EP2834292A1

EP2834292A1 - Pvc membrane with reduced plasticizer migration

Info

Publication number: EP2834292A1
Application number: EP13716987.6A
Authority: EP
Inventors: Elyes Jendoubi; Carine Kerber
Original assignee: Sika Technology AG
Current assignee: Sika Technology AG
Priority date: 2012-04-02
Filing date: 2013-04-02
Publication date: 2015-02-11
Also published as: JP2015519221A; JP6105714B2; US20150118404A1; EP2647660A1; CN104220498B; US9428912B2; RU2014136898A; CN104220498A; WO2013150009A1

Abstract

The present invention relates to a membrane comprising a bulkhead layer, wherein more than 50% by weight of the bulkhead layer is composed of PVC, and a barrier layer. The barrier layer can, on the one hand, be a barrier layer S1, wherein the barrier layer S1 has a polyvinyl alcohol layer comprising more than 50% by weight of copolymer PA, which is connected to the bulkhead layer by a polyurethane layer, wherein more than 10% by weight of the polyurethane layer is composed of polyurethane PUR. The barrier layer can, on the other hand, be a barrier layer S2, wherein the barrier layer S2 has a composition comprising 5-50% by weight of polyurethane PUR and 50-95% by weight of copolymer PA. The membranes according to the invention have significantly lower plasticizer migration compared to the membranes of the prior art and are distinguished by improved resistance to aging, particularly as regards the adherence of the barrier layer on the bulkhead layer, and imperviousness to damp.

Description

PVC ME MB RAN WITH REDUCED SOFT MACHERMIGRATION

Technical area

The invention relates to the field of seals in the construction sector, in particular the roof coverings.

State of the art

For waterproofing in the construction sector, in particular the roof coverings, PVC is an important component of the waterproofing membranes. To control the processability of PVC, plasticizers have long been used. However, these plasticizers have the major disadvantage that they migrate. This means that on the one hand, the plasticizers, on the one hand, migrate to the surface over time and cause surface tack there, or they migrate into the carrier, which connects them to a substrate. Experience has shown that migration is exacerbated by high temperatures, such as those caused by solar radiation.

Furthermore, due to the migration, the PVC web thus depletes plasticizer, causing its elasticity to deteriorate over time, causing the webs to brittle, which sooner or later causes cracks. Thus, the migration of the plasticizer results in the loss of moisture, flexibility and aging resistance properties essential to a PVC web. Presentation of the invention

The object of the present invention is therefore to provide sealing membranes which do not have the aforementioned disadvantages.

Surprisingly, it has been found that a membrane according to claim 1 solves this problem.

The core of the invention is therefore a membrane 1 comprising a Schott layer 2, wherein the Schott layer consists of more than 50% by weight of PVC, based on the total weight of the Schott layer, and a Barrier layer 3. The barrier layer 3 may be either a barrier layer S1 31 or a barrier layer S2 32.

In the case of a barrier layer S1 31 is a barrier layer comprising a polyvinyl alcohol layer 4 comprising more than 50% by weight of copolymer PA, based on the total weight of the polyvinyl alcohol layer 4, which with the Schott layer 2 by a Polyurethane layer 5 is connected, wherein the polyurethane layer 5 to more than 10 wt% of polyurethane PUR, based on the total weight of the polyurethane layer fifth

In the case of a barrier layer S2 32 is a barrier layer consisting of a composition comprising 5-50 wt .-% polyurethane PUR and 50-95 wt .-% co-polymer PA.

The polyurethane PUR has at least one nucleophilic functional group which is selected from the group consisting of hydroxyl group, carboxyl group, sulfonate group and phosphate group. The co-polymer PA is an ethylene-vinyl alcohol co-polymer.

The membranes according to the invention have a significantly lower migration of plasticizers than the membranes of the prior art and are distinguished by improved aging resistance, in particular with regard to the adhesion of the barrier layer 3 to the bulkhead layer 2, and tightness against moisture.

Other aspects of the invention include methods of making membranes mentioned above and subject matter of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims.

Brief description of the drawings

In the following the invention will be described in more detail with reference to the figures, it being understood that only the elements essential for the immediate understanding of the invention are shown. Identical elements are given the same reference numerals in the various figures characterized. It should also be noted that the figures shown here are schematic representations without size references.

FIG. 1 shows a cross section through a membrane according to the invention.

