WO2011038956A1

WO2011038956A1 - Mixture for cement-bound materials having easy-to-clean properties

Info

Publication number: WO2011038956A1
Application number: PCT/EP2010/061214
Authority: WO
Inventors: Manuel Friedel; Wolfgang Lortz; Spomenko Ljesic
Original assignee: Evonik Degussa Gmbh
Priority date: 2009-09-29
Filing date: 2010-08-02
Publication date: 2011-04-07
Also published as: DE102009045112A1

Abstract

The present invention relates to a hydraulically setting mixture, comprising 6 to 25 parts by weight cement, 50 to 90 parts by weight of at least one aggregate, 0.01 to 3 parts by weight of at least one silane-based or siloxane-based hydrophobing agent, 0.01 to 3 parts by weight of at least one silicate additive having an average particle size of 1 nm to 20 μm and an inner surface (BET) of 20 to 800 m²/g, and optionally as further components at least 1 to 20 parts by weight water, 0.05 to 0.5 parts by weight liquefier and 0.01 to 1 parts by weight of at least one further auxiliary agent. The invention further relates to construction materials, components, concrete products or molded bodies made thereof. The invention also relates to the use of a hydraulically setting mixture according to the invention for producing building materials, components, concrete products or molded bodies, for example as face concrete, wherein the surface of corresponding bodies has a low tendency to collect dirt ("easy-to-clean" properties) even when worn down.

Description

Mixture for cementitious materials with easv-to-clean properties

The present invention relates to a special hydraulically setting mixture, wherein a hardened or hardened material surface produced therefrom has dirt-repellent properties.

Hydraulically setting materials, such as cementitious materials, are used in modern construction in many relevant places, such as for the application of concrete paving stones for driveways, sidewalks or terraces. Especially in the outdoors, the pollution of the surfaces of such concrete paving stones by a variety of materials, such as traffic and industrial emissions, especially carbon blacks, pollen, grass stains, oils, especially engine oils, beverage and food residues, especially cola, coffee, red wine or ketchup, and by the growth of microorganisms, such as algae or fungi, from a aesthetic point of view is a major problem. The equipment of hydraulically set materials in such applications with dirt-repellent properties (hereinafter also "easy-to-clean" or ETC called) is therefore desirable.

By dirt-repellent properties is meant the property of the surface to prevent the penetration of both aqueous and oily substances into the material and to facilitate the removal of these substances from the surface.

It is known to produce "easy-to-clean" properties by aftertreatment of finished, hardened surfaces with various materials., For example, EP 0 838 467 teaches the use of a fluorine-containing silane or silane system

Surface Treatment. Disadvantage of such systems for the aftertreatment of a surface on the one hand, the need for a further process step after the production of such materials or materials, on the other hand is often the

Durability of such coatings too low, since they are removed by weathering and abrasion. It is also known to improve hydraulically hardening materials, in particular cement-bonded materials, by the addition of mass modifiers. Thus, EP 0 913 370 teaches the use of aqueous, silane-containing emulsions to obtain water-repellent (hydrophobic) properties of such materials. Unfortunately, the teaching does not lead to the desired "easy-to-clean" surfaces.

From US 5,650,004 a cement-bound plaster mixture is known, which is used for the sealing of swimming pools. The water repellent

Properties and improved durability of the plaster mixture are achieved by the addition of silane-modified powders and pozzolanic fillers. Disadvantage of this plaster mixture is that while permanently water-repellent

Properties can be achieved, so even aqueous contaminants can be rejected, but no dirt-repellent properties are achieved in the sense described above.

From DE 10 346 082 hydraulically hardening mixtures are known whose special composition leads to a changed structure. As a result, wear-resistant workpieces with conditionally dirt-repellent surfaces are obtained.

EP 1 445 242 discloses non-cement-based plasters or coatings for facades which have dirt-repellent properties. The dirt-repellent properties are achieved by the microroughness is reduced so that dirt particles can not penetrate into the pore space and set. The disadvantage here is that kaliwasserglasbasierte, non-cementitious plaster mixtures are modified as such.

