阅读说明：本技术 一种高效复合抗氧剂及其制备方法和应用 (Efficient composite antioxidant and preparation method and application thereof ) 是由 朱浩良 潘勇 于 2019-10-15 设计创作，主要内容包括：本发明涉及抗氧剂领域,更具体地,本发明涉及一种高效复合抗氧剂及其制备方法和应用。所述高效复合抗氧剂,制备原料至少包括：受阻酚类抗氧化剂35-70份、硫醚类抗氧剂2-8份、磷类抗氧剂15-50份、硫代二丙酸双酯1-5份、改性二氧化硅2-3份、催化剂0.03-0.05份。本发明采用长链烷氧基硅烷与烯基烷氧基硅烷对纳米二氧化硅进行改性,制备得到改性二氧化硅进一步与各种氧化剂进行复配得到高效复合抗氧剂,其可应用于聚烯烃体系,不仅提高了材料的抗老化、抗冲压性能,而且也提高了复合抗氧化剂在聚烯烃体系中的耐抽提性与长久稳定性。(The invention relates to the field of antioxidants, in particular to a high-efficiency composite antioxidant and a preparation method and application thereof. The preparation raw materials of the high-efficiency composite antioxidant at least comprise: 35-70 parts of hindered phenol antioxidant, 2-8 parts of thioether antioxidant, 15-50 parts of phosphorus antioxidant, 1-5 parts of thiodipropionic acid diester, 2-3 parts of modified silicon dioxide and 0.03-0.05 part of catalyst. According to the invention, long-chain alkoxy silane and alkenyl alkoxy silane are adopted to modify nano silicon dioxide, the prepared modified silicon dioxide is further compounded with various oxidants to obtain the high-efficiency composite antioxidant, and the high-efficiency composite antioxidant can be applied to a polyolefin system, so that the ageing resistance and the impact resistance of the material are improved, and the extraction resistance and the long-term stability of the composite antioxidant in the polyolefin system are also improved.)

1. The efficient composite antioxidant is characterized by comprising the following preparation raw materials in parts by weight: 35-70 parts of hindered phenol antioxidant, 2-8 parts of thioether antioxidant, 15-50 parts of phosphorus antioxidant, 1-5 parts of thiodipropionic acid diester, 2-3 parts of modified silicon dioxide and 0.03-0.05 part of catalyst.

2. The efficient composite antioxidant as claimed in claim 1, wherein the hindered phenolic antioxidant is selected from one or more of pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-octadecyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, methyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, and methyl 3, 5-di-tert-butyl-4-hydroxy-benzoate.

3. The efficient composite antioxidant as claimed in claim 1, wherein the thioether antioxidant is selected from one or more of bis-benzyl sulfide, 2 '-thiobis (4-methyl-6-tert-butylphenol), and 4, 4' -thiobis (6-tert-butyl-m-cresol).

4. The efficient composite antioxidant as claimed in claim 1, wherein the phosphorus-based antioxidant is bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite and/or tris [2, 4-di-tert-butylphenyl ] phosphite.

5. The efficient composite antioxidant as claimed in claim 1, wherein the diester thiodipropionate is selected from one or more of the group consisting of ditetradecyl thiodipropionate, ditridecyl thiodipropionate, dilauryl thiodipropionate, and distearyl thiodipropionate.

6. The efficient composite antioxidant as claimed in claim 1, wherein the modified silica raw material comprises nano silica and silane compound.

7. The efficient composite antioxidant as claimed in claim 6, wherein the silane compound comprises long chain alkoxy silane and alkenyl alkoxy silane.

8. The efficient composite antioxidant as claimed in claim 7, wherein the weight ratio of the nano-silica, the long-chain alkoxysilane and the alkenylalkoxysilane is 1: (3-9): (3-9).

9. The preparation method of the high-efficiency compound antioxidant as claimed in any one of claims 1 to 8, characterized by comprising at least the following steps:

(1) stirring and melting hindered phenol antioxidant, thioether antioxidant, phosphorus antioxidant and thiodipropionic acid diester to obtain a mixture;

(2) adding the modified silicon dioxide and a catalyst into the mixture, stirring and reacting under the protection of inert gas, filtering, washing and drying to obtain the catalyst.

10. The use of the high-efficiency compound antioxidant according to any one of claims 1 to 8, wherein the high-efficiency compound antioxidant is used as a filler material of a polyolefin compound system.

Technical Field

The invention relates to the field of antioxidants, in particular to a high-efficiency composite antioxidant and a preparation method and application thereof.

