Filtration method of grafted polymeric polyols

FIELD: technological processes.

SUBSTANCE: invention is related to the filtration method of grafted polyol dispersions with use of repeated filter system. Invention describes a method of grafted polyol filtering with use of refillable filter system consisting in a) use of refillable filter system that consists of the first tank and the second tank; b) the first part of the positive-displacement filter material is installed between the first and the second tanks thus developing fluid-tight seal is developed between the first tank and filter material; c) dispersion of grafted polyol is loaded to the first tank; d) dispersion of grafted polyol is let to the second tank through filter material, and e) the first part of positive-displacement filter material is removed from the area between the first and the second tanks and the second part of clean positive-displacement filter material with twisting pores is installed between the first and the second tanks. Received filtered dispersion of grafted polyol has particles of maximum size of 25 microns and is stable for various conditions for minimum period of 9 weeks.

EFFECT: method ensures cost effective and fast filtration of large volumes of grafted polyol dispersion.

17 cl, 1 dwg, 3 ex

 

The present invention in General relates to a method of filtration of dispersions of polyols, in particular method of filtration of dispersions of grafted polyols using the updated filter system (index filtering method). Usually grafted polyols defined as dispersions of vinyl polymers in the polyester polyols, they are also called polyether polyols as described in U.S. Reissue No. Re. 33,291. Typically, the formation of grafted polyols include in situ polymerization has caused unsaturation polyether polyol in situ, usually known as macromer, and Ethylenediamine monomer or mixture Ethylenediamine monomers in the presence of a polyol carrier, the response regulator and initiator of free radical polymerization. The study of the dispersion of grafted polyols under the microscope shows that they contain many desirable small particle size which is generally from 0.1 to 2.5 microns in diameter. However, the dispersion of grafted polyols also typically contain particles, the diameter of which may range from 0.04 to 100.0 microns. Very large particles are undesirable. Graft polyols are widely used in polyurethane foaming systems due to its advantageous properties, they attach to the pins. Many of these desirable characteristics associated with particles of the desired size, presence is relevant in dispersions of grafted polyols.

One of the drawbacks of dispersions of grafted polyols is that while they are receiving often form large particles and large aggregates of particles, which are believed to cause great difficulties in the conventional devices for foaming polyurethane, which is used to produce foam of such graft polyols. This issue becomes extremely important when using carbon dioxide as a foaming agent for polyurethane foam. A blowing nozzle in the foam using carbon dioxide, a much more demanding to the materials used compared to nozzles used in traditional foam, in which the blowing agent used water, acetone or chlorinated fluorocarbon. The blowing agents with carbon dioxide as the foaming agent are particularly suitable in connection with the recently manifested by anxiety about harming the environment chlorinated fluorocarbons, which are used as foaming agents, resulting in the adopted legislative acts in the sphere of environmental protection, which prohibit their use on the territory of the United States.

To mitigate the difficulties that may be caused by the foam generator of large particles and large aggregates of particles of a grafted polyol, Oba is but grafted polyols pre-filter before using them in the foam generator. For practical reasons, it is required that before using the foam generator grafted polyols were subjected to at least several stages of filtering in accordance with the conventional method. Often grafted polyols filter overloaded from the tanks in which they are stored in tank trucks or railroad tank cars in which they are delivered to manufacturers of foams. Often grafted polyols filtered a second time for the unloading of rail tank cars or tank trucks in the tank, which uses the manufacturer of foams.

Often the third filtering is made during the loading of the grafted polyol in the foam generator. In order grafted polyol well used, most of the foam using carbon dioxide as the foaming agent, it is necessary that the grafted polyol passed through a preliminary filter for a long period of time, usually for more than 4 hours without clogging the filter. Typically, such filters have openings of approximately 100 microns for installations Novaflex that are produced by the Hennecke company-Bayer, and installations Beamech and 150 microns for installations Cardio, which are produced by the company Cannon-Viking. Typically the pre-filter is extracted, when the pressure drop on its surface reaches 70 F./square is., while it is desirable that the producers had to replace these pre-filters as possible.

When filtering grafted polyols are faced with many difficulties, partly because of the properties of particles grafted polyols. First of dispersion of the grafted polyol you must remove particles that are larger than desired, instead of the above-mentioned particles need a smaller size, as they provide the required properties. Most preferably filtered from the dispersion of the grafted polyol to remove particles larger than 25 microns with minimal removal of particles of a smaller size. Secondly, by its nature, a polyol carrier in the dispersion is viscous, and the presence of particles of a grafted polyol is doing the dispersion of grafted polyol considerably more viscous. The dispersion of grafted polyols are also very sticky. Thirdly, the particles of the grafted polyol have the ability to deform when the temperature of the filter, which is used to reduce the viscosity so that they can be deformed under pressure, so that they either quickly clog a conventional filter material, or pass through the filter material with a specific pore size, even if the particle size exceeds the pore size of the filter itself. With n the present invention has been set, the use of bulk filter material (depth filter media) with a maximum average effective pore size of from about 15 to 75 microns is preferred, the most preferred is the average effective pore size of 15 to 50 microns, which minimizes clogging of filters in the blowing agent with carbon dioxide as a foaming agent, which, as mentioned above, have a hole size of 100 to 150 microns, and is sufficient to ensure continuous operation of the head expander. The term "average effective pore size" in the context of the present description and claims is defined as the diameter of the smallest pores, which must remain clean for half of the total area of the filter clean (missed). A test that determines this parameter is described in ASTM Method F-316. I believe that the phenomenon consisting in the fact that the material that is filtered through a filter with a nominal pore size 25 microns, can really clog the filter material with a significantly larger holes ranging in size from 100 to 150 microns, is associated with a tendency to the formation of obstructions or the formation of agglomerates in the holes coarser material, aided by large particles, large aggregates of particles, and the sticky part is. The phenomenon of clogging, which clogged the filter material, is a well-known phenomenon, described in many sources, involving the problems of filtering. In addition, the propensity for clogging coarser sieves can also be caused by the fact that the particles or aggregates of particles larger than the pores of the filter material, deform and pass through the filter material.

