FI64564C - MEDEL FOER HYDROFOBERING AV BYGGNADSMATERIAL I SYNNERHET POROESA SAODANA SAMT FOERFARANDE FOER ATT FRAMSTAELLA MEDLET - Google Patents

Description

RSäRl [B] (11) * ANNOUNCEMENT PUBLICATION 64564

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(51) Ky.lk. ^ nt-a.3 C 04 B 41/28 FINLAND — FINLAND (21) PBnnttllMlMnMM - Patentvneknlng 77 3505 (22) HakemiapUvi —Ameknlngadag 21.11.77 (23) Alkupilvi — Glhighetadag 21.11.77 (41) ) Tullut JulklMkal - Blivlt offantllg 02 q6 J8 htMttl · »klmriMIIM. (4Λ NM — ιρΜ.1.ΜΗ »Α.ρη ^ - Pätene · och regittorttyrMMn 7 Am6kan utlagd och utUkrtftan pubi ka rad 21. 08. 83 (32) (33) (31) Pyy4 *« y atuolkau · —Begird prlorkec 12/2/76

Sweden-Sweden (SE) 7613507 ~ 8 (71) Dynamit Nobel Aktiengesellschaft, 5210 Troisdorf, Federal Republic of Germany Förbundsrepubliken Tyskland (DE) (72) Josef Piihringer, Täby, Sweden-Sweden (SE) (7M Oy Jalo Ant-Wuorinen Ab (5 ^) Substance for hydrophobizing particularly porous building materials and method for preparing the substance - Medel för hydofobering av Bygg-nadsmaterial i synnerhet porösa s & Dana samt förfarande för att fram-ställa medlet

The invention relates to a method and a substance for hydrophobizing porous building materials, in particular alkaline mineral building materials, while taking into account economic, professional, technical and functional requirements.

It is known to hydrophobize the surface layers of buildings, i.e. to make them water repellent. The purpose of this treatment is, above all, to prevent the penetration of rain and snow into the surface layers of the house structures and their transport of aggressive substances dissolved in the pore and capillary system and water.

This is achieved in a different way by mixing certain surfactants (stearates, "silicones", etc., i.e. substances with a certain edge angle with respect to water) already at the manufacturing stage with the components of the substance or by treating the finished structures with such preparations or their solutions and emulsions.

One way to use certain types of silanes is described in SE patents 367,616 and 381,453, which relate to an impregnating agent for masonry, 2 64564 priority DE-AS 20 53 110 and DE-AS 22 58 901.

Naturally, emulsions can be prepared from solutions of silanes in organic solvents. Penetration of these emulsions is limited.

Emulsions formed directly from hydrolyzable silanes using water or water / alcohol as emulsifier do not have this disadvantage.

The substance and method for preparing a saturated building material with such emulsions are disclosed in SE patent application 75-01228-6.

It is apparent from this patent application that hydrophobizing agents for building materials can be prepared directly from certain silanes or silane solutions in alcohol and water by mechanical dispersion. However, such emulsions have a greater tendency to separate as the water content increases. In some cases, the mechanical treatment of the emulsion must be repeated during the impregnation step.

In some cases, there is a need in the construction industry to temporarily protect porous (mineral) building materials from the ingress of moisture, especially rain or snow, on the one hand during storage immediately after manufacture, during transport and partly during installation and, of course, during building use. This applies, for example, to brick products made of concrete, aerated concrete, natural stone, asbestos, all types of fired clay, limestone sandstone and the like, as well as paper, wood pulp and the like.

(One advantage of these treatments is that they improve adhesion between mineral substrates and organic coatings, whether of different types, solvent-based paints or dispersion paints and asphalt as a protective layer against moisture or as a bonding layer between substrates and paper coatings).

The treatment with the preservative can already take place in more or less enclosed facilities at the factory in order to take into account, as far as possible, occupational hygiene considerations during the manufacture of the hydrophobizing agent as well as during handling (if hazardous ingredients should be avoided). Due to the large surface area of the surfaces to be treated, the substance and the method for applying the substance to the building material must be economical. It must be possible to improve, repeat and complete the processing. The treatment must not prevent the post-treatment of the surface layer.

