Redetachable adhesive strip

Abstract

The invention relates to an adhesive strip redetachable without residue or destruction by extensive stretching substantially in the bond plane, comprising at least one layer of adhesive which is foamed with microballoons, and at least one carrier B.

Claims

1. An adhesive strip redetachable without residue or destruction by extensive stretching substantially in a bond plane, comprising an adhesive layer A, which is foamed with microballoons, and which comprises a pressure-sensitive adhesive A, a carrier layer B consisting of a carrier B, wherein pressure-sensitive adhesive A comprises an elastomer part (a1) based on at least one kind of a polyvinylaromatic-polydiene block copolymer, where elastomer part (a1) comprises at least 90 wt % of the at least one kind of a polyvinylaromatic-polydiene block copolymer having a polyvinylaromatic content of at least 12 wt % and at most 35 wt %, and a fraction of elastomer part (a1), based on the overall pressure-sensitive adhesive A, is at least 40 wt % and at most 55 wt %, and comprises a tackifying resin part (a2) with at least one kind of a tackifying resin, where tackifying resin part (a2) comprises at least 90 wt % of hydrocarbon resins which are substantially compatible with polydiene blocks in the at least one kind of a polyvinylaromatic-polydiene block copolymer and substantially incompatible with polyvinylaromatic blocks in the at least one kind of a polyvinylaromatic-polydiene block copolymer, and a fraction of tackifying resin part (a2), based on the overall pressure-sensitive adhesive A is at least 40 wt % and at most 60 wt %, and optionally comprises a plasticizing resin part (a3), where a fraction of plasticizing resin part (a3), based on the overall pressure-sensitive adhesive A, is 0 wt % to at most 5 wt %, and optionally comprises further additives (a4), where a fraction of microballoons, based on the overall pressure-sensitive adhesive A, is at least 0.5 wt % and at most 2.5 wt %, where a thickness of adhesive layer A is at least 20 m and at most 75 m, and wherein carrier B comprises an elastomer part (b1) based on at least one kind of a polyvinylaromatic-polydiene block copolymer, where elastomer part (b1) comprises at least 90 wt % of the at least one kind of the polyvinylaromatic-polydiene block copolymer having a polyvinylaromatic content of at least 20 wt % and at most 45 wt %, a fraction, within elastomer part (b1), of at least one triblock copolymer (linear or radial) or multiblock copolymer (linear or radial) is at least 80 wt %, a peak molar mass by GPC of the at least one triblock copolymer (linear or radial) or multiblock copolymer (linear or radial) is at least 85 000 g/mol, a fraction of diblock copolymer(s) is below 20 wt %, and a fraction of elastomer part (b1), based on an overall formulation of carrier B, is at least 40 wt % and at most 60 wt %, and comprises a tackifying resin part (b2) with at least one kind of a tackifying resin, where tackifying resin part (b2) comprises at least 90 wt % of hydrocarbon resins which are substantially compatible with polydiene blocks in the at least one kind of a polyvinylaromatic-polydiene block copolymer, and substantially incompatible with polyvinylaromatic blocks in the at least one kind of a polyvinylaromatic-polydiene block copolymer and a fraction of tackifying resin part (b2), based on the overall formulation of carrier B, is at least 40 wt % and at most 60 wt %, and optionally comprises a plasticizing resin part (b3), where a fraction of plasticizing resin fraction (b3), based on the overall formulation of carrier B, is 0 wt % to at most 5 wt %, and optionally further additives (b4), where a thickness of carrier layer B is at least 70 m and at most 150 m, where a density of carrier B is at least 950 g/cm.sup.3.

2. The adhesive strip according to claim 1, consisting of one or more layers of adhesive layer A, consisting of pressure-sensitive adhesive A, and one or more layers of carrier layer B.

3. The adhesive strip according to claim 1, wherein the polyvinylaromatic content of the at least one kind of a polyvinylaromatic-polydiene block copolymer in elastomer part (a1) is at least 20 wt % and at most 32 wt %, and the fraction of the elastomer part (a1), based on the overall pressure-sensitive adhesive A, is at least 45 wt % and at most 55 wt %.

4. The adhesive strip according to claim 1, wherein tackifying resin part (a2) comprises at least 95 wt % of the hydrocarbon resins which are substantially compatible with the polydiene blocks and substantially incompatible with the polyvinylaromatic blocks.

5. The adhesive strip according to claim 1, wherein the fraction of microballoons, based on the overall pressure-sensitive adhesive A, is at least 1.0 wt % and at most 2.0 wt %.

