Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28042—Shaped bodies; Monolithic structures
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
  • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
  • A61L15/22—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing macromolecular materials
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
  • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
  • A61L15/42—Use of materials characterised by their function or physical properties
  • A61L15/60—Liquid-swellable gel-forming materials, e.g. super-absorbents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
  • B01J20/26—Synthetic macromolecular compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
  • B01J20/28011—Other properties, e.g. density, crush strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28023—Fibres or filaments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28033—Membrane, sheet, cloth, pad, lamellar or mat
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28033—Membrane, sheet, cloth, pad, lamellar or mat
  • B01J20/28038—Membranes or mats made from fibers or filaments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/50—Aspects relating to the use of sorbent or filter aid materials
  • B01J2220/68—Superabsorbents
• • 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity

Definitions

• the present invention relates to materials formed from superabsorbent polymer (SAP) and fibers that are obtainable by pressing at not less than 60° C. and not less than 3 bar. More particularly, the present invention relates to materials which are obtained by in situ polymerization of SAP precursor mixtures on the fiber. The present invention also relates to processes for producing such materials and to their use.
• SAP superabsorbent polymer
• In situ materials have been known since the early 1980s. They are notable for a sheetlike fibrous structure, especially a nonwoven, being treated with liquid medium which, after polymerization on the fibrous structure (in situ), forms an absorbent polymer.
• Polymerization may be initiated in any known way, as by radiation (UV, electron beam, heat), additives (eg redox initiators).
• the liquid medium contains monomers and possibly comonomers for forming the absorbent polymer.
• Crosslinkers, further optional additives eg odor inhibitors, thickeners, SAP fine powder, etc may already be present in the liquid medium or only added to it after the treatment of the sheetlike structure.
• An aftertreatment after the polymerization for example surface postcrosslinking, can follow.
• the treatment of the sheetlike structure with the liquid medium can be accomplished by spraying, drenching or other customary treatment methods.
• SAP Materials formed from SAP and fibers by admixing the SAP to the fibers are known. This can be accomplished in various ways, for example by addition of SAP to the process for producing a sheetlike fibrous material (air laid or wet laid) or by addition of the SAP after the fibrous material has already been shaped into a sheetlike structure.
• the SAP can then be fixed to the fibers by various methods, for example adhesion agents.
• the SAP can also be embedded as a layer between two fibrous layers (see for example: WO 95/30396).
• material formed from SAP and fibers that is obtainable by pressing at not less than 60° C. and not less than 3 bar has the desired properties.
• SAP-nonwoven composites which can be produced according to WO 01/56625.
• the compression takes place in that dimension in which pressure is applied.
• the other two dimensions are left substantially unchanged by the process of compression.
• Compression can be effected by initially heating the material to the requisite temperature and then applying pressure; similarly, the material can first be subjected to an applied pressure before it is heated to the requisite temperature; preferably, however, the material is compressed by the simultaneous application of pressure and heat.
• the material may be compressed not only batchwise—using presses for example—but also continuously—using calendars for example.
• an application of pressure and heat is one way to obtain materials having the desired properties.
• the material properties are significantly more affected by varying the temperature than by varying the pressure. It has also been determined that even relatively low pressures from 3 bar, eg 3 bar, 3.5 bar, 4 bar or 4.5 bar are sufficient to produce the novel materials. Preference is given to pressures of 5 or more bar, eg 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 bar and particular preference is given to pressures above 10 bar, eg 10, 11, 12, 13, 14, 15, 20, 25, 30, 25, 40, 45, 50 or more bar. Pressures of more than 100 bar, in contrast, generally do not lead to a further improvement in material properties.
