DE102006044068A1 - Aqueous polymer dispersion, useful e.g. as adhesive in bookbindery, comprises dispersion containing polyvinyl acetate and/or polyvinyl acetate copolymer; and aqueous silicon dioxide-dispersion with defined silicon dioxide particle size - Google Patents

Abstract

Aqueous polymer dispersion comprises at least a dispersion containing polyvinyl acetate and/or at least a polyvinyl acetate copolymer; and at least an aqueous silicon dioxide-dispersion with an average particle diameter of silicon dioxide particle of 1-400 nm. Independent claims are included for: (1) a method for preparing polymer dispersion comprising mixing silicon dioxide-dispersion optionally with the dispersion containing at least a hydroxy group-containing oligomer or polymer, optionally additive and coating- or adhesive auxiliary material, and finally mixing a dispersion containing polyvinyl acetate and/or at least a polyvinyl acetate copolymer; and (2) a substrate, which is coated or glued with the polymer dispersion.

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 manufacture of sealants and adhesives and Coatings - especially for the production of adhesive coatings - as well as the resulting Sealing or adhesive formulations and a method of bonding the unilaterally or bilaterally coated substrates using of these formulations.

For aqueous silica dispersions there is a wide range of use, e.g. as a binder in foundry and Steel sector in the area of investment casting, as an additive for modifying surfaces, i. Manufacture non-slip paper bags and coating of special papers, antiblocking of films, in the construction sector as an additive for Shotcrete and for the impregnation. (compare: Levasil brochure Fa. C. C. Starck, Goslar Germany, www.hcstarck.com). Farther is the use of silica dispersions in aqueous Adhesive systems known (Ganster et al., New raw materials for solvent-free Adhesives and sealants in "Glue and Dense" magazine, 3/2003).

From the prior art, the use of silica products for different applications is known. While solid SiO ₂ products are widely used to control rheological properties, as fillers or adsorbents, silica dispersions (for example, silica sols) are used as binders for diverse inorganic materials, as semiconductors for polishing, 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. FR-A 2 341 537 and FR-A 2 210 699 describe fumed silicas in combination with polychloroprene latexes for the production of flame-resistant foam coatings or for bitumen coating and in JP-A 06 256 738 in combination with chloroprene-acrylic acid copolymers.

Farther is the use of silica dispersions in the manufacture of adhesive formulations based on polychloroprene dispersions known (WO 03/102066 A2).

Important Characteristics for such Formulations are "open Time and pot life of the dispersions, and "heat resistance" and "water resistance", the resulting dry coating or adhesive films. For adhesives understands one under the "open Time "according to DIN 16920 the period of time after the adhesive application, within which a wet gluing possible is. This is the time from application of the adhesive to insertion the pressing pressure. Usually resins are added to the formulation, e.g. Terpene phenolic resins or cumarone-in resins to increase the processing time (open time) extend. Although the replacement of these resins by silica dispersions increases the temperature resistance gluing, but reduces the "open time." The addition of Silica dispersions to aqueous Although resin-containing polychloroprene dispersions prolongs the "open Time ", reduced however the temperature resistance the bonds.

Under The "pot life" is understood as the Time in which the formulation after mixing at least can process a further dispersion. According to the state of the art, (Ullmann, Encyclopaedia the technical chemistry Bd. 14, 4th edition, p 250) can be by addition of solvents and / or softeners speed up the setting speed and lower the film formation temperature. This measure will but the heat level the coating or the adhesive seam reduced. A higher heat level can be made by adding a second dispersion on the basis of Resorcinol or melamine resin or inorganic salts, e.g. chromium nitrate to reach. These two-component dispersion formulations are but in their "pot life" to a few hours limited.

coatings or adhesives with high water resistance and heat resistance receives one by the so-called "EPI System "(emulsion polymer isocyanate). This is achieved by adding about 15% isocyanate - usually MDI (diphenylmethane-4,4'-diisocyanate) - for polymer dispersion. by virtue of the very short pot life is here only a machine order of Two-component formulation (2K formulation) possible.

Furthermore In these 2K formulations, different metal salt crosslinkers are used as corrosive or oxidising classified. In the case of isocyanate-based crosslinkers, depending on Isocyanate type - its irritant effect and to consider their sensitizing potential on the skin and respiratory tract. (see leaflet TKH-3 "Dispersion-Wood Glues" Edition 2004, from Industrieverband Klebstoffe eV, Dusseldorf (www.klebstoffe.com)).

