Classifications

• • 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
  • A61L15/425—Porous materials, e.g. foams or sponges
• • 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
  • A61L15/26—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof
• • 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
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/0207—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid flow within the bed being predominantly horizontal
  • B01J8/0214—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid flow within the bed being predominantly horizontal in a cylindrical annular shaped bed
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
  • C08G18/4833—Polyethers containing oxyethylene units
• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/71—Monoisocyanates or monoisothiocyanates
  • C08G18/718—Monoisocyanates or monoisothiocyanates containing silicon
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
  • C08J9/122—Hydrogen, oxygen, CO2, nitrogen or noble gases
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
  • C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
  • C08J9/141—Hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
  • C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
  • C08J9/142—Compounds containing oxygen but no halogen atom
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/36—After-treatment
  • C08J9/365—Coating
• • 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
  • C08G2101/00—Manufacture of cellular products
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
  • C08J2375/04—Polyurethanes

Definitions

• the present invention relates to novel polyurethane-based wound dressings which are obtained by foaming and curing of silane-terminated polyurethanes.
• polyurethane foams are generally used, which are prepared by reacting mixtures of diisocyanates and polyols or NCO-functional polyurethane prepolymers with water in the presence of certain catalysts and (foam) additives.
• aromatic diisocyanates are used here since they are best foamed. Numerous embodiments of these methods are known, for example described in US 3,978,266, US 3,975,567 and EP-A 0 059 048.
• polyurethane foams can also be prepared using silane-terminated polyurethane prepolymers which can be foamed by the use of blowing agents.
• silane-terminated polyurethane prepolymers which can be foamed by the use of blowing agents.
• sealing and insulating foams numerous embodiments are known, for example described in EP-A 1 098 920.
• the use of the compositions for the production of wound dressings has not been recognized.
• critical requirements such as good water vapor permeability and high liquid absorption capacity have also not been described.
• Object of the present invention was now to provide wound dressings of polyurethanes, which avoid the aforementioned disadvantages of the use of isocyanate-containing, reactive mixtures.
• silane-terminated polyurethane prepolymers after foaming and curing by crosslinking of the silane groups, can likewise be used excellently as wound dressings for medical applications.
• the present invention therefore provides the use of foams obtainable from silane-terminated polyurethane prepolymers as wound dressings.
• Another object of the invention is a process for the preparation of wound dressings, wherein a composition containing
• foams applied to a substrate before, during or after foaming, and finally cured in the presence of water.
• an object of the present invention are the wound dressings obtainable by the process according to the invention.
• an object of the invention is the use of compositions containing
• silane-terminated polyurethane prepolymers (I) comprising more than one alkoxysilane group
• wound dressings of polyurethane foams are porous materials, preferably with at least partially present open-cell nature, which essentially consist of polyurethanes crosslinked via silicon compounds Si-O-Si and protect wounds in the sense of coverage from germs or environmental influences have fast and high absorption of physiological saline solution or wound fluid and provide by suitable moisture permeability for optimal wound climate.
• Silane-terminated polyurethane prepolymers (I) in the context of the invention are all (pre-) polymers having more than one urethane and more than one alkoxysilane group, which crosslink in the presence of water and optionally catalysts (HI) via siloxane bonds Si-O-Si Polyurethanes can react.
• di- and / or trilkoxysilanes having amino, hydroxyl and / or thiol groups (B), where the amino, hydroxy and / or thiol groups are bonded to the silicon atom via an alkylene radical
• di- and / or trialkoxysilanes having isocyanate and / or isothiocyanate groups, where the isocyanate and / or isothiocyanate groups are bonded to the silicon atom via an alkylene radical
• the free polyurethane prepolymers (A) containing isocyanate groups are obtainable in a manner known per se by the reaction of organic polyisocyanates with polyhydroxy compounds having a functionality of 1.5 to 6, the organic polyisocyanates being used in excess (molar ratio NCO / OH> 1).
• Suitable polyisocyanates are the aromatic, araliphatic, aliphatic or cycloaliphatic polyisocyanates having an average NCO functionality of> 2 which are known to the person skilled in the art.
• Examples are 1, 4-butylene diisocyanate, 1, 6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (EPDI), 2,2,4 and / or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis (4,4'-isocyanatocyclohexyl) methanes or mixtures thereof of any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,2'- and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate, 1,3- and / or 1,4-bis (2-isocyanato-prop-2-yl) -benzene (TMXDI), 1,3-bis (isocyanatomethyl) benzene (XDI
