EP2137275A1

EP2137275A1 - Rapidly curing cyanacrylates as adhesives

Info

Publication number: EP2137275A1
Application number: EP08735982A
Authority: EP
Inventors: Noeleen B. Swords; Louise Gilbride; Colette Hoare
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2007-04-18
Filing date: 2008-04-09
Publication date: 2009-12-30
Also published as: WO2008128888A1; US20100029978A1

Abstract

The present invention relates to a polymerizable adhesive composition which comprises, at least as one constituent, a cyanacrylate component and which requires a comparatively short time for curing when used on surfaces. The present invention therefore also includes a method for the production of the cyanacrylate component described above, and the cyanacrylate component as such.

Description

Fast-curing cyanoacrylates as adhesives

The present invention relates to a polymerizable adhesive composition comprising, as at least one component, a cyanoacrylate component and having no overstabilization by a polymerization inhibitor, so that when used on surfaces, a comparatively short time is required for curing. The present invention therefore also includes a process for preparing the above-described cyanoacrylate component and the cyanoacrylate component as such.

State of the art

Cyanoacrylate-based polymerizable monomeric adhesive compositions have found wide use in both industrial and medical applications because of their ease of use, as well as the high rate of cure and strength of the resulting adhesive bond. It is known that monomeric forms of cyanoacrylates are extremely reactive and polymerize rapidly in the presence of even minute amounts of a polymerization initiator, including airborne or surface moisture. The polymerization is initiated by anions, free radicals, zwitterions or ion pairs. Once the polymerization has been started, the cure speed can be very high. Cyanoacrylate-based polymerizable monomeric adhesive compositions have therefore been found to be attractive, for example, in joining plastics, rubbers, glass, metals, wood, and more recently, biological tissues. Medical applications of cyanoacrylate-based monomeric adhesive compositions include both use as an alternative or in addition to surgical sutures and staples for closing wounds, as well as a use for covering and protecting surface wounds such as lacerations, abrasions, burns, stomatitis, inflammation and other open surface wounds.

Thus, U.S. Patent Nos. 5,328,687 to Leung et al., 3,527,841 to Wicker et al., 3,722,599 to Robertson et al., 3,995,641 to Kronenthal et al. and 3,940,362 to Overhults, by way of example, of monomeric cyanoacrylates which are useful as surgical adhesives. In the medical use of a cyanoacrylate-based adhesive composition, the use is usually in monomeric form. The anionic in situ polymerization directly following the tissue surface then leads to wound bonding or covering. The alternative use of cyanoacrylate-based wound adhesives offers a number of advantages over the use of sutures or staples for wound care. Sutures cause in the immediate vicinity of the injury to be treated by the penetration of the needle into the tissue and Additional injuries may be caused by the administration of an anesthetic if necessary and should only be used in a time-consuming procedure. The same applies to wound treatment using braces. As a result, the use of these agents is associated with problems, especially in pediatric cases, as they trigger strong anxiety and rejection reactions due to the associated impairments in the often very young patients.

By per se painless application of a cyanoacrylate-based wound adhesive according to any of Halpern in U.S. Patent 3,667,472 or to Banitt et al. in US Patent 3,559,652, the problems listed above can be at least partially circumvented or mitigated.

Despite these advantages, the medical use of cyanoacrylate-based adhesive compositions may present some problems since it is known that both the monomers and the polymer formed can cause severe irritation of the tissue in the field of use. This negative tissue reaction is primarily attributed to the in vivo biodegradation process of the polymer which, as described in the following references by F. Leonard et al., Journal of Applied Polymer Science, Vol. 259-272 (1966); F. Leonard, Annai's New York Academy of Sciences, Vol. 146, pp. 203-213 (1968); Tseng, Yin-Chao, et al., Journal of Applied Biomaterials, Vol. 1, pp. 111-119 (1990), and by Tseng, Yin-Chao, et al., Journal of Biomedical Materials Research, Vol. 24, pp. 1355-1367 (1990), leads to the release of formaldehyde.

In order to increase the biocompatibility of the cyanoacrylate-based adhesives, a number of structural modifications have been made in the past. The extension of the alkyl chain in the cyanoacrylate ester, for example, the rate of biodegradation process and thus the rate of release of formaldehyde in the affected tissue could be significantly reduced. While short chain cyanoacrylate esters (e.g., methyl 2-cyanoacrylate) are subject to rapid biodegradation, the longer chain analogs such as butyl 2-cyanoacrylate, octyl 2-cyanoacrylate, or decyl 2-cyanoacrylate are characterized by a significantly reduced rate of degradation.

As described in U.S. Patent 6,667,031 of M. Azevedo, the synthesis of the cyanoacrylate monomers based on the thermal cracking of the resultant in the reaction of cyanoacetate with formaldehyde prepolymer at temperatures of 150 to 200 ⁰ C and the subsequent separation of the monomer formed from the reaction solution by Distillation. The thermal depolymerization succeeds only when this process proceeds in the presence of stabilizers or mixtures of stabilizers which can prevent both a radical and an anionic repolymerization of the monomers formed under the reaction conditions described. As disclosed in US Pat. Nos. 3,559,652 and 5,582,834, the radical stabilizers are exemplified by hydroquinone, hydroquinone monomethyl ether,

Nitrohydroquinone, catechol and hydroquinone monomethyl ether. Anionic polymerization inhibitors are usually, but not exclusively, Lewis acids, such as sulfur dioxide, for example. Nitric oxide or boron trifluoride or inorganic or organic Branstedt acids, such as sulfuric acid, phosphoric acid or sulfonic acids.

The determination of the optimum concentration of the anionic polymerization inhibitor poses a difficult technical problem. Too low a concentration causes a significant repolymerization of the already formed monomers under the drastic conditions of the thermal depolymerization of the prepolymer. On the other hand, a very high concentration of the anionic stabilizer means that part of the stabilizer is carried off during the distillative removal of the monomer from the reaction solution. The resulting residual concentration of the anionic stabilizer in the distilled cyanoacrylate monomer is responsible for overstabilization of the product, which later inhibits effective polymerization of the cyanoacrylate monomer on the fabric surface.

The problem of the high residual concentration of an anionic stabilizer is particularly important in the preparation of long-chain high-boiling monomeric cyanoacrylate esters, such as octyl-2-cyanoacrylate or decyl-2-cyanoacrylate of particular importance. Separation of each resulting monomer from the reaction solution requires higher distillation temperatures and lower distillation pressures compared to short chain cyanoacrylate esters. As an undesirable side effect while a part of the anionic stabilizer is carried off into the monomeric product, which leads to a very negative for later use overstabilization of the long-chain biocompatible cyanoacrylate ester.

This over-stabilization with respect to the anionic polymerization affinity can be compensated for by the addition of polymerization initiators or promoters to the monomeric adhesive composition. As polymerization initiators or promoters, for example, amines can be used which have a sufficiently good solubility under the present conditions.

In the case of all additives, it must be ensured that, especially in the medical field of application, the additives exert no toxicologically harmful effect on the particular organism or the already seriously damaged tissue. Therefore, when developing medical wound adhesives, it is important to limit the number of additives as much as possible in order to minimize the risk for the patient.

