JPH1060181A - Polyolefin resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition having improved processing stability and heat resistance coloring of a polyolefin resin polymerized by a metallocene catalyst. SOLUTION: 100 parts by weight of a polyolefin resin polymerized by a metallocene catalyst are represented by the following general formula (I) and / or
Or a polyolefin resin composition comprising 0.01 to 10 parts by weight of a metal salt such as the phosphate compound represented by (II) or an alkaline earth metal salt thereof. Embedded image Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition having improved processing stability and heat-resistant coloring of a polyolefin resin polymerized by a metallocene catalyst. More specifically, the present invention relates to a composition in which a specific phosphate compound or a metal salt thereof is added. The present invention relates to a composition having improved processing stability and heat-resistant coloring of a polyolefin resin polymerized by a metallocene catalyst.

[0002]

2. Description of the Related Art Polyolefin resins are used in a wide range of applications, such as packaging materials, building materials, automobile parts, household goods, agricultural materials, medical equipment, etc. due to their excellent mechanical and chemical properties. .

As a polymerization catalyst for these polyolefin resins, a Ziegler catalyst has been conventionally used, but the resulting resin has a wide molecular weight distribution and it is difficult to control stereoregularity. However, in recent years, it has become known that the use of a metallocene catalyst provides a resin having a narrow molecular weight distribution and excellent stereoregularity. Further, because of its excellent polymerization activity, copolymerization with various monomers became possible.

[0004] Conventionally, low-molecular-weight substances contained in polyolefin resins are easily extracted by a solvent, causing a problem in hygiene, causing stickiness and a decrease in transparency. A polyolefin resin obtained with a metallocene catalyst has been an effective method for solving these problems. It is also expected that the uniformity of molecular weight and stereoregularity show unique physical properties.

However, since the molecular weight distribution is narrow, the fluidity is low at the time of processing. When a polyolefin having the same average molecular weight is polymerized, the flowability is inferior to the case of processing a polyolefin resin obtained from a Ziegler catalyst. However, when molded by using the method described above, there is a defect that a phenomenon called melt fracture in which the surface smoothness is impaired.

As a method for solving the melt fracture, there is known a method using a wax, an amide compound, a polyester compound, an aliphatic carboxylate of an alkaline earth metal or zinc, or the like as a lubricant. However, these lubricants could not sufficiently improve the melt fracture of the polyolefin polymerized by the metallocene catalyst.

[0007] It is known to use phosphate ester compounds including a phosphate ester compound having a specific structure used in the present invention as a processability improver. That is, JP-A-6-157833 proposes a lubricant for a polyolefin elastomer. Also, Japanese Patent Application Laid-Open
JP-A-196880 proposes a processability improver for a fluorine-containing resin.

The phosphate ester lubricants described in these known documents may be either aromatic or aliphatic, and the phosphate ester compound having a specific structure used in the present invention is effective in polyolefins obtained with a metallocene catalyst. Nothing was suggested. Further, the above-mentioned proposal solves a problem due to sticking at the time of roll processing, and solves a problem peculiar to an elastomer or a fluorine-containing resin. That is, there was no suggestion at all about the problem caused by the narrow molecular weight distribution of the polyolefin obtained by the metallocene catalyst and the effect of improving the surface smoothness in injection molding or extrusion.

[0009]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned situation, and as a result, have found that by adding a specific phosphate compound or a metal salt thereof to a metallocene-catalyzed polyolefin resin. The present inventors have found that a polyolefin resin composition having improved processability and excellent processing cycle can be obtained as a result, and arrived at the present invention.

That is, according to the present invention, at least one phosphoric ester compound represented by the following general formula (I) or (II) or a metal salt thereof is added to 100 parts by weight of a polyolefin resin polymerized with a metallocene catalyst. An object of the present invention is to provide a polyolefin resin composition having improved processability, comprising 10 to 10 parts by weight.

[0011]

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Hereinafter, the present invention having the above gist will be described in detail.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The metallocene catalyst in the present invention is also called a single-site catalyst, and is not particularly limited. Its basic structure is such that two moles of a cyclopentadienyl ring are formed of zirconium, titanium, hafnium or the like. Any structure coordinating with the metal chloride may be used. The cyclopentadienyl ring may have a substituent, and the substituent is an alkyl group such as methyl and tert-butyl, an aryl group such as a phenyl group or a substituent bonded to each other, and indene, tetrahydroindene, A fused ring structure such as fluorene may be formed. Further, these substituents may be those which crosslink the cyclopentadienyl structure as a bonding species such as an alkylene group or a silyl group. These metallocene catalysts may be supported on silica, alumina, magnesium chloride and the like. Further, an alkylaluminoxane, a trialkylaluminum or the like may be used in combination. Regardless of the method of synthesizing the catalyst, the presence or absence of modification, and the presence or absence of a supported substance, any metallocene catalyst that can provide a polyolefin having a small molecular weight distribution may be used.

