POLYUREA COMPOSITION

Abstract

The invention relates to compositions comprising at least one first and one second component; —the first component K1 comprising at least one di(aminobenzoate) ester A1 of formula (I) with an average molecular weight of 500 g/mol to 2000 g/mol, preferably 600 g/mol to 1500 g/mol and particularly preferred between 650 g/mol and 1300 g/mol, G being a divalent group derived from poly(tetramethylene oxide) diol, and —the second component K2 comprising at least one aromatic polyisocyanate B1 with an average molecular weight of 160 g/mol to 1100 g/mol, preferably 500 g/mol to 800 g/mol.

Claims

1. A composition comprising, at least, a first component and a second component, wherein the first component K1 comprises one or more than one di(aminobenzoate) ester A1 of formula (I) ##STR00004## with an average molecular weight of 500 g/mol to 2000 g/mol, preferably 600 g/mol to 1500 g/mol, more preferably 650 g/mol to 1300 g/mol, where G is a divalent moiety deriving from poly(tetramethylene oxide) diol, and the second component K2 comprises one or more than one aromatic polyisocyanate B1 with an average molecular weight of 160 g/mol to 1100 g/mol, preferably 500 g/mol to 800 g/mol, wherein the molar ratio between the isocyanate groups of the second component K2 and the isocyanate-reactive groups of the first component K1 is in the range from 1.3 to 1.0, preferably 1.15 to 1.05.

2. The composition as claimed in claim 1, wherein the polyisocyanate B1 has an NCO functionality of 2.0-4, preferably of 2.1-2.4.

3. The composition as claimed in claim 1, wherein the aromatic polyisocyanate B1 comprises MDI and/or TDI, preferably MDI.

4. The composition as claimed in claim 1, wherein the aromatic polyisocyanate B1 comprises carbodiimides or uretoneimines or urethanes of these polyisocyanates, especially MDI carbodiimides or MDI uretoneimines or MDI urethanes, preferably MDI carbodiimides.

5. The composition as claimed in claim 1, wherein the second component contains 60 to 100 wt %, preferably 98 to 100 wt %, of the aromatic polyisocyanate B1.

6. The composition as claimed in claim 1, wherein the aromatic polyisocyanate B1 comprises 95-100 mol %, especially 99-100 mol %, of all the isocyanate groups of the second component K2.

7. The composition as claimed in claim 1, wherein the second component K2 further contains at least one isocyanate-functional polyurethane polymer B2.

8. The composition as claimed in claim 1, wherein the di(aminobenzoate) ester A1 comprises a compound of formula (II) ##STR00005## where n is 9-14.

9. The composition as claimed in claim 1, wherein the di(aminobenzoate) ester A1 comprises a mixture of di(aminobenzoate) esters A1-1 having an average molecular weight of 700-1000 g/mol and di(aminobenzoate) esters A1-2 having an average molecular weight of 1100-1300 g/mol, wherein the mole ratio of A1-1/A1-2 is from 0.01-100, especially from 0.5-2.

10. The composition as claimed in claim 1, wherein the first component K1 further comprises an aliphatic, preferably a non-branched, polyetherdiamine A2 with an average molecular weight of 900 g/mol to 2100 g/mol, preferably 1200 g/mol to 1500 g/mol, wherein the polyetherdiamine A2 comprises from 1-15 mole percent, preferably 2-11 mole percent, more preferably 2.5-7 mole percent, of the isocyanate-reactive groups of the first component K1.

11. The composition as claimed in claim 1, wherein the first component K1 further comprises an aliphatic, preferably a non-branched, polyetherdiol A3, especially poly(tetramethylene oxide) diol, with an average molecular weight of 600 g/mol to 1200 g/mol, preferably 900 g/mol to 1100 g/mol, wherein the polyetherdiol A3 represents 1-40 mole percent, preferably 2-10 mole percent, of the isocyanate-reactive groups of the first component K1.

12. A method of patching defects in substrates, wherein the substrates comprise elastomeric material comprising unsaturated units, said method comprising a) mixing together a composition as claimed in claim 1, b) introducing the composition into the defects, and c) curing the composition.

