JPH03188141A - Stabilized olefin polymer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition having improved thermal discoloration resistance as well as excellent light stability and thermal deterioration resistance by compounding a plurality of specified compounds. CONSTITUTION:The title composition is prepared by mixing a hindered piperidine compound of formula I (wherein R1 is H or CH3) with a benzoate compound of formula II (wherein R2 is t-butyl or t-amyl) and a phenolic antioxidant of formula III (wherein R3 is 1-4C alkyl; A is the residue of an at least monohydric alcohol; n is an integer equivalent to the valence of A) of formula IV (wherein R4 is R3; and R5 is H or R3) without substantially using any other hindered piperidine compounds.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention not only has excellent stability against light and is stable against deterioration such as embrittlement and softening due to heat, but also has excellent stability against heat. The present invention relates to a stabilized olefin polymer composition that also has improved discoloration properties.

<Prior Art> It is well known that olefin polymers such as polypropylene and polyethylene undergo deterioration such as surface cracking, embrittlement, softening, and discoloration when exposed to light, heat, and oxygen.

In order to prevent such deterioration due to light, heat and oxygen, various stabilizers have been used in combination. For example, various ultraviolet absorbers and hindered piperidine compounds are used to prevent deterioration caused by light. In recent years, hindered piperidine compounds have been particularly popular in order to prevent deterioration caused by light.

On the other hand, when phenolic antioxidants, which are widely used to prevent heat-induced deterioration, are used in combination with hindered piperidine-based compounds, their stabilizing performance against heat deterioration generally increases, perhaps due to an antagonistic effect between the two. There was a problem in that the deterioration rate was rather faster than in the case without the hindered piperidine compound.

JP-A No. 63-241048 discloses that by using a hindered piperidine compound having a molecular weight of 750 or more in combination with a hindered piperidine compound having a low molecular weight, the weather resistance of an olefin polymer can be improved and the brittleness caused by heat can be improved. It has been disclosed that it is also possible to prevent oxidation. However, when such high molecular weight type hindered piperidine compounds are used, discoloration due to heat increases.

<Problem to be solved by the invention> Therefore, when used in fields where hue is important, such as when colored in vivid colors, it is necessary to have excellent stability against light and avoid embrittlement due to heat. There has been a strong desire for an olefin polymer composition that is not only stable against deterioration such as softening and softening, but also has improved thermochromic properties.

The present inventors conducted extensive research to solve this problem, and found that by using a specific hindered piperidine compound, a specific ultraviolet absorber, and a specific phenolic antioxidant in combination, phenol It has excellent stability against light without impairing the performance of antioxidants, and is not only stable against deterioration such as embrittlement and softening due to heat, but also has improved thermochromic properties. This discovery led to the present invention.

Means for Solving the Problem> That is, the present invention provides (A) the following - mathematical formula (1) (in the formula,
R represents a hydrogen atom or a methyl group), (B) a hindered piperidine compound represented by the following general formula (II
) L (wherein R2 represents a t-butyl group or t-amyl group), and (C) a benzoate compound represented by the following general formula ([[) or (rV) (wherein R3 is the number of carbon atoms 1 to 4 alkyl groups, A represents a monovalent or polyhydric alcohol residue, and n is an integer corresponding to the number of bonds of the alcohol residue represented by A. (In the formula, R4 is the number of carbon atoms 1 to 4 alkyl groups, R3 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and substantially free of other hindered piperidine compounds. The object of the present invention is to provide a stabilized olefin-based polymer composition with improved thermochromic properties that does not contain any of the following.

Specific examples of the hindered piperidine compound of the general formula N) used in the present invention include the following.

2-Methyl-2-(2,2,6,6-tetramethyl-4
-piperidyl)amino-N-(2°2.6.6-tetramethyl-4-piperidyl)propionamide, and 2-methyl-2-(1,2,2,6,6-bentamethyl-4-piperidyl)amino -N(1,2,2,6,6-
Bentamethyl-4-piperidyl)propionamide.

Further, specific examples of the benzoate compound represented by the general formula (I[) include the following.

2.4-di-t-butylphenyl 3.5-';-t-
j 4-hydroquine benzoate, and 2,4-di-t-amylphenyl 3,5-di-t-butyl-4-hydroxybenzoate.

