EP2064276A2

EP2064276A2 - Aqueous silicon dioxide dispersions for sealant and adhesive formulations

Info

Publication number: EP2064276A2
Application number: EP07820366A
Authority: EP
Inventors: Dietrich Pantke; Peter-Nikolaus Schmitz; Hartmut Melzer; Rüdiger MUSCH
Original assignee: Akzo Nobel Chemicals International BV
Current assignee: Nouryon Chemicals International BV
Priority date: 2006-09-20
Filing date: 2007-09-20
Publication date: 2009-06-03
Also published as: US8946338B2; WO2008034856A2; WO2008034856A3; US20100029810A1; CN101558111B; CN101558111A

Abstract

The invention relates to aqueous dispersions, characterized in that they comprise (c) at least one aqueous silicon dioxide dispersion with a mean particle diameter of the SiO<SUB>2</SUB> particles of from 1 to 400 nm and (d) at least one water-soluble hydroxyl-containing organic compound, to a process for their preparation and to their use in adhesive and coating formulations.

Description

The invention relates to aqueous dispersions based on silica and hydroxyl-containing water-soluble compounds, a process for their preparation and their use as a component in the production of sealants and adhesives and

Coatings - especially for the production of adhesive coatings gen - and the resulting sealant or Kϊebstoffformulierungen and a method for joining the one-sided or double-coated substrates using these formulations.

For aqueous silica dispersions, there is a wide range of applications, e.g. as a binder in the foundry and steel sector in the area of investment casting, as an additive for the modification of

Surfaces, i. Production of non-slip paperbags and coating of special papers,

Antiblocking of foils, in the building sector as an additive for shotcrete and for impregnation.

(see: Levasil brochure of the company H.C.Starck, Goslar Germany, www.hcstarck.com). Furthermore, the use of silica dispersions in aqueous adhesive systems is known (Ganster et al, New raw materials for solvent-free sealants and sealants in magazine "gluing and

Dichten ", 3/2003).

From the prior art, the use of silica products for different applications is known. While solid SiO ₂ products are often used to control rheological properties, as fillers or adsorbents, silica dispersions (for example, silica sols) are dominated by the use as binders of various inorganic compounds

Materials, as polishing agents of semiconductors or as flocculation partners in colloid chemical reactions. For example, EP-A 0 332 928 discloses the use of polychloroprene latices in the presence of silica sols as an impregnation layer in the production of fire protection elements. In FR-A 2 341 537 and FR-A 2 210 699 fumed silicas in combination with Polychloroprenlatices for the production of flame-resistant foam or

Bitumen and described in JP-A 06 256 738 in combination with chloroprene-acrylic acid copolymers. Furthermore, EP 1652879 A1 describes coatings of fiber products with aqueous dispersions of polychloroprene and silica sols for producing textile-reinforced and fiber-reinforced concrete.

Furthermore, the use of SiHcium dioxide dispersions in the production of adhesive

Formulations based on polychloroprene dispersions known (WO 03/102066 A2).

Important parameters for such formulations are "open time" and "pot life"

Dispersions, as well as "heat resistance" and "water resistance", the resulting dry

Coating or adhesive films. For adhesives, the term "open time" according to DIN 16920 is understood to mean the time after the adhesive application within which wet adhesion is possible. to extend the processing time (open time). Although the replacement of these resins by silica dispersions increases the temperature resistance of the bonds, it reduces the "open time." The addition of silica dispersions to aqueous resinous

Although polychloroprene dispersions increase the "open time", but reduce the temperature resistance of the bonds.

The term "pot life" is understood to mean the time in which the formulation can be processed after mixing in at least one further dispersion. According to the prior art, (Ullmann, Encyklopadie der technischen Chemie, Volume 14, 4th edition, p. can be achieved by adding

Solvents and / or plasticizers accelerate the setting speed and lower the film-forming temperature. By this measure, however, the heat level of the coating or the adhesive seam is reduced. A higher thermal state can be achieved by adding a second dispersion based on resorcinol or mefamine resin or inorganic salts such as e.g. Achieve chromium nitrate. However, these two-component dispersion formulations are limited in their "pot life" to a few hours.

Coatings or bonds with high water resistance and heat resistance are obtained by the so-called "EPI system" (emulsion polymer isocyanate), which is achieved by adding about 15% of isocyanate - mostly MDI (diphenylmethane-4,4'-diisocyanate). - for polymer dispersion Due to the very short pot life, only one machine order of the two

Component formulation (2K formulation) possible

In addition, these 2K formulations classify various metal salt crosslinkers as corrosive or fire promoting. Depending on the isocyanate type, isocyanate-based crosslinkers have to take into account their irritant effect and their sensitizing potential on the skin and respiratory tract (see leaflet TKH-3 "Dispersion wood glues" Edition 2004, vom

Industrieverband Klebstoffe eV, Dusseldorf (www.klebstoffe.com)).

