WO2010057937A1

WO2010057937A1 - Method for manufacturing polyurethane-polyurea coatings

Info

Publication number: WO2010057937A1
Application number: PCT/EP2009/065423
Authority: WO
Inventors: Hans-Dieter Hunger; Werner Klockemann; Vladimir Peshkov
Original assignee: Performance Chemicals Handels Gmbh
Priority date: 2008-11-18
Filing date: 2009-11-18
Publication date: 2010-05-27
Also published as: DE102008043824A1

Abstract

The invention relates to a method for manufacturing elastic polyurethane-polyurea coatings, wherein oligourea nanodispersion polyols (OND polyols) comprising a polyether alcohol in which nanoscale, aminofunctional oligourea molecules exist in dispersed form are reacted with diisocyanates and/or polyisocyanates. The mixture ratio is adjusted such that it corresponds to an isocyanate index of 50 to 125, calculated as the sum of hydroxyl and amino groups.

Description

Process for the preparation of polyurea-polyurea coatings

The invention relates to a process for the preparation of elastic polyurethane-polyurea coatings which have chemically bound oligourea in the polymer main chain as nanoscale reinforcing agents and are outstandingly suitable as coatings. The polyurethane-polyurea coatings are characterized by high hardness and elasticity at the same time.

The production of polyurethane coatings of different hardness, which is generally described by the Shore hardness scale, is known. In general, the hardness range extends from Shore A 25 to Shore D 55. As soon as a hardness above Shore D 40 is to be set, the polyurethanes tend to be brittle. To overcome this undesirable effect, polyurea based polyethers have been developed with amine end groups that are still elastic up to a Shore D hardness of about 55. However, these have the disadvantage that due to the relatively large soft segment, as a rule these are based on polypropylene glycols of molecular weight 2000, a large elastic proportion. In a mechanical load which is connected to a heat generation due to friction, such materials due to the relatively low glass transition temperature of about 5O ⁰ C to flow or the temperature exceeds 70 ° C may tend to smear.

According to the prior art, polyurethane-polyurea coatings are prepared from at least one long-chain polyol, optionally a further polyhydroxyl compound and one or more di- and / or polyamines and one or more di- and / or polyisocyanates or prepolymers based thereon , The main amine component used to date has been and still is bis (3-chloro-4-aminophenyl) methane (MOCA) for large manufacturers. In many cases, the much more reactive bis (4-aminophenyl) methane (MDA) has been and still is used. To reduce the reactivity of the amine component, ortho-alkyl substituted amines are used, e.g. B. bis (3-ethyl-4-amino-phenyl) methane. Another group of amine hardeners for polyurea systems are N-alkylated diamines. These secondary, mostly aromatic diamines have a significantly lower reactivity than the primary amines. With the structural unit between the amino groups, the hardness of the polyureas formed is adjusted.

According to the teaching of US 4,581,433 A z. B. elastomeric polyurethane-polyurea coatings based on prepolymers of bis (4-isocyanatocyclohexyl) methane and polyether alcohols of functionality 2 to 3 and at least one diprimary aromatic amine having at least one alkyl substituent ortho to one or two ortho-alkyl substituents to the other amino group to thereby control the reactivity of the amino groups in relation to the hydroxyl groups.

As an alternative to these two-component coatings, prior art one-component coatings based on polyurethane polyureas are known. These are based on polytetramethylene glycols or polycarbonate diols. The latter are z. B. in DE-AS 22 52 280. According to DE-OS 10 2006 002 154, flexible polyurethane-polyurea coatings are described as one-component systems which are based on polytetramethylene glycol-based polycarbonate dioxides, diamines as chain extenders and diisocyanates, and between 40 and 90% by weight % Solvent included. These coating compositions are preferably used for textiles.

The object of the invention is to provide elastic polyurethane-polyurea coatings with high hardness, in particular coatings with Shore D hardnesses> 30, preferably> 40.

