HK1066234B - Polyurethane resin with high carbonate group content - Google Patents

Description

Polyurethane resins having a high carbonate group content

Cross reference to related patent applications

This patent application claims priority from german patent application No.10251797.5, filed on 7.11.2002, in terms of 35 u.s.c.119(a) - (d).

Technical Field

The present invention relates to solvent-borne polyurethane resins having a high carbonate group content which can be diluted in water, to aqueous coating compositions prepared therefrom, to a process for preparing them and to their use.

Background

"Soft feel" in the context of the present invention refers to the particular tactile sensation (tactile character) of the coated surface. This tactile property can be expressed by terms such as velvet-like, soft, rubbery or warm feel, while for example the surface of a coated vehicle body or a plastic sheet (e.g. ABS, Makrolon) or perspex not coated or coated with a conventional varnish or top coat feels smooth and cold. EP-A0529094 describes, for example, solvent-based surface coatings with a soft touch, the tactile properties being achieved by combining polyurethane resins with elastomer particles or with porous inorganic materials.

Modern aqueous coating compositions can replace binders in organic solutions in many applications. However, for certain applications with specific requirements, such as coating substrates and more particularly plastic substrates with, for example, soft-touch coatings, there has hitherto been a lack of aqueous binders which meet all the requirements required, especially those relating to the resistance of the films. Thus, for example, EP-A0358979 describes aqueous two-component reactive polyurethane systems based on secondary dispersions of vinyl polymers and on polyisocyanate crosslinkers, which already have high levels of various properties, in particular with regard to resistance to solvents and other chemicals. However, the target tactile properties of soft touch are still not achieved with these coating compositions.

EP-A0669352 describes special aqueous polyester-polyurethane dispersions which, in combination with crosslinker resins and, if appropriate, linear, hydroxyl-free polyurethane dispersions, can be cured to give coatings having good soft touch, good mechanical properties, and generally satisfactory solvent resistance. However, for certain applications, there is still a need for improvement in the resistance to sunscreens (sunscreens) in particular.

EP-A0926172 describes aqueous two-component (2K) polyurethane coatings in which the resistance to sun protection agents, which penetrate the membrane and cause delamination and/or other damage, can be improved by using special ester-modified polyisocyanates. The binders used in this case are mixtures of carboxylate-and/or sulfonate-hydrophilized polyester polyol dispersions with physically dry carboxylate-and/or sulfonate-hydrophilized polyurethane dispersions.

It is an object of the present invention to provide novel polyurethane resins which can be processed to aqueous coating compositions, which have good resistance, in particular to damage caused by exposure to sunscreens, and at the same time, in the form of films, have a markedly soft feel. The polyurethane resin should also be readily processable with commercially available hydrophilized or non-hydrophilized polyisocyanates to form coating systems.

Disclosure of Invention

The invention relates to a water-dilutable polyurethane resin which is obtained by reacting:

A1) at least one polycarbonate polyol having a number average molecular weight of 400 to 6000Da,

A2) optionally, a polyester polyol having a number average molecular weight Mn of 400 to 6000Da, different from component (A1),

A3) optionally, a low molecular weight compound containing two or more hydroxyl and/or amino groups having a molecular weight of 60 to 400Da,

A4) optionally a compound which is monofunctional with respect to the reaction with isocyanate groups or contains active hydrogen atoms of different reactivity, these units being located at the end of the polymer chain,

A5) at least one compound containing at least two isocyanate-reactive groups and at least one group capable of forming an anion, and

A6) one or more polyisocyanates.

The polyurethane resin obtained contains 5.8 to 20.0% by weight of the carbonate groups- (C ═ O) O-incorporated and is present in a solvent which is inert to isocyanate groups.

The present invention also relates to an aqueous coating system comprising:

a) at least one non-aqueous component comprising the above water-dilutable polyurethane resin,

b) one or more aqueous binder components comprising at least one non-hydroxyl polyurethane dispersion,

c) optionally, auxiliaries and additives and

d) at least one crosslinker component.

The invention further relates to substrates coated with the above-described aqueous coating system.

Detailed description of the invention

Other than in the operating examples, or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term "about".

The present invention provides a water-dilutable polyurethane resin obtainable by reacting:

A1) at least one polycarbonate polyol having a molecular weight Mn of 400 to 6000Da,

A2) if desired, a polyester polyol which is different from component (A1) and has a number average molecular weight Mn of 400 to 6000Da,

A3) if desired, low molecular weight compounds containing two or more hydroxyl and/or amino groups and having a molecular weight of from 60 to 400Da,

A4) if desired, a compound which is monofunctional for the reaction with isocyanate groups or contains active hydrogen atoms of different reactivity, these units being located in each case at the chain end of the polymer containing urethane groups,

A5) at least one compound containing at least two isocyanate-reactive groups and at least one group capable of forming an anion, and

A6) one or more polyisocyanates selected from the group consisting of,

the resulting polyurethane resin contains 5.8 to 20.0 wt.%, in some cases 7.0 to 14.0 wt.%, and in other cases 8.0 to 12.0 wt.% of the incorporated carbonate groups O (C ═ O) O and is present in a solvent that is inert with respect to isocyanate groups.

The water-dilutable polyurethane resins of the invention have average molecular weights Mn of generally from 1000 to 30000Da, in some cases from 1500 to 10000Da, acid numbers of from 10 to 80, in some cases from 15 to 40mg KOH/g, and OH contents of from 0.5 to 5% (by weight), in some cases from 1.0 to 3.5% (by weight). The solids content of the polyurethane resins of the present invention is at least 50 weight percent, in some cases at least 70 weight percent and in other cases from 75 to 90 weight percent. The remainder, referred to 100% by weight, consists of solvents which are inert to isocyanate groups and, if appropriate, conventional coating auxiliaries and additives.

The present invention also provides an aqueous coating system comprising:

a) at least one non-aqueous component comprising the water-dispersible polyurethane resin of the present invention,

b) one or more aqueous binder components comprising at least one non-hydroxyl, preferably anionically and/or non-ionically hydrophilicized polyurethane dispersion,

c) optionally auxiliaries and additives, and

d) at least one crosslinker component.

"free of hydroxyl groups" means that for the purposes of the present invention the polyurethane does not carry hydroxyl groups, except at the end groups of the polymer chain. Because of the relatively high molecular weight (compared to the water-dilutable polyurethane resins of the present invention), the concentration of end groups is low, corresponding to an OH content of <0.5 wt.%, typically <0.2 wt.%.

The invention further provides a process for preparing aqueous coating systems, characterized in that the water-dilutable polyurethane resins of the invention are introduced into an aqueous phase comprising at least one hydroxyl-free aqueous polyurethane dispersion and, if desired, auxiliaries and additives, and subsequently at least one crosslinker component and, if desired, further auxiliaries and additives are dispersed into this aqueous base varnish.

The polyurethane resin of the present invention has been synthesized from the following components:

A1)25 to 80 wt.%, in some cases 30 to 70 wt.%, of at least one polycarbonate polyol, whose molecular weight Mn is 400 to 6000Da and which has a carbonate group content of at least 10 wt.%,

A2)0 to 60 wt.%, in some cases 10 to 50 wt.%, of at least one polyester polyol which is different from component (A1) and has a number average molecular weight Mn of 400 to 6000Da,

A3)0 to 20 wt.%, in some cases 1 to 15 wt.%, of at least one low molecular weight compound containing two or more hydroxyl and/or amino groups and having a molecular weight of 60 to 400Da,

A4) from 0 to 10% by weight, in some cases 0% by weight, of at least one compound which is monofunctional with respect to the reaction with NCO groups or contains active hydrogen atoms of different reactivity, these units being located in each case at the end of the chain of the polymer containing urethane groups,

A5)2 to 10% by weight, in some cases 3 to 8% by weight, of at least one compound containing at least two isocyanate-reactive groups and at least one group capable of forming anions, and

A6) from 5 to 50% by weight, in some cases from 8 to 30% by weight, of one or more polyisocyanates,

the sum of these components is 100% by weight.

Component (A1) suitably comprises a hydroxyl-containing polycarbonate whose molecular weight Mn is from 400 to 6000Da, in some cases from 600 to 3000Da, and which is obtainable, for example, by reacting a carbonic acid derivative, such as diphenyl carbonate, dimethyl carbonate or phosgene, with a polyol, and in some cases a diol. Examples of suitable such diols include ethylene glycol, 1, 2-and 1, 3-propanediol, 1, 3-and 1, 4-butanediol, 1, 6-hexanediol, 1, 8-octanediol, neopentyl glycol, 1, 4-bishydroxymethylcyclohexane, 2-methyl-1, 3-propanediol, 2, 2, 4-trimethylpentane-1, 3-diol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, bisphenol A, tetrabromobisphenol A, and lactone-modified diols. The diol component contains preferably from 40 to 100% by weight of hexanediol, preferably 1, 6-hexanediol and/or hexanediol derivatives, preferably those which, in addition to terminal OH groups, contain ether groups or ester groups, examples being products obtained by reacting 1mol of hexanediol with at least 1mol, in some cases from 1 to 2mol, of caprolactone or by etherification of hexanediol itself to give dihexylene or trihexylene glycol. It is also possible to use the polyether-polycarbonate diols described in DE-A3717060.

The hydroxy polycarbonate (Al) is preferably linear. However, they may be slightly branched, if appropriate by incorporation of polyfunctional components, in particular low molecular weight polyols. Compounds suitable for this purpose include, for example, glycerol, trimethylolpropane, hexane-1, 2, 6-triol, butane-1, 2, 4-triol, trimethylolethane, pentaerythritol, p-cyclohexanediol, mannitol, and sorbitol, methyl glycoside or 1, 3, 4, 6-dianhydrohexitols.

The polyester polyols which can be used as component (A2) have a number average molecular weight Mn of from 400 to 6000Da, in some cases from 600 to 3000 Da. Their hydroxyl number is generally from 22 to 400, in some cases from 50 to 200 and in other cases from 80 to 160 mgKOH/g. The OH functionality is in the range of from 1.5 to 6, in some cases from 1.8 to 3, and in other cases from 1.9 to 2.5.

Highly suitable compounds are the customary polycondensates of diols and, if appropriate, polyols (triols, tetraols) and dicarboxylic acids and, if appropriate, polycarboxylic (tricarboxylic, tetracarboxylic) acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic anhydrides or the corresponding lower alcohol polycarboxylic esters for preparing the polyesters. Examples of suitable diols are ethylene glycol, butanediol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, and also propylene glycol or butane-1, 4-diol, preferably hexane-1, 6-diol, neopentyl glycol or hydroxypivalic acid (neopentyl glycol) ester. It is likewise possible, if desired, to use polyols such as trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate.

Examples of suitable dicarboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, itaconic acid, malonic acid, suberic acid, 2-methylsuccinic acid, 3, 3-diethylglutaric acid, 2, 2-dimethylsuccinic acid. Possible anhydrides of these acids are likewise suitable. In the context of the present invention, the anhydride is always included by the "acid".

It is also possible to use monocarboxylic acids, such as benzoic acid and hexane carboxylic acid, provided that the average functionality of the polyol is greater than 2. Saturated aliphatic or aromatic acids are preferred, such as adipic acid or isophthalic acid. It is also possible, if desired, to use smaller amounts of polycarboxylic acids, such as trimellitic acid.

Hydroxycarboxylic acids which can be used as reaction partners in the preparation of the polyester polyols having terminal hydroxyl groups are, for example, hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid, hydroxystearic acid and the like. Suitable lactones are, for example, caprolactone or butyrolactone.

The compounds of component (A2) may also comprise, at least proportionally, primary or secondary amino groups as isocyanate-reactive groups.

The low molecular weight polyol (a3) is generally used for the purpose of toughening and/or branching the polymer chain. The molecular weight is in the range of 60 to 400Da, in some cases 62 to 200 Da. They can contain aliphatic, cycloaliphatic or aromatic groups. Suitable polyols (A3) are compounds having up to about 20 carbons per molecule, such as ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-butanediol, 1, 3-butanediol, cyclohexanediol, 1, 4-cyclohexanedimethanol, 1, 6-hexanediol, hydroquinone dihydroxyethyl ether, bisphenol A [2, 2-bis (4-hydroxyphenyl) propane ], hydrogenated bisphenol A (2, 2-bis- (4-hydroxycyclohexyl) propane) and mixtures thereof, and trimethylolpropane, glycerol or pentaerythritol. It is likewise possible to use ester diols, such as delta-hydroxybutyl-epsilon-hydroxy-hexanoate, omega-hydroxyhexyl-gamma-hydroxybutyrate, beta-hydroxyethyl adipate or bis (. beta. -hydroxyethyl) terephthalate.

Diamines or polyamines and hydrazides can likewise be used as (A3), examples being ethylenediamine, 1, 2-and 1, 3-diaminopropane, 1, 4-diaminobutane, 1, 6-diaminohexane, isophoronediamine, isomer mixtures of 2, 2, 4-and 2, 4, 4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine, 1, 3-and 1, 4-xylylenediamine, α, α, α ', α' -tetramethyl-1, 3-and-1, 4-xylylenediamine and 4, 4-diaminodicyclohexylmethane, dimethyl-ethylenediamine, hydrazine or dihydrazide. Component (A3) preferably contains at least 2% by weight, based on components (A1) to (A6), of at least one compound having three or more functional groups which are reactive with NCO groups.

If appropriate, the polyurethane resin also comprises units (A4) which are each located at the chain end and close the chain end. These units are derived on the one hand from monofunctional, isocyanate-reactive compounds, such as monoamines, in particular mono-secondary amines, or monoalcohols. Mention may be made, for example, of methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaminopropylamine, diethyl (methyl) aminopropylamine, morpholine, piperidine or substituted derivatives thereof, amidoamines formed from diprimary amines and monocarboxylic acids, monoketimines of diprimary amines, primary/tertiary amines, such as N, N-dimethylaminopropylamine.

Likewise suitable as component (A4) are compounds containing active hydrogen atoms which are differently reactive toward isocyanate groups, such as compounds which contain secondary amino groups in addition to primary amino groups or COOH groups in addition to OH groups or OH groups in addition to amino groups (primary or secondary). Preference is given to compounds (A4) which contain OH groups in addition to amino groups (primary or secondary). Examples of such compounds are primary/secondary amines, such as 3-amino-1-methylaminopropane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino-1-methylaminobutane; mono-hydroxy-carboxylic acids, such as glycolic, lactic or malic acid, and alkanolamines, such as N-aminoethylethanolamine, ethanolamine, 3-amino-propanol, neopentanolamine, and diethanolamine are particularly preferred. In this way, it is additionally possible to introduce functional groups into the polymer end product.

Ionic or potentially ionic compounds suitable as component (a5) include, for example, mono-and dihydroxycarboxylic acids, mono-and diaminocarboxylic acids, mono-and dihydroxysulfonic acids, mono-and diaminosulfonic acids and their salts, such as dihydroxycarboxylic acids, hydroxypivalic acid, N- (2-aminoethyl) - β -alanine, 2- (2-aminoethylamino) ethanesulfonic acid, ethylenediamine-propyl or butylsulfonic acid, 1, 2-or 1, 3-propylenediamine- β -ethanesulfonic acid, lysine, 3, 5-diaminobenzoic acid, hydrophilicizing agents according to example 1 of EP-a 0916647 and the alkali metal and/or ammonium salts thereof; adducts of sodium bisulfite with poly (ether sulfonate) of but-2-ene-1, 4-diol or 2-butenediol and NaHSO₃Propoxylated adducts of (A) (e.g. in DE-A2446440, pages 5 to 9, formulae I to III). Preferred ionic or potentially ionic compounds (a5) are those having carboxyl and/or carboxylate groups. Particularly preferred ionic compounds (A5) are dihydroxycarboxylic acids, in particular alpha, alpha-dimethylolalkanoic acids, such as 2, 2-dimethylolacetic acid, 2, 2-dimethylolpropionic acid, 2, 2-dimethylolbutyric acid, 2, 2-dimethylolpentanoic acid or dihydroxysuccinic acid.

The polyurethane resin of the present invention preferably does not contain a sulfonic acid group.

The components (a1) to (a5) may also contain C ═ C double bonds, for example from long-chain aliphatic carboxylic acids or fatty alcohols. Functionalization with olefinic double bonds is also possible, for example, by introducing allylic groups or acrylic or methacrylic acid and their respective esters.

Furthermore, the components (A1) to (A5) may also contain compounds having nonionic hydrophilicizing activity, examples being polyoxyalkylene ethers having at least one hydroxyl or amino group. These polyethers comprise a proportion of from 30% to 100% by weight of units derived from ethylene oxide. They suitably include polyethers of linear structure having a functionality of between 1 and 3, and compounds of the general formula (I)

Wherein

R¹And R²Independently of one another, are each a divalent aliphatic, cycloaliphatic or aromatic radical having from 1 to 18 carbon atoms which is capable of inserting oxygen and/or nitrogen atoms, and

R³non-hydroxyl terminated polyesters or preferably polyethers, especially alkoxy terminated polyethylene oxide groups.

Examples of polyisocyanates suitable as component (A6) include diisocyanates having a molecular weight of 140 to 400 containing aliphatically, cycloaliphatically, araliphatically and/or aromatically bonded isocyanate groups, such as 1, 4-diisocyanatobutane, 1, 6-diisocyanatohexane (HDI), 2-methyl-1, 5-diisocyanatopentane, 1, 5-diisocyanato-2, 2-dimethylpentane, 2, 2, 4-and 2, 4, 4-trimethyl-1, 6-diisocyanatohexane, 1, 10-diisocyanatodecane, 1, 3-and 1, 4-diisocyanatocyclohexane, 1, 3-and 1, 4-bis (isocyanatomethyl) cyclohexane, 1-isocyanato-3, 3, 5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 4, 4 ' -diisocyanatodicyclohexylmethane, 1-isocyanato-1-methyl-4 (3) isocyanatomethylcyclohexane, bis (isocyanatomethyl) norbornane, 1, 3-and 1, 4-bis (2-isocyanato-prop-2-yl) benzene (TMXDI), 2, 4-and 2, 6-diisocyanatotoluene (TDI), 2, 4 ' -and 4, 4 ' -diisocyanatodiphenylmethane, 1, 5-diisocyanatonaphthalene or any desired mixtures of such diisocyanates. Preference is given to polyisocyanates or polyisocyanate mixtures of the stated type which contain exclusively aliphatically and/or cycloaliphatically bound isocyanate groups. Particularly preferred starting components (A6) are polyisocyanates or polyisocyanate mixtures based on HDI, IPDI and/or 4, 4' -diisocyanatodicyclohexylmethane.

In addition to these simple diisocyanates, also suitable are those polyisocyanates which contain heteroatoms in the radical linking the isocyanate groups and/or have a functionality of more than 2 NCO groups per molecule. The former are polyisocyanates which are prepared, for example, by modification of simple aliphatic, cycloaliphatic, araliphatic and/or aromatic diisocyanates, are synthesized from at least 2 diisocyanates, and have uretdione (uretdione), isocyanurate, urethane, allophanate, biuret, carbodiimide, iminooxadiazinedione (iminooxadiazinedione) and/or oxadiazinetrione (oxadiazinetrione) structures; an example of a non-modified polyisocyanate having more than 2 NCO groups per molecule may be mentioned 4-isocyanatomethyloctane 1, 8-diisocyanate (nonane triisocyanate).

Also provided by the present invention is a process for preparing the polyurethane resins of the invention, characterized in that OH-and/or NH-functionalized polyurethanes are prepared from components (A1), (A5) and (A6) and, if desired, components (A2) to (A4) in a solvent which is inert with respect to isocyanate groups.

The water-dilutable polyurethane resins of the invention can be prepared, for example, by first preparing an isocyanate-functional prepolymer from component (A6) and components (A1) and (A5) and, if desired, (A2), (A3) or (A4) and then reacting in a second reaction step with one or more compounds (A3), (A4) or, if desired, (A2) in a solvent medium which is inert towards NCO groups to give OH-and NH-functionalized polyurethanes, for example as described in EP-A0355682, p4, lines 39-45.

In a preferred embodiment, the preparation is carried out by directly reacting the components (A1) to (A6) in a nonaqueous medium to form an OH-and/or NH-containing polyurethane resin, for example as described in EP-A0427028, page 4, line 54 to page 5, line 1.

The urethanization reaction in the preparation of the prepolymer is generally carried out at temperatures of from 0 ℃ to 140 ℃ depending on the reactivity of the isocyanate used. To accelerate the urethanization reaction, suitable catalysts may be used, such as those known to those skilled in the art to accelerate the NCO — OH reaction. Examples are tertiary amines such as triethylamine, organotin compounds such as dibutyltin oxide, dibutyltin dilaurate or tin bis (2-ethylhexanoate), or other organometallic compounds.

The urethanization reaction is preferably carried out in the presence of a solvent which is inactive towards isocyanate groups. Particularly suitable for this purpose are those solvents which are compatible with water, such as ethers, ketones and esters, and also N-methylpyrrolidone. The amount of solvent is suitably not more than 30% by weight and in some cases is in the range from 10 to 25% by weight, in each case based on the sum of the polyurethane resin and the solvent. The polyisocyanate (a6) can be added immediately to the solution of the other component.

The acid groups introduced into the polyurethane resin from component (a5) can be neutralized at least in proportion. Particularly suitable for this neutralization are tertiary amines, examples being trialkylamines having from 1 to 12, in some cases from 1 to 6, carbon atoms in each alkyl group. Examples thereof are trimethylamine, triethylamine, methyldiethylamine, tripropylamine and diisopropylethylamine. The alkyl group may, for example, carry a hydroxyl group, as is the case with dialkyl monoalkanols-, alkyl dialkanols-and trialkanolamines. An example of such a compound is dimethylethanolamine, which is preferably used as neutralizing agent. As neutralizing agents, it is also possible, if appropriate, to use inorganic bases, such as ammonia or sodium or potassium hydroxide. The neutralizing agent is used in a molar ratio of 0.3:1 to 1.3:1, and in some cases 0.4:1 to 1:1, to the acid groups of the prepolymer.

The free COOH groups of the polyurethane resin of the present invention can be neutralized before, during or after the urethanization reaction. This neutralization step is preferably carried out after the urethanization reaction, generally between room temperature and 80 ℃ and in some cases between 40 and 80 ℃. It is also possible to provide the water-dilutable polyurethane resin in unneutralized form and not to neutralize it until during the preparation of the aqueous coating composition: for example, when the water-dilutable polyurethane resin of the invention is incorporated into an OH-free polyurethane dispersion.

If desired, in the production of the polyurethane resin of the present invention, for the purpose of hydrophilization, alkylene oxide-containing monomer units may be added in addition to the acid groups and in proportion, in an incorporated form, or an additional emulsifier may be added. The external emulsifiers which can be used here can be emulsifiers of anionic and/or nonionic nature. Among the anionic emulsifiers, those having carboxylate, sulfate, sulfonate, phosphate or phosphonate groups can be used. Preferred emulsifiers have sulfate, sulfonate, phosphate or phosphonate groups. Suitable non-ionically generated external emulsifiers, which may generally be used in combination with the above-mentioned anionic emulsifiers, include the reaction products of aliphatic, araliphatic, cycloaliphatic or aromatic carboxylic acids, alcohols, phenol derivatives and/or amines with epoxides, such as ethylene oxide. Examples thereof are the reaction products of carboxylic acids of ethylene oxide with castor oil, abitic acids, with longer-chain alcohols such as oleyl alcohol, lauryl alcohol, stearyl alcohol, with phenol derivatives such as substituted benzyl-, phenyl-phenols, nonylphenols, and with longer-chain amines such as dodecylamine and stearylamine. The reaction product formed with ethylene oxide is an oligoether or polyether having a degree of polymerization of between 2 and 100, and in some cases between 5 and 50. The external emulsifier can be added to the water-dilutable polyurethane resin or to another component of the aqueous coating system in an amount of from 0.1 to 10% by weight, based on the non-volatile fraction of the water-dilutable polyurethane resin. However, in some cases only acid groups are used for purely internal hydrophilization.

The aqueous coating system is preferably prepared such that the anhydrous component comprising the polyurethane resin of the present invention is incorporated into the aqueous binder component under shear. Then, in a second step under shear, a crosslinker component, which sometimes comprises a polyisocyanate having free NCO groups, is incorporated into the aqueous base varnish thus obtained. Conventional coating auxiliaries and additives can be introduced into the prepared aqueous coating material together with the crosslinker component, together with the binder component, or subsequently.

Polyurethane dispersions (B) free of hydroxyl groups are known from the coating technology. Preference is given to linear, relatively high (compared with the water-dilutable polyurethane resins of the invention) molecular weight polyurethane dispersions as described, for example, in DE-A2651506 (page 6, lines 1 to 13) or in DE-A1570615 (page 2, line 9 to page 3, line 3).

In a preferred example of an aqueous coating system comprising the polyurethanes of the invention, use is made of hydroxyl-free polyurethane dispersions which, in addition to comprising nonionic hydrophilic groups in the form of polyethylene oxide units, also contain, as hydrophilic groups, anionic groups, preferably carboxylate and/or sulfonate groups, more preferably sulfonate groups, and especially their alkali metal salts. In the selection of the matrix material(s), it should be ensured that the amount of nonionic hydrophilic groups in the form of polyethylene oxide units is from 0.1 to 10% by weight, in some cases from 1 to 7% by weight, based on the resin solids, and the amount of ionic groups is from 2 to 20, in some cases from 2.5 to 15mmol per 100g of resin solids. In a particularly preferred embodiment, the hydroxyl-free polyurethane dispersion is used with from 0.5 to 20 weight percent, in some cases from 1 to 10 weight percent, and in other cases from 2.5 to 8 weight percent of a co-solvent.

Suitable cosolvents are those already described above, preference being given to N-methylpyrrolidone. The addition of the co-solvent can be added at any desired point in the preparation operation of the hydroxyl-free polyurethane dispersion.

Aqueous coating systems comprising the polyurethane resins of the invention can, if appropriate, also contain further binders or dispersions based, for example, on polyesters, polyurethanes, polyethers, polyepoxides or polyacrylates, and if appropriate pigments and further auxiliaries and additives known in the coatings industry.

By using in combination with crosslinking agents, depending on the reactivity of the crosslinking agents or, if appropriate, blocking of the crosslinking agents, it is possible to prepare one-component (1K) and two-component (2K) coatings. The 1K coatings used for the purposes of the present invention are coatings in which the binder component and the crosslinker component can be stored together, but any crosslinking reaction does not take place to a significant extent or to an extent that is detrimental to subsequent use. This crosslinking reaction only takes place at the time of application, after the crosslinking agent has been activated. This activation can be performed, for example, by increasing the temperature. The 2K coatings used for the purposes of the present invention are coatings in which the binder component and the crosslinker component have to be stored in separate containers, owing to their high reactivity. The two components are not mixed until immediately prior to application, as they are generally reacted without additional activation. However, it is also possible to use catalysts or to use higher temperatures in order to accelerate the crosslinking reaction.

Examples of suitable crosslinkers are polyisocyanate crosslinkers, amide-and amine-formaldehyde resins, phenol-formaldehyde resins, polyaldehyde resins and ketone resins, such as phenol-formaldehyde resins, resol resins, furan resins, urea resins, urethane resins, triazine resins, melamine resins, benzoguanamine resins, cyanamide resins, aniline resins, as described in "lackkunsharze", h.wagner, h.f.sarx, Carl Hanser Verlag minchen, 1971. The preferred crosslinking agent is a polyisocyanate.

Polyisocyanates can be used as free and/or blocked isocyanate groups. Suitable such crosslinker resins include blocked polyisocyanates, which are based, for example, on isophorone diisocyanate, hexamethylene diisocyanate, 1, 4-diisocyanatocyclohexane, bis (4-isocyanatocyclohexane) methane or 1, 3-diisocyanatobenzene or on a lacquer polyisocyanate, such as those polyisocyanates which contain biuret or isocyanurate groups and are derived from 1, 6-diisocyanatohexane, isophorone diisocyanate or bis (4-isocyanatocyclohexane) methane or on a lacquer polyisocyanate which contains urethane groups and is based, on the one hand, on 2, 4-and/or 2, 6-diisocyanatotoluene or isophorone diisocyanate and, on the other hand, on low molecular weight polyhydroxyl compounds such as trimethylolpropane, isomerized propylene glycol or butylene glycol or any desired mixture of such polyols.

Suitable blocking agents for the polyisocyanates are, for example, monoalcohols such as methanol, ethanol, butanol, hexanol, cyclohexanol, benzyl alcohol, oximes such as acetoxime, methyl ethyl ketoxime, cyclohexanone oxime, lactams such as epsilon-caprolactam, phenols, amines such as diisopropyl amine or dibutyl amine, dimethylpyrazole or triazole, and also dimethyl malonate, diethyl malonate or dibutyl malonate.

Preference is given to using low-viscosity, hydrophobic or hydrophilicized polyisocyanates having free isocyanate groups, based on aliphatic, cycloaliphatic, araliphatic and/or aromatic isocyanates, more preferably aliphatic or cycloaliphatic isocyanates, since in this way it is possible to achieve particularly high levels of resistance in the coating film. The advantages of the binder dispersants of the invention will be particularly clearly demonstrated by the combination with these crosslinkers. These polyisocyanates generally have a viscosity of from 10 to 3500mPas at 23 ℃. If necessary, the polyisocyanate can be used as a blend with a small amount of an inert solvent in order to reduce the viscosity to a level within the range. Triisocyanatononane can likewise be used alone or as a crosslinker component in a mixture.

The water-dilutable polyurethane resins and hydroxyl-free polyurethane dispersions described here are generally sufficiently hydrophilic if the substances are in any case not water-soluble or water-dispersible, which ensures dispersibility of the crosslinker resins. Water-soluble or gap-dispersible polyisocyanates can be obtained, for example, by modification with carboxylate, sulfonate and/or polyethylene oxide groups and/or polyethylene oxide/polypropylene oxide groups.

Hydrophilization of polyisocyanates is possible, for example, by reaction with substoichiometric amounts of monohydroxy hydrophilic polyether alcohols. The preparation of hydrophilicized polyisocyanates of this type is described, for example, in EP-A0540985 (page 3, line 55 to page 4, line 5). Also highly suitable are the allophanate group-containing polyisocyanates described in EP-A-0959087 (page 3, lines 39-51), which can be prepared by reacting low-monomer-content polyisocyanates with polyethylene oxide polyether alcohols under allophanatization conditions. The water-dispersible polyisocyanate mixtures based on triisocyanatononane described in DE-A10007821 (page 2, line 66 to page 3, line 5) are also suitable, since they are polyisocyanates hydrophilicized with ionic groups (sulfonate groups, phosphonate groups), as described, for example, in DE-A10024624 (page 3, lines 13 to 33). A further possibility is to achieve hydrophilization by addition of commercially available conventional emulsifiers.

It is of course also possible in principle to use mixtures of different crosslinker resins.

As conventional auxiliaries and additives, those which have already been described above can be added to the aqueous coating systems either before, during or after their preparation and also to the binder or crosslinker components present in the systems, for example the following are conceivable: defoamers, thickeners, pigments, dispersing aids, matting agents, catalysts, antiskinning agents, antisettling agents or emulsifiers and also auxiliaries which enhance the desired soft-touch effect.

The aqueous coating systems thus obtained, comprising the polyurethane resins of the invention, are suitable for all fields of application in which aqueous paints and coating systems are used which have high requirements with respect to the surface quality resistance of the films, such as, for example: coatings for surfaces of mineral-structured materials, varnishes and sealants for trees and wood, coatings for metal surfaces (metallic coatings), coatings and varnishes for asphalt or bitumen coverings, paints and sealants for various plastic surfaces (plastic coatings) and high-gloss coatings. Preferably, however, they are suitable for producing soft-touch effect coatings which ensure good solvent resistance and particularly good resistance to sunscreens (in the sunscreen test). Coatings of this type are preferably used in plastic coatings or in wood coatings, where curing is generally carried out at temperatures between room temperature and 130 ℃. The two-component technique with non-blocked polyisocyanate crosslinkers allows the use of lower curing temperatures.

Aqueous coating systems comprising the water-dilutable polyurethanes of the invention are generally used for single-coat coatings or for clearcoats or topcoats (outermost coatings) of multicoat coating systems.

Also provided by the present invention is a substrate coated with a crosslinked coating system comprising the water-dilutable polyurethane resin of the present invention.

The coating can be produced by any of a variety of spray methods, such as air pressure spraying, airless spraying or electrostatic spraying methods, for example, using a one-component or, if appropriate, a two-component spray device. However, coatings and coating systems comprising the polyurethane resins of the present invention may also be applied by other methods, for example by brushing, rolling or knife coating.

Detailed Description

The following examples are intended to illustrate the invention without, however, limiting it. All data expressed in% relate to weight unless otherwise noted. According to DIN 53019 at 40s^-1At a shear rate of (a), viscosity measurements were carried out in a cone and plate viscometer.

Example 1 (inventive)

A15 l reaction vessel equipped with stirrer, heating device and separator with cooler was charged with 1281g of phthalic anhydride, 5058g of adipic acid, 6387g of hexane-1, 6-diol and 675g of neopentyl glycol, and these components were then heated to 140 ℃ under nitrogen for 1 hour. Over a further 9 hours, the mixture was heated to 220 ℃ and condensation was carried out at this temperature until an acid number of below 3 had been reached. The polyester resin obtained in this way had a viscosity of 54 seconds (determined from the flow time of an 80% strength solution of the polyester in methoxypropyl acetate at 23 ℃ in DIN4mm cup (Ford cup viscosity)) and an OH number of 160mg KOH/g.

A6 liter reaction vessel with cooling, heating and stirring means was charged with 1560g of the above polyester under nitrogen and this initial charge was then admixed with 1520g of a linear polyestercarbonate diol (Desmophen) of number average molecular weight 2000VP LS 2391, Bayer AG Leverkusen, DE), 120g of trimethylolpropane, 160g of dimethylolpropionic acid, 1000g of N-methylpyrrolidone and 5g of tin (II) octanoate are heated together to 130 ℃ and the mixture is homogenized for 30 minutes. Then cooled to 80 ℃ and 640g of hexamethylene diisocyanate were added with vigorous stirring, and the mixture (using the reaction exotherm) was heated to 140 ℃ and held at this temperature until no NCO groups could be detected anymore.

The polyurethane obtained in this way is subsequently cooled to 90 ℃ to 100 ℃, 53g of dimethylethanolamine (degree of neutralization: 50%) are added, the polyurethane is diluted by adding 280g of N-methylpyrrolidone, and the mixture is then homogenized. After cooling, a water-dilutable polyurethane resin is obtained which has an OH content of 1.4% (based on solid resin), an acid number of 18.5mg KOH/g (based on solid resin) and approximately 20000mPas (23 ℃; D ═ 40 s) at a solids content of 76% by weight^-1) Viscosity of (2). The resin solids had a carbonate group fraction O (C ═ O) O of 8.9 wt%.

Example 2 (not in accordance with the invention)

"Hydroxyester carbamate B" according to EP-A0926172 (page 7, sections [00640] to [0065 ]) is 80% in N-methylpyrrolidone. The resin solids had a carbonate group fraction O (C ═ O) O of 4.7 wt%.

Example 3 (not in accordance with the invention)

A6 liter reaction vessel with cooling, heating and stirring means was charged under nitrogen to 1170g of the polyester of example 1, which was reacted with 1140g of a linear polyestercarbonate diol (Desm) of number average molecular weight 2000ophenVP LS 2391, Bayer AG, Leverkusen, DE), 90g of trimethylolpropane, 120g of dimethylolpropionic acid, 125g of N-methylpyrrolidone and 3.8g of tin (II) octanoate are heated together to 130 ℃ and the mixture is homogenized for 30 minutes. Then cooled to 80 ℃ and 480g of hexamethylene diisocyanate were added with vigorous stirring, and the mixture (using the reaction exotherm) was heated to 140 ℃ and held at this temperature until no NCO groups could be detected anymore.

The polyurethane obtained in this way is subsequently cooled to 90 ℃ to 100 ℃ and 39g of dimethylethanolamine (degree of neutralization: 50%) are added, and the mixture is then homogenized for 15 minutes and dispersed with 2270g of demineralized water. The aqueous polyurethane resin dispersion obtained in this way had an OH content of 1.4% (based on solid resin), an acid value of 18mgKOH/g (based on solid resin) and an approximate value of 1500mPas (23 ℃ C.; D ═ 40 s) at a solids content of 54.3% by weight^-1) Viscosity of (2). The resin solids had a carbonate group fraction O (C ═ O) O of 8.9 wt%.

Example 4: polyurethane Dispersion 4 (Bayhydrol) PR 240，Bayer AG，Leverkusen)

Sulfonate hydrophilized, hydroxyl-free, aliphatic polyester polyurethane dispersions having a solids content of 40% by weight, an average particle size of about 200nm at a pH of about 7; the dispersion is free of organic solvents.

Example 5: polyurethane Dispersion 5

1700 parts by weight of a polyester diol having an OH number of 66, formed from hexane-1, 6-diol, 2, 2-dimethylpropane-1, 3-diol and adipic acid, and 58.5 parts by weight of a polyether monool having an OH number of 25, formed from n-butanol, ethylene oxide and propylene oxide (in a molar ratio of 83: 17), are dehydrated at 100 ℃ under a vacuum of approximately 15 mbar. The vacuum was then broken with nitrogen. After addition of 250 parts by weight of N-methylpyrrolidone, 250 parts by weight of 1-isocyanato-3, 3, 5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate) and 190 parts by weight of hexamethylene diisocyanate, the mixture is stirred at 100 ℃ until the isocyanate content is 4.4% by weight. After the mixture was cooled to 50-60 ℃, 3900 parts by weight of anhydrous acetone was added. The acetone solution was cooled to 45 ℃. Then a mixture of 107 parts by weight of 1-amino-3, 3, 5-trimethyl-5-aminomethyl-cyclohexane (IPDA) in 210 parts by weight of anhydrous acetone is added. The reaction is exothermic. After the exotherm had subsided, a solution of 22 parts by weight of sodium N- (2-aminoethyl) -2-aminoethanesulfonate and 5 parts by weight of hydrazine monohydrate in 250 parts by weight of water was added. After a subsequent 10 minutes of stirring, 2700 parts of water are slowly added with vigorous stirring. A blue-white dispersion of the solid in a mixture of water and acetone was formed. Removal of the acetone by distillation left an aqueous dispersion with a solids content of 45. + -.1 wt.%.

The dispersion had an average particle size of approximately 210nm and a Ford cup viscosity (DIN4mm cup) of 22 seconds, determined by laser correlation spectroscopy. The resulting hydroxyl-free polyurethane dispersion had an organic co-solvent (N-methylpyrrolidone) content of about 4.5 wt%.

The application example is as follows: preparation of Soft touch paint

To prepare the lacquer, 30.9 parts by weight of this polyurethane dispersion 4 (40% strength) were admixed in each case with 16.3 parts by weight of the water-dilutable polyurethane resin of example 1 (76%), with 15.5 parts by weight of the water-dilutable polyurethane resin of example 2 and with 22.8 parts by weight of the polyester-polyurethane dispersion of example 3 (weight ratio of crosslinkable resin to non-functionalized resin in each case 50:50, based on resin solids) in three batches (1, 2, 3). In addition, 0.2 parts by weight of defoamer DNE (K.Obermayer, Bad Berlebburg, DE), 0.3 parts by weight of Tego were added for each batchWet KL245 (50% in water; Tego Chemie, Esen, DE), 0.4 parts by weight of Byk348(Byk Chemie, Wesel, DE), 1.2 parts by weight of Aquacer535(Byk Chemie, Wesel, DE), 2.8 parts by weight of SilitinZ86(Hoffmann & Neuburg, DE), 4.3 parts by weight of PergopakM3(Martinswerk, Bergheim, DE), 1.4 parts by weight of Talc IT Extra (Norwegian Talc, Frankfurt, DE), 11.2 parts by weight of Bayferrox318M (Bayer AG, levirkusen, DE) and 18 parts by weight of demineralized water were dispersed in a ball mill to give an aqueous millbase. After a residence time of 16h at room temperature, 1.4 parts by weight of matting agent OK 412(Degussa, Frankfurt, DE) were introduced by means of a dissolver. Three additional batches (4, 5, 6) were prepared but using 27.5 parts by weight of polyurethane dispersion 5 (45%) instead of polyurethane dispersion 4. All other components are used in the proportions already described.

When using the polyurethane solutions of example 1 or 2, an additional amount of demineralized water can be added in order to set the desired viscosity of the millbase or raw varnish. This gives a storage-stable aqueous base varnish having a binder content of about 27.5%, a pigment and filler content of about 20.5% and an additive content of about 2%. The pH was 7. + -. 0.5.

Subsequently introduced into the raw varnish batches (1-6) by means of a dissolver is the polyisocyanate crosslinker BayhydurA75% strength solution of 3100(Bayer AG, Leverkusen, DE) in methoxypropyl acetate corresponds to an NCO: OH ratio of 1.5: 1. By spraying onto a plastic sheet (e.g. Bayblend)T65 (polycarbonate/ABS blend)) was applied the lacquer obtained in this way, (dry film thickness 40 μm to 50 μm), and then after a flash time of 10 minutes the film formed was dried at 80 ℃ for 30 minutes and then at 60 ℃ for 16 hours. The result obtained was a matt, uniform paint film with a velvety soft feel ("soft-feel" tactile properties). Table 1 shows the results of the coating tests for binder combinations 1-6.

Table 1: technical results of Soft touch coating according to application examples

^*Rated on a scale of 0-5 (0-velvet-like, soft, warm feel; 5-hard, smooth, cold feel)

^**The resistance to sunscreens and insect protectants ("Suntan Losition Test") was tested in a method based on Ford Test/USA (Engineering Material specification/understanding and cleaning FLTM BN 112-08, ISO 105-A02/AATCC). The test was performed on painted plastic sheets. A glass ring (d ═ 19mm ± 3mm) was placed on the paint surface and 0.25ml of sunscreen ("Coppertone kits", obtained from Coppertone) was introduced using a syringe. When the rheological properties of the sunscreen do not cause it to unfold itself, a suitable device can be used to unfold so that the area surrounded by the ring can be wetted. The sample is then stored at RT or at 74 ℃ for 1 hour, after which the ring is removed and the test area is wiped with a cosmetic cloth. The damage form was visually evaluated on the following scale:

0-5：

no damage when 0 ═ 0-

Reversible damage (complete regeneration)

2 ═ mottle/loss of gloss/discoloration

3-scattered bubbles or wrinkles

Wrinkle and bubble

Severe wrinkling/detachment from substrate/film damage

The paints based on the water-dilutable, OH-containing polyurethane resins of the invention of example 1, in combination with the PUR dispersions of example 4 and of example 5 having comparable tactile properties, show a much better resistance to sunscreens than when using binders not according to the invention (examples 2, 3). Furthermore, an improvement in the resistance to sun protection agents is found in each case when the nonfunctionalized polyurethane dispersion of example 5 is used, compared with example 4.

Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.

Claims (16)

1. A water-dilutable polyurethane resin composition obtained by reacting:

A1) at least one polycarbonate polyol having a number average molecular weight of 400 to 6000Da,

A2) optionally, a polyester polyol having a number average molecular weight Mn of 400 to 6000Da, different from component A1),

A3) optionally, a low molecular weight compound containing two or more hydroxyl and/or amino groups having a molecular weight of 60 to 400Da,

A4) optionally a compound which is monofunctional with respect to the reaction with NCO groups or contains active hydrogen atoms of different reactivity, these units in each case being located at the end of the urethane group-containing polymer,

A5) at least one compound containing at least two isocyanate-reactive groups and at least one group capable of forming an anion, and

A6) one or more polyisocyanates selected from the group consisting of,

wherein the water-dilutable polyurethane resins are prepared by first preparing isocyanate-functional prepolymers from component A6), component A1), A5) and, if desired, A2), A3) or A4) and then reacting in a second reaction step with one or more of A3), A4) or, if desired, A2) in a solvent medium which is inert towards NCO groups,

wherein a neutralizing agent is added in a molar ratio of 0.3:1 to 1.3:1 with the acid groups of the prepolymer,

the polyurethane resins obtained contain 5.8 to 20.0% by weight of incorporated carbonate groups- (C ═ O) O-and are present in a solvent which is inert to isocyanate groups, with a solids content of at least 70% by weight, the remainder, relative to 100% by weight, consisting of one or more solvents which are inert to isocyanate groups and customary coating auxiliaries and additives.

2. A water-dilutable polyurethane resin composition according to claim 1, wherein the average molecular weight Mn of the water-dilutable polyurethane resin is from 1000 to 30,000Da, the acid value is from 10 to 80mg KOH/g and the OH content is from 0.5 to 5% by weight.

3. The water-dilutable polyurethane resin composition according to claim 1, wherein the polyurethane consists of:

A1)25 to 80 wt.% of at least one polycarbonate polyol having a number average molecular weight Mn of 400 to 6000Da and having a carbonate group content of at least 10 wt.%,

A2)0 to 60 wt.% of a polyester polyol which is different from component A1) and has a number average molecular weight Mn of 400 to 6000Da,

A3)0-20 wt% of a low molecular weight compound containing two or more hydroxyl groups and/or amino groups and having a molecular weight of 60 to 400Da,

A4) from 0 to 10% by weight of compounds which are monofunctional with respect to the reaction with NCO groups or contain active hydrogen atoms of different reactivity, which units are in each case located at the chain end of polymers containing urethane groups,

A5)2 to 10% by weight of at least one compound containing at least two isocyanate-reactive groups and at least one group capable of forming anions, and

A6)5 to 50% by weight of one or more polyisocyanates, the sum of these components being 100% by weight.

4. The water-dilutable polyurethane resin composition according to claim 1, wherein component a1) is a linear hydroxy polycarbonate a 1).

5. The water-dilutable polyurethane resin composition according to claim 1, wherein the polyurethane resin contains no sulfonic acid group.

6. A process for preparing a water-dilutable polyurethane resin composition according to claim 1, comprising preparing a polyurethane from components a1), a5) and a6) and optionally components a2) to a4) in a solvent which is inert with respect to isocyanate groups.

7. An aqueous coating system comprising

a) At least one non-aqueous component comprising the water-dilutable polyurethane resin composition according to claim 1,

b) one or more aqueous binder components comprising at least one non-hydroxyl polyurethane dispersion,

c) optionally, auxiliaries and additives and

d) at least one crosslinker component.

8. An aqueous coating system according to claim 7, wherein the crosslinker component is a hydrophobic or hydrophilicized polyisocyanate containing free isocyanate groups based on aliphatic, cycloaliphatic, araliphatic and/or aromatic isocyanates.

9. An aqueous coating system according to claim 8, wherein the crosslinker component is a hydrophobic or hydrophilicized polyisocyanate containing free isocyanate groups, based on aliphatic or cycloaliphatic isocyanates.

10. A method of preparing an aqueous coating system according to claim 7, further comprising introducing the water-dilutable polyurethane resin composition into an aqueous phase comprising at least one hydroxyl-free aqueous polyurethane dispersion, and subsequently dispersing at least one crosslinker component into this aqueous base varnish.

11. A method of coating a substrate comprising applying the water-dilutable polyurethane resin composition of claim 1 to a substrate, wherein the substrate is selected from the group consisting of a mineral structure material surface, wood, a metal surface, an asphalt covering, and a plastic surface.

12. A method of varnishing a substrate comprising applying the water-dilutable polyurethane resin composition of claim 1 to a substrate, wherein the substrate is selected from the group consisting of mineral structure material surfaces, wood, metal surfaces, asphalt coverings, and plastic surfaces.

13. A method of sealing a substrate comprising applying the water-dilutable polyurethane resin composition of claim 1 to a substrate, wherein the substrate is selected from the group consisting of a mineral structure material surface, wood, a metal surface, an asphalt overlay, and a plastic surface.

14. A method for producing a soft touch coating material comprising applying the water-dilutable polyurethane resin composition of claim 1 to a substrate.

15. The method of claim 14, wherein the substrate is plastic or wood.

16. A substrate coated with a crosslinked coating system comprising the water-dilutable polyurethane resin composition of claim 1.