POLYMER COMPOSITION WHICH CAN BE CURED AT ROOM TEMPERATURE AND WHICH IS MADE OF POLYALDEHYDE AND 1,3 KETO ESTER

Abstract

A curable composition includesa first component containing aldehyde group-containing compounds which include at least one compound with two or more aldehyde groups anda second component containing 1,3 keto ester group-containing compounds which include at least one compound with two or more 1,3 keto ester groups of the formula (I), wherein the average molecular weight M.sub.n of at least one of the two components, with respect to the aldehyde or 1,3 keto ester group-containing compounds, ranges from 400 to 20,000 g/mol. The composition is largely free of toxic ingredients and cures in ambient conditions using conventional catalysts quickly in order to form a non-tacky elastic polymer with a high degree of strength and elasticity. The composition is particularly suitable for use as an elastic adhesive, sealant, or coating with a high degree of robustness during production, storage, and processing as well as a high degree of resistance after curing.

Claims

1. A curable composition comprising a first component containing compounds containing aldehyde groups, comprising at least one compound having two or more aldehyde groups, and a second component containing compounds containing 1,3-ketoester groups, comprising at least one compound having two or more 1,3-ketoester groups of the formula (I) ##STR00006## where R.sup.1 is a monovalent hydrocarbyl radical having 1 to 6 carbon atoms, where the average molecular weight M.sub.n of at least one of the two components in relation to the compounds containing aldehyde or 1,3-ketoester groups is in the range from 400 to 20000 g/mol.

2. The composition as claimed in claim 1, wherein less than 10% by weight, of water is present, based on the overall composition.

3. The composition as claimed in claim 1, wherein the compound having two or more aldehyde groups is liquid at room temperature, with cone diameter 10 mm, cone angle 1, cone tip-plate distance 0.05 mm, shear rate 10 s.sup.1, and with ball diameter 50 mm for viscosities of less than 1 Pa.Math.s.

4. The composition as claimed in claim 1, wherein the average molecular weight M.sub.n of the first component in relation to the compounds containing aldehyde groups is in the range from 1000 to 20000 g/mol, measured by gel permeation chromatography (GPC) versus polystyrene as standard.

5. The composition as claimed in claim 1, wherein the compounds containing aldehyde groups comprise a polymer having a polymer backbone containing poly(oxyalkylene) units and/or polyester units.

6. The composition as claimed in claim 1, wherein the compounds containing aldehyde groups comprise a polymer containing urethane groups which is liquid at room temperature and has an average molecular weight M.sub.n of 1000 to 20000 g/mol, and an average aldehyde functionality of 1.8 to 3.5

7. The composition as claimed in claim 1, wherein, in the 1,3-ketoester groups of the formula (I), R.sup.1 is methyl, ethyl, propyl, isopropyl, butyl or phenyl.

8. The composition as claimed in claim 1, wherein the average functionality of the second component in relation to the compounds containing 1,3-ketoester groups is in the range from 1.6 to 4.

9. The composition as claimed in claim 1, wherein the average molecular weight M.sub.n of the second component in relation to the compounds containing 1,3-ketoester groups is in the range from 230 to 10000 g/mol.

10. The composition as claimed in claim 1, wherein, based on the overall composition, 10% to 95% by weight, of fillers is present.

11. The composition as claimed in claim 1, wherein, based on the overall composition, 5% to 80% by weight, of plasticizers is present.

12. The composition as claimed in claim 1, wherein less than 10% by weight, of volatile organic solvents having a boiling point at standard pressure of less than 250 C. is present, based on the overall composition.

13. A cured composition obtained from the curable composition as claimed in claim 1 after the two components have been mixed, wherein the cured composition has a tensile strength of at least 1 MPa, and/or an elongation at break of at least 75%, determined to DIN EN 53504 at a strain rate of 200 mm/min on dumbbell-shaped test specimens having a thickness of 2 mm and a length of 75 mm with a bar length of 30 mm and a bar width of 4 mm.

14. A method comprising applying the composition as claimed in claim 1 as elastic adhesive, elastic sealant or elastic coating, wherein the first and second and any further components present are mixed with one another, and the mixed composition is applied in the liquid state to at least one substrate.

15. The method as claimed in claim 14, wherein the cured composition has a layer thickness of at least 1 mm.

Description

EXAMPLES

[0150] Working examples are adduced hereinafter, which are intended to further elucidate the invention described. It will be apparent that the invention is not limited to these described working examples.

[0151] Standard climatic conditions (SCC) refers to a temperature of 231 C. and a relative air humidity of 505%.

