JPH0234977B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a synthetic resin composition having excellent stability against heat and oxidation. Synthetic resins have excellent physical, chemical, and electrical properties, so they can be processed into molded products, pipes, sheets, films, etc. by various methods such as blow molding, extrusion molding, injection molding, and calendering. , used in many fields. It is well known that when such synthetic resins are used alone, they deteriorate due to the effects of heat and oxygen during processing or use, and their physical properties are significantly reduced, accompanied by phenomena such as softening, embrittlement, and discoloration. It is being In order to prevent this phenomenon, various phenolic, phosphorus,
Sulfur-based antioxidants and other antioxidants are used alone or in combination during the production and processing of synthetic resins. For example, 2,6-di-t-butyl-4-methylphenol, n-octadecyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, pentaerythritol-tetrakis [β -(3,5-di-t-butyl-4-hydroxyphenyl)propionate], tris(2,6-
Di-methyl-3-hydroxy-4-t-butylbenzyl)isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene Antioxidants such as and combination technology of these antioxidants with dilaurylthiopropionate, dimyristylthiodipropionate, or distearylthiodipropionate, combinations as shown in Japanese Patent Publication No. 14703/1983 Technology and Special Public Service 1977-
Antioxidant or combination techniques such as those shown in Japanese Patent No. 16381 are known. However, these techniques are still not fully satisfactory in terms of thermal and oxidative stability, compatibility and evaporability. As a result of various studies in order to solve these problems, the present inventors have found that by blending a specific phenol compound and a specific sulfur compound into a synthetic resin, we can overcome the conventional combination technology of antioxidants. It has been discovered that a surprising and unexpected synergistic effect can be obtained, and what is more surprising is that it has extremely superior thermal and oxidative stability compared to the conventional technology, and has excellent compatibility with resins, that is, bleedability and whitening phenomenon. The present inventors have also discovered that the above methods can be significantly improved, leading to the present invention. That is, the present invention provides a synthetic resin with the following formula () compound and () formula compound, ():()=
This is a stabilized synthetic resin composition characterized by being blended at a ratio of 1:1 to 10 (weight ratio). (In the formula, R′ is a group and R″ and R are the same as R′ or a group represents. Here, R ₁ represents a branched alkyl group having 4 to 9 carbon atoms, A represents an alkylene group having 1 to 4 carbon atoms, and R ₂ represents an alkyl group having 4 or more carbon atoms. ) (In the formula, X represents an alkyl group having 4 to 20 carbon atoms, and n represents an integer of 1 to 4.) In the compound of the formula () used in the present invention, the substituent R ₁ is a tertiary alkyl group branched at the α position, such as a t-butyl group,
Preferred are t-amyl group, t-octyl group, α-methylcyclohexyl group, and A has 1 carbon number.
~3 alkylene groups are preferred. Furthermore, in the compound of formula (), the substituent X is n
are two or more, they may be the same or different in one compound, but it is more advantageous for them to be the same in terms of synthesis. n is preferably 3 to 4, particularly preferably 4, in terms of its performance as an antioxidant. Next, Table 1 shows representative examples of compounds of formula () used in the present invention. Incidentally, the substituents R', R'' and R correspond to the above general formula.

[Table] Table 2 also shows representative examples of compounds of formula () used in the present invention.