In this regard, U.S. Patent 6,849,082 to M. Azevedo discloses a method of removing the anionic stabilizer from a monomeric adhesive composition prior to application to the fabric surface. The monomeric adhesive composition is directly contacted with a stabilizer removal agent (Lewis acid or organic / inorganic brominated acid). This substance is exemplified by ion exchangers, molecular sieves, zeolites, chelating agents, activated carbon systems or other substances with an anionic character. A related invention is described in U.S. Patent 6,667,031 to M. Azevedo. The anionic stabilizer is prior to the application of the monomeric adhesive composition by contact with a silicate, a polymer or copolymer based on polyvinylpyrrolidone or a polymer, which has functional groups such as carbonyl, hydroxyl, amide, carboxylate, amine, ether, anhydride, ester, urethane or sulfone, removed by formation of physical interactions such as adsorption or absorption, hydrogen bonds or by the occurrence of a chemical reaction.

The above-described methods combine the approach that by addition of an initiator or by a purification step, the overstabilization of the monomeric cyanoacrylate-based adhesive composition should be addressed so as to enable effective polymerization on the fabric surface or to increase the rate of polymerization. In this connection, it would be desirable to have a cyanoacrylate-based adhesive composition which, due to its manufacturing process, has such a low concentration of undesired polymerization inhibitors that no overstabilization of the polymerizable adhesive composition occurs, allowing for direct application without prior purification steps and without the addition of additives.

task

Accordingly, it is an object of the present invention to provide a cyanoacrylate-based polymerizable adhesive composition which does not have overstabilization by a polymerization inhibitor so that, when applied to surfaces, the curing of the adhesive composition occurs within a comparatively short period of time.

Surprisingly, it has now been found that in the case of cyanoacrylate components having a weight fraction of at least 90% by weight, preferably of at least 95% by weight, more preferably of at least 98% by weight and very particularly preferably of at least 99% by weight of cyanoacrylate or of mixtures of a Cyanoacrylate with other cyanoacrylates, the curing on an ABS surface without the addition of a polymerization initiator or polymerization accelerator in less than 80 s.

Suitable polymerization initiators or polymerization accelerators are widely known to the person skilled in the art. The addition of these substances or mixtures of substances to monomeric cyanoacrylates results in the polymerization process being accelerated compared to identical monomeric cyanoacrylates which have not been mixed with the substances or mixtures of substances in question.

In a preferred embodiment of the invention, the cyanoacrylate component according to the invention essentially consists only of said cyanoacrylate or of a mixture of said cyanoacrylates.

In another preferred embodiment of the invention, in addition to the cyanoacrylate according to the invention, the cyanoacrylate component according to the invention may also contain primary and secondary anionic polymerization inhibitors and optionally at least one free-radical polymerization inhibitor.

The general structure of the cyanoacrylate according to the invention is described by formula (I), wherein R is a substituted or unsubstituted, straight-chain, branched or cyclic alkyl group comprising 5 to 18 C atoms and / or includes an aromatic group or acyl group.

Formula (I) Preferred embodiments include, but are not limited to, n-pentyl-2-cyanoacrylate, / so-pentyl-2-cyanoacrylate (such as 1-pentyl, 2-pentyl and 3-pentyl), cyclopentyl-2-cyanoacrylate, n- hexyl 2-cyanoacrylate, / so-hexyl-2-cyanoacrylate (such as 1-hexyl, 2-hexyl, 3-hexyl and 4-hexyl), cyclohexyl-2-cyanoacrylate, n-heptyl-2-cyanoacrylate, / heptyl-2-cyanoacrylate (such as 1-heptyl, 2-heptyl, 3-heptyl and Aheptyl), cycloheptyl-2-cyanoacrylate, n-octyl-2-cyanoacrylate, 1-octyl-2-cyanoacrylate, 2-octyl 2-cyanoacrylate, 3-octyl-2-cyanoacrylate, 4-octyl-2-cyanoacrylate decyl-2-cyanoacrylate, dodecyl-2-cyanoacrylate. Particularly preferred cyanoacrylates of the general formula (I) are n-octyl-2-cyanoacrylate or 2-octyl-2-cyanoacrylate. Preference is likewise given to mixtures of said cyanoacrylates The cyanoacrylates according to the invention can also be combined with other cyanoacrylates in preferred embodiments of the invention. Thus, for example, the mixture of at least one of said cyanoacrylates with n-butyl-2-cyanoacrylate, such as the mixture of 2-octyl-2-cyanoacrylate with n-butyl-2-cyanoacrylate, is preferred.

In a preferred embodiment of the invention, the cyanoacrylates of the general formula (I) according to the invention are present substantially in monomeric form, i. the proportion of the corresponding polymers and / or oligomers is less than 5% by weight, preferably less than 1% by weight and very preferably less than 0.1% by weight, based in each case on the total amount of the cyanoacrylates according to the invention of the general formula (I) ,

The cyanoacrylates of formula (I) according to the invention can be prepared according to methods known in the art. U.S. Patent Nos. 2,721,858 and 3,254,111 disclose methods of making cyanoacrylates. Thus, the cyanoacrylates may e.g. by reacting an alkyl cyanoacetate with formaldehyde in a non-aqueous organic solvent and in the presence of a basic catalyst followed by thermal depolymerization of the anhydrous prepolymer in the presence of a stabilizer. The cyanoacrylate monomers, which are made with low moisture content and substantially free of impurities, are preferred for biomedical applications.

The determination of the time when curing of the perfect binding takes place is carried out with the aid of 100 mm x 25 mm x 2 mm specimens with an overlapping bond area of 322.6 mm ² . As a surface for determining the time of curing of the adhesive bond is an ABS polymer from Wiliaam Cox Ireland Ltd. used. The specimens are bonded together after application of the cyanoacrylate component (about 10 microliters) to the overlapping binding surface. The determination of the time at which curing of the adhesive bond is achieved is made by applying a tensile force perpendicular to the bonding surface, which is applied by a weight of 1 kg. Is the perfect binding capable to withstand this traction for at least 5 s, this time shall be considered as the date of

Curing defined.

The specified time of curing is the arithmetic mean of five

Determination tests.

In a preferred embodiment of the invention, the curing of a sterile cyanoacrylate component according to the invention on an ABS surface takes place in at most 75 s, preferably in at most 50 s and particularly preferably in at most 35 s.

In a further preferred embodiment of the invention, the curing of a non-sterile cyanoacrylate component on an ABS surface takes place in at most 50 s, preferably in at most 25 s and particularly preferably in at most 15 s.

The determination of the time of curing is carried out in each case by the method described above by applying a tensile force of 1 kg on the perfect binding.

The adhesion shear strength to nylon after curing of a sterile cyanoacrylate component according to the invention is preferably at least 1.6 N / mm ² , more preferably at least 1.8 N / mm ² and most preferably at least 2.0 N / mm ^2, and preferably at least after hardening of a non-sterile cyanoacrylate component according to the invention 1.6 N / mm ² , more preferably at least 1.9 N / mm ² and most preferably at least 2.5 N / mm ² .

The determination of the adhesion shear strength is carried out with the aid of specimens of dimensions 100 mm × 25 mm × 2 mm, which have an overlapping bond area of 322.6 mm ² . As the surface for determining the adhesion shear strength, nylon 101 (type 66, natural) from Industrial Safety Supply Co., CT, USA is used. After applying the cyanoacrylate component (about 10 microliters) to the overlapping binding surface, the specimens are connected to one another by means of staples (clamping force about 45 to 90 N) and the cyanoacrylate component is cured at room temperature for up to 24 hours. The adhesion shear strength of the cyanoacrylate component is then determined by applying a tensile force parallel to the bonding surface and to the major axis of the sample using a tensile tester operated at a test speed of 2 mm / min.

The specified adhesive shear strength is the arithmetic mean of five determination experiments and is given in N / mm ² .

