BE1029901B1 - Expanded polystyrene with a latex for flooring applications - Google Patents

Abstract

The present invention relates to a kit suitable for the composite formation of a recyclable insulating floor layer, the kit comprising: a plurality of expanded polystyrene (EPS) granules with a density of 10-35 kg/m3 and a moisture absorption by immersion of up to 5%; and a binder, wherein the binder comprises a polymer-in-water emulsion. The invention further relates to a kit comprising recyclate, the kit suitable for forming a composite, recyclable insulating floor layer, the kit comprising: a plurality of recycled flakes comprising cut expanded polystyrene (EPS) granules bound by means of a first binder; and a second binder, wherein the binder comprises a polymer-in-water emulsion.

Description

1 BE2021/5864

EXPANDED POLYSTYRENE WITH A LATEX FOR

FLOOR APPLICATIONS

TECHNICAL DOMAIN

The invention relates to insulating and lightweight floor elements. More specifically, the invention relates to a kit suitable for easily applying thermal floor insulation, a method for applying lightweight floor insulation and said lightweight floor insulation.

STATE OF THE ART

Cellular concrete, or aerated concrete, is a type of concrete characterized by its low density and strong insulating properties. Adding a gas-forming aggregate creates a porous and insulating material. The air bubbles formed are not connected to each other. After the mass is removed from the mold, it is cut into the desired product type: blocks, lintels, reinforced slabs, etc.

Expanded polystyrene (EPS) has been used for a wide variety of purposes for over 50 years. It was originally intended as insulation and remains its primary application in this field, in addition to packaging. EPS products are manufactured in the form of blocks, sheets, or molded parts. The blocks can be cut into sheets and many other custom-made shapes. EPS building products are supplied preformed, such as EPS cavity wall panels and composite high-quality products such as sandwich panels or laminated roof insulation.

US Patent No. 5,916,681 teaches the use of EPS as loose-fill insulation, in a sandwich panel, as a preformed sheet, and in combination with cement. US Patent No. 4,1234,242 describes loose-fill insulation consisting of fibers and a granular material.

Concrete is heavy and has poor thermal insulation, which is disadvantageous when insulating multiple floors. Furthermore, EPS is usually supplied either loose or pre-formed.

Compared to other insulation layers, the aim is to improve the insulation layers for floors, particularly in terms of:

2 BE2021/5864 - Recyclability: a major problem with current insulation materials is their limited potential for recycling or reuse; - Improved thermal insulation; - Improved compressive strength; - Reduced ecological impact; and - Simple installation method for such floor layers.

SUMMARY OF THE INVENTION

The invention relates to a kit suitable for compositely forming an insulating floor layer according to claim 1. The inventors have surprisingly discovered that a moisture absorption by immersion of the EPS granules of a maximum of 5% is essential for producing a thermally well-insulating floor layer.

On the one hand, low moisture absorption is necessary to allow recycling of a used floor layer into cut flakes that can be reused for a similar floor layer, especially if washing the flakes is desired.

Furthermore, preventing moisture absorption by the EPS granules contributes to better thermal insulation. Thermal insulation can be continuously improved by applying a thicker insulation layer. However, thicker insulation layers dry and harden more slowly. For example, water from a polymer-in-water binding emulsion can remain in the insulation layer. This absorbed water significantly reduces thermal insulation, which can partially negate the benefit of a thicker insulation layer. Furthermore, water can also enter the insulation layer through other means, such as rising groundwater due to a defective water barrier.

A preferred kit is described in claim 2. Such kits provide increased thermal insulation and compressive strength compared to kits with a lower weight percentage of EPS granules.

In a second aspect, the invention relates to a method for applying an insulating floor layer on a substrate, comprising (a) mixing a plurality of expanded polystyrene granules with a binder resulting in a substantially liquid insulation material according to a kit according to the first

3 BE2021/5864 aspect, (b) distributing the liquid insulation material on the substrate, and (c) hardening the liquid insulation material into an insulating floor layer.

This is advantageous over building boards and other preformed building elements, as the sealant can be used in any shape and any dimensions. The substrate doesn't need to be flat, as the sealant is dimensionless. This also makes the sealant easy to transport and store in various forms, regardless of the shape of the insulated floor layer.

This method is advantageous over conventional insulation foams because it is simpler and cleaner. A limited reaction releases fewer harmful gases, reduces heat generation due to exothermic reactions, and keeps the volume of the insulation material more or less constant. Furthermore, the steps in the second aspect can be performed in the simplest order. This allows large quantities of granules and binder to be easily mixed in industrial concrete mixing plants. Small amounts of binder can be easily applied to the EPS on the substrate, preventing contamination of other materials. Finally, it is possible to simultaneously apply binder to the EPS granules and apply the resulting slurry to the substrate.

