JPS647094B2 - - 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, or calendar processing. , used in many fields. It is well known that when synthetic resins are used alone, they deteriorate due to the effects of heat and oxygen during processing or use, and their physical properties deteriorate significantly with phenomena such as softening, embrittlement, and discoloration. . In order to prevent such a phenomenon, various phenol-based, phosphorus-based, sulfur-based, and other antioxidants have been added singly or in combination during the production and processing steps of synthetic resins. For example, 2,6-di-t-butyl-4-methylphenol, 2,2'-methylenebis(4-methyl-6-t-butylphenol), n-octadecyl-β-(3,5-di-t-butylphenol), -butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis [β-(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4, 6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,1,3-tris(2-
Using antioxidants such as methyl-4-hydroxy-5-tert-butyl)butane or combining these antioxidants with dilaurylthiodipropionate or dimyristylthiodipropionate or distearylthiodipropionate or Special Public Service 1977-
Methods such as a combination with the example in Publication No. 14703 are known. However, these methods 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 even more surprising is that it has extremely superior thermal and oxidative stability compared to conventional technology, and has excellent compatibility with resins, such as bleeding and whitening phenomena. They have found that this is a significant improvement and have arrived at the present invention. That is, the present invention provides a synthetic resin with a compound of the following general formula () and a compound of the general formula () ():()
The present invention provides a stabilized synthetic resin composition which is blended in a ratio of 1:1 to 10 (weight ratio). (In the formula, R represents an alkyl group having 1 to 4 carbon atoms, and + represents a t-butyl group.) (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 above general formula () used in the present invention, R is an alkyl group having 1 to 4 carbon atoms. From the viewpoint of performance as an antioxidant, methyl group and ethyl group are preferred, with methyl group being particularly preferred. Further, in the compound of general formula (), when n is an integer of 2 or more, X may be the same or different within the same molecule, but it is more advantageous for the synthesis to be the same. Further, n is preferably an integer of 3 to 4, particularly preferably 4, in view of its performance as an antioxidant. Next, typical examples of compounds of general formula () and compounds of general formula () used in the present invention are shown in Table-1 and Table-2.

【table】

[Table] The above general formula () compound is the following general formula () (In the formula, R represents an alkyl group having 1 to 4 carbon atoms, and + represents a t-butyl group.) and the following structural formula () It can be produced by reacting the compound represented by the above, 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 formula () and formula () into a synthetic resin, the known equipment and operating methods for mixing and blending stabilizers, pigments, fillers, etc. into thermoplastic resins can be applied almost directly. . 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 Bis[2-(2'-hydroxy-3'-tert-butyl-5'-methylphenylmethyl)-4-methyl-6-tert-butylphenyl]-3,3'-thiodipropionate ( Synthesis of compound 1) 4.28 g of 3,3'-thiodipropionic acid, 50 g of toluene, and thionyl chloride in a 300 ml four-necked flask.
Pour 11.0g and raise the temperature to 90℃ in a nitrogen stream.
Keep warm for 3 hours. After the reaction is completed, excess thionyl chloride is distilled off under reduced pressure together with the solvent. The dichloride of 3,3′-thiodipropionic acid and 2,2′-methylenebis(6-tert-
Dissolve 13.62g of butyl-4-methylphenol in 50g of toluene and keep at 10℃. A toluene solution of 4.9 g of triethylamine was added dropwise to this over 2 hours. After the addition, the triethylamine hydrochloride was filtered and the solvent was concentrated under reduced pressure to obtain 16.3 g of a crude product. By recrystallizing this from n-hexane, white crystals of mp101, 5 to 103.0°C are obtained. Elemental analysis (calculated values in parentheses) C: 75.8% (75.9), H: 8.7% (8.6) S: 3.8% (3.9) Example 1 After mixing the following formulation in a mixer for 5 minutes,
The compound obtained by melt-kneading with a kissing roll at 180°C was molded 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.
Thermal and oxidation stability was evaluated by measuring the time until 30% of the specimen area became brittle in an open gear at 150°C. 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-8 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 2,2'-methylenebis(4-methyl-
6-t-butylphenol) AO-5 Dilaurylthiodipropionate AO-6 Distearylthiodipropionate AO-7 Distearylpentaerythritol diphosphite AO-8 Tris(2,4-di-t-butylphenyl) Phosphite

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【table】

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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 the ABS resin powder after aging in an open gear at 180°C. The results are shown in Table 4.

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【table】

Claims (1)

[Claims] 1. Compounds of the following general formula () and compounds of the general formula () are blended in a polyolefin resin or ABS resin in a ratio of ():()=1:1 to 10 (weight ratio). A stabilized synthetic resin composition characterized by: (In the formula, R represents an alkyl group having 1 to 4 carbon atoms, and + represents a t-butyl group.) (In the formula, X represents an alkyl group having 4 to 20 carbon atoms, and n represents an integer of 1 to 4.)