WO2021208108A1

WO2021208108A1 - Self-adhesive waterproof repairing tape

Info

Publication number: WO2021208108A1
Application number: PCT/CN2020/085463
Authority: WO
Inventors: Shenghua XU; Qin WEI
Original assignee: Sika Technology Ag
Priority date: 2020-04-18
Filing date: 2020-04-18
Publication date: 2021-10-21
Also published as: CN115335225A

Abstract

The invention is directed to a sealing device (1) comprising a top composite layer (2) comprising a first and a second polymeric layer (5, 6) and an adhesive layer (3) covering at least a portion of one of the primary exterior surfaces of the top composite layer (2). The invention is also related to a method for producing a sealing device (1), to a method for waterproofing a substrate (8) by using the sealing device (1), to a waterproofed substrate, and to use of the sealing device (1) for reparation of damaged roof substrates.

Description

Self-adhesive waterproof repairing tape

Technical field

The invention relates to the field of waterproofing of above ground building constructions by using water impermeable sealing devices. In particular, the invention relates to self-adhesive waterproofing tapes, which are used for repairing roof waterproof layers to prevent leakage of water.

Background of the invention

In the field of construction polymeric sheets, which are often referred to as membranes, are used to protect underground and above ground constructions, such as basements, tunnels, and flat and low-sloped roofs, against penetration water. Membranes are applied, for example, to prevent ingress of water through cracks that develop in the concrete structure due to building settlement, load deflection or concrete shrinkage. Roofing membranes used for waterproofing of flat and low-sloped roof structures can be provided as single-ply or multi-ply membrane systems. In a single-ply system, the roof substrate is covered using a roofing membrane composed of a single waterproofing layer, which can be reinforced with a reinforcement layer, such as a layer of fiber material. In multi-ply systems, a roofing membrane composed of multiple waterproofing layers of different or similar materials are used. Single-ply membranes have the advantage of lower production costs compared to the multi-ply membranes, but they are also less resistant to mechanical damages cause by punctures of sharp objects.

Commonly used materials for waterproofing and roofing membranes include plastics, particularly thermoplastics such as plasticized polyvinylchloride (p-PVC) , thermoplastic olefins (TPE-O, TPO) , and elastomers such as ethylene-propylene diene monomer (EPDM) rubber. Bituminous materials are also used for providing membranes since they provide good resistance against environmental factors combined with relatively low costs compared to thermoplastic polymer materials. Bitumen compositions are typically modified with synthetic polymers to increase resistance to UV-radiation, toughness, and flexibility at low temperatures. Roofing membranes are typically delivered to a construction site in form of rolls, unrolled, and cut into suitable pieces to be adhered on the surface of the substrate to be waterproofed. The substrate on which the membrane is adhered may be comprised of variety of materials depending on the installation site. The substrate may be, for example, a concrete, metal, or wood deck, or it may include an insulation board or a cover board and/or an existing waterproofing or roofing membrane.

Especially the polymeric single-ply membranes but also the multi-ply membranes have a relatively low resistance against mechanical impacts caused by sharp objects falling on the surface of the membrane. Damaging of a membrane may occur, for example, during the construction or inspection phases. A membrane may, for example, be damaged as a result of a carelessly conducted cutting operation. Damages may also be generated by extensive traffic across the roof surface or by storing of heavy equipment on the roof, for example, during

cleaning. A roofing membrane may also be damaged due to a naturally occurring phenomena, such as a result of hailstone impacts. Furthermore, the length of service life of a flat roof membrane depends strongly on the environmental conditions of the installation cite. Since the membrane material is made of polymeric components, which are not entirely stable against weathering, local damages are likely to develop especially near the end of the service life of the membrane. Consequently, temporary repairs and repairs after warranty period are commonly conducted to maintain the integrity of the waterproofed structure.

When a damage or a leak in a roofing membrane is discovered, the area can be sealed with a self-adhesive tape designed to repair roof leaks, i.e. with a roof repair tape or repair patch. Requirements for the roof repair tape depend mainly on the material of the roofing membrane to be repaired. In case a breach in a plasticized PVC membrane is patched with a self-adhesive repair tape, migration of plasticizers from the roof membrane to the adhesive layer of the roof repair tape may result in deterioration of the adhesive properties and delamination of the tape from the roofing membrane. Furthermore, renovation of aged bitumen-based roof systems using polymeric repair tapes is risky since the volatile components contained in the bitumen material tend to migrate to the repair tape resulting in degradation of the waterproofing material.

There thus remains a need for an improved self-adhesive waterproof tape, which can be used for repairing of damaged roofing membranes, particularly plasticized PVC-and bitumen roofing membranes.

Summary of the invention

The object of the present invention is to provide a self-adhering sealing device that is suitable for repairing of roof systems comprising a plasticized PVC-or a bitumen roofing membrane.

Another object of the present invention is to provide a self-adhering sealing device, which can be produced with decreased costs compared to State-of-the-Art roof repair tapes.

The subject of the present invention is a sealing device as defined in claim 1.

It was surprisingly found out that a sealing device comprising a top composite layer comprising a first polymeric layer comprising a first thermoplastic polymer and a second polymeric layer comprising a second thermoplastic polymer and an adhesive layer arranged on one of the primary exterior surfaces of the top layer can be used for patching of locally damaged plasticized PVC and bitumen roofing membranes.

One of the advantages of the sealing device of the present invention is that the top layer can be provided to have a high flexibility, which means that the repair tape can be attached to follow tightly with the crests and troughs of a metal roof. This is an essential feature a repair tape since the joints on a metal roof expand upon heating and contract upon cooling. Furthermore, the top layer of the sealing device of the present invention can be provided to have especially good weathering and mechanical resistance, which means that the sealing device is able to maintains its water tightness even for longer periods of time in severe weather conditions. Such top layers are also highly resistant against mechanical impacts. Furthermore, the improvements in flexibility, weathering, and mechanical resistance can be achieved without significant increase in production and raw material costs of the sealing device, particularly compared to the State-of-the-Art roof repair tapes and other solutions available on the market for roof reparations. Other aspects of the present invention are presented in other independent claims. Preferred aspects of the invention are presented in the dependent claims.

Brief description of the Drawings

Fig. 1 shows a cross-section of a sealing device (1) comprising a top composite layer (2) comprising a first polymeric layer (5) having a first and a second major surface and a second polymeric layer (6) having a first and a second major surface, an adhesive layer (3) covering the second major surface of the second polymeric layer (6) , and a release liner (4) covering the outer exterior surface of the adhesive layer (3) on the side opposite to the second polymeric layer (6) .

Fig. 2 shows a cross-section of a sealing device (1) comprising a top composite layer (2) comprising a first polymeric layer (5) having a first and a second major surface, a second polymeric layer (6) having a first and a second major surface, and a metallic layer (7) arranged between the first and second polymeric layer (5, 6) , an adhesive layer (3) covering the second major surface of the second polymeric layer (6) , and a release liner (4) covering the outer exterior surface of the adhesive layer (3) on the side opposite to the second polymeric layer (6) .

Fig. 3.1 and 3.2 show a schematic presentation of a method for waterproofing a substrate.

Fig. 4 shows a cross-section of a waterproofed substrate comprising a substrate (8) and a sealing device (1) as shown in Fig. 1, wherein the second major surface of the second polymeric layer (6) is bonded to the surface of the substrate (8) via the adhesive layer (3) .

Fig. 5 shows a schematic presentation of the arrangement for measurement of a holding power of an adhesive sheet.

The proportion of thicknesses of the layers in Figures 1 to 4 is not true to scale. In particular, the ratio of the thickness of the polymeric layers (5, 6) to the thickness of the metallic layer is in reality far higher than that shown in Figure 2.

Detailed description of the invention

The subject of the present invention a sealing device (1) comprising:

i) A top composite layer (2) having a first and a second primary exterior surface,

ii) An adhesive layer (3) covering at least a portion of one of the primary exterior surfaces of the top composite layer (2) ,

iii) Optionally a release liner (4) covering the outwardly facing surface of the adhesive layer (3) opposite to the side of the top composite layer (3) ,

wherein the top composite layer comprises:

a) A first polymeric layer (5) having a first and a second major surface and comprising at least 50 wt-%of at least one polymer P1 selected from the group consisting of polyamide, polyvinylidene fluoride, and polyvinyl fluoride, and

b) A second polymeric layer (6) having a first and a second major surface and comprising at least 50 wt. -%of at least one polymer P2 selected from the group consisting of polyethylene and polyethylene terephthalate.

Substance names beginning with "poly" designate substances which formally contain, per molecule, two or more of the functional groups occurring in their names. For instance, a polyol refers to a compound having at least two hydroxyl groups. A polyether refers to a compound having at least two ether groups.

