JPH0260686B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a synthetic resin composition, and more specifically, by adding a specific diarylpentaerythritol diphosphite compound and a phenolic antioxidant, the composition is stable for a long period of time against deterioration due to the effects of heat and light. polyethylene,
The present invention relates to a synthetic resin composition selected from polybutene and ethylene-vinyl acetate copolymer. It is known that synthetic resins such as polyethylene, polybutene, and ethylene-vinyl acetate copolymers deteriorate due to the effects of heat and light, becoming discolored and having reduced mechanical strength, making them unusable. In order to prevent such deterioration of synthetic resins, many additives have been used singly or in various combinations. Among these additives, phosphite-based compounds have been widely used because they have the advantage of imparting heat resistance and light resistance to synthetic resins and suppressing discoloration of synthetic resins. Among these phosphite compounds, trisnonylphenyl phosphite, diphenylisodecyl phosphite,
Distearyl pentaerythritol diphosphite and the like have relatively large effects and are prized. However, these phosphite compounds have particularly poor water resistance and are known to easily undergo hydrolysis when left in the air, and they may also cause white spots when added to synthetic resins during use. ,
There has been a need to improve the water resistance of these phosphite compounds since they have the disadvantage of being easily extracted by water. Furthermore, it has been desired that the effects of these phosphite compounds be further improved. In order to improve the water resistance of phosphite compounds, the addition of a small amount of isopropanolamine or the like to the phosphite compound has been done, but the effect was only temporary. In addition, tris(orthoalkylated phenyl) phosphite and the like have been proposed as phosphite compounds with good water resistance, but although these compounds improve water resistance to some extent, they are not effective in terms of heat resistance, light resistance, etc. It was small and unsatisfactory in practical terms. In view of the current situation, the inventors of the present invention have made intensive studies and found that the phosphite compound represented by the following general formula () has extremely excellent water resistance. The present inventors have discovered that when added to a synthetic resin selected from ethylene and vinyl acetate copolymers, a resin composition with excellent heat resistance and light resistance can be obtained, and the present invention has been achieved. (In the above formula, R ₁ represents a tert-butyl group, R ₂ represents a methyl group or a tert-butyl group, and R ₃ represents a hydrogen atom or a methyl group.) In the above formula () used in the present invention, Representative examples of the expressed phosphite compounds are shown in Table 1 below. In the formula, t-Bu represents a tert-butyl group.