FIG. 2 shows a cross section through another possible membrane according to the invention.

Ways to carry out the invention

The present invention relates to a membrane 1 comprising a

Scotch layer 2, wherein the Schott layer consists of more than 50% by weight of PVC, based on the total weight of the Schott layer, and a barrier layer 3. The Schott layer 2 consists of more than 50% by weight of PVC, based on the total weight of the Schott layer. Preferably, the Schott layer consists of more than 70 wt .-% of PVC, based on the total weight of the Schott layer.

In order to be as suitable as a Schott layer, it should be as waterproof as possible and even under prolonged influence of water or moisture, do not decompose or be mechanically damaged. As a Schott layer in particular such films are suitable, as they are used for sealing purposes in building and civil engineering already in the prior art. The Schott layer should advantageously have an at least low degree of elasticity in order to be able to bridge, for example, expansion differences between the sealing membrane and substrate caused by temperatures or stresses caused by cracks in the substrate, without the Schott layer being damaged or tearing and impairing the sealing function of the Schott layer.

Further, the Schott layer 2 may contain materials which as

Processing aids for PVC are suitable. Typically, such materials are selected from the group consisting of high density polyethylene (HDPE), medium density polyethylene (MDPE), lower density polyethylene Density (LDPE), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), ethylene-vinyl acetate (EVA), chlorosulfonated polyethylene, thermoplastic polyolefins (TPO), ethylene-propylene-diene rubber (EPDM ) and polyisobutylene (PIB) and mixtures thereof. Preferably, the Schott layer 2 is less than 5 wt .-%, preferably less than 1 wt .-%, more preferably less than 0.5 wt .-%, of the aforementioned materials which are suitable as processing aids for PVC, based on the Total weight of the Schott layer.

Preferably, the Schott layer has a content of plasticizer of 20-45 wt .-%, particularly preferably 30- 40 wt .-%, based on the total weight of the Schott layer on.

The plasticizers used are typically esters of organic carboxylic acids or their anhydrides, such as phthalates, for example dioctyl phthalate, diisononyl phthalate or diisodecyl phthalate, adipates, for example dioctyl adipate, azelates and sebacates, polyols, for example polyoxyalkylene polyols or polyester polyols, organic phosphoric and sulfonic acid esters or polybutenes.

The Schott layer advantageously has a layer thickness in the millimeter range, typically between 0.2 and 15 mm, preferably between 0.5 and 4 mm.

The barrier layer 3 may be either a barrier layer S1 31 or a barrier layer S2 32.

FIG. 1 shows a cross section through a possible membrane according to the invention, which has a barrier layer S1 31.

The barrier layer S1 31 comprises a polyvinyl alcohol layer 4 comprising more than 50% by weight of co-polymer PA, based on the total weight of the polyvinyl alcohol layer 4, which is connected to the bulkhead layer 2 by a polyurethane layer 5, wherein the Polyurethane layer 5 to more than 10% by weight of polyurethane PUR, based on the total weight of the polyurethane layer. 5 The polyvinyl alcohol layer 4 comprising more than 50% by weight of copolymer PA, based on the total weight of the polyvinyl alcohol layer 4.

The co-polymer PA is an ethylene-vinyl alcohol co-polymer.

Such ethylene-vinyl alcohol co-polymers are typically obtained by copolymerization of ethylene with a vinyl ester monomer. Optionally, other monomers, typically having a C-C unsaturated double bond, may be present in the copolymerization and copolymerized. After obtaining the resulting co-polymer, a hydrolysis step is carried out.

Preferably, it is an ethylene-vinyl alcohol co-polymer prepared by hydrolyzing a co-polymer obtained by copolymerizing ethylene with a vinyl ester monomer and optionally another monomer having a C-C unsaturated double bond.

Preferably, the degree of hydrolysis in mol% in the copolymer PA> 90 mol%, in particular> 95 mol%, most preferably> 99 mol%.

Possible vinyl ester monomers are selected from the list consisting of vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate and vinyl versatate. Preferably, it is vinyl acetate.

The proportion in mol% of ethylene in the copolymer PA is preferably from 20 to 50 mol%, in particular from 25 to 40 mol%, most preferably from 29 to 38 mol%. It is clear to the person skilled in the art that this is ethylene in its copolymerized state in the copolymer PA.