It is an object of the present invention to provide a further hydraulically setting mixture, in particular a cement-bound mixture, wherein the surface of a material produced therefrom after the

Setting or hardening has sufficiently good dirt-repellent properties and these are as durable as possible. This object is achieved according to the features of the claims.

Surprisingly, it has now been found that by adding at least one silane-based and / or siloxane-based hydrophobing agent together with at least one silicatic additive, in particular a well-defined fumed or precipitated silica, to a hydraulically setting mixture, in particular an otherwise conventional concrete mixture, permanent ETC- Characteristics of a produced therefrom, hydraulically set and hardened material can be achieved.

Furthermore, it has surprisingly been found that it may be advantageous to use said silicate additive, especially if it is precipitated

Silica is, together with the other solids of the

mixture according to the invention, such as cement and aggregates, premix in a suitable mixing unit.

The subject of the present invention is thus a hydraulically setting mixture which

- 6 - 25 parts by weight of cement,

- 50 - 90 parts by weight of at least one additional charge,

- 0.01 - 3 parts by weight of at least one silane or siloxane-based

Hydrophobing agent,

0.01 to 3 parts by weight of at least one siliceous additive having an average particle size of 1 nm to 20 μm and an inner surface area (BET) of 20 to 800 m ² / g,

contains.

In addition, a hydraulically setting mixture according to the invention can be advantageously used as further components at least

- 1 - 20 parts by weight of water, and optionally 0.05-0.5 parts by weight of plasticizer, preferably selected from the group of polycarboxylate ethers (PCEs), polymethyl methacrylates and lignosulfonates or naphthalene-formaldehyde sulfonates, and

optionally 0.01-1 parts by weight of at least one further auxiliary agent, preferably selected from the group of dispersing aids and wetting auxiliaries, such as, for example, siliconates or alkylphosphonates, defoamers, such as

for example, trialkyl phosphates, air entraining agents, such as saponified resin acids, retarders and accelerators, such as formates, and / or

water reducer

contain.

Preference is given to mixtures according to the invention, in particular cement-bound mixtures which

- 7 - 24, in particular 8, 9, 10, 1 1, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, and 23 parts by weight of cement,

55-85, in particular 60, 65, 70, 75 or 80 parts by weight of at least one aggregate,

0.05 to 2.5, in particular 0.5, 1, 1, 5 or 2 parts by weight of at least one silane-based or siloxane-based hydrophobizing agent,

0.05 to 2.5, in particular 0.5, 1, 1, 5 or 2 parts by weight of at least one siliceous additive having an average particle size of 2 nm to 20 μm, in particular 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 130, 150, 170, 190, 210, 230, 250 and 270 nm and 0.3, 0.5, 0.75, 1, 1, 25, respectively , 1, 5, 2, 2.5, 3, 4, 5, 10, 12, 15, 18, 19 and 20 μιτι, and an inner surface (BET) of 20 to 800 m ² / g, in particular 40, 60th , 80, 100, 120, 150, 175, 180, 200, 250, 300, 350, 400, 500, 600 and 700 m ² / g, respectively, and

as further components optional at least

- 2 - 10, in particular 3, 4, 5, 6, 7, 8 and 9 parts by weight of water, and

optionally 0.05 to 0.5, in particular 0.1, 0.2, 0.3 or 0.4 parts by weight of plasticizer, preferably selected from the group of polycarboxylate ethers (PCEs), polymethyl methacrylates and lignosulfonates or naphthalene-formaldehyde sulfonates optionally 0.05-0.9, in particular 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8 parts by weight of at least one further auxiliary, preferably selected from the group of dispersing aids and wetting aids, such as, for example, siliconates or alkylphosphonates, defoamers, such as, for example, trialkyl phosphates, air-entraining agents, such as saponified resin acids, retarders and accelerators, such as, for example, formates, and / or water reducers

contain.

Cements in a mixture according to the invention all conventional Portland cements and Portland composite cements and blast furnace cements can be used or contained. Thus, in a mixture according to the invention the cement is preferably - but not exclusively - from the series of

Portland cements, Portland composite cements and blastfurnace cements.

