Patent Grant
8945671
The present application is US national stage of international application, PCT/EP2008/065920 which had an international filing date of Nov. 20, 2008, and which was published in German under PCT Article 21(2) on Jun. 25, 2009. Priority is claimed to European application EP 07123598.0, filed on Dec. 19, 2007 which is hereby incorporated by reference in its entirety.
The invention provides a process for producing coated sodium percarbonate particles by spray application of a sodium sulfate-containing aqueous solution onto sodium percarbonate particles in a fluidized bed and simultaneous evaporation of water, wherein the sodium sulfate-containing aqueous solution is prepared using sodium sulfate and sodium percarbonate-containing dust.
Sodium percarbonate is increasingly being used as a bleaching constituent in detergents and cleaning compositions. For this application, sodium percarbonate must have sufficient storage stability in detergent and cleaning composition formulations, since there is otherwise undesired loss of active oxygen and hence of bleaching action in the course of storage of the detergents and cleaning compositions. Sodium percarbonate is moisture-sensitive and decomposes in detergent and cleaning composition formulations under the action of moisture with loss of active oxygen. To produce detergents or cleaning compositions, sodium percarbonate is therefore typically used in coated form, in which case the coating layer prevents the action of moisture on the coated sodium percarbonate particles.
DE 2 417 572 discloses the stabilization of sodium percarbonate by a coating composed of a mixed salt of sodium carbonate and sodium sulfate. The mixed salts have a molar ratio of sodium carbonate to sodium sulfate in the range from 0.3:1 to 3:1. The coating is applied by spray application of an aqueous solution of sodium carbonate and sodium sulfate onto sodium percarbonate particles and simultaneous evaporation of water. The spray application can be effected in a fluidized bed. The coating composed of a mixed salt of sodium carbonate and sodium sulfate achieves better stabilization than a coating consisting only of sodium carbonate or only of sodium sulfate.
WO 97/19890 discloses the stabilization of sodium percarbonate particles obtainable by fluidized bed granulation by means of a coating of sodium sulfate, which is applied by spray application of an aqueous solution of sodium sulfate to the sodium percarbonate particles in a fluidized bed and simultaneous evaporation of water. The use of sodium percarbonate obtainable by fluidized bed granulation achieves, with sodium sulfate alone, the same stabilizing effect as with a mixed salt of sodium carbonate and sodium sulfate. The sodium percarbonate particles coated with sodium sulfate have better silo storability compared to the particles coated with a mixed salt of sodium carbonate and sodium sulfate.
WO 2006/003155 describes coated sodium percarbonate particles with a mean particle size of 300 to 1600 μm and a coating layer which comprises small sodium percarbonate particles with a mean particle size of less than 100 μm. The particles are produced by applying a solution or suspension of a coating material in a mixer or in a fluidized bed to sodium percarbonate particles, in the course of which the small sodium percarbonate particles are supplied simultaneously and thus incorporated into the coating layer.
In the course of spray application of a solution of sodium sulfate in a fluidized bed, it is possible not only for sodium sulfate dust to form, but also for the abrasion of particles in the fluidized bed to form sodium percarbonate-containing dust which is discharged from the fluidized bed with the fluidizing gas. This sodium percarbonate-containing dust may contain from 50 to 80% by weight of sodium percarbonate, the rest being essentially sodium sulfate. Such a sodium percarbonate-containing dust does not meet the requirements for use in detergents.
In a similar manner, in the course of production of sodium percarbonate by buildup granulation from a sodium carbonate solution and aqueous hydrogen peroxide in a fluidized bed, sodium percarbonate-containing dust forms, which is discharged from the fluidized bed with the fluidizing gas. This sodium percarbonate-containing dust consists essentially of sodium percarbonate and may additionally also contain small amounts of additives which increase the stability of sodium percarbonate. This sodium percarbonate-containing dust too does not meet the requirements for use in detergents.
Finally, in the course of pneumatic delivery of sodium percarbonate particles, abrasion of the particles or fracture of particles may also form sodium percarbonate-containing dust which is not suitable for use in detergents.
