JPH03217441A - Stabilized polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent thermal stability and transparency, resistant to deterioration by radiation and having high processing stability by adding a specific cyclic phosphite compound and a specific nucleation agent to a base resin. CONSTITUTION:The objective composition can be produced by compounding 100 pts.wt. of a polyolefin resin with (A) 0.001-10 pts.wt. of a compound of formula (R1 is tert-butyl or tert-amyl; R2 is 1-9C alkyl; R3 is H or 1-4C alkyl; R4 is 1-30C alkyl) and (B) 0.01-5 pts.wt. of at least one compound selected from the group consisting of aromatic phosphoric acid ester metal salt compound, dibenzylidene sorbitol compound and aromatic carboxylic acid aluminum salt. The oxidation stability of the composition can be further improved by incorporating a phenolic or sulfur-based antioxidant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stabilized polyolefin resin composition. The present invention relates to a polyolefin resin composition that has excellent thermal stability and transparency and is less likely to deteriorate due to radiation irradiation.

[Conventional technology and its problems]

It is known that polyolefin resins such as polyethylene and polypropylene deteriorate due to the action of heat, light, and irradiation, becoming colored or having reduced mechanical strength, making them unable to withstand long-term use.

In order to prevent such deterioration of polyolefin resin,
Up to now, many additives have been used alone or in various combinations. Among these additives, phosphite compounds are known to have a relatively large effect of improving heat resistance and deterioration due to radiation irradiation, and suppressing coloration. As these phosphite compounds, triorganophosphite compounds such as trialkyl phosphite, triaryl phosphite, and alkyl-aryl phosphite, or acidophosphite compounds in which one of these organic groups is a hydroxyl group are generally used. It is being However, these phosphite compounds not only have insufficient stabilizing effect but also have the disadvantage of poor water resistance.
This was not satisfactory in practical terms.

Among these organic phosphite compounds, cyclic phosphite compounds of bisphenols have relatively good stabilizing effect and water resistance; for example, as disclosed in US Pat. No. 32976
Although 2,2゛methylenebis(dialkylphenyl)phosphite compounds have been proposed in Publication No. 31, the stabilizing effect of this compound is still insufficient and is not satisfactory for practical use.

Therefore, as an improved compound of the above-mentioned phosphite compounds, a cyclic phosphite compound of orthobiphenol was proposed in JP-A-54-100391, and in JP-A-57-114,595 and JP-A-58-1035.
Publication No. 37 proposes cyclic polyphosphite compounds of 2,2°-bisphenols, but even when these compounds are used, the effects are still not satisfactory and the manufacturing method is complicated. At the same time, it is not practical.

Furthermore, a compound represented by the general formula (I) and β-(
Method of using ester of 3,5-dialkyl-4-hydroxydiphenyl) propionic acid in combination (JP-A-1-2547)
69) has been proposed, but its effects are still not satisfactory.

In addition, in order to improve the transparency, rigidity, etc. of polyolefin resins, there is also a method of blending 3.2.4-di(alkylbenzylidene) sorbitol, etc. (Japanese Unexamined Patent Publication No. 54-691
．． 55), method of using 1,3,2,4-di(alkylbenzylidene)sorbitol etc. in combination with a metal salt of carboxylic acid (JP-A-58104933), 1,3,2,4-di(
A method of using alkylbenzylidene) sorbitol in combination with a phenolic antioxidant or a phosphorous acid ester antioxidant and a metal salt of a carboxylic acid (JP-A-6:3-
69853) etc. have been proposed.

Also, a method of using I-3,2-4-di(alkylhenzylidene) sorbitol, 1-lis(alkylphenyl) phosphite, and a hindered amine light stabilizer in combination as a radiation-stable polyolefin resin composition. (JP 60-99147, JP 60-112843, JP 62-235344), method of using aromatic phosphate ester metal salt compound and hindered phenol antioxidant etc. 61-53344) has been proposed.

However, the effects of the conventionally known combinations as described above are not practically satisfactory; for example, stability during processing, long-term heat resistance, stability against radiation exposure, etc. are insufficient.