13. A method of adhesively bonding together substrates, wherein either or both, especially both, of the substrates comprise elastomeric material comprising unsaturated units, said method comprising a′) mixing together a composition as claimed in claim 1, b′) coating a substrate S1 with the composition, c′) contacting that part of the substrate S1 which is coated with the composition with a substrate S2 such that the composition is positioned between the two substrates, and d′) curing the composition.

14. The method as claimed in claim 12, wherein the elastomeric material comprising unsaturated units comprises apolar, rubber-like material, especially selected from the group consisting of rubber, EPDM, NBR, SBR, SBS and SIS, more preferably NBR, SBR and EPMD, most preferably NBR.

15. A composite structure obtainable by a method as claimed in claim 12.

16. The method of using a composition as claimed in claim 1 for patching defects, for coating or for adhesively bonding substrates, especially transportation belts, cushioning elements and tires, especially transportation belts, wherein the substrates comprise elastomeric material comprising unsaturated units.

Description

EXAMPLES

Substances Used:

[0124]

TABLE-US-00001 TABLE 1 Versalink Oligomeric poly(tetramethylene oxide) P 650 di-p-aminobenzoate diamine, average molecular (A1-1) weight about 710-950 g/mol, amine number 120 mg KOH/g (Air Products and Chemicals, Inc., USA) Versalink Oligomeric poly(tetramethylene oxide) P 1000 di-p-aminobenzoate diamine, average molecular (A1-2) weight about 1238 g/mol, amine number 95 mg KOH/g (Air Products and Chemicals, Inc., USA) Versalink Trimethylene glycol di-p-aminobenzoate, average 740 M molecular weight about 314 g/mol, amine number 357 mg KOH/g (Air Products and Chemicals, Inc., USA) Prepolymer-1 The prepolymer-1 was prepared by reacting 1300 g of polyoxypropylene diol (Acclaim ® 4200 N, Bayer; OH number 28.5 mg KOH/g), 2600 g of polyoxypropylene-polyoxyethylene triol (Caradol ® MD34-02, Shell; OH number 35.0 mg KOH/g), 600 g of 4,4′-methylenediphenyl diisocyanate (Desmodur ® 44 MC L, Bayer) and 500 g of diisodecyl phthalate in the familiar manner at 80° C. to form an NCO- terminated polyurethane polymer having a free isocyanate group content of 2.05 wt %. Ethacure Ethacure ® 100, mixture of mixtures of 100 (PA) 3,5-diethyl-2,4- and -2,6-tolylenediamines, amine number 630 mg KOH/g, Bayer MaterialScience AG Ancamine Ancamine K54 ®, K54 (TK) 2,4,6-tri(dimethylaminomethyl)phenol, Air Products GmbH (Germany) pTHFdiAmin Poly(tetramethylene oxide)diamine, bis[(4-amino- 1300 butyl)poly(oxy-1,4-butanediyl)]amine, CAS No. (A2) 27417-83-0, average molecular weight about 1300 g/mol, amine number 103 mg KOH/g, (BASF, Germany) pTHF Poly(tetramethylene oxide) diol, CAS No. 25190-06-1, 650 average molecular weight about 625-675 g/mol, OH number about 165-180 mg KOH/g (BASF, Germany) pTHF Poly(tetramethylene oxide) diol, CAS No. 25190-06-1, 1000 average molecular weight about 975-1025 g/mol, OH (A3) number about 110-115 mg KOH/g (BASF, Germany) Isonate M Modified diphenylmethane diisocyanate comprising 143 (B1) MDI carbodiimide adducts, room temperature liquid, NCO content 29.4 wt % (Dow), NCO functionality about 2.2. Desmodur Mixture of diphenylmethane 4,4′-diisocyanate VKS 20 (MDI) with isomers and more highly functional (B1) homologs (PMDI), NCO content 31.5 wt % (Bayer MaterialScience AG), NCO functionality about 2.8. Desmodur Aliphatic polyisocyanate, hexamethylene N3300 1,6-diisocyanate trimer (HDI trimer), NCO content 21.8 wt % (Bayer MaterialScience AG).

