioxidant, a radical generator, and a crosslinking aid into the propylene polymer, respectively;
A specific amount of a carboxylic acid zinc salt (hereinafter referred to as compound A) is added to a crosslinked propylene polymer that has been melt-kneaded at a temperature of 150"C to 300"C.

) and melt-kneaded it again at a temperature of 150°C to 300°C, it was discovered that a crosslinked propylene polymer without coloring could be obtained, and based on this knowledge, the present invention was completed.

As is clear from the above description, the purpose of the present invention is (1)
A propylene polymer containing 5 ppm or more of titanium or 0.5 ppm or more of vanadium in the catalyst residue is treated with a specific amount of a phenolic antioxidant, a zinc salt of carboxylic acid (hereinafter referred to as compound A), and a radical generator. and (2) adding specific amounts of a phenolic antioxidant, a radical generator, and a crosslinking aid to the propylene polymer. Blend and temperature 150℃~3
A crosslinked propylene polymer melt-kneaded at 00°C,
A specific amount of a zinc salt of a carboxylic acid (hereinafter referred to as compound A)
) and melt-kneading the mixture again at a temperature of 150°C to 300°C to provide a method for producing a crosslinked propylene polymer without coloring.

[Means for solving problems] The present invention has the following configuration.

(1) Zinc salt of carboxylic acid (hereinafter referred to as
) and a phenolic antioxidant, respectively, and 1 part by weight, and 0.00 parts by weight of a radical generator.
5 to 5 parts by weight, 0.1 to 20 parts by weight of a crosslinking aid,
A method for producing a crosslinked propylene polymer, comprising melt-kneading at 150°C to 300°C.

(2) 0.0i to lli parts of a phenolic antioxidant and a radical generator per 100 parts by weight of a propylene polymer containing 5 ppm or more of titanium or 5 ppr or more of vanadium in the catalyst residue. from 0.005
5 parts by weight and 0.1 to 20 parts by weight of a crosslinking aid,
A zinc salt of carboxylic acid (hereinafter referred to as compound A) is added to a crosslinked propylene polymer melt-kneaded at 150°C to 300°C in an amount of 0.01 to 1 part by weight per 100 parts by weight of the propylene polymer. Blend so that
A method for producing a crosslinked propylene polymer, which comprises melt-kneading at 00°C.

The propylene polymer used in the production method of the present invention is one containing 5 ppm or more of titanium or 0.5 ppm or more of vanadium in the catalyst residue, for example, by solution polymerization using a saturated charcoal water bladder solvent. , a propylene polymer obtained by a bulk polymerization method, a gas phase polymerization method, or a combination of bulk polymerization method and gas phase polymerization method.In the production method of the present invention, the content of titanium in the catalyst residue There is no problem in using an ungrooved propylene polymer with a vanadium content of less than 5 ppm or a vanadium content of 0.5 ppm, but in this case, the resulting crosslinked propylene polymer may be The polymer does not cause any coloration to a degree that would be a problem in practice. The propylene polymer used in the present invention has a titanium content of 5 ppm in the catalyst residue.
A propylene polymer containing 0.5 ppm or more of vanadium or a propylene homopolymer, propylene containing 70% by weight or more of a propylene component, ethylene, butene-1, pentene-1,4-methyl −
α- such as pentene-11 hexene-1, octene-1, etc.
Crystalline random copolymers or crystalline block copolymers with one or more olefins, copolymers of propylene with vinyl acetate or acrylic esters, or copolymers of these copolymers with Examples include copolymers with unsaturated carboxylic acids or their anhydrides, and reaction products between the copolymers and metal ion compounds. The above propylene polymers can also be used as a mixture.Also, the above propylene polymers and various synthetic rubbers (e.g. ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, polybutadiene, Polyisoprene, polychloroprene, chlorinated polyethylene, chlorinated polypropylene, fluorocarbon rubber,
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 block copolymer, styrene block copolymers, etc.) or thermoplastic synthetic resins (such as ultra-low density polyethylene, low density polyethylene,
Linear low density polyethylene, medium density polyethylene, high density polyethylene, polybutene, polyolefins other than propylene polymers such as poly-4-methylpentene-1, polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer polymer,
Polyamide, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyvinyl chloride, fluororesin, etc.) can also be used in combination.

Propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline pro-syn-butene-1 random copolymer, crystalline ethylene-pro-syn-butene-13 copolymer Copolymerization, crystalline propylene-hexene-butene-13-element copolymer and mixtures of two or more thereof, in which the titanium content of the catalyst residue is 5 ppm or more or the vanadium content is o
, a propylene polymer containing 5 ppm or more is particularly preferred.

