CZ20011972A3 - Substance for bonding, coating and sealing, containing cyanoacrylates and aldehyde or ketone condensation products - Google Patents

Abstract

Gel-forming condensation products of aldehydes or ketones can be used with polyols in cyanoacrylates to obtain dimensionally stable adhesives, coating and sealing substances. These are stable in storage and are especially suitable for bonding porous substrates such as paper or wood. They are particularly easy to handle when produced in the form of rub-off glue sticks.

Description

By using gel-forming aldehyde or ketone condensation products with polyols in cyanoacrylates, shape-stable adhesives, coatings and sealants are obtained. They are storable and suitable for bonding porous substrates such as paper and wood. Handling is particularly simple when it is made of pin-shaped adhesives. In the manufacturing process, the above ingredients are converted by heating into a solution which is subsequently cooled.

(13) Type of document:

(52) Int. Cl.

C09J 4/00

OJ C 08 F 22/32

C 09 J 5/00 •

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Bonding, coating and sealing compound containing cyanoacrylates and CL aldehyde or ketone condensation products

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention

(A) cyanoacrylates; and

B) aldehyde and ketone condensation products.

BACKGROUND OF THE INVENTION

Cyanoacrylate adhesives of this kind are known. Thus, DE 43 17 886 discloses a cyanoacrylate adhesive which contains from 1 to 40% by weight to reduce the adhesion to the skin. fat derivatives, either certain aliphatic alcohols or certain aliphatic carboxylic acid esters. To this mixture is added 10-100,000 ppm of anionic polymerization accelerator. A number of specific substances are mentioned, among others also formaldehyde and acetaldehyde condensation products and polyalkylene oxide ethers, for example with sorbitol as a hydroxyl-containing compound. Particular mention is made of polyoxyethylene sorbitan esters and polyoxyethylene sorbitan addition products. To make the low viscosity liquid cyanoacrylate more viscous or thixotropic, a thickener such as polymethyl methacrylate, acrylic gum, cellulose derivative or silicate is dissolved or dispersed. According to the examples, 0 to 10 wt. The disadvantage of this composition is that even at a high concentration of the thickener, the cyanoacrylate adhesive is liquid, and therefore is not used, for example, as a sealant and is not suitable for bonding porous substrates and generally can only be thoroughly applied.

SUMMARY OF THE INVENTION

The object of the prior art is to provide a cyanoacrylate compound with improved performance, which naturally entails at least the necessary properties for gluing, coating and sealing, first of all sufficient storage at room temperature. For this reason, production should be simple.

The solution according to the invention follows from the claims. It consists essentially in the use of a gelling agent based on the condensation product of aldehydes or. ketones with polyols for cyanoacrylates to produce a dimensionally stable mass at 20 ° C.

Dimensionally stable means that the mass at 20 ° C for 10 days does not change its shape by weight based on its own weight when the cylindrical mass is stored in an open case with a diameter of 1.5 cm and a length of 5 cm at 20 ° C in a horizontal position and protrudes less than 10 mm, preferably less than 0.1 mm from the opening. On the other hand, the stability of the shape should only be so high that, at moderate external pressure, the usual abrasion of commonly sold pin-shaped adhesives on paper remains.

Suitable gelling agents are certain condensation products of aldehydes and / or aldehydes. ketones and polyols.

Compounds having at least one acetal or ketal group are used as gelling agents. Such compounds are obtainable by condensation reactions and are also usually prepared, for example, by partial or complete reaction of polyols in a reaction ratio (OH: = C = O) of 1: 0.5 to 1: 0.01, preferably 1: 0.5 to 1: 0.1 with aldehydes or ketones by dehydration, e.g. in the presence of acid catalysis. Acetals and ketals of the invention may also be prepared by reacting polyols with aldehyde or ketone derivatives, for example, by reacting geminal dichlorides to cleave hydrogen chloride or acetals, respectively. ketals for alcohol cleavage. Suitable compounds have a melting point of at least 50 ° C, in particular at least 100 ° C, preferably at least 150 ° C. Mixtures of acetals and ketals may also be used.