Preparation of Polyurea Compositions

[0125] For compositions 1-64, the ingredients reported in tables 1, 3, 5 and 9 were taken in the reported amounts (in parts by weight) of the first component K1 and processed via a vacuum dissolver in the absence of moisture into a homogeneous paste for keeping. The ingredients reported in tables 1, 3, 5 and 9 for the second component K2 were processed for keeping in a similar way. Subsequently, the two components were processed via a SpeedMixer® (DAC 150 FV, Hauschild) during 30 seconds into a homogeneous paste, which was immediately tested as follows:

[0126] To determine its mechanical properties, the adhesive was made into a dumbbell shape as per ISO 527 Part 2, 1B, and stored at 23° C. for 24 h and then cured at 80° C. for 3 h. After a 24 h conditioning period at 23° C., the modulus of elasticity in the range from 0.05 to 0.25% extension (“E-modulus”), the tensile strength and the breaking extension of the test specimens thus obtained were measured as per ISO 527 on a Zwick Z020 tensile tester at the particular temperature reported in the table and an extension rate of 50 mm/min.

[0127] The gel time was determined as follows: 30 g of a ready-mixed composition were determined by the as-mixed mixture being introduced at room temperature into a thermally insulated vessel (made of Styropor), and being thoroughly stirred through manually with a spatula every 60 seconds. The time until it is no longer possible to move the spatula by hand without exerting considerable force is what is defined as the gel time.

[0128] The Tg values (glass transition temperatures) were determined by means of DMTA measurements on strip-shaped specimens (2-3 mm high, 2-3 mm wide, 8.5 mm long) stored at 23° C. for 24 h and then cured at 80° C. for 3 h, using a Mettler DMA/SDTA 861e instrument. The measurement conditions were: measurement in tension mode, 10 Hz excitation frequency and heating rate of 5 K/min. The specimens were cooled down to −60° C. and warmed to 200° C. to determine the complex modulus of elasticity E* [MPa], a maximum in the curve for the loss angle “tan δ” being read off as Tg value.

[0129] The results are reported in table 8 and FIGS. 1 and 2.

[0130] Table 2 lists the test specimens to be used, which had applied to them the corresponding composition. The composition was in each case cast into molds (1.3 cm wide/13 cm long/0.6 cm deep) firmly connected on the side to the test specimen using an adhesive tape, and left in the mold for 12 hours. Thereafter, the mold was removed and the specimens (beads) were cured at 23° C., 50% relative humidity for 7 days and subsequently tested.

[0131] The adherence of the adhesive was tested using the ‘bead test’. The cured bead is incised at one end just above the adhesive-adherend interface. The incised end of the bead is gripped with a pair of round-nose pliers and pulled away from the adherend. This is done by carefully rolling up the bead on the tip of the pair of round-nose pliers, and also placing a cut all the way down to the blank adherend at right angles to the bead-pulling direction. The rate of bead pulling must be chosen such that a cut has to be made about every 3 seconds. The length of the test track has to be not less than 8 cm. Evaluation is according to the adhesive remaining behind on the adherend (in the event of cohesive failure) after the bead has been pulled off. Bonding properties are assessed by estimating the cohesive proportion of the bond area:

[0132] 1=>95% cohesive failure

[0133] 2=75-95% cohesive failure

[0134] 3=25-75% cohesive failure

[0135] 4=<25% cohesive failure

[0136] 5=0% cohesive failure (purely adhesive failure)

[0137] The following test specimens were used:

TABLE-US-00002 TABLE 2 EPDW test specimen from EPDM, Semperit E9614, Rocholl GmbH, Germany NBR test specimen from NBR, NORA 301 color 5, machining 104, Rocholl GmbH, Germany SBR test specimen from SBR, NORA 302, machining 113, Rocholl GmbH, Germany TPO Folie TPO (thermoplastic polyolefins) sheet (40 mm/200 mm/1.5 mm), Sarnafil TS 77-15, Sika Schweiz PVC hart test specimen from rigid PVC, Kömadur ES, Rocholl GmbH, Germany

[0138] Compositions 1 to 29 and composition 57 are examples in accordance with the present invention. The remaining compositions are comparative examples.

