Curing agent composition for an epoxy resin compound, epoxy resin compound and multi-component epoxy resin system with improved low-temperature curing

Abstract

A curing agent composition can be used for a multi-component epoxy resin compound for the chemical fastening of construction elements. An epoxy resin compound and a multi-component epoxy resin system are useful. A method can be used for the chemical fastening of construction elements in boreholes. A combination of a salt (S) with a phenol derivative can be used for the chemical fastening of construction elements, in particular at low temperatures (≤0° C.), to improve the curing and the pull-out strength.

Claims

1: A curing agent composition (B) for a multi-component epoxy resin compound, comprising: at least one amine which is reactive to epoxy groups, and as an accelerator, at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid, and combinations thereof, wherein the curing agent composition (B) further comprises at least one phenol derivative as an accelerator.

2: The curing agent composition (B) according to claim 1, wherein the at least one phenol derivative is selected from the group consisting of polyphenols from the group of novolac resins, styrenated phenols, phenolic lipids, and combinations thereof.

3: The curing agent composition (B) according to claim 1, wherein the at least one salt (S) is selected from the group consisting of nitrates (NO.sub.3.sup.−), iodides (I.sup.−), triflates (CF.sub.3SO.sub.3.sup.−), and mixtures thereof.

4: The curing agent composition (B) according to claim 1, wherein the at least one phenol derivative comprises at least one polyphenol from the group of novolac resins, which corresponds to the following formula: ##STR00007## in which R.sub.20 and R.sub.21 each denote, independently of one another, H or —CH.sub.3; R.sub.22, R.sub.23, R.sub.24 and R.sub.25 each denote, independently of one another, H, —CH.sub.3, an aliphatic functional group, or an alkaryl functional group, and wherein a is 0 to 20.

5: The curing agent composition (B) according to claim 4, wherein the at least one polyphenol from the group of novolac resins corresponds to the following formula: ##STR00008## in which R.sub.26 denotes a C.sub.1-C.sub.15 alkyl group, b is 0, 1 or 2, and c is 0 to 15.

6: The curing agent composition (B) according to claim 1, wherein the at least one phenol derivative comprises at least one polyphenol from the group of novolac resins and the at least one salt (S) is selected from the group consisting of nitrates.

7: The curing agent composition (B) according to claim 1, wherein the at least one amine which is reactive to epoxy groups is selected from 2-methylpentanediamine (DYTEK A), 3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA), 1,3-benzenedimethanamine (m-xylylenediamine, MXDA), 1,4-benzenedimethanamine (p-xylylenediamine, PXDA), 1,6-diamino-2,2,4-trimethylhexane (TMD), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylene hexamine (PEHA), N-ethylaminopiperazine (N-EAP), (3(4),8(9)bis(aminomethyl)dicyclo[5.2.1.0.sup.2,6] decane, 1,14-diamino-4,11-dioxatetradecane, dipropylenetriamine, 2-methyl-1,5-pentanediamine, N,N′-dicyclohexyl-1,6-hexanediamine, N,N′-dimethyl-1,3-diaminopropane, N,N′-diethyl-1,3-diaminopropane, N,N-dimethyl-1,3-diaminopropane, secondary polyoxypropylenedi- and triamines, 2,5-diamino-2,5-dimethylhexane, bis(amino-methyl)tricyclopentadiene, 1,8-diamino-p-menthane, bis-(4-amino-3,5-dimethylcyclohexyl)methane, 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), dipentylamine, N-2-(aminoethyl)piperazine (N-AEP), N-3-(aminopropyl)piperazine, piperazine, methylcyclohexyl-diamine (MCDA), and combinations thereof.

8: The curing agent composition (B) according to claim 1, wherein the at least one salt (S) comprises a cation from the group consisting of alkali metals, alkaline earth metals, lanthanoids, aluminum, ammonium, and combinations thereof.

9: An epoxy resin compound, containing at least one curable epoxy resin and the curing agent composition (B) according to claim 1.

10: The epoxy resin compound according to claim 9, wherein the epoxy resin compound is a multi-component epoxy resin compound.

11: A multi-component epoxy resin system comprising: an epoxy resin component (A) and a curing agent component, wherein the epoxy resin component (A) contains a curable epoxy resin, and the curing agent component contains at least one amine which is reactive to epoxy groups, and wherein the epoxy resin component (A) and/or the curing agent component contains, as an accelerator, at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, and salts of trifluoromethanesulfonic acid; and at least one phenol derivative.

