阅读说明：本技术 用于改善对聚氨酯树脂的粘合性的聚乙烯组合物 (Polyethylene composition for improving adhesion to polyurethane resins ) 是由 B-A·苏丹 J·朱克维斯特 E·里巴利斯 于 2020-04-28 设计创作，主要内容包括：本发明涉及一种聚乙烯组合物,其包含：(A)含有具有可水解硅烷基团的单体单元的乙烯共聚物,和(B)一种或多种选自如下组的乙烯共聚物(B1)含有具有羟基的单体单元的乙烯共聚物,(B2)含有具有(甲基-)丙烯酸酯基团的单体单元的乙烯共聚物,和(B3)含有具有羟基和(甲基)丙烯酸酯基团的单体单元的乙烯共聚物,包含含有一种或多种选自(B1)、(B2)和(B3)的乙烯共聚物的层(1)的电缆,以及一种或多种选自(B1)、(B2)和(B3)的乙烯共聚物在用于改善包含一种或多种乙烯共聚物的电缆的层和聚氨酯树脂之间的粘合性的用途。(The present invention relates to a polyethylene composition comprising: (A) ethylene copolymer comprising monomer units having hydrolysable silane groups, and (B) one or more ethylene copolymers selected from the group consisting of (B1) ethylene copolymers comprising monomer units having hydroxyl groups, (B2) ethylene copolymers comprising monomer units having (meth-) acrylate groups, and (B3) ethylene copolymers comprising monomer units having hydroxyl groups and (meth) acrylate groups, cables comprising a layer (1) comprising one or more ethylene copolymers selected from the group consisting of (B1), (B2) and (B3), and the use of one or more ethylene copolymers selected from the group consisting of (B1), (B2) and (B3) for improving the adhesion between a layer of a cable comprising one or more ethylene copolymers and a polyurethane resin.)

1. A polyethylene composition comprising:

(A) an ethylene copolymer containing monomer units having hydrolyzable silane groups, and

(B) one or more ethylene copolymers comprising monomer units having hydroxyl groups and (meth-) acrylate groups;

wherein component (B) is present in the composition in an amount such that the monomeric units having hydroxyl groups and (alkyl-) acrylate groups are present in the composition in an amount of 0.14 mol% or more and 7 mol% or less; and

wherein component (A) and component (B) may be present in the composition as separate ethylene copolymers or as one ethylene copolymer containing both groups.

2. The polyethylene composition according to claim 1, wherein component (B) is present in an amount of 2 wt% or more and 35 wt% or less in the total polyethylene composition.

3. Cable comprising a layer (1) comprising a polyethylene composition according to claim 1 or 2.

4. A cable according to claim 3, wherein the layer (1) is a skin layer and/or an insulation layer.

5. Cable according to claim 3 or 4, wherein there is a further layer adjacent to layer (1) comprising polyethylene containing hydrolysable silane groups.

6. The cable according to any one of claims 3 to 5, wherein the cable is a power cable.

7. Use of an ethylene copolymer containing more than 4 to 15 mol% of monomer units having (meth-) acrylate groups for improving the adhesion between a layer of a cable containing the ethylene copolymer and a polyurethane resin.

8. Use according to claim 7, wherein the ethylene copolymer comprises monomers having methyl-, ethyl-, propyl-or butyl acrylate groups.

9. Use according to claim 7 or 8, wherein the ethylene copolymer further comprises monomer units having hydrolysable silane groups.

10. Use according to claim 9, wherein in the ethylene copolymer the monomer units having hydrolysable silane groups are present in an amount of from 0.1 to 1 mol%.

11. Use according to claim 9 or 10, wherein the monomer units having hydrolysable silane groups comprise vinyltrimethoxysilane, vinylbismethoxyethoxysilane, vinyltriethoxysilane, gamma- (meth) acryloxypropyltrimethoxysilane, gamma- (meth) acryloxypropyltriethoxysilane and/or vinyltriacetoxysilane.

12. Use according to any one of claims 9 to 11, wherein the monomer unit having a hydrolysable silane group comprises vinyltrimethoxysilane.

Technical Field

The present invention relates to a polyethylene composition comprising one or more specific ethylene copolymers, in particular a polyethylene composition comprising one or more ethylene copolymers for improving the adhesion between a layer of a cable comprising one or more ethylene copolymers and a polyurethane resin (PUR). The invention also relates to a cable comprising a layer comprising one or more of said ethylene copolymers and to the use of one or more of said ethylene copolymers for improving the adhesion between a layer of a cable comprising one or more ethylene copolymers and a polyurethane resin (PUR).