It has now been found that such sodium percarbonate-containing dust can be used advantageously in combination with sodium sulfate for the coating of sodium percarbonate particles and can thus be recycled into a production process for sodium percarbonate particles for detergent and cleaning composition formulations.
The invention therefore provides a process for producing coated sodium percarbonate particles by spray application of a sodium sulfate-containing aqueous solution onto sodium percarbonate particles in a fluidized bed and simultaneous evaporation of water, in which the sodium sulfate-containing aqueous solution is prepared using sodium sulfate and sodium percarbonate-containing dust.
The sodium percarbonate particles used in the process according to the invention preferably consist essentially of sodium carbonate perhydrate of the composition 2 Na2CO3.3H2O2. They may additionally also contain small amounts of known stabilizers for peroxygen compounds, for example magnesium salts, silicates, phosphates and/or chelate complexing agents, such as phosphonates. The proportion of sodium percarbonate in the sodium percarbonate particles is preferably more than 80% by weight and more preferably more than 95% by weight. The proportion of organic carbon compounds is preferably less than 1% by weight, more preferably less than 0.1% by weight.
The sodium percarbonate particles used preferably contain small amounts of additives which have a stabilizing effect on the active oxygen content, the proportion of stabilizing additives preferably being less than 2% by weight. The stability-increasing additives used are preferably magnesium salts, water-glass, stannates, pyrophosphates, polyphosphates, polyacrylates, and chelate complexing agents from the group of the hydroxycarboxylic acids, aminocarboxylic acids, aminophosphonic acids, phosphonocarboxylic acids and hydroxyphosphonic acids, and the alkali metal, ammonium and magnesium salts thereof. In a particularly preferred embodiment, the sodium percarbonate particles contain, as a stabilizing additive, an alkali metal silicate, preferably waterglass with an SiO2/Na2O modulus in the range from 1 to 3, in an amount of 0.1 to 1% by weight. In the most preferred embodiment, the sodium percarbonate particles contain, in addition to this amount of alkali metal silicate, also a magnesium compound in an amount of 50 to 2000 ppm of Mg2+.
The sodium percarbonate particles used in the process according to the invention can be prepared by one of the known preparation processes for sodium percarbonate. A suitable preparation process for sodium percarbonate is the crystallization of sodium percarbonate from aqueous solutions of hydrogen peroxide and sodium carbonate, the crystallization being performable either in the presence or in the absence of a salt precipitant, on the subject of which reference is made by way of example to EP-A 0 703 190 and DE 2 744 574. Sodium percarbonate particles produced by the crystallization process in the presence of a salt precipitant may also contain small amounts of the salt precipitant used, for example sodium chloride. Likewise suitable is fluidized bed buildup granulation by spray application of aqueous hydrogen peroxide solution and aqueous sodium carbonate solution onto sodium percarbonate nuclei in a fluidized bed with simultaneous evaporation of water, reference being made by way of example to WO 95/06615. A further suitable preparation process is also the reaction of solid sodium carbonate with an aqueous hydrogen peroxide solution and subsequent drying.
In a preferred embodiment, the sodium percarbonate particles used are obtainable by buildup granulation from sodium carbonate and hydrogen peroxide in a fluidized bed. Such a buildup granulation in a fluidized bed affords sodium percarbonate particles which are distinguished from the sodium percarbonate particles obtained by other production processes by a particularly dense, shell-like structure and a smoother surface. Sodium percarbonate particles coated by the process according to the invention, the core of which has been produced by buildup granulation in a fluidized bed, exhibit improved storage stability in detergent and cleaning composition formulations compared to particles whose core has been produced by another process. Surprisingly, sodium percarbonate particles coated by the process according to the invention, the core of which has been produced by buildup granulation in a fluidized bed, also have a further-improved storage stability in detergent and cleaning composition formulations compared to particles whose core has been produced in the same way but which have been coated only with a solution of sodium sulfate.
