Use of special thiol compounds to improve the storage stability of compositions based on epoxy resins containing amine compounds

Abstract

A composition that forms an insulating layer contains an epoxy-thiol-based binder. Because the expansion rate of the composition is relatively high, coatings having the layer thickness required for the relevant fire resistance duration can be applied in a simple and rapid manner, and it is possible to reduce the layer thickness to a minimum while still achieving a good insulating effect. The composition is particularly suitable for fire-protection, in particular as a coating for metal and non-metal substrates, e.g., steel components such as supports, beams, and truss members, to increase the fire resistance duration thereof.

Claims

1: A method of improving the storage stability of a composition containing amine compounds, the method comprising: mixing an ester group-free thiol compound into the composition.

2: The method according to claim 1, wherein the thiol compound has at least two thiol groups.

3: The method according to claim 1, wherein the composition is an epoxy-based composition.

4: The method according to claim 1, wherein thiol groups of the thiol compound are bound to a monomer, an oligomer, or a polymer, as a skeleton.

5: The method according to claim 4, wherein the thiol compound is selected from the group consisting of a liquid 2-hydroxy-3-mercapto-1-propyl-substituted aliphatic alcohol, which is optionally ethoxylated or propoxylated, tris-(2′-hydroxy-3′-mercaptopropyl)-trimethylol propane, ethoxylated tris-(2′-hydroxy-3′-mercaptopropyl)-trimethylol propane, propoxylated tris-(2′-hydroxy-3′-mercaptopropyl)-trimethylol propane, 1,6-hexanedithiol, dithioglycerol, trithioglycerol, poly(ethylene glycol) methyl ether thiol, 2-[(3-aminopropyl)amino]ethanethiol, 3-aminopropane-1-thiol, dithiothreitol, a phenylic thiol, a benzylic thiol, hexadecanedithiol, tetra(ethylene glycol) dithiol, 2-methylsulfanylpropane-1,3-dithiol, 3-ethoxypropane-1,2-dithiol, 3-aminopropane-1,2-dithiol, 3-anilinopropane-1,2-dithiol, and a liquid thiol-terminated polysulfide polymer.

6: The method according to claim 1, wherein the composition contains an epoxy resin which has at least two epoxy groups.

7: The method according to claim 6, wherein the epoxy resin can be obtained by reacting a polyhydroxy compound with an epihalohydrin or a precursor thereof, and has an epoxy equivalent weight (EEW)≤550 g/val.

8: The method according to claim 7, wherein the polyhydroxy compound is selected from the group consisting of polyvalent phenols.

9: The method according to claim 8, wherein the polyhydroxy compound is bisphenol A, bisphenol F, or a mixture thereof.

10: The method according to claim 6, wherein the composition further contains a catalyst for a reaction of the epoxy resin with the thiol compound.

11: The method according to claim 3, wherein the epoxy-based composition is an intumescent composition.

12: The method according to claim 1, wherein the composition contains at least one additive which forms an insulating layer.

13: The method according to claim 12, wherein the A least one additive which forms an insulating layer is a compound selected from the group consisting of a carbon source, an acid former, a blowing agent, a thermally expandable compound, and a combination of two or more thereof.

14: The method according to claim 13, wherein the composition further contains at least one ash crust stabilizer.

15: The method according to claim 1, wherein the composition further contains organic and/or inorganic aggregates and/or further additives.

16: The method according to claim 5, wherein the thiol compound is a benzenedithiol or dimercaptostilbene.

Description

EXAMPLES

[0133] In order to show the influence of the type of thiols on the storage stability of a composition based on epoxy amine, storage tests were first carried out using a simple mixture of a thiol and an amine. For this purpose, the viscosity of the relevant, freshly prepared mixture, and of the mixtures after four and after eight weeks of storage at +40° C. was determined. The storage temperature of +40° C. was chosen to simulate storage or aging of the mixture over a longer time period at room temperature.

