EP0678619B1 - Polymeric menbrane - Google Patents

Abstract

A plastic strip (I) is claimed, consisting of (A) plastic and/or glass fibre base material(s) with (B) porous agglomerates of water-repellent thermoplastic powder(s) (II) produced on at least one side by the action of heat, and fixed to (A) by mechanical anchorage and/or adhesive bonding. Also claimed is a process for the prodn. of (I), by: (1) spreading powder (II) onto a moving base material (A) and opt. spreading other powder(s) onto the first powder if required; (2) heating to agglomerate (II); (3) pressing the hot prod. between two rollers so as to form the required pore structure and fix the agglomerated material to (A) as above; and (4) cooling the prod.. The process can be repeated on-line, or off-line after winding on a spool, to coat the other side with (B).

Description

The present invention relates to a plastic sheet, a process for producing this plastic sheet as well as their use.

There are two groups in the prior art of plastic sheets, which are used as roofing sheets, too "Pliable sarking and underlays" or called "underslating" can be used.

The representatives of the first group are mostly up Based on plasticizer-containing polyvinyl chloride and generally have a thickness between 0.5 and 1.0 mm. They have the advantage of being weldable with hot air or hot wedge welding machines.

On the other hand, they have the disadvantage, among other things, that their permeability to water vapor is usually significantly less than 40 g / m ² d (23 ° C, 90% relative humidity). Therefore, high demands must be placed on the processing quality when laying the web. Likewise, the execution of roof structures with high built-in moisture is generally problematic.

The representatives of the second group do not have a uniform material base. Their main feature is that they have very high water vapor permeability due to their very fine pores, some of which are well over 100 g / m ² d (23 ° C, 90% relative humidity). The products in this group are generally thinner than 0.5 mm. The disadvantage of these plastic sheets is that, partly because of the low material thickness and partly because of the thermoset raw materials used, they cannot be welded under construction site conditions.

This means that there are no seamless sub-roofs execute, which results in these sub-roofs the function of a note covering only incomplete able to fulfill. Connections of such roofing membranes Flat roof plastic sealing sheeting at the transition from Steep to flat roofs are complex to implement.

It is an object of the present invention the advantages of both product groups described above to unite in a single new product. In particular a roofing membrane should be made available, which both have high water vapor permeability has as well as weldable under construction site conditions is.

It is another object of the present invention to provide a plastic sheet, which are no plasticizers, no halogens, no polyvinyl chloride, no bitumen and no heavy metals like such as lead and cadmium.

This new plastic sheet should also be arbitrary combined and connected by gluing or welding can be with a plastic sealing membrane, as for example in the European patent specification No. 0 428 851 B1, or with a vapor barrier based on polyolefins, such as in a simultaneously submitted and a Priority date (April 19, 1994) determining Swiss Patent application entitled "Plastic Railway, which prevents or at least prevents water vapor diffusion significantly reduced "is defined.

It is another object of the present invention to provide a plastic sheet, which are easy to use and process is.

This plastic sheet should preferably also be translucent.

This plastic sheet is said to be based on inexpensive raw materials are built and by means inexpensive processes can be produced.

This new plastic sheet is also intended to be plate-shaped Materials that can be fixed Thermal insulation and / or sound insulation and / or the Serve fire protection.

The raw materials should be selected in such a way that the plastic sheet made from it can be recycled can, especially together with the above Plastic sealing membrane and the vapor barrier mentioned above.

Claim 1 of DE-A-26 21 195 relates to a "Process for the production of with filler reinforced Plastic coated or made of filler reinforced Plastic existing fabrics or moldings ".

The filler must always be present his.

The mixture of plastic powder is important and powdered filler.

It is also important that the plastic powder and the powdered filler a comparable one Have grain size distribution.

A structure with the mixture of powders as in Figure 2 of DE-A-26 21 195 comes according to the present invention out of the question.

According to the 2nd section on page 6 (hand numbering) and claim 1, line 4 of DE-A-26 21 195 the fillers are needed to match each product to give the desired rigidity.

These parts are in shoes and shoe parts used; see claims 1 and 12 of DE-A-26 21 195.

Wood or cork flour, as in claim 5 and in the examples of DE-A-26 21 195 mentioned comes in the present invention is not considered as a filler.

