WO2003011789A1 - Factory mortar - Google Patents

Abstract

The invention relates to factory mortar in the form of shaped bodies. The shaped body is produced in continuously operating or discontinuously operating compression devices for non-plastic materials.The inventive factory mortar is made ready for use by mixing it with water and optionally additional binding agents. The shaped body formed from the inventive factory mortar has a high specific surface and an excellent capillary water-absorption ability enabling it to rapidly disintegrate in water. The inventive factory mortar is especially used as an adhesive for tiles, mortar for joints or as filler.

Description

 "Mortars"

The invention relates to mortar, its production and its use.

Factory mortars are generally understood to mean compositions of binders, additives and additives which are premixed in a precisely metered manner in a factory.

Both mineral materials, such as lime, cement, gypsum, anhydrite and others, as well as non-mineral materials, such as epoxy resin, dispersible polymer powder, methyl cellulose and others come as binders. or combinations of mineral and non-mineral binders.

Aggregates are understood to be mineral and / or organic aggregates, for example natural sands (pit sands), sands produced by crushing (crushing sands) or light aggregates such as pumice, polystyrene, expanded glass, perlite and others. or mixtures of these additives. Inorganic and / or organic additives serve to regulate the product properties. Additives are, for example, agents for regulating water retention, setting accelerators and retarders, wetting agents or hydrophobizing agents for reducing water absorption. Factory mortars are supplied as: a) Factory dry mortar, which is dry premixed and packed in bags, for larger construction projects also in a silo, to the construction site. Only water is added at the construction site; b) Factory pre-mortar, which comes to the construction site as air lime or water lime mortar, where it contains water and possibly additional binders - e.g. B. cement to obtain lime cement mortar - are added.

DIN 18557 applies to factory mortars.

A major disadvantage of commercially available factory mortars, especially factory dry mortars, is the powdery form of the offer. As a result, the Working with factory mortars a not inconsiderable development of dust and dirt occurs. For the application, the working mortar is mixed with water and possibly other binders. Since the ratio of water to solids must be strictly adhered to when mixing, suitable measuring or weighing devices are required to process partial quantities. Experience has shown that do-it-yourselfers in particular often do not have the right equipment. Another disadvantage of the powdered form of supply is that loose powder piles always contain a considerable volume of air, which represents an uneconomical dead volume in the packaging, transport and storage of mortar.

The present invention was therefore based on the object of providing working mortar in a non-dusting form. The positive properties, in particular that the working mortar can be mixed at any time with water and the usual auxiliaries to make ready-to-use mortar, should be retained. Usual aids are understood to be the tools that are usually used in construction engineering for mixing mortars, for example tubs, buckets, trowels, drills with a whisk, and the like.

Another object of the invention was to provide mortar which improves the economy of storage and transportation.

Another object of the invention was to provide working mortar which can be processed in partial quantities without weighing or measuring effort for the user.

The solution to the problem according to the invention can be found in the patent claims.

It essentially consists in the fact that the working mortar is in the form of a molded body. The factory mortar is selected in particular from the group of factory dry mortar and factory pre-mortar.

The working mortar according to the invention contains 10-80% by weight, preferably 15-70% by weight and particularly preferably 25-60% by weight of one or more inorganic mineral binders. The inorganic mineral binders are preferably standardized cement (for example Portland cement), non-standardized cement (for example alumina cement), special cement, latent hydraulic or pozzolanic substances, lime, gypsum and other hydraulically setting substances.

Furthermore, the working mortar according to the invention contains 15-90% by weight, preferably 25-80% by weight and particularly preferably 30-60% by weight of inorganic additives. In particular, silicate or carbonate sands and flours, natural or artificial rock flours, natural or artificial layered minerals, mineral residual and recycling materials, such as glass balls or fly ash, are used as inorganic additives.

Furthermore, the working mortar according to the invention contains 0.1-20% by weight, preferably 0.5-15% by weight and particularly preferably 0.8-10% by weight of one or more inorganic or organic additives for regulating the setting behavior and / or the processing properties of the mixed mortar. These additives are, for example, redispersion powders, natural or synthetic cellulose derivatives, organic acids or salts of organic acids, starch ethers, swellable minerals, organic or mineral fibers.

