Low-melting-point compound antioxidant and preparation method thereof

Abstract

The invention relates to a low-melting-point compound antioxidant and a preparation method thereof, and is characterized in that the low-melting-point compound antioxidant comprises the following components in parts by weight: 20-80 parts of a low-melting-point mixed phenol antioxidant, and 20-80 parts of a mixture of one or more of a phenol antioxidant, an amine antioxidant, a phosphite ester antioxidant and a thioether antioxidant. The low-melting-point compound antioxidant provided by the invention has the characteristics of good low-temperature performance and no solidification, and the use convenience of the antioxidant is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of antioxidants, and more specifically, provides a low melting point compound antioxidant and a preparation method thereof. Background Art

[0002] Polymer materials are widely used in food, medical and health, agriculture and other fields, and have gradually become an indispensable and important material in economic life. However, polymer materials are easily affected by external factors such as light, heat, and oxygen during processing and use, and aging phenomena such as hardening, stickiness, powdering, cracking, and discoloration occur, which greatly shortens the service life. In order to extend the service life of polymer materials and enhance the performance of materials during processing and use, antioxidants are usually added to polymers to inhibit or delay the occurrence of oxidation reactions.

[0003] Antioxidants generally prevent oxidation reactions by capturing free radicals and removing hydroperoxides. Among them, amine antioxidants with good antioxidant effects were used the earliest, phenolic antioxidants with low toxicity and light color were the most widely used, and phosphite and thioether antioxidants generally act as auxiliary antioxidants to decompose peroxides. Since a single antioxidant cannot meet the use requirements, compound antioxidants have gradually become the mainstream development trend in recent years. Compound antioxidants can greatly increase the protective effect of polymers by providing free radical capture and peroxide decomposition, long-term protection and intense oxidation protection in a short period of time through the synergistic effect between various antioxidants. Due to the limitations of polymer production, liquid compound antioxidants have outstanding advantages in ease of use. However, the general liquid compound antioxidant is used at room temperature and is easy to solidify at a lower temperature, which increases the complexity of use. Some antioxidants with low melting points have the problem of low boiling points and easy volatility, and cannot be used in liquid compound antioxidants.

[0004] In order to solve the above problems, the present invention reduces the melting point of the compound antioxidant by using components with low melting point and high boiling point, provides an antioxidant that will not solidify at low temperature, and increases the convenience of using the compound antioxidant. Summary of the invention

[0005] The present invention provides a low melting point compound antioxidant and a preparation method thereof. Compared with other compound antioxidants, the present invention can prevent the compound antioxidant from solidifying at low temperature, thereby improving the convenience of using the compound antioxidant.

[0006] A low melting point compound antioxidant and a preparation method thereof, characterized in that, calculated by weight, the compound antioxidant comprises: 20-80 parts of a low melting point mixed phenolic antioxidant, and 20-80 parts of a mixture of one or more of phenolic, amine, phosphite and thioether antioxidants.

[0007] Among them, the low melting point composite antioxidant and its preparation method are characterized in that the structural formula of the low melting point mixed phenolic antioxidant is

[0008]

[0009] Wherein, n is a mixture of at least two kinds of straight-chain alkanes with 8-15 carbon atoms in any proportion, or a mixture of at least two kinds of branched-chain alkanes with 8-15 carbon atoms in any proportion, or a mixture of at least two kinds of cycloalkanes with 8-15 carbon atoms in any proportion, or a mixture of at least two kinds of straight-chain alkanes, branched-chain alkanes and cycloalkanes with 8-15 carbon atoms in any proportion. Because long-chain alkanes with regular molecular structure are easy to crystallize, resulting in an increase in the melting point of the substance, the present invention uses mixed alkanes with different atomic numbers and molecular structures to break the regularity of the molecular structure arrangement, reduce the melting point of the substance, and compound with other antioxidants to prepare a low-melting-point compound antioxidant, which greatly increases the convenience of low-temperature operation.

[0010] Among them, a low melting point composite antioxidant and its preparation method are characterized in that the phenolic antioxidant is a mixture of one or more of monosubstituted phenol, polysubstituted phenol and polyphenolic antioxidant in any proportion. Preferably, the phenolic antioxidant is 2,4-di(n-octylthiomethylene)-6-methylphenol [CAS: 110553-27-0], β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate [CAS: 125643-61-0] and a mixture of the two in any proportion.

[0011] Wherein, the amine antioxidant is a diaryl secondary amine antioxidant, an alkylaryl secondary amine and an aromatic diprimary amine antioxidant, or a mixture of any proportions thereof. Preferably, the amine antioxidant is a reaction product of N-phenylaniline and 2,4,4-trimethylpentene [CAS: 68411-46-1].