Compound A used in the present invention includes zinc acetate, zinc n-propionate, zinc n-butyrate, zinc n-valerate, n-
Zinc hexanoate, zinc n-octoate, zinc 2-ethylhexanoate, zinc n-decanoate, zinc laurate, zinc myristate, zinc palmitate, zinc stearate,
Zinc fatty acids such as zinc oleate, zinc linoleate, zinc lyrunate, zinc behenate, zinc erucate, zinc lignocerate, zinc cerotate, zinc montanate, zinc triphenylacetate, zinc oxalate, zinc malonate, succinate Zinc acid, zinc glutarate, zinc aliphatic dicarboxylate such as zinc adipate, zinc naphthenate, zinc benzoate, o
-) Zinc toluate, ■-Zinc toluate, p-) Zinc toluate, Zinc pt-butylbenzoate, Zinc 0-methoxybenzoate, Zinc steel-methoxybenzoate, Zinc anisate, Zinc phthalate, Examples include zinc aromatic carboxylates such as zinc isophthalate and zinc terephthalate, and fatty acid zincs such as zinc 2-ethylhexanoate, zinc stearate and zinc montanate are particularly preferred. These zinc salts of carboxylic acids can of course be used alone, and two or more zinc salts of carboxylic acids can also be used in combination. Phenolic antioxidants include 2,6-di-t-butyl-p-cresol, 2-t-butyl-4,6-dimethylphenol, 2,
6-di-t-butyl-4-ethylphenol, 2,6-
Di-t-butyro-n-butylphenol, 2,6-di-i-butyl-4-n-butylphenol, 2,6-di-cyclobenzyl-4-methylphenol, 2-(α-
methylcyclohexyl)-4,6-dimethylphenol, 2,6-di-octadecyl-4-methylphenol, 2,4.6-)dicyclohexylphenol, 2
, 6-di-t-butyl-4-methoxymethylphenol, n-octadecyl-β-(4'-hydroxy-3',
5'-di-t-butylphenyl)propionate, 2,
6-diphenyl-4-octadecyloxyphenol,
2,4,6-tris(3',5'-di-t-butyl-
4'-Hydroxybenzylthio)-1,3,5-)riazine, 2,6-di-t-butyl-4-methoxyphenol, 2,5-di-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-(6-1-butyl-
2-methylphenol), 2,2ξmethylene-bis-(
6-1-butyl-4-methylphenol), 2,2'-
Methylene bis-(6-t-butyl-4-ethylphenol), 2,2'-methylene-bis-[4.methyl-6
-(α-methylcyclohexyl)-phenolco, 2,
2'-methylene-bis-(4-methyl-6-cyclohexylphenol), 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-4-1-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-(5-4-butyl-4-hydroxy-2-methylphenyl)-butane, 2,6-di-(3
-t-butyl-5-methyl-2-hydroxybenzyl)
-4-methylphenol, 1,1.3-tris-(5-
1-butyl-4-hydroxy-2-methylphenyl)-
Butane, bis[3,3-bis(4'-hydroxy-3'
-t-butylphenyl)butyric acid coethylene glycol ester, di(3-t-butyl-4-hydroxy-5-methylphenyl)-dicyclopentadiene, di[2-(3'-t-butyl-2 '-Hydroxy-
5'-methylbenzyl)-6-tert-butyl-4-methylphenylcoterephthalate, 3,9-bis[1,1-dimethyl-2-(β-(3-1-butyl-4-hydroxy-5- methylphenyl)propionyloxy)ethyl]
-2,4,8,10-tetraoxaspiro[5,5]
undecane, 3,9-bis[1,! -dimethyl-2-(
β-(3,5-di-t-butyroothydroxyphenyl)propionyloxy)ethyl] -2,4,8,10
-tetraoxaspiro[5,5]undecane, 3,9-
Bis[1,1-dimethyl-2-(β-(3,5-diphenyl-4-hydroxyphenyl)propionyloxy)
ethyl]-2,4,8,10-tetraoxaspiro[5
, 5 condecane, 3.9-bis[! ,! -dimethyl
2-(β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionyloxy)ethyl]-2.4,
8.10-tetraoxaspiro[5,5]undecane,
1,3,5-)dimethyl-2,4,6-tris(3,5
-di-t-butyl-4-hydroxybenzyl)benzene, 1,3.5-tris-(3,5-di-t-butyroothydroxybenzyl)isocyanurate, 1,3.5-
Tris-(4-t-butyl-3-hydroxy-2,6-
dimethylbenzyl) isocyanurate, 1,3,5-tris-[(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate and tetrakis[methylene-3-(3',5 '-ji-
An example is t-butyl-4'-hydroxyphenyl propionate comethane. These phenolic antioxidants can of course be used alone, and two or more types of phenolic antioxidants can also be used in combination. The blending ratio of compound A is 0.0 parts by weight per 100 parts by weight of the propylene polymer.
The amount 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 coloring prevention effect of the crosslinked propylene polymer will not be sufficiently exhibited, and although it is OK to exceed 1 part by weight, no further improvement in the coloring prevention effect can be expected and in practice Not only is it unsuitable, but it is also uneconomical. In addition, the blending ratio of phenolic antioxidant is 100% propylene polymer! The amount is 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight.
If the amount is less than 0.01 parts by weight, the effect of preventing thermal oxidative deterioration of the cross-linked propylene polymer will not be sufficiently exhibited.Although it may be more than 1 part by weight, the effect of preventing further thermal oxidative deterioration will not be exhibited. Not only is it impractical as no improvement can be expected, but it is also uneconomical.