Suitable polyols contain at least 1,2-diol, 1,3-diol or 1,4-diol. In addition, they may contain other functional groups such as ether, acid, amide, cyano, hemiacetal and halide groups. Examples of such polyols are:

1,2-Ethanediol, 1,3-propanediol, 1,2-propanediol, 2,3-butanediol, 1,4-butanediol,

2,2-dimethyl-1,3-propanediol, 2,2-bis / hydroxymethyl-1,3-propanediol, 2- (bromomethyl) -2- (hydroxymethyl) -1,3-propanediol, 1,3,4-butanetriol, 1-phenyl-1,2,2-propanetriol, 1,2-hexanediol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane,

2-methyl-1,3-propanediol, hexanetriol- (1,2,6), 2- (hydroxyethoxy) butane-1,3,4-triol, glycerin, diglycerin and polyglycerin, diglycerinediacetate, trimethylenepropane, di (trimethylenepropane), trimethylenethane, pentaerythritol, bicyclo [2.2.1] heptane-2,3,5,6-tetrol, 2,2,3,3-tetrahydroxydibutanoic acid, dipentaerythritol, sorbitol, formite, xylite, inosit, glucite, glucose, sucrose, starch cellulose, ascorbic acid, partially or completely hydrolyzed polyvinyl acetate, 9,10-dihydroxystearic acid methyl ester, diacetylsorbit and methyl glycoside.

Preferred polyols are: Sorbitol, xylite and mannitol, especially sorbitol.

Suitable aldehydes or ketones contain at least one substituted or unsubstituted aromatic, heteroaromatic or alicyclic ring. In addition, they may contain other functional groups such as ether, ester, amide, cyano and halide groups.

• <4 ·

-4 Examples of suitable ketones are:

Cyclopentanone, cyclohexanone, cycloheptanone, 1- (3,3-dimethylcyclohexyl) ethanone, 1-cyclopropylethanone, 3-methyl-5-propylcyclohex-2-en-1-one, dicyclopropylmethanone, 4-tert-butylcyclohexanone, dicyclohexylmethanone, 4- methylcyclohexanone, 1- (1-methylcyclopropyl) -ethanone, (4-chlorophenyl) -cyclopropylmethanone, 1- (1H-pyrrol-2-yl) -ethanone, 1- (2,4,6-trimethylphenyl) -ethanone, 1- (2-furanyl) -2-propanone, 1- (2-naphthalenyl) -ethanone, 1- (2-thienyl) -1-propanone, 1- (4-bromophenyl) -ethanone, 1- (4-methoxyphenyl) -ethanone, 1- (naphthalenyl) -ethanone, 1,1-diphenyl-2-propanone, 1,2-diphenyl-ethanone, 1,3-diphenyl-2-propanone, 1-phenyl-1-butanone, 1-phenyl-1-decanone, 1-phenyl- 1-dodecanone, 1-phenyl-1-hexanone, 1-phenyl-

1-octanone, 1-phenyl-1-pentanone, 1-phenyl-1-pentan-3-one, 1-phenyl-1-tetradecanone,

1-phenyl-2-butanone, 1-phenyl-2-propanone, 1-pyrazinyl-ethanone, 2,2,2-trifluorour-1-phenyl-ethanone, 1- (2-furanyl) -ethanone, 1- (2- pyridinyl) ethanone, 1- (2-thienyl) ethanone, 4-chloro-1- (4-fluorophenyl) -1-butanone, 4-phenyl-2-butanone, 1-phenylethanone, bis- (2-hydroxyphenyl) - methanone, bis- (4-chlorophenyl) -methanone, cyclopentylphenylmethanone, cyclopropyl- (4-methoxyphenyl) -methanone, cyclopropyl- (4-methylphenyl) -methanone, cyclopropyl-2-thienylmethanone, cyclopropylphenylmethanone, 1,5-diphenyl-1, 4-pentadien-3-one, phenyl-2-pyridinyl-methanone, 2-bromo-1- (4-nitrophenyl) -ethanone, 2-naphthalenylphenyl-methanone, 3-chloro-1-phenyl-1-propanone, 4- (4-hydroxyphenyl) -2-butanone, 4- (4-methoxyphenyl) -3-buten-2-one, 1- (4-pyridinyl) -ethanone, 1- (4-hydroxyphenyl) -ethanone, 1-phenyl-1-propanone, 4-phenyl 3-buten-2-one, diphenylmethanone, 1-phenyl-2-butanone, 1-phenyl-2-buten-1-one, bis- (4-methylphenyl) methanone, 2-methyl-1-phenyl-1 -propanone, 2-chloro-1-phenylethanone, cyclopropyl- (4-fluorophenyl) -methanone, 1- (p-methoxyphenyl) -2-propanone, cyclohexylphenylmethanone and phenyl- (2-thienyl) methanone.