6. The adhesive strip according to claim 1, wherein the thickness of adhesive layer A is at least 25 m and at most 65 m.

7. The adhesive strip according to claim 1, wherein the polyvinylaromatic content of the at least one kind of a polyvinylaromatic-polydiene block copolymer in elastomer part (b1) is at least 25 wt % and at most 35 wt %, the fraction, within the elastomer part (b1), of the at least one triblock copolymer (linear or radial) or multiblock copolymer (linear or radial) is at least 90 wt %, the fraction of diblock copolymer(s) is at most 10 wt %, and the fraction of elastomer part (b1), based on the overall formulation of carrier B, is at least 45 wt % and at most 55 wt %.

8. The adhesive strip according to claim 1, wherein elastomer part (b1) comprises at least 90 wt % of polyvinylaromatic-butadiene block copolymers and/or polyvinylaromatic-polyisoprene block copolymers.

9. The adhesive strip according to claim 1, wherein tackifying resin part (b2) comprises at least 95 wt % of the hydrocarbon resins which are substantially compatible with the polydiene blocks and substantially incompatible with the polyvinylaromatic blocks.

10. The adhesive strip according to claim 1, wherein the thickness of carrier layer B is at least 80 m and at most 120 m and/or carrier layer B is substantially unfoamed.

11. The adhesive strip according to claim 1, wherein tackifying resin part (a2) and tackifying resin part (b2) are chemically identical.

12. The adhesive strip according to claim 1, wherein the at least one kind of a polyvinylaromatic-polydiene block copolymer of pressure-sensitive adhesive A are based on block copolymers comprising polymer blocks (i) predominantly formed of vinylaromatics (A blocks), and polymer blocks (ii) predominantly formed by polymerization of 1,3-dienes (B blocks).

13. The adhesive strip according to claim 1, wherein vinylaromatic block copolymer in elastomer part (a1) and/or elastomer part (b1) comprise(s) at least one synthetic rubber in the form of a block copolymer having a structure A-B, A-B-A, (A-B).sub.n, (A-B).sub.nX or (A-B-A).sub.nX, in which blocks A independently of one another are a polymer formed by polymerization of at least one vinylaromatic; blocks B independently of one another are a polymer formed by polymerization of conjugated dienes having 4 to 18 carbon atoms and/or isobutylene, or are a partly or fully hydrogenated derivative of such a polymer; X is the radical of a coupling reagent or initiator; and n is an integer 2.

14. The adhesive strip according to claim 13, wherein vinylaromatics for synthesizing blocks A comprise styrene, -methylstyrene and/or other styrene derivatives.

15. The adhesive strip according to claim 13, wherein monomers in blocks B are selected from the group consisting of butadiene, isoprene, ethylbutadiene, phenylbutadiene, piperylene, pentadiene, hexadiene, ethylhexadiene and dimethylbutadiene and any mixture of these monomers.

16. The adhesive strip according to claim 1, wherein pressure-sensitive adhesive A comprises at least 40 wt %, and not more than 55 wt % of the at least one kind of a polyvinylaromatic-polydiene block copolymer.

17. The adhesive strip according to claim 1, wherein tackifying resin (a2) has a diacetone alcohol cloud point (DACP) of greater than +5 C., a mixed methylcyclohexane aniline point (MMAP) of at least +50 C., and/or a softening temperature (ring & ball) of greater than or equal to 70 C.

18. The adhesive strip according to claim 1, wherein at least 75 wt % of the hydrocarbon resins of the at least one kind of a tackifying resin of the tackifying resin part (a2) comprises terpene resins.

19. The adhesive strip according to claim 1, wherein pressure-sensitive adhesive A consists of the following composition: 40 to 55 wt % of the at least one kind of a polyvinylaromatic-polydiene block copolymer; 40 to 59.3 wt % of the tackifying resins and optionally plasticizing resins; 0.5 to 2.5 wt % of the microballoons; and 0.2 to 10 wt % of the additives.

20. The adhesive strip according to claim 1, wherein the absolute density of adhesive layer A is 450 to 950 kg/m.sup.3, and/or the relative density is 0.22 to 0.99.

21. The adhesive strip according to claim 1, wherein carrier B consists of the following composition: 40 to 59.8 wt % of the at least one kind of a polyvinylaromatic-polydiene block copolymer; 40 to 59.8 wt % of the tackifying resins and optionally plasticizing resins; and 0.2 to 10 wt % of the additives.

22. The adhesive strip according to claim 1, having an overall thickness, without temporary release liners or release films, of at most 250 m.

23. The adhesive strip according to claim 1, wherein carrier layer B has a thickness of between 80 to 120 m.

24. A method of bonding components of batteries and electronic devices comprising a step of applying an adhesive strip of claim 1.

Description

(1) With reference to the figures and examples described hereinafter, particularly advantageous embodiments of the invention are elucidated in more detail, without any intention thereby to subject the invention to unnecessary restriction.

