New! View global litigation for patent families

CA2692799A1 - Process for producing polyurethane foams for wound management - Google Patents

Process for producing polyurethane foams for wound management

Info

Publication number
CA2692799A1
CA2692799A1 CA 2692799 CA2692799A CA2692799A1 CA 2692799 A1 CA2692799 A1 CA 2692799A1 CA 2692799 CA2692799 CA 2692799 CA 2692799 A CA2692799 A CA 2692799A CA 2692799 A1 CA2692799 A1 CA 2692799A1
Authority
CA
Grant status
Application
Patent type
Prior art keywords
polyurethane
preferably
acid
materials
foam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA 2692799
Other languages
French (fr)
Inventor
Michael Mager
Michael Ludewig
Mathias Matner
Melita Dietze
Burkhard Fugmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Covestro Deutschland AG
Original Assignee
Michael Mager
Michael Ludewig
Mathias Matner
Melita Dietze
Burkhard Fugmann
Dietzle, Melita
Bayer Innovation Gmbh
Bayer Materialscience Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS 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
    • A61L15/00Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
    • A61L15/16Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
    • A61L15/42Use of materials characterised by their function or physical properties
    • A61L15/425Porous materials, e.g. foams or sponges
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08GMACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00Polymeric products of isocyanates or isothiocyanates
    • C08G18/06Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/40High-molecular-weight compounds
    • C08G18/48Polyethers
    • C08G18/4833Polyethers containing oxyethylene units
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08GMACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00Polymeric products of isocyanates or isothiocyanates
    • C08G18/06Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/71Monoisocyanates or monoisothiocyanates
    • C08G18/718Monoisocyanates or monoisothiocyanates containing silicon
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G
    • C08J9/00Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/04Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
    • C08J9/12Working-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
    • C08J9/122Hydrogen, oxygen, CO2, nitrogen or noble gases
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G
    • C08J9/00Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/04Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
    • C08J9/12Working-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
    • C08J9/14Working-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
    • C08J9/141Hydrocarbons
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G
    • C08J9/00Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/04Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
    • C08J9/12Working-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
    • C08J9/14Working-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
    • C08J9/142Compounds containing oxygen but no halogen atom
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G
    • C08J9/00Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/36After-treatment
    • C08J9/365Coating
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08GMACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2101/00Foams
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G
    • C08J2375/00Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
    • C08J2375/04Polyurethanes

Abstract

The present invention relates to novel polyurethane-based wound contact materials, obtained by foaming and curing of silane-terminated polyurethanes.

Description

PROCESS FOR PRODUCING POLYURETHANE FOAMS FOR WOUND
MANAGEMENT

The present invention provides novel polyurethane-based wound contact materials, obtained by foaming and curing silane-terminated polyurethanes.

The use of wound contact materials made of foams for managing weeping wounds is prior art.
Owing to their high absorbency and their good mechanical properties, polyurethane foams produced by reaction of mixtures of diisocyanates and polyols or NCO-functional polyurethane prepolymers with water in the presence of certain catalysts and also (foam) additives are generally used. Aromatic diisocyanates are generally employed, since they are best foamable. Numerous forms of these processes are known, for example described in US 3,978,266, US
3,975,567 and EP-A 0 059 048. However, the aforementioned processes have the disadvantage that they require the use of reactive mixtures, comprising diisocyanates or appropriate NCO-functional prepolymers, whose handling is technically inconvenient and costly, since appropriate protective measures are necessary for exaniple. Direct application of these mixtures to (human) skin is not possible because of the high reactivity of the isocyanate groups present.

As well as through the use of compositions comprising free isocyanate groups, polyurethane foams can also be produced using silane-terminated polyurethane prepolymers which are foamable through use of blowing agents. Numerous embodiments are known for producing sealing and insulating foams, for example describe(i in EP-A 1 098 920. The use of the compositions for producing wound contact materials was hitherto not recognized. Nor have the critical requirements for use as wound contact materials, such as good water vapour permeability and high liquid uptake capacity, hitherto been described.

It is an object of the present invention to provide polyurethane wound contact materials which avoid the abovementioned disadvantages of using isocyanato-containing, reactive mixtures.

It has now been found that silane-terminated polyurethane prepolymers (STPs), surprisingly, are likewise very useful as wound contact materials for medical applications after foaming and curing through crosslinking of the silane groups.

The present invention accordingly provides for the use of foatns obtainable from silane-terminated polyurethane prepolymers as wound contact materials.

The present invention further provides a process for producing wound contact materials wherein a composition comprising a) silane-terminated polyurethane prepolymers (I) b) (foam) additives (11) c) optionally catalysts (III), d) optionally blowing agents (IV), and also e) optionally further, auxiliary and adjunct materials (V) is foamed, applied to a substrate before, during or after foaming and finally cured in the presence of water.

