EPOXY RESINS FOR USE IN SHAPED BODIES

Abstract

A shaped body comprising at least one solid material and a cured epoxy resin wherein the cured epoxy resin is prepared from an epoxy resin composition containing at least one epoxy resin having at least one epoxy group per molecule; at least one curing agent selected from cyanoalkylated polyamines of formula (A) A(NHXCN), wherein A is a group selected from aryl, arylalkyl, alkyl, and cycloalkyl, wherein A does not contain a primary amino group, X is alkylene having 1 to 10 C-atoms, and n2; and at least one accelerator selected from tertiary amines, imidazoles, guanidines, urea compounds, and Lewis acids.

Claims

1. A shaped body comprising at least one solid material and a cured epoxy resin wherein the cured epoxy resin is prepared from an epoxy resin composition comprising: at least one epoxy resin having at least one epoxy group per molecule; at least one accelerator selected from the group consisting of tertiary amines, imidazoles, guanidines, urea compounds, and Lewis acids; and at least one curing agent selected from the group consisting of cyanoalkylated polyamines of formula (A)
A(NHXCN).sub.n (A), wherein A is aryl, arylalkyl, alkyl, or cycloalkyl, wherein A does not comprise a primary amino group, X is alkylene having 1 to 10 C-atoms, and n2.

2. The shaped body according to claim 1 wherein the shaped body comprises 0.1 to 20 Vol.-% cured epoxy resin and 80 to 99.9 Vol.-% solid material, based on the total volume of the cured epoxy resin and the solid material.

3. The shaped body according to claim 1 wherein the shaped body has a porosity of 20 to 80% based on the total volume of the shaped body.

4. The shaped body according to claim 1, wherein the solid material is a metal or a metal compound.

5. The shaped body according to claim 1, wherein the solid material is a magnetocaloric material.

6. The shaped body according to claim 1, wherein the at least one accelerator is at least one selected from the group consisting of tertiary amines, imidazoles, guanidines, and urea compounds.

7. The shaped body according to claim 1, wherein the epoxy resin composition comprises 1 to 30 wt.-% of the at least one accelerator based on the total weight of the at least one cyanoalkylated polyamine of formula (A).

8. A process for preparing the shaped body according to claim 1, the process comprising: coating solid material particles at least partially with an epoxy resin composition, thereby obtaining coated particles; transferring the coated particles into a mold; and curing the epoxy resin, wherein the epoxy resin composition comprises: at least one epoxy resin having at least one epoxy group per molecule; at least one accelerator selected from the group consisting of tertiary amines, imidazoles, guanidines, urea compounds, and Lewis acids; and at least one curing agent selected from the group consisting of cyanoalkylated polyamines of formula (A)
A(NHXCN).sub.n (A), wherein A is aryl, arylalkyl, alkyl, or cycloalkyl, wherein A does not comprise a primary amino group, X is alkylene having 1 to 10 C-atoms, and n2.

9. The process according to claim 8 wherein the epoxy resin composition further comprises at least one additive selected from the group consisting of catalysts, curing agents, accelerators, lubricants, reactive diluents, corrosion inhibitors, agents for increasing heat conductivity, adhesion promoters, additional curing agents, and stabilizers.

10. The process according to claim 8, wherein the epoxy resin composition comprises at least one solvent, and wherein the process further comprises removing the at least one solvent after coating the particles with the composition and before transferring the coated particles into the mold.

11. The process according to claim 8, further comprising pretreating the solid material particles before coating the particles with the epoxy resin composition by cleaning the surface of the particles, surface treatment or coating of the particles with an auxiliary material.

12. . The process according to claim 8, wherein transferring the coated particles into a mold comprises placing one or more solid place holder articles into the mold together with the coated particles and after curing the epoxy resin removing the solid place holder particles from the shaped body.

13. (canceled)

14. Coated particles comprising: a core of a solid material which is at least partially coated with an epoxy resin composition, the epoxy resin composition comprising: at least one epoxy resin having at least one epoxy group per molecule; at least one accelerator selected from the group consisting of tertiary amines, imidazoles, guanidines, urea compounds, and Lewis acids; and at least one curing agent selected from the group consisting of cyanoalkylated polyamines of formula (A)
A(NHXCN).sub.n (A), wherein A is aryl, arylalkyl, alkyl, or cycloalkyl, wherein A does not comprise a primary amino group, X is alkylene having 1 to 10 C-atoms, and n2.