Background

During the storage and use of polyolefin materials, the polyolefin materials are inevitably interfered by external factors such as illumination, heating, catalytic action of metal ions and the like, so that the surfaces of the polyolefin materials gradually become hard and brittle, discolor, crack, stickiness and the like, the air permeability of the materials is increased, the mechanical properties are reduced, the elongation and the like are greatly reduced, and finally the use value is lost, wherein the phenomenon is called aging of the materials. In particular, methyl branches in polyolefin are easily attacked by free radicals, and are combined with oxygen to form peroxy radicals, so that the problem of thermal oxygen aging is more prominent. Therefore, an antioxidant, which is a substance capable of retarding the aging of polyolefin materials, is added in the preparation process of the polyolefin materials. The antioxidant can prolong the service life of the polyolefin material and improve the use value of the polyolefin material.

At present, the common antioxidant varieties are mainly as follows: phenolic antioxidants, amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like. However, most of the current antioxidants are organic molecules with lower molecular weight, have stronger migration capability and weaker solvent extraction resistance, are easy to hydrolyze in water, have relatively poorer durability and long-acting property in the using process and influence the acting efficiency of the antioxidants in polymers. In addition, in the field of polyolefin materials, high requirements are placed on the mechanical properties, particularly the anti-impact performance, of the composite material after the antioxidant is added.

Disclosure of Invention

In order to solve the technical problems, the first aspect of the invention provides a high-efficiency composite antioxidant, which at least comprises the following raw materials in parts by weight: 35-70 parts of hindered phenol antioxidant, 2-8 parts of thioether antioxidant, 15-50 parts of phosphorus antioxidant, 1-5 parts of thiodipropionic acid diester, 2-3 parts of modified silicon dioxide and 0.03-0.05 part of catalyst.

In a preferred embodiment of the present invention, the hindered phenol antioxidant is selected from one or more of pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-octadecyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, methyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, and methyl 3, 5-di-tert-butyl-4-hydroxy-benzoate.

In a preferred embodiment of the present invention, the thioether antioxidant is one or more selected from the group consisting of bis-benzyl sulfide, 2 '-thiobis (4-methyl-6-tert-butylphenol), and 4, 4' -thiobis (6-tert-butyl-m-cresol).

As a preferred technical scheme of the invention, the phosphorus antioxidant is bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite and/or tris [2, 4-di-tert-butylphenyl ] phosphite.

In a preferred embodiment of the present invention, the dipropionic acid diester is one or more selected from the group consisting of ditetradecyl thiodipropionate, ditridecyl thiodipropionate, dilauryl thiodipropionate and distearyl thiodipropionate.

As a preferable technical scheme of the invention, the raw materials for preparing the modified silicon dioxide comprise nano silicon dioxide and a silane compound.

In a preferred embodiment of the present invention, the silane compound includes a long-chain alkoxysilane and an alkenylalkoxysilane.

As a preferable technical scheme of the present invention, the weight ratio of the nano-silica, the long-chain alkoxysilane, and the alkenylalkoxysilane is 1: (3-9): (3-9).

The second aspect of the invention provides a preparation method of a high-efficiency composite antioxidant, which at least comprises the following steps:

(1) stirring and melting hindered phenol antioxidant, thioether antioxidant, phosphorus antioxidant and thiodipropionic acid diester to obtain a mixture;

(2) adding the modified silicon dioxide and a catalyst into the mixture, stirring and reacting under the protection of inert gas, filtering, washing and drying to obtain the catalyst.

The third aspect of the invention provides an application of a high-efficiency composite antioxidant, wherein the high-efficiency composite antioxidant is applied to a filling material of a polyolefin composite system.

Has the advantages that: the invention provides a high-efficiency composite antioxidant and a preparation method and application thereof, wherein long-chain alkoxy silane and alkenyl alkoxy silane are adopted to modify nano silicon dioxide, the prepared modified silicon dioxide is further compounded with various oxidants to obtain the high-efficiency composite antioxidant, the high-efficiency composite antioxidant can be used as a filling material of a polyolefin composite system, the problem that the antioxidant is easy to absorb moisture and unstable is solved, the extraction resistance and the long-term stability of the composite antioxidant in the polyolefin system are improved, and the ageing resistance and the impact resistance of a polymer in the processing and using processes are also improved.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

In order to solve the technical problems, the first aspect of the invention provides a high-efficiency composite antioxidant, which at least comprises the following raw materials in parts by weight: 35-70 parts of hindered phenol antioxidant, 2-8 parts of thioether antioxidant, 15-50 parts of phosphorus antioxidant, 1-5 parts of thiodipropionic acid diester, 2-3 parts of modified silicon dioxide and 0.03-0.05 part of catalyst.

In a preferred embodiment, the high-efficiency composite antioxidant is prepared from at least the following raw materials in parts by weight: 52 parts of hindered phenol antioxidant, 5 parts of thioether antioxidant, 32 parts of phosphorus antioxidant, 3 parts of thiodipropionic acid diester, 40 parts of organic solvent, 2 parts of modified silicon dioxide and 0.04 part of catalyst.