For the coating and impregnation of textile concrete reinforcing fibers with polymer dispersions, aqueous dispersions based on polychloroprene, acrylate, chlorinated rubber, styrene-butadiene or reactive systems based on epoxy resin and based on unsaturated polyesters were used. The penetration of the rovings takes place by coating the filaments in the roving production or by soaking the rovings before or after the textile production. The curing or crosslinking of the polymeric phase is carried out before the reinforcement textiles are introduced into the concrete. Thereafter, the treated rovings or textiles are embedded in fine concrete. The addition of G

Due to increased ecological requirements for the limitation of emissions of volatile organic compounds, it is also desirable also the residual content of free monomer - hereinafter also referred to as residual monomer content - of polymer dispersions before her

Further processing in an adhesive formulation.

Thus, there has remained a need for aqueous coating and adhesive dispersions which do not have the disadvantages described, i. in formulations extend the pot life, reduce the residual monomer content of the polymer dispersions used and produce bonds with high heat resistance and high water resistance.

The present invention was thus based on the object of providing aqueous silicon dioxide dispersions which, in aqueous polymer-containing adhesive dispersions, have a rapid setting and / or a long open time and high initial strength after application to the substrates to be coated or bonded. It would also be advantageous if the resulting dry coating or adhesive films have high water resistance and heat resistance. Furthermore, a reduced residual monomer content would be advantageous.

Surprisingly, it has been found that dispersions comprising silicon dioxide dispersion and certain water-soluble organic compounds have these properties.

The present invention thus relates to aqueous dispersions, characterized in that they

(A) at least one aqueous Siiiciumdioxid dispersion having an average particle diameter of the SiO ₂ ~ particles of 1 to 400 nm, preferably 1 to 200 nm and

(B) contain at least one water-soluble hydroxyl-containing organic compound.

The water-soluble hydroxyl-containing organic compounds according to the invention are dissolved in the Siiiciumdioxid dispersion before. Undissolved portions are separated before use. These dispersions comprising components (a) and (b) are also referred to below as dispersions according to the invention in the following.

Aqueous silica dispersions have been known for a long time. Depending on the manufacturing process, they are available in different forms. g, py g, ggg.

Fatty acid sols are colloidal solutions of amorphous silica in water, which are also commonly referred to as silica sols but are referred to as silica sols for short. The silica is present in the form of spherical and surface-hydroxylated particles. The particle diameter of the loColloidteilchen is usually 1 to 200 nm, wherein the particle size correlating BET specific surface area (determined by the method of GN Sears, Analytical Chemistry Vol. 28, N. 12, 1981-1983, December 1956) at 15 up to 2000 m ² / g. This correlation can be represented as follows: Assuming that silica sols are present as spherical primary particles and have a density of 2.2 g / cm ³ , this results in a factor of 2750. This factor divided by the specific surface area gives the particle size in nm (For the determination of the factor, see Ralph K. Her, The Chemistry of Silica, John Wiley & Sons New York 1979, pp. 465 f.). The surface of the SiO ₂ particles has a charge which is counterbalanced by a corresponding counterion which results in the stabilization of the colloidal solution.

The alkaline stabilized silicic acid have a pH of 7 to 3 1.5 and contain, for example, small amounts of Na ₂ O, K ₂ O, Li ₂ O, ammonia, organic nitrogen bases, tetraalkylammonium hydroxides or alkali metal or ammonium aluminates as alkalizing agents. Silica sols may also be slightly acidic as semi-stable colloidal solutions. Furthermore, it is possible to produce silica sols which have been cationically adjusted by coating the surface with Ala (OEQsCl) The solids concentrations of the silica sols are preferably from 5 to 60% by weight of SiO ₂ .

The production process for silica sols essentially goes through the production steps of dealkalization of water glass by means of ion exchange, adjustment and stabilization of the respectively desired particle sizes (distribution) of the SKV particles, adjustment of the respectively desired

SiO ₂ concentration and optionally a surface modification of the SiO ₂ particles, such as with Al ₂ (OH) ₅ Cl. In none of these steps do the SiOr particles leave the colloidally dissolved state. This explains the presence of the discrete primary particles,

Silica gels are colloidally shaped or unshaped silicas of elastic to solid consistency with a loose to dense pore structure. The silica is in the form of highly condensed polysilicic acid. On the surface are siloxane and / or silanol groups. The silica gels are prepared from water glass by reaction with mineral acids.

Furthermore, a distinction is made between fumed silica and precipitated silica. In the precipitation process, water is introduced and then water glass and acid, such as H ₂ SO ₄ , Agglomerate and agglomerates verwachs n specifi h O gg 30 to 800 m ² / g (determined according to test specification: DIN 66131) and the primary particle size at 5 to 100 nm. The primary particles of these present as solid silicas are usually firmly networked to secondary agglomerates , The particle size data are average

Particle sizes.

Pyrogenic silica can be prepared by flame hydrolysis or by the arc process. The dominant synthesis method for fumed silicas is flame hydrolysis, in which tetrachlorosilane is decomposed in an oxyhydrogen flame. The resulting silica is X-ray amorphous. Pyrogenic silicic acids have significantly less OH groups than precipitated silica on their virtually pore-free surface. The fumed silica prepared via flame hydrolysis generally has a specific surface area of 50 to 600 m ² / g (determined according to DIN 66131) and a particle size of 5 to 50 nm, and the silica prepared by the arc process has a specific surface area of 25 to 300 m ² / g (determined according to DIN 66131) and a particle size of 5 to 500 nm. Again, the

Primary particles of these present as solid silicas usually crosslinked to secondary agglomerates. The particle size data are average particle sizes which include the size of primary particles and any agglomerates present therefrom.