In a particular embodiment, the working mortar according to the invention contains at least one pressing aid as component (D). In the context of the invention, pressing aids are understood to mean substances which facilitate the sliding of the grains of the powder aggregate with one another, reduce the friction between molds and powder and / or increase the stability of the molding. Press aids are, for example, organic additives, mineral or organic fibers of natural or synthetic origin or residual and recycling materials. The proportion of the pressing aid is between 0.001 and 10% by weight, preferably between 0.005 and 5% by weight and particularly preferably between 0.01 and 2% by weight, based on the total mass of the mortar. The water content in the pressing aid should be less than 5% by weight, preferably less than 1% by weight and particularly preferably less than 0.5% by weight. Paper flour is preferably used as component (D). Paper flour is understood to mean processed fibers from waste paper recycling. The fiber length is between 0.1 and 5 mm, preferably between 0.15 and 3 mm and particularly preferably between 0.2 and 2 mm.

In a further particular embodiment, the working mortar according to the invention contains at least one disintegrant as component (E). The proportion of disintegrant in the mortar composition according to the invention is 0.001-10% by weight, preferably 0.005-5% by weight and particularly preferably 0.01-2% by weight.

Disintegrants are understood to mean disintegration aids which are incorporated into, in particular, highly compressed moldings, facilitate the disintegration of these moldings or shorten the disintegration times as disintegration accelerators. Under Zeelflebeschleurϊigern ι werden Tr ^ rnäß ^~ Rörnp (97 ° wflage, volume 6, page 4440) and Voigt "Textbook of pharmaceutical technology" (6th edition, 1987, pages 182-184) are understood as auxiliary substances which are necessary for the rapid disintegration of tablets in water or gastric juice and ensure the release of the pharmaceuticals in an absorbable form.

These substances, which are also referred to as disintegrants due to their action, increase their volume when water enters, whereby on the one hand the intrinsic volume increases (swelling) and on the other hand a pressure can be generated via the release of gases, which causes the molded body to disintegrate into smaller particles. Well-known disintegration aids are, for example, carbonate / citric acid systems, although other organic acids can also be used. Other gas generators are metal powder or alkaline earth metal carbides. Swelling disintegration aids are, for example, synthetic polymers such as polyvinylpyrrolidone (PVP) or natural polymers or modified natural products such as cellulose and starch and their derivatives, alginates or casein derivatives. A fibrous inner and / or outer structure of the disintegrant is advantageous for a rapid action. Under "fibrous" should be a shape can be understood in which one dimension is at least twice as large as the two other dimensions of approximately the same size. These disintegrants with fibrous inner and / or outer structures are characterized by a high capillary action and good water absorption capacity and bring about the rapid transport of water into the interior of the shaped body. In the context of the invention, a particularly preferred disintegrant is paper flour. The fiber length is between 0.1 and 5 mm, preferably between 0.15 and 3 mm and particularly preferably between 0.2 and 2 mm.

The mixture of components (A) to (C), optionally with the addition of components (D) and / or (E), is a so-called powder pile, which is pressed into a stable molded body.

A stable molded body is understood to mean regularly or irregularly shaped molded bodies which retain their original shape under the usual loads during the packaging, palletizing and transport of building materials and, if need be, have an insignificant abrasion.

For the molded body made of mortar according to the invention, it is important that the gaps and gussets (voids) between the individual grains which are formed during the pressing are filled with smaller granules in order to achieve good internal cohesion of the molded body. For this purpose, the working mortar contains a sieve line of at least two grain size classes tailored to the task. The grain size classes are such that the average grain size of the larger grain size class is 1, 5 - 50 times, preferably 1, 7 - 40 times and particularly preferably 2 - 30 times the average grain size of the smaller grain size class.

Processes for the production of moldings from powder piles are known. In the ceramics and building materials industry in particular, it has long been customary to compress, at least predominantly, mineral powder piles to form stable moldings using pressure and the use of compression or compression aids. This shaping step is usually followed by a further, final solidification by a ceramic fire or hydrothermal treatment. A renewed disintegration of the molded body after compression is not provided and is generally not possible. These methods, which are known per se, are not readily transferable to mortars. The compaction of ceramic masses or building material masses is only possible in the presence of water and / or chemical pressing aids, for example polyvinyl alcohols, which reduce the friction of the grains with one another and with the pressing tools.