So-called supplements in a mixture according to the invention can

For example, be aggregates, such as sands, gravels or grit. Sands may be, for example, quartz sands, river sands and / or fly ash. Thus, a mixture according to the invention may advantageously contain additives which are preferably selected from the series of sands, gravels and chippings, preferably those

Aggregates with a maximum particle size of 8 to 63 mm, more preferably those with 8 mm, 16 mm, 32 mm or 63 mm, in particular aggregates with a maximum particle size of 32 mm, in accordance with the specifications of DIN 1045-2.

Furthermore, mixtures according to the invention are preferably based on at least one silane- or siloxane-based hydrophobing agent selected from the series of aqueous silane- and / or siloxane-based compositions, silane- and / or siloxane-based emulsions, where the silane and / or siloxane-based

Composition or emulsion preferably has an active ingredient content of silane and / or siloxane of from 2.5 to 90 wt .-%, based on the composition or emulsion. Water repellents in the context of the present invention can

be alkyl-substituted silanes of the general formula I.

R

R ² 0-Si-OR ²

OR ² I in which R ^{1 is} linear or branched C ¹ -C 6 -alkyl, groups R ^{2 are} identical or

are different and R ^{2 is} a hydrogen atom or an alkyl radical having 1 to

6 carbon atoms, preferably with 1 or 2 carbon atoms.

Preferred examples are such radicals with:

R ¹ = CH 3, C 2 H ₅ -, C3H7-, C ₄ Hg, iC ₄ Hg, C6H13-, 1-C6H 13, CsHi6-, i-CsHi6- and R ² = H, methyl or Ethyk

In addition, hydrophobicizing agents according to the invention may be oligomeric siloxanes of the general formula II

in the groups R ¹ and R ^{3 are} independently of each other Ci-Cis-alkyl, which may contain one or more heteroatoms such as N, O, F, Cl, P or S, groups R ^{2 are} identical or different and R ^{2 is} a hydrogen atom or is an alkyl radical having 1 to 6 carbon atoms, preferably having 1 or 2 carbon atoms, and n + m the degree of oligomerization as with 2 to 50, preferably 2 to 30, determined. These are advantageously oligomer mixtures with a middle

Oligomerization degree of 2 to 50, preferably from 2 to 30, wherein the average molecular weight is preferably 300 to 10,000 g / mol. The silanoligomers of the general formula II can be present as linear, cyclic and / or branched units. The molecular weight can be determined, for example, by means of GPC according to methods familiar to the person skilled in the art.

Preferred examples of silanoligomers are those having radicals: R ¹ - CH ₃ -, C ₂ H ₅ -, C ₃ H ₇ -, C ₄ Hg-, iC ₄ Hg-, C6H 13-, 1-C6H13, CsHi6-, i-CsHi6- and

R ² = H, methyl or ethyl

R ³ = CH 3, C 2 H ₅ -, C3H ₇ -, C ₄ Hg, iC ₄ Hg, 13- C6H, 1-C6H 13, CsHi6-, ί-ΟβΗ-ιβ-, NH2-C3H6-,

A

NH2-C ₂ H ₄ -NH-C ₃ H6, NH ₂ -C2H ₄ -NH-C 2 H ₄ -NH-C ₃ H 6, H ₂ C-CH-CH ₂ -O-

In addition, mixtures of said hydrophobing agents of the general formulas I and II can be used or used according to the invention. In this case, each of the hydrophobizing agents I and II independently account for between 0% and 100% of the total amount of hydrophobizing agent (proportion of total hydrophobing agent).

Suitable silane or siloxane-based water repellents and their

Preparation can be taken, for example, but not exclusively, from EP 0 838 467, EP 0 814 110, EP 0 960 921, EP 1 205 481, EP 1 099 703 and / or EP 1 306 381. Thus, the entire contents of the aforementioned documents are to be considered as fully within the scope of the present disclosure.

A mixture according to the invention can usually be found in a simple and

economically by combining and mixing the

produce components according to the requirements.

Thus, in general, by mixing the components according to the present main claim, one can first provide a hydraulically setting mixture. This can be, if they then together when applied with a claimed amount of water, optionally with good mixing with or in the person skilled in per se known devices or

Add containers, other components that are listed above, and bring the mixture thus obtained or a mass thus prepared in a desired shape and hydraulically set or harden.