[0012] Wherein, the phosphite antioxidant is one or a mixture of any proportion of alkyl phosphites, aryl phosphites and alkyl aryl phosphites. Preferably, the phosphite antioxidant is tris(nonylphenyl) phosphite [CAS: 26523-78-4], tri-C12-15-alkyl phosphite [CAS: 68610-62-8], diisodecyl phenyl phosphite [CAS: 25550-98-5] and a mixture of any proportion of the three.

[0013] Wherein, the thioether antioxidant is one or a mixture of any proportion of thioester antioxidants. Preferably, the thioether antioxidant is didodecyl thiodipropionate [CAS: 123-28-4], didecyl thiodipropionate [CAS: 693-36-7], 3,3-ditetradecyl thiodipropionate [CAS: 16545-54-3] and a mixture of any proportion of the three.

[0014] Furthermore, the present invention also discloses a method for preparing the low melting point composite antioxidant, which comprises the following steps:

[0015] According to the mass fraction of each component of the low-melting point compound antioxidant, the antioxidants are added into the reaction kettle in sequence, and after stirring for 10-120 minutes, samples are taken for testing, and the low-melting point compound antioxidant is obtained after the test is qualified.

[0016] The present invention uses mixed phenols with different molecular chain structures to break the regularity of the molecular structure of the phenolic antioxidant, reduce the melting point and maintain a high boiling point, and compound with other antioxidants to provide an antioxidant that will not solidify at low temperatures, thereby increasing the convenience of using the compounded antioxidant. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0018] Comparative Example 1

[0019] The compound antioxidant is composed of the following antioxidants in parts by weight:

[0020] 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid n-octadecanol ester, 20 parts of 2,4-di(n-octylthiomethylene)-6-methylphenol, 20 parts of the reaction product of N-phenylaniline and 2,4,4-trimethylpentene, 20 parts of tris(nonylphenyl)phosphite, and 20 parts of didodecanol thiodipropionate.

[0021] The preparation method is as follows:

[0022] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 60°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. If the samples were qualified, a solid-liquid mixed composite antioxidant was obtained.

[0023] Comparative Example 2

[0024] The compound antioxidant is composed of the following antioxidants in parts by weight:

[0025] 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isooctyl ester, N,N'-di-sec-butyl-p-phenylenediamine, tri-C12-15-alkyl phosphite, diisodecyl phosphite, distearyl thiodipropionate, distearyl thiodipropionate

[0026] The preparation method is as follows:

[0027] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 25°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. The melting point of the composite antioxidant was > 0°C after the test.

[0028] Example 1

[0029] The low melting point compound antioxidant is composed of the following antioxidants in parts by weight:

[0030] Low melting point mixed phenol antioxidant: 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotridecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid tetradecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid tridecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid cyclodecyl ester

[0031] Phenolic antioxidant 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isooctyl ester 20 parts, 2,4-di(n-octylthiomethylene)-6-methylphenol 10 parts

[0032] Amine antioxidant N-phenylaniline reaction products with 2,4,4-trimethylpentene

[0033] Phosphite antioxidants Tri-C12-15-alkyl phosphite

[0034] The preparation method is as follows:

[0035] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 60°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. The melting point of the low-melting-point composite antioxidant was <-10°C.

[0036] Example 2

[0037] The low melting point compound antioxidant is composed of the following antioxidants in parts by weight:

[0038] Low melting point mixed phenol antioxidant: 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isododecyl ester, 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotetradecyl ester, 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid tridecyl ester

[0039] Phenolic antioxidant 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isooctyl ester 10 parts, 2,4-di(n-octylthiomethylene)-6-methylphenol 10 parts

[0040] Amine antioxidant N, N'-di-sec-butyl-p-phenylenediamine 10 parts

[0041] Phosphite antioxidant tri-C12-15-alkyl phosphite 10 parts

[0042] The preparation method is as follows:

[0043] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 25°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. The melting point of the low-melting-point composite antioxidant was <-20°C after the test.

[0044] Example 3

[0045] The low melting point compound antioxidant is composed of the following antioxidants in parts by weight:

[0046] Low melting point mixed phenol antioxidant: 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotridecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isododecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotetradecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid dodecyl ester

[0047] Phenolic antioxidant 2,4-di(n-octylthiomethylene)-6-methylphenol 20 parts

[0048] 20 parts of the reaction product of amine antioxidant N-phenylaniline and 2,4,4-trimethylpentene

[0049] Phosphite antioxidant tris(nonylphenyl phosphite) 10 parts

[0050] Thioether antioxidant 10 parts of didodecanol thiodipropionate

[0051] The preparation method is as follows:

[0052] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 25°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. The melting point of the low-melting-point composite antioxidant was <-10°C after the test.