A large number of pressing aids cannot be used for the production of moldings from factory mortars, since the pressing aids either themselves react with the inorganic binders or significantly influence the setting. In addition, a molding made of mortar must be able to be disintegrated at any time without difficulty.

The problem of the sufficient hardness and stability of molded articles with a sufficiently rapid disintegration time of the molded articles upon contact with water is the subject of a large number of patents from the detergent and cleaning agent sector. Special ingredients that promote decay when in contact with water are usually used.

For example, EP 0 522 766 discloses a tablet made of a compressed particulate detergent composition, the tablet or a separate region thereof consisting essentially of a matrix of particles, no more than 5% by weight of which are less than 200 micrometers are. The particles of the detergent-active compound and the detergent builder and optionally the particles of the constituents of the detergent base powder are individually coated with a binding material which, when the tablet is immersed in water, causes the structure of the tablet to split.

DE 40 10 533 describes a process for the production of detergents and / or cleaning agents in the form of portioned compacts, granules being produced in a first stage by extrusion and division of the extruded strands and these being added after the addition of water-soluble, water-emulsifiable and / or water-dispersible plasticizers and / or lubricants are subsequently pressed into portioned pressings. EP 0 711 828 describes a process for the production of tablets, the compression of the tablet composition containing a binder with a melting temperature of 35 ° C. to 90 ° C. taking place at temperatures below the melting point of the composition. All of the documents cited refer to the relatively slow disintegration times of the shaped bodies on contact with water.

In contrast, DE 199 08 025 discloses a process for the production of rapidly disintegrating detergent tablets. The production according to the invention is essentially carried out by pressing at temperatures below 20 ° C.

WO 99/03945 discloses agglomerates and a method for producing these agglomerates, the agglomerates being composed of substances for producing aqueous binder systems, in particular of pastes for wall coverings. The agglomerates are dissolved with the aid of hydrophilic, water-insoluble disintegrants which generate a swelling pressure. The amount of these disintegrants added is particularly preferably 5-15% by weight.

All of the methods known from the cited documents cannot readily be transferred to the design of moldings made from working mortar. On the one hand, the disintegration aids described in the quantities used there have a significant negative impact on the further processing properties and the technical performance of mortar. On the other hand, the detergent tablets are used with amounts of water which are a multiple of the mass of the detergent tablets.

The working mortar according to the invention is first produced by dry mixing the components and then bringing them to the shaped body according to the invention, in particular pressing, using conventional methods with continuously working or discontinuously working compression devices for non-plastic masses is used.

Continuous compression can take place, for example, by means of extrusion presses, and discontinuous, for example, by means of stamping presses.

It will not be difficult for a person skilled in the art to select suitable devices from the large number of compression devices available on the market. Roller presses and hydraulic ram presses are preferred.

According to the invention, the shaped articles have a high specific surface area in order to enrich and accelerate the wetting of the shaped article with water and the penetration of water into the shaped article when mixed with water.

In order to achieve a high specific surface, the surfaces are continuously

Compaction devices manufactured flat or strand-shaped

Molded body granulated.

If the compression is carried out continuously with roller presses, the shaped body according to the invention has the shape of smooth or structured flat

Ribbons, so-called Schülpen. In this case, in order to increase the specific surface, it is preferred to connect this cuff by a connected one

Breaking process or under the influence of gravity to separate granules of defined dimensions.

Fig. 1a) shows schematically a smooth Schülpe and

Fig. 1 b) the resulting broken granules.

In Fig. 2a) a structured Schülpe is shown, which is separated into egg briquette-like granules (Fig. 2b).

If the compression is carried out with stamp presses, the shaped body has a regular geometric shape. The regular geometric shape is preferably a conical or pyramid cut, particularly preferably a cylinder or a cuboid.

3a) shows schematically a cylindrical shaped body,

4a) a cuboid shaped body.

In a preferred embodiment, the shaped body contains depressions, elevations or perforations to increase the specific surface. In FIGS. 3b) and 4b) possible depressions and elevations are shown for better illustration, in FIGS. 3c), d) and 4c), d) possible perforations. These structures are expediently pressed directly into the shape. The depressions also have the function of a dividing groove: they enable the unit of quantity of the molded body (based on weight or area coverage) to be subdivided in a defined form (based on the principle of a chocolate bar).