Examples of suitable aldehydes are:

Benzaldehyde, 3-chlorobenzaldehyde, 4-chlorobenzaldehyde, 2,6-dichlorobenzaldehyde, 2,4-dinitrobenzaldehyde, 3,4-dichlorobenzaldehyde, 3-fluorobenzaldehyde, 4-bromobenzaldehyde, 2-methyltetrahydrobenzaldehyde, tetrahydrobenzaldehyde,

2-Methyl-5-isopropylcyclopenten-1-aldehyde, 2,2,4-trimethylcyclohexa-4,6-diene-1-aldehyde 3 (4) -methyl-1-propylcyclohexen-3-aldehyde, 1,3 (4) -dimethylcyclohexen-3-aldehyde, 2-methyl-1-propylcyclohexen-3-aldehyde, 3-cyclohexene-

1-aldehyde, 1,3,4,5,6-pentafluorobenzaldehyde, 2,4,6-trihydroxybenzaldehyde, 4tolylacetaldehyde, 2-methylbenzaldehyde, 4-hydroxybenzaldehyde, 3-methylbenzaldehyde, 2-hydroxy-1-naphthaldehyde, 4-methylbenzaldehyde, 3,5-dimethoxy-4-hydroxybenzaldehyde, cinnamic aldehyde, 3-nitrobenzaldehyde, 2-cinnamic pentylaldehyde, 4-diethylaminobenzaldehyde, 4-methoxybenzaldehyde, 2-phenylpropionaldehyde, 2-methoxyaldehyde cinnamon, 4-methylbenzaldehyde, methylpyenzaldehyde 2, phenoxyacetaldehyde 2-phenoxyacetaldehyde 5-dimethoxytetrahydrofuran-3-aldehyde, 2,5-dipropyl-3,4-dihydropyran-2-aldehyde, 2,5-diethyl-3,4-dihydropyran-2-aldehyde,

2,5-diisopropyl-3,4-dihydropyran-2-aldehyde, 2,5-dimethyl-3,4-dihydropyran-2aldehyde, 2,5-dibutyl-3,4-dihydropyran-2-aldehyde, thiophene-3- aldehyde, indole-3-aldehyde, thiophene-3-aldehyde, pyridin-3-aldehyde, pyridin-4-aldehyde and N-methylpyrrole-2-aldehyde.

Preferred aldehydes are: Benzaldehyde, 3-chlorobenzaldehyde and 3-fluorobenzaldehyde, especially benzaldehyde.

Examples of acetals and ketals are: Di-o-benzylidene mannitol, di-o- (2-chlorobenzylidene) mannitol, di-o- (4-nitrobenzylidene) mannitol, di-o- (3-fluorobenzylidene) mannitol, o- benzylidensorbit, di-o-benzylidensorbitdiacetate, di-o- (2-chlorobenzylidene) sorbitdiacetate, tri-o- (4-chlorobenzylidene) sorbitol, o-benzylidene threitol, o-benzylidene tartaric acid methyl ester, o-cyclohexylidene glycerin ester, ocyclohexylic acid and ocyclohexyl ester o-benzylidene-9,10-dihydroxystearic acid.