[0139] “MV 100 K1” in tables 3 and 5 and 9 is to be understood as meaning that the recited number of parts by weight of component K2 was used per 100 parts by weight of component K1. Components K1 and K2 are composed of the recited amounts (reported in parts by weight). Thus, for example, component K1 of composition 9 consists of 96.7 parts by weight of Versalink 650 and 3.3 parts by weight of pTHFdiAmin1300. Component K2 consists of 70 parts by weight of Isonate M143 and 30 parts by weight of Prepolymer-1. The two components were mixed in the weight ratio (K1:K2=100:44.3) using the SpeedMixer.

[0140] “NCO: Reakt” represents the molar ratio of NCO groups: NCO-reactive groups.

TABLE-US-00003 TABLE 3 Component K1 Component K2 MV Versalink Versalink pTHF Isonate Desmodur No. 100 K1: NCO:Reakt 650 1000 pTHFdiAmin1300 1000 M143 VKS20 Prepolymer-1 1 32 1.1 100 100 2 44.5 1.1 100 70 30 3 30 1.1 100 100 4 41.5 1.1 100 70 30 5 31.6 1.1 96.7 3.3 100 6 31.6 1.1 90 10 100 7 29.7 1.1 96.7 3.3 100 8 29.5 1.1 90 10 100 9 44.3 1.1 96.7 3.3 70 30 10 44 1.1 93.3 6.7 70 30 11 41.3 1.1 96.7 3.3 70 30 12 41.1 1.1 93.3 6.7 70 30 13 29 1.1 50 50 100 14 27 1.1 50 50 100 15 25 1.1 100 100 16 35.2 1.1 100 70 30 17 24 1.1 100 100 18 32.9 1.1 100 70 30 19 25.3 1.1 96.7 3.3 100 20 25.6 1.1 90 10 100 21 23.7 1.1 96.7 3.3 100 22 23.9 1.1 90 10 100 23 35.3 1.1 96.7 3.3 70 30 24 35.4 1.1 93.3 6.7 70 30 25 33 1.1 96.7 3.3 70 30 26 33.1 1.1 93.7 6.7 70 30 27 24 1.01:1.0 100 100 28 27 1.05:1.0 70 30 100 29 26 1.05:1.0 95 5 100 30 27 1.1 100 100 31 25.5 1.1 100 100 32 22 0.92:1.0 100 100

TABLE-US-00004 TABLE 4 fracture tensile breaking E-modulus E-modulus energy gel strength extension (0.5-5%) (0.05-.25%) [J/ time No. [MPa] [%] [MPa] [MPa] mm{circumflex over ( )}2] [min] 1 17.5 448 73 107 6.828 21 2 15.1 523 55.7 77.8 0.801 23 3 19.9 185 33 45.6 0.369 24 4 6.45 586 53.4 73.9 0.629 22 5 16.5 464 66 96.1 6.801 25 6 17 449 59.5 87.6 0.755 16 7 24 159 38.7 58.6 0.348 21 8 12.6 155 16.5 23.4 6.194 11 9 15.5 539 55 77.1 0.852 18 10 14.8 534 54.2 76.6 6.807 29 11 10.8 644 52.8 73.6 0.839 19 12 11.3 185 11 14.6 6.206 16 13 34.3 484 67.1 101 0.957 30 14 16.8 204 26.1 33.7 6.333 38 15 38.8 525 54.7 86.4 0.973 18 16 33.5 538 46.8 74.6 0.885 38 17 6.13 108 16.8 21.7 0.083 35 18 27.1 677 46.6 67.1 1.098 38 19 37.9 511 51.1 77 0.962 40 20 29.7 451 47.1 74.4 0.74 25 21 8.26 159 15 18.1 0.154 59 22 10.5 110 29 41 0.132 21 23 27.6 528 43.8 66.3 0.804 37 24 29.1 523 40.4 63.4 0.786 41 25 25.4 763 40.8 55 1.23 37 26 6.1 158 9.3 11.4 0.111 32 27 20.2 696 48 75 1.1 40 28 17.6 631 26 39 0.62 40 29 39.7 586 50.5 75 1.14 34 30 n.b. 0 31 n.b. 0 32 5.3 734 44 68 0.6 38 n.b. = not determinable because the rapid and strongly exothermic reaction and the resulting severe inhomogeneity results in gelation and overheating of the reaction mass, preventing preparation of test specimens.

