Abstract: A method of preparing hydrogel particles includes applying a solution including a plurality of hydrogel particles to a stir cell. A retentate side of a filter defines a lower surface of the stir cell. The filter has the retentate side and a permeate side. The method further includes, while stirring the solution within the stir cell, dispensing a buffer solution at a first flow rate to the stir cell and drawing a permeate from the permeate side of the filter using a pump at a second flow rate, the permeate including a subset of the plurality of hydrogel particles.

Abstract: A process for producing water-absorbing polymer particles, wherein surface postcrosslinked water-absorbing polymer particles are remoisturized and classified, and wherein the time between remoisturization and classification is at least 15 minutes.

Abstract: A process for preparing water-absorbing polymer particles by coating water-absorbing polymer particles with a particulate solid in a mixer, wherein the particulate solid is dispersed by means of a gas stream and the supply of the dispersed particulate solid in the mixer ends below the product bed surface.

Abstract: In a method for manufacturing a dispersion which includes a dispersion medium and particles dispersed therein, the method includes bringing at least two types of liquids into contact with each other to form a reaction product comprising the particles, wherein the liquids are ejected from respective nozzles to be brought into contact with each other and then to flow in an integrated manner while forming a spiral flow.

Abstract: An ethylene-vinyl alcohol copolymer (EVOH) solution is introduced into a tower vessel (1) from a first inlet (2) provided at an upper portion of the tower vessel (1). Water vapor is introduced into the tower vessel (1) from a second inlet (3) provided at a lower portion of the vessel (1). The EVOH solution moves downward in the vessel (1), while the water vapor moves upward. The EVOH solution is kept in counter-flow contact with the water vapor. Water is supplied from a water supplying portion (5) located between the first inlet (2) and a tower top (4), whereby a water layer is formed above the first inlet (2). A water/methanol vapor mixture is extracted from the tower top (4) and condensed in a condenser (6) to be thereby recovered in the form of a methanol aqueous solution. Droplets of the EVOH solution contained in the water/methanol vapor mixture are trapped in the water layer formed above the first inlet (2) and, therefore, are less liable to be introduced into the condenser (6).

Abstract: In a method for manufacturing a dispersion which includes a dispersion medium and particles dispersed therein, the method includes bringing at least two types of liquids into contact with each other to form a reaction product comprising the particles, wherein the liquids are ejected from respective nozzles to be brought into contact with each other and then to flow in an integrated manner while forming a spiral flow.

Abstract: A method for manufacturing a dispersion, the method including a step of forming a reaction product by allowing at least two types of liquids to react with each other, the dispersion including a dispersion medium and particles formed from the reaction product dispersed therein. In the method described above, the at least two types of liquids are ejected from independently provided respective nozzles so that traveling directions of the liquids ejected therefrom intersect with each other at an angle of 120° or less and so that the liquids then flow in an integrated manner, whereby the reaction product is generated.

Abstract: A method for manufacturing a dispersion, includes a step of forming a reaction product by allowing at least two types of liquids to react with each other, the dispersion including a dispersion medium and particles formed from the reaction product dispersed therein. In the method described above, the at least two types of liquids are ejected from independently provided respective nozzles so that traveling directions of the liquids ejected therefrom intersect with each other at an angle of 120° or less and so that the liquids then flow in an integrated manner, whereby the reaction product is generated.

Abstract: The present invention is a process for preparing high concentration polyvinyl alcohol (PVA) aqueous mixtures, wherein the PVA solid concentration is at least 14% in the mixture.

Abstract: The present invention is directed to a polymer feed system and a method of using the same wherein clogging of the polymer input line is avoided by the use of air to purge the system of any unwanted polymer or electrolyte. The purging avoids the contact of the water with the polymer and the build-up of unwanted activated polymer and clogging in the supply and in the subsequent conduits.

Abstract: A method of suspension polymerization of a monomeric composition to produce a polymer or a polymer composition is disclosed which method comprises the steps of retaining a disperse phase component composed of the monomeric composition and a continuous phase component composed of a medium in independent vessels, supplying the disperse phase component and the continuous phase component from their respective vessels into a disperser simultaneously and continuously through associated independent passageways, applying shear force in the disperser to form a dispersion having droplets of a desired size, subsequently introducing the dispersion into a polymerization vessel, and completing a polymerizating reaction to produce a polymer or a polymer composition.

Abstract: A polyurethane/urea/thiourea latex having a narrow molecular weight polydispersity and sub-micron particle size can be prepared by first preparing a high solids (between about 65% and 74% solids) latex of a polyurethane/urea/thiourea prepolymer, then contacting the emulsion with a chain-extending reagent under such conditions to form the polymer latex.

