ITUD20110214A1 - "INSULATION PANEL FOR BUILDING AND METHOD OF PREPARATION OF SUCH PANEL" - Google Patents

Description

DESCRIPTION of the patent for invention

Having as title:

INSULATING PANEL FOR BUILDING AND METHOD OF PREPARING THIS PANEL

DESCRIPTION

Technical field

The present invention relates to an insulating panel for building according to the characteristics of the precharacterizing part of claim 1.

Prior art

In the building field, the use of panel materials to be applied to the walls of buildings is known both in order to obtain a surface finish of the wall and to increase the insulating characteristics for energy saving purposes.

Problems of the prior art

The panels to be applied on the walls often have limited insulating characteristics and not sufficient to obtain thermal insulation coefficients aligned with the most recent regulations that are increasingly stringent in terms of thermal conductivity of the walls, so much so as to often make the application between two panels or between a panel and the wall of additional insulating materials, both of natural and artificial origin or a combination of these, such as cellulose fibers, rock wool, cork, etc.

Furthermore, not all the panels of the prior art are able to guarantee the antibacterial or anti-mold characteristics combined with the maintenance of the transpiration of the wall. To obtain the different functions it is often necessary to resort to the application of different products on the panels themselves. In any case, it is not certain that it is possible to obtain all the required characteristics relating to the characteristics of antibacterial, anti-mold, maintenance of perspiration, high degree of thermal insulation.

Purpose of the invention

The purpose of the present invention is to provide a panel with high insulating characteristics that is ready for use for application to the walls of a building and which at the same time maintains good transpiration characteristics of the wall with additional anti-mold and antibacterial functions.

Concept of the invention

The object is achieved with the features of the main claim. The sub-claims represent advantageous solutions.

Advantageous effects of the invention

The solution in accordance with the present invention, through the considerable creative contribution whose effect constitutes an immediate and not negligible technical progress, has various advantages.

The panel according to the present invention is easy to apply and ready for use, giving high insulating characteristics which in some cases prevent or greatly reduce the need to resort to additional insulating materials such as cellulose fibers, rock wool, cork, etc.

Furthermore, the product is completely recyclable and, therefore, reduces the environmental impact. This aspect has particular relevance both as regards the production phases of the product, as any processing waste can be immediately and immediately recycled in a subsequent phase of preparation of further product, both as regards the recycling of the product at the end of its life, and as regards the recycling of any scraps obtained during the application phases of the product itself on the walls. This advantageously also avoids the transfer of large quantities of waste to be sent to landfill and / or to further treatments with consequent additional costs which can also be significant and affect the cost of the final product.

Advantageously, the product according to the present invention also has a high reflectivity of U.V.rays, with benefits both from the point of view of thermal insulation and of the protection of the paint itself and of the underlying material from the aggression of ultraviolet rays, ensuring greater durability over time. and a remarkable resistance to aging.

Description of the drawings

An embodiment solution is described below with reference to the attached drawings to be considered as a non-limiting example of the present invention in which:

Fig. 1 represents a graph illustrating the results obtained by comparing different samples obtained with the inventive formulation and process and a reference sample, according to the data reported in Table 21.

Description of the invention

The present invention relates to an insulating panel for building.

The insulating panel for building according to the present invention is characterized by the presence of at least one sheet, preferably two sheets, preferably in cardboard, possibly treated in such a way as to give the sheets water-repellent characteristics to ensure excellent sealing even in the case of high-grade environments. of humidity, between which a material based on linseed oil and slaked lime is interposed together with the presence of percentages of airgel, which is a substance that in the solid state is similar to a gel but which, instead of the liquid component of the gel, includes a gas. The airgel has high insulating characteristics and, although it is suggested to use it in insulation applications on buildings, generally such applications require the airgel to be used as a filler in the form of granules that are used to occlude and isolate any empty spaces. in the walls. Applications that involve mixing with plastic components in order to facilitate their application, do not take into consideration the fact that the airgel, being essentially made up of gaseous components and, therefore, not liquid, is hygroscopic and it is not possible to obtain a correct mixing of the product, so much so that often the airgel is simply added in the form of grains without worrying about its correct integration in the finished product. To this end, surfactant components are often used in the formulation of products which are not readily miscible with each other and the surfactants act as a binder. However, the use of surfactants has many drawbacks both due to the fact that they lose effectiveness over time, and because they give rise to unnatural and difficult to recycle products. In addition, the use of surfactants involves the loss of the breathable function which, in the case of application on the walls of buildings, is a very important requirement for the healthiness of the home environments.

The lime putty is a hydrated lime paste obtained by quenching the quicklime with water.

The optimal preparation of the intermediate product to be applied between the two cardboard sheets in order to obtain the panel takes place, for 10 kg of product, according to the following operating steps to be carried out in a mixer, preferably at room temperature:

a) addition to the mixer of synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in a quantity equal to 330 g; b) addition of airgel to the mixer in a quantity equal to 10 g;

c) addition to the mixer of a mixture comprising slaked lime, gypsum, cement, silicates, resins in a total quantity equal to 3500 g, preferably a mixture comprising slaked lime and gypsum in a total quantity equal to 3500 gr in a reciprocal ratio of 50 % / - 20%;

d) adding in the mixer an adhesion and plasticity corrector, preferably egg white, in a quantity equal to 150 g;

e) addition to the mixer of linseed oil in a quantity equal to 3450 g;

f) addition to the mixer of water in a quantity equal to 2560 gr.