The present invention further provides the wound contact materials obtainable by the process of the invention.

The invention further provides for the use of compositions comprising a) silane-terminated polyurethane prepolymers (i) comprising more than one alkoxysilane group b) (foam) additives (II) c) optionally catalysts (III), d) optionally blowing agents (IV), and also e) optionally further, auxiliary and adjunct materials (V) for producing contact materials for wound management.

Polyurethane foam wound contact materials herein are porous materials, preferably having at least partly an open-cell content, which consist essentially of polyurethanes crosslinked via siloxane bonds Si-O-Si and protect wounds by closing out germs or ambient effects, provide rapid and high absorption of physiological saline or exudate and ensure optimal wound conditions through suitable perviousness to moisture.

Silane-terminated polyurethane prepo9ymers (1) for the purposes of the invention include all (pre)polymers having more than one urethane group and more than one alkoxysilane group, which are capable in the presence of water and if appropriate catalysts (I11) of reacting via siloxane bonds Si-O-Si to form crosslinked polyuretha(ies.

Such silane-terminated prepolymers are obtainable by reacting i) polyurethane prepolymers (A) having free isocyanate groups to an average NCO

functionality of at least 1.5 with ii) di- and/or trialkoxysilanes (B) having amino, hydroxyl and/or thiol groups bonded to the silicon atom via an alkylene radical, or iii) polyhydroxy compounds (C) having an average OH functionality of at least 1.5 with iv) di- and/or trialkoxysilanes (D) having isocyanate and/or isothiocyanate groups bonded to the silicon atom via an alkylene raclical.

The polyurethane prepolymers (A), which contain free isocyanate groups, are obtainable in a conventional manner by the reaction of organic polyisocyanates with polyhydroxy compounds having a functionality of 1.5 to 6 by using the organic polyisocyanates in excess (molar ratio NCO/OH > 1).

Suitable polyisocyanates include the well-known aromatic, araliphatic, aliphatic or cycloaliphatic polyisocyanates having an average NCO functionality of > 2.

Examples of such suitable polyisocyariates are 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4 and/or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis(4,4'-isocyanatocyclohexyl)methanes or their mixtures of any desired isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and/or 2,6-toluylene diisocyanate, 1,5-naphthylene diisocyanate, 2,2'- and/or 2,4'-and/or 4,4'-diphenyl-methane diisocyanate, 1,3- and/or 1,4-bis(2-isocyanatoprop-2-yl)benzene (TMXDI), 1,3-bis-(isocyanatomethyl)benzene (XDI), and also alkyl 2,6-diisocyanatohexanoate (lysine diisocyanates) having Cl-C8-alkyl groups, and 4-isocyanatomethyl-1,8-octane diisocyanate (nonane triisocyanate) and triphenylmethane 4,4',4"-triisocyanate.

As well as the aforementioned polyisocyanates, it is also possible to use, proportionally, modified diisocyanates or triisocyanates of uretdione, isocyanurate, urethane, alloplianate, biuret, imino-oxadiazinedione and/or oxadiazinetriorne structure.

Preferably, the polyisocyanates or polyisocyanate mixtures of the aforementioned kind have exclusively aliphatically and/or cycloaliphatically attached isocyanate groups and an average NCO
functionality in the range from 2 to 4, preferably in the range from 2 to 2.6 and more preferably in the range from 2 to 2.4. It is particularly preferable to utilize 1,6-hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis(4,4'-isocyanatocyclohexyl)methanes, and also mixtures thereof.

Useful polyhydroxy compounds for component (C) include all well-known polyurethane coating technology polyester polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyether polyols, polyester polyacrylate polyols, polyurethane polyacrylate polyols, polyurethane polyester polyols, polyurethane polyether polyols, polyurethane polycarbonate polyols and polyester polycarbonate polyols that have an average OH functionality of at least 1.5. These can be used individually or in any desired mixtures with each or one another.
Preference, however, is given to using polyether polyols.

Polyester polyols for component (C) are the well-known polycondensates formed from di- and also optionally tri- and tetraols and di- and also optionally tri- and tetracarboxylic acids or hydroxy carboxylic acids or lactones. Instead of the free polycarboxylic acids it is also possible to use the corresponding polyearboxylic anhydrides or corresponding polycarboxylic esters of lower alcohols for preparing the polyesters.

Examples of suitable diols for producing polyester polyols are ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, also 1,2-propanediol, 1,3-propanediol, butanediol(1,3), butanediol(1,4), hexanediol(1,6) and isomers, neopentyl glycol or neopentyl glycol hydroxypivalate, of which hexanediol(1,6) and isomers, neopentyl glycol and neopentyl gtycol hydroxypivalate are preferred.
Trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate are suitable, for example, as triols and tetraols.

