ITUB20154161A1 - MIXTURE, IN PARTICULAR SHAVING MIXTURE, FOR CONSTRUCTION COVERINGS - Google Patents

Description

MIXTURE, IN PARTICULAR SKIN MIXTURE, FOR BUILDING COVERINGS.

DESCRIPTION

Technical field of the invention

The invention concerns a mixture for building coatings. In particular, it is a thermal smoothing compound based on binders and insulating aggregates. A composition of additives for this mixture and a related thermal building coating are also disclosed.

State of the art

Thermal insulation is a fundamental aspect in the construction sector. Great importance is given to improving the thermal insulation of already existing buildings that are not sufficiently insulated. The improvements are aimed at reducing energy consumption used in winter heating and summer cooling, at reducing humidity inside the building, at reducing structural thermal bridges, at attenuating the crack effect (cracking) on external plasters. attributable to the discontinuity of the constructive elements and to the increasingly strong thermal excursions.

The market offers a wide range of products for building coatings which include acrylic, vinyl or acryl-siloxane resins, aluminum powders, titanium dioxide, inert hollow fillers, additives and water or even lime putty paste. These products are not always satisfactory from the point of view of thermal insulation in combination with required qualities such as flexibility, breathability, fire resistance, lightness, mass colorability, adaptability to thickness requirements, mechanical strength, ease of application.

Presentation of the invention

The purpose of the invention is to propose a mixture, in particular a smoothing mixture, for building coatings which, in addition to having good qualities in terms of flexibility, breathability, fire resistance, lightness, mass colorability, adaptability to thickness requirements, resistance mechanical, ease of application has high performance in terms of thermal insulation.

The objects mentioned above, other objects and advantages that will be better highlighted hereinafter are achieved by a mixture as defined by the first claim, and more precisely by a mixture, in particular a smoothing mixture, for building coatings comprising: (a) from 20 to 40 % by weight of a binder;

(b) from 30 to 50% by weight of an insulating aggregate;

(c) 0.5 to 5% by weight of a synthetic resin;

(d) 0.5 to 2.5% by weight of cellulose;

(e) 2 to 10% by weight of a pozzolan aggregate;

(f) 10 to 26% by weight of an inert aggregate; And

(g) 0.1 to 1.5% by weight of workability additives,

in which the percentages by weight refer to the total weight of the mixture. In a preferred variant of the invention, the mixture is a solid dry mixture, in particular a powder. Also conceivable are mixtures in the form of pasta or the like. Preferably, the solid mixture does not comprise further ingredients, but only the ingredients from (a) to (ø). Advantageously, the mixture is an anti-condensation thermal skim coat. The mixture according to the invention is distinguished by excellent thermal insulation when applied as a building coating. This high thermal insulation was obtained thanks to the presence of a particular configuration of additional elements, components (c) to (g), in the basic composition of binders and insulating aggregates (components (a) and (b)). The particular configuration of the components from (c) to (g), as also described in claim 10, has allowed to increase the content of insulating aggregate to percentages from 30 to 50% by weight, in particular to percentages around 40% by weight. . Known smoothing mixtures or plasters do not have such high percentages of insulating aggregates.

Preferably, the mixture according to the invention comprises the aforementioned ingredients in the following concentrations:

(a) 30 to 35% by weight of a binder;

(b) 38 to 42% by weight, preferably about 40% by weight of an insulating aggregate;

(c) from 1.5 to 2.5% by weight, preferably approx. 2% by weight of a synthetic resin;

(d) from 1.0 to 1.6% by weight, preferably approx. Γ 1.3% by weight of cellulose;

(e) from 4 to 6% by weight of a pozzolanic aggregate;

(f) from 15 to 20% by weight, preferably about 17% by weight of an inert aggregate; And

(g) 0.3 to 0.7% by weight, preferably about 0.5% by weight of workability additives,

in which the percentages by weight refer to the total weight of the mixture. In an advantageous variant of the invention, the binder is selected from the group consisting of hydraulic lime, cement, and calcium silico aluminates, and mixtures of these.

Advantageously, the insulating aggregate is an inert expanded hollow material, preferably chosen from the group consisting of expanded glass microspheres, expanded perlite, ceramic microspheres, and mixtures of these.

Preferably, the synthetic resin is a dispersible vinyl resin. Suitable for example are also vinyl versatic copolymers. Such a resin improves the adhesion of the mixture.

