THERMALLY VULCANIZABLE ADHESIVE TAPE WITH SHEAR STRENGTH DURING THE HEATING AND CURING PHASE

Abstract

A thermally vulcanizable pressure-sensitive adhesive comprising a chemically precrosslinked, pressure-sensitively adhesive polybutadiene-polyurethane and ground sulfur, which during the heating phase remains pressure-sensitively adhesive, does not liquefy and hence in this phase, in which the vulcanization has not yet started and the curing has not yet commenced, has shear strength at least under load to moderate low, is able to transmit forces and hence to perform holding, a process for producing it, an adhesive tape comprising this pressure-sensitive adhesive, and a process for producing the adhesive tape.

Claims

1. Thermally vulcanizable pressure-sensitive adhesive comprising a chemically precrosslinked, pressure-sensitively adhesive polybutadiene-polyurethane and ground sulfur.

2. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the chemically precrosslinked, pressure-sensitively adhesive polybutadiene-polyurethane is or comprises the chemical reaction product of at least the following starting materials: a) at least one meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer and b) at least one aliphatic or alicyclic polyisocyanate.

3. Thermally vulcanizable pressure-sensitive adhesive according to claim 2, wherein the aliphatic or alicyclic polyisocyanate is or comprises a diisocyanate and/or a polyisocyanate having an isocyanate functionality of three or greater than three.

4. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the polybutadiene-polyurethane prepolymer is the chemical reaction product of one or more polybutadiene-polyols and/or derivates thereof with one or more aliphatic and/or alicyclic polyisocyanates.

5. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the polybutadiene-polyurethane prepolymer is the chemical reaction product of one or more polybutadiene-polyols and/or derivates thereof and of one or more other polyols and/or derivatives thereof with one or more aliphatic and/or alicyclic polyisocyanates.

6. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is or comprises the chemical reaction product of at least one polybutadiene-diol and/or polybutadiene-diol derivative, in each case having a number-averaged average functionality of between greater than 1.5 and less than or equal to 2.0, and/or of at least one polybutadiene-polyol and/or polybutadiene-polyol derivative, in each case having a number-averaged average functionality of between greater than 2.0 and less than or equal to 3.0, and of at least one chain extender having an hydroxyl-functionality of two and a molar mass of less than or equal to 300 g/mol with at least one aliphatic or alicyclic diisocyanate and/or at least one aliphatic or alicyclic polyisocyanate having an isocyanate functionality of three or greater than three.

7. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the numerical fraction of the hydroxyl groups introduced for forming the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer and originating from the at least one chain extender is between greater than or equal to 20.0% and less than or equal to 80.0%.

8. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the numerical fraction of the hydroxyl groups introduced for forming the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer and originating from the at least one polybutadiene-polyol and/or polybutadiene-polyol derivative having a number-averaged average functionality of between greater than 2.0 and less than or equal to 3.0, is between greater than or equal to 0.0% and less than or equal to 50.0%.

9. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the aliphatic or alicyclic diisocyanate for preparing the polybutadiene-polyurethane prepolymer and/or for reaction with the polybutadiene-polyurethane prepolymer is or comprises isophorone diisocyanate and/or dicyclohexylmethane 4,4-diisocyanate.

10. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein the aliphatic or alicyclic polyisocyanate for preparing the polybutadiene-polyurethane prepolymer and/or for reaction with the polybutadiene-polyurethane prepolymer is or comprises a trimerized or more highly oligomerized form of hexamethylene diisocyanate and/or of isophorone diisocyanate.

11. Thermally vulcanizable pressure-sensitive adhesive according to claim 1, wherein it is composed of the following fractions: 30.0-55.0 wt % of a chemically precrosslinked, pressure-sensitively adhesive polybutadiene-polyurethane 0.1-15.0 wt % of ground sulfur 0.1-10.0 wt % of vulcanization accelerators 1.0-20.0 wt % of an epoxy resin 5.0-30.0 wt % of ground calcium oxide 10.0-50.0 wt % of fillers selected from ground chalk, ground talc and/or ground kaolin, and optionally ageing inhibitors, tackifier resins, bitumen, plasticizers, oils, and other auxiliaries and adjuvants.