Further details on the synthesis and properties of silicic acids in solid form are, for example, K.H. Büchel, H.-H. Moretto, P. Woditsch "Industrial Inorganic Chemistry", Wiley VCH Verlag 1999, chapter 5.8.

If an SiO ₂ raw material present as an isolated solid, such as, for example, pyrogenic or precipitated silica, is used for the novel dispersions, this is converted into an aqueous SiO ₂ dispersion by dispersing.

Dispersants of the prior art are used to prepare the silica dispersions, preferably those suitable for producing high shear rates, e.g. Ultratorrax or dissolver discs

Preference is given to using those aqueous silicon dioxide dispersions (a) whose SiO ₂ particles have a primary particle size of 1 to 400 nm, preferably 5 to 100 nm and particularly preferably 8 to 60 nm. In the case of precipitated silicas are used, they are ground for particle reduction.

The particle size of silica sol particles can be calculated from the BET surface area as described above. Primary particles as well as in the form of agglomerates. The expression "average particle size" in accordance with the invention means the mean particle size determined by means of ultracentrifugation and includes the size of primary particles and any agglomerates present therefrom (see: HG Müller, Progr. Colloid Polym., Sci 107, 180-188 (1997)). The weight average is given).

Preferred dispersions of the invention are those in which the SiOr particles of the silica dispersion (a) are present as discrete uncrosslinked primary particles. Such preferred dispersions according to the invention containing discrete uncrosslinked primary particles are, in particular, silica sols.

It is also preferred that the SiO ₂ particles have hydroxyl groups on the particle surface.

Particular preference is given to using aqueous silica sols as aqueous silicon dioxide dispersions. Suitable silica sols are also commercially available, for example from H.C. Starck GmbH (Levasil®).

Water-soluble hydroxyl-containing organic compounds in the context of the invention are to be understood as meaning all linear or cyclic oligomers or polymers which contain hydroxyl groups in the OHgomer- or polymer chain and are water-soluble. For the purposes of the invention, oligomers are to be understood as meaning those compounds having up to 10 repeat units and a molecular weight of less than 1000, and polymers having more than 10 repeat units, in which case the repeat units may be the same or different. Preferred examples of OH-containing oligomers and polymers are hydroxyalkylcelluloses, polyvinyl alcohols or cyclodextrins. Preferred OH-group-containing oligomers or polymers are cyclodextrins in the context of the invention.

The use of cyclodextrins is based on the possibility that water molecules inside the tubular cyclodextrins can be exchanged for hydrophobic guest molecules. Examples of such monomers or low molecular weight compounds can be found in the yearbook of Heinrich-Heine - University of Düsseldorf 2002, article by H. Ritter and M. Tabatabai (www.uni-duesseldorf.de/home/jahrbuch/2002/ritter/index_html) ,

The inclusion of low molecular weight guest molecules or compounds can be carried out at most in the equimolar range, ie the ratio of cyclodextrin: guest molecule is less than or equal to 1: 1. The diameter of the guest molecules should be 0.95 nm maximum for Cavamax W6, 0.78 nm maximum for Cavamax W6 and 0.57 nm maximum for Cavamax W8. (Fig. 10).

Depending on the complexing constant of the respective low molecular weight compound, uptake by cyclodextrin may also be lower. A calculation of the recording is described by "M.V. Rekharsky and Y. Inoue, Cfwm. Rc'v., 98: 1875-1917, 1998, "Described are such complexes between cyclodextrin and guest molecules in the regions

Food, Tcxtil, Cosmetics, Agriculture and Pharmacy. References in "Tamur Uyar, Nanostricturing polymers with cyclodextrins, Ph.D. thesis at North Carolina State University, Sector Fiber and Polymer Science, September 2005." There is no literature available for use in the adhesives field.

Cydodextrins as water-soluble hydroxyl group-containing organic compounds in the compositions according to the invention have the advantage that the Rcstmonomergehalt can be significantly reduced in the resulting dispersions.

Suitable Cydodextrins are unsubstituted and substituted Cydodextrins.

Preferred cyclodextrins are ά-, ß- and γ-Cyclodcxlriπe and their ester, alkyl ether, hydroxyalkyl ether. Alkoxycarbonylalkylether-, Carboxyalkylcther derivatives or their salts _.