For the radical generator used in the present invention, in order to obtain a uniform composition, it is desirable that the decomposition temperature is not too low.
The temperature for obtaining a half-life of 10 hours is 70°C or higher, preferably 100°C or higher, and 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-dibar adipate, 7-butylperoxy-3,5
, 5-) dimethylhexanoate, methyl-ethylketone peroxide, cyclohexanone peroxide,
Di-t-butyl peroxide, dicumyl 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-butylcumyl peroxide, l,1-bis-
(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis-(t-butylperoxy)cyclohexane, 2,2-bis-(t-butylperoxy)butane, ρ-menthane hydroperoxide,
Di-isopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-cymene hydroperoxide,
Examples include organic peroxides such as 1,1,3.3-tetra-methylbutyl hydroperoxide and 2,5-di-methyl-2,5-di-(hydroperoxy)hexane, especially 2,5 -di-methyl-2,5-di-(t-butylperoxy)hexane, 2,5-di-methyl-2,
5-di(t-butylperoxy)hexyne-3 and 1,3-bis-(t-butylperoxyisopropyl)
Benzene is preferred. These radical generators can be used alone, or two or more radical generators can be used in combination. The ratio of the radical generator to 100 parts by weight of the propylene polymer is usually 0.005 to 5.
Part by weight, preferably 0.01 to 1 part by weight. The melt-kneading process is carried out at a temperature of 150°C to 300°C, preferably 180°C, using various melt-kneading devices or molding devices described below.
Melt-kneading treatment carried out at a temperature of ~270°C, with a temperature of 150°C
If it is less than 300° C., sufficient crosslinking will not take place, and if it exceeds 300° C., the thermal oxidative deterioration of the propylene polymer will be accelerated and the propylene polymer will become noticeably colored, which is not preferable.

The crosslinking aids used in the present invention include polyfunctional monomers, monofunctional monomers, quinone dioxime compounds, nitroso compounds, or maleimide compounds, including ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, and 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 gelicold diacrylate, 1,3-butylene gelicold dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, glycerol triacrylate, glycerol trimethacrylate, glycerol allyloxy diacrylate, glycerol allyloxy dimethacrylate, trimethylol ethane triacrylate Acrylate, Trimethylolethane 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 dimethacrylate, 1,
6-hexanediol diacrylate, 1,6-hexanediol diacrylate, 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-)lyacryloylhexahydro-8-triazine, 1,3.5-
) dimethacryloylhexahydro-5-) riazine,
1,1.1-trishydroxymethylethane diacrylate, 1,1.1-trishydroxymethylethane dimethacrylate, 1.1. Todoris hydroxymethylethane triacrylate, 1,1.1-trishydroxymethylethane trimethacrylate, t,t,i-trishydroxymethylpropane diacrylate, 1,1.1-
Trishydroxymethylpropane dimethacrylate, 1
, 1.1-trishydroxymethylpropane triacrylate, 1.1.1-trishydroxymethylpropane trimethacrylate, 2,2'-methylene-bis-(6
-1-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, 2,2ξ methylene-bis-(4,6-di-1-butylphenol) diacrylate, 2,2' methylene-bis-(4,6-di-t -butylphenol) dimethafrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl phthalate, diallyl terephthalate, triallyl trimellitic acid ester, triallyl trimesic acid ester,
Pyromellitic acid triallyl ester, styrene monomer, vinyltoluene, ethylvinylbenzene, divinylbenzene, diisopropenylbenzene, divinylpyridine, 1)II)'-dibenzoylquinonedioxime, p-
Nitrosophenol, N,N'-(a+-phenylene)bismaleimide, N,N'lp-phenylene)bismaleimide, N,N'-(4-methyl-m-phenylene) and sumaleimide, 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-4,4'-trimethylene glycol-dibenzoate) bismaleimide, N,
Examples include N'-(3,3'-dimethyl-4,4'-)limethylene glycol dibenzoate) bismaleimide, and particularly preferred are trimethylolpropane triacrylate and trimethylolpropane trimethacrylate. Of course, these crosslinking aids can be used alone,
It is also possible to use more than one type of crosslinking aid. 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. If the amount is less than 0.1 parts by weight, the effect of improving the mechanical strength of the crosslinked propylene polymer will not be sufficiently exhibited, and even if it exceeds 20 parts by weight, the degree of improvement in mechanical strength etc. will be small, and The amount of unreacted crosslinking aid remaining in the crosslinked propylene polymer increases, and the color of the resulting molded product changes! This causes disadvantages such as oxidation and formation of bubbles.

In the production method of the present invention, the titanium content of the catalyst residue used is 5 ppm or more, or the vanadium content is 0.5 pp+.
Various additives normally added to propylene polymers, such as thioether-based and phosphorus-based antioxidants, light stabilizers, clarifying agents, nucleating agents, lubricants, antistatic agents, etc. agent, anti-fogging agent, anti-blocking agent, no-drop agent, pigment, heavy metal deactivator (tR harm inhibitor),
Dispersants or neutralizing agents for metal soaps, inorganic fillers (
(e.g. talc, mica, clay, wollastonite, zeolite, asbestos, calcium carbonate, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium silicate, glass fiber, carbon fiber, etc.) or coupling agents (e.g. silanes, titanates) system, boron system,
The inorganic filler or organic filler (for example, wood flour, valve, waste paper, synthetic if! II!
, natural ail, etc.) may be blended and used within a range that does not impair the purpose of the present invention. In particular, when a phosphorus-based antioxidant is used in combination, a synergistic coloring prevention effect is exhibited, so it is preferable to use them together. Preferred phosphorus antioxidants include distearyl pentaerythritol diphosphite and tetrakis(2,4-di-t-butylphenyl').
) -4,4'-biphenylene-diphosphonite, bis(2,tra-t-butylphenyl)-pentaerythritol-siphosphite, bis(2,6-di-t-
-butyl-4-methylphenyl)-pentaerythritol-siphosphite and tris(2,4-di-t-
butylphenyl) phosphite can be exemplified.