In a further preferred embodiment, the elevations do not protrude from the overall limitation of the molded body in order not to endanger the stability. According to the invention, depressions are expediently designed such that they point in the pressing direction and their dimension is at least 1/3, preferably at least half the dimension of the shaped body in the pressing direction. Perforations are designed so that the stability of the molded body is not endangered and a sufficiently high degree of compaction is maintained. The volume proportion of the depressions, elevations and perforations is essential. The volume fraction is understood to mean the volume of the depressions, elevations and perforations divided by the total volume of the shaped body. The volume fraction of the depressions, elevations and perforations is preferably between 1 to 50% by volume, preferably between 5 and 40% by volume and particularly preferably between 10 and 30% by volume.

The pressures required to achieve stable moldings are of course highly dependent on the process chosen, the dimensions of the moldings and the use of pressing aids.

When using roller presses, the specific pressing force is between 50 and 130 kN / cm, preferably between 70 and 120 kN / cm. Specific pressing force is understood to mean the pressing force divided by the roller working width. When using stamp presses, the required pressure is between 30 and 200 N / mm ² and preferably between 50 and 150 N / mm ² . A stamp press with the following properties is preferably used:

- variable filling height up to 120 mm,

- Control / regulation with alternative options venting strokes / vacuum,

- Mold design for direct injection of variable cavity geometries and / or partition structures,

Mold filling system with vibrating and / or vibrating device for uniform filling of the poorly pourable material into the mold,

- Automatic control of the press parameters after a combination of press travel / press pressure to compensate for different bulk densities of the molding compound and

- Divided lower stamp for the separate movement of the displacement bodies to produce the cavity structures (mandrels or the like).

If the molded mortar body according to the invention is produced without the components (D) and (E), higher pressures are used for the compaction.

The pressing process is preferably interrupted several times to vent the powder pile to be compressed. According to the invention, 2 to 20 ventilation strokes are used during pressing, preferably 3 to 15 ventilation strokes and particularly preferably 4 to 10 ventilation strokes. In a special embodiment of the method, the production of the mortar molded body according to the invention is carried out under previously generated negative pressure. In this case, the remaining air pressure or atomic vacuum in the press chamber before the compression process begins is less than 0.5 bar, preferably less than 0.3 bar and particularly preferably less than 0.1 bar.

The compaction of the mortar is carried out in such a way that the stable molded body after compaction has a bulk density of at least 1.2 times, preferably at least 1.5 times and particularly preferably at least 1.7 times the bulk density of the powder aggregate. The molded body has a pore volume of at least 5% by volume, preferably at least 20% by volume. For example, the pore volume is more than 25% with a density of the compact of almost 2.0 g / cm ³

The mortar according to the invention has compared to commercially available

Mortar has the advantage that it can be used dust-free. Storage and transport of the working mortar according to the invention are more efficient and less expensive, since the otherwise usual dead volume is not available.

Another advantage of the invention is that the moldings allow the user precise portioning of the mortar without weighing or

Use measuring devices.

In a further preferred embodiment, shaped bodies are therefore dimensioned such that their mass is an integral multiple or an integral number

Dividers of the basic units 1 kg or 100 g. preferred

Embodiments are shaped bodies of 2 kg, 1 kg, 500 g, 250 g, 200 g, 100 g,

150 g and 25 g.

Another also preferred embodiment of the invention are

Moldings, the area coverage of the mortar mixed from the molding is an integral multiple or an integral divisor of one

Represents application area of 1 m ² . Particularly preferred embodiments are moldings for an area coverage of 2 m ² , 1 m ² , 0.5 m ² , 0.25 m ² and 0.1 m ² .

The working mortar according to the invention results in ready-to-use mortar by mixing with water and possibly additional binders. The mixing ratio of

Water to mortar is 0.1 to 0.5, preferably 0.2 to 0.4.

The molded body produced from the working mortar according to the invention has a high specific surface area and an excellent capillary

Water absorption capacity, which enables its rapid disintegration in water.

The working mortar according to the invention is suitable for the production of tile adhesive, jointing mortar, filler, leveling compound, flowing filler, repair mortar, screed and floor mortar, mineral plaster, sealing compound, slurry mortar, masonry mortar or planar mortar. The invention will now be illustrated using a few examples.