Advantageously, the said silane / siloxane-containing hydrophobizing agents can be used in the form of an aqueous preparation. This allows the

Incorporation into the aqueous, cement-containing mixtures additionally simplified become. Such aqueous preparations may, in particular, be aqueous emulsions which have a content of hydrophobizing agent of the formula I and / or II of in total 2.5% by weight to 90% by weight, preferably 5% by weight to 80% by weight, particularly preferably from 5% by weight to 70% by weight, very particularly preferably from 10% by weight to 60% by weight (in each case based on the total mass of the aqueous emulsion).

If water repellents used according to the invention are present in the form of an aqueous emulsion, they may contain at least one emulsifier which advantageously comprises a series of alkyl sulfates with Cs-Cis-alkyl, alkyl and alkaryl ether sulfates with Cs-Cis-alkyl in the hydrophobic radical and with 1 to 40 ethylene oxide (EO) or propylene oxide (PO) units, alkyl sulfonates with Cs-Cis-alkyl, alkarylsulfonates with Cs-Cis-alkyl and half esters of sulfosuccinic acid with monohydric alcohols or alkylphenols having 5 to 15 carbon atoms, alkali metal and ammonium salts of carboxylic acids having 8 to 20 carbon atoms in the alkyl, aryl, alkaryl or aralkyl radical, alkyl and alkaryl phosphates having 8 to 20 carbon atoms in the organic radical, alkyl ether or alkaryl ether phosphates having 8 to 20 carbon atoms in the alkyl or alkaryl radical and 1 to 40 EO units, alkyl polyglycol ethers and

Alkaryl polyglycol ethers with 8 to 40 EO units and Cs-C2o carbon atoms in the alkyl or aryl radicals, ethylene oxide / propylene oxide (EO / PO) block copolymer with 8 to 40 EO or PO units, addition products of alkylamines with C8-C22 - Alkyl radicals with ethylene oxide or propylene oxide, alkyl polyglycosides with linear or branched saturated or unsaturated Cs-C2 ₄ alkyl radicals and Oligoglykosid- residues with 1 to 10 hexose or pentose units, siliciunnfunktionelle surfactants or mixtures of these emulsifiers is selected.

The content of emulsifier in such an emulsion is preferably 0.01 to 5 wt .-%, based on the total weight of the emulsion.

In addition, an aqueous composition of a hydrophobizing agent used according to the invention may advantageously also contain conventional auxiliaries,

selected from inorganic or organic acids, buffer substances,

Fungicides, bactericides, algicides, microbiocides, fragrances,

Corrosion inhibitors, preservatives, rheology aids included. Furthermore, silicatic additives are advantageously selected from the series of microsilica, fly ash, flame silicic acids, precipitated silicas, zeolites, crystalline in inventive hydraulically setting mixtures

Silica, silica sol, kaolin, mica, kieselguhr, diatomaceous earth, talc,

Wollastonite or clay or a mixture of corresponding microsilica, fly ash, flame silicas, precipitated silicas, zeolites, crystalline

Silica, silica sol, kaolin, mica, kieselguhr, diatomaceous earth, talc,

Wollastonite or clay, or from an aqueous dispersion of at least one pyrogenic silica or at least one precipitated silica or a mixture of pyrogenically prepared and precipitated silicas.

The so-called advantageously used in the present application

silicate additives, i. which are used for the preparation of a hydraulically setting mixture according to the invention or are present in the mixture according to the invention can be oxides, hydroxides or oxide hydrates of the silicon. These may contain other elements, e.g. Lithium, sodium, potassium, magnesium, calcium, boron, aluminum, carbon, phosphorus, sulfur, halogens, titanium, chromium, iron, nickel, copper, zinc, zirconium, molybdenum, silver preferably in ionized form, optionally also in the form of Oxides, included. Such siliceous fillers may be microsilica, fly ash, flame silicic acids, precipitated silicas, silica sols, kaolin, mica, kieselguhr, diatomaceous earth, talc, wollastonite or clay or even silicates inter alia in the form of glass beads, ground glass splinters (glass powder), glass fibers or glass fabrics.