This can be done, for example, using a blower or screw suitable for EPS granules, which are then coated with a binder at the end. Finally, this is beneficial for leveling a floor and providing appropriate insulation around pipes and other facilities in the floor of a building.

Another preferred kit is described in claim 3. Kits containing only

EPS granules and binder, particularly in this ratio, can be processed into a floor layer. This floor layer can later be cut into flakes; these flakes can then be reprocessed into an insulating floor layer in combination with a binder. In a third aspect, the invention relates to a kit consisting of recycled flakes, suitable for a recyclable floor layer according to claims 12-15. The exclusion of additional components prevents the unwanted accumulation or unnecessary processing of these additional components. The addition of cement-based products is particularly strongly discouraged, as these crumble significantly during the recycling process and thus significantly reduce the quality of the recyclate product.

In a fourth aspect, the invention relates to a method for recycling a floor layer.

In a further aspect, the invention relates to the insulation layer formed with a sealant according to the first aspect or by the method according to the second aspect,

This insulation layer offers better thermal insulation and a lower specific weight than aerated concrete and concrete with EPS granules. Furthermore, it has better compressive strength than polyurethane foams. Furthermore, unlike cement- and foam-based products, it is recyclable.

DETAILED DESCRIPTION

The invention relates to a sealant suitable for forming a lightweight, insulating floor layer. The invention also relates to a method for providing an insulating floor layer. Finally, the invention relates to a lightweight insulating floor layer.

Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meaning as commonly understood by one skilled in the art in the field of the invention. To facilitate understanding of the description of the invention, the following terms are explicitly defined. "A," "an," and "the" refer to both the singular and the plural in this document unless the context clearly indicates otherwise. For example, "a segment" means one or more than one segment.

The terms “comprise,” “comprising,” “consist of,” “comprising,” “comprising,” “comprising,” “containing,” “include,” “involving,” “containing,” “containing” are synonyms and are inclusive or open terms indicating the presence of what follows, and do not exclude or preclude the presence of other components, features, elements, members, steps known or described in the prior art. “Dispersion polymerization” is a type of precipitation polymerization, meaning that the solvent chosen is both the reaction medium and a good

BE2021/5864 is a solvent for the monomer and the initiator, but not a good solvent for the polymer. As the polymerization reaction progresses, polymer particles form, resulting in a non-homogeneous solution. In dispersion polymerization, these particles are the site of polymerization.

Quoting numerical intervals through the endpoints includes all integers, fractions, and/or real numbers between the endpoints, including these endpoints,

In a first aspect, the invention relates to a kit suitable for forming a recyclable insulating floor layer, the kit comprising:

A. a plurality of expanded polystyrene (EPS) granules with a density of 10-35 kg/m3 and a moisture absorption by immersion of a maximum of 5%; and

B. a binder, wherein the binder comprises a polymer-in-water emulsion,

A problem with water-based emulsions is that water can be absorbed by EPS granules. EPS granules that absorb water exhibit significantly lower thermal insulation. This is especially problematic with thicker insulation layers, from which water escapes less easily. The inventors have discovered that coating the multiple EPS granules allows for EPS granules with a water absorption of less than 5% upon immersion. As a result, the EPS granules with low water absorption exhibit improved insulation values in the final product. This improvement also increases as the insulation layer increases in thickness.

Preferably, the plurality of expanded polystyrene (EPS) granules are fully pre-expanded. In a preferred embodiment, the EPS granules have a diameter between 1 and 8 mm. Granules smaller than 1 mm resulted in excessive dust. Granules larger than 6 mm negatively affected the insulation performance of the final product. Preferably, the diameter of the EPS granules is between 2 and 6 mm, even more preferably between 3 and 6 mm, and most preferably between 4 and 6 mm. EPS granules with a diameter between 4 and 6 mm resulted in the highest insulation value for the final material.

In a preferred embodiment, the EPS granules are "gray." Gray EPS is known to those skilled in the art and consists of EPS granules containing graphite or carbon. These are produced by adding graphite or carbon during the molding process.

6 BE2021/5864 unexpanded EPS beads. Gray EPS granules have better insulating properties. These are transferred to the final insulation material.

In a further preferred embodiment, the mass fraction of the EPS granules in the kit is between 0.40 and 0.80, preferably between 0.61 and 0.75, even more preferably between 0.62 and 0.75, even more preferably between 0.63 and 0.75, even more preferably between 0.64 and 0.75, even more preferably between 0.65 to 0.75, even more preferably between 0.66 and 0.75, even more preferably between 0.67 and 0.74, even more preferably between 0.68 and 0.73.

In a preferred embodiment, the kit consists of the following components:

A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and

B, the binder in a ratio of 25-39 wt.% to the weight of the complete sealant.

