DE102017206654A1 - Flexible insulation material - Google Patents

Abstract

The invention relates to a flexible insulation material, in particular for thermal and / or acoustic insulation of components.
To further optimize the physical properties, the flexible insulation material is made up of two or more layers, wherein at least one first layer A of the insulation material contains silicone rubber and hollow microspheres.

Description

The invention relates to a flexible insulation material, in particular for thermal and / or acoustic insulation of components.

Flexible insulation material, which can be adapted individually due to their viscosity of the geometry of the component to be isolated, are among others EP2538416A1 . EP2842992A1 . EP2580268A1 or EP2573441A1 known.

These are always single-layer systems, which ensures the excellent flexibility of the material.

A disadvantage of these single-layer systems is that for certain applications, the physical properties of the material, such as. Fire protection, vapor diffusion, chemical resistance, etc. are not sufficient. At the same time, these materials are mostly based on a silicone polymer, which, although compared to alternative polymers has a particularly good heat resistance even at high temperatures of more than 150 ° C, but at the same time subject to a relatively high price of raw materials.

The invention is therefore based on the object to provide a flexible insulating material, which is characterized by improved physical properties, in particular by improved fire properties, improved chemical resistance and / or improved vapor diffusion properties.

This object is achieved according to the invention in that the flexible insulating material is made up of two or more layers, wherein at least one first layer A of the insulating material contains silicone rubber and hollow microspheres.

According to the invention, the first layer A is composed of a rubber mixture containing at least one silicone rubber as the sole rubber component. In this case, all known to those skilled person silicone rubbers can be used. Possible, for example, silicone rubbers, which are also referred to as poly (organo) siloxanes. They have groups accessible to crosslinking reactions, which are predominantly, but not exclusively, hydrogen atoms, hydroxy groups and vinyl groups, which may each be in the chain or at the chain ends.

There are cold-curing silicone rubbers (RTV = room temperature curing) and hot-curing silicone rubbers (HTV = high-temperature crosslinking).

One-component and two-component systems can be distinguished with RTV silicone rubbers. The silicone rubber can also be used as a premix of polymer, filler and oil, as is common in the market.

In particular, for adjusting the viscosity, the rubber mixture additionally contains at least one plasticizer. In this case, it is possible to use all plasticizers known to the skilled person which are compatible with the respective silicone rubber. In particular, the use of silicone oil has proved to be advantageous, since this is well compatible with the silicone rubber. Crosslinking silicone oils, which participate in the crosslinking of the rubber mixture and are often referred to as crosslinkable silicone oils, have proven particularly suitable. These lead to a further significant reduction of possible exudation of plasticizers.

Furthermore, according to the invention, the rubber mixture of the first layer A contains hollow microspheres which are uniformly mixed into the rubber mixture. The hollow microspheres, often simply referred to as microspheres, are hollow spheres (microspheres) with a diameter in the μm range of glass, phenolic resin, carbon or thermoplastic material. They are available in expandable form, being filled with a propellant and expanding on heating, or in pre-expanded form, in which the expansion is already completed.

The rubber mixture preferably contains from 2 to 200 phr of microspheres, particularly preferably from 2 to 30 phr, very particularly preferably from 2 to 15 phr, of already expanded microspheres of thermoplastic material, so that the rubber mixture has an already before the construction of the layer structure of the material or before the crosslinking Having pore structure.

Microspheres offer the advantage of forming a closed pore structure that is more suitable for isolation purposes because of less convection in the pores. The higher the amount of expanded microspheres, the better the insulating effect becomes through the higher pore content. However, excessive amounts of microspheres can result in processing problems in compounding or processing.

The second layer B is preferably a film or a polymer mixture, which in a preferred embodiment has a pore structure, or mineral wool or a fleece or a woven fabric or a knitted fabric.

As the material for the film elastomers, thermoplastic elastomers. Thermoplastics and / or metals are used.

Particularly preferred is the use of films of metal, in particular aluminum or coated aluminum.

Thermoplastic films are preferably weather resistant films e.g. from PE, PP and the like, but also oil-resistant elastomeric films of NBR, BR, SBR or PU come into question.

If the second layer B is a fleece or a woven fabric or a knitted fabric, a particularly good adhesion to the first layer A is given. The nonwoven, woven or knitted fabric is preferably based on at least one thermoplastic.

If the second layer B is composed of a polymer mixture, then it is preferably a rubber mixture containing at least one rubber component and further mixture ingredients. The layer B polymer blend is, in a preferred embodiment, free of silicone rubber, i. the amount of silicone rubber is 0 phr.

Particularly suitable rubber components for the second layer B are: ethylene-propylene copolymer (EPM) and / or ethylene-propylene-diene copolymer (EPDM) and / or nitrile rubber (NBR) and / or (partially) hydrogenated nitrile rubber (HNBR ) and / or fluoro rubber (FKM) and / or chloroprene rubber (CR) and / or natural rubber (NR) and / or styrene-butadiene rubber (SBR) and / or isoprene rubber (IR) and / or butyl rubber (HR) and / or bromobutyl rubber (BIIR) and / or chlorobutyl rubber (CIIR) and / or butadiene rubber (BR) and / or chlorinated polyethylene (CM) and / or chlorosulfonated polyethylene (CSM) and / or polyepichlorohydrin (ECO) and / or ethylene-vinyl acetate rubber (EVA) and / or acrylate rubber (ACM) and / or ethylene-acrylate rubber (AEM) and / or perfluorinated propylene rubber (FFPM) and / or perfluorocarbon rubber (FFKM) and / or polyurethane (PU). The rubber components mentioned can be used alone or in combination.