Useful dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetra-hydrophthalic 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-methylsuccinic acid, 3,3-diethyl glutaric acid and/or 2,2-dimethylsuccinic acid. The corresponding anhydrides can also be used as a source of acid.
Preferred acids are aliphatic or aromatic acids of the aforementioned kind.
Adipic acid, isophthalic acid and optionally trimellitic acid are particularly preferred.

Hydroxy carboxylic acids useful as reaction participants in the preparation of a polyester polyol having terminal hydroxyl groups include for example hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid, hydroxystearic acid and the like. Suitable lactones include caprolactone, butyrolactone and homologues. Caprolactone is preferred.

Useful polyhydroxy compounds for component (C) further include polycarbonates, preferably polycarbonate diols, having number average molecular weights Mõ in the range from 400 to 8000 g/mol, preferably in the range from 600 to 3000 g/mol. These are obtainable in a conventional manner by reaction of carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols.

Examples of diols useful for preparing polycarbonates are ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A
and lactone-modified diois of the aforementioned kind.

The polycarbonate diol preferably contains 40% to 100% by weight of hexanediol, preference being given to 1,6-hexanediol and/or hexanediol derivatives based on the underlying diols. Such hexanediol derivatives are based on hexanediol and have ester or ether groups as well as terminal OH groups. Such derivatives are obtainabhe by reaction of hexanediol with excess caprolactone or by etherification of hexanediol with itself to form di- or trihexylene glycol.

Useful polyhydroxy compounds for component (C) further include polyether polyols. Suitable are for example the polytetramethylene glycol polyethers which are known per se in polyurethane chemistry and are obtainable by polymerization of tetrahydrofuran by means of cationic ring opening.

Preferred polyether polyols for component (C) include the well-known addition products of styrene oxide, ethylene oxide, propylene oxide, butylene oxides and/or epichlorohydrin onto di- or polyfunctional starter molecules, of which addition products of ethylene oxide or propylene oxide, and also mixtures of those mentioned, are particularly preferred. Very particular preference is given to addition products of ethylene oxide and propylene oxide in each of which the weight fraction of ethylene oxide is at least 5% to 80% by weight, preferably 10% to 65% by weight and more preferably 10% to 30% by weight, this weight fraction being based on the total of ethylene oxide and propylene oxide units present in the addition product, plus the starter molecules used.
The alkoxylation with etliylene oxide or propylene oxide can take place under base catalysis or through use of double metal cyanide (DPvIC) compounds.

Useful starter molecules for preparing the polyether polyols of component (C) include 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. Preferi-ed starter molecules are water, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycel, butyl diglycol or any mixtures thereof.

The number average molecular weight Mõ of the polyether polyols is preferably in the range from 300 to 20 000 g/mol, more preferably in the range from 1000 to 12 000 g/inol and most preferably in the range from 2000 to 6000 g/mol.

Reaction of organic di- or polyisocyanates 'with polyhydroxy compounds having a functionality of 1.5 to 6 in an NCO/OH molar ratio < I gives polyhydroxy compounds having urethane groups and likewise useful as component (C).

Di- and/or trialkoxysilanes having amino, hydroxyl and/or thiol groups and useful for component (B) are well known to a person skilled in the art, examples being amino-propyltrimethoxysi lane, mercaptopropyltrimethoxysilane, aminopropylmethyldimethoxysilane, mercaptopropylmethyldimethoxysilane, ,aminopropyltriethoxysilane, mercaptopropyltriethoxy-silane, aminopropylmethyldiethoxysilane, mercaptopropylmethyldiethoxysilane, aminomethyl-trimethoxysilane, aminomethyltriethoxysilane, (aminomethyl)methyldimethoxysi lane, (aminomethyl)methyldiethoxysilane, N-butylaminopropyltrimethoxysilane, N-ethylaminopropyl-trimethoxysi lane, N-phenylaminopropyltrimethoxysilane, diethyl N-(3-triethoxysilylpropyl)-aspartate, diethyl N=(3-trimethoxysilylpropyl)aspartate and diethyl N-(3-dimethoxymethylsilyl-propyl)aspartate. The use of diethyl N-(3-trimethoxysilylpropyl)aspartate and aminopropyltrimethoxysi lane is preferred.

Di- and/or trialkoxysilanes having isocyanate and/or isothiocyanate groups and useful for component (D) are likewise known in principle.

Examples are isocyanatomethyltrimethoxysi lane, isocyanatomethyltriethoxysi lane, (isocyanatomethyl)methyldimethoxysilane, (isocyanatomethyl)methyldiethoxysilane, 3-isocyanato-propyltrimethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropyltriethoxy-silane and 3-isocyanatopropylmethyldiethoxysilane. Preference is here given to the use of 3 -isocyanatopropyltrimethoxysi lane and 3-isocyanatopropyltriethoxysilane.

