Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/02—Polyamines
  • C08G73/028—Polyamidoamines
  • C08G73/0286—Preparatory process from polyamidoamines and epihalohydrins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/02—Polyamines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/02—Solvent extraction of solids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/04—Solvent extraction of solutions which are liquid
  • B01D11/0403—Solvent extraction of solutions which are liquid with a supercritical fluid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/04—Solvent extraction of solutions which are liquid
  • B01D11/0403—Solvent extraction of solutions which are liquid with a supercritical fluid
  • B01D11/0407—Solvent extraction of solutions which are liquid with a supercritical fluid the supercritical fluid acting as solvent for the solute
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/04—Solvent extraction of solutions which are liquid
  • B01D11/0426—Counter-current multistage extraction towers in a vertical or sloping position
  • B01D11/043—Counter-current multistage extraction towers in a vertical or sloping position with stationary contacting elements, sieve plates or loose contacting elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/04—Solvent extraction of solutions which are liquid
  • B01D11/0488—Flow sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F6/00—Post-polymerisation treatments
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/02—Polyamines
  • C08G73/0206—Polyalkylene(poly)amines
  • C08G73/0213—Preparatory process
  • C08G73/022—Preparatory process from polyamines and epihalohydrins
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids

Definitions

• the present invention relates to a process for the production of an nitrogen containing epihalohydrin polymer from a nitrogen-containing precursor comprising a purification step to remove organic impurities, particularly reaction products of epihalohydrin.
• the invention further relates to a process for purifying a solution of a nitrogen containing epihalohydrin polymer made from nitrogen-containing precursor from organic impurities.
• organic by-products may be obtained, some of which frequently are halogenated. Further, unreacted epihalohydrin may also remain in the final product.
• a typical example is the preparation of polyaminoamide epichlorohydrin polymers that are useful as wet strength resins in paper making.
• many halogenated organic compounds are toxic and/or questionable from an environmental point of view and for many applications, such as paper making, it is desirable to decrease the content thereof.
• CN 1350795 discloses removal of DCP and MCP from a hydrolytic liquid of plant protein by treating with liquefied or supercritical carbon dioxide.
• US 2005/0037932 discloses a perfluoropolyether lubricant, the preparation of which includes a supercritical fluid extraction purification step.
• One aspect of the invention concerns a process for the production of a nitrogen containing epihalohydrin polymer involving reaction of a nitrogen-containing precursor selected from the group consisting of amines, poly-amines, polyaminoamides, polyurethanes and mixtures thereof with epihalohydrin to form of a solution of said epihalohydrin polymer, the process comprising a purification step to remove organic impurities from the formed solution of the epihalohydrin polymer, said purification step comprising contacting the solution of the epihalohydrin polymer with a fluid under liquid, supercritical or near supercritical conditions to effect extraction of organic impurities from the solution of the epihalohydrin polymer to the fluid, withdrawing fluid enriched in organic impurities from the solution of the epihalohydrin polymer, and separating extracted impurities from the withdrawn fluid, wherein the fluid comprises a substance that at atmospheric pressure and room temperature (about 25°C) is gaseous.
• Another aspect of the invention concerns a process for purifying a solution of a nitrogen containing epihalohydrin polymer formed by reaction of a nitrogen-containing precursor selected from the group consisting of amines, poly-amines, polyaminoamides, polyurethanes and mixtures thereof with epihalohydrin comprising the steps of contacting the solution of the epihalohydrin polymer with a fluid under liquid, supercritical or near supercritical conditions to effect extraction of organic impurities from the solution of the epihalohydrin polymer to the fluid, withdrawing fluid enriched in organic impurities from the solution of the epihalohydrin polymer, and separating extracted impurities from the withdrawn fluid, wherein the fluid comprises a substance that at atmospheric pressure and room temperature (about 25°C) is gaseous.
• Extracting with a fluid under supercritical or near supercritical conditions has been found to efficiently remove unwanted organic compounds, particularly halogen containing compounds, from the polymer in a comparatively simple procedure without significantly negatively affecting its desired properties, for example as additive in paper making and particularly as wet strength resin.
• Normally such fluid may also be re-used after separation of the extracted impurities.
• Preferred fluids are those that have a critical temperature (T cr ) from about 20°C to about 100°C, most preferably from about 30°C to about 60°C, and a critical pressure (P cr ) from about 30 bar to about 500 bar, most preferably from about 70 bar to about 300 bar.
• T cr critical temperature
• P cr critical pressure
• fluids include carbon dioxide, nitrous oxide, ethane, ethane and propane.
• Carbon dioxide is particularly preferred as it is readily available, non-toxic and non-flammable. Further, carbon dioxide has been found not to give any negative impact to the treated polymer.
• the fluid may by used in substantially pure form or mixed with small amounts of one or more co-solvents, surfactants, complexing agents or the like.