On Reason for increased ecological Requirements for the limitation of emissions of volatile Organic compounds, it is also desirable also the residual content of free monomer - im Also referred to below as residual monomer content - of polymer dispersions prior to their further processing in an adhesive formulation reduce.

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

Of the The present invention was therefore based on the object, aqueous silica To provide dispersions in aqueous polymer-containing adhesive dispersions after application to the surface to be coated or glued Substrates as needed a fast setting and / or a have long open time and high initial strength. Advantageous would be present moreover, if the resulting dry coating or adhesive films a high water resistance and heat resistance exhibit. Further would be a reduced residual monomer content is advantageous.

Surprised has been found to contain dispersions of silica dispersion and certain water-soluble Organic compounds have these properties.

• (a) mindestens eine wässrige Siliciumdioxid-Dispersion mit einem mittleren Partikeldurchmesser der SiO₂-Partikel von 1 bis 400 nm, bevorzugt 1 bis 200 nm und
• (b) mindestens eine wasserlösliche hydroxylgruppenhaltige organische Verbindung enthalten.

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

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

The water-soluble Hydroxyl-containing organic compounds according to the invention in the Dissolved silica dispersion in front. not Solved Shares are separated before use. Containing these dispersions the components (a) and (b) are also briefly referred to below as dispersions of the invention designated.

Aqueous silica dispersions have been known for a long time. Depending on the manufacturing process, they are in different Forms before.

According to the invention suitable Silica dispersions (a) may be based on silica sol, Silica gel, fumed silica, Precipitated silicas or Mixtures of the mentioned can be obtained.

Silica sols are colloidal solutions of amorphous silica in water, which are also commonly referred to as silica sols but are referred to briefly as silica sols. The silica is present in the form of spherical and surface-hydroxylated particles. The particle diameter of the colloid particles 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. Iler, 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 alkali-stabilized silica sols have a pH of 7 to 11.5 and contain as alkalizing agents, for example, small amounts of Na ₂ O, K ₂ O, Li ₂ O, ammonia, organic nitrogen bases, tetraalkylammonium hydroxides or alkali or ammonium aluminates. Silica sols may also be slightly acidic as semi-stable colloidal solutions. Furthermore, it is possible to produce cationic silica sols by coating the surface with Al ₂ (OH) ₅ Cl. The solids concentrations of the silica sols are preferably from 5 to 60 wt .-% 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 SiO ₂ particles, adjustment of the respective desired SiO ₂ concentration and optionally a surface modification of the SiO ₂ particles, such as for example with Al ₂ (OH) ₅ Cl. In none of these steps do the SiO ₂ particles leave the colloidally dissolved state. This explains the presence of the discrete primary particles.

Under Silica gels are understood to mean colloidally shaped or unshaped silicas of elastic to firm consistency with a loose to dense pore structure. The silicic acid is in the form of highly condensed polysilicic acid. Located on the surface 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 , are added simultaneously. This produces colloidal primary particles which agglomerate as the reaction progresses and grow into agglomerates. The specific surface area is generally from 30 to 800 m ² / g (determined according to measurement specification: DIN 66131) and the primary particle size at 5 to 100 nm. The primary particles of these silica present as solid are usually firmly crosslinked 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 Information on the synthesis and properties of silicas in solid form are, for example, K. H. Büchel, H.-H. Moretto, P. Woditsch "Industrielle Inorganic chemistry", Wiley VCH Verlag 1999, chap. 5.8 to take.

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

to Preparation of the silica dispersions become dispersants used in the prior art, preferably those for the production high shear rates are suitable, such as 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 - like described further on - off the BET surface area is calculated become.

at Precipitated silicas and fumed silicas can the particles both as so-called primary particles as well as in the form of agglomerates. The term "average particle size" means according to the invention by means of Ultracentrifugation determines average particle size and excludes the size of primary particles and optionally present agglomerates thereof (see: H. G. Müller, Progr. Colloid Polym. Sci. 107, 180-188 (1997)). It becomes the mass agent specified).

Preferred dispersions of the invention are those in which the SiO ₂ 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 silicic acid sols are also commercially available, for example in the Company HC Starck GmbH (Levasil ^® ).