Preferred acetals and acetals, respectively. ketals are: di-o-benzylidenemenite, di-o- (3-fluorobenzylidene) mannitol and di-o-benzylidene sorbitol, especially di-o-benzylidene sorbitol.

The proportion of aldehyde resp. % of the ketone condensation products is 0.1 to 1 wt.%, preferably 0.4 to 6 wt. based on the total mass of cyanoacrylate.

• · · · · · · · · · ····

The mass of the cyanoacrylate is based essentially on the usual cyanoacrylates; on monoacrylic acid esters and / or on biscyanoacrylates. Their proportion is at least 29.5, preferably at least 50% by weight, based on the total weight of the cyanoacrylate.

'Common esters of monoyanacrylic acid' means the following substances of the general formula:

H ₂ C = C (CN) -CO-OR (I).

In it R is an alkyl, alkenyl, cycloalkyl, aryl, alkoxyalkyl, aralkyl or haloalkyl group, up to 2 conjugated double bonds of CC, with a cycloaliphatic 6-membered ring, with a benzene-derived aromatic ring, and preferably with Br or Cl as halogen, with 1 to 18, preferably 2,3 or 4 C atoms, in particular methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, hexyl, cyclohexyl, heptyl, 2-ethylhexyl, n-octyl, n-nonyl, oxononyl, n-decyl, ndodecyl, 2,2,2-trifluoroethyl, hexafluoroisopropyl, allyl, methallyl, crotyl, propargyl, benzyl, phenyl, cresyl, 2-chloroethyl, 3-chloropropyl, 2-chlorobutyl, tetrahydrofurfuryl, 2-methoxyethyl, butoxyethoxyethyl, 3-methoxybutyl and 2ethoxyethyl. The above cyanoacrylates are known to adhesive specialists, see Ullmanns Encyclopaedia of Industrial Chemistry, Bd.A1, p.240, Verlag Chemie Weinheim (1985) and US 3,254,111. Preferred monomers are allyl, methoxyethyl, ethoxyethyl, methyl, ethyl, propyl, isopropyl or butyl 2-cyanoacrylate.

"Biscyanacrylates" are substances with the following general formula:

[H ₂ C = C (CN) -CO-O] ₂ R ¹ (II).

·····················

In it R ¹ is a branched or unbranched divalent alkane radical with 2-18, in particular 6-12 C atoms, which may also contain heteroatoms such as halogens and oxygen, or aliphatic or aromatic rings. Preferably, however, R ¹ a pure hydrocarbon.

It is important that cyanoacrylates are particularly clean. This requirement is met, for example, by the following production and purification methods: In essence, the monocyanacrylates are esterified with diols and the reaction mixture is subsequently subjected to fractional crystallization.

Thus, a suitable process for the preparation of biscyanacrylates is to produce 2-cyanoacrylic acid or an alkyl ester thereof of the formula

H ₂ C = C (CN) -CO-OR ² (III), wherein R ² is a branched or unbranched alkyl radical having 1 to 6 C atoms, re-esterified with diols of the general formula [HO] ₂ R ¹ (IV), wherein R 1 is a branched or unbranched dibasic C 2 -C 18 alkane radical, which may also contain heteroatoms such as halogens and oxygen or aliphatic or aromatic rings, to the biscyanacrylates of formula II, and then the reaction mixture is purified by fractional crystallization.

Thus, the starting product is a monofunctional cyanoacrylic acid or an alkyl ester thereof according to Formula III. The alkyl moiety must be selected so that the alcohol formed can be easily removed. Suitable possibilities for this purpose are known to those skilled in the art from the general re-esterification reactions. Preferably, the alcohol is removed by distillation. Therefore, R ^{2 is a} branched or unbranched alcohol residue having 1 to 6 C atoms, preferably one or two C atoms. The monofunctional cyanoacrylic ester is conventionally stabilized.

The diols (Formula IV) are dibasic primary or secondary alcohols, preferably primary alcohols. The hydroxyl groups may be in any position, preferably in the alpha / omega position. The diols contain 2 to 18 C atoms, preferably 6 to 12 C atoms. They may have a linear, branched or cyclic configuration. The aliphatic residue may also contain an aromatic group or, in addition to the hydrogen and carbon atoms, heteroatoms such as chlorine or oxygen, preferably in the form of polyethylene glycol or polypropylene glycol units. Specific diols include: Hexanediol, octanediol, decanediol and dodecanediol.

