RU2454438C1 - Method of producing alkyd resins - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing alkyde resins and can be used to produce polymer compounds, particularly high-quality bitumen. The method of producing alkyde resins involves reaction of a mixture of organic acids with a polyatomic alcohol at 160-180°C and molar ratio of mixture of organic acids to polyatomic alcohol equal to 1:1-2 until achieving acid number 5-50 mg KOH/g in the reaction mixture. The mixture of organic acids contains 80-87 wt % terephthalic acid, 8-15 wt % p-toluic acid, up to 0.4 wt % benzoic acid, up to 0.1 wt % carboxybenzaldehyde and water - the balance.

EFFECT: simple process of producing alkyde resins and low power consumption.

2 cl, 1 tbl, 3 ex

Description

The invention relates to a method for producing alkyd resins and can be used to obtain polymer compounds.

A known method of producing polyester resins by polycondensation of phthalic anhydride with polyhydric alcohol in the presence of a catalyst by heating while distilling off the released water [RF Patent 2067594, cl. C08G 63/78, publ. 10/10/1996].

The disadvantage of this method is the use of a catalyst and the process at a sufficiently high temperature.

A known method for producing complex polyether polyols by reacting wastes containing di- and polycarboxylic acids, their esters or anhydrides with polyhydric alcohols - polyglycols - bottoms of rectification of ethylene glycol and diethylene glycol formed during the hydration of ethylene oxide in the presence of a catalyst at a temperature of 190-240 ° C [RF Patent 2236422, cl. C08G 63/12, publ. September 20, 2004].

The disadvantage of this method is the use of a catalyst of complex composition.

A known method of producing a thermoplastic saturated polyester resin by the interaction of waste polyethylene terephthalate with glycol is the bottom residue of the rectification system of ethylene glycol, phthalic anhydride or its mixture with adipic acid when heated in the presence of a catalyst - phosphogypsum at a temperature of 230 ° C [A.S. USSR 1382837, class C08G 63/48, publ. 03/23/1988].

The disadvantage of this method is the use of adipic acid, a deficient reagent.

A known method of producing alkyd resins by the interaction of vegetable oils, glycerol or pentaerythritol, rosin and phthalic anhydride in the presence of bottoms of the rectification or distillation system of ethylene glycol produced by polyethylene terephthalate at a temperature of 240-250 ° C [A.S. USSR 819123, IPC S08G 63/48, publ. 04/07/1981].

The disadvantage of this method is the use of inaccessible and scarce reagents to obtain alkyd resins and the high temperature of the process.

A known method of producing alkyd resins [RF patent No. 2385332, class. C08G 63/49, publ. 03/27/2010] by the interaction of vegetable oil, polyol and acid component, where tall oil fatty acids, distilled tall oil and a mixture of tall oil with sunflower oil in a ratio of 4-5: 1 are used as vegetable oil, pentaerythritol, glycerin as a polyol , as an acid component - waste production of purified terephthalic acid, which is a mixture of terephthalic acid with unoxidized intermediate products of p-xylene oxidation (a mixture of organic acids - JUICE). A mixture of organic acids (SOA) has the following composition, wt.%: Terephthalic acid 80-85, p-toluic acid 8-15, benzoic acid up to 0.4, 4-carboxybenzaldehyde up to 0.1, the rest is water. The process is carried out at a temperature of 250-255 ° C in the fatty acid method with simultaneous loading of the starting reagents with the conclusion of the reaction water by fusion. The resulting alkyd resin is used as the basis for the manufacture of coatings.

The disadvantage of this method is the use of inaccessible reagents, such as tall oil, to obtain alkyd resins and the high temperature of the process.

