JPH0482020B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a modified propylene polymer. More specifically, a specific amount of a phenolic antioxidant, a polyol or a fatty acid partial ester of the polyol (hereinafter referred to as compound A), and a radical generator are blended into a propylene polymer containing 5 ppm or more of titanium in the catalyst residue. The present invention relates to a method for producing a modified propylene polymer, which comprises melt-kneading at a temperature of 150 to 300°C. (Prior art) Propylene polymers are relatively inexpensive and have excellent mechanical properties, so they are used to manufacture various molded products such as injection molded products, films, sheets, fibers, and blow molded products. . However, propylene-based polymers contain tertiary carbon that is susceptible to oxidation, so they are susceptible to thermal oxidative deterioration due to melt kneading during molding, and their thermal stability during practical use is low. There is also a problem. Therefore, in order to prevent thermal oxidative deterioration during melt-kneading, 2,6-di-t-butyl-
Low molecular weight phenolic antioxidants such as p-cresol (BHT) are widely used, and high molecular weight phenolic antioxidants are widely used to provide thermal stability during practical use. However, when the propylene polymer containing the above-mentioned phenolic antioxidant is melt-kneaded, the phenolic antioxidant used is oxidized by the titanium complex compound that is the catalyst residue in the propylene polymer during melt-kneading. However, problems such as coloration of the resulting propylene polymer due to the formation of quinone compounds occur. Therefore, compositions containing pentaerythritol or a polyol that is a reaction product of pentaerythritol and propylene oxide (especially (Kokai No. 58-213036), propylene polymer compositions containing one or more compounds of polyols, fatty acid moieties or complete esters of polyols, phosphite or thiophosphites (Journal of Applied Polymer Science Vol. 29, 4421) ~4426 pages (1984)) have been proposed. Furthermore, in order to improve the moldability of propylene polymers, a method of melt-kneading propylene polymers in the presence of a radical generator is well known. (Problems to be Solved by the Invention) In the process of researching the coloring properties of propylene polymers containing a large amount of titanium as catalyst residues, the present inventors discovered that propylene polymers containing a large amount of titanium as catalyst residues Even if the above-mentioned phenolic antioxidant is blended with the above-mentioned phenolic antioxidant and subjected to melt-kneading treatment, no coloration will occur to the extent that it becomes a practical problem. It has been found that when the propylene polymer is melt-kneaded in the presence of the following, the treated propylene polymer is significantly colored. This phenomenon is not described at all in the above-mentioned Japanese Patent Application Laid-Open No. 58-213036 and Journal of Applied Polymer Science, Vol. 29, pp. 4421-4426 (1984). The present inventors investigated the presence of a radical generator in order to improve the molding processability of a propylene polymer prepared by blending a phenolic antioxidant with a propylene polymer containing a large amount of titanium in the catalyst residue described above. We conducted intensive research on a method to obtain a modified propylene polymer that does not become discolored even when subjected to melt-kneading treatment. As a result, a specific amount of a phenolic antioxidant, a polyol, or a fatty acid partial ester of the polyol (hereinafter referred to as compound A) was added to a propylene polymer containing 5 ppm or more of titanium in the catalyst residue.
It was discovered that a modified propylene polymer without coloring could be obtained by blending the same with a radical generator and melt-kneading the mixture, and based on this knowledge, the present invention was completed. As is clear from the above description, the object of the present invention is to blend Compound A, a phenolic antioxidant, and a radical generator into a propylene polymer containing 5 ppm or more of titanium in the catalyst residue, and then melt-knead the propylene polymer containing a titanium content of 5 ppm or more. It is an object of the present invention to provide a method for producing a modified propylene polymer that is free from coloring due to the process. (Means for solving the problems) The present invention has the following configuration. 0.01 to 1 part by weight of a polyol or a fatty acid partial ester of the polyol (hereinafter referred to as compound A) and a phenolic antioxidant per 100 parts by weight of a propylene polymer containing 5 ppm or more of titanium in the catalyst residue. A method for producing a modified propylene polymer, which comprises blending 0.001 to 0.5 parts by weight of a radical generator and melt-kneading the mixture at 150 to 300°C. The propylene polymer used in the production method of the present invention contains 5 ppm or more of titanium in the catalyst residue, and is polymerized by, for example, bulk polymerization, gas phase polymerization, or a combination of bulk polymerization and gas phase polymerization. It is a propylene-based polymer obtained by this method. In the production method of the present invention, there is no problem in using a propylene polymer whose catalyst residue has a titanium content of less than 5 ppm, but in this case, the above-mentioned compound A must be blended. However, the resulting modified propylene polymer does not cause any coloration that is a problem in practice. The propylene polymer used in the present invention includes:
A propylene-based polymer containing 5 ppm or more of titanium in the catalyst residue, a propylene homopolymer,
Propylene and ethylene, butene-1, pentene-
1. Crystalline random copolymers or block copolymers with one or more α-olefins such as hexene-1 and octene-1, copolymers of propylene with vinyl acetate, acrylic esters, etc. Examples include a saponified product of the copolymer, a copolymer of propylene and an unsaturated carboxylic acid or its anhydride, and a reaction product of the copolymer and a metal ion compound. Of course, it can be used alone, but it can also be used as a mixture of two or more propylene polymers. In addition, the above-mentioned propylene polymers and various synthetic rubbers (e.g. ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, polybutadiene, polyisoprene, chlorinated polyethylene, chlorinated polypropylene, styrene-butadiene) Rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer,
(styrene-propylene-butylene-styrene block copolymers, etc.) or thermoplastic synthetic resins (polyolefins, polystyrene, styrene-acrylonitrile copolymers, excluding propylene polymers such as polyethylene, polybutene, and poly-4-methylpentene-1) , acrylonitrile-butadiene-styrene copolymer, polyamide, polyethylene terephthalate, polybutylene terephthalate, polyvinyl chloride, etc.) can also be used. Propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene-butene-1 ternary copolymer Combined, crystalline propylene-hexene-butene-1
It is a terpolymer with a titanium content of catalyst residue of 5 ppm.
Propylene polymers containing the above are particularly preferred. Compound A used in the present invention includes glycerin, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol,
Polyols such as dipentaerythritol, tripentaerythritol, xylitol, sorbitol, mannitol, etc., glycerin fatty acid monoester, polyglycerin fatty acid monoester (diglycerin fatty acid monoester, triglycerin fatty acid monoester, pentaglycerin fatty acid monoester, etc.), sorbitan fatty acid monoester,
Fatty acid partial esters of polyols such as sucrose fatty acid monoester, pentaerythritol fatty acid monoester or diester, trimethylolethane fatty acid monoester, trimethylolpropane fatty acid monoester, polyoxyethylene glycerin fatty acid monoester, polyoxyethylene sorbitan fatty acid monoester ( Examples of fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and oleic acid. Particularly preferred are trimethylolethane, glycerin fatty acid monoester, and pentaerythritol fatty acid mono- or diester. As a phenolic antioxidant, 2,6-di-t-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-octadecyl-β-
(4'-hydroxy-3',5'-di-t-butylphenyl)propionate, 2,6-diphenyl-4-
Octadesiloxyphenol, 2,4,6-tris(3',5'-di-t-butyl-4'-hydroxybenzylthio)-1,3,5-triazine, 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-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-(6-t-butyl-3-methylphenol) 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)butylphenyl]ethylene glycol ester, di-(3-t
-butyl-4-hydroxy-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)benzyl)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-hydroxyphenyl)propionyloxyethyl]isocyanurate and tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. The blending ratio of Compound A and phenolic antioxidant is that of propylene polymer.
The amount is 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight, per 100 parts by weight. If the content is less than 0.01 part by weight, the coloring prevention effect of the modified propylene polymer will not be sufficiently exhibited, and although it is possible to exceed 1 part by weight, it is not practical as it cannot be expected to further improve the coloring prevention effect. Not only is it not economical, 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, and the temperature required to obtain a half-life of 10 hours is
70°C or higher, preferably 100°C or higher, such as penzoyl peroxide, t-butyl perbenzoate, t-butyl peracetate, t-butyl peroxyisopropyl carbonate, 2,5-
Di-methyl-2,5-di-(benzoylperoxy)hexane, 2,5-dimethyl-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, diquinyl 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 quinyl peroxide,
1,1-bis-(t-butylperoxy)-3,
3,5-trimethylcyclohexane, 1,1-bis-(t-butylperoxy)cyclohexane,
2,2-bis-(t-butylperoxy)butane,
p-menthane hydroperoxide, di-isopropylbenzene hydroperoxide, cymene hydroperoxide, t-butyl hydroperoxide, p-cymene hydroperoxide, 1,1,3,3-tetra-methylbutyl hydroperoxide or 2,5-di-
Examples include organic peroxides such as 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 or 1,3-bis-(t-butylperoxyisopropyl)benzene is preferred. The blending ratio of the radical generator is usually 100% propylene polymer.