Surprisingly, it has been found that elastic, but ultrahard polyurethane polyurethane coatings can be prepared by reacting with diisocyanates and / or polyisocyanates oligurea nanodispersed polyols (OND polyols) comprising a polyether alcohol in which nanoscale, amino-functional oligourea molecules are dispersed implements. The mixing ratio is adjusted according to the invention so that it corresponds to an isocyanate index of 50 to 125, calculated as the sum of the hydroxyl and amino groups.

It is preferable to use OND polyols which comprise specific polyether alcohols with 0.1 to 28% by weight of dispersed nanoscale oligourea molecules having a particle size of 10 to 1000 nm (preferably 20 to 400 nm) which are at least two have free amine functions as primary and / or secondary amino groups.

The oligohydrocarbon nanodispersion polyols (OND polyols) used according to the invention differ substantially from known PHD polyols. PHD polyols are polyurea dispersion polyols. This term has become internationally accepted for the class of polyhydroxyl compounds for polyurethanes, which represent a visible dispersion, ie in the range above 5 microns. As so-called microdispersions they have a milky appearance. The production of PHD polyols (polyurea dispersion polyols) is z. Example by reacting alkanolamines with diisocyanates in Polyetheraikoholen, known per se. The particle sizes are> 10 μm. Such PHD polyols are z. For example, in US 5,068,280 A, US 5,292,778 A, US 5,288,766 A, US 4,326,043 A and US 6,784,243 A are described. The PHD polyols known from the prior art are prepared by in situ polyaddition reactions of isocyanates with amines or aminoalcohols in a base sol. The isocyanate reacts with the amine faster than with the hydroxyl groups of the polyol, ie, the isocyanate reacts preferably with the A- min (or possibly also hydrazine) to the urea group, the polyol serves only as the reaction medium. The solids concentration is limited by the viscosity of the product, solids contents of 20 to 40% can usually be obtained. The PHD poiyols are used in blends with other, highly reactive polyols for the production of HR foams or in the reaction injection molding.

On the other hand, the OND polyols used according to the invention for producing elastic polyurethane-polyurea coatings represent nanodispersions with particle sizes below or up to 1000 nm. This is a completely new type of polyols and consequently also polyurethanes based thereon, since the " Particles "Single molecules with molecular weights of about 500 to 5000 (which corresponds to a chain length of Oligoharnstoffe of 2 to 20 Diphenylmethaneinhei- th each with a urea group between the aromatics).

According to the invention, polyurethane polyurea coatings which comprise nanoparticles in an amount of 0.1 to 23% by weight are preferably provided. Of particular practical importance are Nanoteiichen having free primary or secondary amino groups.

The reaction takes place according to the invention such that the stoichiometry is calculated from the analytically determined number of hydroxyl groups (OH) plus the amino groups (NH) and a ratio to the isocyanate groups (NCO) of 0.5 to 1.25 according to the equation

index = (OH + NH) x 100 = 50 ... 125 NCO

is set. The ratio of the hydroxyl groups to the amino groups in the polyoxy component essentially determines the properties of the coatings and should be between OH: NCO = 20: 1 to 2: 1

lie. Such a ratio is preferably between 10: 1 to 5: 1.

The hardness is controlled according to the invention via the isocyanate ratio, the amount of OND polyol and / or the amount of Oligoharnstoffteilchen and adjusted by the inventively defined isocyanate ratio to a range above Shore D 30.

The Shore hardness, named after Albert Shore, is a material characteristic for elastomers and plastics and is specified in the DIN 53505 and DIN 7868 standards. The core of the Shore hardness tester consists of a spring-loaded pin made of hardened steel. Its depth of penetration into the material to be tested is a measure of the corresponding Shore hardness, which is measured on a scale of 0 Shore (2.5 mm penetration depth) to 100 Shore (0 mm penetration depth). A high number means a high degree of hardness. The setpoint temperature of 23 ⁰ C is limited to the temperature interval of ± 2 K. Shore-D is indicated on toughened elastomers as measured with a needle that tapers at a 30 ° angle and has a spherical tip with a radius of 0.1 millimeter. Weight: 5 kg, hold time: 15 sec.