FR-A-2 559 503 discloses reinforcing materials for leather, in particular for shoes or shoe parts, described; see claims 1 and 10.

It is important that a mixture of 2 polymers with different melting points is used.

In claim 6, page 9, lines 5 and 6 of FR 2 559 503 is a coherent layer ("couche cohérente") mentioned.

This coherent layer is not included those mentioned in claim 1 of the present invention porous agglomerates comparable.

Without this porous structure, the high water vapor permeability, as in the present invention is desired, not attainable at all.

FR-A-2 559 503 does not say anything about like the powder mixture on the mentioned carrier materials is applied; see claim 6 and page 7, Lines 15 and 16 of FR-A-2 559 503.

The invention is characterized by the features in the characterized independent claims.

Preferred embodiments are in the dependent ones Defined claims.

The plastic sheets according to the invention meet the above goals.

The plastic sheets according to the invention have among other things, the enormously important advantage that it is a have high water vapor permeability.

Preferred plastic sheets are also under Construction site conditions - in contrast to laboratory conditions or industrial welding - weldable.

This enables the quality of execution to adapt to the requirements placed on the sub-roof and therefore for very different climatic exposures always a case-based solution with the same product to offer.

Because the plastic sheets according to the invention no plasticizers, all problems are eliminated, caused by plasticizer loss or plasticizer migration can arise. Smoke formation is also eliminated when welding.

The plastic sheets according to the invention contain no halogens, no polyvinyl chloride, no bitumen and no heavy metals such as lead and cadmium.

They arise during production and installation practically no emissions.

The web is recyclable. The disposal through incineration or landfill is harmless.

Therefore, the plastic sheets according to the invention ecologically harmless.

The plastic sheet according to the invention is preferred translucent (translucent).

This means that markings remain on the surface or substructure visible. This will make the application simplified.

For the formation of special details, such as those required for chimneys, smoke pipes or lightning protection devices, prefabricated molded parts can be welded on or the desired shapes can be made from the roofing membrane or another membrane with a similar raw material base, e.g. Sarnafil T ^R , by appropriate heating, stretching and Welded together.

The processing of the plastic sheet according to the invention can be done in different ways. The inventive Plastic sheets can be or wedges by machine or by hand be welded. But you can also use suitable ones Adhesive tapes or adhesive compositions, e.g. made of polyisobutylene, be connected to each other. With a corresponding Requirement profile is also an overlapping, scale-like laying of the sheets possible, without connecting them together.

The manufacturing method according to the invention enables it, a product with excellent from cheap raw materials To generate properties. This results a good price / performance ratio.

In addition, the manufacturing method according to the invention enables the easiest way to apply of hot melt adhesives on the plastic sheet. This allows with little effort by laminating the web, e.g. pre-machined on thermal insulation panels, elements which already have multiple functional layers contain and can be installed very efficiently.

The plastic sheets according to the invention are preferably used as a roofing membrane.

In Figures 1 to 11 cuts are made typical roof structures shown, in which according to the invention Plastic sheets are used.

In Figures 1 to 5, the inventive Plastic sheets used as individual layers.

6 to 11 are those according to the invention Plastic sheets on a plate-shaped material fixed (composite elements).

1 erfindungsgemässe Kunststoffbahn.

2 erfindungsgemässe Kunststoffbahn, fixiert an ein plattenförmiges Material.

3 Dampfsperre, vorzugsweise eine solche Dampfsperre, wie sie in der gleichzeitig eingereichten und ein Prioritätsdatum (19. April 1994) festlegenden Schweizerischen Patentanmeldung mit dem Titel "Kunststoffbahn, welche die Wasserdampfdiffusion verhindert oder zumindest wesentlich reduziert" definiert ist.

4 Dampfsperre analog Bezugszeichen 3, fixiert an ein plattenförmiges Material.

5 Dachlattung.

6 Konterlattung.

7 Wärmedämmung.

8 Sparren.

9 Verkleidung.

10 Dachschalung.

11. Pfette.

The following reference symbols are used:

1 plastic sheet according to the invention.

2 plastic sheet according to the invention, fixed to a plate-shaped material.

