JPS61133251A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:The titled composition having improved heat resistance, improved coloring preventing properties, and improved processing stability, obtained by blending polyolefin resin with a phenolic antioxidant, a specific organic phosphite and hydrotalcite. CONSTITUTION:100pts.wt. polyolefin resin is blended with (A) 0.001-5pts.wt., preferably 0.005-3pts.wt. phenolic antioxidant (e.g., 2,6-di-tertiary butyl-p-cresol, etc.), (B) 0.001-5pts.wt., preferably 0.01-3pts.wt. organic phosphite [e.g., di(isotridecyl)pentaerythritol diphosphite, etc.] shown by the formula I (R1 and R2 are alkyl, aryl, etc.) and (C) 0.001-5pts.wt., preferably 0.01-1pt.wt. hydrotalcite shown by the formula II (0<x<=0.5, A is CO3; n is integer).

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to polyolefin resin compositions.

More specifically, the present invention relates to a polyolefin resin composition containing a phenolic antioxidant, a pe/taerythritol phosphite compound, and hydrotalcites and having improved processing stability, heat resistance, etc.

[Conventional technology]

It is known that polyolefin resins such as polyethylene and polypropylene deteriorate due to the effects of heat, light, etc., becoming discolored or having reduced mechanical strength, making them unusable.

For the purpose of preventing such deterioration of polyolefins, many additives have been used singly or in various combinations. Among these additives, it is known that a combination of a phenolic compound and a phosphite compound has a relatively large effect of improving heat resistance and suppressing discoloration.

For example, Japanese Patent Publication No. 56-25955 describes a combination of a phenolic antioxidant and diorganic pentaerythritol diphosphite, while Publication 4I Publication No. 59-213445 describes a combination of di(dialkylphenyl)pentaerythritol and a phenol-based K il-forming agent. In addition, Japanese Patent Application Laid-Open No. 52-49258 describes a combination of a phenolic anti-hyperodizing agent and hydrotalcites.

[Problem that the invention seeks to solve]

However, although these combinations can improve the heat resistance and coloring resistance of the polyolefin resin to some extent, they are still not sufficient, and further improvement is required. Furthermore, when a combination of these is used, it has been pointed out that the processing stability of the polyolefin resin is poor, and that the melt index of the polyolefin resin changes significantly due to monolysis or crosslinking during processing at high temperatures.

[Means for solving problems]

The inventors of the present invention have conducted extensive studies based on the current situation, and have found that
When &(') a phenolic antioxidant, (b) an organic phosphite represented by the following general formula (r), and (0) hydrotalcites are added to a polyolefin resin, the heat resistance and anti-coloration properties improve. It has been found that a polyolefin resin which has been improved to a satisfactory level and has extremely excellent processing stability can be obtained. The polyolefins used in the present invention include low density polyethylene, high density polyethylene, and linear low density polyethylene (ethylene/α such as ethylene/butene-1 copolymer).
-Olefin (0°~O1) copolymer), polyglopylene, propylene/ethylene copolymer, polybutene-1,
poly-5-methylbutene, poly-4-methylpentene,
Examples include poly-α-olefins and copolymers of α-olefins, such as ethylene/vinyl acetate copolymers.

The phenolic fermentation inhibitor used in the present invention is 1
For example, 2,6-di-tert-butyl-p-cresol, 6-diphenyl-4-octadecyloxyphenol, stearyl-(s,s-c-tert-butyl-4-hydroxyphenyl)propionate. distearyl-5,5-di-5-butyl-4-hydroxybenzylphosphonate,
Thiodiethylenebis((3,5-di-tert-butyl-4-
Hydroxyphenyl)propy#*-)).

4.4'-thiobis(6-5th-butyl-m-cresol), 2-octylthio-4,6-di(s,s-di-5th-butyl-4-hydroxyphenococo)-〇-triazine, 2.2 '-Methylenebis(4-methyl-6-tert-butylphenol)s 2,2'-methylenebis(4-
ethyl-6-5-butylphenol), bis(!5.5
-bis(4-hydroxy-3-tert-butylphenyl)butyric acid coglycol ester, 4.4'
-butylidene bis(6-5th butyl-m-cresol L
212'-ethylidenebis(a,b-di-tert-butylphenol), 2.2'-ethylidenebis(4-sec-butyl-6-tert-butylphenol), 1,1. S-
Tris(2-methyl-4-hydroxy-5-5th-butylphenyl)butane, bis(2-g3butyl-4-methyl-6-(2-hydroxy-3-7g5butyl-S-methylbenzyl)phenylkotelev sauce), 1. ! 5.
5-) Squirrel (2,6-Jime.

methyl-5-hydroxy-4-5-butylbenzyl)in cyanurate, 1. ! 5.5-) Lis(3,5-di-5-butyl-4-hydroxybenzyl)incyanure-
), 1,5.5-) Lis(5,5-di-5-butyl-4-hydroxybenzyl)"L4.6-) Listylbenzene, 1,45.5-Tris[(S,S
-tert-butyl-4-hydroxyphenyl)propionyloxyethyl diisocyanurate, tetrakis [
Examples include methylene-S-, (S,S-di-5-butyl-4-hydroxyphenyl)gropionate]methane, and the like.