12. Process for producing a thermally vulcanizable pressure-sensitive adhesive comprising a chemically precrosslinked, pressure-sensitively adhesive polybutadiene-polyurethane and ground sulfur, wherein first a polybutadiene-polyurethane prepolymer is prepared by chemical reaction of one or more polybutadiene-polyols and/or derivatives thereof, optionally in the presence of other polyols and/or derivatives thereof, with one or more aliphatic and/or alicyclic polyisocyanates, the proportions of polyols and/or polyol derivatives and of polyisocyanates being selected such that the resulting prepolymer is hydroxy-functionalized, meltable and pressure-sensitively adhesive, the polybutadiene-polyurethane prepolymer is admixed with ground sulfur, the polybutadiene-polyurethane prepolymer is admixed in the melt with further aliphatic and/or alicyclic polyisocyanates, and so a reactionhereinafter called precrosslinking reactionof the prepolymer with the polyisocyanates commences.

13. Process according to claim 12, wherein the chemical reaction for preparing the polybutadiene-polyurethane prepolymer takes place with addition of a catalyst, more particularly of a catalyst comprising bismuth and carbon.

14. Process according to claim 12, wherein the ratio of the total number of isocyanate groups introduced in the preparation of the polybutadiene-polyurethane prepolymer and in the reaction thereof, in other words the precrosslinking reaction, to the total number of hydroxyl groups introduced is between greater than or equal to 0.5 and less than or equal to 1.3.

15. Process according to claim 12, wherein the ground sulfur, the further aliphatic and/or alicyclic polyisocyanates and optionally further adjuvants and/or additives are added to the prepolymer in a joint, continuous operation.

16. Process according to claim 12, wherein the blending of the prepolymer with the further aliphatic and/or alicyclic polyisocyanates, advantageously also with the ground sulfur and optionally with the further adjuvants and/or additives, takes place in a solvent-free continuous compounding operation.

17. Process according to claim 16, wherein the continuous compounding operation is followed directly by a continuous coating operation wherein the blended prepolymer is shaped to a layer, more particularly laid onto a carrier material.

18. Process according to claim 15, wherein the continuous compounding operation takes place in a continuous mixing assembly.

19. Process according to claim 15, wherein the temperature of the compound during compounding does not exceed 100 C.

20. An adhesive tape comprising a thermally vulcanizable pressure-sensitive adhesive according to claim 1.

Description

EXAMPLES

Inventive Example 1

[0278] The chemical reaction to form the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer took place in the presence of an epoxy resin. The composition of the polybutadiene-polyurethane prepolymer (Prepo 1), including the epoxy resin, is as follows:

[0279] Composition of Prepo 1:

TABLE-US-00003 Number of OH or NCO Percentage ratio Weight groups introduced, of number of fraction based on percentage OH groups to Raw material [wt %] weight fraction one another Krasol LBH 2000 29.55 26.89 mmol OH 20 Poly bd R-45 HTLO 32.02 26.89 mmol OH 20 2-Ethyl-1,3-hexanediol 5.90 80.68 mmol OH 60 Epikote 828 20.00 Coscat 83 0.10 Desmodur W 12.43 .sup.94.13 mmol NCO Total 100.00

[0280] Production took place in a laboratory batch (1 litre). The weight ratio of Desmodur W is calculated so that the NCO/OH ratio of the polyurethane prepolymer is 0.70. The theoretical gel point is computed to be 0.83.

[0281] Prepo 1 is meltable and at room temperature in terms of consistency is rubber-like and tacky. The test results are summarized in the table below.

[0282] Test Results for Prepo 1 (Including Epoxy Resin):

TABLE-US-00004 G (at 1 rad/sec and 23 C.) 590 Pa G (at 1 rad/sec and 23 C.) 3100 Pa G (at 10 rad/sec and 23 C.) 7600 Pa G (at 10 rad/sec and 23 C.) 20 400 Pa.sup. Complex viscosity * at 10 rad/sec and 23 C. .sup.3200 Pas Complex viscosity * at 10 rad/sec and 80 C. .sup.18 Pas

[0283] Production of the Inventive Chemically Precrosslinked, Thermally Vulcanizable Pressure-Sensitive Adhesive and of the Adhesive Tape Comprising this PSA:

[0284] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0285] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 1:

TABLE-US-00005 Number of OH-functionalized OH or NCO and NCO- groups functionalized raw introduced, materials based on Weight introduced into Weight percentage fraction the Prepo 1 fraction weight Raw material [wt %] preparation [wt %] fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 17.29 14.52 HTLO 2-Ethyl-1,3- 3.19 43.57 hexanediol Desmodur W 6.71 50.83 Epikote 828 (from Prepo 10.80 1 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime CL 15.00 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 15.20 Anox 20 0.50 Desmodur N 3300 2.10 10.89

[0286] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0287] The results achieved were as follows:

[0288] Before Thermal Vulcanization:

TABLE-US-00006 Shearing Fracture Test method Substrate load Result mode Peel adhesion Steel 7.5 N/cm Peel adhesion Aluminium 1.4 N/cm Dynamic L-jig Steel 115 N/cm test Static shear test Steel 500 g >20 000 minutes Static shear test Aluminium 500 g 5700 minutes Dynamic shear Steel against 0.3 MPa adhesive test (lap shear aluminium to strength) aluminium

[0289] During Thermal Vulcanization:

TABLE-US-00007 Overlap Shearing Vulcanization Test method Substrate area load conditions Result Static shear Steel 312.5 mm.sup.2 200 g 30 Slip distance: test against minutes/200 C. 2-4 mm aluminium

[0290] After Thermal Vulcanization:

[0291] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00008 Temperature during Vulcanization measurement Result conditions [ C.] [MPa] Fracture mode 30 min/180 C. 20 6.9 cohesive +23 2.9 cohesive +80 0.5 cohesive 30 min/200 C. 20 8.4 cohesive +23 4.0 cohesive +80 0.8 cohesive 30 min/220 C. 20 8.7 cohesive +23 4.0 cohesive +80 0.9 cohesive

Inventive Example 2

[0292] The chemical reaction to form the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer took place in the presence of an epoxy resin. The composition of the polybutadiene-polyurethane prepolymer (Prepo 2), including the epoxy resin, is as follows:

[0293] Composition of Prepo 2:

TABLE-US-00009 Percentage Number of OH or NCO ratio of Weight groups introduced, number of fraction based on percentage OH groups to Raw material [wt %] weight fraction one another Krasol LBH 2000 60.98 55.50 mmol OH 40 2-Ethyl-1,3- 6.09 83.25 mmol OH 60 hexanediol Epikote 828 20.00 Coscat 83 0.10 Desmodur W 12.83 97.12 mmol NCO Total 100.00

[0294] Production took place in a laboratory batch (1 litre). The weight ratio of Desmodur W is calculated so that the NCO/OH ratio of the polyurethane prepolymer is 0.70. A theoretical gel point does not exist.

[0295] Prepo 2 is meltable and at room temperature in terms of consistency is rubber-like and tacky. The test results are summarized in the table below.

[0296] Test Results for Prepo 2 (Including Epoxy Resin):

TABLE-US-00010 G (at 1 rad/sec und 23 C.) 550 Pa G (at 1 rad/sec und 23 C.) 2900 Pa G (at 10 rad/sec und 23 C.) 7200 Pa G (at 10 rad/sec und 23 C.) 20 000 Pa Complex viscosity * at 10 rad/sec and 23 C. 3050 Pas Complex viscosity * at 10 rad/sec and 80 C. 17 Pas

[0297] Production of the Inventive Chemically Precrosslinked, Thermally Vulcanizable Pressure-Sensitive Adhesive and of the Adhesive Tape Comprising this PSA:

[0298] For producing the inventive PSA and the inventive adhesive tape, Prepo 2 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0299] Composition of the Chemically Precrosslinked, Thermally Vulcanizable PSA Based on Prepo 2:

TABLE-US-00011 Number of OH-functionalized OH or NCO and NCO- groups functionalized raw introduced, materials based on Weight introduced into Weight percentage fraction the Prepo 2 fraction weight Raw material [wt %] preparation [wt %] fraction Prepo 2 (excluding epoxy resin) 43.20 Krasol LBH 2000 32.93 29.97 2-Ethyl-1,3- 3.29 44.95 hexanediol Desmodur W 6.93 52.44 Epikote 828 (from Prepo 10.80 2 preparation) Ground sulfur80/90 1.20 MBTS 2.00 Rapidquell Quicklime CL 15.00 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 15.13 Anox 20 0.50 Desmodur N 3300 2.17 11.24

[0300] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA into the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratios) was 0.85.