[0134] Storage tests were also carried out using, in each case, mixtures of a thiol, an amine, melamine, ammonium polyphosphate and a wetting agent. For this purpose, the viscosity of the relevant, freshly prepared mixture, and of the mixtures after four and after eight weeks of storage at +40° C. was determined.

[0135] Storage tests were also carried out using, in each case, mixtures of a thiol, melamine or pentaerythritol or ammonium polyphosphate or titanium dioxide (TiO.sub.2). For this purpose, the viscosity of the relevant, freshly prepared mixture, and of the mixtures after four and after eight weeks of storage at +40° C. was determined.

[0136] Compounds Used:

TABLE-US-00001 Thiocure pentaerythritol tetra Bruno Bock PETMP (3-mercaptopropionate) Thiocure trimethylolpropane trimercaptoacetate Bruno Bock TMPMA CeTePox CTP 2200H Polythiol liquid resin consisting of a Toray QE 340M polyether backbone, at the ends of which the thiol base is introduced DBU 1,8-diazabicyclo[5.4.0]undec-7-ene Sigma Aldrich, TCl Jeffcat N,N,N′-trimethyl-N′-hydroxyethyl- Huntsman ZF-10 bisaminoethylether Jeffcat bis-(2-dimethylaminoethyl)ether 70% Huntsman ZF-22 in dipropylene glycol DABCO 33 wt. % of triethylenediamine Sigma Aldrich 33-LV in dipropylene glycol PMDETA N,N,N′,N″N″- Sigma Aldrich pentamethyldiethylenetriamine Ancamine 2,4,6-tri(dimethylaminomethyl) AirProducts, Belg K54 phenol 2E4MIZ 2-ethyl-4-methylimidazole 95% Sigma Aldrich Versamin tertiary amine accelerator and curing BASF EH-50 agent DBN 1,5-diazabicyclo[4.3.0]non-5-ene Sigma Aldrich BYK-W solution of a copolymer with filler- BYK-Chemie GmbH 903 affinic groups APP ammonium polyphosphate Exolit Clariant AP 462 Melafine 2,4,6-triamino-1,3,5-triazine OCl nitrogen (melamine) Charmor monopentaerythritol Perstorp PM40 Epilox bisphenol F-based epoxy resin LEUNA-Harze GmbH F16-01 TiO.sub.2 Kronos titanium dioxide 2056 Kronos International Inc Heloxy 1,6-hexanediol diglycidyl ether Momentive, Hexion modifier HD

[0137] Measuring the Viscosity

[0138] The dynamic viscosity of all mixtures was measured using a cone and plate measuring system according to DIN 53019. The diameter of the cone was 20 mm and the opening angle was 1°. The measuring temperature was 23° C. (examples from table 1, table 6, and examples 47 and 48) or 40° C. (examples from table 2 and table 4, excluding examples 47 and 48). All viscosity values shown correspond to the value at 215/s. Three measuring points were established, the corresponding mean values being given in tables 1, 2, 4 and 6.

[0139] The following method was used for examples from table 1: The shear rate was increased logarithmically from 0.010/s to 500/s at 23° C. in 16 steps of 11 seconds each.

[0140] The following method was used for examples from table 2 and table 4 (excluding examples 46 and 47): Shearing took place at 40° C. in a first portion, in 7 steps of 11 seconds each at 0.100/s, 0.215/s, 0.464/s, 1.000/s, 2.154/s, 4.642/s and 10.00/s, and in a second section the shear rate was increased logarithmically from 21.54/s to 464.2/s at 40° C. in 6 steps of 8 seconds each.

[0141] For examples from table 6, and examples 46 and 47, the following method was used: The shear rate was increased logarithmically from 0.100/s to 500/s at 23° C. in 14 steps of 11 seconds each.

