Two component polyurethane composition

Abstract

The present invention relates to a composition comprising a first component containing at least one polyol, and a second component containing at least one polyisocyanate, the composition further comprising at least one aldimine of formula (I). The composition exhibits a long open time and fast curing without odor immissions, wherein a bubble-free, elastic material having a non-tacky surface and good strength, extensibility, elasticity and resistance is produced, which does not tend to problems arising with plasticizer migration.

Claims

1. A composition comprising (A) a first component comprising at least one polyol, (B) a second component comprising at least one polyisocyanate, and (C) at least one aldimine of the formula (I) ##STR00016## where m is 0 or 1 and n is an integer from 1 to 4, where (m+n) is 2 or 3 or 4, Z is an aryl radical having a total of 12 to 26 carbon atoms and the aryl radical is represented by the formula (II) ##STR00017## where R is a branched alkyl or alkoxy radical having 6 to 20 carbon atoms, and A is an (m+n)-valent aliphatic, cycloaliphatic, or arylaliphatic hydrocarbyl radical optionally containing ether oxygen or amine nitrogen and having an average molecular weight in a range of from 28 to 6,000 g/mol, and X is O or S or NR.sup.0 where R.sup.0 is a hydrogen radical or is a hydrocarbyl radical which has 1 to 30 carbon atoms and optionally at least one selected from the group consisting of carboxylic ester, nitrile, nitro, phosphonic ester, sulfone, sulfonic ester group, and aldimino group of the formula ##STR00018##

2. The composition as claimed in claim 1, wherein the at least one aldimine of the formula (I) is an ingredient of the first component.

3. The composition as claimed in claim 1, wherein m is 0 and n is 2 or 3.

4. The composition as claimed in claim 3, wherein A is either a di- or trivalent aliphatic or cycloaliphatic hydrocarbyl radical having a molecular weight in a range of from 28 to 500 g/mol, or a di- or trivalent polyoxyalkylene radical having an average molecular weight in a range of from 170 to 6,000 g/mol.

5. The composition as claimed in claim 1, wherein m is 1 and n is 1.

6. The composition as claimed in claim 5, wherein A is a divalent aliphatic or cycloaliphatic or arylaliphatic hydrocarbyl radical optionally containing ether oxygen or amine nitrogen and having an average molecular weight in a range of from 28 to 500 g/mol.

7. The composition as claimed in claim 1, wherein the composition comprises a mixture including two or more of the aldimine of the formula (I) and R is selected from the group consisting of linear or branched decyl, undecyl, dodecyl, tridecyl, and tetradecyl radicals.

8. The composition as claimed in claim 1, wherein the at least one polyol has an average molecular weight in a range of from 400 to 10,000 g/mol.

9. The composition as claimed in claim 1, wherein: (a) the at least one polyisocyanate is at least one selected from the group consisting of room temperature liquid types of diphenylmethane 4,4′-diisocyanate, a homolog thereof, diphenylmethane 2,4′-diisocyanate, a homolog thereof, diphenylmethane 2,2′-diisocyanate, and a homolog thereof; or (b) the at least one polyisocyanate is at least one polyurethane polymer containing isocyanate groups and the at least one polyurethane polymer is formed from hexamethylene 1,6-diisocyanate, or 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, or toluene 2,4-diisocyanate, or toluene 2,6-diisocyanate, or a mixture including toluene 2,4-diisocyanate and toluene 2,6-diisocyanate, or diphenylmethane 4,4′-diisocyanate, or diphenylmethane 2,4′-diisocyanate, or diphenylmethane 2,2′-diisocyanate; or (c) the at least one polyisocyanate is an oligomer of hexamethylene 1,6-diisocyanate, or 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, or toluene 2,4-diisocyanate, or toluene 2,6-diisocyanate, or a mixture including toluene 2,4-diisocyanate and toluene 2,6-diisocyanate.

10. The composition as claimed in claim 1, wherein the first component further comprises at least one chain extender in the form of a diol having two primary hydroxyl groups and a molecular weight in a range of from 60 to 150 g/mol.

11. The composition as claimed in claim 1, further comprising at least one further ingredient selected from the group consisting of catalysts, fillers, plasticizers, and solvents.

12. The composition as claimed in claim 1, wherein the composition is an adhesive or a sealant or a coating.

13. A method comprising applying the composition as claimed in claim 12, in the form of a coating, as elastic liquid applied membrane to seal a built structure.