The use of EPDM is particularly suitable due to the weathering resistance and the thermal load capacity.

If at the same time oil resistance and water vapor resistance are to be optimized, NR, HNBR or PU are preferably used alone or in combination. Particularly good flame resistance is achieved by the use of CM, CSM or CR alone or in combination.

The usual compounding ingredients include at least one crosslinker or crosslinker system (crosslinker and accelerator). Other compounding ingredients are usually still a filler and / or a processing aid and / or a plasticizer and / or an anti-aging agent and optionally further additives (for example color pigments). In this regard, reference is made to the general state of rubber mixing technology.

In a preferred embodiment, the polymer mixture has a pore structure. This is achieved by suitable blowing agents. As blowing agents are usually pore-forming propellant gases such. As azo and diazo compounds, referred to, which split off under the influence of heat or catalysts gases (eg., N2 or CO2) and therefore serve to produce foamed polymer blends. The blowing agents decompose at a certain temperature during processing to form gas or with the addition of volatile solvents during the polymerization or vulcanization. As blowing agent but also expanded and / or expandable hollow microspheres made of polyacrylonitrile or glass can be used.

The polymer blend for the second layer B may also comprise a blend containing at least one thermoplastic component, i. at least one thermoplastic elastomer (TPE) and / or at least one thermoplastic (TP), at least one rubber component which is at least partially crosslinked, as well as customary mixing ingredients. Preferred thermoplastic components are: polyolefin, in particular polyethylene (PE) or polypropylene (PP), and / or polystyrene and / or polyamide (PA), for example PA6 or PA6.6, and / or polyester (PES).

The second layer B can also be constructed of mineral wool.

Mineral wool is a soft material made of man-made mineral fibers. This may be slag wool, glass wool or rock wool. The mineral wool offers in addition to the particularly high operating temperatures, an additional optimized acoustic insulation. At the same time it leads to no appreciable increase in weight of the entire material.

Mineral wool offers in addition to the low price and a good connection to the first layer A.

The second layer B may be made conductive in a particular embodiment. For this purpose, conductive carbon blacks, carbon nanotubes (CNTs), ionic liquids or other suitable additives are introduced into the second layer B, for example.

The flexible insulation material may consist of two, three or four layers in a preferred embodiment. The lowest layer is always the layer which is in direct contact with the component to be insulated. The topmost layer is the location facing outward to surrounding.

1. a) Unterste Lage: Zweite Lage B aus Mineralwolle Oberste Lage: Erste Lage A Vorteil von a): Isolierung für höhere Temperaturen ab 250°C, gleichzeitig aber robuster und wasserfest
2. b) Unterste Lage: Erste Lage A Oberste Lage: Zweite Lage B aus einer Polymermischung mit Porenstruktur enthaltend Polyurethan Vorteil von b): Isolierung für Temperaturen bis 250°C, gleichzeitig bessere Wärmeleitfähigkeit und geringere Kosten
3. c) Unterste Lage: Zweite Lage B aus Mineralwolle Mittlere Lage: Erste Lage A Oberste Lage: Polymermischung mit Porenstruktur enthalten Polyurethan Vorteil von c): Isolierung von Temperaturen oberhalb 250°C, gleichzeitig robuster und geringere Kosten
4. d) Unterste Lage: Erste Lage A Oberste Lage: Zweite Lage B aus PVC-Folie Vorteil von d): auch Kaltisolierung möglich und verbesserte Dampfdichtigkeit
5. e) Unterste Lage: erste Lage A Oberste Lage: Zweite Lage B aus Metallfolie, z. Bsp. Eisen oder Aluminium Vorteil von e): Bessere Dampfdichtigkeit

The following layer structures are conceivable:

1. a) Bottom layer: Second layer B of mineral wool Top layer: First layer A Advantage of a): Insulation for higher temperatures from 250 ° C, but at the same time more robust and waterproof
2. b) Bottom layer: First layer A Top layer: Second layer B of a polymer mixture with pore structure containing polyurethane Advantage of b): Insulation for temperatures up to 250 ° C, at the same time better thermal conductivity and lower costs
3. c) Bottom layer: Second layer B of mineral wool Middle layer: First layer A Top layer: Polymer mixture with pore structure containing polyurethane Advantage of c): Insulation of temperatures above 250 ° C, at the same time more robust and lower costs
4. d) Bottom layer: First layer A Top layer: Second layer B made of PVC film Advantage of d): Cold insulation also possible and improved vapor-tightness
5. e) Bottom layer: first layer A Top layer: Second layer B of metal foil, e.g. Eg iron or aluminum advantage of e): Better vapor-proof

The flexible insulation material can assume all geometric shapes. So it may be plate-shaped or web-shaped, but also the design of cylindrical hollow bodies or polygonal hollow bodies, etc. is possible.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2538416 A1 [0002]
• EP 2842992 A1 [0002]
• EP 2580268 A1 [0002]
• EP 2573441 A1 [0002]

Claims (4)

Flexible insulating material, characterized in that it is made up of two or more layers, wherein at least a first layer A of the insulating material contains silicone rubber and hollow microspheres. Flexible insulation material after Claim 1 , characterized in that it contains a second layer B, wherein the second layer B is a film or a polymer mixture or mineral wool. Flexible insulation material after Claim 2 , characterized in that the polymer mixture has a pore structure. Flexible insulation material according to one of the Claims 1 to 3 , characterized in that it is composed of two, three or four layers.