LATENT EPOXY-AMINE COMPOSITION FOR CIPP APPLICATION

Abstract

A two-component epoxy resin composition, made of: a resin component including: at least one epoxy resin that contains on average more than one epoxy group per molecule; up to 25 wt.-% of at least one epoxy-functional reactive diluent having one or two epoxy groups per molecule; and a hardener component including: between 40 and 80 wt.-% of at least one amino-functional hardener of formula (I),

##STR00001##

wherein n is an integer with a value of 2 or 3, R.sup.1 is a linear, cyclic or branched alkyl residue that optionally contains ether oxygen atoms and R.sup.2 is a methyl or ethyl group; between 10 and 30 wt.-% of at least one Lewis base having at least one tertiary amino group, amidine group, or guanidine group; and between 10 and 30 wt.-% of at least one carboxylic acid.

Claims

1. A two-component epoxy resin composition, consisting of: a resin component K1 comprising: at least one epoxy resin A that contains on average more than one epoxy group per molecule; up to 25 wt.-%, based on component K1, of at least one epoxy-functional reactive diluent RD having one or two epoxy groups per molecule; and a hardener component K2 comprising: between 40 and 80 wt.-%, based on component K2, of at least one amino-functional hardener B of formula (I), ##STR00008## wherein n is an integer with a value of 2 or 3, R.sup.1 is a linear, cyclic or branched alkyl residue that optionally contains ether oxygen atoms and R.sup.2 is a methyl or ethyl group; between 10 and 30 wt.-%, based on component K2, of at least one Lewis base LB having at least one tertiary amino group, amidine group, or guanidine group; and between 10 and 30 wt.-%, based on component K2, of at least one carboxylic acid AC.

2. The two-component epoxy resin composition according to claim 1, wherein the residue R.sup.1 is an oligomer or polymer containing oxypropylene repeating units.

3. The two-component epoxy resin composition according to claim 1, wherein the hardener B has an amine hydrogen equivalent weight of between 50 and 100 g/eq.

4. The two-component epoxy resin composition according to claim 1, wherein the Lewis base LB is selected from the group consisting of tris-2,4-6-dimethylaminomethyl phenol, 1,1,3,3-tetramethylguanidine, and 1,8-diazabicyclo[5.4.0]undec-7-ene.

5. The two-component epoxy resin composition according to claim 1, wherein carboxylic acid AC is a linear or branched C2 to C18 monocarboxylic acid.

6. The two-component epoxy resin composition according to claim 1, wherein epoxy resin A comprises liquid bisphenol A digylcidyl ethers and optionally liquid bisphenol F diglycidyl ethers with a viscosity at 25° C., measured according to ASTM D-445, in the range of 8 to 12 Pa.Math.s.

7. The two-component epoxy resin composition according to claim 1, wherein reactive diluent RD comprises linear or branched C12 to C14 monoglycidyl ethers and/or linear or branched C2 to C6 diglycidyl ethers.

8. The two-component epoxy resin composition according to claim 1, wherein the two-component epoxy resin composition contains the reactive diluent RD with an amount of between 10 and 20 wt.-%, based on resin component K1.

9. A process for relining a pipe, comprising the steps: 1) preparing a two-component epoxy resin composition according to claim 1; 2) mixing the two-component epoxy resin composition; 3) impregnating a relining felt material with the mixed epoxy resin composition; 4) applying the epoxy-resin impregnated relining felt material in a cured-in-place pipe rehabilitation (CIPP) process.

10. The process according to claim 9, wherein the relining felt material is a polyester felt, a glass-fiber reinforced polyester felt, or a glass fiber felt.

11. The process according to claim 9, wherein between step 3) and step 4) the impregnated felt material is stored up to at least one week at a storage temperature of between −15° C. and 25° C., before step 4) is applied.

12. The process according to claim 9, wherein step 3) is not performed at the same place than step 4).

13. The process according to claim 9, wherein the mixed epoxy resin material with which the felt material is impregnated is cured during the CIPP process by steam or hot water.

14. A felt material impregnated with a mixed two-component epoxy resin composition according to claim 1.

15. A pipe, relined using the process according to claim 9.

Description

EXAMPLES

[0156] Examples are given below which illustrate the invention further but do not limit the scope of the invention in any way and merely illustrate some of the possible embodiments.) “Room temperature” (RT) refers to a temperature of 23° C. and 50% relative humidity (r.h.).

