JPS63130648A - Polyolefin composition - Google Patents

Abstract

PURPOSE:To improve stability during processing under high-temperature conditions and to improve thermal aging resistance during use, by blending a polyolefin with specified antioxidants in combination. CONSTITUTION:100pts.wt. polyolefin is blended with 0.005-1pt.wt. hindered phenolic antioxidant having an MW of not lower than 500, 0.05-1pt.wt. hindered phenolic antioxidant having an MW of lower than 500, or 0.01-1pt.wt. phosphite or phosphonite antioxidant other than the following component, and 0.01-1pt.wt. phosphite of formula I or II (wherein R1 is a 3-8C alkyl, a cycloalkyl or an arom. group; R2 is a 1-30C alkyl, a cycloalkyl, an arom, group or H; and R1 and R2 may be the same or different groups).

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to polyolefin compositions, and more particularly to polyolefin compositions with improved high temperature processing stability.

BACKGROUND OF THE INVENTION Polyolefins are used for a variety of purposes, taking advantage of their excellent mechanical properties and moldability. However, depending on the application, the molding processing conditions may be harsh, which may cause thermal oxidative deterioration and coloring of the product.
Deterioration products may be mixed in, and problems such as a decrease in the strength of the product due to a decrease in the molecular weight of the polyolefin may occur.

In order to solve this problem, it is common to add phenol-based or phosphite-based antioxidants, but satisfactory results have not yet been obtained.

[Summary of the invention]

Summary The present invention aims to solve the above-mentioned problems by providing a polyolefin composition that can withstand molding not only under normal conditions but also at high temperatures.

In order to solve the above-mentioned problems, the present inventors investigated various types of formulations, and as a result, achieved the objective by blending specific antioxidants in combination.

That is, the polyolefin composite according to the present invention has a polyolefin of 100'tl! ! After some treatment, the following (Al-(C)
) is characterized by the addition of ingredients.

(M) 0.005 to 1'yrt part of hindered phenolic acid sulfur inhibitor with a molecular weight of 111,500 or more (average molecular weight t5
Undesired phenolic antioxidant less than 0.00
5 to 1 part by weight or 0.01 to 11 parts by weight of the following (phosphite ester or phosphonite antioxidant other than component 03) (q phosphite having the structure of the following formula I or formula II) type antioxidant 0.01-1 part (here, R1
is a group selected from an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, and an aromatic group. R2 has 1 to 1 carbon atoms
It is a group selected from 30 alkyl groups, cycloalkyl groups, aromatic groups, and hydrogen atoms. R, %R, may be different depending on the composition of the same compound (・.) Effect The composition of the present invention has improved processing stability of polyolefin, and has a relatively low temperature (about 200°C).・It can withstand harsh processing conditions at temperatures above 300°C.

Furthermore, these characteristics, which are imparted with sufficient resistance to heat aging during use, are characteristics that can only be obtained in the combination made in the present invention, and when used individually, they cannot be obtained in comparison with the comparative examples. As shown in Figure 2, :JI cannot be formed in combination with other antioxidants.

[Detailed description of the invention]

Polyolefins The polyolefins used as objects to be stabilized in the present invention include (a) homopolymers or copolymers of α-olefins such as ethylene, propylene, butene, pentene, hexene, 4-methylpentene, heptene, and octene; ) The majority weight of these α-olefins and vinyl esters such as vinyl acetate, unsaturated organic acids (including salts, amides, and esters) such as acrylic acid, maleic anhydride, and methyl methacrylate, vinyl silanes such as vinyltrimethoxysilane, etc. Random, block or graft copolymers, with? 1 and fillerization, sulfonation of these polymers,
Examples include those that have been subjected to modification treatments such as oxidation.

Specifically, low to medium or high density polyethylene, polypropylene, polybutene, ethylene-propylene 7 random or block copolymer, ethylene-propylene-
These include butene copolymers, ethylene-butene copolymers, ethylene-4-methylpentene copolymers, propylene-hexene copolymers, propylene-hexene-butene copolymers, and the like.

Among these polymers, those that are particularly effective are propylene-based polymers such as polypropylene, propylene-ethylene random or block copolymers, propylene-ethylene-butene copolymers, and propylene-hexene-butene copolymers. and ethylene-propylene rubber, ethylene/butene rubber, etc.

These propylene-based polymers, especially resin-like or non-rubber-like ones, are generally produced by polymerization using a Ziegler-Natsuta catalyst. In the hexapolymerization method, which also supports polymers, it is produced in a slurry form in a solvent such as heptane, or it is produced by polymerizing in a liquid phase or vapor phase without a solvent. Furthermore, with recent advances in catalyst technology, polymer creation processes that do not require a decatalyst step have become a reality, but the present invention can also be applied to propylene polymers produced by these processes. The antioxidant used in the present invention has the above-mentioned (A1-(0)
As for the three components, first, the fraction (A) is the molecule t5
It is a hindered phenol antioxidant with a rating of 00 or higher.