Background

In the field of power cables (e.g., Low Voltage (LV) cables), polyurethane casting resin (PUR) is commonly used in connecting such cables. Although PVC is a common material for the layers of power cables and has excellent adhesion to PUR, polyolefins and the vinyl vinylsilane ethylene copolymers thereof have little adhesion to such jointing materials.

Since polyolefins are also frequently used as layers of power cables, it is desirable to provide polyolefins (in particular polyethylene), compositions or power cables having a layer comprising a polyolefin (in particular polyethylene) therein, with enhanced adhesion to the PUR.

The present invention is based on the discovery that this objective can be achieved in the following cases: if the polyethylene composition is used for producing a layer of a cable/cable comprising an ethylene copolymer comprising hydrolysable silane groups and an ethylene copolymer having monomer units comprising hydroxyl groups and/or (meth-) acrylate groups, and/or if the cable comprises a layer comprising an ethylene copolymer having monomer units comprising hydroxyl groups and/or (meth-) acrylate groups.

Disclosure of Invention

Thus, first, the present invention provides a polyethylene composition comprising:

(A) an ethylene copolymer containing monomer units having hydrolyzable silane groups, and

(B) one or more ethylene copolymers selected from the group consisting of

(B1) An ethylene copolymer containing a monomer unit having a hydroxyl group,

(B2) an ethylene copolymer comprising monomer units having a (meth-) acrylate group, and

(B3) an ethylene copolymer comprising monomer units having hydroxyl groups and (meth-) acrylate groups.

As used herein, the term "ethylene copolymer" is intended to mean an ethylene polymer in which one or more other types of monomer units other than ethylene are present.

Components (a) and (B) may be present in the composition as separate ethylene copolymers or as one ethylene copolymer containing both the respective groups/monomer units.

For example, the polyethylene composition may comprise (a) and (B1) in the form of an ethylene copolymer comprising hydrolysable silane groups and monomer units having hydroxyl groups. In the case of (a) and (B3), this may be an ethylene copolymer comprising hydrolysable silane groups and monomer units having hydroxyl groups and (meth-) acrylate groups.

The term "(meth) acrylate" is intended to include both "acrylates" and "methacrylates".

Component (a) is an ethylene copolymer comprising monomer units having hydrolysable silane groups. It is known to crosslink polyolefins by additives, since this improves the properties of the polyolefin, such as mechanical strength and chemical heat resistance. The crosslinking may be carried out by condensation of silanol groups contained in the composition, which may be obtained by hydrolysis of silane groups. The silane group containing compound may be introduced as a crosslinkable group, for example by grafting a silane compound onto the polyolefin, i.e. by addition of silane groups mainly in a free radical reaction, or by chemical modification of the polymer by copolymerization of olefin monomers and silane group containing monomers. Such techniques are known, for example from US 4,413,066, US 4,297,310, US 4,351,876, US 4,397,981, US 4,446,283 and US 4,456,704. If graft polymers are used, this may have been produced by either of two processes as described, for example, in U.S. Pat. No. 3,646,155 and U.S. Pat. No. 4,117,195, respectively.

Preferably, the silane group-containing ethylene copolymer has been obtained by copolymerization. The copolymerization is preferably carried out with an unsaturated silane compound represented by the following formula

R¹SiR² _qY_3-q (V)

Wherein

R¹Is an ethylenically unsaturated hydrocarbon group, a hydrocarbyloxy group or a (meth) acryloyloxyalkyl group,

R²is an aliphatic saturated hydrocarbon group, and is,

y, which may be identical or different, is a hydrolyzable organic radical, and

q is 0, 1 or 2.

Specific examples of unsaturated silane compounds are those wherein R is¹Is vinyl, allyl, isopropenyl, butenyl, cyclohexenyl or gamma- (meth) acryloxypropyl; y is methoxy, ethoxy, formyloxy, acetoxy, propionyloxy or alkyl-or arylamino; r²If present, are those of methyl, ethyl, propyl, decyl or phenyl.

Preferred unsaturated silane compounds are represented by the formula

CH₂＝CHSi(OA)₃ (VI)

Wherein A is a hydrocarbon group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms.