15. A cooling device, climate control unit, heat pump, or thermoelectric generator comprising the shaped body according to claim 5.

16. . The process of claim 8, wherein the mold does not contain a supplemental epoxy resin during the curing of the epoxy resin.

17. The shaped body according to claim 1 wherein the shaped body has a porosity of 35 to 65% based on the total volume of the shaped body, and wherein the shaped body comprises 1 to 15 Vol.-% cured epoxy resin and 85 to 99 Vol.-% solid material, based on the total volume of the cured epoxy resin and the solid material.

18. The shaped body according to claim 5, wherein open space between the particles in the shaped body forms a main path suitable for flow of a heat transfer medium.

19. The shaped body according to claim 5, wherein the solid material is a particulate magnetocaloric material having a diameter of from 0.1 m to 1 mm.

Description

EXAMPLES

[0168] A) Compounds Used [0169] Cyanoethylated lsophorondiamine (Addukt of 2-Propenenitril with 3-Amino-1,5,5-trimethylcyclohexanmethanamine; Baxxodur PC136, BASF) [0170] Dyhard UR500 (Mixture of isomers: N,N-(Methyl-1,3-phenylene)bis[N,N-dimethylurea] and N,N-(4-methyl-m-phenylene)bis[N,N-dimethylurea], Alzchem) [0171] Bisphenol-A-based Epoxy resin (Epilox A19-03, LEUNA HARZE, EEW 183 g/eq) [0172] Bisphenol-A-based Epoxy resin (Epilox A50-02, LEUNA HARZE, EEW 495 g/eq) [0173] D.E.N.431 (Epoxy novolac resin EEW 175 g/eq from Dow Chemical) [0174] Epikote 154 (Polyfunctional epoxy phenol novolac resin EEW 180 g/eq from Hexion) [0175] DICY (Dicyanamide from Alzchem, AHEW 12 g/eq) [0176] Polyetheramine D2000 (BASF)

[0177] Triacetonediamin (TAD, BASF) [0178] N-(3-Aminopropyl)imidazol (Lupragen API, BASF) [0179] Magnetocaloric material (Mn,Fe).sub.2(P,As) in form of granulates having an average diameter of about 100-200 m. The granulates were prepared by ball-milling from the elements followed by cold-isostatic pressing and sintering at 1100 C. They were then granulated using a jaw crusher and sieved to the above-mentioned particle size. [0180] Magnetocaloric material (Mn,Fe).sub.2(P,Si) in form of spheres having an average diameter of 70-200 m. The spheres were prepared by gas atomization from the elements or suited compounds of the elements. Subsequently a heat treatment by sintering e.g. at temperatures in the range of 1000 to 1100 C. is carried out followed by cooling to room temperature. The products were sieved prior to use. [0181] Stainless steel spheres having different ranges of average diameter in the region of 70- 200 m. [0182] B) Procedure For Coating the Particles [0183] 1.) A solution of epoxy resin, compound of formula (A), optionally accelerator and/or optional a further additive in a solvent was prepared (adhesive solution). The solutions employed in the examples had a concentration of 9-12 weight % adhesive in acetone based on the weight of the total composition. The compositions of the epoxy resin composition used are summarized in Table 1. [0184] 2.) The adhesive solution was mixed with the magnetocaloric material until evenly distributed. [0185] 3.) The solvent was removed in vacuum.

[0186] The coated particles obtained can be stored at ambient temperatures for several weeks. [0187] C) Preparation of Shaped Bodies [0188] 1.) The precoated material was filled into a mold and compacted with a plunger. [0189] 2.) The material was then hardened under a defined temperature protocol: heating at a rate of 1 K/min to 180 C., hold the temperature for 2 h to yield stable sample bodies which can be conducted to further testing. Curing was conducted in air (normal) or in nitrogen or argon atmosphere.

