JP2000072926A - Polyolefin resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition inhibited from a change in physical properties due to thermal deterioration during processing and therefore reduced in thermal discoloration by mixing a polyolefin resin with a combination of a specified phosphorous ester compound with a specified hydrotalcite. SOLUTION: This composition comprises 100 pts.wt. polyolefin resin, 0.001-5 pts.wt. phosphorous ester compound represented by the formula, and 0.001-5 pts.wt. hydrotalcite represented by the formula: Znx1Mgx2 Al2(CO3)(OH)2(x1+x2+2).nH2O (wherein 0<=x1<=2; 0<x2<=6; and n>=0). The polyolefin resin used is exemplified by a homopolymer of an α-olefin such as ethylene, propylene, butene-1, hexene-1, or 4-methylpentene or a random or block copolymer of at least two of these monomers. The hydrotalcite may be a natural or synthetic one and is not limited on its crystal structure and its crystal particle diameter. It may be one surface-coated with e.g. a higher fatty acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a stabilized polyolefin resin composition, and more particularly, to a physical property due to thermal deterioration during processing, which is obtained by adding a specific phosphite compound and hydrotalcites in combination. The present invention relates to a polyolefin resin composition which suppresses a change and has small thermal coloring.

[0002]

2. Description of the Related Art Conventionally, polyolefin resins are used at the time of processing and depending on the use environment.
Physical property degradation due to main chain scission crosslinking due to thermal degradation,
There was a problem of loss of merchantability with it.
Various stabilizers have been developed to solve this problem. As these stabilizers, phenolic antioxidants, phosphorus compounds, sulfur compounds, ultraviolet absorbers, hindered amine light stabilizers and the like are known, and these are used alone or in combination of two or more. Japanese Patent Application Laid-Open No. 1-254770 discloses a combination of a specific phosphorus compound and a specific phenolic antioxidant. Also, JP-A-52-492.
No. 58 proposes trapping and stabilizing a catalyst residue by using hydrotalcite, and is disclosed in JP-A-61-113631, JP-A-61-133251, and JP-A-7-23.
No. 3,283 proposes stabilization by using a combination of a specific phosphorus compound and hydrotalcite. But,
The improvement of the stabilizing effect of these combinations is not yet satisfactory, and further improvement is desired.

Accordingly, an object of the present invention is to provide a polyolefin resin composition which suppresses a change in physical properties due to thermal deterioration during processing and has small thermal coloring.

[0004]

As a result of various studies, the present inventors have found that a polyolefin resin composition using a specific phosphite compound and a specific hydrotalcite together achieves the above object. It was found that it could be done.

The present invention has been made based on the above-mentioned findings, and 100% by weight of a polyolefin resin contains (a) a sub-formula represented by the following formula (1) (same as the above-mentioned formula (1)). 0.001 to 5 parts by weight of a phosphoric ester compound and (b) 0.001 to 5 hydrotalcites represented by the following general formula (2) of the following [Formula 4] (same as the above [Formula 2])
An object of the present invention is to provide a polyolefin resin composition containing parts by weight.

[0006]

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[0007]

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[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the polyolefin resin composition of the present invention will be described in detail.

The polyolefin resin used in the present invention may be a homopolymer of α-olefin such as ethylene, propylene, butene-1, hexene-1, 4-methylpentene-1, or a random or block copolymer of two or more of these. Polymers, specifically, high density, medium density,
Low density or linear low density polyethylene, polypropylene, polybutene-1, polyisobutene, poly-3-methylbutene-1, poly-4-methylpentene-1, ethylene-propylene copolymer, ethylene-butene-1 copolymer , Ethylene-4-methylpentene-1 copolymer, propylene-butene-1 copolymer, ethylene-propylene-
Butene-1 copolymer and the like. In the case of a copolymer, a copolymer of a polyunsaturated monomer such as a conjugated diene or a non-conjugated diene, acrylic acid, methacrylic acid, vinyl acetate, or the like may be used together with these α-olefins. Further, these polyolefin resins are produced by a well-known polymerization method, and are produced through a catalyst removal step, or produced using a Ziegler-type catalyst using magnesium chloride, which is called a highly active catalyst, as a carrier. It may be one that does not undergo the removal step, or one that uses a metallocene catalyst.

