WO2017182336A1

WO2017182336A1 - Multilayer thermo-regulating paint system

Info

Publication number: WO2017182336A1
Application number: PCT/EP2017/058699
Authority: WO
Inventors: Loïc BARBOT; Johan PHILIPPE
Original assignee: Protec Industries
Priority date: 2016-04-21
Filing date: 2017-04-11
Publication date: 2017-10-26
Also published as: FR3050457B1; FR3050457A1

Abstract

A multilayer thermo-regulating paint system, characterised in that it comprises at least one layer of a first type obtained by spreading a paint composition comprising, by weight: 25% to 50% of microcapsules of phase-change material, 20% to 60% of binder, and at least one layer of a second type produced by spreading a paint composition; at least one layer chosen from said at least one layer of a first type and said at least one layer of a second type also having, in the composition of same, between 5% and 20% by weight of a filler with a thermal conductivity of less than 1 W.m^-1.K^-1; said system having a thickness of less than 1 mm.

Description

Multilayer system of thermo-regulating paints

Field of the invention

The field of the invention is that thermo-regulating paints used in the building or for industrial applications. Such paints make it possible to regulate the temperature, in particular that prevailing in a room of which they cover all or part of the walls.

More specifically, the invention relates to multilayer systems thermo-regulating paints of thickness less than 1 mm, for floor, wall or ceiling.

In the present description, the term "multilayer system of paints" is understood to mean a superposition of at least two layers of paint applied to a support (wall, floor, ceiling).

Prior art

The regulation of the indoor air temperature of a room is often very complex since the sources of heat input and sources of heat loss within this room are more or less controllable, have different powers. and different inertias.

It can therefore be difficult to maintain a comfortable temperature, generally between 18 and 26 ° C, in a room that is to say in practice to avoid hot temperature peaks and / or cold "peaks" temperature.

A typical situation at the origin of a hot spike in temperatures is, for example, solar radiation on a window.

A usual situation of cold peak temperature is a sudden decrease in the outside temperature at nightfall.

Three prior art paint technologies are known which can be used for the thermal regulation of premises.

One technology is to add aluminum microparticles to a paint composition so that it can reflect infrared rays. This technology only works with solar exposure on facades exterior of buildings. It is therefore used only to limit excess heat due to solar radiation.

Another technology is to add an insulating charge to a paint composition to reduce heat flow through a wall. The insulating load can be ceramic, hollow glass, kaolin. Since the thermal resistance is proportional to the thickness of the insulating material, a paint thickness much greater than 1 mm is necessary for an insulating effect to be effectively felt. This technology therefore makes it possible to improve the energy efficiency of a home but tends to accentuate certain phenomena mentioned above: a peak of heat will be felt all the more for example following the solar radiation on a window that the energy in excess can not be evacuated to the outside environment.

Yet another technology is to incorporate phase change materials within the paint composition. Beyond its phase change temperature, such a material is in liquid form. The phase change reaction of the solid to the liquid, or fusion, being an endothermic reaction, the material will capture the external energy. Conversely, below its phase change temperature the material is solid. Since the phase change reaction of the liquid to the solid, or solidification, is exothermic, the material will release energy to the outside. This technology makes it possible to clip hot peaks by absorbing energy and clipping cold peaks by releasing energy. It is more precisely to this technology that the present invention relates.

Paints incorporating existing phase change materials today have several disadvantages. Some paints can store a large amount of energy per square meter of painted surface but must be several millimeters thick. This first type of paint involves overconsumption of paint compared to the use of conventional paints and a long and tedious application process since such a thickness does not can be obtained only by superimposing a large number of layers, which must be applied then let dry.

Other thin-layer paints, less than 1 millimeter thick, are able to absorb or release a small amount of energy per square meter of painted surface. Their use for the regulation of the temperature of a dwelling therefore remains limited because it is not very effective.

Objectives of the invention

The invention particularly aims to overcome these disadvantages of the prior art.

More specifically, an object of the invention is to provide multilayer thermo-regulating paint systems with total thicknesses of less than 1 mm.

Another object of the invention is to provide such systems for storing a high amount of heat for a given painted surface.

Another object of the invention is to disclose such systems having mechanical properties comparable to those of traditional paints.

Another object of the invention is to describe such systems having rheological properties comparable to those of traditional paints.

Another object of the invention is to provide paint systems that can be used on the floor, wall or ceiling to cover all available surfaces of a room.

Presentation of the invention

These objectives, as well as others which will appear later, are achieved thanks to the invention which concerns any multilayer system of thermo-regulating paints characterized in that it comprises:

at least one layer of a first type obtained by spreading a paint composition comprising, by weight:

25% to 50% microcapsules of phase change material,

20% to 60% binder, and,

at least one layer of a second type made by spreading a paint composition;

at least one of said at least one layer of a first type and said at least one layer of a second type further having in its composition between 5% and 20% by weight of a thermal conductivity load of less than ί Λ / .ιτΛΚ ^"1 ;

said system having a thickness of less than 1mm.