[Table] The above phosphite compound of the present invention has the formula [In the formula, R ₁ , R ₂ and R ₃ have the same meaning as in formula (). ] It can be easily synthesized by reacting the phenol represented by the formula () with pentaerythritol and phosphorus trichloride, or by reacting the phenol represented by the above formula () with pentaerythritol and triphenyl phosphite. . Next, a specific synthesis example of the compound of the present invention will be shown. Synthesis example (synthesis of No. 2 compound in Table 1) 31.0 g (0.1 mol) of triphenyl phosphite, 6.8 g (0.05 mol) of pentaerythritol,
Take 21.6g (0.105 mol) of 2,4-di-tert-butylphenol and 0.06g of potassium carbonate and react at 150℃ for 3 hours under a nitrogen stream, then react at a maximum of 160℃/3mm.
Dephenolization was performed under Hg conditions (phenol removal rate 98%). After cooling, a colorless glassy solid was obtained. The present invention is a synthetic resin selected from polyethylene, polybutene, and ethylene-vinyl acetate copolymer by adding a phosphite compound represented by the above formula () together with a phenolic antioxidant to the synthetic resin. It stabilizes, and the amount added is per 100 parts by weight of synthetic resin.
The amount is 0.001 to 10 parts by weight, particularly preferably 0.01 to 5 parts by weight. The synthetic resins stabilized by the present invention include:
The aforementioned polyethylene, polybutene, ethylene
Examples include vinyl acetate copolymers, but also include crosslinked synthetic resins such as crosslinked polyethylene crosslinked with peroxide or radiation, and foamed synthetic resins such as foamed polyethylene foamed with a foaming agent. . The amount of the phenolic antioxidant used in the present invention is based on 100 parts by weight of the synthetic resin.
The amount is 0.01 to 5 parts by weight, and the phenolic antioxidant acts additively with the phosphite compound represented by the above formula () to improve the oxidation stability of the synthetic resin. Examples of the phenolic antioxidant used in the present invention include 2,6-di-tert-butyl-p-cresol, stearyl (3,5-dimethyl-4-hydroxybenzyl) thioglycolate, and stearyl-β-(4-hydroxybenzyl) thioglycolate. -Hydroxy-3,5-di-tert-butylphenyl)propionate, distearyl (4
-Hydroxy-3-methyl-5-tert-butyl)benzylmalonate, 2,2'-methylenebis(4-
Methyl-6-tert-butylphenol), 4,4'-
Methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], Bis[3,3
-bis(4-hydroxy-3-tert-butylphenyl)butyric acid] glycol ester,
4,4'-Butyldenbis(6-tert-butyl-m-
cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)2 , 4,6-trimethylbenzene, tetrakis[methylene-3-
(3,5-ditert-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-tris(3,5-ditert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5 -Tris[(3,5-ditert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, 2-octylthio-4,6-di(4-hydroxy-3,5-ditert-butyl)phenoxy -1,
Examples include 3,5-triazine and 4,4'-thiobis(6-tert-butyl-m-cresol). By adding a light stabilizer to the composition of the invention, its light resistance can be further improved. Examples of these light stabilizers include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone,
Hydroxybenzophenones such as 2,2-dihydroxy-4-methoxybenzophenone and 2,4-dihydroxybenzophenone, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-
5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5
-benzotriazoles such as chlorobenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole; Benzoates such as enyl salicylate, pt-butylphenyl salicylate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, 2,
2'-thiobis(4-t-octylphenol)Ni
Press, [2,2'-thiobis(4-t-octylphenolate)]-n-butylamine Ni salt, (3,5-
Nickel compounds such as di-t-butyl-4-hydroxybenzyl)phosphonic acid monoethyl ester Ni salt, substituted acrylonitriles, and 2,2,
6,6-tetramethyl-4-piperidinylbenzoate, bis(2,2,6,6-tetramethyl-
4-biperidinyl) sebacate, tris(2,
2,6,6-tetramethyl-4-piperidinyl)
Nitrilotriacetate, tetrakis (2,2,
Examples include piperidine compounds such as 6,6-tetramethyl-4-piperidinyl)butanetetracarboxylate. The composition of the present invention can also contain a sulfur-based antioxidant. Examples of sulfur-based antioxidants include distearylthiopropineate, dilaurylthiodipropionate, pentaerythritol tetra (β-laurylthiopropionate), 1,3,
Examples include 5-tris-β-stearylthiopropionyloxyethyl isocyanurate. Light resistance and heat resistance can be further improved by adding other phosphite compounds to the composition of the present invention, if necessary. Examples of the phosphite-based compounds include trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, triphenyl phosphite, tris(butoxyethyl) phosphite, tris(nonylphenyl) phosphite, and distearyl phosphite. Pentaerythritol diphosphite, tetra(tridisyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite, tetra( _C12 - _C15 mixed alkyl) -4,4'isopropylidene diphenyl diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert-butylphenol) diphosphite, tris(3,5-di-tert-butyl-4 -hydroxyphenyl) phosphite, tris(mono-dimixed nonylphenyl) phosphite, hydrogenated-4,4'-isopropylidene diphenol polyphosphite, bis(octylphenyl) bis[4,4'-butyldenbis(3 −
Methyl-6-tert-butylphenol)]・1,6-
Hexanediol diphosphite, phenyl
4,4'-Isopropylidene diphenol pentaerythritol diphosphite, Tris[4,
4'-isopropylidene bis(2-tert-butylphenol)] phosphite, phenyl diisodecyl phosphite, di(nonylphenyl) pentaerythritol diphosphite, tris(1,3-
Examples include distearoyloxyisopropyl) phosphite, 4,4' isopropylidene bis(2-tert-butylphenol) di(nonylphenyl) phosphite, and the like. Others, as necessary.
Heavy metal deactivators, nucleating agents, metal soaps, organotin compounds, plasticizers, epoxy compounds, pigments, fillers,
Blowing agents, antistatic agents, flame retardants, lubricants, processing aids, and the like can be included. Next, the present invention will be specifically explained using examples. However, the present invention is not limited to these examples. Example 1 The following formulation was kneaded on a mixing roll for 5 minutes at a temperature of 150°C, then at a temperature of 150°C, 180Kg/cm ²
Compression molding was performed for 5 minutes under the following conditions to create a sheet with a thickness of 1.2 mm. This sheet was used as a 10 x 20 mm test piece and a gear open heating deterioration test was conducted on aluminum foil in air at a temperature of 150°C. In addition,
Ten specimens were used for the same sample, and the time when five or more specimens became discolored or waxy was defined as the deterioration time. The results are shown in Table-2. <Formulation> Polyethylene resin (HIZEX 5100E, manufactured by Mitsui Oil Co., Ltd.) 100 parts by weight Dilauryl thiodipropionate 0.3 Stearyl-3.5-di-tert-butyl-4-hydroxyphenylpropionate 0.1 Phosphite compound (Table 2) 0.05