The phosphite compound used in the present invention is a phosphite compound represented by the formula (1), and has a higher heat stability than other well-known phosphites. Not only the improvement effect is remarkably large, but also the feature of extremely low toxicity.

The phosphite compound is added in an amount of
0.001 to 100 parts by weight of polyolefin resin
To 5 parts by weight, preferably 0.01 to 3 parts by weight. If the amount is less than 0.001 part by weight, sufficient effect on thermal stability cannot be obtained, and if it exceeds 5% by weight, no further effect can be expected.

The hydrotalcites used in the present invention are double salt compounds containing magnesium, zinc, aluminum, etc., represented by the general formula (2).

The hydrotalcites may be natural products or synthetic products. Methods for synthesizing the hydrotalcites are described in JP-B-46-2280, JP-B-50-30039 and JP-B-51-2.
A known method disclosed in, for example, US Pat. In the present invention, the above hydrotalcites can be used without being limited by the crystal structure and the crystal particle diameter. In addition, the surface of the above hydrotalcites may be coated with higher fatty acids such as stearic acid, higher fatty acid metal salts such as alkali metal oleate, organic sulfonic acid metal salts such as alkali metal dodecylbenzenesulfonate, higher fatty acid amides and higher fatty acids. Those coated with an ester or wax can also be used.

The amount of the hydrotalcite added is 0.001 to 100 parts by weight of the polyolefin resin.
To 5 parts by weight, preferably 0.005 to 5 parts by weight, more preferably 0.01 to 1 part by weight. When the amount added is 0.0
If the amount is less than 01 parts by weight, the effect is small, and if it exceeds 5 parts by weight, the effect is not only improved, but also disadvantages such as deterioration of physical properties and coloring occur.

In the composition of the present invention, other general-purpose additives for polyolefin resins can be used as long as the object of the present invention is not hindered. Examples of the additive include a phenolic antioxidant, a thioether antioxidant, a phosphorus antioxidant other than the compound of the formula (1), an ultraviolet absorber, a light stabilizer, a nucleating agent, a filler, It may be used in combination with a plasticizer, an epoxy compound, a foaming agent, an antistatic agent, a flame retardant, a lubricant, a modifier, a pigment, and the like, and particularly preferably used in combination with a phenolic antioxidant.

Examples of the phenolic antioxidants include:
Stearyl-β- (3,5-ditert-butyl-4-hydroxyphenyl) propionate, stearyl-β- (3
-Tert-butyl-4hydroxy-5-methylphenyl) propionate, 1,6-hexamethylenebis [β-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol bis [β-
(3-tert-butyl-4hydroxy-5-methylphenyl)
Propionate], 3,9-bis [1,1-dimethyl-
2- (β-3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxyethyl] -2,4
8,10-tetraoxaspiro [5.5] undecane,
1,3,5-tris [β- (3,5-di-tert-butyl-4
(Hydroxyphenyl) propionyloxyethyl] isocinurate, tetrakis [methylene-β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2,6-di-tert-butyl-p-cresol,
2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-
6-tert-butylphenol), 2,2′-ethylidenebis (4,6-ditertbutylphenol), 2,2′-ethylidenebis (4-secbutyl-6-tertbutylphenol), bis [3 3-bis (4-hydroxy-3-tert-butylphenyl) butylic acid] glycol ester, 4,4'-butylidenebis (6-tert-butyl-m
-Cresol), 4,4'-thiobis (6-tert-butyl-m-cresol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane,
1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene,
1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate,
3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate and the like.

The addition amount of these phenolic antioxidants is preferably from 0.001 to 5 parts by weight, more preferably from 0.05 to 5 parts by weight, based on 100 parts by weight of the polyolefin resin.
3 parts by weight.