• modified diisocyanates or triisocyanates having a uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione and / or oxadiazinetrione structure.
• polyisocyanates or polyisocyanate mixtures of the abovementioned type with exclusively aliphatically and / or cycloaliphatically bonded isocyanate groups and an average NCO functionality of 2 to 4, preferably 2 to 2.6 and more preferably 2 to 2.4.
• Particular preference is given to using 1,6-hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis (4,4'-isocyanatocyclohexyl) methanes, and mixtures thereof.
• polyester polyols known per se in polyurethane coating technology, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyether polyols, polyester polyarylate polyols, polyurethane polyacrylate polyols, polyurethanepolyester polyols, polyurethane polyether polyols, polyurethane polycarbonate polyols and polyesterol polycarbonate polyols which have an average OH Have functionality of at least 1.5. These can be used individually or in any mixtures with each other. However, preference is given to using polyether polyols.
• Polyester polyols of component (C) are the known polycondensates of di- and optionally tri- and tetraols and di- and optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols for the preparation of the polyesters.
• Diols which are suitable for the preparation of the polyesterpolyols are, for example, ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols, such as polyethylene glycol
• Neopentyl glycol and hydroxypivalic acid neopentyl glycol esters are preferred.
• Tetraaols are, for example, suitable for use with trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate.
• phthalic acid As dicarboxylic acids, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, itaconic acid, malonic acid, suberic acid, 2-methyl succinic acid, 3,3-diethylglutaric acid and / or 2,2-dimethyl succinic acid are used.
• the acid source used may also be the corresponding anhydrides.
• Preferred acids are aliphatic or aromatic acids of the abovementioned type. Particular preference is given to adipic acid, isophthalic acid and, if appropriate, trimellitic acid.
• Hydroxycarboxylic acids which may be co-used as reactants in the preparation of a hydroxyl-terminated polyester polyol include, for example, hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid, hydroxystearic acid and the like.
• Suitable lactones are caprolactone, butyrolactone and homologs. Preference is given to caprolactone.
• polycarbonates preferably polycarbonatediols, having number-average molecular weights M n of from 400 to 8000 g / mol, preferably from 600 to 3000 g / mol. These are obtainable in a manner known per se by reaction of carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols.
• Suitable diols for the preparation of the polycarbonates are, for example, ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4- Bishydroxymethylcyclohexane, 2-methyl-l, 3-propanediol, 2,2,4-Trimethylpentandiol-l, 3, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A and lactone-modified diols of the aforementioned kind.
• the polycarbonate diol preferably contains from 40 to 100% by weight of hexanediol, preferably 1,6-hexanediol and / or hexanediol derivatives, based on the diols which are the base.
• hexanediol derivatives are based on hexanediol and have ester or ether groups in addition to terminal OH groups.
• Such derivatives are obtainable by reaction of hexanediol with excess caprolactone or by etherification of hexanediol with itself to di- or trihexylenglykol.
• polyether polyols of component (C) may be polyether polyols.
• polytetra methylene glycol polyethers known per se in polyurethane chemistry such as are obtainable by polymerization of tetrahydrofuran by means of cationic ring opening, are suitable.
• Preferred polyether polyols of component (C) are the per se known addition products of styrene oxide, ethylene oxide, propylene oxide, butylene oxides and / or epichlorohydrin to di- or polyfunctional starter molecules, with addition products of ethylene oxide or propylene oxide, and mixtures of those mentioned, are particularly preferred.
• Very particular preference is given to addition products of ethylene oxide and propylene oxide in which the weight fraction of ethylene oxide is at least 5 to 80% by weight, preferably 10 to 65% by weight, particularly preferably 10 to 30% by weight, this weight fraction being based to the total present in the addition product ethylene oxide and propylene oxide units and the starter molecules used.
• the alkoxylation with ethylene oxide or propylene oxide can be carried out under base catalysis or using double metal cyanide compounds (DMC compounds).
• DMC compounds double metal cyanide compounds
• starter molecules for the preparation of the polyether polyols of component (C) it is possible to use all prior art low molecular weight polyols, organic polyamines and / or water, for example butyl diglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, sorbitol, ethylenediamine, triethanolamine , 1,4-butanediol.
• Preferred starter molecules are water, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, butyl diglycol or any mixtures of the abovementioned.
• the polyether polyols preferably have number-average molecular weights M n of from 300 to 20 000 g / mol, particularly preferably from 1 000 to 12 000, very particularly preferably from 2 000 to 6 000 g / mol.
• polyhydroxy compounds having a functionality of from 1.5 to 6 in the molar ratio NCO / OH ⁇ 1 polyhydroxy compounds containing urethane groups are obtained, which can likewise be used as component (C).