[0152] The chemicals used were from Sigma-Aldrich Chemie GmbH, unless stated otherwise.

Description of the Measurement Methods:

[0153] Viscosity was measured on a thermostated Rheotec RC30 cone-plate viscometer (cone diameter 10 mm, cone angle 1, cone tip-plate distance 0.05 mm, shear rate 10 s.sup.1). Viscosities of less than 1 Pa.Math.s were measured with a cone diameter of 50 mm.

[0154] Infrared spectra (FT-IR) were measured as undiluted films on a Nicolet iS5 FT-IR instrument from Thermo Scientific equipped with a horizontal ATR measurement unit with a diamond crystal. Absorption bands are reported in wavenumbers (cm.sup.1).

Preparation of Polymers Containing Isocyanate Groups:

Polymer P-1:

[0155] 780 g of ethylene oxide-terminated polyoxypropylene triol (Desmophen 5031 BT, OH number 28.0 mg KOH/g, OH functionality about 2.3, from Covestro) and 303 g of isophorone diisocyanate (Vestanat IPDI, from Evonik) were converted at 80 C. by a known method to a reaction mixture having an NCO content of 9.1% by weight. Subsequently, the volatile constituents, in particular unconverted isophorone diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 160 C., pressure 0.1 to 0.005 mbar) to obtain a polymer having an NCO content of 1.84% by weight and a monomeric isophorone diisocyanate content of 0.02% by weight.

Polymer P-2:

[0156] 590 g of polyoxypropylene diol (Acclaim 4200, OH number 28 mg KOH/g, from Covestro), 1180 g of ethylene oxide-terminated polyoxypropylene triol (Caradol MD34-02, OH number 35 mg KOH/g, from Shell) and 230 g of isophorone diisocyanate (Vestanat IPDI, from Evonik) were converted at 80 C. by a known method to a polymer having an NCO content of 2.1% by weight.

Polymer P-3:

[0157] 818 g of polyoxypropylene diol (Acclaim 4200, OH number 28.5 mg KOH/g, from Covestro) and 227 g of isophorone diisocyanate (Vestanat IPDI, from Evonik) were converted at 80 C. by a known method to a reaction mixture having an NCO content of 6.6% by weight. Subsequently, the volatile constituents, in particular unconverted isophorone diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 160 C., pressure 0.1 to 0.005 mbar) to obtain a polymer having an NCO content of 1.91% by weight and a monomeric isophorone diisocyanate content of 0.03% by weight.

Polymer P-4:

[0158] 727.0 g of polyoxypropylene diol (Acclaim 4200, OH number 28 mg KOH/g, from Covestro) and 273.0 g of diphenylmethane 4,4-diisocyanate (Desmodur 44 MC L, from Covestro) were converted at 80 C. by a known method to a reaction mixture having an NCO content of 7.6% by weight. Subsequently, the volatile constituents, in particular unconverted diphenylmethane 4,4-diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 180 C., pressure 0.1 to 0.005 mbar, condensation temperature 47 C.) to obtain a polymer having an NCO content of 1.7% by weight and a monomeric diphenylmethane 4,4-diisocyanate content of 0.08% by weight.

Polymer P-5:

[0159] 513.3 g of polyoxypropylene diol (Acclaim 4200, OH number 28 mg KOH/g, from Covestro), 256.7 g of ethylene oxide-terminated polyoxypropylene triol (Caradol) MD34-02, OH number 35 mg KOH/g, from Shell) and 64.2 g of toluene diisocyanate (Desmodur T 80 P, from Covestro) were converted at 80 C. by a known method to a polymer having an NCO content of 1.5% by weight.

Polymer P-6:

[0160] 600 g of polyoxypropylene diol (Voranol 1010 L, OH number 112 mg KOH/g, from Dow) and 533.3 g of isophorone diisocyanate (Vestanat IPDI, from Evonik) were converted at 80 C. by a known method to a reaction mixture having an NCO content of 15.6% by weight. Subsequently, the volatile constituents, in particular unconverted isophorone diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 160 C., pressure 0.1 to 0.005 mbar) to obtain a polymer having an NCO content of 5.18% by weight and a monomeric isophorone diisocyanate content of 0.03% by weight.

Preparation of Compounds Having Two or More Aldehyde Groups:

Compounds D-1 to D-7:

[0161] For each of the compounds, the amounts specified in table 1 (in parts by weight) of the corresponding polymer containing isocyanate groups were reacted, in the presence of 0.02% by weight of dibutyltin dilaurate, with exclusion of moisture at 110 C., with the specified amount (in parts by weight) of the corresponding hydroxy-functional aldehyde until no isocyanate groups were detectable any longer by IR spectroscopy. In the case of the polymers having aromatic isocyanate groups P-4 and P-5, reaction was effected without dibutyltin dilaurate and at 80 C. What was obtained in each case was a clear colorless liquid.

