Process for cold bonding rubber on metal substrates

Abstract

The present invention relates to a process for cold bonding elastomeric rubber substrates to non-elastomeric substrates of a different material, preferably metal, by use of a rubber treatment, preferably a primer composition and a 2k adhesive, preferably a 2k epoxy adhesive as well as the thus obtained bonded substrates.

Claims

1. A process for forming a bond between a first elastomeric rubber substrate and a second metal substrate, comprising: providing the elastomeric rubber substrate; providing the metal substrate; applying an oxidizing rubber treatment and/or a primer composition comprising at least one cyanoacrylate to a to-be-bonded surface of the rubber substrate; providing a curable 2K adhesive comprising a resin component and a hardener component; mixing the resin component and hardener component to form a mixed 2K adhesive composition; applying the mixed 2K adhesive composition to a to-be-bonded surface of the metal substrate; incubating the applied 2K adhesive composition for 0.5 to 10 hours to develop green strength; and contacting the primed surface of the rubber substrate and the applied adhesive on the surface of the metal substrate to form the bond.

2. The process according to claim 1, wherein the 2K adhesive is selected from the group consisting of a 2k polyurea adhesive and a 2k epoxy adhesive.

3. The process according to claim 1, wherein the oxidizing rubber treatment comprises an oxidizing compound selected from the group consisting of iodine monobromide and sodium hypochlorite.

4. The process according to claim 1, wherein the cyanoacrylate is a 2-cyanoacrylate ester of Formula (I)
H.sub.2CC(CN)COOR(I), wherein R is selected from the group consisting of C.sub.1-20 alkyl optionally substituted with halogen, C.sub.2-16 alkenyl or alkynyl group, C.sub.5-8 cycloalkyl, C.sub.6-14 aryl, alkylaryl, alkoxyalkyl, and acylalkyl, preferably C.sub.1-4 alkyl, more preferably ethyl or methyl.

5. The process according to claim 1, wherein the cyanoacrylate is a 2-cyanoacrylate ester of Formula (I)
H.sub.2CC(CN)COOR(I), wherein R is ethyl or methyl.

6. The process according to claim 1, wherein the cyanoacrylate is ethyl cyanoacrylate.

7. The process according to claim 1, wherein the oxidizing rubber treatment and/or the primer composition further comprises up to 40 wt.-% of an organic solvent relative to the oxidizing rubber treatment or primer composition respectively.

8. The process according to claim 1, wherein: the 2k adhesive is a 2k epoxy adhesive; the resin component comprises a liquid bisphenol A-based epoxy resin, optionally modified with phenoxy and/or a liquid bisphenol F-based epoxy resin, optionally modified with phenoxy; and/or the hardener component comprises at least one difunctional mercaptan and/or at least one mercaptane-epoxy adduct and/or at least one member selected from the group consisting of polyamines, polyamides, low molecular weight amines.

9. The process according to claim 1, wherein the 2k adhesive is a 2k polyurea adhesive wherein the hardener component comprises 1) at least one oligomeric amine, and/or 2) at least one amine selected from the group consisting of polyamines, low molecular weight amines and combinations thereof, and the resin component comprises 3) at least one isocyanate containing material including at least one aliphatic isocyanate, at least one aromatic isocyanate, or isocyanate functional prepolymers of the aliphatic isocyanate or aromatic isocyanate.

10. The process according to claim 1, carried out at a temperature of 15-40 C. and a relative humidity below 85%.

11. The process according to claim 1, wherein the curable 2K adhesive comprises a curing indicator to indicate when the applied adhesive has developed sufficient green strength to contact the primed surface of the rubber substrate to the applied adhesive on the surface of the metal substrate.

12. The process according to claim 1, wherein the adhesive composition comprises a color changing azo dye.

13. The process according to claim 1, further comprising a step of cleaning the to-be-bonded surface of the rubber substrate prior to applying the oxidizing rubber treatment and/or a step of cleaning to-be-bonded surface of the metal substrate prior to applying the mixed 2K adhesive composition.

14. The process according to claim 1, wherein the primer composition is applied in an amount of 70-190 g/m.sup.2 or in an amount of 300-500 g/m.sup.2.

15. The process according to claim 1, further comprising a step of drying the oxidizing rubber treatment and/or a primer composition applied to the to-be-bonded surface before the step of contacting.

16. The process according to claim 1, wherein the step of incubating comprises incubating the mixed 2K adhesive composition for 0.5 to 10 hours at ambient temperature until the mixed adhesive has a floating roller peel resistance of 0.5 N/mm to 3 N/mm (ASTMD3167-03).