The additives (II) are nonionic, anionic, cationic or zwitterionic surfactants or mixtures thereof, which serve in the compositions of the invention to improve foam formation, foam stability or the properties of the resulting polyurethane foam. Preferred additives (II) are nonionic surfactants, more preferably nonionic surfactants based on polyether siloxanes.

The preferred additives (11) have not orily a stabilizing effect but also a particularly advantageous influence with regard to the hydrophilicization of the foams, which manifests itself in moisture uptake quantity and rate.

Useful catalysts (III) for inclusion in the compositions of the invention include in principle all materials known per se from silicon chemistry wliich catalyse the hydrolysis and condensation of alkoxysilanes and silanol groups, respectively. Examples are metal salts, metal complexes, organometallic compounds and also a.cids and bases. Preference is given to use of organic and inorganic acids or bases and particular preference to the use of organic or inorganic acids such as for example hydrochloric acid or p-tolueriesulphonic acid. When catalysts (III) are used in the compositions, they are preferably dissolved in water which is also required for the actual crosslinking of the foams.

Blowing agents (IV) can most simply be air or nitrogen, but it is of course also possible to use any other blowing agents for foaming the composition of the invention which are known per se from polyurethane chemistry. Examples are n-butane, i-butane, propane and dimethyl ether and also mixtures thereof.

Useful auxiliary and adjunct materials (V) include for example fillers, thickeners or thixotroping agents, antioxidants, light stabilizers, plasticizers, pigments and/or flow control agents.

Preferred auxiliary and adjunct materials are fillers, preferably inorganic fillers, which can contribute to improving the mechanical properties of the polyurethane foam of the invention.
Useful examples include chalks and finelv divided silicas, in particular fumed silicas.

Useful plasticizers include any natural or synthetic material sufficiently compatible with the polyurethane foam. Examples of suitable plasticizers are camphor, esters of (aliphatic) dicarboxylic acids, for example of adipic acid, polyesters, in particular based on adipic, sebacic, azelaic and phthalic acid acid condensed with 1,3-butanediol, 1,4-butanediol or 1,6-hexanediol, and also phosphoric esters, fatty acid esters and hydroxy carboxylic esters (for example based on citric acid, tartaric acid or lactic acid).

Curing by crosslinking the alkoxysilane groups to form siloxane bridges takes place in the presence of water, which can be directly added in liquid form, for example as a solvent for the catalyst, or can come from the air in the form of atmospheric humidity.

The compositions essential to the invention typically contain, based on dry substance, 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 (11). Preferably, the compositions contain, based on dry substance, 85 to 99.9 parts by weight of silane-terminated polyurethane prepolymer (1) and 0.1 to 15 parts by weiglit of (foam) additive (ll), more preferably 95 to 99.9 parts by weight of (1) and 0.1 to 5 parts by weight of (11).

Auxiliary and adjunct materials (V) are typically added in amounts of 0 to 50 parts by weight, preferably 10 to 40 parts by weight.

Water added for crosslinking beyond ambient moisture 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 preferably less than or equal to 0.75 and more preferably less than or equal to 0.55.

The blowing agent or blowing agent mixture (IV) is typically used in an amount of 1% to 50% by weight, preferably 5% to 40% by weight and more preferably 5% to 20% by weight, the sum total of the employed components (I), (11) and optionally (III), (IV), (V) being 100% by weight.

The mixing of components (I) and (II) can take place in any order, as can the mixture with the optional components (III) to (V).

Preferably, components (I) and (II) and also optionally (III) to (V) are each provided separately;
that is, the reactive component (I) is provided in the absence of water and the optional catalyst (I1I). This gives a composition which is stable in storage at 23 C for at least 6 months (stable in storage is to be understood as meaning an increase in the viscosity of the mixture of less than 50%, preferably less than 25% and more preferably less than 15% based on the starting level of the composition).

Foaming in the process of the invention is accomplished by shaking of the composition, mechanical stirring at high speeds of rotation or by decompressing a blowing gas. After or during foaming, the composition undergoes curing to obtain the desired polyurethane foam. Before complete solidification or curing, i.e. as long as the composition is still flowable, it can be applied to a suitable substrate by common app'lication techniques such as pouring or blade coating. In addition, the composition can be applied directly to human or animal skin, in which case foaming and curing then generally take place simultaneously.

Mechanical foaming can be effected using any desired mechanical stirring, mixing and dispersing techniques. Air is generally introduced in the process, but nitrogen and other gases can also be used for this purpose.

The foam thus obtained is, in the course of foaming or immediately thereafter, applied to a substrate or introduced into a mould and cured.