[Table] Compounds of formula () of the present invention are, for example,
Although it is conceptually included in the compound described in Publication No. 16381, it is not specifically described at all, and the present inventors have developed a compound of formula (), that is, a steric hindrance at the 2-position in the phenol nucleus. A compound characterized by having a methyl group at the 4-position and a carboxyl group bonded to an alkylene group having 1 to 4 carbon atoms at the 5-position is particularly excellent in stabilizing synthetic resins. He found out. Surprisingly, by using a combination of compounds of formula () and (),
It has been found that a synergistic effect which is significantly superior to that achieved by combinations with prior art techniques such as dilaurylthiodipropionate, dimyristylthiodipropionate or distearylthiodipropionate has been found. The compound of the formula () used in the present invention has the general formula () (In the formula, R ₃ and R ₄ are the same or different groups -CH ₂ CH ₂ OH or represents. Here, R ₂ has the same meaning as above. ) Hydroxyethyl isocyanurate represented by the general formula () (In the formula, R ₁ and A have the same meanings as above.) It can be produced by reacting the compound represented by the following formula or its lower alkyl ester or its acid chloride by a known method. In the synthetic resin composition of the present invention, the total amount of the compound of formula () and the compound of formula () added is usually 0.001 to 5 parts by weight, preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the synthetic resin. In addition, the weight ratio of the compound of formula () to the compound of formula () is usually 1 to 10 to 1 of compound of formula (), but 2 to 1.
6 is particularly preferred. In the present invention, in order to blend the compounds of the formulas () and () into the synthetic resin, the known equipment and operation methods for mixing and blending stabilizers, pigments, fillers, etc. into thermoplastic resins can be applied almost as they are. The synthetic resin composition of the present invention may contain other additives such as ultraviolet absorbers, light stabilizers, antioxidants, metal soaps, pigments, and fillers. In particular, by adding ultraviolet absorbers, hindered amine light stabilizers, etc., excellent light resistance can be imparted. The synthetic resins stabilized by the present invention include:
Polyolefin resin, ABS resin, polystyrene resin, high impact polystyrene resin, polyamide resin, polyester resin, polycarbonate resin,
There are polyacetal resins, etc., and it is particularly effective for polyolefin resins. Next, the present invention will be explained in detail with reference to Reference Examples and Examples, but the present invention is not limited thereto. Reference example 1 Tris[2-(2-methyl-4-t-butyl-
Synthesis of 5-hydroxyphenyl)acetyloxy]ethyl isocyanurate (compound I-1) 2-methyl-4-t-
Butyl-5-hydroxyphenylacetic acid 76.6g, tris(2-hydroxyethyl)isocyanurate
30.0 g of toluene, 0.9 g of toluene, and 3.0 g of p-toluenesulfonic acid were charged and heated under reflux in a nitrogen stream for about 10 hours, and the water produced by the reaction was removed from the system by azeotropic distillation.
After the reaction is complete, neutralize with aqueous sodium carbonate solution, wash with water,
After dehydration, toluene was distilled off under reduced pressure to obtain pale yellow tris[2-(2-methyl-4-t
93 g (yield 93%) of -butyl-5-hydroxyphenyl)acetyloxy]ethyl isocyanurate was obtained. This product was recrystallized from n-hebutane to obtain white crystals with a mp of 84 to 86°C. Elemental analysis value (as C ₄₈ H ₆₃ N ₃ O ₁₂ ) C (%) H (%) N (%) Calculated value 66.0 7.3 4.8 Measured value 66.3 7.5 4.7 ¹ H-NMR CDCl ₃ δ (ppm) 1.62 (9Hs) , 2.16 (3Hs), 3.48 (2Hs), 4.20
(2Hm), 4.27 (2Hm), 5.86 (1Hs), 6.49 (1Hs),
6.97 (1Hs) Example 1 After mixing the following formulation with a mixer for 5 minutes,
The compound obtained by melt-kneading with a mixing roll at 180°C was formed into a sheet with a thickness of 1 mm using a hot press at 210°C, and a test piece of 40 x 40 x 1 mm was prepared. 30 of the specimen area in a gear oven at 150 °C
The thermal and oxidative stability was evaluated by measuring the time until % embrittlement. The results are shown in Table-3. <Formulation> Unstabilized polypropylene resin 100 parts by weight Calcium stearate 0.1 Test compound Variables In the table, AO-1 to AO-11 indicate the following compounds. AO-1 2,6-di-t-butyl-4-methylphenol AO-2 n-octadecyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate AO-3 Pentaerythritol -tetrakis[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] AO-4 1,3,5-trimethyl-2,4,6
-Tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene AO-5 1,1,3-tris(2-methyl-4
-Hydroxy-5-t-butylphenyl)butane AO-6 Tris(3,5-di-t-butyl-4
-Hydroxybenzyl)isocyanurate AO-7 Tris[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl-
Oxy]ethyl isocyanurate (Special Publication 1972-
Compounds described in Publication No. 16381) AO-8 Dilaurylthiodipropionate AO-9 Distearylthiodipropionate AO-10 Distearylpentaerythritol diphosphite AO-11 Tris(2,4-di-t-butylphenyl)phosphite

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[Table] Example 2 Put 100 parts by weight of unstabilized ABS resin powder into a crusher and disperse with an appropriate amount of methanol. A test compound was added thereto, and methanol was evaporated while mixing, and the resulting ABS resin powder was used as a test sample. Thermal and oxidative stability was evaluated by the degree of discoloration of ABS resin powder after aging in a gear oven at 180°C. The results are shown in Table 4.

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Claims (1)

[Claims] 1. Compounds of the following formulas () and () are blended into a synthetic resin in a ratio of ():() = 1:1 to 10 (weight ratio). Stabilized synthetic resin composition. (In the formula, R′ is a group and R″ and R are the same as R′ or a group represents. Here, R ₁ represents a branched alkyl group having 4 to 9 carbon atoms, A represents an alkylene group having 1 to 4 carbon atoms, and R ₂ represents an alkyl group having 4 or more carbon atoms. ) (In the formula, X represents an alkyl group having 4 to 20 carbon atoms, and n represents an integer of 1 to 4.)