WO2012116380A1

WO2012116380A1 - Composite body and method for production

Info

Publication number: WO2012116380A1
Application number: PCT/AT2011/000099
Authority: WO
Inventors: Michael Schmid
Original assignee: Geolyth Mineral Technologie Gmbh
Priority date: 2011-03-03
Filing date: 2011-03-03
Publication date: 2012-09-07
Also published as: EP2681172A1

Abstract

The invention relates to a composite body and to a method for producing same. In an especially valuable special case, the composite body according to the invention is a composite plate that can be used especially advantageously as thermal insulation on the inside of building walls. The composite body comprises two sub-bodies that adhere to each other, wherein one body (1) is at least predominantly made of mineral material and wherein the second body has a lower specific weight and is made of a mineral insulating material (2) having pores. In order to produce the composite body, a flowable mass that contains foamed sulfate aluminate cement and that cures to form the insulating material is applied to the body (1) and allowed to cure thereon.

Description

,

description

The invention relates to a composite body and a method for the production thereof.

In a particularly valuable special case, the composite body according to the invention is a composite panel. This is particularly advantageous as a thermal insulation on the inside of building walls applicable.

For the sake of clarity and because it pertains to one outstandingly important special case, the wording "composite panel" or "composite panel manufacturing method" is used throughout the following description, although the generalized formulations "composite body" and "composite body manufacturing method" are also used. would be true. It is to be expressly understood that the scope of the invention described also includes other forms than plates.

Gypsum plasterboards are mainly used for the interior work of buildings. They consist of a plaster layer provided on both sides with a cardboard layer, a few millimeters thick. Usually plasterboard is screwed onto a wooden framework or on a lower layer of chipboard or similar material. Between the plasterboard surface and load-bearing masonry heat-insulating material such as glass wool can be arranged. The plasterboard itself is insignificant as thermal insulation. It can be important as fire protection. In terms of water vapor permeability, it is comparable to conventional mineral plaster. Above all, it is estimated that it is easy to work with and costs little.

So-called calcium silicate boards consist predominantly of silicon oxide, calcium oxide, water glass and cellulose. For the production of a mixture of these substances by means of steam,

- l - Hardened similar to aerated concrete. The material thus formed is simply referred to in this document as "calcium silicate." The plate form is formed either by sawing out of a larger block, or in which the raw material mixture is already poured into plate form and cured.

Calcium silicate boards are already being used as thermal insulation boards in buildings. For use as thermal insulation on the inside of building walls, the high capillarity is particularly valued on these plates and that they are not attacked by mold. In most cases, when using these plates, a vapor barrier is unnecessary. A disadvantage compared to some other heat insulating materials are a higher price and a rather higher heat transfer value.

In DE 10 2007 040 654 AI is proposed as thermal insulation, a composite of a relatively thin, relatively dense, solid calcium silicate board and a thicker plate of less dense and less solid insulation, which isolated better heat and which is also open to diffusion form. As an insulating material are aerated concrete, foam concrete, - expanded clay, pumice or foam glass called. The calcium silicate board should be arranged facing the room in the building and the insulation material between calcium silicate board and the wall. As a method of connection is proposed to stick the insulation layer only to the wall and then gluing calcium silicate to the insulating layer, each with a diffusion-open adhesive. Alternatively, it is also proposed to attach the calcium silicate plates to the wall by means of fastening elements which penetrate the insulation layer. By combining different layers individual advantages of the. individual materials (high capillarity, thermal insulation, strength) added and individual disadvantages (low strength, high cost per volume, low surface suitability, too high heat transmission) of individual laminates defused. As a disadvantage ben but the high effort required for the logistics of the various items and the high assembly costs for attaching the different layers.

On this basis, the object underlying the invention is to provide a usable as thermal insulation on the inside of building walls element, which also has high thermal insulation, high capillarity, good strength of the surface layer and low manufacturing costs and beyond easier to handle during delivery and installation is.

