Polyureas as rheology control agents

Abstract

The invention relates to polyureas having a weight-average molecular weight ranging from 5,000 to 70,000 g/mol, the preparation thereof, and the use thereof as rheology control agents. The invention further relates to rheology control agents containing polyureas and to the use thereof. The invention moreover relates to formulations containing polyureas.

Claims

1. A polyurea of the general formula (I) ##STR00003## wherein: T is a unit comprising at least four urea groups and has the formula (II) ##STR00004## wherein: R.sup.3 and R.sup.4 are each identical or different and independently of one another are branched or unbranched polyester, polyether, C.sub.4-C.sub.22 alkylene, C.sub.3-C.sub.20 cycloalkylene, C.sub.3-C.sub.20 cycloalkenylene, C.sub.5-C.sub.12 arylene or arylalkylene radicals, Z and W are each identical or different and independently of one another are NHCOO or NHCONH, and q is 2-200; R.sup.1 and R.sup.7 independently of one another are branched or unbranched C.sub.4-C.sub.32 alkyl, C.sub.3-C.sub.18 alkenyl, C.sub.2-C.sub.20 alkynyl, C.sub.3-C.sub.20 cycloalkyl, C.sub.3-C.sub.20 cycloalkenyl, C.sub.5-C.sub.12 aryl or arylalkyl, C.sub.mH.sub.2m+1(OC.sub.nH.sub.2n).sub.p(OCH(C.sub.6H.sub.5)CH.sub.2).sub.u, UC.sub.6H.sub.4(CH.sub.2).sub.s(OC.sub.nH.sub.2n).sub.x(OCH(C.sub.6H.sub.5)CH.sub.2).sub.u, C.sub.mH.sub.2m+1(OC.sub.nH.sub.2n).sub.p(OCH(C.sub.6H.sub.5)CH.sub.2).sub.u(OOCC.sub.vH.sub.2v).sub.x, UC.sub.6H.sub.4(CH.sub.2).sub.s(OC.sub.nH.sub.2n).sub.p(OCH(C.sub.6H.sub.5)CH.sub.2).sub.u(OOCC.sub.vH.sub.2v).sub.x, C.sub.4-C.sub.32-hydroxyalkyl, C.sub.4-C.sub.32-carboxyalkyl, C.sub.mH.sub.2mC(O)R.sup.8, C.sub.mH.sub.2mCOOR.sup.8, C.sub.mH.sub.2mC(O)NR.sup.8R.sup.9 or C.sub.mH.sub.2mOC(O)NR.sup.8R.sup.9 radicals, it being possible for the radicals to be substituted or unsubstituted, it being possible for the amino groups and/or carboxyl groups to be present in salified or quaternized form, and C.sub.mH.sub.2m being a linear or branched alkylene group, and R.sup.8 and R.sup.9 independently of one another are hydrogen, branched or unbranched C.sub.1-C.sub.32 alkyl, C.sub.3-C.sub.18 alkenyl, C.sub.2-C.sub.20 alkynyl, C.sub.3-C.sub.20 cycloalkyl, C.sub.3-C.sub.20 cycloalkenyl, C.sub.5-C.sub.12 aryl or arylalkyl, C.sub.1-C.sub.32 alkoxyalkyl or C.sub.1-C.sub.32 acyloxyalkyl groups, where m=0-32, n=2-4, x=0-100, u=0-100, v=1-22, p=0-100, s=0-1, UH, C.sub.1-C.sub.12 alkyl or C.sub.6H.sub.5).sub.1-4, R.sup.2 and R.sup.6 independently of one another are branched or unbranched C.sub.4-C.sub.22 alkylene, C.sub.3-C.sub.20 cycloalkylene, C.sub.3-C.sub.20 cycloalkenylene, C.sub.5-C.sub.12 arylene or arylalkylene radicals, R.sup.5 is a branched or unbranched polyester, polyether, unbranched C.sub.4-C.sub.22 alkylene, C.sub.3-C.sub.20 cycloalkylene, C.sub.3-C.sub.20 cycloalkenylene, C.sub.5-C.sub.12 arylene or arylalkylene radical, B and X independently of one another are O or NR.sup.10 with R.sup.10 is H, branched or unbranched C.sub.1-C.sub.32 alkyl, C.sub.3-C.sub.20 cycloalkyl, C.sub.3-C.sub.20 cycloalkenyl C.sub.5-C.sub.12 aryl or arylalkyl radicals, A and Y independently of one another are NR.sup.10, wherein each R.sup.10 is, independently, H, branched or unbranched C.sub.1-C.sub.32 alkyl, C.sub.3-C.sub.20 cycloalkyl, C.sub.3-C.sub.20 cycloalkenyl, C.sub.5-C.sub.12 aryl or arylalkyl radicals, and the weight-average molecular weight being 5000 to 70000 g/mol.