Preferably the airgel is silicon airgel. Several experiments with preparation of test samples were carried out with good results both with silicon airgel in granular form and in powder form.

As regards the silicon aerogel in granular form, good results have been obtained with silicon aerogel in granular form with an average size of the granules between 0.1 and 1.2 mm, the best results being obtained with silicon in granular form with an average size of the granules between 0.1 and 0.7 mm.

As far as the silicon airgel in powder form is concerned, good results have been obtained with silicon airgels in powder form with an average particle size between 2 and 40 microns, the best results being obtained with silicon in powder form with size particle average between 2 and 24 microns.

In general, therefore, it is possible to use silicon airgels with an average particle size between 2 microns and 1.2 mm.

As for cellulose fiber, it is a natural product and is not dangerous for health. In addition to this it is a material that has no negative effects of environmental impact. Preferably, cellulose fiber will be used in the form of powder or flakes, even more preferably derived from paper recycling processes. Cellulose fiber with a content of at least 40% of fibers longer than 32 microns and content of less than 2% of fibers longer than 2500 microns, or cellulose fiber with a content of at least 50% of fibers will be used of length greater than 32 microns and content of less than 10% of fibers longer than 800 microns, or of cellulose fiber with a content of at least 60% of fibers of length greater than 32 microns and content of less than 10% of fibers of length greater than 200 microns, or a combination thereof.

The cellulose fiber or glass fiber, and in general the fiber of synthetic or natural origin, in the present invention perform the function of incorporating the airgel in the dry phase of the process, while in the wet phase of the preparation process it acts as a thickener and helps to keep the mixture obtained homogeneous. Furthermore, in the ready-to-use paste product, the fiber helps to retain the moist part of the dough, improving its plasticity and workability, facilitating its application. Furthermore, in the final product in the form of a panel in which the intermediate material between the cardboard sheets is dry, the cellulose fiber contributes to the increase of the insulating characteristics of the panel.

Cellulose fiber has the drawback that it can retain moisture, resulting in a decrease in insulating power. The subsequent phase of adding linseed oil prevents the onset of such phenomena as linseed oil is absorbed by the cellulose, waterproofing it. In this way, once the applied product has dried, the cellulose fiber acts only as an element that incorporates the airgel, while the absorption of moisture is prevented thanks to the presence of linseed oil. Other types of synthetic or even natural fibers could be used. However, only with cellulose fiber and glass fiber it is possible to neutralize the mixture in case of drying of the product by mixing and regenerating it without incurring processing waste and consequent rejection. Advantageously, in fact, in the event of the presence of processing waste, they can be directly added during the preparation phases of a new product, avoiding the need to deliver the waste to landfill and / or avoiding the need for particular treatments, with significant benefits both from an economic and environmental point of view.

Egg white is also a natural product and combined with slaked lime improves adhesion and plasticity. In general, the use of binders of natural origin is envisaged, generically defined as adhesion and plasticity correctors, which preferably will consist mainly of albumen. These binders of natural origin and in particular the albumen, have advantages both in the preparation phase, both in the laying phase and from the point of view of the duration of the material over time; in fact, these binders act as regulators of the humidity of the composition, releasing humidity if the humidity of the composition is insufficient or absorbing humidity if the humidity of the composition is in excess. In this way, the right consistency is provided for the application of the intermediate material on the cardboard sheets in order to obtain the panel.

The lime putty and gypsum are used as binders and to give consistency and mass to the intermediate product once it has been applied between the two cardboard sheets.

Preferably, putty is seasoned putty with a dry percentage ranging from 40% to 60%. Various types of putty can be used, including, without limitation for the purposes of the present invention, magnesian and calcium putty. The presence in various percentages of other components within the slab itself, such as alumina (Al203), iron oxide (Fe203), silicon dioxide (Si02), do not change the essential characteristics of the final product. In the ideal composition of the intermediate material to be applied between the cardboard sheets, a combination of putty and plaster is used. The applicants carried out tests with panels made in the absence of gypsum, with the use, therefore, only of slaked lime. These tests have shown that, while obtaining excellent results from the point of view of thermal insulation, the preparation with slaked lime only takes a long time to harden. This would have consequences on the technical time needed to produce the panels, with production cost problems. However, given the good results achieved, it is expected that also insulating panels can be made comprising an intermediate material with a composition in which the mixture of putty and gypsum assumes a variable ratio between the two components between the conditions of slaked lime only, combination with high content of slaked lime and low content of gypsum, combination with equal content of slaked lime and gypsum, combination with low content of slaked lime and high content of gypsum, only gypsum. As an alternative to the mixture comprising slaked lime and gypsum, it could also be used a mixture comprising slaked lime, gypsum, cement, silicates, resins in the same quantities and according to variable proportions until the quantities indicated in the tables are obtained.