In the process according to the invention, the sodium sulfate-containing aqueous solution is prepared using sodium sulfate and sodium percarbonate-containing dust. To prepare the solution, sodium sulfate can first be dissolved in water and the sodium percarbonate-containing dust can be dissolved in this solution. In a preferred alternative embodiment, sodium percarbonate-containing dust is separated from a gas stream in a scrubber and the aqueous solution obtained is used to prepare the sodium sulfate-containing aqueous solution. In this case, an aqueous scrubbing solution is preferably circulated in the scrubber, in which the sodium percarbonate-containing dust dissolves to release sodium carbonate and hydrogen peroxide. The scrubber can be operated such that the hydrogen peroxide released is decomposed to water and oxygen in the scrubbing solution.
In a preferred embodiment, the process according to the invention uses sodium percarbonate-containing dust removed from the offgas from a fluidized bed in which sodium percarbonate is prepared by buildup granulation from sodium carbonate and hydrogen peroxide.
In a further preferred embodiment, the process according to the invention uses sodium percarbonate-containing dust removed from the offgas from the fluidized bed of the process according to the invention. As well as sodium percarbonate, this sodium percarbonate-containing dust also contains sodium sulfate. The proportion of sodium percarbonate in the dust is preferably in the range from 50 to 80% by weight and the proportion of sodium sulfate in the range from 50 to 20% by weight. With this embodiment, it is possible to avoid losses of sodium sulfate when the coating layer is applied to the sodium percarbonate particles, and to use the applied sodium sulfate completely for the production of the coating.
In a likewise preferred embodiment, the process according to the invention uses sodium percarbonate-containing dust removed from a gas stream from a pneumatic delivery of sodium percarbonate particles. With this embodiment, it is especially possible to recycle the abraded coating material which arises in a pneumatic delivery of coated sodium percarbonate particles back into the process, and to use it again for coating.
In a further preferred embodiment, the process according to the invention uses two or more different sodium percarbonate-containing dusts which originate from different stages of a process for producing coated sodium percarbonate particles to produce the sodium sulfate-containing aqueous solution. With this embodiment, it is possible to recycle all dusts obtained in a process for producing coated sodium percarbonate particles completely back into the process, and to use them for coating.
In the process according to the invention, the sodium sulfate-containing aqueous solution is sprayed onto sodium percarbonate particles in a fluidized bed. During the spray application of the sodium sulfate-containing aqueous solution, the majority of the water present therein, especially more than 90% of the water present in the aqueous solution, is preferably already evaporated through supply of heat, such that only a small portion of the underlying material is dissolved again during the application of the coating layer and a firm coating layer forms already during the spray application. The spray application of the aqueous solution is effected preferably by the process described in EP-A 0 970 917, with which a dense coating layer can be achieved even with small amounts of coating layer material. The spray application is effected preferably with supply of a drying gas to the fluidized bed, such that a temperature in the range from 30 to 90° C., preferably 50 to 70° C., is established in the fluidized bed.
Sodium sulfate and sodium percarbonate-containing dust are preferably used in such amounts that the aqueous solution which is sprayed onto the sodium percarbonate particles contains sodium sulfate and sodium carbonate in a weight ratio in the range from 95:5 to 75:25. The spray application of solutions with this ratio of sodium sulfate and sodium carbonate affords coated sodium percarbonate particles which, compared to sodium percarbonate particles with a coating layer of sodium sulfate, have improved storage stability in detergent and cleaning composition formulations and simultaneously have good silo storability.
In a preferred embodiment, the aqueous solution prepared using sodium sulfate and sodium percarbonate-containing dust contains a total of not more than 25% by weight of dissolved salts. While the prior art teaches applying a coating layer by using highly concentrated solutions of the coating components in order to minimize the amount of water to be evaporated, it has been found that, surprisingly, sodium percarbonate particles with a coating layer which has been produced by spray application of an aqueous solution with not more than 25% by weight of dissolved salts have better storage stability in detergent and cleaning composition formulations than sodium percarbonate particles obtainable by spray application of an aqueous solution with a higher content of dissolved salts.
