POLYSILOXANE-FUNCTIONALIZED POLYURETHANES FOR BOOSTING THE HYDROPHOBICITY OF SURFACES

Abstract

The present invention relates to an NCO-terminated polysiloxane prepolymer of the general formula (I) [(Q).sub.q]-(M).sub.m-(P).sub.p—(R).sub.r].sub.t, in which R, P, M, Q, r, p, m, q and t are defined as follows: R in each case independently is at least one polyisocyanate unit and/or at least one diisocyanate unit, P in each case independently is at least one polyol unit, M in each case independently is at least one diisocyanate unit and/or at least one polyisocyanate unit, Q is at least one polysiloxane unit, r in each case independently is a number from 1 to 10, p in each case independently is a number from 1 to 10, m in each case independently is a number from 1 to 10, q in each case independently is a number from 1 to 10, t is an integer from 2 to 5, and the M units present are attached directly to the unit Q; to a process for producing said prepolymer, and to use as curing agent in a coating formulation.

Claims

1: An NCO-terminated polysiloxane prepolymer of the general formula (I)
[(Q).sub.q]-[(M).sub.m-(P).sub.p—(R).sub.r].sub.t  (I), wherein R, P, M, Q, r, p, m, q, and t are defined as follows R in each case independently comprises at least one polyisocyanate unit and/or at least one diisocyanate unit, P in each case independently comprises at least one polyol unit, M in each case independently comprises at least one diisocyanate unit and/or at least one polyisocyanate unit, Q comprises at least one polysiloxane unit, r in each case independently is a number from 1 to 10, p in each case independently is a number from 1 to 10, m in each case independently is a number from 1 to 10, q in each case independently is a number from 1 to 10, t is an integer from 2 to 5, and the units M are attached directly to the unit Q.

2: The polysiloxane prepolymer as claimed in claim 1, characterized in that the at least one polyisocyanate unit R is selected from the group consisting of 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane higher-molecular-weight oligomers having biuret, uretdione, isocyanurate, iminooxadiazinedione, allophanate, urethane- and/or carbodiimide/uretonimine structural units obtainable through reaction of di- or triisocyanates selected from the group consisting of butane 1,4-diisocyanate, pentane 1,5-diisocyanate (pentamethylene diisocyanate, PDI), hexane 1,6-diisocyanate (hexamethylene diisocyanate, HDI), 4-isocyanatomethyloctane 1,8-diisocyanate (triisocyanatononane, TIN), 4,4′-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), naphthalene 1,5-diisocyanate, diisocyanatodiphenylmethane (2,2′-, 2,4′-, and 4,4′-MDI or mixtures thereof), diisocyanatomethylbenzene (tolylene 2,4- and 2,6-diisocyanate, TDI) and technical mixtures of the two isomers and 1,3- and/or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3′-dimethylbiphenyl 4,4′-diisocyanate (TODI), 1,4-para-phenylene diisocyanate (PPDI), cyclohexyl diisocyanate (CHDI), and mixtures thereof.

3: The polysiloxane prepolymer as claimed in claim 1, characterized in that the at least one polyol unit P is selected from the group consisting of polyether polyols, polyester polyols, polyurethane polyols, polysiloxane polyols, polycarbonate polyols, polybutadiene polyols, polyacrylate polyols, polymethacrylate polyols, copolymers of polyacrylate polyols, polymethacrylate polyols, and mixtures thereof.

4: The polysiloxane prepolymer as claimed in claim 1, characterized in that M is at least one diisocyanate unit selected from the group consisting of butane 1,4-diisocyanate, pentane 1,5-diisocyanate (pentamethylene diisocyanate, PDI), hexane 1,6-diisocyanate (hexamethylene diisocyanate, HDI), 4,4′-methylenebis(cyclohexyl isocyanate) (H12MDI), 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H6XDI), naphthalene 1,5-diisocyanate, diisocyanatodiphenylmethane (2,2′-, 2,4′-, and 4,4′-MDI or mixtures thereof), diisocyanatomethylbenzene (tolylene 2,4- and 2,6-diisocyanate, TDI) and mixtures of those two isomers, 1,3- and/or 1,4-bis(isocyanatomethyl)benzene (XDI), 3,3′-dimethylbiphenyl 4,4′-diisocyanate (TODI), 1,4-para-phenylene diisocyanate (PPDI), cyclohexyl diisocyanate (CHDI), and mixtures thereof.

