JPS5927936A - Stabilized polyolefin resin composition - Google Patents

Abstract

PURPOSE:To provide a polyolefin resin compsn. having excellent light stability, by blending a hindered piperidine compd. and a phosphite compd. with a polyolefin resin. CONSTITUTION:A hindered piperidine compd. (A) of formula I (wherein R1, is H, methyl; R2 is H, hydroxyl; R3 is a 2-18C alkylene which may form a ring) and a phosphite compd. (B) of formula II (wherein R4, R5, R6 are each H, a 1-9C alkyl with the proviso that there is no case where R5 and R6 are simultaneously branched alkyl groups) and/or formula III (wherein R7 is a 8-18C alkyl, a 6-15C aryl) in a weight ratio of A:B=1:0.2-10 are blended with a polyolefin resin. When the amount of compd. B is less than 0.2 times that of compd. A, no sufficient effect can be obtd., while when the amount of compd. B exceeds 10 times that of compd. A, no additional effect can be obtained and such an amount has only a disadvantage in cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyolefin resin compositions having excellent stability to light.

Polyolefin resins such as polyethylene and polypropylene have excellent physical, chemical, and electrical properties, so they can be made into molded products, pipes, sheets, etc. by various methods such as blow molding, extrusion molding, injection molding, or calendering. It is processed into films and used in many fields.

However, it is well known that such polyolefin resins deteriorate due to the action of light, and their physical properties are significantly reduced, accompanied by phenomena such as softening, embrittlement, and discoloration.

In order to prevent such deterioration due to light, various light stabilizers such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-42-hydroxy-5- methylphenyl)benzotriazole, 2(241'roxy3
-[-Butyl-5-methylphenyl)-5-chloro-benzotriazole, 2(2-hydroxy-3,5-dipentylphenyl)benzotriazole, ethyl-2-cyano-3,3-diphenylacrylate, 2゜4 -di(-butylphenyl-8,5-di(-butyl-4-hydroxybenzoate, C2,2'-thiobis(4-t
-octylphenolado)) -n-butylamine nickel ([), nickel salt of bis(8,5-di[-butyl)-4-hydroxybenzylphosphoric acid) monoethyl ester, 4-benzoyloxy-2, 2, 6,
Although it is well known to incorporate 6-titramethylpiperidine and the like, these light stabilizers are still not fully satisfactory in terms of light resistance.

In the present invention, Mizo et al. have conducted various studies to solve these problems. As a result, the combination of a specific hindered piperidine compound and a phosphite compound in a specific ratio has an extremely superior property that cannot be predicted from conventional combination techniques. The present invention was based on the discovery that a high light resistance can be obtained.

That is, the present invention provides a polyolefin resin having the general formula f
Hindered piperidine compound (11
and at least one phosphite-based compound ([1) selected from the compounds represented by general formulas ([1-1) and (II-2)], (Il: (b) Pr:o,
The present invention provides a stabilized polyolefin resin composition blended at a ratio of 2 to 1O (medium-thickness ratio).

(In the formula, R1 represents a hydrogen atom or a methyl group, k2 represents a hydrogen atom or a hydroxyl group, and k represents an alkylene group that may form a ring having 2 to 8 carbon atoms.) , R4, R,, R6 are hydrogen atoms or have 1 to 1 carbon atoms
9 shows the alkyl group. However, both R5 and R6 are not branched alkyl groups. (In the formula, P-7 represents an alkyl group having 8 to 18 carbon atoms or an aryl group having 6 to 15 carbon atoms.) Used in the present invention Representative examples of hindered piperidine compounds represented by the above general formula (Il) are shown in Table 11, but from the viewpoint of light resistance, substituents R1 and R2 in the general formula are hydrogen atoms. Preferably, the substituent R is an alkylene group having 8 to 18 carbon atoms and which may form a ring.

Table 1 Such hindered piperidine compounds include carboxylic acids represented by the general formula (it and R2 have the same meanings as above) and the general formula % formula % (R3 has the same meaning as F4; +) It can be easily produced by reacting the diol shown by, for example, by a known method as described in U.S. Pat. No. 4,064,102.

Further, the general formula ([-1) and (t
The phosphite compound represented by l-2) is a variety of organic phosphite compounds that are mainly used as an IJ agent for coloring in the polyolephtyne industry. - phosphite, trisnonylphenyl-phosphite.

tri(>s t-butylphanyl) phosphite, tri(2-t-butyl-4-methylphenyl) phosphite, tri(2,4-di-t-butylph,nyl)
Phosphite, Tory (2,4-G-L-7)L-5-
methylphenyl) phosphite dioctyl pentaerythritol 1--rouge phosphite, dinonyl pentaerythritol-ru diphosphite 1-, dilauriha/-pentaerythritol-diphosphite, cimilistyl-
Pentaerythritol diphosphite, disdearyl pentaerythritol diphosphite, di(methylphenyl)-pentaerythritol diphosphite, di(butylphenyl)-pentaerythritol diphosphite, di(octylphenynolypentaerythrid) Examples include rouge phosphite and di(nonylphenyl)-pentaerythritol diphosphite, and these may be used alone or in combination of two or more.

In the present invention, hindered piperidine compounds (I
) and phosphite compound (Ill) is the weight ratio (
I):(II)=l: 0.2~l Opreferably l
:0.5 to 5.

Here, if the compound (b) is less than 0.2 times the weight of the compound (E), it is difficult to obtain the desired effect, and even if the compound (■) exceeds 100 weight times, the effect will not be commensurate with that. This is difficult to obtain and is economically disadvantageous.