Under water-soluble Hydroxyl-containing organic compounds are within the scope the invention all linear or cyclic oligomers or polymers to understand that in the oligomer or polymer chain hydroxyl groups contained and water-soluble are. Oligomers in the context of the invention are such compounds with up to 10 repeat units and one molecular weight under 1000, among polymers those with more than 10 Repeating units, in both cases repeating units may be the same or different. Preferred examples of OH group-containing Polymers are hydroxyalkylcelluloses, polyvinyl alcohols or polymers Cyclodextrins. Preferred OH-group-containing oligomers or polymers are in the context of the invention cyclodextrins.

cyclodextrins as water-soluble Hydroxyl-containing organic compounds in the compositions of the invention offer the advantage that the residual monomer content in the resulting Dispersions can be significantly reduced.

suitable Cyclodextrins are unsubstituted and substituted cyclodextrins.

preferred Cyclodextrins are ἀ-, β- and γ-cyclodextrins and their ester, alkylether, hydroxyalkylether, alkoxycarbonylalkylether, Carboxyalkyl ether derivatives or their salts.

Especially preferred are methyl-ἀ-cyclodextrin, methyl-β-cyclodextrin, Methyl γ-cyclodextrin, ethyl β-cyclodextrin, Butyl γ-cyclodextrin, butyl β-cyclodextrin, butyl γ-cyclodextrin, 2,6-dimethyl-ἀ-cyclodextrin, 2,6-dimethyl-β-cyclodextrin, 2,6-dimethyl-γ-cyclodextrin, 2,6-diethyl-β-cyclodextrin, 2,6-dibutyl-β-cyclodextrin, 2,3,6-trimethyl-ἀ-cyclodextrin, 2,3,6-trimethyl-β-cyclodextrin, 2,3,6-trimethyl-β-cyclodextrin, 2,3,6-trimethyl-ἀ-cyclodextrin, 2,3,6-trioctyl-β-cyclodextrin, 2,3,6-triacetyl-ἀ-cyclodextrin, 2,3,6-triacetyl-β-cyclodextrin, 2,3,6-triacetyl-γ-cyclodextrin, (2-hydroxy) propyl-ἀ-cyclodextrin, (2-hydroxy) propyl-β-cyclodextrin, (2-hydroxy) propyl-γ-cyclodextrin, partially or completely acetylated, methylated and succinylated ἀ-, β- and γ-cyclodextrin, 2,6-dimethyl-3-acetyl-β-cyclodextrin and 2,6-dibutyl-3-acetyl-β-cyclodextrin.

The Mono-, di- or triether-substituted, mono-, di- or triester-substituted or monoester / -diether substituted derivatives are usually by etherification of ἀ-, β- and γ-cyclodextrins with alkylating agents such as dimethyl sulfate or alkyl halides with 1 to 30 C atoms, such as, for example, methyl, ethyl, propyl, butyl, pentyl, Hexyl, heptyl, octyl chloride, bromide or iodide and / or esterification with acetic acid or succinic acid in the presence of acids receive.

Cyclodextrins are also commercially available, for example from Wacker (Cavamax ^® and Cavasol ^®).

One Another object of the invention is the use of the dispersions of the invention as a component in the production of adhesives and sealants under Use of polymer dispersions (c) and the resulting Adhesives and sealants.

Especially can the dispersions of the invention as a component in the production of sealants and coatings - especially for the production of adhesive coatings - with the addition of at least a polymer dispersion (c) can be used.

at the use of the dispersions of the invention as a component in the production of adhesives and sealants all polymer dispersions (c) are suitable, in which the solid in a liquid phase solved is and this phase in turn with another liquid phase forms an emulsion or those polymer dispersions (c) in which Polymers with the help of emulsifiers or dispersants dispersed in water are. Examples are latices of polymers of dienes or olefinic unsaturated Monomers and their copolymers, 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.

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

Prefers are natural and synthetic polymer dispersions used in the adhesive sector, described in: Irving Skeist, Handbook of Adhesives 2nd edition 1977, Van Nostrand Reinhold New York.

Especially preferred are polymer dispersions (c) whose viscoelastic properties of the dry films in or in the area of the pressure-sensitive adhesive area. The film production took place from the dispersions at room temperature. From the movies were for the measurement plates at 100 ° C pressed and in Rotationsrheometer the memory module G 'at temperatures of 30 ° C up to 100 ° C certainly. The memory module should be in the range of 0.02 to 2 MPa. If the memory module G 'is below 0.02 MPa, then by adding the dispersion of the invention Although the memory module raised, the internal strength of the polymer dispersion c (cohesion) However, it is too low so that the adhesive film cohesively fails in the test. If the memory module G 'is above 2 MPa, then the adhesive film is too hard and the adhesion to the substrate is insufficient.

