A liquid high-efficiency carbon free radical scavenger and its preparation method and application

Abstract

The present invention proposes a liquid high-efficiency carbon free radical scavenger with 2,4-di-tert-butylphenol, glyoxylic acid, aldehyde-containing and phenyl compounds, and a catalyst as raw materials, and also provides a preparation method of the free radical scavenger, first synthesizing intermediate I with 2,4-di-tert-butylphenol and glyoxylic acid under catalyst conditions, and then synthesizing the final free radical scavenger with intermediate I and aldehyde-containing and phenyl compounds. The free radical scavenger prepared by the present invention has a stable and controllable reaction process, can directly obtain the final product without being proposed, and the final product has good capture and decomposition of hydroperoxide, can improve the long-term thermal stability of plastic products, effectively inhibit or delay the oxidative degradation of plastics or rubber and extend the service life. It has a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of C07D307 / 83, and more specifically to a liquid high-efficiency carbon free radical scavenger and a preparation method and application thereof. Background Art

[0002] Antioxidants are highly efficient carbon free radical capture agents commonly used in the field of plastic processing. They can be used in combination with a variety of other types of antioxidants to exert significant antioxidant effects. Chinese patent CN109651314A discloses a highly efficient catalytic synthesis method for antioxidants, which uses 2,4-di-tert-butylphenol, glyoxylic acid, and o-xylene as raw materials and reacts them in a one-pot reaction at 90-160°C to obtain a solid antioxidant. This synthesis method requires the removal of by-products and recrystallization of the reaction product after the reaction to obtain more and purer antioxidants.

[0003] However, most antioxidants are solid powder substances. When directly added to plastics and other products, the antioxidant effect and anti-yellowing effect may be reduced due to uneven distribution. When used in combination with other types of antioxidants, especially in combination with liquid antioxidants, uneven mixing may also cause a decrease in antioxidant effect. Based on this, the present invention proposes a liquid high-efficiency carbon free radical scavenger and its preparation method and application. Summary of the invention

[0004] The corresponding product of the high-efficiency carbon free radical scavenger prepared by this patent is planned to be an antioxidant.

[0005] The first aspect of the present invention provides a liquid high-efficiency carbon free radical scavenger, wherein the raw materials for preparation include 2,4-di-tert-butylphenol, glyoxylic acid, an aldehyde- and phenyl-containing compound, a catalyst A and a catalyst B.

[0006] In a preferred embodiment, the weight ratio of the compound containing an aldehyde group and a phenyl group to glyoxylic acid is (5-6): 4. More preferably, the weight ratio of the compound containing an aldehyde group and a phenyl group to glyoxylic acid is 58.5:44.

[0007] In a preferred embodiment, the structural formula of the compound containing an aldehyde group and a phenyl group also contains a hydroxyl group.

[0008] In a preferred embodiment, the aldehyde-, phenyl- and hydroxyl-containing compound is selected from at least one of salicylaldehyde, 3-methyl salicylaldehyde, 4-methoxy salicylaldehyde, 2,6-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 4-fluoro-2-hydroxybenzaldehyde and 4-hydroxy-2-methoxybenzaldehyde.

[0009] In a preferred embodiment, the compound containing aldehyde group, phenyl group and hydroxyl group is salicylaldehyde.

[0010] The second aspect of the present invention provides a method for preparing a liquid high-efficiency carbon free radical scavenger, comprising the following steps:

[0011] (1) heating 2,4-di-tert-butylphenol and glyoxylic acid under reflux in the presence of catalyst A to obtain intermediate I;

[0012] (2) The intermediate I is reacted with an aldehyde- and phenyl-containing compound to obtain a product, which is a free radical scavenger.

[0013] In a preferred embodiment, the step (1) is heated to 80-90° C. for reflux.

[0014] In a preferred embodiment, the specific process of step (1) is as follows: 2,4-di-tert-butylphenol and glyoxylic acid are heated to 80-90° C. under the condition of catalyst A, refluxed for 3-6 hours, and the by-products are separated to obtain intermediate I.