Examples of the alkyl group constituting the organic phosphite represented by the general formula (X) are methyl and ethyl.

Propyl, inglovir, butyl, sec-butyl.

Tertiary butyl, amyl, neopentyl, isoamyl, hexyl, isohexyl, hegetyl, octyl, inoctyl, 2-ethylhexyl, decyl, isodecyl, lauryl, tridecyl, 01□~.

Mixed alkyl, stearyl, etc. can be mentioned.

Examples of the cycloalkyl group include cyclohexyl, 4-methylcyclohexyl, p-C2-(4-hydroxycyclohexyl))-2-propylcyclohexyl, and the like. Examples of aryl groups include phenyl and phenyl phenyl groups; examples of arylalkyl groups include benzyl, β-phenylethyl, γ-phenylglobil, β-phenylpropyl and the like. Examples of alkylaryl groups include tolyl, xylyl, ethylphenyl, phthylphenyl,
gs butylphenyl, octylphenyl, tertiary octyl 7-enyl, in-octylphenyl, nonylphenyl, dinonylphenyl, 2.4-')-57'-tylphenyl% 214-c-tertiary octyl 7-enyl, 2 .4-
Di-5th amyl phenyl, 2-5th butyl-4-methylphenyl, 2,4-di5th phthyl-5-methylphenyl, 2-cyclohexylphenyl hp-('-hydroxycumyl)phenyl, and the like.

Used in the present invention. Specific examples of the phosphite compound represented by the formula (r) include di(intridecyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, and ditetradecyl pentaerythritol diphosphite. phyto, dicyclohexylpentaerythritol diphosphite.

Dibenzylpentaerythritol diphosphite, diphenylpentaerythritol diphosphite, cy(nonylphenyl)pentaerythritol diphosphite, di(2,4-di-t-butylphenyl)pentaerythritol diphosphite, di(2,4 -di-t-amylphenyl)pentaerythritol diphosphite, cy(2゜a-di-t-octylphenyl)pentaerythritol diphosphite, di(2-1-butyl-a-fimethylphenylpentaerythritol diphosphite) Fight, Ji (2
-Phenylphenyl)pentaerythritol diphosphite, di(2-cyclohexylphenyl)pentaerythritol diphosphite, phenyl bisphenol A
- Examples include pentaerythritol diphosphite.

The hydrotalcites used in the present invention are hydrous double salt compounds consisting of magnesium and aluminum represented by the following general formula (phantom).

Mg1-Ey Eng(on)2A,/,-mu2o
(Illusion (in the formula, υ is a real number in the range of 0 and υ 0.5.

A indicates CO, and 1m indicates a real number. ) The above hydrotalcites may be natural products or synthetic products. As a synthesis method, Japanese Patent Publication No. 46-2280, Japanese Patent Publication No. 50-50059, and Japanese Patent Publication No. 51-29
A known method disclosed in Japanese Patent No. 129 and the like can be exemplified. Furthermore, in the present invention, the above-mentioned hydrotalcites can be used without being restricted by their crystal structure or crystal particle size. In addition, the surface of the above-mentioned hydrotalcites is coated with a high-grade fat such as stearin 13! Also usable are those coated with higher fat metal salts such as oleic alkali metal salts, organic sulfonic acid metal salts such as dodecylbenzenesulfonic acid alkali metal salts, higher fatty acid amides, higher fatty acid esters or waxes.

In addition, the amount of the phenolic antioxidant used in the present invention (a) is % based on 100 parts by weight of the polyolefin.
0.001 to 5, preferably o, oos to 5 parts by weight, and the amount of the organic phosphite (I+) component added is 0.001 to 5, preferably 0.01 to 5 parts by weight, per 100 parts by weight of the polyolefin. parts, and the amount of hydrotalcites as component (C) added is 0.001 to 5.0 parts per 100 parts by weight of polyolefin. Preferably it is 0.01 to 1 part by weight.