All particularly preferred are polymer dispersions (c) containing polymers, carry the hydroxyl groups in the polymer chain. The resulting higher Hydroxylgruppengehalt can in terms of a better crosslinking behavior be of particular advantage.

The dispersions according to the invention containing components (a) and (b) preferably have one Content of dispersed silica (a) of 98% by weight to 25% Wt .-%, preferably from 93 wt .-% to 45 wt .-%. The proportions of water-soluble Polymers or oligomers (b) in the dispersions are at 2% by weight to 75 wt .-%, preferably 7 wt .-% to 55 wt .-%., Wherein the Refer to percentages by weight of nonvolatile matter and add to 100 wt .-%.

at the use of the dispersions of the invention - containing the components (a) and (b) - as Component contained in adhesive and sealant formulations the formulations of the dispersions of the invention in the field from 3% to 45%, preferably 5%, by weight. to 30% by weight. The Polymer dispersions (c) are in the formulations to 97 wt .-% to 55 wt .-%, preferably to 95 wt .-% to 70 wt .-%, wherein the percentages refer to the weight of non-volatile components and to Add 100 wt .-%.

• (a) mindestens eine wässrige Siliciumdioxid-Dispersion mit einem mittleren Partikeldurchmesser der SiO₂-Partikel von 1 bis 400 nm, bevorzugt 1 bis 200 nm,
• (b) mindestens eine wasserlösliche Hydroxylgruppenhaltige organische Verbindung und

mindestens eine Polymerdispersion (c).The resulting adhesives and sealants are containing such formulations

• (a) at least one aqueous silica dispersion having a mean 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).

The according to the invention and sealant formulations other additives and optionally coating and adhesive adjuvants contain.

For example can fillers such as quartz, quartz sand, barite, calcium carbonate, chalk, dolomite or talc, optionally together with wetting agents, for example Polyphosphates, such as sodium hexametaphosphate, naphthalenesulfonic acid, ammonium or sodium polyacrylic acid salts be added, the fillers in amounts of from 10 to 60% by weight, preferably from 20 to 50% by weight, and the wetting agents in amounts of 0.2 to 0.6 wt .-%, all information based on the non-volatile Shares are added. Further suitable, if necessary to be used Auxiliaries are, for example, in amounts of from 0.01 to 1% by weight, based on non-volatile Proportions, organic thickeners to be used, such as cellulose derivatives, Alginates, starch, Starch derivatives, Polyurethane thickener or polyacrylic acid or in amounts of 0.05 to 5 wt .-%, based on non-volatile components, to be used inorganic thickeners, such as bentonites. to Conservation can the dispersion of the invention also fungicides are added. These come in quantities of 0.02 to 1 wt .-%, based on non-volatile components used. Suitable fungicides are, for example, phenol and cresol derivatives or organotin compounds. If necessary, too tackifying resins, so-called tackifier resins, e.g. unmodified or modified natural resins such as rosin esters, hydrocarbon resins or synthetic resins such as phthalate resins of the polymer dispersion of the invention in dispersed form (see, e.g., in " Adhesive Resins " R. Jordan, R. Hinterwaldner, Pp. 75-115, Hinterwaldner Verlag Munich 1994). Preferred are alkylphenol resin and terpene-phenolic resin dispersions with Softening points greater than 70 ° C, especially preferably greater than 110 ° C. Also plasticizers, such as those based on adipate, phthalate or phosphate can the dispersions according to the invention in amounts of from 0.5 to 10 parts by weight, based on nonvolatiles be added.

Also possible is the use of organic solvents such as aromatic hydrocarbons such as toluene or xylene, ethers such as dioxane, ketones such as acetone, or methyl ethyl ketone, esters such as butyl acetate or ethyl acetate, or mixtures thereof in amounts of up to Weight 10% Such additions of organic solvents may, for example, improve the adhesion to the substrate to be coated or bonded or serve for the solution of the optionally described further additives or, optionally, coating and adhesive adjuvants described above.

to Production of the Adhesive and Sealant formulations are the proportions the individual components chosen so that the resulting formulation according to the invention the components (a), (b) and (c) and optionally further additives or Coating or adhesive adjuvants in the above Contains quantities.