The most preferred compounds are vinyltrimethoxysilane, vinylbismethoxyethoxysilane, vinyltriethoxysilane, gamma- (meth) acryloxypropyltrimethoxysilane, gamma- (meth) acryloxypropyltriethoxysilane, and vinyltriacetoxysilane.

The silane group containing ethylene copolymer preferably contains 0.001 to 15 wt%, more preferably 0.01 to 5 wt%, most preferably 0.1 to 2 wt% of monomer units having hydrolyzable silane groups.

Preferably, the monomer units having hydrolysable silane groups are present in the composition in an amount of from 0.1 to 1 mol%, more preferably from 0.15 to 0.8 mol%, most preferably from 0.2 to 0.5 mol%.

For the crosslinking of such ethylene copolymers containing silanol groups, silanol condensation catalysts have to be used. Conventional catalysts are, for example, tin-organic compounds, such as dibutyltin dilaurate (DBTDL). It is also known that the crosslinking process is advantageously carried out in the presence of an acidic silanol condensation catalyst. The acidic catalyst allows for rapid crosslinking at room temperature compared to conventional tin-organic catalysts. Such acidic silanol condensation catalysts are disclosed, for example, in WO 95/17463 or EP 1309631 and EP 1309632.

In a preferred embodiment of the invention, the polyethylene composition further comprises a silanol condensation catalyst.

The presently most preferred compounds are dodecylbenzene sulfonic acid and tetrapropylbenzene sulfonic acid.

Preferably, the silanol condensation catalyst is present in the polyethylene composition in an amount of from 0.0001 wt% to 6 wt%, more preferably from 0.001 wt% to 2 wt%, most preferably from 0.02 wt% to 0.5 wt%.

In a preferred embodiment, component (B) is present in an amount of 2 wt% or more, more preferably 4 wt% or more, and still more preferably 5 wt% or more, in the total polyethylene composition.

Further, preferably, component (B) is present in an amount of 35 wt% or less, more preferably 30 wt% or less, and most preferably 25 wt% or less, in the total polyethylene composition.

In one embodiment, component (B) comprises or consists of component (B3), component (B3), i.e. an ethylene copolymer containing monomer units having hydroxyl groups and (meth-) acrylate groups.

In the ethylene copolymer, the hydroxyl group and the (meth) acrylate group may be present in the same monomer unit, or may be present in separate monomer units.

Preferably, in component (B3), both hydroxyl and (meth-) acrylate groups are present in the same monomer unit, more preferably component (B3) comprises or consists of an ethylene copolymer comprising (meth-) acrylates in which the alcohol component of the esters comprises hydroxyl groups, more preferably the ethylene copolymer comprises monomer units of hydroxyalkyl (meth) acrylates.

In a particularly preferred embodiment, component (B3) comprises or consists of an ethylene copolymer comprising monomer units of hydroxyalkyl (meth-) acrylates, wherein alkyl is C1-to C4-alkyl, in particular methyl, ethyl or propyl.

Further preferably, in component (B3), the monomer units having both a hydroxyl group and a (meth-) acrylate group are present in the ethylene copolymer in an amount of 1.0 mol% or more, i.e., both the hydroxyl group and the (meth-) acrylate group are each present in the ethylene copolymer in an amount of 1.0 mol% or more, more preferably 1.5 mol% or more, still more preferably 2.0 mol% or more.

Further preferably, in component (B3), the monomer units having both a hydroxyl group and a (meth-) acrylate group are present in the ethylene copolymer in an amount of 10 mol% or less, i.e., both the hydroxyl group and the (meth-) acrylate group are each present in the ethylene copolymer in an amount of 10 mol% or less, more preferably 7 mol% or less, still more preferably 5 mol% or less, and most preferably 3 mol% or less.

Further preferably, component (B3) is present in the composition in an amount such that the monomer units having both a hydroxyl group and an (alkyl-) acrylate group are present in the composition in an amount of 0.14 mol% or more, i.e., both the hydroxyl group and the (meth-) acrylate group are each present in the composition in an amount of 0.14 mol% or more, more preferably 0.16 mol% or more, still more preferably 0.2 mol% or more, most preferably 0.25 mol% or more.

