Preparation method of light-color disproportionated rosin potassium soap

Abstract

The invention discloses a preparation method of light-color disproportionated rosin potassium soap, which comprises the following steps: (1) adding an organic solvent into gum rosin, melting and distilling to remove turpentine in the gum rosin to obtain refined rosin; (2) under the protection of inert gas, adding a catalyst into the refined rosin obtained in the step (1), carrying out disproportionation reaction, and then adding an antioxidant to obtain disproportionated rosin; (3) continuously adding small molecule alcohol into the disproportionated rosin obtained in the step (2), carrying out saponification reaction in the presence of alkali, cooling to room temperature after the reaction is finished, adding a free radical scavenger, stirring, and then discharging to obtain the disproportionated rosin potassium soap with uniform light color; and inert gas replacement protection is carried out before saponification. The process is simple and low in cost, and the prepared product is light in color and luster, free of color reversion, free of gel and low in cloud point under the condition that safe production is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of rosin deep processing, and particularly relates to a method for preparing light-colored disproportionated rosin potassium soap. Background Art

[0002] Disproportionated rosin is one of the deep-processed products of rosin and has a very wide range of applications. In the presence of a catalyst, with the help of inorganic acid and heat, part of the rosin is oxidized and the other part is reduced, that is, a disproportionation reaction occurs. Dehydroabietic acid, the main component of disproportionated rosin, can be made into dehydroabietic acid metal soap and become an emulsifier, which has obvious advantages over the original fatty acid soap. It can greatly improve the heat resistance, wear resistance and tear resistance of rubber, thus greatly improving the quality of rubber tires, and meets the requirements of "green" emulsifiers.

[0003] At present, the defects in product performance caused by the shortcomings of rosin itself can be partially eliminated through methods such as modification and preparation of rosin derivatives. The modified products obtained by disproportionation reaction still have problems to varying degrees, such as too dark color, strong crystallization tendency, and easy oxidation, which affect the quality and market competitiveness of disproportionated rosin and its deep-processed products such as paints, coatings, papermaking sizing agents, high-quality inks, and advanced medical non-toxic adhesives.

[0004] Compared with the dark disproportionate rosin acid potassium soap, the original substances that affect the color, such as terpene aldehydes, sterols, various ethers and ketones, etc., are mostly removed or converted into other substances in the light disproportionate rosin acid potassium soap after decolorization. At the same time, the content of the active ingredient resinate and the quality of the rosin acid potassium soap will also be improved. In addition, as an emulsifier widely used in industry, the purity of the light disproportionate rosin acid potassium soap directly determines the emulsification effect of the prepared emulsion. Therefore, the economic and environmental benefits brought by the light disproportionate rosin acid potassium soap are considerable.

[0005] CN103435473A and CN103451050B propose that peroxide K is added as a decolorizing agent during the saponification process of disproportionated rosin, and the material is discharged after half an hour of heat preservation, so that a potassium soap product with a Ghana color number about 1 to 3 color numbers lower can be prepared. However, the strong oxidizing property of peroxide K leads to its flammable and explosive safety hazards. CN105039029A proposes that adding hydrogen peroxide to the saponification reaction also acts as a decolorizing agent. However, as the storage time of potassium soap increases, hydrogen peroxide decomposes, causing the potassium soap Ghana color number to increase and the color reversion phenomenon occurs. CN111088126A proposes that a chemical additive is added to sodium silicate during the saponification process to prepare a light-colored soap solution. The introduction of sodium silicate will slow down the reaction rate of rubber polymerization and have an adverse effect on subsequent reactions.

[0006] Therefore, it is very important to provide a preparation method with simple process and low cost to prepare high-quality disproportionated rosin potassium soap with light color, no color reversion, no gelation and low cloud point while ensuring safe production. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for preparing light-colored disproportionated rosin potassium soap, which can prepare high-quality disproportionated rosin potassium soap with light color, no color reversion, no gelation and low cloud point under the condition of ensuring safe production.