[0190] The shaped bodies obtained contained 1.0 to 3.2 wt.-% of cured epoxy resin based on the total weight of magnetocaloric material and cured epoxy resin. [0191] D) Test Procedures Applied

Porosity Measurement

[0192] To measure the porosity of the sample pucks a pycnometer has been used. As working liquid, isopropanol has been used assuming a density of 0.789 g/cm3 at room temperature. Cylindrical sample pucks are used for the measurements. First, their height h and diameter d and their dry mass m.sub.s are determined. Then the mass of the pycnometer filled with isopropanol m.sub.p is recorded. Next the sample puck is placed in the pycnometer. Air is removed from open porosity of the sample puck by shaking. The mass of the pycnometer with the sample puck m.sub.p,s immersed in isopropanol is determined.

[0193] The porosity p is calculated by

p=100%[(m.sub.s+m.sub.pm.sub.p,s)/(0.789 g/cm.sup.3*pi*(d/2).sup.2*h)]

Pressure Drop Measurement

[0194] The pressure drop has been determined on a sample puck fixed in a sample holder which can be attached to a flow system. The pressure drop has been determined using a flow of 245 L/h of argon gas. The flow system's background pressure does not contribute significantly to the measurement.

Compression Tests

[0195] Cylindrical sample pucks with a height h=10 mm and a diameter d=16 mm were used for the measurements. Sample pucks were compressed at a rate of 2mm/min with an Instron PM08SK316 (maximum force 100 kN; accuracy class 1 according to ISO 7500-1) at 23 C. and the forces along the compression direction were recorded (force is perpendicular to the surface of the puck). Prior to the measurements, the sample pucks were exposed to a fluid (water with a corrosion inhibitor) and subsequently transferred to the pressure cell. This method delivers force-distances-curves whereat each curve features a maximum force F.sub.max at a certain distance. F.sub.max translates to a maximum pressure which each puck is able to withstand. It is a measure for the stability of a puck provided by the epoxy coating. Between 3 and 6 pucks were prepared for each investigated formulation. Table 1B lists the specifications of the samples (used formulation and experimentally determined porosity (mean values)), Table 2 gives the mean pressure values measured according to the aforementioned methodology. [0196] E) Results

[0197] Samples 1 to 14 were prepared with (Mn,Fe)2(P,As) in form of granulates having diameters in the range of 100-200 m (Table 1A).

[0198] Samples 15 to 27, 30 and 31 were prepared with (Mn,Fe).sub.2(P,Si) in form of spheres having diameters in the ranges of 70-200 m, 100-150 m and 100-200 m (Tables 1B and 2).

[0199] Samples 28 and 29 were prepared with stainless steel spheres having diameters in the ranges of 70-200 m and 100-150 m (Tables 1B and 2).

TABLE-US-00001 TABLE 1A Compositions, pressure drop and porosity of (Mn,Fe).sub.2(P,As) samples Epoxy formulation Curing Pres- Resin Curing agent 1 Curing agent 2 Accelerator solvent environ sure Poros- weight weight weight weight weight ron- drop ity Example Name [g] Name [g] Name [g] Name [g] Name [g] ment [mbar] [%] 1 A19-03 100 Baxxodur 15 UR500 3 Acetone 1062 Normal 20 49.5 (inventive) PC136 2 A19-03 100 Baxxodur 15 UR500 3 Acetone 1062 Nitro- 24 47.4 (inventive) PC136 gen 3 A19-03 100 Baxxodur 15 UR500 3 Acetone 1062 Argon 26 49.7 (inventive) PC136 4 A19-03 100 Baxxodur 30 UR500 3 Acetone 1197 Normal 26 47.3 (inventive) PC136 5 A19-03 100 Baxxodur 14.2 D2000 14.2 UR500 3 Acetone 1182.6 Argon 22 50.2 (inventive) PC136 6 A19-03 100 Baxxodur 14.2 D2000 14.2 UR500 3 Acetone 1182.6 Normal 32 45.1 (inventive) PC136 7 A19-03 100 Baxxodur 14.7 D2000 6.3 UR500 3 Acetone 1116 Normal 28 47.9 (inventive) PC136 8 A19-03 100 Baxxodur 14.9 D2000 1.7 UR500 3 Acetone 1076.4 Argon 28 39.0 (inventive) PC136 9 A19-03 100 Baxxodur 14.9 D2000 1.7 UR500 3 Acetone 1076.4 Normal 32 45.9 (inventive) PC136 10 A19-03 100 Baxxodur 14.3 TAD 1.6 UR500 3 Acetone 1070.1 Normal 30 49.7 (inventive) PC136 11 A19-03 100 Baxxodur 15 API 3 Acetone 1062 Normal 28 40.6 (inventive) PC136 12 A19-03 100 Baxxodur 15 API 3 Acetone 1062 Argon 26 45.0 (inventive) PC136 13 A19-03 100 Baxxodur 12.5 TAD 5.4 UR500 3 Acetone 1088.1 Argon 26 51.3 (inventive) PC136 14 A19-03 100 Baxxodur 12.5 TAD 5.4 UR500 3 Acetone 1088.1 Normal 22 42.5 (inventive) PC136