Application to a substrate can be for e3s:ample by pouring or blade coating, but other conventional techniques are also possible. Multilayer application with optionally intervening curing steps is also possible in principle.

A satisfactory curing rate for the foanis is observed at a temperature as low as 20 C. However, liigher temperatures of preferably more than 30 C can also be employed for faster curing and fixing of the foams, for example with t'he aid of conventional heating and drying apparatus, such as (circulating air) drying cabinets, hot air or IR radiators.

The compositions may be applied, after foaming or while foaming, directly to the skin or, in the course of an industrial manufacture of wound contact materials, to release papers or foils/films which facilitate simple detachment of the wound contact material before its use for covering an injured site.

Application and curing can each be carried out batchwise or continuously, but an entirely continuous process is preferable for the industrial manufacture of wound contact materials.

When the composition is applied directly, by spraying for example, to human or animal skin, curing likewise takes place very rapidly at ambient conditions and as a result of the body's temperature, respectively. The assistance of an external source of heat is similarly possible here, although not preferable.

In one embodiment of the present invention, the sitane-terminated polyurethane prepolymer (I) is mixed with the additive (II) and optionally further, auxiliary and adjunct materials (V). After foaming of the mixture, for example due to mechanical incorporation of air or of some other gas, catalyst (I11) is added, the (foamed) mixture is applied to a suitable substrate and finally cured in the presence of atmospheric humidity. To speed the curing of the foamed mixture, moreover, water can be added, which is preferably done tcigether with the (dissolved) catalyst (III).

In a further embodiment of the present invention, the silane-terminated polyurethane prepolymer (I) is mixed with the additive (II) and optionally further, auxiliary and adjunct materials (V) and transferred into a suitable pressure container, for example a spray can.
Thereafter, the blowing agent (IV) is added; as the mixture is applied to a suitable substrate, it foams and is cured through atmospheric humidity.

In a further embodiment of the present invention, the silane-terminated polyurethane prepolymer (I) is mixed with the additive (II) and optionally further, auxiliary and adjunct materials (V) and transferred into a firs1: chamber of a suitable pressure container, for example into a spray can, the pressure container having at least 2 separate chambers.
Catalyst (III), which is preferably mixed with a suitable amolunt of water, is introduced into a second chamber of the pressure container. The auxiliary and adjunct materials (V) can also be admixed in the second chamber, but this is less preferably. Thten, the blowing agent (IV) is added to either or both of the chambers and, finally, the two-component mixture is applied to a suitable substrate, and at the same time foaming and curing takes place.

Before curing, the foam densities of the polyurethane foams are typically in the range from 50 to 800 g/litre, preferably in the range from 100 to 500 g/litre and more preferably in the range from 100 to 250 g/litre (mass of all input materials [in g] based on the foam volume of one litre).

After drying, the polyurethane foams have a microporous, at least partially open-cell structure comprising intercommunicating cells. The density of the cured foams is typically below 0.4 g/cm3, preferably less than 0.35 g/cm; and more preferably in the range from 0.01 to 0.2 g/cm-.

The DIN EN 13726-1 Part 3.2 physiological saline absorbency is typically 100 and 1500% and preferably in the range from 300 to 800 /0 for the polyurethane foams (mass of liquid taken up, based on mass of dry foam). The DIN EN 13726-2 Part 3.2 vapour transmission rate is typically in the range from 500 to 8000 g/24 h * m2, preferably in the range from 1000 to 6000 g/24 h * m2 and more preferably in the range from 2000 to 5000 g/24 h * m2.

The polyurethane foams exhibit good mechanical strength and high elasticity.
Typically, maximum stress is greater than 0.1 N/mm2 and maximum extension is greater than 100%.
Preferably, extension is greater than 200% (determined according to DIN 53504).

After curing, the thickness of the polyurethane foams is typically in the range from 0.1 mm to 50 mm, preferably in the range from 0.5 mm to 20 mm, more preferably in the range from I to 10 mm and most preferably in the range from 1 to 5 mm.

The polyurethane foams can moreover be adhered, laminated or coated to or with further materials, for example materials based on hydrogels, (semi-) permeable films/foils, coatings, hydrocolloids or other foams.

It is likewise possible to add, incorporate or coat with antimicrobially or biologically active components which for example have a positive effect with regard to wound healing and the avoidance of germ loads.

Examples=

Unless indicated otherwise, all percentages are by weight.

NCO contents were unless expressly mentioned otherwise determined volumetrically in accordance with DIN-EN ISO 11909.