[0142] a) Assessment of the Storage Stability of Mixtures of a Thiol and an Amine, Based on the Viscosity and the Curing Time of the Mixtures

[0143] Tables 1 and 2 below show the viscosities of freshly prepared thiol-amine mixtures and of the thiol-amine mixtures after one, four and eight weeks of storage at +40° C.

[0144] All viscosities were measured at a shear rate of 215 s.sup.−1 and a temperature of +23° C. (table 1) (cooled down to +23° C. after storage at +40° C.) or +40° C. (Table 2). The amount of the amine or amine solution is given in wt. % relative to the amount of thiol.

TABLE-US-00002 TABLE 1 Results of the measurement of the viscosity of the thiol-amine mixtures, measured at +23° C. Viscosity of the Viscosity Viscosity Viscosity Freshly prepared after 1 week after 4 weeks after 8 weeks Example Thiol Amine (wt. %) formulation of storage of storage of storage 1 Thiocure PETMP DBU (1.1%) 0.49 0.67 0.95 1.71 2 Thiocure PETMP Jeffcat ZF-10 (1.0%) 0.38 — 0.42 0.62 3 Thiocure PETMP Jeffcat ZF-10 (6.5%) 0.28 — 0.37 0.53 4 Thiocure PETMP DABCO 33-LV (6.5%) 0.33 0.37 0.45 0.56 5 Thiocure PETMP PMDETA (6.5%) 0.26 0.36 — 2.32 6 TMPMA Ancamine K54 (4.5%) 0.13 0.38 2.37 — 7 TMPMA DBU (1.2%) 0.11 0.51 2.31 — 8 TMPMA Jeffcat ZF-10 (2.3%) 0.10 0.16 0.27 — 9 TMPMA Jeffcat ZF-22 (3.4%) 0.09 0.22 1.2 — 10 TMPMA PMDETA (6.6%) 0.11 — — — 11 TMPMA DABCO 33-LV (3.4%)* 0.09 0.16 0.59 — 12 TMPMA 2E4MIZ (10.4%) 0.21 2.88 — — 13 CeTePox 2200H Ancamine K54 (3.1%) 14.97 14.77 12.99 14.56 14 CeTePox 2200H Versamin EH-50 (2.3%) 14.5 13.9 14.21 16.59 15 CeTePox 2200H Jeffcat ZF22 (2.3%) 14.5 10.11 10.6 11.49 16 CeTePox 2200H Jeffcat ZF10 (1.6%) 11.91 10.71 9.95 11.78 17 CeTePox 2200H DBU (1.6%) 19.64 18.79 23.28 41.54 18 CeTePox 2200H DABCO (2.3%) 13.01 11.74 9.93 12.05 19 Polythiol QE 340M Ancamin K54 (4.5%) 13.74 13.85 14.54 15.43 20 Polythiol QE 340M DBN (1.6%) 16.92 19.35 25.10 41.97 21 Polythiol QE 340M Jeffcat ZF-10 (1.6%) 12.25 11.82 13.35 13.64 22 Polythiol QE 340M Jeffcat ZF-22 (2.3%) 10.94 11.42 12.07 13.26 23 Polythiol QE 340M DBU (1.6%) 16.33 17.79 24.11 31.40 24 Polythiol QE 340M DABCO 33-LV (2.3%)* 11.59 11.74 12.67 13.68 25 Polythiol QE 340M Versamin EH-50 (2.3%) 14.01 14.43 15.71 17.31 26 Polythiol QE 340M DBN (0.79%) 15.50 17.71 19.13 21.75 27 Polythiol QE 340M DBU (0.79%) 14.84 15.89 16.60 17.71 *based on the solution (=DABCO 33-LV)