[Means for Solving the Problems] In view of the current situation, the present inventors have conducted extensive studies in order to find a combination that can significantly improve the processing stability, heat resistance, stability against radiation irradiation, etc. of polyolefin resins. As a result, at least one compound selected from a cyclic alkyl phosphite compound of 2,2'-alkylidene bisphenol, an aromatic phosphate metal salt compound, a dibenzylidene sorbitol compound, and an aluminum salt of an aromatic carboxylic acid. The present invention was completed by discovering that the above object can be achieved by adding them in combination.

That is, the present invention uses 0.001 to 10 parts by weight of a compound represented by the following general formula (I), an aromatic phosphate ester metal salt compound, a dibenzylidene sorbitol compound, and 100 parts by weight of a synthetic resin. The present invention provides a stabilized synthetic resin composition containing 0.01 to 5 parts by weight of at least one type of aluminum salt of an aromatic carboxylic acid.

R1 (wherein R1 represents a tertiary butyl group or tertiary amyl group, R2 represents an alkyl group having 1 to 9 carbon atoms, R3 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
R4 represents an alkyl group having 1 to 30 carbon atoms. ) In the above general formula (I), the alkyl group having 1 to 9 carbon atoms represented by R2 includes methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl,
Examples include isobutyl, amyl, tertiary amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, tertiary octyl, nonyl, tertiary nonyl, and the alkyl group having 1 to 4 carbon atoms represented by R3. , methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, and the alkyl group having 1 to 30 carbon atoms represented by R4 is methyl,
Ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, tertiary amyl, hexyl, hebutyl, octyl, isooctyl, 2-ethylhexyl, tert-octyl, nonyl, tert-nonyl, decyl, isodecyl , dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, triacontyl, and the like.

Next, representative examples of the phosphite compound represented by the above general formula (I) used in the present invention will be shown.

t-C4II q t-C4119 L C . I+. tC. I19tC. II 9 t C. I1. tC. I+, t-Callv tC. I+. ? -Call ■ t-C411q t-C411q M C a It q t C . I1 9 The amount of these phosphite compounds added is 100% of the synthetic resin.
It is 0.001 to 10 parts by weight, more preferably 0.01 to 3 parts by weight.

The compound represented by the above general formula (I) used in the present invention can be prepared by, for example, reacting phosphorus trichloride with 2,2'-alkylidene bisphenol to obtain R in the above general formula (I).
4101 Produces a compound in which 1 is a chlorine atom, and this and R,
It can be easily produced by reacting with the alcohol represented by -011.

The aromatic phosphate metal salt compound used in the present invention is represented by the following general formula (II) or (I[l).

(In the formula, R5 and R. are each a hydrogen atom or a carbon number of 1 to 8
represents an alkyl group, M represents a Group Ia or Group II metal, a represents the valence of M, and A represents an alkylidene group. ) In the above general formulas (II) and (III), R5, R6
Examples of the alkyl group having 1 to 8 carbon atoms represented by include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, tertiary amyl, hexyl, heptyl, octyl, isooctyl. , 2-
Examples of the alkylidene group represented by A include ethylhexyl and tertiary octyl, and examples of the alkylidene group represented by A include methylidene group, ethylidene group, and butylidene group.

In addition, as the metal of group 1a or group II represented by M,
Examples include lithium, sodium, potassium, magnesium, and calcium.

Specific examples of general formulas (It) and (III) include, for example, sodium salt of bis(4-sec-butylphenyl) phosphoric acid;
Potassium and lithium salts, 2,2'methylene bis(
Sodium salts, potassium salts and lithium salts of 4,6-di-tert-butylphenyl) phosphoric acid, sodium salts and lithium salts of 2.2"-ethylidene-bis(4.6-di-tert-butylphenyl) phosphoric acid, etc. but not limited to these. Particularly preferred are the sodium salt of bis(4-sec-butylphenyl) phosphate, 2,2"-
The sodium salt of methylene bis(4,6-di-tert-butylphenyl) phosphate is used.

The sorbitol compound used in the present invention is represented by the following general formula (rV).