Aqueous solutions of siliconates, especially methylsiliconate, have been known to make these treatment agents economically acceptable; for aqueous reasons, relatively large amounts of sodium or potassium lye must be added to these aqueous solutions, which contributes to the pH rising above 13.

The object of the invention is to provide an economical and, to a certain extent, stable and, from a medical point of view, safe and effective and technically simple substance and method for hydrophobing porous building materials. The invention has been made economical by using silanes and water or water / alcohol mixtures as emulsifiers, with water forming a considerably larger or only part of the liquid.

The professional medical aspects of the invention have been taken into account in part by the non-use of hazardous or toxic solvents (in solutions or emulsions) and preferably by the use of certain types of silanes, namely alkyltrialkoxysilanes, which are only demonstrably mildly irritating to skin and eyes.

The technical advantages of the invention allow that the routines or treatments of the use of the ingredients do not require more extensive information or the use of protective equipment or devices. It must be possible to mix immediately before treatment, possibly in a specially prepared mixing nozzle or suitably in advance, in which case the mixture must have suitable stability.

The object of the invention is therefore also to avoid high-efficiency mechanical emulsification of the components contained in the emulsion - mixing must take place by technically less demanding measures, for example simply by stirring or mixing directly in or outside the tubes or special nozzles. It must, of course, be possible to use the emulsion and possibly also mix it using all conventional and non-conventional application methods, e.g. painting with a brush or roller, spraying or mixing in spray boxes and the like, or in lines or equipment otherwise adapted to the production process.

It is known that emulsions of silanes and their hydrolysis products can be prepared directly in water or water-alcohol mixtures using high performance mechanical emulsification. It has been shown that great advantages can be achieved with this method in terms of e.g. emulsion stability and particle size reduction by adding surfactants (surfactants) to the emulsion medium, in this case water and water / alcohol mixtures. Unfortunately, however, it has also been shown that the hydrophobic effect of these emulsions is completely reduced or eliminated by the general addition of such surfactants. However, it has surprisingly been found that advantages can be obtained with these additives 4 64564 without corresponding drawbacks, by using surfactants which can lose their surfactant properties when suitably processed during the preparation or application of the impregnating agent. This can be done by adding surfactants to the mixture of condensation products of silanes and their hydrolysis products in water and alcohol which can be decomposed and which have lost their surfactant properties either due to their material properties or by reaction with other substances involved in the hydrophobic surface layer production process. after manufacture or impregnation treatment.

Accordingly, the invention relates to an agent for hydrophobing building materials, in particular porous building materials, based on an emulsion of water-insoluble silanes, in particular alkyltrialkoxysilane and / or their condensation products and / or hydroxyl products, known as a dispersed phase and water, continuous aqueous alcohol mixtures. in that it contains a disintegrant as a dispersant, the silane content of the emulsion being 1-50% by volume of the emulsion and the surfactant content being about 0.01-1% by volume of the emulsion.

The hydrophobizing agent can be prepared and the building materials can be hydrophobized in the following manner. Mix silanes and their immediate hydrolysis products directly or their solutions in organic solvents, preferably their alcoholic solutions with water and water-alcohol mixtures and with non-alkali or non-acid-resistant surfactants or surfactants which are not stable in contact with oxidizing or with reducing agents. In this case, stable emulsions are obtained using simple mixing methods, such as agitation.

The hydrophobizing agent used is preferably water-insoluble alkyltrialkoxysilanes according to SE patent 367,616 and the hydrolysis and condensation products obtained therefrom. Ten ties can be mentioned e.g. esters of different compositions, e.g. phosphoric acid esters or silicic acid esters, as well as e.g. also fatty acid esters, fatty acid polyglycol esters and various alcohol alkylene oxide adducts and a number of other surfactants suitable for the purposes of the invention.

64 5 6 4

The mixing can take place in different ways in different steps, e.g. silanes and at the same time possibly surfactants can be dissolved in alcohol and emulsified in water, whereby mixing with water leads to hydrolysis and condensation products in water or water / alcohol mixtures. Silanes and their hydrolysis and condensation products or possibly their solutions in organic solvents can be emulsified in water by adding the above-mentioned surfactants. The decomposition of the surfactants into non-surfactants then takes place either in interaction and reaction with the ingredients in the treatment, or after treatment (impregnation) with the degrading component in a subsequent treatment step.

