EP2021096A1

EP2021096A1 - Use of tannins in filters

Info

Publication number: EP2021096A1
Application number: EP07712373A
Authority: EP
Inventors: Stephan Hüffer; Oliver Reese; Günter Scherr; Sebastien Garnier
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2006-05-17
Filing date: 2007-02-28
Publication date: 2009-02-11
Also published as: CN101489641B; US20090269378A1; WO2007131812A1; CN101489641A

Abstract

The invention relates to the use of a tannin in or on filters, in particular consisting of natural or synthetic woven fibres or foams, for preventing infections, said filters forming in particular part of respirator masks or respirator equipment.

Description

Use of tannins in filters

description

The present invention relates to the use of a tanning agent in or on filters, in particular natural or synthetic fiber fabrics or foams, for the prevention of infections, which filters are in particular part of respiratory masks or respiratory protective devices. Furthermore, the present invention also relates to the filters as those containing (at least) one tanning agent.

The use of filters in the form of textile protective clothing or protective masks to prevent infections has long been known. The protective effect can serve both the wearer and the environment. The protective effect is mainly based on a retention of germs (pathogens) in the tissue. The problem here is that, for example, by the breath, the body sweat or the ambient air moisture is constantly supplied to the tissue, so that the germs in the tissue may remain active for a long time under certain circumstances. In sudden strong air movements, such as sneezing or deep breath, such agents can leave the tissue or the filter again.

Thus, EP-B 0 859 547 relates to protective equipment such as surgical masks or surgical drapes and other surgical clothing useful for inactivating viruses upon contact. This is achieved by applying to the corresponding fabric substrate a coating of immobilized polymer molecules which provides the fabric substrate with non-leachable antiviral activity, the polymer molecules comprising a hydrophilic polymer having pendant antiviral groups comprising a plurality of pendant cationic groups and a plurality of hydrocarbon moieties. Side chains include and the polymer molecules further comprise the residues of photochemically reactive side groups. The hydrophilic polymer comprising the coating base of the textile substrate may be, for example, a copolymer of vinylpyrrolidone or acrylamide.

US-A-4,897,304 relates to protective clothing against viruses wherein the protective garment is based on cellulosic or non-woven fabric which in turn contains an anionic surfactant and an acid such as citric acid or benzoic acid.

US-A 5,690,949 relates to a microporous membrane which can prevent the passage of viruses. The microporous membrane material comprises a thermoplastic polymer, another compound which is miscible with the thermoplastic polymer, for example, a liquid hydrocarbon such as mineral oil, and a water and oil repellent fluorine-containing compound that allows the barrier to viruses in the membrane.

However, it is also not known that tanning agents can be used to prevent or prevent infections in filters such as natural or synthetic fiber fabrics and microporous membrane materials, which are particularly part of respirators or respirators.

Gerbstoffe can in principle be divided into three main classes (see Rompps Chemie Lexikon, 9th edition (1995), Georg Thieme Verlag Stuttgart, keyword "Gerbstoffe", pages 1541 to 1542):

1. inorganic tanning agents such as chromium (III) salts or polyphosphates; 2. Synthetic organic tanning agents, which are mostly obtainable by sulfonation of solubilized aldehyde condensation products of aromatic bases, in particular of phenol, cresol, naphthalene and naphthol; and 3. tannins of vegetable origin, such as those found in leaves (tea), seeds (coffee), berries, gall or wood. In the narrower sense, tannins of vegetable origin are understood to mean the tannins or tannins, catechins or gallic acid derivatives.

Examples of synthetic tanning agents can be found, for example, in German application no. DE 10 2005 050 193.1 and in EP-A 0 301 406. These documents describe the "classic use" of tannins, ie the tanning of leathers or (animal) skins. However, other uses of tannins, such as a drug, are not disclosed therein.

Both the tanning agents of vegetable origin (hereinafter referred to as vegetable or natural tanning agent) and the synthetic organic tanning agents (hereinafter referred to as synthetic tanning agent) are associated in the literature with the use as Arnzeimittel, in particular with antiviral activity. This applies in particular to vegetable or synthetic tanning agents, which are referred to as so-called polyphenols.

For example, for plant tanning agents such as tannins in T. Okuda, Phytochemistry, Volume 66 (2005), pages 2012 to 2031 or Fukuji et al., Antiviral Res. 11 (1989), pages 285 to 298 an antiviral activity (in particular against Herpes simplex) and an antitumor activity of these natural tanning agents. Further examples of the use of natural tanning agents as drugs can be found in H. Sakagami et al., Anticancer Research 17 (1997), pages 377-380; H. Nakas hima et al., Antiviral Research 18 (1992), pages 91 to 103, and H. Sakagami et al., Anticancer Research 15 (1995), pages 2121 to 2128.

Furthermore, propolis, which is collected from bees from the buds, barks and resins of certain trees and contains vegetable tannins, among others, an antiviral activity, for example, against herpes simplex attributed. Depending on the bee colony, propolis, which is a polyphenol, may contain up to 200 different ingredients, in particular chalkones, flavanones, flavones and flavanols (S. Bogdanov, Swiss Center for Bee Research, article available on the Internet; //www.apis.admin.ch/en/bienenprodukte/docs/products/propolis_e.pdf). Propolis can also act as a protective coating impregnating wood, for example, by coating the outer walls of beehives with concentrated propolis-methylated spirits solution.

Also in the case of synthetic tanning agents, pharmaceutical applications are already known. Thus, WO 95/14479 relates to a condensation polymer of aromatic sulfonic acids and an aldehyde for inhibiting the HIV virus. It is described that the higher the molecular weight of the polymer, the greater its therapeutic activity. Similarly, US Pat. No. 4,604,404 describes the use of sulfonated naphthalene-formaldehyde condensation polymers for controlling the herpes simplex virus.