Another object of the present invention is a polymerizable adhesive composition containing as at least one component of a cyanoacrylate according to the invention. In a preferred embodiment of the invention, the polymerizable adhesive composition comprises as the primary anionic polymerization inhibitor at least one inorganic acid and as secondary polymerization inhibitor at least one organic sulfonic acid, said sulfonic acid being represented by the general formula (II)

O

Il

R1 - S-OH

Formula (II) is described and R ¹ is an unsubstituted or a mono-, di-, tri-, tetra- or penta-substituted aryl group.

In a very particularly preferred embodiment of the invention, R 1 in formula (II) is described by the general formula (III) wherein R 2 is a hydrogen atom, a halogen atom, a substituted heteroatom, a substituted or unsubstituted, straight-chain, branched or cyclic alkyl chain which is 1 to 10 carbon atoms, or includes an aromatic group and / or acyl group. Formula (III)

A heteroatom is to be understood as meaning all atoms which are not carbon or hydrogen.

Particularly preferably, R 2 is a methyl, methoxy, ethyl, ethoxy, n-propyl, / propyl or n-butyl group, in particular a methyl group.

The primary anionic polymerization inhibitor in a preferred form of the invention may be an oxo, halo or Lewis acid or a combination of said acids. Particularly preferred embodiments include, but are not limited to, sulfur dioxide, boron trifluoride, dinitrogen monoxide, hydrogen fluoride, hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid or phosphorus pentoxide or combinations of said acids.

These mentioned polymerization inhibitors inhibit the polymerization. The primary anionic polymerization inhibitors, in addition to having a stabilizing effect, may optionally also exert a catalytic function in the thermal depolymerization of the prepolymer and / or neutralize bases used in the preparation of the prepolymer.

The amount of the primary anionic polymerization inhibitor for the liquid phase and for the vapor phase for stabilizing the polymerizable adhesive composition is dependent on the The nature of the particular inhibitor used, the monomer to be stabilized, and can be determined by one of ordinary skill in the art using known techniques.

In a preferred embodiment of the polymerizable adhesive composition according to the invention, the proportion of the secondary anionic polymerization inhibitor based on the cyanoacrylate according to the invention of formula (I) or on the mixture of a cyanoacrylate according to formula (I) according to the invention with further inventive cyanoacrylates according to formula (I) is less than 150 ppm , preferably less than 140 ppm, 130 ppm, 120 ppm, 110 ppm, 100 ppm, more preferably less than 90 ppm, 80 ppm, 70 ppm, 60 ppm, 50 ppm, most preferably less than 40 ppm, 30 ppm, 20 ppm and most preferably less than 10 ppm.

In addition, in a particular embodiment of the invention, the cyanoacrylate component and / or the polymerizable adhesive composition may also be added with a free-radical polymerization inhibitor at a concentration which is easily determined by a person skilled in the art. Suitable free-radical polymerization inhibitors are, for example, phenolic compounds such as hydroquinone, butylated hydroxyanisole (BHA), 2,6-di-tert-butyl-4-methylphenol (BHT), f-butylcatequinone, catechol and p-methoxyphenol. Mixtures of said radical chain polymerization inhibitors may also be used. A particularly preferred free radical polymerization inhibitor is butylated hydroxyanisole (BHA).

The polymerizable adhesive composition of the present invention preferably further comprises at least one other component selected from the groups of plasticizers, thickening agents, antimicrobial agents, thixotropic agents, skin care actives, perfumes, and formaldehyde reducing agents.

If there is a plasticizer, it imparts flexibility to the polymer formed from the monomer and preferably contains little or no moisture and should not significantly affect the stability or polymerization of the monomer. Such plasticizers are useful in polymerized compositions which are to be used to close or cover wounds, cuts, abrasions, inflammations or other applications in which flexibility of the adhesive is desirable.

Particularly suitable plasticizers are triaryl or trialkyl phosphates and ester compounds. The alcohol component of the ester is preferably alcohols having from 1 to 5, in particular from 2 to 4, OH groups and from 2 to 5, in particular 3 or 4, directly connected carbon atoms. The number of not directly connected C atoms can be up to 110, in particular up to 18 carbon atoms. Suitable monohydric alcohols are the following: methanol, ethanol, 1-propanol, 2-propanol, 1-

Butanol, 2-butanol, 2,2-dimethyl-1-propanol, 2-methyl-1-propanol, 2,2-dimethyl-1-propanol, 2-methyl

2-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 1-

Pentanol, 2-pentanol, 3-pentanol, cyclopentanol, cyclopentenol, glycidol, tetrahydrofurfuryl alcohol,

Tetrahydro-2H-pyran-4-ol, 2-methyl-3-buten-2-ol, 3-methyl-2-buten-2-ol, 3-methyl-3-buten-2-ol, 1-

Cyclopropylethanol, 1-penten-3-ol, 3-penten-2-ol, 4-penten-1-ol, 4-penten-2-ol, 3-pentin-1-ol, 4-

Pentin-1-ol, propargyl alcohol, allyl alcohol, hydroxyacetone, 2-methyl-3-butyn-2-ol.

Suitable dihydric alcohols are, for example: 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol,

Dihydroxyacetone, thioglycerol, 2-methyl-1,3-propanediol, 2-butyne-1,4-diol, 3-butene-1,2-diol, 2,3-

Butanediol, 1, 4-butanediol, 1, 3-butanediol, 1, 2-butanediol, 2-butene-1, 4-diol, 1, 2-cyclopentanediol, 3-methyl

1, 3-butanediol, 2,2-dimethyl-1,3-propanediol, 4-cyclopenten-1, 3-diol, 1, 2-cyclopentanediol, 2,2-dimethyl

1, 3-propanediol, 1, 2-pentanediol, 2,4-pentanediol, 1, 5-pentanediol, 4-cyclopenten-1, 3-diol, 2-methylene-1, 3-propanediol, 2,3-dihydroxy 1,4-dioxane, 2,5-dihydroxy-1,4-dithiane.

The following trihydric alcohols can be used: glycerol, erythrulose, 1, 2,4-butanetriol,

Erythrose, threose, trimethylolethane, trimethylolpropane and 2-hydroxymethyl-1,3-propanediol.

Of the tetrahydric alcohols, for example, erythritol, threitol, pentaerythritol, arabinose,

Ribose, xylose, ribulose, xylulose, lyxose, ascorbic acid, glucono-γ-lactone can be used.

As examples of pentahydric alcohols may be mentioned: arabitol, adonite, xylitol.

Other suitable monohydric or polyhydric alcohols are familiar to the person skilled in the art.

The polyhydric alcohols described above can also be used, for example, in the form of ethers. The ethers can be prepared, for example, by condensation reactions, Williamson ether synthesis or by reaction with alkylene oxides such as ethylene, propylene or butylene oxide from the abovementioned alcohols. Examples include: diethylene glycol, triethylene glycol, polyethylene glycol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, polyglycerol, technical mixtures of the condensation products of glycerol, glycerol, Diplycerinpropoxylat, pentaerythritol, Dipentaeryrthrit, Ethylenglykolmonobutylether, Propylenglykolmonohexylether, Butyldiglykol, Dipropylenglykolmonomethylether.