17. The process according to claim 1, wherein the step of contacting the primed surface of the rubber substrate and the applied adhesive on the surface of the metal substrate is carried out by rolling.

18. The process according to claim 1, wherein the step of incubating comprises incubating the mixed 2K adhesive composition for 0.5 to 10 hours at ambient temperature until the mixed adhesive has a viscosity of 250 to 15,000 Pas.

Description

EXAMPLES

Example 1

(1) Primer Composition

(2) 66.67 wt.-% ethyl cyanoacrylate (Loctite CA 406, Henkel), 33.33 wt.-% 1,6-dichlorohexane.

(3) 2K Epoxy Adhesive

(4) Resin Formulation

(5) 39.49 wt.-% DER 331 P (Bisphenol-A based epoxy resin, Dow), 59.23 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.3 wt.-% Automate Red BXL (curing indicator, Rohm&Haas). Viscosity 120 Pa s.

(6) Hardener Formulation

(7) 80.04 wt.-% DMDO-DER 331 P adduct, 17.05 wt.-% Jeffamine D-400 (di-functional polyetheramine), 1.94 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.97 wt.-% Versamine EH-30 (tris(dimethylaminomethyl)phenol; BASF). Viscosity 84 Pa s.

(8) Preparation

(9) 1. Ethyl cyanoacrylate and 1,6-dichlorohexane were vigorously mixed under inert environment.

(10) 2. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(11) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(12) Roll Peel Assembly

(13) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(14) 2. Resin and hardener formulations were mixed. Pot life: 30 minutes

(15) 3. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(16) 4. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the color of the indicator)

(17) 5. The primer composition was applied to the rubber surface.

(18) 6. The rubber substrate was kept at ambient temperature until its surface was dry (at least 30 minutes).

(19) 7. Rubber and metal substrate were assembled and bonded by rolling.

(20) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(21) Roll peel after complete curing (3 days at 20 C.): 13 N/mm

(22) Roll peel after 2 hours from assembly (green strength): 1.6 N/mm

(23) Roll peel after 4 hours from assembly (green strength): 3.3 N/mm

Example 2

(24) Primer Composition

(25) 96.49% Ethyl cyanoacrylate; 0.01% BF.sub.3 (Boron trifluoride); 3.5% PMMA (Polymethylmetacrylate).

(26) 2K epoxy adhesive

(27) Resin Formulation

(28) 39.49 wt.-% DER 331 P (Bisphenol-A based epoxy resin, Dow), 59.23 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.3 wt.-% Automate Red BXL (curing indicator, Rohm&Haas). Viscosity 120 Pa s.

(29) Hardener Formulation

(30) 81.62 wt.-% DMDO-DER 331 P adduct, 17.39 wt.-% Jeffamine D-400 (di-functional polyetheramine), 0.99 wt-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot). Viscosity 84 Pa s.

(31) Preparation

(32) 1. Ethyl cyanoacrylate, BF.sub.3 and PMMA were mixed until a homogenous mixture under inert environment.

(33) 2. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(34) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(35) Roll Peel Assembly

(36) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(37) 2. The primer composition was applied to the rubber surface.

(38) 3. The rubber substrate was kept at ambient temperature until its surface was dry (at least 24 hours).

(39) 4. Resin and hardener formulations were mixed. Ratio A:B 100:183 Pot life: 45 minutes

(40) 5. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(41) 6. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the color of the indicator)

(42) 7. Rubber and metal substrate were assembled and bonded by rolling.

(43) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(44) Roll peel after complete curing (3 days at 20 C.): 12 N/mm

(45) Roll peel after 2 hours from assembly (green strength): 1.5 N/mm

(46) Roll peel after 4 hours from assembly (green strength): 2 N/mm

Example 3

(47) Primer Composition

(48) 96.49% Ethyl cyanoacrylate; 0.01% BF.sub.3 (Boron trifluoride); 3.5% PMMA (Polymethylmetacrylate).

(49) 2K Epoxy Adhesive

(50) Resin Formulation

(51) 46.06 wt.-% DER 356 P (Bisphenol-NF based epoxy resin, Dow), 8.23 wt.-% Paraloid EXL-2600 (Styrene-methyl methacrylate-butadiene copolymer), 0.01 wt.-% defoamer, 27.43 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 1.81 wt.-% Silane A187 (Glycidoxypropyl)trimethoxysilane), 16.46% Versalink P1000-Tolane X-Flo100 prepolymer. Viscosity 45 Pa s.