Furthermore, DE-A 33 41 122 describes externally applicable virucidal drugs, especially against herpes labilis and viral diseases of the skin. These medicines are synthetic tanning agents, produced by condensation of, for example, urea with phenol / cresol, formaldehyde and a sulfonating agent.

DE 10 2004 034613 describes condensation products which are obtainable by reacting at least one aromatic compound, at least one sulfonating agent, at least one carbonyl compound and optionally at least one urea derivative. Following the synthesis, the condensation products are subjected to at least one molecular size-dependent separation process. The condensation product was separated into three fractions, a high molecular weight, a medium molecular weight and a low molecular weight fraction. It has been found that the high molecular weight fractions have improved activity in inhibiting the activity of human leukocyte elastase enzyme than the corresponding mid molecular weight fraction of this condensation product.

The uses of synthetic or vegetable tannins described above relate in particular to their use as (constituent of) a medicinal product. means. The synthetic or vegetable tanning agents are in this context therefore administered to a mammal, in particular humans, for example for oral administration. However, the state of the art does not describe anywhere that tanning agents in general, in particular synthetic or vegetable tanning agents, can also contribute to the prevention of infections outside of the human body (ie without direct administration as medicaments), for example as part of a respiratory mask, a respiratory protective device, a surgical mask or as part of a filter system for air treatment such as in air conditioning systems and locks.

The invention was thus based on the object to provide further filters, for example in the form of natural or synthetic fiber fabrics, in particular as part of a respiratory mask or a respiratory protective device.

According to the invention, this object is achieved by the use of one or more tanning agents in or on filters to prevent infections or by filters as such, containing at least one tanning agent.

An advantage of the present invention is that tannins can be fixed stably on or in the corresponding filters, for example in or on fibrous webs. This is advantageous, in particular, in the case of their use as a component of respiratory masks and respiratory protection devices, since respiratory masks and respiratory protective devices or filter systems known from the prior art are often provided with volatile and / or mucous membrane-irritating substances. Tannins, on the other hand, are neither volatile (or at least only very slightly volatile), nor irritating to the mucous membranes, and in addition fixation on the corresponding filter is easily possible. For this reason, tannins are particularly effective in preventing or preventing infection as well as spreading the infections. The tannins eliminate (largely) the pathogens and thus prevent the penetration of the filters used even under unfavorable conditions. Furthermore, the tanning agents are active for a longer period of time in terms of the properties described above.

In principle, any tanning agent known to the person skilled in the art is suitable as a tanning agent. As already mentioned above, provides Römpp's Chemielexikon, 9th edition (1995), Georg Thieme Verlag, Stuttgart, keyword "tanning", pages 1541 to 1542 an overview of the specialist known Gerbstoffe. Preferably, vegetable or synthetic tanning agents are used in the present invention. Particularly preferred are synthetic tanning agents. Examples of vegetable tanning agents are tannins such as catechins or gallic acid derivatives such as gallate. Vegetable tanning agents based on gallic acid derivatives (such as gallates) differ from the condensation products (A) according to the invention in particular, that the latter have in their chemical structures (a plurality of) -CR ¹ R ² bridges (crosslinks) derived from the carbonyl compound used a2) and are not present in vegetable tannins. If, for example, formaldehyde is used as component a2), the condensation products have (A) -CH ₂ -bridges. Vegetable tanning agents (gallates) are typically oligomeric systems, while the condensation products according to the present invention are preferably polymers.

Preferred vegetable tanning agents are tannins from the group of catechins, epicopes and epigallocatechins and their gallates.

Tannin is understood as meaning, in principle, naturally occurring polyphenols, as described, for example, in T. Okuda Phytochemistry, Volume 66 (2005), pages 2012 to 2031 or Römpp's Chemielexikon, 9th edition (1995), Georg Thieme Verlag, Stuttgart, keyword "tannins", Pages 4452 to 4453 are listed. Preferred tannins are ellagitannins and dehydroellagitannins, in particular geraniin, dehydrogeraniin, furosinin, ascorbican, geraniynic acid, mallotusic acid, pentagalloylglucose, camelliatannin A, casuariin, euphorbin E, camelliatannin F, agrimoniin, trapanin B, oenothein A, oednotine B or Gemin D, lignin and lignosulfonates. Also preferred are catechins, epicatechins and epigallocatechins.

Examples of a suitable catechin or derivatives thereof include in particular flavan-3-ols, flavan-3,4-diols (leucoanthocyanidins) and also flavanones, flavones, chalcones or dihydrocychalcones, epicatechins and epigallocatechins.

Examples of suitable gallic acid derivatives are listed, for example, in H. Sakagami et al, Anticancer Research 17 (1997), pages 377-380. These are preferably gallic acid, methyl tri-O-methyl gallate, tri-O-methyl gallic acid, methyl tri-O-acetyl gallate, methyl gallate, ethyl gallate, n-propyl gallate, isoamyl gallate, lauryl gallate, stearyl gallate, epigallocatechin gallate and gallic acid.

For example, extracts of green tea can be used as vegetable tannins, as are extracts of chestnuts or mimosa.

As a synthetic tanning agent are in principle all tanning agents that can be prepared by synthetic routes. As a synthetic tanning agent not vegetable tanning agents, such as the aforementioned tannins or catechins and Gallussäurenderivate be understood, even if they are also accessible by synthetic routes. Preferred synthetic tanning agents are selected from the condensation products (A) to (C), which are defined below.

Condensation product (A)

Condensation product (A) is obtainable by reaction of

a1) at least one aromatic or heteroaromatic, a2) at least one carbonyl compound, a3) optionally at least one sulfonating agent and a4) optionally at least one urea derivative.

The individual components are defined as follows:

a 1) at least one aromatic or heteroaromatic

Aromatic means compounds having at least one phenyl ring which may be substituted and which may also comprise a plurality of fused phenyl systems, for example naphthyl system, phenanthrene systems and anthracene systems. if appropriate, in the case of bicyclic or polycyclic systems, individual cycles may also be completely or partially saturated, provided that at least one cycle is aromatic.