• Temperature for the purposes of this invention is the temperature in the material pressed or to be pressed. When comparatively long residence times are employed for the pressing operation (1 minute for example), the temperature in the material will be substantially equal to the temperature on the surface of the press. Temperatures below 60° C. are generally not sufficient. In general, temperatures of 60° C. or more are employed, for example 60° C. or 65° C. Preference is given to temperatures of 70° C. or more, for example 70° C., 75° C., especially of 80° C. or more, eg 80° C., 85° C., 90° C., 95° C., 100° C. or more. The maximum temperature is dependent on the residence time of the material at the temperature, since thermal degradation of the material should be avoided.
• the optimum temperature range is between 80° C. and 180° C., for example 110° C., 120° C., 130° C., 140° C., 150° C., 160° C. or 170° C. as well as the temperatures recited above. At temperatures above 200° C., the properties may deteriorate.
• the desired material properties are achievable after very short times of applying pressure and heat. Residence times of 1 minute are generally sufficient. Longer residence times are generally not harmful, but not desirable for economic reasons. Typical residence times are 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds or 60 seconds. But is it also possible to make the pressing time shorter for industrial fabrication, ie to use pressing times of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 seconds for example. Short pressing times are used with the comparatively higher temperatures. The short residence times are responsible for the fact that the compressed material can be produced continuously, using calenders or roll mills for example.
• SAP refers to superabsorbent polymer.
• Superabsorbent polymer is capable of absorbing at least 10 times its own weight in 0.9% NaCl solution in the CRC test.
• SAP is known from the prior art and in this invention is preferably based on polyacrylate.
• the SAP can be present in any desired form, for example in particulate form, as a fiber, film or foam, particulate being preferred.
• Various SAPs and their production are described for example in WO 01/56625 page 3 line 37 to line 16 on page 19.
• Fibers in the context of this invention comprehends all fibers which have been combined with SAP in the prior art.
• Preferred fibers are those which are present as a nonwoven.
• Preferred fibers are described for example in WO 01/56625 page 19 line 40 to line 27 on page 20.
• Pressing refers to the application of force to the surface of the material. This can be accomplished by means of classic presses, calenders or other suitable means.
• the present invention is the first to provide a material which expands not less than 5-fold in one dimension and by less than 20% in the other two dimensions on addition of water (distilled water) or aqueous fluids (0.9% NaCl solution).
• the material exhibits a substantially one-dimensional swelling performance on application of water or aqueous fluids.
• the expansion in water is generally not more than 20%, preferably not more than 18%, 16%, 14% or 12%, particularly preferably not more than 10%, 8%, 7%, or 6%, especially not more than 5%, 4%, 3%, 2% or even 1% in the x- and y-axes, while the material swells in the z-axis to more than 5-fold, 6-fold or 7-fold, preferably more than 8-fold or 9-fold, especially more than 10-fold, 11-fold, 12-fold, 13-fold, 14-fold or even 15-fold or more.
• the material after the application of pressure and heat is dimensionally stable; that is, little if any expansion takes place in the direction of the dimension in which the material was compressed.
• the increase in the thickness of the material according to the present invention 60 days after compression is preferably less than 100%, preferably less than 80%, more preferably less than 60% and especially less than 50% based on the thickness directly after compression.
• the material according to the present invention is preferably obtainable by pressure and heat treatment of material obtainable by in situ polymerization (as defined above and known from the prior art) of the SAP.
• the ultrathin materials according to the present invention are suitably producible using the webs recited in WO 01/56625.
• the SAP is preferably polymerized in situ on this web, but it is also possible for example for materials to be compressed according to the present invention where the SAP has been sprinkled in or adhered atop the web.
• additives to the starting material before compression. This can be effected for example by spraying with the additive or an additive solution, by drenching and also by sprinkling solid additives into the starting material or adhering solid additives atop the starting material.
• Additives refers for example to flavor and aroma chemicals, biocides and other odor-inhibiting materials, other active components, fertilizers and nutrients, dyes, surfactants, salts, polymers, softeners and others.
• Possibilities include not only sandwich structures, where top and bottom layers of the same material enclose a second layer different than the top and bottom layers, but also structures having two or more (partly or partially) different layers.