The proportion in mol% of vinyl alcohol in the copolymer PA is preferably 80-50 mol%, in particular 75-60 mol%. It is that It is clear to a person skilled in the art that this is vinyl alcohol in its copolymerized state in the copolymer PA.

Further, it may be advantageous if the co-polymer PA additionally has a further monomer. Preferably, the proportion in mol% of the further monomer in the copolymer PA is 0.1-30 mol%. It is clear to the person skilled in the art that this is a monomer in its copolymerized state in the copolymer PA. Preferably, the density of the copolymer PA 1 .25 - 1 .1 g / cm ³ , in particular 1 .21 - 1 .17 g / cm ³ .

The melting point of the co-polymer PA, measured by DSC, is preferably 150-200 ° C., in particular 170-190 ° C.

The glass transition temperature of the co-polymer PA, measured by DSC, is preferably 50-70 ° C., in particular 55-65 ° C.

Preferred co-polymers PA are, for example, commercially available under the name Soarnol® from The Nippon Synthetic Chemical Industry Co., Ltd.

Preferably, the barrier layer S1 consists of more than 80 wt .-%, particularly preferably more than 95 wt .-%, of co-polymer PA, based on the total weight of the barrier layer S1.

The barrier layer S1 advantageously has a layer thickness in the micrometer range, typically between 100 and 1 μιη, preferably between 10 and 2 μιη.

The ethylene-vinyl alcohol layer 4 of the barrier layer S1 31 is connected to the bulkhead layer 2 by a polyurethane layer 5. The polyurethane layer 5 consists of more than 10% by weight of polyurethane PUR, based on the total weight of the polyurethane layer 5, in particular to more than 20% by weight, particularly preferably more than 40% by weight.

Substance names beginning with "poly", such as polyol or polyisocyanate, in the present document refer to substances which formally contain two or more of the functional groups occurring in their name per molecule.

The term "polymer" in the present document comprises, on the one hand, a collective of chemically uniform, but different in terms of degree of polymerization, molecular weight and chain length macromolecules, which was prepared by a polyreaction (polymerization, polyaddition, polycondensation) Derivatives of such a collective of macromolecules from polyreactions, ie compounds which have been obtained by reactions such as additions or substitutions of functional groups on predetermined macromolecules and which may be chemically uniform or chemically non-uniform is called reactive oligomeric pre-adducts whose functional groups are involved in the construction of macromolecules.

The term "polyurethane polymer" encompasses all polymers which are prepared by the so-called diisocyanate-polyaddition process, including those polymers which are almost or completely free of urethane groups.Examples of polyurethane polymers are polyether polyurethanes, polyester polyurethanes, Polyether polyureas, polyureas, polyester-polyureas, polyisocyanurates and polycarbodiimides.

Preferably, the polyurethane PUR is a polyester polyurethane or a poly (meth) acrylate PAC. Polyurethanes PUR which have at least one nucleophilic group can be prepared, in particular, from at least one polyisocyanate and at least one polyol and at least one monomer M1 which has at least one isocyanate group or one opposite isocyanate groups reactive group and moreover at least one nucleophilic functional group.

Commercially available aliphatic, cycloaliphatic or aromatic polyisocyanates, especially diisocyanates, can be used as polyisocyanates.

Particularly suitable polyols are polyester or polyether polyols, preferably polyester or polyether diols. Other suitable polyols as low molecular weight dihydric or polyhydric alcohols such as 1, 2-ethanediol, 1, 3- and 1, 4-butanediol, 1, 2 and 1, 3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, dimeric fatty alcohols, 1,1,1-trimethylolethane , 1, 1, 1 -Trimethylolpropan, glycerol, pentaerythritol, sugar alcohols such as xylitol, sorbitol or mannitol, sugars such as sucrose, other higher alcohols, low molecular weight alkoxylation of the above dihydric and polyhydric alcohols, and mixtures of the above.

Suitable monomers M1 preferably have at least one carboxyl group and / or one sulfonate group. The monomer M1 is preferably an aminocarboxylic acid, a hydroxycarboxylic acid, in particular a dihydroxyalkylcarboxylic acid, such as, for example, dimethylolpropionic acid or a structure-like diolcarboxylic acid, or an NCO-reactive sulfonic acid, for example a dihydroxysulfonic acid. Preferably, the monomer M1, which has a sulfonate group, the sodium salt of N- (2-aminoethyl) -2-aminoethane sulfonic acid.