The closest method to the claimed one is the method of producing alkyd resins by acidifying a vegetable oil with terephthalic acid, followed by the interaction of the obtained product with glycerin, and a mixture of organic acids (SOA), which is an unoxidized product of the oxidation of p-xylene in the production of terephthalic acid, is used as terephthalic acid, composition (in wt.%): terephthalic acid 80-87, p-toluic acid 8-15, benzoic acid up to 0.4, carboxybenzaldehyde up to 0.1, the rest is water [Patent RU 2375382, l C08G 63/48, publ. 12/10/2009]. Acidolysis of vegetable oil is carried out preliminary with a mixture of organic acids at a temperature of 260 ° C until an acid number of 80 mg KOH / g is reached, then the temperature is reduced to 230 ° C and glycerol is charged. Next, the polycondensation process is carried out at a temperature of 260 ° C until an acid number of not more than 15 mg KOH / g is reached. As vegetable oil, use sunflower or linseed oil. The ratio of the starting reagents is: oil 54.3-62%, RNS 26-32%, glycerol - the rest (12-15%).

The disadvantage of this method is the complexity of the process due to the preliminary acidolysis of vegetable oil and the process at high temperature.

The purpose of the invention is to simplify the process of producing an alkyd resin based on polyhydric alcohol and a mixture of organic acids, which is a waste of the purified production of terephthalic acid, reducing energy consumption by carrying out the process at lower temperatures.

The goal is achieved by the proposed method for producing alkyd resins, including the interaction of a mixture of organic acids containing in wt.%: Terephthalic acid 80-87, p-toluic acid 8-15, benzoic acid up to 0.4, carboxybenzaldehyde up to 0.1, the rest is water and polyhydric alcohol, moreover, glycerol, ethylene glycol, diethylene glycol, a mixture of glycerol and ethylene glycol, a mixture of glycerol and diethylene glycol are used as the polyhydric alcohol, and the reaction is carried out at a temperature of 160-180 ° C until the acid number (CN) in ktsionnoy weight of 5-50 mg KOH / g.

The formation of an alkyd resin is carried out by polycondensation and esterification reactions due to the interaction of the carboxyl groups of terephthalic acid with the hydroxyl groups of a polyhydric alcohol (ethylene, diethylene glycol, glycerol) with the formation of a polyalphthalic acid bis-alcohol ester. The process is carried out at a temperature of 160-180 ° C and with a molar ratio of RNS: polyhydric alcohol equal to 1: 1-2, until the acid number in the reaction mass of 5-50 mg KOH / g is reached, while obtaining an alkyd resin of the required quality is achieved. The esterification and polycondensation reactions are accompanied by the release of water, and the production process proceeds with the evaporation of the source water present in the unoxidized product and the reaction water. Lowering the temperature leads to an increase in the reaction time, and an increase of more than 180 ° C - leads to an increase in the consumption rates of raw materials due to the loss of the initial reagents. To obtain a high-quality product - alkyd resin, the molar ratio of the RNS: polyhydric alcohol is maintained equal to 1: 1-2. With a decrease in the consumption of polyhydric alcohol below a ratio of 1: 1, the yield of the product decreases, and an increase in the consumption of polyhydric alcohol above a ratio of 1: 2 is not economically feasible due to overuse of the reagent. The ratio of alcohols in a mixture of glycerol and ethylene glycol, a mixture of glycerol and diethylene glycol can vary in any ratio, provided that the molar ratio of RNS: polyhydric alcohol (total) = 1: 1-2 is maintained. The molecular weight of the target product is in the range of 1500-3500 and the acid number is in the range of 5-50 mg KOH / g due to the quality requirements of alkyd resins used as feedstock in petrochemicals, for example, to produce bitumen compositions.

The proposed method is as follows:

Example 1. 102 g of a mixture of organic acids (SOA) (1 mol) and 40 g of ethylene glycol (2 mol) are charged into a flask. The molar ratio of JUICE: polyhydric alcohol = 1: 2. The reaction mixture is gradually heated to 160-180 ° C with stirring for 35-40 minutes. Further, the interaction of a mixture of organic acids and alcohol is carried out at a given temperature until the acid number (CN) of the reaction mass of 50 mg KOH / g is reached for 30 hours. Obtain 68 g of an alkyd resin with a molecular weight of 2300.

Example 2. 102 g of JUICE (1 mol) and 32 g of glycerol (1 mol) are charged into a flask. The molar ratio of JUICE: polyhydric alcohol = 1: 1. The reaction mixture is gradually heated to 160-180 ° C with stirring for 35-40 minutes. The interaction of a mixture of organic acids and alcohol is carried out at this temperature until the acid number of the reaction mass is 5 mg KOH / g for 20 hours. Obtain 70 g of alkyd resin with a molecular weight of 3000.

