DE2557594A1 - BUILDING MATERIAL BASED ON CALCIUM SULFATE-ALPHA-HALBHYDRATE - Google Patents

Description

Hoechst Aktiengesellschaft
HOE 75 / K 061

Building material based on calcium sulfate-cc-halfohydrate.

The present invention relates to a building material composition dor basis: of calcium sulfate-a-IIajhhydrat and a process for the production of a "flowable" material this building material mass as well as the use of this material .for self-leveling screeds.

Laying a useful floor, for example made of tiles or Hol- '. prirkett, is only on a horizontal and level Surface, but not on the mostly uneven and rough ceilings of buildings possible.

While earlier to make the necessary horizontal and flat surfaces screeds made of GuSasphc.lt, cement or magnesite were used, the application of which, Leveling and smoothing involve a considerable amount of work, have been mortar mixes for some time known, which after the addition of water have a flowable and pumpable consistency and under the influence of the Leveling and smoothing by gravity like a liquid itself.

For example, from DT-OS 1 9kJ> 634 a mortar mass is known which consists of anhydrite and sand as well as a substance which retards the sedimentation of the solids in water and a substance which increases the strength of the hardening mass, whereby the first substance can be a cellulose ether while aiii second substance a sulfite- or sulfonic acid-modified resin based on an amino-ε-triazine with at least

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zv / el Νίΐρ groups is suitable. This mixture is made with water in a weight ratio of up to 2: 1 to a flowable mass and poured onto a supporting base, where it flows apart to form a horizontal surface and solidifies in this state.

The disadvantage of this mortar mass is that it sets very slowly with water, so that poor early strengths result. In addition, in the interests of good flowability of the mixture, the proportion of sand must be kept low however, this adds a considerable amount of strength the hardening mass-increasing modified resin based on an amino-s-triazinSy which is relatively expensive is required.

To the disadvantage of the slow setting of the mortar mass To counter the basis of anhydrite, a building material mass is proposed in DT-OS 2 359 290, which consists of calcium sulfate-ß-hemihydrate, Alumina cement and / or Portland cement, the above-mentioned modified resin based on aminos-triazine as a strength-increasing substance and a setting retarder and / or a filler. This building material mass is mixed with water in the amount required for flowability Amount staggered.

This amount of water is relatively large, since only for ' complete setting of both calcium sulfate-ß-hemihydrate as well as the cement contained in the building material, a lot of water is required. This will on the one hand the construction progress hindering long drying times required, while, on the other hand, when the excess water evaporates in the set building material, there is a large pore volume arises, whereby the final strength of the mass is reduced.

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Finally, from DT-OS 2 247 756 a screed compound for floors is known, which consists of a screed of calcium sulfate a-hemihydrate, white lime, a liquefier, for example water-soluble high-molecular aminoplasts or polysilicic acids, and a setting retarder, for example Retardan '- * , to which the same amount of construction sand has been added * After adding water and subsequent stirring, this screed compound can be poured.

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The disadvantage of this screed compound is its low flowability, so that it does not level and smooth itself under the influence of gravity alone before it solidifies.

It is the object of the present invention to provide a building material compound based on. To indicate calcium sulfate-et-hemihydrate, which does not have the mentioned tile parts be mixed to a material with good flowability, on the one hand to lairze drying times and on the other hand under the influence of gravity to ensure self-leveling and smoothing, taking into account the addition of leaning agents like sand in the interest of good flowability and dispensed with the addition of expensive substances to increase the final strength must be »This is achieved according to the invention by adding one or more phosphoric acid esters to the building material and contains a surfactant mixture.

