AAC - Autoclaved Aerated Concrete

Description

The present invention relates to insulation components for buildings, and methods for preparation of the insulation components, and uses of said insulation components.

More specifically it relates to insulation components comprising an insulation material and a hydrothermal hardened calcium silicate hydrate material, and methods for preparation of the insulation components.

The governments around the civilized world face the consumers of energy for heating both in private housings and in industrial buildings with still higher requirements to lower heat loss to the environment in order to save energy and thus decrease CO ₂ emission. The purpose is to mitigate the increasing average temperatures and consequences of the climate change caused by e.g. increased concentration of CO ₂ in the air.

The buildings today are insulated to avoid loss of heat through the walls.

One typical method is to plaster the walls, if on the outside, with mineral wool and, put on top of that a wind barrier and finally cladding. First the wall is covered with laths of wood, then mineral wool is inserted between the laths. After that the wind barrier has to be created. On the wind barrier a ventilated cladding has to be mounted. Finally, the cladding is protected against algae and rod by painting the cladding with a chemical fungicide. The disadvantages of the method of prior art are that the insulation process requires several steps and is very work intensive and costly.

Maintaining the construction is work intensive and has to be done in short intervals.

Thus, the objective problem of the invention is to provide a material for insulation of buildings whereby the heat loss and installation costs are lowered, while the fabrication process of the materials is not more expensive than materials of prior art.

Summary of the invention.

The above problem has surprisingly been solved by providing a material for insulation of buildings according to claim 1 wherein said material is a composite of a diffusion open rigid insulating layer and a diffusion open load bearing hydrothermal hardened calcium silicate hydrate layer.

The layers are attached to each other by an adhesive diffusion open third layer as in claim 2, or by the adhesive character of the first layer as in claim 20.

The fire protecting by using the invention is highly improved compared with traditional methods due to the second layer which cannot burn.

An anticipated embodiment of the invention is where the diffusion open insulation material, which may be a rigid phenol foam, is attached to the diffusion open load bearing hydrothermal hardened calcium silicate hydrate layer, which may be an aircrete layer, wherein the attachment is facilitated by an adhesive layer as in claim 3, or, preferably, by the adhesive character of the diffusion open insulation material as in claim 21 .

It is anticipated that the layers are diffusion open and rigid, and the foam layer has a closed cell structure i.e. about 90% of the cells are closed. A phenolic foam layer as the insulation layer provides a fire protection, which is highly improved compared to traditional methods for insulation as the second layer cannot burn and the first layer according to fire tests is much more resistant than other insulation materials to fire. An anticipated embodiment of the invention as in claim 4 is where the phenolic foam is formed from a liquid resole resin, calcium carbonate, using a catalyst and a blowing agent.

Another embodiment is where the adhesive third layer is a layer of a glue as anticipated in claim 5. The adhesive layer may be a glue e.g. a thin layer mortar as claimed.

The layer of glue is anticipated to be a Kunstharzdispersion (synthetic aqueous copolymer dispersion) which as claimed in claim 6 is an air-hardening moistens fast synthetic aqueous copolymer dispersion which in the present case is based on styrene and an acrylic acid ester with a solid content of 20-80%, preferably 50% +/- 1 %.

Other anticipated embodiments are as claimed in claim 7 to 10.

Further product claims are, a board of an insulting composite of the invention as claimed in claim 1 1 .

The invention further provides in claim 12 a board comprising at least a composite insulation material according to claim 1 1 wherein the board further comprises fixing means for attaching the board to a wall.

A wall made from any of the boards of claim 1 1 or 12 is claimed in claim 13.

An anticipated embodiment of such a wall is where the boards of insulating composites are of different thicknesses, claim 14. An embodiment of a wall where the board are mechanically fixed are anticipated in claim 15, and optionally as in claim 16 combined with glue. Methods for preparing a composite of the invention where the layers are glued together by a layer of glue are claimed in claim 17 to 18.

Another anticipated method is wherein the diffusion open insulation material is a phenolic foam resin as claimed in claim 19.

Further, claims 19 to 21 are claims on a board or a wall comprising the

composite of the invention.

An anticipated method thus comprises to prepare the composite by

- preparing the foam layer on a support layer which also serves as a first protective layer,

- provide an aircrete layer pre-prepared using standard methods,

- applying an adhesive layer to the foam layer's free side or to the aircrete layer using an adhesive allowing the final composite to be diffusion open,

- attaching the foam layer to the adhesive layer whereby the foam layer is attached to the aircrete layer.