Heteroaromatics in the present invention are aromatic systems which are preferably monocyclic or bicyclic, and optionally also polycyclic, and which contain at least one heteroatom, preferably selected from nitrogen, oxygen and sulfur. Examples of a heteroaromatic are: pyrrol, furan, thiophene, imidazole, pyrazole, 1, 2,3-triazole, 1, 2,4-triazole, 1, 3-oxazole (= oxazole), 1, 2-oxazole ( = isoxazole), oxadiazole, 1, 3-thiazole (= thiazole), 1, 2-thiazole (= isothiazole), tetrazole, pyridine, pyridazine, pyrimidine, pyrazine, 1, 2,3-triazine, 1, 2,4- Triazine, 1, 3,5-triazine, 1, 2,4,5-tetrazine, indazole, indole, benzothiophene, benzofuran, benzothiazole, benzimidazole, quinoline, isoquinoline, quinazoline, cinnoline, quinoxaline, phthalazine, thienothiophene, 1, 8- Naphthyridine, other naphthyridines, purine or pteridine. Unless they are monocyclic systems, in each of the aforementioned heteroaromatics for the second ring, the saturated form (perhydroform) or the partially unsaturated form (for example, the dihydroform or tetrahydroform) or the maximum unsaturated (not aromatic) form, provided that the respective forms are known and stable. Thus, in the present invention, the term heteroaromatic also includes, for example, bi or polycycles in which (in the case of the bicycle) both rings are aromatic as well as bicycles in which only one ring is aromatic. Such examples of heteroaromatics are: 3H-indoline, 2 (1H) -quinolinone, 4-oxo-i, 4-dihydroquinoline, 2H-1-oxoisoquinoline, 1, 2-dihydroquinoline, 3,4-dihydroquinoline, 1, 2-dihydroisoquinolinyl, 3,4-dihydroisoquinoline, oxindolyl, 1, 2,3,4-tetrahydroisoquinoline, 1, 2,3,4-tetrahydroquinoline, 5,6-dihydroquinoline, 5,6-dihydroisoquinoline, 5,6,7,8-tetrahydroquinoline or 5,6,7,8- tetrahydroisoquinoline.

Preferably, at least one aromatic or heteroaromatic is selected from benzene, naphthalene, anthracene, aromatic alcohols, aromatic ethers and aromatic sulfones.

The aromatic or heteroaromatic (component a1) may be unsubstituted or at least monosubstituted. If one or more substituents are present, they are independently selected from C 1 -C 10 -alkyl groups such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n -Pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1, 2-dimethylpropyl, iso-amyl, n-hexyl, iso -hexyl, sec-hexyl, n-heptyl, n-octyl, 2-ethylhexyl , n-nonyl, n-decyl; particularly preferably C 1 -C ₄ -alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl,

C ₂ -C alkenyl groups, in particular vinyl, 1-allyl, 3-allyl, 2-allyl, cis- or trans-2-butenyl, ω-butenyl,

C ₆ -C ₄ aryl groups aryl, such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl and 9 Phenanthryl, preferably phenyl, 1-naphthyl and 2-naphthyl, more preferably phenyl,

or benzyl groups.

Examples of preferred aromatics or heteroaromatics are:

Benzene, toluene, ortho-xylene, meta-xylene, para-xylene, ethylbenzene, cumene, para-methylcumene, biphenyl, 2-methylbiphenyl, 3-methylbiphenyl, 4-methylbiphenyl, bitolyl (4,4'-dimethylbiphenyl), para- Terphenyl, indene, fluorene, methylindenes (mixture of isomers). Naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1, 8-dimethylnaphthalene, 2,7-dimethylnaphthalene, phenanthrene, anthracene, 9-methylanthracene, 9-phenyl-anthracene.

Examples of aromatic alcohols which may be mentioned are: phenol, ortho-cresol, meta-

Cresol, para-cresol, 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 3,4-dimethylphenol, 3, 5

Dimethylphenol, gallic acid (trihydroxybenzoic acid) α-naphthol, β-naphthol, 9- Hydroxyanthracene as a tautomer of anthrone, 9-hydroxyphenanthrene, diphenylmethane, phenyl (2-methylphenyl) methane, phenylparatolylmethane, phenylmetatolylmethane.

Examples of aromatic ethers which may be mentioned are: diphenyl ether, di-ortho-tolyl ether, di-meta-tolyl ether and di-para-tolyl ether.

Examples of aromatic sulfones include diphenylsulfone and 4,4'-dihydroxydiphenylsulfone.

The component a1) is particularly preferably at least one compound selected from phenol, phenolsulfonic acid, 4,4'-dihydroxydiphenylsulfone and gallic acid.

In one embodiment of the present invention, mixtures of at least 2 aromatics are used as component a1), for example mixtures of naphthalene and phenol, naphthalene and cresol (mixture of isomers), naphthalene and diphenyl ether, naphthalene and ditolyl ether or phenol and ditolyl ether.

a2) at least one carbonyl compound

selected from aldehydes and ketones, preferably with at least one aldehyde such as

Formaldehyde, acetaldehyde or propionaldehyde and in particular with formaldehyde.

If it is desired to use formaldehyde, it is preferred to use formaldehyde in aqueous solution.

a3) optionally at least one sulfonating agent

Suitable sulfonating agents are, for example, sulfuric acid, in particular concentrated sulfuric acid, furthermore oleum having an SO ₃ content of from 1 to 30% by weight, furthermore chlorosulfonic acid and sulfamic acid. Preference is given to concentrated sulfuric acid and oleum containing from 1 to 15% by weight of SO ₃ .

a4) optionally at least one urea derivative

In principle, urea and all derivatives thereof are suitable as component a4). Preference is given to a urea derivative which carries at least one hydrogen atom on each nitrogen atom.