Particularly preferred are methyl-ά-cyclodextrin, methyl-β-cyclodextrin, methyl-γ-cydodextrin, ethyl-β-cyclodextrin, β-butylcyclodextrin, butyl-β-cyclodextrin, butyl-γ-cyclodextrin, 2,6-DimethyUά -cyclode ^χ triii, 2,6-dimethyl-.beta.-cyclθdexirin, 2,6-Ditnαhyl-γ-cyclodexlriπ, 2,6-DJethyl-ß-cydodex.lrin, 2,6-dibutyl-ß-cyclodcxtrin, 2.3 , 6-trimethyl-ά _{'Cyclodextriπ,} 2,3,6-TrJmcthyl-ß-cyclodcxtrin, 2,3,6-trimethyl-γ-cyclodextrin, 2,3,6-trioctyl-ά-cyclodexlrin,

^2, 3,6-trioctyl-ß ^{^} cyclodextrin, 2,3,6-triacetyl-ά-cycIodextriü, 2,3,6-TriacetyI-.beta.-cyclodextrin, 2,3,6-Trmcetyl-γ-cycludextrin, (2 -Hydroxy) propyl-ά-cyclodeχttin, (2-hydroxy) propyl-β-cyclodextrin, (2-hydroxy) propyl-γ-cyclodextrin, partially or completely acetylated, methylated and succinylated ά-, β- and γ-cyclodextrin, 2, _{6-Dϊmethyl-3-acetyl-.beta.-L;} yclodextri _t ι and 2,6-dibutyl-3-acetyl-ß-cyclodextrin.

The mono-, di- or triether-substituted, mono-, di- or triester-substituted or monocKterZ-diether-substituted derivatives are generally obtained by the preparation of ά- _, β- and γ-cyclodextrins with alkylating agents such as dimethyl sulfate or alkyl halides m from 1 to 30 carbon atoms, for example methyl, ethyl, propyl, bulyl, pentyl ^, hexyl, heptyl, octyl chloride, bromide or iodide and / or esterification with acetic acid or succinic acid in the presence of acids ,

Cydodextrins are likewise commercially available, for example from Wicker (Cavamax® and CavasoK®). A further object of the invention is the use of the dispersions according to the invention as a component in the production of adhesives and sealants using polymer dispersions (c) and the resulting adhesives and sealants.

In particular, the dispersions of the invention can be used as a component in the preparation of dichrofaces and coatings-in particular for the production of adhesive coatings

- be used with the addition of at least one polymer dispersion (c).

When using the inventive dispersions as a component in the production of adhesives and sealants, all polymer dispersions (c) are suitable in which the solid is dissolved in a liquid phase and this phase in turn forms an emulsion with another liquid phase or such polymer dispersions ( c), in which polymers with the aid of

Emulators or dispersants are dispersed in water. Examples are latexes of polymers of dienes or olefinically unsaturated monomers and copolymers thereof, such as polystyrene-butadiene latex, acrylonitrile-butadiene-latex, polychloroprene latex, latex of a copolymer of chloroprene and dichlorobutadiene, latex of chlorinated polyisoprene or (meth) acrylate -Latex. Furthermore, these polymers (c) may also be water-soluble, e.g. Polyvinylpyrralidon

The polymer dispersions (c) may contain one or more such polymer dispersions.

Preference is given to natural and synthetic polymer dispersions used in the adhesive sector, described in: Irving Skeist, Handbook of Adhesives 2, Edition 1977, Van Nostrind Reinhold New York

Particular preference is given to polymer dispersions (c) whose viscoplastic properties of the dry films are in or in the region of the pressure-sensitive adhesive range. The film production took place from the dispersions at room temperature. From the films boards were pressed at 100 ⁰ C and determined in red & tionsrheometer the storage modulus G ^'at temperatures of 30 C to 100 ^u ⁰ C for measurement. The memory module should be in the range of 0.02 to 2 MPa. If the storage modulus G is less than 0.02 MPa, then the addition of the dispersion according to the invention increases the storage modulus, but the internal strength of the polymer dispersion e (cohesion) is too low, so that the adhesive film cohesively fails in the test. If the storage modulus G ^'is greater than 2 MPa, then the adhesive film is too hard and the adhesion to the substrate is insufficient.

Very particular preference is given to polymer dispersions (c) containing polymers which carry hydroxyl groups or carboxyl groups in the polymer chain. The resulting higher Hydroxylgn ^j ppengehalt may be in terms of a better Vemetzungsverhaltena particularly advantageous. The dispersions according to the invention containing the components (a) and [d] (b) preferably have a content of dispersed silicon dioxide (a) of 99.9% by weight to 25% by weight _, preferably of 99.5% by weight ^. -% to 45 wt .-%. The proportions of the water-soluble polymers or oligomers (b) in the dispersions are from 0.1% by weight to 75% by weight, preferably from 0.5% by weight to 55% by weight _, the process inputs being based on refer to the weight of non-volatile components and add to 100 wt .-%.

When using the dispersions according to the invention containing db components (a) and (b) as a component in adhesive and sealant formulations, the formulations contain the dispersions of the invention in the range from 3% to 45% by weight, preferably 5% Gcw ^, -% ^. to 30% by weight. The polymer dispersions (c) are in the formulations m 97 wt _. % to 55 wt .-%, preferably to 95 wt .-% to 70 wt .-%, wherein the percentages are based on the weight of non-volatile components and add to 100 wt .-%.

The resulting adhesives and sealants are containing such formulations

(a) at least one aqueous silica dispersion having an average particle diameter of the SiO ₂ particles of 1 to 400 nm, preferably 1 to 200 nm,

(B) at least one water-soluble hydroxyl group-containing organic compound and

at least one polymer dispersion (c).

D ⁱ e erfindirngsgemäßen adhesives and Dichtstofffoimulierungen can enlhslten more Zusatanittel and optionally coating and Klebstofthilfsstoffe.