In a preferred embodiment of the method, the isocyanate ratio (calculated as the sum of the hydroxyl and amino groups) between 55 and 125 at a given concentration of nanoparticles in the range of 1, 0 to adjust the hardness in a range of Shore D 30 to 80 chosen to 23 wt .-%. In another preferred embodiment of the method, the hardness is adjusted by the proportion of oligoureas between 0.25 and 23 wt .-% in the OND poiyol component of the coating between Shore D 30 to 80 at a preselected isocyanate ratio.

The adjustment of the hardness is therefore possible in two ways. The amount of nanoparticles with reactive amino groups used determines the hard-elastic urea phase in the polymer; As the content of these nanoparticles increases, the Shore D hardness increases. So z. For example, at a nanoparticle concentration of 5.5% by weight in the polyol, a Shore D hardness of 46 and at 18% by weight of 74 are obtained under otherwise identical conditions. At a nanoparticle concentration of 17% by weight, the Shore D hardness at an isocyanate ratio of 100 is 71, at an isocyanate ratio of 85 at 65 and at an isocyanate nat ratio of 72 at 59. By means of these two control parameters, therefore, a predetermined hardness in the range can be set.

According to the invention, preference is given to using OND polyols which comprise 35 to 65% by weight of polyether alcohols of molecular weight 1000 to 8000 and a hydroxyl functionality of between 1, 9 and 3.0 with a content of amine-functional oligoureas having a particle size of from 10 to 1000 nm of 0, 25 to 25 wt .-%, which are dispersed in Poiyetheral- kohol, and 10 to 40 wt .-% short-chain glycols. They are calculated in the process according to the invention with one or more di- or polyisocyanates at an isocyanate index calculated as the sum of the hydroxy and amino groups of 50 to 125.

The coatings produced according to the invention are preferably processed during the reaction under shaping. That is, the components are mixed, applied to a substrate and cured depending on the application. The erfindungemäßen coatings are usually processed with two- or multi-component mixing machines, which are common in the polyurethane industry, including high-pressure and airless machines as two- or multi-component systems.

According to the invention, OND polyols with nanoparticles are used. Neither the OND polyols with particle sizes in the nanometer range nor coatings on their basis have been described so far.

The OND polyols with dispersed nanoscale oligourea particles used in the process according to the invention can be prepared, for example, by reacting elastic polyurethanes, preferably polyurethane flexible foams, with mixtures of diols or mixtures of diols and triols having an ethylene oxide content of from 20 to 50% by weight in the presence of di- and polyamines at temperatures between 150 and 25O ⁰ C, so that dispersions of nanoscale oligoureas having a particle size of 10 to 1000 nm are formed in the polyether alcohols and dioic and / or triols.

The OND polyols used according to the invention preferably contain according to their preparation

(a) from 40 to 60% by weight of one or more long chain polyether alcohols containing from 0 to 21% by weight of ethylene oxide and having a hydroxyl functionality f _0H = 2.00 to 3.00,

(b) 10 to 22% by weight of a short-chain, oligomeric ethylene glycol, (c) 10 to 22% by weight of a short-chain, oligomeric propylene glycol,

(d) 2 to 28% by weight of oligoureas in dispersed form,

(E) 0.1 to 3 wt .-% additives (catalysts, stabilizers, fillers, etc.), wherein their hydroxyl number between 120 and 400 mg KOH / g and their amine number between 10 and 100 mg KOH / g. Compositions which have hydroxyl values between 200 and 390 mg KOH / g and the amine numbers between 25 and 80 mg KOH / g are preferred.

The resulting nanoscale oligoureas have a preferred particle size between 20 and 400 nm, as determined by laser light scattering. Depending on the size of the molecule and the amine used, it has an amine functionality of from 1 to 25, the amine functionality of the oligoureas in the lower nanometer range being between 2 and 9.

Catalysts are often not needed with the OND polyols. If catalysts are to be used, tertiary amines such as triethylenediamine, tetra-methylbutandiamin, dimethylcyclohexylamine, N-methylmorpholine or metalorganic compounds of tin, lead or bismuth, z. As dibutyltin dilaurate, Zinndi- octoate, dibutyltin diacetate, etc. used. Stabilizers are almost always included in the OND polyols; it is additionally possible to use UV stabilizers, biocides or antioxidants. Furthermore, inorganic fillers, for. As chalk, barite, precipitated silica, titanium dioxide, or organic fillers, eg. As melamine, melamine cyanurate, powdered melamine resin, etc. are used.