For example, 50% mixtures of putty lime and gypsum could be used with a percentage variation of each component of / - 20% while maintaining the total quantity of this mixture of putty lime and gypsum unchanged. For example, mixtures of 50% of putty lime and cement could be used with a percentage variation of each component of / - 20% while maintaining the total quantity of this mixture of putty lime and gypsum unchanged. For example, 50% mixtures of cement and gypsum could be used with a percentage variation of each component of / - 20% while maintaining the total quantity of this mixture of lime putty and gypsum unchanged. For example, mixtures of 50% of putty lime and silicates could be used with a percentage variation of each component of / - 20% while maintaining the total quantity of this mixture of putty lime and gypsum unchanged. For example, 50% mixtures of putty lime and resins could be used with a percentage variation of each component of / - 20% while maintaining the total quantity of this mixture of putty lime and gypsum unchanged. However, the mixture comprising slaked lime and gypsum is preferable as it favors the recycling in the same production process of any processing waste that can be advantageously added to a subsequent product mixture to be recovered without sending them to the landfill, with considerable benefits from the point of view of costs as the costs of disposal of waste produced during the process are almost completely eliminated.

As for linseed oil, as previously noted, it helps prevent moisture absorption. Also in this case, other types of oil with equivalent characteristics may be used, the preferential solution providing for the use of linseed oil. The combination of linseed oil with the mixture of lime putty and gypsum contributes to the maintenance of stable conditions of the mixture, even after drying following the application of the mixture between the cardboard sheets to make the panel. Linseed oil also helps the mixture of lime putty and gypsum to retain the airgel. For this reason, there are considerable differences in mixing, as to obtain a more insulating mixture, more linseed oil is added, which, once crystallized, has a better thermal conductivity than the mixture of slaked and gypsum. In fact, the lamda coefficient or thermal conductivity of the slaked assumes values of the order of 0.36 W / mK, while the lamda coefficient or thermal conductivity of linseed oil assumes values of the order of 0.20 W / mK. Linseed oil further neutralizes the cellulose and the mixture of putty and gypsum itself, making the product more waterproof, leaving the function of maintaining perspiration only to the airgel. The same product in the form of a panel can be used in walls with a lot of humidity, as it does not allow water to penetrate the panel but at the same time keeps transpiration towards the outside of the wall. In this case, that is, in the case of walls subject to high exposure to humidity, the use of mixtures of putty and gypsum with a greater amount of putty is preferably envisaged as the gypsum is more subject to retain moisture. Furthermore, in this case, as noted, it will also be possible to provide additional treatments of the cardboard sheets to improve the behavior towards exposure to humidity.

The obtainable thermal conductivity varies according to the percentage of airgel that can be bound, as well as according to the form of airgel that is used, that is, whether in the form of grains or powder. Thermal conductivity values obtainable with the present invention range from a minimum 0.0986-0.0917 W / mK to a maximum of 0.0813-0.0769 W / mK, even up to values of the order of 0.067 W / mK.

The applicants have verified that upon maturation of the product, which takes place approximately in a period of sixty days, thermal conductivity values of the order of 0.041 W / mK are obtained.

These obtainable values are to be considered good for competing with other insulating materials on the market, such as polystyrene usually used for the construction of external insulation coats of buildings, which has thermal conductivity values of the order of 0.045 W / mK.

The product in the form of panels can be applied, for example, in both dry and humid environments of a building, obtaining considerable benefits from the point of view of the thermal insulation function without however preventing the transpiration of the wall.

With regard to the preparation of the intermediate product to be applied between the cardboard sheets, the water addition phase takes place at the end of the manufacturing process to make the mixture more workable. The amount of water may vary according to the type of slaked and / or type of gypsum. For example, the optimal conditions are obtained when the percentage of dryness present in the slaked lime is between 45 and 50%. If the percentage is lower, less water is added, while if the percentage of dryness is higher, it is added until the mixture is optimized to compensate for the lower presence of water in the slaked lime. Further factors that can lead to a variation in the amount of water added with respect to the total composition can be given by the composition of the slaked and / or gypsum used.

In general, for the preparation of the intermediate product to be applied between the cardboard sheets, the individual components can be added according to the following quantities:

a) addition of synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in quantities ranging from 295 to 360 g; b) addition of airgel in quantities between 2 and 15 g;

c) addition to the mixer of a mixture comprising putty lime, gypsum, cement, silicates, resins in a total quantity between 3150 and 4200 g, preferably a mixture comprising putty lime and gypsum in a total quantity between 3150 and 4200 g in reciprocal ratio of 50% / - 20%; d) addition of an adhesion and plasticity corrector, preferably egg white, in quantities ranging from 145 to 160 g;

e) adding oil, preferably linseed oil, in quantities ranging from 345 to 6650 g;

f) addition of water in quantities between 2000 and 3500 gr.

As for linseed oil, it has a very wide variability due to the fact that linseed oil can be added in very variable quantities to give the final product different characteristics from the point of view of waterproofing properties. By adding lower quantities of linseed oil, of the order of 345 - 2000 g, a product with lower waterproofing properties is obtained, suitable for example for applications in dry environments or in any case on walls that are not subject to humidity. By adding intermediate quantities of linseed oil, of the order of 2000 - 4000 g, a product with medium waterproofing properties is obtained. By adding high quantities of linseed oil, of the order of 4000 - 6650 g, a product with high waterproofing properties is obtained, suitable for example for applications in very humid environments or even exposed to direct contact with water, or in any case suitable for walls characterized by high presence of humidity.