Example 3. 102 g of JUICE (1 mol) and a mixture of alcohols containing 18 g of ethylene glycol (1 mol) and 26 g of glycerol (1 mol) are loaded into the flask. The molar ratio of JUICE: polyhydric alcohol = 1: 2. The reaction mixture is gradually heated to 160-180 ° C with stirring for 35-40 minutes. The interaction of a mixture of organic acids and alcohol is carried out at this temperature until the acid number of the reaction mass reaches 10 mg KOH / g for 20-26 hours. Obtain 70 g of alkyd resin with a molecular weight of 2200.

Table 1 presents the loading of the starting components, process parameters and characteristics of the target product obtained in the experiments.

Table 1 Getting alkyd resin Experience number The starting components, mol Process parameters Product feature JUICE Ethylene glycol Diethylene glycol Glycerol The molar ratio. JUICE: alcohol τ, hour T, ° C Cf, mg KOH / g Like weight one 1,0 1,0 - - 1: 1 thirty 180 fifty 1500 2 1,0 1.5 - - 1: 1,5 thirty 160 43 1800 3 1,0 2.0 - - 1: 2 thirty 170 35 2300 four 1,0 - 1,0 - 1: 1 28 180 43 2450 5 1,0 - 1,5 - 1: 1,5 28 180 32 2350 6 1,0 - 2.0 - 1: 2 28 160 thirty 1850 7 1,0 - - 1,0 1: 1 twenty 160 5 3000 8 1,0 - - 1,5 1: 1,5 twenty 170 twenty 3500 9 1,0 - - 2.0 1: 2 eighteen 170 24 3450 10 1,0 1,0 - 1,0 1: 2 twenty 180 10 1600 eleven 1,0 0.5 - 0.5 1: 1 21 180 fifteen 2050 12 1,0 0.75 - 0.75 1: 1,5 26 180 13 1900 13 1,0 - 0.2 0.8 1: 1 24 160 16 2050 fourteen 1,0 - 0.6 0.9 1: 1,5 24 160 12 1900 fifteen 1,0 - 1.4 0.6 1: 2 25 180 10 1600 16 1,0 1,5 1: 1,5 35 150 55 1200 17 1,0 1,5 1: 1,5 16 190 45 1100 eighteen 1,0 0.8 1: 0.8 35 170 67 1050 19 1,0 2.2 1: 2.2 25 170 55 1035

The proposed method allows by the interaction of a mixture of organic acids containing in wt.%: Terephthalic acid - 80-87, p-toluic acid - 8-15, benzoic acid - up to 0.4, carboxybenzaldehyde - up to 0.1, the rest is water and polyhydric alcohol at a temperature of 160-180 ° C with a molar ratio of RNS: polyhydric alcohol equal to 1: 1-2, to obtain alkyd resins with a molecular weight of 1500-3500 and an acid number of 5-50 mg KOH / g The obtained alkyd resin can be used to produce high quality bitumen. This simplifies the process of obtaining alkyd resins by conducting the process in one stage without conducting preliminary reactions, using two components as a feedstock. Due to the process at lower temperatures (160-180 ° С instead of 230-260 ° С), energy consumption for obtaining the target product is reduced.

Claims (2)

1. A method of producing alkyd resins, comprising reacting a mixture of organic acids containing, wt.%: Terephthalic acid 80-87, p-toluic acid 8-15, benzoic acid up to 0.4, carboxybenzaldehyde up to 0.1, the rest water and polyhydric alcohol, characterized in that the interaction is carried out at a temperature of 160-180 ° C with a molar ratio of a mixture of organic acids: polyhydric alcohol equal to 1: 1-2, until the acid number in the reaction mass of 5-50 mg KOH / g is reached. 2. The method according to claim 1, characterized in that ethylene glycol, diethylene glycol, glycerin or a mixture of glycerol and ethylene glycol, glycerol and diethylene glycol in any ratio are used as the polyhydric alcohol.