12: The multi-component epoxy resin system according to claim 11, wherein the at least one salt (S) and the at least one phenol derivative are contained in the curing agent component.

13: A method, comprising: chemical fastening of construction elements in boreholes using the epoxy resin compound according to claim 9.

14: A method for improving the pull-out strength of an epoxy resin compound at low temperatures, the method comprising: mixing at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, and salts of trifluoromethanesulfonic acid, with at least one phenol derivative; to form an accelerator for an epoxy resin compound.

15: The curing agent composition (B) according to claim 4, wherein in the formula (III), R.sub.22, R.sub.23, R.sub.24 and R.sub.25 each denote, independently of one another, H, —CH.sub.3, an aliphatic functional group, or an alkaryl functional group, wherein the aliphatic functional group is a linear, optionally partially unsaturated, unbranched hydrocarbon chain having up to 15 carbon atoms, and/or wherein the alkaryl functional group is —C.sub.8H.sub.9.

16: A method, comprising: chemical fastening of construction elements in boreholes using the multi-component epoxy resin system according to claim 11.

Description

EXAMPLES

Epoxy Resin Component (A)

[0116] Starting Materials

[0117] In the examples, the bisphenol A-based and bisphenol F-based epoxy resins, commercially available under the names Araldite GY 240 and Araldite GY 282 (Huntsman), respectively, were used as the epoxy resins.

[0118] 3-Glycidyloxypropyl-trimethoxysilane, available under the name Dynalsylan GLYMO™ (Evonik Industries), was used as the adhesion promoter.

[0119] 1,4-Butanediol-diglycidyl ether and trimethyolpropane-triglycidyl ether, commercially available under the names Araldite DY-026 and Araldite™ DY-T (Huntsman), respectively, were used as the reactive diluents.

[0120] The liquid components were premixed by hand. Subsequently, quartz (Millisil™ W12 or Millisil W4™ from Quarzwerke Frechen) was added as a filler and fumed silica (Cab-O-Sil™ TS-720 from Cabot Rheinfelden or Aerosil R 805 from Evonik) was added as a thickener and the mixture was stirred in the dissolver (PC laboratory system, volume 1 L) for 10 minutes at a negative pressure of 80 mbar at 3500 rpm.

[0121] The composition of the epoxy resin components A1 to A9 used in the examples is given in table 1 below.

TABLE-US-00001 TABLE 1 Compositions of the epoxy resin components Al to A9 in wt. % Al A2 A3 A4 AS A6 A7 A8 A9 3-Glycidy- 3.4 3.4 3.4 3.4 3.4 3,4 3.4 3.4 3.4 loxypropyi- trimettioxysysilane Bisphenol A-based 34.6 34.2 31.0 27.9 31.1 33.1 32.7 29.4 29.3 epoxy resin Bisphenol F-based 18.6 18.4 16.7 15.0 16.8 17.8 17.6 15.8 15.8 epoxy resin 1,4-Butanediol 6.7 6.6 6.0 5.4 6.0 6.4 6.3 5.7 5.6 diglycidyi ether Trirnethyloipropane 6.7 6.6 6.0 5.4 6.0 6.4 6.3 5.7 5.6 triglycidyi ether Quartz (W12) 27.4 28.7 34.2 41.1 33.9 30.2 Quartz (W4) 31.3 38.0 38.1 Silica (Aerosil) 2.7 2.8 2.8 Silica (Cab-O-Sil) 2.7 2.2 1.8 2.4 2.1 2.1 EEW [g/Eq] 230 232 255 282 254 240 242 269 269

[0122] The composition of the epoxy resin components VA1 to VA9 used in the comparative examples is given in table 2 below.