The inventors have discovered that the higher weight percentages of EPS granules result in improved insulation (lower lambda value) in both the initial product and, in particular, in the recyclate that can be produced from this initial product. This results in a more affordable, higher-quality recyclate.

The binder is a polymer-in-water emulsion. The chain of this polymer consists primarily of carbon, oxygen, nitrogen, and silicon, such as polysiloxane. Preferably, the binder is a latex. Latex in this text is defined as a stable dispersion or emulsion of polymer particles in a solvent. This solvent is water. Even more preferably, the binder is a polymer-based binder. A binder based on dispersion polymerization will generally result in a latex, which is a dispersion of polymer particles in a solvent. In a preferred embodiment, the polymer is selected from the group consisting of: polystyrene (PS), polystyrene-butadiene copolymer, polybutadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene-propylene-diene monomer (EPDM), isobutylene isoprene rubber (IIR), polyisobutylene (PIB), silicone rubber (VMQ), fluororubber (FKM), ethyl vinyl acetate rubber (EVA), chlorosulfonated polyethylene rubber (CMS), acrylate rubber (ACM), or polyurethane rubber (AU or EU). More preferably, the polymer is selected from the group consisting of: polystyrene (PS), polystyrene-butadiene copolymer, polybutadiene rubber (BR), isoprene rubber (IR), ethylene-propylene-diene

7 BE2021/5864 monomer (EPDM), isobutylene isoprene rubber (IIR), polyisobutylene (PIB), or ethyl vinyl acetate rubber (EVA). Even more preferably, the polymer is selected from the group consisting of: polybutadiene rubber (BR), isoprene rubber (IR), ethylene-propylene-diene monomer (EPDM), and polystyrene-butadiene copolymer. The polymer is most preferably polystyrene-butadiene copolymer. Polystyrene-butadiene copolymer provides good adhesion to polystyrene surfaces. This is particularly important for preventing microcracks and associated thermal bridges. The inventors have surprisingly discovered that using a polystyrene-butadiene-based binder allows for lambda values lower than 0.030 W/mK. Furthermore, polystyrene-butadiene copolymer has very good mechanical properties, resulting in a floor layer with high compressive strength. The use of a largely polystyrene-based insulation layer for both the beads and the binder allows for better recycling. The absence of heteroatoms, particularly chlorine and fluorine, but also, to a lesser extent, nitrogen, phosphorus, and silicon, also contributes to this.

Even more preferably, the binder is based on dispersion polymerization or copolymerization, preferably copolymerization. In a further preferred embodiment, the solvent used for dispersion polymerization or copolymerization can be water. This is environmentally friendly.

In a preferred embodiment, said binder, being a latex whether or not based on dispersion polymerization, has a dry matter content of between 20 and 70%, preferably between 25 and 65%, even more preferably between 25 and 60%, even more preferably between 30 and 50%, even more preferably between 35 and 45%,

Using a solvent-based binder allows the granules to be fully mixed with the binder, with the solvent completely covering the surface of the EPS granules. This improves the bond between the EPS granules and the polymer matrix. However, the solvent does not remain in large quantities in the final product, but leaves the insulation material almost completely during curing.

Preferably, the latex is formed by dispersion polymerization, which is stopped at a high degree of polymerization. In a further preferred embodiment, a latex based on dispersion polymerization is capable of further polymerization after mixing with the EPS granules. This results in a strong,

8 BE2021/5864 created a three-dimensional matrix. Polymerization during this final step can still be very minimal; the vast majority of the polymer chains are formed during the production of the latex based on dispersion polymerization. This allows the properties of both the polymer and the latex to be controlled without being dependent on the user. This is advantageous for use as a sealant, for example, by DIYers.

A latex can be supplied ready-to-use in liquid form. This is advantageous over familiar polymer foams, such as polyurethane, which require exothermic reactions to form the polymer. Polymerization reactions in foams generally also lead to a significant volume increase. This makes applying these materials to form a floor more difficult. Because of this on-site reaction, the microscopic and macroscopic properties of these insulating foams are less consistent.

The degree of polymerization, branching and end functionalities can be better controlled,

This is because these properties change only very slightly, as most of the polymerization occurs during latex production, not when the latex is used as a binder. Control over the degree of crosslinking is, however, very important.

Curing insulation foams releases volatile, potentially toxic, and environmentally harmful gases. Curing a water-based latex polymer involves the evaporation of water and minimal reaction. This is both environmentally friendly and healthier for the installer.

In a further preferred embodiment, the latex has a Brookfield viscosity of 1 to 10,000 mPa.s, preferably 5 to 5,000 mPa.s, even more preferably 1 to 1,000 mPa.s, even more preferably 50 to 500 mPa.s, most preferably 50 to 300 mPa.s. This Brookfield viscosity is the viscosity measured with a

Brookfield viscometer with spindle 1, at 50 revolutions per minute at a temperature of 20°C.