Abstract: A process and a high pressure apparatus are disclosed which are useful in preparing magnetic dispersions and other dispersions of hard, non-compliant particulates. The apparatus can be monitored for clogs and wear and allows for relatively quick and inexpensive replacement of orifices. The apparatus includes a high pressure pump and a series of impingement chambers comprising an input manifold where the process stream is split into two or more streams and an output manifold where the streams are recombined after passing through restrictive orifices configured in such a manner that the streams impinge on each other at high velocities. The orifices in each succeeding impingement zone are the same size or smaller than the orifices in the preceding impingement zone, and the orifices in the final impingement zone must be smaller than the orifices in the first impingement zone.

Abstract: The present invention is directed to a polymer feed system and a method of using the same wherein clogging of the polymer input line is avoided by the use of air to purge the system of any unwanted polymer or electrolyte. The purging avoids the contact of the water with the polymer and the build-up of unwanted activated polymer and clogging in the supply and in the subsequent conduits.

Abstract: The present invention relates to a process for the production of aqueous dispersions which form powder coatings at room temperature, have an average particle size of 0.1 to 10 .mu.m, contain polyols and blocked polyisocyanate crosslinking agents, and, after stoving, yield coatings with improved water and solvent resistance, in particular on metallic substrates.

Abstract: A process and a high pressure apparatus are disclosed which are useful in preparing magnetic dispersions and other dispersions of hard, non-compliant particulates. The apparatus can be monitored for clogs and wear and allows for relatively quick and inexpensive replacement of orifices. The apparatus includes a high pressure pump and a series of impingement chambers comprising an input manifold where the process stream is split into two or more streams and an output manifold where the streams are recombined after passing through restrictive orifices configured in such a manner that the streams impinge on each other at high velocities. The orifices in each succeeding impingement zone are the same size or smaller than the orifices in the preceding impingement zone, and the orifices in the final impingement zone must be smaller than the orifices in the first impingement zone.

Abstract: Stable photographic coating compositions comprising a polymer latex are prepared by mixing an aqueous solution comprising gelatin with a latex dispersion of a polymer of the formula(A).sub.x (B).sub.y (C).sub.zwhereA and B are formed from nonionic monomers,C is formed from anionic monomers, andx, y and z are monomer weight fractions where x=0 to 1.0, y=0 to 1.0, x+y=about 0.98 to 1.0, and z=0 to about 0.02,wherein A, B, x and y are such that latex dispersions of polymers of the formula (A).sub.x (B).sub.y have calcium ion critical coagulation concentrations of less than 80 mM Ca.sup.+2 in gelatin solutions,wherein the gelatin of the aqueous solution mixed with the latex dispersion comprises a gelatin of low calcium ion content such that the coating composition has a calcium Ca.sup.2+ concentration of less than 2 mM. The method of the invention allows for the preparation of aqueous gelatin coating solutions comprising latex dispersions of polymers which are unstable in the presence of calcium ions.

Abstract: Loaded latex dispersions of hydrophobic photographically useful compounds with a wide variety of polymer latices are prepared by preparing an oil phase solution of the hydrophobic compound or compounds, preferably essentially free of water-miscible or volatile solvent, combining the oil solution with one or more aqueous solutions, at least one of which contains a polymer latex, and mixing the combination of oil solution, aqueous solution and latex under high shear or turbulence sufficient to cause loading of the photographically useful compound into the dispersed polymer latex wherein the pH of the mixture does not need to be significantly changed.

Abstract: Apparatus and method of hydrating a particulated polymer and producing a well treatment gel includes a mixer for spraying the polymer with water at a substantially constant water velocity and at a substantially constant water spray pattern at all flow rates of the water. A centrifugal diffuser is connected to the mixer for receiving the mixture, centrifugally diffusing the motive energy of the mixture, and hydrating the mixture into a gel. A centrifugal separator and constant velocity jet pump may be connected between the mixer and the centrifugal diffuser. A dilution valve is connected to the discharge of the centrifugal diffuser for mixing water with the gel at a substantially constant mixing energy at all flow rates of the gel and producing a diluted gel. A viscometer may be connected to the discharge of the dilution valve for measuring the viscosity of the diluted gel and regulating the flow of gel from the centrifugal diffuser to the dilution valve in order to control the viscosity of the diluted gel.

Abstract: Continuous agglomeration of an absorbent resin powder is accomplished by a method which comprises introducing the absorbent resin powder into a cylindrical member having an open lower end by means of a current of air through a dispersing member disposed in the upper part of the cylindrical member and, at the same time, spraying minute droplets of an aqueous liquid downwardly through a nozzle disposed inside the dispersing member thereby establishing mutual parallel flow contact between the absorbent resin powder descending toward the lower part of the cylindrical member as dispersed with the current of air and the liquid droplets descending toward the lower part of the cylindrical member as diffused in the radial direction, and removing the produced agglomerate having a plurality of particles of the absorbent resin powder cohesively united through the medium of the liquid droplets via the lower part of the cylindrical member. An apparatus for working the method is also disclosed.

