JPH0892430A - Polyolefinic resin composition - Google Patents

Abstract

PURPOSE: To obtain a polyolefinic resin composition improved in processing stability, prevention of thermal discoloration, and weather resistance by combining a polyolefinic resin with organophosphite compounds. CONSTITUTION: This resin composition comprises 100 pts.wt. polyolefinic resin and 0.01-10 pts.wt. mixture of a diarylpentaerythritol diphosphite compound represented by formula I with a triaryl phosphite compound represented by formula II in a weight ratio of 1/1 to 1/9 and 0.01-20 pts.wt. hydrotalcite. In formulas I and II, R is a 4 or 5 C alkyl, R<1> and R<2> are each hydrogen or a 1-5 C alkyl; R<3> is a 4 or 5 C alkyl; and R<4> and R<5> are each a hydrogen or a 1-5 C alkyl.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin composition having improved processing stability, colorability and weather resistance by adding two types of phosphite compounds and hydrotalcites in combination. More specifically, the present invention relates to a polyolefin resin composition having improved processing stability, colorability and weather resistance by adding a diarylpentaerythritol diphosphite compound and a triarylphosphite compound together with hydrotalcites. .

[0002]

2. Description of the Related Art Polyolefin resins are used as various molded products, films, fibers, etc. because of their excellent mechanical properties, thermal properties, moldability, light weight and relatively low price. However, it has a drawback that it is inferior in stability at the time of high temperature processing, and it is known that the physical properties are deteriorated or it is colored.

Further, the polyolefin resin has a drawback that it is colored in a short period of time when it is exposed to ultraviolet rays when it is used outdoors.

In order to prevent such deterioration of the polyolefin resin, many additives have been used singly or in various combinations, and generally, trialkyl phosphite, triaryl phosphite and alkyl aryl phosphite are used. It is known that an organic phosphite compound such as a triorganophosphite compound or an acid phosphite compound in which one of these organic groups is a hydroxyl group improves heat resistance and has a relatively large effect of suppressing coloring. .

As the stabilization using these organic phosphite compounds, JP-A-61-113631 and JP-A-61-133251 propose stabilization in combination with hydrotalcite. -179
No. 076 proposes stabilization by the combined use of triaryl phosphite and alkylaryl phosphite, but none of the stabilization effects was still satisfactory.

[0006]

[Means for Solving the Problems] The present inventors have conducted extensive studies in view of the present situation, and as a result, have found that two types of organic phosphite compounds of different types are used together in a specific ratio in a polyolefin resin. It was found that a polyolefin resin composition having improved processing stability, heat colorability and weather resistance can be obtained by further adding hydrotalcites to the present invention.

That is, the present invention relates to (a) a diarylpentaerythritol diphosphite compound represented by the following general formula (I) and (b) the following general formula (II) with respect to 100 parts by weight of a polyolefin resin. And a triarylphosphite compound represented by
A total of 0.01 to 10 parts by weight of (c) and 0.01 to 20 parts by weight of hydrotalcites (c) are added to provide a polyolefin resin composition.

[0008]

[Chemical 2]

The polyolefin resin composition of the present invention will be described in detail below.

Examples of the polyolefin resin to be stabilized in the present invention include low density, linear low density or high density polyethylene, polypropylene, polybutene,
Examples thereof include poly-3-methylbutene, poly-4-methyl-1-pentene, ethylene-propylene random copolymers or block copolymers, and ethylene-propylene-diene copolymers. Among these polyolefin resins, the polypropylene may be any stereoregular one such as isotactic polypropylene or syndiotactic polypropylene, and may or may not have been subjected to the step of removing the catalyst residue. Further, it may have any physical properties such as melt flow rate, degree of polymerization, presence or absence of branching.

In the diarylpentaerythritol diphosphite compound represented by the general formula (I), R is
Examples of the alkyl group having 4 or 5 carbon atoms represented by are bryl, secondary butyl, tertiary butyl, isobutyl, amyl, secondary amyl, tertiary amyl and isoamyl groups, and are represented by R ¹ and R ^2. Examples of the alkyl group having 1 to 5 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, sec-butyl, isobutyl, amyl, sec-amyl, sec-amyl and isoamyl groups.