2. The polyurea as claimed in claim 1, wherein T comprises no urethane groups.

3. The polyurea as claimed in claim 1, wherein the polyurea has a weight-average molecular weight of 5000 to 12000 g/mol.

4. The polyurea as claimed in claim 1, wherein the polyurea has a weight-average molecular weight of 10000 to 26000 g/mol.

5. The polyurea as claimed in claim 1, wherein the polyurea has a weight-average molecular weight of 24000 to 55000 g/mol.

6. The polyurea as claimed in claim 3, wherein the radicals R.sup.1 and/or R.sup.7 are substituted by polar functional groups and/or comprise polyester groups and/or polyether groups.

7. The polyurea as claimed in claim 1, wherein the polyurea is present as a solution in at least one solvent and/or vehicle.

8. The polyurea as claimed in claim 1 preparable by a. the reaction of at least one diisocyanate with at least one component K which has two NCO-reactive groups, in a molar ratio of diisocyanate to component K of (f+1):f with f1, to form intermediately an isocyanate-terminated urea having on average two free isocyanate groups in the molecule, and subsequent complete reaction of the free isocyanate groups of the intermediate with at least one component L that is reactive toward isocyanate groups, or b. the reaction of at least one diisocyanate with at least one component K which has two NCO-reactive groups, in a molar ratio of diisocyanate to component K of f:(f+1) with f1, to form an intermediate having on average two free isocyanate-reactive, terminal groups in the molecule, and subsequent complete reaction of the free isocyanate-reactive groups of the intermediate with at least one monoisocyanate-functional compound, or c. the reaction of a mixture of at least one diisocyanate and at least one monoisocyanate-functional compound with at least one component K which has two NCO-reactive groups, in a molar ratio of diisocyanate to component K to monoisocyanate-functional compound of f:(f+1):2 with f1, d. the reaction of a mixture of at least one component K which has two NCO-reactive groups and at least one component L that is reactive toward isocyanate groups with at least one diisocyanate, in a molar ratio of component K to diisocyanate to component L of f:(f+1):2 with f1, where component K has as NCO-reactive groups either two primary amine groups or one primary amine group and one OH group, and component L has at least one primary amine group, one secondary amine group or one OH group.

9. A process for preparing the polyurea as claimed in claim 1, wherein a. at least one diisocyanate is reacted with at least one component K which has two NCO-reactive groups, in a molar ratio of diisocyanate to component K of (f+1):f with f1, to form intermediately an isocyanate-terminated urea having on average two free isocyanate groups in the molecule, and the free isocyanate groups of the intermediate are subsequently completely reacted with at least one component L that is reactive toward isocyanate groups, or b. at least one diisocyanate is reacted with at least one component K which has two NCO-reactive groups, in a molar ratio of diisocyanate to component K of f:(f+1) with f1, to form an intermediate having on average two free isocyanate-reactive, terminal groups in the molecule, and the free isocyanate-reactive groups are subsequently reacted completely with at least one monoisocyanate-functional compound, or c. at least one diisocyanate is mixed with at least one monoisocyanate-functional compound and this mixture is subsequently reacted with at least one component K which has two NCO-reactive groups, in a molar ratio of diisocyanate to component K to monoisocyanate-functional compound of f:(f+1):2 with f1, d. at least one component K which has two NCO-reactive groups is mixed with at least one component L that is reactive toward isocyanate groups and this mixture is subsequently reacted with at least one diisocyanate, in a molar ratio of component K to diisocyanate to component L of f:(f+1):2 with f1, where component K has as NCO-reactive groups either two primary amine groups or one primary amine group and one OH group, and component L has at least one primary amine group, one secondary amine group or one OH group.

