JPH05179076A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition improved in processing stability and resistance to discoloration and NOx contamination by incorporating a polyolefin resin with each specified amount of a diaryl pentaerythritol diphosphite and triaryl phosphite. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100 pts.wt. of a polyolefin resin with (B) a total of 0.01-10 pts.wt. of (1) a diaryl pentaerythritol phosphite of formula I (R and R' are each H or 1-4C alkyl) and (2) a triaryl phosphite of formula II (R1 and R2 are each H or 1-4C alkyl) at the weight ratio (1)/(2) of (1:1) to (1:9).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides processing stability by adding two kinds of phosphite compounds in combination.
More specifically, the present invention relates to a polyolefin-based resin composition having improved coloring properties and NOx contamination properties. By adding a diarylpentaerythritol diphosphite compound and a triarylphosphite compound in combination, processing stability, coloring properties and The present invention relates to a polyolefin resin composition having an improved NOx pollution property.

[0002]

2. Description of the Related Art Polyolefin resins are used as various molded products, films, fibers, etc. because they are excellent in mechanical properties, thermal properties, moldability, etc., lightweight and relatively inexpensive. However, it has a drawback that it is inferior in stability during high-temperature processing, and it is known that physical properties are deteriorated or it is colored.

Further, the polyolefin resin has a drawback that it is markedly colored when exposed to nitrogen oxide gas (NOx gas) contained in exhaust gas of automobiles, waste gas from heating appliances and the like.

In order to prevent such deterioration of the polyolefin resin, many additives have been used so far alone or in various combinations. Generally, trialkyl phosphite, triaryl phosphite, alkylaryl 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 coloration. ..

Among these organic phosphite compounds, the diarylpentaerythritol diphosphite compound has good thermal discoloration prevention property and processing stability and is widely used, but it has a drawback that it is colored by NOx gas. The improvement was strongly demanded.

Further, although the triaryl phosphite compound has a relatively good NOx contamination property, it has a great drawback in thermal coloring property and processing stability, which is a great obstacle in practical use.

[0007]

[Means for Solving the Problems] As a result of intensive studies in view of the present situation, the present inventors have found that two types of organic phosphite compounds of different types are used together in a specific ratio in a polyolefin resin. The present invention was found by the addition of these compounds, and it was found that a polyolefin resin composition with improved NOx contamination can be obtained while maintaining the excellent processing stability and heat colorability of the diarylpentaerythritol diphosphite compound. did.

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. The present invention provides a polyolefin-based resin composition obtained by adding 0.01 to 10 parts by weight in a weight ratio of 1/1 to 1/9 with a triarylphosphite compound represented by.

[0009]

[Chemical 2]

(In the formula, R and R ′ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₁ and R ₂ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. )

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,
Poly-3-methylbutene, ethylene-propylene random copolymer or block copolymer, ethylene-propylene-diene copolymer, ethylene-4-methyl-1
-Pentene copolymer, poly-4-methyl-1-pentene and the like.

In the diarylpentaerythritol diphosphite compound represented by the general formula (I), R is
Examples of the alkyl group having 1 to 4 carbon atoms represented by R'include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl and isobutyl groups.

In the triaryl phosphite compound represented by the general formula (II), the alkyl group having 1 to 4 carbon atoms represented by R ₁ and R ₂ is represented by R and R'described above. Selected from alkyl groups having 1 to 4 carbon atoms.

Therefore, specific examples of the specific diarylpentaerythritol diphosphite compound represented by the above general formula (I) used in the present invention include, for example, bis (2,4-ditertiarybutylphenyl) penta. Erythritol diphosphite, bis (2,6-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6 -Di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-isopropylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-tertiary Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-tertiary Butylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butyl -
6-methylphenyl) pentaerythritol diphosphite and the like.

Of these specific diarylpentaerythritol diphosphite compounds, bis (2,4-
Di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-tert-butylphenyl) pentaerythritol Diphosphite is particularly preferred.