TABLE-US-00005 TABLE 5 Component K1 Component K2 MV pTHF pTHF Isonate Desmodur No. 100 K1: NCO:OH 650 1000 pTHFdiAmin1300 M143 VKS20 Prepolymer-1 33 45.8 1.1 100 100 34 42.8 1 1 100 100 35 63.6 1.1 100 70 30 36 59.4 1.1 100 70 30 37 45.2 1.1 96.7 3.3 100 38 42.2 1.1 96.7 3.3 100 39 62.6 1.1 96.7 3.3 70 30 40 58.5 1.1 96.7 3.3 70 30 41 43.8 1.1 93.3 6.7 100 42 40.9 1.1 93.3 6.7 100 43 60.8 1.1 93.3 6.7 70 30 44 56.8 1.1 93.3 6.7 70 30 45 29.3 1.1 100 100 46 27.3 1.1 100 100 47 40.6 1.1 100 70 30 48 37.9 1.1 100 70 30 49 29.2 1.1 96.7 3.3 100 50 27.2 1.1 96.7 3.3 100 51 40.4 1.1 96.7 3.3 70 30 52 37.8 1.1 96.7 3.3 70 30 53 28.9 1.1 93.3 6.7 100 54 27 1.1 93.3 6.7 100 55 40.1 1.1 93.3 6.7 70 30 56 37.5 1.1 93.3 6.7 70 30

TABLE-US-00006 TABLE 6 fracture tensile breaking E-modulus E-modulus energy gel strength extension (0.5-5%) (0.05-.25%) [J/ time No. [MPa] [%] [MPa] [MPa] mm{circumflex over ( )}2] [min] 33 1.08 327 2.07 3.26 0.045 157 34 0.95 39 3 2.8 0.005 182 35 6.12 573 2.08 4 0.161 136 36 1.5 80 2.72 2.27 0.014 132 37 1.61 330 2.43 3.79 0.067 119 38 1.65 54 4.16 3.93 0.011 104 39 1.85 331 2.36 3.37 0.075 210 40 2.25 94 3.67 3.56 0.024 150 41 2.59 184 3.72 4 0.064 120 42 1.98 63 4.4 5.61 0.15 34 43 1.85 328 2.19 3.11 0.073 110 44 1.62 63 3.59 4 0.012 23 45 1.08 595 1.65 2.47 0.072 233 46 0.38 28 1.7 2.18 0.002 296 47 1.52 908 1.18 2.17 0.088 182 48 0.35 36 1.18 2.42 0.002 300 49 1.31 684 1.37 3.26 0.083 172 50 0.9 43 2.64 3.45 0.005 157 51 3.1 741 1.07 1.68 0.114 270 52 0.98 66 2.05 3.46 0.008 210 53 3.05 521 1.73 2.73 0.12 140 54 1.18 58 2.85 3.12 0.008 19 55 1.68 400 1.73 2.6 0.077 40 56 1.11 52 2.94 3.79 0.007 21

TABLE-US-00007 TABLE 7 No. 15 16 17 20 1 2 3 6 NBR 1 4 5 1 1 4-5 4-5 4-5 + + − + + + + + SBR 4 4 4-5 4 4 4 4-5 4 + + − + + + + + EPDM 4-5 5 5 4-5 5 5 5 5 + + + + + + + + TPO 5 5 5 5 5 5 5 5 Folie + + + + + + + + PVC 5 5 5 5 5 5 5 5 hart + + + + + + + + Mechanical properties of bead: + = the bead does not rupture and the force is transferred to the adhesive-adherend interface − = the bead is very “weak”, ruptures very quickly and the force is not transferred to the adhesive-adherend interface

TABLE-US-00008 TABLE 8 TG1 TG2 TG3 No. [° C.] [° C.] [° C.] 15 −35 145 170 17 −30 20 170 19 −25 147 170 21 −35 40 165 1 10 150 — 3 40 150 — 5 0 145 175 7 55 170 —