Examples of monohydric carboxylic acids which can be used for the esterification with the abovementioned alcohols are: formic acid, acrylic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, 2-oxovaleric acid, 3-oxovaleric acid, pivalic acid, acetoacetic acid, levulinic acid, 3-methylpentanoic acid. 2-oxo-butyric acid, propiolic acid, tetrahydrofuran-2-carboxylic acid, methoxyacetic acid, dimethoxyacetic acid, 2- (2-methoxyethoxy) acetic acid, pyruvic acid, 2-methoxyethanol, vinylacetic acid, allylacetic acid, 2-pentenoic acid, 3-pentenoic acid. Examples of polybasic carboxylic acids which may be mentioned are: oxalic acid, malonic acid, fumaric acid, maleic acid, succinic acid, glutaric acid, acetylenedicarboxylic acid, oxalacetic acid, acetonedicarboxylic acid, mesoxalic acid, citraconic acid, dimethylmalonic acid, methylmalonic acid, ethylmalonic acid.

Hydroxycarboxylic acids can also be used as starting materials, e.g. Tartronic, lactic, malic, tartaric, citramalic, 2-hydroxyvaleric, 3-hydroxyvaleric, 3-hydroxybutyric, 3-hydroxyglutaric, dihydroxyfumaric, 2,2-dimethyl-3-hydroxypropionic, dimethylolpropionic, glycolic, citric.

The esterification can be either complete or partial. Optionally, mixtures of these acids can be used for the esterification.

The esters prepared from these alcohols and carboxylic acids or the corresponding derivatives are preferably free of catalysts, in particular of alkali metals and amines. This can be achieved by treating the esters according to the invention with acids, ion exchangers, acetic clays, aluminum oxides, activated carbon or other auxiliaries known to the person skilled in the art. For drying and further purification can be distilled.

Examples of esters which are particularly suitable as plasticizers are: ethyl acetate, butyl acetate, glycerol triacetate, glycerol tripropionate, triglycerol pentaacetate, polyglycerol acetate,

Diethylene glycol diacetate, ethyl 3-hydroxyvalerate, butyl lactate,

Isobutyl lactate, ethyl 3-hydroxybutyrate, diethyl oxalate,

Diethyl malonate, dimethyl malate, diisopropyl malate,

Diethyl tartrate, tartaric acid dipropyl ester, diisopropyl tartrate, dimethyl glutarate, dimethyl succinate, succinic acid diethyl ester, diethyl maleate,

Diethyl fumarate, diethyl malonate, 2-hydroxyethyl acrylate, 3

Methyl oxovalerate, glycerol diacetate, glycerol tributyrate, glycerol tripropionate,

Glycerol dipropionate, glycerol triisobutyrate, glycerol diisobutyrate, glycidyl butyrate,

Butyl acetoacetate, levoic acid ethyl ester, dimethyl 3-hydroxyglutarate,

Glycerol acetate dipropionate, glycerol diacetate butyrate, butyl propionate, propylene glycol diacetate, propylene glycol dibutyrate, diethylene glycol dibutyrate, trimethylolethane triacetate, trimethylolpropane triacetate, trimethylolethane tributyrate, neopentyl alcohol dibutyrate, methoxyacetate,

Butyl dimethoxyacetate, butyl glycolate.

The esters mentioned may be added in an amount of up to 50% by weight, preferably in an amount of 0.5 to 30% by weight, more preferably in an amount of 1 to 20% by weight, based on the total amount of the polymerizable adhesive composition. Further suitable plasticizers are, for example, esters such as abietic acid esters, adipic acid esters, azelaic acid esters, benzoic acid esters, butyric acid esters, acetic acid esters, esters of higher fatty acids containing from about 8 to about 44 carbon atoms, esters containing OH groups or epoxidized fatty acids, fatty acid esters and fats, glycolic esters, phosphoric esters, phthalic acid esters , linear or branched alcohols containing 1 to 12 carbon atoms, propionic acid esters, sebacic acid esters, sulfonic acid esters, thiobutyric acid esters, trimellitic acid esters, citric acid esters, and mixtures of two or more thereof. Particularly suitable are the asymmetric esters of difunctional, aliphatic or aromatic dicarboxylic acids, for example the esterification product of adipic acid monooctyl ester with 2-ethylhexanol (Edenol DOA, Cognis, Dusseldorf) or the esterification product of phthalic acid with butanol.

Also suitable as plasticizers are the pure or mixed ethers monofunctional, linear or branched C4-16 alcohols or mixtures of two or more different ethers such

Alcohols, for example dioctyl ether (available as Cetiol OE, Cognis, Dusseldorf).

In addition, end-capped polyethylene glycols are suitable as plasticizers.

For example, polyethylene or polypropylene glycol di-C1-4-alkyl ethers, in particular the dimethyl or diethyl ethers of diethylene glycol or dipropylene glycol, and mixtures of two or more thereof.

Particularly preferred plasticizers are tributyl citrate, triaryl phosphate and acetyltributyl citrate.

In addition, it is a preferred embodiment of the polymerizable adhesive composition of the invention when polymers are added, e.g. to increase the viscosity or to vary the adhesive properties. These additives serve as thickeners and affect the rheology of the adhesive mixture in the desired manner. The polymers can be used in an amount of 1 to 60, in particular 10 to 50, preferably 10 to 30 wt .-% based on the total formulation. Especially suitable are polymers based on vinyl ethers, vinyl esters, esters of acrylic acid and methacrylic acid having 1 to 22 carbon atoms in the alcohol component, styrene or copolymers and terpolymers derived therefrom with ethene, butadiene. Preferred are vinyl chloride / vinyl acetate copolymers having a vinyl chloride content of 50 to 95 wt .-%. The polymers may be in liquid, resinous or even solid form. Most importantly, the polymers do not contain any impurities from the polymerization process that inhibit the curing of the cyanoacrylate-based adhesive composition. If the polymers have too high a water content, it may be necessary to dry them.

The molecular weight may be dispersed in a wide range should be at least Mw = 1.5 kg / mol, but not more than 1000 kg / mol, otherwise the final viscosity of the adhesive formulation is too high. It is also possible to use mixtures of the abovementioned polymers become. In particular, the combination of low and high molecular weight products has particular advantages in terms of the final viscosity of the adhesive formulation. Examples of suitable polymers based on vinyl acetate are: the Mowilith types 20, 30, and 60, the Vinnapas types B1, 5, B100, B17, B5, B500 / 20VL, B60, UW 10, UW1, UW30, UW4 and UW50. Examples of suitable acrylate-based polymers include: Acronal 4F and Laromer types 8912, PE55F and PO33F. Examples of suitable polymers based on methacrylate are: Elvacite 2042, Neocryl types B 724, B999 731, B 735, B 811, B 813, B 817 and B722, Plexidon MW 134, Plexigum types M 825, M 527, N 742, N 80, P 24, P 28 and PQ 610. As an example of suitable polymers based on vinyl ethers may be mentioned: Lutonal A25. For thickening CeIIu losederivate and silica gel can be used. Particularly noteworthy is the addition of polycyanoacrylates.

The polymerizable adhesive composition of the present invention may preferably contain one or more antimicrobial agents in an amount of usually 0.0001 to 3% by weight, preferably 0.0001 to 2% by weight, especially 0.0002 to 1% by weight, more preferably 0.0002 to 0.2% by weight, most preferably 0.0003 to 0.1% by weight, based in each case on the total amount of the polymerizable adhesive composition.