Further preferably, component (B3) is present in the composition in an amount such that the monomer units having both a hydroxyl group and an (alkyl-) acrylate group are present in the composition in an amount of 7 mol% or less, i.e., both the hydroxyl group and the (meth-) acrylate group are each present in the composition in an amount of 7 mol% or less, more preferably 5 mol% or less, still more preferably 4 mol% or less, most preferably 3 mol% or less.

In another embodiment, component (B) comprises or consists of component (B1), component (B1), i.e. an ethylene copolymer containing monomer units having hydroxyl groups.

In this embodiment, component (B1) preferably comprises or consists of an ethylene vinyl alcohol copolymer.

Preferably, the vinyl alcohol comonomer units are present in the ethylene vinyl alcohol copolymer in an amount of 10 mol% or more, more preferably 15 mol% or more, still more preferably 18 mol% or more, most preferably 20 mol% or more.

Preferably, the vinyl alcohol comonomer units are present in the ethylene vinyl alcohol copolymer in an amount of 50 mol% or less, more preferably 45 mol% or less, still more preferably 40 mol% or less, and most preferably 38 mol% or less.

In yet another embodiment, component (B) comprises or consists of component (B2).

Preferably, component (B2) comprises or consists of an ethylene copolymer comprising monomer units having methyl-, ethyl-, propyl-or butyl-acrylate groups.

In component (B2), the monomer units having a (meth-) acrylate group are preferably present in the ethylene copolymer in an amount of 2.5 mol% or more, more preferably 3 mol% or more, more preferably 3.5 mol% or more, more preferably 4.25 mol% or more, more preferably 4.5 mol% or more, more preferably 5 mol% or more, more preferably 5.5 mol% or more, more preferably 6 mol% or more, most preferably 7 mol% or more.

In component (B2), the monomer units having a (meth-) acrylate group are preferably present in the ethylene copolymer in an amount of 15 mol% or less, more preferably 10 mol% or less, still more preferably 8 mol% or less.

Preferably, component (B2) is present in the composition in an amount such that the monomeric units having a (meth-) acrylate group are present in the composition in an amount of 1.0 mol% or more, more preferably 1.5 mol% or more, more preferably 2.0 mol% or more.

Preferably, component (B2) is present in the composition in an amount such that the monomer units having a (meth) acrylate group are present in the composition in an amount of 14 mol% or less, more preferably 9 mol% or less, more preferably 7 mol% or less.

Component (B2) is preferably produced in a tubular reactor.

In a preferred embodiment, the adhesive strength between the composition and a standard polyurethane resin is at least 1N/mm according to the standard test defined in the experimental section below. In general, the bond strength is not more than 50N/mm, preferably not more than 25N/mm. A standard polyurethane resin according to the present application is Protolin 2000, commercially available from Lovink-Enertech.

In one embodiment, components (a) and (B) constitute at least 85 wt% of the inventive polyethylene composition in any of the above embodiments, at least 90 wt% of the composition in another embodiment, and at least 95 wt% of the composition in yet another embodiment.

The invention also relates to a cable comprising a layer (1) comprising or consisting of one or more ethylene copolymers selected from the group consisting of:

(B1) an ethylene copolymer containing a monomer unit having a hydroxyl group,

(B2) an ethylene copolymer comprising monomer units having a (meth-) acrylate group, and

(B3) an ethylene copolymer comprising monomer units having hydroxyl groups and (meth) acrylate groups.

All the embodiments and preferred embodiments described above for components (B1), (B2) and (B3) also apply to components (B1), (B2) and (B3) of layer (1) of the cable of the invention.

For example, in any of the embodiments described herein, the cable may comprise a layer (1) comprising or consisting of component (B2), wherein the layer is a skin layer (i.e., the outermost layer of the cable).

In a preferred embodiment, the adhesion strength between the cable and the standard polyurethane resin is at least 1N/mm according to the standard test defined in the experimental section below.

In one embodiment, the one or more ethylene copolymers selected from (B1), (B2), and (B3) constitute at least 85 wt% of layer (1) in any of the above embodiments, at least 90 wt% of layer (1) in another embodiment, and at least 95 wt% of layer (1) in yet another embodiment.

In a preferred embodiment, the layer (1) comprises or consists of the polyethylene composition according to the invention in any of the above embodiments.