At least one urea derivative is particularly preferably selected from compounds of the general formula (I) O

I i

R1 R2

in which the variables are defined as follows: X ¹ , X ² are different or preferably the same and are selected from hydrogen and

-CH ₂ OH,

R ¹ , R ² are different or preferably identical and selected from hydrogen, C 1 -C 10 -alkyl, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert. Butyl, n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1, 2-dimethylpropyl, iso-amyl, n-hexyl, iso-hexyl, sec-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-

decyl; particularly preferably C 1 -C ₄ -alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, or

R ¹ and R ² together form a C ₂ -Cio-alkylene unit, unsubstituted or substituted with 2 to 5 hydroxyl groups, such as - (CH ₂ ) ₂ -, -CH ₂ -CH (CH ₃ ) -, - (CH ₂ ) ₃ -, -CH ₂ -CH (C ₂ H ₅ ) -, - (CH ₂ J ₄ -, - (CH ₂ ) ₅ -, - (CH ₂ ) ₆ -, - (CH ₂ ) ₇ -, - ( CH ₂ ) ₈ -, - (CH ₂ ) ₉ -, - (CH-OH) ₂ -

(cis or trans), preferably C ₂ -C ₄ -alkylene; in particular - (CH ₂ ) ₂ -, - (CH ₂ ) ₃ -, and

- (CH-OH) ₂ - (ice or trans).

Very particular preference is given to (unsubstituted) urea, melamine or the cyclic urea derivatives of the formulas 1.1, 1.2 or 1.3.

1.1 I.2 I.3

Processes for the preparation of a condensation product (A) are known to the person skilled in the art, for example they are described in DE-A 10 2004 034 631, DE-A 1 1 13 457, EP-A 26314 and in Ullmann ^'s Encyclopedia of Industrial Chemistry, Volume A15, pages 259-282, δ.Auflage, (1990), Verlag Chemie Weinheim.

In principle, you can implement the individual output components in any order. For example, in one embodiment of the present invention, one or more further reactants a5) can also be added during the reaction, for example NaHSO ₃ , Na ₂ S ₂ O ₅ , KHSO ₃ , K ₂ S ₂ O ₅ , aqueous alkali metal hydroxide. solution, in particular aqueous sodium hydroxide solution and aqueous potassium hydroxide solution, and aqueous ammonia. The reactant a5) is used in particular for adjusting the pH and for controlling the solubility of the end product

In a further embodiment of the present invention, in the preparation of the condensation product (A) after reaction of the components a1) and a2) and optionally a3) and a4), a molecular size-dependent separation process can be carried out, preferably an ultrafiltration, giving individual fractions of the condensation product (A ), for example, a low molecular weight, a medium molecular weight and a high molecular weight fraction. The high molecular weight fraction has, for example, an M _w value> 9000 g / mol (M _w = weight-average molecular weight), preferably an M _w value of 10,000 to 100,000 g / mol. The low molecular weight fraction preferably has an M _w value of 300 to 3000 g / mol.

Suitable molecular size-dependent separation processes are, for example, preparative gel permeation chromatography and membrane separation processes such as microfiltration, nanofiltration and, in particular, ultrafiltration. Combinations of microfiltration and ultrafiltration are also suitable. Microfiltration and ultrafiltration and membranes required for this purpose are known as such and described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, Vol. 21, Wiley-VCH Weinheim, pages 243-321. Nanofiltration and the associated membranes are known as those likewise known and described in R. Rautenbach, "Membrane Process", Springer Verlag Berlin Heidelberg 1997. The exact execution of the separation of the condensation product (A) into individual fractions as a function of the molecular weight is known to the person skilled in the art and, for example, in DE-A 10 2004 034 613.

Condensation product (B)

Condensation product (B) is obtainable by reaction of

b1) at least one cyclic organic carbonate with b2) at least one compound having at least two nucleophilic groups per molecule, selected from sulfonic acid, hydroxyl, primary or secondary amino or mercapto groups.

The condensation product (B) preferably has an M _w value of between 300 and 3000 g / mol.

Condensation products (B) as such and processes for their preparation are known in the art, they are for example in the German application with the Number DE 10 2005 050 193.1 is disclosed and incorporated by reference in the present invention.

In the context of the present invention, cyclic organic carbonates (component b1) are understood as meaning organic carbonic acid esters which have at least one cyclic group.

Cyclic organic carbonates are preferably those organic carbonic acid esters in which the carbonic ester group is part of a cyclic system.

In one embodiment of the present invention, cyclic organic carbonate (b1)) is selected from compounds of the general formula (II)

where the variables are defined as follows:

R ¹ selected from C ¹ -C ₄ -alkyl, branched or preferably linear, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, very preferably methyl and Ethyl, and most preferably hydrogen,

R ^{2 is} optionally different or preferably identical and independently selected from hydrogen and C 1 -C ₄ -alkyl, branched or preferably linear, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl

Butyl, tert-butyl, most preferably methyl and ethyl, and most preferably each same and hydrogen,

a is an integer in the range of 1 to 3, preferably 2 and more preferably 1.

Particularly preferred cyclic organic carbonates b1) are propylene carbonate, ethylene carbonate. Mixtures of propylene carbonate (R ¹ = methyl, R ² = hydrogen, a = 1) and ethylene carbonate (R ¹ = R ² = hydrogen, a = 1), in particular at room temperature liquid mixtures of propylene carbonate and ethylene carbonate are also particularly preferred.