In the past, methods of filtering grafted polyols used bushing strainers, bag filters and cartridge filters. However, for the above reasons, all these methods have disadvantages, because they are completely irrelevant to the dispersions of polyols in General. When using the filters quickly become clogged grafted polyol, they are complex to use, when to stop filter system, remove clogged filters or cleaning or replacement with subsequent re-Assembly of the filter system needs a lot of time. Usually in order to avoid clogging of such filters, they are set in tiers with the top tier holds the largest fraction of particles, then the next tier holds the material with smaller particles. This allows less often to change the entire filter material, however, still requires a large area. N what are the cases for filtering grafted polyols you can use self-cleaning filters. Such self-cleaning filters, such as filters manufacturing company Ronningen-Petter, Inc., have a scraper, which continuously cleans the surface of the cylindrical filter screens to prevent clogging, and the filter is periodically cleaned from accumulated therein contained material. In General, such devices are not used sieves with small enough holes that would allow to obtain a product suitable for use in the blowing agent with carbon dioxide. If they do establish a sieve with small holes, such devices have a low throughput and a significant loss of pressure, resulting in deformation of the particles and their passage through the filter material, and the need to frequently clean the sieves because of their frequent clogging. For most of dispersions of grafted polyols such sieves are practically not applicable.

Given the above difficulties, it would be desirable to develop a method of filtering grafted polyols, which would allow quick filtering grafted polyols with obtaining particles of appropriate size, would provide significant throughput of the system, would facilitate replacement of the filter material and would ensure the stability of the filtered dispersion of the grafted polyol in the long term.

A SUMMARY of the SU AND INVENTIONS

According to a first embodiment the present invention relates to a method of filtering grafted polyol using the updated filter system, which is that use rechargeable filtration system, consisting of the first tank and the second tank; have the first part of the filter material volume of the filter between the first and second tank and form impermeable to liquid shutter between the first tank and the filter material; load the dispersion of grafted polyol in the first tank, take the dispersion of the grafted polyol in the second tank after it will be ignored through the first tank and the filter material, remove waste the first part of the filter material with tortuous pores of the zone between the first and second tank and install the second piece of clean filter material volume of the filter between the first and second tank.

According to the second variant of the present invention relates to a method of filtration grafted polyol using the updated filter system, which is that use rechargeable filtration system consisting of first and second tank, have the first part of the filter material volume filter with an average effective pore size from 1 to 75 microns between the first and second tank and form impermeable to liquid shutter between the first vessel and the filter material, download the dispersion of grafted polyol in the first tank, let the variance of the grafted polyol through the filter material and take the dispersion of the grafted polyol in the second tank after it has passed through the first tank and the filter material, move waste the first part of the filter material volume of the filter from the zone between the first and second tank and install the second piece of clean filter material with tortuous pores between the first and second reservoir. Because the present invention uses the filter material volume of the filter, such a material also removes some particles whose size is smaller than the size of the smallest pores, with the bulk of the filtering mechanism.

These and other features and advantages of the present invention will be more obvious to a person skilled in the art from the following detailed description of a preferred variant embodiment of the invention.

BRIEF DESCRIPTION of DRAWINGS

The drawing shows a schematic diagram of the cross-section updated filter system according to this invention.

A DETAILED DESCRIPTION of the PREFERRED OPTION of carrying out the INVENTION

The present invention relates to a method of filtering grafted polyols, which uses the t updated filtering system on one stage. In normal rechargeable filtration system, working under pressure, a portion of the filter material is transferred into a position across the filter area by means of a mechanical system, typically using a motor-driven belt or rollers. Updated filter system typically contains a first reservoir and a second reservoir with filter material located between the two tanks. As soon as the filter material is positioned, the first tank is hermetically connected to the filter material in order to form impermeable to liquid shutter. Typically, a perforated plate covering the second tank is also tightly connected with filter material, forming impermeable to liquid shutter, however, this is not always necessary. Then to be filtered dispersion of the grafted polyol is loaded into the first tank and is passed through the filter material, using the pressure of the fluid as a driving force. The first tank begins to fill dispersion, when the rate of passage through the filter material becomes smaller than the download speed in the first tank, usually because the filter begins to clog, thus slowing the rate of filtration. The time during which the user can continue to download the aspersio in the first tank before it happens depends on the dispersion and used filter material. This period of load dispersion can last for a very short period of time or to last for a long time, if the variance is not too viscous, and good filterability. As the filling of the first tank system pressure begins to increase as the variance of the compressed gas. This increase in pressure is determined by the system, and the flow of the dispersion in the first tank is automatically terminated. At this point, the remainder of the variance in the first tank is subjected to additional pressure, thus forcing it through the filter material to collect in the second tank. Typically, the pressure increase is achieved by using air or nitrogen at a pressure of from 20 to 150 F./CVD Immediately after passing the greater part of the filtered dispersion through the filter material is "leakage", i.e. the rapid release of pressure due to the total expenditure variance from the first tank. After the "breakthrough" most updated filtering systems pass into the drying cycle, which may include increasing the gas pressure to displace as many as possible of the dispersion through the filter material. After the drying cycle cease to create additional gas pressure, and the excess pressure is discharged through the open is ment exhaust valve. The first tank is separated from the filter material and the filter material is moved or Supplement to ensure a clean unused part of the filter material between the first and second tank so that you can repeat the cycle of filtration. If the filter material becomes clogged and the variance is retained above the filter material, in this case, the overshoot does not occur. The gas pressure remains at maximum, and additional gas is not included in the system. Upon expiration of the term, which is denoted as the long cycle of drying, the system usually detects this, and the exhaust valve on the exhaust pipe opens. An excessive amount of dispersion comes from the first tank through the discharge pipe and is collected in the chamber to recyclization at a later stage. In some cases, the updated filter system also includes a scraper located at the receiving roller for used filter material that is designed to recover some portion of unfiltered dispersion from the surface of the filter material, to recyclization in the system. This can be important if the variance is expensive and quite viscous, as in the case of dispersions of grafted polyols. As such recovered dispersion contains a large number of particles bol is our size, it should in most cases be subjected to rough cleaning before re-filtered using the updated filter system, or it should be used in systems in which the foaming agent does not use carbon dioxide. Regular updated filter system is highly automated, often it has the ability to automatically regulate the flow and the drying cycle when the filterability is changed, the drying cycle is short and the system itself is very useful in its application according to the present invention.