For example, in any of the embodiments as described herein, the cable may comprise a layer (1) comprising or consisting of a polyethylene composition comprising or consisting of components (a) and (B2), wherein the layer is the skin layer (i.e. the outermost layer of the cable), and wherein (a) and (B2) may be present in the composition as an ethylene copolymer comprising monomer units having hydrolysable silane groups and monomer units having (meth-) acrylates.

In the cable of the invention, there may be a further layer or layers adjacent to layer (1), which layer or layers may comprise or consist of: ethylene copolymers with hydrolysable silane groups, polypropylene, polyethylene (e.g., LLDPE or HDPE), and/or thermoplastics.

Preferably, in the cable according to the invention, adjacent to layer (1) there is a further layer comprising or consisting of a polyethylene comprising hydrolysable silane groups.

The layer (1) is preferably a surface layer and/or an insulating layer, more preferably a surface layer.

Preferably, the cable of the invention is a power cable, for example a low voltage power cable.

The invention also relates to the use of one or more ethylene copolymers selected from the group consisting of:

(B1) an ethylene copolymer containing a monomer unit having a hydroxyl group,

(B2) an ethylene copolymer comprising monomer units having a (meth-) acrylate group, and

(B3) an ethylene copolymer containing monomer units having hydroxyl groups and (meth) acrylate groups,

in any of the embodiments described herein, for improving the adhesion between a layer of a cable comprising one or more ethylene copolymers and a polyurethane resin.

The invention also relates to the use of an ethylene copolymer comprising monomer units having from more than 4 mol% to 15 mol% or less of (meth) acrylate groups for improving the adhesion between a layer of a cable comprising said ethylene copolymer and a polyurethane resin. All embodiments of the ethylene copolymer comprising monomer units having (meth-) acrylate groups as described above are also preferred embodiments of the use of the ethylene copolymer comprising monomer units having (meth-) acrylate groups.

Preferably, the monomer units having (meth-) acrylate groups are present in the ethylene copolymer comprising monomer units having (meth-) acrylate groups in an amount of 4.25 mol% or more, more preferably 4.5 mol% or more, more preferably 5 mol% or more, more preferably 5.5 mol% or more, more preferably 6 mol% or more, more preferably 7 mol% or more, most preferably 8 mol% or more.

Preferably, the monomer unit having a (meth-) acrylate group is present in the ethylene copolymer comprising the monomer unit having a (meth-) acrylate group in an amount of 12.5 mol% or less, more preferably 10 mol% or less.

Preferably, the ethylene copolymer comprises monomers having methyl-, ethyl-, propyl-, or butyl acrylate groups, more preferably monomers having methacrylate groups.

Preferably, the ethylene copolymer further comprises monomer units having hydrolysable silane groups. In particular, the monomer units having hydrolysable silane groups are preferably present in the ethylene copolymer in an amount of from 0.1 to 1 mol%, more preferably from 0.2 to 0.7 mol%, and most preferably from 0.3 to 0.5 mol%.

Furthermore, the monomer units having hydrolyzable silane groups may comprise, or consist of, vinyltrimethoxysilane, vinylbismethoxyethoxysilane, vinyltriethoxysilane, gamma- (meth) acryloxypropyltrimethoxysilane, gamma- (meth) acryloxypropyltriethoxysilane, and/or vinyltriacetoxysilane.

In a preferred embodiment of the invention, the monomer unit having a hydrolyzable silane group comprises or consists of vinyltrimethoxysilane.

Detailed Description

Examples

1. Measurement method

a) Melt flow rate

The Melt Flow Rate (MFR) is determined according to ISO 1133 and is expressed in g/10 min. The MFR is an indication of the flowability and hence the processability of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer.

MFR of polyethylene (co) Polymer₂Measured at a temperature of 190 ℃ and a load of 2.16 kg.

b) Adhesive strength

The adhesive strength is measured according to standard HD603S 1/A3:2008, see section G of section 5. The standard specifies a minimum adhesive strength of 1N/mm for cable samples between the cable insulation and the joint casting resin (usually polyurethane but also epoxy groups are present).

The data in the present invention are based on adhesion to tape samples having a thickness of 0.5 mm and a length of 30 cm. Tapes were prepared on a Collin TeachLine E20T tape extruder with 4.2:1, 20D compression screw, D ═ 20mm, temperature profile 135/165/755 ℃ and 30 rpm. The tape samples were then conditioned at 23 ℃ and 59% relative humidity for at least 24 hours and then cleaned with IPA.