The production method of the present invention includes (1) reducing the titanium content of the catalyst residue to 5pp;
The above compound A, a phenolic antioxidant, a radical generator, a crosslinking aid, and the various additives mentioned above that are usually added to a propylene polymer are added to a propylene polymer having an IQ or higher or containing a vanadium content of 0.5 ppm or more. A predetermined amount is mixed using a normal mixing device such as a Hensel mixer (trade name), a super mixer, a ribbon blender, a panburi mixer, a tumbler, etc. at a temperature that does not decompose the blended radical generator, to form a mixture. The mixture is melt-kneaded using various types of melt-kneading equipment such as an ordinary single-screw extruder, twin-screw extruder, Brabender, or roll, at a melt-kneading temperature of 1.
By melt-kneading the pellets at 50°C to 300°C, preferably 180°C to 270°C, or (2
) A phenolic antioxidant, a radical generator, a crosslinking aid, and the above-mentioned substances usually added to a propylene polymer are added to a propylene polymer containing 5 ppm or more of titanium or 0.5 ppm or more of vanadium in the catalyst residue. Mix predetermined amounts of various additives using a regular mixing device such as a Hensel mixer (trade name), super mixer, ribbon blender, Pan Bali mixer, tumbler, etc. at a temperature that does not decompose the blended radical generator. The mixture is then melt-kneaded using various melt-kneading devices such as a conventional single-screw extruder, twin-screw extruder, Brabender or roll,
Melt kneading temperature 150°C to 300°C, preferably 180°C
A predetermined amount of Compound A is usually added to the pellets by melt-kneading at ~270°C in the form of a so-called masterbatch or a mixture or pellets containing a high concentration of Compound A in a propylene polymer. Mixing equipment such as Hensel Mixer (trade name), Super Mixer, Ribbon Blender, Pan Bali mixer, tumbler, etc. is used to form a mixture, and the mixture is transferred to a conventional single-screw extruder, twin-screw extruder, or tumbler. Using various melt kneading devices such as lavender or rolls, or various molding devices such as spinning machines, film forming machines, injection molding machines, or blow molding machines, the melt kneading temperature is 150°C to 300°C, preferably 18°C.
This is carried out by melt-kneading at 0°C to 270°C and pelletizing or molding.

[Function] In the present invention, the phenolic antioxidant acts as a radical chain inhibitor, and the radical generator generates radicals by melt-kneading, that is, heating, and extracts hydrogen atoms from the propylene polymer. It is well known that the crosslinking aid reacts with the radicals of the propylene polymer to crosslink the propylene polymer and improve mechanical strength etc. In the production method of the present invention The aforementioned compound A is a propylene polymer stabilized by a phenolic antioxidant,
When crosslinking is performed by melt-kneading using a crosslinking aid in the presence of a radical generator, the mechanism of action on titanium or vanadium complex compounds is not clear, but compound A acts on the complex compound of titanium or vanadium to produce a stable chelate compound, that is, deactivates the active titanium or vanadium, and Compound A acts as a crosslinking agent for the propylene polymer stabilized by the phenolic antioxidant. When crosslinking is performed by melt-kneading using a compound A in the presence of a radical generator, the zinc of compound A acts on the colored phenoxy coordination complex formed by the complex compound of titanium or vanadium, and the zinc of the compound A forms the phenoxy coordination complex. It is presumed that a colorless phenoxy-zinc coordination complex is produced by substituting titanium or vanadium inside.

[Effects of the Invention] The crosslinked propylene polymer obtained by the production method of the present invention is disclosed in the above-mentioned Japanese Patent Application No. 61-147 filed by the present inventors.
Compared to the crosslinked propylene polymer related to No. 581, there is no coloring and mechanical strength is improved, so it can be used to manufacture desired molded products by various molding methods such as injection molding, extrusion molding, and blow molding. It can be suitably used for.

[Examples] The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The evaluation method used in Examples and Comparative Examples was as follows.

Coloring property: Y I (Yellow
The colorability was evaluated based on the magnitude of the yr value.

The smaller this value is, the less coloring there is.

Examples 1 to 15, Comparative Examples 1 to 7 As a propylene polymer, MFR (discharge amount of molten resin in 10 minutes when applying a load of 2.16 kg at 230°C) was stabilized at 2.0 g/10 minutes. Powdered propylene homopolymer (titanium content 30 ppm)
To 100 parts by weight, zinc 2-ethylhexanoate, zinc stearate, zinc montanate or zinc benzoate as compound A, 2゜6-di-t-butyl-p-cresol, tetrakis[methylene as phenolic antioxidant] -3-(3',5'-di-t-butyl 4'-hydroxyphenyl)propionate comethane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl) -butyl-4-hydroxybenzyl)benzene, 1,3.5-
) lis-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate or n-octadecyl-
β-(4'-hydroxy-3'.

51-di-t-butylphenyl) propionate, 2,5-di-methyl-2,5-di-(
Predetermined amounts of t-butylperoxy)hexane or 1,3-bis-(t-butylperoxyisopropyl)benzene, trimethylolpropane triacrylate as a crosslinking aid, and other additives are listed in Table 1 below. Put it in the Hensel mixer (product name) at the mixing ratio,
After stirring and mixing for 3 minutes, use a single screw extruder with a diameter of 40+ am to
The mixture was melt-kneaded at 00°C to crosslink and form pellets.