[0301] The results achieved were as follows:

[0302] Before Thermal Vulcanization:

TABLE-US-00012 Shearing Fracture Test method Substrate load Result mode Peel adhesion Steel 9.1 N/cm Peel adhesion Aluminium 1.8 N/cm Dynamic L-jig Steel 125 N/cm test Static shear test Steel 500 g 9000 minutes Static shear test Aluminium 500 g 2100 minutes Dynamic shear Steel against 0.2 MPa adhesive test (lap shear aluminium to strength) aluminium

[0303] During Thermal Vulcanization:

TABLE-US-00013 Overlap Shearing Vulcanization Test method Substrate area load conditions Result Static shear Steel 312.5 mm.sup.2 200 g 30 Slip distance: test against minutes/200 C. 9-11 mm aluminium

[0304] After Thermal Vulcanization:

[0305] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00014 Temperature during Vulcanization measurement Result conditions [ C.] [MPa] Fracture mode 30 min/180 C. 20 6.4 cohesive +23 2.6 cohesive +80 0.4 cohesive 30 min/200 C. 20 8.0 cohesive +23 3.8 cohesive +80 0.7 cohesive 30 min/220 C. 20 8.9 cohesive +23 4.1 cohesive +80 1.0 cohesive

Inventive Example 3

[0306] The composition of the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer (Prepo 3) is as follows:

[0307] Composition of Prepo 3:

TABLE-US-00015 Percentage Number of OH or NCO ratio of Weight groups introduced, number of fraction based on percentage OH groups to Raw material [wt %] weight fraction one another Krasol LBH 2000 76.25 69.39 mmol OH 40 2-Ethyl-1,3- 7.61 104.08 mmol OH 60 hexanediol Coscat 83 0.10 Desmodur W 16.04 121.43 mmol NCO Total 100.00

[0308] Production took place in a laboratory batch (1 litre). The weight ratio of Desmodur W is calculated so that the NCO/OH ratio of the polyurethane prepolymer is 0.70. A theoretical gel point does not exist.

[0309] Prepo 3 is meltable and at room temperature in terms of consistency is rubber-like and tacky. The test results are summarized in the table below.

[0310] Test Results for Prepo 3:

TABLE-US-00016 G (at 1 rad/sec and 23 C.) 12 000 Pa G (at 1 rad/sec and 23 C.) 21 000 Pa G (at 10 rad/sec and 23 C.) 41 000 Pa G (at 10 rad/sec and 23 C.) 52 000 Pa Complex viscosity * at 10 rad/sec and 23 C. 12 100 Pas Complex viscosity * at 10 rad/sec and 80 C. 62 Pas

[0311] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0312] For producing the inventive PSA and the inventive adhesive tape, Prepo 3 was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film.

[0313] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 3:

TABLE-US-00017 Number of OH-functionalized OH or NCO and NCO- groups functionalized raw introduced, materials based on Weight introduced into Weight percentage fraction the Prepo 3 fraction weight Raw material [wt %] preparation [wt %] fraction Prepo 3 54.00 Krasol LBH 2000 41.18 37.47 2-Ethyl-1,3- 4.11 56.20 hexanediol Desmodur W 8.66 65.57 Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime CL 90-Q 15.00 Talkum Pharma M 10.00 Omyacarb 5-GU 14.59 Anox 20 0.50 Desmodur N 3300 2.71 14.05

[0314] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0315] The results achieved were as follows:

[0316] Before Thermal Vulcanization:

TABLE-US-00018 Shearing Fracture Test method Substrate load Result mode Peel adhesion Steel 2.4 N/cm Peel adhesion Aluminium 0.5 N/cm Dynamic L-jig Steel 35 N/cm test Static shear test Steel 500 g 6000 minutes Static shear test Aluminium 500 g 1400 minutes Dynamic shear Steel against 0.2 MPa adhesive test (lap shear aluminium to strength) aluminium

[0317] During Thermal Vulcanization:

TABLE-US-00019 Overlap Shearing Vulcanization Test method Substrate area load conditions Result Static shear Steel 312.5 mm.sup.2 200 g 30 Slip distance: test against minutes/200 C. 5-7 mm aluminium

[0318] After Thermal Vulcanization:

[0319] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00020 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 not determined +23 1.7 Adhesive +80 not determined 30 min/200 C. 20 5.4 Adhesive +23 2.0 Adhesive +80 0.3 Adhesive 30 min/220 C. 20 not determined +23 3.1 Cohesive and adhesive +80 not determined

Inventive Example 4

[0320] The chemical reaction to form the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer took place in the presence of an epoxy resin. The composition of the polybutadiene-polyurethane prepolymer (Prepo 4), including the epoxy resin, is as follows:

[0321] Composition of Prepo 4:

TABLE-US-00021 Number of OH or NCO Weight groups introduced, Percentage ratio of fraction based on percentage number of OH groups Raw material [wt %] weight fraction to one another Krasol LBH 2000 30.30 27.57 mmol OH 20 Poly bd R-45 HTLO 32.82 27.57 mmol OH 20 2-Ethyl-1,3-hexanediol 6.05 82.72 mmol OH 60 Epikote 828 20.00 Coscat 83 0.10 Vestanat IPDI 10.73 .sup.96.51 mmol NCO Total 100.00

[0322] Production took place in a laboratory batch (1 litre). The weight ratio of Vestanat IPDI is calculated so that the NCO/OH ratio of the polyurethane prepolymer is 0.70. The theoretical gel point is computed to be 0.83.