According to the invention, at least one of the layers composing such a system contains a large concentration of phase-change microcapsules. However, the multilayer system according to the invention has a very small thickness, in practice between 500 μιη and 1 mm.

Microcapsules of phase change material are commercially available materials. For the realization of the invention, they will be chosen according to the destination of the system according thereto. In practice, the phase-change material composing them will have a phase change temperature of between -5 ° C and 80 ° C. For systems intended for living quarters, this material may advantageously have a phase change temperature between 18 ° C and 26 ° C.

Preferably, the phase-change material of these microcapsules will be a vegetable wax. The inventors have indeed demonstrated that the use of a vegetable wax was particularly advantageous especially in comparison with the use of a petrochemical paraffin. Indeed, the phase change enthalpy of a vegetable wax having a given phase change temperature is generally much greater than the phase change enthalpy of a petrochemical paraffin having a phase change temperature of the same value. or of value close to that of vegetable wax.

This phase-change material may thus advantageously be composed of fatty esters originating from palm oil which changes phase at 23 ° C. Preferentially, the microcapsules of phase change material have a minimum energy capacity of 160 J / g of microcapsule.

The system according to the invention further comprises at least a thermal conductivity of load of less than 1 W.rr ^ .K ^"1. This charge reduces the flow of heat between the ambient air and microcapsules change material phase of the paint composition. Thus, the higher the proportion of the thermal conductivity of load of less than 1 Wm ^-1 .K ¹ is, the more time it will take to the paint to absorb the energy due to a temperature change of The combination of such a thermal conductivity load less than ΐνν.ιτ κ ¹ with the microcapsules of phase change material makes it possible to potentiate the efficiency of the latter.

Both the layer of the first type and the layer of the second type of the systems according to the invention also comprise other conventional ingredients of the paint compositions, namely in particular:

pigments such as, for example, titanium dioxide (white opacifying pigment);

dispersants for maintaining in suspension the insoluble particles and in particular ensuring a homogeneous suspension of the microcapsules of phase-change material;

where appropriate, thixotropic additives to facilitate their spreading;

other fillers or additives known to those skilled in the art, such as, for example, plasticizers, pH modifiers, anti-foam agents, biocides, etc.

According to a variant of the invention, the multilayer system according to the invention is intended to be applied to a wall or a ceiling and is characterized in that said layer of first type constitutes a primary layer of attachment is applied directly to said wall or said ceiling and is obtained by spreading a paint composition comprising by weight:

25% to 50%, preferably 30% to 40%, of microcapsules of phase change material, 20% to 60%, preferably between 20% and 30%, of acrylic or glycerophthalic binder,

5% to 20% of a thermal conductivity of load of less than 1 Wm ^-1 .K ^_1; and in that said at least one layer of the second type constitutes a finishing layer applied to said layer of first type and is obtained by spreading a paint composition comprising, by weight:

40% to 60% of acrylic or glycerophthalic binder,

25% to 50%, preferably 30% to 40%, of microcapsules of phase change material.

In such a system for walls or ceilings, the thermal conductivity load below ¹ W.m -1 .K ¹ is preferably chosen from silica aerogels, vermiculite, cork and perlite. This is, according to an interesting variant of a silica airgel.

According to another variant of the invention, the multilayer system according to this is intended to be applied on a floor and is characterized in that said at least one layer of second type is applied directly to said floor and is obtained by spreading a composition comprising by weight:

20% to 80% of epoxy binder,

5% to 20% by weight of a first thermal conductivity of load of less than 1 Wm ^-1 .K ^_1;

to which a hardener was added just before spreading;

and in that said layer of first type is applied to said second type layer and is obtained by spreading a paint composition comprising by weight:

25% to 50% microcapsules of phase change material,

20% to 60% of epoxy binder,

5% to 20% by weight of a second charge of thermal conductivity less than ΐνν.ΐΎΐ κ ¹ ,

to which a hardener was added just before spreading. According to this variant, said first charge of thermal conductivity less than 1 νν.ιη κ ^_1 is preferably selected from the group consisting of silica aerogels, vermiculite, cork, perlite. This is, in an interesting variant, a silica airgel.