The term “molecular weight” designates the molar mass (g/mol) of a molecule or a part of a molecule, also referred to as “moiety” . The term “average molecular weight” refers to number average molecular weight (M _n) of an oligomeric or polymeric mixture of molecules or moieties. The molecular weight may be determined by conventional methods, preferably by gel permeation-chromatography (GPC) using polystyrene as standard, styrene-divinylbenzene gel with porosity of 100 Angstrom, 1000 Angstrom and 10000 Angstrom as the column and tetrahydrofurane as a solvent, at 35℃.

The term “softening point” or “softening temperature” designates a temperature at which compound softens in a rubber-like state, or a temperature at which the crystalline portion within the compound melts. The softening point can be measured by a Ring and Ball method as defined in DIN EN 1238 standard.

The term “melting temperature” designates a temperature at which a material undergoes transition from the solid to the liquid state. The melting temperature (T _m) is preferably determined by differential scanning calorimetry (DSC) according to ISO 11357-3 standard using a heating rate of 2 ℃/min. The measurements can be performed with a Mettler Toledo DSC 3+ device and the T _m values can be determined from the measured DSC-curve with the help of the DSC-software. In case the measured DSC-curve shows several peak temperatures, the first peak temperature coming from the lower temperature side in the thermogram is taken as the melting temperature (T _m) .

The term “glass transition temperature” (T _g) designates the temperature above which temperature a polymer component becomes soft and pliable, and below which it becomes hard and glassy. The glass transition temperature is preferably determined by dynamical mechanical analysis (DMA) as the peak of the measured loss modulus (G” ) curve using an applied frequency of 1 Hz and a strain level of 0.1 %.

The “amount or content of at least one component X” in a composition, for example “the amount of the at least one thermoplastic polymer” refers to the sum of the individual amounts of all thermoplastic polymers contained in the composition. Furthermore, in case the composition comprises 20 wt. -%of at least one thermoplastic polymer, the sum of the amounts of all thermoplastic polymers contained in the composition equals 20 wt. -%.

The term “room temperature” designates a temperature of 23 ℃.

The sealing device of the present invention comprises a top composite layer comprising a first and a second polymeric carrier layer. The term “layer” refers in the present disclosure generally to a sheet-like element having first and second major surfaces, i.e. top and bottom surfaces, a width defined between longitudinally extending edges, and a thickness defined between the first and second major surfaces. Preferably, a layer has a length and width at least 15 times, preferably at least 25 times, more preferably at least 50 times greater than the thickness of the element.

The term “polymeric layer” refers in the present disclosure to a layer comprising a continuous phase composed of one or more polymers. The term “polymer” refers to a collective of chemically uniform macromolecules produced by a polyreaction (polymerization, polyaddition, polycondensation) where the macromolecules differ with respect to their degree of polymerization, molecular weight and chain length. The term also comprises derivatives of said collective of macromolecules resulting from polyreactions, that is, compounds which are obtained by reactions such as, for example, additions or substitutions, of functional groups in predetermined macromolecules and which may be chemically uniform or chemically non-uniform.

According to one or more embodiments, the at least one polymer P1 is polyamide, wherein the top composite layer preferably further comprises a metallic layer arranged between the first polymeric layer and the second polymeric layer or the at least one polymer P1 is selected from the group consisting of polyvinylidene fluoride and polyvinyl fluoride, wherein the top composite layer is preferably composed of the first and second polymeric layers.

Suitable polyamides to be used as the at least one polymer P1 include aromatic and aliphatic crystalline and semi-crystalline polyamides. Amorphous polyamides are in generally not preferred. The term “amorphous polyamide” refers here to polyamides that lacking a crystalline melting point (T _m) as determined by differential scanning calorimetric (DSC) or an equivalent technique. Amorphous polyamides are distinct from the crystalline or semi-crystalline nylons, such as Nylon 6 and Nylon 12.

Suitable polyamides include, for example, Nylon 6 (PA6) , which is synthetized by ring-opening polymerization of caprolactam; Nylon 6-6 (PA66) , which is synthesized by polycondensation of hexamethylenediamine and adipic acid; and Nylon 12 (PA12) , which can be synthetized either by polycondensation of ω-aminolauric acid or by ring-opening polymerization of laurolactam. Bioplastic polyamides, such as Nylon 11, which is synthetized by polymerization of 11-aminoundecanoic acid, are also suitable. Suitable polyamides are commercially available, for example, under the trade name of

(from EMS Chemie) , such as

G16 and G21, which are copolyamides having both linear aliphatic units and ring-like aromatic components; under the trade name of

(from Gabriel Performance Products) , such as

100, which is an aliphatic polyamide; under the trade name of Rilsan (from Arkema) , such as

TMNO TLD,

BMNO TLD, and

AMNO TLD; and under the trade name of

(from Evonik) .

Suitable polyvinylidene fluorides to be used as the at least one polymer P1 have a relatively high vinylidene difluoride content, such as at least 65 wt. -%, preferably at least 75 wt. -%, more preferably at least 85 wt. -%, even more preferably at least 95 wt. -%, based on the weight of the polyvinylidene fluoride.

Suitable monomers that may be copolymerized with the vinylidene difluoride monomers preferably contain carbon-carbon double bonds, which may be allylic, styrenic, ethylenic, alpha-methyl styrene groups, (meth) acrylamide groups, cyanate ester groups, vinyl ether groups, or (meth) acrylic moieties. Examples of suitable co-monomers include ethylene, propylene, isobutylene, styrene, vinyl chloride, vinylidene chloride, difluorochloroethylene, chlorotrifluoroethylene tetrafluoroethylene, trifluoropropylene, hexafluoropropylene, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylonitrile, N-butoxymethyl (meth) acrylamide, isopropenyl acetate. Homopolymers of vinylidene difluoride repeat units of the formula are also suitable. Thermoplastic polyvinylidene fluorides are preferred but chemically crosslinked versions are also suitable.

Suitable polyvinylidene fluorides and polyvinyl fluorides are commercially available, for example, under the trade name of

(from Arkema) ; under the trade name of

(from Solvay) ; and under the trade name of

(from Shanghai 3F New Material) , such as

FR903.

Suitable polyethylene to be used as the at least one polymer P2 include ethylene homopolymers, such as low-density polyethylene, linear low-density polyethylene, and high-density polyethylene.

According to one or more embodiments, the at least one polymer P2 is a polyethylene, preferably having a melting temperature (T _m) , determined by differential scanning calorimetry (DSC) according to ISO 11357-3 standard using a heating rate of 2 ℃/min, of at or above 100 ℃, preferably at or above 105 ℃, more preferably at or above 110 ℃.

The term “polyethylene terephthalate (PET) ” refers in the present disclosure to a thermoplastic polyester resin that includes both PET polymers and copolymers. For example, PET can be provided as a copolymer having, in addition to terephthalic acid residues and ethylene glycol residues, additional isophthalic acid residues and/or cyclohexanedimethanol residues. PET can exist both as an amorphous (transparent) and as a semi-crystalline (opaque and white) material. PET can also exist as a semi crystalline transparent material.

Especially suitable polyethylene terephthalates to be used as the at least one polymer P2 have a high content of ethylene terephthalate units, such as at least 90 wt. -%, preferably at least 95 wt. -%, more preferably at least 97.5 wt. -%, based on the weight of the polyethylene terephthalate and/or a low content of dioxyethylene terephthalate units, such as not more than 10 wt. -%, preferably not more than 5 wt. -%, more preferably not more than 2.5 wt. -%, based on the weight of the polyethylene terephthalate.

According to one or more embodiments, the at least one polymer P2 is a polyethylene terephthalate, preferably having a melting temperature (T _m) , determined by differential scanning calorimetry (DSC) according to ISO 11357-3 standard using a heating rate of 2 ℃/min, of at or above 200 ℃, preferably at or above 225 ℃, more preferably at or above 250 ℃.

Suitable polyethylene terephthalates are commercially available, for example, under the trade name of

(from Goodyear Chemical Company) ; under the trade name of

(from Celanese) , and under the trade name of

(from Dupont) .

In embodiments, where the top composite layer further comprises a metallic layer arranged between the first polymeric layer and the second polymeric layer, the first polymeric layer and the metallic layer can be directly or indirectly connected to each other over at least a portion of their opposing major surfaces and the second polymeric layer and the metallic layer can be directly or indirectly connected to each other over at least a portion of their opposing major surfaces.

The expression “directly connected” is understood to mean in the context of the present disclosure that no further layer or substance is present between the two layers and that the opposing surfaces of the two layers are directly bonded to each other or adhere to each other. At the transition area between the two layers, the materials forming the layers can also be present mixed with each other. The expression “indirectly connected” is understood to mean in the context of the present disclosure that the layers are connected to each other via a connecting layer, such an adhesive layer.

According to one or more preferred embodiments, the first polymeric layer and the metallic layer are indirectly connected to each other over at least a portion of their opposing major surfaces and/or the second polymeric layer and the metallic layer are indirectly connected to each other over at least a portion of their opposing major surfaces.