Component b2) is understood as meaning compounds which have two groups which are capable of nucleophilic reactions, for example sulfonic acid groups, hydroxyl groups, mercapto groups or primary or secondary amino groups. Examples of suitable compounds b2) may comprise: at least two nucleophilic hydroxyl groups per molecule, at least two nucleophilic mercapto groups per molecule, at least two nucleophilic primary or secondary amino groups per molecule, for example two or three nucleophilic primary or secondary amino groups per molecule, at least one nucleophilic hydroxyl group or Mercapto group and at least one nucleophilic primary or secondary amino group per molecule or at least one nucleophilic hydroxyl group and at least one nucleophilic mercapto group per molecule,

at least one nucleophilic hydroxyl group or primary or secondary amino group and one sulfonic acid group per molecule.

Sulfuric acid is not a compound b2) in the context of the present invention.

Examples of nucleophilic hydroxyl groups are OH groups of primary and secondary alcohols and in particular phenolic OH groups. Examples of nucleophilic mercapto groups are SH groups, aliphatic or aromatic.

Examples of nucleophilic amino groups are -NHR ³ groups, aliphatic or aromatic, wherein R ^{3 is} selected from hydrogen, C 1 -C ₄ -alkyl, as defined above, and CN, or the NH ₂ -group of, for example, amidosulfonic acid.

OH groups and NH groups which are constituents of aminal groups, semiaminal groups or hydrate groups of ketones or aldehydes are not nucleophilic hydroxyl groups or amino groups in the context of the present invention. OH groups and NH groups which are constituents of carboxylic acid groups or carboxamide groups are also not nucleophilic hydroxyl groups or amino groups in the sense of the present invention.

Preferred examples of compounds b2) are

i) ureas, unsubstituted or mono- or disubstituted N, N'-substituted with CrC ₄ -

Alkyl, biuret, in particular unsubstituted urea, ii) heterocyclic compounds having at least two NH ₂ groups per molecule, for example adenine and in particular melamine, iii) benzoguanamine, dicyandiamide, guanidine, iv) compounds of the general formula (III)

in which A is a divalent group, for example -CH ₂ -, -CH ₂ CH ₂ -, -CH (CH ₃ ) -, -C (CH ₃ ) ₂ -, -CO-, -SO ₂ -, preferably 4, 4'-dihydroxybiphenyl, 2,4'-dihydroxydiphenylsulfone, more preferably 4,4'-dihydroxydiphenylsulfone, mixtures of 4,4'-dihydroxydiphenylsulfone and 2,4'-dihydroxydiphenylsulfone, for example in a weight ratio of 8: 1 to 8: 1, 5, and bisphenol A.

Further preferred examples of compound b2) are 4-hydroxyphenylsulfonic acid and amidosulfonic acid.

Particularly preferred compounds b2) are selected from melamine, biuret, dicyandiamide, amidosulfonic acid, and 4,4 ^" dihydroxydiphenyl sulfone.

Condensation product (C)

Condensation product (C) is obtainable by reaction of

d) melamine, and / or urea c2) glyoxal, glyoxylic acid and / or an alkali salt thereof, c3) optionally at least one aromatic compound having at least one phenolic hydroxyl group and c4) optionally at least one condensable compound having a reactive nitrogen-containing group.

The condensation product (C) preferably has an M _w value of between 300 and 3000 g / mol.

The condensation products (C) as such and processes for their preparation are known in the art. For example, these are described in EP-A 0 301 406 and are incorporated by reference in the present invention.

Suitable components c3) are, for example, phenolsulfonic acid, sulfosalicylic acid, salicylic acid and 8-hydroxyquinoline. Suitable as component c4) are carboxylic acid amides, sulfonic acid amides, imides, ureas, amino and imino acids and dialkylamines and dialkanolamines. Examples are acetamide, benzoic acid amide, formamide, Amidosulphonic acid, succinimide, glycine, iminodiacetic acid, phenylglycine, urea, dicyandiamide, diethanolamine or diethylamine. Acidic compounds can be condensed in the form of their alkali metal salts. Particularly preferred as component c4) acetamide and amidosulfonic acid.

A preferred condensation product (C) is obtainable by reacting

c1) melamine and / or urea) and c2) glyoxal and / or glyoxylic acid, and also c4) optionally amidosulfonic acid.

In a preferred embodiment of the present invention, a tanning agent is used which contains at least one hydroxyl group or is substituted by such a group. In the case of the condensation products (A), (B) or (C), this is preferably achieved by

component a1) contains at least one compound which is substituted by at least one hydroxyl group and / or component b2) contains at least one compound which is substituted by at least one hydroxyl group and / or component c3) is present.

In the context of the present invention, the term filter will in principle be understood to mean any type of materials (substrates or filter base) which exert a filter effect. Preferably, the filter comprises a natural or synthetic fibrous web, a foam, a film, a textile, polymeric fibers and / or a matrix having voids within the matrix. The filter may comprise one or more of these preferred components, if appropriate, the filter may also be formed completely from one or more of these components. The term "fiber fabric" is intended to include such fiber fabrics that are not textiles, as well as the term "textile" should also include those textiles that are not fiber fabrics. Films are preferably porous, polymer fibers are preferably water-insoluble. Fiber tissues can be natural or vegetable. Particularly preferred filters are foams or natural or synthesized fibrous webs. As a filter, especially as natural or synthetic fiber tissue but not hides, especially derived from animals hides and wood or wood products should be understood.

The natural or synthetic fiber fabric is preferably woven or non-woven fiber fabric, in particular cellulose,

Cellulose derivatives, cotton, fleece, wool, silk, polyamides (nylon), polypropylene, Polyester, other plastics (eg viscose, acetate (partially synthetic), polyacrylates, polyvinyl chloride (PVC) and blends of polymers) and glass fibers. The fibers may also be interconnected via a polymer matrix.

Foam should preferably be understood as meaning polyurethane-amino resin condensates which preferably form a microporous and / or open-pore system. Particularly preferred are melamine-formaldehyde condensates. Foams as such are known to the person skilled in the art.