Advantageously, the cellulose is present in the form of a powder. The cellulose has the function of workability of the mixture.

In a preferred variant of the invention, the pozzolanic aggregate is chosen from the group consisting of cocciopesto, kaolin and mixtures of these.

The inert aggregate, preferably, is chosen from the group consisting of carbonates, siliceous materials and mixtures of these.

The workability additives are preferably chosen from fluidifying, hydrophobic, microfibers and mixtures of these, in particular they are a mixture of a fluidifier, a hydrophobic agent and microfibers.

With the aforementioned specific ingredients and in the preferred concentration ranges, the blend exhibits the best performance in terms of thermal insulation.

The specific types of ingredients can be chosen independently from each other or combined with each other, as is apparent from the dependent claims.

The mixture according to the invention can be applied on any support. For this purpose a mixture is produced by adding water or another solvent. A further aspect of the invention concerns a mixture comprising the mixture according to the invention and one or more solvents; preferably the solvent is water. The amount of solvent is dictated by the consistency of the mixture to be obtained to apply the mixture, for example with a spatula, brush or spray. The mixture can be applied in varying thicknesses. Preferred thicknesses are ≥ 2 mm, preferably ≥ 3 mm. Thicknesses up to 5 mm, 10 mm or even higher are conceivable. The overlapping of several layers is conceivable, which is preferable for total thicknesses greater than 5 mm. The mixture can be applied, for example, by spatula, brush or even by spray.

Another aspect of the invention relates to a building coating which includes the mixture according to the invention. Once dried, such a coating does not melt, does not absorb moisture, is not attackable by parasites, and is fireproof. The thicknesses of the coating according to the invention correspond to those mentioned above for the layers of mixture applied.

A further aspect of the invention concerns a composition of additives for mixtures, in particular for smoothing mixtures, for building coatings which consists of:

(i) 5 to 50 parts by weight of a synthetic resin;

(ii) 5 to 25% parts by weight of cellulose;

(ii) from 20 to 100 parts by weight of a pozzolanic aggregate;

(iv) from 100 to 260 parts by weight of an inert aggregate; And

(v) from 1 to 15 parts by weight of workability additives.

Such a composition allows, if added to a basic mixture for building coatings including binders and insulating aggregates, to reach high concentrations of insulating aggregates in mixtures for building coatings and consequently in the mixture to be applied and in the final coating. The concentration of the insulating aggregate (preferably ≥ 30% by weight) in the coating, after the evaporation of solvents present in the applied mixture, essentially corresponds to the concentration of the insulating aggregate in the mixture according to the invention.

A final aspect of the invention therefore also refers to the use of the aforementioned composition of additives in mixtures for building coatings to increase the concentration of the insulating aggregate in the coating, in particular to obtain concentrations> 30% by weight.

The mixture according to the invention is preferably obtained by mixing all the ingredients indicated in the first claim in the respective quality and quantity chosen. A particular order of mixing is not necessary.

All the characteristics indicated above for the mixture according to the invention are, mutatis mutandis, transferable to the mixture, the composition of additives and the coating according to the invention.

The aforementioned purposes and advantages will be better highlighted during the description of preferred embodiments of the invention given as an indication, but not limitative.

Variants of the invention are the subject of dependent claims. The description of preferred examples of execution of the mixture, of the composition of additives and its use, of the mixture and of the coating according to the invention is given by way of non-limiting example.

Description of preferred execution examples

The following table 1 summarizes preferred compositions of the mixture according to the invention (the percentages by weight refer to the total weight of the mixture):

Table 1

component examples% by weight% by percentage minimum weight by maximum weight preferred (product H-55 PV RasoTherm by HERES SRL) binder silica aluminates of 20 40 30 - 35 calcium (hydraulic lime

or concrete)

aggregate inert expanded cables 30 50 40 thermally insulating

(glass microspheres

expanded, perlite

expanded, microspheres

ceramic)

dispersible vinyl resin 0.5 5 2

synthetic

cellulose in 0.5 2.5 1.3

dust

cocciopesto and kaolin aggregates 2 10 4 - 6

pozzolanics

carbonate or siliceous aggregates 10 26 17

inert

fluidifying additives, 0.1 1.5 0.5

hydrophobic workability,

microfiber

An executive example within the aforementioned mixture is a fiber-reinforced hydraulic smoothing compound, based on NHL lime (Naturai jHydraulic Lime - natural hydraulic lime), hydrated lime, cocciopesto, coated expanded perlite (preferably coated with a silicone-based coating), glass cellular, light aggregates and resins.

