RU2348667C1 - Method of alkyd varnish production and method of bulk component feed to reactor with explosive medium, such as used in alkyd varnish production - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention concerns paint-and-varnish industry, particularly alkyd varnish production using automated control system of technological process, as well as feeding of bulk components to reactor with explosive medium. Method of alkyd varnish production involves alcoholytic re-etherification of vegetable oil by pentaerythritol with heating in inert gas flow in the presence of catalyst, followed by polyetherification of re-etherification products by phthalic anhydride with heating, water distillation with azeotropic solvent, reaction product - alkyd resin - cooling to 160-180°C, varnish preparation by mixing obtained resin with organic solvent. Re-etherification and polyetherification process is performed in reactor featuring electric induction heating system and connected to technological pipelines with stop valves. Reactor has at least one pipe socket with heat-resistant gate installed in it, and at least two water heat exchangers in the form of worm pipes, mixer, nozzle column, vertical cooler, condenser and separation vessel. Alkyd resin dissolution is performed in mixer with stop valves, mixer, jacket and reverse heat exchanger for condensation and recycling of evaporating solvents in the mixer; vegetable oil dosing and loading to reactor is performed by automated control system, where stop valves of oil feed line are opened and closed by remote controls automatically or steered from control console; dosing and loading of bulk component, such as pentaerythritol and phthalic anhydride is performed and controlled over automated control system for bulk component dosage and loading, including depacker, tanker on tension weighing device, pneumatic lift, at least one ripper, snail feeder and mentioned heat-resistant gate in pipe socket of reactor; dosing and loading of azeotropic solvent and water to worm pipes of reactor, as well as recycled water feed and control and solvent feed to mixer are performed with remote automatic control of stop valves. In addition invention claims method of bulk component feed to reactor used in production of alkyd varnish.

EFFECT: reduced labour cost, improved fire protection and environmental safety.

22 cl, 1 tbl, 2 dwg, 2 ex

Description

The invention relates to the paint and varnish industry, in particular to the production of alkyd varnishes using an automated process control system, and also relates to the supply of bulk components to a reactor with an explosive atmosphere and can be used to obtain, for example, various paints based on it and coatings for various purposes and, in particular, used for painting metal, wood and other surfaces operated in atmospheric conditions and indoors.

Paints and varnishes based on alkyd resins modified with vegetable oils are widely known. Coatings based on these resins have good physical and mechanical properties, but an insufficient cure rate.

Known technologies for producing glyphthalic and pentaphthalic resins are based on the stage of transesterification of vegetable oils with glycerol or pentaerythritol and the stage of polyesterification with phthalic anhydride when heated - resins GF-046, PF-053-TU 6-10-612-76. The transesterification temperature is usually 240-260 ° C, and the exposure time up to 3 hours. In order to reduce the temperature of the stage of transesterification of alkyd resins, catalysts are used - soda ash, lead oxide (litharge) and others. However, it is possible to reduce the temperature and reduce the exposure time slightly.

A high synthesis temperature, duration of exposure, the catalysts used cause the appearance of dark foci that are not compatible with the resin, which leads to the production of lacquers based on these resins, the dark colors - 60 mg J _2/100 cm ³ Iodometric scale.

A known method of producing alkyd pentaphthalic resin PF-060. According to this method, the stage of alcoholysis (transesterification) is carried out at 255 ± 5 ° C and holding for 2.5-3.0 hours in the presence of a catalyst - soda ash (Reference manual edited by M.M. Goldberg "Raw materials and intermediates for paints and varnishes" M., Chemistry, 1978, pp. 103-105, 116-117).

The resultant lacquer on the basis of this PF-060 resin has a sufficiently dark color - J ₂ 60 mg / 100 cm ^3, a varnish film has a long time of complete drying at 20 ± 2 ° C, namely 24 hours.

A known method of producing alkyd resins by the interaction of linseed oil, glycerol and / or pentaerythritol in the presence of a basic catalyst at 220-240 ° C followed by the interaction of the obtained product with phthalic anhydride and a modifier at 250 ° C. As a modifier, 7-8% by weight of the reaction mixture of pomegranate oil is used. Varnish coatings based on this alkyd resin dry to a degree of 3 for 1 h at 80 ° C and have a hardness of 0.35 cu (SU 806696, 1980). The disadvantage of this method is the high temperature at the stages of alcoholysis (transesterification) and polycondensation, as well as the high temperature of the drying of the varnish coatings until they completely dry.

A known method of producing alkyd resins by alcoholysis of PET waste - ground waste food containers based on PET with up to 10% impurities of polyethylene and polypropylene - and vegetable oils with pentaerythritol in the presence of a catalyst, followed by polycondensation with phthalic anhydride. The catalyst used is cadmium or nickel salts of saturated or unsaturated aliphatic monocarboxylic acids with a chain length of C ₆ -C ₁₈ or cadmium, nickel or zinc salts of acylsalicylic acids with a chain length of the acyl substituent C ₆ -C ₁₈ in an amount of 0.1-0.5% by weight of the components. Alcoholysis is carried out while loading pentaerythritol and PET waste into a heated vegetable oil with a catalyst. The known method also involves the use of high temperature at the stage of alcoholysis (up to 250 ° C), in addition, it is technologically complicated and requires sophisticated equipment (RU 2209818, 08/10/2003).

From RU 2200741, 03/20/2003, another method is known for producing modified alkyd resins based on glyptal and pentaphthalic oligomers by carrying out the transesterification (alcoholysis) of vegetable oils with glycerol or pentaerythritol in the presence of a catalyst, then carrying out the polyesterification reaction with phthalic anhydride when heated in the presence of as a catalyst reactions of transesterification of lead 2-ethylhexanate, while at the stage of polycondensation of glyphthalic resin, a para-based phenolic resin is additionally introduced t-butylphenol and formaldehyde in an amount of 3-4 wt.%, and at the polycondensation stage of the pentaphthalic resin, a mixture of benzoic and para-tert-butylbenzoic acids is additionally introduced in a ratio of 1: 1.5-2.