The simplified scheme replenished filtration system is operating under pressure, according to the invention indicated by the position 10 in the drawing. The system 10 includes a first reservoir 20 with the sealing surface 23 and the second reservoir 22. The second tank 22 contains optional perforated plate 27. General view of site control loading of the filter is indicated by position 24. The control unit 24 typically contains a source of clean filter material 26, usually in the form of a roll. The control unit 24 loads clean the filter material 28 between the first reservoir 20 and the second tank 22 and is supported by the plate 27, if any. The control unit 24 also includes a manifold used to filter the found material, indicated by the position 30. The filter material 28 is usually served either by using a motor-driven tape, or using engine manifold 30 for the used filter material 30. When using a tape (not shown)used filter material 34 is typically freely discharged into the collection. Usually when in the manifold 30 for the used filter material used causes the engine, the manifold 30 includes a roller 32 that is used by the control unit 24 for accumulating the used filter material 34. The manifold 30 for the used filter material may also contain a block with scraper 36 is moved in the direction of used filter material 34, and suscribase the remainder of the filtered dispersion of the grafted polyol with the surface of the used filter material 34 to collect in the third tank 38. In a conventional control unit 24 source of clean filter material 26 and the collector of the used filter material 30 are driven by means of at least one engine (not shown), designed for rapid replenishment of clean filter material 28 in the system 10. Any of the collection methods used filter material 34 is suitable for use in this invention, however, lucheprelomleniya belt system, used filter material 34 may be subjected to processing with a scraper to remove the remaining variance from its surface.

The inlet pipe 44 is used to load subject to filtering grafted polyol through valve 46 into the reservoir 20. The inlet for gas 48 is connected through the valve 50 to the inlet pipe 44 for supplying compressed gas. The system 10 further comprises a discharge pipe 52, located very close to the bottom of the first tank 20 and is connected through an exhaust valve 54 and the pump 60 with the inlet pipe 44 for recovery unfiltered dispersion of the grafted polyol. The third tank 38 is connected through the tubing 40 with another collector (not shown). Its contents may be either roughly filtered and passed through the system 10, or may be used in other foam generators that are less demanding. The first reservoir 20 includes a pressure sensor 62 to determine the increase in pressure when the filter material 28 begins to clog.

The system 10 further includes a control mechanism 25 of the tank for moving the first tank 20 with respect to the second tank 22, as shown by the arrow 21. The control mechanism 25 may include any known mechanism, including a pneumatic cylinder for lifting and lowering the first tank 20, a hydraulic mechanism, the mechanism for lifting and lowering the first tank 20 or gear mechanism for lifting and lowering the first tank 20. Such systems are publicly available.

The variant of execution shown in the drawing, in which the first and second tanks 20, 22 fixed relative to each other. The valve is normally filled with fluid, located between the two tanks and it put pressure, forming a gate between the filtering material 28 and the first tank 20. When the pressure on the bolt is removed, the tension of the filter material 28 is weakened, and it is possible to move and to replenish or using a roller, or by using a motor-driven tape. Such alternative replenished filtration system is operating under pressure, produced by the company Filtra Systems Company of Farmington hills, Michigan, USA.

Specialists in the art it is obvious that some dispersion of grafted polyols with a high filterability can afford to use other equipment to filter using the updated filter system. Some dispersion of grafted polyols with high filterability may need to reset the pressure in the cross section of filter material 28 does not exceed 14,7 F./CVD in order to obtain a dispersion with a high degree of filterability, while to the filtering rate was high, and the flow rate of the filter material 28 was dost is just low. Such dispersion can be filtered using vacuum updated filtering systems, in which the driving force for filtration is the vacuum that is created through the filter material 28. In such system the filtered suspension is contained in the first tank on one side of the filter material and the filter material hermetically connected to the second tank from the opposite side. The second tank is under vacuum. In this embodiment, the dispersion is sucked by vacuum into the second tank, and then is output from the system. When the filter material is partially clogged, the vacuum in the second reservoir increases, the system detects this change and starts recharging the filter material. The advantage of such systems is that they are in General cheaper than the updated system 10, working under pressure, shown on the drawing. Again, specialists in the art can determine whether or not the dispersion of the grafted polyol to be used with a specific filter material updated in a vacuum filtration system. Such vacuum updated system are produced, for example, Henry Filter Company, Incorporated, of Bowling green, Ohio, USA, and Filtra Systems Company of Farmington hills, Michigan, USA.

During operation of the system 10, the control mechanism 25 of the tank atod iget the first tank 20 from the second tank 22, what is the first stage of the process. The valves 42, 50 and 54 are closed. Node 24 control loading filter delivers clean the filter material 28 between the first reservoir 20 and the second reservoir 22. The manifold 30 for the used filter material collects used filter material 34 on shaft 32. The control mechanism 25 of the tank then pushes the first tank 20 to clean the filter material 28, creating an impenetrable to liquid shutter relative to the sealing surface 23. Impervious to liquid shutter may be provided by hydraulic pressure, the inflatable chamber or with another seal on the sealing surface 23, as is known from the prior art. An alternative control mechanism 25 can exert sufficient pressure to the first reservoir 20, through which he tightly squeezes clean the filter material 28 between itself and the second tank 22, creating an impenetrable to liquid shutter. Load cycle begins when the dispersion of the grafted polyol falls within the first tank 20 through the inlet pipe 44 and valve 46, and the level of dispersion begins to grow, filling the first reservoir 20. The dispersion passes through the filter material 28 in the second tank 22 under the influence of gravity and under the influence of pressure increase due to a reduction in freely what about the space in the first tank 20. The level of dispersion in the first tank 20 eventually begins to rise due to clogging of the filter material 28, thereby starting even more to fill the first tank 20. When this happens, eventually reached a predetermined pressure level in the first tank 20, and the valve 46 is closed. Optional variance may be filed within a specified time period, not to achieve a certain level of pressure. After that, the valve 50 is opened, and the gas through the inlet 48, puts pressure on the dispersion of the grafted polyol in the first tank 20. At this stage, the dispersion of the grafted polyol passes through a clean filter material 28 in the second tank 22 through we apply pressure through the inlet for air 48. This is called the primary stage of drying. When most of the grafted polyol skipped through the filter material 28 in the second tank 22, there is a "breakthrough", which is expressed in a sudden pressure release. This pressure relief is determined by the system 10, which then goes to the final stage of drying, during which over a certain period of time, the valve 50 remains open in order to push the remaining grafted polyol through the filter material 28 in the second tank 22. After this the th exhaust valve 54 is opened, and the residual pressure in the first reservoir 20 is reset. If the variance lingered over the filter material 28, i.e. when there was no breakthrough, it goes through the recovery pipe 52. Released material can be collected in a separate collection, or reservoir 38, which stores waste. Upon completion of the final drying cycle, the first tank 20 is separated from impermeable to liquid shutter with filter material 28, usually lifting it, and the node control loading of the filter 24 replenishes clean the filter material 28 in position between the first reservoir 20 and the second reservoir 22. Used filter material 34 is collected by means of a header 30 for the used material, as described above. Scraper site 36 removes unfiltered grafted polyol with the surface of the used filter material 34 to be harvested in the third tank 38.