Suitable fiber-based filter materials are commercially available, e.g. from Freudenberg Faserfliesstoffe KG (Weinheim, Germany), Sontara Technologies (subsidiary of DuPont Corporation, Old Hickory, Tenn., USA), Lystil S.A. (Brignoud Cedex, France), Dexter Nonwovens (Windsor Locks, Conn., USA). Suitable foam-based filter materials can be obtained, for example, under the trademark Basotect® from BASF AG (Ludwigshafen, Germany).

Another object of the present invention is thus a filter as such, containing at least one tanning agent (according to the above definitions with respect tannins).

Preferably, the filter is part of a respirator or a respirator or a filter system, for example, from an air conditioner. Optionally, the filter may also fully form the respirator or respirator. It is also possible to use the filter (article) in a multi-ply design, among others. equipped with foamed, open-pore polymer inserts. These foamed polymers (polyurethanes, melamine-formaldehyde condensates such as Basotect® from BASF AG) can also serve to receive the active substrate according to the invention in the form of a surface coating.

Furthermore, the filters according to the invention can also be part of surgical articles, in particular surgical drapes or surgical masks, or the filters according to the invention can form these objects completely. A method for producing a filter, for example a fiber fabric, and methods for producing respiratory masks, respiratory protective devices or surgical articles or the introduction of the corresponding filters in respiratory masks, respiratory protective devices or surgical articles are known in the art. Furthermore, it is also known to the person skilled in the art how tanning agents can be applied to objects, such as leather. The tanning agent (s) may, according to the present invention, be applied or incorporated, in particular incorporated, in or on the filter, in particular the fiber fabric. If the tanning agent is applied to the fiber fabric, it is preferably in the form of a coating. Preferably, the filter or the fiber fabric is drummed or sprayed with an aqueous solution of one or more tanning agents or treated by roll coating. For example, the coating may be applied to the article or to the article itself prior to processing a textile. Also conceivable is a process in which the fibers are adequately impregnated / coated during or immediately after fiber production (for example in the case of viscose, nylon or polypropylene (PP) fibers). Optionally, the tanning agent (s) may also be incorporated into the fibrous web and the fibrous web is covered with another fibrous web which may be the same or different.

The presence of one or more tanning agents in or on filters, especially natural or synthetic fiber fabrics or foams, results in avoidance of infection. This applies in particular if the corresponding filter is part of a respiratory mask or respiratory protective device or completely forms it. By using the tanning agents, a depletion and / or elimination of germs such as viruses or bacteria from the air, in particular from the breath, can be achieved.

The invention will be illustrated by the following examples.

Examples

Synthesis Examples Formaldehvdfreier low molecular weight tanning agent

Example NM1 condensation product (C)

reactants:

urea

glyoxal

33.0 g (549 mmol) of urea are dissolved in 180 ml of water in a flask and heated to 50 ° C. with stirring. At this temperature, 218 g (1, 50 mol) of glyoxal solution (40%) are added and a further 30 min. touched. After cooling to room temperature, a pH of 5 is set with sodium hydroxide solution (50%). This gives about 430 g of a clear solution with a solids content of 28%. M _w = 2850 g / mol, M _w / M _n = 1 1, 3 with M _w = weight-average molecular weight, M _n = number-average molecular weight. Example NM2 condensation product (C)

Reactants: melamine glyoxal

A mixture of 193.0 g of 40% strength aqueous glyoxal solution (1.33 mol) and 21.0 g of melamine (0.17 mol) is heated for 15 min. to 40 ° C, creating a clear solution. It is then cooled and adjusted with 31, 5 g of water to a solids content of calculated 40% M _w = 2640 g / mol, MJM _n = 8.8.

Example NM3 condensation product (B)

Reactants: melamine

Ethylene carbonate sulfuric acid

24.0 g (190 mmol) of melamine, 200 g (2.27 mol) of ethylene carbonate and 1.40 g (17.5 mmol) of aqueous sodium hydroxide solution (50% by weight) are placed in a flask and heated to boiling point

Stirring at 170 ° C. The resulting mixture is stirred at 170 ° C until no gas evolution is observed. It is then cooled to room temperature and 102 g of water are added. With aqueous sulfuric acid (50 wt .-%), a pH of 5 is set. This gives about 250 g of condensation product (B), solids content: 48% M _w = 960 g / mol, MJM _n = 3.6.

Example NM4 condensation product (B)

Reactants: urea

ethylene

potassium carbonate

sulfuric acid

7.60 g (127 mmol) of urea, 200 g (2.27 mol) of ethylene carbonate and 1.5 g (10.9 mmol) of potassium carbonate are placed in a flask and heated to 170 ° C. with stirring. The resulting mixture is stirred at 170 ° C until no gas evolution is observed. The mixture is then cooled to room temperature, 125 g of water are added and adjusted to pH 5 with aqueous sulfuric acid (50 wt .-%). 250 g of condensation product (B) are obtained. Solids content: 47%, M _w = 1920 g / mol, MJM _n = 4.8. Examples of condensation products (A)

General preliminary remarks:

Solutions are always understood to mean aqueous solutions, unless expressly specified otherwise. ppm always refer to parts by weight.

The molecular weight determinations are carried out by gel permeation chromatography (GPC):

Stationary phase: poly (2-hydroxymethacrylate) gel crosslinked with ethylene glycol dimethacrylate, commercially available as HEMA BIO from PSS, Mainz, Germany.

Eluent: Mixture of 30% by weight of tetrahydrofuran (THF), 10% by weight of acrylonitrile, 60

% By weight 1 molar NaNO ₃ solution Internal standard: 0.001% by weight of benzophenone, based on the mobile phase

Flow: 1, 5 ml / min

Concentration: 1% by weight in eluent with internal standard Detection: UV / Vis spectrometry at 254 nm Calibration with polystyrene calibration part from PSS. M _n : number average molecular weight in [g / mol] M _w : weight average molecular weight in [g / mol]

For the determination of free formaldehyde, a Huber flow-injection apparatus is used, s. Fresenius Z. Anal. Chem. 1981, 309, 389. The column used is a thermostatted reaction column 17O × 10 mm, filled with glass beads which are operated at 75 ° C. The detector (flow detector) is set to a wavelength of 412 nm. The procedure is as follows:

To prepare a reagent solution, dissolve 62.5 g of ammonium acetate in 500 ml of distilled water, add 7.5 ml of concentrated acetic acid and 5.0 ml of acetylacetone and make up to 1000 ml with distilled water.