(52) Hardener Formulation

(53) 93.38% Ancamine 1922A-DER 331P adduct; 4.41% Cab-O-Sil TS 720; 2.21% Silane A1110. Viscosity 2 Pa s.

(54) Preparation

(55) 1. Ethyl cyanoacrylate, BF.sub.3 and PMMA were mixed until a homogenous mixture under inert environment.

(56) 2. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(57) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(58) Roll Peel Assembly

(59) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(60) 2. The primer composition was applied to the rubber surface.

(61) 3. The rubber substrate was kept at ambient temperature until its surface was dry (at least 24 hours).

(62) 4. Resin and hardener formulations were mixed. Ratio A:B 100:28 Pot life: 45 minutes

(63) 5. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(64) 6. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the color of the indicator)

(65) 7. Rubber and metal substrate were assembled and bonded by rolling.

(66) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(67) Roll peel after complete curing (3 days at 20 C.): 11 N/mm

(68) Roll peel after 2.5 hours from assembly (green strength): 1.5 N/mm

(69) Roll peel after 4 hours from assembly (green strength): 3 N/mm

Example 4

(70) Primer Composition

(71) SICOMET 102 (cyanoacrylate containing primer)

(72) 2K Epoxy Adhesive

(73) Resin Formulation

(74) 39.49 wt.-% DER 331 P (Bisphenol-A based epoxy resin, Dow), 59.23 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.3 wt.-% Automate Red BXL (curing indicator, Rohm&Haas). Viscosity 120 Pa s.

(75) Hardener Formulation

(76) 81.62 wt.-% DMDO-DER 331 P adduct, 17.39 wt.-% Jeffamine D-400 (di-functional polyetheramine), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot). Viscosity 84 Pa s.

(77) Preparation

(78) 1. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(79) 2. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(80) Roll Peel Assembly

(81) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(82) 2. The primer composition was applied to the rubber surface.

(83) 3. The rubber substrate was kept at ambient temperature until its surface was dry (at least 24 hours).

(84) 4. Resin and hardener formulations were mixed. Ratio A:B 100:183 Pot life: 45 minutes

(85) 5. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(86) 6. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the colour of the indicator)

(87) 7. Rubber and metal substrate were assembled and bonded by rolling.

(88) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(89) Roll peel after complete curing (3 days at 20 C.): 12 N/mm

(90) Roll peel after 2 hours from assembly (green strength): 1.5 N/mm

(91) Roll peel after 4 hours from assembly (green strength): 2 N/mm

Example 5

(92) Primer Composition 1

(93) 96.49% Ethyl cyanoacrylate; 0.01% BF.sub.3 (Boron trifluoride); 3.5% PMMA (Polymethylmetacrylate).

(94) Primer Composition 2 (2K Epoxy Primer)

(95) Part A: 84% DER 356; 15% Paraloid EXL-2600; 0.01% Defoamer 1244; 0.99% Silane A187.

(96) Part B: 3% Cab-o-Sil TS 720; 1% Versamine EH30; 0.01% Defoamer 1244; 95.99% DER331P-Ancamine 1922A adduct.

(97) 2K Epoxy Adhesive

(98) Resin Formulation

(99) 39.49 wt.-% DER 331 P (Bisphenol-A based epoxy resin, Dow), 59.23 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.3 wt.-% Automate Red BXL (curing indicator, Rohm&Haas). Viscosity 120 Pa s.

(100) Hardener Formulation

(101) 81.62 wt.-% DMDO-DER 331 P adduct, 17.39 wt.-% Jeffamine D-400 (di-functional polyetheramine), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot). Viscosity 84 Pa s.

(102) Preparation

(103) 1. Ethyl cyanoacrylate, BF.sub.3 and PMMA were mixed until a homogenous mixture under inert environment.

(104) 2. The components of the primer 2, part A as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(105) 3. The components of the primer 2, part B as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(106) 4. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(107) 5. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(108) Roll Peel Assembly

(109) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(110) 2. The primer composition 1 was applied to the rubber surface.

(111) 3. The rubber substrate was kept at ambient temperature until its surface was dry (at least 24 hours).

(112) 4. For primer 2, part A and B were mixed. Ratio A:B 100:50

(113) 5. Primer 2 was applied to the rubber surface already coated with primer 1 and primer 2 was cured at ambient conditions for 6 hours.

(114) 6. Resin and hardener formulations were mixed. Ratio A:B 100:183 Pot life: 45 minutes

(115) 7. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(116) 8. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the color of the indicator)

(117) 9. Rubber and metal substrate were assembled and bonded by rolling.