The stabilized polyolefin resin composition of the present invention is obtained by blending the above-mentioned compound (I) and (mountain) in the polyolefin resin in the above ratio.
) and (11) is usually 0.01 to 5 parts by weight, preferably o, i Ni, per 100 parts by weight of the polyolefin resin.

As a method for blending the compounds (1) and (b) into the polyolefin resin, conventionally known equipment and operating methods for mixing and blending stabilizers, pigments, fillers, etc. into the polyolefin resin can be applied as they are.

The polyolefin resin composition of the present invention may contain other additives such as antioxidants, light stabilizers, metal deactivators, metal phosphors, nucleating agents, lubricants, antistatic agents, flame retardants, pigments and fillers. It may also contain agents.

In particular, the thermal and oxidative stability can be improved by adding phenolic antioxidants. Examples of these phenolic antioxidants include 2,6-di-1-butyl-4-methylphenol, n-octadecyl-β-(8,5-di-butyl-4-hydroxyphenyl)propionate, 111. 8-Tris(2-methyl-4-hydroxy-5-[-butylphenyl)phthane, l.

8, 5-trimethyl-2
,4,6-) Lis(8,5-di(-butyl-4-hydroxybenzyl)benzene, l,8,
5-) Lis(8,5-di-t-butyl-4-hydroxybenzyl)in cyanurate, 1.8.5-Tris[β
-(8,5-di[-butyl-4-hydroxyphenyl)propyloxyethyl]in cyanurate, 1.
8.5-Tris(2,6-di-methyl-3-hydroxy-4-t-butylbenzyl)in cyanurate, tetrakis-[methylene-8-(8,5-di-t-butylbenzyl)
-Hydroxyphenyl)propionate comethane and the like.

Moreover, a sulfur-based antioxidant can also be added to the polyolefin resin composition of the present invention. Examples of these sulfur-based antioxidants include dilauryl thiodipropionate, simiristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis (β-hexylthiopropionate), and pentaerythritol tetrakis (β-hexylthiopropionate). β-dodecylthiopropionate), pentaerythritol-tetrakis (β-
Examples include octadecylthiopropionate).

Polyolefin resins stabilized by the present invention include low-density polyethylene, medium-high density polyethylene, linear low-density polyethylene, polypropylene, polybutene-
Polyα-olefins such as 1, propylene-ethylene random or block copolymers, ethylene-butene-1
Poly α-olefin copolymers such as random copolymers,
Copolymers of polyα-olefins and hinyl monomers such as maleic anhydride-modified polypropylene and mixtures thereof are exemplified, and among these, polypropylene is particularly effective.

EXAMPLES Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 The following composition was mixed with a mixer for 5 minutes, and then melt-kneaded with a 180°C mixing roll. The obtained compound was formed into a sheet with a thickness of 1#Ij+ using a hot press at 210°C, and the sheet size was 150 x 80 x 1! A # test piece was prepared.

This test piece was connected to a sunshine weather meter (light source:
Carbon arc, black panel temperature: 288±8℃, spray cycle: 120 minutes, 1 hour of spraying = 18 minutes), bend it into a shrimp shape every 60 hours, measure the time until it breaks, and check the light resistance. The gender was evaluated. Table the results.
Shown in 2.

<Formulation> Unstabilized polypropylene 100 parts by weight Calcium stearate 001 2.6-di[-butyl-4-methylphenol 0.2 Its fine compounds are listed in Table 2. Table 2
In the compound at compound points I-8, I-6, l
-10, I-11, l-12 and 1-18 are Table-11
(Hindered piperidi〉'-based compounds are shown, and the others are as follows.

1-21 4-benzoyloxy-2゜2.6.6-titramethylpiperidine ■-22 Kimasorb 944 (Kimosa product) (hindered piperidine light stabilizer) ■-28 Fostabin I'M N-20 (Hoechst Company product) (hindered piperidine light stabilizer) U-t Triphenyl-phosphite [1-2) Lisnonylphenyl-phosphite low 8 Tri(2-t-butyl-4-methylphenyl) phosphite 1-4 tri-(2,4-di-t
-butylphenyl) phosphite -5 dinonyl-pentaerythritol-diphosphite [1-6 distearyl-pentaerythritol-diphosphite [1-7 diphenyl-pentaerythritol-diphosphite] 8 di(nonylphenyl)-pentaerythritol phosphite

Claims (1)

[Scope of Claims] (11) The polyolefin resin contains at least one compound selected from a hindered piperidine compound (I) represented by the following general formula (I) and a compound represented by the following general formulas (Row 1) and (Roh 2). One type of phosphite compound ([I)
A stabilized polyolefin resin composition formed by blending (I): ([Il=l:0.2 to 10 (weight ratio). (In the formula, R1 is a hydrogen atom or a methyl group, R2 represents a hydrogen atom or a hydroxyl group, and R3 represents an alkylene group that may form a ring having 2 to 18 carbon atoms. represents an alkyl group.However, k, and R
Neither 6 is a branched alkyl group. ) (In the formula, k represents an alkyl group having 8 to 18 carbon atoms or an aryl group having 6 to 1 lb carbon atoms.) (2) The stabilization according to claim 1, wherein the polyolefin resin is polypropylene. Polyolefin resin composition. (8) In the hindered piperidine compound represented by the general formula (Il), the substituents R and R2 are H,
The stabilized polyolefin resin composition according to claims 1 and 2, wherein R1 is. (4) The polyolefin resin composition according to claims 1 to 3, wherein the phosphite compound is tri(2,4-di-butylphenyl)phosphite. The polyolefin resin composition according to claims 1 to 8, which is stearyl-pentaerythritol-diphosphite.