In addition, as Comparative Examples 1 to 7, 100 parts by weight of an unstabilized powdered propylene homopolymer with an MFR of 2.0 g/10 min and a titanium content of 30 pp @) were mixed with additives listed in Table 1 below. Predetermined amounts of each were blended, and Examples 1-
Cross-linked pellets were obtained by melt-kneading in accordance with No. 15.

Using the obtained pellets, colorability was evaluated according to the test method described above. These results are shown in Table 1.

Examples 16-30. Comparative Examples 8 to 14 As a propylene polymer, a powdery crystalline ethylene-propylene random copolymer (ethylene content 2.5% by weight, titanium content 33pp
m) To 100 parts by weight, zinc 2-ethylhexanoate, zinc stearate, zinc montanate or zinc benzoate as compound A, and 2.6- as a phenolic antioxidant.
Di-t-butyl-p-cresol, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate comethane, 1.3.5-
) listyl-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, As a radical generator 2
, 5-di-methyl-2,5-di-(t-butylperoxy)hexane or 1,3-bis-(t-butylperoxyisopropyl)benzene, trimethylolpropane triacrylate as a crosslinking agent and others. A predetermined amount of each of the additives was put into a Hensel mixer (trade name) at the mixing ratio shown in Table 2 below, and after stirring and mixing for 3 minutes, the mixture was melt-kneaded at 200°C using a single-screw extruder with a diameter of 40 m. It was then cross-linked and pelletized. In addition, as Comparative Examples 8 to 14, powdered crystalline ethylene-propylene random copolymer (ethylene content 2.5
% by weight, titanium content 33 Pl) I) A predetermined amount of each of the additives listed in Table 2 below was blended with 100 parts by weight, and a crosslinked pellet was melt-kneaded according to Examples 16 to 30. Obtained.

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

Examples 31 to 45, Comparative Examples 15 to 21 As the propylene polymer, a powdery crystalline ethylene-propylene block copolymer with an MFR of 4.0 g/10 minutes (ethylene content 12.0% by weight, titanium content 33p) was used.
pm) to 100 parts by weight, zinc 2-ethylhexanoate, zinc stearate, zinc montanate or zinc benzoate as compound A, and 2.
6-di-t-butyl-p-cresol, tetrakis[methylene-3-(3'',5'-di-t-butyl-4'-hydroxyphenyl)propionate comethane, 1,3.
5-trimethyl-2,4,6-tris(3,5-di-t
-butyl-4-hydroxybenzyl)benzene, 1,3
．． 5-) Lis-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate or n-octadecyl-β-(4'-hydroxy-3',5ξdi-t-butylphenyl)propionate, radical generation 2,5-di-methyl-2,5-di-(t-butylperoxy)hexane or 1,3-bis-(t-butylperoxyisopropyl)benzene as a crosslinking agent, and trimethylolpropanetri as a crosslinking agent. Predetermined amounts of acrylate and other additives were placed in a Hensel mixer (trade name) at the mixing ratios listed in Table 3 below, and after stirring and mixing for 3 minutes, the mixture was heated at 200°C using a single-screw extruder with a diameter of 40 m. It was melt-kneaded, crosslinked, and pelletized. In addition, Comparative Examples 15 to 2
Powdered crystalline ethylene-propylene block copolymer with MFR of 4.0 g and 710 min. Ethylene content: 1
2.0% by weight, titanium content 33ppm) and a predetermined amount of each of the additives listed in Table 3 below were blended with 100 parts by weight, and crosslinked pellets were melt-kneaded and crosslinked according to Examples 31 to 45. I got it.

Using the obtained pellets, colorability was evaluated according to the test method described above. These results are shown in Table 3.

Examples 46 to 60, Comparative Examples 22 to 28 As the propylene polymer, MFR7, Og/10 minutes powdered crystalline ethylene-propylene-butene-13 copolymer (ethylene content 2.5% by weight, butene -1 content 4.5% by weight, titanium content 33ppm) 100
In the weight part, zinc 2-ethylhexanoate as compound A,
Zinc stearate, zinc montanate or zinc benzoate, 2,6-di-t-butyl-p-cresol, tetrakis[methylene-3-(
3'51-di-t-butyl-4'-hydroxyphenyl)propionate comethane, 1,3,5-tristyl-
2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3.5-tris-
(3,5-di-t-butyrotohydroxybenzyl)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 trifluoride as a crosslinking agent. Predetermined amounts of methylolpropane triacrylate and other additives were placed in a Hensel mixer (trade name) at the mixing ratios listed in Table 4 below, and mixed with stirring for 3 minutes. Crosslinked by melt-kneading at 200°C,
Pelletized φ Also, as Comparative Examples 22 to 28, MF
Powdered crystalline ethylene-propylene-butene-13 element copolymer with R of 4.0 g/10 min. Ethylene content: 2.
5% by weight, butene-1 content 4.5% by weight, titanium content 33 ppm), and predetermined amounts of each of the additives listed in Table 4 below were blended into 100 parts by weight, and the additives were prepared according to Examples 46 to 60. The mixture was melt-kneaded to obtain crosslinked pellets.

Using the obtained pellets, colorability was evaluated according to the test method described above. These results are shown in Table 4.