[Table] Example 2 In order to examine the effect of the stabilizer of the present invention on polybutene resin, the following formulation was kneaded with a mixing roll at a temperature of 140°C for 5 minutes, then kneaded at a temperature of 160°C,
Compression molding was performed for 5 minutes at a pressure of 200 kg/cm ² to produce a sheet with a thickness of 1 mm. The obtained sheets were cut into pieces of 40 x 150 mm and hung in separate cylinders, and the time at which oxidative deterioration started was measured. The results are shown in Table-3. The inside of the cylinder is in an oxygen atmosphere with a pressure of 1 atm.
The temperature was set at 160°C. In addition, the start time of oxidative deterioration was determined by reading the time point at which the pressure inside the cylinder began to decrease rapidly using a recorder. <Formulation> Unstabilized polybutene resin 100 parts by weight Calcium stearate 1.0 Distearyl thiodipropionate 0.3 Tris (3.5-di-tert-butyl-4-hydroxybenzyl) isocyanurate 0.2 Phosphite compound (Table 3) 0.2

[Table] Example 3 In order to examine the effect of the compound according to the present invention on ethylene-vinyl acetate copolymer, a sample was prepared with the following formulation, and the thermal stability and initial coloring property were measured in a gear oven at 175°C. was measured. Regarding initial coloration, yellowness was determined using a Hunter colorimeter. The results are shown in Table 4. <Formulation> Ethylene-vinyl acetate copolymer resin 100 parts by weight Montanic acid lubricant 0.3 1,1,3-tris(2'.methyl.4'-hydroxy-5'-tert-butylphenyl)butane
0.05 Phosphite compound (Table-4) 0.1

【table】

[Table] Example 4 In order to check the water resistance of the phosphite compound used in the present invention, 3 g of the phosphite compound was
24 in a desiccator filled with water.
I left it for a while. The trivalent phosphorus content of this phosphite was measured. Since the trivalent phosphorus of phosphite changes to pentavalent phosphorus through hydrolysis, it is thought that the rate of decrease of trivalent phosphorus matches the hydrolysis rate of phosphite. The results are shown in Table-5.

【table】

Claims (1)

[Scope of Claims] 1. A synthetic resin selected from polyethylene, polybutene, and ethylene-vinyl acetate copolymer containing at least one compound represented by the following general formula () and at least one phenolic antioxidant. A synthetic resin composition made of (In the above formula, R ₁ represents a tert-butyl group, R ₂ represents a methyl group or a tert-butyl group, and R ₃ represents a hydrogen atom or a methyl group.)