Alternatively, special nanoscale OND polyols can be used in the process according to the invention, which are obtained by Solvoiyse of cold forming flexible foams (HR foam) with polyether diols and / or triols in the presence of a tertiary amine. These are elastic polyurethanes with Oiigoharnstoffen as dispersed nanoscale particles.

Thus, in the process according to the invention, as sols of a cold forming flexible foam are preferably used as OND polyols, which by mixing the soft cellular foam (polyurethane flexible foam) with 5 to 60% by weight of one or more polyether diols and / or during solvolysis. triols can be prepared in the presence of a tertiary amine as a catalyst.

It is also possible with preference to use, for example, OND polyols which are formed by the soivoly of a poly (urethane urea) based on one or more polyether alcohols, water, catalysts and one or more di- and / or polyisocyanates with a mixture of diethylene glycol and Dipropylengiykol in the presence of di-n-butylamine arise.

The OND polyols preferably used according to the invention can be used as reaction component in polyurethane or polyurea coatings together with other polyhydroxyl compounds in order to set special properties by the degree of loading with the oligourea particles. In this way, stable coatings are obtained with a content of oligoureas between 0.25 and 20 wt .-%. The content of oligoureas in such coatings is preferably adjusted to values between 2.5 and 15% by weight. Thus, the restoring force of the polyurethane-polyureas can be significantly improved. Accordingly, elastic polyurethane-polyurea coatings are obtained by mixing a Solvolysates a polyurethane flexible foam with 5 to 60 wt .-% of one or more polyether diols and / or triols and their reaction with di- and / or polyisocyanates.

Flexible polyurethane foams (HR foam) are known to the person skilled in the art. They are z. In H. Oertel, Polyurethane Handbook, Hanser Verlag, Munich, 1989.

Polyether alcohols are selected from the group of anionically or metal complex catalyzed ethylene oxide and / or propylene oxide polymers, oligomers or block copolymers.

Preferred polyetherdiols are polypropylene glycols of molar mass 1000 to 2000 and their ethoxylation products with 5 to 30% by weight of ethylene oxide end blocks or as a random distribution or as an internal block. As polyether trioxide, it is possible to use all glycerol or trimethylolpropane-based typical polyether trioxide used in the polyurethane industry, as well as specific polyether trioxide with internal ethylene oxide blocks or an ethylene oxide random distribution.

Di- or polyamines can be ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2- or 1,3-propylenediamine, dipropylenetriamine, tripropylenetetramine, N-methyl-bis (2-aminopropyl) amine, etc.

Diisocyanates or polyisocyanates are 4,4'-, 2,4'- and / or 2,2'-diphenylmethane diisocyanate, polymeric diphenyimethane diisocyanate (p-MDI), tolylene diisocyanate (2,4- or 2,6-diisocyanate). Isomer or mixtures thereof), 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, etc.

Diols or mixtures of diols and triols are selected from ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, higher ethylene glycols of molecular weight up to 600, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, higher oligopropylene glycols up to molecular weight 2000, glycerol, trimethylolpropane, ethylene or propylene oxide adducts of glycerol or trimethylolpropane with a molecular weight of up to 800, etc.

Triethylenediamine, tetramethylbutanediamine, dimethylcyclohexylamine, N-methylmorpholine are preferably used as tertiary amines

Organotin compounds are selected from dibutyltin dilaurate, tin dioctoate, dibutyltin diacetate.

A preferably used OND polyoi consists of

From 35 to 65% by weight of polyether alcohol with 0 to 30% by weight of ethylene oxide endblock,

10-20% by weight of diethylene glycol, 10-20% by weight of dipropylene glycol and / or butane-1,4-diol,

5% to 20% by weight of oligoureas,

- 0.1 - 1, 0 wt .-% tertiary amine catalyst, preferably triethylenediamine. 0.05-0.2% by weight of organotin compounds, preferably tin dioctoate.

