CN1098345C - Antioxidative succinimide dustless dispersing agent - Google Patents

Abstract

The present invention relates to an ashless dispersant with antioxidative succinimide, which is prepared according to the following method: alpha H-phenol, polyene polyamine and formaldehyde are mixed for a Mannich reaction under the condition that 2, 6-ditertiary butyl phenol exists, and condensed amine as an intermediate product is prepared after reaction products are separated; an aminating reaction is carried out between the condensed amine and alkenyl butanedioic anhydride, and a final product is obtained. The polyene polyamine in the dispersant is coupled when oxidation resistant groups are introduced, which increases the content of nitrogen, achieves favorable resistance to high temperature oxidation, improves the dispersibility and ensures favorable oil solubility. Therefore, the present invention can be used for internal combustion engine oil or fuel oil.

Description

Antioxidant succinimide ashless dispersant

The invention relates to an oil additive, specifically a succinimide ashless dispersant with oxidation resistance for internal combustion engine oil or fuel oil.

The succinimide dispersant has been widely used since the 1960s, and it is still the most widely used and the largest amount of dispersant. Its preparation method is: first react polyisobutylene with a molecular weight of 1000-3000 and maleic anhydride, Generate polyisobutenyl maleic anhydride, and then react with different proportions of polyene polyamines to obtain mono-, di-, and polyisobutenyl succinimides.

Due to the wide operating temperature range of the engine, under the operating conditions of stop and go in winter, the temperature of the crankcase of the car is low, and the fuel hydrocarbons and moisture (moisture) are not easily discharged from the lubricating oil, resulting in a large amount of sludge in the engine oil , affecting the normal operation of the engine; in summer, continuous driving causes the operating temperature to rise, and the internal combustion engine oil is prone to oxidation, which causes the viscosity to increase rapidly, and the carbon deposit and paint film on the piston increase. Therefore, internal combustion engine oil is required to have good low-temperature sludge dispersibility and excellent high-temperature oxidation resistance.

US 4973412 discloses a multifunctional lubricating oil additive. Its preparation method is: first use organic dibasic acid coupling partially acylated succinimide, then treat it with unsaturated fatty acid, and finally combine it with The reaction of nitroso-p-phenylenediamine can be obtained. The additive improves the oxidation resistance of succinimide, but its preparation process is relatively complicated.

US 4636322, 4699724, 4713189 disclose coupled succinimide dispersants, which are made of phenol, bisphenol A, resorcinol, monononylphenol or β-naphthol through Mannich reaction coupling butanedi The imide is prepared by acylation of part of the polyene polyamine with glycolic acid. This additive improves dispersibility and adaptability to rubber seals, but does not mention improving oxidation stability.

The purpose of the present invention is to provide a succinimide type ashless dispersant which is different from the structure of the prior art and can not only improve the low-temperature dispersion performance but also enhance the oxidation resistance.

The antioxidant succinimide ashless dispersant provided by the present invention contains the following groups in structure: alkenyl succinyl group, polyene polyamine group coupled with phenol, 2,6- Di-tert-butylphenol. The dispersant is prepared as follows:

(1) In the presence of 2,6-di-tert-butylphenol, mix αH-containing phenol, polyene polyamine and formaldehyde

Combine, carry out Mannich reaction, separate product, make intermediate product condensed amine;

(2) Alkenyl succinic anhydride and the above-mentioned condensed amine are subjected to amination reaction to obtain the final product.

Specifically, the dispersant provided by the invention can be prepared as follows:

(1) Under the protection of nitrogen, mix 2,6-di-tert-butylphenol, phenol containing αH, polyene polyamine and formaldehyde, slowly heat up under stirring, at room temperature ~ 150 ° C, preferably 60 ~ 120 ° C React for 1 to 10 hours, preferably 2 to 8 hours, and distill under reduced pressure to remove water and unreacted substances to obtain a coupled polyene polyamine containing antioxidant groups, that is, condensed amine.

Wherein, the phenol containing αH can be selected from one of phenol, p-cresol, hydroquinone, bisphenol A or β-naphthol, or a mixture of two or more thereof. The molar ratio of polyamine is 1: 1～4, the molar ratio of the phenol containing αH and 2,6-di-tert-butylphenol is 1: 0.2～3, preferably 1: 0.5～2, these two kinds of phenols can be combined with Formaldehyde and polyene polyamine are added to the reactor at the same time, or they can be added later, and the temperature of addition should not exceed 70°C.