Test Methods

Viscosity

[0157] Viscosity was measured at 25° C., or the temperature indicated in the respective Table 3, 5, or 7, according to the following table:

TABLE-US-00001 Technical data C1 C2 (Ref.) C3 (Ref.) C4-C12 Component K1 spindle 2, 25 spindle 3, 6 spindle 3, 6 spindle 2, 12 Brookfield LVT rpm rpm rpm rpm Component K2 spindle 1, 60 spindle 1, spindle 1, spindle 1, 60 Brookfield RVT rpm 100 rpm 100 rpm rpm Mixture K1 + K2 spindle 2, 25 spindle 2, 30 spindle 2, 12 spindle 2, 12 LAMY rheometer rpm rpm rpm rpm with Peltier plate (cone/plate)

[0158] The mixture K1+K2 was measured after mixing in the ratio as specified in Tables 2, 4, and 6 at room temperature or the temperature indicated in the respective Table during 1 min.

Gel Time

[0159] Gel time was measured according to DIN 16945, § 6.3, method A, using a gel timer Gelnorm® from Gel Instrumente AG using mixtures of K1+K2 measured after mixing at room temperature during 1 min in the ratio as specified in Table 2. The actual measurements were done at 50° C. and 80° C., respectively.

T.SUB.g .Full Cure Onset/Midpoint

[0160] These data values were obtained using DSC (differential scanning calorimetry) according to ISO 11357-2.

Heat Deflection Temperature

[0161] Heat deflection temperature was measured according to ISO 75-2, method A (1.8 MPa) on fully cured samples after 16 h at 80° C. in a ventilated oven.

Flexural Modulus of Elasticity, Flexural Strength, and Elongation at Flexural Strength

[0162] These values were determined according to ISO 178 on fully cured samples after 16 h at 80° C. in a ventilated oven.

Tensile Modulus, Tensile Strength, and Elongation at Break

[0163] These values were determined according to ISO 527-2 on fully cured samples after 16 h at 80° C. in a ventilated oven.

Fulfillment of ISO 11296-4:2018 Table 2 Requirement

[0164] This requirement stating that the heat reflection temperature needs to be above 70° C. according to ISO 75-2:2013 was evaluated and if the sample fulfilled the requirement, the result was “yes”.

Example Two-Component Epoxy Resin Compositions

[0165] A series of two-component example composition were prepared using the substances listed in Table 1. Tables 2, 4, and 6 show example compositions consisting of components K1 and K2. All amounts are in wt.-% (percent by weight) based on the respective component K1 or K2.

[0166] The individual components K1 and K2 in each experiment were prepared by adding the ingredients in their respective amount to a centrifugal mixer and mixing them homogeneously.

TABLE-US-00002 TABLE 1 Employed chemicals and ingredients. Trade name Abbreviation Description (supplier) BPADGE1 Liquid bisphenol A diglycidyl ether (EEW: 176- D.E.R. ®330 185 g/eq (ASTM D-1652); Viscosity (25° C.): 7.0- (Olin) 10.0 Pa .Math. s (ASTM D-445)) (epoxy resin A) BPADGE2 Liquid bisphenol A diglycidyl ether (EEW: 182- D.E.R. ®331 192 g/eq (ASTM D-1652); Viscosity (25° C.): (Olin) 11.0-14.0 Pa .Math. s (ASTM D-445)) (epoxy resin A) BPFDGE Liquid bisphenol F diglycidyl ether (EEW: 167- D.E.R. ®354 174 g/eq (ASTM D-1652); Viscosity (25° C.): 3.4- (Olin) 4.2 Pa .Math. s (ASTM D-445)) (epoxy resin A) Araldite DY-D Diglycidylether of butanediol (epoxy-functional Araldite ® DY-D reactive diluent RD) (Huntsman) Ancamine K54 2, 4, 6-tris(dimethylaminomethyl) phenol (Lewis Ancamine ® K54 base LB) (Evonik) Jeffamine T- Trifunctional polyether amine having primary Jeffamine ® T-403 403 amino groups (n = 3, R.sup.1 = poly(oxypropylene), (Huntsman) R.sup.2 = methyl) (amino-functional hardener B) Jeffamine D- Difunctional polyether amine having primary Jeffamine ® D- 205 amino groups (n = 2, R.sup.1 = poly(oxypropylene), 205 (Huntsman) R.sup.2 = ethyl) (amino-functional hardener B) EHA 2-Ethyl hexanoic acid (carboxylic acid AC) (Sigma Aldrich) VAA n-Valeric acid (carboxylic acid AC) (Sigma Aldrich) MBA 2-Methylbutyric acid (carboxylic acid AC) (Sigma Aldrich) INA Isononanoic acid (carboxylic acid AC) (Sigma Aldrich) OLA Oleic acid (carboxylic acid AC) (Sigma Aldrich)