3 vapor barrier, preferably such a vapor barrier as defined in the Swiss patent application filed simultaneously and setting a priority date (April 19, 1994) entitled "Plastic web which prevents or at least significantly reduces water vapor diffusion".

4 vapor barrier analogous to reference number 3, fixed to a plate-shaped material.

5 roof battens.

6 counter battens.

7 thermal insulation.

8 rafters.

9 paneling.

10 roof formwork.

11. Purlin.

The following examples are intended to illustrate the present Illustrate invention.

example 1

For the production of a 1.2 mm thick plastic sheet, where the upper class and the lower class was obtained as follows:

The high-pressure polyethylene powder (a low density polyethylene) "Coathylene" ^R HL 2548 from Plast-Labor SA in CH-1630 Bulle / Switzerland was applied to a glass fleece passing at a speed of 2.2 m / min with a basis weight of 50 g / m ² sprinkled on.

The application quantity was 350 g / m ² .

The product thus obtained was in a 2 m long furnace using infrared radiation from above onto a Temperature of maximum 150 ° C warmed.

This temperature was measured using a temperature sensor measured on the product surface.

The product thus obtained was passed through a calender guided with two water-cooled steel rollers. The The gap between these rollers was 0.9 mm.

The temperature of the plastic sheet was immediate before entering the gap 115 ° C.

This product was passed around a chill roll and wound up.

The above steps were for the other Repeated side of the plastic sheet. The was Speed of the web coated on one side 2.4 m / min.

The temperature reached by infrared radiation was a maximum of 145 ° C.

The gap between the two water-cooled Steel rolling was 1.2 mm.

The temperature of the plastic sheet immediately before entering the gap was 118 ° C.

The plastic sheet produced in this way had the following properties: exam standard value Permeability to water vapor ASTM E 398-83 (38 ° C, 90%) 240 g / m ² 24 h Longitudinal tear strength analogous to DIN 53455 with a 5 cm wide strip 450 N / 5 cm Tear strength across 365 N / 5 cm Elongation at tear along analogous to DIN 53455 with a 5 cm wide strip 2.2% Elongation at tear across 2.4% Coefficient of expansion along internal EMPA 105x10 ^-6 K ^-1 Expansion coefficient across Standard SOP 01'126 130x10 ^-6 K ^-1 Tear resistance along DIN 53363 191 N / mm Tear resistance across 214 N / mm Brand code Association of Cantonal Fire Insurance Companies (VKF) 4.2

Example 2

For the production of a 0.9 mm thick plastic sheet was done as follows:

The high-pressure polyethylene powder described in Example 1 was sprinkled onto a polyester fine fleece passing at a speed of 2.5 m / min and having a weight per unit area of 40 g / m ² .

The application quantity was 350 g / m ² .

The product thus obtained was in a 2 m long furnace using infrared radiation from above onto a Temperature of maximum 130 ° C warmed.

This temperature was measured using a temperature sensor measured on the product surface.

The product thus obtained was passed through a calender guided with two water-cooled steel rollers. The The gap between these rollers was 0.9 mm.

The temperature of the plastic sheet was immediate before entering the gap 115 ° C.

This product was passed around a chill roll and wound up.

In analogy, the steps above for the other side of the plastic sheet repeated.

The Abifor 1605 hot melt adhesive from Billeter Kunststoffpulver AG, CH-8033 Zurich / Switzerland was sprinkled in an amount of 75 g / m ² .

The speed of the passing train was 3.5 m / min.

The temperature reached by infrared radiation was a maximum of 97 ° C.

The gap in the calender was open.

The plastic sheet produced in this way had the following properties: exam standard value Permeability to water vapor ASTM E 398-83 (38 ° C, 90%) 860 g / m ² 24 h Longitudinal tear strength analogous to DIN 53455 with a 5 cm wide strip 200 N / 5 cm Elongation at tear along analogous to DIN 53455 with a 5 cm wide strip 7.5% Tear resistance along DIN 53363 89 N / mm Brand code Association of Cantonal Fire Insurance Companies (VKF) 4.2

The side coated with the hot melt adhesive this plastic sheet was made with a hot air dryer warmed that the hot melt adhesive melted. The temperature was in the range between 75 ° C and 110 ° C.