It has been found that particularly suitable polyurethanes are those described, for example, as "polymer (PN)" in DE 100 00 656 A1 or WO 01/34559 A1, or as "polyurethane" in DE 195 21 500 A1. Poly (meth) acrylates PAC which have at least one nucleophilic group can be prepared, in particular, from at least one (meth) acrylate monomer and at least one monomer M2 which is polymerizable with the (meth) acrylate monomer and moreover has at least one nucleophilic functional group , For example, such poly (meth) acrylates are copolymers of at least one (meth) acrylate monomer and at least one unsaturated carboxylic acid, in particular (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid or the like, a (meth) acrylamide or a (meth) acrylic ester, which has a hydroxyl group, in particular hydroxyalkyl (meth) acrylate such as hydroxybutyl acrylate (HBA), hydroxybutyl methacrylate (HBMA), hydroxypropyl acrylate (HPA), hydroxypropyl methacrylate (HPMA), hydroxyethyl acrylate (HEA) or hydroxyethyl methacrylate (HEMA), or a partial ester of a polyol, preferably glycerol or trimethylolpropane, with (meth) acrylic acid.

Preferably, these are polyurethanes PUR, with a

Molecular weight of 10Ό00 - 500Ό00 g / mol.

The polyurethane layer 5 advantageously has a layer thickness in the micrometer range, typically between 10 and 0.1 μιη, preferably between 5 and 0.2 μιη, particularly preferably between 4 and 0.5 μιτι

FIG. 2 shows a cross section through a possible membrane according to the invention which has a barrier layer S2 32.

In the case of a barrier layer S2 32 is a barrier layer consisting of a composition comprising 5-50 wt .-%, preferably 5-20 wt .-%, polyurethane PUR and 50-95 wt .-%, preferably 80-95 wt .-%, co-polymer PA.

The polyurethane PUR and the co-polymer PA are polyurethane PUR and co-polymer PA, as described above. Further preferred polyurethanes PUR and co-polymer PA are those which have been mentioned above as the preferred polyurethane PUR and co-polymer PA. The barrier layer S2 32 advantageously has a layer thickness in the micrometer range, typically between 100 and 1 μιη, preferably between 10 and 2 μιη. Preferably, the barrier layer S2 32 consists of more than 90 wt .-%, particularly preferably more than 98 wt .-%, of the sum of copolymer PA together with polyurethane PUR, based on the total weight of the barrier layer S2. It is also advantageous if membrane 1 is a flexible one

Membrane, in particular a flexible web is. This can simply be rolled and thus easily stored or transported. Thus, the membrane simply reaches the construction site and can be unrolled there and cut to the required dimensions.

In a further aspect, the invention also encompasses a method for producing a membrane 1 comprising a Schott layer 2, wherein the Schott layer consists of more than 50% by weight of PVC, based on the total weight of the Schott layer. The membrane further comprises a barrier layer S1 31, the barrier layer comprising a polyvinyl alcohol layer 4 comprising more than 50% by weight of co-polymer PA, based on the total weight of the polyvinyl alcohol layer 4, which is bonded to the bulkhead layer 2 by a polyurethane. Layer 5 is connected. The polyurethane layer 5 consists of more than 10% by weight of polyurethane PUR, based on the total weight of the polyurethane layer 5. The method comprises the steps;

(i) applying a polyurethane dispersion composition PD to a Schott layer 2;

(ii) flash-drying the polyurethane dispersion composition PD to form a polyurethane layer 5;

(iii) forming a polyvinyl alcohol layer 4 on the polyurethane layer 5.

Preferably, the steps take place in the chronological order of step (i), followed by step (ii), followed by step (iii). The polyurethane PUR, the copolymer PA, the Schott layer 2, the barrier layer S1 31, the polyvinyl alcohol layer 4 and the polyurethane layer 5 have been described above. Polyurethane PUR, co-polymer PA, Schott layer 2, barrier layer S1 31, polyvinyl alcohol layer 4 and polyurethane layer 5 are suitable and preferred are those which are considered as suitable and preferred polyurethane PUR, copolymer PA, bulkhead 2, barrier S1 31, polyvinyl alcohol layer 4 and polyurethane layer 5 are mentioned.

By "flash off" is meant throughout the document a drying of a polyurethane dispersion composition after the application thereof, wherein the solvent or the dispersant completely or at least mainly, evaporates.