Based on alkyd resins obtained by this known method, paints and varnishes are obtained suitable for carrying out internal and external work on various surfaces.

According to the conventional method was prepared and modified glyptal Nitrocellulose alkyd resin with an acid number of 10-15 mg KOH / g, having the color of iodine scale 15mg J _2/100 cm ^3; drying at 20 ± 2 ° C for 4-5 hours.

From RU 2249017, 03/27/2005, a method for producing alkyd resin and varnish based on it is known. An alkyd resin is obtained by alcoholysis of vegetable oils and possibly rosin with polyhydric alcohol (glycerol or pentaerythritol) in the presence of a catalyst, which is used as a mixture of lead and cadmium salts of saturated or unsaturated aliphatic monocarboxylic acid with a chain length of C ₆ -C ₁₈ in the form of a solution in white spirit in an amount of 0.009-0.02% by weight of the components, when heated. Next, polycondensation is carried out with a dicarboxylic acid anhydride and a modifier — a phenolic resin based on alkyl phenol and formaldehyde with a ratio of 1: 1 to 1: 2 or aromatic monobasic carboxylic acid in a mixture of it with substituted aromatic monobasic carboxylic acid, taken in certain quantities. Based on such modified alkyd resins, various paints and varnishes are obtained, containing, if necessary, various fillers, pigments, desiccant, an organic solvent and, if necessary, a thickener, as well as various target additives (flame retardants, corrosion inhibitors, and others). Light resins are obtained, with a high content of non-volatiles, a low acid number, and quickly drying, which provides paints and varnishes based on them with improved physical and mechanical properties (hardness, elasticity), as well as good protective properties. The alkyd resin is synthesized periodically by the azeotropic method in an inert gas, such as nitrogen, in an induction heating reactor, an internal coil for cooling with water and a frame stirrer. Vegetable oil, a portion of glycerol or pentaerythritol, is charged to the reactor. Turn on the stirrer and heat to a temperature of 150-160 ° C, add the catalyst. The transesterification reaction is carried out at a temperature of 180-230 ° C.

Sampling of the reaction mass is carried out every 15 minutes. The process is considered complete when the solubility of the transesterification sample in ethyl alcohol is achieved in a ratio of at least 1: 2-5 at a temperature of 20 ± 2 ° C. At a temperature of 180-190 ° C, a second portion of glycerol or pentaerythritol, phthalic anhydride, a modifier, as well as xylene for azeotropic distillation of water are introduced. After loading, the temperature is slowly raised to 220-230 ° C, every hour, and then every 30 minutes, resin samples are taken to determine the acid number and conditional viscosity.

The resin is quickly cooled to 170-180 ° C and poured into a mixer, where white spirit was previously loaded.

From the monograph by M.L. Lifshits, B. I. Pshiyalkovsky “Paints and varnishes”, 1982, M., Chemistry, pp. 28-30, a periodic method for the production of alkyd varnishes is known, according to which a liquid (10 m ³ ) is loaded into the reactor raw materials (vegetable oil, glycerin) coming by gravity from a dosing vessel, solid components - phthalic anhydride (less often - maleic) and rosin coming in the form of a melt through a dosing vessel by gravity, pentaerythritol from a hopper by pneumatic transport, solvents (white spirit, xylene, solvent etc.) entering the reactor amotekom after carrying out steps and polyesterification alcoholysis (with the exception of xylene is added to form an azeotropic mixture). Released reaction gases and vapors enter the condenser, and then in liquid form into the separation vessel, from where the xylene separated from the water is returned to the reactor, and water and gas emissions are removed for combustion through the trap. From the reactor, the lacquer base enters a mixer (25 m ³ capacity) equipped with a condenser for mixing with solvents.

The resulting varnish is put on the type, its properties are determined. To obtain it, a reactor is used, for example, with electric induction heating and an anchor blade mixer and a mixer with a propeller stirrer or a frame mixer that is blocked with the reactor.

Used in the known method, the installation, including the reactor, mixer and other auxiliary equipment (sumps, pumps, capacitors, separation vessels, receivers) is widely used to produce any alkyd resins and varnishes based on them.

The disadvantage of these methods, including those taken as the closest in patent RU 2249017, is the inability to obtain alkyd resin or alkyd varnish with stable characteristics, low sanitary and hygienic and environmental conditions for its production, the use of manual labor when performing heavy technological stages of the process .

The technical task of the claimed invention is to ensure and improve the stability of the characteristics of the process itself (conditions for carrying out various stages of the process) and the resulting finished product at different stages (resin and varnish), and as a result, simplification of the process, improvement of its fire and environmental safety.

The stated technical problem is achieved by the claimed group of inventions, which directly includes the method of producing alkyd varnish, as well as the method of supplying loose components to a reactor with an explosive atmosphere, for example, upon receipt of alkyd varnish.

The problem in terms of the method for the production of alkyd varnish is solved due to the fact that the method according to the invention includes transesterification — alcoholization of vegetable oil with pentaerythritol when heated in an inert gas stream in the presence of a catalyst, subsequent polyesterification of transesterification products with phthalic anhydride when heated, distillation of water with an azeotropic solvent, cooling of the reaction product - alkyd resin - up to 160-180 ° С, preparation of varnish by mixing the obtained resin with an organic solvent, while the process The esterification and polyesterification is carried out in a reactor equipped with an electric induction heating system, connected to technological pipelines, equipped with shut-off valves and at least one reactor with a heat-resistant shutter installed on it, and also equipped with at least two water heat exchangers in the form of coils, a stirrer , a packed column, a vertical refrigerator, a condenser and a separation vessel, while dissolving the alkyd resin is carried out in a mixer equipped with shut-off valves, stirrer, jacket and equipped with a return heat exchanger for condensation and returning to the mixer evaporating solvents, and the dosage and loading of vegetable oil into the reactor is carried out using an automatic control system, in which the closing-opening of shut-off valves on the line for loading oil into the reactor is carried out remotely, automatically and control the process from the control panel, the dosage and loading of bulk components such as pentaerythritol and phthalic anhydride into the reactor is carried out and ontroliruyut using automated dosing control system and loading particulate ingredients comprising rastarivatel on tenzovesah hopper pneumolift the at least one ripper, screw bearer and said heat-resistant choke valve on the reactor; the dosage and loading of the azeotropic solvent, water into the reactor coils, as well as the supply and regulation of recycled water, the supply of solvents to the mixer are carried out with remote automatic control of shutoff valves.