Regarding the structure of the metallocene catalyst, the synthesis method, the concomitant substance, the supporting method and the modification method, see, for example,
-51393, JP-A-5-59077, JP-A-5-148284, JP-A-5-178874
JP-A-5-208987, JP-A-5-20887
No. 09013, JP-A-5-239081, JP-A-5-239082, JP-A-5-239083
JP, JP-A-5-345793, JP-A-6-4
No. 1169, JP-A-6-100579, JP-A-6-122692, JP-A-6-157569, JP-A-6-157660, JP-A-6-15
7661, JP-A-6-172443, JP-A-6-184179, JP-A-6-206890, JP-A-6-220119, JP-A-6-25
No. 6369, JP-A-6-340684, JP-A-6-345807, JP-A-7-25925, JP-A-7-70161, JP-A-7-1019
No. 71, JP-A-7-126317, JP-A-7-126317
-138275, JP-A-7-149781,
JP-A-7-149782, JP-A-7-16577
7, JP-A-7-173208, JP-A-7-173208
188272, JP-A-7-215987,
JP-A-7-224079, JP-A-7-24731
7, JP-A-7-252263, JP-A-7-252
JP-A-252287, JP-A-7-258282,
JP-A-7-267974, JP-A-7-27816
8, JP-A-7-278169 and JP-A-7-278169.
291985, JP-A-7-292020,
Examples described in JP-A-7-330820 are cited. However, the metallocene catalyst of the present invention is not limited by the above examples.

The polyolefin resin constituting the composition of the present invention may be a polyolefin having a narrow molecular weight distribution, which is polymerized by a metallocene catalyst, and has a molecular weight, a density, a melt flow, and a ratio of components dissolved in various organic solvents. However, it is not limited by the type and degree of stereoregularity, the softening point, and the like. The molecular weight distribution (Mw / Mn) of the polyolefin obtained by the metallocene catalyst is usually 3 or less, and particularly, in the case of a polyolefin of 2.5 or less,
The processability improving effect of the present invention shows a remarkable effect.

The polyolefin resin obtained by the metallocene catalyst constituting the composition of the present invention includes, for example, homopolymers of α-olefins such as polyethylene, polypropylene and polybutene, as well as ethylene-propylene copolymers and ethylene-methyl acrylate. A copolymer such as a copolymer may be used. The metallocene catalyst shows excellent copolymerization activity in copolymerization, and a uniform polymer can be easily obtained, so that a copolymer that cannot be obtained with a Ziegler catalyst is obtained,
Naturally, these copolymers are also included in the polyolefin resin constituting the composition of the present invention.

The alkyl group represented by R ¹ in the general formulas (I) and (II) representing the above phosphate ester compound includes, for example, hexyl, heptyl, octyl, 2-
Ethylhexyl, tertiary octyl, nonyl, isononyl,
Examples include decyl, isodecyl, undecyl, dodecylisodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, isooctadecyl and the like. Examples of the alkenyl group include those corresponding to these alkyl groups.

Similarly, R ² includes, for example, ethylene, propylene, trimethylene, methylethylene, ethylethylene, tetramethylene, hexamethylene and the like.

Examples of the metal to be the metal salt of the phosphate compound of the present invention include alkali metals such as lithium, sodium and potassium, alkaline earth metals such as magnesium, calcium and barium, zinc and aluminum. These can be used in any form of a phosphate ester compound, a normal salt, a basic salt, and an acidic salt. Among the metal salts, alkaline earth metal salts are
It is preferable because the effect of improving workability is particularly excellent.

The general formulas (I) and (II) in the present invention
More specifically, the phosphate compound represented by the following compound No. 1 to No. 13 are mentioned.
However, the present invention is not limited by the following examples.

[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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The phosphoric ester compounds represented by the above general formulas (I) and / or (II) and their metal salts can be used alone or in combination.

The polyolefin resin composition of the present invention comprises a polyolefin obtained by polymerizing the above specific phosphate compound (I) or (II) or a metal salt thereof with a metallocene catalyst as a lubricant (fluidity improver) during processing. The amount is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, per 100 parts by weight of the polyolefin resin. If the amount is less than 0.01, the effect of improving the processability is not obtained, and even if the amount exceeds 10 parts by weight, the effect of improving the processability is not improved, and the bleeding deteriorates the appearance of the polyolefin resin, which is economically disadvantageous. become. There is no particular limitation on the method of addition, and it may be in accordance with the method of compounding a usual additive into a polyolefin resin.