In a 10 ml volumetric flask, weigh 0.1 g of the condensation product to be analyzed, make up to 10 ml with distilled water and obtain the respective sample solution.

Each 100 .mu.l sample solution, mix it with reagent solution and sets a mean residence time of 1, 5 minutes, which corresponds to a flow of 35 ml / min.

To determine the absolute values, the flow-injection apparatus is calibrated with formaldehyde solutions of known content. 1. Preparation of reaction solutions

1.1 Preparation of Reaction Solution 1.1

Reactants: a) phenol, b) concentrated sulfuric acid, c) formaldehyde, d) urea

Action:

2.04 kg of phenol are initially charged in a stirred apparatus and 2.48 kg of concentrated sulfuric acid (96 wt .-%) are added over 20 minutes. Care is taken to ensure that the temperature does not exceed 105 ° C. Subsequently, the reaction mixture is stirred for 2 hours at 100 to 105 ° C and then diluted with 0.34 kg of water at 20 ° C and cooled to 70 ° C. 2.06 kg of aqueous urea solution (68% by weight) are metered in, during which the temperature rises to 95 ° C .; then cooled to 75 ° C. Over a period of 90 minutes 4.10 kg of aqueous formaldehyde solution (30 wt .-%) are added, taking care that the temperature does not rise above 75 ° C. It is then partially neutralized with 0.78 kg of aqueous sodium hydroxide solution (50% by weight), 0.30 kg of water are added, the mixture is stirred for 30 minutes and cooled further. At a temperature of 50 ° C, 1.36 kg of phenol are added. At 50 ° C then 1, 14 kg aqueous formaldehyde solution (30% by weight) are added over 20 minutes and then stirred at 55 ° C for 30 minutes. The final adjustment of concentration and pH is carried out by adding 1.40 kg of sodium hydroxide solution (50% by weight) and 2.5 kg of water. This gives 18.5 kg of reaction solution 1.1 with 43 wt .-% nonvolatile fractions.

The analysis of the reaction solution 1.1 gives the following values:

Sodium sulfate by IC (in terms of nonvolatiles): 6.8% by weight;

Phenol by HPLC (based on nonvolatiles): 0.36 wt%;

4-phenolsulfonic acid by HPLC (based on non-volatile content): 2.89% by weight; free formaldehyde: 75 ppm, based on non-volatile components.

M _n = 890 g / mol, M _w = 7820 g / mol, determined by GPC.

1.2 Preparation of reaction solution

Reactants: a) Dioxide diphenyl sulphone b) sodium sulfite c) formaldehyde d) sodium hydrogen sulfate

1, 3 l of water are placed in a stirring apparatus and 4.1 kg Dioxidiphenylsulfon- mixture (58 wt .-%) are added. The pH should be above 7.0. 0.8 kg of sodium sulfite are then added and 1, 155 kg of formaldehyde (30 wt .-%) added. If necessary, the solution is neutralized with sodium hydroxide to a pH of 8.0 to 8.5. The stirrer is then closed and heated to the set point of 1 15 ° C. The onset of exothermic reaction, the internal temperature rise to 150 - 155 ° C and the reactor pressure to 4 - 4.5 bar. After reaching the internal temperature of 150 ° C set temperature is retraced to 150 ° C and maintained the reactor contents for 8 hours at 150 ° C, before the solution is cooled with stirring to 70 ° C. 400 g of sodium bisulfate are then added to the solution. This gives 7.8 kg of product with 47 wt .-% of nonvolatile fractions.

The analysis of product 1.2.1 gives the following values: M _n = 640 g / mol, M _w = 3920 g / mol, determined by GPC.

1.3 Preparation of Reaction Solution 1.3

Reactants: a) phenol, b) concentrated sulfuric acid, c) formaldehyde, d) urea

Action:

2.04 kg of phenol are initially charged in a stirred apparatus and 2.48 kg of concentrated sulfuric acid (96 wt .-%) are added over 20 minutes. Care is taken that the temperature does not exceed 105 ° C. Subsequently, the reaction mixture is stirred for 2 hours at 100 to 105 ° C and then diluted with 340 g of water. 2.05 kg of urea solution (68% by weight) are metered in, taking care that the temperature does not exceed 95 ° C. Then 3.60 kg of aqueous formaldehyde solution (30 wt .-%) are added over a period of 1, 5 hours at 83 to 93 ° C. After stirring for 15 minutes, 800 g of aqueous sodium hydroxide solution (50% by weight) are added, taking care that the temperature does not exceed 85 ° C., so that the pH is then between 7.3 and 7.5. 11.3 kg of reaction solution 1.3 are obtained with 47% by weight of non-volatile constituents. The analysis of the reaction solution 1.3 gives the following values:

Sodium sulfate by IC (in terms of nonvolatiles): 10.3 wt%; Phenol by HPLC (relative to non-volatile content): 0.74 wt%; 4-phenolsulfonic acid by HPLC (relative to non-volatile fractions): 1.36% by weight; free formaldehyde: 99 ppm, based on non-volatile components. M _n = 1990 g / mol, M _w = 17,020 g / mol, determined by GPC.

Filter containing at least one tanning agent

Equipment of cotton and mixed fabrics with synthetic and / or vegetable tannins:

The fabrics are treated with an aqueous solution of the tanning agent or tanning agents, so that after drying a sufficiently large, uniformly distributed amount of tanning agent remains in the tissue.