To produce the coated sodium percarbonate particles, sodium percarbonate particles which have been produced from aqueous hydrogen peroxide solution and aqueous sodium carbonate solution by fluidized bed buildup granulation by the process described in EP-B 0 716 640, and had a mean particle diameter x50 of 0.70 mm and a fines fraction smaller than 0.2 mm of less than 2% by weight, were used. The coating layer was applied to these particles by the process described in paragraph [0021] of EP-B 0 863 842, by spray application of a 20% by weight aqueous solution of the coating materials in a fluidized bed at a fluidized bed temperature of 60° C. and simultaneous evaporation of water. In total, 4% by weight in each case of coating materials, calculated without water of crystallization, relative to the total amount of sodium percarbonate particles and coating materials used, were sprayed on.
The dust 1 used in examples 2, 3 and 4 to produce the coating material solutions was separated from the air discharged from a production plant for coating sodium percarbonate particles with sodium sulfate in a fluidized bed. The dust 2 used in examples 5, 6 and 7 was separated from the air discharged from a production plant for producing sodium percarbonate particles by fluidized bed buildup granulation. The composition of the two dusts is depicted in table 1.
In example 8, the solution of the coating materials was prepared by dissolving 20 parts by weight of sodium sulfate in 80 parts by weight of an aqueous solution which was obtained in a scrubber in which dust was separated from the air discharged from a production plant for coating sodium percarbonate particles with sodium sulfate in a fluidized bed and from the air discharged from a production plant for producing sodium percarbonate particles by fluidized bed buildup granulation. The solution from the scrubber contained a total of 6.1% by weight of dissolved solids.
In comparative example 9, the dust 2 was not dissolved together with sodium sulfate, and instead a solution of pure sodium sulfate was sprayed on and the dust was supplied directly in solid form to the fluidized bed.
Storage Stability in Detergents
To determine storage stability in detergents, 405 g of zeolite-containing IEC-A* BASE heavy-duty powder detergent (wfk-Testgewebe GmbH, Krefeld) were mixed with 15 g of TAED and 80 g of sodium percarbonate in a tumbling mixer for at least 10 min. The mixture was introduced into an E2 powder detergent box (dimensions 19×14×4.5 cm) with water-repellent impregnation, which was sealed with hot-melt adhesive. The powder detergent box was then stored in a climate-controlled cabinet at 35° C. and 80% relative humidity. After the powder detergent box had been cooled to room temperature outside the climate-controlled cabinet, the contents of the powder detergent box were divided into samples of 12 g each using a sample divider. The active oxygen content before and after storage was determined by permanganometry in a customary manner. The retention of the active oxygen content (Oa retention) in percent was determined from the active oxygen content before storage and the active oxygen content after 8 weeks of storage as a measure of the storage stability in detergents.
The test results compiled in table 2 show that the use of sodium percarbonate-containing dust to prepare the solution of the coating materials gives coated sodium percarbonate particles with an improved storage stability in detergents. This result was unforeseeable since it is known from WO 97/19890 examples B1 and VB5 that, when the sodium percarbonate particles with the coating layer composed of a mixture of sodium sulfate and sodium carbonate known from DE 2 417 572 were used for the tests, the storage stability achieved was no better than with a coating of pure sodium sulfate.