Furthermore, in the phenolic antioxidant of the general formula (I[r) used in the present invention, A is a monohydric or polyhydric alcohol residue, such as a monohydric to hexavalent alcohol residue. and is preferably a monovalent, divalent, trivalent or tetravalent alcohol residue. Specific examples of A include stearyl alcohol residue, pentaerythritol residue,
In addition to relatively simple monohydric or polyhydric alcohol residues such as triethylene glycol residues, for example 3,9-bis(2-hydroxy-1,1-dimethylethyl)2.4
．． Examples include spiroglycol residues such as those of 8.10-tetraoxaspiro[5,5]undecane. The phenolic antioxidant represented by the general formula (II[) includes, for example, the following compounds.

Tetrakis[methylene 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate comethane, 3.9-bis(2-(3-(3-t-butyl-4-hydro,xy-5- methylphenyl) flopionyloxy)
-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, and n-octadecyl 3-(3,5-di to monobutyl-4
-Hydroxyphenyl)propionate.

Furthermore, examples of the phenolic antioxidant represented by formula (TV) include the following compounds.

1.3.5-tris(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, and 1.3.5-)tris(4-t-butyl-3-hydroxy-2,6- dimethylbenzyl) incyanurate.

The olefin polymer composition of the present invention comprises such a hindered piperidine compound represented by formula (I),
It contains a benzoate compound represented by the formula (II) and a phenolic antioxidant represented by the formula (II[) or (TV>), but the total amount of each of these compounds is based on the olefinic heavy The amount is usually preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the combined product.The weight ratio of the hindered piperidine compound to the benzoate compound is usually 20 parts by weight. The ratio is preferably about 80 to 95:5, more preferably about 40:260 to 90:10.Furthermore, the content of the phenolic antioxidant is usually 0.01 to 100 parts by weight of the olefin polymer. ~4 parts by weight is preferred;
More preferably, it is 0.02 to 2 parts by weight.

Further, the olefin polymer composition of the present invention has the formula (1)
It does not substantially contain hindered piperidine compounds other than the compounds represented by. If such other hindered piperidine compounds are present in significant amounts, the desired effects of the present invention may not be fully exhibited in many cases. In particular, the presence of a high molecular weight type hindered piperidine compound is not preferable because thermal discoloration becomes large.

However, in the present invention, other additives, such as metal deactivators, metal soaps, nucleating agents, lubricants, antistatic agents, flame retardants, pigments, and fillers, may be used as long as they do not impair the properties of the polymer composition. etc. may be used together.

As a method for blending the olefin polymer composition of the present invention, known apparatuses and operating methods for blending stabilizers, pigments, fillers, etc. into resins can be applied as they are.

The olefinic polymer applied in the present invention is not only a homopolymer obtained by polymerizing olefinic monomers, but also has an olefinic monomer as a main component and other copolymerizable vinyl monomers. It also includes copolymers obtained from Here, olefinic monomers include compounds with one double bond in the molecule, such as ethylene, propylene, and 1-butene, as well as compounds with two or more double bonds in the molecule, such as 1,3-butadiene. Also includes compounds with heavy bonds.

Other vinyl monomers that can be copolymerized with these olefinic monomers include acrylic esters, methacrylic esters, vinylidene chloride, styrene, α-methylstyrene, acrylonitrile, maleic anhydride, maleimide, N- Examples include methylmaleimide.

The olefin polymer in the present invention is a mixture of the above-mentioned olefin polymer and other polymers such as polystyrene, polycarbonate, polyamide, polybutylene terephthalate, polyethylene terephthalate, polyphenylene oxide, and polyvinyl chloride. You can.

<Examples> Next, the present invention will be explained in more detail by giving Examples, but the present invention is not limited thereto.

Example 1 The following formulation was processed using a 40sφ extrusion granulator (manufactured by Braco, PDA
After extrusion granulation using a 5.5-ounce injection molding machine (manufactured by Toshiba, model 15100E), test pieces were prepared.