The general formula of said polyene polyamine is H ₂ N(CH ₂ CH ₂ NH) _n H, where n is an integer of 1 to 6, such as ethylenediamine (EDA), diethylenetriamine (DETA), tri Ethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (DEHA), etc.

Said formaldehyde can be paraformaldehyde that can be decomposed into formaldehyde after being heated; it can also be an aqueous solution of formaldehyde, preferably a saturated aqueous solution of formaldehyde with a concentration of 36% by weight. If it is paraformaldehyde, it can be mixed with other reactants at the same time; if it is a formaldehyde solution, it is best to mix other reactants first, and then gradually add the formaldehyde solution. The amount of formaldehyde should be in excess, preferably 1 to 2 times the sum of reactive H in αH-containing phenol and 2,6-di-tert-butylphenol.

In the structure of the condensed amine prepared in this step, the phenol containing αH can be connected with 1 to 4 polyene polyamines according to the amount of reactive H contained in it, and can be connected with primary amino groups or with on the secondary amino group. For example, phenol not only has two ortho Hs, but also has a para H that can also participate in the reaction, so there are three reactive Hs. The para-position of 2,6-di-tert-butylphenol can be connected with a polyene polyamine, also can be connected with the primary amino group, and also can be connected with the secondary amino group. The relative content of αH-containing phenol and 2,6-di-tert-butylphenol in the product structure depends on the feed ratio.

(2) In the presence of diluent oil and nitrogen, the condensed amine prepared in step (1) is reacted with alkenyl succinic anhydride at 60 to 160° C., preferably 80 to 140° C., for 1 to 8 hours, preferably 2 to 6 hours, Remove the water generated by the reaction under reduced pressure, and filter to obtain the final ashless dispersant. The amount of alkenyl succinic anhydride added is 0.6 to 3 times, preferably 0.7 to 2.5 times, the molar number of polyene polyamine in step (1). In addition, in order to facilitate the smooth progress of the reaction, alkenyl succinic anhydride can be dissolved in diluent oil under the protection of nitrogen, heated to 60-90°C, and then slowly added condensed amine for reaction.

The alkenyl in said alkenyl succinic anhydride is a C ₂ -C ₁₀ olefin copolymer or homopolymer, preferably polyisobutylene. The number average molecular weight of the alkenyl group can be 500-5000, preferably 900-2500, and the molecular weight distribution is generally 1.5-4.5, preferably 1.5-3.5.

When generating the final product, alkenyl succinic anhydride can be connected to a primary amino group to form an imide; it can also be connected to two secondary amino groups after ring opening to form an amide. Alkenyl succinic anhydride is prepared by alkylating long-chain olefin polymers with maleic anhydride, and can be made by yourself or purchased from the market.

The ashless dispersant provided by the present invention couples polyene polyamines while introducing anti-oxygen groups to increase nitrogen content, so it not only has good high-temperature anti-oxidation performance, but also improves dispersion performance, and can ensure good oil soluble.

Below by embodiment the present invention will be further described.

Embodiments 1-8 are the preparation of condensed amine intermediates.

Example 1

Add 56.8g (0.3mol) of tetraethylenepentamine and 16.5g of paraformaldehyde into a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, and heat to 90°C under nitrogen protection for 1h , cooled to 65°C, added 20.6g (0.1mol) 2,6-di-tert-butylphenol and 9.4g (0.1mol) phenol, kept for 0.5h, slowly heated to 120°C, kept for 3h, decompressed distillation to remove water and Unreacted material, condensed amine intermediate A prepared.

Example 2

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 56.8g (0.3mol) tetraethylenepentamine, 9.4g (0.1mol) phenol, 20.6g (0.1mol) 2,6-di tert-butylphenol and 15g paraformaldehyde, under the protection of nitrogen, slowly heated to 90°C, kept for 2h, then continued to heat to 110°C, kept for 2h, decompressed distillation to remove water and unreacted substances, and the condensed amine intermediate prepared Body B.

Example 3

In a 250ml three-neck flask equipped with mechanical stirring, temperature control thermocouple and thermometer, add 38.0g (0.2mol) tetraethylenepentamine and 12.0g paraformaldehyde, under the protection of nitrogen, heat to 65°C and keep for 1 hour , add 10.3g (0.05mol) 2,6-di-tert-butylphenol (0.1mol) and 9.4g (0.1mol) phenol, keep for 1h, slowly heat to 120°C, keep for 1h, distill under reduced pressure to remove water and unused The substance of the reaction, the condensed amine intermediate C obtained.