Examples of the thioether antioxidants include dialkylthiodipropionates such as dilauryl-, dimyristyl-, distearyl-thiodipropionate and the like, and alkyl (C = 8) such as pentaerythritol tetra (dodecylthiopropionate). -18) Esters of thiopropionic acid.

The addition amount of these thioether-based antioxidants is preferably 0.001 to 10 parts by weight, more preferably 0.001 to 10 parts by weight, based on 100 parts by weight of the polyolefin resin.
5 to 5 parts by weight.

Examples of the phosphorus antioxidants include tris (nonylphenyl) phosphite, tris (mono,
Di-mixed nonylphenyl) phosphite, tris (2,4
- di-tert-butylphenyl) phosphite, tetra (C ₁₂
~ ₁₅ mixed alkyl) bisphenol A diphosphite, tetra (tridecyl) -4,4'-butylidenebis (3-methyl-6-tert-butylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2
-Methyl-5-tert-butyl-4-hydroxyphenyl)
Butanetriphosphite, distearylpentaerythritol diphosphite), bis (2,4-ditertbutylphenyl) pentaerythritol diphosphite, bis (2,6-ditertbutyl-4-methylphenyl) pentaerythritoldiphosphite Phosphite, 2,2′-ethylidenebis (4,6-ditertbutylphenyl) fluorophosphite, 2,2′-methylenebis (4,6-ditertbutylphenyl) octylphosphite, tetrakis (2
Organic phosphite compounds such as 4-di-tert-butylphenyl) biphenylenediphosphonite.

The amount of the phosphorus-based antioxidant to be added is preferably 0.00 to 100 parts by weight of the polyolefin resin.
1 to 5 parts by weight, more preferably 0.01 to 3 parts by weight.

As the ultraviolet absorber, for example, 2,4-
2-hydroxybenzophenones such as dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone); (2 ′ 2 -Hydroxy-5'-
Methylphenyl) benzotriazole, (2 ′ 2-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5-ditert-butylphenyl) 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'-
2- (2'hydroxyphenyl) such as methylenebis (4-tert-octyl-6-benzotriazolyl) phenol
Benzotriazoles; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3 ′, 5′-di-tert-butyl-4′-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4
Benzoates such as hydroxybenzoate; 2,
4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) 1,3,5-triazine, 2,4-bis-
(2,4-dimethylphenyl) -6- (2-hydroxy-4-octoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-
Hexyloxy) triazines such as 1,3,5-triazine; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β , Β-diphenylacrylate, methyl-2-cyano-3-methyl-3- (p
Cyanoacrylates such as (-methoxyphenyl) acrylate.

The amount of the ultraviolet absorber added is preferably 0.05 to 100 parts by weight of the polyolefin resin.
10 to 10 parts by weight, more preferably 0.01 to 5 parts by weight.

As the light stabilizer, for example, 2,2,6
6-tetramethyl-4-piperidyl stearate, 1,
2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) Sebacate, screws (1, 2, 2,
6,6-pentamethyl-4-piperidyl) sebacate,
Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4- Butanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6 , 6-Pentamethyl-4-piperidyl) di (tridecyl)-
1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3,5-di-tert-butyl-4-
Hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4piperidinol / diethyl succinate polycondensate, 1,6-bis (2,2,6,6-tetra Methyl-4-piperidylamino) hexane / dibromoethane polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-tert-octyl Amino-s-triazine polycondensate, 1,6-bis (2,
Hindered amine compounds such as 2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate.

The amount of the light stabilizer varies depending on the type and use of the polyolefin resin, but is preferably 0.001 to 5 parts by weight based on 100 parts by weight of the polyolefin resin.
Parts by weight, more preferably 0.05 to 3 parts by weight.

The polyolefin resin composition of the present invention can be used for various molded products, fibers, biaxially stretched films, sheets and the like.