Below are some tables illustrating some particular combinations of the components according to percentage quantities to obtain the product in the form of a paste.

With regard to the preparation with dosage of the components by weight, in the case in which the basic product of the present invention is to be obtained, the applicants have defined the following recipe for obtaining optimal results.

Table 1

Alternatively, the reciprocal percentages of slaked lime and gypsum can vary with a greater prominence of slaked lime according to the following composition.

Table 2

Alternatively, the reciprocal percentages of lime putty and gypsum can vary with a greater prominence of gypsum according to the following composition.

Table 3

Obviously it is foreseen that it is also possible to use lime putty and gypsum compositions according to proportions intermediate to those indicated in tables 2 and 3.

Regarding the preparation with dosage of the components by weight, in the case in which a less viscous product is desired, the applicants have defined the following recipe for obtaining optimal results.

Table 4

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

With regard to the preparation with dosage of the components by weight, in the case in which a more viscous product is desired, the applicants have defined the following recipe for obtaining optimal results.

Table 5

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Furthermore, with regard to the preparation with dosage of the components by weight, in the case in which, as explained, it is desired to have a lower quantity of oil for applications in very dry environments, the applicants have defined the following recipe for obtaining optimal results.

Table 6

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Furthermore, with regard to the preparation with dosage of the components by weight, in the case in which, as explained, it is desired to have a higher quantity of oil for applications in very humid environments subject to the presence of conditions of contact with water, the applicants have defined the following recipe for best results.

Table 7

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Alternatively, the applicants also carried out dosing tests based on volume measurements of the components. It should be noted that there are considerable variations with respect to the quantities expressed in grams, since, for example for the airgel, it has a very low specific weight and, therefore, even a few grams of product correspond to a high volume percentage compared to the total. as the airgel has a significant gaseous component. It is therefore preferable to use volume measurements to prevent even a minimal error in the measured weight of the airgel from resulting in large volume errors. In the event that the dosage is based on volume measurements of the components, which facilitates the identification of the correct% of the various components, the applicants have found that the optimal formulation of the intermediate product to be applied between the cardboard sheets takes place, for 100 liters of product, according to the following operating phases to be carried out in a mixer:

a) addition of synthetic or natural cellulose fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in quantities equal to 100 of; b) addition of airgel in a quantity equal to 540 of;

c) addition to the mixer of a mixture comprising slaked lime, gypsum, cement, silicates, resins in a total quantity equal to 100 di, preferably a mixture comprising slaked lime, gypsum in a total quantity equal to 100 di in a reciprocal ratio of 50 % / - 20%;

d) addition of adhesion and plasticity corrector, preferably egg white, in a quantity equal to 15 of;

e) addition of oil, preferably linseed oil, in a quantity equal to 145 of;

f) addition of water in a quantity equal to 100 of.

In general, for the preparation of the product the single components can be added according to the following quantities:

a) addition of synthetic or natural cellulose fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in quantities ranging from 90 to 110 of;

b) addition of airgel in quantities ranging from 160 to 890 of;

c) addition of a mixture comprising slaked lime, gypsum, cement, silicates, resins in a total quantity comprised between 90 and 120 di, preferably a mixture comprising slaked lime, gypsum in a total quantity comprised between 90 and 120 di in reciprocal ratio 50% / - 20%;

d) addition of adhesion and plasticity corrector, preferably egg white, in quantities ranging from 10 to 20 of;

e) addition of oil, preferably linseed oil, in quantities ranging from 15 to 280 of; f) addition of water in quantities ranging from 80 to 135 of.

Also in this case the variability of the quantities of linseed oil is high to allow the achievement of more or less high waterproofing properties, as explained above. By adding lower quantities of linseed oil, of the order of 15 - 70 of, a product with lower waterproofing properties is obtained, suitable for example for applications in dry environments or in any case on walls that are not subject to the presence of humidity. By adding intermediate quantities of linseed oil, of the order of 70 - 150 of, a product with medium waterproofing properties is obtained. By adding high quantities of linseed oil, of the order of 150 - 280 of, a product with high waterproofing properties is obtained, suitable for example for applications in very humid environments or even exposed to direct contact with water, or in any case suitable for walls characterized by high presence of humidity.

With regard to the preparation with dosage of the components by volume, in the case in which the basic product of the present invention is to be obtained, the applicants have defined the following recipe for obtaining optimal results.

Table 8

Alternatively, the reciprocal percentages of slaked lime and gypsum can vary with a greater prominence of slaked lime according to the following composition.

Table 9

Alternatively, the reciprocal percentages of lime putty and gypsum can vary with a greater prominence of gypsum according to the following composition.

Table 10

Obviously it is foreseen that it is also possible to use lime putty and gypsum compositions according to proportions intermediate with respect to those indicated in tables 9 and 10.

Regarding the preparation with dosage of the components by volume, in the case in which a less viscous product is desired, the applicants have defined the following recipe for obtaining optimal results.