• the starting material can be converted together with cotton webs, polyester webs, cotton-polyester blend webs, paper, paperboard into laminates by one-minute compression at 150° C. and 80 bar, the starting material being simultaneously compressed and effective in holding the components together.
• the present invention provides a material having a density of not less than 0.5 g/ccm, preferably not less than 0.6 g/ccm, more preferably not less than 0.7 g/ccm, even more preferably 0.8 g/ccm, yet more preferably not less than 0.9 g/ccm and especially up to not less than 1 g/ccm or more.
• the maximum density is generally not more than 1.2 g/ccm.
• Pre-compression density is typically about 0.05 g/ccm. Since the material is flexible even after compression, the compressed material occupies a significantly smaller volume than the starting product.
• Density refers to the weight of the material per unit volume, volume referring to the expanse of the material (length*width*thickness).
• the ratio of teabag to retention in 0.9% NaCl solution is typically greater than 1.7 preferably greater than 1.9, more preferably greater than 2, especially greater than 2.2 (for granular SAP the value is on the order 1.2 to 1.5).
• This high value indicates that the compressed material is capable of taking up larger amounts of water than granular SAP. This could be because the higher water uptake is due to the pores in the unfolding web structure (sponge effect). Following the rapid uptake of water, the water can subsequently be taken up by the SAP (water storage).
• the compressed material according to the present invention accordingly has a comparable performance profile to fluff plus SAP.
• the material according to the present invention has a retention in 0.9% NaCl solution of preferably more than 3 g/ccm, more preferably more than 5 g/ccm and especially more than 6.5 g/ccm or even 7 g/ccm.
• Retention (even in the unit g/g) is higher for the pressed material than for the uncompressed, starting material. Compressing consequently leads to a material having better properties than are possessed by the starting material. The higher the temperature at which the compressing is carried out, the higher the retention value.
• the compressed material When the compressed material is placed in an atmosphere containing a high water vapor concentration, the material softens.
• the material according to the present invention preferably has an FSEV after 60 seconds which is at least double that of the uncompressed material.
• the material according to the present invention also preferably has an FSEV after 2 minutes which is at least 60% higher than that of the uncompressed material.
• the material according to the present invention preferably has an EVUL after 60 seconds which is at least double that of the uncompressed material.
• the material according to the present invention also preferably has an EVUL after 2 minutes which is at least 60% higher than that of the uncompressed material.
• the AAP (0.7 psi) value of the material according to the present invention in 0.9% NaCl solution is preferably greater than 5 g/ccm or greater than 6.5 g/ccm, preferably greater than 9 g/ccm, more preferably greater than 10 g/ccm, even more preferably greater than 11 g/ccm, especially greater than 12 g/ccm or even greater than 13 g/ccm.
• the materials according to the present invention are also useful as a (multilayer) material to absorb water vapor. This property is reversible and survives a plurality of absorption-drying cycles.
• hygiene articles for example as absorbent core, storage and/or acquisition layer in infant diapers or adult incontinence articles, sanitary napkins, etc
• bed underlays surgical drapes, wound contact materials, compresses, underlays for animal toilets, doormats, mats for absorbing snow, room climate improvement, climate improvement in seating and lying furniture, shoe soles and inserts, interlinings, garments, tablecloths, serviettes, cleaning cloths, seals or base material for seals, for example in the building sector, inner and outer pipe seals, cable sheaths, insulating and sealing material in the building industry, roof membranes (water and vapor barriers), sealing membranes for landfills, flood control (building protection, tank systems), waterways, tunnel constructions, roadbuilding, pipe liner for drilling, siccatives for transportation and storage (cereals, for example), agricultural films, including erosion control, underlays for plants, encasement of root balls, mats for germin
• the compressed material naturally has a smaller surface area than the starting material and hence a lower water takeup rate.