The metallic layer is preferably a metallized plastic film or a metal film, more preferably an aluminum or aluminum alloy film, even more preferably an aluminum film. The thickness of the metallic film is preferably not more than 100 μm, more preferably not more than 50 μm, even more preferably not more than 25 μm. According to one or more embodiments, the metallic layer has a thickness of 1 –50 μm, preferably 2.5 –35 μm, more preferably 2.5 –25 μm, even more preferably 2.5 –15 μm.

In embodiments, where the top composite layer does not further comprise a metallic layer arranged between the first polymeric layer and the second polymeric layer, the first polymeric layer and the second polymeric layer can be directly or indirectly connected to each other over at least a portion of their opposing major surfaces. According to one or more preferred embodiments, the first and second polymeric layers are indirectly connected to each other over at least a portion of their opposing major surfaces, wherein the top composite layer does not comprise a metallic layer.

There are no strict limitations for the width and length of the top composite layer, and these depend on the intended use of the sealing device. The term “width” and “length” refer to the two perpendicular dimensions measured in the horizontal plane of the first and second major surfaces of a sheet-like element. Generally, the “width” of a sheet like element is the smaller of the horizontal dimensions of the sheet-like element. Consequently, the “width” of the top composite layer refers to the minor dimension measured in the horizontal plane of the top composite layer in a direction perpendicular to the length of the sealing device.

For example, the sealing device can be provided in form of a narrow strip, wherein the top composite layer has a width, for example, in the range of 10 –500 mm, such as 50 –350 mm, particularly 75 –250 mm. The sealing device can also be provided in form of a broad sheet, wherein the top composite layer has a width of, for example, in the range of 0.75 –5 m, such as 1 –3.5 m, particularly 1 –2.5 m. The sealing device of the present invention is typically provided in form of a prefabricated article, which is delivered to the construction site in form of rolls, which are then unwounded and cut to provide sheet-like articles having length of several times the width.

According to one or more embodiment, the top composite layer has a width of 10 –1000 mm, preferably 25 –750 mm, more preferably 50 –500 m, even more preferably 75 –350 mm, still more preferably 100 –350 mm. According to one or more embodiments, the sealing device is a roof repair tape, wherein the top composite layer preferably has a width of 10 –500 mm, preferably 25 –450 mm, more preferably 50 –350 m, even more preferably 75 –350 mm, still more preferably 100 –350 mm.

According to one or more embodiments, the at least one polymer P1 is polyamide and the top composite layer has a thickness of at least 25 μm, preferably at least 35 μm, such as 50 –300 μm, preferably 50 –250 μm, more preferably 50 –200 μm, even more preferably 65 –150 μm.

According to one or more further embodiments, the at least one polymer P1 is selected from the group consisting of polyvinylidene fluoride or polyvinyl fluoride and the top composite layer has a thickness of at least 50 μm, preferably of at least 75 μm, such as 100 –1000 μm, preferably 100 –500 μm, more preferably 100 –350 μm, even more preferably 125 –250 μm.

The thickness of the individual layers of the sealing device can be determined by using the measurement method as defined in DIN EN 1849-2 standard.

The sealing device further comprises an adhesive layer covering at least a portion of one of the primary exterior surfaces of the top composite layer. According to one or more embodiments, the adhesive layer is arranged on the outward facing side of the second polymeric layer opposite to the side of the first polymeric layer.

Preferably, the adhesive layer covers at least 50 %, more preferably at least 75 %, even more preferably at least 85 %, still more preferably at least 95 wt. -%of the area of the second major surface of the second polymeric layer. According to one or more embodiments, the adhesive layer covers essentially the whole area of the second major surface of the second polymeric layer, such as at least 97.5 %, preferably at least 99 %of the area of the second major surface of the second polymeric layer.

The adhesive layer can be present on the second major surface of the second polymeric layer in form of a continuous or a discontinuous adhesive layer. The term “continuous adhesive layer” refers in the present disclosure to layers consisting of one single area coated with an adhesive composition whereas the term “discontinuous adhesive layer” refers to layers consisting of two or more areas coated with an adhesive composition, which areas are not connected to each other to form a continuous layer. According to one or more embodiments, the adhesive layer is a continuous adhesive layer.

Preferably, the adhesive layer has a thickness of at least 10 μm, preferably at least 25 μm, more preferably at least 50 μm, such as 25 –500 μm, preferably 50 –350 μm, more preferably 75 –250 μm, even more preferably 75 –200 μm and/or a coating weight of at least 75 g/m ², preferably least 100 g/m ², more preferably at least 125 g/m ², such as 100 –1000 g/m ², preferably 125 –750 g/m ², more preferably 150 –500 g/m ², even more preferably 150 –350 g/m ².

According to one or more embodiments, the first major surface of the first polymeric layer forms one of the primary exterior surfaces of the sealing device. The term “primary exterior surface of the sealing device” refers in the present disclosure to the outermost surfaces of the sealing device.

Preferably, the adhesive layer is composed of a pressure sensitive adhesive (PSA) . The term “pressure sensitive adhesive” refers in the present disclosure to viscoelastic materials, which adhere immediately to almost any kind of substrates by application of light pressure and which are permanently tacky. The tackiness of an adhesive layer can be measured, for example, as a loop tack. Preferably, the pressure sensitive adhesive has a loop tack adhesion to a glass plate measured at a temperature of 23 ℃ of at least 2.5 N/25 mm, preferably at least 5 N/25 mm, more preferably at least 10 N/25 mm. The loop tack adhesion can be measured using a "FINAT test method no. 9 (FTM 9) as defined in FINAT Technical Handbook, 9th edition, published in 2014.

Suitable pressure sensitive adhesives to be used in the adhesive layer include water-based, solvent-based, hot-melt, and crosslinked pressure sensitive adhesives, such as UV-cured pressure sensitive adhesives. The term “hot-melt pressure sensitive adhesive (HM-PSA) ” refers in the present disclosure to solvent-free pressure sensitive adhesives, which are applied as a melt.

Suitable adhesives to be used in the adhesive layer include adhesives based on acrylic polymers, styrene block copolymers, amorphous polyolefins (APO) , amorphous poly-alpha-olefins (APAO) , vinyl ether polymers, bitumen, and elastomers such as, for example, styrene-butadiene rubber (SBR) , ethylene propylene diene monomer (EPDM) rubber, butyl rubber, polyisoprene, polybutadiene, natural rubber, polychloroprene rubber, ethylene-propylene rubber (EPR) , nitrile rubber, acrylic rubber, ethylene vinyl acetate rubber, and silicone rubber. In addition to the above-mentioned polymers, suitable pressure sensitive adhesives typically comprise one or more additional components including, for example, tackifying resins, waxes, and additives, for example, UV-light absorption agents, UV-and heat stabilizers, optical brighteners, pigments, dyes, and desiccants.

According to one or more embodiments, adhesive layer is composed of a plasticizer-resistant pressure sensitive adhesive. The term "plasticizer-resistant adhesive" designates in the present disclosure an adhesive that has improved resistance against softening caused by the migration of plasticizers into the adhesive from the substrate on which the adhesive has been coated.

Typical plasticizers used in substrates, such as in plasticized PVC membranes include, for example, linear and branched phthalates such as di-isononyl phthalate (DINP) , di-nonyl phthalate (L9P) , diallyl phthalate (DAP) , di-2-ethylhexyl-phthalate (DEHP) , dioctyl phthalate (DOP) , diisodecyl phthalate (DIDP) , and mixed linear phthalates (911P) . Other suitable plasticizers include phthalate-free plasticizers, such as trimellitate plasticizers, adipic polyesters, and biochemical plasticizers. Examples of suitable biochemical plasticizers include epoxidized vegetable oils, for example, epoxidized soybean oil and epoxidized linseed oil and acetylated waxes and oils derived from plants, for example, acetylated castor wax and acetylated castor oil.

According to one or more preferred embodiments, the adhesive layer is composed of an acrylic pressure sensitive adhesive. The term “acrylic pressure sensitive adhesive” designates in the present disclosure pressure sensitive adhesive compositions containing one or more acrylic polymers as the main polymer component.

Suitable acrylic pressure sensitive adhesives include, for example, water-based acrylic pressure sensitive adhesives, solvent-based acrylic pressure sensitive adhesives, acrylic hot-melt pressure sensitive adhesives (HM-PSA) , and UV-cured acrylic pressure sensitive adhesives.