TABLE-US-00002 TABLE 1B Compositions, pressure drop and porosity of (Mn,Fe).sub.2(P,Si) and stainless steel samples Epoxy formulation Pres- Resin Curing agent 1 Curing agent 2 Accelerator solvent Curing sure Poros- weight weight weight weight weight environ- drop ity Example Name [g] Name [g] Name [g] Name [g] Name [g] ment [mbar] [%] 15 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 46.2 (inventive) PC136 16 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 476 Argon 44.3 (inventive) PC136 17 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 49.6 38.5 (inventive) PC136 18 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 47 38.0 (inventive) PC136 19 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 44 38.4 (inventive) PC136 20 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 59.8 39.1 (inventive) PC136 21 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 51.2 39.3 (inventive) PC136 22 A50-02 100 Baxxodur 10.04 UR500 4 Acetone 1026 Argon 43.4 (inventive) PC136 23 A50-02 100 Baxxodur 7.53 UR500 4 Acetone 1004 Argon 43.3 (inventive) PC136 24 A50-02 100 Baxxodur 6.03 UR500 4 Acetone 990 Argon 43.2 (inventive) PC136 25 A50-02 100 Baxxodur 5.02 UR500 4 Acetone 981 Argon 43.4 (inventive) PC136 26 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 42.5 42.3 (inventive) PC136 27 A50-02 100 Baxxodur 15.07 UR500 4 Acetone 1072 Argon 31.9 42.5 (inventive) PC136 28 D.E.N.431 100 DICY 5 Acetone 945 Argon 39.7 (compar- ative) 29 Epikote 100 DICY 5 Acetone 945 Argon 43.6 (compar- 154 ative)

TABLE-US-00003 TABLE 2 Particle Size Resin/ wt. % Porosity Max. Pressure Solid Material Range Curing agent Epoxy in % in MPa 15 (Mn,Fe).sub.2(P,Si) 100-200 m A50-02/PC136 2 46.2 13.3 16 (Mn,Fe).sub.2(P,Si) 100-200 m A50-02/PC136 2 44.3 15.1 17 (Mn,Fe).sub.2(P,Si) 100-150 m A50-02/PC136 1 38.5 11.2 18 (Mn,Fe).sub.2(P,Si) 100-150 m A50-02/PC136 1.5 38.0 18.2 19 (Mn,Fe).sub.2(P,Si) 100-150 m A50-02/PC136 2 38.4 20.2 20 (Mn,Fe).sub.2(P,Si) 70-200 m A50-02/PC136 3 39.1 24.8 21 (Mn,Fe).sub.2(P,Si) 100-150 m A50-02/PC136 3 39.3 27.3 22 (Mn,Fe).sub.2(P,Si) 100-200 m A50-02/PC136 3 43.4 15.8 23 (Mn,Fe).sub.2(P,Si) 100-200 m A50-02/PC136 3 43.3 14.5 24 (Mn,Fe).sub.2(P,Si) 100-200 m A50-02/PC136 3 43.2 15.2 25 (Mn,Fe).sub.2(P,Si) 100-200 m A50-02/PC136 3 43.4 15.9 26 Stainless Steel 70-200 m A50-02/PC136 3 42.3 26.9 Spheres 27 Stainless Steel 100-150 m A50-02/PC136 3 42.5 26.4 Spheres 28 (Mn,Fe).sub.2(P,Si) 100-200 m D.E.N.431/ 3 39.7 11.7 DICY 29 (Mn,Fe).sub.2(P,Si) 100-200 m Epikote 154/ 3 43.6 11.1 DICY