Examples 61 to 75, Comparative Examples 29 to 35 As the propylene polymer, a powdery crystalline ethylene-propylene block copolymer (ethylene content 12.0% by weight, vanadium content 0) with MFR 4, Og/10 minutes was used.
．． 6 ppm) 10 parts by weight of compound A: zinc 2-ethylhexanoate, zinc stearate, zinc montanate, or zinc benzoate, and phenolic antioxidants: 2,6-di-t-butyl-p-cresol, tetrakis. [Methylene-3-(3',5'-di-t-butyl-4
'-Hydroxyphenyl)propionate comethane, 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! as a radical generator. , 3-bis-(t-butylperoxyisopropyl)benzene, trimethylolpropane triacrylate as a crosslinking aid, and other additives in the proportions listed in Table 5 below. After stirring and mixing for 3 minutes, the mixture was melt-kneaded at 200'C in a single-screw extruder with a diameter of 40 am to crosslink and pelletize. In addition, as Comparative Examples 29 to 35, powdered crystalline ethylene-propylene block copolymer with an MFR of 4.0 g/10 min (ethylene content 12.0 wt%, vanadium content 0.6 pp
m) 1011 parts were blended with predetermined amounts of each of the additives listed in Table 5 below, and melt-kneaded according to Examples 61 to 75 to obtain crosslinked pellets.

Using the obtained pellets, colorability was evaluated according to the test method described above. These results are shown in Table 5.

Examples 76 to 90, Comparative Examples 36 to 42 As a propylene polymer, 100 parts by weight of an unstabilized powdered propylene homopolymer with an MFR of 2.0 g/10 minutes (titanium content 30 ppm) and a phenolic antioxidant 2,6-di-t-butyl-p-cresol, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate comethane, 1.3. 5-tristyl-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- as a radical generator
di-t-butylperoxy)hexane or l,3
-bis-(t-butylperoxyisopropyl)benzene, trimethylolpropane triacrylate as a crosslinking coagent, and other additives in the following sixth step.
Add the blending ratio listed in the table to a Hensel mixer (trade name), stir and mix for 3 minutes, then melt-knead and crosslink at 200°C in a single-screw extruder with a diameter of 40 m++ to pellet (hereinafter referred to as pellets) I. It is abbreviated as ) was obtained. To 90 parts by weight of the obtained Beretsu) I, 10 parts by weight of an unstabilized powdered propylene homopolymer (titanium content 30 ppm) with an MFR of 2.0 g/10 minutes and zinc 2-ethylhexanoate as compound A. , zinc stearate, zinc montanate, or zinc benzoate in the mixing ratios listed in Table 6 below in a Hensel mixer (trade name), stirred and mixed for 1 minute, and then mixed with a single shaft with a diameter of 40 mm. The mixture was melt-kneaded at 200° C. using an extruder to obtain pellets (hereinafter abbreviated as pellets ①). Also, comparative example 3
6-42 is an unstabilized powdered propylene homopolymer (titanium-containing 4
130 ppm) 100 parts by weight of the additives listed in Table 6 below. A predetermined amount of each was put into a Hensel mixer (trade name) at the mixing ratio listed in Table 6 below, and after stirring and mixing for 3 minutes, the mixture was melt-kneaded at 200°C in a single-screw extruder with a diameter of 40 mm. A crosslinked pellet (hereinafter abbreviated as pellet I) was obtained. To 90 parts by weight of the obtained pellets) I, 10 parts by weight of an unstabilized powdered propylene homopolymer (titanium content 30 ppm) with an MFR of 2.0 g/10 minutes and the addition as described in Table 6 below. A predetermined amount of each agent was put into a Hensel mixer (trade name) at the mixing ratio shown in Table 6 below, and after stirring and mixing for 1 minute, the mixture was melt-kneaded at 200°C in a single-screw extruder with a diameter of 40 m. A pellet (hereinafter abbreviated as pellet ■) was obtained.

Using the obtained pellets (1) and (2), the colorability was evaluated using the test method described above. The results are shown in Table 6.

Examples 91-105, Comparative Examples 43-49 Propylene-based 1
As a combination, powdered crystalline ethylene-propylene block copolymer (ethylene content 12,0% by weight, vanadium content 0.6 ppm) with MFR 4,0 g/10 min.
2.6 as a phenolic antioxidant in the toe section
-di-t-butyl-p-cresol, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate comethane, 1,3.5
-) listyl-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-(butylperoxy)hexane or 1,3-bis-(t-butylperoxyisopropyl)benzene as a radical generator, and trimethylolpropane as a crosslinking aid. Predetermined amounts of triacrylate and other additives were added to a Hensel mixer (trade name) at the mixing ratios listed in Table 7 below, and after stirring and mixing for 3 minutes, the mixture was heated to 200°C using a single-screw extruder with a diameter of 40 mm. The pellets (hereinafter abbreviated as pellets) were obtained by melt-kneading and crosslinking.To 90 parts by weight of the obtained pellets I, MF
10 parts by weight of a powdered crystalline ethylene-propylene block copolymer (ethylene content 12.0% by weight, vanadium content 0.6 ppm) with R of 4.0 g/10 min and 2-ethylhexanoic acid as compound A. Predetermined amounts of zinc, zinc stearate, zinc montanate, or zinc benzoate were placed in a Hensel mixer (trade name) at the mixing ratios listed in Table 7 below, stirred and mixed for 1 minute, and then mixed using a single shaft with a diameter of 40 m. The mixture was melt-kneaded using an extruder at 200° C. to obtain pellets (hereinafter abbreviated as pellets ①).