The term “water-based acrylic pressure sensitive adhesive” designates in the present disclosure pressure sensitive adhesive compositions comprising one or more acrylic polymers, which have been formulated as an aqueous dispersion, an aqueous emulsion, or as an aqueous colloidal suspension. The term “aqueous dispersion” or “aqueous emulsion” refers to dispersions or emulsions containing water as the main continuous (carrier) phase. Typically, a water-based acrylic pressure sensitive adhesive comprises surfactants to stabilize the hydrophobic polymer particles and to prevent these from coagulating to each other. In case of a water-based acrylic pressure sensitive adhesive, the expression “adhesive layer is composed of an acrylic pressure-sensitive adhesive” is understood to mean that the adhesive layer has been obtained by using a water-based acrylic pressure sensitive adhesive composition. A water-based adhesive composition can be applied directly as a wet film to a surface of the top composite layer and then dried by allowing volatile components to evaporate. Alternatively, the water-based adhesive composition can be applied as a wet film to a carrier sheet, dried, and then transferred to a surface of the top composite layer.

The term “solvent-based acrylic pressure sensitive adhesive” designates in the present disclosure pressure sensitive adhesive compositions comprising a solvent and one or more acrylic polymers, which are substantially completely dissolved in the solvent. Typically, the solvent comprises at least 20 wt. -%, preferably at least 30 wt. -%, more preferably at least 40 wt. -%, of the total weight of the adhesive composition. Suitable solvents for the solvent-based acrylic pressure sensitive adhesives include, for example, alcohols, aliphatic and aromatic hydrocarbons, ketones, esters, and mixtures thereof. It is possible to use only a single solvent or a mixture of two or more solvents. Suitable solvent-based acrylic pressure sensitive adhesives are substantially water-free, for example, containing less than 10 wt. -%, preferably less than 5 wt. -%, more preferably less than 1 wt. -%of water, based on the total weight of the adhesive composition.

In case of a solvent-based acrylic pressure sensitive adhesive, the expression “adhesive layer is composed of an acrylic pressure sensitive adhesive” is understood to mean that the adhesive layer has been obtained by using a solvent-based acrylic pressure sensitive adhesive composition. A solvent based adhesive composition can be applied directly as a wet film to a surface of the top composite layer and then dried by allowing volatile components to evaporate. Alternatively, the solvent based adhesive composition can be applied as a wet film to a carrier sheet, dried, and then transferred onto a surface of the top composite layer.

The term “acrylic hot-melt pressure sensitive adhesive” refers in the present disclosure to solvent-free acrylic pressure sensitive adhesives, which are applied as a melt. In case of an acrylic hot-melt pressure sensitive adhesive, the adhesive layer has preferably been obtained by applying an acrylic hot-melt pressure sensitive adhesive composition as a melt onto a surface of the top composite layer and allowing the applied adhesive composition to cool and to solidify.

The term “UV-cured acrylic pressure sensitive adhesive” refers in the present disclosure to acrylic pressure sensitive adhesives, which have been cured by initiation of photochemical curing reactions. The term “curing” refers here to chemical reactions comprising forming of bonds resulting, for example, in chain extension and/or crosslinking of polymer chains. In case of an UV-cured acrylic pressure sensitive adhesive, the expression “adhesive layer is composed of an UV-cured acrylic pressure sensitive adhesive” is understood to mean that the adhesive layer has been obtained by using an UV-curable acrylic pressure sensitive adhesive composition. An UV-curable acrylic pressure sensitive adhesive composition can be applied as an adhesive film directly on a surface of the top composite layer followed by subjecting the adhesive film to UV-irradiation thereby to effect curing of the adhesive composition. Alternatively, the UV-curable acrylic pressure sensitive adhesive composition can be applied as an adhesive film onto a carrier sheet, subjected to UV-irradiation to obtain an at least partially cured adhesive film, which is then transferred to a surface of the top composite layer.

According to one or more embodiments, the acrylic pressure sensitive adhesive comprises at least 50 wt. -%, preferably at least 65 wt. -%, more preferably at least 75 wt. -%, even more preferably at least 85 wt. -%, of at least one acrylic polymer AP, based on the total weight of the acrylic pressure sensitive adhesive.

The term "acrylic polymer" designates in the present disclosure homopolymers, copolymers and higher inter-polymers of an acrylic monomer with one or more further acrylic monomers and/or with one or more other ethylenically unsaturated monomers. The term “acrylic monomer” refers in the present disclosure to monomers having at least one (meth) acryloyl group in the molecule. The term “ (meth) acryloyl” designates methacryloyl or acryloyl. Accordingly, “ (meth) acrylic” designates methacrylic or acrylic. A (meth) acryloyl group is also known as (meth) acryl group.

Examples of suitable acrylic monomers include, for example, (meth) acrylates, (meth) acrylic acid or derivatives thereof, for example, amides of (meth) acrylic acid or nitriles of (meth) acrylic acid, and (meth) acrylates with functional groups such as hydroxyl group-containing (meth) acrylates and alkyl (meth) acrylates.

According to one more embodiments, the at least one acrylic polymer AP has a glass transition temperature (T _g) , determined by dynamical mechanical analysis (DMA) as the peak of the measured loss modulus (G” ) curve using an applied frequency of 1 Hz and a strain level of 0.1 %, of below 0 ℃, preferably below -10 ℃ and/or an average molecular weight (M _n) in the range of 50’000 –1’000’000 g/mol, in particular 100’000 –750’000 g/mol, more preferably 150’000 –500’000 g/mol.

According to one or more embodiments, the acrylic polymer AP has been obtained from a monomer mixture comprising at least 45 wt. -%, preferably at least 55 wt. -%, more preferably at least 65 wt. -%, even more preferably at least 75 wt. -%, still more preferably at least 85 wt. -%, based on the total weight of the monomer mixture, of acrylic monomers of the following formula (I) :

where

R ₁ represents a hydrogen or a methyl group; and

R ₂ represents a branched, unbranched, cyclic, acyclic, or saturated alkyl group having from 2 to 30 carbon atoms.

Examples of preferred acrylic monomers of formula (I) include methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, n-butyl methacrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, n-octyl methacrylate, n-nonyl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate, and their branched isomers, as for example isobutyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, and also cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate or 3, 5-dimethyladamantyl acrylate.

Suitable comonomers to be used with the acrylic monomers of formula (I) include, for example, hydroxyl group containing acrylic monomers. Examples of suitable hydroxyl group containing acrylic monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl butyl (meth) acrylate, 2-hydroxy-hexyl (meth) acrylate, 6-hydroxy hexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate. Furthermore, suitable are (4-hydroxymethyl cyclohexyl) methyl acrylate, polypropylene glycol mono (meth) acrylate, N-hydroxyethyl (meth) acrylamide, and N-hydroxypropyl (meth) acrylamide. Preferably, hydroxyl group containing acrylic monomers are present in the monomer mixture. Preferably, the above listed hydroxyl group containing acrylic monomers comprise not more than 25 wt. -%, more preferably not more than 20 wt. -%, such as 0.01 –15 wt. -%, preferably 0.1 –10 wt. -%of the monomer mixture used for obtaining the at least one acrylic polymer AP.

Other suitable comonomers for the synthesis of at least one acrylic polymer AP include vinyl compounds, such as vinyl esters, vinyl halides, vinylidene halides, ethylenically unsaturated hydrocarbons with functional groups, and nitriles of ethylenically unsaturated hydrocarbons. Examples of suitable vinyl compounds include, for example, maleic anhydride, styrene, styrenic compounds, acrylic acid, beta-acryloyloxypropionic acid, vinylacetic acid, fumaric acid, crotonic acid, aconitic acid, trichloroacrylic acid, itaconic acid, and vinyl acetate.

According to one or more embodiments, the monomer mixture used for obtaining the at least one acrylic polymer AP comprises at least 0.1 wt. -%, preferably at least 0.5 wt. -%, such as 0.1 –20 wt. -%, preferably 0.5 –15 wt. %, of one or more vinyl compounds, preferably selected from the group consisting of maleic anhydride, styrene, styrenic compounds, (meth) acrylamides, N-substituted (meth) acrylamides, acrylic acid, beta-acryloyloxypropionic acid, vinylacetic acid, fumaric acid, crotonic acid, aconitic acid, dimethylacrylic acid, trichloroacrylic acid, itaconic acid, vinyl acetate, and amino group-containing (meth) acrylates.

In addition to the at least one acrylic polymer AP, the acrylic pressure sensitive adhesive may comprise one or more additional constituents including, for example, tackifying resins, waxes, and plasticizers as well as one or more additives such as, for example, UV-light absorption agents, UV-and heat stabilizers, optical brighteners, pigments, dyes, and desiccants. Preferably, the amount of such additional constituents and additives is not more than 25 wt. -%, more preferably not more than 15 wt. -%, even more preferably not more than 10 wt. -%, based on the total weight of the acrylic pressure sensitive adhesive.

According to one or more embodiments, the at least one acrylic polymer AP is obtained by radical polymerization of a starting composition comprising at least 35 wt. -%, preferably at least 45 wt. -%, more preferably at least 55 wt. -%, even more preferably at least 65 wt. -%, still more preferably at least 75 wt. -%, based on the total weight of the starting composition, of one or more acrylic monomers of formula (I) .