The venting can be done by evaporation in air with and without aeration. As a bleeding, for example, a fan, in particular an air blower serve. Preferably, a venting agent is used. The venting can be done at room temperature or at elevated temperature. Preferably, the flash-off of the polyurethane dispersion composition (PD) in step (ii) is carried out at 100-170 ° C for 1-5 min.

The polyurethane dispersion composition PD is typically a dispersion of polyurethane PUR in a liquid phase, wherein the polyurethane PUR is present as a solid. The liquid phase is preferably water.

Preferably, the polyurethane dispersion composition PD in step (ii) comprises a dispersed phase consisting of polyurethane PUR and a liquid phase, especially water.

It is also advantageous if the polyurethane PUR of the dispersed

Phase is a non-reactive polyurethane.

Typically, the proportion of the dispersed phase is 0.1-90 wt .-%, based on the total weight of Polyurethane dispersion composition PD. The proportion of the dispersed phase is preferably 30-60% by weight, based on the total weight of the polyurethane dispersion composition PD. The polyurethane dispersion composition PD is preferably an aqueous polyurethane dispersion, wherein the polyurethane PUR is present as a solid and the proportion of the polyurethane PUR preferably 15 to 55 wt .-%, in particular 25 to 50 wt .-%, preferably 35 to 45 wt .-%, based on the total weight of the polyurethane dispersion composition PD.

The formation of the barrier layer S1 31 in step (iii) is preferably carried out by applying a composition Z2 in the liquid state consisting of copolymer PA and a solvent to the polyurethane layer 5.

The solvent is typically selected from the group consisting of water, ethanol, methanol, ethanol, propan-1-ol, butan-1-ol, propan-2-ol, butan-2-ol, ethane-1, 2-diol, 1, 2-propanediol, propane-1, 3-diol, butane-1, 2-diol, butane-1, 3-diol, 1, 4-butanediol, 2,3-butanediol, pentane-1, 5-diol and Prop-2-en-1-ol.

Preferably, the solvent is a propane-1-ol / water mixture, preferably the weight ratio of propane-1-ol: water is from 99: 1 to 1:99, particularly preferably from 5: 1 to 3: 1.

It is also advantageous if, after application of the composition Z2 in the liquid state, the applied composition Z2 is heated at 100-170 ° C. for 1 to 5 minutes. This is advantageous in that this contributes to the formation of a homogeneous and gapless barrier layer S1. Further, it is advantageous for the inhibition of plasticizer migration, if the composition Z2 has a proportion of 1 -25 wt .-% co-polymer PA, particularly preferably 15-20 wt .-%, based on the total weight of the composition Z2.

In the composition Z2, the weight ratio of copolymer PA to solvent is preferably from 1: 100 to 1: 4, in particular from 1:10 to 1: 5. In another aspect, the invention also includes another

A process for producing a membrane 1 comprising a Schott layer 2, wherein the Schott layer consists of more than 50% by weight of PVC, based on the total weight of the Schott layer. The membrane further comprises a barrier layer S2 32, wherein the

Barrier layer S2 32 consisting of a composition comprising 5-50% by weight, preferably 5-20% by weight, polyurethane PUR and 50-95% by weight, preferably 80-95% by weight, copolymer PA, comprising the steps;

() Applying a composition Z1 comprising polyurethane PUR, co-polymer PA and solvent to a bulkhead layer 2;

(ϋ ') aerating the composition Z1 to form a barrier layer S2 32;

The steps preferably take place in the chronological order of step (Γ), followed by step (ϋ ').

The polyurethane PUR, the co-polymer PA, the Schott layer 2 and the barrier layer S2 32 have already been described above. Suitable as polyurethane PUR, co-polymer PA, Schott layer 2 and barrier layer S2 32 are those which are mentioned above as suitable and preferred polyurethane PUR, co-polymer PA, Schott layer 2 and barrier layer S2 32. It is also advantageous if the application of the composition Z1 in step (Γ) is carried out by applying the composition Z1 in the liquid state. Preferably, the viscosity of the composition Z1 at 25 ° C measured according to: DIN EN ISO 3219 / A.3 500-30000 mPas.

Further, it is advantageous if the flash-off of the composition Z1 in step (ϋ ') for 1 -5 min at 100-170 ° C takes place.