• the absorption rate can be increased by increasing the surface area for example.
• suitable measures are roughening the surface or compressing in the presence of structure-conferring, surface-enlarging elements.
• the base material used was Luquafleece IS from BASF Aktiengesellschaft. It is typically possible to use nonwovens having a basis weight from 20 to 2000 g/m 2 .
• the examples which follow utilize a PET nonwoven having a basis weight of 100 g/m 2 (Sawafill 8135 from Sandler).
• Luquafleece IS can be produced similarly to Example 9 of WO 01/56625 by loading the abovementioned nonwoven with 200 g/m 2 of SAP (100 g/m 2 each on both sides). It is also possible to use other loads, which are generally between 50 g/m 2 and 1000 g/m 2 . The loads can be applied from one side or from both sides. Preference is given to loads between 100 g/m 2 and 300 g/m 2 .
• AUL or AAP were measured as described in WO 01/56625 page 30 lines 16 ff. Teabag was determined in the same way as retention but without centrifugation.
• Typical values for the material according to the present invention are reported hereinbelow, the parenthetical values being those of the uncompressed starting material and of the material compressed as per WO 01/56625 at lower temperatures.
• the nonwoven without SAP exhibits fundamentally different properties than Luquafleece IS. There are even bigger differences between compressed nonwoven and compressed Luquafleece IS.
• the pure nonwoven has a high teabag value of 37 g/g in NaCl owing to the sponge effect and since the salt content is immaterial to this effect the same value in distilled water at 38 g/g.
• the CRC value is extremely low in both the media mentioned, at 0.4 g/g; this is because the centrifuging removes substantially all of the liquid from the web.
• Ultrathin materials according to the present invention can in principle also be produced by sprinkling SAP granules or powder into a nonwoven, optionally fixing the SAP to the nonwoven using an adhesive or anchoring it to the web by way of other techniques.
• the physical properties are similar to those of the pressed in situ material, products which have been reversibly fixed on the nonwoven have the disadvantage that the SAP will become detached again from the nonwoven by the swelling in the presence of water.
• the SAP is firmly attached to the fiber and does not become detached again even in the presence of water.
• the compressed material is dimensionally stable; that is, the material expands insignificantly, if at all, even in the course of prolonged storage at room temperature and relative humidities of preferably less than 60%. This dimensional stability was found with all samples which were compressed at a temperature of more than 60° C. and a pressure of more than 5 bar.
• an expansion of the material took place under the abovementioned conditions: Thickness directly after Sample [mm] compression [mm] Thickness after 60 days 1 0.8 2.4 2 0.7 1.8 3 0.7 1.9 4 0.8 2.3 Free-Swell Expansion Volume as a Function of Time
• the samples produced according to the present invention are faster than the comparative sample in water takeup under pressure of 0.5 psi. Only the sample produced at 80° C./150 bar gives the same value after 10 seconds, but here too all the other measured results are better than with the comparative sample.
• the compressed material is capable of absorbing significant amounts of water vapor and rereleasing them at low relative humidities (comparable properties to Luquafleece IS).
• Various specimens (each 100 ⁇ 100 mm) which were compressed for one minute at 160 bar and different temperatures were stored in a desiccator at room temperature and 95% relative humidity for 24 h. The specimens were then dried in air at 23° C. and 45% relative humidity. The results are discernible from Table A. Subsequently, the specimens were again stored in a desiccator at 95% relative humidity for 24 h and thereafter again dried at room temperature and 45% relative humidity. This cycle was carried out a third time. The results after the third cycle are reported in Table B.
• the tests were carried out on samples measuring 30 ⁇ 50 mm in area.
• the MP tests were carried out using a circular piece 6 cm in diameter (area 28.3 cm 2 ).
• the tests were carried out at 0.7 psi.
• the 30 ⁇ 50 mm samples were observed to swell essentially in the z-direction. A swelling of about 10% was measured in the x- or y-direction, the third dimension remained unchanged (the web is more easily extendable in one axis than in the other dimension).