Substances and abbreviations used:
PO propylene oxide EO ethylene oxide DBTL dibutyltin dilaurate Tegostab` B 1048 polyethersiloxane (from Degussa, Dusseldorf, Germany) Aerosil R 9200 finely divided, fumed silica (from Degussa, D'usseldorf, Germany) Mesamoil plasticizer based on an alkylsulphonic ester (from Lanxess, Leverkusen, Germany) Preparation of silane-terminated prepolymer 1(STP 1):

A mixture of 2003.6 g of a difunctional, ethoxylated polyether (OH number 28, molecular weight 4000 g/mol, PO/EO ratio = 6.5), 214.3 g of 3-isocyanatotrimethoxysilane and 133 l of DBTL was heated to 60 C with stirring until the NCO content was 0.

Example 1: Production of a foam by base catalysis 1 17.5 g of STP I and 3.8 g of Tegostab B 1048 were mixed in a plastic beaker using a hand stirrer and foamed to a volume of about 300 ml over 10 min. Thereafter, 2.5 g of aqueous potassium hydroxide solution (1.25 mol/L) were added, whereupon curing took place within 20 s.
A white foam was obtained.

Example 2: Production of foams by acid catalysis a) 1 17.5 g of STP I and 3.8 g of Tegostab'o B 1048 were mixed in a plastic beaker using a hand stirrer and foamed to a volume of about 300 ml over 10 min. Thereafter, 2.5 g of a 5% aqueous solution of p-toluenesulphonic acid were added, whereupon curing took place within 20 s. A white foam was obtained.

b) Experiment a) was repeated with 2 g of a 20% aqueous solution of p-toluenesulphonic acid. Curing to form a white foam took place after just 50 s.

Example 3: Foam with filler and plasticizer A dissolver was used to initially disperse 50 g of Aerosil R 9200 in 1 17.5 g of STP 1(almost transparent dispersion). Thereafter, 25 g of Mesamoll and 3.8 g of Tegostab B 1048 were added, and finally the mixture was foamed in a plastic beaker with a hand stirrer to a volume of about 300 ml over 10 min. After addition of 2.5 g of a 5% aqueous solution of p-toluenesulphonic acid, curing to form a white foam was achieved within 20 s.

Claims (8)

1. Use of foams obtainable from silane-terminated polyurethane prepolymers as wound contact materials.
2. Process for producing wound contact materials wherein a composition comprising a) silane-terminated polyurethane prepolymers (1) comprising more than one alkoxysilane group obtainable by reacting i) polyurethane prepolymers (A) having free isocyanate groups to an average NCO
functionality of at least 1.5 with ii) di- and/or trialkoxysilanes (B) having amino, hydroxyl and/or thiol groups bonded to the silicon atom via an alkylene radical, or iii) polyhydroxy compounds (C) having an average OH functionality of at least 1.5 with iv) di- and/or trialkoxysilanes (D) having isocyanate and/or isothiocyanate groups bonded to the silicon atom via an alkylene radical, b) (foam) additives (II) c) optionally catalysts (III), d) optionally blowing agents (IV), and also e) optionally further, auxiliary and adjunct materials (V) is foamed, applied to a substrate before, during or after foaming and finally cured in the presence of water.
3. Process according to Claim 2, characterized in that the silane-terminated prepolymers (I) are based on polyisocyanates or polyisocyanate mixtures having exclusively aliphatically and/or cycloaliphatically bound isocyanate groups and an average NCO functionality of 2 to 4.
4. Process according to Claim 2 or 3, characterized in that additives (II) comprise nonionic surfactants based on polyether siloxanes.
5. Process according to any one of the Claims 2 to 4, characterized in that the compositions to be foamed comprise, 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 (II) and also 0 to 50 parts by weight of auxiliary and adjunct materials (V).
6. Process according to any one of the Claims 2 to 5, characterized in that water is added for curing, in an amount such that the molar ratio of alkoxysilane groups in the silane-terminated prepolymer to added water is less than or equal to 1.
7. Wound contact materials obtainable by a process according to any one of the Claims 2 to 6.
8. Use of compositions comprising a) silane-terminated polyurethane prepolymers (I) comprising at least one alkoxysilane group b) (foam) additives (II) c) optionally catalysts (III), d) optionally blowing agents (IV), and also e) optionally further, auxiliary and adjunct materials (V) for producing contact materials for wound management.
CA 2692799 2007-07-10 2008-06-27 Process for producing polyurethane foams for wound management Abandoned CA2692799A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP20070013425 EP2014314A1 (en) 2007-07-10 2007-07-10 Method for manufacturing polyurethane foams for treating wounds
EP07013425.9 2007-07-10
PCT/EP2008/005259 WO2009007018A8 (en) 2007-07-10 2008-06-27 Process for producing polyurethane foams for wound management

Publications (1)

Publication Number Publication Date
CA2692799A1 true true CA2692799A1 (en) 2009-01-15