According to one or more further embodiments, the at least one acrylic polymer AP has been obtained by free radical polymerization of a starting composition comprising:

- At least 45 wt. -%, preferably at least 55 wt. -%, more preferably at least 65 wt. -%of one or more acrylic monomers of the formula (I) where R ₁ is a hydrogen or a methyl group and R ₂ is an alkyl group having from 2 to 9 carbon atoms and

- 0 –25 wt. -%, preferably 1.5 –20 wt. -%, of at least one vinyl compound, preferably selected from the group consisting of (meth) acrylic acid, beta-acryloyloxypropionic acid, vinylacetic acid, fumaric acid, crotonic acid, aconitic acid, dimethylacrylic acid, trichloroacrylic acid, itaconic acid, vinyl acetate, and hydroxy-functionalized (meth) acrylates and alkyl (meth) acrylates.

According to one or more preferred embodiments, the acrylic pressure sensitive adhesive is a solvent-based acrylic pressure sensitive adhesive composition, preferably comprising

- 25 –85 wt. -%, preferably 35 –75 wt. -%, of the at least one acrylic polymer AP,

- 0 –5 wt. -%, preferably 0.1 –3.5 wt. -%, of at least one curing agent,

- 5 –85 wt. -%, preferably 10 –75 wt. -%, of at least one organic solvent,

- 0 –35 wt. -%, preferably 2.5 –25 wt. -%, of at least one tackifying resin, all

- 0 –15 wt. -%, preferably 0.1 –10 wt. -%, of one or more additives selected from the group consisting of plasticizers, adhesion promoters, pigments, fillers, antioxidants, UV-stabilizers, and UV-absorbers, all the proportions being based on the total weight of the solvent-based acrylic pressure sensitive adhesive composition.

Suitable curing agents include, for example, metal complexes, such as titanium and aluminum acetyl acetonates and triacetylacetones, and multi-functional isocyanates, for example, aromatic isocyanates, such as tolylene 2, 4-and 2, 6-diisocyanate and any desired mixtures of these isomers (TDI) and diphenylmethane 4, 4’-, 2, 4'-and 2, 2'-diisocyanate and any desired mixtures of these isomers (MDI) ; aliphatic isocyanates, such as hexamethylene 1, 6-diisocyanate (HDI) , 2, 2, 4-and 2, 4, 4-trimethyl-hexamethylene diisocyanate and any desired mixtures of these isomers (TMDI) , tetramethylene diisocyanate, bis (4-isocyanato hexyl) methane; cycloaliphatic diisocyanates, such as 1-isocyanato-3, 3, 5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) , 4, 4′-Methylenebis (cyclohexyl isocyanate) (HMDI) , and heterocyclic diisocyanates, such as uretdione of 2, 4 diisocyanato toluene.

According to one or more embodiments, the at least one curing agent is a multi-functional isocyanate, preferably selected from the group consisting of aromatic and heterocyclic isocyanates, more preferably from the group consisting of tolylene 2, 4-and 2, 6-diisocyanate and any desired mixtures of these isomers (TDI) and diphenylmethane 4, 4’-, 2, 4'-and 2, 2'-diisocyanate and any desired mixtures of these isomers (MDI) , and uretdione of 2, 4 diisocyanato toluene.

The term "organic solvent" refers to an organic substance that is able of at least partially dissolving another substance. In particular, the term “organic solvent” refers to an organic solvent that is liquid at a temperature of 25 ℃.

Suitable organic solvents include, for example, aliphatic esters, aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, aromatic hydrocarbons, aliphatic alcohols, aliphatic ketones and mixtures thereof. According to one or more embodiments, the at least one solvent is selected from the group consisting of pentane, hexane, heptane, octane, cyclohexene, cyclohexane, benzene, naphthalene, toluene, xylene, methanol, ethanol, isopropanol, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl n-butyl ketone, and tetrahydrofuran.

Suitable organic solvents include solvents having a standard boiling point of not more than 250℃, preferably not more than 200℃. The term 'standard boiling point' refers in the present disclosure to boiling point measured at a pressure of 1 bar. The standard boiling point of a substance or composition can be determined, for example, by using an ebulliometer.

According to one or more embodiments, the at least one organic solvent has a relative evaporation rate determined according to DIN 53170: 2009-08 standard of not more than 40, preferably not more than 30, more preferably not more than 20 and/or a Hildebrandt solubility parameter δ in the range of 5 –40 MPa ^1/2, more preferably 10 –30 MPa ^1/2.

The relative evaporation rate is the quotient of the evaporation time of the test liquid and that of diethyl ether as reference liquid at a temperature of 293 ± 2 K and at a relative humidity of 65 %± 5 %.

The Hildebrandt solubility parameter δ can be calculated using the equation:

, wherein ΔH _v is heat of vaporization,

R is gas constant,

T is temperature, and

V _m is molar volume.

The term “tackifying resin” designates in the present disclosure resins that in general enhance the adhesion and/or tackiness of an adhesive composition. The term “tackiness” designates in the present disclosure the property of a substance of being sticky or adhesive by simple contact. The tackiness can be measured, for example, as a loop tack. Preferred tackifying resins are tackifying at a temperature of 25 ℃.

Examples of suitable tackifying resins to be used in the acrylic pressure sensitive adhesive include natural resins, synthetic resins and chemically modified natural resins.

Examples of suitable natural resins and chemically modified natural resins include rosins, rosin esters, phenolic modified rosin esters, and terpene resins. The term “rosin” is to be understood to include gum rosin, wood rosin, tall oil rosin, distilled rosin, and modified rosins, for example dimerized, hydrogenated, maleated and/or polymerized versions of any of these rosins.

Suitable terpene resins include copolymers and terpolymers of natural terpenes, such as styrene/terpene and alpha methyl styrene/terpene resins; polyterpene resins generally resulting from the polymerization of terpene hydrocarbons, such as the bicyclic monoterpene known as pinene, in the presence of Friedel-Crafts catalysts at moderately low temperatures; hydrogenated polyterpene resins; and phenolic modified terpene resins including hydrogenated derivatives thereof.

The term “synthetic resin” refers to compounds obtained from the controlled chemical reactions such as polyaddition or polycondensation between well-defined reactants that do not themselves have the characteristic of resins.

Monomers that may be polymerized to synthesize the synthetic resins may include aliphatic monomer, cycloaliphatic monomer, aromatic monomer, or mixtures thereof. Aliphatic monomers can include C ₄, C ₅, and C ₆ paraffins, olefins, and conjugated diolefins. Examples of aliphatic monomer or cycloaliphatic monomer include butadiene, isobutylene, 1, 3-pentadiene, 1, 4-pentadiene, cyclopentane, 1-pentene, 2-pentene, 2-methyl-1-pentene, 2-methyl-2-butene, 2-methyl-2-pentene, isoprene, cyclohexane, 1-3-hexadiene, 1-4-hexadiene, cyclopentadiene, dicyclopentadiene, and terpenes. Aromatic monomer can include C ₈, C ₉, and C ₁₀ aromatic monomer. Examples of aromatic monomer include styrene, indene, derivatives of styrene, derivatives of indene, coumarone and combinations thereof.

Particularly suitable synthetic resins include synthetic hydrocarbon resins made by polymerizing mixtures of unsaturated monomers that are obtained as by-products of cracking of natural gas liquids, gas oil, or petroleum naphthas. Synthetic hydrocarbon resins obtained from petroleum-based feedstocks are referred in the present disclosure as “hydrocarbon resins” or “petroleum hydrocarbon resins” . These include also pure monomer aromatic resins, which are made by polymerizing aromatic monomer feedstocks that have been purified to eliminate color causing contaminants and to precisely control the composition of the product. Hydrocarbon resins typically have a relatively low average molecular weight (M _n) , such in the range of 250 –5000 g/mol and a glass transition temperature, determined by dynamical mechanical analysis (DMA) as the peak of the measured loss modulus (G” ) curve using an applied frequency of 1 Hz and a strain level of 0.1 %, of above 0 ℃, preferably equal to or higher than 15 ℃, more preferably equal to or higher than 30 ℃.

Examples of suitable hydrocarbon resins include C5 aliphatic hydrocarbon resins, mixed C5/C9 aliphatic/aromatic hydrocarbon resins, aromatic modified C5 aliphatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, mixed C5 aliphatic/cycloaliphatic hydrocarbon resins, mixed C9 aromatic/cycloaliphatic hydrocarbon resins, mixed C5 aliphatic/cycloaliphatic/C9 aromatic hydrocarbon resins, aromatic modified cycloaliphatic hydrocarbon resins, C9 aromatic hydrocarbon resins, polyterpene resins, and copolymers and terpolymers of natural terpenes as well hydrogenated versions of the aforementioned hydrocarbon resins. The notations "C5" and "C9" indicate that the monomers from which the resins are made are predominantly hydrocarbons having 4-6 and 8-10 carbon atoms, respectively. The term “hydrogenated” includes fully, substantially and at least partially hydrogenated resins. Partially hydrogenated resins may have a hydrogenation level, for example, of 50 %, 70 %, or 90 %.