[0167] For testing, either the individual components K1 and K2 were tested directly (viscosity) or a homogenous mixture of each respective component K1 and K2 in each example two-component composition was prepared using a stirrer and the respective testing protocol (see above) was employed.

[0168] Test data is shown for each composition in Tables 3, 5, and 7.

TABLE-US-00003 TABLE 2 Details of compositions C1 to C3. C1 C2 (Ref.) C3 (Ref.) Component K1 BPADGE1 81.5 — — BPADGE2 — 100.0 70.0 BPFDGE 5.0 — 30.0 Araldite DY-D 14.0 — — TOTAL 100 100 100 Component K2 Ancamine K54 20.0 — — Jeffamine T-403 — — 100.0 Jeffamine D-205 60.0 100.0 — EHA 20.0 — — TOTAL 100 100 100 Mixing ratio (K1:K2) (weight/weight) 100:10 100:30 100:46 Index (amine/epoxy) n/a 0.98 1.06

TABLE-US-00004 TABLE 3 Test data of compositions C1 to C3. * viscosity increased and reached gel point within the test procedure time. Test data C1 C2 (Ref.) C3 (Ref.) Viscosity component K1 (mPa .Math. s) 1300 13000 8500 Viscosity component K2 (mPa .Math. s) 90 29 118 Mix viscosity (K1 + K2) initially at 850 500 1200 23° C.(mPa .Math. s) Mix viscosity (K1 + K2) after 1 day 200 Gelled after Gelled after at 23° C. (Pa .Math. s) 15 h * 10 h* Mix viscosity (K1 + K2) after 7 days 90 Gelled after 6 Gelled after 4 at 5° C. (Pa .Math. s) days * days * Gel time at 50° C. (h) 4.2 4.1 2.8 Gel time at 80° C. (min) 33 38 21 T.sub.g full cure onset/midpoint (° C.) 92/94 82/85 84/86 Heat deflection temperature (° C.) 84 80 78 Fulfillment of ISO 11296-4:2018 Yes Yes Yes table 2 requirement Flexural modulus of elasticity 3000 3000 3200 (MPa) Flexural strength (MPa) 112 110 106 Elongation at flexural strength (%) 6.7 6.1 n/m Tensile modulus (MPa) 3300 3400 3800 Tensile strength (MPa) 57 69 64 Elongation at break (%) 3.8 7.9 8.5

TABLE-US-00005 TABLE 4 Details of compositions C4 to C8. C4 C5 C6 C7 C8 Component K1 BPADGE1 81.5 81.5 81.5 81.5 81.5 BPFDGE 5.0 5.0 5.0 5.0 5.0 Araldite DY-D 14.0 14.0 14.0 14.0 14.0 TOTAL 100 100 100 100 100 Component K2 Ancamine K54 18.2 19.8 19.8 17.9 14.6 Jeffamine D-205 54.5 59.4 59.4 53.6 43.8 EHA 27.3 — — — — VAA — 20.8 — — — MBA — — 20.8 — — INA — — — 28.6 — OLA — — — — 41.6 TOTAL 100 100 100 100 100 Mixing ratio (K1:K2) (weight/weight) 100:11 100:10.1 100:10.1 100:11.2 11:13.7