The selection of an appropriate filter material 28 is extremely important to the efficiency of the present invention. According to the present invention the filter material 28 is selected to provide a massive filtering unlike surface of the filter or filtering through the sediment material. In the system of surface filtration, the filtering material usually has a clearly defined constant size of the holes and is often monovoltine single-layer woven sieve. Surface filter filters out particles that are larger than the size of the holes, and allows only particles smaller than the size of its holes. Such filter material more quickly clogged or clog the grafted polyols according to the invention. Thus, the filter materials of this type are unsuitable for use in the present invention. The filter system through the sediment material is a system in which sediment particles accumulated on the surface of the filter material. In fact, this is accumulated on the surface of the filter material sediment filters.

As opposition to the filter material 28, suitable for three-dimensional filtering in General is either a multilayer nonwoven material, or needle-punched material. Despite the fact that they are unsuitable for use according to the invention, thick sand filters operate under a similar principle. Volumetric filtering occurs if the particles are held within the material 28, despite the fact that the particles themselves are significantly less than ducts or pores in the material 28. The mechanisms responsible for this filtering, complex, and include the attraction between the walls of the pores of the filter material 28 and particles, PR is the tension between the neighboring particles, the strength of van der Waals and other forces that occur on the surface. Volumetric filtering allows the use of filter material 28 with relatively large pores to ensure sufficient capacity, with the possibility of retention at the pore walls and the removal of the dispersion of particles smaller than the pore size of the filter material 28. Particles that are larger than the pore size are filtered out on the surface of the filter material 28. Another important component of the filter material 28 according to the present invention is that it has a sufficient thickness that provides sufficient volume filtration. In relation to this important inventions used by the characteristics of the filter material 28 to surround the filter is that its average effective pore size is from 15 to 75 microns, and more preferably from 15 to 50 microns, and he has a sufficient thickness. As described below, this can be achieved by using the filter material 28 to the greater thickness with a high average value of the effective pore size or finer filter material 28 with a lower average effective pore size.

One type of filter material 28, which confirmed its effectiveness against a variety grafted polyols produced the usual firm Crystal Filtration Company called Crystal 2220. The filter material 28, Crystal 2220 is non-woven, laid in the wet state, multi-layer material 28, which includes a complex polyester as the top layer; the middle layer of the 97% cellulose and 3% microtesla, which is a milled fiber, mixed with paper pulp, and complex polyester as the bottom layer. The top layer, through which first passes grafted polyol has an average pore size, while the middle layer has the smallest pore size. The bottom layer has a large pore size, which allows filtered the grafted polyol quickly go through it. The filter material 28 preferably has a thickness of approximately 0.06 inches, which provides the average effective pore size of approximately 25 microns. Another type of suitable filter material 28, manufactured by Crystal, includes needle-punched material, such as material series Crystal 3195 and Crystal 3220. Such needle-punched material has a thickness of approximately 0.25 inches and the average effective pore size from 42 to 49 microns. Another suitable filter material is Crystal 510, having an average effective pore size of about 18 microns. The average effective pore size being an important parameter, is not the only selection criteria to filter the corresponding material 28. As you can see from the above information, the average effective pore size can vary from 18 to 49 microns and still provide the proper filtering grafted polyols, provided that the thickness of the filter material 28 is sufficient to provide deep filtering required for the present invention. I believe that when the desired thickness of the present invention may make use of the material even with a mean effective pore size of 75 microns or more, in particular if the pre-filter used in the foam generator has large holes. Preferably the thickness of the filter material 28 is from 0.04 to 0.3 inches, which provides a sufficient degree of volumetric filtering.

Another important aspect of the present invention is the temperature at which the dispersion of the grafted polyol load on the filter material 28 in the first tank 20. The viscosity of dispersions of grafted polyols can be very high and the temperature increase leads to the decrease of viscosity. Heat can be in many ways, including pre-heating the dispersion of the grafted polyol before it is loaded into the first reservoir 20 and/or heating the first tank 20. For the present invention, it is preferable that the temperature of filterregistry grafted polyol ranged from 25 to 98° C. More preferably, the temperature of the filtered dispersion of the grafted polyol ranged from 50 to 80°C. the Pressure in the first reservoir 20 in the updated filter system, working under pressure, through the opening 48 may be from 20 to 150 F./CVD, more preferably from 20 to 80 F./CVD and most preferably from 20 to 50 F./CVD Obviously, in the above-described vacuum updated filter systems the pressure in the vacuum usually below 20 F./CWD

Other filter media 28 that provides three-dimensional filtering, also suitable for use according to this invention. The suitability of the proposed filter material 28 can be easily estimated using laboratory system with pressurised filter periodic operation, as is well known to specialists in this field of technology. Key parameters include the filtration rate per unit area, the number of processed dispersion before it is clogged the filter material, as well as the quality of the resulting filtrate. The quality is usually evaluated on the basis of the tendency to clogging of the sieves with a pore size of approximately 100 microns in the filtrate when it is mixed with standard foam composition. Standard foamable composition includes the following components: the dispersion of grafted polyol, a conventional polyol, Catala is congestion, surface-active agents and activators. To obtain the foam composition is then mixed with at least one polyisocyanate and carbon dioxide as a foaming agent.