Example 4

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 56.8g (0.3mol) tetraethylenepentamine, 9.4g (0.1mol) phenol, 41.2g (0.2mol) 2,6-di tert-butylphenol and 19g of paraformaldehyde, under the protection of nitrogen, slowly heated to 90°C, kept for 2h, then continued to heat to 110°C for 2h, distilled under reduced pressure to remove water and unreacted substances, the obtained condensed amine Intermediate D.

Example 5

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 73g (0.5mol) triethylenetetramine, 9.4g (0.1mol) phenol, 61.8g (0.3mol) 2,6-ditertiary Butylphenol, under the protection of nitrogen, gradually added 42ml of formaldehyde solution, then heated to 100°C, refluxed for 4 hours, and distilled under reduced pressure to remove water and unreacted substances to obtain the condensed amine intermediate E.

Example 6

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 75.7g (0.4mol) tetraethylenepentamine, 9.4g (0.1mol) phenol, 30.9g (0.15mol) 2,6-di tert-butylphenol and 15g paraformaldehyde, under the protection of nitrogen, slowly heated to 90°C, kept for 2h, then continued to heat to 110°C, kept for 2h, decompressed distillation to remove water and unreacted substances, and the condensed amine intermediate prepared Body F.

Example 7

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 38.2g (0.2mol) tetraethylenepentamine, 10.9g (0.1mol) p-cresol, 20.6g (0.1mol) 2,6 - Di-tert-butylphenol, under the protection of nitrogen, gradually drop 32ml of aqueous formaldehyde solution, slowly heat to 100°C, reflux for 4 hours, and then distill off water and unreacted substances under reduced pressure to obtain the condensed amine intermediate G.

Example 8

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 79.5 (0.42mol) g tetraethylenepentamine, 22.2g (0.1mol) bisphenol A, 30.2g (0.15mol) 2,6 -Di-tert-butylphenol, under the protection of nitrogen, gradually drop 32ml of aqueous formaldehyde solution, slowly heat to 100°C, reflux for 2h, and distill under reduced pressure to remove water and unreacted substances to obtain the condensed amine intermediate H.

Examples 9-16 are preparations of anti-oxidant succinimide ashless dispersants.

Example 9

In a 250ml three-neck flask with mechanical stirring, temperature control thermocouple and thermometer, add 50g of alkenyl succinic anhydride (the molecular weight of polyisobutylene is 2300) and 50g of 150SN diluent oil, heat to 85°C under nitrogen protection, add the example 5.1g of condensed amine intermediate A in 1, keep for 1h, raise the temperature to 140°C, keep for 2h, vacuum dehydrate for 1h, and filter to get the final ashless dispersant.

Example 10

The amination conditions are the same as in Example 9, and the condensed amine B in Example 2 is used instead of the condensed amine A, so that the molar ratio of the alkene anhydride to the condensed amine (equivalent to tetraethylenepentamine) is 1.5:1, and an ashless dispersant is obtained. Its performance evaluation is shown in Table 1.

Example 11

The amination conditions were the same as in Example 9, and the condensed amine C with the same molar number as in Example 3 was used instead of the condensed amine A to prepare an ashless dispersant. See Table 1 for performance evaluation.

Example 12

The amination conditions were the same as in Example 9, and the condensed amine D was replaced by the condensed amine A with the same molar number in Example 4, and polyisobutylene alkene anhydride with a molecular weight of 900 was used to prepare an ashless dispersant. The performance evaluation is shown in Table 1.

Example 13

The amination conditions were the same as in Example 9, and the condensed amine E with the same molar number as in Example 5 was used instead of the condensed amine A to obtain an ashless dispersant, and its performance evaluation is shown in Table 1.

Example 14

The amination conditions were the same as in Example 9, and the condensed amine F with the same molar number as in Example 6 was used instead of the condensed amine A to obtain an ashless dispersant, and its performance evaluation is shown in Table 1.

Example 15

The amination conditions were the same as in Example 9, and the condensed amine G with the same molar number as in Example 7 was used to replace the condensed amine A, and polyisobutylene alkene anhydride with a molecular weight of 1300 was used to prepare an ashless dispersant. The performance evaluation is shown in Table 1.

Example 16

The amination conditions are the same as in Example 9, and the condensed amine F in Example 8 is used to replace the condensed amine A, so that the molar ratio of the alkene anhydride to the condensed amine (equivalent to tetraethylenepentamine) is 0.78:1, and an ashless dispersant is obtained. Its performance evaluation is shown in Table 1.

Comparative example 1

This comparative example is the preparation of a common single-hanging ashless dispersant.