The method for molding the polyolefin resin composition obtained in the present invention is not particularly limited, and examples thereof include extrusion, injection molding, roll, compression molding, blow molding, and calendering.

The polyolefin resin composition of the present invention comprises:
Additives such as general-purpose antioxidants, ultraviolet absorbers and hindered amine light stabilizers can be added.

Particularly preferable examples of these additives include phenol-based, phosphorus-based, and sulfur-based antioxidants, ultraviolet absorbers, and hindered amine-based light stabilizers. The combined use is preferable because it has an excellent effect of improving the thermal stability.

Examples of the phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6
-Diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol Bis [(3,5-ditert-butyl-
4-hydroxyphenyl) propionate], 1,6-
Hexamethylene bis [(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylene bis [(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], 4,4′-thiobis (6-tert-butyl-m-cresol), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butyl) Tributylphenol), bis [3,3-bis (4-hydroxy-3-tert-butylphenyl) butylic acid]
Glycol ester, 4,4'-butylidenebis (6-
Tert-butyl-m-cresol), 2,2′-ethylidenebis (4,6-di-tert-butylphenol), 2,2′-
Ethylidenebis (4-sec-butyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [2-
Tert-butyl-4-methyl-6- (2-hydroxy-3-
Tert-butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-
Hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-
Hydroxylbenzyl) isocyanurate, 1,3,5-
Tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3,5-
Tris [(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate,
Tetrakis [methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert- Butyl-5-methylbenzyl) phenol, 3,9-bis [1,1-dimethyl-2-
{(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,1
0-tetraoxaspiro [5.5] undecane, triethylene glycol bis [(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] and the like. The addition amount of these phenolic antioxidants is
0.001 to 100 parts by weight of polyolefin resin
5 parts by weight, preferably 0.01 to 3 parts by weight.

Examples of the phosphorus-based antioxidant include trisnonylphenyl phosphite, tris (mono- and dinonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, di (tridecyl) pentane Erythritol diphosphite, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphite, bis (2,
4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tetra (tridecyl) isopropylidenediphenol diphosphite, tetra (tridecyl) -4,4'-n-butylidenebis (2-tert-butyl-5- Methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (3-tert-butyl-4
-Hydroxy-5-methylphenyl) butanetriphosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) Octadecyl phosphite, 2,2′-methylenebis (4,6-ditert-butylphenyl) fluorophosphite, tris (2
-[(2,4,8,10-tetrakis-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphepin-6
-Yl) oxy] ethyl) amine, tetrakis (2,4
-Di-tert-butylphenyl) biphenylenediphosphonite, 9,10-dihydro-9-oxa-10phosphaphenanthrene-10-oxide and the like. The addition amount of these phosphorus antioxidants is 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, per 100 parts by weight of the resin.
Parts by weight.

The sulfur-based antioxidants include, for example, dilauryl thiodipropionate, dimyristyl,
Examples include dialkylthiodipropionates such as distearyl and β-alkylmercaptopropionates of polyols such as pentaerythritol tetra (β-dodecylmercaptopropionate). The addition amount of these sulfur-based antioxidants is 100
0.001 to 5 parts by weight, preferably 0.1 to 5 parts by weight, per part by weight.
01 to 3 parts by weight.

Examples of the ultraviolet absorber include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-
2-hydroxybenzophenones such as 4-octoxybenzophenone and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone); 2- (2-hydroxy-5-methylphenyl) benzotriazole,
-(2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-butylphenyl) -5-chlorobenzotriazole,
2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-
Hydroxy-3,5-dicumylphenyl) benzotriazole, 2,2′-methylenebis (4-tert-octyl-
2- (2-hydroxyphenyl) benzotriazoles such as 6-benzotriazolyl) phenol and polyethylene glycol ester of 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole; phenyl salicylate; Benzoates such as resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; 2- Substituted oxanilides such as ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-
and cyanoacrylates such as β, β-diphenylacrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate. The amount of these UV absorbers added is 10
The amount is 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 0 parts by weight.