The so heated web was continuously with a Sarnaroc Nova mineral fiber board, which mainly serves as thermal insulation, brought together, pressed on and chilled.

The product thus obtained was based on the respective cut the desired size.

Claims (18)

1. A polymeric membrane, wherein porous agglomerates of at least one powder of hydrophobic thermoplastic material, formed by influence of heat, are fixed onto at least one side of a carrier material or of a mixture of carrier materials by a mechanical anchoring in the carrier material and/or by an adhering onto the carrier material, characterized in that
      at least one of the used powder of hydrophobic thermoplastic materials is composed of a polyethylene-homopolymer with a density of 0.899 to 0.940 g/cm³ and/or a copolymer which is composed of the monomer ethylene and a comonomeric vinylester of a C₂-to C₃-alkane carboxylic acid, whereby the comonomeric portion amounts to 1 - 30 percent by weight and the ethylene-monomeric portion amounts to 70 - 99 % by weight, whereby the total of the % by weight is 100, and whereby the melt flow index, abbreviated with MFI, of the above mentioned polymers, measured at 190°C and 2.16 kg weight, corresponding to DIN 53735, code D lies between 0.1 and 10 g/10 min, preferably between 1 and 5 g/10 min.
2. The polymeric membrane according to claim 1, characterized in that the powder of hydrophobic thermoplastic material contains in a worked in, compounded form at least one component which is selected from the group consisting of color pigments, stabilizers, specifically light protection agents, antioxidants, auxiliary materials, which reduce the combustibility of the polymeric membrane, e.g. aluminum hydroxide, magnesium hydroxide, and filler materials, specifically chalk, kaolin, talcum, quartz powder.
3. The polymeric membrane according to one of claims 1 to 2, characterized in that the powder of hydrophobic thermoplastic material is mixed with at least one component selected from the group consisting of auxiliary processing agents which increase the flowability of the powder, specifically aluminum oxide, and antistatic agents, for instance calcium stearate and zinc stearate.
4. The polymeric membrane according to one of claims 1 to 3, characterized in that said carrier material or mixture of carrier materials is porous and structured in such a manner,

   that it ensures the dimensional stability of the polymeric membrane during the production process and/or the application of the polymeric membrane, and/or

   that it ensures the weldability of the polymeric membrane by means of hot air and/or heating wedge, and/or

   that it ensures the resistance against tearing and the resistance against a continued tearing during application of the polymeric membrane,

      and is specifically a woven fabric, a non-woven fabric, a web or a fleece, or any combination thereof, of plastic and/or glass fibres.
5. The polymeric membrane according to one of claims 1 to 4, characterized in that said carrier material or mixture of carrier materials is structured in such a manner that it itself is water tight up to such a hydrostatic head which amounts to at least 20 percent, specifically at least 50 percent, of the hydrostatic head of the entire polymeric membrane.
6. The polymeric membrane according to one of claims 1 to 5, characterized in that the grain size of at least 65 % by weight of the powder of thermoplastic material is in the range of 150 to 500 micrometers, and in that preferably less than 15 % by weight of the powder of thermoplastic material have a grain size of more than 400 micrometers.
7. The polymeric membrane according to one of claims 1 to 6, characterized in that its water vapor permeability, measured at 38°C and a relativ humidity of the air of 10 % at the dry side of the specimen and 100 % at the damp side of the specimen, amounts in accordance with the standards NF H00-044, ASTM E 398-83, JIS K 7129 to 100 to 3000 g/m² 24 h, preferably to 500 to 1500 g/m² 24 h.
8. The polymeric membrane according to one of claims 1 to 7, characterized in that a intermediate layer of said porous agglomerates improving the adhering to the carrier material is located between said carrier material and an outer layer of said porous agglomerates, whereby this intermediate layer is thinner in comparison with said outer layer, and whereby this intermediate layer is composed of a thermoplastic material which in comparison to the thermoplastic material, used in the outer layer, has a lower melting point and/or a lower viscosity.
9. The polymeric membrane according to one of claims 1 to 8, characterized in that in case of a coating on one side by said agglomerates said carrier material, and in case of a coating on both sides by said agglomerates one of the two uppermost layers of material of said agglomerates is discontinuously coated at the outer side by at least one hot-melt adhesive, specifically selected from the group of the ethylene vinylacetate-copolymers and the group of the polyamide-copolymers.
10. The polymeric membrane according to one of claims 1 to 9, characterized in that an uppermost layer of material of said agglomerates is structured or discontinuously coated at the outer side, so that in the state of use and of application the danger of persons slipping thereon is reduced, whereby a possibly present hot-melt adhesive is not to be located at the same outer side as said anti slipping surface, and whereby said anti slipping surface is composed specifically of a powder of hydrophobic thermoplastic material and/or non metallic inorganic substances, for instance quartz sand.
11. The polymeric membrane according to one of claims 1 to 10, characterized in that a foil on the basis of a thermoplastic material is laminated either onto said carrier material or mixture of carrier materials or at least on one uppermost layer of material of said agglomerates, whereby this foil has a water vapor permeability, measured at 38°C and a relative humidity of air of 10 % at the dry side of the specimen and of 100 % at the damp side of the specimen, according the standards NF H00-044, ASTM E 398-83, JIS K 7129 of at least 50 g/m² 24 h, and whereby this foil is not to be located either on said hot-melt adhesive layer or on said anti slipping surface.
12. The polymeric membrane according to one of claims 1 to 11, characterized in that said porous agglomerates are formed of powders of thermoplastic materials which contain