For example, fillers such as Quaizmehl, quartz sand, barite, calcium carbonate,

Chalk, dolomite or talc, optionally together with Netziiπitteln, for example Polyphosphatcn, such as sodium hexamctaphosphate, naphthalenesulfonic acid, ammonium or Nadiumpolyacryl-Situresalze be added, wherein the fillers in amounts of 10 to 60 wt ^. %, preferably from 20 to 50% by weight, and the wetting agents in amounts of from 0.2 to 0.6% by weight, all data relating to the nonvolatile components being added. Further suitable, optionally used adjuvants are, for example, in amounts of 0.01 _. to 1 wt _. -%, based on πichtflüchtige shares, organic thickening agents, such as Celluloscderivate, Algiπate, starch, starch derivatives, polyurethane Verdickuπgsmittel or polyacrylic acid or in amounts of 0.05 to 5 Gcw .-%, based on non-volatile components, to be used inorganic thickening, such as for example bentonites. For preservation, fungicides can also be added to the dispersion according to the invention. These come in amounts of 0.02 to 1 wt .-%. based on non-volatile components used. Suitable fungicides are, for example, phenol and cresol derivatives or organotin compounds. Optionally, tackifying resins, so-called adhesive resins, such as. unmodified or modified natural resins, such as rosin esters, carbonyl hydrogen resins or synthetic resins, such as phthalate resins, are added in dispersed form to the polymer dispersion according to the invention (see, for example, "Klebharze" R. Jordan, R. Htnterwaldner, pp. 75-115, Hinterwaldner Verlag, Munich 1994). Alkylpbenol resin and terpene phenolhar are preferred: _>

Dispersions with softening grölier 70 ⁰ C, more preferably greater than 110 ⁰ C. Plasticizers, such as those based on adipate, phthalate or phosphate may be present to erf indungsgemäßeπ dispersions in amounts of 0.5 to tenth parts by weight, based on non-volatile Shares are added.

It is also possible to use organic solvents such as aromatic hydrocarbons, e.g. Toluene or xylene, ethers, e.g. Dioxane, ketones, e.g. Acetone, or methyl ethyl ketone, esters, e.g. Butyl acetate or ethyl acetate, or mixtures thereof in amounts of up to 10% by weight based on the total adhesive formulation Such additives of organic solvents, for example, improve the adhesion to the substrate to be coated or bonded or the solution of the above-described optionally further additives or optionally coating and adhesive adjuvants are used

To prepare the adhesive and sealant formulations according to the invention, the proportions of the individual components are chosen such that the resulting formulation according to the invention comprises components (a), (b) and (c) and optionally further

Contains additives or coating or adhesive adjuvants in the amounts indicated above.

The dispersions according to the invention are outstandingly suitable as adhesives or coating agents for various substrates. For example, substrates such as wood, paper, plastics, textiles, leather, rubber or inorganic materials such as Keram ik, earthenware,

Glass fiber or cement to be coated or glued. When bonding substrates tons substrates of the same or different types are bonded. Despite the high water content, the adhesive and sealant formulations according to the invention exhibit a high initial strength and the resulting dry coating or adhesive films have a high water resistance and heat resistance compared with known adhesive formulations

The present invention furthermore relates to the use of the adhesive and sealant molds according to the invention as adhesives or coating adhesives, the use as contact adhesives, pressure-sensitive adhesives, flock adhesives or laminating adhesives, or agents for coating and impregnating Fader products for the manufacture of textile or fiber reinforced concrete or other cement based products.

The application of the polymer dispersions of the invention may be carried out in known manners, e.g. by brushing, pouring, knife coating, spraying, rolling or dipping. The drying of the coating or adhesive film can at room temperature or elevated

Temperature, wherein a heating of the dry Klebstoffsch light to 80 ° C to 200 ° C over a period of 10 seconds to 20 minutes is advantageous to achieve a higher heat of the adhesive seam.

Likewise provided by the present invention are substrates which are coated or bonded with a formulation according to the invention and a method for bonding the substrates coated on one or both sides using the formulations.

The following examples serve to exemplify the invention and are not to be considered as limiting.

Examples

1.1. Substances used Tab. Cl: polymer dispersions (c)

Tab. C2: Polymer dispersions (c) nb = not determined

Table C4: Polymer dispersions (c)

nb = not determined g ()

Tab E: Pressure sensitive adhesive

1.2 Measurement methods:

1.2.1. Thermo-mechanical analysis (TMA)

The dispersions are dried in a Teflon dish as a film and that for 3 days at room temperature, for 1 hour at 80 ⁰ C and then again for 3 days at room temperature, with a film to be formed with a thickness of 1.0 mm to 1.5 mm. It is measured with a Perkin Elmer DMA 7 device at a load of 500 mN and a temperature program of pp, gp substrate. This measurement correlates with the determination of the heat resistance of the bonds in the heating cabinet. Example of such a heat resistance test: The test specimens are loaded with 4 kg and placed in a heating cabinet within 30 min. tempered to 4O ⁰ C. Subsequently, the test specimens with a linear heating rate of 0.5 ^o C / min. heated to 15O ⁰ C. The softening temperature, ie the temperature at ⁰ C at which the adhesion fails under the 4 kg load, is registered.