Example 1 - Compacting on a roller press

A factory dry mortar consisting of

- 33% by weight of Portland cement CEM I

- 45% by weight of fine quartz sand (average grain size approx. 0.1 mm)

- 15% by weight of coarse quartz sand (average grain size approx. 0.3 mm)

5% by weight of dispersion powder

- 1.5% by weight of cellulose derivatives and / or starch ether

- 0.5% by weight of setting regulators

1.5% by weight of paper meal based on the total weight of factory dry mortar and paper meal are added. The mass is mixed thoroughly and then pressed on a roller press with a specific pressing force of 90 to 100 kN / cm. These flakes are subsequently broken down to a granulate size of 40-50 mm.

Example 2 - Compacting on a stamp press with pressing aids

0.5% by weight of paper flour, based on the total weight of factory dry mortar and paper flour, is added to a factory dry mortar as in Example 1. The mass is mixed thoroughly and then pressed on a stamp press at a pressure of 70 N / mm ² with 5 venting strokes to form cuboid shaped bodies.

Example 3 - Compacting on a stamp press without pressing aids

The factory dry mortar, as in Examples 1 and 2, is placed directly in the mold. A pressure in the press room of 0.3 bar is set. With a pressure of 100 N / mm ² , the mixture is pressed into cuboid shaped bodies. LIST OF REFERENCE NUMBERS

slug

Scattered granules

moldings

surveys

wells

perforations

pressing direction

Claims

claims 1. mortar, characterized in that it is present as a molded body. 2. Factory mortar, according to claim 1, characterized in that it is selected from the group factory dry mortar and factory pre-mortar and preferably contains the following components. A) 10-80% by weight of at least one inorganic binder, B) 15-90% by weight of at least one inorganic additive, C) 5-20% by weight of at least one inorganic and / or organic additive. 3. mortar according to claim 1 or 2, characterized in that it contains as component (D) 0.001 to 10 wt .-% of a pressing aid, in particular with a water content below 5 wt .-%. 4. mortar according to claim 3, characterized in that it contains paper flour as a pressing aid, in particular with a fiber length of 0.1 to 0.5 mm. 5. mortar according to at least one of claims 1 to 4, characterized in that it contains as component (E) 0.001 to 10 wt .-% of a disintegrant, in particular made of cellulose, especially paper flour. 6. mortar according to at least one of claims 1 to 5, characterized in that it contains at least two grain size classes, the mean grain diameter of the larger grain size class being 1, 5 - δO times the mean grain diameter of the smaller grain size class. 7. mortar according to at least one of claims 1 to 6, characterized in that the molded body has a pore volume of at least 5 percent by volume. 8. mortar according to at least one of claims 1 to 7, characterized in that the shaped body is designed with depressions, elevations or perforations, the volume fraction of which is preferably 1 to 50 percent by volume. 9. mortar according to at least one of claims 1 to 8, characterized in that the mass of the molded body is an integer multiple or an integer divisor of the basic units 1 kg or 100 g. 10. mortar according to at least one of claims 1 to 9, characterized in that the area performance of the mortar mixed from the molded body is an integer multiple or an integer divisor of the basic unit 1 m ² . 11. Process for the production of mortar according to at least one of claims 1 to 10, characterized in that the shaped body is produced in continuously working or discontinuously working compression devices for non-plastic masses. 12. The method according to claim 11, characterized in that the sheet or strand-shaped molded articles produced in continuous compacting devices are granulated. 13. The method according to claim 11, characterized in that it is in the continuously operating compression devices to roller presses, which are preferably used with a specific pressing force between 50 and 130 KN / cm. 14. The method according to claim 11, characterized in that the discontinuously operating compression devices are stamp presses, which are preferably used with a pressure of 30 to 200 N / mm ² . 15. The method according to at least one of claims 11 to 14, characterized in that 2 to 20 ventilation strokes are used during the pressing. 16. The method according to claim 11, characterized in that a negative pressure is generated in the press chamber before the pressing, in particular less than 0.5 bar. 17. Use of working mortar according to at least one of claims 1 to 10 as tile adhesive, joint mortar, filler, leveling compound, tile filler, repair mortar, screed and floor mortar, mineral plaster, sealing compound, slurry mortar, masonry mortar or planar mortar. 18. Use according to claim 17, characterized in that the working mortar by mixing with water and optionally additional binders results in a ready-to-use mortar, the mixing ratio of water to working mortar preferably being 0.1 to 0.5.