Example 1

Commercially available grafted Pluracol polyol® 1442 BASF Corporation held in the tank for transportation. Pluracol® 1442 is grafted polyetherdiols with terminal secondary hydroxyl groups with approximately 43% of a copolymer of styrene and Acrylonitrile. The temperature Pluracol® 1442 in the tank was raised to 52-54°using steam coil. The outlet of the tank was connected to the inlet pipe 44 updated filter system 10. The desired temperature of the inlet pipe 44 and the connection with the tank supported by means of the water jacket. Updated filter system 10 had the filtration area of 20 inches by 17,25 inch, 2.4 square feet of filtration area. Filter system 10 used with filter material 28 type Crystal 3195 firms Crystal Filtration Company. The filter material 28 has a thickness of 3/16 inch, while the lower side of the filter material 28 were scorching to prevent shedding of the filter material 28 in the filtered grafted polyol. Such filter material 28 is a non-woven material, namely 100% of complex polyester. Eleven gallons per cycle is isperia grafted polyol was loaded into the first tank 20 at 7 gallons per minute. The dispersion of grafted polyol pushed through the filter material 28 and collected in the second tank 22 for approximately one minute after the download is complete, under the influence of air pressure at 40 F./CVD supplied through the opening 48. Within two minutes was carried out by the drying cycle, as described above, to dry the filter material 28, and the air pressure was maintained at 40 F./CVD through the hole 48. Used filter material 34 scraped off by a scraper site 36 in the reservoir 38, and recovered the dispersion of grafted polyol kept for further processing, as described above. The variance, detained over the filter material 28 in the case when there was no breakthrough, was retained for subsequent filtering. Filter system 10 was able to filter 1100 pounds per hour dispersion of the grafted polyol, and the whole tank managed to filter in about 37 hours. Loss Pluracol® 1442 if used filter material 34 was 1.6%. When using filtered Pluracol® 1442 standard foaming composition according to the invention the pre-filter with a pore size of 150 microns, mounted on the expander, no plugging in for 40 hours, then as Pluracol® 1442 filtered through previously known himself is to clean the filter from Ronningen-Petter with holes the size of 50 microns using a slotted screen with holes of size 500 microns, clogs the filter for approximately one to two hours.

Example 2

Used tank Pluracol® 1543 from BASF Corporation. Pluracol® 1543 is grafted polyetherdiols with terminal secondary hydroxyl groups, containing approximately 44% of solid copolymerizing styrene and Acrylonitrile. The tank was connected to the filter system 10, as described in example 1 with the difference that the updated filter system 10 has an area filter size 7 square feet. Used filter material 28 was a three-layer product of the manufacture of Crystal Filtration Company called Crystal 2220. Such filter material 28 is non-woven, three-layer, stacked wet paper material, such as described in U.S. patent No.4925560. The filter material 28 contains a top layer of 100% of a complex of the polyester, the middle layer of the 97% cellulose and 3% microtesla (milled glass fiber, mixed with paper pulp) and the bottom layer of a complex of the polyester. The filter material 28, Crystal 2220 has an average effective pore size of approximately 25 microns and a thickness of 0.06 inch. Pluracol® 1543 downloaded in the first reservoir 20 with a speed of 22 gallons per minute and in each cycle used 15 gallons. Temperature Pluracol® 1543 was 65°C. the drying Cycle lasted around is about 2.5 minutes, and Pluracol® 1543 can be processed with the speed of 2450 pounds per hour, the total processing time of the tank contents amounted to 18.3 hours. Filtered Pluracol® 1543 was wspanialy on the expander Hennecke using standard foaming composition, and unlike the case with filtering Pluracol® 1543 through the self-cleaning filter Ronningen-Petter wire fabric with a pore size of 50 microns to 500 microns, which is hammered in approximately 15 minutes, this foaming system is not scored the filter in the foaming process.

Example 3

Used tank available on the market Pluracol® 2130 production BASF Corporation. Pluracol® 2130 contains a dispersion of grafted polyetherdiol end of primary hydroxyl groups, containing approximately 31% of solid copolymerizing styrene and Acrylonitrile. Pluracol® 2130 loaded into the filter system 10, as described in example 2. Used the same filter material as in example 1. The system 10 is installed on the filtering 95 gallons per cycle when the download speed of 24 gallons per minute and a temperature of downloadable Pluracol® 2130 in the first tank 20 about 75°C. the drying Cycle lasted 40 seconds. Pluracol® 2130 can be filtered with the speed 12700 pounds per hour.

When used in the above-described system 10 of the filter material 28, described the CSOs in examples 1, 2 and 3, the system 10 can be used to filter a range of dispersions of grafted polyols. Laboratory studies on the filtration indicate that the dispersion of the grafted polyol which can be effectively filtered using the above-described system 10, include the following products, produced by BASF Corporation: Pluracol® 1543; Pluracol® 2145; Pluracol® 2130; Pluracol® 2115; Pluracol® 1528; Pluracol® 973; Pluracol® 1218; Pluracol® 1525; Pluracol® 1442; Pluracol® 1524 and Pluracol® 1365.

Sustainability filtered grafted polyols after filtration in the system 10 was studied in two ways. In the first test sample filtered grafted polyol kept at room temperature for up to nine weeks, with each week took samples. Each sample was investigated with the aim of identifying retained whether it is obtained through their filtering properties. As the number of samples was small, the filterability was determined by measuring the amount of variance, which is at a temperature of 60°passes through a sieve with openings 28 microns at a pressure of 40 F./CVD before clogged sieve.

Filterability taking into account the error of the experiment was not changed during the nine weeks. In the second test with the aim of recreating the conditions of temperature fluctuations in the sample was placed in an autoclave and ran W is techsavvy cycle, during which the sample was heated to 77°and allowed to cool to 43°C for six hours, and this cycle was repeated for nine weeks. The sample was shaken at 50 rpm during the heating portion of each cycle. In both cases, the filtered grafted polyol remained stable, and its ability to pass through a sieve with openings 28 microns when it is heated to 60°not changed in the last nine weeks.

The above invention has been disclosed in accordance with applicable laws; therefore, the description is illustrative and does not limit the scope of legal protection of the invention. Possible changes or modifications to the technical solutions may be obvious to experts in the art and are included in the scope of legal protection of the present invention. Accordingly, the scope of legal protection given to this invention can only be determined by analysis of the attached claims.

1. The method of filtration grafted polyol for use in systems spinning polyurethanes using the updated filter system, namely, that

a) use the updated filter system, consisting of the first reservoir and the second reservoir;

b) between the first and second roeser what Varos have the first part of the porous or needle-punched filter material for deep filtration, including the layer with 97% cellulose and layer with 3% microstella, and having an average effective pore size of from 15 to 75 microns and a thickness of from 0.04 to 0.3 inches, and form impermeable to liquid shutter between the first reservoir and a filter fabric

C) load the dispersion of grafted polyol in the first tank, and the pressure on the dispersion of the grafted polyol during her stay in the first reservoir for its displacement through the filter material in the second tank,

d) pass the dispersion of grafted polyol to the second reservoir through the filter material, and

d) moving the first portion of the filter material for deep filtration from the zone between the first and second tank and install the second part of the filter material for deep filtration between the first and second tank.