[0162] The properties of compounds D-1 to D-7 are reported in table 1.

TABLE-US-00001 TABLE 1 Preparation and properties of compounds D-1 to D-7. Compound D-1 D-2 D-3 D-4 D-5 D-6 D-7 Polymer P-1 500.0 500.0 Polymer P-2 500.0 Polymer P-3 500.0 Polymer P-4 500.0 Polymer P-5 500.0 Polymer P-6 500.0 5-Hydroxymethylfurfural 27.7 31.5 28.9 25.5 23.8 77.8 2-(2-Hydroxyethoxy)- 37.4 benzaldehyde Viscosity (20 C.) [Pa .Math. s] 63.7 138.3 111.7 33.2 146.4 138.4 438.0 Average aldehyde 2.3 2.3 >2 2.0 2.0 >2 2.0 functionality Equivalent weight [g/eq] 2381 2381 2128 2326 2604 2857 937

[0163] The average molecular weight M.sub.n of compound D-1 was additionally determined by gel permeation chromatography (GPC) versus polystyrene (474 to 2520000 g/mol) as standard with tetrahydrofuran as mobile phase and refractive index detector. The average molecular weight M.sub.n was 6100 g/mol.

Preparation of Compounds Having Two or More 1,3-Ketoester Groups:

Compounds B-1 to B-5:

[0164] For each of the compounds, the amount specified in table 2 (in parts by weight) of the particular polyfunctional alcohol was admixed with the specified amount (in parts by weight) of the appropriate 1,3-ketoester and 0.1% by weight of tetra-n-butyl titanate (Tyzor TnBT, from Dorf Ketal), and the mixture was converted at a temperature of 140 C. under reduced pressure and with removal of the volatile constituents. What was obtained in each case was a clear colorless liquid.

TABLE-US-00002 TABLE 2 Preparation and properties of compounds B-1 to B-5. Compound B-1 B-2 B-3 B-4 B-5 PPG triol 300 .sup.1 50.0 51.0 50.0 1,4-butanediol 20.0 Polyester 1000 .sup.2 50.0 Ethyl acetoacetate 67.0 60.7 14.0 Ethyl benzoylacetate 105.7 Ethyl 3-oxohexanoate 87.0 Viscosity (20 C.) [Pa .Math. s] 0.8 <0.1 13.8 42.5 0.14 Average acetoacetate 3 2 2 3 3 functionality Equivalent weight [g/eq] 186 129 572 248 214.6 .sup.1 trimethylolpropane-started polyoxypropylene triol (Desmophen 4011 T, OH number 550 mg KOH/g, from Covestro) .sup.2 amorphous, dimer fatty acid-based polyester diol (Priplast 1837, OH number 115 mg KOH/g, from Croda)

Production of Curable Compositions:

Examples E-1 to E-29

[0165] For each example, the ingredients of the first component (K1) that are specified in tables 3 to 7 were mixed with one another in the specified amounts (in parts by weight) using a centrifugal mixer (SpeedMixer DAC 150, FlackTek Inc.) and stored in a closed container.

[0166] The ingredients of the second component (K2) that are specified in tables 3 to 7 were likewise processed and stored.

[0167] The precipitated CaCO.sub.3 used was Socal U1S2 (from Imerys), a precipitated and stearate-coated calcium carbonate.

[0168] The carbon black used was Monarch 570 (from Cabot).

[0169] Subsequently, the two components of each composition were then processed using the centrifugal mixer to give a homogeneous paste, which was tested as described below.

[0170] Gel time was determined by stirring a freshly mixed amount of about 3 g under standard climatic conditions with a spatula at regular intervals until this was no longer possible as a result of gelation of the mass.

[0171] Mechanical properties were determined by applying the mixed composition to a silicone-coated release paper to give a film of thickness 2 mm, leaving the film to cure under standard climatic conditions for 7 days, punching a few dumbbell-shaped test specimens having a length of 75 mm with a bar length of 30 mm and a bar width of 4 mm out of the film and testing these in accordance with DIN EN 53504 at a strain rate of 200 mm/min for Tensile strength, Elongation at break, and modulus of elasticity MoE 5% (at 0.5%-5% elongation) and MoE 50% (at 0.5%-50% elongation). Furthermore, a number of test specimens were punched out for determination of Tear propagation resistance and were tested in accordance with DIN ISO 34-1, Method B (angular test specimens) at a strain rate of 500 mm/min.