It has surprisingly been found that emulsions made from silanes and their hydrolysis and condensation products in water or water / alcohol mixtures can be prepared using both very high and very low silane contents in the emulsion. It has surprisingly been found that the penetration depth of emulsions prepared in this way is of the same order of magnitude as the penetration depth of the solutions.

When preparing emulsions according to the present invention, different concentrations of silanes (or their reaction products with water) can be used, especially to a concentration of about 1-50% depending on the type of silane. The amount of surfactant should be as low as less than 1% of the volume of the emulsion, preferably 0.1 ° / o to 1.0% / oo. Alkyltrialkoxysilanes are preferably used as the solution. Esters and alcohol-alkylene oxide adducts are preferably used as the degradable surfactant. The amount of water in the alcohol-li-water mixture used as the emulsifying liquid may be 100 to 50%, preferably 95 to 75%. The substance can be used e.g. for the industrial hydrophobization of lightweight concrete, concrete, asbestos products, limestone sandstone, concrete roof tiles, paper, wood and cellulosic products, whereby these products can be treated to provide a temporary water-repellent surface during storage, transport and installation, or the products can be durable The treatment can also take place in situ, for example on plasters, silicate paints, water glass paints and limestone-sandstone bricks.

Gypsum boards can also be hydrophobized by one of the methods according to the invention. Wood and paper can also be hydrophobized.

Degradation of surfactants is most often due to the alkalinity of the building materials, in reactions with metal oxides or the like during or immediately after the manufacturing or installation phase, but can also be achieved by simultaneous or subsequent impregnation with liquids, especially water or aqueous alcohol mixtures containing temporal or acidic substances or oxidizing agents. or reducing agents, or with gases which themselves form or contain these substances or are mixed with them.

It has surprisingly been found that the emulsions prepared according to the invention have a considerably longer stabilization time than the emulsions prepared from silanes according to SE patent application 75-01228-6.

Another advantage associated with this type of hydrophobization is that it can already be used on hydrophobic surfaces, despite the fact that the emulsifier liquid contains considerable amounts of water, whereby the surfactant content temporarily removes the hydrophobicity of the surface layer until the surfactant has disappeared.

The substance according to the invention can be hydrophobized as building materials or other substances which consist of or contain components which react with silanes. These components may be hydroxyl-containing substances (e.g. lime) or metal oxides, or they may react with silanes in other ways to form a siloxane film on their surface. Eligible building materials include concrete, lightweight gravel and lightweight aggregate concrete, lightweight concrete, masonry and plaster, gypsum mortar, and products made of gypsum, asbestos cement, materials and products made of fired or sintered clay, silicon, glass-containing aggregates and fibers, products consisting of or containing cellulose, such as timber, paper, fibreboard and the like.

In order to illustrate the features and modes of operation of the invention in comparison with the prior art, a few experiments are presented below.

Mixtures containing hydrophobizing agents, surfactant (wetting agent), alcohol and water were prepared. These mixtures were used to treat the wire-cut outer surface of lightweight concrete blocks with a density of 0.5. The pH of lightweight concrete was about 8.

1. Test pieces and impregnation method

Lightweight concrete slabs with a diameter of 80 mm and a thickness of 10 mm were used as test specimens, which were in principle prepared in accordance with the recommendations of the Swedish ER Commission for mortar diffusion tests.

The impregnation took place by immersing the test pieces in the upper surface of the liquid, whereby the impregnation of the impregnating liquid took place by "capillary self-suction".

The impregnation effect was determined after hydrophobization by measuring the non-wettable cross-section after wetting the split specimens.

2. Handling fluids

The mixture ABC according to the invention

Water ml 1000 1000 1000

Ethyl alcohol

Mixture of alkyltrialkoxysilanes ml 50 50 50

Wetting agent 1, ml 0.25 0 0

Wetting agent 2, ml 0 0.25 0

Mixing method I Stirring

Mixing method II Mixing at high power

In the Speedmix, 80,000 rpm.