14. The composition as claimed in claim 1, wherein m is 0.

15. The composition as claimed in claim 3, wherein n is 2.

16. The composition as claimed in claim 1, wherein 1% to 70% of a number of groups reactive toward isocyanate groups comes from the at least one aldimine of the formula (I).

17. The composition as claimed in claim 1, wherein 2% to 50% of a number of groups reactive toward isocyanate groups comes from the at least one aldimine of the formula (I).

18. The composition as claimed in claim 1, wherein the at least one polyol includes a polyoxyalkylenetriol.

19. The composition as claimed in claim 1, wherein A is a divalent aliphatic or cycloaliphatic or arylaliphatic hydrocarbyl radical optionally containing ether oxygen or amine nitrogen and having an average molecular weight in a range of from 28 to 500 g/mol.

20. The composition as claimed in claim 9, wherein the at least one polyisocyanate includes the at least one polyurethane polymer.

Description

EXAMPLES

(1) Adduced hereinafter are working examples which are intended to elucidate the invention described in detail. It will be appreciated that the invention is not restricted to these described working examples.

(2) Aldehydes used:

(3) Aldehyde—Fractionated reaction mixture obtained from formylation, catalyzed 1: by means of HF-BF.sub.3, of C.sub.10-14-alkylbenzene, containing mainly branched 4-(C.sub.10-14-alkyl)benzaldehydes. (mean aldehyde equivalent weight 290 g/eq)

(4) 2,2-Dimethyl-3-lauroyloxypropanal

(5) Aldehyde-1 is a mixture of aldehydes of the formula (IV). 2,2-Dimethyl-3-lauroyloxypropanal serves as a comparison.

(6) Preparation of Aldimines:

(7) The amine value (including aldimino groups) was determined by means of titration (with 0.1N HClO.sub.4 in acetic acid versus crystal violet).

(8) The viscosity was measured with a thermostated Rheotec RC30 cone-plate viscometer (cone diameter 50 mm, cone angle 1°, cone tip-plate distance 0.05 mm, shear rate 10 s.sup.−1).

(9) Aldimine A1:

(10) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.93 g of 3-aminomethyl-3,5,5-trimethylcyclohexylamine were added and then the volatile constituents were removed at 80° C. and a reduced pressure at 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20° C. of 21.3 Pa.Math.s and an amine value of 150.1 mg KOH/g was obtained.

(11) Aldimine A2:

(12) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.58 g of hexane-1,6-diamine solution (70% by weight in water) were added and then the volatile constituents were removed at 80° C. and a reduced pressure at 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20° C. of 1.0 Pa.Math.s and an amine value of 161.6 mg KOH/g was obtained.

(13) Aldimine A3:

(14) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 11.14 g of 1,3-bis(aminomethyl)benzene were added and then the volatile constituents were removed at 80° C. and a reduced pressure at 10 mbar. A pale yellow, odorless and pH-neutral liquid having a viscosity at 20° C. of 2.6 Pa.Math.s and an amine value of 155.7 mg KOH/g was obtained.

(15) Aldimine R1:

(16) 48.92 of 2,2-dimethyl-3-lauroyloxypropanal were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.93 g of 3-aminomethyl-3,5,5-trimethylcyclohexylamine were added and then the volatile constituents were removed at 80° C. and a reduced pressure at 10 mbar. A pale yellow, odorless liquid having an amine value of 153.0 mg KOH/g was obtained.

(17) The aldimines A1 to A3 are aldimines of the formula (I). Aldimine R1 serves as a comparison.

(18) Production of Two-Component Polyurethane Compositions:

(19) Compositions Z1 to Z3 and Ref1:

(20) For each composition, a first component component K1 was produced by processing 46.82 parts by weight (PW) of Voranol® CP 4755 (EO-endcapped polyoxypropylenetriol, OH number 35.0 mg KOH/g, from Dow) 7.61 PW of 1,4-butanediol, in each case the aldimine specified in table 1 in the amount specified, 1.87 PW of 1,3-bis(aminomethyl)benzene, 35.18 PW of calcined kaolin, 3.74 PW of Sylosiv® A3 (molecular sieve powder, from Grace), and 0.09 PW of water
in a vacuum dissolver with exclusion of moisture to give a homogeneous paste, and storing it.