The solvent of composition Z1 is typically selected from the group consisting of water, ethanol, methanol, ethanol, propane-1-ol, butane-1-ol, propan-2-ol, butan-2-ol, ethane-1,2 -diol, 1, 2-propanediol, propane-1, 3-diol, butane-1, 2-diol, butane-1, 3-diol, 1, 4-butanediol, 2,3-butanediol, pentane-1, 5 -diol and prop-2-en-1-ol.

It is also advantageous if the proportion of the sum of polyurethane PUR together with co-polymer PA is 1-30% by weight, in particular 15-25% by weight, based on the total weight of the composition Z1.

The membrane 1 produced in this way can now be cut to length as required, cut off, rolled up or further processed directly. The rolls with the membrane can be stored or transported as needed.

Another aspect of the present invention relates to the use of the previously described in detail sealing membrane 1 for sealing of substrates. The membrane 1 is typically used as a prefabricated web.

In this case, the membrane is preferably manufactured by an industrial process in a film factory and arrives at the construction site

preferably in the form of a membrane from a roll for use. The However, membrane can also be in the form of stiffeners with a width of

typically 1 - 20 cm are used, for example to

Seal joints between two roofing membranes. Furthermore, the membrane can also be present and used in the form of flat bodies for repairing damaged areas in seals, for example roofing membranes.

A preferred use of the membrane 1 is therefore a

Use for sealing against moisture of buildings in civil engineering, in particular of roofs and floors.

In a further aspect, the present invention relates to a molded body whose surface has a membrane 1, wherein the membrane with its side facing away from the Schott layer 2 side on the molding

is arranged. The molded body is typically a building construction or civil engineering. The term "shaped body" refers to an object with a three-dimensional extension.

Examples

Preparation of compositions Za and Zb

The component Co-polymer PA of compositions Za and Zb was Soarnol D2908 or Soarnol D3808, commercially available from Nippon Gohsei, Japan. The component solvent used was water and n-propanol. The two components were mixed together in the amounts indicated in Table 1 to the compositions Za and Zb in the parts by weight given in Table 1.

Za Zb

Soarnol 20

D2908

Soarnol 20

D3808

Water 16 16

n-propanol 64 64

Sum of 100 100

Parts by weight

Table 1, compositions Za and Zb.

Preparation of the Polyurethane Dispersion Compositions (PD)

The compounds listed in Table 2 in the parts by weight given in Table 2 were mixed together to give the polyurethane dispersion compositions PD1 and PD2. Polyurethane PURs used were: Incorez® W2400 (both INCOREZ LTD, UK) and Bayhydrol® UH 2606 (Bayer Material Science, Germany). The film-forming additive is a tripropylene glycol n-butyl ether, the liquid phase is water, a siloxane compound is used as the wetting agent, and hydrophobic fumed silica is used as the thixotropic agent.

PD1 PD2

PURE

Incorez W2400 71 .4 ^** -

Bayhydroll XP 2606 - 94.3 ^*

Film-forming additive 10 0.5

Water 16.6 3.7

Wetting agent 2 1 .5

Thixotropic agent - -

Sum of the parts by weight 100 100 Table 2, Polyurethane Dispersion Compositions PD1 and PD2 ^* The 94.3 parts by weight refers to a 35% dispersion of polyurethane PUR in water, ^** the 71.4 parts by weight refers to a 40% dispersion of polyurethane PUR in water.

Production of the Schott layer

It was a composition consisting of:

PVC (55% by weight, based on the total weight of the composition), plasticizer, diisononyl phthalate from Sigma-Aldrich, Switzerland (39% by weight, based on the total weight of the composition), stabilizer, tin stabilizer dibutyltin diacetate from Sigma-Aldrich, Switzerland (1% by weight, based on the total weight of the composition), CaC0 ₃ from Sigma-Aldrich, Switzerland (5% by weight, based on the total weight of the composition), by flat die extrusion to a 1. 5 mm thick film molded.

Testing for softener migration

Sample bodies with the dimensions 120 mm × 120 mm were prepared from the membranes and weighed (weight dO). Subsequently, these specimens were placed on a body with the dimensions 120mm x 120 mm and a thickness of about 40-50 mm of EPS (expanded polystyrene foam). On the specimen was further a glass plate with the dimensions 100 mm x 100 mm and then a weight of 2 kg arranged. This arrangement was stored at 70 ° C, 50 ± 5% relative humidity for 28 days. Thereafter, the specimens were weighed again (weight d28) and the weight difference in percent determined from the weight dO.