According to the invention, it is proposed to form the element as a composite plate of two adhering layers, wherein the first layer is a plate of an at least predominantly mineral material, and wherein the second layer is specifically lighter and by a mineral, pores. formed insulating material, which is formed from a self-curing formulation of a hydraulically setting binder, a pozzolanic setting binder and a sulfate, and from a foamed component added to this formulation.

In a preferred embodiment, the plate is a calcium silicate plate. The advantage of this is especially high capillarity that they are not attacked by mold.

In another preferred embodiment, the plate is a gypsum board. Particularly advantageous in this are the ease of processing and the low price.

An advantage of both plates is that they are well suited both for building physics and in terms of their strength for use as a surface material on inner walls and thus protect the mechanically sensitive but very effective as thermal insulation mineral, pore-containing insulation. Furthermore, the term "formulation" is used briefly for the mixture of hydraulically setting binder, pulverulent binder and sulfate, and the term "slurry" is also used for the slurry which can be stirred therefrom with the addition of water.

Preferably, the hydraulically setting binder is formed based on a sulfate aluminate cement. It contains a sulphate component and an aluminum component and is included in the formulation at least 50% by weight.

According to the invention it is also proposed to produce the composite panel by the above-mentioned, the stirred as a flowable slurry with the addition of water formulation including added mixed foam component is applied to an existing calcium silicate board ^'and the calcium silicate board allowed to cure is.

Preferably, the foam component of the previously blended and stirred with the addition of water to a slurry formulation is mixed in a second mixing stage.

Thus, the insulating layer can be produced without the need for autoclaving, whereby the process can be handled easily and therefore cost-effectively.

In order to ensure the creation of a reliable connection of said plates with the insulating layer in high quality, it does not require a separate interconnecting intermediate layer. It is sufficient to pretreat the surface of the plate to be bonded before applying the mixture of slurry and foam component. A very good pretreatment for the calcium silicate board is to spray this surface with a jet of water, as is typically emitted from a high-pressure cleaner at, for example, five bar spray pressure, thus superficially slightly removing material from it and the platinum te in the wet state with slurry and foam component in contact.

This method is simple, inexpensive and environmentally friendly, because you do not need environmentally hazardous chemicals as a primer, binder, etc. In addition, one gains an aspect of quality control. Namely, if the calcium silicate plate has too low strength, it is well worn away when sprayed with the water jet.

A good pretreatment for the surface of a plasterboard panel to be joined is to wet the plasterboard with water, for example by spraying it with a mist of water.

Said hydraulically setting binder causes the insulating material layer does not or only very slightly shrink during hardening. Too much shrinkage - which would occur with many other materials - would cause the insulating layer to separate from the calcium silicate board, either by breaking the bond at the interface or by breaking the insulating layer close to the calcium silicate board.

The proportion of the sulfate-aluminate cement in the formulation is preferably at least 60 parts by weight, in particular at least 70 parts by weight. As a result, the mechanical properties and the insulating properties of the insulation layer are favorably influenced.

The sulfate component is preferably selected from a group comprising calcium sulfate, α- or β-hemihydrate or dihydrate of calcium sulfate, anhydrite, sodium sulfate, iron (II) sulfate, magnesium sulfate and mixtures and derivatives thereof. It will thus hydrate phases are generated during the hardening of the insulating layer, which lie in the course of time a phase transformation, the strength increases. The aluminum component is preferably selected from a group comprising aluminum oxide (Al 2 O 3), aluminum hydroxides, aluminum silicates, aluminates and mixtures and derivatives thereof. It can thus be positively influenced the solidification behavior and the setting time of the insulating layer.

The ratio of the sulphate component to the aluminum component can be selected according to one embodiment from a range with a lower limit of 4:10 and an upper limit of 20:30. It is thus achieved that the setting time of the slurry does not take so long that the danger is that the added foam coincides and thus the porosity of the insulating layer is reduced. It is thus simplified by keeping the ratio of the two components in this area, the processing.

In particular, to further improve this behavior, the ratio of the sulfate component to the aluminum component may be selected from a range having a lower limit of 6:12 and an upper limit of 13:22, preferably a lower limit of 10:18 range and an upper one Limit of 12: 24.