Silica acids, such as flame silicic acids, precipitated silicas, crystalline silicic acids or zeolites are preferably used. Particularly preferred flame silicas and / or precipitated silicas. Siliceous fillers used according to the invention may be pulverulent solids, but they are preferably in the form of aqueous dispersions. Also, grinding and / or sifting of the powders may be carried out before or after.

The average particle size used according to the invention or present in a mixture according to the invention silicate additives advantageously 1 nm to 20 μηη including all intervening numbers, preferably 2 nm to 10 μιτι, particularly preferably 3 nm to 5 μιτι. The

Average particle size can be determined, for example, by means of transmission electron microscopy (TEM).

The specific surfaces used according to the invention or in one

mixture of present silicate additives according to the invention are advantageously from 20 to 800 g / m ² including all numbers lying between them, preferably from 25 to 600 g / m ² , particularly preferably from 50 to 500 g / m ² , very particularly preferably from 60 to 400 g / m ² , in particular 70 and 300 g / m ² . The specific surface area (BET) can be determined, for example, on the basis of DIN 66131.

If the silicatic additives according to the invention in the form of aqueous

Dispersions are used or a mixture according to the invention contains an aqueous dispersion of silicate additives, these advantageously have a content of at least one of said silicate additives from 2 wt .-% to 80 wt .-%, preferably 2 wt .-% to 60 wt. -%, particularly preferably 5 wt .-% to 50 wt .-%, most preferably 10 wt .-% to 40 wt .-% (each based on the total mass of the aqueous dispersion). Thus, the content of silicate additive in a for the purposes of the present invention

used aqueous dispersion preferably 2 to 80 wt .-%.

Aqueous dispersions of silicate additives used according to the invention can be stabilized by salts of elements of main groups I and II of the Periodic Table of the Elements (PSE) and by salts of compounds of main group V of PSE, in particular by oxides, hydroxides, nitrates, nitrites, sulfates , Sulfites, sulfides, halides, phosphates, hydrogen phosphates, dihydrogen phosphates, carbonates, bicarbonates of sodium, potassium and / or ammonium.

If precipitated silicas are used as additives in the present invention, they can advantageously be premixed in suitable mixing units. Suitable mixing units are, for example, Lödige type mixers. Advantageously precipitated silicas are premixed at 100 to 1000, in particular at 150 to 500 revolutions using a ploughshare mixer for a period of 30 minutes.

The silicate additive used according to the invention or present in the mixture according to the invention can have a content of carbon in pure or chemically bound form of between 0.1 and 25% by weight, preferably between 0.1 and 10% by weight, more preferably between 0 and 0 , 1 and 5 wt .-% (based on the total mass of the siliceous filler) have.

The silicate additive used according to the invention or present in the mixture according to the invention can furthermore contain a content of physically and chemically bound alcohol between 0 and 25% by weight, preferably between 0 and 15% by weight, particularly preferably between 0 and 10% by weight. % (based on the total mass of the siliceous filler).

A used in the context of the invention silane-modified oxidic or

Silicate additive may be predominantly homogeneous or inhomogeneous.

Silane-modified silicate additives are obtainable by mixing at least one microbeaded or microgranular silicate additive according to the invention in a compressed gas with at least one silane from the series of organosilicon compounds of general formula I and / or II and / or an organosilicon compound, as described in DE 198 44 607 described, implemented. Furthermore, suitable silane-modified silicate additives can be obtained, for example, by treating silicate additives with a silanizing reagent. The treatment can be carried out, for example, by wetting (mixing, kneading, grinding, dipping, flooding) said silicate additives with the silanizing reagent and subsequent thermal aftertreatment, for example in a drying cabinet. But the treatment can also be by spraying the silicate additives with a silanizing reagent, optionally under the influence of a higher temperature and

optionally in vapor form. A silicate, silane-modified additive used according to the invention may contain from 0.1 to 50% by weight, preferably from 0.1 to 25.0% by weight, particularly preferably from 0.1 to 10% by weight, of silane in a tethered or unbonded form contain.

A silane-modified silicate additive used in accordance with the invention may further contain from 50 to 99.9% by weight of microbeaded or microbaked, siliceous filler.