[0008] The technical solution adopted by the present invention is: a method for preparing light-colored disproportionated rosin potassium soap, comprising the following steps: (1) In an inert atmosphere, an organic solvent is added to the gum rosin, melted, and heated to remove turpentine from the gum rosin by distillation to obtain refined rosin; (2) under the protection of inert gas, adding a catalyst to the refined rosin obtained in step (1), continuing to increase the temperature and carrying out a disproportionation reaction, and then adding an antioxidant to obtain a disproportionated rosin;

[0009] (3) Adding small molecule alcohol to the disproportionated rosin obtained in step (2) to carry out saponification reaction in the presence of alkali, after the reaction is completed, cool to room temperature, add free radical scavenger, stir, and then discharge to obtain disproportionated rosin potassium soap with a solid content of 25% and a light color. Before the reaction, perform inert gas replacement protection.

[0010] The present invention refines the gum rosin because the oxidation products of the main component of turpentine in the gum rosin are relatively complex, containing various oxidation products such as alkanes, enaldehydes, enols, alcohols, ketones, enones, enaldehydes, etc. By adding a solvent in an inert atmosphere and then removing the turpentine by distillation, the unsaponifiable matter in the saponification can be reduced, the reaction rate can be increased, and the reaction time can be reduced; and the stratification and turbidity of the soap solution gel can also be prevented.

[0011] In addition, adding antioxidants during the disproportionation process not only has a decolorizing effect, but also can protect the rosin from oxidation during the saponification process, thereby achieving the purpose of producing a light-colored product. Finally, the inventor unexpectedly discovered through a large number of experiments that adding small molecule alcohols to the saponification reaction can reduce the cloud point of the soap solution and obtain a more stable product.

[0012] Preferably, in step (1), the mass ratio of the organic solvent to the gum rosin is 1:10.

[0013] Preferably, the organic solvent in step (1) is toluene or xylene.

[0014] Preferably, in step (1), the melting temperature is 150°C-200°C.

[0015] Preferably, in step (2), the antioxidant is a phosphorus compound and a phenolic sulfide, or a phosphorus compound and a hindered phenolic compound; wherein the phosphorus compound is diphenyl monoisooctyl phosphite, diisodecyl phosphite, tris(2,4-di-tert-butylphenyl)phosphite, the phenolic sulfide is 4,4'-thiobis(6-tert-butyl-3-methylphenol), and the hindered phenolic compound is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0016] The antioxidants used for rosin disproportionation are mainly phosphorus compounds and phenolic sulfides. According to the mechanism of action, antioxidants are divided into two types: free radical inhibitors and peroxide decomposers. Among free radical inhibitors, phenolic sulfides have the dual functions of decolorization and antioxidant. Their antioxidant activity is mainly manifested in: phenolic hydroxyl can capture free radicals, and thioether can decompose hydroperoxides. Peroxide decomposers decompose the intermediate products of oxidative degradation into non-free radical products, and phosphorus compounds have the functions of reducing agents, hydroperoxide decomposers and free radical scavengers.

[0017] Further preferably, the total mass of the antioxidant accounts for 1.9‰~2.8‰ of the mass of the refined rosin, wherein the mass ratio of the phosphorus compound to the phenolic sulfide is 1~2.5:1; the mass ratio of the phosphorus compound to the hindered phenol compound is 1~2.5:1.

[0018] Preferably, in step (2), the temperature when the catalyst is added is 210-220°C, the temperature of the disproportionation reaction is 265-285°C, and the reaction time is 2-4 hours.

[0019] Preferably, the catalyst in step (2) is a Pd / C catalyst, the mass of which accounts for 3‰-6‰ of the mass fraction of the refined rosin.

[0020] Preferably, in step (3), the alkali is an aqueous solution of potassium hydroxide, and its mass fraction is 40% to 60%.

[0021] Preferably, the saponification reaction temperature in step (3) is 40-60°C, preferably 50±3°C, and the reaction time is 1-2h.

[0022] Preferably, the small molecule alcohol in step 3) is methanol, ethylene glycol or propylene glycol.