The aircrete may deviate in its composition for the example as follows.

Base materials / Auxiliaries Description Value Unit

Sand 40-72 %

Cement 9-45 %

Caustic lime 10-20 %

Anhydrite / Gypsum 2-5 %

Aluminium 0.01 -0.4 %

A composite insulation material according to claim 1 wherein the layers of the composite are attached to each other by the adhesive force of the first layer is claimed in claim 21 .

An embodiment of a composite insulation material according to claim 20, is wherein the first layer, 1 , is a rigid phenolic foam with closed cells though still diffusion open, and wherein the second layer, 2, is a diffusion open autoclaved aerated concrete layer, as anticipated in claim 22.

An embodiment of a composite insulation material as claimed in claim 23 is where the rigid phenolic foam is formed from a liquid resole resin, calcium carbonate, using a catalyst and a blowing agent.

Yet other embodiments are claimed in claim 24 to 26.

Two different embodiments of a board comprising at least a composite as in any of the claim 21 to 26 are claimed in claim 27 and 28.

A wall comprising at least one board of claim 27 or 28 is claimed in claim 29. A wall comprising at least one board of claim 27 or 28 of one thickness and at least one and different other board of claim 27 or 28 of a different thickness is claimed in claim 30.

Other embodiments of such wall wherein the boards are mechanically fixed to the wall, optionally with glue are anticipated in claim 31 and 32. A method for the preparation of a composite where the attachment is provided by the adhesive character of the diffusion open rigid insulation layer is anticipated in claim 33.

A method is anticipated in claim 34 wherein the diffusive rigid open insulation material is a rigid phenolic foam with a major part such as 90% closed cells though still diffusion open.

Another anticipated method for preparing a composite according to claim 34 is claimed in claim 35. The rigid phenolic foam layer is prepared first. The resin mixture for the foam layer is prepared as in claim 34 and poored onto the diffusion open load bearing hydrothermal hardened calcium silicate hydrate layer, which should have a temperature of e.g. 60 °C to 70 °C prior to curing the composite by the remaining heat. The diffusion open load bearing hydrothermal hardened calcium silicate hydrate layer, 2, has initially the temperature of 180°C of the autoclaving process but the heat may be applied in the above method prior to applying the resin mixtureThe process for making the composite this takes advantage of the adhesive character of the formed foam.

Uses of the composite of the invention are claimed in claim 36 to 38.

In order that the invention may be well understood, some non-limiting examples will now be described in which: Fig. 1 shows a composite insulation board according to the invention for plastering a wall.

The foam layer, 1 , is attached to an aircrete layer, 2. Either, the foam layer is sticking to the aircrete layer, or an adhesive layer (not shown) joins the foam and aircrete layer together. Fig. 2 shows a composite insulation board according to the invention for rendering a wall for paint. The foam layer, 1 , is attached to an aircrete layer, 2. Either, the foam layer is sticking to the aircrete layer, or an adhesive layer (not shown) joins the foam and aircrete layer together. The edges are chamfered.

Fig. 3 shows a cross section of the board in Fig. 1 which has a plaster layer, 3, on the outside.

Fig. 4 shows a cross section of the board in Fig. 2. The outmost layer is a layer of paint, 4. As seen, the edges are chamfered and the joint sealed, 5. The paint covers both the boards and the joint.

Fig. 5 shows an example of how composite insulations boards for plastering are installed.

Fig. 6 shows an example of how composite insulations boards for paint are installed.

Fig. 7 shows an example of a composite comprising in addition to an insulation layer, B, and an aircrete layer, D, also the support layers of e.g. diffusion open glass fibre layers, A. B is the phenolic foam insulation layer, C the adhesive layer and D the aircrete layer.

One way of manufacturing of the phenolic foam needs a surface covering to prevent the foam from sticking to the production equipment but also a firm support layer or surface to form the foam. So, on the market such phenolic foam layers are sold sticking to a special glass surface with a releasable protective foil on the other surface.

The composite layer of the invention may or may not comprise this support layer. Thus, according to the present invention other manufacturing methods for preparing a phenolic foam layer may not need a surface covering or a firm support layer. Such another manufacturing method is the parallel vertical placement of two surfaces of any two of an aircrete wall or a firm support layer e.g. a glass plate and forming the foam layer in between this set of layers.