The individual components can in principle be combined in any order.

The dispersions according to the invention are ideal as adhesives or coating agents for various Substrates. For example, you can Substrates such as wood, paper, plastics, textiles, leather, rubber or of inorganic materials such as ceramics, earthenware, glass fiber or cement coated or glued. When bonding by Substrates can Substrates of the same or different kind are glued. The adhesive and sealant formulations show over known adhesive formulations despite the high water content, a high initial strength and the resulting dry coating or adhesive films high water resistance and heat resistance.

Farther The present invention thus relates to the use of according to the invention and sealant formulations as adhesives or coating agents.

The Application of the polymer dispersions of the invention can be determined in known ways, e.g. by brushing, pouring, knife coating, Spraying, rolling or dipping are performed. The drying of the Coating or adhesive films can at room temperature or increased Temperature, wherein a heating of the dry adhesive layer at 80 ° C up to 200 ° C over a Period of 10 seconds to 20 minutes is beneficial to one higher thermal stability to achieve the bond line.

Also The present invention relates to substrates with a inventive formulation coated or glued and a method of bonding the unilaterally or bilaterally coated substrates using the formulations.

• (*) Mittelwerte, berechnet aus der spezifischen Oberfläche

The following examples serve to exemplify the invention and are not to be considered as limiting. Examples 1.1. Substances used Tab. A: Silica dispersions (silica sols) from HC Starck GmbH (aqueous silicon dioxide dispersion (a))

• (*) Mean values calculated from the specific surface

Tab. B: cyclodextrins from Wacker Burghausen Germany (water-soluble hydroxyl-containing compound (b))

Table C1: Polymer dispersions (c)

Tab. C2: Polymer dispersions (c)

Table C3: Polymer dispersions (c)

Table C4: Polymer dispersions (c)

1.2 Measurement methods:

1.2.1. thermomechanical Analysis (TMA)

The Dispersions are dried in a Teflon dish as a film and Although 3 days at room temperature, 1 hour at 80 ° C and then again 3 days at room temperature, leaving a film with a thickness of 1.0 mm to 1.5 mm should arise. It is measured with a device of the company Perkin Elmer DMA 7 at a load of 500 mN and a temperature program from -100 ° C to + 240 ° C, rate of increase 5 ° / min. Measured The penetration depth of the measuring head is at the corresponding temperature. The softer the film gets, the deeper the probe penetrates into it Substrate. This measurement correlates with the determination of the heat resistance the bonds in the heating cabinet. Example of such a heat resistance test: The Be test specimen loaded with 4 kg and in a heating cabinet within 30 min. at 40 ° C tempered. Subsequently are the test specimen with a linear heating rate of 0.5 ° C / min. to 150 ° C heated. The softening temperature, i. the temperature in ° C at the the bond under the 4 kg load fails, is registered.

1.2.2. Determination of peel strength

The exam complies with EN 1392. On two test specimens Linen with dimensions 100 × 30 mm, becomes a 100 μm thick wet film of the formulation applied and at room temperature ventilated. Subsequently become the candidates Shock activated for 10 seconds and assembled at 4 bar. It takes place a tear test on a commercial one tensile testing machine at room temperature. It will be the strength values after one day determined.

1.2.3. cooling test in the rotational rheometer (Bohlin)

The Investigations of the viscoelastic properties were carried out a rotary rheometer from Bohlin by means of oscillating deformation in the plate / plate geometry. The film production took place from the Dispersions at room temperature. From the films were for the measurement Plates at 100 ° C pressed.

The viscoelastic properties are dependent on the temperature of 100 ° C to 20 ° C with a cooling of 4 ° C / min at a measuring frequency of 1 Hz and a deformation of 0.05.

1.2.4. Determination of 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 networking behavior takes place on a moving The rheometers 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 ° C up to 200 ° C. The deformation resistance is measured by the increasing Networking increases as thrust or torque. It is stated the minimum force at the beginning of the measurement (S'min in dNm) and the maximum force (S'max in dNm) at Reaching the networking plateau.

1.2.5. Determination of Residual monomer content in the adhesive formulation

10 g of adhesive formulation are weighed into a 20 ml roll edge bottle, sealed gas-tight and capillary gas chromatographically by means of headspace technology analyzed. Device: Gas Chromatograph Type Perkin Elmer 8420; Fused silica capillary column. The Sample is at 70 ° C for 30 min thermostated, then determined the residual monomer content in the gas phase.