[0023] Preferably, in step (3), the mass of the small molecule alcohol accounts for 2% of the total mass of the soap solution, and the total mass of the soap solution is the sum of the masses of water, disproportionated rosin, potassium hydroxide and the small molecule alcohol.

[0024] Preferably, in step (3), the free radical scavenger is 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide, and the amount of the free radical scavenger is 0.2% of the total mass of the disproportionated rosin, potassium hydroxide and small molecule alcohol.

[0025] Beneficial effects of the present invention: The invention prepares high-quality disproportionated rosin potassium soap through refining, disproportionation and saponification reaction. The method has simple process and low cost. Under the condition of ensuring safe production, the prepared product has light color, no color reversion, no gel generation and low turbidity point. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with a preferred implementation manner.

[0027] Test standards: The test standards for solid content, Ghana color number, pH, potassium abietic acid and potassium dehydroabietic acid are LY / T 1358-2014. The test standard for turbidity point (℃) is GB / T 5559-1993. Example 1

[0028] (1) Under N2 gas atmosphere, 165 g of Masson pine rosin and 15 mL of toluene were added to a 1 L reactor and melted at 150-200 °C. The turpentine fraction at 160-180 °C was distilled off to obtain 158 g of refined rosin. (2) Continue to raise the temperature to 210°C, add 4‰ (0.63 g) of Pd / C palladium carbon catalyst (containing 20% ​​water), continue to raise the temperature to 282±3°C, and the reaction time is 4 h. Then add antioxidants 0.3 g of diphenyl monoisooctyl phosphite and 0.15 g of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and continue stirring for 1 h to obtain disproportionated rosin.

[0029] (3) In a 2L reactor, add 100g of crushed disproportionated rosin, 310g of distilled water, 10g of ethylene glycol and 32.6g of 49% KOH solution. Perform nitrogen replacement before the reaction, maintain the reaction temperature at 40±3℃, stir for 1.2h, and after the reaction is completed, add 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide after cooling to room temperature, the amount of which is 0.2% of the soap solution, stir for 0.5h, and the reaction is completed. Discharge the material and obtain 452g of disproportionated rosin potassium soap. The test results are shown in Table 1. Example 2

[0030] (1) Under N2 gas atmosphere, 165 g of Masson pine rosin and 24 mL of toluene were added to a 1 L reactor and melted at 150-200 °C. The turpentine fraction at 160-180 °C was distilled off to obtain 158 g of refined rosin. (2) Continue to raise the temperature to 220°C, add 3‰ (0.63 g) of Pd / C palladium carbon catalyst (containing 20% ​​water), continue to raise the temperature to 275±3°C, and the reaction time is 2 h. Then, add antioxidants 0.2 g of monoisodecyl phosphite and 0.2 g of 4,4'-thiobis(6-tert-butyl-3-methylphenol) at the same time, and continue stirring for 1 h to obtain disproportionated rosin.

[0031] (3) In a 2L reactor, add 100g of crushed disproportionated rosin, 315g of distilled water, 10g of glycerol and 32.6g of 49% KOH solution. Perform nitrogen replacement before the reaction, maintain the reaction temperature at 60±3℃, stir for 1h, and after the reaction is completed, add 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide after cooling to room temperature, the amount of which is 0.2% of the soap solution, stir for 0.5h, and the reaction is completed. Discharge the material and obtain 458g of disproportionated rosin potassium soap. The test results are shown in Table 1. Example 3

[0032] (1) Under N2 gas atmosphere, 165 g of Masson pine rosin and 12 mL of toluene were added to a 1 L reactor and melted at 150-200 °C. The turpentine fraction at 160-180 °C was distilled off to obtain 158 g of rosin. (2) Continue to raise the temperature to 218°C, add 6‰ (0.63 g) of Pd / C palladium carbon catalyst (containing 20% ​​water), continue to raise the temperature to 270±3°C, and the reaction time is 3 h. Then add antioxidants 0.2 g of tris(2,4-di-tert-butylphenyl) phosphite and 0.1 g of 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and continue stirring for 1 h to obtain disproportionated rosin.