10. A rheology control agent comprising at least one polyurea as claimed in claim 1.

11. The rheology control agent as claimed in claim 10, wherein the rheology control agent is free from film-forming resins.

12. The rheology control agent as claimed in claim 10, wherein the fraction of polyurea in a formulation is 0.05% to 10% by weight, based on the total weight of the formulation.

13. The rheology control agent as claimed in claim 12 for rheology control in polar solvents, as antisettling agent, for avoiding the propensity to sagging, for rheology control of baking systems, or for adjusting the sagging characteristics of high-build systems.

14. A formulation comprising a polyurea as claimed in claim 1.

15. The polyurea of claim 1, wherein: R.sup.2 and R.sup.6 are identical or different and are branched or unbranched C.sub.5-C.sub.12 arylene, C.sub.5-C.sub.12 arylalkylene, C.sub.3-C.sub.20 cycloalkylene or C.sub.4-C.sub.22 alkylene radicals; R.sup.3, R.sup.4, and R.sup.5 are identical or different and are branched or unbranched polyester, polyether, C.sub.4-C.sub.22 alkylene, C.sub.3-C.sub.20 cycloalkylene, or C.sub.5-C.sub.12 arylene or arylalkylene radicals; R.sup.8 and R.sup.9 are independently of one another, hydrogen or branched or unbranched C.sub.1-C.sub.32 alkyl, C.sub.1-C.sub.32 alkoxyalkyl, C.sub.5-C.sub.12 aryl or arylalkyl radicals; and R.sup.10 is H or a branched or unbranched C.sub.1-C.sub.32 alkyl, C.sub.3-C.sub.20 cycloalkyl, C.sub.5-C.sub.12 aryl or arylalkyl radical.

Description

EXAMPLES

(1) The percentage figures are, unless anything different is indicated, percentages by weight. The term active substance refers to the urea compounds prepared in comparative example 1 and in examples 1 to 6.

Comparative Example 1

As Per Prior Art

(2) First of all a monoadduct is prepared in accordance with patent specification EP 1188779 from a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (Desmodur 165, Bayer) and butyltriglycol.

(3) In a reaction vessel, with stirring, 4.1 g (0.096 mol) of LiCl are dissolved in 171.4 g of N-ethylpyrrolidone. Thereafter 27.2 g (0.2 mol) of meta-xylylenediamine are added and the clear mixture is heated to 60 C.

(4) Subsequently 154.4 g (0.4 mol) of the monoadduct of Desmodur 165 and butyltriglycol are added dropwise with stirring over the course of 1 hour, such that the temperature does not rise above 65 C. To complete the reaction, the reaction mixture is stirred at 60 C. for 3 hours. A clear and liquid product is obtained. The weight-average molecular weight is 2200 g/mol.

Example 1

(5) In a reaction vessel, with stirring, 0.7 g (0.017 mol) of LiCl is dissolved in 76.4 g of N-methylpyrrolidone. Thereafter 2.3 g (0.017 mol) of meta-xylylenediamine are added and the clear mixture is heated to 35 C. Subsequently 5.9 g (0.034 mol) of tolylene diisocyanate (Desmodur T80, Bayer) are added dropwise with stirring over the course of 1 hour, such that the temperature does not rise above 45 C. After the end of addition of the tolylene diisocyanate, 10.2 g (0.034 mol) of hydroxystearic acid heated to 65 C. are added dropwise. To complete the reaction, the reaction mixture is stirred at 80 C. for 3 hours. This gives a hazy, homogeneous, and liquid product. The weight-average molecular weight is 49000 g/mol.

