阅读说明：本技术 一种道路沥青光稳定剂及其制备方法 (Road asphalt light stabilizer and preparation method thereof ) 是由 陈团结 樊孟孟 曹海波 臧晓宁 许丽 皎晓明 苗思雨 闫朗 于 2021-09-29 设计创作，主要内容包括：本发明涉及一种道路沥青光稳定剂及其制备方法。将马来酸酐溶入溶剂中,并不断搅拌,加入共轭双烯后逐渐升到60～90℃,恒温搅拌1～3h后,得到新的酸酐。新的酸酐加入三口烧瓶中,并加入溶剂,搅拌加热到60～80℃,在30min内滴加完2,2,6,6-四甲基-4-哌啶醇,反应2～3h后,冷却至常温,采用无水乙醇冲洗3次,过滤,之后在60℃真空环境下干燥,得到邻二酸单四甲基哌啶醇酯。邻二酸单四甲基哌啶醇酯加入三口烧瓶中,加入固体氢氧化钠和溶剂,逐渐升温到50℃并不断搅拌,待完全溶解后加入盐,保温搅拌1h后,冷却至常温,过滤,干燥,得到目标产物,邻二酸单四甲基哌啶醇酯盐。本发明具有持久有效的光稳定效果,且原料安全可靠,制备易于控制,操作简单。(The invention relates to a road asphalt light stabilizer and a preparation method thereof. Dissolving maleic anhydride into a solvent, continuously stirring, gradually increasing the temperature to 60-90 ℃ after adding conjugated diene, and stirring at constant temperature for 1-3 h to obtain new anhydride. Adding new anhydride into a three-neck flask, adding a solvent, stirring and heating to 60-80 ℃, dropwise adding 2,2,6, 6-tetramethyl-4-piperidinol within 30min, reacting for 2-3 h, cooling to normal temperature, washing for 3 times by using absolute ethyl alcohol, filtering, and drying at 60 ℃ in a vacuum environment to obtain the o-diacid mono-tetramethyl piperidinol ester. Adding o-diacid mono-tetramethyl piperidinol ester into a three-neck flask, adding solid sodium hydroxide and a solvent, gradually heating to 50 ℃, continuously stirring, adding salt after complete dissolution, keeping the temperature and stirring for 1h, cooling to normal temperature, filtering, and drying to obtain a target product, i.e. o-diacid mono-tetramethyl piperidinol ester salt. The invention has lasting and effective light stabilization effect, safe and reliable raw materials, easy preparation control and simple operation.)

1. A preparation method of a road asphalt light stabilizer comprises the following steps:

(1) dissolving maleic anhydride into a solvent, continuously stirring, adding conjugated diene, gradually increasing the molar ratio of the maleic anhydride to the conjugated diene to be 1.04-1.15: 1 to 60-90 ℃, stirring at a constant temperature for 1-3 h, cooling to room temperature, filtering, and drying to obtain new anhydride;

(2) adding new anhydride into a three-neck flask, adding a solvent, stirring and heating to 60-80 ℃, dropwise adding 2,2,6, 6-tetramethyl-4-piperidinol within 30min, cooling to normal temperature after reacting for 2-3 h, washing with absolute ethyl alcohol for several times, filtering, and drying at 60 ℃ in a vacuum environment to obtain mono-tetramethyl piperidinol ortho-diacid;

(3) adding o-diacid mono-tetramethyl piperidinol ester into a three-neck flask, adding solid sodium hydroxide and a solvent, gradually heating to 50 ℃, continuously stirring, adding salt after complete dissolution, keeping the temperature and stirring for 1h, cooling to normal temperature, filtering, and drying to obtain a target product, i.e. o-diacid mono-tetramethyl piperidinol ester salt.

2. The method for preparing the road asphalt light stabilizer according to claim 1, wherein in the step (1), the conjugated diene is a conjugated diene with 4-18 carbons such as furan, anthracene, butadiene or isoprene.

3. The method for preparing a road asphalt light stabilizer according to claim 1 or 2, wherein in the step (1), the solvent is toluene, xylene, acetone or a mixture thereof.

4. The method for preparing the road asphalt light stabilizer according to claim 3, wherein in the step (2), the solvent is a mixed solution of xylene and N-methylpyrrolidine with a mass ratio of 3: 1.

5. The method for preparing the road asphalt light stabilizer according to claim 4, wherein in the step (3), the solvent is acetone or methanol.