1.3. General regulations for the Preparation of the dispersions of the invention and formulations

1.3.1 Production of dispersions according to the invention containing components (a) and (b)

For the production the dispersions of the invention The silica dispersion (a) was placed in sealable glass bottles submitted and the water-soluble hydroxyl-containing polymer or oligomer (b) added 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 production the adhesive formulations according to the invention was the polymer dispersion (c) presented in a beaker. The dispersion according to the invention was then successively obtained and if necessary, additives and optionally adhesive adjuvants with stirring added. After a storage period of 24 hours, the formulation became for the Trials used.

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

1.4. Examples

1.4.1. Production of the dispersions according to the invention of silica dispersions and cyclodextrin

Tab. 1a: Addition of cyclodextrin according to Tab. B in solid form to 100 g of the silica dispersion according to Tab. A

+

= vollständig löslich

B

= Bodensatz von Cylodextrin

• *) Vergleichsbeispiele

The evaluation took place after storage of 7 days.

+

= completely soluble

B

= Sediment of cyclodextrin

• *) Comparative Examples

Table 1b: Addition of cyclodextrin according to Tab. B in solid form to 100 g of the silica dispersion according to Tab. A

• *) Vergleichsbeispiele

The rating after storage of 12 months.

• *) Comparative Examples

The silica according to the invention Dispersions contain only dissolved ones organic oligomers or polymers and are at least 1 year without Eliminations and gelation resistant.

1.4.2. Determination of the Crosslinking behavior and heat balance of adhesive formulations when using the silica according to the invention Dispersion I and polychloroprene

Substances used:

• - Dispersion I: silica sol D + 7% by weight of cyclodextrin F, (Tab. 1 Approach 4)
• - polychloroprene Dispersion L.

Tab 2a: Recipes

• *) Comparative Examples

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

Tab 2c: Thermomechanical properties of the formulation (heat level)

Compared to the use of the standard formulations - with and without the addition of cyclodextrin (batch 15, 16, 18), formulations 17 and 19 according to the invention show markedly higher resistance under thermal stress and the best crosslinking behavior. The curve is in 1 and 2 shown.

1 : Course of the measurements of the resistance to thermal stress of films from dispersions according to Tab. 2a-c, batches 15-17

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 Crosslinking behavior and heat balance of adhesive formulations when using the silica according to the invention Dispersion I and II and polychloroprene

Substances used:

• - Dispersion I: silica sol D + 7% by weight of cyclodextrin F, (Tab. 1 Approach 4)
• - Dispersion II: Silica sol D + 5% by weight of cyclodextrin F (Tab. 1 Approach 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)

Compared with the resinous and resin-free standard formulation 15, 20, 22, the resin-free formulations 21 and 23 according to the invention show a significantly higher resistance under thermal stress and the best crosslinking behavior. The curve is in 3 and 4 shown.

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

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 silica according to the invention Dispersion I and II and polychloroprene with different content at hydroxyl groups on the polymer chain

Substances used:

• - Dispersion I: silica sol D + 7% by weight of cyclodextrin F, (Tab. 1 Approach 4)
• - Dispersion II: Silica sol D + 5% by weight of cyclodextrin F (Tab. 1 Approach 4)
• - polychloroprene Dispersion L and K.

Tab. 4a: Recipes

• *) Comparative Examples

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

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

1.4.5 .: Viscoelastic Properties of the Polymer Dispersions C

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

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

6 : Cooling test with polymer dispersions W, X and V Bohlin VOR: 100 ° C> 20 ° C, 4 ° C / min, frequency: 1 Hz

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

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

How to get in 5 see, the cooling curves of the polymer dispersions S, T and N meet the criteria of the invention, ie in the determination of viscoelastic properties of the storage module G 'is at temperatures of 30 ° C to 100 ° C in the range of 0.02 to 2 MPa, while the storage modulus of the dispersion U in the low temperature range is too high for the application range of adhesive.

According to 6 For example, dispersions W and X meet the criteria of the invention, while dispersion V is too soft for the adhesive insert, ie, the curve is below the desired range of 0.2 MPa.