Depending on the antimicrobial spectrum and mechanism of action, antimicrobial agents are distinguished between bacteriostats and bactericides, fungistatics and fungicides, etc. Important substances from these groups are, for example, benzalkonium chlorides, alkylarylsulfonates, halophenols and phenolmercuric acetate. The terms antimicrobial action and antimicrobial agent have the usual meaning within the scope of the teaching according to the invention. Suitable antimicrobial agents are preferably selected from the groups of the alcohols, amines, aldehydes, antimicrobial acids or their salts, carboxylic acid esters, acid amides, phenols, phenol derivatives, diphenyls, diphenylalkanes, urea derivatives, oxygen, nitrogen acetals and formals, benzamidines, isothiazolines , Phthalimide derivatives, pyridine derivatives, antimicrobial surface active compounds, guanidines, antimicrobial amphoteric compounds, quinolines, 1, 2-dibromo-2,4-di-cyanobutane, iodo-2-propyl-butyl-carbamate, iodine, iodophores, peroxo compounds, halogen compounds and any Mixtures of the preceding.

The antimicrobial agent is preferably selected from undecylenic acid, benzoic acid, salicylic acid, dihydracetic acid, o-phenylphenol, N-methylmorpholine-acetonitrile (MMA), 2-benzyl-4-chlorophenol, 2,2'-methylene-bis (6 bromo-4-chlorophenol), 4,4'-di-chloro-2'-hydroxydiphenyl ether

(Dichlosan), 2,4,4'-trichloro-2'-hydroxydiphenyl ether (trichlosan), chlorhexidine, N- (4-chlorophenyl) -N- (3,4-dichlorophenyl) -urea, N, N '- (1 , 10-decanediyldi-1-pyridinyl-4-ylidene) bis- (1-octanamine) dihydrochloride, N, N'-bis (4-chlorophenyl) -3,12-diimino-2,4,11 , 13-tetraaza-tetradecandiimidamid,

Glucoprotamines, antimicrobial surface-active quaternaries, guanidines including the bi- and polyguanidine diamines such as 1,6-bis (2-ethylhexyl-biguanido-hexane) dihydrochloride, 1,6-di- (Nl, N1'-phenyldiguanido-N5, N5 ') -hexane -tetrahydrochloride, 1,6-di- (NI, N1'-phenyl-N1, N1-methyldiguanido-N5, N5 ') - hexane dihydrochloride, 1,6-di- (Nl, N1'-o-chlorophenyldiguanido -

N5, N5 ') - hexane dihydrochloride, 1,6-di- (NI, N1' -2, 6-dichlorophenyldiguanido-N5, N5 ') hexane dihydrochloride, 1,6-di- [NI, NΙ'-beta - (p-methoxyphenyl) diguanido-N5, N5 '] - hexanedihydrochloride, 1,6-di- (Nl, N1' -alpha-methyl-beta-phenyldiguanido-N5, N5 ') - hexane-dihydro chloride, 1,6-di- (NI, N1'-p-nitrophenyldiguanido-N5, N5 ') hexane-dihydrochloride, omega: onnega-di- (N1, N1'-phenyldiguanido-

N5, N5 ') - di-n-propyl ether dihydrochloride, omega: omega'-di- (N1, N1'-p-chlorophenyldiguanido-N5, N5') - di-n-propyl ether tetrahydrochloride, 1,6-di - (NI, N1 '-2, 4-dichlorophenyldiguanido-N5, N5') hexane-tetrahydrochloride, 1,6-di- (Nl, N1 '-p-methylphenyl-nigiguanido-N5, N5') hexane-dihydrochloride, 1 , 6-di- (N1, N1'-2,4,5-trichlorophenyldi guanido-N5, N5 ') hexane-tetrahydrochloride, 1,6-di- [NI, N1'-alpha (p-chlorophenyl) -ethyldiguanido -N5, N5 '] hexane dihydrochloride, omega: omega-di- (N1, N1'-p-chlorophenyldiguanido-N5, N5') m-xylene dihydrochloride, 1,12-di- (NI, N 1 '-p-chlorophenyldiguanido-N5, N5') dodecane dihydrochloride, 1, 10-di- (N1, N 1 '-phenyl-diguanido-N5, N5') -decane-tetrahydrochloride, 1, 12-di- (N1, N1 '-phenyldiguanido-N5, N5') dodecane-tetrahydrochloride, 1,6-di- (Nl, N1 '-o-chlorophenyl-guanido-N5, N5') hexane-dihydrochloride, 1,6-di- (Nl, N1 '-o-chlorophenyldiguanido-N5, N5'), hexane-tetrahydrochloride, ethylene-bis (i-tolyl-biguanide), ethylene-bis- (p-tolyl-biguanide), ethylene-bis- (3,5 - dimethylphenylbiguanide), ethylene bis (p-tert-amylphenylbiguanide), ethylene bis (nonylphenylbiguanide), ethylene bis (phenylbiguanide), ethylene bis (N-butylphenylbiguanide), ethylene bis (2.5 - diethoxyphenylbiguanide), ethylene bis (2,4-dimethylphenylbiguanide), ethylene bis (o-diphenylbiguanide), ethylene bis (mixed amyl naphthyl biguanide), N-butyl ethylene bis (phenylbiguanide), trimethylene bis (o-tolylbiguanide), N-butyl-trimethyl-bis (phenylbiguanide) and the corresponding salts such as acetates, gluconates, hydrochlorides, hydrobromides, citrates, bisulfites, fluorides, polymaleates, N-cocoalkyl sarcosinates, phosphites, hypophosphites, perfluorooctanoates, Silicates, sorbates, salicylates, maleates, tartrates, fumarates, ethylenediaminetetraacetates, iminodiacetates, cinnamates, thiocyanates, arginates, pyromellitates, tetracarboxybutyrates, benzoates, glutarates, monofluorophosphates, perfluoropropionates and any mixtures thereof. Also suitable are halogenated xylene and cresol derivatives, such as p-chloromethacresol or p-chlorometaxylene, and natural antimicrobial agents of plant origin (for example, from spices or herbs), of animal and microbial origin. Preferably, antimicrobial surface-active quaternary compounds, a natural antimicrobial agent of plant origin and / or a natural antimicrobial agent of animal origin, most preferably at least one natural antimicrobial agent of plant origin from the group comprising caffeine, theobromine and theophylline and essential oils such as eugenol, thymol and geraniol, and / or at least one natural antimicrobial agent of animal origin from the group, comprising enzymes such as protein from milk, lysozyme and lactoperoxidase, and / or at least one antimicrobial surface-active quaternary compound with an ammonium, sulfonium, phosphonium, iodonium - or Arsoniumgruppe, peroxo compounds and chlorine compounds are used. Also substances Microbial origin, so-called bacteriocins, can be used. Glycine, glycine derivatives, formaldehyde, compounds which readily split off formaldehyde, formic acid and peroxides are preferably used.

Particularly preferred antimicrobial agents are quaternary ammonium compounds (QAVs). The quaternary ammonium compounds (QAV) have the general formula (R 1) (R 2) (R 3) (R 4) N + X-, in which R 1 to R 4 are identical or different C 1 -C 22 -alkyl radicals, C 7 -C 28 -aralkyl radicals or heterocyclic radicals, wherein two or, in the case of an aromatic inclusion as in pyridine, even three radicals together with the nitrogen atom form the heterocycle, for example a pyridinium or imidazolinium compound, and X are halide ions, sulfate ions, hydroxide ions or similar anions. For optimum antimicrobial activity, preferably at least one of the radicals has a chain length of 8 to 18, in particular 12 to 16, carbon atoms.

QACs can be prepared by reacting tertiary amines with alkylating agents, such as, for example, methyl chloride, benzyl chloride, dimethyl sulfate, dodecyl bromide, but also ethylene oxide. The alkylation of tertiary amines with a long alkyl radical and two methyl groups succeeds particularly easily, and the quaternization of tertiary amines with two long radicals and one methyl group can be carried out with the aid of methyl chloride under mild conditions. Amines having three long alkyl radicals or hydroxy-substituted alkyl radicals are less reactive and are preferably quaternized with dimethyl sulfate.