0.001 to 0.5 parts by weight, preferably
It is 0.01-0.2 parts by weight. In addition, the melt-kneading process is performed using various melt-kneading equipment described below at temperatures ranging from 150°C to 300°C.
It is carried out at a temperature of 180°C to 270°C. If the melt-kneading treatment temperature is less than 150℃, a sufficient processability improvement effect, that is, a modification effect, cannot be obtained, and if it exceeds 300℃, thermal oxidative deterioration of the propylene polymer will be accelerated, and the resulting modified propylene polymer will deteriorate. This is not preferable because coloring becomes noticeable. In the production method of the present invention, various additives that are normally added to propylene polymers, such as thioether-based, phosphorus-based antioxidants, etc., are added to the propylene-based polymer containing 5 ppm or more of titanium in the catalyst residue used. , light stabilizer, clarifying agent, nucleating agent, lubricant, antistatic agent, antifogging agent, antiblocking agent, anti-drop agent, pigment, heavy metal deactivator (copper anti-toxic agent), metal soaps dispersants or neutralizing agents, inorganic fillers (e.g. talc, mica, clay, wollastonite, zeolite, asbestos, calcium carbonate, aluminum hydroxide, magnesium hydroxide,
barium sulfate, calcium silicate, glass fiber,
The inorganic filler or organic filler (e.g., wood flour) whose surface has been treated with a surface treatment agent such as carbon fiber, etc.) or a coupling agent (e.g., silane, titanate, boron, aluminate, zircoaluminate, etc.) , pulp, waste paper, synthetic fibers,
Natural fibers, 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, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene-di-phosphonite, bis(2,
4-di-t-butylphenyl)-pentaerythritol-diphosphite, bis(2,6-di-
Examples include t-butyl-4-methylphenyl)-pentaerythritol-di-phosphite and tris(2,4-di-t-butylphenyl) phosphite. The production method of the present invention reduces the titanium content of the catalyst residue to 5 ppm.
Predetermined amounts of the aforementioned compound A, a phenolic antioxidant, a radical generator, and the aforementioned various additives that are normally added to propylene polymers are added to the propylene polymer containing the above using a conventional mixing device such as a Hensel mixer ( Product name), Super Mixer,
Mix using a ribbon blender, Banbury mixer, etc. at a temperature that does not decompose the blended radical generator, and then mix using a regular single-screw extruder, twin-screw extruder,
Melt kneading temperature with Brabender or roll etc.
This is carried out by melt-kneading at 150°C to 300°C, preferably 180°C to 270°C. The propylene polymer modified by the method of the present invention has no coloration,
Since the molding processability is improved, it can be suitably used for producing desired molded products by various molding methods such as injection molding, extrusion molding, and blow 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 cleaves the main chain of the propylene polymer. It is well known that it reduces the molecular weight of the polymer and improves moldability. In the production method of the present invention, the above-mentioned compound A is
When a propylene polymer stabilized by a phenolic antioxidant is melt-kneaded in the presence of a radical generator, it is not clear how it acts on a titanium complex. However, since the effect of the present invention is not achieved when a complete fatty acid ester of polyol is used, it is presumed that the alcoholic hydroxyl group of compound A acts on the titanium complex compound to produce a stable chelate compound. . [Effects] The modified propylene polymer obtained by the production method of the present invention is produced by using a propylene polymer blended with a conventionally known phosphorus antioxidant or a complete fatty acid ester of a polyol. Compared to propylene-based polymers obtained by the method of modifying the polypropylene polymer, it is free from coloring and has improved moldability, so it can be suitably used in the production of various molded products. [Examples] Hereinafter, the present invention will be specifically explained using Examples, Comparative Examples, and Reference Examples, but the present invention is not limited thereto. The evaluation method used in Examples, Comparative Examples, and Reference Examples was as follows. Colorability: YI (Yellowness) of the obtained pellets
Measure the index (according to JIS K 7103),
The colorability was evaluated based on the magnitude of this YI value.
The smaller this number is, the less coloring there is. Examples 1 to 16, Comparative Examples 1 to 3, Reference Rows 1 to 3 As a propylene polymer, MFR (discharge amount of molten resin for 10 minutes when applying a load of 2.16 kg at 230°C) 2.0 g/10 minutes To 100 parts by weight of powdered propylene homopolymer (titanium content 30 ppm), trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate as compound A, 2, as phenolic antioxidant, 6-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 as a radical generator ,5-di-(t-butylperoxy)
Predetermined amounts of hexane or 1,3-bis-(t-butylperoxyisopropyl)benzene and other additives were placed in a Hensel mixer (trade name) at the mixing ratios listed in Table 1 below.