The invention is now described in further detail and where possible by referring to the figures above.

Fig. 1 to 7 show each at least one composite insulation board according to the invention for insulating a wall. It is anticipated that the foam layer may be made from a phenolic resin such as a resole resin.

The insulating phenolic resin is commercially available and may be converted into a thermoset modified resin according to the known method published in Kooltherm K5 from Kingspan. The thermoset modified resin may also be performed according to the example below. It has a composition, if it includes a facing material, of:

About 70% resole resin, about 15% additives, 9% facing material e.g. a glass plate onto which the resin is foamed, and a propellant with no ozone depletion potential 5%. Due to the closed cells propellant remains in the closed cells. The thermoset modified resin is made from a liquid resole resin, calcium carbonate, additives and a blowing agent. The foam is rigid and has 90 % closed cells. The cell structure is formed in the resin under the influence of heat generated by the chemical reaction.

An insulation composite for insulation of a building according to the invention is a composite comprising a diffusion open rigid phenol layer as the one above and a diffusion open calcium silicate hydrate layer, which has especially good properties. It is fire resistant, has low heat conductivity and is strong and not brittle.

A method for insulation of a building according to the invention is by insulation of the walls of the building where the method comprises applying a layer of a glue to the first layer of said insulation composite and attaching said composite to the wall or vice versa.

Another method for insulation of a building according to the invention is to insulate its walls where the method comprises providing an insulation composite which has a protective layer on top a layer of glue. The method comprises removing said protective layer and attaching the composite to the wall.

The boards are fixed to a wall either mechanically or with glue.

An advantage of the composite of the invention is the combination of properties to improve the thermal insulation properties while maintaining a low thermal conductivity.

Further advantages are:

The second layer, 2, reduces noise as the mineral layer has a high density compared to conventional insulation composites for walls of buildings.

The product is much more stable compared to traditional external thermal insulation composite systems (ETICS) against mechanical impacts.

The thickness of the second layer, 2, may also vary from board to board in order to obtain a variated design structured facade surface.

The composite of claim 1 and especially claim 2 and 3, is also very fire resistant and the composite cannot be modified by constructors making it very attractive for tall buildings from which it is difficult to escape in case of fire.

Further, the insulation composite material of the invention provides a high heat capacity at the outside wall. The thermal buffer keeps up the temperature during night whereby less condensed water is generated, making it easier to keep the surface clean.

Example A phenol layer may be prepared as follows:

A phenol resole resin composition comprising 240 g of the commercially available liquid phenol formaldehyde resin supplied by Sumikomo Bakelite, R330, having a viscosity of 8000-10000 cP at 25°C, weight average molecular weight 600-1200 and pH 5,3 to 6,3, containing from 2 to 4% free phenol and 3 to 4% free formaldehyde, with a phenol/formaldehyde molar ratio of 1 :2 and a water content of 1 1 to 13%, is mixed at 15°C with 12,0 g powdered urea and 6,0 g of a castor oil-ethylene oxide adduct as plasticiser and allowed to stand 14 hours. Then 12 g calcium carbonate is added and mixed into the resin until uniformly dispersed. Finally, 20 g of blended isopropyl chloride/isopentane 85/15 parts by weight as blowing agent is mixed at 1 °C into the resin. Once a uniform

suspension is formed the resin mixture is cooled to 8°C. Then 40,0 g liquid para- toluene sulfonic acid/xylene sulfonic acid blend 65/35 parts by weight at 92% concentration at 8°C is quickly mixed in. 200 g of the resin mix is quickly poured onto a glass plate, and then cured at elevated temperature 70°C. 50kPa is applied to a lid over the casing with the glass plate and foamed layer. The foam is cured for 10 minutes and cured in an oven afterwards for another 2 hours. See also EP1922356B1 or EP1922357B1 for a description of a similar process for preparation of a rigid phenol resole foam from a resole resin.

According to the present invention a glass plate is not used. Instead the second layer of the composite i.e. for example an aircrete layer is serving as the support layer becoming part of the composite to be formed at the same time. The heat of lower temperature from the preparation of e.g. an aircrete layer may be used for heating up and partly or fully curing the phenol resin.

A composite of the invention may be prepared applying the above inventive method taking advantage of the adhesive properties of the formed diffusive open rigid phenol foam of the composite. The composite of the invention has superior properties in terms of low heat conductivity, high fire resistance, load bearing strength, and being not brittle.