At the same time, the visualization of the technological process can be carried out by displaying the position of the stop valves, the operation of other nodes of the equipment used and the process parameters on at least one monitor and a mnemonic diagram.

As a vegetable oil can use sunflower oil.

Soybean oil may be used as a vegetable oil.

As vegetable oil can use camelina oil.

Tall oil may be used as a vegetable oil.

As vegetable oil, fatty acids of vegetable oil may be used.

Distilled tall oil may be used as a vegetable oil.

As the catalyst, soda ash or a drier, in particular a lead drier, such as lead octoate, can be used.

In the polyesterification step, maleic anhydride may additionally be added.

At the stage of transesterification - alcoholysis, rosin can additionally be introduced.

After loading vegetable oil into the reactor, the contents of the reactor can be heated to a transesterification temperature of at least 240 ° C and maintained until the sample is soluble in ethanol in the range of ratios from (1: 2) to (1:10), and the process of heating and transesterification of the oil is carried out in a stream of inert gas, preferably nitrogen.

The reactor can be equipped with an adjustable vacuum system and a system for collecting phthalic anhydride and acrolein taken from it, while the vegetable oil is pre-heated in the reactor, which in turn is also pre-heated to a temperature of at least 50 ° C, then pentaerythritol is loaded, and the charge phthalic anhydride is produced at the end of the stage of transesterification and cooling to a temperature of at least 200 ° C, and the loading of pentaerythritol and phthalic anhydride is preceded by connecting the reactor to the evacuation system of the existing varnish production and the capture system of phthalic anhydride and acrolein carried away from the reactor.

The polyesterification process can be carried out until the desired viscosity and acid number of the alkyd resin are achieved.

The problem in terms of the method for supplying bulk components to a reactor with an explosive atmosphere, for example, in the production of alkyd varnishes, is solved due to the fact that in the inventive method according to the invention, the reactor is in communication with process pipelines equipped with shut-off valves and is equipped with at least one fitting with a heat-resistant damper installed on it, a vacuum system equipped with at least one vacuum pump, and a system for dispensing and loading bulk components, and before starting to supply bulk comp The components in the reactor include a system for evacuating the explosive atmosphere of the reactor and, upon reaching the required degree of evacuation, open the heat-resistant shutter, and after introducing the required amount of these components into the reactor, close the shutter, sealing the reactor.

The system for dispensing and loading bulk solids may include a stripper, a hopper on a strain gauge, a pneumatic hoist, a cultivator, a screw feeder and the aforementioned heat-resistant shutter on the reactor nozzle, while the bulk solids are pre-loaded into separate hoppers equipped with strain gauges for regulating the dosed loading and unloading of components, followed by the supply of these components is carried out by a pneumatic hoist into the cultivator, then they are fed into the reactor, including a screw feed, at it includes evacuation system before feeding screw loose components.

As bulk components in the production of alkyd varnishes, at least the components necessary for the alkyd varnish production process can be used selected from the group consisting of pentaerythritol, phthalic anhydride, maleic anhydride.

Prior to supplying the bulk components, a vacuum of at least 0.15 atm, preferably 0.2 atm, can be created in the reactor.

Vacuum can be created by means of a vacuum pump equipped with inlet and outlet nozzles, the latter being in communication with the external atmosphere.

Bulk components can be fed into the explosive atmosphere of the reactor sequentially using screw feeders.

The control valves when loading bulk components into the reactor can be carried out remotely, automatically with the display of operations on the monitor or mimic diagram.

Switching the vacuum system of the explosive atmosphere of the reactor on and off can be carried out remotely, automatically by displaying operations on a monitor or mimic diagram, while turning off the vacuum system of the explosive atmosphere of the reactor is preferably done after closing the heat-resistant damper.

The technical result achieved by the claimed invention is to increase the efficiency, fire and environmental safety while reducing the complexity and energy consumption of the processes of alkyd varnish production due to automatic weighing, dosing and loading of the reactor, mixer bulk and liquid components and other technological operations, such as an azeotropic separation of water at all stages of the preparation of the resin and the final product - alkyd varnish, with a significant increase Ecological safety is achieved due to the selection of technological equipment made in the invention, as well as due to the closed system developed for the loading of bulk components into the explosive atmosphere of the reactor when combined with the sequential pneumatic and mechanical transportation of bulk components and the inclusion of a vacuum system for the explosive atmosphere of the reactor for the period of direct introduction into bulk components reactor. Reducing the complexity and technological simplicity of process control is ensured by installing bins and a mixer on a tenzovyzah and displaying operational data on the parameters of the technological process on a remote display - monitor and control panel for alkyd varnish preparation processes.

Technical solutions are illustrated by drawings, which show a special case of a method for the production of alkyd varnishes and a method for supplying bulk components to a reactor with an explosive atmosphere, not covering and, moreover, not limiting the entire scope of the claims of this solution, where

figure 1 schematically shows the installation used to implement the method according to the invention;

figure 2 - reactor with a system of electric induction heating.

A method for the production of alkyd varnish includes transesterification - alcoholization of vegetable oil with pentaerythritol when heated in an inert gas stream in the presence of a catalyst, subsequent polyesterification of transesterification products with phthalic anhydride when heated, distillation of water with an azeotropic solvent, cooling of the reaction product - alkyd resin - to 160-180 ° C, preparation of varnish by mixing the obtained resin with an organic solvent.

The process of transesterification and polyesterification is carried out in a reactor 1 equipped with an electric induction heating system, connected to technological pipelines 2, equipped with shut-off valves 3 and at least reactor 1 is equipped with one fitting with a heat-resistant shutter 4 installed on it, and also equipped with at least two water heat exchangers in the form of coils 5, a stirrer 6, a packing column 7, a vertical refrigerator 8, a condenser 9 and a separation vessel 10.