By incorporating a thioether antioxidant into the composition of the present invention, the antioxidant properties thereof can be further improved. Examples of the thioether antioxidant include diracryl thiodipropionate, dimyristyl thiodiglobionate, distearyl thiodiglobionate, pentaerythritol tetra (β-dodecylthiodiglobionate), and the like.

Calcium stearate in the composition of the present invention.

The processability and heat resistance can also be significantly improved by adding high-grade fatty acids of group III metals such as calcium ratate, zinc stearate, barium stearate, and magnesium stearate.

By adding a light stabilizer to the composition of the invention, its light resistance can be improved. These light stabilizers include, for example, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone.

Hydroxybenzophenones such as 2.2'-dihydroxybenzophenone, 2.4-dihydroxybenzophenone 7, 2-(2'-hydroxy-5'-
t-Butyl-5'-methyl7enyl)-5-chlorobenztriazole, 2-(2'-hydroxy-sl, s
l-di-t-butylphenyl)-5-chlorobencitriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'- and toxy5').

Benzotriazoles such as s'-C t-amyl phenyl) benzotriazole, phenyl t IJ syre)
, pt-butylphenyl salicylate, 2,4-di-
Benzoates such as t-butylphenyl-3,5-di-t-buf-4-hydroxybenzoate, 2.2
'-thiobis(at-octylphenol) Ni salt,
(2,2'-thiobis(4-t-octylphenolate)]-]n-butylamine N1 salt, S,S-di-t-butyl-4-hydroxypenzyl)phosphonic acid monoethyl ester N1 salt, etc. Nickel compounds, substituted acrylic c1
Nitriles and 2,2,6.6-teto2methyl-4-piperidinylbenzoate, bis(2s2*6*6-tetramethyl-4-piperidinyl)sepacate, tris(2
, 2,6,6-tetramethyl-4-piperidinyl)nitrilotriacetate, and tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)butanetetracarboxylate.

In addition, if necessary, a heavy metal deactivator, a nucleating agent, a plasticizer, an epoxy compound, a pigment, a filler, a foaming agent, an antistatic agent, a fuel agent, etc. can be included.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. However, the present invention is not limited to the following examples.

Example 1. Comparative Example 1 The following formulation was mixed in a grinder for 5 minutes and then extruded at 250°C. Then injection molded at 250°C,
A test piece with a thickness of 1H was prepared. Using this test piece, 16
A thermal stability test was conducted with the gear open at 0°C.

In addition, in order to check the anti-coloration property, the yellowness of the test piece was measured using a Hunter colorimeter. Furthermore, in order to examine the processing stability, the melt index (M process) when extrusion was turned around 5 times at 250℃ (2SO℃, W weight 2160F)
) was measured. The results are shown in Table-1.

Compounded polypropylene (Profax 4501) 10
0, parts by weight organic phosphite (Table-t)
a, 1z” MgO0-noo, 3(OH) z
(''3) (I,1,・O-541! 20 Example 2. Comparative Example 2 A test similar to Example 1 was conducted using the following formulation. The results are shown in Table 2.

Compounded polypropylene (Profax 6so1)
100 parts by weight S7ite' Hydrotalcites (Table-2) Table-2
Example 3. Comparative Example 3 The following formulation was kneaded with a mixing roll at a temperature of 150°C for 5 minutes, then kneaded at a temperature of 150°C for 180h/cm20.
Compression molding was performed under these conditions for 5 minutes to create a sheet with a thickness of 1.2 mm. This sheet was used as a 10 x 20 size test piece and a gear open heating deterioration test was conducted on aluminum foil in air at a temperature of 150°C. In addition, 1 for the same sample
Using 0 specimens, the time when S or more specimens changed color and became waxy was defined as the deterioration time.

Furthermore, after extruding the same formulation at 230°C, the change in melt index was measured when it was allowed to stay in a melt indexer at 290°C. The results are shown in Table 5.

Combined dilawalylthiodigropio*-) 0.11 stearyl-
(3,5-di-tert-butyl-4-hydroxyphenyl)
Propione-o, oat additive
0.05t Example 4. Comparative Example 4 In order to examine the processing stability of linear low-density polyethylene, the following formulation was used.
℃, 80 rpm), and the change in torque was measured over time. In addition, in order to check the heat resistance, the coloration of the resin was measured using a Hunter colorimetric needle and expressed as yellowness (%). The results are shown in Table 4 ◇Combination

Claims (1)

[Scope of Claims] A polyolefin resin containing (a) a phenolic antioxidant, (b) an organic phosphite represented by the following general formula (I), and (c) hydrotalcites in a polyolefin resin. Composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1 and R_2 each independently represent an alkyl, aryl, cycloalkyl, alkylaryl, or arylalkyl group.)