II CO I+? al■0[1 (wherein, R is hydrogen, halogen atom, carbon number 1-8
These groups are selected from alkyl groups, alkoxy groups, and hydroxyl groups, and may be different in the same compound. ) In the above general formula (IV), the alkyl group having 1 to 8 carbon atoms represented by R is methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, Examples include amyl, tertiary amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, tertiary octyl, and the like. In addition, when it is an alkoxy group, it is preferable that the number of carbon atoms in the argyl moiety is 1 to 8, and specific examples include methoxy, ethoxy, propoxy, butoxy, hexyloxy, octyloxy groups, etc., and as a halogen atom, Examples include chlorine and bromine atoms.

Specific examples include dibenzylidene sorbitol,
Bis(o-, m-, or p-methylbenzylidene) sorbitol, bis(p-tertiary butylhenzylidene) sorbitol, bis(om or p-chlorobenzylidene) sorbitol, bis(o-, m-, or p-ethylbenzylidene) sorbitol, bis(o-, m-, or p-
hydroxybenzylidene) sorbitol, bis(0m-
, or p-methyl-xybenzylidene) sorbyl-1.

Examples of the aluminum salts of aromatic carboxylic acids include aluminum salts of aromatic monocarboxylic acids such as benzoic acid, methoxybenzoic acid, and p-t-butylbenzoic acid, with p-t-butylbenzoic acid being particularly preferred. The aluminum salt of the acid is used.

Moreover, these may be normal salts or basic salts.

The amount of at least one compound selected from the group consisting of aromatic phosphate metal salt compounds, dibenzylidene sorbitol compounds, and aluminum salts of aromatic carboxylic acids is 0.00 parts by weight per 100 parts by weight of the synthetic resin.
01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight.

At least one compound selected from the group consisting of the general formula (I) of the present invention, aromatic phosphate metal salt compounds, dibenzylidene sorbitol compounds, and aluminum salts of aromatic carboxylic acids is added to the synthetic resin. The method is not particularly limited, and commonly used methods can be applied as they are.

For example, a method of dry blending synthetic resin powder or pellets and additive powder, a method of spraying a solution or melt of the additive onto synthetic resin powder or pellets, etc. can be used.

Examples of the polyolefin resin stabilized by the present invention include homopolymers and copolymers of α-olefins such as polyethylene, polypropylene, polybutene, and poly-3-methylbutene.

By adding a phenolic antioxidant to the composition of the present invention, the oxidative stability can be further improved. Examples of this phenolic antioxidant include 2,6
-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl (
3.5-ditert-butyl-4-hydroxybenzyl)phosphone l., 4.4'-thiobis(6-tert-butyl-m-cresol), 2-octylthio-4,6-di(
3゜5''-dihydroxyphenoxy)-S-triazine, 2.2'-methylenebis(4-methyl-6-sec-butylphenol), 2.2゜-methylenebis(4-ethyl-6-sec-butylphenol), Bis [3,3-bis (
4゜-Hydroxy-3-tert-butylphenyl)butyric acid] glycol ester, 4.4"-butylidene bis(6-tert-butylphenyl), 2,2"-ethylidene bis(4.6-di-tert-butylphenol) )2
．． 2"-ethylidene bis(4-sec-butyl-6-tert-butylphenol), 2-tert-butyl-4-methyl-6-(2
゜ -acryloyloxy-3゜tert-butyl-5"1-methylbenzyl)phenol, bis[2-tert-butyl-4
-Methyl-6(2'-hydroxy-3'-tertiary-butyl-5"methylbenzyl)phenyl]terephthalate, l
．． 1.3-Tris(2"-methyl-4"-hydroxy-5"-tert-butylphenyl)butane, 1,3,5-
Tris(2',6'-dimethyl-3'-hydroxy-4'-tert-butylbenzyl) isocyanurate, 1,
3.5-}lith(3',5'-di-tert-butyl-4'
-hydroxybenzyl)isocyanurate, 1,3.5
monotris(3'5'-ditert-butyl-4'hydroxybenzyl)-2.4.6-trimethylbenzene, octadecyl-3-(3,5-ditert-butyl-4-hydroxyphenyl)probionate , tetrakis[methylene-3-(3.5-di-tert-butyl-4-hydroxyphenyl)propione 1.)methane, 2,2-thiodiethylenebis(3-(3.5-di-tert-butyl-4-hydroxyphenyl) -hydroxyphenyl)propionate], 3.9-bis[1
,1-dimethyl-2-[β-(3-sec-butyl-4-hydro-tocy-5-methylphenyl)propionyloxy]ethyl)-2.4,8.10-tetraoxasbiro(
5,5) undecane and the like.