Cyanoacrylic ester is used in excess. Thus, the molar ratio of the monofunctional cyanoacrylic ester to the diol is at least 2.0: 1.0, preferably 2.5: 1.0, in particular 2.2: 1.0.

The esterification is also catalyzed by strong acids, in particular sulfonic acids, preferably aromatic sulfonic acids, such as p-toluenesulfonic acid. Naphthaline sulfonic acid and benzenesulfonic acid and acidic ion exchangers are suitable. The concentration of the re-esterification catalyst should be between 1 and 20% by weight, based on the monofunctional cyanoacrylate.

The esterification is carried out, as is customary, in solution. Aromatics and halogenated hydrocarbons are used as solvents. A preferred solvent is toluene and xylene. The concentration of the solution lies in the range of 10 to 50%, preferably 10 to 20%.

The resulting monobasic alcohol or the like. the resulting water is removed in a known manner, preferably distilled off with a solvent. The re-esterification turnover is controlled, for example, by NMR spectra. The reaction takes many hours. In the case of toluene as the solvent and p-toluenesulfonic acid as the catalyst, the reaction is completed after 10 to 15 hours, i. no alcohol is separated.

The preparation of the reaction mixture is now very important. The acid ion exchangers as catalyst can be simply filtered off. Dissolved sulfonic acids as a catalyst such as p-toluenesulfonic acid are separated by solvent substitution: Toluene is replaced by a mixture of hexane, heptane or decane. After double traction crystallization, pure biscyanacrylate is obtained. Purity was &gt; 99% by NMR.

The obtained bisyanacrylate is storable with the usual stabilizers and in the usual concentrations, i.e. does not change practically its melting point at 20 ° C during 6 months.

However, the obtained biscyanacrylates polymerize very rapidly, preferably practically as fast as the corresponding monocyanacrylates in the presence. As with monofunctional cyanoacrylates, traces of water are sufficient. This results in a three-dimensional cross-linked polymer with relatively good thermal properties.

According to the invention, it is therefore used in known cyanoacrylate compositions, namely in an amount of from 0.5 to 50, preferably from 1 to 10, in particular from 2 to 5% by weight, based on the total yanoacrylate composition.

As cyanoacrylic esters are known to be accessible to both anionic and chain radical polymerization, it is therefore desirable to protect the ester masses from both types of polymerization to avoid premature hardening of the ester, thereby avoiding storage problems. In order to prevent anionic polymerization, anionic polymerization inhibitor can be added to the adhesives according to the invention. Suitable are all anionic polymerization inhibitors which have hitherto been used in the field of cyanoacrylate ester adhesives. For example, it may be an anionic polymerization.

An inhibitor of an acidic gas, a protonic acid or an anhydride thereof. A preferred anionic polymerization inhibitor for the adhesives of the invention is sulfur dioxide, preferably in an amount of 0.001 to 0.5% based on the adhesive. Other useful anionic polymerization inhibitors are nitrous oxide, hydrogen fluoride, hydrochloric acid, sulfuric acid, phosphoric acid, organic sulfonic and carboxylic acids and their anhydrides, phosphorus pentoxide and acid chlorides. Depending on the purpose, a free-radical chain polymerization inhibitor is also added to the adhesives of the invention in an amount of 0.01 to 0.05%. This free-radical chain polymerization inhibitor may be any of the free-radical chain polymerization inhibitors known to cyanoacrylic acid ester masses. Generally, phenolic compounds are used, for example hydroquinone, t-butyl catechinone, pyrocatechin and p-methoxyphenol. The above commercially available cyanoacrylic acid ethyl ester formulations are already stabilized. If it is necessary to adjust the concentration of the stabilizer when using formulations available on the market, this is not a problem for the skilled person.