[0323] Prepo 4 is meltable and at room temperature in terms of consistency is rubber-like and tacky. The test results are summarized in the table below.

[0324] Test Results for Prepo 4 (Including Epoxy Resin):

TABLE-US-00022 G (at 1 rad/sec and 23 C.) 570 Pa G (at 1 rad/sec and 23 C.) 2900 Pa G (at 10 rad/sec and 23 C.) 7100 Pa G (at 10 rad/sec and 23 C.) 19 800 Pa.sup. Complex viscosity * at 10 rad/sec and 23 C. 2900 Pas Complex viscosity * at 10 rad/sec and 80 C. 16 Pas

[0325] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0326] For producing the inventive PSA and the inventive adhesive tape, Prepo 4 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0327] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 4:

TABLE-US-00023 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 4 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 4 (excluding epoxy resin) 43.20 Krasol LBH 2000 16.36 14.89 Poly bd R-45 HTLO 17.73 14.89 2-Ethyl-1,3-hexanediol 3.27 44.67 Vestanat IPDI 5.79 52.11 Epikote 828 (from Prepo 4 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 15.15 Anox 20 0.50 Desmodur N 3300 2.15 11.17

[0328] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0329] The results achieved were as follows:

[0330] Before Thermal Vulcanization:

TABLE-US-00024 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 7.9 N/cm Peel adhesion Aluminium 1.8 N/cm Dynamic L-jig test Steel 109 N/cm Static shear test Steel 500 g 15 000 minutes Static shear test Aluminium 500 g 5100 minutes Dynamic shear test Steel against 0.2 MPa adhesive to (lap shear strength) aluminium aluminium

[0331] During Thermal Vulcanization:

TABLE-US-00025 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 3-4 mm

[0332] After Thermal Vulcanization:

[0333] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00026 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 7.2 cohesive +23 2.8 cohesive +80 0.4 cohesive 30 min/200 C. 20 8.8 cohesive +23 4.3 cohesive +80 0.9 cohesive 30 min/220 C. 20 8.8 cohesive +23 4.2 cohesive +80 0.7 cohesive

Inventive Example 5

[0334] The chemical reaction to form the meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer took place in the presence of an epoxy resin. The composition of the polybutadiene-polyurethane prepolymer (Prepo 5), including the epoxy resin, is as follows:

[0335] Composition of Prepo 5:

TABLE-US-00027 Number of OH or NCO Weight groups introduced, Percentage ratio of fraction based on percentage number of OH groups Raw material [wt %] weight fraction to one another Krasol LBH 2000 14.55 13.24 mmol OH 10 Poly bd R-45 HTLO 47.30 39.73 mmol OH 30 2-Ethyl-1,3-hexanediol 5.81 79.46 mmol OH 60 Epikote 828 20.00 Coscat 83 0.10 Desmodur W 12.24 .sup.92.70 mmol NCO Total 100.00

[0336] Production took place in a laboratory batch (1 litre). The weight ratio of Desmodur W is calculated so that the NCO/OH ratio of the polyurethane prepolymer is 0.70. The theoretical gel point is computed to be 0.77.

[0337] Prepo 5 is meltable and at room temperature in terms of consistency is rubber-like and tacky. The test results are summarized in the table below.

[0338] Test Results for Prepo 5 (Including Epoxy Resin):

TABLE-US-00028 G (at 1 rad/sec and 23 C.) 610 Pa G (at 1 rad/sec and 23 C.) 3300 Pa G (at 10 rad/sec and 23 C.) 7800 Pa G (at 10 rad/sec and 23 C.) 24 700 Pa.sup. Complex viscosity * at 10 rad/sec and 23 C. .sup.3800 Pas Complex viscosity * at 10 rad/sec and 80 C. .sup.25 Pas

[0339] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0340] For producing the inventive PSA and the inventive adhesive tape, Prepo 5 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0341] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 5:

TABLE-US-00029 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 5 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 5 (excluding epoxy resin) 43.20 Krasol LBH 2000 7.86 7.15 Poly bd R-45 HTLO 25.54 21.45 2-Ethyl-1,3-hexanediol 3.14 42.91 Desmodur W 6.61 50.06 Epikote 828 (from Prepo 5 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 15.23 Anox 20 0.50 Desmodur N 3300 2.07 10.73