Table 11

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Regarding the preparation with dosage of the components by volume, in the case in which a more viscous product is desired, the applicants have defined the following recipe to obtain optimal results.

Table 12

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Furthermore, with regard to the preparation with dosage of the components by volume, in the case in which, as explained, it is desired to have a lower quantity of oil for applications in very dry environments, the applicants have defined the following recipe to obtain optimal results.

Table 13

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Furthermore, with regard to the preparation with dosage of the components by volume, in the case in which, as explained, it is desired to have a higher quantity of oil for applications in very humid environments subject to the presence of conditions of contact with water, the applicants have defined the following recipe for best results.

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Furthermore, with regard to the preparation with dosage of the components by volume, in the event that a lower quantity of airgel is desired, the applicants have defined the following recipe for obtaining optimal results.

Table 15

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

Furthermore, with regard to the preparation with dosage of the components by volume, in the case in which it is desired to have a higher quantity of airgel, the applicants have defined the following recipe for obtaining optimal results.

Table 16

Also in this case it is expected that greater quantities of slaked lime can be added up to 20% more, correspondingly reducing the quantities of gypsum, and vice versa, smaller quantities of slaked lime up to 20% less, correspondingly increasing the quantities of plaster.

In all the previous tables the gypsum can be replaced by cement, silicates, resins in the same quantities, possibly increasing or reducing their content by correspondingly varying the quantity of lime putty. Combinations including slaked lime, gypsum, cement, silicates, resins in the same overall quantities indicated for the set of lime putty and gypsum can also be envisaged.

Advantageously, the intermediate product to be applied between the gypsum sheets is in the form of a wet paste, ready for use. The ready-made product in the form of a wet paste can be easily used by any operator, it does not breathe dust, it has no unpleasant and noxious odors.

Advantageously, the intermediate product to be applied between the cardboard sheets has characteristics of good insulation, maintaining a high transpiring function. At the same time, the product also performs an antibacterial and anti-mold function. The product is further fireproof, dehumidifying. The product is not putrescible so it keeps over time without spoiling and losing its characteristics. Advantageously, the product is recyclable even when dry.

It should also be emphasized that the product is an almost completely natural product. The applicants found that thanks to the combination of cellulose fiber and linseed oil, the combination of putty and gypsum, or the other indicated materials, with the airgel is regulated and optimized as the cellulose fiber performs the function of incorporating the airgel while the absorption of humidity by the cellulose is prevented thanks to the presence of linseed oil. Normally the attempts conducted previously have not led to good results as the airgel is hygroscopic and only with the inventive combination it is possible to obtain stable results over time with the previously explained characteristics.

Advantageously, the mixing process for the preparation of the intermediate product to be applied between the cardboard sheets takes place at room temperature, so that the preparation of the product is also particularly simple and economical.

The panel according to the present invention is particularly suitable for use as an insulating panel for building and in particular as a replacement for plasterboard panels, improving the performance from the point of view of insulation compared to these.

However, the applicants have found that the panel according to the present invention can also be advantageously used as an insulating panel to be applied to boilers and machinery which require insulation from heat or cold or both.

It should be noted that the order shown in the steps of adding the product is fundamental to obtain the inventive product, but that eventually the steps of adding water and linseed oil could be reversed, or proceeding with subsequent additions of water and linseed oil in the previously defined quantities until the desired consistency is obtained. For example, greater quantities of water and / or linseed oil could be added than the other components to obtain a more liquid product or, conversely, lower quantities of water and / or linseed oil could be added compared to the other components to obtain a product. more viscous, depending on the application needs of the product, or depending on the need to add further components such as pigments or aggregates of various kinds such as marmorino.

In the case of application on the external wall of a building, the applicants also noted that the panels according to the present invention give the wall good reflection characteristics of solar and / or thermal energy. In this way, by applying the panels, for example, on the wall both from the inside and from the outside, it will be possible to obtain a reflection function of the solar energy in summer, helping to keep the house cool and, in winter, an energy function can be obtained. heating system contributing to energy saving, without however blocking transpiration as do many products of the prior art.

The applicants carried out numerous tests on different samples the results of which are reported below. In the tests carried out, the cardboard coatings to obtain the sheet were not applied, but it will be evident that for the purposes of the comparison between a plasterboard sheet and a sheet comprising the inventive intermediate product applied between the cardboard sheets, it will be sufficient to compare the characteristics of the product between the cardboard sheets.

Example 1 - Sample 1

A sample was prepared (Sample 1) to be considered as a reference sample prepared with gypsum only. The reference sample is used as a comparison sample to verify the characteristics of the inventive product.

Characteristics of the sample:

Composition: gypsum 100%

Sample size: discs with a diameter of 8 cm and a height of 3 cm

Application of sensor on the circular surface of the sample

Conducting the experiment: with reference to the sample prepared as described, the coefficients λ (lambda) which expresses the conductivity or thermal conductivity, P <C> P (ro cp) which expresses the volumetric heat capacity were measured. The results are shown in Table 21.

Example 2 - Sample 2

A sample was prepared (Sample 2) to verify the characteristics of the inventive product.