(21) In addition, for each composition, a second component component K2 was prepared by processing 55.65 parts by weight (PW) of polymer-1, the preparation of which is described hereinafter, 38.51 PW of Desmodur® CD (modified diphenylmethane diisocyanate containing MDI-carbodiimide adducts, liquid at room temperature, NCO content 28% by weight, from Covestro) 5.35 PW of hydrophobically modified fumed silica, 0.43 PW of solution of 5% by weight of salicylic acid in diisopropyl phthalate, and 0.06 PW of K-Kat® A-209 (zirconium(IV) chelate complex in reactive diluent and tert-butyl acetate, from King Industries)
in a vacuum dissolver with exclusion of moisture to give a homogeneous paste, and storing it.

(22) Polymer-1 was prepared by reacting 1300 g of Acclaim® 4200 (polyoxypropylenediol, OH number 28.5 mg KOH/g, from Covestro), 2600 g of Voranol® CP 4755 (EO-endcapped polyoxypropylenetriol, OH number 35.0 mg KOH/g, from Dow), 600 g of Desmodur® 44 MC L (4,4′-methylene diphenyl diisocyanate, from Covestro) and 500 g of diisodecyl phthalate by a known method at 80° C. to give a polyurethane polymer containing isocyanate groups and having a content of free isocyanate groups of 2.1% by weight.

(23) For the use, the two components were processed in the specified mixing ratio K1/K2 (in parts by weight, w/w) according to table 1 by means of a SpeedMixer® (DAC 150 FV, Hauschild) for 30 seconds to give a homogeneous paste, and the latter was tested immediately as follows:

(24) From each composition, a film of thickness 2 mm was produced and left to cure under standard climatic conditions for 7 days, and the mechanical properties of Tensile strength, Elongation at break and 5% modulus of elasticity (at 0.5-5% elongation) were tested according to DIN EN 53504 at a strain rate of 200 mm/min. These results are identified as “fresh” in table 1.

(25) As a measure of the open time, the Tack-free time was determined. For this purpose, a few grams of the freshly mixed composition were applied to cardboard in a layer thickness of about 2 mm and, under standard climatic conditions, the time until, when the surface of the composition was gently tapped by means of an LDPE pipette, there were for the first time no residues remaining any longer on the pipette was determined. These results are identified as “fresh” in table 1.

(26) Shore A hardness was determined according to DIN 53505 on test specimens cured under standard climatic conditions for the time specified in table 1.

(27) In addition, Sag resistance was determined for each composition. For this purpose, 8 mL of the freshly mixed compound was applied from a commercial 10 mL plastic syringe that had been cut open at the front onto a piece of horizontal cardboard from above, and the latter was tipped immediately into a vertical position, such that the composition applied ended up horizontal. Subsequently, the extent of sagging from the horizontal position downward during the curing under standard climatic conditions was assessed, with sagging of not more than 20 mm assessed as “good”, sagging of not more than 30 mm as “moderately good”, and sagging of not more than 40 mm as “moderate”. These results are identified as “fresh” in table 1.

(28) Finally, the same tests were repeated for each composition, except that the first component K1 had been stored beforehand in a moisture-tight container in an air circulation oven at 60° C. for 48 hours. These results are identified as “stored” in table 1.

(29) For all compositions, no odor was perceptible during and after curing by smelling by nose at a distance of 2 cm.

(30) The results are reported in table 1.

(31) Compositions Z1 to Z3 are inventive examples. Composition Ref1 is a comparative example.

(32) Compositions Z1 to Z3 are especially suitable as elastic adhesives.

(33) TABLE-US-00001 TABLE 1 Composition Ref1 Z1 Z2 Z3 Aldimine R1 A1 A2 A3 4.69 PW 4.79 PW 4.45 PW 4.54 PW K1/K2 mixing ratio 100/87 100/87 100/87 100/87 (w/w) Tack-free time fresh,  42′  35′  27′  35′ stored  41′  32′  22′  27′ Sag resistance fresh, moderate moderately good good good stored moderately good good good good Shore A fresh after 3 h 16 48 54 55 after 1 d 77 78 79 82 after 3 d 79 80 81 82 Shore A stored after 3 h 37 54 55 55 after 1 d 80 75 75 76 after 3 d 83 79 79 76 Mechanical properties fresh Tensile strength  2.1 MPa  5.5 MPa  5.0 MPa  5.2 MPa Elongation at break 51% 160% 92% 136% Modulus of 16.8 MPa 22.0 MPa 25.0 MPa 22.8 MPa elasticity 5% Mechanical properties stored Tensile strength  3.3 MPa  6.0 MPa  5.2 MPa  5.8 MPa Elongation at break 81% 151% 96% 139% Modulus of 23.4 MPa 19.9 MPa 25.5 MPa 22.3 MPa elasticity 5%