[0015] In the present application, the structural formula of intermediate I is as follows:

[0016] In a preferred embodiment, the specific process of step (2) is as follows: the intermediate I is subjected to an alkylation reaction with an aldehyde group and a phenyl group-containing compound to obtain a product, which is a free radical scavenger.

[0017] In a preferred embodiment, the specific process of step (2) is as follows: intermediate I is reacted with an aldehyde- and phenyl-containing compound under catalyst B conditions at 100-120° C. for 3-10 hours to obtain a product, which is a free radical scavenger.

[0018] The applicant found in the experiment that when a two-step method is used to first synthesize intermediate I from 2,4-di-tert-butylphenol and glyoxylic acid, and then the intermediate I and salicylaldehyde are used to synthesize the final free radical scavenger, the generation of by-products can be reduced, and the product does not need to be purified twice, and a free radical scavenger with higher purity can be obtained. At the same time, the applicant found in the experiment that the use of salicylaldehyde as the third reaction raw material of the present application, after the synthesis of intermediate I, the aldehyde group and hydroxyl group will be retained in the free radical scavenger finally obtained, and during the use of the free radical scavenger, the ability to capture and decompose hydroperoxides is improved, and the thermal oxidation ability of plastic products to which the free radical scavenger is added can also be reduced, thereby improving the long-term thermal stability of the plastic products.

[0019] If the one-pot method is used as the synthesis method of the present application, salicylaldehyde may react with glyoxylic acid, increasing the types and contents of byproducts in the final product, increasing the complexity of the process, and reducing the purity of the final product. The appearance of byproducts will also reduce the content of hydroxyl and aldehyde groups in the substance, resulting in a reduction in its ability to capture and decompose hydroperoxides, reducing the thermal stability of the plastic material added to the product, and causing obvious yellowing of the plastic product. In addition, the product will also reduce its mixing compatibility with other types of antioxidants such as liquid phosphite antioxidants due to the reduction in the content of hydroxyl and other groups therein, and stratification will occur after long-term storage after mixing.

[0020] In a preferred embodiment, the weight ratio of 2,4-di-tert-butylphenol to glyoxylic acid is (5-6):4, and more preferably, the weight ratio of 2,4-di-tert-butylphenol to glyoxylic acid is 51.5:44.

[0021] In a preferred embodiment, the catalyst is selected from a composite material of a benzenesulfonic acid catalyst and a trifluoromethanesulfonic acid catalyst.

[0022] In a preferred embodiment, the catalyst is trifluoromethanesulfonic acid and p-toluenesulfonic acid, and the weight ratio of trifluoromethanesulfonic acid to p-toluenesulfonic acid is 5:1.

[0023] In the present application, the catalyst A and the catalyst B are both composite substances with a weight ratio of trifluoromethanesulfonic acid to p-toluenesulfonic acid of 5:1.

[0024] In a preferred embodiment, the weight ratio of the catalyst A to the catalyst B is 3:2.

[0025] In a preferred embodiment, the weight ratio of the catalyst to glyoxylic acid is 1:(8-9). More preferably, the weight ratio of the catalyst to glyoxylic acid is 5:44.

[0026] In a preferred embodiment, the raw materials for preparing the free radical scavenger include, by weight: 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, 58.5 parts of aldehyde- and phenyl-containing compounds, and 5 parts of catalysts.

[0027] The third aspect of the present invention proposes an application of a highly efficient carbon free radical scavenger, which is applied to the fields of plastic processing and foam material preparation.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The free radical scavenger prepared by the present invention is a liquid substance, which can effectively prevent the acid value or viscosity of lubricating oil and fuel oil from increasing during use.

[0030] 2. The free radical scavenger prepared by the present invention is prepared by a two-step method, firstly, 2,4-di-tert-butylphenol and glyoxylic acid are used to synthesize the intermediate product I under catalyst conditions, and then the intermediate product I is reacted with salicylaldehyde to prepare the final product, thereby improving the controllability and stability of the reaction, reducing the generation and types of by-products, and the product does not need to be purified twice, so that a free radical scavenger with higher yield and purity can be obtained.