These polymers provide better thermal insulation than cement. This also makes the sealant more thermally insulating than aerated concrete based on similar EPS granules.

The preferred polymers provide a good balance of compressive strength, weight and insulation.

3 BE2021/5864

In a further preferred embodiment, the mass fraction of the binder in the kit is between 0.10 and 0.60, preferably between 0.20 and 0.50, even more preferably 0.22 to 0.45, even more preferably 0.25 to 0.40, even more preferably 0.25 to 0.39, even more preferably 0.25 to 0.35, even more preferably 0.26 to 0.34, most preferably between 0.27 and 0.33. d10 is the particle size at which 10 wt.% of the expanded polystyrene granules have a smaller particle size and 90 wt.% of the expanded polystyrene granules have a larger particle size. d90 is the particle size at which 90 wt.% of the expanded polystyrene granules have a smaller particle size and 10 wt.% of the expanded polystyrene granules have a larger particle size. In a preferred embodiment, the EPS granules have a narrow particle size distribution. More preferably, dso - dio, i.e. particle size distribution of the 80 wt.% EPS granules with the middle particle sizes, is less than 3.0 mm, more preferably less than 2.5 mm, more preferably less than 2.0 mm, more preferably less than 1.5 mm, more preferably less than 1.2 mm, more preferably less than 1.0 mm, more preferably less than 0.9 mm, more preferably less than 0.8 mm, more preferably less than 0.7 mm, more preferably less than 0.6 mm, more preferably less than 0.5 mm, more preferably less than 0.4 mm, more preferably less than 0.3 mm, more preferably less than 0.2 mm, most preferably less than 0.1 mm. Such narrow particle size distributions are advantageous for, on the one hand, laying the floor layer, in particular covering all granules with sufficient binder and leveling the resulting floor layer, for obtaining an insulating layer with constant and predictable insulation values and pressure values, and for optimal recycling of the floor layer into flakes. With a narrow particle size distribution, the flake size can be better matched to the particle size of the EPS granules.

In a preferred embodiment, the sealant includes further additives. These can be added to the sealant as an additional component, or incorporated into the latex or EPS granules. Additives that improve polymer properties are known to those skilled in the art, for example, flame retardants to improve the flammability of the final material, additives to enhance chemical resistance, and the like. Adding materials with a high specific gravity, such as sand or quartz sand, to enhance the material's sound insulation is also known.

10 BE2021/5864

In a further preferred embodiment, the sealant contains lithium silicate as an additive. This additive is known as a densifier and hardener for concrete. Surprisingly, lithium silicate also proved to have a very beneficial effect on the compressive strength of a polymer matrix with EPS granules in between. In a further preferred embodiment, the lithium silicate mass fraction is preferably between 0.005 and 0.15, even more preferably between 0.02 and 0.10, and most preferably between 0.03 and 0.07.

In another preferred embodiment, the kit contains as few additives as possible, preferably none at all. In another preferred embodiment, the kit contains neither cement nor lithium silicate. In another preferred embodiment, the kit is free of foaming agents, particularly polysorbate, sodium lauryl ether sulfate, sodium coceth sulfate, sodium dodecyl sulfate, sodium bicarbonate, and isocyanates, particularly methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI). These additives, particularly cement, lithium silicate, and foaming agents, pose problems during recycling. They make the recycling process more difficult to control and/or significantly reduce the insulation quality of the recyclate.

In its most preferred embodiment, the kit consists of the following components:

A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and

B, the binder in a ratio of 25-39 wt.% to the weight of the complete sealant.

This results in a building material with a compressive strength exceeding 150 kPa and a lambda value of 0.030-0.036 W/mK. This material is cheaper to install than polyurethane foam (PUR) and has a higher compressive strength. It is lighter than aerated concrete and provides better thermal insulation.

In one embodiment, the kit further comprises reinforcement. This typically consists of metal, such as steel, or a fibrous material. This reinforcement serves to improve the structural properties of the matrix. In a preferred embodiment, polymer-based fibers are used. These adhere better in a polymer matrix and have an expansion coefficient similar to the surrounding polymer matrix. This is advantageous in preventing delamination, the loosening of the

11 BE2021/5864 reinforcement from the polymer matrix formed by the drying of the latex.

In the second aspect, the invention relates to a method for applying an insulating floor layer to a substrate, comprising (a) applying a binder to at least a portion of a surface of a plurality of expanded polystyrene (EPS) granules to form a slurry, (b) applying the slurry to the substrate, and (c) curing the slurry to form an insulating floor layer.