• Nitrogen containing epihalohydrin polymers in the process of the present invention include those that have been prepared with epihalohydrin, e.g. epichlorohydrin, as a reactant, either during the polymerisation or in the modification of an existing polymer.
• the invention is particularly advantageous for nitrogen containing epihalodydrin polymers that are water soluble.
• Nitrogen containing epihalohydrin polymers include those formed by reactions of nitrogen containing precursors selected from amines, poly-amines, polyaminoamides, polyurethanes and mixtures thereof. Most preferably, the polymers are polyaminoamide- epihalohydrin polymers, which also may be referred to as polyamidoamine-epihalohydrin polymers, and are useful as wet strength resins in paper making.
• Epihalohydrins that can be used include epibromohydrin and epichlorohydrin, preferably epichlorohydrin.
• the polymers are produced using from about 0.5 to about 2 moles of epihalohydrin per mole of basic nitrogen in the nitrogen-containing precursor.
• the nitrogen-containing precursor is preferably the polyaminoamide reaction product of a polycarboxylic acid or a derivative thereof, suitably a dicarboxylic acid or derivative thereof, and a polyamine.
• carboxylic acids include e.g. anhydrides, esters and half esters.
• Suitable poly-carboxylic acids include saturated or unsaturated aliphatic or aromatic dicarboxylic acids.
• the polycarboxylic acids contains less than 10 carbon atoms.
• Preferred polycarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and derivatives and mixtures thereof, of which adipic acid is particularly preferred.
• Preferred polyamines include polyalkylene polyamines, or mixtures thereof, having the following formula:
• Preferred polyalkylene polyamines include diethylene triamine, tri- ethylene tetra amine, tetraethylene penta amine, dipropylene triamine, and mixtures thereof.
• the polyamines of formula (I) can be combined with other polyamines or mixtures of other amines.
• these amines have any of the following formulae N-VII: H-(-NH-(CH 2 ) ⁇ -CR 6 H-)rNCH 2 CH 2 NH (II)
• the polycarboxylic acid and the polyamine may, for example, be applied in a molar ratio from about 1 :0.5 to about 1 :1.5.
• the nitrogen-containing epihalohydrin-based polymer is preferably present in an aqueous solution, that further may comprise a water-miscible solvent such as methanol, ethanol or dimethyl formamide.
• the aqueous polymer solution is preferably prepared from an aqueous solution of a nitrogen-containing precursor.
• the molecular weights of the polymers are not critical and may, for example, be within the range of from about 50000 to about 1000000 or higher.
• Preparation of epihalodydrin polymers can be performed by any known process, such as those disclosed in any one of US 4450045, US 331 1594, US 4336835,
• the solution of the epihalohydrin polymer is preferably an aqueous solution and it has been found that only small amount of water are withdrawn in the purification step.
• the solids content of the solution to be purified is preferably as high as possible without causing handling problems and can in many cases be as high as about 35 wt% or more, but is preferably from about 5 to about 30 wt%, most preferably from about 10 to about 25 wt%.
• the viscosity of the solution is preferably from about 1 to about 250 mPas, most preferably from about 5 to about 200 mPas.
• the viscosity may be from about 1 to about 100 mPas or from about 5 to about 60 mPas.
• the invention is particularly advantageous for removing halogen containing organic impurities.
• Halogen containing impurities that can be removed include epihalohydrin as such, particularly epichlorohydrin, and reactions products thereof such as 1 ,2- and 1 ,3-dihalo-2-propanol (DXP) and 3-halo-1 ,2-propanediol (XPD), particularly
• DCP 1,2- and 1 ,3-dichloro-2-propanol
• CPD 3-chloro-1 ,2-propanediol
• DXP and XPD as well as any remaining epihalohydrin can be removed and eventually destructed.
• polyaminoamide epichlorohydrin polymers with a content of organic chlorines below about 0.01 wt% and even below about 0.0001 wt% or less.
• the extraction takes place under conditions in which the fluid is in a liquid, supercritical or near supercritical state.
• the temperature in K is preferably at least about 0.9 x T ⁇ most preferably at least 0.95 x T CT .
• the pressure is preferably at least about 0.9 x P c -, most preferably at least 0.95 x P a .
• DCP is efficiently removed from polyaminoamide epichlorohydrin at a preferred temperature from about 30°C to about 180°C, most preferably from about 40 0 C to about 100°C and a preferred pressure from about 60 bar to about 500 bar, most preferably from about 75 bar to about 300 bar
• CPD is efficiently removed from polyaminoamide epichlorohydrin at a preferred temperature from about 30°C to about 180 0 C, most preferably from about 50°C to about 100 0 C and a preferred pressure from about 60 bar to about 500 bar, most preferably from about 150 bar to about 400 bar
• the extraction may be a one stage process, but can also be performed in two or more stages with the same or different conditions, the latter being of interest if different optimal conditions for extracting different kinds of halogen containing impurities apply.