After stirring and mixing for a minute, use a single-screw extruder with a diameter of 40 mm to
The mixture was modified by melt-kneading at ℃ and pelletized. In addition, as Comparative Examples 1 to 3 and Reference Examples 1 to 3, each of the additives listed in Table 1 below was added to 100 parts by weight of a powdered propylene homopolymer (titanium content 30 ppm) with an MFR of 2.0 g/10 min. Mix the specified amount,
Modified pellets were obtained by melt-kneading according to Examples 1 to 16. The resulting pellets were evaluated for colorability using the test method described above. The results are shown in Table 1. Examples 17-32, Comparative Examples 4-6, Reference Examples 4-6 As the propylene polymer, a crystalline powdery ethylene-propylene random copolymer (ethylene content 2.5% by weight, titanium Content: 33 ppm) 100 parts by weight, trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate as compound A, 2,6-di-t-butyl as phenolic antioxidant -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, as a radical generator
Predetermined amounts of 5-di-(t-butylperoxy)hexane or 1,3-bis-(t-butylperoxyisopropyl)benzene and other additives were mixed in the proportions listed in Table 2 below. The mixture was placed in a cell mixer (trade name) and stirred and mixed for 3 minutes, then melt-kneaded at 200°C in a single-screw extruder with a diameter of 40 mm to reform and pelletize. In addition, as Comparative Examples 4 to 6 and Reference Examples 4 to 6, MFR is
7.0g/10min crystalline powdered ethylene-propylene random copolymer (ethylene content 2.5% by weight,
A predetermined amount of each of the additives listed in Table 2 below was blended with 100 parts by weight (titanium content: 33 ppm), and
Modified pellets were obtained by melt-kneading according to 17-32. Using the obtained pellets, the coloring property was evaluated according to the test method described above. The results are shown in Table 2. Examples 33 to 48, Comparative Examples 7 to 9, Reference Examples 7 to 9 As the propylene polymer, a crystalline powdery ethylene-propylene block copolymer (ethylene content 8.5% by weight, titanium Content: 33 ppm) 100 parts by weight, trimethylol-lethane, glycerin monostearate, pentaerythritol monostearate, or pentaerythritol distearate as compound A, and 2,6-di-t-butyl- as a phenolic antioxidant. 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)
-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 other additives. A predetermined amount of each was put into a Hensel mixer (trade name) at the mixing ratio shown in Table 3 below, and after stirring and mixing for 3 minutes, the mixture was melt-kneaded at 200℃ using a single-screw extruder with a diameter of 40 mm. and pelletized. In addition, as Comparative Examples 7 to 9 and Reference Examples 7 to 9
Crystalline powdered ethylene-propylene block copolymer with MFR of 4.0 g/10 min (ethylene content 8.5
A predetermined amount of each of the additives listed in Table 3 below was blended with 100 parts by weight (titanium content: 33 ppm) and melt-kneaded according to Examples 33 to 48 to obtain modified pellets. Ta. Using the obtained pellets, the coloring property was evaluated according to the test method described above. The results are shown in Table 3. Examples 49-64, Comparative Examples 10-12, Reference Examples 10-12 As a propylene polymer, MFR is 7.0g/10
Crystalline powdered ethylene-propylene-butene-1 ternary copolymer (ethylene content 2.5% by weight,
Butene-1 content 4.5% by weight, titanium content 33ppm)
To 100 parts by weight, trimethylolethane, glycerin monostearate, pentaerythritol monostearate or pentaerythritol distearate as compound A, 2,6-di-t-butyl-p-cresol, tetrakis as phenolic antioxidant [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 as a radical generator Or 1,
3-bis-(t-butylperoxyisopropyl)
Predetermined amounts of benzene and other additives were added to the Hensel mixer (trade name) at the mixing ratios listed in Table 4 below, and after stirring and mixing for 3 minutes, the diameter
The mixture was melt-kneaded at 200°C in a 40 mm single-screw extruder, modified, and pelletized. In addition, as Comparative Examples 10 to 12 and Reference Examples 10 to 12, crystalline powder ethylene-propylene-butene-1 with an MFR of 7.0 g/10 min.