6. The method for preparing a road asphalt light stabilizer as claimed in claim 5, wherein in the step (3), the added salt is chloride, nitrate or acetate containing calcium, magnesium and zinc.

7. The method for preparing a road asphalt light stabilizer according to claim 6, wherein in the step (3), the salt added is calcium chloride.

8. The road asphalt light stabilizer prepared by the method for preparing the road asphalt light stabilizer according to claim 1.

Technical Field

The invention belongs to the technical field of road materials, and particularly relates to a road asphalt light stabilizer and a preparation method thereof.

Background

The construction of high-grade roads in China tends to be gradually improved, wherein most high-grade pavements select asphalt with relatively better performance as a bonding material. Asphalt is used as a high polymer material mixture, the performance of the asphalt is greatly influenced by the external environment, particularly the influence of ultraviolet rays is most prominent, and particularly, the aging resistance of the asphalt pavement in northwest plateau areas of China is poorer, so that pavement diseases are frequent, and the normal service of the asphalt pavement is seriously influenced. At home and abroad, many research reports on asphalt aging exist, but research and development on asphalt light stabilizers are relatively few, and the following methods are mainly adopted: firstly, the asphalt is modified by adopting the layered montmorillonite, and the method has a certain effect on improving the thermal oxidation and the light stability of the asphalt. But the anti-aging performance of the asphalt is not obviously improved because the asphalt cannot be well and uniformly dispersed in the asphalt; and secondly, the nano material is adopted to modify the asphalt so as to improve the light stability of the asphalt. The method has the advantages that the anti-aging performance of the modified asphalt is improved obviously, but the problems of easy agglomeration and insufficient dispersibility of the nano particles after the nano particles are contacted with the asphalt still exist, and other solvents are mostly needed to dissolve the nano particles firstly or dissolve the nano particles into the asphalt after the surface treatment; thirdly, the existing light stabilizer is adopted to modify the asphalt, and the method has limited effect of improving the light stability of the asphalt and weak pertinence. The main reason is that the existing light stabilizer is widely applied to material systems with fixed molecular structures such as plastics, rubber or textiles, and the system with complex composition such as road asphalt has weak pertinence.

Disclosure of Invention

The invention aims to provide a road asphalt light stabilizer and a preparation method thereof, which aim to solve the problems that in the prior art, ultraviolet rays have great influence on an asphalt pavement, so that pavement diseases are frequent and the normal service of the asphalt pavement is seriously influenced.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a preparation method of a road asphalt light stabilizer comprises the following steps:

(1) dissolving maleic anhydride into a solvent, continuously stirring, adding conjugated diene, gradually increasing the molar ratio of the maleic anhydride to the conjugated diene to 60-90 ℃ at a ratio of 1.02-1.15: 1, stirring at a constant temperature for 1-3 h, cooling to room temperature, filtering, and drying to obtain new anhydride;

(2) adding new anhydride into a three-neck flask, adding a solvent, stirring and heating to 60-80 ℃, dropwise adding 2,2,6, 6-tetramethyl-4-piperidinol within 30min, cooling to normal temperature after reacting for 2-3 h, washing with absolute ethyl alcohol for several times, filtering, and drying at 60 ℃ in a vacuum environment to obtain mono-tetramethyl piperidinol ortho-diacid;

(3) adding o-diacid mono-tetramethyl piperidinol ester into a three-neck flask, adding solid sodium hydroxide and a solvent, gradually heating to 50 ℃, continuously stirring, adding salt after complete dissolution, keeping the temperature and stirring for 1h, cooling to normal temperature, filtering, and drying to obtain a target product, i.e. o-diacid mono-tetramethyl piperidinol ester salt.

In the step (1), the conjugated diene is furan, anthracene, butadiene or isoprene with 4-18 carbon atoms.

In the step (1), the solvent is toluene, xylene, acetone or the like or a mixture thereof.

In the step (2), the solvent is a mixed solution of xylene and N-methylpyrrolidine with a mass ratio of 3: 1.

In the step (3), the solvent is acetone or methanol.

In the step (3), the added salt is chloride, nitrate or acetate containing calcium, magnesium and zinc.

In the step (3), the salt added is calcium chloride.

The road asphalt light stabilizer prepared by the preparation method.

Compared with the prior art, the invention has the following advantages:

1. the road asphalt light stabilizer obtained by the invention is synthesized by adopting raw materials with better asphalt solubility, and simultaneously, chloride, nitrate or acetate containing calcium, magnesium and zinc are added in the preparation process, so that the light stabilizer can be hydrated into organic salt, and the light stabilizer can be uniformly dispersed in asphalt to obtain a lasting and effective light stabilization effect.