Suitable hydrocarbon resins are commercially available, for example, under the trade name of

series,

Plus,

Extra, and

STS (all from Cray Valley) ; under the trade name of

1000 series,

2000 series, and

5000 series (all from Exxon Mobile Chemical) ; under the trade name of

T series,

TT series,

TD series,

TL series,

TN series,

TK series, and

TV series (all from

Novares GmbH) ; and under the trade name of

and

(all from Eastman Chemicals) .

According to one or more embodiments, the at least one tackifying resin has:

- a softening point measured by a Ring and Ball method according to DIN EN 1238 standard in the range of 65 –185 ℃, preferably 75 –175 ℃, more preferably 80 –170 ℃ and/or

- an average molecular weight (M _n) in the range of 150 –5000 g/mol, preferably 250 –3500 g/mol, more preferably 250 –2500 g/mol and/or

- a glass transition temperature (T _g) determined by dynamical mechanical analysis (DMA) as the peak of the measured loss modulus (G” ) curve using an applied frequency of 1 Hz and a strain level of 0.1 %of at or above 0 ℃, preferably at or above 15 ℃, more preferably at or above 25 ℃, even more preferably at or above 30 ℃, still more preferably at or above 35 ℃.

According to one or more embodiments, the acrylic pressure sensitive adhesive is an UV-cured acrylic pressure sensitive adhesive (PSA) or an UV-cured acrylic hot-melt pressure sensitive adhesive (HM-PSA) .

According to one or more embodiments, the acrylic pressure sensitive adhesive is an at least partially cured UV-curable acrylic pressure sensitive adhesive composition comprising:

- At least 65 wt. -%, preferably at least 75 wt. -%, more preferably at least 85 wt. -%, of the at least acrylic polymer AP,

- 0.01 –5 wt. -%, preferably 0.1 –1 wt. -%, of at least one cross-linking agent,

- 0.1 –5 wt. -%, preferably 0.25 –2.5 wt. -%, of at least one photo initiator, and

- 0 –30 wt. -%, preferably 5 –20 wt. -%, of at least one tackifying resin, all proportions being based on the total weight of the UV-curable acrylic pressure sensitive adhesive composition.

The at least one cross-linking agent is preferably a multifunctional acrylate selected from the group consisting of butanediol dimethacrylate, ethyleneglycol dimethacrylate, diethyleneglycol dimethacrylate, triethyleneglycol dimethacrylate, trimethylolpropane trimethacrylate, butanediol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, and tripropyleneglycol diacrylate, trimethylolpropane ethoxy triacrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate, propylene glycol dimethacrylate, dipropylene glycol diacrylate, dipentaerythritol hydroxy pentaacrylate, neopentyl glycol propoxylate diacrylate, bisphenol A ethoxylate dimethacrylate, alkoxylated hexanediol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated neopentyl glycol diacrylate, propoxylated glyceryl triacrylate, polybutadiene diacrylate, and polybutadiene dimethacrylate.

Suitable compounds to be used as the at least one photo initiator include, for example, benzoic ethers, dialkoxyacetophenones, alpha-hydroxycyclohexyl aryl ketones, alpha-ketophenylacetate esters, benzyldialkylketals, chloro-and alkylthioxanthones and alpha-amino-and alpha-hydroxyalkyl aryl ketones.

According to one or more further embodiments, the acrylic pressure sensitive adhesive is an UV-cured acrylic hot-melt pressure sensitive adhesive (HM-PSA) , wherein the at least one acrylic polymer AP comprises polymerized units that serve as photoinitiators. Suitable polymerized units that serve as photo initiators may be obtained by using copolymerizable photo initiators, such as acetophenone and benzophenone derivatives.

According to one or more embodiments, the acrylic pressure sensitive adhesive is an at least partially cured UV-curable acrylic hot-melt pressure sensitive adhesive composition comprising.

- At least 65 wt. -%, preferably at least 85 wt. -%, of at least one UV-curable acrylic polymer UV-AP having one or more photo initiator groups,

- 0 –15 wt. -%, preferably 0.1 –10 wt. -%, of at least one reactive diluent, and

- 0 –20 wt. -%, preferably 1 –15 wt. -%, of at least one filler and/or at least one flame retardant, all proportions being based on the total weight of the adhesive composition.

According to one or more embodiments, the at least one UV-curable acrylic polymer UV-AP comprises 0.05 –10 wt. -%, preferably 0.1 –5 wt. -%, more preferably 0.1 –1.5 wt. -%, based on the weight of the polymer, of at least one ethylenically unsaturated compound having a photo initiator group.

Suitable UV-curable acrylic hot-melt pressure sensitive adhesives are commercially available, for example, under the trade name of

(from BASF) ; under the trade name of

(form Ashland Chemical) ; and under the trade name of

(from NovaMelt) .

According to one or more embodiments, the sealing device further comprises a release liner arranged on the outward facing side of the adhesive layer opposite to the side of the top composite layer.

Preferably, the adhesive layer and the release liner are directly connected to each other over at least portion of their opposing major surfaces. The release liner may be used to prevent premature unwanted adhesion and to protect the adhesive layer from moisture, fouling, and other environmental factors. In case the sealing device is provided in form of rolls, the release liner enables ease of unwind without sticking of the adhesive to the back side of the sealing device. The release liner may be sliced into multiple sections to allow portioned detachment of the liner from the adhesive layer.

Suitable materials for the release liner include Kraft paper, polyethylene coated paper, silicone coated paper as well as polymeric films, for example, polyethylene, polypropylene, and polyester films coated with polymeric release agents selected from silicone, silicone urea, urethanes, waxes, and long chain alkyl acrylate release agents.

According to one or more embodiments, sealing device is composed of the layers i) to iii) .

The preferences given above for the top composite layer, the first polymeric layer, the second polymeric layer, the metallic layer, the adhesive layer and the release liner apply equally to all subjects of the present invention unless otherwise stated.

Another subject of the present invention is a method for producing a sealing device of the present invention, the method comprising steps of:

I) Providing the top composite layer (2) and

II) Providing the adhesive layer (3) on one of the primary exterior surfaces of the top composite layer (2) , and

III) Optionally covering the outwardly facing surface of the adhesive layer (3) opposite to the side of the top composite layer (2) with a release liner (4) .

The step of providing the top composite layer preferably comprises providing the first and second polymeric layers and optionally the metallic layer, and coupling the layers to each other.

The coupling of the individual layers can be conducting using any conventional techniques known to a person skilled in the art, such as heat-melting, thermo-laminating, and adhesive lamination. The term “thermo-lamination” refers in the present disclosure to a process in which the respective layers are bonded to each other by the application of heat and pressure and without using an adhesive, such that the layers remain adhered to each other when the pressure is removed. Furthermore, the term “adhesive lamination” refers to a process in which the respective layers are bonded to each by using an adhesive composition.

The further details of the method for producing the sealing device depend on the embodiment of the sealing device, particularly on the type of the adhesive layer.

In case the adhesive layer is composed of a water-or a solvent-based pressure sensitive adhesive, step II) of the method can comprise applying the adhesive composition as a wet film onto one of the primary exterior surfaces of the top composite layer and drying the wet adhesive film by allowing the volatile components to evaporate. Alternatively, the adhesive composition can be applied as a wet film onto a surface of a carrier sheet, dried by allowing at least a portion of the volatile components to evaporate, and then transferred to one of the primary exterior surfaces of the top composite layer.

In case the adhesive layer is composed of a hot-melt pressure sensitive adhesive, step II) of the method can comprise heating the adhesive composition to provide a melted adhesive composition, applying the melted adhesive composition onto one of the primary exterior surfaces of the top composite layer, and allowing the applied adhesive composition to cool and to solidify.

In case the adhesive layer is composed of an UV-cured pressure sensitive adhesive, step II) of the method can comprise applying the adhesive composition as a film onto one of the primary exterior surfaces of the top composite layer and subjecting the adhesive film to UV-radiation thereby to effect curing of the adhesive composition. Alternatively, the adhesive composition can be applied as a film to a carrier sheet, cured with UV-radiation, and then transferred to one of the primary exterior surfaces of the top composite layer. The step of subjecting the applied adhesive film to UV-radiation can also be conducted after adhesive film has been transferred to the surface of the top composite layer or after the adhesive layer has been covered with a release liner in step III) .

An adhesive composition may be applied to a surface of the top composite layer by using any conventional techniques such as slot die coating, extrusion coating, roller coating, direct gravure coating, offset gravure coating, reverse gravure roll-coating, powder dispersion, or spray lamination techniques.