Therefore, specific examples of the diarylpentaerythritol diphosphite compound represented by the general formula (I) include the following compounds.

[0013]

[Chemical 3]

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6]

[0017]

[Chemical 7]

[0018]

Embedded image

In the triarylphosphite compound represented by the general formula (II), the alkyl group having 1 to 5 carbon atoms represented by R ³ , R ⁴ and R ⁵ is the same as the above R ¹ and 1 to 5 carbon atoms represented by R ²
Selected from among the alkyl groups of

Specific examples of the triarylphosphite compound represented by the above general formula (II) include the following compounds.

[0021]

[Chemical 9]

[0022]

[Chemical 10]

[0023]

[Chemical 11]

The diarylpentaerythritol diphosphite compound represented by the general formula (I) and the general formula (I
The triaryl phosphite compound represented by I) is used together in a weight ratio of 1/1 to 1/9, and the combined product is 0.01 to 10 parts in total with respect to 100 parts by weight of the polyolefin resin. Parts by weight, preferably 0.05 to 5 parts by weight.

When the combined ratio of the above two phosphite compounds is out of the above range, the synergistic effect of the two becomes difficult to appear, and when the total addition amount of both is less than 0.01 parts by weight. Almost no effect was observed, and the stabilizing effect was not further improved even if added in excess of 10 parts by weight.
It is economically disadvantageous.

The hydrotalcites used in the present invention may be natural products or synthetic products, but synthetic products are preferred because the contamination of the resin by impurities is small. As the composition of hydrotalcites, those represented by the following general formula (III) can be used. The carbonate ion of these hydrotalcites may be replaced with another anion. The addition amount of hydrotalcites is not particularly limited, but it is 0.00 per 100 parts by weight of the resin.
1 to 20 parts by weight is preferable, and 0.05 to 10 parts by weight is particularly preferable. If it is less than this, the effect of hydrotalcites is not recognized, and if it is used more than this, the stabilizing effect is not improved so much, which is economically disadvantageous.

[0027]

[Chemical 12]

If necessary, a phenolic antioxidant, a thioether antioxidant, an ultraviolet absorber, a hindered amine light stabilizer, etc. are added to the polyolefin resin of the present invention to improve its oxidation stability and light resistance. The stability can be further improved.

Examples of the phenol-based antioxidant which can be used in the present invention include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-phenol). Tributyl-4-hydroxyphenyl) propionate, distearyl (3,5-ditertiarybutyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5
-Di-tert-butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4,6-di (3,5-)
Di-tert-butyl-4-hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), bis [3,3-bis (4-hydroxy-3-tert-butyl) Phenyl) butyric acid] glycol ester, 4,4′-butylidene bis (6-tert-butyl-m-cresol), 2,2′-ethylidene bis (4-tert-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-hydroxybenzyl) isocyanurate, 1,3,5-Tris (3,5-di-tert-butyl-4-hydroxybenzyl)
-2,4,6-trimethylbenzene, 1,3,5-tris [(3,5-ditert-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-hydroxyethyl) -2,4 , 8,10-Tetraoxaspiro [5,5] undecane-bis [β- (3-tert-butyl-
4-hydroxy-5-methylphenyl) propionate], triethylene glycol bis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) bropionate] and the like.

The amount of the phenolic antioxidant added is usually 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the polyolefin resin.

Examples of the thioether type antioxidant include dialkylthiodipropionates such as dilauryl, dimyristyl and distearyl esters of thiodipropionic acid, and polyhydric alcohols such as pentaerythritol tetra (β-dodecylmercaptopropionate). .Beta.-alkyl mercaptopropionic acid esters of.

The amount of these thioether antioxidants added is usually 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the polyolefin resin.

Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone and 5,5'-methylenebis (2-hydroxy-4-methoxy). 2-hydroxybenzophenones such as benzophenone); 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-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-5-tert-octylphenyl) benzotriazole, 2
-(2-hydroxy-3,5-dicumylphenyl) benzotriazole, 2,2'-methylenebis (4-tertiaryoctyl-6-benzotriazolylphenol), 3-
2- (2-Hydroxyphenyl) benzotriazoles such as (3-tert-butyl-4-hydroxy-5-benzotriazolylphenyl) propionic acid-polyethylene glycol ester; phenyl salicylate, resorcinol monobenzoate, 2,4- Benzoates such as di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate and hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; 2-ethyl-
Substituted oxanilides such as 2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β, β-diphenylacrylate, methyl-2-cyano-3-methyl-3- Examples include cyanoacrylates such as (p-methoxyphenyl) acrylate.

The amount of these ultraviolet absorbers added is usually 0.001 with respect to 100 parts by weight of the polyolefin resin.
-5 parts by weight, preferably 0.01-3 parts by weight.

As the hindered amine light stabilizer, for example, 2,2,6,6-tetramethyl-4-piperidinol or 1,2,2,6,6-pentamethyl-4-piperidinol monovalent or divalent carboxylic acid. Ester compound of 2,2,6,6-tetramethyl-4-piperidyl benzoate, 2,2,6,6-tetramethyl-4-piperidyl laurate, 2,2,6,6-tetramethyl-4
-Piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, bis (2,2
2,6,6-Tetramethyl-4-piperidyl) terephthalate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (1,2,2,6,6-)
Pentamethyl-4-piperidyl) succinate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-
4-piperidyl) sebacate], 2,2,6,6-tetramethyl-4-piperidinol or 1,2,2,6
1,2-, 3-, 6-pentamethyl-4-piperidinol
4-butane tetracarboxylate, 2,2,6,6-
Tetramethyl-4-piperidinol or 1,2,2,
6,6-pentamethyl-4-piperidinol and 1,2,
Condensate of 3,4-butanetetracarboxylic acid and tridecyl alcohol, 2,2,6,6-tetramethyl-4-piperidinol or 1,2,2,6,6-pentamethyl-4-piperidinol and 1, 2,3,4-butanetetracarboxylic acid and β, β, β ', β'-tetramethyl-3
9- (2,4,8,10-tetraoxapyro [5,5]
Undecane) diethanol condensate, poly [[6- (1,1,3,3-tetramethylbutyl) amino-1,
3,5-triazine-2,4-diyl] ・ [(2,2,
6,6-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], poly [(6-morpholino 1,
3,5-triazine-2,4-diyl)] [[2,
2,6,6-Tetramethyl-4-piperidyl) imino]
Hexamethylene [(2,2,6,6-tetramethyl-4
-Piperidyl) imino]], N, N'-bis (3-aminopropyl) ethylenediamine and 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-
Piperidyl) amino] -6-chloro-1,3,5-triazine condensate, 1,6,11-tris [(4,6-
Examples thereof include bis [N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino] -1,3,5-triazin-2-yl] amino] undecane.

The amount of these hindered amine light stabilizers added is usually 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the polyolefin resin.

Other examples of the polyolefin resin of the present invention include inorganic fillers such as talc, calcium carbonate and glass fiber, calcium stearate, metallic soaps such as calcium stearyl lactate, aluminum-p-tertiary butyl benzoate and glycerin. Zinc, dibenzylidene sorbitol, bis (4-methylbenzylidene) sorbitol, bis (4-tert-butylphenyl) phosphate sodium salt, 2,2′-methylenebis (4,6-ditert-butylphenyl) phosphate sodium salt, etc. Nucleating agents, pigments, dyes, etc. may be added as desired.

The polyolefin resin composition of the present invention is
By mixing the polyolefin-based resin and each other blending component by a known method, and melt-kneading, to obtain, for example, in the form of pellets, injection molding using this,
It can be molded by a conventional method such as extrusion molding or blow molding, but is not limited by the molding method or its form.

Further, the composition of the present invention can be processed into a sheet, a film, various molded articles and the like, and its surface characteristics can be improved by subjecting it to well-known radiation treatment such as low temperature plasma treatment after molding. It can be used in applications where sterilization treatment is performed by γ-ray irradiation.