In addition, as Comparative Examples 43 to 49, MFR was 4.0 g/1
To 100 parts by weight of a powdered crystalline ethylene-propylene block copolymer (ethylene content: 12.0% by weight, vanadium content: 0.6 ppm), predetermined amounts of each of the additives listed in Table 7 below were added. , put in a Hensel mixer (trade name) at the mixing ratio listed in Table 7 below, stirred and mixed for 3 minutes, and then melt-kneaded at 200°C in a single-screw extruder with a diameter of 40 mm to produce crosslinked pellets (hereinafter referred to as , pellet!) was obtained. A powdered crystalline ethylene-propylene block copolymer (ethylene content: 1
2.0% by weight, vanadium content o, spp ■) 10
! A predetermined amount of each of the additives listed in Table 7 below was added to a Hensel mixer (trade name) at the mixing ratio listed in Table 7 below, and after stirring and mixing for 1 minute, a diameter of 4.
The pellets were melt-kneaded at 200° C. using a single-screw extruder ○- to obtain pellets (hereinafter abbreviated as pellets ①).

Using the obtained pellets I and Pellet II, the colorability was evaluated according to the test method described above. The results are shown in Table 7.

The compounds and additives shown in Tables 1 to 7 are as follows.

Compound A [I]; 2.Zinc ethylhexanoate Compound A [
Zinc stearate compound A [ml; Zinc montanate compound A [IV]; Zinc benzoate phenolic antioxidant [I]; 2,6-di-t-butyl-p-cresol phenolic antioxidant [■]; Tetrakis [methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate comethane phenolic antioxidant [ml; 1,3.5-)dimethyl- 2,4,6-tris(3,5-di-t-butyl-
4-Hydroxybenzyl)benzenephenolic antioxidant [■C; 1,3.5-tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate phenolic 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 [I[];]1,3-bis-t-butylperoxyisopropyl)benzene crosslinking aid; trimethylolpropane triacrylate,
Thorin antioxidant 1; Tetrakis (2,4-di-t-
butylphenyl') -4,4'-biphenylene diphosphonite phosphorous antioxidant 2; bis(2,4-di-t-butylphenyl)-pentaerythritol-siphosphite polyol compound; pentaerythritol mono Zinc stearate compound phosphate compound (zinc salt of organic phosphoric acid); stearyl phosphate mono-, di-mixture) zinc (Sakai Chemical Industry ■
Product name [LBT-18301) ZnO; Zinc oxide Z n S; Zinc sulfide Mg-5t; Magnesium stearate Ca-5t
Calcium stearate The Examples and Comparative Examples listed in Table 1 are cases where a propylene homopolymer was used as the propylene polymer. As can be seen from Table 1, in Examples 1 to 15, compound A was added to a propylene homopolymer containing 30 ppm of titanium in the catalyst residue according to the present invention.
1 A product prepared by blending a phenolic antioxidant, a radical generator, and a crosslinking aid, and then melt-kneading and crosslinking the mixture. Examples 1 to 15, Comparative Examples 1 to 2 (using a phosphorous antioxidant as a coloring inhibitor), and Comparative Example 3 (using a crosslinked propylene-based heavy duty compound as proposed by the present inventors in Japanese Patent Application No. 61147581). In comparison with the production method of the composite (i.e., a propylene polymer mixed with a partial ester of a polyol and a fatty acid, a phenolic antioxidant, a radical generator, and a crosslinking aid, and then melt-kneaded and crosslinked), Examples It was found that Comparative Examples 1 to 2, in which a phosphorous antioxidant was used instead of the compound, showed significant coloration, whereas Examples 1 to 15 showed little coloration, and Example 1 to 15 showed that the coloration was significant in Comparative Examples 1 to 2, in which a phosphorous antioxidant was used instead of the compound. It can be seen that the coloring prevention properties are further improved than in Comparative Example 3, which used an ester. Comparative Examples 4 to 7, in which a zinc compound other than Compound A was used instead of Compound A, and Examples 1 to 15 are compared. It can be seen that in Comparative Examples 4 to 7, the anti-coloring property was hardly improved.

Furthermore, in Examples 9 and 10, Compound A according to the present invention, a phenolic antioxidant, a radical generator, a crosslinking aid, and a phosphorus antioxidant were blended, melt-kneaded, and crosslinked. It can be seen that, compared to No. 6, the excellent anti-coloring effect on the compound is not inhibited, and a remarkable synergistic effect is observed due to the combined use of the phosphorus antioxidant.

Tables 2 to 5 show crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, and crystalline ethylene-propylene block copolymer as propylene polymers, respectively.
A 13-element copolymer of pro and rene-butene and a crystalline ethylene-propylene block copolymer were used, and the same effects as described above were confirmed for these as well.

Further, the Examples and Comparative Examples listed in Table 6 are cases where a propylene homopolymer was used as the propylene polymer. As can be seen from Table 6, Examples 76 to 90 were prepared by blending a phenolic antioxidant, a radical generator, and a crosslinking aid into a propylene homopolymer containing a titanium content of 30 pH■ in the catalyst residue according to the present invention. Compound A was blended into a crosslinked propylene polymer that had been melt-kneaded and cross-linked, and then melt-kneaded again. Comparing Examples 76 to 90 and Comparative Examples 36 to 42 (using a phosphorus antioxidant, a partial ester of polyol and fatty acid, or a zinc compound other than Compound A in place of Compound A), Example 76 It can be seen that, although the coloring of pellets) I of 90 is remarkable, the coloring of pellets) If obtained by using compound A is significantly improved.