It is also possible to further add a sulfur-based antioxidant to the composition of the present invention to improve its oxidative stability.

By adding a light stabilizer such as an ultraviolet absorber or a Hinder 1/amine compound to the composition of the present invention, its light resistance can be further improved.

Examples of the light stabilizer include 2,4-dihydroxyhenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5.5゜-methylenebis(2-hydroxy -4
2-hydroxybenzophenones such as 2
-(2'-hydroxy-3',5'-di-tert-butylphenyl)pen/' }lyazole, 2- (2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chloropenzo Triazole, 2-(2hydroxy-3゜1-tert-butyl-=-5゛-methylphenyl)-5-chloropenzotriazole, 2(2゛-hydroxy-3'.5'
-dicumylphenyl)penzotriazole, 2.2
2-(2'-Hydroxyphenyl)penzotriazoles such as -methylenebis(4-tert-octyl-6-penzotriazolyl)phenol; phenyl salicylate, resorcinol monobenzoate, 2.4- Penzoates such as di-tert-butylphenyl-3゜,5゜-di-sec-butyl-4゜-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; 2-ethyl 2'-monoethoxyoxani Lido, 2
-Substituted oxanilides such as ethoxy-4'dodecyloxanilide; ethyl-α-cyanoβ. to β-diphenyl acrylate-1, methyl-2-cyano-3-methyl-3 (
Cyanoacrylates such as p-m-1-xyphenyl) acrylate; 2,2,6.6-tetramethyl-4-biperidyl stearate, 1,2.2,6.6-pentamethyl-4-biveridyl Steerley 1, 2, 2, 6, 6-
Tetra-lamythyl-4-biveridylhenzoe-1., bis(2,2,6.6-tetramethyl-4-piveridyl)sehake-1., bis(I,2,2,6.6-pentamethyl- 4-pibenozyl) sebacate, tetrakis (2,2,
6.6-te! -ramethyl-4-piveridyl)butanetetracarpoxylate-1.,te1.rakis(].,2,2,
6.6-pentamethyl-4-piveridyl)-1,2,3
．． 4-Butanetetracanoleboxylate, bis(I,2
．． 2,6.6-pencmethyl-4-piperidyl) di(
tridecyl)-1,2,3,4-butanetetracarpoxylate, bis(I,2,2,6,6-pentamethyl-4
-piperidyl)2-butyl-2-(3,5-ditert-butyl-4-hydroxybenzyl)malonate, 1-(2-
Hydroxyethyl)-2.2,6.6-te1-lamythyl-4-piveridinol/diethyl succinate polycondensate, 1
．． 6-bis(2,2,6.6-teI-ramethyl-4-biveridylamino)hexane/dibromoethane polycondensate,
1,6-bis(2,2,6.6-te1-ramethyl-4-
biperidylamino)hexane/2,4-dichloro-6-tertiary octylamino-s-triazine polycondensate, 1.6
Examples include hindered amine compounds such as -bis(22,6.6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-morpholinose-triazine polycondensate.

In addition, if necessary, the composition of the present invention may contain heavy metal deactivators, metal soaps, hydrotalcites, pigments, fillers, organotin compounds, plasticizers, epoxy compounds, blowing agents,
Antistatic agents, flame retardants, lubricants, processing aids, etc. can be included.

〔Example] Next, the present invention will be specifically explained with reference to Examples.

However, the present invention is not limited to these examples.

Example 1 Peresoto was prepared by extrusion processing at 250°C using the following formulation. Next, injection molding was performed at 250°C.
A test piece having a thickness of lIII1 was prepared.