According to the reaction conditions of Example 9, 5.1 g of condensed amine was changed to 3.2 g of tetraethylenepentamine to obtain a common single-hanging ashless dispersant, and its performance evaluation is shown in Table 1.

Comparative example 2

This comparative example is the preparation of a common double-hanging ashless dispersant.

According to the reaction conditions in Example 9, 5.1 g of condensed amine was changed to 1.7 g of tetraethylenepentamine to prepare a common double-hung ashless dispersant. Its performance evaluation is shown in Table 1.

Example 17

This example is for the evaluation of dispersion performance.

Using countercurrent viscosity growth method, carbon black is used as soot simulant, dispersed in 150SN base oil containing 0.5% dispersant, and the amount of carbon black is 1%, the viscosity growth rate is measured, and the dispersion with small growth rate is better. The test results are shown in Table 1.

Example 18

This example is for the evaluation of anti-oxidation performance.

The PDSC pressure differential scanning calorimeter was used to measure the oxidation induction period of the additive, and the larger the value, the better the antioxidant performance. The test conditions are: American DuPont2100 instrument, O ₂ atmosphere, pressure 5kg/cm ² , constant temperature 220°C, sample size 2mg. The test results are shown in Table 1.

It can be seen from Table 1 that the antioxidant succinimide ashless dispersant provided by the present invention not only has anti-oxidation performance but also improves dispersion performance compared with common single-hung and double-hung ashless dispersants.

Table 1 additive Viscosity growth rate, % Oxidation induction period, min Example 9 13.6 10.8 Example 10 16.7 6.4 Example 11 15.4 9.8 Example 12 11.8 24.8 Example 13 20.0 8.2 Example 14 14.4 15.5 Example 15 13.8 25.2 Example 16 14.6 18.9 Comparative example 1 27.6 0 Comparative example 2 69.3 0

Claims (9)

1. An antioxidant succinimide ashless dispersant, containing the following groups in structure: alkenyl succinyl, phenol-coupled polyene polyamine, 2,6 polyene polyamine linked to polyene polyamine - di-tert-butylphenol, characterized in that it is prepared as follows: (1) in the presence of 2,6-di-tert-butylphenol, αH-containing phenol, polyene polyamine and formaldehyde are mixed, Carry out Mannich reaction, the reaction temperature is room temperature ~ 150 ℃, the reaction time is 1 ~ 10 hours, the product is separated, and the intermediate product condensed amine is obtained; (2) alkenyl succinic anhydride and the above condensed amine are subjected to amination reaction, The reaction temperature is 60-160° C., and the reaction time is 1-8 hours to obtain the final product. 2. according to the said dispersant of claim 1, it is characterized in that, the phenol containing αH is selected from phenol, p-cresol, hydroquinone, one of bisphenol A or β-naphthol, or wherein two kinds or both mixture of the above. 3. According to the said dispersant of claim 1 or 2, it is characterized in that the mol ratio of the phenol containing αH to polyene polyamine is 1: 1～4, the phenol containing αH and 2,6-di-tert-butyl The molar ratio of phenol is 1:0.2～3. 4. according to the said dispersing agent of claim 1, it is characterized in that, formaldehyde is selected from paraformaldehyde or formaldehyde aqueous solution, and the consumption of formaldehyde is the phenol that contains αH and 2, the H that has reactivity in 6-di-tert-butylphenol 1 to 2 times the sum of 5. According to the said dispersant of claim 1, it is characterized in that, said polyene polyamine is selected from the compound having following general formula: H ₂ N(CH ₂ CH ₂ NH) _n H, n is 1 in the formula An integer of ~6. 6. According to the said dispersant of claim 1, it is characterized in that the addition of alkenyl succinic anhydride in step (2) is 0.6～3 times of the molar number of polyene polyamine in step (1). 7. According to the said dispersing agent of claim 1, it is characterized in that, the alkenyl group in the alkenyl succinic anhydride is C ₂ ～C ₁₀ olefin copolymer or homopolymer, and its number average molecular weight is 500～5000, molecular weight The distribution ranges from 1.5 to 4.5. 8. According to the said dispersant of claim 1 or 7, it is characterized in that the alkenyl group in the alkenyl succinic anhydride is polyisobutylene, the number average molecular weight is 900-2500, and the molecular weight distribution is 1.5-3.5. 9. according to the said dispersant of claim 1, it is characterized in that, the reaction temperature of step (1) is 60～120 ℃, and the reaction time is 2～8 hours, and the reaction temperature of step (2) is 80～140 ℃, The reaction time is 2 to 6 hours.