In one embodiment, applying binder to the surface of the EPS granules comprises thoroughly mixing or blending the granules with the binder.

Mixing can be accomplished using a variety of methods. Traditional concrete mixers or other mechanical stirring or mixing methods are sufficient. Furthermore, adding liquid latex when applying the EPS granules to a floor, for example, using a blower or feed screw, is also possible. Finally, mixing, especially for smaller quantities, can also be accomplished by manual stirring.

The application of EPS and/or binder to the substructure includes any method that provides EPS granules and binder at the location where the structural element is formed.

In this text, a slurry is a mixture consisting of small, solid particles and a liquid. In bulk, the properties of a slurry resemble those of a viscous liquid. In this text, the small, solid particles are always EPS granules. A slurry is easy to apply because it is "shapeless." This means that a slurry, like a fluid such as a viscous liquid, will take on the shape of the container it is in. This is advantageous for applying an insulation layer along pipes, foundations, and structural elements, for example. It is also very beneficial for home renovations, such as insulating an existing home. Space is often limited within an existing frame, which requires work to be done around it.

Furthermore, the slurry's shape-free nature ensures a tight fit. This is beneficial for the insulation, as small gaps in the insulation create thermal bridges. These thermal bridges are places where the insulation is interrupted and have a very detrimental effect on the overall insulation of a home.

12 BE2021/5864

Finally, the slurry is not blown in under pressure. Mixing common polymer foams is usually done simultaneously with their application, under pressure. Due to the high pressure, this work is generally not clean. The house is usually masked off with paper or plastic, or it must be cleaned again. It is preferable not to apply the slurry under pressure.

The sealant components can be combined and applied simultaneously, separately, or sequentially. The EPS granules and latex can first be combined to form a slurry, for example, in conventional concrete mixers, after which this slurry is applied to a floor. This makes it easy to mix large quantities of EPS with the binder. It is also possible to apply and mix the EPS granules and latex simultaneously to the floor. This ensures that the EPS and latex are evenly mixed. Furthermore, the amount of material that comes into contact with the latex is reduced. Finally, simultaneous mixing and application is the fastest method for many floors. It is also possible to apply the EPS granules first and then add the latex. Conversely, the latex can be applied first, which promotes careful application along existing elements, after which the EPS granules are added. It is important that some of the latex is still more or less liquid before adding the EPS granules. It is also possible to work in layers, with a layer

EPS and latex are used to lay multiple layers of insulation material at varying intervals. This can accelerate the insulation's curing process. A combination of the above is also possible. For example, it can be advantageous to first apply a layer of latex to irregular structural elements, further preventing thermal bridges.

Preferably, the steps (b) mixing the EPS granules and the binder and (c) applying the expanded polystyrene to a floor and (d) applying the binder to a floor can be performed simultaneously, separately or sequentially.

"Leveling" or "leveling" refers to making the floor surface flat, even, or level. Leveling the slurry can be done in one or more steps.

This can be done both before and after the slurry has hardened into an insulating layer. Ideally, initial leveling should take place before the slurry hardens. This can be done very quickly by spreading the slurry out, for example, with a rake. If a completely flat surface is desired, the slurry can be completely leveled before or during hardening. Furthermore, the surface can be polished or leveled after hardening.

13 BE2021/5864 can be sanded smooth. This is easier than with concrete because the material is considerably less hard.

In a preferred embodiment, the EPS granules and the binder are mixed for 30 seconds to 15 minutes, preferably for 30 seconds to 10 minutes, more preferably for 40 seconds to 5 minutes, even more preferably for 50 seconds to 4 minutes,

The curing time of the slurry ranges from 2 to 96 hours. This depends primarily on the thickness of the insulation layer and, to a lesser extent, on the temperature and humidity. The curing process can be carried out in the open air. In a preferred method, the curing process is stimulated by forced or natural convection above the floor surface, for example, by properly ventilating the house. The use of absorbents can also accelerate the curing process.

In a preferred embodiment, the thickness of the insulation layer is between 1 and 60 cm, preferably between 2 and 50 cm, even more preferably between 3 and 50 cm, and even more preferably between 4 and 50 cm. The upper limit of 50 cm is generally used only when constructing a floor, and obviously not an intermediate floor, where both an insulation layer and a structurally supporting and leveling layer are required. Above 60 cm, lower lambda values are observed.

In a preferred embodiment, the EPS granules and binder are applied under low pressure. Applying under high pressure is often difficult to do cleanly. Masking and/or cleaning up the application results in additional costs.

The substructure is the surface on which the floor is laid. This can be a concrete layer, another floor layer, the subsoil, the foundation, or a combination of these. The substructure can also include structural elements, pipes, and the like. The slurry can be applied directly on top of these elements, regardless of their structure.

