GAS-PERMEABLE PLANAR STRUCTURE

Abstract

The aim of the invention is to provide polymeric planar structures having good gas permeability, wherein a high variability with regard to the product design is made possible. This aim is achieved by means of a planar structure that comprises at least two directly successive layers, wherein the two directly successive layers are each independently from another a polymer foam or a film. At least one of the two directly successive layers has channels in the surface thereof facing the other layer, which extend from one of the edges bounding the interface plane formed by the two successive layers to another of these edges such that the channels have a free volume sufficient for vapor permeability. The invention further relates to a method for producing planar structures according to the invention, and to the use thereof.

Claims

1. A sheetlike structure comprising at least two directly successive layers, wherein the two directly successive layers independently of one another are each a polymer foam or a film and at least one of the two directly successive layers, in its surface facing the other layer, has channels which reach from one to another of the edges bounding the interfacial plane formed by the two successive layers, such that the channels have a free volume sufficient for vapor permeability.

2. The sheetlike structure as claimed in claim 1, wherein at least one of the two directly successive layers is a polymer foam.

3. The sheetlike structure as claimed in claim 2, wherein this polymer foam has the channels.

4. The sheetlike structure as claimed in claim 2, wherein the polymer foam is a closed-cell foam.

5. The sheetlike structure as claimed in claim 1, wherein both directly successive layers independently of one another are each a polymer foam.

6. The sheetlike structure as claimed in claim 5, wherein only one of the two directly successive layers has the channels.

7. The sheetlike structure as claimed in claim 1, wherein the polymer basis of the polymer foam is selected from the group consisting of polyethylenes, copolymers of ethylene and a 1,2-olefin having 4 to 8 carbon atoms, ethylene-vinyl acetate copolymers, blends of polyethylene and an ethylene-vinyl acetate copolymer, poly(meth)acrylates, and blends of poly(meth)acrylate and synthetic rubber.

8. A method for producing a sheetlike structure as claimed in claim 1, comprising a) heating at least one surface of a first web of a polymer foam or of a film, b) impressing channels into the heated surface of this web, c) providing a second web of a polymer foam or of a film, and d) laminating the two webs to one another such that the channel-containing surface of the first web enters into direct contact with one of the surfaces of the second web.

9. A single-sided or double-sided adhesive tape comprising a carrier which is the sheetlike structure of claim 1.

10. A spacer in structural glazing or curtain wall construction applications, which is the sheetlike structure of claim 1.

Description

EXAMPLES

[0064] Sheetlike structures were formed each from two polymer foam layers joined to one another, of which one in each case was provided with channels. The assembly was produced such that the channels faced the second polymer foam layer. The polymer foam layers used were commercially available foams which are indicated in the table below.

[0065] Regarding the Production Procedure in Detail:

[0066] Impressing of the Channels:

[0067] The channels were generated using an impression tool made of anodized aluminum. This was done by first heating the foam until it was thermally deformable. Sufficient deformability was reached after 20 seconds at 160 C. Only then was the cold impression tool pressed into the foam. During this impression procedure of 60 seconds, the foam lost its thermoformability and the impressed negative, accordingly, remained dimensionally stable. The impression operation took place under a pressure of 20 kPa; the maximum impressed depth was limited at the same time by machine limits/spacers. All of the channels were impressed in such a way that they ran at a right angle transversely to the machine direction (corresponding to FIGS. 1 and 2).

[0068] Joining of the Layers to One Another:

[0069] The polymer foam layers were joined to one another via thermal welding. For this purpose, the surface of one of the layers to be joined was brought into a sealable state by using a hot air stream with a temperature of around 200 C. to heat a thin, near-surface layer of this foam. The duration of this treatment was a few seconds, and immediately preceded the application of the second foam ply. Rolling over the assembly under gentle pressure then ensured that all of the contact areas fused to one another.

TABLE-US-00001 TABLE 1 examples Water vapor Compressive permeability strength (as equivalent at 10% air layer Density compression Thick- thickness (Product) ASTM D1621 - ness Area sd.sub.(1 mm)) Matrix Cell DIN EN 10 (2.5 mm/ ISO fraction to DIN EN Tradename polymer structure ISO 845 min) 1923 (channels)* ISO 12572 No. Manufacturer of foams of foams of foams [kg/m.sup.3] [kPA] [mm] [%] [m] 1 SEKISUI TEE SR 0401.48 polyolefin closed- 274 210 3.0 11 0.01 ALVEO AG with channels + cell TEE SR 0401.48 2 SEKISUI TEE SR 0401.48 polyolefin closed- 208 147 4.5 7 0.01 ALVEO AG with channels + cell TEE HD SR 0503 3 SEKISUI TEE SR 0401.48 polyolefin closed- 129 123 8.5 4 0.03 ALVEO AG with channels + cell NEE 0805.5 4 SEKISUI TEE HD SR 0503 polyolefin closed- 204 98 4.5 7 0.02 ALVEO AG with channels + cell TEE SR 0401.48 5 SEKISUI TEE HD SR 0503 polyolefin closed- 175 105 6.0 5 0.02 ALVEO AG with channels + cell TEE HD SR 0503 6 SEKISUI TEE HD SR 0503 polyolefin closed- 145 111 8.5 4 0.03 ALVEO AG with channels + cell NEE 0805.5 7 Evonik Rohacell 71 HF; polymethacrylimide closed- 74 1050 6.0 5 0.02 Industries AG 2 3 mm, one cell layer with channels 8 BASF SE Neopolen P polypropylene closed- 69 336 6.0 5 0.02 (70 kg/m.sup.3); cell (bead foam) 2 3 mm, one layer with channels 9 Saint-Gobain Thermalbond polyurethane open- 352 110 6.4 0.04 Corporation V2200 cell (semi- rigid) 10 tesa SE 51955 polyurethane open- 294 99 6.4 0.13 cell 11 3M 2111 polyurethane open 500 210 6.4 0.05 Corporation cell *= (orthogonal section in longitudinal direction/MD)