Family

ID=38521740

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2692799 Abandoned CA2692799A1 (en) 2007-07-10 2008-06-27 Process for producing polyurethane foams for wound management

Country Status (7)

Country Link
US (1) US9168324B2 (en)
EP (2) EP2014314A1 (en)
JP (1) JP5192040B2 (en)
KR (1) KR20100035703A (en)
CN (1) CN101687058B (en)
CA (1) CA2692799A1 (en)
WO (1) WO2009007018A8 (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007032342A1 (en) * 2007-07-11 2009-01-15 Bayer Materialscience Ag A process for the production of polyurethane foams based on specific alkoxysilane polymers
DE102009028636A1 (en) * 2009-08-19 2011-02-24 Evonik Goldschmidt Gmbh Novel silylated prepolymers containing urethane groups and methods for their preparation
DE102009028640A1 (en) * 2009-08-19 2011-02-24 Evonik Goldschmidt Gmbh A curable composition containing silylated urethane polymers and their use in sealants and adhesives, binders and / or surface modifiers
US8772567B2 (en) 2010-08-19 2014-07-08 Paul Hartmann Ag Use of a polyurethane foam as a wound dressing in negative pressure therapy
ES2461916T3 (en) * 2010-08-19 2014-05-21 Paul Hartmann Ag Foam dressing containing ointment base and for negative pressure therapy
CN103946259A (en) * 2011-09-29 2014-07-23 拜耳知识产权有限责任公司 Alpha-alkoxysilane-terminated prepolymer for fast-curing spray foams with improved propellant gas solubility
US9572868B2 (en) 2011-09-29 2017-02-21 Covestro Deutschland Ag Fast-setting alkoxysilane spray foams
CN107778442A (en) * 2011-09-29 2018-03-09 科思创德国股份有限公司 Fast curing alkoxysilane spray foam
EP2725044B1 (en) 2012-10-24 2017-06-21 Covestro Deutschland AG Alkoxysilane terminated prepolymer based on polyethercarbonate polyols for spray foams
US20150274918A1 (en) * 2012-10-24 2015-10-01 Bayer Materialscience Ag Multicomponent system for production of alkoxysilane-based spray foams
DE102013107464A1 (en) * 2013-07-15 2015-01-15 Wilhelm Fleischmann wound dressing
DE102015007622A1 (en) * 2015-06-16 2016-12-22 Paul Hartmann Ag An apparatus for vacuum treatment of wounds containing silicone-containing polyurethane foam
WO2017050840A1 (en) * 2015-09-21 2017-03-30 Poly Terra Innovation Gmbh Synthetic foam material comprising silane-terminated polymers

Family Cites Families (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1207594A (en) * 1967-03-16 1970-10-07 Union Carbide Corp One component room temperature vulcanizable silicon terminated polymers
BE789739A (en) * 1971-10-05 1973-04-05 Lock Peter M surgical dressing
US3978266A (en) 1972-10-05 1976-08-31 Ionics Lyo Products Company Surgical dressings
US3979344A (en) * 1974-11-19 1976-09-07 Inmont Corporation Vulcanizable silicon terminated polyurethane polymer composition having improved cure speed
US4222925A (en) * 1978-08-02 1980-09-16 Inmont Corporation Vulcanizable silicon terminated polyurethane polymer compositions having improved cure speed
US4502479A (en) * 1979-09-04 1985-03-05 Minnesota Mining And Manufacturing Company Water-activated casting material
DE3267220D1 (en) 1981-02-13 1985-12-12 Smith & Nephew Ass Wound dressing
JPH0313902B2 (en) * 1981-02-13 1991-02-25 Sumisu Ando Nefuyuu Asosheitetsudo Co Plc
US4619578A (en) * 1985-04-19 1986-10-28 Routledge James H Retractable wheel suspension apparatus
US4667661A (en) * 1985-10-04 1987-05-26 Minnesota Mining And Manufacturing Company Curable resin coated sheet having reduced tack
JPH0363061A (en) * 1989-07-31 1991-03-19 Sanyo Chem Ind Ltd Medical adhesive
GB8917788D0 (en) * 1989-08-03 1989-09-20 Smith & Nephew Adhesive dressing
US5409472A (en) * 1989-08-03 1995-04-25 Smith & Nephew Plc Adhesive polymeric foam dressings
US5423735A (en) * 1993-04-16 1995-06-13 Minnesota Mining And Manufacturing Company Orthopedic cast composed of an alkoxysilane terminated resin
US5603691A (en) * 1993-04-16 1997-02-18 Minnesota Mining And Manufacturing Company Method of using water soluble films in curable casting tapes
JP4260878B2 (en) * 1994-01-21 2009-04-30 スリーエム カンパニー Orthopedic casting tape and a method of manufacturing the same
CA2161712A1 (en) * 1994-11-03 1996-05-04 Ketan N. Shah Silane modified elastomeric compositions and articles made therefrom
GB9505495D0 (en) 1995-03-18 1995-05-03 Smith & Nephew Adhesives
US5984884A (en) * 1997-05-05 1999-11-16 Ebi Medical Systems, Inc. Casting tape article and method for molding casts
US5925004A (en) * 1997-05-05 1999-07-20 Ebi Medical Systems, Inc. Method for controlled lubricant delivery when molding tacky materials
US6369188B1 (en) * 1998-03-27 2002-04-09 Polymeright, Inc. Polyfunctional urethane- or urea-containing oligomers and polymers prepared therefrom
DE19831285A1 (en) * 1998-07-13 2000-01-20 Rathor Ag Appenzell Prepolymer mixture for producing closed sound and heating insulation includes silane-terminated polyurethane prepolymer with alkyl siloxane groups
DE60220591T2 (en) * 2001-07-02 2008-02-14 Tosoh Corp., Shinnanyo A process for producing a rigid polyurethane foam
US6596786B2 (en) * 2001-08-17 2003-07-22 Alcatel Radiation-curable coating composition including oligomeric photoinitiator and/or oligomeric adhesion promoter
DE10204523A1 (en) * 2002-02-05 2003-08-07 Bayer Ag Alkoxysilane and OH-terminated polyurethane prepolymers with a reduced functionality, a process for their preparation and their use
US6979713B2 (en) * 2002-11-25 2005-12-27 3M Innovative Properties Company Curable compositions and abrasive articles therefrom
DE102005041953A1 (en) 2005-09-03 2007-03-08 Bayer Materialscience Ag Low viscosity alkoxysilane prepolymers, a process for their preparation and their use