[0342] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0343] The results achieved were as follows:

[0344] Before Thermal Vulcanization:

TABLE-US-00030 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 6.1 N/cm Peel adhesion Aluminium 1.2 N/cm Dynamic L-jig test Steel 81 N/cm Static shear test Steel 500 g >20 000 minutes Static shear test Aluminium 500 g 4900 minutes Dynamic shear test Steel against 0.3 MPa adhesive to (lap shear strength) aluminium aluminium

[0345] During Thermal Vulcanization:

TABLE-US-00031 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 2-4 mm

[0346] After Thermal Vulcanization:

[0347] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00032 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 7.7 cohesive +23 3.1 cohesive +80 0.6 cohesive 30 min/200 C. 20 8.7 cohesive +23 4.4 cohesive +80 0.8 cohesive 30 min/220 C. 20 8.8 cohesive +23 4.5 cohesive +80 1.2 cohesive

Inventive Example 6

[0348] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1.

[0349] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0350] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0351] Composition of the Chemically Precrosslinked, Thermally Vulcanizable PSA Based on Prepo 1:

TABLE-US-00033 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 12.40 Anox 20 0.50 Desmodur N 3300 4.90 25.41

[0352] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 1.05.

[0353] The results achieved were as follows:

[0354] Before Thermal Vulcanization:

TABLE-US-00034 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 4.9 N/cm Peel adhesion Aluminium 1.0 N/cm Dynamic L-jig test Steel 79 N/cm Static shear test Steel 500 g 6000 minutes Static shear test Aluminium 500 g 2200 minutes Dynamic shear test Steel against 0.1 MPa adhesive to (lap shear strength) aluminium aluminium

[0355] During Thermal Vulcanization:

TABLE-US-00035 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 7-10 mm

[0356] After Thermal Vulcanization:

[0357] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00036 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 6.7 cohesive +23 2.8 cohesive +80 0.6 cohesive 30 min/200 C. 20 8.8 cohesive +23 3.9 cohesive +80 0.8 cohesive 30 min/220 C. 20 8.1 cohesive +23 4.2 cohesive +80 1.1 cohesive

Inventive Example 7

[0358] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1.

[0359] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0360] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0361] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 1:

TABLE-US-00037 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 13.80 Anox 20 0.50 Desmodur N 3400 3.50 18.15

[0362] The percentage weight fraction of Desmodur N 3400 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.95.

[0363] The results achieved were as follows:

[0364] Before Thermal Vulcanization:

TABLE-US-00038 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 9.9 N/cm Peel adhesion Aluminium 2.3 N/cm Dynamic L-jig test Steel 102 N/cm Static shear test Steel 500 g 9500 minutes Static shear test Aluminium 500 g 2800 minutes Dynamic shear test Steel against 0.2 MPa adhesive to (lap shear strength) aluminium aluminium

[0365] During Thermal Vulcanization:

TABLE-US-00039 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 3-6 mm

[0366] After Thermal Vulcanization:

[0367] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00040 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 6.4 cohesive +23 2.7 cohesive +80 0.4 cohesive 30 min/200 C. 20 8.8 cohesive +23 4.1 cohesive +80 0.9 cohesive 30 min/220 C. 20 8.7 cohesive +23 4.3 cohesive +80 0.9 cohesive

Inventive Example 8

[0368] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1.

[0369] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0370] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0371] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 1:

TABLE-US-00041 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Ground sulfur 80/90 1.20 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 17.20 Anox 20 0.50 Desmodur N 3300 2.10 10.89

[0372] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0373] The results achieved were as follows:

[0374] Before Thermal Vulcanization:

TABLE-US-00042 Fracture Test method Substrate Shearing load Result mode Peel adhesion Steel 7.4 N/cm Peel adhesion Aluminium 1.5 N/cm Dynamic L-jig test Steel 110 N/cm Static shear test Steel 500 g >20 000 minutes Static shear test Aluminium 500 g 5100 minutes Dynamic shear test Steel against 0.3 MPa adhesive to (lap shear strength) aluminium aluminium

[0375] During Thermal Vulcanization:

TABLE-US-00043 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 8-10 mm

[0376] After Thermal Vulcanization:

[0377] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00044 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 not determined +23 0.6 cohesive +80 not determined 30 min/200 C. 20 6.1 cohesive +23 3.1 cohesive +80 0.3 cohesive 30 min/220 C. 20 not determined +23 3.9 cohesive +80 not determined

Inventive Example 9

[0378] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1.