The building material route according to the invention can optionally also be characterized in that

a) it contains O ₄ 1 to 2 weight ^, preferably 0.3 to 0.7 weight ^ phosphoric acid ester, based on the calcium sulfate-oc-hemihydrate!

b) as phosphoric acid esters, mono-, bi- or tri-alkyl esters with 3 or 10 carbon atoms, preferably with 4 to 6 carbon atoms, or their biscuits

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c) they are 0.1 to 2% by weight, preferably 0.3 to 0.7% by weight Tens idgemi sch, based on the calcium sulfate oc hemihydrate jcontains;

d) the surfactant mixture of 5 to 40 weight ^, of an alkyl ether sulfate with 10 to 18 carbon atoms, 5 to 15 weight ^ of an .Alkali salt of oleic acid -M-Me thyltauri ds, 5 to 30 weight ^ of an olefin sulfonate with 10 to " ¹ C-atoms, 10 to 40 percentages of a diglycol with 2 to 6 C-atoms and the remainder water Confesses?

e) the surfactant mixture of 11.5 weight ^ C- * pCi 4 "ether sulfate j 10 weight ^ of the sodium salt of oleic acid-N-methyltauride, 6 weight ^ C ^^ - Cg-olefinsulfonat, 25 weight ^ butyl diglycol and
47.5% by weight consists of water;

f) they additionally Q, 01 to 2 weight ^ alkylene oxide high polymers, based on the calcium sulfate oc hemihydrate, contains;

g} they are additionally based on 0.01 to 2 weight cellulosic ether

on the calcium sulfate ec hemihydrate, contains; h) it contains carboxyethyl cellulose as cellosis ether; i) the cellulose ether contains methy! cellulose »

A flowable material is made from the building material composition according to the invention can be produced by adding the building material and lasser in a weight ratio of 3.0 to 3.7 to 1, preferably 3j3 up to 3.5 to 1, intimately mixed with one another.

£> closing <; 1a is the flowable material for selljstnivellie-

Screeds can be used to form floor coverings with pore-free giaiter 0l3Brfläc1ae.

The calcium sulfate a hemihydrate should be such a ύμ, which has a water gypsum value (determined according to DIN 1168, part 2, page 3 * July 19753 edition of 0.37 Ms 0.50, preferably 0.40 to 0 * 43). This condition is fulfilled by the customary hard plaster of paris as well as a calcium sulfate-a-hemihydrate produced according to DT-PS 1 157 128 in an aqueous _{solution after filtering #} drying and grinding to a grain fineness of <10öμ »

All additives according to the invention can, although they are partially Liquids are, with the help of suitable mixing units be distributed homogeneously in the calcium sulfate a hemihydrate. the Building material according to the invention is sufficiently stable in storage, so that only the required amount of water has to be measured and added on the construction site.

If the building material according to the invention is mixed with water, for example in a weight ratio of 3.5: 1, a flowable material is obtained which, after pouring, spreads like a liquid, so there is no need for expensive leveling and smoothing by hand or with aids is. After the flowable material has set, with this ratio of building material to water, only about 5 to 7 % of water has to be evaporated in order to achieve the residual moisture of about 3 to 5 % that is usual for laid screed.

With the building material composition according to the invention, a flowable material can be produced whose setting behavior is almost ideal. Thus, the delayed start of stiffening enables sufficient _; Processing time, while the relatively short stiffening end that follows avoids unnecessary waiting times. The delayed start of stiffening occurs even though the building material composition according to the invention does not contain any setting retarders which, apart from their additional costs, reduce the strength of the set screed and are often the cause of undesired efflorescence.

Floor coverings produced with the building material composition according to the invention have such a high early strength that they can be walked on even a short time after pouring. After a few days, the floor coverings show compressive strengths of more than 300 .. kp / cm and bending tensile strengths of over 80 kg /

cm and are thus above the values specified in DIN 4109 (cf. Sheet 4, page 3, edition *? 962) required values for unsuitable

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lean plaster screeds.

The invention will now be explained on the basis of examples.

example 1

50 kg of a commercially available hard plaster of paris with a Y / water plaster of paris value of 0.42 are added to 200 g Tri-iso-butyl phosphate, 200 g of a surfactant mixture and 100 g a high polymer based on alkylene oxide intimately mixed, resulting in a homogeneous and lump-free mass with good storage stability.

The surfactant mixture used consists of: 11.5% by weight of ^ C ^ -C ^ ether sulfate 10% by weight of the sodium salt of oleic acid-N-methyl-

taurids

6 weight ^ C ^ gC ^ g-olefin sulfonate 25 weight ^ butyl diglycol
47.5 weight ^ water.

The homogeneous mass is mixed with water in a weight ratio of 3.7: 1, whereby a suspension with excellent Flow behavior results.

To illustrate the flow behavior, the suspension is left out of a Vicatring, which is placed on a spreading table lies, flow out (cf. the determination of the slump according to DIN 1168, part 2, pages 3 and 4, July 1975 edition). The slump is 40 cm.

The suspension begins to stiffen at around 60 minutes.

The pressure resp. Flexural strengths are 316 and 86 kp / cm, respectively.

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Example 2

Gypsum obtained as a by-product in the production of wet phosphoric acid is converted to calcium sulfate according to DT-PS 1 157 128 Gc hemihydrate implemented and after filtering off and Drying ground to a grain fineness of O00 μ.

150 kg of this calcium sulfate oc hemihydrate with a water gypsum value of 0.40 are mixed with 750 g of tri-n-butyl phosphate, 750 g of the surfactant mixture used in Example 1 and 115 g einor Methyl cellulose, the 2% aqueous solution of which is a medium Has a viscosity of about 1000 cP, intimately mixed.

100 kg of this mixture are mixed with 28.6 l of water and the flowable material is conveyed to a supporting base with the aid of a screw pump via hose lines. In a divided area element of 1 χ 2 m, the material flows independently to form an approximately 3 cm thick layer, levels itself and hardens after about an hour to form a pore-free and smooth surface. The area can be walked on after 3 hours. After 4 to 5 days, the surface has a compressive or flexural tensile strength of 326 and 108 kp / cm ^2, respectively.

Example 3

50 kg of a commercially available hard plaster of paris with a water gypsum value of 0.42 obtained from natural gypsum are 250 g Tri-isobutyl phosphate and 250 g of a surfactant mixture intimately mixed, resulting in a homogeneous and lump-free mass with good storage stability.

The surfactant mixture used consists of:

6 weight of ^ C ^ -C ^ ether sulfate 27.5 weight # G ₁₀ -C ₁ ^ ether sulfate

5 weight ^ of the sodium salt of oleic acid-N-methyl tauride

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7.5 weight ^ C ₁ 6-C ₁ g-0lefinsulfonat 12.5 Gewlchts5i butyldiglycol
41.5 weight $ »water.

The homogeneous mass is mixed with water in a weight ratio 3.6: 1, resulting in a suspension with excellent flow behavior.

To illustrate the flow behavior, the suspension is allowed to _{flow out of a Vicat ring, which is located on a spreading table 4} (cf. DIN 1168). The spread is 38 cm.

The start of stiffening of the suspension is around 70 Minutes.

The pressure resp. Flexural strengths are 304 and 82 kp / cm, respectively.

Example 4

Gypsum obtained as a by-product in the production of wet phosphoric acid is converted to calcium sulfate a hemihydrate according to DT-PS 1 157 128 and, after filtering off and drying, it is ground to a grain size of <100 μ.

2 kg of this calcium sulfate a-hemihydrate with an ¥ assergipswert of 0.40 are mixed with 12 g of an equimolar mixture of mono- and dihexyl phosphoric acid ester, 10 g of the surfactant mixture used in Example 1 and 2 g of a methyl cellulose., Whose 25% aqueous solution is a medium Has a viscosity of about 1000 cP, intimately mixed.

This mixture is stirred with 570 ml of water. If part of the suspension is allowed to flow out of a Yicatring as indicated in Example 1, the slump is 36 cm. The pressure or pressure measured on test specimens according to DIN 11 68

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Flexural strengths are 310 and 85 kp / cm. Example 5

In the production of wet phosphoric acid, gypsum that occurs as a by-product is converted into calcium sulfate ~ e: - hemihydrate according to DT-PS 1 157 128 and, after filtering off and drying, ^{ground to a grain size of 1} CiOO μ.

2 kg of this Calciurasulfat-ct-llalbhydrate with a water gypsum value of 0.45 are with 1Λ g dibiity! Phosphoric acid ester, 12 g of the surfactant mixture used in Example 3 and 1.5 g a Mcthylcellulose, whose 2% aqueous solution a middle-3.ere Has a viscosity of about 1000 cP, intimately mixed.

This mixture is stirred with 600 ml of water. One lets If part of the suspension as indicated in Example 1 flows out of a Vicat ring, the slump is 38 cm. The compressive and flexural strengths measured on test specimens in accordance with DIN 1168 are 302 and 81 kp / cnT ", respectively.

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Claims (12)

HOE 75 / ϊί ü6i Patent claims: Building material based on calcium sulfate ~ cc hemihydrate, thereby ^ f; ^ kGnn? ^ eichnt; t that they have an or contains several phosphoric acid esters and a ten & id mixture. 2) Building material mass according to claim 1 _f thereby gek e nnze i chnf? 1 ₁ that it contains 0.1 to 2 weight ^, preferably 0.3 to 0.7 weight ^ phosphoric acid ester, based on the calcium sulfate a-hemihydrate. 3) Baust off rna sse according to claim 1 or 2, dadj ^ rch ^^ ejceriji records that they are mono-, 'di- or tri-alkyl esters with 3 to 10 carbon atoms, preferably with h to 6 carbon atoms, as phosphoric acid esters , or their mixtures. 4) Building material according to any one of claims 1 to 3, characterized geken in that it contains 0.1 to 2 weight ^, preferably 0.3 to 0.7 weight ^ surfactant mixture, based on the calcium sulfate-α-hemihydrate. 5) Building material according to one of claims 1 to 4, characterized in that the surfactant mixture of 5 to 40 weight ^ of an alkyl ether sulfate 10 to 18 carbon atoms, 5 to 15 weight? 6 of an alkali metal of oleic acid-N- Methyl taurides, 5 to 30 wt% of an olefin sulfonate with 10 to 18 carbon atoms, 10 to 40 weight ^ of a digylcol with 2 to 6 carbon atoms and consists of water. 6} building material mass. To claim 5, characterized, that from the Tensictgeiaisch
31.5 weight of ^ C ^ ₂ -C ^ ether sulfate 2557b94 ■ I- 10 weight /; ^ ties of the sodium salt of oleic acid-N-methyl- taurids 6 weight ^ C ₁ gC _1B -olefin sulfonate 25 weight chtsj-i butyldi glycol and
47.3Gex «RichtriK water consists. · Γ \ building material according to one of claims 1 to -6 ,, thereby jS ^ iS ^ i ^ TLSMi-iiiiiii ^cIa ß ^they additionally 0.01 to 2 Gov / ichti; ^ 'alkylene oxide high polymers, based on the calcium sulfate Ä- HalMiydrate, contains » 8) building material according to one of claims 1 to 6, ö ^ -ürdb i £ -I!] £ i * öass it in addition 0.01 to 2 weight ^ Cellxilose ether, based on the Calciunisull'at-a-Kalbliydrate, contains. 9) Building material according to claim 8, dad urch g ekenazeiohnet that carboxymethyl cellulose is contained as cellulose ether. . 10) building material according to claim 8, characterized by, that methyl cellulose is contained as ceilulose ether. 11) Process for the production of a flowable material from animal building material mass according to claims 1 to 10, characterized in that one dxe building material mass and water in each weight ratio of 3.0 to 3.7 to 1, preferably 3 , 3 to 3.5 to 1, intimately mixed with one another. 12) Use of the flowable material according to claim 11 for self-leveling screeds for the formation of floor coverings with pore-free and .glatter surface.