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

• *) Vergleichsbeispiele

According to 8th Both dispersions K and L fulfill the criteria according to the invention. 4.1.6 .: Thermomechanical properties (heat resistance) of the examples Polymer Dispersion N and Z Tab 5a: Formulations

• *) Comparative Examples

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

at Use of the silica according to the invention Dispersion in Runs 36 and 40 are formulations the highest thermal stability reached.

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

Proportions of used Products:

• - Polymer dispersion 100 parts by weight,
• - Silica dispersion D: 40 parts by weight
• - Silica dispersion according to the invention I: 43 parts by weight

Tab. 6a: Recipes

• *) = Comparative experiment
• + = Formulation contains in addition to the polymer dispersion, this silica dispersion

Tab. 6b: Peel strength and crosslinking behavior.

• N

  = Storage modulus G 'at temperatures of 30 ° C up to 100 ° C outside of the range from 0.02 to 2 MPas

  P

  = Storage modulus G 'at temperatures of 30 ° C up to 100 ° C in the range of 0.02 to 2 MPas;

  n.d

  = not determined

Tab. 7a: Recipes

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

Tab. 7b: Peel strength and crosslinking behavior.

• N

  = Storage modulus G 'at temperatures of 30 ° C up to 100 ° C outside of the range from 0.02 to 2 MPas

  P

  = Storage modulus G 'at temperatures of 30 ° C up to 100 ° C in the range of 0.02 to 2 MPas;

  n.d

  = not determined.

Tab. 8a: Recipes

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

Tab. 8b: Peel strength and crosslinking behavior.

• N

  = Memory module G at temperatures of 30 ° C up to 100 ° C outside of the range from 0.02 to 2 MPas

  P

  = Storage modulus G 'at temperatures of 30 ° C up to 100 ° C in the range of 0.02 to 2 MPas;

  n.d

  = not determined.

• *) Vergleichsbeispiele

Tab 9b: Restmonomergehalt (freies Monomer) der Dispersion in ppm

• *) Vergleichsbeispiele

Particularly preferred polymer dispersions whose viscoelastic properties (storage modulus G ') are in the range of 0.02 to 2 MPa at temperatures of 30 ° C. to 100 ° C. show, in combination with the silicon dioxide dispersion according to the invention, the best peel strengths of the bonded substrates the highest crosslinking (S'max), cf. in particular experiments 42, 48, 57, 60, 69, 72. This also applies to Tests 45 and 51, of which the corresponding memory module curves are not available. 4.1.7 Determination of the residual monomer content Table 9a: Formulations

• *) Comparative Examples

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

• *) Comparative Examples

As Experiment 75 shows is by addition of the dispersion of the invention the content of free residual monomer, shown by the example polychloroprene latex, significantly lowered.

Claims (11)

Aqueous dispersions, characterized in that they contain (a) at least one aqueous silica dispersion having an average particle diameter of the SiO ₂ particles of from 1 to 400 nm and (b) at least one water-soluble hydroxyl group-containing organic compound and the water-soluble hydroxyl-containing organic compounds in the Silica dispersion are dissolved. Aqueous dispersions according to claim 1, characterized in that the SiO ₂ particles have a particle diameter of 1 to 200 nm, preferably from 5 to 100 nm, particularly preferably from 8 to 60 nm. aqueous Dispersions according to claim 1 or 2, characterized in that the aqueous silica dispersion an aqueous one Silica sol is. aqueous Dispersions according to at least one of the claims 1 to 3, characterized in that the water-soluble (s) Hydroxyl-containing organic compound (s), one or more multiple cyclodextrin (s) is (are). Use of the dispersions according to at least one of claims 1 to 4 in the production of adhesives and sealants. Formulations comprising (a) at least one aqueous silica dispersion having an average particle diameter of the SiO ₂ particles of from 1 to 200 nm, (b) at least one water-soluble hydroxyl group-containing organic compound and at least one polymer dispersion (c). Formulations according to Claim 6, characterized in that the polymer dispersion (s) (c) are latices of polymers of dienes or olefinically unsaturated Monomers and their copolymers are. Formulations according to claim 6 or 7, characterized characterized in that the polymer dispersion (s) (c) contain polymers, carry the hydroxyl groups in the polymer chain. Use of the formulations according to at least one of claims 6 to 8 as adhesives or coating agents. Substrates, characterized in that they a formulation according to at least one of the claims 6 to 8 are coated or glued. Method for connecting the one-sided or double-sided coated substrates according to claim 10th