<Hindered phenol antioxidants>

The hindered phenol antioxidant is a phenol compound with a space hindered structure, is mainly used for plastic products, and shows a synergistic effect with auxiliary antioxidants such as phosphite ester, thioether and the like.

In one embodiment, the hindered phenolic antioxidant is selected from one or more combinations of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (CAS: 6683-19-8), n-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS: 2082-79-3), methyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS: 6386-38-5), methyl 3, 5-di-tert-butyl-4-hydroxy-benzoate (CAS: 2511-22-0).

In a preferred embodiment, the hindered phenolic antioxidant is pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ].

<Thioether antioxidant>

The thioether antioxidant according to the present invention is a substance which does not contain an ester group and acts to scavenge hydrogen peroxide present in a polymer.

In one embodiment, the thioether antioxidant is selected from the group consisting of one or more combinations of dibenzyl sulfide (CAS: 538-74-9), 2 '-thiobis (4-methyl-6-tert-butylphenol) (CAS: 90-66-4), 4' -thiobis (6-tert-butyl-m-cresol) (CAS: 96-69-5).

In a preferred embodiment, the thioether antioxidant is bis-benzyl sulfide.

<Phosphorus antioxidant>

The phosphorus antioxidant is a phosphorus-containing organic compound capable of decomposing hydrogen peroxide.

In one embodiment, the phosphorus-based antioxidant is bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite (CAS: 26741-53-7) and/or tris [2, 4-di-tert-butylphenyl ] phosphite (CAS: 31570-04-4).

In a preferred embodiment, the phosphorus antioxidant is bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite.

<Thiodipropionic acid diester>

The thiodipropionate diester is an auxiliary antioxidant which is used together with a hindered phenol antioxidant.

In one embodiment, the bis-ester of thiodipropionic acid is selected from one or more combinations of bis (tetradecyl) thiodipropionate (CAS: 16545-54-3), bis (isotridecyl) thiodipropionate (CAS: 10595-72-9), dilauryl thiodipropionate (CAS: 123-28-4), and distearyl thiodipropionate (CAS: 693-36-7).

In a preferred embodiment, the dipropionate diester is dipropionate ditetradecanol.

<Modified silica>

The modified silicon dioxide is prepared by modifying nano silicon dioxide.

In one embodiment, the modified silica preparation raw material comprises nano silica and a silane compound.

In a preferred embodiment, the silane compound includes a long chain alkoxysilane and an alkenylalkoxysilane.

Nano silicon dioxide

The invention is not particularly limited to the manufacturers who purchase the nano-silica, and in one embodiment, the nano-silica is amorphous white powder, is nontoxic, tasteless and pollution-free, has a spherical microstructure, is in a flocculent and reticular quasi-particle structure, and is purchased from Hangzhou Wanjing New Material Co., Ltd, and has the model number of K-SP 30.

Long chain alkoxysilanes

The long-chain alkoxy silane is an alkoxy silane with 12-14 carbon atoms.

In one embodiment, the long chain alkoxysilane is selected from one or more combinations of dodecyl trimethoxysilane (CAS: 3069-21-4), dodecyl triethoxysilane (CAS: 18536-91-9), tetradecyl triethoxysilane (CAS: 16153-27-8), dodecyl (methyl) dimethoxysilane (CAS: 163131-89-3).

In a preferred embodiment, the long chain alkoxysilane is dodecyl (methyl) dimethoxysilane.

Alkenylalkoxysilanes

The alkenyl alkoxy silane is alkoxy silane containing unsaturated bond double bonds.

In one embodiment, the alkenylalkoxysilane is selected from one or more combinations of vinyltriisopropoxysilane (CAS: 18023-33-1), [ (E) -but-2-enyl ] -triethoxysilane (CAS: 13436-82-3), methylvinyldimethoxysilane (CAS: 16753-62-1), allyltriethoxysilane (CAS: 2550-04-1), allyltrimethoxysilane (CAS: 2551-83-9).

In a preferred embodiment, the alkenylalkoxysilane is vinyltriisopropoxysilane.

In a more preferred embodiment, the weight ratio of nanosilica, long chain alkoxysilane to alkenylalkoxysilane is from 1: (3-9): (3-9); more preferably, the weight ratio of the nanosilica, the long-chain alkoxysilane and the alkenylalkoxysilane is 1: 6: 6.

the preparation process of the modified silicon dioxide comprises the following steps: dispersing nano silicon dioxide in absolute ethyl alcohol, then sequentially adding dodecyl (methyl) dimethoxysilane and vinyl triisopropoxysilane into the absolute ethyl alcohol, adjusting the pH to 10 with ammonia water, magnetically stirring the mixture at the temperature of 60-80 ℃ to react for 3-5 h to obtain a reaction product, repeatedly washing and filtering the reaction product for three times by using methanol, removing unreacted substances, and drying the reaction product in vacuum to obtain the nano silicon dioxide; the mass ratio of the total mass of the nano silicon dioxide, the long-chain alkoxy silane and the alkenyl alkoxy silane to the absolute ethyl alcohol is 1: 5.