The upper limit of the molecular weight is about 3,000.

"Hindered phenolic antioxidant" means that at least a part of the antioxidant ability is attributed to phenol, and the oni-nol hydroxyl group is bulkier than the K methyl group on at least one side (preferably on both sides). substituents (e.g. t-
butyl group).

Among these rare phenolic antioxidants,
Some specific examples of those having a molecular weight of 500 or more are as follows (the present invention is not limited to these).These can be used in combination.

(a) D-octadecyl-β-(4'-hydroxy-
31,5+ -c t -7'tylphenyl) flobionate (b) 1,1,3-tris(21-methyl-4'-hydroxy-5'-t-phthylphenyl]butane (c)
1,3.5-)Listyl-2,4,6-)Listyl(31,
51-di-t-butyl-4'-hydroxybenzylbenzene) tetraxy[methylene-3-(3', 5'-di-t-7'' thyl-41-hydroxyphenyl) flobionate comethane (e) 1,3,5-tris(31,51-di-t-butyl-4'-hydroxybenzyl)-8-) 177
Jin-2.4.6 (1) 1.3B, 511 tontrione(he)calcium (3,5-di-t-butyl-4-hydroxy-benzyl-monoethyl-phosphate) (t1 1,3.5- Tris(4-t-butyl-3-hydroxy-2,6-dimethylpenzyl)iricyanurate 2,4-bis(n-octylthio)-6-(4'-
Hydroxy-31,51-di-t-butylanilino)-
1,3,5-)Ryazine(S) Triethylene glycol-bis[3-(3'-
Butyl-5″-methyl-4′-hydroxyphenyl) flobionate] 1.6-hexanethiol bis(31-(31
゜5'-t-phthyl-4'-hydroxyphenyl)
propionate] to) 2,2-thio-diethylenebis[31-al.

5''-t-phthyl-41-hydroxyphenyl)propionate] (2) Bis[2-methyl-4-(3'-n-alkyl(
C12 or 014) thiopropionyloxy)-5
-t-7'tylphenyl] sulfide v) 3, 9
-his[1', 1'-shi)fk-2-(β-(3'
-t-butyl-4@-hydroxy-5″-methylphenyl)fropionyloxy)ethyl]-2,4,8,10
-tetraoxaspiroC5,5]undecane/x) 1.3.5-tris(2-hydroxyethyl-8-triazine-2, 4,6(IH,3H,5H
)-trione triester ■) Bis[3,3-bis(41-hydroxy-31,
-t-butylphenyl A-)-881 glycol ester (z+ 3,5-di-phenyl-4- and droxy-stearyl ether (Incorporated) N, N'-hexamethylene bis(3,5-
(T-7'' thyl-4-hydroxy-hydrocinnamamide) The blending amount is as described below.

Component (B) is a hindered phenol antioxidant with a molecular weight of less than 500 (the lower limit of molecular weight is about 100)
(B-13) is a phosphite-based or physphonite-based acid inhibitor (B-2) other than component (C) (details later).The latter antioxidant has antioxidant ability. At least a part of this is due to the attributes of phosphite or phosphite, and it is commonly used and well known as a stabilizer for resin materials.

Specific examples of the Φ) component used in the present invention include the following. As in the case of component (A), the present invention is not limited to these, and multiple types can be used in combination. A combination of (B-1) and (B-2) is also possible.

(a) 3,5-di-t-butyl-4-hydroxytoluene trunk) 2,6-di-t-butyl-4-ethylphenol (c) 2,6-di-t-butyl-4-hydroxyanisole (to ) Tocopherol → 2,2'-methylenebis(41-methyl-61-
t-butylphenol) (f) 4.4+-butylidene bis < 6 m-t-butyl-m-cresol) (t) tris(mixed mono and dinonylphenyl) phosphite cisstearyl pentaerythritol diphosphite or cyclic neo Pentanetetryrubis(octadecylphosphite)
-t-7'tylphenyl-di-tridecyl) phosphite) 1,1,3-tris(21-methyl-41-di-
Mixture with tridecylphosphite-s'-t,-y'tylphenyl)butanetocyphenylphosphitecF 41-di-t-butylphenyl)4.4'-
The amount of biphenylene phosphonite blended is as described below.

Antioxidant (0) Component (q is a phosphite-based antioxidant represented by the above formula [I] or [■]).

Examples of the component (0) used in the present invention include formula CI)
In the compound of formula CIII, there are compounds in which R1 is a t-butyl group and R2 is a methyl group, compounds in which R1 and R2 are both t-butyl groups, and in the compound of formula CIII, R1 is a t-butyl group.
Good examples include compounds where R1 is a butyl group and R2 is a hydrogen atom, compounds where R1 is a t-butyl group and R2 is a methyl group, and compounds where R1 and R2 are both t-butyl groups.

Blend amount The amount of each of these components added is (A), (El - (11), (B) - (21
, and (C) are respectively 0.005 to 1 double part, 0.
005 to 1 part by weight, 0.01 to 1 part by weight, and 0.01 to 1 part by weight.
01 to 1 part by weight.

