JPH0579245B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a polyether polymer useful as a polymeric antioxidant in polymeric materials such as rubber or plastic, and a method for producing the same. (Prior art) Antioxidants are usually added to polymeric materials such as rubber or plastics in order to suppress their oxidative deterioration, but at high temperatures the antioxidant effect is lost mainly through volatilization and surface migration. is often lost. One possible method for preventing this is to polymerize a monomer having a group having an antioxidant effect to form a polymer. In this case, from the viewpoint of compatibility, a polyether-based polymeric antioxidant is preferable for polyether-based materials such as epichlorohydrin rubber. However, very few polyether polymers with antioxidant activity in their side chains have been disclosed, and the only low molecular weight polyether polymer is poly(4-hydroxy-
There is only 3,5-di-t-butylphenyl glycidyl thioether (T. Fujisawa et al., J.
Polym. Sci., Part B12, 557 (1974)). (Problems to be Solved by the Invention) However, as described in the literature, a high polymer cannot be obtained even if a diethylzinc-water catalyst, which is a high polymerization catalyst for an epoxy compound, is used. One of the reasons for this is thought to be that the phenolic hydroxyl group or thioether group inhibits the high polymerization reaction. (Means for Solving the Problems) In view of the above points, the present inventors conducted extensive studies with the aim of obtaining a polymeric antioxidant whose antioxidant effect does not deteriorate. As a result, it was discovered that a polyether polymer obtained by polymerizing a specific glycyl ether having a sterically hindered phenol type antioxidant group in the side chain in the presence of a specific catalyst can fully satisfy the above objectives, and the present invention was completed. This is what I came to do. That is, the present invention provides a sterically hindered phenol in the side chain whose repeating unit is represented by the following formula ( It is a polyether polymer () with type antioxidant groups.

[Chemical formula] The present invention also provides a method for combining the compound 4-hydroxy-3,5-di-t-butylphenyl glycidyl ether represented by the following formula () with an organotin compound (A) represented by the following general formula (). This is a method for producing a polyether polymer having a sterically hindered phenol type antioxidant group in the side chain, which is characterized by polymerizing in the presence of a catalyst that is a thermal condensation product with an acid alkyl ester (B).

[Chemical formula] RbSnOc (i) (However, in formula (), R is selected from an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkenyl group, a cycloalkyl group, an aryl group, and an aralkyl group. (b is 1 or 2, when b is 1, c is 3/2, and when b is 2, c is 1.) The above formula () which is a raw material monomer of the polymer of the present invention The compound is a new substance filed by the present applicant (Japanese Patent Application Laid-Open No. 129178/1999). This compound is
It can be synthesized by reacting 2,6-di-t-butylhydroquinone and epichlorohydrin in the presence of a quaternary basic salt and a base by a known method. The present invention provides that the thermal condensation product of a specific organotin compound (A) and a phosphoric acid alkyl ester (B) described in U.S. Patent No. 3,773,694 by the present applicant is a compound of the above formula (). This is based on the discovery that it acts selectively as a catalyst for the ring-opening polymerization of epoxides, and that the resulting polymer is also highly effective as a highly functional polymer having sterically hindered phenolic antioxidant groups in its side chains. Specific examples of the organotin compound (A) of the above formula () which is a catalyst component of the present invention include the following. Compounds belonging to general formula () include (CH ₃ ) ₂ SnO, (C ₄ H ₉ ) ₂ SnO, (C ₈ H ₁₇ ) ₂ SnO, (C ₆ H ₅ ) ₂ SnO, CH ₃ SnO _3/2 Examples include C ₄ H ₉ SnO _3/2 . The phosphoric acid alkyl ester (B), which is another component constituting the catalyst of the present invention, has the following general formula ()
A complete or partial ester of orthophosphoric acid represented by is particularly preferably used. (R ² O) ₃ P=O () (However, in formula (), R ² is hydrogen or an alkyl group, alkenyl group, or cycloalkyl group having 2 or more carbon atoms, and at least one of R ²
is a group other than a hydrogen atom. ) Specific examples of the above formula () are: (C ₂ H ₅ ) ₃ PO ₄ , (C ₃ H ₇ ) ₃ PO ₄ , (C ₄ H ₉ ) ₃ PO ₄ , (C ₈ H ₁₇ ) ₃ PO ₄ , (CH ₂ = CH−CH ₂ ) ₃ PO ₄ , (C ₆
H ₁₁ ) ₃ PO ₄ , (ClCH ₂ −CH ₂ ) ₃ PO ₄ , (Cl ₂ C ₃ H ₅ ) ₃ PO ₄ , (C ₂ H ₅ ) ₂ HPO ₄ , (C ₄ H ₉ ) ₂ HPO ₄ , _{( C4H9} ) _H2
Examples include PO ₄ . The catalyst of the present invention is obtained as a condensation product by heating a mixture of the organotin compound (A) and the phosphoric acid alkyl ester (B) in a temperature range of 150 to 300°C. A solvent may be used if necessary.