Characteristics of the sample:

Composition:

Table 17

Sample size: as per sample 1

Preparation method: mixing of the added components in the order indicated within a mixer; mixing at room temperature. Once the dough was made, it was poured into a mold with an internal diameter of 8 cm and a height of 3 cm, it was then left to dry and mature

Sensor application: same as sample 1

Conduct of the experiment: as for sample 1. The results are shown in Table 21.

Example 3 - Sample 3

A sample was prepared (Sample 3) to verify the characteristics of the inventive product.

Characteristics of the sample:

Composition:

Table 18

Sample size: as per sample 1

Preparation method: as for sample 2

- Sensor application: as for sample 1

Conduct of the experiment: as for sample 1. The results are shown in Table 21.

Example 4 - Sample 4

A sample was prepared (Sample 4) to verify the characteristics of the inventive product.

Characteristics of the sample:

Composition:

Table 19

Sample size: as per sample 1

Preparation method: as for sample 2

Sensor application: same as sample 1

- Conduct of the experiment: as for sample 1. The results are shown in Table 21.

Example 5 - Sample 5

A sample was prepared (Sample 5) to verify the characteristics of the inventive product.

Characteristics of the sample:

Composition:

Table 20

Sample size: as per sample 1

Preparation method: as for sample 2

Sensor application: same as sample 1

- Conduct of the experiment: as for sample 1. The results are shown in Table 21.

Results

The results of the tests carried out on the various samples previously defined and described are shown in the following Table 21 and, for the samples 1, 2, 3, 4, 5, the relative results have been reported in Figure 1.

As can be seen from the numerical values obtained, for all inventive samples considerable reductions in the coefficients of conductivity or thermal conductivity and kinematic viscosity were found. Samples 5, prepared with a combination of granulated airgel and powdered airgel with average grain size between 2 and 24 microns, showed the best characteristics as regards conductivity or thermal conductivity which is surprisingly considerably reduced.

Table 21

Example 6

A comparative measurement relative to the cold storage capacity was carried out between a reference sample (sample 1) prepared as for example 1, i.e. a sample, prepared with plaster only and having the dimensions of a disk with a diameter of 8 cm and a height 3 cm, and a sample (sample 5) prepared as for example 5, ie a sample prepared with a mixture of lime-airgel and having the dimensions of a disk with a diameter of 8 cm and a height of 2 mm.

The samples were placed in a freezer at a temperature of -29 ° C. The temperatures of the samples were measured periodically. It was found that in the first hours sample 1, composed only of gypsum, had a more constant drop in temperature, and then slowly decreased and recovered on the last day. The same value was then kept constant in the measurements of the following days.

Sample 5, consisting of the lime-airgel mixture, had very significant fluctuations at the beginning of the measurements on the same day, and then stabilized in good and balanced values in the measurements made daily in the following days. The changes are due to the fact that in the sample 5 lime and airgel are mixed and the compactness of the mixture was not homogeneous, creating preferential cooling zones, which, due to the fact that the mass of the sample remained in a constant temperature environment of -29 ° C, it finally stabilized when the conditions of thermal equilibrium were reached.

An inverse test was also carried out, i.e. restabilization at room temperature of the samples in which the samples were extracted from the freezer at -29 ° C after reaching thermal equilibrium and were exposed to an environment at a temperature of 16 ° C. .

Sample 1, starting from a temperature of 4.5 ° C, reached a temperature of 10.8 ° C after 7 minutes, a temperature of 12 ° C after 10 minutes and a temperature of 13 ° C after 12 minutes.

Sample 5, starting from a temperature of 2.1 ° C, reached a temperature of 12 ° C after 10 minutes.

It is believed that the temperature difference of the specimens was determined by the different thickness that for the sample 1 containing only gypsum was 3 cm, while for the sample 5 containing the lime-airgel mixture, it was 2 mm.

Very satisfactory results are obtained with the lime-airgel mixture.

Lime has a lot of thermal inertia and the airgel acts as an insulator, this coupling of the two materials allows you to isolate and keep the temperature of the masonry constant, without creating thermal changes to it.

Example 7

Further samples (7a, 7b, 7c) were prepared to verify the characteristics of the inventive product. The following measurement method was adopted. Thermal conductivity measurements were conducted using a LaserComp FOX314 heat flow meter. The FOX 314 thermo flow meter is capable of measuring the thermal conductivity of insulating materials in a range between 0.005 and 0.35 W / mK. Acceptable sample dimensions for the instrument are maximum dimensions 305x305 mm, minimum dimensions 150x150 mm, thickness between 1 mm and 102 mm. Measuring principle: the LaserComp Fox 314 thermo flowmeter allows you to conveniently enclose a sample of insulating material between the two plates at different temperatures, measuring their thickness. The temperature of each plate is controlled by a Peltier system with a resolution of 0.01 ° C. In this way, a heat flow is established between the two plates that crosses the sample. Once the equilibrium condition has been reached, it is therefore possible to measure the thermal conductivity λ of the sample at the temperature given by the average of the two plates. The heat flux and thermal conductivity are measured on both plates and the management software allows you to view the values. The overall thermal conductivity of the sample will be expressed as the average of the thermal conductivity values of the individual plates. Measurement method: the thermal conductivity of the samples was determined at an average temperature of 10 ° C with a temperature difference between the plates of 10 ° C for samples 7a, 7b and 12 ° C for sample 7c. To dispose of the heat produced by the Peltier cells, a TermoHaake F3C thermo cryostat was used at a temperature of 18.0 ° C.