Specific examples of the triarylphosphite compound represented by the general formula (II) include tris (2-tert-butylphenyl) phosphite and tris (2,4-ditert-butylphenyl). Phosphite, tris (2,5-ditert-butylphenyl) phosphite, tris (2-tert-butyl-4-methylphenyl) phosphite, tris (2-tert-butyl-5-methylphenyl)
Examples thereof include phosphite and tris (2-tert-butyl-4,6-dimethylphenyl) phosphite.

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

When the ratio of the above two kinds of phosphite compounds is more than 50% of the diarylpentaerythritol diphosphite compound, the processing stability and the heat colorability are excellent, but the colorability due to NOx contamination is poor.
If it is less than 10%, the processing stability and heat colorability are poor.

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

The phenolic antioxidant which can be used in the present invention includes 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-di-tert-butyl-4-hydroxyphenyl) propionate],
4,4'-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4,6-di (3,5-ditert-butyl-4-hydroxyphenoxy) -s-triazine, 2,2 '-Methylenebis (4-methyl-6-tert-butylphenol), bis [3,3-bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4'-butylidenebis (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-di-tert-butyl-4-hydroxyphenyl)
Propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3,5-ditert-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
5] Undecane-bis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], triethylene glycol bis [β- (3-tert-butyl-4)
-Hydroxy-5-methylphenyl) bropionate]
Etc.

The amount of these phenolic antioxidants added is 0.
001 to 5 parts by weight, preferably 0.01 to 3 parts by weight.

As the thioether type antioxidant, dialkylthiodipropionates such as dilauryl, dimyristyl and distearyl esters of thiodipropionic acid, and β-of a polyol such as pentaerythritol tetra (β-dodecylmercaptopropionate). Examples thereof include alkylmercaptopropionic acid esters.

The amount of these thioether antioxidants added is 0.0 with respect to 100 parts by weight of the polyolefin resin.
The amount is 01 to 5 parts by weight, preferably 0.01 to 3 parts by weight.

As the ultraviolet absorber, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5'-methylenebis (2-hydroxy-) is used.
2-hydroxybenzophenones such as 4-methoxybenzophenone); 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-)
3,5-di-tert-butylphenyl) benzotriazole,
2- (2-hydroxy-3,5-ditert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-
Chlorobenzotriazole, 2- (2-hydroxy-5)
-Tertiary octylphenyl) benzotriazole, 2-
(2-Hydroxy-3,5-dicumylphenyl) benzotriazole, 2,2'-methylenebis (4-tertiaryoctyl-6-benzotriazolylphenol), 3- (3
2- (2-hydroxyphenyl) benzotriazoles such as tert-butyl-4-hydroxy-5-benzotriazolylphenyl) propionic acid-polyethylene glycol ester; phenyl salicylate, resorcinol monobenzoate, 2,4-di-primary Tributylphenyl-
3,5-di-tert-butyl-4-hydroxybenzoate,
Benzoates such as hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; 2-ethyl-2 '
Substituted oxanilides such as -ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α
-Cyano-β, β-diphenyl acrylate, methyl-
Examples include cyanoacrylates such as 2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate.

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

As the hindered amine light stabilizer, 2,
2,6,6-tetramethyl-4-piperidinol or 1,2,2,6,6-pentamethyl-4-piperidinol mono- or divalent carboxylic acid ester compound, 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 (2,2,6,6
-Tetramethyl-4-piperidyl) terephthalate, bis (2,2,6,6-tetramethyl-4-piperidyl)
Succinate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) succinate, bis (2,2,2
6,6-tetramethyl-4-piperidyl) sebacate,
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate], 2,2,6,6-tetramethyl-
4-piperidinol or 1,2,2,6,6-pentamethyl-4-piperidinol 1,2,3,4-butane tetracarboxylate, 2,2,6,6-tetramethyl-4-piperidinol or 1, A condensate of 2,2,6,6-pentamethyl-4-piperidinol with 1,2,3,4-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- (2,2
Condensation product of 4,8,10-tetraoxapyro [5,5] undecane) diethanol, poly [[6- (1,1,1,
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-bis [N
-Butyl-N- (2,2,6,6-tetramethyl-4-
Piperidyl) amino] -1,3,5-triazine-2-
Il] amino] undecane and the like.