2. The method according to claim 1, wherein stage b) includes the compression of the filter material between the first and second tank with the formation impermeable to liquid shutter.

3. The method according to claim 1, comprising exerting pressure from 20 to 150 pounds per square inch on the dispersion of the grafted polyol in the first tank.

4. The method according to claim 1, comprising exerting pressure from 20 to 80 pounds per square inch on the dispersion of the grafted polyol in the first tank.

5. The method according to claim 1, include the rd exerting pressure from 20 to 50 pounds per square inch on the dispersion of the grafted polyol in the first tank.

6. The method according to claim 1, wherein stage b) further includes heating the solution of the grafted polyol to a temperature of from 25 to 98°when it is loaded into the first tank.

7. The method according to claim 1, wherein stage b) further includes heating the solution of the grafted polyol to a temperature of from 50 to 80°when it is loaded into the first tank.

8. The method according to claim 1, wherein stage b) includes the establishment of a porous filter material comprising a complex layer of polyester and a layer with 97% cellulose and 3% microstella, between the first and second tanks.

9. The method according to claim 1,wherein stage b) includes establishing between the first and second reservoirs of porous filter material comprising the first complex layer of polyester, a second adjacent layer of 97% cellulose and 3% microstella, and adjacent the third layer, the pore size of which is larger than the pore size of the first layer, and the pore size of the first layer is larger than the pore size of the second layer.

10. The method according to claim 1, wherein stage b) includes establishing Meizu first and second tank filter material for deep filtration, representing a needle-punched material.

11. The method according to claim 10, in which stage b) includes establishing Meizu first and second tank filter material for deep filtration, representing poprobyu the second material, one side of which has been scorched.

12. The method according to claim 1, wherein stage b) includes establishing Meizu first and second tank filter material for deep filtration with a mean effective pore size of 15 to 50 microns.

13. The method according to claim 1, wherein stage b) includes establishing Meizu first and second tank filter material for deep filtration with a thickness of from 0.06 to 0.15 inches.

14. The method according to claim 1, in which stage d) further includes removing the dispersion of grafted polyol with the first part of the filter material for deep filtration when it is moved from the zone between the first and second tank.

15. The method according to 14, further comprising collecting remote dispersion of the grafted polyol and its load in the first tank.

16. The method according to claim 1, in which stage (a) includes the use of replenishable filtration system is operating under pressure.

17. The method according to claim 1, wherein stage a) comprises the use of a vacuum updated filter system.



 

Same patents:

FIELD: chemistry of polymers, chemical technology.

SUBSTANCE: invention relates to prepolymer with terminal isocyanate groups and characterizing the NCO-number value in the range 5-30 wt.-%, and representing a reaction product of excessive amount of diphenylmethane diisocyanate comprising at least 80 wt.-% of 4,4'-diphenylmethane diisocyanate and polyoxyethylene polyoxypropylene polyol of the mean molecular mass in the range 2000-10000 Da, average nominal hydroxy-functionality in the range 2-6, the content level of ethylene oxide in the range 21-45 wt.-%, and the presence of structure relating to type -PO-PO/EO-EO wherein PO-block comprises 60-90% of PO, and the ratio of terminal EO : statistically distributed EO is in the range from 3:1 to 1:3. Also, invention relates to polyisocyanate composition used for preparing polyurethanes and characterizing by NCO-number value maximally 52.5 wt.-% comprising 1-99 mass parts of the claimed prepolymer and 1-99 mass parts of other polyisocyanate per 100 mass parts of this polyisocyanate composition. Also, invention relates to a method for preparing elastic foam polyurethane from prepolymer or polyisocyanate composition corresponding to the invention as result of carrying out reaction in press-form at index in the range 70-120. Such elastic foam polyurethanes show improved stability and characterized by improved rigidity and good additional properties, for example, strength, residual compression deformation, indices of creep, elasticity, ability for vibration transferring, relative elongation and pleasant by feel. Foam materials made of such prepolymer or composition are used in furniture and automobile branches of industry in making seats, steering wheels, instrument board, furniture and mattress soft packing, and for sound damping and sound insulation.

EFFECT: improved preparing method, valuable properties of composition and material.

10 cl, 2 tbl, 3 ex

FIELD: crude water treatment.

SUBSTANCE: invention, in particular, relates to water-oil emulsion demulsifiers for treatment of crude oil before refining. Method of enhancing efficiency of commercial forms of demulsifiers is implemented by preparing said commercial forms using binary solvent consisting of a hydrocarbon and an alcohol soluble therein. Optimal concentration of alcohol and active part of a reagent in the solvent ensure formation in crude oil of critical emulsion with coacervate phase of high-molecular weight compounds contained in demulsifier. Optimal composition of solvent and presence of active part in the commercial form of given reagent corresponds with maximum optical density of that commercial form in hexane. In this case, demulsification efficiency is enhanced owing to extraction of naturally occurring emulsifiers contained in crude oil by coacervate phase of demulsifier.

EFFECT: enhanced demulsification capacity of commercial forms of demulsifiers due to transfer thereof in hydrocarbon into state of critical emulsion.

5 dwg

FIELD: polymer production.

SUBSTANCE: process comprises interaction of (a) polyol component, containing at least one polyoxyalkylenated polyether-polyol obtained in the form of aluminum phosphonate-based catalyst and having average equivalent weight from about 100 to about 10000, with (b) organic isocyanate in presence of (c) if necessary, one or several lengtheners, (d) if necessary, catalyst, foaming agent and (e) if necessary, crosslinking agents, surfactants, fire retardants, pigments, antioxidants, and stabilizers. Polyurethane foam obtained as described above is also described as well as catalyst based on aluminum phosphonate and having general formula RPO-(AAlR'R")2, wherein P denotes pentavalent phosphorus, O oxygen, Al aluminum, R hydrogen, alkyl or aryl group, and R' and R", independently from each other, halogen, alkyl group, aryl group, aryloxyl group, or derivatives of thus specified aluminum phosphonate, in amount from about 0.001 to about 5.0% based on the total weight.

EFFECT: improved quality, in particular homogeneity of polyurethane foam.

2 cl, 3 tbl, 7 ex

FIELD: polymer production.