According to one or more embodiments, the method for producing a sealing device comprises a further step IV) of winding the composite element obtained in step II) or III) into a roll.

Another subject of the present invention is a method for waterproofing a substrate (8) , the method comprising steps of:

I. Providing a sealing device (1) according to the present invention,

II. Applying the sealing device (1) onto a surface of the substrate (8) such that at least a portion of the outer major surface of the adhesive layer (3) is directly connected to the surface of the substrate (8) , and

III. Pressing the sealing device (1) against the surface of the substrate (8) with a pressure sufficient to affect adhesive bonding between the top composite layer (2) and the surface of the substrate (8) .

Figure 3 shows a schematic presentation of the method for waterproofing a substrate.

The sealing device (1) is typically provided in form of a roll and cut to a suitable length before being applied onto the surface of the substrate (8) , as shown in Figure 3.1. In case the sealing device comprises a release liner, it is removed before the sealing device is applied onto the surface of the substrate. It may be preferred that the surface of the substrate is pre-treated by chemical and/or physical cleaning methods, such as de-greasing or brushing and/or by the application of an adhesion promoter, an adhesion promoter solution or a primer, before the application of the sealing device. In general, it is not necessary to pre-treat the surface of the substrate by the application of an adhesion promoter, an adhesion promoter solution or a primer.

In order to bond the top composite layer onto the surface of the substrate, the sealing device is pressed against the surface of the substrate. Pressing of the sealing device can be conducted, for example, by using a roller or a scraper as shown in Figure 3.1. Figure 3.2 shows the sealing device after it has been pressed against the surface of the substrate to affect adhesive bonding between the top composite layer and the surface of the substrate. The substrate as depicted in Figures 3.1 and 3.2 can have a substantially planar surface, such that of an existing roofing membrane, or a corrugated surface with consecutive peaks and valleys, such as that of a metal roof sheet.

According to one or more embodiments, the substrate is a roof substrate, preferably a metal roof sheet, such as a steel roof sheet, or an existing roofing membrane, such as a thermoplastic polyolefin (TPO) membrane, a polyvinylchloride (PVC) membrane, or a bitumen membrane, preferably a metal roof sheet, PVC membrane, or a bitumen membrane.

According to one or more embodiments, the substrate is damaged metal roof sheet, preferably a damaged steel roof sheet, or a damaged roofing membrane, preferably a damaged PVC membrane or a damaged bitumen membrane.

A suitable PVC membrane to be used as the roof substrate preferably comprises at least one PVC-based waterproofing layer having a first and a second major surface. The term “PVC-based layer” refers in the present disclosure to layers comprising PVC resin as the main polymer component.

According to one or more embodiments, the PVC-based waterproofing layer comprises:

- 25 –65 wt. -%, preferably 30 –60 wt. -%, of a PVC resin,

- 15 –50 wt. -%, preferably 20 –40 wt. -%, of at least one plasticizer, and

- 0 –30 wt. -%, preferably 0 –20 wt. -%, of at least one inert mineral filler, all proportions being based on the total weight of the PVC-based waterproofing layer.

Preferably, the PVC resin has a K-value determined by using the method as described in ISO 1628-2-1998 standard in the range of 50 –85, more preferably 65 –75. The K-value is a measure of the polymerization grade of the PVC-resin and it is determined from the viscosity values of the PVC homopolymer as virgin resin, dissolved in cyclohexanone at 30℃.

Preferably, the composition of the PVC-based waterproofing layer has a glass transition temperature (T _g) , determined by dynamical mechanical analysis (DMA) using an applied frequency of 1 Hz and a strain level of 0.1 %, of below –20 ℃, more preferably below –25 ℃.

Suitable plasticizers for the PVC-based waterproofing layer include but are not restricted to, linear or branched phthalates such as di-isononyl phthalate (DINP) , di-nonyl phthalate (L9P) , diallyl phthalate (DAP) , di-2-ethylhexyl-phthalate (DEHP) , dioctyl phthalate (DOP) , diisodecyl phthalate (DIDP) , and mixed linear phthalates (911P) . Other suitable plasticizers include phthalate-free plasticizers, such as trimellitate plasticizers, adipic polyesters, and biochemical plasticizers. Examples of biochemical plasticizers include epoxidized vegetable oils, for example, epoxidized soybean oil and epoxidized linseed oil and acetylated waxes and oils derived from plants, for example, acetylated castor wax and acetylated castor oil.

According to one or more embodiments, the at least one plasticizer is selected from the group consisting of phthalates, trimellitate plasticizers, adipic polyesters, and biochemical plasticizers.

The term “inert mineral filler” designates in the present document mineral fillers, which, unlike mineral binders are not reactive with water, i.e. do not undergo a hydration reaction in the presence of water. Preferably the at least one inert mineral filler is selected from the group consisting of sand, granite, calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, magnesium carbonate, calcium hydroxide, calcium aluminates, silica, fumed silica, fused silica, aerogels, glass beads, hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, and zeolites.

According to one or more embodiments, the at least one inert mineral filler is present in the PVC-based waterproofing layer in an amount of 5 –30 wt. -%, preferably 10 –30 wt.-%, more preferably, 15 –30 wt. -%, based on the total weight of the PVC-based waterproofing layer.

The PVC-based waterproofing layer can further comprise one or more additives, for example, UV-and heat stabilizers, UV-absorbers, antioxidants, flame retardants, dyes, pigments such as titanium dioxide and carbon black, matting agents, antistatic agents, impact modifiers, biocides, and processing aids such as lubricants, slip agents, antiblock agents, and denest aids.

According to one or more embodiments, the PVC membrane has a thickness of 0.35 –5 mm, preferably 0.55 –4.5 mm, more preferably 0.75 –3 mm, even more preferably 0.85 –2.5 mm, still more preferably 1.0 –2.5 mm.

Preferably, one of the first and second major surfaces of the PVC-based waterproofing layer forms the surface of the substrate, which is directly contacted with the adhesive layer of the sealing device to form an adhesive bond between the top composite layer and the substrate.

A suitable bitumen membrane to be used as the roof substrate preferably comprises at least one bitumen-based waterproofing layer having a first and a second major surface. The term “bitumen-based layer” refers in the present disclosure to layers comprising at least 50 wt. -%of bitumen or a polymer-modified bitumen.

The term "bitumen" designates blends of heavy hydrocarbons, having a solid consistency at room temperature, which are normally obtained as vacuum residue from refinery processes, which can be distillation (topping or vacuum) and conversion (thermal cracking and visbreaking) processes of suitable crude oils. Furthermore, the term “bitumen” also designates natural and synthetic bitumen as well as bituminous materials obtained from the extraction of tars and bituminous sands.

The bitumen contained in a bitumen-based waterproofing layer is typically modified with one or more polymers in order to improve the mechanical properties of the bitumen component.

According to one or more embodiments, the bitumen-based waterproofing layer comprises:

- 50 –99 wt. -%, preferably 75 –95 wt. -%, of bitumen,

- 1 –35 wt. -%, preferably 5 –25 wt. -%, of at least one modifying polymer, and

- 0 –50 wt. -%, preferably 0 –45 wt. -%, of at least one inert mineral filler, all proportions being based on the total weight of the bitumen-based waterproofing layer.

Suitable polymers to be used in at the at least one modifying polymer include, for example, atactic polypropylenes (APP) , amorphous polyolefins (APO) , styrene block copolymers, in particular SIS, SBS, and SEBS block copolymers as well as elastomers, for example, styrene-butadiene rubber (SBR) , ethylene propylene diene monomer (EPDM) rubber, polyisoprene, polybutadiene, natural rubber, polychloroprene rubber, ethylene-propylene rubber (EPR) , nitrile rubbers, and acrylic rubbers. Suitable amorphous polyolefins (APO) include, for example, homopolymers of propylene and copolymers of propylene with one or more α-olefin comonomer, such as, for example, ethylene, 1-butene, 1-hexene, 1-octene and 1-decene.

Suitable inert mineral fillers include those described above suitable for use in the PVC-based waterproofing layer.

According to one or more embodiments, the bitumen membrane further comprises a support sheet that is at least partially embedded, preferably fully embedded into the bitumen-based waterproofing layer. By the expression “fully embedded” is understood to mean that the support sheet is substantially fully covered by the matrix of the bitumen-based waterproofing layer.

Preferably, the support sheet comprises at least one layer of fiber material, preferably selected from the group consisting of non-woven fabrics, woven fabrics, and laid scrims.

The term “non-woven fabric” refers in the present disclosure to materials composed of fibers, which are bonded together by using chemical, mechanical, or thermal bonding means, and which are neither woven nor knitted. Non-woven fabrics can be produced, for example, by using a carding or needle punching process, in which the fibers are mechanically entangled to obtain the nonwoven fabric. In chemical bonding, chemical binders such as adhesive materials are used to hold the fibers together in a non-woven fabric. Typical materials for the non-woven fabrics include synthetic organic and inorganic fibers.