Still according to this variant, said second load of thermal conductivity less than ΐνν.ιη κ ^_1 is preferably selected from the group consisting of kaolin, ceramics, glass microspheres. This is, in an interesting variant, glass microspheres. Embodiments of the invention

Two non-limiting embodiments of the invention are described below with reference to the figures in which:

- Figure 1 is a schematic sectional view of a multilayer system of heat-regulating paints for walls or ceilings according to the present invention;

- Figure 2 is a schematic sectional view of a multilayer system of thermo-regulating paints for floors according to the present invention;

FIG. 3 is a graph showing the change in temperature over time during an absorption test of an example of a floor paint system according to the present invention;

FIG. 4 is a graph indicating the evolution of the temperature over time during a restitution test of the same example of a floor paint system according to the present invention.

Example 1

A first example of a system according to the invention for walls or ceilings consists of a layer of a first type constituting a primer layer and two layers of a second type constituting finishing layers.

The primer layer has the following composition in percentages by weight: 35% of INERTEK P23 microcapsules marketed by MCI Technologies and comprising a phase change material consisting of fatty esters derived from palm oil;

- 5% of ENOVA IC3110 silica airgel sold by CABOT having a thermal conductivity of 12 mW / m ^ .K ^"1 ;

30% acrylic binder TEXICRYL 13-601 marketed by Scott

Bader;

- 10% water;

8% titanium dioxide;

- 7.5% of SYNTHALAT PWM 883 urethane alkyd binder marketed by Synthopol;

- 2% thickening agent OPTIFLO H370 VF marketed by BYK;

- 1% of dispersing agent BORCHI GEN 1253 marketed by BORCHERS;

- 1.4% of various additives.

For the production of this composition, the components are mixed together using conventional mixers used by those skilled in the art to prepare a paint composition. The process comprises three main steps:

the dispersion of titanium dioxide in water, of the dispersing agent and of the thickening agent;

- the addition of binding agents; and,

- the addition of microcapsules.

The various additives are added during these three steps. Viscosity adjustment is further achieved by adding a small amount of water and / or thickening agent at the end of the process.

The composition of the topcoats is the following in percentages by mass:

- 30% microcapsules INERTEK P23;

48.5% acrylic binder TEXICRYL 13-601;

- 12% titanium dioxide; 1% of BORCHI GEN 1253 dispersing agent;

- 8.5% various additives.

the dispersion of the titanium dioxide in approximately half of the binding agent;

adding the other half of the binding agent, and

- the addition of microcapsules.

The various additives are added during these three steps. A viscosity adjustment is further achieved by adding a small amount of water at the end of the process.

Referring to Figure 1, a primer layer 1 is spread on a wall M according to any technique known to those skilled in the art (airless gun, brush, roller ...) at a rate of 400 g / m ² . Because of its thixotropic properties, the composition can be applied in a single pass and without a trace of coulure in a layer with a thickness of 200 μιη to 400 μιη. After drying of the latter, a first topcoat 2 is applied. After drying of this first topcoat, a second topcoat 2a is applied at a rate of 200 g / m ² . Because of its thixotropic properties, the composition of the topcoats can be applied in a single pass and without a trace of coulure in a layer of thickness from 150 μιη to 300 μιη.

Since the enthalpy of the microcapsules used is between 160 J / g and 200 J / g, the quantity of theoretical energy that can be stored by the primary layer is between 51 KJ / m ² and 64 KJ / m ² (at the rate of 320 grams of microcapsules per square meter of system).

Example 2

A second example of a system according to the invention for floors consists of a layer of a second type constituting a base layer and a layer of a first type.

The base layer has the following composition in percentages by mass: - 80% EPOTEC YDFM 253 epoxide binder marketed by Aditya Birla Chemical;

- 10% of ENOVA IC3110 silica airgel sold by CABOT has a thermal conductivity of 12 mW / m ^_1 .K ^_1 ;

2% of BORCHIGEN 1253 dispersing agent;

- 4% reactive diluent;

- 4% various additives.

These different compounds are mixed together using conventional mixers. Just before spreading the composition, a polyamine hardener is added at a mass ratio of 42%.

The layer of the first type has the following composition in percentages by weight:

40% EPOTEC YDFM 25 binder;

- 25% of microcapsules INERTEK P23;

- 15% titanium dioxide;

8% SPHERIGLASS 2000 glass microspheres marketed by Potters Industries LLC;

- 5% Kaolin METASIAL V800;

- 2% BORCHIGEN 1253;

- 5% of various additives.

These different compounds are mixed together using conventional mixers in three steps:

dispersion of the titanium dioxide in 80% to 90% of the total quantity of epoxy resin and addition of the various additives,

adding the rest of the epoxy resin and the plasticizer,

- addition of microcapsules.

The various additives are added during these three steps.

Just before spreading the composition a polyamine hardener is added at a weight ratio of 21%.

With reference to FIG. 2, a layer of second type 3 is spread on a floor S according to any technique known to those skilled in the art at a rate of 130 g / m ² .