In a third aspect, the invention relates to a kit comprising recyclate, the kit being suitable for compositely forming a recyclable insulating floor layer, the kit comprising:

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A. a plurality of recycled flakes comprising shredded expanded polystyrene (EPS) granules bonded by means of a first binder; and

B. a second binder, wherein the binder comprises a polymer-in-water emulsion.

In a preferred embodiment, the average particle size of the recycled flakes d50,rec is at least 0.5 mm larger, preferably at least 1.0 mm larger, more preferably at least 1.5 mm larger, more preferably at least 2.0 mm larger, most preferably at least 2.5 mm larger, than the average particle size d50, ps of the bound expanded polystyrene (EPS) granules.

In a preferred embodiment, the first and second binders are based on the same polymer or copolymer. Even more preferably, the first and second binders are based on the same polymer-in-water emulsion.

In a preferred embodiment, the plurality of recycled flakes have a density of between 4 and 25 kg/m3, preferably between 15 and 25 kg/m3.

In one embodiment, a quantity of (virgin) expanded polystyrene (EPS) granules can also be added to the recycled flakes. This addition will improve the insulation value and compressive strength. Furthermore, a more manageable and predictable insulation layer is achieved. However, the amount of recycled material is lower, and the amount of fresh material is higher, meaning this measure also has an ecological impact. It is therefore advantageous to produce the first floor layer and all recycled floor layers in such a way that the amount of new (virgin) material remains as low as possible, in order to keep the recycled material fraction as high as possible and to optimize the ecological impact of the first product and the recyclates based on it.

In a fourth aspect, the invention relates to a method for recycling a floor layer, this floor layer consisting essentially of bonded expanded polystyrene granules, comprising the steps of: - cutting said bonded expanded polystyrene granules into recycled flakes,

In a preferred embodiment, the flakes are cut to an average particle size of the recycled flakes dso,rec of at least 0.5 mm

15 BE2021/5864 larger, preferably at least 1.0 mm larger, more preferably at least 1.5 mm larger, more preferably at least 2.0 mm larger, most preferably at least 2.5 mm larger than the average particle size d50 of the bound expanded polystyrene (EPS) granules being cut. This improves the compressive strength and insulation value of the recycled product.

In a preferred embodiment, the method further comprises the step of: - binding the recycled flakes by means of a binder, preferably a polymer-in-water emulsion, even more preferably the same polymer that binds said bound expanded polystyrene granules.

In a preferred embodiment, the recycled flakes have a density between 4 and 25 kg/m3, more preferably between 15 and 25 kg/m3.

The fifth aspect of the invention comprises an insulating floor layer formed with a sealant according to the first or third aspect, or by the method according to the second aspect.

This insulating floor layer is more advantageous than aerated concrete due to its higher insulation value. Furthermore, the insulating floor layer is lighter. Compared to conventional polymer foams, the insulating floor layer according to the current invention has better compressive strength and is easier to install.

A floor layer according to this text can be located either between the foundation and the ground floor, or between any two floors. Using lightweight insulation reduces stress on the building's structural elements. A building according to this text can be any type of building, such as homes or office buildings, but also stables, storage facilities, and the like.

In a preferred embodiment, the final, solid insulation layer has a lambda value of less than 0.040 W/mK, preferably less than 0.037 W/mK, even more preferably less than 0.035 W/mK, even more preferably less than 0.034

W/mK, even more preferably lower than 0.033 W/mK, preferably lower than 0.032

W/mK.

The lambda value is the thermal conductivity coefficient of a material and expresses how much heat is conducted per unit of time through a surface of 1 m² with a thickness of 1 m at a temperature difference of 1°C (1 K). This is related to the

18 BE2021/5864 Thermal resistance coefficient R of a material layer with thickness d as À = R/d. These units are defined according to ISO 10456.

A low lambda value is beneficial for good insulation. It has been shown that using a polymer-based binder provides better thermal insulation than cement.

In a preferred embodiment, the structurally stable insulation layer has a minimum compressive strength of 100 kPa, preferably the minimum compressive strength is higher than 110 kPa, even more preferably the minimum compressive strength is higher than 120 kPa, even more preferably the minimum compressive strength is higher than 130 kPa, even more preferably the minimum compressive strength is higher than 140 kPa, even more preferably the minimum compressive strength is higher than 150 kPa.

This compressive strength is sufficient for use as a building material and offers an excellent compromise between weight, insulation, and structural element. Its compressive strength is significantly higher than that of many polymer-based pre-printed panels and foams.

In a preferred embodiment, the insulation layer has a specific weight of 10 to 50 kg/m3, preferably 15 to 35 kg/m3, even more preferably 15 to 30 kg/m3, even more preferably a specific weight of 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28 or 29 kg/m3.