The test results also show that the addition of sodium percarbonate-containing dust directly into the coating without preceding dissolution of the dust, known from WO 2006/003155, gives sodium percarbonate particles with significantly poorer storage stability in detergents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07123598 | Dec 2007 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2008/065920 | 11/20/2008 | WO | 00 | 6/13/2010 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2009/077289 | 6/25/2009 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4105827 | Brichard et al. | Aug 1978 | A |
| 4135010 | Klebe et al. | Jan 1979 | A |
| 4146571 | Will et al. | Mar 1979 | A |
| 4156039 | Klebe et al. | May 1979 | A |
| 4325933 | Matsumoto et al. | Apr 1982 | A |
| 4329244 | Brichard et al. | May 1982 | A |
| 4428914 | Brichard et al. | Jan 1984 | A |
| 4526698 | Kuroda et al. | Jul 1985 | A |
| 5332518 | Kuroda et al. | Jul 1994 | A |
| 5458801 | Oyashiki et al. | Oct 1995 | A |
| 5462804 | Kokubu et al. | Oct 1995 | A |
| 5560896 | Bewersdorf et al. | Oct 1996 | A |
| 5851420 | Kim et al. | Dec 1998 | A |
| 5906660 | Pardini et al. | May 1999 | A |
| 5935708 | Schuette et al. | Aug 1999 | A |
| 6022404 | Ettlinger et al. | Feb 2000 | A |
| 6113805 | Schutte et al. | Sep 2000 | A |
| 6159252 | Schutte et al. | Dec 2000 | A |
| 6165963 | Delroisse et al. | Dec 2000 | A |
| 6239095 | Bertsch-Frank et al. | May 2001 | B1 |
| 6245115 | Appel et al. | Jun 2001 | B1 |
| 6267934 | Pardini et al. | Jul 2001 | B1 |
| 6387861 | Van Asperen et al. | May 2002 | B1 |
| 6465408 | Lee et al. | Oct 2002 | B1 |
| 6583098 | Cassie | Jun 2003 | B1 |
| 6800775 | Bachmann et al. | Oct 2004 | B1 |
| 6900169 | Wasserman et al. | May 2005 | B2 |
| 7588697 | Zimmermann et al. | Sep 2009 | B2 |
| 7718592 | Zimmermann et al. | May 2010 | B2 |
| 7956027 | Leininger et al. | Jun 2011 | B2 |
| 8153576 | Leininger et al. | Apr 2012 | B2 |
| 8658590 | Leininger et al. | Feb 2014 | B2 |
| 20020041843 | Jakob et al. | Apr 2002 | A1 |
| 20020086807 | Lee et al. | Jul 2002 | A1 |
| 20030031786 | Rumpler et al. | Feb 2003 | A1 |
| 20030104967 | Jakob et al. | Jun 2003 | A1 |
| 20060014658 | Zimmermann et al. | Jan 2006 | A1 |
| 20060063693 | Jakob et al. | Mar 2006 | A1 |
| 20060148669 | Ulrike Kottke et al. | Jul 2006 | A1 |
| 20060148670 | Rabe et al. | Jul 2006 | A1 |
| 20060249707 | Zimmermann et al. | Nov 2006 | A1 |
| 20070135323 | Wiedemann et al. | Jun 2007 | A1 |
| 20070275243 | Sontgerath et al. | Nov 2007 | A1 |
| 20080108538 | Sontgerath et al. | May 2008 | A1 |
| 20080274937 | Venbrux et al. | Nov 2008 | A1 |
| 20130059765 | Leininger et al. | Mar 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| B-3175495 | Apr 1996 | AU |
| 2170599 | Mar 1995 | CA |
| 2 417 572 | Nov 1974 | DE |
| 26 22 610 | Dec 1976 | DE |
| 27 44 574 | Apr 1978 | DE |
| 27 12 139 | Sep 1978 | DE |
| 195 44 293 | Jun 1997 | DE |
| 196 08 000 | Sep 1997 | DE |
| 103 20 196 | Jul 2004 | DE |
| 0 651 053 | May 1993 | EP |
| 0 544 490 | Jun 1993 | EP |
| 0 567 140 | Oct 1993 | EP |
| 0 703 190 | Mar 1996 | EP |
| 0 722 992 | Jul 1996 | EP |
| 0 737 738 | Oct 1996 | EP |
| 0 787 682 | Aug 1997 | EP |
| 0 970 917 | Jan 2000 | EP |
| 1 149 800 | Oct 2001 | EP |
| 1 612 185 | Jan 2006 | EP |
| 1 612 186 | Jan 2006 | EP |
| 16121686 | Jan 2006 | EP |
| 1 728 762 | Dec 2006 | EP |
| 1 903 098 | Mar 2008 | EP |
| 1 466 799 | Mar 1977 | GB |