In this case, the silane-modified silicate additive may have a bead fraction greater than 1000 μηη of less than 30% by weight, preferably less than 20% by weight, more preferably less than 10% by weight, and / or a bead fraction greater than 500 μηη of less than 30 Wt .-%, preferably less than 20 wt .-%, more preferably less than 10 wt .-%, have.

The above-mentioned silane may be chemically and / or physically linked to the surface of the additives.

The silane used may in particular be an organosilicon compound or mixtures of organosilicon compounds of the general formula I and / or II.

As silane may also be advantageous compounds such as described in

DE 198 44 607, can be used.

As silanes in the context of the present invention for the modification of siliceous additives, it is also possible to use mixtures of silanes,

For example, mixtures of different silanes of the general formula I and / or II or mixtures of oligomeric or polymeric siloxanes of the general formula II with silanes of the general formula I or mixtures of silanes of the general formula I with mixtures of oligomeric or polymeric siloxanes of the general formula II. A silicate additive used in accordance with the invention and / or the silane which can be used to modify the additive can be admixed with additives before the reaction.

Also, the silicate additive during the implementation of

Silane modification can be brought into contact with additional additives.

As additives, water, short-chain or long-chain alcohols,

for example, dodecanol, tetradecanol, hexadecanol, octadecanol, or other alcohols with molecular weights> 50 g / mol, short-chain or long-chain polyether or polyether, for example diethylene glycol, triethylene glycol or others with molecular weights> 100 g / mol, short-chain or long-chain amines with molecular weights> 50 g / mol, emulsion formers or else short-chain or long-chain silicone oils, for example silicone oils with molecular weights> 100 g / mol, or mixtures of the abovementioned compounds.

The modification reaction can take place at temperatures between 1 and 300 ° C,

preferably between 1 and 200 ° C, more preferably between 1 and 150 ° C, and most preferably at temperatures between 1 and 130 ° C,

be performed.

A silane-modified silicate additive to be used according to the invention can additionally be subjected to a compaction or processing step.

Finally, mixtures of at least two of the aforementioned

silicate, optionally silanized, additives are used.

If the hydrophobizing agents of the general formula I and / or II according to the invention and / or the silicatic additives according to the invention are used in the form of their aqueous preparations, then it is advantageous for the calculation of the total composition of the cement-bound mixture to use only the proportion of active substance in the respective aqueous composition as inventive Silane / siloxane-containing hydrophobizing agent, or inventive silicate Additive, taken into account. Advantageously, the water content of these aqueous preparations in the calculation of the necessary addition amount of water

considered.

Condensers may be all common flow aids, in particular polycarboxylate ethers (PCEs) and / or polymethyl methacrylates and lignosulfonates or naphthalene-formaldehyde sulfonates.

Hydraulically setting mixtures according to the invention can be used as further

Adjuvants, for example, dispersants and wetting aids, such as, for example, siliconates or alkyl phosphonates, defoamers, such as, for example, trialkyl phosphates, air entraining agents, such as saponified resin acids, retarders and

Accelerators, such as formates, and / or water reducers.

Advantageously, hydraulically setting mixtures according to the invention can be used in the concrete industry, these being mixed in conventional compulsory mixers.

In this case, one can advantageously proceed by premixing powdery silicate additives with the cement and the other solid additives, liquid, non-aqueous water repellents of the general formulas I and / or II also premixed with the cement, aqueous formulations such as

By contrast, aqueous emulsions according to the invention of hydrophobizing agents and / or said aqueous dispersions of the well-defined silicatic additives are added together with the mixing water. The content of additionally introduced water can advantageously be taken into account when setting the desired w / c value. The processability of the invention

Mixtures is advantageously unchanged compared to unmodified mixtures.

However, it is also possible to submit a mixture of solids of a hydraulically setting mixture according to the invention in a compulsory mixer and to add and mix a defined amount of water in one batch or portionwise. A hydraulically setting mixture of the invention obtained in this way can subsequently be subjected to shaping and curing known per se to the person skilled in the art, whose surfaces in the sense of the invention advantageously also have a lower tendency to become soiled ("easy-to-clean" property) during abrasion.