[0172] Shore A hardness was determined to DIN 53505 on test specimens cured under standard climatic conditions for 7 days. These results are given the addition 7 d SCC. Resistance to heat and water was determined by storing further Shore A test specimens, after curing under standard climatic conditions for 7 days, either additionally in an air circulation oven at 100 C. for 7 days or additionally at 70 C. and 100% relative humidity for 7 days, cooling them down to room temperature and then determining Shore A hardness as described in each case. These results are given the addition +7 d 100 C. or +7 d 70/100.

[0173] The curing of the inventive examples in each case gave a nontacky, elastic material.

[0174] The results are reported in tables 3 to 7.

TABLE-US-00003 TABLE 3 Composition and properties of E-1 to E-7. Example E-1 E-2 E-3 E-4 E-5 E-6 E-7 Component K1: Compound D-1 30.0 30.0 30.0 30.0 30.0 30.0 30.0 Diisodecyl phthalate 20.0 20.0 20.0 20.0 20.0 20.0 20.0 Precipitated 30.0 30.0 30.0 30.0 30.0 30.0 30.0 CaCO.sub.3 Carbon black 10.0 10.0 10.0 10.0 10.0 10.0 10.0 DBU .sup.1 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Component K2: Compound B-1 2.26 2.71 3.16 3.38 3.62 4.07 4.52 Acac/Ald ratio.sup.2 1.0 1.2 1.3 1.4 1.5 1.7 1.9 Gel time [min] 15 15 15 15 15 15 15 Tensile strength [MPa] 2.4 2.8 2.8 3.3 3.3 3.2 3.2 Elongation at break [%] 208 187 154 155 157 134 122 MoE 5% [MPa] 1.9 2.6 3.4 3.9 3.9 4.6 5.15 MoE 50% [MPa] 1.15 1.5 1.8 2.25 2.2 2.5 2.8 Shore A (7d SCC) 41 49 53 55 54 58 61 (+ 7 d 100 C.) 63 62 63 n.d. 59 59 62 (+ 7 d 70/100) 42 48 52 n.d. 53 55 50 .sup.1 1,8-diazabicyclo[5.4.0]undec-7-ene (Lupragen.sup. N700, from BASF) .sup.2ratio of the number of acetoacetate groups to aldehyde groups

TABLE-US-00004 TABLE 4 Composition and properties of E-4 and E-8 to E-13. Example E-4 E-8 E-9 E-10 E-11 E-12 E-13 HC-112 Component K1: Compound D-1 D-2 D-3 D-4 D-5 D-6 D-7 30.0 30.0 30.0 30.0 30.0 30.0 30.0 Diisodecyl phthalate 20.0 20.0 20.0 20.0 20.0 20.0 20.0 Precipitated CaCO.sub.3 30.0 30.0 30.0 30.0 30.0 30.0 30.0 Carbon black 10.0 10.0 10.0 10.0 10.0 10.0 10.0 DBU .sup.1 0.3 0.6 0.3 0.3 0.3 0.3 0.3 Component K2: Compound B-1 3.38 3.38 3.83 3.51 3.13 2.85 8.72 Acac/Ald ratio.sup.2 1.4 1.4 1.5 1.5 1.5 1.5 1.5 Gel time [min] 15 40 n.d. 15 15 n.d. 120 Tensile strength [MPa] 3.3 3.8 2.7 2.0 2.2 2.0 2.4 Elongation at break [%] 155 164 128 120 166 137 70 MoE 5% [MPa] 3.9 5.0 4.6 3.3 2.1 2.3 4.2 MoE 50% [MPa] 2.25 2.4 2.6 2.1 1.8 1.9 3.5 Tear resistance [N/mm] 3.8 n.d. n.d. 3.7 n.d. n.d. 3.6 Shore A (7d SCC) 55 59 59 51 46 47 58 (+ 7 d 100 C.) n.d. n.d. 73 n.d. 60 58 77 (+ 7 d 70/100) n.d. n.d. 55 n.d. 42 43 47 n.d. stands for not determined .sup.1 1,8-diazabicyclo[5.4.0]undec-7-ene (Lupragen.sup. N700, from BASF) .sup.2ratio of the number of acetoacetate groups to aldehyde groups