Manufacture of comparative membranes (Ref.2, Ref.3)

The respective composition Za (for Ref.2) and Zb (for Ref.3) were used to form a polyvinyl alcohol layer by means of a

Doctor blade applicator (K-CONTROL COATER system K 202, ERICHSEN, Germany) in a layer thickness of 24 μιη at a temperature of 30 ° C. on a Schott layer of 20cm x 30cm x 1 .5mm, their production

previously described, applied and heated for 2 minutes at a temperature of 160 ° C in an oven. Preparation of inventive membrane comprising a Schott layer S1 {Exp.1, Exo.2)

The polyurethane dispersion PD1 was for Exp.1 and Exp.2 by means of a Rakelauftragsgerätes (K-CONTROL COATER system K 202, ERICHSEN, Germany) in a layer thickness of 4 μιη on a Schott layer of 20cm x 30cm x 1 .5mm, their preparation previously described, applied. The films were heated for 2 minutes at a temperature of 160 ° C in an oven. Immediately afterwards, the corresponding composition Za (for Exp.1), Zb (for Exp.2) was applied to the bulkhead layer by means of the previously mentioned doctor blade applicator to form a polyvinyl alcohol layer in a layer thickness of 24 μm at a temperature of 30 ° C. and 2 minutes heated at a temperature of 160 ° C in an oven.

Preparation of inventive membrane comprising a Schott layer S2 (Exo.3, Exo.4)

80 parts by weight of the above-described composition Za (for Exp.3) or Zb (for Exp.4) were mixed with 20 parts by weight of the previously described polyurethane dispersions PD1 and by means of a doctor blade applicator (K-CONTROL-COATER system K 202, ERICHSEN, Germany) in a layer thickness of 24 μιτι (layer thickness immediately after application) on a Schott layer of 20cm x 30cm x 1 .5mm, the preparation of which has been described above, applied. The films were heated for 2 minutes at a temperature of 160 ° C in an oven (layer thickness after heating was 4-6 μιη).

Weichmachermiqrationstest

An untreated Schott layer Ref. 1, a comparative membrane with a polyvinyl alcohol layer of composition Za (Ref Comparative membranes with a polyvinyl alcohol layer of composition Zb (Ref.3), two membranes according to the invention with a Schott layer S1 (Exp.1, Exp.2) and two membranes according to the invention with a Schott layer S2 (Exp.3, Exp.4) were the preceding subjected to a plasticizer migration test described.

The weight losses in% by weight are shown in Table 3.

of the membranes in the

Plasticizer migration test in% by weight

A plasticizer migration test was made with membranes corresponding to membranes of the invention Exp.1, Exp.2, Exp.3, and Exp.4, but replacing PD1 with PD2. The same weight losses in wt% of the membranes were detected in the plasticizer migration test as found in Table 3 using PD1.

Testing for aging

From the aforementioned inventive membranes and the

Membranes Ref.2, and Ref.3 samples were prepared with the dimensions 20 cm x 10 cm. The specimens were stored for 28 days at a temperature of 70 ± 2 ° C in a convection oven. Thereafter, the specimens were bent 20 x in the middle and folded on each other and then visually assessed the detachment of the barrier layer of the membrane. The Membrane according to the invention showed, in contrast to the membranes Ref.2, and Ref.3, no delamination of the barrier layer S1, respectively S2.

LIST OF REFERENCE NUMBERS

1 membrane

2 Schott layer

3 barrier layer

31 barrier layer S1

32 barrier layer S2

4 polyvinyl alcohol layer

5 polyurethane layer

Claims

claims

1 . A membrane (1) comprising a bulkhead layer (2), wherein the bulkhead layer consists of more than 50% by weight of PVC, based on the total weight of the bulkhead layer, and a barrier layer (3), wherein the barrier layer (3) :

either a barrier layer S1 (31), the barrier layer S1 (31) comprising a polyvinyl alcohol layer (4) comprising more than 50% by weight of copolymer PA, based on the total weight of the polyvinyl alcohol layer (4), which is bonded to the bulkhead layer (2) by a polyurethane layer (5), the polyurethane layer (5) being more than 10% by weight of polyurethane PUR, based on the total weight of the polyurethane layer (5); or

is a barrier layer S2 (32), wherein the barrier layer S2 (32) is made of a composition comprising 5-50% by weight of polyurethane

PUR and 50-95% by weight of co-polymer PA;

and wherein the polyurethane PUR has at least one nucleophilic functional group which is selected from the group consisting of hydroxyl group, carboxyl group, sulfonate group and phosphate group, and wherein the co-polymer PA is an ethylene-vinyl alcohol

Co-polymer is.