The amount of these hindered amine compounds added is 0.00 based on 100 parts by weight of the polyolefin resin.
It is 1 to 5 parts by weight, preferably 0.01 to 3 parts by weight.

In addition, the polyolefin resin of the present invention includes 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 dibenzylidene. Sorbitol, bis (4
-Methylbenzylidene) sorbitol, bis (4-tert-butylphenyl) phosphate sodium salt, 2,2 '
Nucleating agents such as methylenebis (4,6-di-tert-butylphenyl) phosphate sodium salt, pigments, dyes, etc. may be added as desired.

The polyolefin resin composition of the present invention is
It can be molded by a conventional method such as injection molding, extrusion molding or blow molding, and is not limited by the molding method or its form.

Further, the composition of the present invention can have its surface characteristics improved by subjecting it to well-known radiation treatment such as low-temperature plasma treatment after molding, and is also suitable for use in sterilization treatment by γ-ray irradiation. Can be used.

[0032]

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

[Example 1] <Compound> Parts by weight Polypropylene (Profax 6501) 100 Calcium stearate 0.05 Tetrakis [methylene-3- (3,5-di-tert-butyl 0.1-4-hydroxyphenyl) propionate ] Methane phosphite compound Table-1

Extrusion number of 1 above at 280 ° C.
Melt flow rate (MFR) (g /
The change of 10 minutes) was measured. Further, the pellets of the first and fifth extrusions were injection-molded at 250 ° C. to prepare a test piece having a thickness of 1 mm, the yellowness of which was measured by a Hunter colorimeter, and the change was observed.

A test piece obtained by injection-molding a pellet extruded for the first time was subjected to 24% at room temperature in 3.3% NO ₂ gas.
After standing for a time, the NO ₂ gas was exhausted and the yellowness of the test piece was measured to determine the color difference from the untreated test piece. The results are shown in Table-1.

[0036]

[Table 1]

Example 2 <Compound> Parts by weight Polypropylene (Profax 6501) 100 Calcium stearate 0.05 Stearyl (3,5-di-tert-butyl-4-hydroxy 0.1 phenyl) propionate bis (2,6) -Di-tert-butyl-4-methylphenyl) 0.03 pentaerythritol diphosphite triarylphosphite compound (Table-2) 0.07

The above compound was molded in the same manner as in Example 1, and the same test was conducted. The results are shown in Table-2.

[0039]

[Table 2]

Example 3 <Composition> Parts by weight Polypropylene (Mitsui Noblene) 100 Calcium stearate 0.05 Stearyl (3,5-di-tert-butyl-4-hydroxy 0.1 phenyl) propionate Tris (2,4) -Di-tert-butylphenyl) phosphite 0.07 diarylpentaerythritol diphosphite (Table 3) 0.03

The above compound was molded in the same manner as in Example 1 and the same test was conducted. The results are shown in Table-3.

[0042]

[Table 3]

From the results of each example, it is clear that the process stability, heat colorability and NOx contamination of the polyolefin resin composition can be remarkably improved by adding two different phosphite compounds of the present invention together. Is.

On the other hand, when the diarylpentaerythritol diphosphite compound alone or the diarylpentaerythritol diphosphite compound is in excess, the processing stability and the heat colorability are relatively excellent, but N
Although the Ox stain resistance is high, and the triaryl phosphite compound alone has a relatively good NOx stain resistance, it is not practically satisfactory because it is extremely inferior in processing stability and heat colorability.

[0045]

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

Claims (1)

[Claims] 1. A diarylpentaerythritol diphosphite compound represented by the following general formula (I) and (b) represented by the following general formula (II) with respect to 100 parts by weight of a polyolefin resin. With a triaryl phosphite compound in a weight ratio of 1/1 to 1/9 in total of 0.0
A polyolefin resin composition comprising 1 to 10 parts by weight. [Chemical 1] (In the formula, R and R ′ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₁ and R ₂ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)