• Suitable di- and / or trialkoxysilanes of component (B) having amino, hydroxyl and / or thiol groups are well known to the person skilled in the art, examples being aminopropyltrimethoxysilane, mercaptopropyltrimethoxysilane, aminopropylmethyldimethoxysilane, mercaptopropylmethyldimethoxysilane, aminopropyltriethoxysilane, mercaptopropyltriethoxysilane, aminopropylmethyldiethoxysilane, mercaptopropylmethyldiethoxysilane, aminomethyltrimethoxy silane, aminomethyltriethoxysilane, (aminomethyl) methyldimethoxysilane, (aminomethyl) methyldiethoxysilane, N-butylaminopropyltrimethoxysilane, N-ethylaminopropyltrimethoxysilane, N-phenylaminopropy
• Suitable isocyanate and / or isothiocyanate groups containing di- and / or trialkoxysilanes of component (D) are also known in principle. Examples which may be mentioned are isocyanatomethyltrimethoxysilane, isocyanatomethyltriethoxysilane, (isocyanatomethyl) methyldimethoxysilane, (isocyanatomethyl) methyldiethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropyltriethoxysilane and 3-isocyanatopropylmethyldiethoxysilane. Preference is given here to the use of 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane.
• the additives (II) are nonionic, anionic, cationic or zwitterionic surfactants or mixtures of said surfactants, which serve in the compositions of the invention to improve the foaming, the foam stability or the properties of the resulting polyurethane foam.
• Preferred additives (H) are nonionic, particularly preferably nonionic surfactants based on polyethersiloxanes.
• the preferred additives (ff) also have a particularly advantageous influence with regard to the hydrophilization of the foams, which is noticeable in terms of amount and speed of moisture absorption.
• catalysts (HT) it is possible in principle to add to the compositions of the invention all substances known per se from silicon chemistry which catalyze the hydrolysis and condensation of alkoxysilanes or silanol groups. Mention may be made, for example, metal salts, metal complexes, organometallic compounds, and acids and bases. Preferred is the use of organic and inorganic acids or bases, more preferably the use of organic or inorganic acids such as hydrochloric acid or p-toluenesulfonic acid. If catalysts (EI) are used in the compositions, they are preferably dissolved in water, which at the same time is necessary for the actual crosslinking of the foams.
• blowing agent air or nitrogen can be used as blowing agent (FV), but of course all other blowing agents known per se from polyurethane chemistry can also be used for foaming the composition according to the invention. Examples which may be mentioned are n-butane, isobutane, propane and dimethyl ether, and mixtures of the abovementioned.
• auxiliaries and additives (V) it is possible, for example, to use fillers, thickeners or thixotropic agents, antioxidants, light stabilizers, plasticizers, pigments and / or leveling agents.
• Preferred auxiliaries and additives are fillers, preferably inorganic fillers, which improve the mechanical properties of the polyurethane according to the invention.
• Foam can contribute.
• Suitable examples are chalks and highly disperse silicas, in particular silicas prepared by flame pyrolysis.
• plasticizer it is possible to use all natural or synthetic substances which have a sufficiently good compatibility with the polyurethane foam.
• suitable plasticizers are camphor, esters of (aliphatic) dicarboxylic acids, e.g. the adipic acid, polyester, in particular based on adipic, sebacic, azelaic and phthalic acid condensed with 1,3-butanediol, 1, 4-butanediol or 1, 6-hexanediol, and phosphoric acid esters, fatty acid esters and hydroxycarboxylic (eg based on Citric acid, tartaric acid or lactic acid).
• camphor esters of (aliphatic) dicarboxylic acids
• esters of (aliphatic) dicarboxylic acids e.g. the adipic acid, polyester, in particular based on adipic, sebacic, azelaic and phthalic acid condensed with 1,3-butanediol, 1,
• Curing with crosslinking of the alkoxysilane groups to siloxane bridges is carried out under the action of water, which in liquid form, e.g. as a solvent for the catalyst, can be added directly or can come from the air in the form of atmospheric moisture.
• compositions essential to the invention contain, based on dry matter, typically 80 to 99.9 parts by weight of the silane-terminated polyurethane prepolymer (I) and 0.1 to 20 parts by weight of the (foam) additive (U).
• the compositions preferably contain, based on dry substance, 85 to 99.9 parts by weight of silane-terminated polyurethane prepolymer (I) and 0.1 to 15 parts by weight of the (foam) additive (ET), more preferably 95 to 99.9 parts by weight (I) and 0.1 to 5 parts by weight (II).
• Auxiliaries and additives (V) are typically added in amounts of 0 to 50 parts by weight, preferably 10 to 40 parts by weight.
• water is added for crosslinking beyond the ambient humidity, it is typically added in an amount such that the molar ratio of alkoxy groups to added water is less than or equal to 1 (excess water).
• the molar ratio is less than or equal to 0.75, more preferably less than or equal to 0.55.
• the propellant or propellant mixture (FV) is typically used in an amount of 1 to 50 wt .-%, preferably 5 to 40 wt .-% and particularly preferably 5 to 20 wt .-%, wherein the sum of the components used (I. ), (H) and optionally (HI), (FV), (V), 100% by weight.
• the mixing of the components (I) and (IT) can be carried out in any order, as well as the mixture with the optionally contained components (IH) to (V).
• the components (I) and (II) and optionally (HI) to (V) are each provided separately, that is, the reactive component (I) is in the absence of water and the optionally used catalyst (EI) provided.