TABLE-US-00003 TABLE 2 Viscosities of the thiol-amine mixtures, measured at +40° C. Viscosity of the Viscosity Viscosity Viscosity freshly prepared after 1 week after 4 weeks after 8 weeks Example Thiol Amine (wt. %) formulation of storage of storage of storage 28 Thiocure PETMP DBU (1.1%) 0.17 0.21 0.28 0.42 29 Thiocure PETMP Jeffcat ZF-10 (2.3%) 0.12 0.13 0.15 0.15 30 Thiocure PETMP PMDETA (6.5%) 0.10 0.12 0.22 0.50 31 TMPMA DBU (1.2%) 0.05 0.13 0.50 1.00 32 TMPMA Jeffcat ZF-10 (2.3%) 0.04 0.06 0.14 0.27 33 TMPMA DABCO 33-LV (3.4%)* 0.04 0.06 0.11 0.15 34 CeTePox 2200H Ancamine K54 (3.1%) 2.0 2.0 2.0 2.0 35 CeTePox 2200H Jeffcat ZF-10 (1.6%) 1.78 1.73 1.85 1.67 36 CeTePox 2200H DABCO 33-LV (2.3%) 1.84 1.85 1.89 1.79 37 Polythiol QE 340M Ancamin K54 (4.5%) 2.80 2.77 3.0 3.0 38 Polythiol QE 340M Jeffcat ZF-10 (1.6%) 2.55 2.45 2.80 2.37 *based on the solution (=DABCO 33-LV)

[0145] In order to determine how the storage stability of the mixtures of the examples from table 1 affects the curing, the mixtures, after they had been cooled down to room temperature (+23° C.), were cured by mixing at room temperature (+23° C.) with fresh epoxy resin (Epilox F 16-01). The amount of epoxy resin was calculated such that a stoichiometrc reaction could take place (functional ratio of epoxy:amine=1:1).

TABLE-US-00004 TABLE 3 Curing times of the mixtures from table 1 in minutes [min] Curing time of a Curing time Curing time Curing time freshly prepared after 1 week after 4 weeks after 8 weeks Example Thiol Amine mixture of storage of storage of storage 1 Thiocure PETMP DBU (1.1%) 1.7 3 2.5 4 2 Thiocure PETMP Jeffcat ZF-10 (1.0%) 17 — 56 >1440 3 Thiocure PETMP Jeffcat ZF-10 (6.5%) 9 — 17 44 4 Thiocure PETMP DABCO 33-LV (6.5%)* 4 5 6 10 5 Thiocure PETMP PMDETA (6.5%) 6 7 14 38 6 TMPMA Ancamine K54 (4.5%) 10 14 50 — 7 TMPMA DBU (1.2%) 4 5 19 — 8 TMPMA Jeffcat ZF-10 (2.3%) 16 45 >900 — 9 TMPMA Jeffcat ZF-22 (3.4%) 10 15 51 — 10 TMPMA PMDETA (6.6%) 4 — — — 11 TMPMA DABCO 33 LV (3.4%) 8 16 >900 — 12 TMPMA 2E4MIZ (10.4%) 4 >900 — — 13 CeTePox 2200H Ancamine K54 (3.1%) 9 9 9 12 14 CeTePox 2200H Versamin EH-50 (2.3%) 9 9 10 10 15 CeTePox 2200H Jeffcat ZF22 (2.3%) 6 8 9 10 16 CeTePox 2200H Jeffcat ZF10 (1.6%) 8 10.5 10 10 17 CeTePox 2200H DBU (1.6%) 1 1 1 1 18 CeTePox 2200H DABCO 33 LV (2.3%)* 5 5 5 5 19 Polythiol QE 340M Ancamin K54 (4.5%) 15 13 13 13 20 Polythiol QE 340M DBN (1.6%) 1 2 2 2 21 Polythiol QE 340M Jeffcat ZF-10 (1.6%) 32 25 32 32 22 Polythiol QE 340M Jeffcat ZF-22 (2.3%) 24 14 16 17 23 Polythiol QE 340M DBU (1.6%) 2 3 2 3 24 Polythiol QE 340M DABCO 33-LV (2.3%)* 5 8 9 8 25 Polythiol QE 340M Versamin (2.3%) 18 20 23 22 26 Polythiol QE 340M DBN (0.79%) 2 12 46 71 27 Polythiol QE 340M DBU (0.79%) 4 44 — 137 *based on the solution (=DABCO 33-LV)