Characteristics of sample 7a:

Composition:

Table 22

Sample size: 300mm x 300mm panel, 2.4mm thick

Preparation method: as for sample 2a.

Characteristics of sample 7b:

Composition: as for sample 7a

Sample size: 300mm x 300mm panel, 4.8mm thick

Preparation method: as for sample 2.

Characteristics of sample 7c:

Composition: as for sample 7a

Sample size: 300mm x 300mm panel, 3.5mm thick

Preparation method: as for sample 2. Once the panel was dry, marmorino was applied on the two surfaces of 300 mm x 300 mm

Characteristics of sample 7d:

Composition: as for sample 7a

Sample size: 300mm x 300mm panel, 3.3mm thick

Preparation method: as for sample 2. When the sample was partially dried but still damp, a glass fiber fixing was carried out and, once dried, resin was applied to the external parts, obtaining a panel similar to that of a common resin glass panel.

The results of the tests were better than the previous ones and are shown in Table 23.

Table 23

As for the sample 7d, it should be noted that it gave the best results compared to all the other samples due to the fact that the glass fiber increases the thermo reflectance. The applicants subsequently made further tests by replacing the cellulose fiber with glass fiber in the same quantities indicated for the cellulose fiber, obtaining improved results with respect to the analogous samples containing cellulose fiber.

For example, the applicants prepared samples in which the preparation of the product took place, for 10 kg of product, according to the following operating steps to be carried out in a mixer, preferably at room temperature:

a) adding 330 g of glass fiber to the blender;

b) addition of airgel to the mixer in a quantity equal to 10 g;

c) addition to the mixer of a mixture comprising slaked lime, gypsum, cement, silicates, resins in a total quantity equal to 3500 g, preferably a mixture comprising slaked lime and gypsum in a total quantity equal to 3500 gr in a reciprocal ratio of 50 % / - 20%;

d) adding in the mixer an adhesion and plasticity corrector, preferably egg white, in a quantity equal to 150 g;

e) addition to the mixer of linseed oil in a quantity equal to 3450 g;

f) addition to the mixer of water in a quantity equal to 2560 gr.

In general, for the preparation of the product the quantities of glass fiber will be equal to the corresponding quantities of cellulose fiber.

Similarly, in the case where the dosage is based on volume measurements of the components, which facilitates the identification of the correct% of the various components, the applicants have found that the optimal formulation of the product occurs, per 100 liters of product, according to the following operational steps to be carried out in a mixer:

a) addition of glass fibers, in quantities equal to 100 of;

b) addition of airgel in a quantity equal to 540 of;

c) addition of a mixture comprising slaked lime, gypsum, cement, silicates, resins in a total quantity equal to 100 di, preferably a mixture comprising slaked lime, gypsum in a total quantity equal to 100 di in a reciprocal ratio of 50% / - 20%;

d) addition of adhesion and plasticity corrector, preferably egg white, in a quantity equal to 15 of;

e) addition of oil, preferably linseed oil, in a quantity equal to 145 of;

f) addition of water in a quantity equal to 100 of.

Further, both for the dosage by weight and for the dosage by volume, the applicants have also tried some preparations in which the cellulose fibers and the glass fibers have been mixed together according to variable ratios while maintaining the total quantity of the fibers present in the whole. product, obtaining improvement products from the point of view of thermal conductivity as the quantity of glass fiber increases compared to cellulose fiber. Advantageously, therefore, it is possible to provide compositions in which both glass fiber and cellulose fiber are present in an overall quantity equal to the quantity of synthetic or natural fibers indicated, with a variable ratio between the quantity of cellulose fiber and glass fiber, in which in the limit there may be only glass fiber, only cellulose fiber or a combination of the same in various proportions, thus giving preference to the greater insulating characteristics of glass fiber or to the natural characteristics of cellulose fiber.

Further, keeping the samples monitored, after a month, it was possible to see a significant improvement in the tests carried out previously, in the order of 10-20%. This is given by the carbonation of the lime, the calcite crystals forming automatically improves the reflectance, thus providing better insulation. We can see that this material will improve continuously over time, up to total carbonation. Therefore, the invention demonstrates that unlike other materials that degrade both in matter and in insulating power over time, the invention tends to improve its very initial characteristics.

The naturalness of the invention and the combination of the materials that compose it, allows the use of lime as a binder, with its transpiration, antibacterial and thermo-reflective characteristics, helping to create healthy environments.

In general, the present invention, therefore, refers to an insulating panel for building comprising a core and at least one reinforcing sheet in which the core is composed of a mixture comprising the following components:

A) synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof;

B) airgel;

C) mixture comprising slaked lime and / or gypsum and / or cement and / or silicates; D) adhesion and plasticity corrector, preferably albumen;

E) oil, preferably linseed oil;

F) water.

The reinforcement sheet can be a cardboard sheet, possibly applied on one or both sides of the panel, or a reinforcement made of fiberglass and resin applied on one or both sides of the panel. Optionally at least one surface of the building insulation panel is treated by applying glass fiber and resin.