2. Aiming at the research of the composition structure of the road asphalt, the invention adopts the raw materials with better asphalt solubility, namely 4-18 carbon conjugated diene and maleic anhydride, and the optically sensitive substance 2,2,6, 6-tetramethyl-4-piperidinol to carry out chemical synthesis, and simultaneously introduces metal ions to prepare the specific organic salt asphalt light stabilizer. The hindered amine structure asphalt light stabilizer can form a stable and uniform blending system with asphalt, so that the light stability of the asphalt is durably and obviously improved. The light stability effect is good, and the aging resistance of the pavement is improved.

3. The preparation method has the advantages of safe and reliable raw materials, easy control of preparation and simple operation. The product of the invention is particularly suitable for being used on asphalt pavements in northwest plateau areas in China, effectively reduces pavement diseases, prolongs the normal service of the asphalt pavements, and has great popularization and application significance.

Detailed Description

The present invention will be described in detail with reference to specific embodiments.

The preparation method of the road asphalt light stabilizer provided by the invention comprises the following three steps of reaction:

example 1: a preparation method of a road asphalt light stabilizer comprises the following steps:

the first step of reaction:

the conjugated diene adopts furan, the molar ratio of maleic anhydride to furan is 1.02:1.0, and the solvent adopts dimethylbenzene.

Adding 20g of maleic anhydride into 250ml of three-neck flask provided with a reflux and stirring device, pouring 100g of dimethylbenzene, continuously stirring, adding 13.6g of furan, gradually raising the temperature to 60 ℃, stirring at constant temperature for 2h, cooling to room temperature, filtering, and drying to obtain the new anhydride.

The second step of reaction:

the molar ratio of the novel acid anhydride to the 2,2,6, 6-tetramethyl-4-piperidinol in the first step is 1.1: 1; xylene and N-methylpyrrolidine are used as solvents according to the mass ratio of 3: 1.

Adding newly prepared 11g of anhydride into a 250ml three-neck flask provided with a reflux and stirring device, adding 100g of mixed solvent, stirring and heating to 60 ℃, dropwise adding 9.4g of 2,2,6, 6-tetramethyl-4-piperidinol within 30min, reacting for 2h, cooling to normal temperature, washing for 3 times by using absolute ethyl alcohol, filtering, and drying at 60 ℃ in a vacuum environment to obtain the o-diacid mono-tetramethyl piperidinol ester.

The third step of reaction:

adding 16g of o-diacid mono-tetramethyl-piperidinol ester into a 100ml three-neck flask provided with a reflux and stirring device, adding 2.1g of solid sodium hydroxide and 40g of methanol, gradually heating to 50 ℃, continuously stirring, adding 2.78g of calcium chloride after complete dissolution, keeping the temperature and stirring for 1h, cooling to normal temperature, filtering, and drying to obtain a target product, i.e. o-diacid mono-tetramethyl-4-piperidinol ester calcium salt.

Example 2

The first step of reaction:

the conjugated diene adopts 1, 3-butadiene, the molar ratio of maleic anhydride to 1, 3-butadiene is 1.08:1.0, and the solvent adopts toluene.

Adding 10.6g of maleic anhydride into 250ml of three-neck flask provided with a reflux and stirring device, pouring 100g of toluene, continuously stirring, adding 5.4g of 1, 3-butadiene, gradually raising the temperature to 60 ℃, stirring at constant temperature for 1h, cooling to room temperature, filtering, and drying to obtain the new anhydride.

The second step of reaction:

the molar ratio of the novel anhydride to 2,2,6, 6-tetramethyl-4-piperidinol in the first step is 1.08: 1; xylene and N-methylpyrrolidine are used as solvents according to the mass ratio of 3: 1.

Adding 9.85g of newly prepared anhydride into 250ml of three-neck flask provided with a reflux and stirring device, adding 100g of mixed solvent, stirring and heating to 60 ℃, dropwise adding 9.4g of 2,2,6, 6-tetramethyl-4-piperidinol within 30min, reacting for 2.5h, cooling to normal temperature, washing for 3 times by using absolute ethyl alcohol, filtering, and drying at 60 ℃ in a vacuum environment to obtain the o-diacid mono-tetramethyl-piperidinol ester.

The third step of reaction: the same as in example 1.

Example 3

The first step of reaction:

the conjugated diene adopts anthracene, the molar ratio of maleic anhydride to anthracene is 1.15:1.0, and the solvent adopts dimethylbenzene.