(118) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(119) Roll peel after complete curing (3 days at 20 C.): 13 N/mm

(120) Roll peel after 2 hours from assembly (green strength): 1.5 N/mm

(121) Roll peel after 4 hours from assembly (green strength): 2 N/mm

Example 6

(122) Primer Composition

(123) 5% Iodine Monobromide (IBr); 95% 1,6-Dichlorohexane (DCH).

(124) 2K Epoxy Adhesive

(125) Resin Formulation

(126) 39.49 wt.-% DER 331 P (Bisphenol-A based epoxy resin, Dow), 59.23 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.3 wt.-% Automate Red BXL (curing indicator, Rohm&Haas). Viscosity 120 Pa s.

(127) Hardener Formulation

(128) 81.62 wt.-% DMDO-DER 331 P adduct, 17.39 wt.-% Jeffamine D-400 (di-functional polyetheramine), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot). Viscosity 84 Pa s.

(129) Preparation

(130) 1. Iodine Monobromide and 1,6-Dichlorohexane were mixed

(131) 2. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(132) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(133) Roll Peel Assembly

(134) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(135) 2. The primer composition was applied to the rubber surface by placing a piece of cloth over the rubber surface, applying the primer composition to the cloth and placing a plastic foil over the impregnated cloth.

(136) 3. The rubber substrate was kept for at least 15 minutes before the plastic foil and the cloth was removed.

(137) 4. Resin and hardener formulations were mixed. Ratio A:B 100:183 Pot life: 45 minutes

(138) 5. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(139) 6. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the color of the indicator)

(140) 7. Rubber and metal substrate were assembled and bonded by rolling.

(141) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(142) Roll peel after complete curing (3 days at 20 C.): 10 N/mm

(143) Roll peel after 2 hours from assembly (green strength): 1.5 N/mm

(144) Roll peel after 4 hours from assembly (green strength): 2 N/mm

Example 7

(145) Primer Composition

(146) 5% Iodine Monobromide (IBr); 95% 1,6-Dichlorohexane (DCH).

(147) 2K polyurea adhesive:

(148) Amine Formulation

(149) 72.43 wt.-% Versalink P-1000 (Polytetramethlyeneoxide-di-p-aminobenzoate), 7.24 wt.-% Monarch 580, 3.62 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 16.71 wt.-% (Tolonate XFlo100+Ethacure 420) adduct (aliphatic polyisocyanatebis(sec-butylamino)diphenylmethane adduct). Viscosity 15 Pa s.

(150) Hardener Formulation

(151) 13.91 wt.-% Tolonate HDT (hexamethylene diisocyanate), 53.08 wt.-% Macroplast QR88 (polyurethane prepolymer), 30.06 wt.-% Desmodur VK5 (Diphenylmethanediisocyanate/MDI), 2.95 wt.-% Silquest A187. Viscosity 3 Pa s.

(152) Preparation

(153) 1. Iodine Monobromide and 1,6-Dichlorohexane were mixed

(154) 2. The components of the polyurea formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(155) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(156) Roll Peel Assembly

(157) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(158) 2. The primer composition was applied to the rubber surface by placing a piece of cloth over the rubber surface, applying the primer composition to the cloth and placing a plastic foil over the impregnated cloth.

(159) 3. The rubber substrate was kept for at least 15 minutes before the plastic foil and the cloth was removed.

(160) 4. Mix part A and B, ratio A:B 100:42 Pot life: 45 min

(161) 5. One coat of the mixed 2K polyurea adhesive was applied to the metal substrate.

(162) 6. The metal substrate was kept at ambient temperature until green strength had developed (4-6 hours)

(163) 7. Rubber and metal substrate were assembled and bonded by rolling.

(164) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(165) Roll peel after complete curing (3 days at 20 C.): 8 N/mm

(166) Roll peel after 4 hours from assembly (green strength): 1.5 N/mm

(167) Roll peel after 6 hours from assembly (green strength): 2 N/mm

(168) Roll peel after 8 hours from assembly (green strength): 3.5 N/mm

Example 8

(169) Primer Composition

(170) 5% Iodine Monobromide (IBr); 95% 1,6-Dichlorohexane (DCH).

(171) 2K Polyurea Adhesive

(172) Amine Formulation

(173) 81.27 wt.-% Versalink P-1000 (Polytetramethlyeneoxide-di-p-aminobenzoate), 8.13 wt.-% Monarch 580, 4.06 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 6.5 wt.-% Ethacure 420). Viscosity 42 Pa s.