To improve the mechanical properties of the insulation layer, the formulation may additionally contain SiO 2 particles in a proportion of not more than 10 parts by weight. However, the proportion of SiO 2 particles is preferably not more than 7.5 parts by weight, in particular not more than 7.5 parts by weight.

According to another embodiment variant, the formulation contains special SiO 2 particles in the form of so-called silica fumed. This is a reactive SiO 2, which can improve the fire resistance of the insulation layer, by using SiO 2 as a "cooling" effect for reactions, especially DABEI. used without lead-free SiO 2 particles with a purity of at least 97%.

In one embodiment, it is provided that the SiO 2 particles have a BET surface area between 5 m ² / g and 35 m ² / g, in order to increase the reactivity. The SiO 2 particles preferably have a BET surface area between 10 m ² / g and 25 m ² / g, in particular between 16 m ² / g and 20 m ² / g. Preferably, the SiO 2 particles have a particle size of at most 45 μm, wherein in particular the proportion of the coarse grain is limited to a maximum of 2% and the rest of the SiO 2 particles have a particle size of at most 1 μm, preferably at most 0.3 μm.

The formulation may further contain at least one so-called high-performance liquefier. in order to influence the rheological behavior of the slurry formed from the formulation, provided that the addition of silica fumed, which also has a liquefying effect due to the spherical shape of the particles, is not sufficient solely for this purpose, the proportion being limited to a maximum of 3% by weight , In particular, when silica fumed is included in the formulation, the proportion of the high-performance plasticizer is limited to a maximum of 0.5 percent by weight, preferably at most 0.3 percent by weight.

The high-performance liquefier is preferably a polycarboxylate ether or a derivative thereof in order to be able to reduce the water content of the slurry so that less water is available for setting and thus the desired phases are formed more reliably.

It is also possible that the formulation for stabilizing the slurry and thus for better processability of the slurry at least one thickener is added in a proportion of not more than 0.5 percent by weight. The thickener is preferably added in a proportion of not more than 0.25 percent by weight, in particular not more than 0.02 percent by weight. The thickener is preferred selected from a group comprising hydroxymethylpropylcellulose, methylhydroxyethylcellulose and mixtures and derivatives thereof, since it has been found within the scope of the tests carried out for the invention that these thickeners have better properties with regard to processing, such as eg the rheology, the dispersion of the solids , or the water requirement and the water retention capacity. With regard to the processability of the slurry, it has also been found that improvements occur when the proportion of the thickener is at most 70% of the proportion of the high-performance liquefier.

It is further possible that the formulation of fibers in a proportion of not more than 3 percent by weight, in particular not more than 1 percent by weight, preferably 0.3 percent by weight, are added in order to improve the flexural strength of the insulating material. But it can also be used to stabilize the foam component. In addition, e.g. Store cellulose fibers water, which is needed in the setting process, this physically "bound" water is better controlled with respect to the hardening of the mineral foam.

Cellulose fibers can also be used as thickeners.

The fibers preferably have a maximum length of 50 mm, in particular not more than 30 mm, and are in particular selected from a group comprising cellulose fibers, basalt fibers, glass fibers, in particular alkali-resistant glass fibers, polypropylene fibers, and mixtures thereof.

Fibers of greater length, so for example with a length between 3 mm and 50 mm, in particular between 3 mm and 30 mm, preferably between 3 mm and 12 mm, the diameter of which preferably between 13 pm and 25 μιη, preferably between 13 μτ and 18 pm is added, especially when the bending tensile strength is to be increased.

Fibers up to a length of 0.1 mm, preferably up to 30 pm, and in particular a diameter of up to 2 pm, preferably up to 1.5 μπι, however, are preferably added for rheological reasons.

The formulation may be added to improve the rheology at least one processing aid from a group comprising an alkali metal carbonates, alkali metal sulfates, fruit acids, for example as a retarder.