1.2.2. Determination of the resistance to damage

The test is carried out in accordance with EN 1392. On two test pieces of linen measuring 100 × 30 mm, a 100 μm thick wet film of the formulation is applied and ventilated at room temperature. Subsequently, the specimens are shock activated for 10 seconds and joined together at 4 bar. There is a tear test on a commercial tensile testing machine at room temperature. The strength values are determined after one day.

1.2.3. Cooling test in a rotary rheometer (Bohlin)

The investigations of the viscoelastic properties were carried out with a rotary rheometer from Bohlin by means of oscillating deformation in the plate / plate geometry. Fi ini production took place from the dispersions at room temperature. From the films plates were pressed at 100 ⁰ C for the measurement.

The viscoelastic properties are determined as a function of the temperature of 100 ⁰ C to 20 ⁰ C with a cooling rate of 4 ⁰ C / min at a measuring frequency of 1 Hz and a deformation of 0.05.

1.2.4. Determination of the Crosslinking Behavior of the Adhesive Formulations

20 g of the aqueous formulations are dried for 4 days at room temperature (RT). The

Determination of the crosslinking behavior takes place on a moving The rheometer of the company Alpha Technologies. The test is carried out according to the method ASTM D 5289-95. This standard is equivalent to ISO 6502-1991 and DIN 53529 Part 3. The measurement is usually carried out at temperatures of 100 ⁰ C to 200 ⁰ C. The deformation resistance is measured by the increasing cross-linking increases as a thrust or torque. Indicated is the minimum force at

Start of measurement (S 'min in dNm) and maximum force (S'max in dNm) when reaching the crosslinking plateau. 10 g of adhesive formulation are weighed in a 20 ml rolled rim bottle, sealed gas-tight and analyzed by capillary gas chromatography using a headspace technique. Apparatus: gas chromatograph type Perkin Elmer 8420; Fused silica capillary column. The sample is thermostated for 30 min at 70 ⁰ C, then determined the residual monomer content in the gas phase.

1.2.6. Determination of the softening point of the thickening (heat resistance)

The test is carried out in accordance with EN 1392. From two test strips made of KASX (butadiene-acrylonitrile rubber), roughened with sandpaper (grain size = 40), test specimens are cut out, dimensions 20 x 60 mm. A 100 μm thick wet of the adhesive formulation is applied with a brush on a surface to be bonded of 10 x 20 mm and ventilated for 1 hour at room temperature. Subsequently, the test pieces are shock activated for 10 seconds and pressed against each other so that only the adhesive surfaces are joined at an angle of 180 ° to each other. The composite is pressed in the press for 10 seconds with 4 bar (effective).

After a storage period of 3 - 7 days, the KASX test specimens are loaded with 4 kg and placed in a heating cabinet within 30 min. tempered to 40 ⁰ C. Subsequently, the test specimens with a linear heating rate of ö, 5 ° C / min. heated to 150 ⁰ C. The softening temperature, ie the temperature at ⁰ C at which the adhesion fails under the 4 kg load in the shear test, is registered. In each case 4 individual measurements are carried out.

shock activation

The adhesive surfaces are illuminated for 10 seconds with an infrared radiator from Funk (shock activator

2000). The bonding takes place immediately after heat activation of the adhesive-coated specimens by the activated adhesive layers are placed against each other and pressed in a press. The test specimens thus prepared are stored at 23 ° C and 50% relative humidity.

1.2.7 Pull-out - An attempt to determine the force at which the coated fiber (roving) detaches from the concrete matrix.

The experiments were carried out according to the formulation and experimental set-up described in EP. 1.3.1 Preparation of the Dispersions of the Invention Containing the Components (a) and (b)

For the preparation of the dispersions of the invention, the silica dispersion (a) was placed in closable glass bottles and added the water-soluble hydroxyl-containing polymer or oligomer (b) with stirring. After a stirring time of 1 hour, the glass bottles were sealed and stored.

1.3.2. Production of the Adhesive Formulations According to the Invention

For the preparation of the inventive adhesive formulations, the polymer dispersion (c) was placed in a beaker. The dispersion according to the invention and, if necessary, additives and optionally adhesive adjuvants were then added with stirring. After a storage time of 24 hours, the Fonnulierung was used for the experiments.

The data in Tables 2a, 3a, 4a and 5a are parts by weight of the respective dispersions (unless stated otherwise).

1. 4. Examples

1.4.1. Preparation of the dispersions according to the invention from SBI dispersions and cyclodextrin Tab. Ia: Addition of cycodextrin according to Tab. B in solid form to 100 g each

Silica dispersion according to Tab. A

The evaluation took place after storage of 7 days.

+ = completely soluble

B = sediment of Cylodextrϊn

*) Comparative Examples

Tab Ib; Addition of cycodextrin according to Tab. B in solid form to 100 g of the silica dispersion according to Tab. A

The rating after storage of 12 months.

*) Comparative Examples oy nd sggg

1.4.2. Determination of the Vernelzungsverhaltens and the heat of adhesive formulations when using the inventive silicon dioxide dispersion I and polychloroprene

Substances used:

Dispersion I: Silica D + 7% by weight of cyclodextrin F, (Tab.l batch 4)

- Polychloroprene Dispersion L.