Examples of the hindered amine light stabilizer include, for example, 2,2,6,6-tetramethyl-4-
Piperidyl benzoate, N- (2,2,6,6-tetramethyl-4-piperidyl) dodecylsuccinimide,
1-[(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] -2,2,6,6-tetramethyl-4-piperidyl- (3,5-di-tert-butyl-4- (Hydroxyphenyl) propionate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-
4-piperidyl) sebacate, bis (1,2,2,6)
6-pentamethyl-4-piperidyl) -2-butyl-2
-(3,5-di-tert-butyl-4-hydroxybenzyl)
Malonate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine, tetra (2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate, Tetra (1, 2,
2,6,6-pentamethyl-4-piperidyl) butanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) di (tridecyl) butanetetracarboxylate, bis (1,2,2 2,6,6-pentamethyl-4-piperidyl) di (tridecyl) butanetetracarboxylate, 3,9-bis [1,1-dimethyl-2- {tris (2,2,6,6-tetramethyl- 4-piperidyloxycarbonyloxy) butylcarbonyloxydiethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis [1,
1-dimethyl-2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyloxy)
Butylcarbonyloxydiethyl] -2,4,8,10
-Tetraoxaspiro [5.5] undecane, 1,5
8,12-tetrakis [4,6-bis {N- (2,2,
6,6-tetramethyl-4-piperidyl) butylamino {-1,3,5-triazin-2-yl] -1,5.
8,12-tetraazadodecane, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / dimethyl succinate condensate, 2-tert-octylamino-4,6-dichloro -S-triazine / N, N '
-Bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine / And dibromoethane condensates. The amount of these hindered amine-based light stabilizers is 0.00 0.00 parts by weight of the polyolefin resin.
It is 1 to 10 parts by weight, preferably 0.01 to 5 parts by weight.

If necessary, the polyolefin resin composition of the present invention may contain a heavy metal deactivator, pt-butyl aluminum benzoate, dibenzylidene sorbitol, 2,2′-methylenebis (2,4-diphenyl A nucleating agent such as a metal salt of -t-butylphenyl) phosphate, an aliphatic carboxylate of an alkali metal or an alkaline earth metal, or hydrotalcite in which part or all of magnesium may be substituted with an alkali metal , Nonionic surfactants, cationic surfactants, anionic surfactants, antistatic agents including amphoteric surfactants, flame retardants such as halogen-based, phosphorus-based or metal oxides, and the phosphoric acid of the present invention Lubricants other than the ester compound, processing aids, fillers, and the like can be included.

[0046]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

Example 1 A high-density polyethylene resin polymerized with a metallocene catalyst (density 0.98 g / cm ³ , M
w = 54500, Mw / Mn = 2.4) 100 parts by weight of tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane 0.05 part by weight And 0.1 part by weight of calcium stearate and 0.2 part by weight of tris (2,4-di-tert-butylphenyl) phosphite, a lubricant (see Table 1)
And extruded at 230 ° C. into pellets,
An MFI test piece was used. In addition, the obtained pellets were
Injection molding was performed at 0 ° C. to obtain a 5 cm × 3 cm × 2 mm sheet. The presence or absence of melt fracture was confirmed by observing the surface of the obtained sheet. 13 of the obtained sheet
The heat resistance is increased by the blackening time in an oven
Thermal coloring was evaluated from the yellowness measured by a Hunter colorimeter after × 300 hours and the color difference between the original sheet and the color. The melt fracture was evaluated as surface-good when the surface was smooth and glossy, evaluated as Δ when the surface appeared smooth but lacked gloss, and evaluated as poor when surface irregularities were observed. The results are shown in Table 1.

[0048]

[Table 1]

Example 2 A linear low-density polyethylene resin polymerized with a metallocene catalyst (density 0.92 g / c
m ³ , Mw = 51200, Mw / Mn = 2.2) 100
Parts by weight of 0.05 parts by weight of tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxymethyl] methane, 0.1 part by weight of calcium stearate, and bis (2,2) 6-ditert-butyl-4-
Methylphenyl) pentaerythritol diphosphite 0.2 parts by weight and a lubricant (see Table 2) were added and the mixture was heated to 230 ° C.
And extruded into pellets to obtain MFI test pieces. The obtained pellets were injection molded at 260 ° C. to obtain a 5 cm × 3 cm × 2 mm sheet. The presence or absence of melt fracture was confirmed by observing the surface of the obtained sheet. The heat resistance was evaluated based on the blackening time of the obtained sheet in a 130 ° C. oven, and the thermal coloring was evaluated based on the yellowness measured by a Hunter colorimeter after 130 ° C. × 300 hours and the color difference between the original sheet. Table 2 shows the results.

[0050]

[Table 2]

[0051]

By adding the specific phosphate compound of the present invention, excellent processability can be imparted to the polyolefin resin polymerized by the metallocene catalyst.

Claims (2)

[Claims] 1. The method of claim 1, wherein 100 parts by weight of the polyolefin resin polymerized by the metallocene catalyst is represented by the following general formula (I):
Or a polyolefin resin composition comprising 0.01 to 10 parts by weight of the phosphate compound represented by (II) or a metal salt thereof. Embedded image 2. The polyolefin resin composition according to claim 1, wherein the metal salt of the phosphate compound is an alkaline earth metal salt.