• the reactive component (I) is in the absence of water and the optionally used catalyst (EI) provided.
• the foaming in the process of the invention is done by shaking the composition, mechanical stirring at high speeds or by relaxation of a propellant gas. After or during foaming, the composition is cured, after which the desired polyurethane foam is obtained. Before complete solidification or curing, i. As long as the composition is still flowable, it can be applied to a suitable substrate by common application techniques, such as casting or knife coating. Moreover, a direct application of the composition to the human or animal skin can be carried out, wherein the foaming and curing usually takes place simultaneously.
• the mechanical foaming can be carried out with any mechanical stirring, mixing and dispersing techniques. As a rule, this air is entered, but also nitrogen and other gases can be used for this purpose.
• the foam thus obtained is applied to a substrate during foaming or immediately thereafter or placed in a mold and cured.
• the order can be made, for example, by casting or knife coating, but other techniques known per se are possible.
• a multi-layer application with optionally intermediate hardening steps is also possible in principle.
• a satisfactory curing speed of the foams is already observed at 20 0 C.
• higher temperatures preferably more than 30 0 C may be used, for example with the aid of known heating and drying equipment, such as (convection) drying cabinets, hot air or IR emitters.
• compositions can already be foamed or foamed directly onto the skin or, in the context of industrial production of wound dressings, on release papers or films which allow easy release of the wound dressing prior to its use to cover an injured site.
• the application and the curing can each be carried out batchwise or continuously, but in the case of the industrial production of wound dressings, a completely continuous process is preferred.
• a direct application of the composition for example by spraying, on the animal or human skin, the curing is also already very quickly at ambient conditions or by the body temperature.
• the use of external heat source is also possible here, although not preferred.
• the silane-terminated polyurethane prepolymer (I) is mixed with the additive (II) and, if appropriate, further auxiliaries and additives (V).
• the catalyst (IE) is added, the (foamed) mixture applied to a suitable substrate and finally cured in the presence of atmospheric moisture.
• water can be added, which preferably takes place together with the (dissolved) catalyst (UT).
• the silane-terminated polyurethane prepolymer (I) is mixed with the additive (IT) and optionally further auxiliaries and additives (V) and introduced into a suitable pressure vessel, e.g. a spray can, transferred. Thereafter, the propellant (FV) is added; during the application of the mixture to a suitable substrate foaming and curing takes place by atmospheric moisture.
• a suitable pressure vessel e.g. a spray can
• the silane-terminated polyurethane prepolymer (I) is mixed with the additive (II) and optionally further auxiliaries and additives (V) and introduced into a first chamber of a suitable pressure vessel, e.g. a spray can, transferred, wherein the pressure vessel has at least 2 separate chambers.
• a suitable pressure vessel e.g. a spray can, transferred
• the catalyst (IH) is added, which is preferably mixed with a suitable amount of water.
• the auxiliaries and additives (V) can also be mixed in the second chamber, but this is less preferred.
• the propellant (FV) is added to one or both of the chambers and finally the application of the two-component mixture to a suitable substrate, wherein at the same time the foaming and the curing takes place.
• the polyurethane foams Before curing, the polyurethane foams typically have foam densities of 50 to 800 g / liter, preferably 100 to 500 g / liter, particularly preferably 100 to 250 g / liter (mass of all starting materials [in g] relative to the foam volume of one liter).
• the polyurethane foams have after drying a microporous, at least partially open-pore structure with communicating cells.
• the density of the cured Foams are typically below 0.4 g / cm 3 , preferably less than 0.35 g / cm 3, and more preferably 0.01 to 0.2 g / cm 3 .
• the absorption capacity with respect to physiological saline solution in the polyurethane foams is typically 100 and 1500%, preferably 300 to 800% (mass of the liquid absorbed based on the mass of the dry foam, determined according to DIN EN 13726-1, part 3.2).
• the permeability to water vapor is typically 500 to 8000 g / 24 h * m 2 , preferably 1000 to 6000 g / 24 h * m 2 and particularly preferably 2000 to 5000 g / 24 h * m 2 (determined according to DIN EN 13726-2, Part 3.2).
• the polyurethane foams have good mechanical strength and high elasticity.
• the values for the maximum stress are greater than 0.1 N / mm 2 and the maximum elongation is greater than 100%.
• the elongation is greater than 200% (determined according to DIN 53504).
• the polyurethane foams after curing typically have a thickness of 0.1 mm to 50 mm, preferably 0.5 mm to 20 mm, more preferably 1 to 10 mm, most preferably 1 to 5 mm.
• the polyurethane foams can moreover be bonded, laminated or coated with other materials, for example based on hydrogels, (semi-) permeable films, coatings, hydrocolloids or other foams.
• NCO contents were determined volumetrically in accordance with DIN-EN ISO 11909, unless expressly stated otherwise.
• Tegostab ® 1048 polyether (Messrs. Degussa, Dusseldorf, DE)
• Aerosil ® R 9200 Highly dispersed silicic acid produced by flame pyrolysis
• Example 1 Preparation of a foam under base catalysis