TABLE-US-00002 TABLE 2 Compositions of the epoxy resin components VA1 to VA9 in wt. % VA1 VA2 VA3 VA4 VA5 VA6 VA7 VA8 VA9 3-Glycidy- 3.4 3.4 3.4 3.4 3.4 3.4 3.4 3.4 3.4 loxypropyl- trimethoxysysilane Bisphenol A-based 34.0 39.0 39.1 25.9 31.1 32.2 32.0 29.1 29.0 epoxy resin Bisphenol F-based 18.3 21.0 15.7 13.9 16.7 17.3 17.2 15.7 15.6 epoxy resin 1,4-butahediol 6.5 7.5 5.6 5.0 6.0 6.2 6.2 5.6 5.6 diglycidyl ether Trimethylolpropane 6.5 7.5 5.6 5.0 6.0 6.2 6.2 5.6 5.6 triglycidyl ether Quartz (W12) 29.0 18.8 38.3 44.8 33.9 32.0 Quartz (W4) 32.7 38.0 38.8 Silica (Aerosii) 2.3 2.7 2.7 Silica (Cab-O-Sil) 2.2 2.8 2.0 2.4 2.1 2.1 EEW [g/Eq] 233 204 271 303 254 246 248 271 272

[0123] Curing Agent Composition (B)

[0124] Starting Materials

[0125] m-Xylylenediamine (MXDA) and 1,3-cyclohexanedimethanamine (1,3-BAC) from MGC, Japan, 2-methyl-1,5-pentamethylene diamine (Dytek A) from Invista, the Netherlands, 3-aminomethyl-3,5,5-trimethylcyclohexane (isophorone diamine, IPDA, trade name Vastamin IPD) from Evonik Degussa, Germany, methylcyclohexanediamine (Baxxodur EC 210, MCDA) from BASF SE, Germany, N-(2-aminomethyl)piperazine (N-AEP) from TCI Europe and 4,4′-methylene-bis-cyclohexylamine (PACM) from Evonik were used as amines for the preparation of the curing agent composition (B).

[0126] Quartz (Millisil™ W12 or Millisil™ W4 from Quarzwerke Frechen) and calcium aluminate cement (Secar 80 from Kemeos SA) were used as a filler and fumed silica (Cab-O-Sil™ TS-720 from Cabot Rheinfelden or Aerosil R 805 from Evonik) was used as a thickener.

[0127] Salts (S) and Phenol Derivatives

[0128] The constituents given in table 3 below were used to prepare the salts (S), novolac resins and further accelerators used in the curing agent composition (B).

TABLE-US-00003 TABLE 3 List of salts (S), novolac resins and further accelerators used Salt (S) or accelerator Trade name Manufacturer Calcium nitrate Calcium nitrate tetrahydrate Sigma-Aldrich Calcium carbonate Calcium carbonate Sigma-.Aldrich Nitric acid 70% Nitric acid Sigma-Aldrich Calcium triflate Calcium Sigma-Aldrich trifluoromethanesulfonate Phenolite TD-2131 DIC Europe CNSL-based novolac Cardolite NC-370 Cardolite (cashew nut shell liquid, Specialty CNSL) Chemicals Cardanol Cardolite NX-2026 Cardolite Specialty Chemicals Cresol novolac Phenolite KA 1160 DIC Europe Phenol modified Novares CA 80 Rutgers indeneoumarone resin Novares GmbH Styrenated phenol Novares LS 500 Rutgers Novares GmbH Salicylic acid Salicylic acid Merck 2,4,6-Tris(dimethylamino- Ancamin K54 Evonik methyl)phenol, bis[(dimethylamino)methyl]- phenol

[0129] The salt calcium nitrate was used as a solution in glycerol (1,2,3-propanetriol, CAS No. 56-81-5, Merck, G). To prepare the calcium nitrate solution, 400.0 g calcium nitrate tetrahydrate was added to 100.0 g glycerol and stirred at 50° C. until completely dissolved (3 hours). The solution prepared in this way contained 80.0% calcium nitrate tetrahydrate.

[0130] A calcium nitrate/nitric acid solution was also used as the accelerator. To prepare this solution, 52.6 g calcium carbonate was slowly added to 135.2 g nitric acid and then stirred for 5 minutes.

Examples 1 to 9

[0131] The liquid components were mixed to prepare the curing composition (B) of the following examples B1 to B9. If the phenol derivative used as the accelerator was a solid, it was added to the solution and dissolved at a slightly increased temperature (up to 50° C.) with stirring. Liquid phenol derivatives and the salt (S) were added and quartz powder and silicic acid were then added and stirred in the dissolver (PC laboratory system, volume 1 L) for 10 minutes at a negative pressure of 80 mbar at 2500 rpm.