In order to reduce the proportion of sorption moisture in the finished insulation layer and thus to improve the thermal insulation (λ value), it can be provided that at least one hydrophobicizing agent is added, in particular for the mass-hydrophobicization of the formulation. The proportion of the hydrophobizing agent in the formulation may be up to 3 percent by weight, preferably up to 1 percent by weight.

According to another embodiment of the formulation, it may be provided that these additives are free of aggregates, i. is filler-free, so contains no non-reactive constituents, whereby the density of the Dämmstoffschicht can be further reduced.

The foam component is preferably formed by a protein foam and / or a surfactant foam. Thus, the foaming behavior can be better controlled than with the method of direct foaming by means of a blowing agent. In particular, the pore size and the pore distribution can thus be better reproducible and influenced in a wider range. Thus, the thermal conductivity or the sound absorption capacity of the insulation layer can be better adjusted.

The proportion of foam component per m ^{3 of} slurry is preferably between 30 kg / m ³ and 70 kg / m ³ , in particular between 40 kg / m ³ and 60 kg / m ³ . In this area, particularly good insulation behavior of the insulating layer can be achieved. To stabilize the foam during mixing in the slurry from the formulation with water, a surfactant may be added to the foam component.

According to a preferred embodiment variant, the insulation layer has a pore content of at least 70%, in particular between 80% and 95%. Due to this high proportion of pores, not only the insulation behavior per se can be improved, but also a lower density of the insulating material layer can be achieved. In this case, the pores preferably have a diameter of at most 0.5 mm, in particular not more than 0.25 mm or not more than 0.1 mm, on the one hand to achieve a positive Dämmverhalten and on the other hand to improve the mechanical stability of the finished Dämmstoffschicht.

The foam component may also include air entraining agents, such as e.g. Alkyl polyglycol ethers, alkyl sulfates or sulfonates, i.a. to improve the stability of the foam.

According to one embodiment variant of the method, it is provided that the foam component is added to water and possibly processing aids before addition to the slurry in a foam generator, whereby its processability, in particular the stability of the foam during mixing with the slurry, can be improved. It can be arranged in the device for foaming the foam component, a foam generator, in which a protein mixed with water with a gas, in particular air, is foamed.

The invention is illustrated by means of a drawing.

FIG. 1 shows, in a not to scale, simplified schematic form, an exemplary arrangement for producing a composite panel according to the invention in a sectional view.

According to FIG. 1, a rectangular calcium silicate plate 1 is placed on a flat, solid base. The edges of the cal- ziumsilikatplatte are bordered by a formwork 3, which has the shape of a lateral surface of a prism. The formwork 3 is also on the flat solid base. Towards the top, it projects beyond the calcium silicate board 1.

Through a feed 4, which may be formed for example by a tube with a screw conveyor disposed therein, flowable mass 2 from the slurry of the formulation described above and the foam component blended therein in the limited by shuttering 3 and calcium silicate plate 1, upwardly open well volume filled.

If a sufficient amount of this mixture 2 is filled in said tub, the supply of further mass 2 is turned off and the surface of the mass is smoothed by means of a straight bar 5, which projects beyond the width of the formwork 3 and therefore simultaneously at two opposite, upper edges the formwork 3 can rest, is deducted over the mass 2. As a result, the surface of the mass 2 is flat and flush with the top of the formwork 3 is formed.

The mass 2 hardens to an insulating layer, which is connected to the calcium silicate plate 1. The rate of curing is dependent on the exact composition of the formulation in the mass 2. In particular, by the proportion of fruit acid, such as citric acid, the curing rate can be influenced. Green steady, the mass 2 is typically after five to ten minutes; The formwork 3 can thus be removed after this time without the shape of the consisting of hardening mass 2 and calcium silicate board 1 composite body still changes. Eighty percent of the final strength of the composite panel thus formed is typically achieved within a few hours.

In the arrangement according to FIG. 1, instead of the calcium silicate board 1, a plasterboard panel could also be used. Based on the described basic principle, it is in the field of professional trade to automate individual steps of the production process or even the entire procedure. Therefore, the topic "automation of the manufacturing process" will not be discussed here.