Example 2

(6) In a reaction vessel, with stirring, 15.1 g (0.36 mol) of LiCl are dissolved in 878.8 g of N-methylpyrrolidone. Thereafter 49.3 g (0.36 mol) of meta-xylylenediamine are added and the clear mixture is heated to 80 C. Subsequently 44.4 g (0.3 mol) of hexamethylene diisocyanate are added dropwise with stirring over the course of 45 minutes. After the end of addition of the hexamethylene diisocyanate, 110.9 g (0.12 col) of a monoadduct prepared by the process described in patent specification EP 1188779 from Desmodur 165 and methoxypolyethylene glycol (MPEG750) are added dropwise. To complete the reaction, the reaction mixture is stirred at 80 C. for 3 hours. This gives a clear, colorless, and liquid product. The weight-average molecular weight, is 34500 g/mol.

Example 3

(7) First of all a monoadduct is prepared in accordance with patent specification EP 1188779 from a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (Desmodur 180, Bayer) and butylpolyalkylene glycol (Polyglycol B11/50, Clariant).

(8) In a reaction vessel, with stirring, 3.8 g (0.09 mol) of LiCl are dissolved in 146.3 g of dimethyl sulfoxide. Thereafter 10.3 g (0.075 mol) of para-xylylenediamine are added and the clear mixture is heated to 60 C. Subsequently a mixture of 10.4 g (0.06 mol) of Desmodur T65 and 38.2 g (0.03 mol) of the monoadduct of Desmodur T80 and butoxypolyalkylene glycol are added dropwise with stirring over the course of 1 hour, such that the temperature does not rise above 65 C. To complete the reaction, the reaction mixture is stirred at 60 C. for 3 hours. A clear, colorless, and liquid product is obtained. The weight-average molecular weight is 15000 g/mol.

Example 4

(9) In a reaction vessel, 69.6 g (0.4 mol) of Desmodur T80 are introduced and 145.6 g (0.2 mol) of polyester formed from 5 mol of caprolactone and 1 mol of decanol are metered in with stirring over the course of 45 minutes. The temperature during this time is held below 45 C. After the end of the addition, stirring is continued for hours. In a second reaction vessel, with stirring, 12.6 g (0.3 mol) of LiCl are dissolved in 627.4 g of N-ethylpyrrolidone. Thereafter 41.1 g (0.3 mol) of meta-xylylenediamine are added and the solution is heated to 60 C. Subsequently the mixture of the monoadduct and the excess Desmodur T80 from the first reaction vessel is added dropwise with stirring, over the course of 90 minutes, into the second reaction vessel, such that the temperature does not rise above 65 C. To complete the reaction, the reaction mixture is stirred at 60 C. for 3 hours. This gives a clear, colorless, and viscous product. The weight-average molecular weight is 12500 g/mol.

Example 5

(10) In a reaction vessel, 10.0 g (0.045 mol) of isophorone diisocyanate are introduced and 12.1 g (0.045 mol) of oleyl alcohol are metered in with stirring over the course of 15 minutes. The temperature during this time is held below 45 C. After the end of the addition, stirring is continued for a further 2 hours. In a second reaction vessel, with stirring, 4.3 g (0.102 mol) of LiCl are dissolved in 126.3 g of N-methylpyrrolidone. Thereafter 7.9 g (0.068 mol) of hexamethylenediamine are added and the mixture is heated to 60 C. Subsequently a solution of the monoadduct from the first reaction vessel and 7.8 g (0.045 mol) of Desmodur T65 is added dropwise with stirring, over the course of 2 hours, into the second reaction vessel, such that the temperature does not rise above 65 C. To complete the reaction, the reaction mixture is stirred at 60 C. for 3 hours. This gives a yellow and viscous product. The weight-average molecular weight is 7500 g/mol.