[0379] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0380] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0381] Composition of the Chemically Precrosslinked, Thermally Vulcanizable PSA Based on Prepo 1:

TABLE-US-00045 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Ground sulfur 80/90 3.50 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 12.90 Anox 20 0.50 Desmodur N 3300 2.10 10.89

[0382] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0383] The results achieved were as follows:

[0384] Before Thermal Vulcanization:

TABLE-US-00046 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 7.9 N/cm Peel adhesion Aluminium 1.6 N/cm Dynamic L-jig test Steel 120 N/cm Static shear test Steel 500 g >20 000 minutes Static shear test Aluminium 500 g 5800 minutes Dynamic shear test Steel against 0.3 MPa adhesive to (lap shear strength) aluminium aluminium

[0385] During Thermal Vulcanization:

TABLE-US-00047 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 2-3 mm

[0386] After Thermal Vulcanization:

[0387] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00048 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 15.5 cohesive +23 10.8 cohesive +80 1.9 cohesive 30 min/200 C. 20 16.2 cohesive +23 12.4 cohesive +80 2.9 cohesive 30 min/220 C. 20 18.4 cohesive +23 13.6 cohesive +80 2.8 cohesive

Inventive Example 10

[0388] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1.

[0389] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0390] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0391] Composition of the Chemically Precrosslinked, Thermally Vulcanizable PSA Based on Prepo 1:

TABLE-US-00049 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Avosulf IS 75 S 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Kaolin Pharma 25.20 Anox 20 0.50 Desmodur N 3300 2.10 10.89

[0392] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0393] The results achieved were as follows:

[0394] Before Thermal Vulcanization:

TABLE-US-00050 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 7.9 N/cm Peel adhesion Aluminium 1.6 N/cm Dynamic L-jig test Steel 102 N/cm Static shear test Steel 500 g >20 000 minutes Static shear test Aluminium 500 g 5200 minutes Dynamic shear test Steel against 0.3 MPa adhesive to (lap shear strength) aluminium aluminium

[0395] During Thermal Vulcanization:

TABLE-US-00051 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 2-6 mm

[0396] After Thermal Vulcanization:

[0397] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00052 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 6.2 cohesive +23 2.5 cohesive +80 0.4 cohesive 30 min/200 C. 20 7.6 cohesive +23 3.6 cohesive +80 0.7 cohesive 30 min/220 C. 20 8.9 cohesive +23 4.3 cohesive +80 1.0 cohesive

Inventive Example 11

[0398] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1. Production took place in a 200 litre mixing tank.

[0399] Production of the inventive chemically precrosslinked, thermally vulcanizable pressure-sensitive adhesive and of the adhesive tape comprising this PSA:

[0400] For producing the inventive PSA and the inventive adhesive tape, Prepo 1 (including epoxy resin) was blended further in a twin-screw extruder in accordance with the formula below, and shaped to form a film. The addition of the precrosslinking Desmodur N 3300 was made last. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0401] Composition of the chemically precrosslinked, thermally vulcanizable PSA based on Prepo 1:

TABLE-US-00053 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) 43.20 Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 15.20 Anox 20 0.50 Desmodur N 3300 2.10 10.89

[0402] The percentage weight fraction of Desmodur N 3300 was selected such that the ratio of the total number of isocyanate groups introduced into the preparation of the chemically precrosslinked, thermally vulcanizable PSA to the total number of hydroxyl groups introduced in the preparation (total NCO/OH ratio) was 0.85.

[0403] The results achieved were as follows:

[0404] Before Thermal Vulcanization:

TABLE-US-00054 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 7.1 N/cm Peel adhesion Aluminium 1.6 N/cm Dynamic L-jig test Steel 110 N/cm Static shear test Steel 500 g >20 000 minutes Static shear test Aluminium 500 g 5900 minutes Dynamic shear test Steel against 0.3 MPa adhesive to (lap shear strength) aluminium aluminium

[0405] During Thermal Vulcanization:

TABLE-US-00055 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Slip shear against 200 C. distance: test aluminium 2-4 mm

[0406] After Thermal Vulcanization:

[0407] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00056 Vulcanization Temperature during Result Fracture conditions measurement [ C.] [MPa] mode 30 min/180 C. 20 6.1 cohesive +23 3.3 cohesive +80 0.6 cohesive 30 min/200 C. 20 8.9 cohesive +23 4.2 cohesive +80 0.9 cohesive 30 min/220 C. 20 8.9 cohesive +23 4.1 cohesive +80 0.9 cohesive

Comparative Example 1

[0408] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 1 from Inventive Example 1.