[0031] 3. The free radical scavenger prepared by the present invention adopts salicylaldehyde as one of the reaction raw materials and is prepared by a two-step method, thereby improving the ability of the product to capture and decompose hydroperoxides, reducing the thermal oxidation ability of plastic products added with the product, improving the long-term thermal stability of plastic products, and effectively inhibiting or delaying the oxidative degradation of plastics or rubbers to extend the service life.

[0032] 4. The free radical scavenger prepared by the present invention can be used as a food additive to delay the rancidity of food. It can be used in animal and vegetable oils and foods containing animal and vegetable oils. In addition, it can also be used in inks, adhesives, leather, casting, printing and dyeing, coatings and electronic industries, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A is a foamed sponge containing a free radical scavenger prepared by Example 1 of the present invention;

[0034] Figure 1 B is a foamed sponge without using the radical scavenger of Example 1 of the present invention. DETAILED DESCRIPTION

[0035] Example 1

[0036] This embodiment proposes a liquid high-efficiency carbon free radical scavenger and a preparation method and application thereof, which are applied in the fields of plastic processing and foam material preparation. Figure 1 A is a diagram showing the anti-yellowing effect of using the free radical scavenger prepared in this example in the preparation of foamed sponge.

[0037] The raw materials for preparation include, by weight, 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, 58.5 parts of salicylaldehyde, and 5 parts of a catalyst.

[0038] The catalyst is a mixture of trifluoromethanesulfonic acid and p-toluenesulfonic acid in a weight ratio of 5:1.

[0039] The preparation method is specifically as follows:

[0040] (1) 51.5 parts of 2,4-di-tert-butylphenol and 44 parts of glyoxylic acid were heated to 88° C. in the presence of 5 parts of a catalyst, and refluxed for 4 hours to separate the generated water to obtain an intermediate I;

[0041] (2) 35 parts of intermediate I and 58.5 parts of salicylaldehyde are directly subjected to an alkylation reaction, the temperature is maintained at 110° C., the reaction is refluxed for 4 hours, and the reflux is maintained for 4 hours. During the reflux process, the generated water is separated to obtain a product, which is a free radical scavenger.

[0042] Example 2

[0043] This embodiment proposes a liquid high-efficiency carbon free radical scavenger and a preparation method and application thereof, which are applied in the fields of plastic processing and foam material preparation.

[0044] The raw materials for preparation include, by weight, 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, 58.5 parts of salicylaldehyde, and 5 parts of a catalyst.

[0045] The catalyst is a mixture of trifluoromethanesulfonic acid and p-toluenesulfonic acid in a weight ratio of 5:1.

[0046] The preparation method is specifically as follows:

[0047] (1) 51.5 parts of 2,4-di-tert-butylphenol and 44 parts of glyoxylic acid were heated to 90° C. in the presence of 5 parts of a catalyst, and refluxed for 4 hours to separate the generated water to obtain an intermediate I;

[0048] (2) 35 parts of intermediate I and 58.5 parts of salicylaldehyde are directly subjected to an alkylation reaction, the temperature is maintained at 120° C., the reaction is refluxed for 4 hours, and the reflux is maintained for 4 hours. During the reflux process, the generated water is separated to obtain a product, which is a free radical scavenger.

[0049] Example 3

[0050] This embodiment proposes a liquid high-efficiency carbon free radical scavenger and a preparation method and application thereof, which are applied in the fields of plastic processing and foam material preparation.

[0051] The raw materials for preparation include, by weight, 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, 58.5 parts of o-xylene, and 5 parts of a catalyst.

[0052] The catalyst is a mixture of trifluoromethanesulfonic acid and p-toluenesulfonic acid in a weight ratio of 5:1.

[0053] The preparation method is specifically as follows:

[0054] (1) 51.5 parts of 2,4-di-tert-butylphenol and 44 parts of glyoxylic acid were heated to 88° C. in the presence of 5 parts of a catalyst, and refluxed for 4 hours to separate the generated water to obtain an intermediate I;

[0055] (2) 35 parts of intermediate I and 58.5 parts of o-xylene are directly subjected to an alkylation reaction, the temperature is maintained at 110° C., the reaction is refluxed for 4 hours, and the reflux is maintained for 4 hours. During the reflux process, the generated water is separated to obtain a product, which is a free radical scavenger.