[0053] Example 4

[0054] The low melting point compound antioxidant is composed of the following antioxidants in parts by weight:

[0055] Low melting point mixed phenol antioxidant: 30 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotridecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isododecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotetradecyl ester

[0056] Phenolic antioxidant 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isooctyl ester 10 parts, 2,4-di(n-octylthiomethylene)-6-methylphenol 20 parts

[0057] Phosphite antioxidants: 10 parts of tris(nonylphenyl)phosphite, 10 parts of diisodecylphenyl phosphite

[0058] The preparation method is as follows:

[0059] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 25°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. The melting point of the low-melting-point composite antioxidant was <-20°C after the test.

[0060] Example 5

[0061] The low melting point compound antioxidant is composed of the following antioxidants in parts by weight:

[0062] Low melting point mixed phenol antioxidant: 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isotetradecyl ester, 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid tetradecyl ester, 10 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid tridecyl ester

[0063] Phenolic antioxidant 2,4-di(n-octylthiomethylene)-6-methylphenol 20 parts

[0064] 10 parts of the reaction product of amine antioxidant N-phenylaniline and 2,4,4-trimethylpentene, 10 parts of N,N'-di-sec-butyl-p-phenylenediamine

[0065] Phosphite antioxidant tri-C12-15-alkyl phosphite 20 parts

[0066] The preparation method is as follows:

[0067] The antioxidants were added into the reactor in sequence according to the weight ratio, the temperature was 25°C, the stirring speed was 50 rpm, and samples were taken for testing after stirring for 60 minutes. The melting point of the low-melting-point composite antioxidant was <-20°C after the test.

[0068] Example 6

[0069] The low melting point compound antioxidant is composed of the following antioxidants in parts by weight:

[0070] Low melting point mixed phenol antioxidant: 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid dodecanol ester, 20 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid tetradecyl ester, 30 parts of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid cyclodecyl ester

[0071] Phenolic antioxidant 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid isooctyl ester 10 parts

[0072] 10 parts of the reaction product of amine antioxidant N-phenylaniline and 2,4,4-trimethylpentene

[0073] Phosphite antioxidant tri-C12-15-alkyl phosphite 10 parts

[0074] The preparation method is as follows: Antioxidant, antioxidant, antioxidant, and antioxidant are added to the reaction kettle, the temperature is 25°C, the stirring speed is 50rpm, and samples are taken for testing after stirring for 60 minutes. After the test, the melting point of the low-melting point composite antioxidant is qualified and is <-20°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 : Molecular structure diagram of low melting point mixed phenolic antioxidants.

Claims

1. A low melting point composite antioxidant and a preparation method thereof, characterized in that: Calculated by weight, it includes: 20-80 parts of low melting point mixed phenol antioxidant, and 20-80 parts of a mixture of one or more of phenol, amine, phosphite and thioether antioxidants.

2. A low melting point composite antioxidant and a preparation method thereof according to claim 1, characterized in that: The structural formula of the low melting point mixed phenol antioxidant is Wherein, n is a mixture of at least two of the straight-chain alkanes having 8 to 15 carbon atoms in any proportion, or a mixture of at least two of the branched-chain alkanes having 8 to 15 carbon atoms in any proportion, or a mixture of at least two of the cycloalkanes having 8 to 15 carbon atoms in any proportion, or a mixture of at least two of the straight-chain alkanes, branched-chain alkanes and cycloalkanes having 8 to 15 carbon atoms in any proportion.

3. A low melting point composite antioxidant and a preparation method thereof according to claim 1, characterized in that: The phenolic antioxidant is a mixture of one or more of monosubstituted phenol, polysubstituted phenol and polyphenolic antioxidants in any proportion.

4. A low melting point composite antioxidant and a preparation method thereof according to claim 3, characterized in that: The amine antioxidant is a diaryl secondary amine antioxidant, an alkyl aryl secondary amine antioxidant and an aromatic diprimary amine antioxidant, or a mixture of any proportions of the two or more thereof.

5. A low melting point composite antioxidant and a preparation method thereof according to claim 3, characterized in that: The phosphite antioxidant is one or a mixture of any proportion of alkyl phosphites, aryl phosphites and alkyl aryl phosphites.

6. A low melting point composite antioxidant and a preparation method thereof according to claim 1, characterized in that: The thioether antioxidant is one or a mixture of several thioester antioxidants in any proportion.

7. A low melting point composite antioxidant and a preparation method thereof according to claim 1, characterized in that: The low melting point compound antioxidant and its preparation method are as follows: according to the mass fraction of each component of the low melting point compound antioxidant, the antioxidant is added into the reaction kettle in sequence, and after stirring for 10-120 minutes, sampling and testing are performed, and the low melting point compound antioxidant is obtained after the test is qualified.

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