Suitable QACs are, for example, benzalkonium chloride (N-alkyl-N, N-dimethylbenzylammonium chloride, CAS No. 8001-54-5), benzalkone B (m, p-dichlorobenzyl-dimethyl-C 12 -alkylammonium chloride, CAS No. 58390- 78-6), benzoxonium chloride (benzyldodecyl-bis (2-hydroxyethyl) ammonium chloride), cetrimonium bromide (N-hexadecyl-N, N-trimethyl-ammonium bromide, CAS No. 57-09-0), benzetonium chloride (N, N-dimethyl-N- [2- [2- [p- (1,1,3,3-tetramethylbutyl) phenoxy] ethoxy] ethyl] benzyl ammonium chloride, CAS No. 121-54-0), dialkyldimethylammonium chlorides such as Di-n-decyldimethylammonium chloride (CAS No. 7173-51-5-5), didecyldimethylammonium bromide (CAS No. 2390-68-3), dioctyldimethylammonium chloride 1-cetylpyridinium chloride (CAS No. 123- 03-5) and thiazoline iodide (CAS No. 15764-48-1) and mixtures thereof. Particularly preferred QACs are the benzalkonium chlorides with C 8 -C 18 -alkyl radicals, in particular C 1 -C -alkyl-alkyl-benzyl-dimethyl-ammonium chloride.

Benzalkonium halides and / or substituted benzalkonium halides are commercially available, for example, as Barquat® ex Lonza, Marquat® ex Mason, Variquat® ex Witco / Sherex and Hyamine® ex Lonza, and Bardac® ex Lonza. Other commercially available antimicrobial Active ingredients are N- (3-chloroallyl) -hexaminium chloride such as Dowicide® and Dowicil® ex Dow, benzethonium chloride such as Hyamine® 1622 ex Rohm & Haas, methylbenzethonium chloride such as Hyamine® 10X ex Rohm & Haas, cetylpyridinium chloride such as Cepacolchloride ex Merrell Labs.

Suitable thixotropic agents are known to those skilled in the art and include, but are not limited to, silica gels such as those treated with silyl isocyanate. Examples of suitable thixotropic agents are e.g. in U.S. Patent No. 4,720,513.

In a further preferred embodiment, the polymerizable adhesive composition according to the invention may contain one or more skin-care active substances. Skin care actives may, in particular, be those which give the skin a sensory benefit, e.g. by supplying lipids and / or moisturizing factors, thus assisting the healing of the affected tissue part.

Skin-care active substances are known to the person skilled in the art and can preferably be selected from the following substance groups or from mixtures of the following substance groups, without, however, being restricted to these:

a) waxes such as carnauba, spermaceti, beeswax, lanolin and / or derivatives thereof and others. b) Hydrophobic plant extracts c) Hydrocarbons such as squalene and / or squalanes d) Higher fatty acids, preferably those having at least 12 carbon atoms, for example lauric acid, stearic acid, behenic acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, isostearic acid and / or polyunsaturated fatty acids and other. e) Higher fatty alcohols, preferably those having at least 12 carbon atoms, for example lauryl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, cholesterol and / or 2-hexadecanol and others. f) esters, preferably such as cetyloctanoates, lauryl lactates, myristyl lactates, cetyl lactates, isopropyl myristates, myristyl myristates, isopropyl palmitates, isopropyl adipates, butyl stearates, decyl oleates, cholesterol stearates, glycerol monostearates, glycerol distearates, glycerol tristearates, alkyl lactates, alkyl citrates and / or alkyl tartrates and others. g) lipids such as cholesterol, ceramides and / or sucrose esters and others. h) vitamins such as vitamins A and E, vitamin C esters, including vitamin C.

Alkyl esters and others, i) sunscreens j) phospholipids k) derivatives of alpha-hydroxy acids I) Germicides for cosmetic use, both synthetic and, for example, salicylic acid and / or other natural as well as neem oil and / or others, m) silicones

In another preferred embodiment, the polymerizable adhesive composition may contain perfume as a further component. Suitable perfumes are known to the person skilled in the art

In a preferred embodiment of the polymerizable adhesive composition of the present invention, there may also be included at least one biocompatible agent effective to reduce the concentration levels of active formaldehyde produced during biodegradation of the polymer in vivo (also referred to herein as "means for reducing the The amount will depend on the type of agent for reducing the active formaldehyde concentration and may be readily determined by one skilled in the art without undue experimentation.

A further subject of the present invention is a process for the preparation of a cyanoacrylate component according to the invention, the following steps being carried out in the order indicated:

(a) thermally cracking a cyanoacrylate prepolymer in the presence of at least one inorganic acid as a primary anionic polymerization inhibitor and at least one organic sulfonic acid as a secondary anionic polymerization inhibitor, said sulfonic acid being represented by the general formula (II)

O

Il

R1 -S-OH

(b) separating the obtained preferably monomeric cyanoacrylate of formula (I) from the anionic polymerization inhibitor by a suitable physical method, wherein the boiling point of the obtained preferably monomeric cyanoacrylate is below the boiling point of the at least one secondary anionic polymerization inhibitor and separating the resulting preferably monomeric cyanoacrylate according to Formula (I) of the anionic polymerization inhibitor under normal or reduced pressure by distillation.

In this context, the boiling points of the individual components at normal pressure are to be regarded as relevant boiling points. The targeted tuning of the boiling points increases the efficiency of the distillation process, since the polymerization inhibitor used can be separated much more effectively from the respective cyanoacrylate in this way. The overstabilization of the polymerizable adhesive composition with respect to its polymerization properties is thus avoided, since the residual concentration of the organic acid in the resulting monomer is substantially lower than is the case with conventional processes. Purification steps of the polymerizable adhesive composition to be carried out directly before the application are therefore not required, as is the addition of polymerization initiators or promoters as additives.

For the purposes of the invention, the term "cyanoacrylate prepolymer" is preferably understood as meaning the reaction of a cyanoacetate derivative with formaldehyde, preferably in the presence of a basic catalyst Depolymerization are accessible.

In a particularly preferred embodiment of the said process, R 1 in formula (II) is described by the general formula (III) wherein R 2 is a hydrogen atom, a halogen atom, a substituted heteroatom, a substituted or unsubstituted, straight-chain, branched or cyclic alkyl chain which is 1 to 10 carbon atoms, or includes an aromatic group and / or acyl group. Formula (III)

Preferably, R 2 is a methyl, methoxy, ethyl, ethoxy, n-propyl, / propyl or n-butyl group, in particular a methyl group.

The primary anionic polymerization inhibitor may preferably be an oxo, halo or Lewis acid or a combination of said acids. Particularly preferred embodiments include, but are not limited to, sulfur dioxide (SO ₂ ), boron trifluoride (BF ₃ ), nitrous oxide (N ₂ O), hydrogen fluoride (HF), hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), Phosphoric acid (H ₃ PO ₄ ), perchloric acid (HCIO ₄ ) or phosphorus pentoxide (P ₂ O ₅ ) or combinations of said acids.

In a particularly preferred embodiment of the process according to the invention, the at least one inorganic acid is present as primary anionic polymerization inhibitor in the thermal cracking of the cyanoacrylate prepolymer in a concentration of 800 to 35000 ppm, especially in a concentration of 2000 to 34000 ppm and most preferably in a concentration of 29000 to 33000 ppm.