[0033] (3) In a 2L reactor, add 100g of crushed disproportionated rosin, 312g of distilled water, 10g of methanol and 32.6g of 49% KOH solution. Perform nitrogen replacement before the reaction, maintain the reaction temperature at 50±3℃, stir for 2 hours, and after the reaction is completed, add 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide after cooling to room temperature, the amount of which is 0.2% of the soap solution, stir for 0.5h, and the reaction is completed. Discharge the material and obtain 455g of disproportionated rosin potassium soap. The test results are shown in Table 1. Example 4

[0034] (1) Under N2 gas atmosphere, add 165g of Masson pine rosin and 20mL of toluene into a 1L reactor and melt at 150-200℃. Distill off the turpentine fraction at 160-180℃ to obtain 158g of rosin. (2) Continue to raise the temperature to 210°C, add 4‰ (0.63 g) of Pd / C palladium carbon catalyst (containing 20% ​​water), continue to raise the temperature to 265±3°C, and the reaction time is 3 h. Then, add antioxidants 0.25 g of diphenyl monoisooctyl phosphite and 0.1 g of 1,3,5-trimethyl-2,4,6-tri(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and continue stirring for 1 h to obtain disproportionated rosin.

[0035] (3) In a 2L reactor, add 100g of crushed disproportionated rosin, 318g of distilled water, 10g of isopropylene glycol and 32.6g of 49% KOH solution. Perform nitrogen replacement before the reaction, maintain the reaction temperature at 50±3℃, stir for 1.2h, and add 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide after cooling to room temperature, the amount of which is 0.2% of the soap solution. After stirring for 0.5h, the reaction is completed and the material is discharged to obtain 461g of disproportionated rosin potassium soap. The test results are shown in Table 1.

[0036] Comparative Example 1 Compared with Example 1, 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide was not added to prepare disproportionated rosin potassium soap. The test results are shown in Table 1.

[0037] Comparative Example 2 Compared with Example 2, 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide was not added to prepare disproportionated rosin potassium soap. The test results are shown in Table 1.

[0038] Comparative Example 3 Compared with Example 3, 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide was not added to prepare disproportionated rosin potassium soap. The test results are shown in Table 1.

[0039] Comparative Example 4 Compared with Example 4, 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide was not added to prepare disproportionated rosin potassium soap. The test results are shown in Table 1.

[0040] Comparative Example 5 Disproportionation: 165 g of masson pine rosin and 20 mL of toluene were added to a 1L reactor under N2 gas atmosphere to melt, and the temperature was continued to rise to 210°C, 4‰ (0.63 g) of Pd / C palladium carbon catalyst (containing 20% ​​water) was added, and the temperature was continued to rise to 268±3°C. The reaction time was 3.5 h. The disproportionation reaction was completed, and 444 g of disproportionated rosin was obtained.

[0041] Saponification: In a 2L reactor, add 100g of crushed disproportionated rosin, 315g of distilled water and 32.6g of 49% KOH solution. Perform nitrogen replacement before the reaction, maintain the reaction temperature at 50±3℃, stir for 1.2h, and after the reaction is completed, cool down and discharge to obtain 447g of disproportionated rosin potassium soap. The test results are shown in Table 1.

[0042] Comparative Example 6 Disproportionation: 165 g of masson pine rosin and 20 mL of toluene were added to a 1L reactor under N2 gas atmosphere to melt, and the temperature was continued to rise to 210°C, and 4‰ (0.63 g) of Pd / C palladium carbon catalyst (containing 20% ​​water) was added, and the temperature was continued to rise to 268±3°C. The reaction time was 3.5 h. The disproportionation reaction was completed, and 445 g of disproportionated rosin was obtained.

[0043] Saponification: In a 2L reactor, add 100g of crushed disproportionated rosin, 317g of distilled water, 32.6g of 49% KOH solution, and 0.9g of sodium silicate. Perform nitrogen replacement before the reaction, maintain the reaction temperature at 50±3℃, stir for 1.2h, and after the reaction is completed, cool down and discharge to obtain 449g of disproportionated rosin potassium soap. The test results are shown in Table 1.