(174) Hardener Formulation

(175) 9.89 wt.-% Tolonate HDT (hexamethylene diisocyanate), 87.89 wt.-% Macroplast QR88 (polyurethane prepolymer), 2.22 wt-% Silquest A187. Viscosity 80 Pa s.

(176) Preparation

(177) 1. Iodine Monobromide and 1,6-Dichlorohexane were mixed

(178) 2. The components of the polyurea formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(179) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(180) Roll Peel Assembly

(181) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(182) 2. The primer composition was applied to the rubber surface by placing a piece of cloth over the rubber surface, applying the primer composition to the cloth and placing a plastic foil over the impregnated cloth.

(183) 3. The rubber substrate was kept for at least 15 minutes before the plastic foil and the cloth was removed.

(184) 4. Mix part A and B, ratio A:B 100:108 Pot life: 40 min

(185) 5. One coat of the mixed 2K polyurea adhesive was applied to the metal substrate.

(186) 6. The metal substrate was kept at ambient temperature until green strength had developed (6-7 hours)

(187) 7. Rubber and metal substrate were assembled and bonded by rolling.

(188) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(189) Roll peel after complete curing (3 days at 20 C.): 6 N/mm

(190) Roll peel after 6 hours from assembly (green strength): 1.5 N/mm

(191) Roll peel after 7 hours from assembly (green strength): 2.8 N/mm

Example 9

(192) Primer Composition 1

(193) 5% Iodine Monobromide (IBr); 95% 1,6-Dichlorohexane (DCH).

(194) Primer Composition 2 (2K Polyurea Primer)

(195) Amine Formulation

(196) 86.96 wt.-% Versalink P-1000 (Polytetramethlyeneoxide-di-p-aminobenzoate), 8.7 wt.-% Monarch 580, 4.34 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot).

(197) Hardener Formulation

(198) 14.07 wt.-% Tolonate HDT (hexamethylene diisocyanate), 53.66 wt.-% Macroplast QR88 (polyurethane prepolymer), 2.11 wt-% Silquest A187, 30.16 wt.-% Desmodur VK5 (Diphenylmethanediisocyanate/MDI)

(199) 2K Epoxy Adhesive

(200) Resin Formulation

(201) 39.49 wt.-% DER 331 P (Bisphenol-A based epoxy resin, Dow), 59.23 wt.-% LER-HH (phenoxy-modified epoxy resin, InChem), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot), 0.3 wt.-% Automate Red BXL (curing indicator, Rohm&Haas). Viscosity 120 Pa s.

(202) Hardener Formulation

(203) 81.62 wt.-% DMDO-DER 331 P adduct, 17.39 wt.-% Jeffamine D-400 (di-functional polyetheramine), 0.99 wt.-% Cab-O-Sil TS 720 (PDMS-treated fumed silica, Cabot). Viscosity 84 Pa s.

(204) Preparation

(205) 1. Iodine Monobromide and 1,6-Dichlorohexane were mixed

(206) 2. The components of the polyurea formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(207) 3. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(208) 4. The components of the resin formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(209) 5. The components of the hardener formulation as listed above were loaded into a high-speed disperser and dispersed with dynamic vacuum until a homogeneous mixture was obtained.

(210) Roll Peel Assembly

(211) 1. Dirt, grease, oil and the like were removed from the substrate surfaces with Loctite SF 7063 (Henkel).

(212) 2. 2. The primer composition was applied to the rubber surface by placing a piece of cloth over the rubber surface, applying the primer composition to the cloth and placing a plastic foil over the impregnated cloth.

(213) 3. The rubber substrate was kept for at least 15 minutes before the plastic foil and the cloth was removed.

(214) 4. For primer 2, part A and B were mixed. Ratio A:B 100:41

(215) 5. Primer 2 was applied to the rubber surface already coated with primer 1 and primer 2 was cured at ambient conditions for 6 hours.

(216) 6. Resin and hardener formulations were mixed. Ratio A:B 100:183 Pot life: 45 minutes

(217) 7. One coat of the mixed 2K epoxy adhesive was applied to the metal substrate.

(218) 8. The metal substrate was kept at ambient temperature until green strength had developed (2-4 hours by observing the color of the indicator)

(219) 9. Rubber and metal substrate were assembled and bonded by rolling.

(220) The assembly was done at ambient temperature (20) and a relative humidity less than 85%.

(221) Roll peel after complete curing (3 days at 20 C.): 10 N/mm

(222) Roll peel after 2 hours from assembly (green strength): 1.5 N/mm

(223) Roll peel after 4 hours from assembly (green strength): 2 N/mm