2. membrane (1) according to claim 1, characterized in that the proportion in mol% of ethylene in the copolymer PA 20 - 50 mol%, in particular 25 - 40 mol%, most preferably 29 - 38 mol % is.

3. Membrane (1) according to claim 1 or 2, characterized in that the polyurethane PUR is prepared from at least one polyisocyanate and at least one polyol and at least one monomer M1, wherein the monomer M1 has at least one nucleophilic functional group and the monomer M1 has at least one isocyanate group or an isocyanate-reactive group.

4. membrane (1) according to claim 3, characterized in that the monomer M1 as a nucleophilic functional group having a carboxyl group and / or a sulfonate group.

5. membrane (1) according to claim 3 or 4, characterized in that it is the monomer M1 is an amino carboxylic acid, a hydroxy carboxylic acid, in particular a Dihydroxyalkylcarbonsäure is.

6. A process for producing a membrane (1), comprising a Schott layer (2), wherein the Schott layer consists of more than 50% by weight of PVC, based on the total weight of the Schott layer, and a barrier layer S1 (31), wherein the barrier layer a polyvinyl alcohol layer (4) comprising more than 50% by weight of co-polymer PA, based on the total weight of the polyvinyl alcohol layer (4), which is joined to the bulkhead layer (2) by a polyurethane layer (5) wherein the polyurethane layer (5) consists of more than 10% by weight of polyurethane PUR, based on the total weight of the polyurethane layer (5);

comprising the steps;

(i) applying a polyurethane dispersion composition PD to a Schott layer (2);

(ii) flash-drying the polyurethane dispersion composition PD to form a polyurethane layer (5);

(iii) forming a polyvinyl alcohol layer (4) on the polyurethane layer

(5);

Co-polymer is.

7. The method according to claim 6, characterized in that forming the barrier layer S1 (31) in step (iii) by applying a composition Z2 in the liquid state consisting of co-polymer PA and a solvent on the polyurethane layer (5). he follows.

8. The method according to claim 7, characterized in that after the application of the composition Z2 in the liquid state, the applied composition Z2 is heated for 1 - 5 min at 100-170 ° C.

9. The method according to any one of claims 7-8, characterized in that the composition Z2 has a proportion of 1 -25 wt .-% co-polymer PA, based on the total weight of the composition Z2.

10. The method according to any one of claims 6-9, characterized in that the polyurethane dispersion composition (PD) in step (ii) has a dispersed phase consisting of polyurethane PUR and a liquid phase, in particular water.

1 1. A process according to claim 10, characterized in that the polyurethane PUR of the dispersed phase is a non-reactive polyurethane.

12. A method for producing a membrane (1), comprising a Schott layer (2), wherein the Schott layer consists of more than 50% by weight of PVC, based on the total weight of the Schott layer, and a barrier layer S2 (32), wherein the barrier layer S2 (32) is composed of a composition comprising 5-50% by weight of polyurethane PUR and 50-95% by weight of copolymer PA comprising the steps;

(Γ) applying a composition Z1 comprising polyurethane PUR, co-polymer PA and solvent to a Schott layer (2); (ϋ ') deaerating the composition Z1 to form a barrier layer S2 (32);

and wherein the polyurethane PUR has at least one nucleophilic functional group selected from the group consisting of hydroxyl group, carboxyl group, sulfonate group and phosphate group, and wherein the co-polymer PA is an ethylene-vinyl alcohol co-polymer.

A method according to claim 12, characterized in that the application of the composition Z1 in step (Γ) by applying the composition Z1 takes place in the liquid state.

A method according to claim 12 or 13, characterized in that the flash-off of the composition Z1 in step (ϋ ') for 1 -5 min at 100- 170 ° C.

A method according to any one of claims 12-14, characterized in that the proportion of the sum of polyurethane PUR together with co-polymer PA 1 -30 wt .-%, based on the total weight of the composition Z1, is.