3. Preparations used

Alkyltrialkoxysilane (Dynasilan BSM) manufactured by Dynamit Nobel, Froisdorf, Germany, was used as the silane preparation. Industrial alcohol was used as ethyl alcohol. As wetting agent 1, a wetting agent manufactured by Berol Kemi, Stenungsund, Sweden, under the trademark Berol 08, dissolved in ethyl alcohol, was used. The wetting agent is a non-ionic surfactant based on normal primary alcohol, is highly hydrophilic and is considered an alcohol alkylene oxide adduct.

The surfactant is not resistant to alkalis and acids, oxidation! against reducing agents.

As a surfactant 2, a wetting agent manufactured by Berol Kemi, Stenungsund, Sweden, under the trademark Berol 452 was used. The wetting agent is a flowable anionic surfactant of the type alkyl ether sulfate. This surfactant is resistant to alkalis up to a pH of about 13.0.

4. Manufacturing options

In principle, the preparation took place according to different options, but no differences in the properties and behavior of the substance used and the treatment result could be demonstrated.

In principle, the alternatives can be selected, for example, according to the field of use of the product or the technical aspects of storage.

Options a Mix water and solvent (alcohol) and then add surfactants. The silane (optionally mixed with an alcoholic solvent) is then added. b Mix silane and alcohol, which is added to water and surfactant (and possibly alcohol). c Mix silane, alcohol and surfactant, add to water (and possibly alcohol).

d The silane and surfactant are mixed and then added to water and possibly alcohol, e The experiments were also carried out after varying storage times of the mixtures, during which the reactions described in .5 developed, in whole or in part.

Various experiments were performed using mixtures containing different volumes of the components contained in the mixture, namely silane, alcohol, water and surfactant in proportions apparent from the description of the invention - in which case no deviations from the conditions described below could be observed.

5. Reactions in mixture

Upon contact with water, the silanes hydrolyze to silanols which, upon condensation, form water-repellent siloxanes. Reactions can occur between the siloxanes 64564 and between these and the treated support.

These reactions are time-bound and can occur after mixing the liquid, during storage, or immediately upon handling the substance.

6. Comparison between treatment according to the invention and treatment according to another technique Type of treatment

ABC

Miscibility in confusion Easy Easy Difficult

Stability of the mixture According to the invention, separation after a few A few Immediate-day hours

Mixability with Speedmix Easy Easy Easy

Stability of the mixture, separation 1 year Months After a few hours

No separation was detected Treatment penetration depth, contact time 300 s 6 mm 6 mm 2 mm

Hydrophobing effect, drop test, drop 0.05 ml drop disappears after 3600 0 s after 3600 s of ice

Penetration depth when already treating a hydrophobic surface t = 1 mm after a cotactic time of 300 s 3 mm 3 mm 0 mm

Claims (9)

10 64564 A substance for hydrophobizing building materials, in particular porous building materials, based on an emulsion of water-insoluble silanes, in particular alkyltrialkoxysilane and / or their condensation products and / or hydrolysis products as a dispersed phase and water, known as a continuous mixture thereof, or aqueous alcohol mixtures as a dispersant contains a disintegrant surfactant, wherein the silane content of the emulsion is 1-50% by volume of the emulsion and the surfactant content is about 0.01-1% by volume of the emulsion. Substance according to Claim 1, characterized in that the unstable surfactant is degradable by temporal or acidic substances or by oxidizing or reducing agents. Substance according to Claim 2, characterized in that the surfactant is degradable by the alkalinity of the building material. Substance according to one of the preceding claims, characterized in that the surfactant is degradable by the action of air. Substance according to one of the preceding claims, characterized in that the surfactant is an alcohol-alkylene oxide adduct. Substance according to one of the preceding claims, characterized in that the surfactant is an ester. Process for preparing a substance according to Claim 1, characterized in that the alcoholic solution of the silanes and / or their condensation products and / or hydrolysis products is mixed with a dispersion medium consisting of water or aqueous-alcohol mixtures while adding a decomposable surfactant. A process for hydrophobing a by-product, the synergist of a powder, a silk-based emulsion from a water-soluble silane, a specially alkyltrialkoxysilane and / or a solid condensation product and / or a hydrolysic product, such as a dispersion of water. of-