In a further preferred embodiment of the process according to the invention, the at least one organic sulfonic acid according to the invention is a secondary anionic polymerization inhibitor in the thermal cracking of the cyanoacrylate prepolymer in a concentration of 10 to 2000 ppm, in particular in a concentration of 100 to 1000 ppm and most preferably in one Concentration of 500 to 800 ppm in pre.

In a preferred embodiment of the process according to the invention, the residual concentration of the secondary anionic polymerization inhibitor in the resulting preferably monomeric cyanoacrylate of the general formula (I) or in a mixture of different cyanoacrylates of the general formula (I) is less than 150 ppm, preferably less than 140 ppm, 130 ppm , 120 ppm, 110 ppm, 100 ppm, more preferably less than 90 ppm, 80 ppm, 70 ppm, 60 ppm, 50 ppm, most preferably less than 40 ppm, 30 ppm, 20 ppm, and most preferably less than 10 ppm.

The present application also provides a polymerizable adhesive composition according to the invention for topical and / or internal application to mammals, in particular for medical use on their tissue, and the use of the polymerizable adhesive composition according to the invention for the preparation of a pharmaceutical composition for topical and / or internal application to mammals , in particular for medical use on the tissue thereof.

In a preferred embodiment of the invention, said tissue is human skin and / or said tissue is a surgically cut or traumatically ruptured tissue, wherein the polymerizable adhesive composition of the invention is preferably applied to close or to close a wound cover.

The polymerizable adhesive composition of the present invention, regardless of its inherent bacteriostatic effect in a particular embodiment of the invention, can be sterilized directly after production and / or after packaging by a method exemplarily selected from heat, ultrafiltration and irradiation or by a combination of said methods.

A further subject of the present invention is a process for the preparation of a compound of general formula (Ia), wherein R is a substituted or unsubstituted, straight, branched or cyclic alkyl group comprising 5 to 18 C atoms and / or containing an aromatic group or acyl group, comprising the steps:

O

Il

R1 - S-OH

(b) separating the obtained preferably monomeric compound of the general formula (Ia) from the primary and secondary anionic polymerization inhibitors by distillation, wherein the distillation is carried out at normal or reduced pressure.

Preferred compounds of general formula (Ia) include, but are not limited to, n-pentyl-2-cyanoacrylate, / so-pentyl-2-cyanoacrylate (such as 1-pentyl, 2-pentyl and 3-pentyl), cyclopentyl- 2-cyanoacrylate, n-hexyl-2-cyanoacrylate, / so-hexyl-2-cyanoacrylate (such as 1-hexyl, 2-hexyl, 3-hexyl and 4-hexyl), cyclohexyl-2-cyanoacrylate, n-heptyl-2 cyanoacrylate, so-heptyl-2-cyanoacrylate (such as 1-heptyl, 2-heptyl, 3-heptyl and 4-heptyl), cycloheptyl-2-cyanoacrylate, n-octyl-2-cyanoacrylate, 1-octyl-2- cyanoacrylate, 2-octyl-2-cyanoacrylate, 3-octyl-2-cyanoacrylate, 4-octyl-2-cyanoacrylate decyl-2-cyanoacrylate, dodecyl-2-cyanoacrylate. Particularly preferred cyanoacrylates of the general formula (Ia) are n-octyl-2-cyanoacrylate or 2-octyl-2-cyanoacrylate. Also preferred are mixtures of said cyanoacrylates

In a preferred embodiment of the invention, the compounds of the general formula (Ia) according to the invention are present essentially in monomeric form, ie the proportion of Corresponding polymers and / or oligomers is less than 5 wt.%, Preferably less than 1 wt.% And most preferably less than 0.1 wt.%, Each based on the total amount of the compounds of general formula (Ia).

Preferably, R 2 is a methyl, methoxy, ethyl, ethoxy, n-propyl, / propyl or n-butyl group and in particular a methyl group.

In a particularly preferred embodiment of the process according to the invention, the at least one inorganic acid is the primary anionic polymerization inhibitor in the thermal cracking of the cyanoacrylate prepolymer in a concentration of 800 to 35000 ppm, in particular in a concentration of 2000 to 34000 ppm and most preferably in a concentration of 29000 to 33000 ppm before.

It is further preferred that in the separation of the resulting preferably monomeric compound of general formula (Ia) from the anionic polymerization inhibitor by distillation the boiling point of the obtained preferably monomeric compound of the general formula (Ia) is below the boiling point of the secondary anionic polymerization inhibitor.

The relevant boiling points in this context are the boiling points at atmospheric pressure.

The specific adjustment of the boiling points increases the efficiency of the distillation process, since the secondary anionic polymerization inhibitor used can be separated much more effectively from the respectively obtained preferably monomeric compound of general formula (Ia) in this way. An overstabilization of the preferably monomeric compound of the general formula (Ia) is avoided, since the residual concentration of the secondary anionic polymerization inhibitor according to the invention in the preferably monomeric compound of the general formula (Ia) is substantially lower than is the case with conventional processes.

In a preferred embodiment of the process according to the invention, the residual concentration of the at least one organic sulfonic acid according to the invention as a secondary anionic polymerization inhibitor in the resulting preferably monomeric compound of general formula (Ia) or in a mixture of different compounds of general formula (Ia) is less than 150 ppm, preferably less than 140 ppm, 130 ppm, 120 ppm, 110 ppm, 100 ppm, more preferably less than 90 ppm, 80 ppm, 70 ppm, 60 ppm, 50 ppm, most preferably less than 40 ppm, 30 ppm, 20 ppm and most preferably less than 10 ppm.

The curing of the resulting preferably monomeric compound of general formula (Ia) on an ABS surface, in an extremely preferred embodiment of the method according to the invention, without the addition of a polymerization initiator or polymerization accelerator in less than 80 s, preferably in at most 50 s, highly preferred in no more than 25 seconds and most preferably in no more than 15 seconds.

The determination of the time of curing is carried out according to the method described above.

The adhesion shear strength of the obtained preferably monomeric compound of general formula (Ia) to nylon after curing said cyanoacrylate, in a highly preferred embodiment of the inventive method at least 1.6 N / mm ² , more preferably at least 1.8 N / mm ^2, and most preferably at least 2.0 N / mm ² .

The determination of the adhesive shear strength is carried out according to the method described above. EXEMPLARY EMBODIMENTS

Example 1 :

2-octyl cyanoacetate is reacted with an equimolar amount of formaldehyde in the presence of a basic catalyst. After the condensation reaction is completed, the solvent is removed and phosphoric acid and p-toluenesulfonic acid are added. This is followed by the thermal depolymerization of the prepolymer, wherein the collecting vessel contains a stock solution of sulfuric acid. The monomeric crude product is additionally stabilized by the addition of butylhydroxyanisole (BHA) and BF ₃ from a stock solution of BF ₃ -2H ₂ O and then purified by distillation, stabilizing the monomer in the receiver with a suitable amount of SO ₂ and BHA , This gives 2-Octylcyanacrylat in high purity, which cures on an ABS surface under the conditions mentioned in 45 s and whose adhesive shear strength under the conditions mentioned on nylon 2.3 N / mm ² .