Also Published As

Publication number Publication date Type
CN101687058B (en) 2016-06-22 grant
EP2014314A1 (en) 2009-01-14 application
KR20100035703A (en) 2010-04-06 application
WO2009007018A8 (en) 2010-01-07 application
EP2175896A1 (en) 2010-04-21 application
WO2009007018A1 (en) 2009-01-15 application
JP5192040B2 (en) 2013-05-08 grant
US20090018480A1 (en) 2009-01-15 application
JP2010532691A (en) 2010-10-14 application
CN101687058A (en) 2010-03-31 application
US9168324B2 (en) 2015-10-27 grant
EP2175896B1 (en) 2015-08-19 grant

Similar Documents

Publication Publication Date Title
US5968995A (en) Polyurethane prepolymer compositions, foams made therefrom and methods of making each thereof
US5554709A (en) Moisture-curing alkoxysilane-terminated polyurethanes
US6642303B2 (en) Polyurethane-polyurea dispersions as coating compositions
US20020062097A1 (en) Polyurethane foam composition and method of manufacture thereof
US20080057316A1 (en) Solid polymeric substrate having adherent resin component derived from curable silylated polyurethane composition
US20020122929A1 (en) Polyurethane foams and method of manufacture thereof
US4945149A (en) Coating composition a non-porous moisture-permeable coating layer or film of a hydrophilic polyurethane resin
US20070270730A1 (en) Polyurethane foams for wound management
US20070254974A1 (en) Production of polyurethane wound dressing foams
US20120029090A1 (en) Modified alkoxylation products having at least one non-terminal alkoxysilyl group, with increased storage life and increased stretchability of the polymers prepared using them
US20060079589A1 (en) Polyurethane foam sheet and process for layered sheet with the same
EP0235949A1 (en) Cohesive dressing
US20110045723A1 (en) Two-component composition for producing flexible polyurethane gelcoats
US4861826A (en) Aqueous polyurethane adhesive dispersions
JP2003129024A (en) Adhesive composition for laminate and the laminate
US20100119775A1 (en) Aqueous dispersions and their use for the production of sheet-like substrates
US4644018A (en) Hydrophilic foam
WO2012022485A1 (en) Use of a polyurethane foam as a wound dressing in negative pressure therapy
US20090092647A1 (en) Polyurethane foams for wound management
CN102206410A (en) Preparation method of high-solid-content aqueous polyurethane for leather
WO1989001346A1 (en) Wound dressings
JP2003246830A (en) Highly durable solvent-free moisture-curing hot-melt urethane resin composition, foam and sheet structure using this
JP2007191628A (en) Thermoplastic polyurethane resin composition and moisture-permeable film
CN1648145A (en) Water base block polyurethane, its preparing method and water-proof, heat insulation and wet permeable material made thereof
US5705547A (en) Moisture-cure urethane adhesives containing γ-butyrolactone

Legal Events

Date Code Title Description
EEER Examination request

Effective date: 20130625

FZDE Dead

Effective date: 20160525