JPS62143B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to new substances having an improved stabilizing effect on oxidizing organic substances, and more particularly to new phenolic compounds effective as antioxidants. The prior art has taught that antioxidant protection is achieved by mechanically mixing antioxidants that act by different mechanisms into oxidizable organic polymers. Such antioxidant compounds are often lost from organic materials through extraction or evaporation, thereby altering the optimum concentration of each required for best antioxidant efficacy. One of the objects of the present invention is to provide an antioxidant that prevents the oxidative decomposition of polymers. Further objects of the invention will become apparent as the description progresses. The phenolic compound of the present invention has a structure represented by the following general formula (). In the above formula (), R ₁ and R ₂ each independently represent an alkyl group having 1 to 10 carbon atoms,
A represents -K-X- (wherein K is an alkylene group having 1 to 10 carbon atoms, and X is oxygen), and m is 1 or 2. The above-mentioned compound is a phenolic compound represented by the following general formula () containing a reactive hydroxyl group, It can be produced by reacting with an ester-forming compound represented by the following general formula (). where R ₁ , R ₂ , m and A are as defined above and E is selected from the group consisting of hydrogen and an alkyl radical containing 1 to 3 carbon atoms. Although the reaction can be catalyzed by small amounts of acidic catalysts,
Some reactions do not require a catalyst. The amount of catalyst used can vary within a wide range. However, usually 0.25 to 5.0 grams of catalyst per 100 grams of reactants is sufficient. Higher proportions of catalyst can also be used, but there is usually no advantage. Representative examples of acidic catalysts useful in the present invention include toluenesulfonic acid, sulfuric acid,
These are boron trifluoride, benzenesulfonic acid, hydrochloric acid, phosphoric acid, ion exchange resins, and acid-activated clays. The reaction can also be carried out without a solvent. However, the solvent
For example, xylene, benzene or toluene
Usually assists in carrying out reactions. Although the reaction can be carried out at room temperature, it is usually carried out at a temperature up to the boiling point of the solvent. When a solvent is not used, the reaction is carried out below the boiling point of the reactants. The molar ratio of the phenolic compound represented by the above general formula () to the ester-forming compound represented by the above general formula () is 1:1,
Excess of ester-forming compound can also be used to speed up the reaction and reduce side reactions. Although the ester-forming compound can be used in any excess amount, the molar ratio of the phenolic compound to the ester-forming compound is preferably from 1:1 to 1:2. Compounds represented by the general formula () useful in obtaining the phenolic compound of the present invention include:
3-(3,5-di-tert-butyl-4-hydroxyphenyl)-1-propanol, 3,5-di-tert
-butyl-4-hydroxybenzyl alcohol,
3-(3,5-di-tert-butyl-4-hydroxyphenyl)-2-butanol, 10-(3,5-di-tert-butyl-4-hydroxyphenyl)
tert-butyl-4-hydroxyphenyl)-1-
Decanol, 3-(3,5-di-tert-butyl-4
-hydroxyphenyl)-2,2-dimethyl-1
Typical examples include -propanol and 3,5-dimethyl-4-hydroxybenzyl alcohol. Representative examples of the phenolic compound of the present invention obtained by the method explained above include [3-(3.5
-di-tert-butyl-4-hydroxyphenyl)propyl]3-mercaptopropionate, 3.5
-di-tert-butyl-4-hydroxybenzylmercaptoacetate, 3,5-di-tert-butyl-4
-Hydroxybenzyl 3-mercaptopropionate, [10-(3,5-di-tert-hexyl-4-hydroxyphenyl)decyl]3-mercaptopropionate, [3-(3,5-di-tert-butyl) -4
-hydroxyphenyl)-2,2-dimethylpropyl]3-mercaptopropionate. Typical ester-forming compounds represented by the general formula () include 3-mercaptopropionic acid, 2-mercaptopropionic acid, mercaptoacetic acid, propyl 3-mercaptopropionate, and methyl 2-mercaptopropionate. , ethyl mercaptoacetate. Due to their transparency, the phenolic compounds of the present invention are useful in transparent polymers such as polypropylene and polyethylene. The compounds are also superior to those known from the prior art in preventing the curing of oxidizable polymers. In addition, this compound can also act as a chain transfer agent. This compound can be chemically incorporated into the polymer to some extent during processing due to the free thiol group (-SH). This compound can prevent curing in styrene/butadiene polymers. Antioxidants having a stabilizing effect on oxidizable organics according to the present invention are generally used at about 0.0005% to about 10% by weight of the composition to be stabilized, although this will vary with the particular polymer. A particularly advantageous range is approximately
It ranges from 0.025% to about 1.5%. This compound is
Particularly effective in stabilizing polyethylene and polypropylene, but also effective against olefin polymers. The following examples illustrate typical procedures used in the production of phenolic antioxidants. Example 1 53 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-1 propanol, 25.4 g of 3-mercaptopropionic acid and 1 g of toluenesulfonic acid are dissolved in 100 ml of benzene,
Heat to reflux. After refluxing for 2 1/2 hours, 4 ml
of water was collected. Thin layer chromatography revealed that all the phenolic alcohols had reacted. The reaction product was washed with water, decanted,
The reactor was removed at 80°C and 15mmHg. [3-(3・
5-di-tert-butyl-4-hydroxyphenyl)
The sulfur content of propyl]3-mercaptopropionate was 9.3% (theoretical value of sulfur content is
9.1%). In the ¹ H-NMR spectrum (solvent: CDCl ₃ , internal standard: TMS, 60 MHz) of the obtained reaction product, absorption lines with the following δ values were obtained. 6.93 (s, 2H); 5.08 (s, 1H); 4.11 (T,
2H, J=6.5Hz); 2.95-2.40 (m, 6H); 2.22
~1.63 (m, 3H); 1.37 (s, 18H) Example 2 221 g of mercaptoacetic acid, 2 g of toluenesulfonic acid, and 94.4 g of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol were mixed with a thermometer, Placed in a flask equipped with a water condenser and stirrer. The reaction product was stirred at room temperature for 1 hour and then left without further stirring for 16 hours. The reaction product was washed with warm water. The benzene solvent was removed until the reaction product crystallized in the form of white crystals. Then hexane was added to wash the white crystals. 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate from 107.5℃
It had a melting point of up to 108.5°C. Example 3 27.9 g of 3-(3,5-di-tert-butyl-4-
Hydroxyphenyl)-2-butanol, 1 g toluenesulfonic acid, and 21.2 g 3-mercaptopropionic acid were dissolved in 120 ml benzene. The reaction mixture was heated to reflux and the water formed was collected. After refluxing for 5 hours at 84°C, a total of 2 milliliters of water was collected. Thin layer chromatography revealed that all of the phenolic alcohol had reacted. The reaction product was washed with warm water and then volatile components were removed under reduced pressure at 75°C. In the ¹ H-NMR spectrum (solvent: CDCl ₃ , internal standard: TMS, 60 MHz) of the obtained reaction product, absorption lines with the following δ values were obtained. 6.87 (s, 2H); 5.20-4.67 (m, 2H); 2.93
~2.28 (m, 6H); 2.17 ~ 1.58 (m, 3H); 1.37
(s, 18H); 1.11 (d, 3H, J = 5.6Hz) Example 4 50g of 2,2-dimethyl-3-(3,5-dimethyl
tert-butyl-4-hydroxyphenyl)-1-
Propanol, 1.0g toluenesulfonic acid, 100
ml of benzene and 27 g of 3-mercaptopropionic acid were heated to reflux using a water trap. After refluxing for 2 hours, the reaction was complete. The reaction product was washed with 50 ml of water and decanted. The benzene solution was cooled to 8°C and filtered.
Washed with hexane. The white [2,2'-dimethyl-3-(3,5-ditert-butyl-4-hydroxyphenyl)propyl]3-mercaptopropionate had a melting point of 105°C to 106°C.