According to the purpose, polymers are added to the cyanoacrylate compositions according to the invention, for example in order to increase their viscosity (thickener) or to increase their viscosity. to change the properties of the adhesive. The polymers may be used in an amount of 1 to 60, in particular 10 to 50, preferably 10 to 30% by weight, based on the total formulation. Particularly suitable are polymers based on vinyl ethers, vinyl esters, acrylic esters and methacrylic acid and from 1 to 22 carbon atoms in the alcohol component, styrene and the like. copolymers and terpolymers derived therefrom with ethene, butadiene. Vinyl chloride / vinyl acetate copolymers having a vinyl chloride content of 50 to 95% by weight are preferred. The polymers may exist in liquid, resin or solid form. It is particularly important that the polymers do not contain any impurities from the polymerization process that inhibit the curing of the cyanoacrylate. If the polymers have too high a water content, they must be dried if necessary. The molecular weight can be spread over a wide range, it should be at least MH = 1500, but at most 1,000,000, otherwise the final viscosity of the adhesive formulation will be too high. Mixtures of the above polymers can also be used. In particular, the combination of low and high molecular weight products has particular advantages with respect to the final viscosity of the adhesive formulation. Examples of suitable vinyl acetate-based polymers are: Mowilith types 20, 30 and 60, Vinnapas B1.5, B100, 17, B5, B500 / 20VL, B60, UW10, UW1, UW30, UW4 and UW50. Examples of suitable acrylate-based polymers are: Acronal 4F, and Laromer 8912, PE55F and PO33F types. Examples of suitable methacrylate-based polymers include: Elvacite 2042, Neocryl types B724, B999 731, B735, B811, B813, B817, B722, Plexidon MW 134, Plexigum M 825, M 527, N 742, N 80, P24 types , P28 and PQ 610. Examples of suitable vinyl ether-based polymers include: Lutonal A25. Cellulose and silica gel derivatives may also be used for thickening. The addition of polycyanacrylates is particularly preferred.

Accordingly, the cyanoacrylate composition according to the invention may also contain further auxiliaries in order to achieve certain effects appropriate to the intended use. These include primarily the polymerization accelerators described in DE 43 17 886, namely polyalkylene oxides and their derivatives, in particular their esters and ethers. Other polymerization accelerators are: CROWNETHERS and their derivatives, silicacrown compounds, cyclic sulfur compounds. These polymerization accelerators are known to be added in an amount of 10 to 100,000 ppm, in particular 30 to 10,000 ppm, based on the cyanoacrylate mass. Another accelerator is cyclodextrin.

Fatty derivatives as described in DE 197 52 893 or DE 43 17 886 can also be used as plasticizers. These are fats and fat derivatives, in particular aliphatic alcohols, aliphatic carboxylic acid esters or carboxylic acid esters of carbocyclic compounds. Further details can be obtained directly from the aforementioned patents.

Of course, conventional plasticizers such as phthalates, citric acid esters, chloroparaffin and trimellithic acid esters are also suitable.

Solvents may also be added to increase, in particular, the solubility of the aldehyde and / or aldehyde. of the ketone condensation product, respectively. to make this product easier to incorporate in the form of a solution. Suitable organic solvents are, for example, low molecular weight alcohols, ethers, ketones and alkyl esters. Particularly useful are isopropanol, methoxypropanol, ethoxypropanol, ethoxyethanol, propoxyethanol, butoxyethanol, methylethylketone and N-methyl-2-pyrrolidone. However, the solvent content of the cyanoacrylate mass should be as low as possible in order not to compromise the shape stability, preferably less than 20% by weight.

Other excipients are activators, dyes, color pigments, fragrances, preservatives, antiseptics and fillers.