| 1 538 893 | Jan 1979 | GB |
| 2 123 044 | Jan 1984 | GB |
| 2 309 976 | Aug 1997 | GB |
| WO 9506615 | Mar 1995 | WO |
| WO 9515292 | Jun 1995 | WO |
| WO 9719890 | Jun 1997 | WO |
| WO 9964156 | Dec 1999 | WO |
| WO 0012808 | Mar 2000 | WO |
| WO 0027975 | May 2000 | WO |
| WO 0052124 | Sep 2000 | WO |
| WO 0060043 | Oct 2000 | WO |
| WO 0071666 | Nov 2000 | WO |
| WO 0105925 | Jan 2001 | WO |
| WO 03031045 | Apr 2003 | WO |
| WO 2004039932 | May 2004 | WO |
| WO 2004056954 | Jul 2004 | WO |
| WO 2004058640 | Jul 2004 | WO |
| WO 2006003155 | Jan 2006 | WO |
| WO 2007127641 | Nov 2007 | WO |
| WO 2008135464 | Nov 2008 | WO |
| WO 2011134972 | Nov 2011 | WO |
| Entry |
|---|
| Response to Office Action filed Oct. 18, 2010 for copending U.S. Appl. No. 12/320,393. |
| Office Action dated Oct. 27, 2010 for copending U.S. Appl. No. 12/310,817. |
| Notice of Allowance dated Nov. 11, 2010 for copending U.S. Appl. No. 12/320,394. |
| Office Action dated Nov. 17, 2010 for copending U.S. Appl. No. 12/320,393. |
| Response to Office Action dated Oct. 27, 2010 for copending U.S. Appl. No. 12/310,817, (Response filed on Jan. 25, 2011). |
| Response to Office Action dated Nov. 17, 2010 for copending U.S. Appl. No. 12/320,393, (Response filed on Feb. 4, 2011). |
| Examiner's Answer mailed Jul. 12, 2011 for copending U.S. Appl. No. 12/310,817. |
| Response to Office Action filed Mar. 23, 2011 for copending U.S. Appl. No. 12/320,393. |
| Species Election Requirement mailed Jul. 11, 2011 for copending U.S. Appl. No. 12/442,865. |
| Response to Species Election Requirement filed Aug. 6, 2011 for copending U.S. Appl. No. 12/442,865. |
| Amendment filed Aug. 6, 2011 for copending U.S. Appl. No. 12/442,865. |
| English language translation of the Written Opinion of the International Searching Authority for PCT/EP2008/065920 filed Nov. 20, 2008. |
| Response to Office Action of Dec. 12, 2011 filed on Apr. 12,2012 for copending U.S. Appl. No. 12/442,865. |
| Final Rejection mailed Aug. 10, 2012 for copending U.S. Appl. No. 12/442,865. |
| Response to Final Rejection of Aug. 10, 2012 filed on Oct. 7, 2012 for copending U.S. Appl. No. 12/442,865. |
| Non-Final Rejection mailed Oct. 19, 2012 for copending U.S. Appl. No. 12/442,865. |
| Preliminary Amendment filed Oct. 24, 2012 for copending U.S. Appl. No. 13/643,174. |
| U.S. Appl. No. 13/643,174, filed Oct. 24, 2012, Leininger. |
| Advisory Action mailed Feb. 10, 2011 for copending U.S. Appl. No. 12/310,817. |
| Notice of Appeal filed on Feb. 27, 2011 for copending U.S. Appl. No. 12/310,817. |
| Appeal Brief filed on Apr. 21, 2011 for copending U.S. Appl. No. 12/310,817. |
| Office Action mailed Mar. 2, 2011 for copending U.S. Appl. No. 12/320,393. |
| Notice of Allowance dated Apr. 14, 2011 for copending U.S. Appl. No. 12/320,394. |
| Office Action mailed Dec. 12, 2011 for copending U.S. Appl. No. 12/442,865. |
| Reply Brief filed Sep. 6, 2011 for copending U.S. Appl. No. 12/310,817. |
| Notice of Allowance mailed Oct. 20, 2011 for copending U.S. Appl. No. 12/320,393. |
| English language translation of pp. 1/3-3/3 of an Opposition to counterpart European patent reference EP 2 080 544, filed with the European Patent Office on Sep. 1, 2011. |
| Non-final Office Action for co-pending U.S. Appl. No. 12/442,865, mailed Sep. 10, 2013. |
| Notice of Allowance for co-pending U.S. Appl. No. 12/310,817, mailed Sep. 30, 2013. |
| Opposition to counterpart European patent EP 2 080 544 filed with the European Patent Office on Sep. 1, 2011. |