Table: The material according to the invention was also tested for its coloring properties in polypropylene and compared with transparent polypropylene without antioxidant. Clear polypropylene without stabilizers is
Profax6501 sold by Hercules Chemical Company
It is. Regarding the symbols used for various coloration scales,
Defined below. The symbol Rd is the Gardner colorimeter (Gardner colorimeter).
Colorimeter) is a measure of reflection that gives the MgO standard a value of 91.1. This value indicates the position of a light gray color on the color axis from black to white, and the higher the value, the higher the reflection or the brighter the color. The symbol "a" represents the primary colors red (for positive values) and green (for negative values). The intensity of each color is indicated by the magnitude of the value, regardless of its sign. The standard is magnesium oxide, which gives a value of 0.0. The symbol "b" represents the primary colors of yellow (for positive values) and blue (for negative values). The intensity of each color is indicated by the magnitude of the value, regardless of its sign. The standard is magnesium oxide, which gives a value of 0.0. Percentage coloring is a measure of the total colorability of the polymer;
Calculated by Rd/(a+b).

【table】

Although certain examples and details have been set forth for the purpose of illustrating the invention, it will be obvious that various changes and modifications may be made to such techniques and are not intended to depart from the spirit or scope of the invention. do not have.

Claims (1)

[Claims] 1. The following general formula () [In the above formula, R ₁ and R ₂ are each independently 1 or
an alkyl group having 10 carbon atoms, A is -K-
Each represents X- (wherein K is an alkylene group having 1 to 10 carbon atoms, and X is oxygen), and m is 1 or 2. ] A phenolic compound characterized by having a structure shown in the following.