The product is biocompatible and aimed at energy saving in buildings, reducing condensation and consequent molds, improving insulation and thermal bridges on traditional plasters, pillars, old discontinuous walls, door and window shoulders, cell blocks, panels for thermal insulation.

The insulating power of the coated expanded perlite and the cellular glass microspheres, combined with that of the cocciopesto generate a large presence of air cells as a source of insulation while maintaining breathability and mass. The more air it is enclosed in small spaces, the more its insulating power increases. The applied mixture does not absorb heat, lowering the thermal conductance value. The minimum thickness is advantageously 3 mm / m <2>; greater thicknesses improve the insulating properties.

To eliminate thermal bridges deriving from pillars and beams, it is advisable to apply the product on all four sides, with a thickness of 5 - 6 mm, as well as to eliminate condensation problems.

Table 2 shows the technical data of a water-based mixture obtained with a mixture with the preferred concentrations indicated above:

Table 2

mixing water about 24% in particle size approx. 1 mm weight of base mix particle size approx. 0.3 mm fine mixture

conductivity λ = 0.05 W / mK thickness 5 mm maximum thermal for

layer

powder mass approx. 550 kg / m <3> strength at approx. 0.5 N / mm <2> compression a

28 days

yield approx. 0.6 kg / m <2> x 1 resistance to μ <8

mm of steam thickness

lime-based binder NHL 3.5 compliance UNI EN 998-1

In an executive example, the application is performed on well-aggregated supports; any flaky or flaking parts are eliminated. In the presence of absorbent substrates, it is advisable to wet the surfaces before applying the product. The mixture is mixed with about 5-6 liters of clean water per 15 kg bag. For a homogeneous and lump-free mixture it is advisable to mix mechanically (with a mixer), adding 2/3 of the water at the beginning and the remaining after a few minutes of mixing until the desired fluidity is reached. Small quantities can however be mixed manually. When applying the smoothing compound, the insertion of a glass fiber reinforcement mesh is recommended.

The first layer is applied with a toothed steel American trowel, toothed according to the thickness, the reinforcing mesh is fixed, as soon as possible proceed with a new straight blade application to plan the surface and if the application of paint, float the applied with a sponge or plastic tool before it is completely dry.

Preferably, the thickness of 5 mm per single layer is not exceeded. High thicknesses are achieved by applying multiple layers, even with the aid of guides. Before proceeding with the realization of the finishing coating, wait for the complete drying of the smoothing compound, even in depth (for example: at least 36 hours at 20 ° C for thicknesses of 5 mm). The times may lengthen depending on the climatic conditions and thicknesses of the product applied. In the case of crumbly substrates, the prior application of a consolidating agent (natural in lime water or a water fixative) is recommended.

The product is stored in a dry environment and protected from frost, rain and humidity. It is advisable to operate at temperatures between 5 ° C and 32 ° C and to protect the covering from frost, rain, wind and sun until it is completely dry. Rapid drying should also be avoided if possible to avoid cracking and detachment. The mixture according to the invention is preferably not mixed with other cements, additives, or other substances in general.

Initial Type Tests (ITT) and tests were performed to determine the winter and summer thermal performance on your Ή-55 PV RasoTherm ”product (last column, table 1).

As initial ITT tests, according to the provisions of Appendix ZA of the UNI EN 998-1: 2010 standard, the following tests were carried out: water absorption (C) (UNI EN 1015-18: 2004); permeability to water vapor (μ) (UNI EN 1015-19: 2008); and thermal conductivity (μ) (UNI EN 12667: 2002).

For the determination of thermal properties, the following tests were carried out on a 30 cm masonry before and after the application of the product "H-55 PV RasoTherm" (UNI EN 1934: 2000 - Thermal performance of buildings. Determination of thermal resistance by means of the hot chamber method with thermo flow meter. Masonry).