Comparative Example 2 shows the change in adhesive properties when using methanesulfonic acid as a relatively volatile secondary anionic polymerization inhibitor under otherwise identical conditions:

Comparative Example 2

2-octyl cyanoacetate is reacted with an equimolar amount of formaldehyde in the presence of a basic catalyst. After the condensation reaction is completed, the solvent is removed and phosphoric acid and methanesulfonic acid are added. Subsequently, the thermal depolymerization of the prepolymer takes place, wherein the collecting vessel contains a stock solution of methanesulfonic acid. The monomeric crude product is additionally stabilized by the addition of butylhydroxyanisole (BHA) and BF ₃ from a stock solution of BF ₃ -2H ₂ O and then purified by distillation, stabilizing the monomer in the receiver with a suitable amount of SO ₂ and BHA , This gives 2-octyl cyanoacrylate, which cures on an ABS surface under the conditions mentioned in 120 s and whose adhesive shear strength on nylon under the conditions mentioned is 0.34 N / mm ² . Example 3

Example 3 shows the physical properties of some cyanoacrylate components shown in a method analogous to Example 1.

[1] Based on the total amount of the cyanoacrylate component; [2] cyanoacrylates (CA) according to formula (I); [3] Adhesive Shear Strength of a Non-Sterile Cyanoacrylate Component; [4] Adhesive Shear Strength of a STERILE Cyanacrylate Component; [5] Curing time of a non-steroids cyanoacrylate component; [6] Curing time of a STERILE cyanoacrylate component. The determination of the adhesive strength and the hardening time takes place under the conditions mentioned.

Claims

. Patent claims

(1) A cyanoacrylate component for use in adhesives, characterized in that the cyanoacrylate component contains a cyanoacrylate according to formula (I) or a mixture of a cyanoacrylate according to formula (I) with further cyanoacrylates according to formula (I) and the curing of the sterile or non-sterile sterile cyanoacrylate component without the addition of a polymerization initiator or polymerization accelerator on an ABS surface, determined by applying a tensile force of 1 kg for at least 5s, in less than 80 s, the proportion of cyanoacrylate according to formula (I) being at least 90% by weight represents the total amount of the cyanoacrylate component and R is a substituted or unsubstituted, straight-chain, branched or cyclic alkyl group which comprises 5 to 18 carbon atoms and / or contains an aromatic group or acyl group.

(2) Sterile cyanoacrylate component according to claim 1, characterized in that the curing on an ABS surface, determined by applying a tensile force of 1 kg for at least 5 s, in a maximum of 75 s, preferably in a maximum of 50 s, particularly preferably in a maximum of 35 s he follows.

(3) Non-sterile cyanoacrylate component according to claim 1, characterized in that the curing on an ABS surface, determined by applying a tensile force of 1 kg for at least 5 s, in a maximum of 50 s, preferably in a maximum of 25 s, particularly preferably in a maximum 15 s.

(4) Sterile cyanoacrylate component according to at least one of claims 1 and 2, characterized in that the adhesive shear strength of the cyanoacrylate component when applying a tensile force parallel to the bonding surface and to the main axis of the sample on nylon is at least 1.6 N/mm ² , preferably at least 1.8 N/mm ² , particularly preferably at least 2.0 N/mm ² .

(5) Non-sterile cyanoacrylate component according to at least one of claims 1 and 3, characterized in that the adhesive shear strength of the cyanoacrylate component when applying a tensile force parallel to the bonding surface and to the main axis of the sample on nylon is at least 1.6 N/mm ² , preferably at least 1.9 N/ mm ² , particularly preferably at least 2.5 N/mm ² .

(6) Cyanoacrylate component according to one of claims 1 to 5, characterized in that R is selected from the following groups: n-pentyl, /so-pentyl, cyclopentyl, n-hexyl, /so-hexyl, cyclohexyl, n-heptyl, / so-heptyl, cycloheptyl, n-octyl, 1-octyl, 2-octyl, 3-octyl, 4-octyl, decyl and dodecyl. .

(7) Polymerizable adhesive composition containing as at least one component a cyanoacrylate component according to any one of claims 1 to 6.

(8) Polymerizable adhesive composition according to claim 7, characterized in that the composition contains at least one inorganic acid as the primary anionic polymerization inhibitor and at least one organic sulfonic acid as the secondary polymerization inhibitor, said sulfonic acid being represented by the general formula (II)

O

Il R1 -S-OH

Il

⁰ Formula (II) is described and R1 represents an unsubstituted or a mono-, di-, tri-, tetra- or penta-substituted aryl group.

(9) Polymerizable adhesive composition according to claim 8, characterized in that the primary anionic polymerization inhibitor is an oxo, halogen or Lewis acid or a combination of said acids.

(10) Polymerizable adhesive composition according to at least one of claims 8 or 9, characterized in that the primary anionic polymerization inhibitor is selected from sulfur dioxide, boron trifluoride, nitrous oxide, hydrogen fluoride, hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid or phosphorus pentoxide or from combinations of the acids mentioned.

(11) Polymerizable adhesive composition according to claim 8, characterized in that R1 is described by the general formula (III), Formula (III) where R2 contains a hydrogen atom, a substituted heteroatom, a substituted or unsubstituted, straight-chain, branched or cyclic alkyl chain comprising 1 to 10 carbon atoms or an aromatic group and/or acyl group.

(12) Polymerizable adhesive composition according to claim 11, characterized in that R2 is selected from the following groups: methyl, methoxy, ethyl, ethoxy, n-propyl-, /-propyl- or n-butyl.

(13) Polymerizable adhesive composition according to one of claims 7 to 12, characterized in that the proportion of the secondary polymerization inhibitor based on the cyanoacrylate according to formula (I) or on the mixture of a cyanoacrylate according to formula (I) with further cyanoacrylates according to formula (I) fewer than 150 ppm.

(14) Polymerizable adhesive composition according to one of claims 7 to 13, characterized in that additionally at least one further component selected from the groups of plasticizers, thickeners, antimicrobial active ingredients, thixotropic agents, skin-care active ingredients, perfumes and reducing agents the formaldehyde concentration is contained.

(15) Process for producing a cyanoacrylate component according to one of claims 1 to 6 comprising the steps:

(a) Thermal cracking of a cyanoacrylate prepolymer in the presence of at least one inorganic acid as a primary anionic polymerization inhibitor and at least one organic sulfonic acid according to claim 8 as a secondary anionic polymerization inhibitor;

(b) separating the preferably monomeric cyanoacrylate obtained according to formula (I) from the anionic polymerization inhibitor by a suitable physical process, the boiling point of the preferably monomeric cyanoacrylate obtained being below the boiling point of the secondary anionic polymerization inhibitor and the separation of the preferably monomeric cyanoacrylate obtained from the anionic polymerization inhibitor at normal or reduced pressure by distillation.

(16) Process for preparing a compound of general formula (Ia)

Formula (Ia), where R is a substituted or unsubstituted, straight-chain, branched or cyclic alkyl group comprising 5 to 18 carbon atoms and/or containing an aromatic group or acyl group, comprising the steps:

(b) separation of the preferably monomeric compound obtained according to formula (Ia) from the primary and secondary anionic polymerization inhibitor by distillation, the distillation being carried out at normal or reduced pressure. .

(17) Polymerizable adhesive composition according to any one of claims 7 to 14 for topical and/or internal use on mammals.

(18) Polymerizable adhesive composition according to claim 17 for medical use on tissue.

(19) Polymerizable adhesive composition according to claim 18, characterized in that the tissue is human skin.

(20) The polymerizable adhesive composition according to any one of claims 17 to 19, wherein the tissue is surgically cut or traumatically torn tissue.

(21) A polymerizable adhesive composition according to any one of claims 17 to 20, wherein the polymerizable adhesive composition is applied to close or cover a wound.

(22) Polymerizable adhesive composition according to one of claims 7 to 14, characterized in that the polymerizable adhesive composition has been sterilized by the following methods or combinations of the following methods: heat, ultrafiltration, irradiation.