[0146] b) Assessment of the Storage Stability of Mixtures of an Ester Group-Free Thiol and Inorganic Fillers on the Basis of the Viscosity and the Curing Time of the Mixtures

[0147] Table 4 below shows the viscosities of freshly prepared thiol-amine-filler mixtures and of the thiol-amine-filler mixtures after one, four and eight weeks of storage at +40° C. The mixture in example 46 corresponds to the mixture in example 47, which was stored at +23° C. instead of +40° C.

[0148] All viscosities were measured at a shear rate of 215 s.sup.−1 and a temperature of +40° C. The amount of the amine is given in wt. % relative to the amount of thiol.

TABLE-US-00005 TABLE 4 Viscosities [Pa .Math. s] of the thiol-amine filler mixtures, measured at +40° C. Example Viscosity of the Viscosity Viscosity Viscosity (storage freshly prepared after 1 week after 4 weeks after 8 weeks temperature) Thiol Amine Filler(s) formulation of storage of storage of storage 39 Thiocure DBU (0.5%) Byk W 903 (1%) 4.33 5.48 13.84 10.01 (40° C.) PETMP APP (15%) Melafine (15%) TiO.sub.2 (15%) Charmor PM 40 (15%) 40 Thiocure Pmdeta Byk W 903 (1%) 2.17 3.14 5.98 8.84 (40° C.) PETMP (2.5%) APP (15%) Melafine (15%) TiO2 (15%) Charmor PM 40 (15%) 41 Thiocure DBU (0.5%) Byk W 903 (1%) 2.01 4.39 9.68 10.66 (40° C.) TMPMA APP (15%) Melafine (15%) TiO.sub.2 (15%) Charmor PM 40 (15%) 42 Thiocure DABCO 33- Byk W 903 (1%) 1.43 10.21 3.00 2.79 (40° C.) TMPMA LV (1.3%) APP (15%) Melafine (15%) TiO.sub.2 (15%) Charmor PM 40 (15%) 43 CeTePox Ancamine Byk W 903 (1%) 15.40 17.09 48.25 11.66 (40° C) 2200H K54 (1%) APP (14%) Melafine (14%) TiO.sub.2 (14%) Charmor PM 40 (14%) 44 CeTePox DABCO 33- Byk W 903 (0.9%) 9.77 22.74 42.25 16.32 (40° C.) 2200H LV (1%) APP (13%) Melafine (13%) TiO.sub.2 (13%) Charmor PM 40 (13%) 45 Polythiol Ancamine Byk W 903 (0.9%) 13.92 15.56 16.38 10.24 (40° C.) QE K54 (2.2%) APP (13%) 340M Melafine (13%) TiO.sub.2 (13%) Charmor PM 40 (13%) 46 CeTePox DABCO 33- Byk W 903 (1%) 23.84 22.31 22.57 20.77 (23° C.) 2200H LV (0.2%)* APP (30%) Melafine (30%) 47 CeTePox DABCO 33- Byk W 903 (1%) 23.84 22.48 22.84 22.19 (40° C.) 2200H LV (0.2%) APP (30%) Melafine (30%) *based on the solution (=DABCO 33-LV)

[0149] In order to determine how the storage stability of the thiol-amine-filler mixtures from examples 39 to 47 affects the curing, the mixtures from examples 39 to 45, after they had been cooled down to room temperature (+23° C.), were mixed at room temperature (+23° C.) with fresh epoxy resin (Epilox F 16-01). The amount of epoxy resin was calculated such that a stoichiometric reaction could take place (functional ratio of epoxy:amine=1:1).