(2) In the drawings:

(3) FIG. 1 shows a three-layer pressure-sensitive self-adhesive strip of the invention.

(4) FIG. 2 shows a three-layer pressure-sensitive self-adhesive strip of the invention in an alternative embodiment.

(5) FIG. 3 shows a thermogram and steps to determine glass transition temperature.

(6) FIG. 4 shows the basic construction of Test IXResistance to tears (detachment test).

(7) FIG. 1 shows the self-adhesive strip of the invention composed of three layers 1, 2, 3, which can be redetached by extensive stretching.

(8) The strip consists of a carrier 1, the carrier 1 being of single-layer embodiment. On the carrier there are external PSA layers 2, 3 of the invention on either side.

(9) The protruding end of the carrier layer 1 may serve as a grip tab, but is not necessarily present.

(10) In FIG. 2, the pressure-sensitive self-adhesive strip of the invention is shown in a variant. The self-adhesive strip consists of three layers 1, 2, 3, which are arranged congruently one above another.

(11) In order to produce a grip tab for pulling, to achieve the extensive stretching, one end of the self-adhesive film strip is made non-adhesive on both sides, by the application of preferably siliconized pieces of film or of paper 4.

(12) The invention below is elucidated in more detail by a number of examples, without thereby wishing to restrict the invention in any form whatsoever.

(13) Pressure-Sensitive Adhesives

(14) The constituents of the pressure-sensitive adhesives (PSAs) were dissolved in this case at 40% in benzene/toluene/acetone, admixed with a benzene slurry of the microballoons, and coated out with a coating bar onto a PET film furnished with a silicone release in the desired layer thickness, after which the solvent was evaporated off at 100 C. for 15 minutes in order to dry the adhesive layer. In the examples given, this is possible because in this case microballoons are utilized which have an expansion temperature above 100 C. When using other microballoons, the skilled person selects production temperatures suitable accordingly, without departing from the scope of the present invention.

(15) After the drying, the adhesive layer was lined with a second ply of PET liner, free from any air inclusions, and foamed in an oven between the two liners at 150 C. for 5 minutes. Foaming between two liners allows products to be obtained that have particularly smooth surfaces. All of the examples given feature an R.sub.a of less than 15 m. R.sub.a, the arithmetic mean roughness, is the arithmetic mean value of all profile values of the roughness profile.

(16) Carrier Layers

(17) The constituents of the formulations for the carrier layers were dissolved in this case at 40% in benzine/toluene/acetone and the solution was coated out with a coating bar onto a PET film furnished with a silicone release in the desired layer thickness, after which the solvents evaporated off at 100 C. for 15 minutes to dry the layer of composition.

(18) Production of the Multilayer Self-Adhesive Strips

(19) To produce the multilayer self-adhesive strips, two plies of a foamed pressure-sensitive adhesive layer and one ply of a carrier layer in each case were made ready. Using a rubber roller, a ply of a layer of pressure-sensitive adhesive was first laminated manually onto the first surface of the carrier layer, without bubbles, after which a second layer of pressure-sensitive adhesive was laminated onto a second surface of the carrier layer. For this purpose, in each case, liners were removed beforehand from the surfaces of the individual plies that were to be contacted. Adhesive strips in the desired dimensions were obtained by diecutting.

EXAMPLES

(20) Raw Materials Used

(21) TABLE-US-00012 Raw material Nature Characteristics Elastomer part KRATON D1102 Linear SBS PS fraction: 29%** (a1) and/or (b1) AS polymer Diblock fraction: 17%** KRATON D1118 Linear SBS PS fraction: 33%** ES polymer Diblock fraction: 78%** M.W. (Triblock): 150 000 g/mol KRATON D1116 Radial SBS PS fraction: 23%** AT polymer Diblock fraction: 16%** M.W. (Multiblock radial): 300 000 g/mol KRATON D1101 Linear SBS PS fraction: 31%** AS polymer Diblock fraction: 16%** M.W. (Triblock): 150 000 g/mol VECTOR Linear SIS PS fraction: 18%*** 4111N resin Diblock fraction: < 1%*** M.W. (Triblock): 150 000 g/mol KRATON D1165 Linear SIS PS fraction: 30%** PT polymer Diblock fraction: 20%** M.W. (Triblock): 120 000 g/mol Tackifying resin PICCOLYTE Poly-- Softening part (a2) and/or A115 terpene temperature: (b2) (Pinova Inc.) 115 C. DERCOLYTE Poly-- Softening A115 terpene temperature: (Les Drivs 115 C. Rsiniques & Terpniques) Plasticizing WINGTACK 10 Liquid C5 resin part (Cray Valley USA, hydrocarbon (a3) and/or (b3) LLC) resin Additives IRGANOX 1010 Primary (a4) and/or (b4) (BASF SE) ageing inhibitor Microballoons EXPANCEL 920 DU20 (Akzo Nobel Pulp and Performance Chemicals AB)

