CN106008205A - Method for synthesizing (methyl) acrylate glyceride through catalysis of calcium glyceroxide - Google Patents

Abstract

The invention discloses a method for synthesizing glycerol (meth)acrylate with calcium glycerol catalysis, which belongs to the field of fine chemical industry. Reaction-distillation process is adopted, using a modified rectification column with copper wire mesh packing, adding alkyl (meth)acrylate, glycerin, polymerization inhibitor and catalyst, under stirring conditions, feeding air and raising the temperature to the reflux of the reaction solution, The temperature is 60-140°C. After the reaction, cool the reaction solution to 50°C, add activated carbon, and continue to heat and stir for 0.5h-1h. After the end, the reaction solution is filtered under reduced pressure, and the filtrate is rotary evaporated under reduced pressure to remove excess raw material ester to obtain (meth)acrylic acid Glyceride reactive diluent products. The invention overcomes many shortcomings of existing transesterification catalysts, and has high yield, simple post-treatment, and easy availability.

Description

A kind of method of glycerin calcium catalyzed synthesis (meth)acrylic acid glyceride

technical field

The invention belongs to the field of fine chemical industry, and relates to the preparation of glycerol (meth)acrylate by a solid base catalyst catalyzing glycerin and (meth)acrylate through a transesterification synthesis method.

Background technique

Glyceryl (meth)acrylate has the characteristics of high double bond content, low volatility, low toxicity, high crosslinking density, and fast curing speed. The cured film formed by it is wear-resistant and solvent-resistant. Functional acrylate reactive diluent, which has wide application prospects in many fields such as light-curing coatings, inks and polymer modification and crosslinking agents

Formula 1 (meth)acrylic acid glycerides reactive diluent chemical structure

According to existing literature reports, the synthesis of (meth)acrylate reactive diluents can be through direct esterification, acid chloride and transesterification. The direct esterification method uses a strong acid such as concentrated sulfuric acid as a catalyst for the direct esterification of alkyds. The strong acid catalyst not only causes many side reactions, difficulties in product separation and purification, and high requirements for equipment, but also leads to the discharge of a large amount of waste water, causing environmental pollution; the acid chloride method is The acid is first chlorinated into acid chloride and then esterified with alcohol, but the chlorination process will increase the reaction steps; the synthesis of (meth)acrylate can be carried out under the action of a catalyst, using alkyl (meth)acrylate and alcohol as raw materials It can be obtained by transesterification, and the pure product can be obtained after rectification.

Catalysts for synthesizing (meth)acrylic esters by transesterification can be p-toluenesulfonic acid, calcium oxide and titanate, etc., but acidic catalysts will corrode equipment, and basic catalysts have low activity selectivity, and the amount of neutral organometallic catalysts should be considered problems and poisoning inactivation problems.

In recent years, solid base catalysts have attracted more and more attention because of their high catalytic activity, environmental protection, low cost and easy availability. We use solid base to catalyze the transesterification reaction to prepare (meth)acrylic acid glyceride reactive diluent.

Contents of the invention

The object of the present invention is to provide solid alkali calcium glycerol as a catalyst for synthesizing glycerol (meth)acrylate by transesterification. The catalyst has the advantages of high catalytic activity, simple post-treatment process, simple and easy-to-obtain catalyst, etc., and is suitable for industrial production.

For accomplishing the object of the present invention, adopt following technical scheme:

A method for calcium glycerol catalyzed synthesis of (meth)glycerol acrylate, carried out according to the following steps:

(1) Add a certain amount of alkyl (meth)acrylate, glycerin and catalyst calcium glycerol, heat and reflux and stir, so that the alcohol produced by the reaction is continuously azeotropically distilled from the upper end of the rectification column, and the reaction stops until no alcohol is distilled out. The reaction liquid is filtered, the catalyst is recovered, and the product (meth)acrylic acid glyceride is obtained.

(2) A synthetic method of glycerol (meth)acrylate reactive diluent, characterized in that, using alkyl (meth)acrylate and glycerol as raw materials, adopting reaction-rectification coupling process, using copper wire mesh The modified rectification column with packing, adding catalyst calcium glycerol, and after simple post-treatment process, can obtain sufficient product purity and yield.

1) Reaction-rectification process is adopted, using a modified rectification column with copper wire mesh packing, adding alkyl (meth)acrylate, glycerin, polymerization inhibitor and catalyst, under stirring conditions, feeding air and raising the temperature to the reaction liquid Reflux at a temperature of 60-140°C. After the reaction, cool the reaction liquid to 50°C, add activated carbon, and continue to heat and stir for 0.5h-1h. After the end, the reaction liquid is filtered under reduced pressure, and the filtrate is rotary evaporated under reduced pressure to remove excess raw material ester to obtain (meth)acrylic acid Glyceride reactive diluent products.

The alkyl (meth)acrylate The specific structure of the ester is: Wait;

The R is H or methyl;

The R' is a methyl group.

The alcohol (R"-OH) includes for example but not limited to: aliphatic straight chain monohydric alcohol, branched chain monohydric alcohol, alicyclic alcohol, aromatic alcohol, alcohol containing other functional groups, ethylene oxide of ethylene urea Alcohols of alkane adducts, the specific structure is: Wait;

The molar ratio of the raw material glycerin to alkyl (meth)acrylate is 1.0:6.0˜1.0:9.0.

Described catalyst is solid alkaline compound calcium glycerol etc., and compound is self-made calcium glycerol, and its preparation method is as follows:

Calcium oxide was refluxed in a glycerol-methanol (volume ratio 1:1) mixed solution for 2 hours, cooled to room temperature, washed with methanol, dried at 120°C for 24 hours, and roasted at a certain temperature in a muffle furnace for 4 hours to obtain calcium glycerol catalysts. The dosage of the catalyst is 0.5%-5.0% of the total mass of the reaction.

The catalyst can be added by any known conventional delivery means, such as but not limited to mixing the catalyst and methyl methacrylate into the slurry mixture.

The polymerization inhibitor includes: diethylhydroxylamine, p-hydroxyanisole, hydroquinone, phenothiazine, 2,6-di-tert-butyl-p-cresol, 3,5-di-tert-butyl-4-hydroxy Anisole, 2,5-di-tert-butylhydroxyanisole, 4-hydroxy-2,6,6-tetramethylpiperidine radical and 4-hydroxy-2,6,6-tetramethyl-N - Hydroxypiperidine, preferably p-hydroxyanisole.

When using the above-mentioned polymerization inhibitor, generally control the molar ratio of the polymerization inhibitor to the raw material alcohol within the range of (0.001-0.004):1;

The reaction temperature of the method of the present invention (ie the temperature of the reaction mixture during the transesterification reaction) is 60-140°C, preferably 80-100°C. The reaction pressure was 760 mmHg (atmospheric pressure).

The invention overcomes many shortcomings of existing transesterification catalysts, and has high yield, simple post-treatment, and easy availability. Compared with traditional catalysts, the following advantages are included:

1) Compared with the traditional transesterification method, the method of the present invention can improve the total yield and processing capacity, utilize the heat of reaction for the energy required for separation, reduce energy consumption, and reduce investment.

2) The process flow of the method of the present invention is short, the raw materials are easy to obtain, the equipment is simple, and it is easy to realize automatic control.

3) The reaction conditions of the method are mild, the purification process is simple, the product is stable and easy to separate, and the polymerization phenomenon is not easy to occur.

4) Glycerol bis(meth)acrylate has two functional groups, and the mixed use of glycerol tri(meth)acrylate can not only speed up the crosslinking and curing speed, but also maintain good dilution ability, so most of the products will Contains a certain amount of the corresponding diester.

detailed description

The present invention is described in detail with specific embodiments. The protection scope of the present invention is not limited by the specific embodiments, but by the claims.

The preparation of embodiment 1 glyceryl acrylate

In the there-necked flask equipped with electromagnetic stirring, thermometer, rectifying column, receiving tube, and receiving bottle, add 77.5g (0.9mol) methyl acrylate, 9.2g (0.1mol) of glycerol and 0.5g calcium glycerol, heat and reflux and stir, Make the methanol produced by the reaction continue to be azeotropically distilled from the upper end of the rectifying column, and react until no methanol is distilled off, then filter the reaction solution, reclaim the catalyst, distill off the raw material methyl acrylate, and obtain 28.3 g of the product, in which glyceryl diacrylate and The glycerol triacrylate content was 22.5% and 42.3%, respectively.

The preparation of embodiment 2 glyceryl acrylate

Add a magnetic stirrer bar in a 250mL four-necked flask equipped with an air inlet, a copper mesh packing rectification column and a temperature measuring device, add 9.2g (0.1mol) glycerol, 0.50g (0.5% glycerol mass) and 0.05g glycerol calcium For p-hydroxyanisole, raise the temperature to the reaction liquid at 60°C, put 77.5g of methyl acrylate into the constant pressure dropping funnel and add it dropwise within 2-3 hours, let the air in and raise the temperature until the reaction liquid refluxes, and take samples regularly during the reaction The end point of the reaction was analyzed by gas chromatography. After the reaction reaches the end point, add 0.1g of neutral activated carbon and reflux at about 50°C for 0.5h-1h. After the end, the reaction solution is filtered under reduced pressure, and the filtrate is rotary evaporated to obtain 31.4g of the product. The contents of glyceryl diacrylate and glyceryl triacrylate are respectively 32.4% and 45.1%.

The preparation of embodiment 3 (meth) glyceryl acrylate

In a three-necked flask equipped with electromagnetic stirring, a thermometer, a rectifying column, a receiving tube, and a receiving bottle, add 90.1 g (0.9 mol) of methyl acrylate, 9.2 g (0.1 mol) of glycerol and 0.5 g of calcium glycerol, and heat to reflux and stir. Make the methanol produced by the reaction continue to be azeotropically distilled from the rectifying column upper end, react until no methanol is distilled off, filter the reaction solution, reclaim the catalyst, distill the raw material methyl acrylate to obtain 29.6 g of product glyceryl acrylate, di(methyl acrylate) Glyceryl) acrylate and glyceryl tri(meth)acrylate content were 37.5% and 40.4%, respectively.

The preparation of embodiment 4 (meth) glyceryl acrylate

Add a magnetic stirrer bar in a 250mL four-necked flask equipped with an air inlet, a copper mesh packing rectification column and a temperature measuring device, add 9.2g (0.1mol) glycerol, 0.50g (0.5% glycerol mass) and 0.05g glycerol calcium For p-hydroxyanisole, the temperature was raised to 60°C of the reaction liquid, 90.1 g (0.9 mol) of methyl methacrylate was put into a constant pressure dropping funnel and added dropwise within 2-3 hours, and air was introduced and the temperature was raised to reflux of the reaction liquid. Samples were taken regularly during the reaction to analyze the end point of the reaction by gas chromatography. After the reaction reaches the end point, add 0.1g of neutral activated carbon and reflux at about 50°C for 0.5h-1h. The glycerol meth)acrylate contents were 52.2% and 37.3%, respectively.

The preparation of comparative example 1 trimethylolpropane tri(meth)acrylate

A mixture of the following components was added to a 29 cm diameter copper wire mesh packed column with temperature display/controller, magnetic stirrer, dry air inlet, distillation head, distillate ratio-removal vapor pressure temperature control In the 250ml four-neck flask of the receiver and the step-by-step distillate receiver: 13.42g (0.5mol) trimethylolpropane (TMP), 77.5g (0.9mol) MA, 0.07g (0.0006mol) MEHQ, 0.50g (0.004mol) ) anhydrous potassium carbonate, feed into air and heat up to the reflux of the reaction solution, stabilize the reaction to the end of the reaction. Post-processing: Cool the reaction liquid to 50°C, add 0.10g of neutral activated carbon, and continue to heat and stir for 1 hour. After the end, the reaction liquid is vacuum filtered, and the filtrate is rotary evaporated under reduced pressure. The highest were 77.1% and 90.1% respectively.