The adjusted tape was placed on a plate made of HDPE. The plate contained openings having a width of 10 mm, a length of 150 mm and a depth of 15 mm. The tape sample is placed over the opening. The strap is secured over the opening by another sheet of HDPE. The PUR is mixed with the curing agent and poured into the opening. The mold was then adjusted for 24 hours. During this time, the PUR crosslinks and hardens. The tape and PUR samples were removed from the holder and the adhesion was measured in a tensile tester with a special sample holder as described in VDE 0472-.

The masterbatch (MB-CAT) was dry blended with the polymers/compounds listed in tables 1 and 2. Strips of 1.8mm thickness were then extruded at 30rpm on a Collin Teachline E20T strip extruder equipped with a 4.2:1, 20D compression screw, D ═ 20mm, at a temperature profile of 135/145/155 ℃.

2. Experimental methods

a) Cross-linking

The samples containing the crosslinking catalyst masterbatch CM-A were crosslinked in water at 90 ℃ for 24 hours prior to adjustment of the adhesion test. CM-a is dry blended into the particular polymer mixture selected prior to the ribbon extrusion step.

3. Material

a) Ethylene copolymers

The ethylene copolymers used in the present invention having the indicated comonomer type or comonomers and amounts are given in table 1 below. Nucrel 0903HC, Nucrel 1202, Surlyn 9320, Surlyn 8320, Escor 6060, Escorene UL00119, Levapren 400, EVAL G156B, and EVAL F101A are commercially available ethylene copolymers from the indicated suppliers. In Table 1 below, polymers C and D are terpolymers.

Polymers A-F were produced in a 660m long split-feed high-pressure tubular reactor (Union Carbide type A-1). The inner wall diameter was 32 mm. Chain transfer agent (propylene), initiator (t-butyl peroxy 2-ethylhexanoate (Luperox 26) and air) and comonomer were fed to the reactor in a conventional manner. The polymerization pressure of all polymers was 230 MPa. The maximum polymerization temperature for polymers A and B was 310 ℃ and the maximum polymerization temperature for polymers C-G was 285 ℃.

Table 1: ethylene copolymers

AA-acrylic acid

BA-butyl acrylate

MA-methyl acrylate

MAA-methacrylic acid

HEMA-hydroxyethyl methacrylate

VA-vinyl acetate

VOH-vinyl alcohol

VTMS-vinyltrimethoxysilane

n.a. -not obtaining

b) Crosslinking catalyst masterbatch CM-A

CM-A, consisting of a crosslinking catalyst (1 wt% dibutyltin dilaurate) and a stabilizer (2 wt% Irganox 1010), was compounded to an ethylene Butyl Acrylate (BA) copolymer having a BA content of 17 wt%, and an MFR₂＝8g/10min。

c) Polyurethane resin (PUR)

The polyurethane resin (PUR) used as the cable tie casting resin in the present invention is Protolin 2000, commercially available from Lovink-Enertech. It is a two-component non-filled and non-pigmented two-component casting resin.

4. Results

The results of adhesion test of the polyethylene composition to the polyurethane resin Protolin 2000 are shown in table 2 below. Inventive examples IE1 to IE3 are polyethylene compositions comprising a polyethylene polymer containing hydrolysable silane groups (a) and an ethylene copolymer (B).

Table 2: adhesion of polyethylene composition to Cable connection casting resin Protolin 2000

The results of the adhesion tests of one or more ethylene copolymers (B) useful for forming layer (1) of the cable of the invention with the polyurethane resin Protolin 2000 are shown in table 3 below.

Table 3: adhesion of polyethylene copolymer to Cable Joint casting resin Protolin 2000

The results shown in tables 2 and 3 indicate that vinyltrimethoxysilane, vinyl acetate, methacrylic acid, acrylic acid and ionomer functional groups do not improve adhesion to PUR casting resins (CE 4-11). On the other hand, acrylates (IE3, IE7 and IE8) and hydroxy-functional copolymers have a very positive effect (IE4 and IE5) and can provide adhesion well above 1N/mm, i.e. meet the adhesion requirements of HD603S 1. The same is true for copolymers having hydroxyl and acrylate functional groups in the same comonomer (IE1, IE2 and IE 6). It has also been shown that adhesive strength can be achieved by blending polyolefins such as polymer a, which itself has little adhesion to PUR (IE1), with acrylate or hydroxy-functional polymers.