The present invention thus also relates to components, concrete products or molded articles obtainable using a hydraulically setting mixture according to the invention.

Next object of the present invention is the use of a

inventive hydraulically setting mixture for the production of

Components, concrete goods or moldings, the surface of which has a low tendency to fouling even when attrition ("easy-to-clean" property).

Thus, it is advantageously possible to use a hydraulically setting mixture according to the invention in the construction sector, in particular for the production of workpieces, for concrete paving stones, or else as facing concrete.

It should be noted that for the manufacturers of cement-bonded workpieces, in particular for the manufacturers of concrete blocks, it was until today of great interest to sustainably modify hydraulically setting, especially cement-bonded workpieces and despite abrasion and weathering easy-to-clean properties to ensure the surface.

By providing and using mixtures according to the invention, it is possible, due to the newly achieved, despite abrasion and weathering permanent easy-to-clean properties of hydraulically hardened workpieces cleaning and

Maintenance costs are significantly reduced by extended cleaning cycles. Such mass modifications can advantageously be carried out in particular during operation of a production plant and the workpieces can already be delivered completely protected. Additional effort on the site is eliminated. But also on site an application compositions of the invention can be prepared and used advantageously.

The invention will be explained in more detail with reference to the following examples, without, however, limiting the scope of the invention.

Examples

The mortar test specimens used were from a commercial

Universal mortar (mortar group II according to DIN V 18580, mortar group P II according to DIN V 18550) made by Quick-Mix. For this purpose, about 90 g of the mortar were thoroughly stirred with about 13 ml of water. Those listed in the examples, respectively

Water repellents and additives were each predispersed in the mixing water. The resulting mixture was filled in PE cups, dried for 24 days at 25 ° C, then disconnected from the PE cup and cured for a further 28 days at 25 ° C. The pollution properties were in

Based on DIN EN ISO 10545-14, the test is described in more detail below.

Data in% by weight relate in each case to the weight of the mortar used, d. H. the complete dry mix.

Example 1 (comparative example)

A mortar specimen was prepared as described above. However, no silane-based or siloxane-based water repellents, silicate additives or other auxiliaries were used.

Example 2

A mortar test specimen was prepared as described above. In the mixing water, before addition, 2% by weight of an aqueous emulsion containing 50% by weight of a propylethoxyoligosiloxane having an average molar mass of about 700 g / mol, and 3 wt .-% of a finely divided precipitated silica which has a specific

Surface of 175 m ² / g and an average particle size of 5 μιτι dispersed.

Example 3

A mortar test specimen was prepared as described above. In the mixing water before addition 2 wt .-% of an aqueous emulsion containing 50 wt .-% of an octyltriethoxysilane, and 5 wt .-% of an aqueous dispersion containing 20 wt .-% of a fumed silica and is stabilized with KOH, and which is characterized by a mean aggregate size of 0.12 μιτι and a pH of 9.0 to 10.0, dispersed.

Example 4

A mortar test specimen was prepared as described above. In the mixing water before addition 2 wt .-% of an aqueous emulsion containing 50 wt .-% of an octyltriethoxysilane, and 1 wt .-% of a hydrophilic, pyrogenic

Silica with a specific surface area of 200 m ² / g and an average size of the primary particles of 12 nm, dispersed.

Example 5 (Comparative Example)

A mortar test specimen was prepared as described above. In the mixing water 2 wt .-% of an aqueous emulsion containing 50 wt .-% of an octyltriethoxysilane, dispersed before addition.

Example 6 (comparative example)

A mortar test specimen was prepared as described above. In the mixing water before addition 5 wt .-% of an aqueous dispersion containing 20 wt .-% of a fumed silica and is stabilized with KOH and which is characterized by a mean aggregate size of 0.12 μιτι and a pH of 9.0 to 10.0, dispersed.