(22) SBS: Polystyrene-polybutadiene block copolymer

(23) SIS: Polystyrene-polyisoprene block copolymer

(24) PS: Polystyrene

Example 1.1 (Inventive)

(25) TABLE-US-00013 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1102 AS 50.0 wt % polymer Resin part PICCOLYTE 49.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Thickness 80 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin PICCOLYTE 48.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 1.2 (Inventive)

(26) TABLE-US-00014 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1102 AS 50.0 wt % polymer Resin part PICCOLYTE 49.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Thickness 100 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 1.3 (Inventive)

(27) TABLE-US-00015 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1102 AS 50.0 wt % polymer Resin part PICCOLYTE 49.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Thickness 70 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing resin -/- part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 2.1 (Comparative)

(28) TABLE-US-00016 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 10 3.0 wt % part Additives IRGANOX 0.5 wt % 1010 Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1101 AS 50.0 wt % polymer Resin part DERCOLYTE A115 46.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Thickness 30 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 2.2 (Comparative)

(29) TABLE-US-00017 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1101 AS 50.0 wt % polymer Resin part DERCOLYTE A115 46.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Thickness 50 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer 8.0 wt % KRATON D1118 ES polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 2.3 (Inventive)

(30) TABLE-US-00018 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1101 AS 50.0 wt % polymer Resin part DERCOLYTE A115 46.5 wt % Plasticizing resin WINGTACK part 10 3.0 wt % Additives IRGANOX 1010 0.5 wt % Thickness 80 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 2.4 (Inventive)

(31) TABLE-US-00019 Type Fraction Adhesive A1 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m Carrier B Elastomer part KRATON D1101 AS 50.0 wt % polymer Resin part DERCOLYTE A115 46.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Thickness 100 m Adhesive A2 Elastomer part KRATON D1102 AS 42.0 wt % polymer KRATON D1118 ES 8.0 wt % polymer Resin part DERCOLYTE A115 45.5 wt % Plasticizing resin WINGTACK 3.0 wt % part 10 Additives IRGANOX 1010 0.5 wt % Microballoons EXPANCEL 1.0 wt % 920 DU20 Thickness* 50 m

Example 3.1 (Comparative)

(32) TABLE-US-00020 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier Polyurethane Polyethylene-coated B film thermoplastic polyurethane Thickness 80 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 4.1 (Comparative)

(33) TABLE-US-00021 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt% D1118 ES polymer Resin part DERCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- -/- Unfoamed balloons Thickness 50 m Carrier Elastomer KRATON 42.0 wt% B part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part DERCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 50 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part DERCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- -/- Unfoamed balloons Thickness 50 m

Example 4.2 (Comparative)

(34) TABLE-US-00022 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier Elastomer KRATON 42.0 wt % B part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt% resin part 10 Additives IRGANOX 0.5 wt% 1010 Microballoons EXPANCEL 1.0 wt% 920 DU20 Thickness* 50 m Adhesive Elastomer KRATON 42.0 wt % A2 part polymer D1102 AS KRATON 8.0 wt % polymer D1118 ES Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 5.1 (Comparative)

(35) TABLE-US-00023 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier Elastomer KRATON 42.0 wt % B part D1102 AS polymer 8.0 wt % KRATON D1118 ES polymer Resin part DERCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 80 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 6.1 (Inventive)

(36) TABLE-US-00024 Type Fraction Adhesive Elastomer KRATON 18.0 wt % A1 part D1116 AT polymer KRATON 30.0 wt % D1118 ES polymer Resin part PICCOLYTE 47.5 wt % A115 Plasticizing WINGTACK 1.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 25 m Carrier B Elastomer KRATON 50.0 wt % part D1102 AS polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing WINGTACK 1.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 100 m Adhesive Elastomer KRATON 18.0 wt % A2 part D1116 AT polymer KRATON 30.0 wt % D1118 ES polymer Resin part PICCOLYTE 47.5 wt % A115 Plasticizing WINGTACK 1.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 25 m

Example 6.2 (Inventive)

(37) TABLE-US-00025 Type Fraction Adhesive Elastomer KRATON 18.0 wt % A1 part D1116 AT polymer KRATON 30.0 wt % D1118 ES polymer Resin part PICCOLYTE 47.5 wt % A115 Plasticizing WINGTACK 1.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 35 m Carrier Elastomer KRATON 50.0 wt % B part D1102 AS polymer Resin part PICCOLYTE 48.5 wt % A115 Plasticizing WINGTACK 1.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 80 m Adhesive Elastomer KRATON 18.0 wt % A2 part D1116 ATpolymer KRATON 30.0 wt % D1118 ES polymer Resin part PICCOLYTE 47.5 wt % A115 Plasticizing WINGTACK 1.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 35 m