    50 to 100 % by weight of polyethylene-homopolymers and/or copolymers, which are mentioned in claim 1,

    0 to 10 % by weight of colour pigments,

    0 to 5 % by weight of stabilizers,

    0 to 50 % by weight of auxiliary materials which reduce the combustibility of the polymeric membrane, and

    0 to 25 % by weight of fillers,

       whereby the total of the % by weight amounts to 100.
13. The polymeric membrane according to one of claims 1 to 12, characterized in that a board shaped material which serves specifically for thermal insulation and/or sound protection and/or fire protection is affixed onto one side, specifically by a hot-melt adhesive mentioned in claim 9.
14. A method of producing a polymeric membrane according to one of claims 1 to 13, characterized in that in a first step a first powder, which contains the respective needed recipe-components and has the desired grain size, is strewn onto a passing carrier material, then, if desired, one or a plurality of (a) further powder (s) with the respective recipe-components and the desired grain sizes are strewn subsequently onto the mentioned first powder, then the product obtained thereby is heated in a second step in such a manner that the individual powder particles are connected to each other to porous agglomerates, further wherein the product obtained thereby is pressed in a third step in a heated state in such a manner between two cylinders that at the one side the desired pore structure is formed and that at the other side the agglomerates are fixed by a mechanical anchoring in the carrier material and/or by an adhearing onto the carrier material, and wherein the product obtained in this manner is cooled in a fourth step, and thereafter, if desired, the above steps are repeated for the other side of the carrier material on-line or after a previous winding off-line, and then the polymeric membrane obtained in this manner is wound.
15. The method according to claim 14, characterized in that

    either a foil, such as defined in claim 11, is laminated onto the carrier material passing in the first step,

    or in the third step the product obtained is pressed together with one of the above mentioned foils between said two cylinder,

    or after the fourth step one of the above mentioned foils is laminated thereon.
16. The method according to one of claims 14 to 15, characterized in that after the third step either a hot-melt adhesive, mentioned in claim 9, or the starting material from which the anti-slipping surface is formed, as mentioned in claim 10, is strewn as a powder onto the desired side of the membrane and thereafter the product obtained is heated in such a manner that at the one side the powder, which has been strewn on, is fixed on the membrane and at the other side the membrane does not begin to melt, and is thereafter cooled.
17. The method according to one of claims 14 to 16, characterized in that the polymeric membrane is heated at the side, where the hot-melt adhesive is located, in such a manner that at the one side the hot-melt adhesive melts and at the other side the membrane does not begin to melt, and wherein thereafter the polymeric membrane is united at the side, on which the hot-melt adhesive is located, with a board shaped material, which is mentioned in claim 13, under the influence of pressure and is cooled.
18. Use of the polymeric membranes according to one of claims 1 to 13 for a sealing of buildings, preferably high-rise buildings, specifically as subroof membrane, also termed underlay membrane, or as covering membrane of rear aerated facades, or for wrapping or covering of articles.

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