After drying of this layer, a layer of first type 4 is spread at a rate of 1210 g / m ² .

Because of its thixotropic properties, the composition can be applied in a single pass and without a trace of sagging in a layer of thickness less than 1 mm.

The enthalpy of the microcapsules used being between 160 J / g and 200 J / g, the theoretical energy quantity that can be stored by the primary layer is between 40 to KJ / m ² and 50 KJ / m ^2. 250 grams of microcapsules per square meter of system).

Temperature measurement tests

Temperature measurement tests were carried out in the cubic chambers of 1 ^m3 to demonstrate efficacy for floor paint system according to the invention with respect to a standard surface painting.

Each blank wall of the boxes consists of a set of plasterboard, a wooden panel and an insulator. Each box is equipped with a lamp of 1000 W. The walls of the first box are covered with a 1mm thick layer of the floor paint system according to Example 2. The walls of the second box (control box) are covered a 1 mm thick layer of a control floor coating. The paint used for the control coating is a standard paint with no phase change material and a thermal conductivity load of less than 1 Wm ^_1 .K ¹ .

The first test, called "absorption test", aims to simulate a significant amount of heat in a home. The initial equilibrium temperature inside the caissons is 18 ° C. The temperature outside the boxes is maintained at 5 ° C throughout the test. The 1000 W lamp is lit for 25 min in each box then off.

Figure 3 shows the measurement of temperatures over time in the first box (dotted line curve) and in the second box (black curve). A difference of 3.5 ° C is observed between the two boxes after 25 minutes of exposure. The temperature in the first box reaches a maximum of 26 ° C while the temperature in the second box (control) reaches a maximum of 29.5 ° C.

The second test, called "restitution test", aims to simulate a significant loss of heat in a home. The initial equilibrium temperature inside the caissons is 30 ° C. The temperature outside the boxes is maintained at 5 ° C throughout the test.

Figure 4 shows the measurement of temperatures over time in the first box (dotted line curve) and in the second box (black curve).

The temperature drops to 20 ° C in just 65 minutes for the second box (control) and 105 minutes for the first box.

Claims

1. multilayer system of thermo-regulating paints characterized in that it comprises:

25% to 50% microcapsules of phase change material, 20% to 60% binder,

and at least one layer of a second type made by spreading a paint composition;

said system having a thickness of less than 1mm.

2. System according to claim 1 characterized in that said phase change material has a phase change temperature between -5 ° C and 80 ° C.

3. System according to claim 2 characterized in that said phase change material is a vegetable wax.

4. System according to one of claims 1 to 3 intended to be applied to a wall or a ceiling characterized in that said layer of first type is a primary layer of attachment and is applied directly to said wall or said ceiling and is obtained by spreading a paint composition comprising, by weight:

5% to 20% of a thermal conductivity load of less than 1W.m ^_1 .K ^_1 ; and in that said at least one layer of the second type constitutes a finishing layer applied to said layer of first type and is obtained by spreading a paint composition comprising, by weight:

40% to 60% of acrylic or glycerophthalic binder,

25% to 50%, preferably 30% to 40%, of microcapsules of phase change material.

5. System according to claim 4 characterized in that said load of thermal conductivity less than 1 νν.ιη κ ^_1 is selected from the group consisting of silica aerogels, vermiculite, cork, perlite.

6. System according to claim 5 characterized in that said load of thermal conductivity less than 1 Wm ^_1 .K ^_1 is a silica airgel.

7. System according to claim 1 to 3 for application to a floor characterized in that said at least one layer of second type is applied directly to said floor and is obtained by spreading a composition comprising by weight:

20% to 80% of epoxy binder,

5% to 20% by weight of a first thermal conductivity of load below lW.m .K ^_1 ^_1;

to which a hardener was added just before spreading;

and in that said first-type layer is applied to said second-type layer and is obtained by spreading a paint composition comprising:

25% to 50% microcapsules of phase change material,

20% to 60% of epoxy binder, 5% to 20% by weight of a second charge of thermal conductivity less than ΐνν.ΐΎΐ κ ¹ ,

to which a hardener was added just before spreading.

8. System according to claim 7 characterized in that said first charge of thermal conductivity less than 1 νν.ιη κ ^_1 is selected from the group consisting of silica aerogels, vermiculite, cork, perlite.

9. System according to claim 8 characterized in that said first load of thermal conductivity less than 1 Wm ^_1 .K ¹ is a silica airgel.

10. System according to one of claims 7 to 9 characterized in that said second load of thermal conductivity less than 1 νν.ιη κ ^_1 is selected from the group consisting of kaolin, ceramics, glass microspheres.

11. System according to claim 10 characterized in that said second load of thermal conductivity less than 1 W.m ^ .K ^"1 is constituted by glass microspheres.