Tab 2a: Recipes

*) Comparative Examples

Tab 2b: Vulkameter data, maximum force (S'max)

Tab 2c: Theπnomechanische properties of the formulation (heat)

Compared to the use of standard formulations - with and without the addition of cyclodextrin - (Approach 15, 16, 18) show the inventive formulations 17 and 19 a significantly higher resistance to thermal stress and the best crosslinking behavior. The curve is shown in Fig. 1 and 2. Dispersions according to Tab. 2a-c, batches 15-17

Fig. 2: Course of the measurements of the resistance to thermal stress of films from dispersions according to Tab. 2a-c, batches 15, 18, 19

1.4.3 .: Determination of the Ironing Behavior and the Heat Content of Adhesive Formulations When Using the Invention Siiiciumdioxid Dispersion I and II and Polyehϊoropren

Substances used:

Dispersion I: SiHcium dioxide D + 7% by weight of cyclodextrin F, (Tab.l batch 4)

Dispersion II: silicon dioxide D + 5% by weight of cyclodextrin F (Tab 1 batch 4)

- Polychloroprene Dispersion L.

Tab 3a: recipes

*) Comparative Examples

Tab 3b: Vulkameter data, maximum force (S'max)

Tab. 3c: Thermomechanical properties of the formulation (heat level)

Resin-free formulations of the invention 21 and 23 a significantly higher resistance to thermal stress and the best crosslinking behavior. The curve is shown in Fig. 3 and 4.

Fig. 3: Course of the measurements of the resistance to thermal stress of films from dispersions according to Tab. 3, Batches 15, 22, 21

Fig. 4: Course of the measurements of the resistance to thermal stress of films from dispersions according to Tab. 3, Batches 15, 22, 23

1.4.4 .: Determination of the Crosslinking Behavior of Adhesive Formulations When Using the Inventive Silica Dispersion I and II and Polychloroprene with Different Content of Hydroxyl Groups on the Polymer Chain

Substances used:

Dispersion I: Silica D + 7% by weight of cyclodextrin F, (Tab.l batch 4)

Dispersion II: Silica D + 5% by weight of cyclodextrin F (Tab. 1 batch 4)

Polychloroprene Dispersion L and K.

Tab. 4a: Recipes

*) Comparative Examples

Tab 4b: Vulkameter data, maximum force (S'max)

In all combinations, the polymer dispersions L with a higher content of hydroxyl groups shows a better crosslinking behavior than the same polymer dispersion K with a lower content of hydroxyl groups.

1.4.5.Viscoelastic Properties of Polymer Dispersions C

The viscoelasic properties of the polymer dispersions used, determined on the Bohlin Rheometer, are shown in FIGS. 5-8.

Fig.5: cooling test with polymer dispersions S, T, N, and U Bohlin VOR 100 ⁰ C> 20 ⁰ C, 4 ° C / min, frequency: 1 Hz

Fig.6: cooling test with polymer dispersions W, X and V Bohlin VOR: 100 ° C> 20 ⁰ C, 4

° C / min, frequency: 1 Hz

Fig.7: cooling test with polymer dispersions O, P and M Bohlin VOR 100 ⁰ C> 20 ⁰ C, 4 ° C / min, frequency: 1 Hz

Fig. 8: Cooling test Bohlin with polymer dispersions K and L VOR: 100 ⁰ C> 20 ⁰ C, 4 ° C / min, frequency: 1 Hz

The cooling curves of the polymer dispersions S, T and N as seen in Fig. 5, meet the criteria of the present invention, that is, in the determination of the viscoelastic properties of the storage modulus G is located at temperatures from 30 ⁰ C to 100 ⁰ C in the range of 0.02 to 2 MPa, while the storage modulus of the dispersion U in the low temperature range for the application adhesive is too high.

As shown in Fig. 6, the dispersions W and X satisfy the criteria of the present invention, while the adhesive dispersion V is too soft, i. the curve is below the desired range of 0.2 MPa.

According to Fig.7 meet the dispersions O and P, the criteria of the invention, while the dispersion M is too soft for the adhesive, ie the storage modulus of the polymer decreases rapidly with increasing temperature and is already at temperatures above 50 ⁰ C below the desired range of 0.2 MPa.

According to FIG. 8, both dispersions K and L fulfill the criteria according to the invention Polymer dispersion N and Z

Tab 5a: Recipes

*) Comparative Examples

Tab. 5b: Theπnomechanische properties of the formulation (heat).

When using the inventive silica dispersion in Experiments 36 and 40, formulations with the highest heat resistance are achieved.

1.4.7 .: Determination of the peel strength and the cross-linking behavior of formulations based on various polymer dispersions

Shares of the products used:

Polymer dispersion 100 parts by weight, silicon dioxide dispersion D: 40 parts by weight Siiicium dioxide dispersion I according to the invention; 43 parts by weight

*) = Comparative experiment

H = formulation contains, in addition to the polymer dispersion, this silica dispersion

Tab. 6b: Peel strength and crosslinking behavior.