SUBSTANCE: invention relates to in situ production of mixture from polyethermonool and polyetherpolyol, which comprises following steps: (A) loading a mixture to reactor, which mixture contains (1) initial initiator (Si) including one or several monofunctional compounds and (2) double metal cyanide catalyst; (B) supplying epoxide including propylene oxide and ethylene oxide to reactor at weight ratio between 100:0 and 10:80; (C) bringing epoxide mixture into interaction with initial initiator (Si) and performing polymerization of epoxides until equivalent weight of multifunctional compound rises by at least 10 wt % and achieves value from about 1500 to about 6000; (D) continuously adding low molecular weight initiator (Sc) having functionality from 2.0 to 8 and equivalent weight from about 28 to about 400 to reactor while continuing addition of epoxides; (E) ending continuous addition of initiator (Sc); and (F) continuing polymerization of the mixture in reactor until resulting monool/polyol mixture achieves average equivalent weight from about 350 to about 750 and average functionality from about 2 to about 4 and includes (1) about 25 to about 75 wt % polyethermonool having equivalent weight from about 1500 to about 6000 and (2) about 25 to about 75 wt % polyetherpolyol having equivalent weight from about 200 to about 500 and average functionality from about 20 to about 8. In situ produced mixtures of polyethermonool and polyetherpolyol as well as viscous-elastic foam production process are also described.

EFFECT: avoided need of preparation, storage, and mixing of separate polyethers and so reduced requirements for multiple tanks, which enhances production efficiency.

3 cl, 6 dwg, 2 tbl

FIELD: polymer production.

SUBSTANCE: invention relates to production of polyurethane foam used in vehicles, construction, and other fields where heat- and acoustic-insulation materials are required. Process comprises following operations: mixing polyetherpolyol with amine activator, polyatomic alcohol, and foaming agent; adding preliminarily prepared mixture of expanded graphite, melamine cyanurate, and gypsum in amount 5 to 50 % by weight based on the total amount of components; and adding polyisocyanate. Expanded graphite is mixed with melamine cyanurate at ratio (1-2):1 and in summary amount corresponding to 15-30 % by weight on the total amount of components. Foaming agent utilized is water or Freon. Composition may further contain trichloroethyl phosphate as fire-retardant additive.

EFFECT: increased strength and heat resistance of polymer material.

2 tbl, 6 ex

FIELD: organic chemistry, chemistry of polymers.

SUBSTANCE: invention relates to chemistry of polyurethans, namely, to spandex improved composition. Spandex is product of reaction of at least one polymeric glycol and at least one polyol comprising alkoxylated aromatic functional group with at least one organic diisocyanate followed by the polymerization process of synthesized protected glycol with at least one diamine. Alkoxylated diphenol or alkoxylated dihydrophenol is used as polyol comprising alkoxylated aromatic functional group. Also, invention describes a method for synthesis of spandex that comprises (with exception for steps in preparing isocyanate-protected polyols and their polymerization with diamines) molding steps from reaction mixture, molding from a melt, dry molding or wet molding of polyurethane also. Spandex possesses the best stability to high-temperature coloring and minimal loss of physical properties, such as elastic recovery of form.

EFFECT: improved method of synthesis.

16 cl, 4 tbl, 5 dwg

FIELD: polymer materials.

SUBSTANCE: invention relates to polyurethane foams and urethane rubbers, in particular to compositions for manufacturing cushioning polyurethane foams containing: at least one polyetherpolyol having average molecular mass between 10 and 20 thousands; aromatic polyisocyanate; tackiness-enhancing resin; surfactant; and optionally plasticizer in amount between 0.1 and 10 wt parts per 100 wt parts polyetherpolyol. Such polyurethane foams are non-soft cushioning polyurethane materials showing low elasticity and having a wide application area. Urethane rubbers obtained from at least two polyetherpolyols, tackiness-enhancing polymeric resin, aromatic polyisocyanate, and at least one catalyst also show low-elasticity properties and can be employed to manufacture of medicinal and orthopedic articles. A method for manufacturing such rubbers is proposed.

EFFECT: increased assortment of useful polyurethane foams.

4 cl, 8 tbl

FIELD: polymer materials.

SUBSTANCE: invention relates to moisture-hardenable polyurethane compositions, namely to those containing at least one polyurethane prepolymer with isocyanate groups obtained from at least one polyisocyanate and at least one polyol. In addition to prepolymer, composition further contains at least one polyaldimine prepared from at least one polyamine with primary aliphatic amino groups and at least one aldehyde of general formula: wherein Y1 and Y2, independently from each other, represent alkyl, aryl, or arylalkyl group, which is optionally substituted, may contains heteroatoms and/or unsaturated fragments, or Y1 and Y2 together form carbocyclic or heterocyclic ring, which is composed of 5-8, preferably 6 atoms and optionally contains one or two unsaturated bonds; and R1 represents either linear or branched C11-C30-alkyl chain, optionally with at least one heteroatom, especially with at least one ether oxygen atom, or linear or branched C11-C30-alkyl chain with one or numerous unsaturated bonds, or R1 represents group or in which R2 represents linear, branched, or cyclic hydrocarbon chain with 2-16 carbon atoms, optionally incorporating at least one heteroatom, especially at least one ether oxygen atom, or linear, branched, or cyclic C2-C16-hydrocarbon chain with one or numerous unsaturated bonds; and R3 represents linear, branched, or cyclic hydrocarbon chain with 1-8 carbon atoms. Invention describes methods for preparing such compositions and polyaldimine. Compositions can be used as glues, sealing formulations, coatings, or floorings hardening without unpleasant smell and suitable to seal layers inside buildings or to join structural members in vehicle interiors.

EFFECT: extended assortment of hardenable liquid polymer compositions.

24 cl, 4 tbl, 14 ex

FIELD: polymer production.

SUBSTANCE: invention provides process for manufacture of rigid polyurethane foams suitable as heat-insulation coatings via interaction of polyisocyanates with polyether component in presence of foaming and curing catalysts, foaming agent, foaming control agent, and fire retardant by way of bringing polyisocyanates into contact with hydroxyl-containing mixture comprising hydroxyl-containing compound, polyether supplemented by cyclic compound of formula I (appendix 1). As low-toxicity catalyst serving for cross-linking chains, cyclic compound of formula II (appendix 2) is additionally used in amounts from 1 to 200 wt parts per 100 wt parts hydroxyl-containing compound and ether. Invention assures manufacture of foamed plastic with heat resistance at a level of 210°C, compaction stress 0.48 MPa, and moisture absorption 6.8% without significant increase in brittleness of material, which allows material to be used in construction, power engineering, ship and automobile building, oil-and-gas and refrigeration industries. Appendix 1: . Appendix 2: .