TABLE-US-00009 TABLE 9 Component K1 Component K2 MV Versalink Ancamine Ethacure Isonate Desmodur No. 100 K1: NCO:Reakt 1000 K54 100 M143 N3300 57 25.4 1.05 30 7.6 58 25.4 1.05 30 0.9 7.6 59 36.3 1.5 30 10.9 60 23.0 0.95 30 6.9 61 39.7 1.05 27 3 11.9 62 29.7 1.05 29.1 0.9 8.9 63 28.3 1.05 29.4 0.6 8.5 64 34.3 1.05 30 10.3

TABLE-US-00010 TABLE 10 fracture tensile breaking E-modulus E-modulus energy strength extension (0.5-5%) (0.05-.25%) [J/ No. [MPa] [%] [MPa] [MPa] mm{circumflex over ( )}2] 57 30.5 668 54 64 1.23 58 n.b. n.b. n.b. n.b. n.b. 59 31.4 400 67 136 0.84 60 14.3 1045 44 56 1.52 61 n.b. n.b. n.b. n.b. n.b. 62 27.5 539 41 36 1.16 63 32.5 541 41 48 1.11 64 2.4 113 3.35 7.34 0.03 n.b. = not determinable because the rapid and strongly exothermic reaction and the resulting severe inhomogeneity results in gelation and overheating of the reaction mass, preventing preparation of test specimens.

Preparation of Further Polyurea Compositions

[0141] 96.5 parts by weight of MS-23 were processed together with 3.5 parts by weight of Ethacure 100 for 30 seconds in a SpeedMixer® (DAC 150 FV, Hauschild) to form a homogeneous paste which was immediately tested as follows. Severe inhomogeneity results in local gelation and overheating of the reaction mass, preventing preparation of test specimens.

[0142] A first component K1 was prepared to consist of 100 parts by weight of Versalink P 1000 and 39 parts by weight of Ethacure 100. This first component K1 was processed in a weight ratio of K1:K2=100:65.6 with Isonate M 143 for seconds using a SpeedMixer® (DAC 150 FV, Hauschild). Severe inhomogeneity results in local gelation and overheating of the reaction mass, preventing preparation of test specimens.

[0143] A first component K1 was prepared to consist of 100 parts by weight of Versalink P 1000 and 69 parts by weight of Versalink 740M. This first component K1 was processed in a weight ratio of K1:K2=100:54 with Isonate M 143 for 30 seconds using a SpeedMixer® (DAC 150 FV, Hauschild). Severe inhomogeneity results in local gelation and overheating of the reaction mass, preventing preparation of test specimens.

Results:

DMTA Measurements

[0144] The compositions of the invention display a minimal change in the E-modulus across a wide temperature range.

[0145] Compositions comprising Versalink P 1000 (A1-2) have the first Tg at lower temperatures versus Versalink P 650 (A1-1). This is advantageous in that the advantageous mechanical properties found persist down to low temperatures and/or remain relatively constant. They further lead to a distinct temperature interval ranging from −20° C. to 40° C., preferably from −20° C. to 50° C., between two successive Tgs, which is advantageous in relation to unchanging mechanical properties, since there are many technical applications, especially for conveyor belts, particularly in the mining industry, which fall within this temperature range.

[0146] Compositions comprising Isonate M143 versus Desmodur VKS20 have two discrete Tgs instead of one mixed Tg, and/or the temperature interval between the individual Tgs is greater, which is conducive to unchanging mechanical properties, especially across a larger temperature range.

Adherence Measurements

[0147] The compositions of the invention were surprisingly found to display adherence to rubber only, but not to TPO or rigid PVC.

[0148] The compositions all display their best adherence to NBR, their second best adherence to SBR and their third best adherence to EPDM.

[0149] Compositions comprising Isonate M143 instead of Desmodur VKS20 display superior adherence to all rubber substrates.

[0150] Compositions comprising Versalink P1000 A1-2 only instead of Versalink P650 A1-2 only display superior adherence to EPDM.