Example 6

(11) In a reaction vessel, with stirring, 2.8 g (0.0675 mol) of LiCl are dissolved in 134.7 g of N-methylpyrrolidone. Thereafter 40.5 g (0.0675 mol) of Jeffamin ED600 and 0.915 g (0.015 mol) of aminoethanol are added and the clear mixture is heated to 80 C. Subsequently 13.05 g (0.075 mol) of Desmodur T65 are metered in with stirring over the course of 2 hours, such that the temperature does not rise above 85 C. After the end of the addition, the reaction mixture is stirred at 80 C. for 3 hours. This gives a clear, colorless, and liquid product. The weight-average molecular weight is 20000 g/mol.

Performance Results

(12) The rheology control agents of the invention display performance advantages over the prior art in terms, for example, of compatibility and/or shear stability, and also a universal activity in formulations of different polarity.

(13) Test for Compatibility:

(14) For this purpose the rheology control agents, comprising polyurea and solvent, are incorporated with stirring, using a Dispermat CV at 2 m/s, for 2 minutes at room temperature into a polyester-melamine-based automotive clearcoat. The compatibility of the rheological control agent in the coating system is assessed on the basis of the cloudiness of the wet coating material, one day following incorporation. The assessment is made visually, using a scale of 1-6 (1=clear to 6=very cloudy), and is shown in table 1.

(15) Test formulation 1: Automotive clearcoat based on Setal 1715 VX-74 Setamine US 138 BE 70

(16) TABLE-US-00001 Comparative Test formulation 1 Component formulation 1 (as per EP 198519) Setal 1715 VX-74 52.0% 33.2% Setal 91715 SS-55 25.2% Setamine US 138 BB 70 24.0% 24.0% Shellsol A 6.0% 4.4% Solvesso 150 6.0% 4.4% xylene 6.0% 4.4% isobutanol 6.0% 4.4% Total 100.0% 100.0% Setal 1715 VX-74: polyester binder, 72% in Solvesso 100/xylene 75:25, from Nuplex Resins Setamine US138 BB 70: melamine binder, 70% in 1-butanol, from Nuplex Resins Setal 91715 SS-55: polyester binder, 53% in xylene/Solvesso 100 53:47, from Nuplex Resins (contains 3.5% by weight sag control agent) Shellsol A solvent from Shell Solvesso 100/150 solvents from Exxon Mobil Chemical Amount added: 0.9% by weight active substance, based on the total formulation.

(17) TABLE-US-00002 TABLE 1 Test formulation 1 Additive (0.9% by weight active Clouding in wet substance, based on total) coating Control (without additive) 1 Comp. ex. 1 4 Ex. 2 2 Ex. 3 1 Ex. 4 1 Comparative formulation 1: Clouding in wet coating 25.2% by weight Setal 91715 SS-55 5 (corresponding to 0.9% by weight SCA in the comparative formulation)

(18) Test for Shear Stability:

(19) For testing the shear stability of the theology control agents of the invention, the products from the examples are used in an anticorrosion formulation based on Epikote 828. Here again, incorporation takes place simply by stirring with a Dispermat CV at 2 m/s for 2 minutes at room temperature into component A of the listed formulation.

(20) Activity and shear stability are verified 1 day after the incorporation of the products, after addition of the curing agent (component B). For this purpose the coating materials are applied using a stepped coater 50-500 m and 550-1000 m to 2801 contrast charts using an automatic applicator from BYK Gardner, at a rate of 5 cm/s, and are dried hanging vertically. The holdout is read off wet in m, and is a measure of the rheological activity of a product.

(21) To test for shear stability, the samples are applied before and after a shearing load. The shearing load is exerted using a Skandex paint shaker BA S20 (620 rpm, 5 minutes). The smaller the difference in the holdout before and after shearing load, the better the shear stability of a product. The results of the testing are set out in table 2.