Example 7.1 (Comparative)

(38) TABLE-US-00026 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resinpart 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier Elastomer VECTOR 50.0 wt % B part 4111N resin Resin part DERCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 50 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 7.2 (Comparative)

(39) TABLE-US-00027 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier Elastomer VECTOR 50.0 wt % B part 4111N resin Resin part PICCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 80 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 7.3 (Comparative)

(40) TABLE-US-00028 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier B Elastomer KRATON 50.0 wt % part D1165 PT polymer Resin part DERCOLYTET 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 1010 0.5 wt % Thickness 50 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 7.4 (Comparative)

(41) TABLE-US-00029 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness 50 m Carrier B Elastomer KRATON 50.0 wt % part D1165 PT polymer Resin part DERCOLYTE 46.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Thickness 80 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 8.1 (Comparative)

(42) TABLE-US-00030 Type Fraction Adhesive Elastomer KRATON 42.0 wt % A1 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part DERCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 1010 0.5 wt % Micro- EXPANCEL 1.0 wt % balloons Thickness* 50 m Carrier B Elastomer KRATON 99.5 wt % part D1102 AS polymer Resin part -/- Plasticizing -/- resin part Additives IRGANOX 0.5 wt % 1010 Thickness 50 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

Example 8.2 (Comparative)

(43) TABLE-US-00031 Type Fraction Adhesive Elastomer KRATON 42.0 wt% A1 part D1102 AS polymer KRATON 8.0 wt% D1118 ES Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- -EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m Carrier B Elastomer KRATON 99.5 wt % part D1102 AS polymer Resin part -/- Plasticizing -/- resin part Additives IRGANOX 0.5 wt % 1010 Thickness 80 m Adhesive Elastomer KRATON 42.0 wt % A2 part D1102 AS polymer KRATON 8.0 wt % D1118 ES polymer Resin part PICCOLYTE 45.5 wt % A115 Plasticizing WINGTACK 3.0 wt % resin part 10 Additives IRGANOX 0.5 wt % 1010 Micro- EXPANCEL 1.0 wt % balloons 920 DU20 Thickness* 50 m

(44) TABLE-US-00032 Diblock fraction Peel Shock Resistance Carrier layer adhesion resistance to tears Example 17% 10.3 N/cm 633 mJ 0/3 1.1 @ 800 mm/min Example 17% 10.8 N/cm 603 mJ 0/3 1.2 @ 800 mm/min Example 17% 9.8 N/cm 662 mJ 0/3 1.3 @ 800 mm/min Example 16% 9.5 N/cm 589 mJ 0/3 2.1 @ 500 mm/min 3/3 @ 700 mm/min Example 16% 9.5 N/cm 618 mJ 2/3 2.2 @ 500 mm/min 3/3 @ 700 mm/min Example 16% 9.8 N/cm 662 mJ 0/3 2.3 @ 800 mm/min Example 16% 10.8 N/cm 662 mJ 0/3 2.4 @ 800 mm/min Example / 7.6 N/cm 559 mJ 0/3 3.1 @ 300 mm/min 3/3 @ 500 mm/min Example 26.8%.sup. 13.6 N/cm 383 mJ 0/3 4.1 @ 800 mm/min Example 26.8%.sup. 10.9 N/cm 662 mJ 3/3 4.2 @ 100 mm/min Example 26.8%.sup. 10.3 N/cm 647 mJ 3/3 5.1 @ 300 mm/min Example 17% 10.6 N/cm 740 mJ 0/3 6.1 @ 800 mm/min Example 17% 11.4 N/cm 840 mJ 0/3 6.2 @ 800 mm/min Example <1% 10.3 N/cm 750 mJ 3/3 7.1 @ 500 mm/min Example <1% 10.6 N/cm 750 mJ 3/3 7.2 @ 500 mm/min Example 20% 11.4 N/cm 589 mJ 3/3 7.3 @ 500 mm/min Example 20% 14.1 N/cm 574 mJ 3/3 7.4 @ 500 mm/min Example 17% 4.6 N/cm 353 mJ 0/3 8.1 @ 800 mm/min Example 17% 2.3 N/cm 338 mJ 0/3 8.2 @ 800 mm/min

(45) Examples 1.1, 1.2 and 1.3 show that the inventive architecture of self-adhesive strips meets the specified performance requirements. The advantageous resistance to shock exposure is attributable to the foamed layers of adhesive. The example products can be detached from a test bonded assembly through inventive design of the carrier layer under very challenging conditions (detachment angle of approximately 180 around two edges even at a high detachment speed of 800 mm/min).

