Crosslinking of IPMS adducts with aminosilanes

Abstract

The present invention relates to coating materials at least comprising A) an adduct of isocyanatosilanes with hydroxy-functional compounds, B) a tin-containing compound and C) an aminosilane, to the use of the coating materials and also to the coatings obtained.

Claims

1. A coating material, comprising: A) from 10-90 wt. % based on the total weight of the coating material of an adduct of at least one isocyanatosilane with at least one hydroxy-functional compound; B) a tin-containing compound of the formula
R.sup.1.sub.4aSnX.sub.a, wherein: a is 1, 2, or 3, R.sup.1 independently is selected from the group consisting of a linear or branched optionally substituted C1-C30 alkyl group, C5-C14 cycloalkyl group, C6-C14 aryl group, triorganylsilyl group, and C1-C30 diorganylalkoxysilyl group, and X is selected from the group consisting of halogen, OR.sup.2, OC(O)R.sup.3, OH, SR.sup.4, NR.sup.5.sub.2, NHR.sup.6, OSiR.sup.7.sub.3, OSi(OR.sup.8).sub.3, in which the substituents R.sup.2 to R.sup.8 in each case independently of one another are selected from an optionally substituted C1-C8 alkyl, C6-C14 aryl and/or C2-C8 alkenyl group; and C) from 10 to 20 wt. %, based on the total weight of the coating material, of an aminosilane wherein said at least one hydroxyl-functional compound is at least one compound selected from the group consisting of a diol having 1 to 22 carbon atoms, a triol having 1 to 22 carbon atoms and a tetrol having 1 to 22 carbon atoms; and wherein said at least one hydroxyl-functional compound and said adduct are not a polyether.

2. The coating material of claim 1, wherein the isocyanatosilane is a compound of the formula (I):
OCN-(alkyl)-Si(alkoxy).sub.3(I), wherein alkyl represents a linear or branched alkylene chain having 1-4 carbon atoms; and alkoxy independently represents a methoxy, ethoxy, propoxy, or butoxy group.

3. The coating material of claim 1, wherein a ratio of OH groups from the at least one hydroxy-functional compound to NCO groups from the at least one isocyanatosilane is from 0.8:1 to 1.2:1.

4. The coating material of claim 1, wherein the tin-containing compound is at least one selected from the group consisting of di-n-butyltin dichloride, di-n-octyltin dichloride, di-n-butyltin oxide, di-n-octyltin oxide, di-n-butyltin diacetate, di-n-butyltin dilaurate, di-n-butyltin maleate, di-n-butyltin bis-2-ethylhexanoate, di-n-butyltin dineodecanoate, di-n-octyltin diacetate, di-n-octyltin dilaurate, di-n-octyltin maleate, di-n-octyltin bis-2-ethylhexanoate, di-n-octyltin dineodecanoate, and di-n-butyltin diacetylacetonate.

5. The coating material of claim 1, wherein the aminosilane comprises aminosilane or aminoalkylsilane of the formula (III):
A.sub.mSiY.sub.n(III), wherein: A is a substituted or unsubstituted aminoalkyl group, a substituted or unsubstituted diaminodialkyl group or substituted or unsubstituted triaminotrialkyl group, Y each independently represents OH, ONa, OK, OR, OCOR, OSiR.sub.3, Cl, Br, I, or NR.sub.2, m is 1 or 2, n is 1, 2, or 3, with the proviso that m+n=4, and R each independently represents hydrogen, a linear or branched alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl group, having in each case 1 to 18 C atoms and may in each case optionally be substituted.

6. The coating material of claim 1, further comprising a binder component, auxiliary, adjuvant, and/or solvent.

7. The coating material of claim 1, wherein the ratio of OH groups from the at least one hydroxy-functional compound to NCO groups from the at least one isocyanatosilane is from 0.9:1 to 1.1:1.

Description

EXAMPLES

(1) Preparation protocol for the coating materials:

(2) The individual compounds, according to formula, are weighed out in succession into a 250 mL glass bottle and stirred thoroughly using a laboratory stirrer until the resulting solution is homogeneous and thoroughly mixed.

(3) Production protocol for the coatings:

(4) The individual coating materials are applied to a glass plate with a wet film thickness of 100 m, using a four-way film-drawing frame.

(5) The coating films spend 24 hours in a controlled-climate chamber at 23 C. and a relative humidity of 50%. After an interval of 1 hour, 3 hours, 6 hours and 12 hours and after one day, the Knig pendulum hardnesses of the films produced are ascertained, in order to determine the drying behaviour of the individual samples. The results of the coatings obtained are set out in Table 1. The hardness of the coating material is determined by determination of the pendulum hardness:

(6) The basis for the pendulum hardness is that the greater the damping effect of the substrate and the absorption of swing energy, the more quickly the amplitude of swaying of the self-supporting pendulum is reduced.

(7) The sample plate (coating film) is placed on the reciprocating platen. With the lever arm, which can be operated from the outside, the reciprocating platen is subsequently moved up to the pendulum. The pendulum is deflected to the 6 scale position, fixed with the wire trigger, and then let go. A determination is made of the number of swings needed to cause the pendulum swing to subside from 6 to 3 relative to the vertical. The measurement is conducted at 2 different positions within the sample. Multiplying the swings by a factor of 1.4 gives the calculated Knig pendulum damping in seconds.

(8) TABLE-US-00001 TABLE 1 Example A B C D E F Vestanat M 95 (1) 100 90 89.7 50 45 44.9 Dynasylan 10 10 5 5 AMMO (2) TIB Kat 226 (3) 0.3 0.15 Desmophen A 50 50 50 450 BA; 25% (4) All figures in weight percent Determination of drying Pendulum hardness 1 h liquid 19.6/29.4 44.8/44.8 tacky 9.8/9.8 22.4/22.4 3 h liquid 32.2/40.6 46.2/47.6 tacky 21.0/21.0 82.6/81.2 6 h liquid 33.6/35.0 85.4/84.0 tacky 39.2/37.8 121.8/121.8 12 h liquid 43.4/42.0 112.0/113.4 tacky 84.0/81.2 134.4/133.0 1 d liquid 81.2/84.0 134.4/140.0 tacky 141.4/138.6 155.4/152.6 (1) Adduct of isocyanatopropyltrimethoxysilane and 1,9-nonanediol (ratio of isocyanatopropyltrimethoxysilane to 1,9-nonanediol is 2:1) (2) 3-Aminopropyltrimethoxysilane from Evonik Industries AG (3) Di-n-butyltin dineodecanoate, TIB Chemicals AG (4) Hydroxyl group-containing polyacrylate from Viverso

Result

(9) The results show that a combination of Vestanat M 95, Dynasylan AMMO and TIB Kat 226, ratio: 90:10:0.3, sample C, as coating material exhibits good drying behaviour at room temperature. With this combination, good drying properties are also apparent in conjunction with a further dissolved reactive acrylic resin, Desmophen A 450, sample F.

(10) The coating films of Vestanat M 95, sample A, and also the mixture of Vestanat M 95 and Desmophen A 450 BA, sample D, still exhibit no initial drying after 24 hours. The films are tacky. As a result of the addition of Dynasylan AMMO, sample B and sample E, an initial drying is recorded after 1 hour, with through-drying in the subsequent course of drying. Nevertheless, the two samples do not attain the good drying behaviour of the C and F samples. The use of the catalyst TIB Kat. 226 further significantly improves and accelerates drying.