[0150] The thiol-amine-filler mixture in examples 46 and 47 was not cured using a freshly prepared epoxy resin, but instead using an aged epoxy composition. For this purpose, the thiol-amine mixture of examples 46 and 47 was mixed with 26 wt. % Epilox F16-01, 20 wt. % Charmor PM 40, 20 wt. % Exolit AP 462, 20 wt. % Kronos 2056, 13 wt. % Heloxy modifier HD and 1 wt. % BYK W-903.

[0151] The curing times were determined at 23° C.

TABLE-US-00006 TABLE 5 Curing times in minutes [min] for the mixtures from Examples 39 to 47 Curing time of a Curing time Curing time Curing time freshly prepared after 1 week after 4 weeks after 8 weeks Example Thiol Amine Filler(s) mixture of storage of storage of storage 39 Thiocure DBU (0.5%) Byk W 903 (1%) 2.5 4.5 6 7 (40° C.) TMPMA APP (15%) Melafine (15%) TiO.sub.2 (15%) Charmor PM 40 (15%) 40 Thiocure PMDETA Byk W 903 (1%) 5 12.5 21 39 (40° C.) PETMP (2.5%) APP (15%) Melafine (15%) TiO.sub.2 (15%) Charmor PM 40 (15%) 41 Thiocure DBU (0.5%) Byk W 903 (1%) 3 10 1440 >4320 (40° C.) TMPMA APP (15%) Melafine (15%) TiO.sub.2 (15%) Charmor PM 40 (15%) 42 Thiocure DABCO 33- Byk W 903 (1%) 7.5 55 >4320 >4320 (40° C.) TMPMA LV (1.3%)* APP (15%) Melafine (15%) TiO.sub.2(15%) Charmor PM 40 (15%) 43 CeTePox Ancamine Byk W 903 (1%) 11 10 12 12.5 (40° C.) 2200H K54 (1%) APP (14%) Melafine (14%) TiO.sub.2 (14%) Charmor PM 40 (14%) 44 CeTePox DABCO 33- Byk W 903 (0.9%) 4 6 8 8 (40° C.) 2200H LV (1%) APP (13%) Melafine (13%) TiO.sub.2(13%) Charmor PM 40 (13%) 45 Polythiol Ancamine Byk W 903 (0.9%) 12 14 20 18 (40° C.) QE K54 (2.2%) APP (13%) 340M Melafine (13%) TiO.sub.2 (13%) Charmor PM 40 (13%) 46 CeTePox DABCO 33- Byk W 903 (1%) 140 167 126 144 (23° C.) 2200H LV (0.2%) APP (30%) Melafine (30%) 47 CeTePox DABCO 33- Byk W 903 (1%) 128 156 127 154 (40° C.) 2200H LV (0.2%) APP (30%) Melafine (30%) *Based on the solution (= DABCO 33-LV)

[0152] c) Assessment of the Storage Stability of Mixtures of an Ester Group-Free Thiol and Individual Inorganic Fillers One the Basis of the Viscosity of the Mixtures

[0153] Table 6 below shows the viscosities of the freshly prepared thiol-filler mixtures and of the thiol-filler mixtures after one, four and eight weeks of storage at +40° C., in order to clarify that the reduced storage stability is due to the interaction of thiol with amine, and not due to an interaction of thiol with filler.

[0154] All viscosities were measured at a shear rate of 215 s.sup.−1 and a temperature of +23° C.

TABLE-US-00007 TABLE 6 Viscosities of the thiol-filler mixtures, measured at +23° C. Viscosity of the Viscosity Viscosity Viscosity freshly prepared after 1 week after 4 weeks after 8 weeks Example Thiol Filler formulation of storage of storage of storage 48 CeTePox Melafine (12.5%) 12.77 13.33 13.27 13.04 49 2200H TiO.sub.2 (12.5%) 9.60 10.09 10.95 10.04 50 APP (25%) 18.31 16.22 15.23 13.07 51 Charmor (12.5%) 13.71 12.87 13.51 14.02