On the other hand, in Comparative Examples 36 to 42, the co-coloring of Pellet) I and Pellet I was remarkable, and in particular, a phosphorus antioxidant, a partial ester of a polyol and a fatty acid, or a zinc compound other than Compound A was used instead of Compound A. The beret obtained using
It can be seen that the material is significantly colored due to being subjected to two melt-kneading treatments, that is, heat history.

Table 7 shows crystalline ethylene as a propylene polymer.
A propylene block copolymer was used, and the same effects as in Table 6 were confirmed for this as well.

Therefore, it can be seen that the crosslinked propylene polymer obtained by the production method of the present invention is free from coloration and has improved mechanical strength.

Therefore, the crosslinked propylene polymer obtained by the production method of the present invention is formulated with a compound having a conventionally known coloring prevention effect and a phenolic antioxidant, and a crosslinking aid is used to prevent the presence of a radical generator. It is conventionally known that there are two types of crosslinked propylene polymers: one that has been melt-kneaded and cross-linked, and the other that has been cross-linked by blending a phenolic antioxidant and melt-kneading it with a cross-linking aid in the presence of a radical generator. It was found that the discoloration prevention property was significantly superior to that obtained by blending and melt-kneading a compound having the discoloration prevention effect, thus confirming the remarkable effects of the present invention.

Claims (12)

[Claims] (1) Zinc salt of carboxylic acid (hereinafter referred to as compound A) and phenol antioxidant for 100 parts by weight of a propylene polymer containing 5 ppm or more of titanium or 0.5 ppm or more of vanadium in the catalyst residue. 0.01 to 1 part by weight of the agent, and 0.005 part of the radical generator.
~5 parts by weight, 0.1 to 20 parts by weight of crosslinking aid, 1
A method for producing a crosslinked propylene polymer, comprising melt-kneading at 50°C to 300°C. (2) The method for producing a crosslinked propylene polymer according to claim (1), wherein one or more compounds selected from zinc fatty acids and zinc aromatic carboxylates are blended as compound A. (3) 2,6-di-t- as a phenolic antioxidant
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 and n-octadecyl-β-(4
The crosslinked propylene polymer according to claim (1), which contains one or more selected from '-hydroxy-3',5'-di-t-butylphenyl) propionate. manufacturing method. (4) 2,5-di-methyl-2, as a radical generator
5-di-(t-butylperoxy)hexane, 2,5-
Contains one or more selected from di-methyl-2,5-di-(t-butylperoxy)hexyne-3 and 1,3-bis-(t-butylperoxyisopropyl)benzene. A method for producing a crosslinked propylene polymer according to claim (1). (5) Claim No. 1 in which one or more selected from polyfunctional monomers, monofunctional monomers, quinone dioxime compounds, nitroso compounds, and maleimide compounds are blended as crosslinking aids. A method for producing a crosslinked propylene polymer as described in 2. (6) As a propylene polymer, propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene - One or more types selected from a butene-13 element copolymer and a crystalline propylene-hexene-butene-13 element copolymer, and the titanium content of the catalyst residue is 5 ppm or more or the vanadium content is 0.5pp
The method for producing a crosslinked propylene polymer according to claim (1), in which the crosslinked propylene polymer contains m or more. (7) A phenolic antioxidant is added to 100 parts by weight of a propylene polymer containing 5 ppm or more of titanium or 0.5 ppm or more of vanadium in the catalyst residue.
0.01 to 1 part by weight, 0.005 to 5 parts by weight of a radical generator, and 0.1 to 20 parts by weight of a crosslinking aid,
A zinc salt of carboxylic acid (hereinafter referred to as compound A) is added to a crosslinked propylene polymer that has been melt-kneaded at a temperature of 300°C to 300°C.
0.0 parts by weight per 100 parts by weight of the propylene polymer
Blend to 1 to 1 part by weight and heat at 150°C to 300°C
1. A method for producing a crosslinked propylene polymer, the method comprising melt-kneading the crosslinked propylene polymer. (8) The method for producing a crosslinked propylene polymer according to claim (7), wherein one or more compounds selected from zinc fatty acids and zinc aromatic carboxylates are blended as compound A. (9) 2,6-di-t- as a phenolic antioxidant
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 and n-octadecyl-β-(4
The crosslinked propylene polymer according to claim (7), which contains one or more selected from '-hydroxy-3',5'-di-t-butylphenyl) propionate. manufacturing method. (10) 2,5-di-methyl-2 as a radical generator
, 5-di-(t-butylperoxy)hexane, 2,5
-di-methyl-2,5-di-(t-butylperoxy)
One or two selected from hexyne-3 and 1,3-bis-(t-butylperoxyisopropyl)benzene
The method for producing a crosslinked propylene polymer according to claim (7), which comprises blending more than one species. (11) Claim No. 7 in which one or more selected from polyfunctional monomers, monofunctional monomers, quinone dioxime compounds, nitroso compounds, and maleimide compounds are blended as crosslinking aids. A method for producing a crosslinked propylene polymer as described in 2. (12) As a propylene polymer, propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene - One or more types selected from a butene-13 element copolymer and a crystalline propylene-hexene-butene-13 element copolymer, and the titanium content of the catalyst residue is 5 ppm or more or the vanadium content is 0.5p
Claim No. (7) using a substance containing pm or more
A method for producing a crosslinked propylene polymer as described in 2.