The cyanoacrylate composition according to the invention is essentially produced by dissolving the cyanoacrylic acid ester and the aldehyde or ketone condensation products by heating with polyl and then converting them into solid phase by cooling. Generally, a stabilized cyanoacrylate mass is first prepared from an acrylic acid ester and an anionic polymerization inhibitor with N ₂ as a shielding gas and heated to 50-90 ° C. Now, with vigorous stirring, it dissolves. suspending the desired components until a homogeneous mixture is obtained. A condensation product is added in portions at a temperature of 80 to 95 ° C and further dissolved at 90 to 95 ° C. The mixture is then cooled, preferably to ca. 80 ° C, filtered and then poured into the desired molds. After ca. As a rule, the material hardens for 1 hour and is stable after 24 hours for use as a glue stick. In spite of this shape stability, the cyanoacrylate mass can be rubbed down onto a substrate, eg paper, with a slight pressure.

Because of this dimensional stability, the cyanoacrylate composition is suitable for geometric shaping, in particular for a pin shape. Advantageous is the production of a cylindrical adhesive pin. Depending on the purpose, the shape is directed for later use. However, all forms are possible, in particular geometric forms with at least one symmetric axis or symmetrical plane, eg balls, blocks, pyramids, ♦ 9 9 9

9 9 9 9 9 9 9 9 9

9 9 9 9 - · · · · 9 9 9 · · 9 9 9 · _e jO ··· 9 9 9 9 9 9 *

Also in 9 9 9 9 9 9 9 9 9 9 9 9 9 cone, cylinder, pegs, tapes, plates, foil and cushions. Preferred is a mold in two dimensions smaller than in the third. Such forms are, for example, hotmelt-stick pellets. lead wax pins. Podstava resp. the geometric feature may be corner, triangular, quadrilateral or hexagonal or round (e.g., circular or elliptical). The diameter can be 2 to 100 mm and the length up to 150 mm. Thus, the form and amount of the cyanoacrylate composition according to the invention is very variable and is essentially governed by what is appropriate for the particular application.

Liquid cyanoacrylate compositions with strong thixotropic properties are obtainable by shearing the prepared cyanoacrylate composition at high speed. The cyanoacrylate compositions according to the invention are suitable for bonding, coating and sealing, in particular for bonding porous substrates such as leather, textile, paper, cardboard, cardboard, wood and bark. Due to the pin form, the cyanoacrylate compositions according to the invention can be used particularly advantageously as an adhesive for the repair of shoes, PVC pipes and artificial nails. Wound bonding, especially using long chain cyanoacrylic esters, is also well possible. By combining with primers such as aliphatic amines, polyolefins can also be adhered well. The primers can also be made in the form of a pin with the gelling agent according to the invention. Dyed and corrective pins can be produced by the addition of a covering pigment and / or dye. Such pins are particularly environmentally friendly in the absence of solvent. It is also conceivable to use it as a material for filling and bridging cracks and openings in diverse materials. Depending on the purpose, both substrates are coated with an adhesive, for example by rubbing the adhesive pin. Cracking is also possible.

When used as a sealant, rapid cure is remarkable.

Surprisingly, the cyanoacrylate composition according to the invention has an exceptional shelf life. For example, it can be stored in traditional glue plug cases at room temperature for many weeks and remains usable without reducing the adhesive force.

Other advantages of the Cyanoacrylate Compound of the Invention are: Simple application, certain handling (no staining, e.g., in the eyes or skin), flat coating, bonding of perpendicular substrates.

The invention is illustrated in detail by means of examples:

After 6 months at a temperature of 2 to 5 ° C, the adhesive pegs were still usable; the consistency and properties of the adhesive were good.

After 9 months at -18 [deg.] C., the adhesive pegs were also still usable; no breakage of the gel structure and no polymer formation was observed:

After heating to 20 ° C, the plugs could be easily removed from the housing. The setting time and adhesive force were virtually unchanged during the experiments on paper (paper crack). Shelf life at -18 ° C for more than 9 months is particularly important for medical applications.

Examples of embodiments of the invention

1. Production of cyanoacrylate materials

A stabilized cyanoacrylic ester was placed in a three-necked flask under shielding N2 and mixed portionwise with polymethacrylate at 50 ° C with vigorous stirring. after 10 minutes the solution was clear and homogeneous.