The alkyd resin is dissolved in a mixer 11 equipped with shutoff valves, a stirrer, a jacket and equipped with a return heat exchanger 12 for condensation and returning to the mixer 11 of evaporating solvents.

The dosage and loading of vegetable oil into the reactor 1 is carried out using an automatic control system, in which the closing-opening of shutoff valves 3 on the line for loading oil into the reactor 1 is carried out remotely, automatically and control the process from the control panel.

The dosage and loading of bulk components, such as pentaerythritol and phthalic anhydride, into the reactor 1 is carried out and controlled by an automated control system for the dosage and loading of bulk components, including a scraper 13, a hopper 14 on a strain gauge, an air lift 15, at least one cultivator 16, screw feeder 17 and the aforementioned heat-resistant valve 4 on the union of the reactor 1.

The dosage and loading of the azeotropic solvent, water in the coils 5 of the reactor 1, as well as the supply and regulation of recycled water, the supply of solvents to the mixer 11 is carried out with remote automatic control of shutoff valves 3.

Visualization of the technological process is carried out by displaying the position of the stop valves 3, the operation of other components of the equipment used and the process parameters on at least one monitor and mimic diagram.

As vegetable oil, use sunflower, soybean, camelina oil, as well as tall oil fatty acids, vegetable oil fatty acids and distilled tall oil.

The catalyst used is soda ash or a drier, in particular a lead drier, such as lead octoate.

In the polyesterification step, maleic anhydride may additionally be added.

At the stage of transesterification - alcoholysis, rosin can additionally be introduced, which is pre-crushed and loaded in the form of a solution in vegetable oil.

As solvents, xylene, solvent, uyat spirit or mixtures thereof in various combinations are used.

The inert gas used is preferably nitrogen obtained in a gas separation membrane unit 18.

After loading vegetable oil into the reactor, the contents of the reactor are heated to a transesterification temperature of at least 240 ° C and maintained until the sample is soluble in ethanol in the range of ratios from (1: 2) to (1:10), and the process of heating and transesterification of the oil is carried out in a stream of inert gas, preferably nitrogen.

The reactor 1 is equipped with an adjustable vacuum system and a system for collecting phthalic anhydride and acrolein taken from it, while the vegetable oil is pre-heated in the reactor, which in turn is also pre-heated to a temperature of at least 50 ° C, then pentaerythritol is loaded, and the phthalic charge anhydride is produced at the end of the stage of transesterification and cooling to a temperature of at least 200 ° C. The loading of pentaerythritol and phthalic anhydride is preceded by connecting the reactor 1 to the vacuum system of the existing varnish production and the capture system of phthalic anhydride and acrolein carried away from the reactor 1.

The polyesterification process is carried out until the desired viscosity and acid number of the alkyd resin are achieved.

In the method for supplying bulk components to a reactor with an explosive atmosphere, for example, in the production of alkyd varnishes, the reactor 1 is in communication with process pipelines 2 provided with shutoff valves 3, and is equipped with at least one fitting with a heat-resistant shutter 4 installed on it, a vacuum system, equipped with at least one vacuum pump 19, and a system for dispensing and loading bulk solids.

Before starting the supply of bulk components to the reactor 1, a vacuum system for the explosive atmosphere of the reactor 1 is turned on, and upon reaching the required degree of evacuation, the heat-resistant shutter 4 is opened, and after introducing the required amount of these components into the reactor 1, the shutter 4 is closed, sealing the reactor 1.

The system for dispensing and loading bulk solids includes a stripper 13, a hopper 14 on a strain gauge, a pneumatic hoist 15, a ripper 16, a screw feeder 17 and the aforementioned heat-resistant damper 4 on the nozzle of the reactor 1. Preloading of the bulk components is carried out in separate bins (not shown in the drawings) equipped with strain gauges to regulate the dosed loading and unloading of components, the subsequent supply of these components is carried out by a pneumatic hoist 15 to the ripper 16, then they are fed into the reactor 1, incl. tea feed screw by bearer 17, wherein the vacuum system includes before feeding screw loose components.

As bulk components in the production of alkyd varnishes, at least the components necessary for the alkyd varnish production process are selected from the group consisting of pentaerythritol, phthalic anhydride and, if necessary, maleic anhydride.

Before feeding the bulk components in the reactor 1, a vacuum is created with a depth of not less than 0.15 atm, preferably 0.2 atm. Vacuum is created by means of a vacuum pump 19, equipped with inlet and outlet nozzles, the latter being in communication with the external atmosphere.

The flow of bulk components into the explosive atmosphere of the reactor is carried out sequentially using screw feeders 17.

The control valves when loading bulk components into the reactor 1 is carried out remotely, automatically with the display of operations on a monitor or mimic diagram (not shown in the drawings). Turning on and off the evacuation system of the explosive atmosphere of the reactor 1 is carried out remotely, automatically displaying operations on a monitor or mimic diagram, while turning off the evacuation system of the explosive atmosphere of the reactor 1 is preferably done after closing the heat-resistant damper 4.

The following is an example illustrating, but not limiting the method of the invention.

Example 1

Getting alkyd varnish.

The loading of liquid components into the reactor 1 and mixer 11 from the existing warehouse 20 of liquid raw materials (oil, xylene, mineral spirits) is carried out through individual process pipelines 2.

Bulk components are fed in bags on pallets to the shop floor warehouse of solid raw materials from the factory warehouse of raw materials with an existing electric forklift.

The dosage of white spirit and xylene in the reactor 1 is carried out using liquid counters 21, and the dosage of white spirit and solvent in the mixer 11 according to the readings of the weights on which the mixer is installed. When the supply line is shut off, the feed pump 22 automatically stops at the liquid stock 20.

Vegetable oil is metered into the reactor 1 by mass flowmeters. After passing the set dose, the feed pump 22 in the warehouse automatically stops. The dose is set and the device is selected from the instrumentation room.

The production of varnish is carried out, for example, by a periodic azeotropic method.

Alkyd varnish is a solution of pentaphthalic resin in white spirit and solvent. Synthesis of resin is provided in a reactor 1 with a capacity of preferably 16.0 m ³ with an electric induction heating system, equipped with one fitting with a heat-resistant shutter 4 mounted on it, mainly three coils 5, a mixer 6 and equipped with a packing column 7, a vertical heat exchanger-cooler 8, a condenser 9 and a separation vessel 10.

Resin synthesis includes the stages of transesterification (alcoholysis) of vegetable oil with pentaerythritol at a temperature of (250 ± 5) ° С in the presence of a catalyst - soda ash and polyesterification.

Sunflower oil is loaded into the reactor 1 by a pump from the mixer 11, previously heated to a temperature of 70 ° C, or by a feed pump 22 directly from the warehouse 20 of liquid raw materials through a mass flow meter. Then pentaerythritol and soda ash are charged.

The contents of the reactor 1 are heated to a temperature of (250 ± 5) ° C and maintained at this temperature until the sample is soluble in ethanol in a ratio of 1: 5. The reactor 1 is equipped with a sampler.

Oil heating and transesterification are carried out in a stream of inert gas supplied through a rotameter to the reaction mass layer.

At the end of the exposure, the reaction mass is cooled to ~ 180 ° C by feeding water to the coils 5, after which phthalic anhydride is charged. When loading phthalic anhydride, the reactor 1 through the heat exchanger 8 is connected to a vacuum system of the existing production of varnishes to capture phthalic anhydride and acrolein carried away from the reactor 1. The existing collection unit includes a packed column 7 irrigated with an alkali solution.

The polyesterification process is accompanied by the release of reaction water. To remove it, xylene is charged into reactor 1.

The azeotropic mixture - xylene-water, passing the packed column 7, condenses in the heat exchanger 8 and enters the separation vessel 10, from where the xylene is returned through the overflow pipe to the reactor 1, and the water flows into the apparatus.

The polyesterification process is carried out at a temperature of (250 ± 5) ° C to the required viscosity and acid number, while the temperature in the reactor 1 is maintained automatically.

Upon reaching the required indicators, the contents of the reactor 1 are cooled to a temperature of 160-180 ° C and, when inert gas is supplied to the reactor 1, the resulting resin is poured into the mixer 11 under a layer of pre-loaded solvent (white spirit and solvent).

The mixer 11 with a capacity of preferably 25 m ^{3 is} mounted on a strain gauge and is equipped with a frame mixer, a jacket and a heat exchanger 12.

The resin is mixed with a solvent until a homogeneous solution is obtained, and the resulting varnish is put “on type” in viscosity and mass fraction of non-volatile substances until the required parameters are achieved. The finished varnish is pumped by the pump 23 for filtration to the cartridge filter 24, from where it enters the collector 25 of the finished varnish with a capacity of preferably 25 m ³ .

So, the synthesis of alkyd (pentaphthalic) varnish is carried out by the periodic azeotropic method in the installation shown in figure 2.

The work described below also illustrates the method for supplying bulk solids to an explosive atmosphere reactor.

Before putting into operation, the reactor 5 is checked for cleanliness by visual inspection through the hatch. Check the bottom fittings of the reactor 5 for serviceability by opening and closing the fittings. Check the operation of the mixer with a test switch. Check the connection of instrumentation by visual inspection.

Transesterification (alcoholysis) of vegetable oils.

Empty reactor 1 before loading the oil in it is heated to a wall temperature (90-95) ° C. In prepared for operation, the reactor 1 is loaded with oil, preheated to (70-80) ° C, from the warehouse 20 of liquid raw materials by the feed pump 22 according to the flow chart. After loading the oil, shut off valves on the oil loading line at the reactor 1, turn on the mixer 6, illuminate and heat the reactor 1.

At a temperature of 90 ° C, the inert gas — nitrogen — is switched on through the rotameter “per layer” of the reaction mixture, setting the feed rate to 2–2.5 nm ³ / h.

In the temperature range (110-120) ° C, the heating is stopped and the oil is held at this temperature for (0.5-1) hours to avoid foaming due to possible moisture content of the raw material. After foaming is stopped, heating is continued.

During exposure, the flow of cooling water on the refrigerator 8 is reduced to a minimum.

If, according to the recipe and the flow chart, rosin loading is provided, then the temperature in the reactor 1 is raised to 150 ° C and the inert gas supply to the reactor 1 is turned off. The reactor 1 is connected via a condenser 9 to the vacuum created by the vacuum pump 19 through the packing column 7 , irrigated with a solution of alkali to trap vapors of harmful substances from the reactor during loading of bulk components.

The loading of rosin solution in the reactor is automatic, it is carried out in the form of its solution in oil by a pump through a process pipe, but the preparation of rosin solution in oil is carried out on a separate mixer (not shown in the drawings).

After loading the rosin, the flow of nitrogen and the heating of the reaction mixture are resumed.

When reaching 250 ° C, turn off the nitrogen supply and connect the reactor 1 to the vacuum circuit. Download 1 pentaerythritol and lead drier (lead octoate) into the reactor according to the flow chart. At the end of the load, the reactor vacuum system is turned off, the inert gas is turned on through the rotameter with a feed rate of 2-2.5 nm ³ / h, and the reaction mass is continued to be heated.

The alcoholysis of vegetable oils with pentaerythritol (transesterification) is carried out at a temperature not exceeding 265 ° C. After reaching a temperature of 265 ° C, exposure is made for (1-2) hours and sampling begins every (15-30) minutes to check the degree of transesterification.

The transesterification process is considered complete when the solubility of the sample in ethanol is achieved in a ratio of at least 1: 5 by volume at a temperature of (23-27) ° С. If after holding the reaction mass for (2.5-3.0) hours at a temperature of 265 ° C, solubility in a ratio of 1: 5, but not less than 1: 2, is not achieved, the transesterification (alcoholysis) process is also considered complete.

After completion of the transesterification process, the heating of the reactor 1 is turned off and the reaction mass is cooled through the coils 5 to a temperature of (180-220) ° C and the inert gas supply is stopped.