Using this test piece, a thermal stability test was conducted in an oven at 160°C. In addition, in order to examine light resistance, this test piece was irradiated with a fluorescent lamp for 72 hours, and its yellowness was measured using a Hunter colorimeter.

Stiffness was measured based on ASTM D-747-63.

Furthermore, in order to examine the processing stability, the melt index (Ml and Ml(5): g/10 min, 230
℃, load 2160 g) was measured. The results are shown in Table-1.

<Formulation> Polypropylene tetrakis [methylene-3-(3.5-t-butyl-4-hydroxyphenyl)probynate] Calcium methane stearate 2.2'-methylene-bis(4I6-t-butyl-4-hydroxyphenyl) phosphate Sodium sample Compound 00 parts by weight 0.1 0. 05 Example 2 A test piece was prepared using the following formulation in the same manner as in Example 1, and tested for thermal stability, yellowness, and melt index in the same manner as in Example 1.

Haze value is ASTM D-1
Measured based on 00363. The results are shown in Table-2.

Blend> Polypropylene tetrakis [Methylene-3-(3.5-butylene-4-hydroxyphenyl) propylate] Calcium methane stearate L3,2,4-(baramethylbensorithene) sorbitol sample compound 00 Parts by Weight Example 3 Using the following formulation, test pieces were prepared in the same manner as in Example 1, and the same tests as in Example 1 were conducted. The results are shown in Table-3.

Blend> Polypropylene 100 parts by weight Tetrakis [Methylene-3-(3.5-sheets
methane
0.1 Calcium stearate
0.051-3 compound 0.
1 sample compound 0. 1
Example 4 100 parts by weight of unstabilized linear low density polyethylene, 0.02 parts by weight of octadecyl-3-(3.5-L-dibutyl-4-hydroxydi)propionate, 2,2°-methylene bis(4.6-t) -butylphenyl) sodium phosphate 0. llil part and 0.02 part by weight of the sample compound were placed in a Brabender plastograph, and heated at 230°CX80r.
The mixture was mixed for 60 minutes under pm conditions, and changes in yellowness and carbonyl index (CI) were observed.

The results are shown in Table 4.

Table 5 Example 5 Pellets were prepared by extrusion processing at 250°C using the following formulation. Next, injection molding was performed at 250° C. to create a test piece with a thickness of 1 mm. Cobalt 6 was added to this test piece.
After irradiation with 2.5 Megaland of T-rays from a zero source, the sample was left at 80°C for two weeks. The impact resistance, transparency, and color difference before and after irradiation were investigated.

In addition, impact resistance is Izod impact value (Kg-crs/cI
ll2) and the color difference was measured using a Hunter colorimeter.

If the color difference is 1.5 or less, almost no discoloration is observed;
~3.0 indicates slight discoloration, and 3.0 or more indicates a large degree of discoloration.

The results are shown in Table 5 below.

Blend> Polypropylene 100 parts by weight Tetrakis [Methylene-3-(3.5-di-t-butyl-4
methane
0. 1 Calcium stearate
0.051-3 compound
0. 1 sample compound 0.
1 [Effect of the invention] As described above, the above-mentioned 2,2゜-alkylidene bisphenol to cyclic alkyl phosphite 1 compound, aromatic phosphate ester metal salt compound, dibenzylidene sorbitol compound, aromatic carboxylic acid aluminum Processing stability is improved by adding at least one type of salt.
A polyolefin resin composition having excellent heat resistance and stability against radiation irradiation can be obtained.

Claims (1)

[Scope of Claims] Based on 100 parts by weight of synthetic resin, 0.001 to 10 parts by weight of a compound represented by the following general formula (I), an aromatic phosphate ester metal salt compound, a dibenzylidene sorbitol compound, 0.01 of at least one compound selected from the group consisting of aluminum salts of aromatic carboxylic acids.
A stabilized polyolefin resin composition containing ~5 parts by weight. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a tertiary butyl group or tertiary amyl group, R_2 represents an alkyl group having 1 to 9 carbon atoms, and R
_3 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R_4 represents an alkyl group having 1 to 30 carbon atoms. )