[0409] Production of the Thermally Vulcanizable Pressure-Sensitive Adhesive and of the Adhesive Tape Comprising this PSA (Comparative Example 1):

[0410] For producing the Comparative Example 1 and the corresponding adhesive tape, Prepo 1 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0411] Composition of the thermally vulcanizable PSA based on Prepo 1 (Comparative Example 1):

TABLE-US-00057 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 1 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 1 (excluding epoxy resin) Krasol LBH 2000 15.96 14.52 Poly bd R-45 HTLO 17.29 14.52 2-Ethyl-1,3-hexanediol 3.19 43.57 Desmodur W 6.71 50.83 Epikote 828 (from Prepo 1 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 17.30 Anox 20 0.50

[0412] The results achieved were as follows:

[0413] Before Thermal Vulcanization:

TABLE-US-00058 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 9.4 N/cm Peel adhesion Aluminium 3.1 N/cm Dynamic L-jig test Steel 97 N/cm Static shear test Steel 500 g <60 minutes Static shear test Aluminium 500 g <60 minutes Dynamic shear test Steel against 0.1 MPa adhesive to (lap shear strength) aluminium aluminium

[0414] During Thermal Vulcanization:

TABLE-US-00059 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Failure shear against 200 C. (complete test aluminium slippage) after less than 5 minutes

[0415] After Thermal Vulcanization:

[0416] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00060 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 6.6 cohesive +23 2.8 cohesive +80 0.5 cohesive 30 min/200 C. 20 8.3 cohesive +23 3.4 cohesive +80 0.7 cohesive 30 min/220 C. 20 8.2 cohesive +23 3.6 cohesive +80 0.8 cohesive

Comparative Example 2

[0417] The meltable, pressure-sensitively adhesive, hydroxyl-functionalized polybutadiene-polyurethane prepolymer is Prepo 2 from Inventive Example 2.

[0418] Production of the Thermally Vulcanizable Pressure-Sensitive Adhesive and of the Adhesive Tape Comprising this PSA (Comparative Example 2):

[0419] For producing the Comparative Example 2 and the corresponding adhesive tape, Prepo 2 (including epoxy resin) was blended further in a laboratory batch in accordance with the formula below, and shaped to form a film. The epoxy resin, already incorporated by mixing during the production of the polybutadiene-polyurethane prepolymer, is listed separately in the following table.

[0420] Composition of the Thermally Vulcanizable PSA Based on Prepo 2 (Comparative Example 2):

TABLE-US-00061 OH-functionalized and NCO-functionalized raw Number of OH or NCO Weight materials introduced Weight groups introduced, fraction into the Prepo 2 fraction based on percentage Raw material [wt %] preparation [wt %] weight fraction Prepo 2 (excluding epoxy resin) 43.20 Krasol LBH 2000 32.93 29.97 2-Ethyl-1,3-hexanediol 3.29 44.95 Desmodur W 6.93 52.44 Epikote 828 (from Prepo 2 10.80 preparation) Ground sulfur 80/90 1.20 MBTS 2.00 Rapidquell Quicklime 15.00 CL 90-Q Talkum Pharma M 10.00 Omyacarb 5-GU 17.30 Anox 20 0.50

[0421] The results achieved were as follows:

[0422] Before Thermal Vulcanization:

TABLE-US-00062 Test method Substrate Shearing load Result Fracture mode Peel adhesion Steel 9.5 N/cm Peel adhesion Aluminium 2.5 N/cm Dynamic L-jig test Steel 82 N/cm Static shear test Steel 500 g <60 minutes Static shear test Aluminium 500 g <60 minutes

[0423] During Thermal Vulcanization:

TABLE-US-00063 Vulcani- Test Overlap Shearing zation method Substrate area load conditions Result Static Steel 312.5 mm.sup.2 200 g 30 minutes/ Failure shear against 200 C. (complete test aluminium slippage) after less than 5 minutes

[0424] After Thermal Vulcanization:

[0425] Dynamic Shear Test (Lap Shear Strength), Bonded Substrates: Steel Against Aluminium

TABLE-US-00064 Vulcanization Temperature during Result Fracture conditions measurement[ C.] [MPa] mode 30 min/180 C. 20 6.7 cohesive +23 2.3 cohesive +80 0.3 cohesive 30 min/200 C. 20 7.1 cohesive +23 3.5 cohesive +80 0.5 cohesive 30 min/220 C. 20 8.1 cohesive +23 4.0 cohesive +80 0.7 cohesive