The stage of polyesterification

After cooling the reaction mass to (180-220) ° C, the reactor 1 is connected to the vacuum system of the reactor.

1 Phthalic anhydride and maleic anhydride are loaded into the reactor, if necessary, according to the flow chart. The reaction mass is heated to 180 ° C and exposure is done at this temperature for 1 hour.

The polyesterification (polycondensation) reaction proceeds with the release of reaction water in the amount of one kg / mol for each kg / mol of phthalic anhydride, free fatty acid and rosin. To facilitate the removal of water from the reaction zone, 1 xylene is added to the reactor through the liquid meter in the quantity indicated in the flow chart from the warehouse 20 of liquid raw materials through the process pipeline by the feed pump 23. For the process of xylene circulation (azeotropic distillation of water), regenerated xylene is allowed.

Water vapor in the form of an azeotropic mixture along with xylene vapor is sent to the packing column 7 and cooler 8, cooled, the excess xylene condenses and flows back to reactor 1, and the azeotropic mixture and the non-condensed part of xylene enter condenser 9, where it condenses and flows into the separation vessel 10. In the lower part of the separation vessel, water with partially dissolved xylene is collected, in the upper part - xylene with partially dissolved water.

Xylene from the separation vessel 10 through the overflow nozzle and water trap flows back into the reactor 1 or is supplied for irrigation to the top of the nozzle column 7. At the beginning of the polycondensation process, distillation xylene is fed to the nozzle column 7 for 4-6 hours to capture phthalic anhydride vapor and return him into the reaction mass.

After this time, the flow of distillate xylene is switched directly to the reactor 1, and the supply of cooling water to the refrigerator 8 is changed to a minimum, be sure to leave a small flow rate.

From the moment the xylene begins to circulate, the reaction moisture begins to flow from the reaction zone to the separation vessel 10.

After each discharge of the reaction water, an appropriate amount of xylene is removed from the xylene circulation system, and the temperature of the reaction mass is gradually increased.

Since the beginning of the circulation of xylene, using the above technological method, the temperature of the reaction mixture is raised to 220 ° C for no more than (3.5-5) hours. The technological process is carried out in the temperature range (220-240) ° C until an acid number of not more than 10 is reached with constant xylene circulation.

After reaching an acid number of 10, if necessary, the temperature of the reaction mass is gradually raised and the process of increasing viscosity is carried out to a stop value. In this case, with the chain of viscosity increase, it is possible to conduct a process with a weak xylene circulation.

Upon reaching the required performance in viscosity and acid number, the heating is turned off and the resin is cooled to (150-180) ° C using the supply of recycled water to the reactor coil, as described above.

After cooling the reaction mass to (150-180) ° C, the water supply to the coil is closed, the water outlet from the coil is left open.

After cooling, the resin is analyzed for viscosity and acid number.

The viscosity of the resin before draining into the mixer should not be lower than specified in the flow sheet and the acid number should not exceed 10 mg KOH / g.

The resin from the reactor is drained by gravity into the mixer 11. During the discharge of the resin into the mixer 11, the reactor 1 is flushed. For this purpose, approximately a third of the resin is poured into the mixer 11. The stirrer 6 is stopped and loaded onto the remaining resin (500-1000) liters of white spirit. Continue pouring the resin into the mixer without stirring. Heated white spirit vapors rise into the vertical part of the reactor, condense and flow down the walls of the apparatus, washing it. Before loading the white spirit for washing, open the maximum supply of cooling water to the refrigerator 8, in order to prevent solvent vapors from entering the separation vessel 10. After draining the reaction mass into the mixer, close the bottom stop valves of the reactor and load (500-1000) l white Spirit. The solvent is heated with stirring to a temperature of (80-100) ° C, maintained at this temperature (0.5-1) hour and the solvent is drained to the bulk in mixer 11. The amount of solvent loaded into the reactor is taken into account when the resin is dissolved and set to "type "

Dissolution of the resin and setting the varnish to "type"

Dissolution of the resin and setting the varnish to “type” is carried out in a mixer 11, equipped with a jacket for cooling with circulating water, a stirrer and equipped with a heat exchanger 12. Based on the viscosity of the obtained resin, solvent and xylene can be used in addition to white spirit. The use of regenerated xylene for setting to "type" is not allowed.

To set the varnish to "type" is loaded into the mixer 11 through a white spirit counter in accordance with the technological map. Water is supplied to the mixer jacket and to the heat exchanger 12, the mixer is turned on.

The resin from the reactor 1 at a temperature of (150-180) ° C is poured into the mixer 11. The resin is reshaped with a solvent to obtain a homogeneous solution, which is checked by pouring the sample onto the glass, and then the varnish is set to “type” according to viscosity and mass fraction of non-volatile substances in accordance with the specifications by adding solvents.

Solvent vapors formed during the dissolution of the resin enter the heat exchanger 12, condense and flow back to the mixer 11.

When setting the varnish to “type”, solvents are used: white spirit, solvent, xylene.

After each addition of solvent, the resin solution is thoroughly mixed for at least (1-2) hours, and the varnish is checked for compliance with technical specifications.

The varnish should comply with the following indicators:

- the viscosity of the varnish at (20 ± 0.5) ° С (50% solution in white spirit) according to the B3- 246 viscometer with a nozzle diameter of 4 mm should be at least 70 s;

- acid number not more than 10 mg KOH / g for the highest grade, not more than 15 mg KOH / g for the 1st grade:

- mass fraction of non-volatiles not less than (60 ± 2)% or

- the viscosity of the varnish at (20 ± 0.5) ° С according to the B3-246 viscometer with a nozzle diameter of 4 mm should be (60-80) s;

- acid number not more than 12 mg KOH / g for the highest grade, not more than 15 mg KOH / g for the 1st grade, not more than 20 mg KOH / g for the 2nd grade;

- mass fraction of non-volatile substances (52-55)% for the highest grade, (51-55)% for the 1st and 2nd grade.

Upon reaching these indicators, varnish from the mixer 11 is fed to the filtration. The temperature of the varnish before filtering should be (50-60) ° C, but not lower than 40 ° C.