Since the green strength can be achieved in the curing of the mass 2 on the calcium silicate plate 1 or gypsum board in a very short time, it is also quite possible instead of manufacturing discontinuous composite plates as described continuously or quasi-continuously. For this purpose, in a moving in their longitudinal direction, for example on a conveyor belt gutter whose base is occupied by calcium silicate boards or gypsum board and whose side walls are formed by shuttering panels and have the function of a formwork, mass 2 are poured. In a longitudinal region remote from the pouring point in the direction of movement of the channel, the mass 2 is hardened, the formwork panels can be removed there and composite panels can be cut from the resulting composite profile.

Within the scope of the invention and the skilled person, it is easily possible to modify the described manufacturing process such that composite panels are not formed from two flat, mutually parallel, different layers, but that differently shaped composite bodies are formed by mass 2 to a somehow shaped body Is applied calcium silicate or plasterboard composite and by using a shaped differently than in the manner of a prism shell surface formwork.

By the invention can in the best possible way the high mechanical strength of calcium silicate boards or plasterboard with the high thermal insulation capability of very light and thus very porous and thus forcibly mechanically very little resilient mineral insulating materials are combined. The insulating material may be formed in the described composition with a density lower than 300 kg / m ³ and with a lower thermal conductivity than 0.05 W / mK.

Mechanically sensitive insulating material and mechanically robust calcium silicate body or plasterboard body arrive together as a monolithic composite on the site. The connection of the individual body parts is associated with no disadvantages such as loss of diffusion openness, requirement of adhesive, etc.

Claims

claims

1. A composite body of two mutually adhering part bodies, wherein a body (1) consists at least predominantly of mineral material, wherein the second body has lower specific weight and formed by a mineral, pore-containing insulating material (2), characterized in that the Insulating material (2) is formed from a self-hardening formulation of a hydraulically setting binder, a pozzolanic setting binder and a sulfate, and from a foam component admixed to this formulation.

2. Composite body according to claim 1, characterized in that the first body (1) consists of calcium silicate.

3. Composite body according to claim 1, characterized in that the first body consists of plasterboard.

4. A composite according to claim 1 or claim 2, characterized in that the hydraulically setting binder is formed on the basis of a sulfate aluminate cement and is contained in the formulation with at least 50 weight percent.

5. A composite according to claim 3, characterized in that proportion of the sulfate aluminate cement to the formulation is at least 60 parts by weight, in particular at least 70 parts by weight.

6. Composite body according to one of claims 1 to 5, characterized in that the foam component is a protein foam and / or a surfactant foam.

7. Composite body according to one of claims 1 to 6, characterized in that the proportion of the foam component per m ³ formulation between 30 kg / m ³ and 70 kg / m ³ , in particular between 40 kg / m ³ and 60 kg / m ³ ,

8. The composite body according to one of claims 1 to 7, characterized in that the body of calcium silicate is a calcium silicate board and that the insulating material is a one-sided and parallel thereto planar layer.

9. Composite body according to one of claims 1 to 8, characterized in that the body (1) and the insulating material are connected to each other without intermediate layer.

10. A method for producing a composite body of ^' two mutually adhering bodies, wherein a body (1) consists at least predominantly of mineral material and wherein the second part body has specifically lower weight, is formed by a mineral, pore-containing insulating material, wherein the insulating material a self-hardening formulation of a hydraulically setting binder, a pozzolanic setting binder and a sulfate, and a foam component added to this formulation,

characterized in that

on which a mass (2) is applied to the body (1) and allowed to harden to an insulating material, wherein the mass (2) consists of the self-curing formulation mixed with the addition of water to form a flowable slurry and the foam component added to it ,

11. The method according to claim 10, characterized in that the surface of the body (1) which comes into contact with the material which sets the insulating material (2) is brought into contact with said mass in a pre-wetted state.

12. The method according to claim 10 or 11, characterized in that the body (1) consists of calcium silicate and that of its with the hardening compound (2) coming into contact surface as a pretreatment for the bonding process Spraying with water under high pressure, material is removed.