If t is less than these lower limits, no effect will be exhibited, and if t exceeds the upper limit, it will not only be uneconomical but also cause unfavorable effects such as coloring and bleeding.

The preferred blending amount is 0.01 to 0.5 parts by weight, 0.01
~0.5 parts by weight, 0.02-0.5 parts by weight, and 0.5 parts by weight.
02 to 0.5 weight -31 parts (all based on 100 parts of polyolefin).

Desired Ingredients Other additional ingredients can be added to the polyolefin compositions of the present invention.

Namely, 1-sulfur-based antioxidants, light stabilizers such as benzoate-based, benzophenone-based, triazole-based, hindered amide/nickel-based, and other metal deactivators, antistatic agents, lubricants, organic and inorganic as necessary. pigments, fillers,
Peroxides, blowing agents, flame retardants, nucleating agents, etc. can be added within the range that does not impair the effects of the present invention.

Examples of sulfur-based antioxidants include the following.

(a) Cirauri A/-3,3'-thiodiprobio/acid ester (b) Similistyl-3,31-thiodipropionic acid ester (c) Distearyl-3,31-thiodipropionic acid ester (b) Laurylstearyl Creation of -3,3'-thiodipropionic acid ester (e) dioctadecyl disulfide (e) pentaerythritol-tetra(β-lauryl-thiopropionate) ester composition The polyolefin composition according to the present invention It can be created by any method. For example, component (A) of the present invention may be added to a powder of a polyolefin such as a propylene polymer.
(Add the homogeneous ingredients and component (C), add other ingredients as necessary, stir and smooth with a mixer such as Hensche or Lumixer, then melt-knead and extrude with an extruder, and pelletize. This pellet is generally processed into the desired molded product using a molding machine such as injection molding, compression molding, sheet molding, film molding, blow molding, or vacuum forming. The additives used in the following experimental examples are as follows.

(A) Component (a): Tetrakis [methylene-3-(3', 5'
-di-tert-butyl-4-hydroxy-phenyl)propionate comethane (1): 1,3,5-tris(al,
sl-di monobutyl-4'-hydroxyp/dyl)-
a-Triazine-2,4,6(IH,3H,5H)-trione CB) Component (Q): 3,5-di-t-butyl-4-hydroxy-toluene (d): ) Liss (purified monomer) and dinonylphenyl) phosphite (e) nidris(2,4-di-t-butylphenyl) phosphite (f): cystearylpentaerythritol diphosphite (-: bis(2,4-di-t-butyl) phenyl) pentaerythritol sifosphite defeat): f trachys (2
8,41-di-t-butylphenyl) -4,4'-biphenylene phosphonite (0) Component (1) In the two formulas [I], a compound (j ) In the formula (It''), R1 is a t-butyl group, and the be/zene ring is a compound in which R2 is a t-butyl group and the other R2 is a methyl group. Robionate (1) Calcium nistearate (ml: 2-hydroxy-4-n-octoxybenzophenone (nl: 2-(2'-hydroxy-31-t-butyl-5'-, +(f-ruphenyl-5-chloro) Benzotriazole (0): bis(2,2,6,6-tetramethyl-4-
(piperidyl) sebacate ethylene content 6 type percent and melt flow rate: MPR (VXB K7210.230°C) -5,
Add the food stabilizers listed in the table below to 5 g/10 min of propylene-ethylene fip copolymer (100 parts), blend with a Henschel mixer, and then 30 m! The mixture was melt-kneaded using a IIIφ extruder to form pellets. The obtained pellet was placed in an injection molding machine set at 320°C and molded into 90m x 1
A specimen of 20m x 2mm was prepared and tested. This sample was cut and the MFR was measured, which was used as a measure of high temperature deterioration. In addition, the sample was held in a melt indexer set at 290° C. for 15 minutes, then taken out, and the normal MFRt was set to -Y ++ as a measure of high-temperature deterioration. Comparative examples were also evaluated in the same manner. The results were as shown in the table below.

In the table, does physical property number 1 mean the following? have

Claims (1)

[Claims] The following (A) to (C) based on 100 parts by weight of polyolefin
) A polyolefin composition characterized in that it is made by adding a component. (A) 0.005 to 1 part by weight of a hindered phenolic antioxidant with a molecular weight of 500 or more (B) 0.005 to 1 part by weight of a hindered phenolic antioxidant with a molecular weight of less than 500, or the following component (C) 0.01 to 1 part by weight of a phosphite-based or phosphonite-based antioxidant other than (C) 0.01-1 part by weight of a phosphite-based antioxidant having the structure of the following formula I or II▲ There are mathematical formulas, chemical formulas, tables, etc.▼[I] (Here, R_1 is a group selected from an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, and an aromatic group.R
_2 is a group selected from an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group, an aromatic group, and a hydrogen atom. R
_1 to R_2 may be different in the same compound. )