The above components (A) and (B) are used so that the ratio of tin atoms to phosphorus atoms contained is usually in the range of 1:10 to 10:1. In the above catalyst production reaction, various relatively simple substances are produced and eliminated in the condensation reaction depending on the types of components (A) and (B). The resulting condensate exhibits the desired activity at various stages of the degree of condensation. The optimal degree of condensation varies depending on the type and ratio of components (A) and (B), but can be easily determined experimentally. The condensate is generally initially soluble in a solvent such as hexane or benzene, but becomes insolubilized as the condensation reaction progresses. The polymer () of the present invention is a compound of the formula (4-hydroxy-3,
It is obtained by polymerizing 5-di-t-butylphenyl glycidyl ether in the presence or absence of a solvent at 0 to 80°C, usually with stirring or shaking. The appropriate amount of the catalyst to be used is 0.01 to 3.0 parts by weight per 100 parts by weight of the raw material monomer. During the reaction, it is desirable to keep the water content of the reaction system as low as possible. The resulting polymer suitably has a reduced viscosity in the range of 0.1 to 3, preferably in the range of 0.5 to 3, as measured in a 0.1% chlorobenzene solution at 80°C. If it is less than 0.1, when used as an antioxidant, there is a risk that volatile surface migration or extraction will occur, and sufficient effects will not be obtained. (Effects of the Invention) The polymer of the present invention is obtained by polymerizing a glycidyl ether having a novel sterically hindered phenol type antioxidant group as a monomer using a specific catalyst. It is a novel polyether polymer having groups, and is a highly functional polymer useful as a high molecular weight antioxidant. (Example) Example 1 (1) Synthesis of 4-hydroxy-3,5-di-t-butylphenyl glycidyl ether In 3 flasks equipped with a stirrer, a thermometer, a nitrogen inlet and an outlet, 2, Add 320 g of 6-di-t-butylhydroquinone, 1200 g of epichlorohydrin, and 6.6 g of triethylbenzylammonium chloride, and dropwise add 144 g of a 48% aqueous sodium hydroxide solution under a nitrogen stream while maintaining the temperature at 58 to 61°C over 2 hours. It was held at this temperature for an hour. After the reaction, the reaction mixture was filtered, and the aqueous layer was separated from the filtrate and concentrated to obtain 395 g of an oily substance. This was subjected to column chromatography on alumina using benzene as an eluent, and the benzene eluent was concentrated and gas chromatography was performed to obtain a living body with a purity of 95%.
Obtained 328g (crude yield 82%). This was recrystallized three times from n-hexane and the gas chromatography purity was 99.