[0040]

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

(Example 1) The formulations shown in Table 1 below were added to 280
Repeatedly extruded at ℃, extruded number 1 and 5
For the second pellet, the change in melt flow rate (MFR) (g / 10 minutes) was measured at 230 ° C. under a load of 2.16 Kg. In addition, 2 pellets for the first extrusion
A 1 mm-thick test piece was prepared by injection molding at 50 ° C., and its yellowness was measured by a Hunter colorimeter, and the change was observed.

Further, the time until the occurrence of cracks in the test piece prepared by the injection molding was measured with a sunshine weatherometer as weather resistance. Further, the test piece obtained in the same manner was put in a gear oven at 160 ° C. and the heat resistance was measured by the blackening time. Furthermore, it was allowed to stand in 3.3% NO ₂ gas for 24 hours, and the NOx resistance due to the color difference from before the test.
The sex was evaluated. The results are shown in Table-2.

[0043]

[Table 1]

[0044]

[Table 2]

(Example 2) In the same manner as in Example 1, the compounds shown in Table 3 below were molded, and the same test was conducted except for weather resistance. The results are shown in Table-4.

[0046]

[Table 3]

[0047]

[Table 4]

(Example 3) One of the formulations shown in Table 5 below was used.
The mixture was kneaded with a mixing roll at a temperature of 50 ° C. for 5 minutes, and then compression molded at a temperature of 150 ° C. for 5 minutes under the condition of 180 kg / cm ² to prepare a sheet having a thickness of 1.2 mm. Using this sheet as a test piece of 10 × 20 mm, a gear oven heating deterioration test in air was performed on an aluminum foil at a temperature of 150 ° C. In addition, 10 test pieces were used for the same sample, and the time when 5 or more sheets were discolored or formed into a wax was defined as the deterioration time. The weather resistance was evaluated by measuring the yellowness of the sheet after 720 hours with a sunshine weather meter (without rain). Further, after the same composition was extruded at 230 ° C., the processing stability was evaluated from the ratio of the melt index to the original when the mixture was allowed to stay in the melt indexer at 290 ° C. for 20 minutes. The results are shown in Table-6. The compounds used for comparison are as follows.

[0049]

[Chemical 13]

[0050]

Embedded image

[0051]

[Table 5]

[0052]

[Table 6]

Example 4 The formulations shown in Table 7 below were used in a torque rheometer at a temperature of 230 ° C. and 80 rpm.
Depending on the number of revolutions, the torque change over time after 5 minutes and 3
The measurement was performed after 0 minutes. The heat resistance was evaluated by measuring the yellowness of the resin after 30 minutes. In addition,
In the comparative example, the following comparative compound 3 was used. The results are shown in Table-8.

[0054]

[Table 7]

[0055]

[Chemical 15]

[0056]

[Table 8]

From the results of the respective examples, by adding together two different phosphite compounds and hydrotalcites of the present invention, the processing stability, heat resistance, NOx resistance and weather resistance of the polyolefin resin composition can be improved. It is clear that the sex can be significantly improved.

On the other hand, when only one kind of phosphite compound and hydrotalcites are used together, or when two kinds of phosphite compounds are used together and no hydrotalcites are used together, processing stability is improved. Properties, heat colorability, NOx resistance, and weather resistance are insufficient and not satisfactory in practice, and the effect of the combined use of the two phosphite compounds and hydrotalcites of the present invention is extremely remarkable. Obviously it is.

[0059]

The polyolefin resin composition of the present invention improves processing stability, heat resistance, NOx resistance and weather resistance.

Claims (1)

[Claims] 1. A diarylpentaerythritol diphosphite compound represented by the following general formula (I) and (b) based on 100 parts by weight of a polyolefin resin.
A total of 0.01 to 10 parts by weight of a triarylphosphite compound represented by the following general formula (II) in a weight ratio of 1/1 to 1/9, and 0 to (c) hydrotalcites. Polyolefin resin composition obtained by adding 0.01 to 20 parts by weight. [Chemical 1]