• the average residence time for the solution of the epihalohydrin polymer in contact with fluid under supercritical or near supercritical conditions is preferably from about 5 minutes to about 120 minutes, most preferably from about 15 minutes to about 60 minutes.
• the purification through an extraction may be performed batchwise, continuously or a combination thereof.
• the extraction is performed by maintaining a solution of the epihalohydrin polymer in vessel, preferably under agitation, and contacting it with a continuous flow of fluid under liquid, supercritical or near supercritical conditions during a time sufficient to achieve removal of halogen containing impurities to a satisfactory degree.
• the temperature and pressure may remain substantially constant during the entire time but may also be changed stepwise or continuously.
• the purified solution of the polymer can then withdrawn as a product or be transferred to a further extraction step or any other treatment.
• the extraction is performed by contacting the solution of the epihalohydrin polymer with the fluid under liquid, supercritical or near supercritical conditions in a through-flow vessel or column, in each case with or without a packaging.
• Both the solution of the polymer and the fluid flow continuously through the vessel or column, preferably counter-currently, but also co-current flow could come into question.
• part of the purified polymer solution may be recirculated.
• the temperature and pressure may be the same or different in various parts of the vessel or column. Any kind of vessels or columns commonly used for extraction can be used, such as tray-type columns or packed columns with structured or non-structured packings made of e.g. glass, metal or ceramic materials.
• the separation of extracted impurities from the withdrawn fluid is suitably done by altering the temperature and/or pressure thereof to change the solubility properties so the impurities are precipitated. Usually this is easiest done by lowering the pressure to a level below P cr . If necessary the extracted impurities can removed from the carbon dioxide by purification with water or active carbon. After the separation the fluid can be reused after restoring the temperature and pressure to conditions suitable for the extraction.
• the separated impurities may be destructed by any suitable means.
• Figure 1 is a flow sheet for batchwise extraction while Figure 2 is a flow sheet for continuous extraction.
• Example 1 An aqueous solution of polyaminoamide epichlorohydrin polymer
• PAAE PAAE having a dry content of 20.7 wt%
• concentrations of DCP was 267 ⁇ g/g and of CPD 289 ⁇ g/g.
• the solution of PAAE was maintained under agitation in a 250 ml extraction vessel 4 and subjected to a continuous flow of supercritical carbon dioxide CO 2 brought from a vessel via a cooler 1 , a pump 2 and a heat exchanger 3 under various conditions in respect of temperature, pressure and time. In a separator 5 the pressure was released, resulting in precipitation of the extracted components from the carbon dioxide.
• the content of DCP and CPD in the purified PAAE solution was determined by gas chromatography. The results are shown in Table 1 : Table 1 Batch extraction
• Examples 2-4 An aqueous solution of polyaminoamide epichlorohydrin polymer (PAAE) having a dry content of 21.2 wt% was purified by continuous extraction with supercritical carbon dioxide in an experimental setup according to Fig. 2. Before the purification the concentrations of DCP was 269.7 ⁇ g/g and of CPD 308.1 ⁇ g/g.
• the polymer solution F was brought via a pump 6, and a pre-heater 7 to a packed column 4 where it was contacted by a counter-current flow of carbon dioxide circulating via a cooler 1 , a pump 2 a heat exchanger 3 and, after the column 4, a separator 5.
• the purified polymer solution was brought from the column 4 to a raffinate vessel R.
• Example 2 In a separator 5 the pressure was released and after purification with active carbon the carbon dioxide was recycled.
• Examples 2 and 3 were run as bubble extraction with the column 4 filled with polymer solution, while Example 4 was run as film extraction with the polymer solution flowing as a film on the packings in the column 4. The results are shown in Table 2.
• Example 5 The treated polymers obtained in Examples 3 and 4 as well as the commercially available polyaminoamide epichlorohydrin polymer solution Eka WS 320 were tested as wet strength agents in paper making on a pilot paper machine. The following conditions were applied:
• Pulp 40 wt% eucalyptus, 40 wt% birch, 20 wt% pine sulfate

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• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
• Epoxy Compounds (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
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• 2006
  • 2006-06-09 NZ NZ564123A patent/NZ564123A/en not_active IP Right Cessation
  • 2006-06-09 KR KR1020087001805A patent/KR20080028446A/ko not_active Application Discontinuation
  • 2006-06-09 EP EP06748028A patent/EP1902086A1/en not_active Withdrawn
  • 2006-06-09 WO PCT/SE2006/050188 patent/WO2007004972A1/en active Application Filing
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  • 2006-06-09 RU RU2008103316/04A patent/RU2399633C2/ru not_active IP Right Cessation
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