[0044] Table 1 Technical quality indicators of disproportionated rosin potassium soap in the examples and comparative examples

[0045] According to the test data of Examples 1 to 4 and Comparative Examples 1-4, adding a small amount of free radical scavenger can further reduce the color number of the soap solution; according to the test data of Examples 1 to 4 and Comparative Example 5, adding an antioxidant after rosin refining and disproportionation and adding a free radical scavenger after saponification can effectively reduce the color number of the soap solution; adding a small molecule alcohol during saponification can significantly reduce the cloud point and improve stability. According to the test data of Examples 1 to 4 and Comparative Example 6, adding only sodium silicate during saponification has little effect on the preparation of light-colored soap solution, and has no effect on stability and cloud point; according to the test data of Examples 1-4, the product prepared by the present invention has no change in hue after standing for one week, and no color reversal phenomenon occurs.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also within the protection scope of the present invention.

Claims

1. A method for preparing a light-colored disproportionated rosin potassium soap, characterized in that: The following steps are involved: (1) In an inert atmosphere, an organic solvent is added to the gum rosin, melted, and the turpentine in the gum rosin is removed by distillation to obtain refined rosin; (2) under the protection of inert gas, adding a catalyst to the refined rosin obtained in step (1) to carry out a disproportionation reaction, adding an antioxidant, and obtaining a disproportionated rosin; (3) adding a small molecule alcohol to the disproportionated rosin obtained in step (2), and performing a saponification reaction in the presence of an alkali. After the reaction is completed and the temperature is lowered to room temperature, a free radical scavenger is added, the mixture is stirred, and then the mixture is discharged to obtain a light-colored uniform disproportionated rosin potassium soap; an inert gas replacement protection is performed before the saponification reaction.

2. The preparation method according to claim 1, characterized in that: In step (1), the melting temperature is 150°C-200°C.

3. The preparation method according to claim 1, characterized in that: In step (2), the antioxidant is a phosphorus compound and a phenolic sulfide, or a phosphorus compound and a hindered phenol compound; wherein the phosphorus compound is diphenyl monoisooctyl phosphite, diisodecyl phosphite or tris(2,4-di-tert-butylphenyl)phosphite, the phenolic sulfide is 4,4'-thiobis(6-tert-butyl-3-methylphenol), and the hindered phenol compound is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

4. The preparation method according to claim 3, characterized in that: The total mass of the antioxidant accounts for 1.9‰ to 2.8‰ of the mass of the refined rosin, wherein the mass ratio of the phosphorus compound to the phenolic sulfide is 1 to 2.5:1; or the mass ratio of the phosphorus compound to the hindered phenol compound is 1 to 2.5:

1.

5. The preparation method according to claim 1, characterized in that: In step (2), the temperature when the catalyst is added is 210-220°C, the temperature of the disproportionation reaction is 265-285°C, and the reaction time is 2-4 hours.

6. The preparation method according to claim 1, characterized in that: In step (2), the catalyst is a Pd / C catalyst, and its mass accounts for 3‰-6‰ of the mass of the refined rosin.

7. The preparation method according to claim 1, characterized in that: In step (3), the temperature of the saponification reaction is 40-60° C., and the reaction time is 1-2 h.

8. The preparation method according to claim 1, characterized in that: In step (3), the small molecule alcohol is methanol, ethylene glycol or propylene glycol.

9. The preparation method according to claim 1, characterized in that: In step (3), the mass of the small molecule alcohol accounts for 2% of the total mass of the soap solution, and the soap solution is a mixture of water, disproportionated rosin, alkali and small molecule alcohol.

10. The preparation method according to claim 1, characterized in that: In step (3), the free radical scavenger is 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitrogen oxide, and the amount of the free radical scavenger is 0.2% of the total mass of the disproportionated rosin, the alkali and the small molecule alcohol.

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