[0056] Example 4

[0057] This embodiment proposes a liquid high-efficiency carbon free radical scavenger and a preparation method and application thereof, which are applied in the fields of plastic processing and foam material preparation.

[0058] The raw materials for preparation include, by weight, 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, 58.5 parts of salicylaldehyde, and 5 parts of a catalyst.

[0059] The catalyst is a mixture of trifluoromethanesulfonic acid and p-toluenesulfonic acid in a weight ratio of 5:1.

[0060] The preparation method is as follows: 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, and 58.5 parts of salicylaldehyde are heated to 110°C in the presence of 5 parts of a catalyst, refluxed for 4 hours, and refluxed for 4 hours. During the reflux process, the generated water is separated to obtain a product, which is a free radical scavenger.

[0061] Example 5

[0062] This embodiment proposes a liquid high-efficiency carbon free radical scavenger and a preparation method and application thereof, which are applied in the fields of plastic processing and foam material preparation.

[0063] The raw materials for preparation include, by weight, 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, 58.5 parts of o-xylene, and 5 parts of a catalyst.

[0064] The catalyst is a mixture of trifluoromethanesulfonic acid and p-toluenesulfonic acid in a weight ratio of 5:1.

[0065] The preparation method is as follows: 51.5 parts of 2,4-di-tert-butylphenol, 44 parts of glyoxylic acid, and 58.5 parts of o-xylene are heated to 110° C. in the presence of 5 parts of a catalyst, refluxed for 4 hours, and refluxed for 4 hours. The generated water is separated during the reflux process to obtain a product, which is a free radical scavenger.

[0066] Performance Testing

[0067] 1. The free radical scavenger prepared in the example was mixed with the liquid phosphite antioxidant TNPP in a total ratio of 2:1. The mixture was placed at room temperature for 6 months and 12 months to observe whether the mixture was uniform and whether stratification and precipitation occurred. The results are recorded in Table 1.

[0068] Table 1

[0069] 6 months 12 months Example 1 Uniform, no stratification Uniform, no stratification Example 2 Uniform, no stratification Uniform, no stratification Example 3 Uniform, precipitation Uniform, precipitation Example 4 Uniform, no stratification Uniform, layered Example 5 Uniform, precipitation Uniform, precipitation

[0070] 2. The free radical scavenger prepared in Example 1 was used in the sponge foaming process to prepare a foamed sponge, and the addition amount was 0.1wt%, and the anti-yellowing effect was compared with the foamed sponge without adding Example 1. The test standard refers to HG / T3689-2001.

[0071] The results are as follows Figure 1 The results show that the yellowing degree of the foam sponge with 0.1wt% free radical scavenger added is significantly weaker than that of the foam sponge without free radical scavenger added.

Claims

1. A method for preparing a liquid high-efficiency carbon free radical scavenger, characterized in that: The raw materials for preparing the free radical scavenger include 2,4-di-tert-butylphenol, glyoxylic acid, an aldehyde- and phenyl-containing compound, a catalyst A and a catalyst B; The structural formula containing aldehyde group and phenyl group also contains hydroxyl group, which is salicylaldehyde; The preparation method of a liquid high-efficiency carbon free radical scavenger is characterized by comprising the following steps: (1) heating 2,4-di-tert-butylphenol and glyoxylic acid to 80-90° C. in the presence of catalyst A, reflux for 3-6 hours, and separating by-products to obtain intermediate I; (2) reacting the intermediate I with an aldehyde- and phenyl-containing compound under the condition of catalyst B at 100-120° C. for 3-10 hours to obtain a product, which is a free radical scavenger; The weight ratio of the aldehyde group- and phenyl group-containing compound to glyoxylic acid is (5-6):4; The weight ratio of the aldehyde group- and phenyl group-containing compound to glyoxylic acid is 58.5:

44.

2. An application of the liquid high-efficiency carbon free radical scavenger according to claim 1, characterized in that: It is used in the fields of plastic processing and foam material preparation.

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