Comparative example 2 ethylene glycol diacrylate

A mixture of the following components was added to a 29 cm diameter copper wire mesh packed column with a temperature display/controller, magnetic stirrer, dry air inlet, distillation head, distillate ratio-removal vapor pressure thermostat and In the 100ml four-neck flask of the distillate receiver gradually: 3.1g (0.05mol) ethylene glycol, 25.83g (0.3mol) methyl acrylate (MA), 0.03g (0.0002mol) p-hydroxyanisole and 0.11g ( 0.0002mol) dibutyltin dilaurate. The mixture was then warmed to reflux. During the reaction process, a certain amount of air was introduced, and the reflux was continuously heated under normal pressure, and the reaction azeotropic mixture MA-methanol was removed at the same time. After the reaction reaches the end point, cool the reaction liquid to 50°C, add 0.10g of neutral activated carbon, and continue to heat and stir for 0.5-1 hour. After the end, the reaction liquid is filtered under reduced pressure, and the filtrate is rotary evaporated under reduced pressure to obtain ethylene glycol diacrylate 5.35g, yield 76.9%, purity 54.8%.

Claims (6)

1. a method for calcium glycerol catalyzed synthesis of (meth)glyceryl acrylate, characterized in that it is carried out according to the following steps: 1) Reaction-rectification process is adopted, using a modified rectification column with copper wire mesh packing, adding alkyl (meth)acrylate, glycerin, polymerization inhibitor and catalyst, under stirring conditions, feeding air and raising the temperature to the reaction liquid Reflux at a temperature of 60-140°C; after the reaction, cool the reaction liquid to 50°C, add activated carbon, and continue to keep warm and stir for 0.5h-1h. raw material ester to obtain (meth)acrylic acid glycerides reactive diluent products. 2. the method for a kind of calcium glycerol catalysis synthesis (meth)acrylic acid glyceride according to claim 1 is characterized in that described (meth)acrylic acid alkyl ester The specific structure of the ester is: Wait; The R is H or methyl; The R' is a methyl group. 3. a kind of calcium glycerol according to claim 1 catalyzes the method for synthesizing (meth)acrylic acid glyceride, it is characterized in that described alcohol (R "-OH) includes for example but not limited to: aliphatic linear monohydric alcohol , Branched chain monohydric alcohol, alicyclic alcohol, aromatic alcohol, alcohol containing other functional groups, alcohol of ethylene oxide adduct of ethylene urea, the specific structure is: Wait; The molar ratio of the raw material glycerin to alkyl (meth)acrylate is 1.0:6.0˜1.0:9.0. 4. a kind of calcium glycerol according to claim 1 catalyzes the method for synthesizing (meth)glycerol, it is characterized in that described catalyzer is solid alkaline compound calcium glycerol, and its preparation method is as follows: Reflux reaction of calcium oxide in glycerol-methanol (volume ratio 1:1) mixed solution for 2 hours, cool to room temperature, wash with methanol, dry at 120°C for 24 hours, roast at a certain temperature in a muffle furnace for 4 hours to obtain calcium glycerol catalyst, etc.; The amount of catalyst used is 0.5% to 5.0% of the total mass of the reaction; The catalyst can be added by any known conventional delivery means, such as but not limited to mixing the catalyst and methyl methacrylate into the slurry mixture. 5. the method for a kind of glycerol calcium catalysis synthesis (meth) glyceryl acrylate according to claim 1 is characterized in that described polymerization inhibitor comprises: diethylhydroxylamine, p-hydroxyanisole, hydroquinone, Phenothiazine, 2,6-di-tert-butyl-p-cresol, 3,5-di-tert-butyl-4-hydroxyanisole, 2,5-di-tert-butyl-hydroxyanisole, 4-hydroxy-2 , 6,6-tetramethylpiperidine radical and 4-hydroxy-2,6,6-tetramethyl-N-hydroxypiperidine, preferably p-hydroxyanisole; When using the above-mentioned polymerization inhibitor, generally control the molar ratio of the polymerization inhibitor to the raw material alcohol within the range of (0.001-0.004):1. 6. the method for a kind of glycerol calcium catalyzed synthesis (meth)glycerol ester according to claim 1, it is characterized in that temperature of reaction (being the temperature of reaction mixture in transesterification reaction process) is 60-140 ℃, Preferably 80-100°C. The reaction pressure was 760 mmHg (atmospheric pressure).