% or more crystals were obtained (yield 43%). Melting point 55.0
~56.0℃. NMR (CDCl ₃ , TMS internal standard) δ1.44 (18H, t-C ₄ H ₉ ) δ2.75-4.15 (5H, glycidyl group) δ4.80 (1H, hydroxyl group) δ6.80 (2H, aromatic) IR (KBr) ν _OH 3430cm ^-1 (2) Production of polyether polymer Put 12.5 g of dibutyltin oxide and 26.6 g of tributyl phosphate into a three-necked flask equipped with a stirrer, thermometer, and distillation device, and stir under a nitrogen stream. While heating at 250° C. for 20 minutes, the distillate was distilled off, and a solid condensation material was obtained as a residue. The following polymerization was carried out using this product as a catalyst. The inside of a glass ampoule with a content capacity of 50 ml was replaced with nitrogen, and 59 mg of the above catalyst and the above 4-3 with a moisture content of 10 ppm or less were added.
20 ml of a 25% benzene solution of hydroxy-3,5-di-t-butylphenyl glycidyl ether was charged, and after sealing the tube, the ampoule was reacted at 30° C. for 120 hours with shaking. After the reaction, the reaction product was poured into 500 ml of hexane to precipitate a polymer, the hexane was decanted, and the mixture was dried under reduced pressure to obtain 4.1 g of polymer () (yield: 83%). The reduced viscosity of this polymer () measured with a 0.1% chlorobenzene solution at 80°C was 2.14. NMR (CDCl ₃ , TMS internal standard) δ1.34 (18H, t-C ₄ H ₉ ) δ4.66 (1H, hydroxyl group) δ6.67 (2H, aromatic) IR (KBr) ν _OH 3610cm ^-1 Example 2 The reaction was carried out in the same manner as in Example 1 (2) except that tetrahydrofuran was used instead of benzene in Example 1 to obtain 3.8 g of polymer (yield 77%). The reduced viscosity of this polymer measured in a 0.1% chlorobenzene solution at 80°C was 0.98. Example 3 In order to investigate the antioxidant function of the polyether polymer () obtained in Example 1, polyethylene glycol monomethyl ether (Mn=
2000, hereinafter referred to as PEG-M. ) and its thermal decomposition temperature was measured. Using a differential thermal balance “PTC-3” manufactured by Rigaku Denki Co., Ltd., we measured the temperature increase rate in an air atmosphere.
The measurement conditions were 10°C/min. That is, 1 g of PEG-M was added to a solution of 5 mg and 10 mg of polymer () dissolved in 5 ml of benzene.
was added and dried at room temperature to obtain sample A with 0.5% () addition and sample B with 1.0% () addition. The starting temperature of thermal decomposition of Sample A and Sample B is 164℃, respectively.
It was 170℃. On the other hand, the thermal decomposition onset temperature of additive-free PEG-M was 135°C. Comparative Example 1 g of PEG-M was added to a solution of 5 mg and 10 mg of 4-hydroxy-3,5-di-t-butyltoluene (BHT) dissolved in 5 ml of benzene, dried at room temperature, and 0.5% BHT was added. Sample C, 1.0%
Sample D with BHT added was obtained. The thermal decomposition onset temperatures of Sample C and Sample D are 151℃ and 151℃, respectively.
It was 154℃. According to the test results of Example 3 and Comparative Example above,
It can be seen that the polyether polymer of the present invention has superior antioxidant ability compared to BHT, which is generally known as a good antioxidant, and is useful as a high molecular weight antioxidant.

Claims (1)

[Claims] 1. The repeating unit is represented by the following formula (), and 80
A polyether polymer having a sterically hindered phenol type antioxidant group in a side chain, characterized in that the reduced viscosity measured in a 0.1% chlorobenzel solution at °C is in the range of 0.1 to 3. [Chemical formula] 2 Thermal condensation of the compound 4-hydroxy-3,5-di-t-butylphenyl glycidyl ether represented by the following formula () with an organotin compound represented by the following general formula () and a phosphoric acid alkyl ester. 2. The method for producing a polyether polymer having a sterically hindered phenol type antioxidant group in a side chain according to claim 1, wherein the polymerization is carried out in the presence of a catalyst as a product. [Chemical formula] RbSnOc (i) (However, in formula (), R is selected from an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkenyl group, a cycloalkyl group, an aryl group, and an aralkyl group. (b is 1 or 2; when b is 1, c is 3/2; when b is 2, c is 1).