Example 2. Synthesis of an alkyd resin using tall oil fatty acids (GLC) or distilled tall oil (DTM).

An empty reactor 1 is heated to a wall temperature (95-100) ° C before loading the GIT (DTM) into it. In the prepared reactor 1 is loaded GIT (DTM), preheated to (70-80) ° C, by the feed pump from the warehouse 20 of liquid raw materials in quantity, according to the flow chart.

After loading the GCTM (DTM) include a stirrer 6 and heating of the reactor 1.

In the case when the recipe containing rosin is included in the routing, then when it reaches 150 ° C, it is loaded in portions, as described above. After loading the rosin, the mass is heated to 200 ° C, as described above.

If the loading of rosin is not provided, then the gastrointestinal tract (DTM) is heated to 200 ° C.

Then pentaerythritol, phthalic anhydride, and xylene are loaded into the reactor 1 for circulation according to the flow chart, as described above.

Further, the process is carried out similarly to the process using vegetable oil.

The following is an illustration of a description of the method for supplying granular components to an explosive atmosphere reactor (for example, the production of alkyd varnishes), while the use of an automated control system for the production of alkyd varnish according to the invention is shown.

1) Carry out the loading of oil from the shop floor through the mass flow meter. The pump is switched on remotely from the control instrumentation panel from the control panel. Pump shutdown is automatic at a given dose.

Closing-opening of shut-off valves on the line for loading oil into the reactor is carried out remotely, automatically and is controlled from the control panel from the control instrumentation and automation panel with the display of operations on the PC and the mimic diagram.

2) The pentaerythritol and phthalic anhydride are loaded into the reactor using an automated bulk component loading system consisting of a hopper on a tenzovyzov, a pneumatic hoist, a cultivator, a screw feeder and a heat-resistant shutter on the reactor nozzle. This system is controlled by PC from the control panel in the instrumentation panel. Download starts at the signal of the operator and ends automatically at the set dose. The automated loading system also includes a unloading unit for filling bunkers on tenge weights with bulk raw materials. The change in the weight of the hopper is automatically fixed on the display panel in the unloader area and is displayed on the control panel in the instrumentation panel.

3) The solvent is loaded into the reactor for azeotropic boiling and for washing the reactor through an electronic meter with remote automatic control of shutoff valves and pumps from the control panel from the control panel. Pump shutdown is automatic after loading a predetermined dose. The amount of solvent loaded is displayed on the PC monitor. The status of the shutoff valves and pumps is displayed on the PC monitor and on the mimic diagram.

4) Distribution of azeotropic xylene flow and emptying of the separation vessel is carried out remotely, automatically from the control panel in the instrumentation panel with the display of the position of the shutoff valves on the mimic diagram.

5) The supply and regulation of circulating water is carried out remotely automatically from the control panel in the instrumentation panel with the display of the position of the shut-off valves on the mimic diagram. Regulation of the water supply to the condenser can be carried out automatically according to the value of the set temperature.

6) Water supply to the reactor coils is carried out remotely automatically from the control panel in the instrumentation panel with the display of the position of the shut-off valves on the monitor and mimic diagram.

7) The mixers are mounted on a strain gauge with the display of the weight on the board in place and with the display of indications on the monitor and mimic diagram on the control panel in the instrumentation panel.

8) Supply of solvents to the mixer, i.e. control valves and pumps are carried out remotely automatically at a predetermined dose from the control panel in the instrumentation panel with the position of the valves and the status of the pumps on the monitor and mimic diagram in the instrumentation panel.

9) When filtering, the regulation of circulation flows is automatic according to the set pressure on the pump. Automatic shutoff valves and pumps are controlled remotely from the control panel in the instrumentation panel with the status of shutoff valves and pumps displayed on the monitor and on the mimic diagram.

10) The operation of the pumps of the vacuum unit is remote automatic from the control panel in the instrumentation panel with the status of the pumps displayed on the monitor and mimic diagram.

All this allows you to secure the entire process, make it environmentally friendly, ensure stability of the conditions for all stages and the process as a whole, as well as the stability of the set properties of the resulting varnish.

The table shows the main properties of alkyd varnish according to the invention.

The pentaphthalic alkyd varnish in its quality indicators meets the requirements and values specified in the table.

p / p The name of indicators Value Test methods top grade 1 grade one 2 3 four 5 one Iodometric lacquer color scale mg J _2/100 cm ^3, which is darker than fifteen 80 According to GOST 19266 section 1 2 Appearance of varnish Transparent, slight opalescence is allowed (slight whiteness or turbidity) According to clause 4.3 of TU 3 Purity of varnish The layer of varnish applied to the glass plate must be transparent. Must not have mechanical impurities and rash According to clause 4.4 of TU four Mass fraction of nonvolatile substances,%, not less than 60.0 60.0 According to GOST 17537 and clause 4.5 of TU 5 Viscosity at a temperature of (20.0 ± 0.5) ° С (50% solution in white spirit) according to a VZ-246 or VZ-4 viscometer with a nozzle diameter of 4 mm, s, not less than 70 70 According to GOST 8420 and clause 4.6 of TU 6 Acid number, mg KOH / g, not more than 10 fifteen According to GOST 23995 met. 1 and p. 4.6 TU 7 Hardness of the varnish film, arbitrary units, according to the pendulum device of the TML type (pendulum A) not less 0.12 0.12 According to GOST 5233 8 Drying time to a degree of 3 hours, no more According to GOST 19007 at a temperature of (20 ± 2) ° С 24.0 24.0 at a temperature of (80 ± 2) ° С 2.0 2.0

Thus, as follows from the presented data, the claimed group of inventions allows to obtain alkyd varnish with high stable properties in a more advanced environmentally friendly and fireproof way; the use of an automated process control system allows you to directionally adjust and control the condition of the individual stages of the process (supply of bulk components to the reactor, for example) and the whole process. This, in turn, allows you to directionally receive varnish with stable preset characteristics, regardless of the choice of source components.