Preferably the glass fiber is an alkali-resistant glass fiber. Types of glass fibers suitable for the present application are glass fibers, for example with specific weight of about 1.9 kg / dm <3>. However, variations are possible based on the strength characteristics that you want to provide, for example if you also want to provide characteristics of greater or lesser impact resistance. Similarly, on the basis of the same evaluations, the average length of the usable glass fibers may also vary.

The description of the present invention has been made with reference to preferred embodiments thereof, but it is evident that many possible alterations, modifications and variations will be immediately clear to those skilled in the art in the light of the preceding description. Thus, it should be emphasized that the invention is not limited by the foregoing description, but includes all those alterations, modifications and variations in accordance with the appended claims.

Claims (14)

CLAIMS 1. Insulating panel for building comprising a core and at least one reinforcement sheet characterized by the fact that said core is composed of a mixture comprising the following components: A) synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof; B) airgel; C) mixture comprising slaked lime and / or gypsum and / or cement and / or silicates; D) adhesion and plasticity corrector, preferably albumen; E) oil, preferably linseed oil; F) water. 2. Insulating panel for building according to the preceding claim characterized in that said core is composed of a mixture comprising the following components: A) synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in quantities ranging from 295 to 360 g; B) airgel in quantities ranging from 2 to 15 g; C) mixture comprising slaked lime and / or gypsum and / or cement and / or silicates in quantities between 3150 and 4200 g; D) adhesion and plasticity corrector, preferably egg white, in quantities ranging from 145 to 160 g; E) oil, preferably linseed oil, in quantities ranging from 345 to 6650 g; F) water in quantities between 2000 and 3500 gr. 3. Insulating panel for building according to the preceding claim characterized in that said core, for 10 kg of product constituting said core, comprises said components in the following quantities: A) synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in a quantity equal to 330 g; B) airgel in a quantity equal to 10 g; C) mixture comprising slaked lime and / or gypsum and / or cement and / or silicates in quantities equal to 3500 g; D) adhesion and plasticity corrector, preferably egg white, in a quantity equal to 150 g; E) oil, preferably linseed oil, in a quantity equal to 3450 g; F) water in a quantity equal to 2560 gr. 4. Insulating panel for building according to claim 1 characterized in that said core is composed of a mixture comprising the following components: A) synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in quantities ranging from 90 to 110 of; B) airgels in quantities ranging from 160 to 890 of; C) mixture comprising slaked lime and / or gypsum and / or cement and / or silicates in quantities ranging from 90 to 120 of; D) adhesion and plasticity corrector, preferably albumen, in quantities ranging from 10 to 20 of; E) oil, preferably linseed oil, in quantities ranging from 15 to 280 of; F) water in quantities between 80 and 135 of. 5. Insulating panel for building according to the preceding claim characterized in that said core, for 100 liters of product constituting said core, comprises said components in the following quantities: A) synthetic or natural fibers, preferably cellulose fiber, glass fiber and / or combinations thereof, in quantities equal to 100 of; B) airgel in a quantity equal to 540 of; C) mixture comprising slaked lime and / or gypsum and / or cement and / or silicates in a quantity equal to 100 of; D) adhesion and plasticity corrector, preferably albumen, in a quantity equal to 15 of; E) oil, preferably linseed oil, in a quantity equal to 145 of; F) water in a quantity equal to 100 of. 6. Insulating panel for building according to any one of the preceding claims characterized in that said airgel is silicon airgel. 7. Insulating panel for building according to the preceding claim characterized in that at least a part of said silicon airgel is silicon airgel in granular form with an average size of the granules between 0.1 and 1.2 mm, preferably with an average size of the granules between 0.1 and 0.7 mm. 8. Insulating panel for building according to any one of the preceding claims 6 to 7 characterized in that at least a part of said silicon airgel is silicon airgel in powder form with an average particle size between 2 and 40 microns, preferably with average particle size between 2 and 24 microns. 9. Insulating panel for building according to any one of the preceding claims characterized in that said cellulose fiber is selected from the group consisting of cellulose fiber with a content of at least 40% of fibers having a length greater than 32 microns and a content of less than 2% of fibers longer than 2500 microns, cellulose fiber with a content of at least 50% of fibers longer than 32 microns and content of less than 10% of fibers longer than 800 microns, cellulose fiber with a content of at least 60% of fibers longer than 32 microns and less than 10% of fibers longer than 200 microns, or a combination thereof. 10. Insulating panel for building according to any one of the preceding claims, characterized in that said glass fiber is an alkali-resistant glass fiber. 11. Insulating panel for building according to any one of the preceding claims characterized in that said mixture comprising slaked lime and / or gypsum and / or cement and / or silicates consists of a mixture of lime and gypsum in a reciprocal ratio of 50% +/- 20%. 12. Insulating panel for building according to any one of the preceding claims characterized in that at least one of said reinforcing sheets is made of cardboard. 13. Insulating panel for building according to any one of the preceding claims characterized in that at least one of said reinforcing sheets is made of glass fiber and resin. 14. Insulating panel for building according to any one of the preceding claims characterized in that at least one surface of said panel is treated by applying glass fiber and resin.