For gel production, the temperature was raised to 85 ° C and dibenzylidensorbital was added in portions to prevent the formation of lumps. After 10 minutes, the gelling agent was further dissolved. After cooling to about 80 ° C, the undissolved particles were removed by filtration. The still hot solution was filled into a conventional glue stick housing and then cooled. After ca. 1 hour solid consistency was formed. The next day the glue plug was usable and was durable for several weeks despite multiple opening and closing.

2. Tests

(a) For the shelf life test, the cyanoacrylate mass was tested weekly in the adhesive peg housing at a temperature of 23 ° C at a relative atmospheric humidity of 50% for paper adhesion.

b) To determine the setting time, the cyanoacrylate mass was applied on one side to a 30 cm long strip of paper and immediately followed by a second strip of paper and pressed. The time needed to tear off the paper by breaking the glued joint was determined.

• · · ·

c) To determine the tensile strength of the longitudinal adhesive joints, a) 2 drops of liquid adhesive were applied to a 10 x 25 mm substrate area and spread or b) a comparable amount was applied unilaterally by rubbing the adhesive pin. Immediately thereafter, the second substrate was pressed lightly. After a delay of 2 days at 23 ° C and 50% relative humidity, beech wood as well as non-wood specimens with EN 205 support were tested for tensile strength (speed: 10 mm / min).

Mean values of the 5th measurement were reported. The substrates were pretreated as follows:

Beech wood: untreated,

PMMA: degreased,

ABS: degreased,

PVC: degreased,

Alu: sandblasted and degreased.

3. Results

The results of the tests are summarized in Tab. 1. They show that in any case the required strength is achieved, which in the case of beech wood exceeds the traditional cyanoacrylate adhesives.

• · · · · · · · · · · · · · · 0 · 0 0 4 0 0 · 0

- 17 Tab.1: Composition (in parts by weight) and properties of cyanoacrylate masses

B1 B2 I. Composition 1. Cyanoacrylic acid ethyl ester 100 ALIGN! 100 ALIGN! 2. SO ₂ + + 3. Phosphoric acid, methanesulfonic acid + + 4. Polymethacrylate 5 5 5. Dibenzylidensorbital 0 1,8 II. Properties (a) Shelf life [weeks] - > 10 b) Setting time [sec] no gluing 20 May (c) Tensile strength [Mpa] - Beech wood 7,33 TA 7.75 - PMMA 7,01 MB 6,11 MB - ABS (plastic, mass) 8,10 MB 6,21 č.MB - aluminum (sandblasted) 14.75 7.08 - PVC 14,59 MB 4,90 MB

TA = tear of the material

MB = material breakage part.MB = material breakage for individual test specimens

Represented by:

Patent claims

Claims (9)

1. Cyanoacrylate compound for gluing, coating and sealing, characterized in that it is based on a mixture of (a) at least one cyanoacrylate; and b) at least one aldehyde or ketone condensation product with one polyol. Compound according to claim 1, characterized in that it contains at least one substance from the following group of aldehydes or ketones: Benzaldehyde, 3-chlorobenzaldehyde and 3-fluorobenzaldehyde, in particular benzaldehyde. A composition according to claim 1, characterized in that it comprises at least one substance from the following group of polyols: Sorbitol, xylitol and mannitol, in particular sorbitol. A composition according to claim 1, characterized in that it contains at least one substance from the following group of aldehyde or ketone condensation products with polyols: especially di-o-benzylidensorbit. 5. A composition according to claim 1 having the following composition (based on total cyanoacrylate composition): (A) 99,8 to 29,5% by weight of at least one cyanoacrylate and B) 0.1 to 10% by weight of at least one aldehyde or ketone condensation product with one polyol and C) 0.001 to 0.5% by weight of stabilizers, D) 0 to 60% by weight of thickeners, solvents, plasticizers, fillers and other excipients. Material according to claim 1, characterized in that it has a geometric shape, in particular a pin shape. Production of the mass according to at least one of Claims 1 to 6, characterized in that a solution is first produced from components A) and B) by heating, which is then subsequently cooled. Use of the composition according to at least one of claims 1 to 6 for gluing, coating and sealing. Use according to claim 8 for bonding porous substrates. Represented by: