HU192788B - Gypsum mixtures for the building industry, cuch as materials for prefabricated members, coating, floating, and pointing materials - Google Patents

Abstract

Compsns. for the building trade contain based on the amt. of gypsum in the compsn., 0.01-2.0 wt.% polymer powder, 20-80 wt.% of the polymer, pref. 25-30 wt.% being a blocked vinylalcohol-vinylacetate copolymer or a blocked vinylalcohol-vinylester copolymer in which 60-90 mole % of the vinylalcohol gps. occur in blocks, and 50-95 wt.%, pref. 70-75 wt.% carboxymethyl-cellulose modified with 2-20 molecules hexamethylene-tetramine and/or hexamethylene-diamine for every 100 glucoside units, 0.0001-0.01 wt.% crosslinking agent, pref. terephthalic-aldehyde and maleic-acid or maleic-anhydride, or boric-acid or borax, 0.001-1.0 wt.% surfactant, pref. an alkyl-sulphate or alkyl-aryl-sulphonate, opt. together with further suitable additives.

Description

FIELD OF THE INVENTION The present invention relates to gypsum compositions, such as materials suitable for prefabricated elements, cladding, trowel, grout and the like.

It is known that there is a demand in the building materials industry for cladding, smoothing and grouting materials and the like, which can be used on both external and internal surfaces. For these purposes, high concentrations of aqueous suspensions are generally used, consisting of cement, lime, gypsum or mixtures of these in various proportions, usually containing additives (eg sand, perlite). Some special purpose coatings are also known, such as barium sulphate-containing coatings, which absorb X-rays.

Recently, there has been a worldwide expansion of plastic-containing products (plasters, sealants, etc.) as well as the use of building materials made from a combination of traditional and new materials, with significantly improved properties in many ways.

Intensive research on additives that can be mixed with conventional binders is mainly motivated by technological and economic considerations. The use of additives can generally be accomplished by minor modifications to existing technology and their introduction, even at relatively low concentrations, can be accomplished at no significant additional cost.

Many researchers have addressed the effect of various additives on the bonding time of gypsum and on the properties of a solid product (see Neuhauser, Zement-Kalk-Gips, 5, 1976) that adding LTX potassium sulfate significantly reduces the bonding time. The effects of some mono-, di-, and tricarboxylic acids and their derivatives on building materials have also been studied (Raul, H .: Zement-Kalk-Gips, 7, 1977). Studies showed that malonic acid, citric acid, succinic acid, malic acid, lactic acid, etc. even at concentrations of 0.03-0.1 mX (based on the total amount of material) significantly slows down the plaster bond.

Similar effects are seen with different protein hydrolysates and amino acid formaldehyde condensates.

The possibility of influencing the plaster bonding process with other additives has also been discussed (Bertoldi, G.A .: Zement-Kalk-Gips, 5, 1977). Among the substances tested, potassium iodide, silver nitrate, ammonium sulfate, potassium sulfate, and potassium oxacyanoformate reduced; while humic acid, aspartic acid, picric acid, ethanolamine, albumin and the like. increased curing time. It is also known (Preialer, E .: Zement-Kalk-Gips, 5, 1977) to influence the binding time of gypsum by different salts and by adjusting the pH of the medium. In this regard, it has been found that some inorganic salts (potassium sulfate, sodium sulfate, potassium chloride) accelerate the bonding and increase the bonding time in both acidic and alkaline media. The binding time also increases with the addition of salts with higher positively charged cations (aluminum sulfate, iron sulfate). A significant amount of additives (e.g., inorganic salts, low molecular weight organic ewes) adversely affect the mechanical properties of the solidified system (see Knauf, A.N., Krönert, W., Haubert, P .: Zement-Kalk-Gips 11, 1972). For example, at a water / plaster ratio of 0.75, 1.6 mX of potassium sulfate has a bending strength of 47 kp / cm 'to 23 kp / cm' and 0.16 mX of citric acid from 47 kp / cm '3 kp / cm *. Plant-extractable organic colloids have also been used to slow the hydration of gypsum (see Duma, G .: Zement-Kalk-Gips, 5, 1977). The colloidal solution is mixed with gypsum to produce a plastic, slow-setting, high-strength material.

It is also evident from the above brief review that the effects of many different additives have been studied in plaster binder systems, mainly to control the setting time. It can be stated that, besides the advantageous properties of the known compositions, there have always been unfavorable properties. For example, the use of additives in the form of an aqueous solution or an aqueous dispersion does not allow the gypsum-containing mixture to be stored for an extended period of time before use, since the hydration of the gypsum begins in the aqueous suspension. Salts and acids of low relative molecular weight, although they allow for relatively wide control of the setting time, cause considerable deterioration of the mechanical properties of the solidified system.

There are several problems with the use of polymeric additives. If the plastic is mixed with the plaster in powder form, it is necessary to wait for the polymer to dissolve completely after the addition of water. This, even with continuous mixing, usually takes longer and is difficult to track. If a part of the polymer is in the form of aggregates, not only will the paste become difficult to incorporate, but the resulting system, after drying, will be inhomogeneous and easily cracked. A further disadvantage of using water-soluble plastics is that the hardened gypsum compositions have low water resistance. The plastic component already swells when exposed to water vapor, and the swelling under pressure is cracked by the solid. If the solid polymer is in contact with water for a long time, the plastic component will gradually dissolve therefrom by diffusion into the liquid3.

-2l'.IZIOÖ goes into phase, which is accompanied by a sharp deterioration in mechanical properties.

The drawbacks described above include, for example, the following solutions:

322 No. 896 A composition disclosed in British Patent No. 4,102,105 which is a powder composition of an aqueous suspension of elastomers (100 parts) gypsum (150-190 parts) and a stabilizer and other additives for plastering. Examples of elastomeric materials include PVC, polystyrene, polyacrylates and polyolefins.

Gypsum plaster composition (in powder form) is also described in U.S. Pat. British Patent Specification. The product consists of calcium sulphate alpha hemihydrate and an aqueous resin emulsion. The resin is present in at least 10% by weight, and may be chemically acrylic, vinyl, or styrene resins, or copolymers thereof.

No. 4,229,223. U.S. Pat. No. 4,122,115 describes a building material which is suitable, for example, for making prefabricated elements and is a hard binder, i.e. calcium and magnesium-containing water binder sludge such as gypsum sludge, with conventional detergents and resins. The amount of plastic is 0.5-15%; any foamed plastic may be used. The composition may also contain fillers such as perlite. The foamed plastics and gypsum sludge are mixed together to form the building material when solidified. Cement can be used instead of plaster.

No. 3,941,632. U.S. Pat. No. 4,123,195 describes a process and composition for coating walls or similar surfaces. The method also involves coating the surface with aqueous latex to such an extent that water in the latex hydrates and binds the gypsum semihydrate. In this way, lalex is modified to function as an adhesive. Specifically described are poly / vinyl acetate / latex.

It is an object of the present invention to provide gypsum-based plastics-modified cladding, smoothing and grouting materials, as well as compositions for making prefabricated elements, which (in addition to the above-mentioned adverse effects) can achieve the following additional effects. in:

- after mixing the components, the powder mixture can be stored for a long time without any adverse effect on its usefulness;

- the powder mixture can be used immediately after homogenization with water;

- after use, the solidified system is highly resistant to water;

by suitable choice of polymeric components, the surface properties of the solid system can thus be controlled over a wide range.

The invention is based on the one hand on the recognition that gypsum powder and water-soluble block4

polymer such as vinyl alcohol vinyl acellal or vinyl alcohol vinyl ester block polymer and from 2 to 20 molecules of carboxymethylcellulose modified with hexamethylenetetramine or hexamethylenediamine per 100 units of glucoside, and crosslinking agents, preferably, the rate of dissolution of the polymer components in water is substantially increased in a mixture of leraldehyde aldehyde and muleic acid or maleic anhydride, or boric acid or borax, and surfactants, preferably alkylsulfate or alkylarylsulfonate. On the other hand, it has been surprisingly found that the mechanical properties of the solidified material do not change significantly even when it is in contact with water for an extended period of time. An important new finding is that the surface properties of the solid system can be influenced over a wide range by changing the chemical composition of the copolymer and the sequence of the comonomers.

In the case of the modified carboxymethylcellulose used in the present invention, the essence of the modification is that the carboxymethylcellulose is mixed with a dilute aliphatic alcoholic, preferably ethanol or isopropanolic solution of the amino compound (s) providing the modifying effect, followed by 1- After 5 hours, the alcohol was evaporated.

The gypsum compositions or prefabricated elements made with carboxymethylcellulose treated in this way have significantly better water resistance than those made with untreated carboxymethylcellulose.

These findings are surprising in many ways. It is also surprising that two or more polymers (the cellulose derivative used in the present invention and the vinyl polymer) of very different chemical structure are compatible with one another. In general, even similar polymers (eg acrylates and methacrylates) are not compatible; mutually precipitating each other in a common solution. It is also surprising that the polymer components are virtually insoluble in the dry system, which may be due to the fact that the low relative molecular weight components crosslink the copolymers. In this case, however, it would be expected that as the crosslinked copolymer swells in water, the mechanical properties of the system will change due to the swelling pressure that accompanies the swelling. The influence of the surface properties may be related to the surface activity of the copolymers used. Surprisingly, however, this effect also occurs in the presence of a surfactant, since due to the high concentration of surfactant in the water / air interface due to the positive adsorption of surfactant molecules, it would be expected that and is primarily determined by the surfactant, not the polymer.

The main advantages of the powder composition according to the invention are the following:

1. The application is easy to use and does not require any special equipment, equipment or investment.

2. The components of the composition are readily available or can be prepared and are inexpensive.

3. Depending on your needs, the product can be applied on a variety of substrates (eg brick, wood, glass, plaster, concrete) and has good adhesion.

4. There is practically no stress or shrinkage during drying.

5. The product is highly resistant to weathering and mechanical stress (such as thermal expansion).

6. From the system in the form of suspension, casting can be made into shapes of any complexity, also suitable for making hollow bodies.

7. The product can be formed into good snow and acoustic insulation products with varying vapor permeability as required.

8. The product is suitable for high aesthetic requirements, it can be well colored both in material and surface.

9. The composition of the present invention may be advantageously used to form acoustic acoustic coatings when used; furthermore

10. It is also suitable for the production of low volume foamed elements.

Powdered products are prepared and used as follows:

1, Solid solids (binders + additives) are weighed in appropriate proportions and carefully homogenized by mixing. The powder material thus obtained may be packaged in suitable packaging. By adding a given volume of water from the contents of the package when applied

a) or making a paste which can be directly applied e.g. fabricating prefabricated elements on a wall surface or in suitable equipment; obsession

b) preparing a dilute suspension that can be applied to the surface by spraying or spraying.

2. For further processing of prefabricated elements

(a) one side of the appropriate size of the prefabricated dry element is shown in l. according to the invention, in a uniform layer with a liquid product (or other suitable adhesive) and then applied to the surface to be coated;

b) one or both sides of the prefabricated element are shown in l.) a. and evenly glue two or more sheets together. The protruding lamellar elements offer a wide variety of applications. (For example: low-strength, high-thermal and acoustic insulation liners can be bonded to both sheets of low mechanical strength, high-perlite gipB sheet by gluing thin gypsum sheets with vinyl alcohol-vinyl acetal block polymer additive.) 2) a. above;

c) the prefabricated sheets are fixed in a horizontal position and l.) a. to a suitable thickness. After the layer has dried, the process can be repeated several times. The products with a layered structure thus prepared are hereinafter referred to as 2.) a. can be processed in accordance with point.

d) two prefabricated plates, side and underside, are fixed in a molded frame, at a fixed distance, parallel to each other, and the space between them is latched to l.) a. Fully fill with the concentrated suspension prepared in accordance with. After drying, use the batteries as described in 2.) a. above.

3.) Prefabricated elements 1., 2.) b., 2.) c. ye 2) d. The preparation or further processing of any one of the claims 1 to 4 is carried out by applying textiles, fiberglass, metal mesh, etc., to the paste (concentrated suspension) in a consistency material. we also bed.

Hereinafter, some examples will illustrate the composition of the invention. a date is given. The examples are not to be construed as limiting the applicability of the invention, but are merely to illustrate some embodiments.

Example 1

For the production of high tack adhesives, 100 parts by weight of gypsum powder, 1 part by weight of vinyl alcohol vinyl acetate (20 mol% vinyl acetate - 80 mol% vinyl alcohol) block polymer powder, 1 part by weight 100 molecules of hexamethylenediamine per 100 g of glucoside Modified Carboxymethyl Cellulose Powder 0.05 parts by weight of sodium dodecyl Bisulfate, 0.01 parts by weight of terephthalaldehyde and 0.01 parts by weight of maleic acid are dry mixed and 50 parts of water are added with constant stirring. The paste produced by ig.v is applied to the joints and cracks. Cure time approx. 1.5 hours.

Example 2

Production of filler paste

100 parts by weight. gypsum powder, 0.1 parts vinyl alcohol vinyl butyral (90 mol% vinyl alcohol -10 mol% vinyl butyral) block polymer powder, 0.3 parts by volume, 5 molecules of hexoxyethylenetetramine modified carboxylic acid per 100 glucose units a dry homogeneous mixture of methylcellulose powder, 0.05 parts by weight of sodium dodecyl sulfate and 0.1 parts by weight of borax is prepared. From the mixture, 30 parts by weight of water are added to form a paste which is applied to the surface. It is very advantageous to be used for smoothing partitions for filling plasterboard joints, for gluing plasterboard sheets, for sealing concrete and aerated concrete walls. Curing time: 3-4 hours.

Example 3

Production of highly moisture resistant smoothing material

100 parts by weight of gypsum powder, 1.5 parts by weight of vinyl formalin-vinyl alcohol (40 mol% vinyl-formalin - 60 mol% vinyl alcohol) in block polymer powder, 0.5 parts by weight, 3 molecules modified with hexamethylene tetramine per 100 glucoside units a paste is prepared from carboxymethylcellulose powder, 0.01 parts by weight of boric acid, 1 part by weight of sodium dodecylbenzene sulphonate and 40 parts by weight of water. The paste is advantageously used for grouting and gelling in rooms exposed to high humidity (eg cellars), as well as for repairing wall surfaces (wooden floors, wooden stairs) and gluing plastic coverings.

Example 4

Production of a widely applicable filler compound

100 parts by weight of gypsum powder, 0.5 parts by weight, 4 molecules per 100 glucose units modified carboxymethylcellulose modified with hexamethylenediamine, 1.2 parts by weight vinyl acellate vinyl alcohol (32 mol% vinyl acetate - 68 mol% vinyl alcohol) ) a paste is prepared from block polymer powder, 0.2 parts by weight of boric acid, 0.1 parts by weight of sodium dodecylbenzene sulfonate and 60 parts by weight of water. The paste can be used directly for grouting or plastering, and is also useful for bonding internal cladding elements (eg plasterboard). Suitable for both brick and interior walls. The plaster can be applied in successive layers. The time required for complete consolidation is approx. 5-6 hours.

Example 5

Good grouting paste, easy to apply

100 parts by weight of gypsum powder, 0.1 parts by weight of vinyl alcohol vinyl propionate (90 mol% vinyl alcohol-10 mol% vinyl propionate) in block polymer powder, 0.5 parts by weight, 3 molecules per 100 glucose units modified with hexamethylene tetramine a dry homogeneous mixture of carboxymethylcellulose powder, 0.2 parts by weight of boric acid and 0.1 parts by weight of sodium butyl naphthalene sulfonate is prepared. To the homogenized powder is added with stirring 30 to 16 parts of water. The concentrated suspension thus obtained can be advantageously used for filling concrete slits, as well as for plasterboard joints, for smoothing partitions and for surface preparation. Curing time approx. 2-3 hours.

Example 6

Hydrophobic product, which can be used for external cladding purposes, decorative elements

100 parts by weight of gypsum powder, 1.8 parts by weight of vinyl alcohol vinyl laurate (60 mol% vinyl alcohol - 40 mol% vinyl laurate) in block polymer powder, 0.2 parts by weight, modified with 2 molecules of hexamethylenediamine per 100 glucoside units a dry homogeneous mixture of carboxymethylcellulose powder, 0.1 parts by weight of sodium dodecylbenzene sulfonate and 0.01 parts by weight of borax is prepared. 70 parts by weight of water are added to the powder mixture while stirring, and the slurry, in a layer corresponding to the thickness of the element to be manufactured, is poured into a pouring frame for this purpose and allowed to solidify.

Example 7

Production of high strength, good thermal and acoustic insulation, layered structure, internal cladding elements

100 parts by weight of gypsum powder, 1 part by weight of vinyl alcohol-vinyl propanal (70 mol% vinyl alcohol-30 nyl x vinyl propanal), block polymer powder, 0.1 part by weight of maleic anhydride, 0.1 part by weight, 5 molecules of hexamethylene per 100 glucoside units slurry of carboxymethylcellulose modified with dimethyldiamine, sodium lauryl sulphate (0.8 mol) and 35 parts by weight of water, from which molding sheets with a surface area of 1-2 m ¹ and thicknesses of 0.5 to 3 cm were cast. Two solid sheets - bottom and side in a closed frame - are fastened to each other at a distance of 5-15 cm from each other, and the space between them is 100 parts by weight of plaster, 2 parts by weight of vinyl alcohol-vinyl propanal (70 mol% vinyl alcohol -30 mol%). vinyl propanal) and a suspension of 10 parts by weight of perlite in 70 parts by weight of water. Slight heating to speed up the drying process

-511 (40-60 ° C). The low volume elements produced can advantageously be used to form partitions.

Example 8

Preparation of high vapor permeability, good snow and acoustic insulation, foam structure elements by weight of gypsum powder, 1.0 part by weight of vinyl alcohol vinyl acetate (80 mol% vinyl alcohol-20 mol% vinyl acetate, block polymer powder, 1.0 parts by weight) , 2 molecules of carboxymethylcellulose modified with hexamethylenetetramine, 100 parts by weight of petroleum sulfonate and 0.01 parts by weight of boric acid are added to 100 parts by weight of glucoside by adding 60 parts of water. After the total amount of the mixture has been foamed, an additional 60 parts by weight of gypsum powder are gradually added to the resulting molded, foam-like concentrated dispersion, and the solidified dry boards are advantageously used for interior cladding due to their good thermal and acoustic properties.

Example 9

Production of glaze paste

100 parts by weight of gypsum powder, 0.5 parts by weight of 19 molecules per 100 glucosidone-modified carboxymethylcellulose powder, 0.3 parts by weight of vinyl alcohol-vinyl acetate (82 mol% vinyl alcohol-18 mol% vinyl). acetate), a paste of block polymer powder, 0.1 molar sodium sodium dodecylbenzene sulfonate, 0.2 parts fumaric acid and 60 parts water. The paste can be used directly for grouting or glazing, and is also useful for gluing internal cladding elements (such as plasterboard). Suitable for both brick and concrete walls. The plaster can be applied in successive layers.

It takes 5 to 6 hours to fully solidify.

Claims (1)

PATENT CLAIMS Plastics-modified gypsum mixes for construction, such as materials suitable for prefabricated elements, surfacing, leveling and grouting materials, characterized in that 20 vinyl alcohol vinyl acellal or vinyl alcohol vinyl ester block polymers containing from 60 to 90 mol% of vinyl alcohol units and 2 to 20 molecules of hexamethylene tetramine and / or hexamethylene per 100 glucoside units diamine-modified carboxymethylcellulose and a crosslinking agent, preferably terephthalaldehyde and maleic acid, or maleic anhydride or boric acid or borax, and a surfactant, preferably 30 alkyl sulfate or alkylaryl sulfonyl containing from 0.01 to 2.0% by weight of gypsum block polymer and modified carboxymethylcellulose, preferably 20 to 80% by weight, preferably 35% by weight. 25-30% by weight of vinyl block polymer and 20-80% by weight, preferably 70-75% by weight of modified cellulose derivative, 0.01 to 2% by weight of crosslinking agent and 0.001 to 1.0% by weight of surfactant content, optionally together with other known building materials additives and / or fillers.