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Polymers & Plastics (AREA)
• Medicinal Chemistry (AREA)
• Materials Engineering (AREA)
• Engineering & Computer Science (AREA)
• Public Health (AREA)
• General Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Veterinary Medicine (AREA)
• Epidemiology (AREA)
• Animal Behavior & Ethology (AREA)
• Hematology (AREA)
• Dispersion Chemistry (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Polyurethanes Or Polyureas (AREA)
• Silicon Polymers (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=38521740

Family Applications (1)

Country Status (8)

Cited By (7)

Families Citing this family (23)

Citations (4)

Family Cites Families (23)

• 2007
  • 2007-07-10 EP EP07013425A patent/EP2014314A1/de not_active Withdrawn
• 2008
  • 2008-06-27 JP JP2010515376A patent/JP5192040B2/ja not_active Expired - Fee Related
  • 2008-06-27 EP EP08773730.0A patent/EP2175896B1/de active Active
  • 2008-06-27 CA CA 2692799 patent/CA2692799A1/en not_active Abandoned
  • 2008-06-27 CN CN200880023844.0A patent/CN101687058B/zh not_active Expired - Fee Related
  • 2008-06-27 WO PCT/EP2008/005259 patent/WO2009007018A1/de not_active Ceased
  • 2008-06-27 KR KR1020107000438A patent/KR20100035703A/ko not_active Ceased
  • 2008-07-09 TW TW097125807A patent/TW200918108A/zh unknown
  • 2008-07-09 US US12/169,842 patent/US9168324B2/en active Active

Patent Citations (4)

Also Published As

Similar Documents

Legal Events