Method:

The tissues are 60 min. drummed at 50 ° C in a 40% tannin solution. They are then at 60 ° C for 90 min. dried long in a dry air stream. The following fabrics / tiles are used in the examples: a) cotton fleece from Freudenberg (Weinheim, Germany), b) Freudenberg's polycellulose fleece, c) polypropylene fleece from Freudenberg.

Filling foams with synthetic and / or vegetable tannins:

A microporous foam (Basotect from BASF AG, cut into 100 mm × 100 mm × 7 mm slices) is mixed with 25 ml of the tannin solutions. Soaked table and left at 50 ° C for 30 minutes. The excess solution is removed by squeezing between tissue sheets (15 g of the original solution). The moist foams are dried at 60 ° C for 90 minutes in a stream of air. The weight gain is typically 2.5 - 4 g.

Examples

Examples 1-6 describe typical formulations for the treatment of the filter substrates, wherein the treatment can be carried out both by spraying and by impregnation. Fixing takes place by drying at 60 ° C in a drying cabinet or in a stream of dry air. The compounds 1.1 and 1.2 are listed above as an example of a condensation product (A). example 1

Example 2

Example 3

Chestnut extract (powder, Silvachimica srl, Italy, S.Michele Mondovi)

Example 4

Mimosa extract (powder, Silvachimica srl, Italy, S.Michele Mondovi) Example 5

Example 6

^* Green tea extract

6 different tanning agent formulations (Examples 1-6) including chestnut extract and epigallocatechin gallate (green tea extract) are applied to 3 different carrier substrates (non-woven cellulose, Freudenberg, PP-Flies (Freudenberg) and Basotect-Schaum (BASF AG)

The test for the inhibition of viral activity is carried out as far as possible in accordance with test procedures EN 14675. Avian influenza A virus (A / carduelis, H7N 1).

First, the filter substrates as described above are flowed through at 15 ° C at 35 ° C with water vapor-saturated air (35 ° C). The virus suspension is then sprayed onto the filters and passed through with humid air (35 ° C) for a further 30 minutes. Before determining the titer, the filters are cut into small pieces a 10 X 10 mm and taken up in a container with 50 ml of deionized water.

The zero value (negative control) is determined in each case on the basis of the non-impregnated carrier. The impregnated filters consistently deliver significantly lower virus titers.

Table 1: Virus activity against avian influenza A virus on different filter substrates with and without (negative control) or different impregnation

Claims

claims

1. Use of one or more tanning agents in or on a filter to avoid infections.

Use according to claim 1, characterized in that the filter comprises a natural or synthetic fibrous web, a foam, a film, a textile, polymeric fibers and / or a matrix with voids within the matrix.

3. Use according to claim 1 or 2, characterized in that the filter is part of a respirator, a respirator, a surgical drape or a surgical mask or that the filter forms each of these items completely.

4. Use according to any one of claims 1 to 3, wherein a depletion and / or elimination of germs such as viruses or bacteria from the air, in particular from the respiratory air, is achieved by the tanning agent.

5. Use according to one of claims 1 to 4, characterized in that it is the woven or non-woven fiber fabric, in particular those of cellulose, cellulose derivatives, cotton, fleece, wool, silk, polyamides, polypropylene, in the natural or synthetic fiber fabric, Polyester, other plastics or glass fibers and / or the foam is a polyurea-amino resin condensate, in particular a melamine-formaldehyde condensate

6. Filter containing at least one tanning agent.

A filter according to claim 6, characterized in that the filter comprises a natural or synthetic fibrous web, a foam, a film, a textile, polymeric fibers and / or a matrix with voids within the matrix.

8. Filter according to claim 6 or 7, characterized in that the filter is part of a respirator, a respirator, a surgical drape or a surgical mask or that the filter completely forms these objects.

9. Filter according to any one of claims 6 to 8, characterized in that it is the woven or natural or synthetic fiber fabric nonwoven fibrous webs, especially those of cellulose, cellulose derivatives, cotton, fleece, wool, silk, polyamides, polypropylene, polyesters, other plastics or glass fibers and / or the foam is a polyurethane-amino resin condensate, in particular a melamine-formaldehyde Condensate, is

10. A filter according to any one of claims 6 to 9, characterized in that it is the tanning agent is a synthetic or vegetable tanning agent.

11. The filter according to claim 6, wherein the vegetable tanning agent is i) a tannin, in particular a catechin, epicatechin or epigallocatechin or ii) a gallic acid derivative.

12. A filter according to any one of claims 6 to 1 1, characterized in that it is the synthetic tanning agent is at least one condensation product selected from:

Condensation product (A) obtainable by reaction of

a1) at least one aromatic or heteroaromatic, a2) at least one carbonyl compound, a3) optionally at least one sulfonating agent and a4) optionally at least one urea derivative,

Condensation product (B) obtainable by reaction of

b1) at least one cyclic organic carbonate having b2) at least one compound having at least two nucleophilic groups per molecule, selected from sulfonic acid, hydroxyl, primary or secondary amino or mercapto groups,

or

Condensation product (C) obtainable by reaction of

d) melamine and / or urea, c2) glyoxal, glyoxylic acid and / or an alkali metal salt thereof, c3) optionally at least one aromatic compound having at least one phenolic hydroxyl group and c4) optionally at least one condensable compound having a reactive nitrogen-containing group.

13. A filter according to any one of claims 6 to 12, characterized in that the tanning agent is introduced into the filter and / or applied to the filter in the form of a coating.

14. A method for producing a filter according to any one of claims 6 to 13, characterized in that at least one tanning agent is applied to the filter or introduced into the filter.

15. The method according to claim 14, characterized in that the filter is drummed with an aqueous solution of one or more tannins, sprayed or treated by roll coating method.

16. Use of a filter according to any one of claims 6 to 13 for the prevention of infections.