TABLE-US-00006 TABLE 5 Test data of compositions 04 to C8. “n/m” means “not measured”. Test data C4 C5 C6 C7 C8 Viscosity component K1 (mPa .Math. s) 1300 1300 1300 1300 1300 Viscosity component K2 (mPa .Math. s) 200 n/m n/m 200 147 Mix viscosity (23° C.) (K1 + K2) 1.0 1.1 1.1 1.0 1.2 initially at 23° C. (Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 130 146 142 104 60 1 day at 23° C. (Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 1600 700 850 1000 150 2 days at 23° C. (Pa .Math. s) Mix viscosity (50° C.) (K1 + K2) 6 n/m n/m 6 3 after 1 day at 23° C. (Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 35 33 29 30 38 7 days at 5° C. (Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 350 400 380 350 190 10 days at 5° C. (Pa .Math. s) Gel time at 80° C. (min) 35 33 29 30 38 T.sub.g full cure onset/midpoint (° C.) 88/92 n/m n/m 88/93 79/88 Heat deflection temperature (° C.) 82 n/m n/m 86 78 Fulfillment of ISO 11296-4:2018 Yes n/m n/m Yes Yes table 2 requirement Flexural modulus of elasticity 2925 n/m n/m 2775 2700 (MPa) Flexural strength (MPa) 110 n/m n/m 114 105
The data in Table 5 shows that various acids are suitable as carboxylic acid AC. The compositions in Table 4 were formulated and mixed such that an Index (molar ratio) carboxylic acid groups/tertiary amino groups of about 0.9 resulted in each composition. The shown compositions C4 to C8 are all highly suitable for CIPP processes. The initial mix viscosity was in every case low enough that a liner material can be easily impregnated. Furthermore, the mix viscosity after 1 day was high enough to render the impregnated felt sag-resistant in a CIPP application and finally, the gel time was in each experiment short enough for a fast curing process.

Influence of Amino-Functional Hardener B

[0169] A series of experiments C9 to C12 was performed to demonstrate the effect of hardener B according to formula (I), and additionally, the ratio of acid groups of acid AC to tertiary amino groups of Lewis base LB.

[0170] The compositions and test results are shown in Tables 6 and 7.

TABLE-US-00007 TABLE 6 Details of compositions C9 to C12. C9 (Ref.) C10 C11 (Ref.) C12 Component K1 BPADGE1 81.5 81.5 81.5 81.5 BPFDGE 5.0 5.0 5.0 5.0 Araldite DY-D 14.0 14.0 14.0 14.0 TOTAL 100 100 100 100 Component K2 Ancamine K54 50.0 20.0 40.0 18.2 Jeffamine D-205 — 60.0 — 54.5 EHA 50.0 20.0 60.0 27.3 TOTAL 100 100 100 100 Acid: Tertiary amine 0.63 0.63 0.9 0.9 (mol/mol) Mixing ratio (K1:K2) (weight/weight) 100:4 100:10 100:5 100:11

TABLE-US-00008 TABLE 7 Test data of compositions 09 to C12. C9 C11 Test data (Ref.) C10 (Ref.) C12 Viscosity component K1 (mPa .Math. s) 1500 1500 1500 1500 Viscosity component K2 (mPa .Math. s) 600 100 630 200 Mix viscosity (23° C.) (K1+ K2) 1300 900 1200 1000 initially at 23° C. (mPa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 14 200 14 130 1 day at23° C.(Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after >2000 >2000 1350 1100 2 days at 23° C. (Pa .Math. s) Mix viscosity (50° C.) (K1 + K2) after 1 13 1 6 1 day at 23° C.(Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 5 90 4 80 7 days at 5° C. (Pa .Math. s) Mix viscosity (23° C.) (K1 + K2) after 35 800 8 350 10 days at 5° C.(Pa .Math. s) Gel time at 80° C. (min) 60 33 58 35 T.sub.g full cure onset/midpoint (° C.) 79/88 88/93 73/82 88/92 Heat deflection temperature (° C.) 81 85 76 82 Fulfillment of ISO 11296-4:2018 Yes Yes Yes Yes table 2 requirement Flexural modulus of elasticity 2970 2780 3070 2925 (MPa) Flexural strength (MPa) 117 117 118 110

[0171] Table 7 shows that the addition of relatively small amounts of hardener B (in every experiment 6 weight parts per 100 weight parts resin component) in connection with the Lewis salt obtained from acid AC and Lewis base LB, already leads to an improvement of the processability of the composition and thus suitability for CIPP applications. First, the initial viscosity of the mix is at least 30% lower in the composition containing hardener B, which makes impregnation of a felt material easier. Second, the mix viscosity after 1 day at room temperature is significantly higher, with the effect that sagging is avoided when the felt is inserted in a tube during the CIPP process. Third, the gel time is significantly shorter in the inventive examples, thus accelerating the curing step in a CIPP application. Lastly, the mix viscosity of the mixed compositions according to the present invention after 10 days storage at 5° C. is still conform with the CIPP inversion process according to ASTM F1216.