EFFECT: improved performance characteristics of polyurethane foam.

2 tbl, 6 ex

FIELD: polymer materials.

SUBSTANCE: production of polymer-polyol comprises two staged performed under laminar motion conditions at elevated temperature and pressure. In the first stage, a monomer and catalyst are consecutively added to polyether or polyether mixture with molecular weight 2000-6000 and primary hydroxyl content 40-80%, whereupon mixture is stirred to form adduct. In the second stage, monomer and catalyst are consecutively added to above adduct and resulting reaction mixture is then stirred. Monomer is selected from styrene, acrylonitrile, acrylate, butadiene, and mixture thereof.

EFFECT: enabled production of polymer with stable particle size.

6 cl, 3 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: proposed filter for filtering a water stream consists of filtering material made from a water soluble fibrous material, made from polyvinyl alcohol, and a carrier for the fibrous material, in which the filtering material contains a thread or bundle made from polyvinyl alcohol and the carrier has a core. The thread or bundle is wound around the core. A method of filtering a stream of water using the given filter is also proposed.

EFFECT: invention is efficient for eliminating wastes.

20 cl, 5 dwg

Filtering material // 2292229

FIELD: material for purifying of liquids and gases from solid particles, may be used in automobile manufacture, chemical, petroleum-chemical, metallurgical and other branches of industry using filters in main and auxiliary production, in ecological processes for cleaning of sewage and flue gases, in pouring of oil from tankers, oil pipelines and oil storage tanks, as well as in removal of oil products from water surface.

SUBSTANCE: filtering material has tubular knitted fabric with porous rubber tubes having diameter of 12-20 mm and uniformly distributed within said fabric. Said tubes comprise 0.2-1.6 mm sized rubber crumbs. Rubber tube has additional outer layer formed as tubular knitted fabric made from non-stretchable and stretchable threads containing lining filaments.

EFFECT: wider range of usage, improved quality of filtering in the process of purifying liquids and gasses, and improved extent of removal of oil products from torrential and industrial sewage water.

2 dwg, 1 tbl, 3 ex

Filtering material // 2288024

FIELD: chemical industry; petrochemical industry;, metallurgical industry;, motor-car industry; other industries; devices for filtering gases and solid particles.

SUBSTANCE: the invention is pertaining to purification of liquids and gases from the solid particles and may be used in chemical, petrochemical, metallurgical, motor-car and other industries, which use the filters in the main production and the auxiliary production process, in the ecological processes of purification of the waste waters and the combustion gases, at the spillage of oil from the tank ships, the oil pipelines and the petroleum storages, and also for collection of the oil products from the water surface. Substance of the invention is that the filtering material been out of the synthetic filaments in the form of the tubular knitted fabric with disposed inside the knitted fabric the rubber crumbs of 1.2-2.6 mm size and the pebble gravel of 3.2-4.5 mm size. The tubular knitted fabric contains the filling threads, which diameter exceeds the size of the rubber crumbs in 0.5-1.2 times. At that the volumetric ratio between the rubber crumbs and the pebble gravel makes 3:1. The technical result of the invention is the improved quality of filtration in the process of purification of the liquids and gases, and the increased efficiency of purification of the shower flows and the industrial waste waters.

EFFECT: the invention ensures the improved quality of filtration in the process of purification of the liquids and gases, and the increased efficiency of purification of the shower flows and the industrial waste waters.

3 ex, 1 tbl, 2 dwg

Filtering material // 2256483

FIELD: liquid purification.

SUBSTANCE: filtering material is made of piping knitted fabric produced by slicking . The priming fiber is made of synthetic threads , and slicking fiber is made of rubber threads which define fleecy surface on the face side. The length of the rubber thread in the loop is greater than that of the synthetic thread in the loop by a factor of 1.2-1.8. The piping knitted fabric receives cellulose fibrous cloth, rubber fibers or rubber crumb and polyurethane crumb whose volume ratio is 1:(2-4):(1.5-3), respectively.

EFFECT: enhanced quality of filtering.

2 dwg, 1 tbl

FIELD: filter materials.

SUBSTANCE: invention relates to purification of liquids and gases to remove solids and can be used in a variety of industries utilizing filters in mainline and secondary production areas, in environmentally oriented waste water and emission gas treatment processes, in oil spill cases from tankers, oil pipelines, and oil storehouses, and also in need of collecting petroleum products from water surface. invention provides filter material composed of synthetic threads in the form of tubular hosiery constituted by two parts, one of which contains rubber crumb and the other polyurethane foam crumb at volume ratio 1:(1-4), respectively. According to claim 2, tubular hosiery consists of several interconnected alternating sections, in particular sections constituted by two parts, one of which contains rubber crumb and the other polyurethane foam crumb at volume ratio 1:(1-2), respectively, alternate with sections containing only polyurethane foam crumb.

EFFECT: improved quality of filtration, increased floatability on water surface to be purified, and increased purification area.

2 cl, 1 dwg, 1 tbl, 6 ex

Protective hood // 2233680

The invention relates to a filter material for purification of industrial gases and liquids from solids and can be used in chemical, petrochemical, automotive, agricultural, engineering, defense and other industries, requires a high clearance dispersion medium from mechanical particles

The invention relates to the production of heat-resistant filter materials, namely fire-resistant filter materials in the texture of the fabric, which can be used for high temperature filtration of flue gases from solid particles in the nuclear, chemical, metallurgy, power engineering, production of carbon black and so on
The invention relates to the production of sorbents based on activated carbon materials for absorption of organic vapors (benzene, toluene, acetone, etc.,), vapors of ammonia and mercury

FIELD: mechanical engineering; filtering materials.

SUBSTANCE: group of invention relates to production of filtering materials featuring high absorbing and filtering properties, namely, to production of filtering materials on base of synthetic polymeric fibers for cleaning and decontamination of water, water solutions and other liquids. Proposed filtering material contains, as base, a polymeric fibrous material obtained by electroforming modified with particles of aluminum hydroxide attached to surface of base fibers to improved sorption properties and forming positive electric charge on material. Said filtering material is formed by modification of polymeric fibrous base received by method of electroforming. For this purpose initial aluminum-based material is applied to polymeric fibrous material and then hydrolysis of initial material is carried out, as a result of which particles of aluminum hydroxide are formed and attached to polymeric fibrous material.

EFFECT: provision of filtering material of low hydrodynamic resistance and high efficiency of filtration.

20 cl, 4 ex, 4 tbl, 1 dwg

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