Stock material or miscellaneous articles – Sheet including cover or casing – Complete cover or casing
Reexamination Certificate
1996-10-02
2001-02-27
Thibodeau, Paul (Department: 1773)
Stock material or miscellaneous articles
Sheet including cover or casing
Complete cover or casing
C428S078000, C428S213000, C428S423100, C428S516000, C428S515000, C428S157000, C052S409000, C405S052000, C156S244190, C156S244210
Reexamination Certificate
active
06194049
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to a polymeric waterproofing membrane, having a considerably improved biaxial elongation, compared with conventional polymeric waterproofing membranes, and comprising a composite of an upper layer and a lower layer as well as an in between situated barrier layer.
The present invention is also directed to processes for the preparation of this polymeric waterproofing membrane as well as to its use.
BACKGROUND OF THE INVENTION
Polymeric waterproofing membranes on the basis of ethylene-homopolymers and/or ethylene-copolymers as well as propylene-homopolymers and/or propylene-copolymers are known. See for example the products of the firm National Seal Company in Aurora, Ill 60504, USA and products of the firm Montell Polyolefins in I-44100 Ferrara, Italy.
Polymeric waterproofing membranes made of PE-HD (Polyethylene-high density) with a barrier layer of exclusively rolled aluminum foils (from about 50 to about 250 micrometer thick) are known.
Already at a small, unimportant biaxial, elongation this aluminum-barrier layer tears, and the barrier function is reduced considerably.
In the in DE OS 35 14 383, corresponding to EP 0 199 099 A2, described polymeric waterproofing membrane the inside situated layers must have—citation—at least approximative the same mechanical characteristics as those of the outside situated polymeric membranes—end of citation -.
The in DE OS 35 14 383 mentioned—citation—high elongation—end of citation—concerns a monoaxial elongation, which has nothing to do with a biaxial elongation.
For the coating of deposits and land-fills are used mainly waterproofing membranes made of PE-HD.
Polymeric membranes of this kind have a small biaxial elongation and, due to their small flexibility, they adapt themselves correspondingly bad to the sealing carrier.
When the maximum value of the biaxial elongation is trespassed, then the polymeric membrane tears. This results therein that detrimental compounds may come through the originated leakages into the water, into the ground or into the atmosphere.
Conventional waterproofing membranes on the basis of polyethylene should practically not be used for the sealing of deposits and land-fills, due to their high permeation rates, such as for example for halogenated hydrocarbons, such as dichloro benzene.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the above mentioned drawbacks.
It is a further object of the present invention to provide a polymeric waterproofing membrane, having a the diffusion of detrimental compounds, such as aromatic and halogenated hydrocarbons, for example dichloro benzene, dichloro methan, hindering barrier layer made of organic material.
This polymeric waterproofing membrane shall have a high flexibility, combined with a high biaxial elongation and a high relaxation behaviour.
There shall be provided especially a new, in the use temperature range from −40° C. to +70° C. flexible product having a thickness (strength) from 1.5 mm to 5 mm, which contains no plasticizing agents or bitumen, and which has a good resistance to atmospheric corrosion, as well as a good and simple workability, especially welding (heat-sealing) with conventional welding (heat-sealing) technics and welding (heat-sealing) devices (double welding tool weld, extrusion weld, manual hot gas welding, by machine hot gas welding), as well as a good chemical, biological resistance and a resistance against bitumen.
In addition it shall not contain heavy metal stabilizers.
The new product shall be composed, prepared and be correspondingly workable in such a way for the at times application, that therefrom, compared with the prior art, a very good price/result ratio results.
For the use in underwater sealings, for example underwater deposits, the density of this polymeric waterproofing membrane shall be adjustable for an easier laying.
At this application the density shall preferably be from 1.2 g/cm
3
to 1.4 g/cm
3
.
In addition, there shall be provided simple and cheap processes for the preparation of this new product.
The foregoing, as well as other objects, advantages, features and aspects of the invention will become more apparent by reference to the following detailed description and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
The polymeric waterproofing membrane according to the present invention have an improved biaxial elongation compared with conventional polymeric waterproofing membranes, and comprise a composite of a first layer, a second layer, and a barrier layer between the first and second layers. The barrier layer comprises at least one organic polymeric material; the first layer and the second layer comprise at least one organic polymeric material which has better mechanical characteristics in comparison to the organic polymeric material used in the barrier layer; and the first layer and the second layer comprise the same or different materials.
The polymeric waterproofing membrane according to the invention may include an adhesive promoter between the first layer and the barrier layer, as well as an adhesion promoter between the second layer and the barrier layer, wherein the adhesion promoter between the first layer and barrier layer is selected independently from the adhesion promoter between the second layer and the barrier layer. The adhesion promoter includes adhesive polyolefins, such as an adhesive polyolefin modified with maleic anhydride, adhesive acetate resins, copolymers of vinylacetate, adhesive polyurethane, adhesive acrylate resins, and copolymers of acrylic esters.
The organic polymeric material of the barrier layer includes polyamides, polyvinyl halides, polyvinylidene halides, polyethylene terephthalates optionally vapor-blasted with metallic aluminum, and ethylene vinyl alcohols and their copolymers. Preferred organic polymeric materials of the barrier layer are polyvinyl fluoride and polyvinylidene chloride.
The organic polymeric material of the first layer and the second layer includes polyurethanes, ethylene-homopolymers, ethylene-copolymers, propylene-homopolymers, and propylene-copolymers. Preferred organic polymeric materials of the first and second layers are an ethylene-homopolymer or ethylene-copolymer with a density of 0.920 g/cm
3
or less, a propylene-homopolymer or propylene-copolymer with a density of 0.920 g/cm
3
or less, and an ethylene-copolymer with a density ranging from 0.900 g/cm
3
to 0.915 g/cm
3
wherein the comonomers are &agr;-olefins with 4 to 12 carbon atoms, more preferably with 6 to 10 carbon atoms.
The first layer and second layers of the polymeric waterproofing membrane may further comprise at least one of a pigment, a stabilizer, a filler, and a processing auxiliary agent. Preferably, the pigment is titanium dioxide or lightproof color pigments, the stabilizer is a light stabilizer, antioxidant or heat stabilizer, the filler is chalk, kaolin, talcum, quartz powder or barium sulfate, and the processing auxiliary agent is a lubricant such as glycerin monostearate.
In one embodiment, the first and the second layers of the polymeric waterproofing membrane comprise from 0 to 15% by weight of pigment, from 0 to 5% by weight of stabilizer, from 0 to 40% by weight of filler, from 0 to 5% by weight of processing auxiliary agent, wherein the total of all present components is 100% by weight.
Preferably, the polymeric waterproofing membrane has a biaxial elongation of 40%, and the barrier layer is not damaged and separation of the layers does not occur.
In another embodiment, the first layer and the second layer of the polymeric waterproofing membrane each have a thickness ranging from 0.75 mm to 2.5 mm, and the barrier layer has a thickness ranging from 50 micrometers to 200 micrometers.
Preferably, the width of the first layer and the width of the second layer on each side of the polymeric waterproofing membrane is greater than the width of the barrier layer, and the first layer and the second layer are welded together thermically in the border area. More preferably, th
Bindschedler-Galli Urs Alexander
van de Walle Lucas Evaristus
Burns Doane , Swecker, Mathis LLP
Sarna Patent-und Lizenz AG
Tarazano D. Lawrence
Thibodeau Paul
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