Claims (22)

1. A method for the production of alkyd varnish, characterized in that it involves transesterification - alcoholization of vegetable oil with pentaerythritol when heated in an inert gas stream in the presence of a catalyst, subsequent polyesterification of transesterification products with phthalic anhydride when heated, distillation of water with an azeotropic solvent, cooling of the reaction product - alkyd resin up to 160-180 ° С, preparation of varnish by mixing the obtained resin with an organic solvent, while the process of transesterification and polyesterification is carried out they are installed in a reactor equipped with an electric induction heating system in communication with technological pipelines equipped with shutoff valves, and at least the reactor is equipped with one fitting with a heat-resistant damper installed on it, and is also equipped with at least two water heat exchangers in the form of coils, a stirrer, and a nozzle a column, a vertical refrigerator, a condenser and a separation vessel, while dissolving the alkyd resin is carried out in a mixer equipped with shutoff valves, a stirrer, a jacket and equipped with a reverse heat exchanger to condense and return to the mixer evaporating solvents, and the dosage and loading of vegetable oil into the reactor is carried out using an automatic control system, in which the closing-opening of shut-off valves on the line for loading oil into the reactor is carried out remotely automatically and control the process from the control panel, the dosage and loading of bulk components, such as pentaerythritol and phthalic anhydride, into the reactor is carried out and controlled using an automated Dosage control systems and loading particulate ingredients comprising rastarivatel on tenzovesah hopper pneumolift the at least one ripper, screw bearer and said heat-resistant choke valve on the reactor; the dosage and loading of the azeotropic solvent, water into the reactor coils, as well as the supply and regulation of recycled water, the supply of solvents to the mixer are carried out with remote automatic control of shutoff valves. 2. The method according to claim 1, characterized in that the visualization of the technological process is carried out by displaying the position of the stop valves, the operation of other nodes of the equipment used and the process parameters on at least one monitor and mimic diagram. 3. The method according to claim 1, characterized in that sunflower oil is used as a vegetable oil. 4. The method according to claim 1, characterized in that soybean oil is used as vegetable oil. 5. The method according to claim 1, characterized in that camelina oil is used as vegetable oil. 6. The method according to claim 1, characterized in that fatty acids of tallow oil are used as vegetable oil. 7. The method according to claim 1, characterized in that fatty acids of vegetable oil are used as vegetable oil. 8. The method according to claim 1, characterized in that the distilled tallow oil is used as a vegetable oil. 9. The method according to claim 1, characterized in that the catalyst used is soda ash or drier, in particular a lead drier, such as lead octoate. 10. The method according to claim 1, characterized in that at the stage of polyesterification, maleic anhydride is additionally introduced. 11. The method according to claim 1, characterized in that at the stage of transesterification - alcoholysis, rosin is additionally introduced. 12. The method according to claim 1, characterized in that after loading vegetable oil into the reactor, the contents of the reactor are heated to a transesterification temperature of at least 240 ° C and maintained until the sample is soluble in ethanol in the range of ratios from (1: 2) to (1 : 10), and the process of heating and transesterification of the oil is carried out in a stream of inert gas, preferably nitrogen. 13. The method according to claim 1, characterized in that the reactor is equipped with an adjustable vacuum system and a system for collecting phthalic anhydride and acrolein carried away from it, while the vegetable oil is pre-heated in the reactor, which in turn is also pre-heated to a temperature of at least 50 ° C, then pentaerythritol is charged, and phthalic anhydride is charged at the end of the transesterification and cooling to a temperature of at least 200 ° C, and pentaerythritol and phthalic anhydride are pre-charged they are shown by connecting the reactor to the vacuum system of the existing varnish production and to the system for collecting phthalic anhydride and acrolein carried away from the reactor. 14. The method according to claim 1, characterized in that the polyesterification process is carried out until the desired viscosity and acid number of the alkyd resin are achieved. 15. The method of supplying bulk components to a reactor with an explosive atmosphere, for example, in the production of alkyd varnishes, characterized in that the reactor is in communication with process pipelines equipped with shut-off valves, and is equipped with at least one fitting with a heat-resistant shutter installed on it, a system evacuation, equipped with at least one vacuum pump, and a system for dispensing and loading granular components, and before starting the flow of granular components into the reactor include a vacuum evacuation system voopasnoy medium reactor and after reaching the required degree of evacuation of the heat-resistant flap is opened, and after introduction into the reactor the necessary amounts of these components close said valve, sealing the reactor. 16. The method according to clause 15, wherein the system for dispensing and loading bulk solids includes a razvaritel, a hopper on a tenzovyzov, a pneumatic hoist, a cultivator, a screw feeder and the aforementioned heat-resistant shutter on the nozzle of the reactor, while the pre-loading of bulk components is carried out in separate bunkers, equipped with strain gauges for regulating the dosed loading and unloading of components, the subsequent supply of these components is carried out by a pneumatic hoist into the cultivator, then they are fed into the reactor p, including a screw pitch, wherein the vacuum system includes before feeding screw loose components. 17. The method according to p. 15, characterized in that as bulk components in the production of alkyd varnishes use at least the components necessary for the production of alkyd varnishes selected from the group consisting of pentaerythritol, phthalic anhydride, maleic anhydride. 18. The method according to p. 15, characterized in that before the supply of bulk components in the reactor create a vacuum with a depth of not less than 0.15 atm, preferably 0.2 atm. 19. The method according to clause 15, wherein the vacuum is created by means of a vacuum pump equipped with inlet and outlet nozzles, the latter communicating with the external atmosphere. 20. The method according to p. 15, characterized in that the flow of bulk components into the explosive atmosphere of the reactor is carried out sequentially using screw feeders. 21. The method according to p. 15, characterized in that the regulation of valves when loading bulk components into the reactor is carried out remotely automatically with the display of operations on the monitor or mimic diagram. 22. The method according to p. 15, characterized in that the on / off system for evacuating the explosive atmosphere of the reactor is carried out remotely automatically with the display of operations on a monitor or mimic diagram, while turning off the evacuation system for the explosive atmosphere of the reactor is carried out, preferably after closing the heat-resistant damper.

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