The results obtained from the measurements were the following:

ITT-TYPE INITIAL TESTS

Water absorption: C = 0.1 (kg / m <2> min ° '<5>) (class W2) Permeability to water vapor: μ = 9

Thermal conductivity: λ = 0.12 W / mK

WINTER THERMAL PROPERTIES

Table 3

Size Masonry as it is With thermal smoothing (30 cm masonry) H-55 PV RasoTherm Thermal resistance R = 1.33 m <2> K / W R = 1.78 m <2> K / W from surface to

surface R (m <2> K / W)

Thermal conductance Λ = 0.75 W / m <2> K A = 0.57 W / m <2> K from surface to

surface

Λ (W / m <2> K)

Thermal resistance RT = 1.51 m * K / W RT = 1.95 m * K / W total RT (m <2> K / W)

Transmittance from U = 0.66 W / m <2> K U = 0.51 W / m <2> K environment to

environment U (W / m <2> K)

Thermal conductivity λ = 0.012 W / mK λ of the H-55 PV RasoTherm product only <*>

<*> Calculated from the overall thermal resistance of the wall for a smoothing thickness of 5 mm

SUMMER THERMAL PROPERTIES

Table 4

Wall size as it is With thermal smoothing H-55 PV RasoTherm Thermal transmittance 0,204 W / m <2> K 0,100 W / m <2> K periodic Yie

(W / m <2> K)

Factor of 0.309 0.196

attenuation does

Phase shift Wa (h) 11 h 13.5 h

The results clearly demonstrate the great thermal insulation power of the H-55 PV RasoTherm product, a representative of the mixtures according to the invention.

In the executive phase, further modifications or executive variants not described may be made to the mixture, the composition of additives and its use, to the mixture and coating subject of the invention. Should such modifications or variations fall within the scope of the following claims, they must all be considered protected by this patent.

Claims (10)

CLAIMS 1) Mixture, in particular a smoothing mixture, for building coatings comprising: (a) 20 to 40% by weight of a binder; (b) from 30 to 50% by weight of an insulating aggregate; (c) 0.5 to 5% by weight of a synthetic resin; (d) 0.5 to 2.5% by weight of cellulose; (e) 2 to 10% by weight of a pozzolan aggregate; (f) 10 to 26% by weight of an inert aggregate; And (g) 0.1 to 1.5% by weight of workability additives, in which the percentages by weight refer to the total weight of the mixture. 2) Mixture according to claim 1, characterized in that it comprises: (a) 30 to 35% by weight of a binder; (b) 38 to 42% by weight, preferably about 40% by weight of an insulating aggregate; (c) from 1.5 to 2.5% by weight, preferably approx. 2% by weight of a synthetic resin; (d) from 1.0 to 1.6% by weight, preferably approx. 1.3% by weight of cellulose; (e) from 4 to 6% by weight of a pozzolanic aggregate; (f) from 15 to 20% by weight, preferably about 17% by weight of an inert aggregate; And (g) 0.3 to 0.7% by weight, preferably about 0.5% by weight of workability additives, in which the percentages by weight refer to the total weight of the mixture. 3) Mixture according to one of claims 1) or 2, characterized in that said binder is selected from the group consisting of hydraulic lime, cement, and calcium silico aluminates, and mixtures of these. 4) Mixture according to any one of the preceding claims, characterized in that said insulating aggregate is an inert expanded hollow material, preferably selected from the group consisting of expanded glass microspheres, expanded perlite, ceramic microspheres, and mixtures thereof. 5) Mixture according to any one of the preceding claims, characterized in that said synthetic resin is a dispersible vinyl resin. 6) Mixture according to any one of the preceding claims, characterized in that said pozzolanic aggregate is selected from the group consisting of cocciopesto, kaolin and mixtures thereof. 7) Mixture according to any one of the preceding claims, characterized in that said inert aggregate is selected from the group consisting of carbonates, siliceous materials and mixtures thereof. 8) Blend according to any one of the preceding claims, characterized by the fact that said workability additives are chosen from among fluidifying, hydrophobic agents, microfibers and mixtures thereof. 9) Building coating comprising the mixture according to any one of the preceding claims. 10) Composition of additives for mixtures, in particular for smoothing mixtures, for building coatings consisting of: (i) 5 to 50 parts by weight of a synthetic resin; (ii) 5 to 25% parts by weight of cellulose; (iii) from 20 to 100 parts by weight of a pozzolanic aggregate; (iv) from 100 to 260 parts by weight of an inert aggregate; And (v) from 1 to 15 parts by weight of workability additives.