Class / Patent application number | Description | Number of patent applications / Date published |
526077000 | Including step of purifying monomer | 9 |
20080214750 | Method for Producing Water-Absorbing Polymers - The invention relates to processes for preparing water absorbing polymers by polymerization of a monomer solution comprising allyl acrylate and/or allyl alcohol, the solution comprising not more than 0.002% by weight of allyl acrylate and/or allyl alcohol, based on acrylic acid, to aqueous monomer solutions for producing water absorbing polymers, to water absorbing polymers, to processes for producing hygiene articles and also to hygiene articles. | 09-04-2008 |
20090030165 | Process for manufacturing reduced water content (meth) acrylic acid - A method is provided herein for purifying (meth)acrylic acid to provide a purified (meth)acrylic acid product having a low aldehyde concentration and not more than 0.2 wt % water. One embodiment of the method includes distilling (meth)acrylic acid in the presence of an aldehyde treating compound. Another embodiment of the method includes also distilling crude (meth)acrylic acid in the presence of a reactive drying agent. (Meth)acrylic acid produced in this manner is especially suitable for use in specialty (meth)acrylic acid polymers, such as for example superabsorbent polymers, binders, and ethylene-(M)AA copolymers. | 01-29-2009 |
20090076232 | PROCESS FOR OPERATING A CONTINUOUS REMOVAL OF A TARGET PRODUCT X IN THE FORM OF FINE CRYSTALS OF THE TARGET PRODUCT X - A process for operating a continuous removal of a target product X in the form of fine crystals of a liquid phase P comprising the target product X and constituents other than the target product X by cooling suspension crystallization in the secondary chamber of an indirect heat exchanger to which liquid phase P flows continuously with simultaneous continuous flow through the primary chamber of the indirect heat exchanger with a coolant, and continuous withdrawal of a crystal suspension S having a degree of crystallization Y from the secondary chamber in two operating states I and II, wherein the coolant temperature is lower, the mass flow of liquid phase P is greater and the molar proportion of the constituents other than the target product X in the liquid phase P in operating state II is greater than in operating state I. | 03-19-2009 |
20090105430 | USE OF ALKALI METAL-SILICA GEL (M-SG) MATERIALS IN SOLVENT AND MONOMER DRYING AND PURIFICATION FOR THEIR USE IN ANIONIC POLYMERIZATION - Stage I Group 1 metal/porous metal oxide compositions or Stage II Group 1 metal/porous metal oxide compositions are shown to be useful to remove impurities and act as drying agents for various types of solvents and for olefinic monomers used in anionic polymerizations. One important advantage of these compositions is their ability to dry simultaneously solvent and monomers, without inducing a significant polymerization of the latter. Another important characteristic is the capacity of the compositions to be totally inactive toward conventional anionic polymerization which allows them to be left in situ during the polymerization itself. | 04-23-2009 |
20100234542 | PREPARATION OF REACTIVE, ESSENTIALLY HALOGEN-FREE POLYISOBUTENES FROM C4-HYDROCARBON MIXTURES WHICH ARE LOW IN ISOBUTENE - The present invention relates to a process for preparing reactive and essentially halogen-free, especially fluorine-free, polyisobutenes from low-isobutene C | 09-16-2010 |
20100261856 | METHODS FOR THE REMOVAL OF IMPURITIES FROM POLYMERIZATION FEED STREAMS - Methods for the removal of impurities, for example, carbon monoxide, from a polymerization feed streams are provided. | 10-14-2010 |
20100286347 | PRODUCTION OF SOLUTIONS OF VINYL POLYMERS IN REACTIVE MONOMERS - The invention relates to a method for producing solutions of vinyl polymers in reactive monomers by a) polymerizing by radical initiation one or more ethylene unsaturated monomers selected from the group comprising vinyl esters, acrylic acid esters, and methacrylic acid esters, and optionally one or more further ethylene unsaturated monomers, and subsequently b) optionally distilling off volatile components, and e) optionally adding one or more inert solvents, d) mixing with one or more reactive monomers, and e) optionally distilling off the inert solvent, characterized in that the vinyl polymers are not present as isolated solids in any of the steps a) through e). | 11-11-2010 |
20100331502 | GAS-PHASE PROCESS FOR THE POLYMERIZATION OF ALPHA-OLEFINS - A continuous gas-phase process for the polymerization of alpha-olefins, in particular ethylene, comprising passing an alpha-olefin monomer stream through an oil filter in order to reduce the amount of oil to less than 8 ppm, and polymerizing the thus purified monomer feed in gas-phase reactor; the reduction of the amount of oil improves the operability of the plant over time. | 12-30-2010 |
20110028664 | SUPERABSORBENT POLYMER MADE FROM ACRYLIC ACID - The invention relates to a superabsorbent polymer that includes a (meth)acrylic acid made by a process that comprises the following process steps: a) (meth)acrylic acid is crystallized out from a mother liquor; b) crystallized (meth)acrylic acid is separated from the mother liquor; c) at least part of the separated (meth)acrylic acid crystals are melted; d) the melted part is at least partially recycled to the step a) or step b). The superabsorbent polymer according to the present invention includes an process to make (meth)acrylic acid, the apparatus suitable for implementing the process, and the use of the apparatus for the production of (meth)acrylic acid characterized by a high purity of the thereby obtainable (meth)acrylic acid as well as by a high efficiency with regard to the achievable yield and necessary energy requirement, thereby providing an improved superabsorbent polymer. | 02-03-2011 |