Abstract: This invention concerns a method for precipitating polymers from a liquid using at least one precipitant fluid, including a feed line, a nozzle plate having at least one outlet orifice for a polymer containing fluid with the outlet orifice communicating with the feed line, at least one nozzle for at least one precipitant fluid, the axis of which is arranged approximately perpendicularly to the axis of the outlet orifice, a precipitation chamber positioned on the side of the nozzle plate wherein at least one nozzle for at least one precipitant fluid is located, a discharge line for discharging a mixture which contains the precipitated polymer and a degassing chamber which is connected to the discharge line.

Abstract: High strength material composite structures are formed with oriented fibers to provide controlled anisotropic fibers. Fibers suspended in non-dilute concentrations (e.g., up to 20 volume percent for fibers having an aspect ratio of 20) in a selected medium are oriented by moving an axially spaced array of elements in the direction of desired fiber alignment. The array elements are generally perpendicular to the desired orientation. The suspension medium may also include sphere-like particles where the resulting material is a ceramic.

Abstract: A device for precipitating polymers from a liquid by at least one precipitant fluid includes a feed line, a nozzle plate having at least one outlet orifice for a polymer containing fluid with the outlet orifice communicating with the feed line, at least one nozzle for at least one precipitant fluid, the axis of which is arranged approximately perpendicularly to the axis of the outlet orifice, a precipitation chamber positioned on the side of the nozzle plate wherein at least one nozzle for at least one precipitant fluid is located, a discharge line for discharging a mixture which contains the precipitated polymer and a degassing chamber which is connected to the discharge line.

Abstract: Polymer activation apparatus for activating a liquid polymer emulsion in dilution water includes a first processing zone in which the polymer solution is subjected to a high mean shear rate for a predetermined period of time, and a second processing zone in which the polymer solution is subjected to a low mean shear rate for a longer period of time. The shear rates and residence times in the zones are selected to produce maximum activation in less total processing and aging time than that required in known apparatus.

Abstract: A spray polyurea elastomer is made in combination with a filler material by spraying together two reactive elastomers and dispensing filler material into the spray pattern.

Abstract: A polymer hydrogel substantially free from monomers and oligomers is prepared by contacting a previously prepared polymer hydrogel with a single-phase mixture of water and a solvent and then separating the mixture of water and solvent from the hydrogel.

Abstract: A process and apparatus for preparing a homogeneous dissipation of a viscous, liquid-dissipatable polymer. The process comprises continuously feeding molten polymer into a first inlet of a mixing chamber, feeding a stream of a relatively low viscosity dissipating liquid into a second inlet of said mixing chamber at an angle, at a velocity and at a flow rate relative to the structure of said chamber such that shearing action is created at the advancing end of the polymer to continuously erode the end of the polymer, and further mixing the polymer and dissipating liquid downstream from an outlet of the chamber to form a homogeneous dissipation of polymer in dissipating liquid.

Abstract: The method of continuously operating a counter-flow washing column which is supplied with a slurry of solid polymer particles in a diluent from a continuous polymerization zone and with washing liquid for extracting wash slurry and introducing it into a heat tube to separate the vapor of the washing liquid and the solid polymer particles.The improvement involves controlling the extraction amount of the wash slurry from the column by means of:(i) controlling the quantity of heat added to the heat tube, and further(ii) controlling the amount of liquid to be separately introduced into the heat tube,said controls (i) and (ii) being determined by monitoring the amount of the slurry in the last one of reaction cells in the continuous polymerization zone and, on the basis of the monitored amount, determining the amount of extracted slurry.

Abstract: The present invention relates to a process for the preparation of mixtures of isocyanate and water which are stable for a short time for glueing particulate material, in particular chips, fibers, or the like, in which isocyanate is injected at high pressure into the water, characterized in that the water is delivered to the site of injection as a stream under low pressure, and to an apparatus for carrying out such process.

Abstract: A polymer slurry is passed past a filter and a wash fluid is caused to flow at a substantial angle with respect to the flow of the polymer slurry and toward the filter such as to replace at least a substantial portion of the fluid of the polymer slurry.

Abstract: The invention relates to a process and device for the production of highly concentrated spinning solutions from acrylonitrile polymers, where the dissolving is carried out in one step in a stirred mixing vessel, which has a disc-shaped stirrer rotating in a horizontal plane, the polymeric material to be dissolved and the solvent are metered in separately at room temperature into the stirring vortex which is formed, and the temperature of the solution being formed is maintained at a constant preset value in the range from 60.degree. to 120.degree. C. by controlling the peripheral velocity of the stirrer.

Abstract: A method of rapidly compounding melt forming resin, mica and chlorinated hydrocarbon wherein the mica has a coating comprising the chlorinated hydrocarbon, which method comprises providing a molten mass of the resin, contacting the molten mass with the coated mica and kneading the so contacted mica and resin to provide mixing thereof. The compounding is rapid and at optimal temperature.

Abstract: The present invention relates to a process for the preparation of mixtures of isocyanate and water which are stable for a short time for glueing particulate material, in particular chips, fibers, or the like, in which isocyanate is injected at high pressure into the water characterized in that the water is delivered to the site of injection as a stream under low pressure, and to an apparatus for carrying out such process.