(22) Test formulation 2: Anticorrosion primer based on Epikote 828/Epikure 3155

(23) Component A:

(24) TABLE-US-00003 Epikote 828 42.0% BYK-066N 1.0% BYK-P104 0.5% Blanc Fixe N 18.5% Talc AT-1 20.0% Bayferrox 130M 10.0% Dispersing: Dispermat CV, 4 cm toothed disk, 8500 rpm, 30 minutes at 50 C. BYK-358 1.0% Araldite DY-E 7.0% Total (comp. A) 100.0%

(25) Component B:

(26) TABLE-US-00004 Epikure 3155 32.7%

(27) The curing agent is incorporated with stirring. Epikote 828: liquid bisphenol A epoxide binder, 100% form, from Hexion Specialty Chemicals Epikure 3155: low-viscosity modified polyamide curing agent, from Hexion Specialty Chemicals BYK-066 N: solution of foam-destroying poly-siloxanes in diisobutyl ketone, from BYK-Chemie GmbH BYK-P104: wetting and dispersing agent from BYK-Chemie GmbH BYK-358: acrylate additive for improving leveling and increasing the gloss, from BYK Chemie GmbH Blanc Fixe N: synthetic barium sulfate from Sachtleben Talc AT-1 filler from Norwegian Talc Deutschland GmbH Bayferrox 130M iron oxide pigment from Lanxess Araldite DY-E reactive diluent from Huntsman Level of addition: 0.9% by weight active substance, based on the total formulation.

(28) TABLE-US-00005 TABLE 2 Holdout [m] Holdout [m] Additives before shearing after shearing Control 250 250 (no additive) Comp. ex. 1 500 350 Example 1 850 800 Example 5 550 400 Example 6 550 450

(29) Test for Temperature-Stable Effect

(30) To verify the temperature-stable effect, comp. ex. 1 and example 3 were incorporated into test formulation 1, in the same way as with the procedure described under the test for compatibility. The samples were investigated 1 day after incorporation, using an Anton Paar rheometer MCR 301. For this purpose a disposable plate/plate system with a 0.2 mm slot was used. The shear rate D was 1 s.sup.1. The sample was heated at a rate of 6 C./min and characterized rheologically in the temperature range from 30 to 140 C. The temperature stable behavior of example 3 in comparison to comp. example 1 and the control (without additive) is shown in FIG. 1.

(31) Test for Universal Activity:

(32) To verify the universal activity of rheology control agents of the substance class according to the invention, the products are incorporated into diluted binders and into clearcoat formulations with different chemical foundations and polarities. The binders are diluted in order to obtain a comparable processing viscosity. Incorporation is carried out merely with stirring using a Dispermat CV at 2 m/s for 2 minutes at room temperature. One day after the incorporation of the products, a visual inspection is made to determine whether a gel has formed or whether the diluted binder/the clearcoat has remained liquid (+ gel/ no gel).

(33) The results are summarized in table 3.

(34) Level of addition: 2% by weight by active substance, based on the weight of the total composition

(35) Test formulations 3:

(36) TABLE-US-00006 Binders/Clearcoats Diluent/Formula Alkydal F26 15% xylene Bayhydrol D 270 Epikote 1001 20% X/MIBK 3:1 Macrynal SM515 15% Buac Nail varnish NC E400 33% butyl acetate 54% isopropanol 6% plasticizer 7% Plioway AC80 Anl. 30% in TB K30:Shellsol A 4:1 Worlekyd S 365 15% TB K30 Alkydal F26: short-oil alkyd, 60% in xylene, from Bayer Bayhyrol D270: water-dilutable polyester, 70% in W/BTG, from Bayer Macrynal SM515: OH-functional acrylate, 70% in Buac, from Cytec Epikote 1001: epoxy resin, 75% in xylene, from Hexion Spec. Worlekyd S365: long oil alkyd, 60% in TB, from Worle Plioway AC80: thermoplastic styrene-acrylate copolymer, 100% form, from Eliokem NC E400: nitrocellulose, 70% strength in isopropanol, from Waldsrode

(37) TABLE-US-00007 TABLE 3 Binder/clearcoat Example 1 Example 3 Example 5 Example 6 Alkydal F26 + Bayhydrol D 270 + + Epikote 1001 + + + Macrynal SM515 + + Nail varnish + + Plioway AC80 Anl. + Worlekyd S 365 + +