(46) Examples 2.1, 2.2, 2.3 and 2.4 show the influence of the thickness of the carrier layer. Carrier thicknesses of 30 m or 50 m do not afford the improved resistance to tears during detachment. At 700 mm/min, all three test strips already suffer tearing. If carrier thicknesses of 80 m or 100 m are selected, detachment is possible even at 800 mm/min.

(47) A polyurethane film 80 m thick (Example 3.1) as carrier layer is suitable for numerous applications. However, it does allow detachment to take place under the very challenging detachment speeds imposed here.

(48) Examples 4.1 and 4.2 show that a fully unfoamed 150 m self-adhesive strip (Example 4.1) can be parted from the test bond very well even under the difficult detachment conditions employed here. Without the foaming, however, the shock resistance is not at the required level. A completely foamed self-adhesive strip, in contrast, does have outstanding shock resistance, but does not afford sufficient resistance to tears in the detachment test.

(49) From Example 5.1 it is apparent that a composition for the carrier layer that is not inventive with regard to the diblock fraction in the elastomer part (b1) does not meet the requirements imposed for detachability under the very challenging conditions set here.

(50) Examples 6.1 and 6.2 show further inventive product architectures with the corresponding advantageous performance properties of peel adhesion, shock resistance and detachment behaviour. The shock resistance here is very high, in spite of the fact that the foamed layers of adhesive have thicknesses of only 25 m and 35 m respectively.

(51) In Examples 7.1, 7.2, 7.3 and 7.4, the results are summarized for an investigation with a different elastomer basis for the carrier layer. Here, formulation took place with polystyrene-polyisoprene block copolymers rather than with polystyrene-polybutadiene block copolymers. The Vector 4111N used in Example 7.1 and 7.2 has a polystyrene fraction of 18%. This proves to be too low for sufficient detachability, even at a carrier layer thickness of 80 m (Example 7.2). Examples 7.3 and 7.4 used KRATON D1165 PT, a polystyrene-polyisoprene block copolymer, with a polystyrene fraction of 30%. A carrier layer with a thickness of 50 m again proves to be too thin to meet the required resistance to tears for the detachment process. If an inventive carrier layer thickness of 80 m is selected, then it is found that a diblock fraction in the elastomer part of 20% is no longer sufficient to achieve the required detachability under the very challenging conditions. Peel adhesion and shock resistance are each at the required level for these inventive specimens.

(52) Finally, Examples 8.1 and 8.2 reveal that with a carrier layer which, while being formed of an elastomer, contains no resins present in the outer pressure-sensitive adhesive layers, the resulting multilayer assembly lacks sufficient stability. Detachment properties found are good, admittedly. Within a short time, however, the self-adhesive strip suffers significant loss of peel adhesion, a factor attributable at least partly to migration of tackifying resin and plasticizing resin from the pressure-sensitive adhesive layers into the carrier layer.

TEST METHODS

(53) Unless otherwise indicated, all measurements were carried out at 23 C. and 50% relative humidity.

Test IGlass Transition Temperature (DSC)

(54) The glass transition temperature of polymer blocks in block copolymers is determined by means of dynamic scanning calorimetry (DSC). For this purpose, about 5 mg of the untreated block copolymer samples are weighed into an aluminium crucible (volume 25 L) and closed with a perforated lid. For the measurement, a DSC 204 F1 from Netzsch is used, and is operated under nitrogen for inertization. The sample is cooled initially to 150 C., heated to +150 C. at a rate of 10 K/min, and cooled again to 150 C. The subsequent, second heating curve is run again at 10 K/min and the change in the heat capacity is recorded. Glass transitions are identified as steps in the thermogram. The glass transition temperature is evaluated as follows (see in this regard FIG. 3): A tangent is applied in each case to the baseline of the thermogram before 31 and after 32 of the steps. In the region of the step, a balancing line 33 is placed parallel to the ordinate in such a way that it intersects the two tangents, specifically so as to form two areas 34 and 35 of equal content (between each tangent, the balancing line and the measuring plot). The point of intersection of the balancing line thus positioned with the measuring block gives the glass transition temperature.

Test IIMolar Mass (GPC)

(55) (i) Peak Molar Mass of Individual Block Copolymer Modes

(56) GPC is an appropriate technical measuring method for determining the molar mass of individual polymer modes in mixtures of different polymers. For the block copolymers which can be used for the purposes of this invention, prepared by living anionic polymerization, the molar mass distributions are typically narrow enough that polymer modes which can be assigned to triblock copolymers, diblock copolymers or multiblock copolymers occur with sufficient resolution from one another in the elugram. The peak molar mass for the individual polymer modes can then be read off from the elugram.