The term “laid scrim” refers in the present disclosure web-like non-woven products composed of at least two sets of parallel yarns (also designated as weft and warp yarns) , which lay on top of each other and are chemically bonded to each other. The yarns of a non-woven scrim are typically arranged with an angle of 60 –120°, such as 90 ± 5°, towards each other thereby forming interstices, wherein the interstices occupy more than 60%of the entire surface area of the laid scrim. Typical materials for laid scrims include metal fibers, inorganic fibers, in particular glass fibers, and synthetic organic fibers, in particular polyester, polypropylene, polyethylene, and polyethylene terephthalate (PET) .

According to one or more embodiments, the bitumen membrane has a thickness of 0.35 –5.0 mm, preferably 0.55 –4.5 mm, more preferably 0.75 –3.5 mm, even more preferably 0.85 –3 mm, still more preferably 1.0 –2.5 mm.

Preferably, one of the first and second major surfaces of the bitumen-based waterproofing layer forms the surface of the substrate, which is directly contacted with the adhesive layer of the sealing device to form an adhesive bond between the top composite layer and the substrate.

The preferences given above to the PVC and bitumen membranes apply equally to all subjects of the present invention unless otherwise stated.

Another subject of the present invention is a waterproofed structure comprising a sealing device (1) according to the present invention, wherein at least a portion of the second major surface of the second polymeric layer is bonded to the surface of the substrate (8) via the adhesive layer (3) .

According to one or more embodiments, the substrate is a roof substrate, preferably a metal roof sheet, such as a steel roof sheet, or an existing roofing membrane, such as a thermoplastic polyolefin (TPO) membrane, a polyvinylchloride (PVC) membrane, or a bitumen membrane, preferably a metal roof sheet, a PVC membrane, or a bitumen membrane.

Suitable and preferred embodiments of the PVC membrane and the bitumen membrane have already been described above.

According to one or more embodiments, the substrate is damaged metal roof sheet, preferably a damaged steel roof sheet, or a damaged roofing membrane, preferably a damaged PVC membrane or a damaged bitumen membrane, more preferably a damaged PVC membrane.

Still another subject of the present invention is use of the sealing device of the present invention for reparation of damaged roof substrates, preferably of damaged metal roof sheets or damaged roofing membranes, such as PVC membranes and bitumen membranes, preferably PVC membranes.

Examples

Preparation of test specimens

An exemplary sealing device had the following buildup:

i) A top composite layer composed of

a) A first polymeric layer composed of polyamide film, thickness 30 μm,

b) A second polymeric layer composed of polyethylene film, thickness 30 μm, and

c) An aluminum film arranged between the first polymeric layer and the second polymeric layer, and

ii) An adhesive layer composed of a solvent-based acrylic pressure sensitive adhesive, thickness 100 μm, and

iii) A release liner covering the outer surface of the adhesive layer.

The exemplary sealing device was prepared by applying the adhesive layer to the bottom surface of the second polymeric layer followed by covering the adhesive layer with a conventional release liner. The thus obtained sealing device was then tested for its adhesive and mechanical properties.

The values for holding power from stainless steel plate, heat resistance of the adhesive bond, low temperature flexibility, and adhesive shear and peel resistance from a PVC sheet and an aluminum plate are shown in Table 1.

Holding power

The measurements for the holding power were conducted according to GB/T 4851-1998 standard. A sample having dimensions of 150 x 50 mm was cut from the exemplary sealing device, folded over itself, and adhered to a first stainless-steel plate and to a second stainless-steel plate via the adhesive layer as shown in Figure 5 below. The bonding area between the portion of the adhesive layer and the steel plates had dimensions of 50 x 50 mm. A weight of 1 kg was attached to the lower end of the second stainless-steel plate and the length of the time period between bonding of the sample and adhesive bond failure (detachment of the sample from the steel plate) was recorded.

In Figure 5, number 1 refers to the first and second stainless-steel plates, number 2 refers to the sample, and number 3 refers to the 1 kg weight attached to the lower end of the second steel plate.

Low temperature flexibility

The measurements for the low temperature flexibility were conducted according to GB/T 12953-2003 standard. In the measurement, a sample of the exemplary sealing device was bended at a temperature of -40 ℃ and then visually analyzed for the presence of cracks in the polymeric layers.

Shear and peel strength

Samples having dimensions of 50 x 250 mm were cut from the exemplary sealing device and bonded via the adhesive layer to a PVC sheet or an aluminum plate followed by measurement of the sheer and peel resistances. All the tests were conducted at a temperature of 23 ±2 ℃. The measurements for shear resistance were conducted according to GB/T 12953-2003 standard and the measurements for the peel resistance at an angle of 180° were conducted according to GB/T 2792-2014 standard.

Claims

A sealing device (1) comprising:

i) A top composite layer (2) having a first and a second primary exterior surface,

ii) An adhesive layer (3) covering at least a portion of one of the primary exterior surfaces of the top composite layer (2) ,

iii) Optionally a release liner (4) covering the outwardly facing surface of the adhesive layer (3) opposite to the side of the top composite layer (3) ,

wherein the top composite layer comprises:

a) A first polymeric layer (5) having a first and a second major surface and comprising at least 50 wt-%of at least one polymer P1 selected from the group consisting of polyamide, polyvinylidene fluoride, and polyvinyl fluoride, and

b) A second polymeric layer (6) having a first and a second major surface and comprising at least 50 wt. -%of at least one polymer P2 selected from the group consisting of polyethylene and polyethylene terephthalate.
The sealing device (1) according to claim 1, characterized in that the at least one polymer P1 is polyamide and the top composite layer (2) further comprises a metallic layer (7) arranged between the first polymeric layer (5) and the second polymeric layer (6) or characterized in that the at least one polymer P1 is selected from the group consisting of polyvinylidene fluoride and polyvinyl fluoride and the top composite layer (2) is composed of the first and second polymeric layers (5, 6) .
The sealing device (1) according to claim 2, characterized in that the metallic layer (7) is an aluminum or aluminum alloy film.
The sealing device (1) according to claim 2 or 3, characterized in that the metallic layer (7) has a thickness of 1 –50 μm, preferably 2.5 –35 μm.
The sealing device (1) according to any one of previous claims, characterized in that the top composite layer (2) has a width of 10 -1000 mm, preferably 50 –500 mm.
The sealing device (1) according to any one of previous claims, characterized in that the at least one polymer P1 is polyamide and the top composite layer (2) has a thickness of at least 25 μm, preferably 50 –250 μm or characterized in that the at least one polymer P1 is selected from the group consisting of polyvinylidene fluoride or polyvinyl fluoride and the top composite layer (2) has a thickness of at least 50 μm, preferably 100 –1000 μm.
The sealing device (1) according to any one of previous claims, characterized in that the adhesive layer (3) is arranged on the outward facing side of the second polymeric layer (6) opposite to the side of the first polymeric layer (5) .
The sealing device (1) according to any one of previous claims, characterized in that the adhesive layer (3) has a thickness of at least 25 μm, preferably 25 –500 μm.
The sealing device (1) according to any one of previous claims, characterized in that the adhesive layer (3) is composed of a plasticizer resistant pressure sensitive adhesive.
The sealing device (1) according to any one of previous claims, characterized in that the adhesive layer (3) is composed of an acrylic pressure sensitive adhesive, preferably a solvent-based acrylic pressure sensitive adhesive.
The sealing device according to any one of previous claims, characterized in that the sealing device (1) is composed of the layers i) to iii) .
A method for producing a sealing device (1) according to any one of previous claims, the method comprising steps of:

I) Providing the top composite layer (2) and

II) Providing the adhesive layer (3) on one of the primary exterior surfaces of the top composite layer (2) , and

III) Optionally covering the outwardly facing surface of the adhesive layer (3) opposite to the side of the top composite layer (2) with a release liner (4) .
A method for waterproofing a substrate (8) , the method comprising steps of:

I. Providing a sealing device (1) according to any one of claims 1-11,

II. Applying the sealing device (1) onto a surface of the substrate (8) such that at least a portion of the outer major surface of the adhesive layer (3) is directly connected to the surface of the substrate (8) , and

III. Pressing the sealing device (1) against the surface of the substrate (8) with a pressure sufficient to affect adhesive bonding between the top composite layer (2) and the surface of the substrate (8) .
The method according to claim 16, characterized in that the substrate (8) is a roof substrate, preferably a metal roof sheet or an existing roofing membrane.
A waterproofed structure comprising a substrate (8) and a sealing device (1) according to any one of claims 1-11, characterized in that at least a portion of the second major surface of the second polymeric layer is bonded to the surface of the substrate (8) via the adhesive layer (3) .
Use of the sealing device (1) according to any one of claims 1-11 for reparation of damaged roof substrates.