5: The polysiloxane prepolymer as claimed in claim 1, characterized in that the at least one polysiloxane unit Q is derived from one selected from the group consisting of a polysiloxane polyol, a polysiloxane polyamine, and a polysiloxane polythiol.

6: The polysiloxane prepolymer as claimed in claim 1, characterized in that the at least one polysiloxane unit is present in an amount of from 0.1% to 5% by weight based on the total polysiloxane prepolymer.

7: The polysiloxane prepolymer as claimed in claim 1, characterized in that the polysiloxane prepolymer has a number-average molecular weight Mn of <4000 g/mol, preferably of >450 g/mol and <3000 g/mol, particularly preferably of >650 g/mol and <2500 g/mol, and very particularly preferably of >800 g/mol and <2500 g/mol.

8: A process for preparing the NCO-terminated polysiloxane prepolymer as claimed in claim 1, comprising the following steps: (A) reacting at least one of a polysiloxane polyol, a polysiloxane polyamine and a polysiloxane polythiol with at least one diisocyanate and/or at least one polyisocyanate to obtain at least one NCO-terminated polysiloxane, (B) optionally, removing the excess of at least one diisocyanate and/or at least one polyisocyanate, (C) reacting the at least one NCO-terminated polysiloxane from step (A) or (B) with at least one polyol to form a product, (D) reacting the product obtained in step (C) with at least one diisocyanate or at least one polyisocyanate to obtain the NCO-terminated polysiloxane prepolymer.

9: The process as claimed in claim 8, characterized in that step (B) is carried out by one selected from the group consisting of thin-film evaporation, phase separation, precipitation, and combinations thereof.

10: The process as claimed in claim 8, characterized in that, after step (B), the content in the reaction mixture of the at least one diisocyanate or the at least one polyisocyanate is not more than 5% by weight.

11: A formulation comprising at the least one NCO-terminated polysiloxane prepolymer as claimed in claim 1, in an amount of from 5% to 70% by weight based on the weight of the formulation.

12: The formulation as claimed in claim 11, characterized in that it is a paint formulation.

13: A curing agent in a paint formulation comprising the NCO-terminated polysiloxane prepolymer as claimed in claim 1.

14: The polysiloxane prepolymer as claimed in claim 1, characterized in that the polysiloxane prepolymer has a number-average molecular weight Mn of >450 g/mol and <3000 g/mol.

15: The polysiloxane prepolymer as claimed in claim 1, characterized in that the polysiloxane prepolymer has a number-average molecular weight Mn of >650 g/mol and <2500 g/mol.

16: The polysiloxane prepolymer as claimed in claim 1, characterized in that the polysiloxane prepolymer has a number-average molecular weight Mn of >800 g/mol and <2500 g/mol.

Description

EXAMPLES

[0249] All experiments were unless otherwise stated carried out at 23° C. and 50% relative humidity.

[0250] NCO contents were determined titrimetrically in accordance with DIN EN ISO 11909:2007-05.

[0251] OH values were determined titrimetrically in accordance with DIN 53240-2:2007-11.

[0252] Acid values were determined in accordance with DIN EN ISO 2114:2002-06.

[0253] The OH contents reported were calculated from the analytically determined OH values. The reported values are in each case based on the total weight of the respective composition including any solvent also used.

[0254] The residual monomer contents were measured according to DIN EN ISO 10283:2007-11 by gas chromatography with internal standard.

[0255] The solids content was determined in accordance with DIN EN ISO 3251:2008-06.

[0256] The drying times (T1, T3, and T4) were determined in accordance with DIN EN ISO 9117-5:2010-07 (drying tests—part 5: Modified Bandow-Wolff method).

[0257] The viscosity was determined at 23° C. in accordance with DIN EN ISO 3219/A:1994-10. Unless otherwise stated, this is the dynamic viscosity.

[0258] The number-average molecular weight Mn is determined by gel-permeation chromatography (GPC) in tetrahydrofuran at 23° C. The procedure is in accordance with DIN 55672-1:2016-03: “Gel-permeation chromatography, part 1—Tetrahydrofuran as elution solvent” (SECurity GPC System from PSS Polymer Service, flow rate 0.6 ml/min; columns: 2×PSS SDV (100 A), 2×PSS SDV (50 A), 8×300 mm, 5 μm; RID detector (RI-Agilent 1260). Polystyrene samples of known molar mass are used for calibration. The number-average molecular weight is calculated by the software.

[0259] The gloss at 20° of the coatings obtained was measured reflectometrically in accordance with DIN EN ISO 2813:2015-02.

[0260] The condensation water test was carried out in accordance with DIN EN ISO 6270-2 CH:2018-04.

[0261] The contact angle was determined in accordance with DIN 55660-2:2011-12. For each value, 10 points on the plate of the contact angle with water were examined and the average value of these measurements was reported.

[0262] The wet scratch resistance of the coatings was tested using a laboratory washing unit in accordance with DIN EN ISO 20566:2013-06. The value reported is the loss of gloss in gloss units (GU) after scratching (10 cycles). The lower the loss of gloss in GU, the more resistant the coating is to wet scratching.

[0263] The resistance to dry scratching was carried out using a linear stroke device (crockmeter) in accordance with DIN 55654:2015-08. A weight (950 g) covered on its flat underside with polishing paper (company 3M, grade: 9 MIC) was positioned on the coating without scratching the coating and then mechanically guided over the coating in one track. 10 or 20 back-and-forth strokes were each time executed. After the exposure to the scratching medium, the test area was cleaned with a soft cloth and the gloss then measured in three different places transverse to the direction of scratching. The lower the loss of gloss in GU, calculated from the average for this measurement, the more resistant the coating is to scratching.

[0264] König pendulum damping was determined in accordance with DIN EN ISO 1522:2007-04 on glass plates.

[0265] The described coatings were spray applied. The dry film thickness was for all films 35 to 40 μm.

[0266] Solvent and water resistances were determined in accordance with DIN EN ISO 4628-1:2016-07. The solvent resistance test was carried out using the solvents xylene (also abbreviated hereinafter as “Xy”), methoxypropyl acetate (MPA), ethyl acetate (EA), and acetone (Ac). The contact time was in each case 5 min. For the measurement of water resistances, the contact time was in each case 24 h. The inspection was carried out according to the specified standard. The test surface is assessed visually and by scratching, using the following classification: 0=no change apparent; 1=swelling ring, surface hard, only visible change; 2=swelling ring, slight softening; 3=distinct softening (possibly slight blistering); 4=significant softening (possibly severe blistering), can be scratched through to the substrate; 5=coating completely destroyed without external stressing.

[0267] The reflow describes the recovery of a scratched coating surface, based on the gloss value, after thermal stress. A coating composition is scratched by wet or dry scratching. The residual gloss was determined after the scratching cycle. The coating was placed in the oven at 60° C. for 2 h and the gloss then determined according to the procedure described above. The reflow is reported in percent, i.e. the ratio of residual gloss to reflow value.

[0268] The contact angle was carried out in accordance with DIN 55660-2:2011-12.

[0269] The examples and comparative examples employed the following reagents:

[0270] Diisocyanates:

[0271] Hexamethylene 1,6-diisocyanate (HDI) and isophorone diisocyanate (IPDI) were obtained from Covestro and used without purification.

[0272] Polyols:

[0273] Polyol 1 is based on a polyether diol (Dianol® 320 HP, solid), which contains secondary OH groups and has a hydroxyl value of 325 mg KOH/g). Reaction with propylene oxide gives polyol 1 having a molecular weight of 550 g/mol.

[0274] Polyol 2 is a polyester polyol formed from hexanediol, butanediol, adipic acid, and propanediol, having a functionality of 2, a molecular weight of approx. 400 g/mol, an OH content of approx. 8 wt, and a viscosity of 80 mPa.Math.s

[0275] Polyol 3 is a polyacrylate polyol formed from methyl methacrylate, acrylic acid, styrene, and hydroxyethyl methacrylate that has an OH content of 2.8% by weight based on the solid substances, dissolved in butyl acetate with a solids content of 75% by weight. The viscosity is 5000 mPa.Math.s.

[0276] Polyol 4 is an α,ω-hydroxypropyl-terminated polydimethylsiloxane (Baysilone OF OH 702 (4% by weight)) having an OH content of 4% by weight and a molecular weight of 600 to 800 g/mol. The clear liquid has a kinematic viscosity of 37 mm.sup.2.Math.s.sup.−1.

[0277] Polyol 5 is an aliphatic hydroxy-functional polycarbonate polyester polyurethane dispersion. It was obtained from Covestro and has the following properties: [0278] Viscosity: 300-1500 mPa.Math.s [0279] Nonvolatiles content: 50.0-54.0% [0280] OH content: approx. 1%

[0281] Polyol 6 is a polyester polyacrylate dispersion. It was obtained from Covestro and has the following properties: [0282] Viscosity: 700-7200 mPa.Math.s [0283] Nonvolatiles content: 41-43% [0284] OH content: 3.8%

[0285] Polyol 7 is a polyacrylate polyol. It was obtained from Allnex and is sold under the trade name Setalux DA 870 BA and has the following properties: [0286] Viscosity: 3500 mPa.Math.s [0287] Nonvolatiles content: 70% [0288] OH content: 4.2% (based on solids)

[0289] Amine 1 is a secondary amine produced from 4,4′-methylenebis(cyclohexylamine) and diethyl maleate and has the following properties: [0290] Amine value: 200 mg KOH/g [0291] Viscosity (25° C.): 900-2000 mPa.Math.s [0292] Color index (Hazen): ≤250

[0293] TMP stands for 1,1,1-trimethylolpropane, a trifunctional polyol having a molecular weight of 134 g/mol.

[0294] Polyisocyanates:

[0295] Polyisocyanate 1 is a trimer of hexamethylene 1,6-diisocyanate, having a functionality of 2.8 to 3.6, an NCO content of 23% by weight, an equivalent weight of 183 g/mol, and a viscosity of 1200 mPa.Math.s.

[0296] Polyisocyanate 2 is a trimer of hexamethylene 1,6-diisocyanate, having a functionality of 2.8 to 3.6, an NCO content of 21.8% by weight, a viscosity of 3000 mPa.Math.s, and an equivalent weight of 193 g/mol.

[0297] Polyisocyanate 3 is an allophanate based on hexamethylene 1,6-diisocyanate and propanol/butanol, having a functionality of 2.0 to 2.8, an equivalent weight of 215 g/mol, and a viscosity of 500 mPa.Math.s.

[0298] Polyisocyanate 4 is a trimer of isophorone diisocyanate, having a functionality of 2.8 to 3.6, an NCO content of 11.9% by weight, a solids content of 70%, solvent naphtha 100 (30% by weight), an equivalent weight of 360 g/mol, and a viscosity of 1600 mPa.Math.s.

[0299] Polyisocyanate 5 is an ionically hydrophilized polyisocyanate based on an HDI trimer and a sulfonate-based hydrophilizing agent, having a functionality of ≤2.8, an NCO content of 20.3% by weight, and a viscosity of 3500 mPa.Math.s.

[0300] Additives and Catalysts:

[0301] Tinuvin 292, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (509 g/mol) and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (370 g/mol), is a light stabilizer based on a sterically hindered amine. The viscosity is 400 mPa.Math.s. The product was obtained from BASF and used without further purification.

[0302] Tinuvin 1130, a mixture of β-[3-(2H-benzotriazol-2-yl)-4-hydroxy-5-tert-butylphenyl]propionic acid poly(ethylene glycol) 300 ester (637 g/mol) and bis{b-[3-(2H-benzotriazole-2-yl)-4-hydroxy-5-tert-butylphenyl]propionic acid} poly(ethylene glycol) 300 ester (975 g/mol), is a UV absorber. The viscosity is 7400 mPa.Math.s. The product was obtained from BASF and used without further purification.

[0303] BYK® 141 (solid, 96.8% as supplied), BYK® 331 (solid, 100% as supplied), and BYK® 348 (solid, 100% as supplied) are silicone-containing leveling agents formed from a siloxane and a polyether, covalently linked. The products were obtained from BYK.

[0304] Addocat® 201 is a standard catalyst based on dibutyltin dilaurate (DBTL), used in a concentration of 0.03% by weight on a solid binder. The catalyst was obtained from Lanxess.

[0305] Lucrafoam® DNE 01 is a mineral oil-based defoamer that is used in all pH ranges. The defoamer was obtained from Levaco Chemicals.

[0306] Tego®-Wet KL 245 is a siloxane-based wetting agent having an active content of 100%. It was obtained from Evonik Industries.

[0307] Aquacer 513 is a VOC-free HDPE-based wax emulsion used to improve surface protection in aqueous media. The wax emulsion was obtained from BYK.

[0308] Decosoft Transparent® 7 D is highly crosslinked aliphatic polyurethane particles (100%) that give the coating a soft-feel effect and a matt finish. The product was obtained from Microchem.

[0309] Matting agent Acematt® 3300 ACEMATT 3300 is a fumed silica that has been further treated with a special polymer. This matting agent is characterized by ultrahigh matting efficiency with high transparency.

[0310] Solvents such as butyl acetate (BA) and methoxypropyl acetate (MPA) were obtained from Azelis.

Example 1 (Inventive)

[0311] An initial charge of 441 g of HDI was heated to 105° C. To this was added 280 g of Baysilone OFOH 702 and the reaction mixture was stirred for 3 h at 100° C. under a nitrogen atmosphere. After stirring for a further 2 h at 110° C., the unreacted HDI monomer was removed in a thin-film evaporator at a temperature of 150° C. and a pressure of 0.1 mbar. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained. [0312] NCO content: 6.65% by weight [0313] Solids content: 100% [0314] Viscosity 320 mPa.Math.s [0315] HDI: <0.3% by weight

Example 2 (Inventive)

[0316] An initial charge of 583 g of IPDI was heated to 105° C. To this was added 280 g of Baysilone OFOH 102 and the reaction mixture was stirred for 3 h at 100° C. under a nitrogen atmosphere. After stirring for a further 2 h at 110° C., the unreacted HDI monomer was removed in a thin-film evaporator at a temperature of 150° C. and a pressure of 0.1 mbar. A practically colorless, clear NCO-terminated prepolymer (425 g) having the following properties was obtained. [0317] NCO content: 7.35% by weight [0318] Solids content: 100% [0319] Viscosity 3500 [0320] IPD: <0.3% by weight

Example 3 (Comparative Example, One-Pot Reaction)

[0321] An initial charge of 756 g of Desmodur H was heated to 105° C. A mixture of 8 g of TMP, 33 g of polyol 1, and 120 g of polyol 4 was then added and the reaction mixture was stirred for 2 h at 110° C. under a nitrogen atmosphere. After stirring for a further 2 h at 110° C., the unreacted HDI monomer was removed in a thin-film evaporator at a temperature of 130° C. and a pressure of 0.1 mbar. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained. [0322] NCO content: 9.5% [0323] Solids content: 100% [0324] Viscosity 960 mPa.Math.s

Example 4 (Inventive)

[0325] 30.5 g of the product from example 1 was reacted with 21.3 g of polyol 2, 50% by weight solution in MPA, and in the presence of Addocat 201 (0.03% by weight). The reaction was carried out at 60° C. under a nitrogen atmosphere. Once the measured NCO content was less than 0.1% by weight, 55.5 g of Desmodur N3600 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. until an NCO content of 4.9% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained. [0326] NCO content: 4.9% [0327] Solids content: 50% [0328] Viscosity 190 mPa.Math.s

Example 5 (Inventive)

[0329] 15.25 g of the product from example 1 was reacted with 3.35 g of 1,1,1-trimethylolpropane, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 82.5 g of polyisocyanate 3 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 6.8% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained. [0330] NCO content: 6.75% by weight [0331] Solids content: 50% by weight [0332] Viscosity 232 mPa.Math.s

Example 6 (Inventive)

[0333] 15.3 g of the product from example 1 was reacted with 3.35 g of 1,1,1-trimethylolpropane, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 92.5 g of polyisocyanate 1 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 8.5% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0334] NCO content: 8.5% by weight [0335] Solids content: 50% by weight [0336] Viscosity 110 mPa.Math.s

Example 7 (Inventive)

[0337] 5.28 g of the product from example 2 was reacted with 1.08 g of 1,1,1-trimethylolpropane, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 29.3 g of polyisocyanate 1 was added. The reaction mixture was adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 8.48% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0338] NCO content: 8.48% by weight [0339] Solids content: 50% by weight [0340] Viscosity 175 mPa.Math.s

Example 8 (Inventive)

[0341] 5.28 g of the product from example 2 was reacted with 1.08 g of 1,1,1-trimethylolpropane, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 32.8 g of polyisocyanate 5 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 6.75% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0342] NCO content: 6.75% by weight [0343] Solids content: 50% by weight [0344] Viscosity 145 mPa.Math.s

Example 9 (Inventive)

[0345] 11.02 g of the product from example 2 was reacted with 2.24 g of 1,1,1-trimethylolpropane, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 120 g of polyisocyanate 4 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 6.48% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0346] NCO content: 6.48% by weight [0347] Solids content: 50% by weight [0348] Viscosity 180 mPa.Math.s

Example 10 (Inventive)

[0349] 11.02 g of the product from example 2 was reacted with 108 g of polyol 2, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 120 g of polyisocyanate 4 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 5.71% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0350] NCO content: 5.71% by weight [0351] Solids content: 50% by weight [0352] Viscosity 30 mPa.Math.s

Example 11 (Inventive)

[0353] 11.02 g of the product from example 2 was reacted with 40.5 g of polyol 3, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 120 g of polyisocyanate 4 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 5.96% was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0354] NCO content: 5.96% by weight [0355] Solids content: 50% by weight [0356] Viscosity 160 mPa.Math.s

Example 12 (Inventive)

[0357] 6.76 g of the product from example 1 was reacted with 1.49 g of 1,1,1-trimethylolpropane, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 44.9 g of polyisocyanate 5 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 7.82% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0358] NCO content: 7.82% by weight [0359] Solids content: 50.0% by weight [0360] Viscosity 115 mPa.Math.s

Example 13 (Inventive)

[0361] 6.76 g of the product from example 1 was reacted with 27.0 g of polyol 3 BA, 50% by weight solution in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 44.9 g of polyisocyanate 5 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 5.84% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0362] NCO content: 5.84% by weight [0363] Solids content: 50% by weight [0364] Viscosity 100 mPa.Math.s

Example 14 (Inventive)

[0365] 6.76 g of the product from example 1 was reacted with 7.17 g of polyol 2, 50% by weight in MPA, in the presence of Addocat 201. Once the measured NCO content was less than 0.1% by weight, 44.9 g of polyisocyanate 5 (0.03% by weight) was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 7.14% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0366] NCO content: 7.14% by weight [0367] Solids content: 50% by weight [0368] Viscosity 70 mPa.Math.s

Example 15 (Inventive)

[0369] 6.09 g of the product from example 1 was reacted with 24.3 g of polyisocyanate 3, 50% by weight in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 38.6 g of polyisocyanate 2 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 6.75% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0370] NCO content: 6.75% by weight [0371] Solids content: 50% by weight [0372] Viscosity 110 mPa.Math.s

Example 16 (Inventive)

[0373] 6.09 g of the product from example 1 was reacted with 1.34 g of 1,1,1-trimethylolpropane, 50% by weight in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 38.6 g of polyisocyanate 2 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 6.75% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0374] NCO content: 6.75% by weight [0375] Solids content: 50% by weight [0376] Viscosity 200 mPa.Math.s

Example 17 (Inventive)

[0377] 6.09 g of the product from example 1 was reacted with 6.45 g of polyol 2, 50% by weight in MPA, in the presence of Addocat 201 (0.03% by weight). Once the measured NCO content was less than 0.1% by weight, 38.6 g of polyisocyanate 2 was added and the reaction mixture adjusted with MPA to a solids content of 50% by weight. The reaction was carried out at 60° C. with stirring until an NCO content of 6.75% by weight was attained. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0378] NCO content: 6.75% by weight [0379] Solids content: 50% by weight [0380] Viscosity 90 mPa.Math.s

Example 17 (Inventive)

[0381] 12.63 g of the product from example 1 was stirred with 16.56 g of amine 1 and at RT for 8 h. 77.20 g of polyisocyanate 2 was then added and the mixture likewise stirred at RT for 8 h. A practically colorless, clear NCO-terminated prepolymer having the following properties was obtained: [0382] NCO content: 7.01% by weight [0383] Solids content: 50% by weight [0384] Viscosity 100 mPa.Math.s

Use Examples

[0385] Table 1 presents various paint systems. The components of the paint formulations were mixed with one another and applied by means of a spray application process on glass and basecoat (multilayer construction). The coated specimens are dried at 60° C. for 30 min.

TABLE-US-00001 TABLE 1 The formulations were spray-applied and baked at 60° C. for 30 min. All analytical values were determined after 7 days. Byk Byk Example Xylene MPA Butyl Addocat Tinuvin Tinuvin 331 141 50 0 0 0 1 50 50 10 96.8 — 10.60 6.44 10.60 1.50 2.00 1.00 1.50 0.25 — 10.60 6.44 10.60 1.50 2.00 1.00 — — — 10.09 6.15 10.09 1.50 2.00 1.00 1.50 0.25 — 10.09 6.15 10.09 1.50 2.00 1.00 — — — 9.95 6.06 9.95 1.50 2.00 1.00 1.50 0.25 — 9.95 6.06 9.95 1.50 2.00 1.00 — — — 11.08 6.74 11.08 1.50 2.00 1.00 1.50 0.25 — 11.08 6.74 11.08 1.50 2.00 1.00 — — 2.39 11.23 6.86 11.23 1.5 2.00 1.00 1.50 0.25 Polyiso- Polyol cyanate 7 Product 1 Example Example Example 70 Solids 100 50 50 50 48.33 Weight (g) Paint 1 14.71 — — 3.07 48.33 Weight (g) Paint 2 14.71 — — 3.07 47.96 Weight (g) Paint 3 13.55 — 5.91 — 47.96 Weight (g) Paint 4 13.55 — 5.91 — 48.37 Weight (g) Paint 5 13.03 6.39 — — 48.37 Weight (g) Paint 6 13.03 6.39 — — 49.21 Weight (g) Paint 7 15.63 — — — (comp.) 49.21 Weight (g) Paint 8 15.63 — — — (comp.) 47.82 Weight (g) Paint 9 14.11 — — — (comp.) comp. = comparative example

[0386] For the various paint formulations, the contact angle against H.sub.2O after spray application was determined. For paint 1 (with leveling agent) in comparison to paint 2 (without leveling agent), it is shown here by way of example that the employed silicone-containing leveling agents have no effect on the contact angle, since the values are of the same order (97° and 100° respectively) and are accordingly comparable. For paint 1 to paint 5 it has been shown that the addition of NCO-terminated prepolymers containing siloxane chains is able to achieve an increase in contact angle without affecting customary paint parameters such as gloss.

[0387] In addition, only a slight fluctuation in contact angle is observed after dry scratching and, surprisingly, in the condensation water test (SWT). The observed results show marked differences from the comparisons paint 8 and paint 9, which contain no NCO-terminated, siloxane-containing prepolymers; these have a contact angle that is approx. 20° low. Comparative example paint 9 does also comprise siloxane-terminated prepolymer, but this has a different composition. As a consequence, a decrease in contact angle is observed in the condensation water test.

TABLE-US-00002 TABLE 2 Determination of the contact angle of various clearcoats before and after stressing by scratching and condensation water test (SWT). Contact angle Paint Paint Paint Paint Paint 7.sup.[1] Paint 8 Paint 9 H.sub.2O [°] 1.sup.[1] 2 3.sup.[1] 5.sup.[1] (comp.) (comp.) (comp.) Basecoat 97 100 96 96 83 80 101 (before) After PP 94 93 95 94 82 80 — and reflow (2 h 60° C.) After SWT.sup.[2] 97 95 96 95 73 74 913 Δ 0 5 0 3 30 6 10 .sup.[1]with leveling agent. .sup.[2]SWT = condensation water test.

[0388] The siloxane-containing coatings were surprisingly observed to have better reflow by comparison with the comparative examples. This is explained by way of example by comparing paint 3 with paint 7. After dry scratching, the gloss for both clearcoats falls—from the same baseline value—to approx. 11 gloss units. After reflow, a value of 87 gloss units is obtained for paint 3, whereas for paint 7 a value of only 77 gloss units is observed.

TABLE-US-00003 TABLE 3 Dry scratching using a hammer for various paint systems. Reflow: 2 h, 60° C. All paint systems comprise leveling agents. Dry scratching with a hammer Paint 1 Paint 3 Paint 5 Paint 7 Paint 9 Gloss 20° before 91.1 91.1 91.4 91.4 89.6 Gloss 20° afterwards 11.2 11.5 11.5 11.0  9.9 Residual gloss after 12.3 12.6 12.6 12.0 11.0 PP [%] Gloss 20° reflow 86.1 87.3 85.8 70.4 77.3 Residual gloss after 94.5 95.8 93.9 77.0 86.3 reflow [%]

[0389] Table 4 compares paint systems that all comprise leveling additives. Here, too, it is clearly evident that the siloxane-containing systems have markedly better residual gloss and reflow (e.g. paint 6 vs. paint 8).

TABLE-US-00004 TABLE 4 Dry scratching using a crockmeter for various paint systems. Reflow: 2 h, 60° C. All paint systems contain no leveling agents. Dry scratching using crockmeter Paint 2 Paint 4 Paint 6 Paint 8 Gloss 20° before 91 91 91 92 Gloss 20° afterwards 42 34 38 15 Residual gloss after 46 37 42 16 PP [%] Gloss 20° reflow 81 69 63 29 Residual gloss after 89 76 70 46 reflow [%]

[0390] A further surprising beneficial effect observed through addition of the NCO-terminated siloxane prepolymers was an improved appearance: The coating of the standard formulation forms in the absence of leveling additives an “orange peel” surface. When the NCO-terminated siloxane prepolymers of the invention were used and leveling additives omitted, no orange peel was observed. The addition of the NCO-terminated siloxane prepolymers of the invention thus eliminates the need for additives in the clearcoat, without this being accompanied by orange peel formation.

[0391] In addition, the compatibility of the NCO-terminated polysiloxane prepolymers was investigated. This is illustrated using the formulations shown in Table 5 by way of example.

TABLE-US-00005 TABLE 5 Paint formulations with increased NCO-terminated siloxane content. Paint 10 Paint 11 Paint 12 PIC/NCO-siloxane 8:2 7:3 6:4 (binder solid-on-solid) Polyol 7 50.86 47.54 44.23 Tinuvin 292 1.08 1.04 0.99 Tinuvin 1130 2.16 2.08 1.98 Addocat 201 1.62 1.55 1.38 BA/MPA/XY 33.28 29.27 27.51 Example 4 7.40 11.10 14.80 Polyisocyanate 1 14.80 12.95 11.10 Solids (%) 50% 50% 50%

[0392] As shown in Table 6, the new paint raw materials could be used over a broad concentration range.

TABLE-US-00006 TABLE 6 Spray-painting of paint 10 and paint 11 Paint 10 Paint 11 Paint 12 Optical properties Clear Clear Clear Spray optics Smooth Smooth Smooth Gloss (20°/60°) 91/94 92/95 90/94 Haze 11 11 10 Solvent resistances 2244 2244 2244 Xy-MPA-EA-Ac (5 min)

[0393] The following example examined the suitability of the new siloxane-containing paint raw materials in water-based paints. The corresponding formulations are given in Table 7.

TABLE-US-00007 TABLE 7 2C water-based paints for soft-feel coatings Solids Paint 13 (comp.) Paint 14 content Weight Weight Product [%] [g] (g) Polyol 5 52 25 25 Polyol 6 42 31 31 Dist. water 0 13.7 13.7 Lucrafoam DNE 01 100 0.2 0.2 Tego-Wet KL 245 50 0.4 0.4 Byk 348 100 0.6 0.6 Aquacer 513 35 1.7 1.7 Decosoft Transparent 7 D 100 7.7 7.7 Matting agent Acematt 3300 100 3.1 3.1 Polyisocyanate 5 100 4.98 4.98 Example 4 50 — 1.87 Polyisocyanate 1 100 11.62 11.62

[0394] In these studies, the guideline formulation was retained unchanged and the novel, highly compatible NCO-terminated siloxanes additionally added. The tests showed that an identical mail paint appearance was obtained. The contact angle measurements showed that the contact angle could be increased from 90° to 110°.

TABLE-US-00008 TABLE 8 Water-based paints were applied by spray application, substrate glass. Paint 13 (comp.) Paint 14 Film appearance Matt, like Matt, like paint 14 paint 13 Contact angle H.sub.2O [°] 89.6 111