(57) Peak molar masses Mp are determined by means of gel permeation chromatography (GPC). The eluent used is THF. Measurement takes place at 23 C. The pre-column used is PSS-SDV, 5, 10.sup.3 , ID 8.0 mm50 mm. Separation is carried out using the columns PSS-SDV, 5, 10.sup.3 and also 10.sup.4 and 10.sup.6 each with ID 8.0 mm300 mm. The sample concentration is 4 g/l, the flow rate 1.0 ml per minute. Measurement takes place against PS standards (=m; 1 =10.sup.10 m).

(58) (ii) Weight-Average Molar Mass, Particularly of Tackifying Resins

(59) The weight-average molecular weight M.sub.w (M.W.) is determined by means of gel permeation chromatography (GPC). The eluent used is THF. Measurement takes place at 23 C. The pre-column used is PSS-SDV, 5, 10.sup.3 , ID 8.0 mm50 mm. Separation is carried out using the columns PSS-SDV, 5, 10.sup.3 and also 10.sup.4 and 10.sup.6 each with ID 8.0 mm300 mm. The sample concentration is 4 g/l, the flow rate 1.0 ml per minute. Measurement takes place against PS standards (=m; 1 =10.sup.10 m).

Test IIIDACP

(60) 5.0 g of test substance (the tackifying resin specimen under examination) are weighed out into a dry test tube, and 5.0 g of xylene (isomer mixture CAS [1330-20-7], 98.5%, Sigma-Aldrich #320579 or comparable) are added. The test substance is dissolved at 130 C. and then the solution is cooled to 80 C. Any xylene that has escaped is made up for with further xylene, so that 5.0 g of xylene are again present. Then 5.0 g of diacetone alcohol (4-hydroxy-4-methyl-2-pentanone, CAS [123-42-2], 99%, Aldrich #H41544 or comparable) are added. The test tube is shake until the test substance has dissolved completely. For this purpose the solution is heated to 100 C. The test tube containing the resin solution is then introduced into a Novamatics Chemotronic Cool cloud point measuring instrument and heated therein to 110 C. Cooling takes place at a cooling rate of 1.0 K/min. The cloud point is detected optically. For this purpose, the temperature is registered at which the turbidity of the solution is 70%. The result is reported in C. The lower the DACP, the higher the polarity of the test substance.

Test IVMMAP

(61) 5.0 g of test substance (the tackifying resin specimen under examination) are weighed out into a dry test tube, and 10 ml of dry aniline (CAS [62-53-3], 99.5%, Sigma-Aldrich #51788 or comparable) and 5 ml of dry methylcyclohexane (CAS [108-87-2], 99%, Sigma-Aldrich #300306 or comparable) are added. The test tube is shaken until the test substance has dissolved completely. For this purpose, the solution is heated to 100 C. The test tube containing the resin solution is then introduced into a Novamatics Chemotronic Cool cloud point measuring instrument and heated therein to 110 C. Cooling takes place at a cooling rate of 1.0 K/min. The cloud point is detected optically. For this purpose, the temperature is registered at which the turbidity of the solution is 70%. The result is reported in C. The lower the MMAP, the higher the aromaticity of the test substance.

Test VTackifying Resin Softening Temperature

(62) The tackifying resin softening temperature is carried out according to the relevant methodology, which is known as ring & ball and is standardized according to ASTM E28.

Test VIMelt Viscosity

(63) For determining the melt viscosity of the plasticizing resins, a shear stress sweep is carried out in rotation in a shear stress-controlled DSR 200 N Rheometer from Rheometrics Scientific. A cone/plate measuring system with a diameter of 25 mm (cone angle 0.1002 rad) is employed; the measuring head is air-mounted and is suitable for standard force measurements. The gap is 0.053 mm and the measuring temperature is 25 C. The frequency is varied from 0.002 Hz to 200 Hz and the melt viscosity is recorded at 1 Hz.

(64) A mechanical and technical adhesive data were ascertained as follows:

Test VIIPenetration Toughness; z-Plane (DuPont Test)

(65) A square sample having frame format (external dimensions 33 mm33 mm; border width 2.0 mm; internal dimensions (window cutout) 29 mm29 mm) was cut from the adhesive tape under investigation. This sample was adhered to a polycarbonate (PC) frame (external dimensions 45 mm45 mm; border width 10 mm; internal dimensions (window cutout) 25 mm25 mm; thickness 3 mm). Adhered on the other side of the double-sided adhesive tape is a PC window of 35 mm35 mm. The bonding of PC frame, adhesive tape frame and PC window was carried out such that the geometric centres and the diagonals lay above one another in each case (corner to corner). The bond area was 248 mm.sup.2. The bond was pressed at 248 N for 5 seconds and stored for 24 hours with conditioning at 23 C./50% relative humidity.