Adding 11.3g of maleic anhydride into a 250ml three-neck flask provided with a reflux and stirring device, adding 100g of dimethylbenzene, continuously stirring, adding 17.8g of anthracene, gradually raising the temperature to 80 ℃, stirring at constant temperature for 2 hours, cooling to room temperature, filtering, and drying to obtain the new anhydride.

The second step of reaction:

the molar ratio of the novel acid anhydride to the 2,2,6, 6-tetramethyl-4-piperidinol in the first step is 1.12: 1.0; xylene and N-methylpyrrolidine are used as solvents according to the mass ratio of 3: 1.

Adding 18.5g of newly prepared anhydride into a 250ml three-neck flask provided with a reflux and stirring device, adding 100g of mixed solvent, stirring and heating to 70 ℃, dropwise adding 9.4g of 2,2,6, 6-tetramethyl-4-piperidinol within 30min, reacting for 2.5h, cooling to normal temperature, washing for 3 times by using absolute ethyl alcohol, filtering, and drying at 60 ℃ in a vacuum environment to obtain the o-diacid mono-tetramethyl-piperidinol ester.

The third step of reaction:

same as example 1

Example 4

The first step of reaction:

the conjugated diene adopts 2, 4-hexadiene, the molar ratio of maleic anhydride to 2, 4-hexadiene is 1.12:1.0, and the solvent adopts acetone.

Adding 11g of maleic anhydride into a 100ml three-neck flask provided with a reflux and stirring device, adding 40g of acetone, stirring to dissolve, adding 8.2g of 2, 4-hexadiene, gradually raising the temperature to 75 ℃, stirring at a constant temperature for 1.5h, cooling to room temperature, filtering, and drying to obtain the new anhydride.

The second step of reaction:

the molar ratio of the novel acid anhydride to the 2,2,6, 6-tetramethyl-4-piperidinol in the first step is 1.05: 1.0; xylene and N-methylpyrrolidine are used as solvents according to the mass ratio of 3: 1.

Adding 11.3g of newly prepared anhydride into a 250ml three-neck flask provided with a reflux and stirring device, adding 100g of mixed solvent, stirring and heating to 75 ℃, dropwise adding 9.4g of 2,2,6, 6-tetramethyl-4-piperidinol within 30min, reacting for 2h, cooling to normal temperature, washing for 3 times by using absolute ethyl alcohol, filtering, and drying at 60 ℃ in a vacuum environment to obtain the o-diacid mono-tetramethyl piperidinol ester.

The third step of reaction:

adding 16.9 of the o-diacid mono-tetramethyl-piperidinol ester prepared in the previous step into a 100ml three-neck flask provided with a reflux and stirring device, adding 40g of acetone, adding 2.1g of solid sodium hydroxide, continuously stirring, gradually raising the temperature to 50 ℃, adding 2.78g of calcium chloride after complete dissolution, keeping the temperature and stirring for 1h, cooling to the normal temperature, filtering, and drying to obtain the target product, i.e. the o-diacid mono-tetramethyl-4-piperidinol ester calcium salt.

Example 5

The first step of reaction:

the conjugated diene adopts 1, 3-cyclohexadiene, the molar ratio of maleic anhydride to 1, 3-cyclohexadiene is 1.06:1.0, and the solvent adopts acetone.

Adding 10.4g of maleic anhydride into a 100ml three-neck flask provided with a reflux and stirring device, adding 40g of acetone, adding 8.0g of 1, 3-cyclohexadiene while continuously stirring, gradually raising the temperature to 80 ℃, stirring at constant temperature for 3 hours, cooling to room temperature, filtering, and drying to obtain the new anhydride.

The second step of reaction:

the molar ratio of the novel acid anhydride to the 2,2,6, 6-tetramethyl-4-piperidinol in the first step is 1.1: 1.0; xylene and N-methylpyrrolidine are used as solvents according to the mass ratio of 3: 1.

Adding 11.7g of newly prepared anhydride into a 100ml three-neck flask provided with a reflux and stirring device, adding 40g of mixed solvent, stirring and heating to 70 ℃, dropwise adding 9.4g of 2,2,6, 6-tetramethyl-4-piperidinol within 30min, reacting for 2.5h, cooling to normal temperature, washing for 3 times by using absolute ethyl alcohol, filtering, and drying at 60 ℃ in a vacuum environment to obtain the o-diacid mono-tetramethyl-piperidinol ester.

The third step of reaction:

the same as in example 4.