A 40 x 60 x 1 mm test piece was placed in a sunshine weather meter (light source: carbon arc), and the test piece was irradiated with light under the conditions of a black panel temperature of 83 ± 3°C, a spray cycle of 120 minutes, and a spray time of 18 minutes. The surface condition of the test piece was observed every hour. Then, the time required for surface cracks to appear on the test piece was measured, and the performance against photodeterioration was evaluated based on this surface crack time.

On the other hand, a test piece marked 40×40×1 was placed in a gear oven at 160° C. and heated. and 3 on the surface of the test piece.
The time until 0% becomes brittle is measured, and the color difference △YI between the test piece before deterioration and the test piece 3 days after the start of the test is measured, and the performance against thermal deterioration is determined by the embrittlement time and thermal discoloration. was evaluated.

The results of these tests are shown in Table-1.

[Distribution]

Unstabilized polypropylene 100 parts by weight Calcium stearate 0.1 part by weight Test stabilizer
Table 1 Description The symbols of the stabilizers tested in Table 1 are as follows.

HALS-1: 2-methyl-1-(2,2,6,6
Tetramethyl-4-piperidyl)amino-N-(2,2,6,6-tetramethyl-4-piperidyl)propionamide HALS-2: 2-methyl-2-(1,2,2,6
゜6-bentamethyl-4-piperidyl) Amino-N-(1,2,2,6,6-bentamethyl-4-piperidyl)propionamide HALS-3+ Bis(2,2,6,6-tetramethyl-4-piperidyl) Sebacate HALS-4: Poly[(6-(1,1,3,3-tetramethylbutyl)amino-1,3゜5-triazine-2,4-diyl) ((2,2,6,6-tetramethylbutyl) Methyl-4-piperidyl)imino)-1,6-hexanediyl ((2,2,6,6-tetramethyl-4-piperidyl)imino)] UVA-1: 2,4-di-t-butylphenyl 3 .5-
Di-t-butyl-4-hydroxybenzoate LIV^-2 = 2-hydroxy-4-octyloxybenzophenone UVA-3: 2-(3-t-butyl-2-hydroquine-5-methylphenyl)-5-chloro Benzotriazole 80-1 80-2 A-low 3 80-4 ^0-5 O-6: Tetrakis [methylene 3- (3゜5-di-t-
Butyl-4-hydroxyphenyl)propionate comethane di 3.9-bisC2-(3-(3-tbutyl-4-
hydroxy-5-methylphenyl)propionyloxy) 1.1-dimethylethyl>2.4゜8.10-tetraoxaspiro[5.5]undecane: n-octadenyl 3-(3,5-di-t-butyl -4-Hydroxyphenyl)propionate: 1. 3. 5-) Squirrel
(3,5-di-t-phthyl-4-hydroxybenzyl) in cyanurate + 1.3.5-)lis(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) in cyanurate: Effects of the Invention of 2,6-di-t-butyl-4-methylphenol> The olefin polymer composition of the present invention has excellent stability against photodeterioration, and is also resistant to deterioration such as embrittlement and softening caused by heat. It is stable against heat and has little discoloration due to heat. Therefore, this olefin polymer composition can be effectively used for members that require stability against light and heat, and has great utility value particularly in fields where hue is important.

Claims (2)

[Claims] (1) (A) The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a hydrogen atom or a methyl group) Hindered piperidine-based compound, (B ) A benzoate compound represented by the following general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R_2 represents a t-butyl group or a t-amyl group), and (C) the following: General formula (III) or (IV) ▲Mathematical formulas, chemical formulas, tables, etc.▼(III) (In the formula, R_3 is an alkyl group having 1 to 4 carbon atoms, and A is 1
Represents a valent or polyhydric alcohol residue, where n is an integer corresponding to the number of bonds in the alcohol residue represented by A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(IV) (In the formula, R_4 is An alkyl group having 1 to 4 carbon atoms, R_5
represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) and has improved thermochromic properties and is substantially free of other hindered piperidine compounds. Stabilized olefinic polymer composition. (2) The phenolic antioxidant is tetrakis[methylene 3-(3,5-di-t-butyl-
4-hydroxyphenyl)propionate]methane, 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-
1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, n-octadecyl 3-(3,5-di-t-butyl-4-
hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, or 1,3,5-tris(4-t-butyl-3-hydroxy- 2. The composition of claim 1, which is 2,6-dimethylbenzyl)isocyanurate.