• Luquafleece IS was compressed at 100° C. and 160 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in distilled water:
• Luquafleece IS was compressed at 100° C. and 80 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in distilled water:
• Luquafleece IS was compressed at 150° C. and 80 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in distilled water:
• Luquafleece IS was compressed at 200° C. and 80 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in distilled water:
• Luquafleece IS was compressed at 150° C. and 10 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in distilled water:
• Luquafleece IS compressed at 6 bar and 50° C. for 48 s
• Luquafleece IS was compressed at 100° C. and 160 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in 0.9% NaCl:
• Luquafleece IS was compressed at 100° C. and 80 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in 0.9% NaCl:
• Luquafleece IS was compressed at 150° C. and 160 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in 0.9% NaCl:
• Luquafleece IS was compressed at 150° C. and 80 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in 0.9% NaCl:
• Luquafleece IS was compressed at 150° C. and 10 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in 0.9% NaCl:
• Luquafleece IS was compressed at 200° C. and 160 bar for one minute. 30 ⁇ 50 mm samples were measured. The following data were obtained in 0.9% NaCl:
• Luquafleece IS Compressed at 6 Bar and 50° C. for 48 s
• Luquafleece IS is Compressed at 80 Bar and 50° C. for 60 s
• Hardness and moisture absorption rate can be influenced for example by adding softening chemicals or by structuring (enlarging) the surface area of the ultrathin material.
• useful softening chemicals are tertiary alkanolamines.
• the free acid groups of the SAP are preferably at least 20 mol % neutralized.
• Preferred alkanolamines are selected from the group consisting of triethanolamine, methyidiethanolamine, dimethylaminodiglycol, dimethylethanolamine, N,N,N′,N′-tetra(hydroxyethyl)ethylenediamine. These possibilities are not new per se, but are new in connection with influencing the water absorption capacity of superabsorbent sheetlike structures.
• the ultrathin material can be made softer by a specifically targeted addition of small amounts of water.
• the softening possibilities mentioned can also be combined.
• the material is preferably treated with water vapor or water mist. To preserve the softness, however, it is subsequently necessary to pack the material airtight.
• the change in hardness can be measured for example using an apparatus with which a sphere is pressed into the material for a defined distance while the force required for this distance is measured.
• the ultrathin material was placed in a saturated water vapor atmosphere at room temperature for 24 h. In the course of this period, the material absorbed 70% of its own weight in moisture. After 24 h, the sample was taken out of this atmosphere and the force needed to press the sphere 10 mm deep into the material was measured. The measurement was repeated in an hourly rhythm. The material was situated for this period in an environment of 50% relative humidity at 24° C.; that is, the moisture content decreased steadily in this period and had almost returned back to the starting value after 7 h.
• the materials used for the hardness measurement had been compressed at 160 bar and different temperatures for 1 minute. The following measurements (10 mm path length) were obtained.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Analytical Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Epidemiology (AREA)
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• Hematology (AREA)
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• Absorbent Articles And Supports Therefor (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Nonwoven Fabrics (AREA)
• Polyesters Or Polycarbonates (AREA)
• Polymerisation Methods In General (AREA)
• Polymers With Sulfur, Phosphorus Or Metals In The Main Chain (AREA)

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• 2002
  • 2002-10-31 DE DE2002151137 patent/DE10251137A1/de not_active Withdrawn
• 2003
  • 2003-10-28 AU AU2003274091A patent/AU2003274091A1/en not_active Abandoned
  • 2003-10-28 JP JP2004547573A patent/JP4739756B2/ja not_active Expired - Fee Related
  • 2003-10-28 DE DE50311022T patent/DE50311022D1/de not_active Expired - Lifetime
  • 2003-10-28 WO PCT/EP2003/011930 patent/WO2004039493A1/de active Application Filing
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