[0132] The composition of the curing agent compositions (B) prepared in this way is given in table 4 below:

TABLE-US-00004 TABLE 4 Composition of the curing agent composition (B) in wt. % Example B1 B2 B3 B4 B5 B6 B7 B8 B9 Amine mXDA 8.0 12.0 — 32.2 32.2 — — — — DYTEK A 32.2 28.2 32.2 — — 32.2 — — — IPDA — — 8.0 8.0 — — — — — MCDA — — — — — — — — — 1,3-BAC — — — — — 8.0 42.0 42.0 31.5 N-AEP — — — — — — 8.0 8.0 5.6 PACM — — — — — — — — 13.0 Phenol Phenolite TD-2131 10.2 11.5 — — — — 10.2 — 10.0 derivative CNSL-based novolac — — 10.1 — — — — — — Cardolite NX-2026 — — — 10.1 — — — — — Cresol-based novolac — — — — 10.0 — — — — Phenol modified indene- — — — — — 10.2 — — — cournarone resin Styrenated phenol — — — — — — — 20.0 — Salt (S) Calcium nitrate 3.8 2.5 6.3 6.3 — 3.8 3.8 3.8 3.8 Calcium nitrate/nitric — — — — 4.0 — — — — acid Further Ancarnin K54 2.4 2.4 — 2.4 2.4 2.4 — — accelerators Quartz (Millisil W4) 39.0 41.2 34.0 40.5 40.5 39.3 31.3 22.9 34.2 Thickener (Cab-o-Sil) 4.4 2.2 2.9 2.3 3.3 1.9 Thickener (Aerosil) 3.4 2.9 4.1 AHEW [g/Eq] 74 75 77 88 77 75 73 73 79

Comparative Examples 1 to 9

[0133] The liquid components were mixed to prepare the curing agent composition (B) of the following comparative examples VB1 to VB5. If the phenol derivative used as the accelerator was a solid, it was added to the solution and dissolved at a slightly increased temperature (up to 50° C.) with stirring. Liquid phenol derivative and the salt (S) were added and quartz powder and silica were then added and stirred in the dissolver (PC laboratory system, volume 1 L) for 10 minutes at a negative pressure of 80 mbar at 2500 rpm.

[0134] Table 5 shows the composition of the curing agent components (B) of comparative examples VB1 to VB9.

TABLE-US-00005 TABLE 5 Composition of the curing agent compositon (B) in wt.% Compacative example VBI VB2 VB3 VB4 VB5 VB6 VB7 VB8 VB9 Amine mXDA 8.0 8.0 — 32.2 32.2 — — — — DYTEK A 32.2 32.2 32.2 — — 32.2 — — — IPDA — 8.0 8.0 — — — — — — MCDA — — — 8.0 — — — — — 1,3-BAC — — — — — 8.0 42.0 42.0 31.5 N-AEP — — — — — — 8.0 8.0 5.6 PACM — — — — — — — — 13.0 Phenol Phenolite TD-2131 14.0 — — — — — 14.0 — 10.0 derivative CNSL-based novolac — — 14.0 — — — — — — Caudate NX-2026 — — — 16.4 — — — — — Cresol-based novolac — — — — 14.0 — — — — Phenol modified indene- — — — — — 14.0 — — — coumarone resin Salt (S) Calcium nitrate 6.3 — — — — — 3.8 — — Further Ancamin K54 2.4 2.4 2.4 — 2.4 2.4 2.4 — — accelerants Salicylic acid — — — — — — — 4.0 4.0 Styrenated phenol — — — — — — — 19.8 — Quartz (Millisil W4) 41.3 48.5 38.9 40.5 40.3 39.4 31.3 23.2 33.6 Thickener (Cab-o-Sil) 2.1 2.6 — 2.9 — — 2.3 3.0 2.3 Thickener (Aeros1) — — 4.5 — 3.1 4.0 — — — AHEW [g/Eq] 74 74 77 88 77 75 73 73 79

[0135] Mortar Compounds and Pull-Out Tests

[0136] The epoxy resin components A1 to A9 and VA1 to VA9 were each filled with the curing agent composition B1 to B9 and VB1 to VB9, respectively (A1 with B1, A2 with B2, VA1 with VB1 etc.), in hard cartridges at a volume ratio of 3:1 and injected into the borehole via a static mixer (Quadro™ mixer from Sulzer). The injection is usually carried out at room temperature. For the tests for curing at −5° C., the mortar compound is temperature-controlled to +5° C. and injected into the borehole.