| Winge, U., Master's Thesis: “Fluid-bed granulering,” Lund University, published Nov. 2002 with English translation of p. 10; chapter 5; appendix 1 and appendix 2, cited as documents D1 and D1(a) in European Opposition to EP 080 544. |
| Patent Board Decision mailed May 23, 2013 for copending U.S. Appl. No. 12/310,817. |
| International Search Report for PCT/EP2008/065920 filed Nov. 20, 2008. |
| English language translation of the Written Opinion of the International Searching Authority for PCT/ EP2008/065920 filed Nov. 20, 2008. |
| English language translation of the Internation Preliminary Report on Patentability for PCT/EP2008/065920 filed Nov. 20, 2008. |
| Cole, et al., “Characterization of the Sodium Sulfate-Sodium Phosphate System,” J. Mol. Struct. 643:101-107 (2002). |
| Eysel, et al., “Crystal Chemistry and Structure of Na2SO4(I) and Its Solid Solutions,” Acta. Cryst. B41:5-11 (1985). |
| Linnow, et al., “Investigation of Sodium Sulfate Transitions in a Porous Material Using Humidity- and Temperature-Controlled X-ray Diffraction,” Anal. Chem. 78:4683-4689 (2006). |
| Reinhardt, et al., “Neue reaktive Bleichaktivatoren-eine Gratwanderung zwischen Bleicheffizienz und Farb-/Faserschädigung,” Tenside Surf. Det. 34(6): 404-409 (1997). |
| Sakaguchi, et al., “The Phase-Transition Phenomenom in a Sodium Sulfate Crystal,” J. Electrochem. Soc. 131:1942-1943 (1984). |
| Singhvi, et al., “Effect of Aliovalent Cation Doping on the Electrical Conductivity of Na2SO4: Role of Charge and Size of the Dopant,” J. Solid State Chem. 138: 183-192 (1998). |
| Steiger, et al., “Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4—H2O and the generation of stress,” Geochimica et Cosmochimica Acta 72:4291-4306 (2008). |
| English language translation of Khlapova, et al., “The Hexagonal Burkeite Solid Solution in the Na2SO4—Na2CO3 System,” N.S. Kurnakov General and Inorganic Chemistry Institute, Academy of Science USSR. Translated from Zhurnal Struturnoi Khimi 4(4):569-575 (1963). |
| English language abstract for DE 27 12 139. |
| English language abstract for EP 0 703 190. |
| English language abstract for EP 0 787 682. |
| English language abstract for WO 95/06615. |
| English language abstract for WO 03/031045. |
| Office Action mailed Jul. 19, 2010 for copending U.S. Appl. No. 12/320,393. |
| Preliminary Amendment filed for U.S. Appl. No. 12/320,393 on Jan. 26, 2009. |
| Office Action mailed May 26, 2010 for copending U.S. Appl. No. 12/320,394. |
| Response to Office Action filed on Aug. 31, 2010 for copending U.S. Appl. No. 12/320,394. |
| Office Action mailed Jun. 8, 2010 for copending U.S. Appl. No. 12/310,817. |
| Response to Office Action filed on Sep. 8, 2010 for copending U.S. Appl. No. 12/310,817. |
| Preliminary Amendment filed for copending U.S. Appl. No. 12/442,865, on Mar. 25, 2009. |
| Response to Non-Final Office Action of Oct. 19, 2012 filed on Jan. 16, 2013 for copending U.S. Appl. No. 12/442,865. |
| Response to Office Action of Sep. 10, 2013 for co-pending U.S. Appl. No. 12/442,865, filed Dec. 7, 2013. |
| Final Office Action for co-pending U.S. Appl. No. 12/442,865, mailed Dec. 20, 2013. |
| Office Action for co-pending U.S. Appl. No. 13/643,174, mailed Sep. 16, 2014. |
| Response to Office Action of Sep. 16, 2014 for co-pending U.S. Appl. No. 13/643,174, filed Dec. 16, 2014. |
| Number | Date | Country | |
|---|---|---|---|
| 20100266763 A1 | Oct 2010 | US |