Ternary copolymer (ethylene content 2.5% by weight, butene-1 content 4.5% by weight, titanium content 33ppm) 100
Predetermined amounts of the additives listed in Table 4 below were added to the parts by weight, and the mixture was melt-kneaded in accordance with Examples 49 to 64 to obtain modified pellets. The resulting pellets were evaluated for colorability using the test method described above. The results are shown in Table 4. The various compounds and additives shown in Tables 1 to 4 are as follows. Compound A []; Trimethylolethane compound A []; Glycerin monostearate compound A []; Pentaerythritol monostearate compound A []; Pentaerythritol distearate phenolic antioxidant []; 2,6-di -t
-Butyl-p-cresol phenolic antioxidant []; Tetrakis [methylene-3-(3',5'-di-t-butyl-4'-
1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzenephenol oxidation Inhibitor [); 1,3,5-tris-(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate phenolic antioxidant []; n-octadecyl-β-(4'-hydroxy -3',5'-G-t-
Butylphenyl)propionate radical generator []; 2,5-di-methyl-2,
5-di-(t-butylperoxy)hexane radical generator []; 1,3-bis-(t-butylperoxyisopropyl)benzenephosphorus antioxidant 1; Tetrakis(2,4-di-
t-Butylphenyl)-4,4'-biphenylene-di-phosphonitophosphorous antioxidant 2; bis(2,4-di-t-butylphenyl)-pentaerythritol-diphosphite polyol compound (polyol fatty acid complete ester); pentaerythritol tetrastearate Ca-St; calcium stearate

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[Table] The examples, comparative examples, and reference 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 16, Compound A, a phenolic antioxidant, and a radical generator were blended with a propylene homopolymer containing 30 ppm of titanium in the catalyst residue according to the present invention, and the mixture was melt-kneaded. It has been processed.
Comparing Examples 1 to 16 and Comparative Examples 1 to 2, Examples 1 to 16 have little coloration, and Comparative Examples 1 to 2, in which a phosphorous antioxidant was used instead of Compound A, have significant coloration. I understand. Comparing Comparative Example 3, in which a fatty acid complete ester of polyol was used in place of Compound A, and Examples 1 to 16, Comparative Example 3 shows that although the colorability is improved to some extent, it is still not fully satisfactory. Furthermore, in Examples 9 to 10, Compound A according to the present invention, a phenolic antioxidant, a radical generator, and a phosphorus antioxidant were blended and melt-kneaded in each Example, compared to Example 5. It can be seen that a remarkable synergistic effect can be observed by the combined use of phosphorous antioxidants without inhibiting the excellent anti-coloration effect of phosphorus antioxidants. In addition, Reference Examples 1 to 3 were melt-kneaded without using a radical generator.
It is clear that no significant coloration occurred when compared with Comparative Examples 1 and 2, and it can be said that the aforementioned significant coloration is a unique phenomenon observed when melt-kneading treatment is performed in the presence of a radical generator. . However, it can be seen that the modified propylene polymer obtained by the production method of the present invention is free from coloration and has improved moldability. Tables 2 to 4 show crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, and crystalline ethylene-propylene-butene 13 as propylene polymers, respectively.
The original copolymers were used, and the same effects as described above were confirmed for these as well. Therefore, the modified propylene polymer obtained by the production method of the present invention is modified by melt-kneading in the presence of a radical generator containing a conventionally known compound having an anti-coloring effect. In comparison, it was found that the coloring prevention properties were significantly superior, confirming the remarkable effects of the present invention.

Claims (1)

[Scope of Claims] 1. A polyol or a fatty acid partial ester of the polyol (hereinafter referred to as compound A) and a phenolic antioxidant based on 100 parts by weight of a propylene polymer containing 5 ppm or more of titanium in the catalyst residue. A method for producing a modified propylene polymer, which comprises blending 0.01 to 1 part by weight of each of these and 0.001 to 0.5 part by weight of a radical generator, and melt-kneading the mixture at 150 to 300°C. 2. The method for producing a modified propylene polymer according to claim 1, wherein trimethylolethane, glycerin fatty acid monoester, or pentaerythritol fatty acid mono- or diester is blended as compound A. 3 2,6-di- as a phenolic 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-
Claim 1, which contains t-butyl-4-hydroxybenzyl) isocyanurate or n-octadecyl-β-(4'-hydroxy-3',5'-di-t-butylphenyl) propionate. A method for producing a modified propylene polymer. 4 2,5-di-methyl- as a radical generator
2,5-di-(t-butylperoxy)hexane,
2,5-di-methyl-2,5-di-(t-butylperoxy)hexyne-3 or 1,3-bis-
The method for producing a modified propylene polymer according to claim 1, which comprises blending (t-butylperoxyisopropyl)benzene. 5 As the propylene polymer, propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene- The method for producing a modified propylene polymer according to claim 1, using a butene-1 terpolymer or a crystalline propylene-hexene-butene-1 terpolymer.