TABLE-US-00005 TABLE 5 Composition and properties of E-14 to E-21. Example E-14 E-15 E-16 E-17 E-18 E-19 E-20 E-21 Component K1: Compound D-1 30.0 30.0 30.0 30.0 Compound D-4 30.0 30.0 30.0 30.0 Diisodecyl phthalate 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 Precipitated 30.0 30.0 30.0 30.0 30.0 30.0 30.0 30.0 CaCO.sub.3 Carbon black 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 DBU .sup.1 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Component K2: Compound B-2 1.64 2.46 3.28 4.10 1.68 2.52 3.36 4.20 Acac/Ald ratio.sup.2 1 1.5 2 2.5 1 1.5 2 2.5 Gel time [min] 20 25 50 110 >150 >150 >150 >150 Tensile strength [MPa] 3.0 3.9 3.7 4.1 1.5 4.1 4.4 5.0 Elongation at break [%] 317 203 176 245 341 323 304 433 MoE 5% [MPa] 1.7 4.0 4.9 3.8 1.3 2.9 3.6 3.0 MoE 50% [MPa] 1.2 2.5 2.9 2.3 0.7 1.85 2.1 1.7 Tear resistance [N/mm] 5.8 5.4 5.6 7.7 4.7 7.3 8.1 9.9 Shore A (7d SCC) 40 57 63 55 28 53 55 52 (+ 7 d 100 C.) 66 66 67 60 53 63 58 47 (+ 7 d 70/100) 52 46 33 17 39 44 25 10 .sup.1 1,8-diazabicyclo[5.4.0]undec-7-ene (Lupragen.sup. N700, from BASF) .sup.2ratio of the number of acetoacetate groups to aldehyde groups

TABLE-US-00006 TABLE 6 Composition and properties of E-4, E-15 and E-22 to E-25. Example E-4 E-15 E-22 E-23 E-24 E-25 Component K1: Compound D-1 30.0 30.0 30.0 30.0 30.0 30.0 Diisodecyl phthalate 20.0 20.0 20.0 20.0 20.0 20.0 Precipitated 30.0 30.0 30.0 30.0 30.0 30.0 CaCO.sub.3 Carbon black 10.0 10.0 10.0 10.0 10.0 10.0 DBU .sup.1 0.3 0.3 0.3 0.3 0.3 0.3 Component K2: Compound B-1 3.38 1.69 Compound B-2 2.46 Compound B-3 8.09 10.09 12.14 5.05 Acac/Ald ratio.sup.2 1.4 1.5 1.1 1.4 1.7 1.4 Gel time [min] 15 25 n.d. 30 n.d. n.d. Tensile strength [MPa] 3.3 3.9 3.7 4.9 5.3 3.6 Elongation at break [%] 155 203 513 467 519 276 MoE 5% [MPa] 3.9 4.0 1.6 2.4 2.4 3.3 MoE 50% [MPa] 2.25 2.5 0.8 1.2 1.2 1.7 Tear resistance [N/mm] n.d. 5.4 10.4 n.d. 8.2 n.d. Shore A (7d SCC) 55 57 35 45 47 51 (+ 7 d 100 C.) n.d. 66 58 57 52 66 (+ 7 d 70/100) n.d. 46 37 36 34 45 n.d. stands for not determined .sup.1 1,8-diazabicyclo[5.4.0]undec-7-ene (Lupragen.sup. N700, from BASF) .sup.2ratio of the number of acetoacetate groups to aldehyde groups

TABLE-US-00007 TABLE 7 Composition and properties of E-26 to E-29. Example E-26 E-27 E-28 E-29 Component K1: Compound D-1 30.0 30.0 30.0 30.0 Diisodecyl phthalate 20.0 20.0 20.0 20.0 Precipitated CaCO.sub.3 30.0 30.0 30.0 30.0 Carbon black 10.0 10.0 10.0 10.0 DBU .sup.1 0.6 0.6 0.6 0.6 Component K2: Compound B-4 3.13 4.69 6.25 Compound B-5 4.06 1,3-KE/Ald ratio.sup.2 1 1.5 2 1.5 Gel time [min] >300 >300 >300 20 Tensile strength [MPa] 4.7 5.8 5.2 4.6 Elongation at break [%] 492 371 304 203 MoE 5% [MPa] 1.5 2.7 3.2 3.8 MoE 50% [MPa] 0.8 1.3 1.6 2.2 Tear resistance [N/mm] 10.6 8.3 6.1 4.2 Shore A (7 d SCC) 39 48 50 57 (+7 d 100 C.) 50 43 40 48 (+7 d 70/100) 25 23 14 38 .sup.1 1,8-diazabicyclo[5.4.0]undec-7-ene (Lupragen N700, from BASF) .sup.2ratio of the number of 1,3-ketoester groups to aldehyde groups