<catalyst and process for preparing same>

The catalyst of the present invention is a catalyst for transesterification.

In one embodiment, the catalyst is selected from one or more of p-toluenesulfonic acid, sodium methoxide, potassium tert-butoxide, anhydrous potassium carbonate.

In a preferred embodiment, the catalyst is sodium methoxide (CAS: 124-41-4).

The second aspect of the invention provides a preparation method of a high-efficiency composite antioxidant, which at least comprises the following steps:

(1) stirring and melting hindered phenol antioxidant, thioether antioxidant, phosphorus antioxidant and thiodipropionic acid diester to obtain a mixture;

(2) adding the modified silicon dioxide and a catalyst into the mixture, stirring and reacting under the protection of inert gas, filtering, washing and drying to obtain the catalyst.

In a preferred embodiment, the preparation method of the high-efficiency compound antioxidant at least comprises the following steps:

(1) stirring and melting hindered phenol antioxidant, thioether antioxidant, phosphorus antioxidant and thiodipropionic acid diester at 80-120 ℃ to obtain a mixture;

(2) adding the modified silicon dioxide and a catalyst into the mixture, stirring and reacting for 4-6 h at 120-130 ℃ under the protection of inert gas, filtering after reaction to obtain a product, washing for three times by using 50-110 mL of organic solvent, and drying for 6-8 h in a vacuum drying oven at 100-120 ℃ to obtain the catalyst.

<Organic solvent>

The organic solvent is mainly used as a washing solvent.

In one embodiment, the organic solvent is selected from one or more of methanol, ethanol, acetone, xylene, N-dimethylformamide in combination.

In a preferred embodiment, the organic solvent is ethanol.

The third aspect of the invention provides an application of a high-efficiency composite antioxidant, wherein the high-efficiency composite antioxidant is applied to a filling material of a polyolefin composite system.

In the process of preparing the composite antioxidant, although the positive synergistic effect among the antioxidants can bring about better antioxidant effect, simultaneously, as a plurality of antioxidants, particularly phosphorus antioxidants, are easy to hydrolyze in water, the long-term use and storage of the antioxidants are influenced, namely the durability is poor; and the used hindered phenol antioxidants and thioether antioxidants have the problems of strong migration capability and poor extraction resistance, and greatly influence the use of materials in the processing and long-term aging processes of polyolefin substances, thereby limiting the application of the composite antioxidants. In the experimental process, the inventor finds that the antioxidant performance of the composite antioxidant obtained by reacting various antioxidants with modified silicon dioxide is greatly improved, the solvent extraction resistance is enhanced, the durability and the long-acting performance in the use process are better, and the impact resistance of the material is improved. The reason for this is probably that in the preparation process of the modified silica, the hydrolyzed long-chain alkoxysilane generates hydroxyl, the existence of the long-chain structure brings steric hindrance, which hinders the progress of the condensation polymerization reaction, more dehydration condensation occurs with the hydroxyl of the nano-silica to form the modified silica with inactive long-chain alkyl, and the modified silica is not easy to absorb moisture because the sigma bond in the alkyl has very small polarity and the dipole moment of the molecule is zero, which belongs to an nonpolar molecule, so that the durability of the antioxidant is enhanced. In addition, the existence of long-chain alkyl in the product can bring about improvement of the flexibility of the modified silicon dioxide, so that the framework of the modified silicon dioxide is relatively flexible, and the modified silicon dioxide can be added into a polyolefin system to synergistically improve the mechanical strength of the material, particularly the anti-impact performance of the material after the modified silicon dioxide is acted with a hindered phenol antioxidant of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, a phosphorus antioxidant of bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite and the like. In addition, probably because alkenyl alkoxy silane added in the modification process of silicon dioxide is hydrolyzed and then condensed with hydroxyl on the surface of nano silicon dioxide, on one hand, hydrophobic groups are introduced to further improve the hydrophobicity of the system, and on the other hand, the introduced unsaturated bonds can graft the composite antioxidant on polyolefin macromolecules, so that the composite antioxidant with better dispersity and solvent extraction resistance is obtained, meanwhile, the fixation of the composite antioxidant on the polyolefin macromolecules is realized, and the durability of use is improved.

In addition, the inventor finds out through experiments that the addition of the long-chain alkoxy silane is not suitable for too much, otherwise, the impact resistance of the prepared composite antioxidant is greatly reduced after the composite antioxidant is added into the polyolefin, probably because the long-chain alkoxy silane can cause too much flexibility of the material so as to influence the stamping resistance.