Further, the polyolefin resin composition of the present invention can be used as a medical application in a syringe, a syringe preparation, an infusion bag, etc., and further subjected to various post-treatments, for example, a medical application, food It can be used for applications such as packaging, which is sterilized by radiation, or for applications, such as low-temperature plasma treatment after molding, for the purpose of improving surface properties such as paintability.

[0028]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited by these examples.

Example 1 0.1 parts by weight of tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane was added to 100 parts by weight of a polypropylene resin, and dilaurylthiodiene was added. 0.2 parts by weight of a propionate, a phosphorus compound shown in Table 1, and DHT-4A (hydrotalcite manufactured by Kyowa Chemical Co., Ltd.):
Mg _4.5 Al ₂ CO ₃ and _{(OH) 13 · 3.5H 2 O} ) was added amount shown in Table 1 (parts by weight), extruded at 280 ° C., 1 time and the fifth melt flow rate (MFR) ( g
/ 10 min) was measured. Further, the first and fifth pellets were extruded at 250 ° C. and 475 kg / cm 2.
A 1 mm thick test piece was prepared by injection molding. The yellowness of the obtained test piece was measured with a Hunter colorimeter and the change was observed. Table 1 shows the results.

[0030]

[Table 1]

Example 2 Using 0.1 part by weight of the phosphite compound of the formula (1) as a phosphorus compound,
Evaluation was performed by the same evaluation method as in Example 1 except that the type and amount of hydrotalcite were changed as shown in Table 2. Table 2 shows the results.

[0032]

[Table 2]

Example 3 100 parts by weight of an ethylene / propylene block polymer was mixed with tetrakis [methylene-3].
-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane 0.1 part by weight, the phosphorus compound described in Table 3 0.2 part by weight, and DHT-4A0.1
The parts by weight were added and extruded by repeated extrusion at 280 ° C., and the MFRs at the first and fifth times were measured, and the rate of change was measured. Further, the first and fifth extrusion pellets were injection-molded at 250 ° C. to prepare a test piece having a thickness of 1 mm, and the yellowness was measured with a Hunter colorimeter. Table 3 shows the results.

[0034]

[Table 3]

Example 4 To confirm the processing stability of linear low-density polyethylene, the following compound was used, and the change in torque over time was measured by a Brabender blast graph (230 ° C., 80 rpm). . In order to check the heat resistance, measure the coloring of the resin with a Hunter colorimeter and measure the yellowness (%).
Indicated by Table 4 shows the results.

<Blending> 100 parts by weight of linear low-density polyethylene (Unipol; manufactured by Union Carbide Co.) Tetrakis [methylene-3- (3,5-di-tert-butyl-0.02 4-hydroxyphenyl) propionate] Methane Compound of formula (1) 0.03 Additive 0.03

[0037]

[Table 4]

From the above results, the polyolefin resin was
By adding the phosphite compound represented by the formula (1) and the hydrotalcites represented by the general formula (2) in combination, a change in physical properties due to thermal deterioration during processing is suppressed, and thermal coloring is performed. It can be seen that a polyolefin resin composition having a small particle size can be obtained, and this effect is remarkably greater than when a phosphorus-based antioxidant conventionally used is used.

As described above, the polyolefin resin composition of the present invention comprises:
Changes in physical properties due to thermal degradation during processing are suppressed, and thermal coloring is small.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Takeuchi 5-2-13-Shirahata, Urawa-shi, Saitama F-term (reference) in Asahi Denka Kogyo Co., Ltd. 4J002 BB031 BB051 BB121 BB151 BB171 DE287 EW066 FB237 FB247 FB257 FD040 FD050 FD070

Claims (1)

[Claims] 1. A polyolefin resin having 100 parts by weight,
(A) 0.001 to 5 parts by weight of a phosphite compound represented by the following formula (1) represented by the formula (1) and (b) hydrotal represented by the following formula (2): A polyolefin resin composition containing 0.001 to 5 parts by weight of sites. Embedded image Embedded image