A lightweight, insulating material can be used cost-effectively in apartments and similar buildings, saving significant weight. During renovations, the goal is often to add insulation without modifying the building's structural elements. Aerated concrete is often too heavy for this.

EXAMPLES

It is understood that the present invention is not limited to the embodiments described above and that some modifications or changes may be added to the described examples without reappraising the appended claims.

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Expanded polystyrene granules 1

Expanded polystyrene granules were purchased as non-expanded beads.

These unexpanded beads are white, meaning they contain no graphite or carbon. They were partially expanded in a pre-foamer under the influence of steam. The pre-foamer is equipped with a mixer. Pre-foaming was carried out for 45 seconds using steam at a pressure of 0.25 bar. This steam has a temperature between 104 and 120°C.

After pre-foaming, the semi-expanded polystyrene granules are dried in a drying bed. Hot air is blown into this drying bed from beneath the semi-expanded granules. The hot air has a temperature of approximately 60°C at the beginning of the bed, dropping to approximately 40°C at the end. The granules typically undergo two cycles through the drying bed. The EPS granules remain in the drying bed for approximately 2 minutes per cycle. The dry, semi-expanded PS granules are stored in a silo, where they also cool further.

The semi-expanded polystyrene granules are fully expanded in a 4m x 1m x 1.2m block press. Superheated steam is used for this, at a pressure of 900 bar and a temperature of 210°C, which acts on the pre-foamed polystyrene granules for a short burst of 6 seconds.

The moisture absorption upon immersion, after 24 hours, was 9%.

Expanded polystyrene granules 2

Example 1 was repeated using beads from the same commercial series but with a higher specific gravity. Furthermore, hydrophilic polymer was added to the block press's steam tank at a ratio of 0.0001 wt.% to water.

The moisture absorption of the produced EPS granules during immersion was now only 3%. This is likely due to the coating of the EPS granules with the polymer during the expansion process and/or the closing of micropores in the EPS granules by the water-soluble polymer.

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Example 1: Kit

The EPS granules 1, with a diameter of 4 mm, were combined with a latex based on a dispersion copolymer. These were thoroughly mixed and poured into a mold to a height of 8 cm. Approximately 15-16 kg of beads and 14 kg of latex were used for 1 m³ of finished material. These were mixed together in a concrete mixer for 2 minutes. The slurry was then poured into a mold. The slurry hardened into a solid insulation layer after 4 hours. The lambda value of the solid insulation layer was measured as 0.0356 W/mK. The compressive strength was 40 kPa.

Example 2: Lithium silicate kit

In Example 2, the same procedure as in Example 1 was repeated. When mixing the latex and EPS granules, an additional 2 kg of lithium silicate hardener solution was added. This again produced a solid insulation layer.

2 kg of lithium silicate hardener was added. The solid insulation layer had a lambda value of 0.0364 W/mK. The final compressive strength of the material was 157 kPa.

Example 3: Kit with different EPS diameters

An insulation layer was produced according to Example 2. Various diameters of EPS granules were tested for their influence on the lambda value. The mass fraction of the EPS granules as in Examples 1-2 was retained. Dust problems were experienced for EPS granules with diameters under 1 mm. For EPS granules with diameters greater than 6 mm, the insulation value of the final result decreased significantly. For EPS granules with a diameter between 1 and 6 mm, the lambda value was consistently between 0.0350 W/mK and 0.0370.

W/mK. For EPS granules with a diameter between 4 and 6 mm, the lambda value was consistently between 0.0350 W/mK and 0.0362 W/mK.

Example 4: Kit with gray EPS granules

Example 1 was repeated, but the EPS granules are now "gray" polystyrene granules. These gray granules contain graphite and are known to those skilled in the art. From this

On 19 BE2021/5864, a new solid insulation layer was created. This insulation layer was also gray in color and resulted in a lower lambda value of 0.0329 W/mK.

Example 5: Kit with gray EPS granules and lithium silicate

Example 2 was repeated using the gray polystyrene granules from Example 4. Here, lithium silicate was again found to significantly improve the compressive strength of the final material. The compressive strength was 159 kPa, and the lambda value for this product was 0.03344 W/mK. The acoustic insulation of the material was calculated at 17 dB/10 cm. The use of silicate significantly improved the compressive strength but had a negative impact on the insulating properties.

Example 6: Floor

For a new construction on hard ground, concrete foundations were constructed.

An EPDM sheet was placed between the foundations and the subsoil as a water barrier. A slurry was produced containing 16 kg of gray EPS beads, 13 kg of latex, and 2 kg of lithium silicate per 1 m³ of insulation material. These components were mixed in a concrete mixer for 4 minutes, forming a slurry. The slurry was poured on top of the EPDM sheet to the height of the foundations, with an average thickness of 8 cm. The minimum thickness was 5 cm. The slurry was leveled first with the serrated side of a harp, and then with the flat side of a rake. The slurry hardens into a solid, flat insulation layer.