Example 7 (comparative example)

A mortar test specimen was prepared as described above. In the mixing water 3 wt .-% of a finely divided precipitated silica having a specific surface area of 175 m ² / g and an average particle size of 5 μιτι, were dispersed before addition.

evaluation

On the surface of the cured mortar test specimens (not on the shell side) was ever a drop (about 0.5 ml) of the pollution agents coffee (sweetened), cola, red wine, and olive oil applied. After 1 hour reaction time at 25 ° C, the surface was blotted with a soft cloth and charged with deionized water for 3 min. Finally, the water is blotted with a soft cloth and visually assessed the contamination of the surface after drying. 5 means that no soiling is visible, 4 means that soiling is poorly visible, 3 means that soiling is visible, 2 means that soiling is clearly visible, and 1 means that soiling is highly visible. Good easy-to-clean properties can only be mentioned if a significant improvement compared to an untreated control sample is achieved. Very good easy-to-clean properties can be used when the 3 aqueous

Polluting agents (coffee, cola, red wine) each achieve a 4 or 5 and at the same time olive oil a marked improvement over an untreated one

Comparative sample reached.

Table 1 below shows the results of the soiling test. Pollution pollution game coffee (sweetened) with cola with red wine with olive oil

1 1 5 1 1

2 4 5 4 3

3 4 5 4 ¹

4 4 5 4 ¹

5 2 4 1 ¹

6 2 2 1 ¹

7 2 2 1 ¹

Results of the contamination test

It is clear that according to the definition above with the mixture according to the invention of Example 2, very good easy-to-clean properties are achieved and with the mixtures 3 and 4 according to the invention still good easy-to-clean properties are achieved. Comparative blends 5, 6 and 7 show no such clear improvement in cleaning properties

Claims

claims:

1 . A hydraulically setting mixture that

- 6 - 25 parts by weight of cement,

- 50 - 90 parts by weight of at least one additional charge,

- 0.01 - 3 parts by weight of at least one silane or siloxane-based

Hydrophobing agent,

0.01 to 3 parts by weight of at least one siliceous additive having an average particle size of 1 nm to 20 μm and an internal surface area (BET) of 20 to 800 m ² / g,

contains.

2. Hydraulically setting mixture according to claim 1,

characterized,

that the mixture as further components at least

- 1 - 20 parts by weight of water,

- optionally 0.05 - 0.5 parts by weight of plasticizer and

- Optionally 0.01 to 1 parts by weight of at least one further adjuvant.

3. Hydraulically setting mixture according to claim 1 or 2,

characterized,

the cement is selected from Portland cements, Portland composite cements and blastfurnace cements.

4. Hydraulically setting mixture according to one of claims 1 to 3,

characterized,

that aggregates are selected from the range of sands, gravels and chippings, in particular those with 32 mm largest grain.

5. Hydraulically setting mixture according to one of claims 1 to 4,

characterized, a silane- or siloxane-based hydrophobizing agent is selected from the series of aqueous silane- and / or siloxane-based compositions, silane- and / or siloxane-based emulsions, silane- and / or siloxane-based compositions or emulsions having an active ingredient content of silane and / or siloxane of 2 , 5 to 90 wt .-%, based on the composition or emulsion.

6. Hydraulically setting mixture according to one of claims 1 to 5,

characterized,

that silicate additives are selected from the group of microsilica, fly ash, flame silicic acids, precipitated silicas, zeolites, crystalline silicas, silica sols, kaolin, mica, kieselguhr, diatomaceous earth, talc, wollastonite or clay or from a mixture of microsilica, fly ash, flame silicic acids, precipitated silicas, Zeolites, crystalline silicic acids, silica sols, kaolin, mica, kieselguhr, diatomaceous earth, talc, wollastonite or clay, an aqueous dispersion of at least one pyrogenically prepared silica or at least one precipitated silica or a mixture of pyrogenically prepared and precipitated silicas.

7. Hydraulically setting mixture according to claim 6,

characterized,

the content of silicate additive in the aqueous dispersion is from 2 to 80% by weight.

8. components, concrete products or moldings, available using a

hydraulically setting mixture according to one of claims 1 to 7.

9. Use of a hydraulically setting mixture according to one of

Claims 1 to 7 for the production of components, concrete products or moldings according to claim 8, wherein the surface also has a low tendency to fouling even when attrition ("easy-to-clean" property).

0. Use of a hydraulically setting mixture according to at least one of claims 1 to 9 as facing concrete.