[0137] The pull-out strength of the mortar compounds obtained by mixing the epoxy resin component (A or VA) and curing agent composition (B or VB) according to the above examples was determined using a high-strength anchor threaded rod M12 according to ETAG 001 Part 5, which was doweled into a hammer-drilled borehole having a diameter of 14 mm and a borehole depth of 69 mm by means of the relevant mortar compound in C20/25 concrete. The boreholes were cleaned by means of compressed air (2×6 bar), a wire brush (2×) and again by compressed air (2×6 bar).

[0138] The boreholes were filled up, by two thirds from the bottom of the borehole, with the mortar compound to be tested in each case. The threaded rod was pushed in by hand. The excess mortar was removed using a spatula. After the curing time and temperature specified for the relevant test, the failure load was determined by centrally pulling out the threaded anchor rod with close support. The following tests were carried out:

[0139] A1

[0140] Dry concrete, embedding depth 68 mm, curing 24 hours at 25° C., support confined;

[0141] A23, −5° C., 168 hours

[0142] Dry concrete, embedding depth 68 mm, curing 168 hours at −5° C. (substrate temperature), mortar compound temperature when setting the anchor rod +5° C.

[0143] The load values obtained with the mortar compounds using the epoxy resin components A1 to A9 and VA1 to VA9 and the curing agent components B1 to B39 and VB1 to VB9 according to examples 1 to 9 and comparative examples 1 to 9 are shown in tables 5 and 6 below, respectively.

TABLE-US-00006 TABLE 6 Determination of the load values of the examples according to the invention by pull-out tests Examples 1 2 3 4 5 6 7 8 9 Pull-out tests Load value [N/mm.sup.2] Al 38.1 34.6 34.5 32.9 33.4 29.9 35.4 37.4 35.7 A23, −5° C., 40.4 28.1 32.5 34.8 31.5 33.4 19.6 22.5 21.0 168 h

TABLE-US-00007 TABLE 7 Determination of the load vaiues of the comparative exampies by put-out tests Comparative examples 1 2 3 4 5 6 7 8 9 Pull-out tests Load value [N/mm.sup.2] Al 34.1 33.1 32.8 23.2 33.9 31.0 37.2 35.3 37.7 A23, −5° C., 168 h 25.1 30.3 31.8 33.3 28.3 29.0 18.2 19.7 18.9

[0144] The pull-out tests show that the mortar compounds of the examples according to the invention each have significantly higher load values during curing and pulling out at −5° C. than the mortar compounds of the comparative examples.

[0145] Determination of the Gel Time by Temperature Measurement

[0146] To determine the gel time by temperature measurement, 100 g of a mixture of the epoxy resin component (A) with the curing agent component (B) were poured into a 150 ml plastic container in a volume ratio of 3:1. A temperature sensor was placed in the center of the plastics container. The temperature change was recorded (device: Yokogawa, DAQ station, model: DX1006-3-4-2). With this method, the curing of the mortar could be followed over the course of the temperature development. If there was an acceleration during curing, the maximum temperature is shifted to shorter times, associated with a higher temperature. T.sub.max (maximum temperature reached) and t.sub.T.sub.max (time after which the maximum temperature was reached) were measured. The gel time correlates with the time that remains for the user to process the mixed mortar before curing. A long gel time with simultaneously rapid curing is advantageous for the user.

[0147] The gel times for examples 1 according to the invention and comparative examples 1 and 2 were determined. The only difference between these three examples is the accelerator combination. Example 1 according to the invention had a gel time of 6:38 minutes, comparative example 1 a considerably longer gel time of 17:51 minutes and comparative example 2 had a gel time of 5:10 minutes. However, the curing of comparative example 1 is still not complete even after 168 hours at −5° C. Comparative example 2 and example 1 exhibit acceptable load values after 168 hours at −5° C., but example 1 has the most advantageous combination for the user of the longest possible processing time and high final load after 168 hours. The combination according to the invention of phenolic accelerator and inorganic salt therefore achieves the best overall property profile.