Above this, a layer of screed was applied, followed by floor tiles.

Example 7: Floor

During a renovation, water pipes and cable conduits for electricity and communication were exposed and partially replaced on a concrete subfloor. A slurry with the same composition and using the same method as Example 5 was produced in a concrete mixer. The slurry was poured on top of the concrete layer. The slurry was compacted around the pipes and conduits with a rake. The resulting layer was 12 cm high and was leveled. The pipes and conduits, except for their connections, lay entirely within the flat insulation layer.

20 BE2021/5864

Example 8: Mezzanine floor

An existing mezzanine floor with wooden joists and OSB boards was further insulated and finished. A polypropylene sheet was applied over the OSB boards. A slurry with the same composition and using the same method as Example 5 was produced. This slurry was mixed on top of the sheet to a thickness of 4 cm. The sheet was then leveled completely. Wood laminate was applied above this.

After this improvement, the floor was not only better insulated thermally but also significantly quieter compared to walking or running on the mezzanine floor. The applied insulation layer had a dampening (acoustic) effect.

Example 9:

Example 1 was repeated, using EPS granules 2 with lower moisture absorption. The lambda value of the solid insulation layer was measured as 0.0321 W/mK. The compressive strength was 41 kPa.

Examples 10-12:

The insulation layer from Examples 1, 2, and 9 was cut into flakes with an average particle size of 7 mm. The flakes were re-bonded with a latex binder. The insulation values were 0.044 W/mK, 0.048 W/mK, and 0.039 W/mK, respectively, for the recyclate from Examples 1, 2, and 9.

Claims (15)

21 BE2021/5864 CONCLUSIONS 1, Kit suitable for the composite formation of a recyclable insulating floor layer, the kit comprising: A. a plurality of expanded polystyrene (EPS) granules with a density of 10-35 kg/m3 and a moisture absorption by immersion of a maximum of 5%; and B. a binder, wherein the binder comprises a polymer-in-water emulsion. 2. A kit according to claim 1, the kit comprising: A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete sealant; and B, the binder in a ratio of 25-39 wt.% to the weight of the complete sealant. 3. A kit according to claim 1 or 2, the kit comprising: A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and B, the binder in a ratio of 25-39 wt.% to the weight of the complete kit. Kit according to any of the preceding claims 1-3, wherein the expanded polystyrene (EPS) granules have a density of 20-35 kg/m³ and preferably a density of 22-35 kg/m³. 5. Kit according to any one of the preceding claims 1-4, wherein the expanded polystyrene (EPS) granules are coated. 6. Kit according to any one of the preceding claims 1 to 5, wherein the binder has a viscosity of maximum 300 mPa.s. 7. A kit according to any one of the preceding claims 1 to 6, wherein the binder comprises a polymer-in-water emulsion, the polymer being a styrene-butadiene copolymer, 8. Kit according to any of the preceding claims 1-7, wherein the kit has a chloride content of maximum 0.1 wt.%, preferably 0.01 wt.%. 22 BE2021/5864 9. A kit according to any one of claims 1 to 8, wherein the kit does not comprise cement or lithium silicate. 10. Kit according to any one of the preceding claims 1-9, wherein the kit is free from foaming agents, in particular free from polysorbate, sodium lauryl ether sulphate, sodium coceth sulphate, sodium dodecyl sulphate, sodium bicarbonate and isocyanate, in particular methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). 11. Kit according to any one of the preceding claims 1-10, wherein 10 wt.% of the expanded polystyrene (EPS) granules have a particle size less than d 0 and 90 wt.% of the expanded polystyrene (EPS) granules have a particle size less than d 0 , wherein d 0 — d 0 is less than 3.0 mm, preferably smaller than 1.5 mm, preferably smaller than 0.5 mm. 12. Kit containing recyclate, the kit suitable for the composite formation of a recyclable insulating floor layer, the kit comprising: C. a plurality of recycled flakes comprising shredded expanded polystyrene (EPS) granules bonded by means of a first binder; and D. a second binder, the binder comprising a polymer-in-water emulsion, A kit according to claim 12, wherein the average particle size of the recycled flakes d50,rec is at least 1 mm larger, preferably at least 2 mm larger, than the average particle size d50, ps of the bound expanded polystyrene (EPS) granules. A kit according to any one of the preceding claims 12 or 13, wherein the first binder and the second binder comprise the same polymer. Kit according to any of the preceding claims 12-14, wherein the plurality of recycled flakes have a density of between 4 and 25 kg/m3, preferably between 15 and 25 kg/m3.