(66) Immediately after storage, the bonded assembly of PC frame, adhesive tape and PC window was clamped, by the protruding edges of the PC frame, into a sample mount in such a way that the assembly was aligned horizontally. The PC frame here lies flat on the protruding edges on the sample mount, and so the PC window was in free suspension (held by the adhesive tape specimen) beneath the PC frame. The sample mount was subsequently inserted centrically into the holder provided on the DuPont Impact Tester. The impact head, which weighed 150 g, was inserted such that the circular striking geometry with the diameter of 24 mm lay centrically and flush against the area of the PC window that was freely accessible from above.

(67) A weight with a mass of 150 g, guided on two guide rods, was dropped vertically from a height of 5 cm onto the thus-disposed assembly made of sample mount, sample and impact head (measuring conditions 23 C., 50% relative humidity). The height of the drop weight was raised in steps of 5 cm until the impact energy introduced destroys the sample, as a result of the penetration load, and the PC window underwent detachment from the PC frame.

(68) In order to be able to compare experiments with different samples, the energy was calculated as follows:
E [J]=height [m]*mass of weight [kg]*9.81 kg/m*s.sup.2

(69) For each product, five samples were tested, and the mean energy was recorded as an index of the penetration toughness.

Test VIIIPeel Adhesion

(70) The peel adhesion was determined (according to AFERA 5001) as follows: the defined adhesion base is a polished steel plate having a thickness of 2 mm. The bondable sheet-like element under test (equipped on the reverse with a 36 m etched PET support film) is trimmed to a width of 20 mm and a length of approximately 25 cm, provided with a handling section, and pressed immediately thereafter onto the respective adhesion base selected, this pressing operation taking place five times using a steel roller of 4 kg at an advance velocity of 10 m/min. Immediately after that, the bondable sheet-like element is pulled from the adhesion base at an angle of 180 using a tensile tester (from Zwick) with a velocity v=300 mm/min, and the force required to achieve this at room temperature is recorded. The recorded value (in N/cm) is obtained as the average value from three individual measurements.

Test IXResistance to Tears (Detachment Test)

(71) In order to create particularly challenging detachment conditions reproducibly for the testing of the test strips, a mechanical method was selected in which an adhesive strip under test is extracted from a bonded assembly by extensive stretching at a detachment angle of approximately 180. The higher the detachment velocity at this detachment geometry, which is already selected so as to be extremely challenging, the greater the risk of tearing in the course of extensive stretching in the detachment operation. The test is carried out on a tensile tester (from Zwick).

(72) For each specimen, three test strips are die-cut. The geometry of the individual strips comprises a length of 5 cm and a width of 12 mm. One end of the test strips has a taper in the form of an equilateral triangle (height 1 cm).

(73) These test strips are used to produce test assemblies, for which two test plates (polyethylene terephthalate of type Centrolyte PET-P, from ThyssenKrupp Plastics GmbH; 3 mm thick; sawn, unsanded edges), which beforehand were cleaned with isopropanol and then dried for 20 minutes, were bonded to one another. For this purpose, one test strip was first adhered to one of the PET plates in such a way that the non-tapering end of the strip protrudes 1 cm beyond the edge of the test plate. The second liner is removed and the second PET plate is bonded. For this purpose, a 4 kg roller is rolled back and forth over the assembly five times (velocity: 1 m/min). The second plate is positioned such that part of this plate protrudes beyond the edge of the first plate, thus allowing the protruding part of the second plate to be clamped into the lower fixed part of the tensile testing machine. During production of the assembly, care is taken to ensure that the end of the strip protruding at the edge of the first plate is not bonded to the protruding part of the second plate. The assembly is clamped into the lower fixed part of the tensile testing machine. The protruding part of the adhesive tape is guided around the narrow side of the first plate and clamped into the upper, moveable part of the tensile testing machine. The adhesive tape is stripped from the assembly at an angle of approximately 180 and at a velocity x.

(74) This measurement is carried out on three individual samples per specimen per test velocity. The number of test strips not torn for a pre-set removal velocity is recorded. 0/3 means that out of three test strips, none of them tore at the specified removal velocity. 3/3 means that all three test strips tore at the specified removal velocity.

(75) FIG. 4 shows the basic construction of the test. In that figure the reference numerals have the following meanings: 11 Test assembly 12 Test plate 13 Test plate 14 Test strip 15 Clamp (displaceable) 16 Clamp (fixed)