N = spoke modulus G at temperatures of 30 ⁰ C to 100 ⁰ C outside the range of 0.02 to 2 MPa s

P = storage modulus G at temperatures of 30 ⁰ C to 100 ⁰ C in the range of 0.02 to 2 MPa s; nb = not determined

Tab. 7a: Recipes

+ = Formulation contains, in addition to the polymer dispersion, this silica dispersion

N = storage modulus G at temperatures of 30 ⁰ C to 100 ⁰ C outside the range of 0.02 to 2 MPa s

P = storage modulus G ^' at temperatures from 3O ⁰ C to 100 ⁰ C in the range of 0.02 to 2 MPa s; nb = not determined.

Tab. 8a: Recipes

Tab. 8b: Peel strength and crosslinking behavior.

N = storage modulus G at temperatures of 30 ⁰ C to 100 ⁰ C outside the range of 0.02 to 2 MPa s nb not determined.

Particularly preferred polymer dispersions whose viscoelastic properties (G Speichermodui) at temperatures of 3O ⁰ C to 100 ⁰ C are in the range of 0.02 to 2 MPa s show in combination with the inventive silica dispersion, the best peel strengths of the bonded substrates, and show the highest crosslinking (S'max), cf. in particular experiments 42, 48, 57, 60, 69, 72. This also applies to the experiments 45 and 51, of which the corresponding memory module curves are not present.

4. 1. 7 Determination of the residual monomer content

Tab 9a: Formulations

^¥ ) Comparative Examples

Tab. 9b: Residual monomer content (free monomer) of the dispersion in ppm

*) Comparative Examples

As experiment 75 shows, the addition of the dispersion according to the invention, the content of free

Residual monomer, shown by the example polychloroprene latex, significantly reduced.

4.1.8 Determination of the heat level of adhesive formations (determination by test method 1.2.6)

Tab 10a: Compositions of the adhesive formulations

The numerical values given are parts by weight of the individual components in the respective adhesive formulations.

Dispersion III: Silica D + 0.9% by weight of cyclodextrin G (Tab 1 batch 6) Dispersion V: Silica D + 2.5% by weight of cellulose compound AB

Dispersion VI: Silica D + 2.5% by weight of cellulose compound AC

*) Comparative Examples,

Sources:

⁽¹⁾ Borchers GmbH, Langenfeld

Tab. 10b: Heat rating of the adhesive seam

Compared with the comparative examples (Experiments 76 and 77), the formulations 78-82 produced according to the invention show a significantly higher heat resistance.

1.4.9 .: Reduction of creep behavior of pressure-sensitive adhesives Tab IIa: Formulations

*) Comparative Examples

The viscoelastic properties of the polymer dispersions used, determined on the Bohlin Rheometer, are shown in FIG. 9. Level and drops very quickly as the temperature rises. Here it can be expected that this polymer shows a strong creep behavior when used as a pressure-sensitive adhesive. By adding the mixture according to the invention (experiment 85), the creep behavior can be significantly reduced.

Fig.9: cooling test with polymer dispersions AD, Bohlin VOR 100 ⁰ C> 20 ⁰ C, 4 ° C / min, frequency: 1 Hz

4. 1. 9 Determination of the force at which the coated fiber (roving) can be pulled out of the concrete.

Tab 12a: Recipes

*) Comparative Example

Tab 12b: Force at which the roving slips out of the concrete test specimen.

*) Comparative Example

Claims

1. Aqueous dispersions, characterized in that they

(A) at least one aqueous silica dispersion having a mean particle dew point of the SiO ₂ particles of 1 to 400 ran and

(B) at least one water-soluble hydroxyl-containing organic compound

and the water-soluble hydroxyl-containing organic compounds are dissolved in the silica dispersion.

2. Aqueous dispersions according to claim 1, characterized in that the SiC> ₂ -Parükel have a particle diameter of 1 to 200 nm, preferably from 5 to 100 nm, more preferably from 8 to 60 nm.

3. Aqueous dispersions according to claim 1 or 2, characterized in that the aqueous silica dispersion is an aqueous silica sol.

4. Aqueous dispersions according to at least one of claims 1 to 3, characterized in that the water-soluble (s) Hydroxylgrυppenhaltige (n) organic (s)

Compounds) one or more cyclodextrin (s) is (are).

5. Use of the dispersions according to at least one of claims 1 to 4 in the production of adhesives and sealants.

6. containing formulations

(a) at least one aqueous silica dispersion having an average particle diameter of the SiO ₂ particles of 1 to 200 nm,

(B) at least one water-soluble hydroxyl group-containing organic compound and

at least one polymer dispersion (c).

7. Formulations according to claim 6, characterized in that the

Polymer Dispersion (s) (c) Latices of polymers of dienes or olefinically unsaturated monomers and their copolymers. yp () () carry yp alone or in combination in the polymer chain.

9. Use of the formulations according to at least one of claims 6 to 8 as adhesives or coating agent, in particular as a contact adhesive, pressure-sensitive adhesive

Flock adhesive or laminating adhesive.

10. Substrates, characterized in that they are coated or glued with a formulation according to at least one of claims 6 to 8,

11. A method for bonding the single-sided or double-coated substrates according to claim 10.