In one embodiment, OND polyols used according to the invention are, in particular, products which are provided by the solvolysis of the cold molding flexible foam with a mixture of diethylene glycol and dipropylene glycol in the presence of di-n-butylamine having the following composition:

(a) 49.1% by weight of polyether alcohol with 13% by weight of ethylene oxide endblock,

(b) 15.5% by weight of diethylene glycol,

(c) 15.5% by weight of dipropylene glycol,

(d) 18.7% by weight of oligoureas,

(e) 1.0% by weight of tertiary amine catalyst, namely triethylenediamine.

(f) 0.2% by weight of organotin compounds, namely tin dioctoate

They have a total content of ethylene oxide blocks of 21, 4%. The hydroxyl number of this OND polyol is 339 mg KOH / g, the amine number is 57 mg KOH / g, the Viscosity 3500 mPas (25 ⁰ C). By using the polyamines, terminal primary and / or secondary amino groups are formed on the oligoureas.

The amine number is therefore composed of the tertiary amines of the original catalysts and the amino groups of Oligoharnstoffe.

In another embodiment, the OND polyols used are in particular products obtained by the solvolysis of a poly (urethane urea) based on one or more polyether alcohols, water, catalysts and one or more di- and / or polyisocyanates with a mixture of diethylene glycol and dipro - Pylene glycol is formed in the presence of di-n-butylamine having the above composition (a) to (f) and having a total content of ethylene oxide blocks of 21.4%.

The poly (urethane urea) used can be adjusted in its chain length of the oligoureas by the ratio of hydroxyl groups of the polyether alcohols and that of the water between 1: 1 and 1:20. Advantageously, by the ratio of hydroxyl groups of the polyether alcohols and that of the water, the particle size of the oligoureas in the OND polyol can be controlled.

In another embodiment of the invention, the particle size of the noskaligen oligoureas in targeted OND polyols by the use of polyTHF, polybutadiene, polycaprolactone and the ratio of the OH groups of the polyols and the water can be controlled.

Suitable di- or polyisocyanates for the reaction with the OND polyols are all common isocyanates of polyurethane chemistry. In particular, aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate (MDI), other position isomers of this isocyanate, 2,4- and / or 2,6-toluene diisocyanate (TDI) or isomer mixtures, xylylene diisocyanate (XDI) or 1,5 Naphthylene diisocyanate (NDI), their technical products or polymeric products, in particular polymeric MDI (p-MDl), cycloaliphatic diisocyanates such as bis (4-isocyanatocyclohexyl) methane, isophorone diisocyanate or 1,4-cyclohexyl diisocyanate, aliphatic diisocyanates such as hexane-1, 6-diisocyanate (HDI) can be used. Preferred are MDI ₁ p-MDI and bis (4-isocyanatocyclohexyl) methane.

The reaction according to the invention of the OND polyols with the di- or polyisocyanates in the stated stoichiometric ratio requires that the amino groups react preferentially with the isocyanate groups because of their higher reactivity. The ratio of isocyanate to hydroxyl to amine groups sets the properties of the coatings. In principle, the higher the proportion of amine groups in the coating and the higher the isocyanate index, the higher the hardness of the polyurethane polyurea and the lower the elasticity.

By measuring the mechanical loss factor tan δ above the temperature by means of DMA, it can be shown that at least two discrete transition regions are formed, which are determined on the one hand by the type of polyether alcohol and on the other hand by the amine-functional oligoureas. As a rule, there is no complete phase separation, but more can be detected between the two transition regions, which can be attributed to the oligoglycols and not separate phases.

The process according to the invention provides hard-elastic polyurethane-polyurea coatings having a preferred Shore D hardness of> 30, in particular> 40, preferably with hardnesses of between 50 and 90, which are outstandingly suitable for coatings. The coatings according to the invention very particularly preferably have hardnesses between 65 and 80. The nanoscale oligourea particles are incorporated as blocks in the polymer chains, while the polyether alcohols are completely, partially or not reacted depending on the isocyanate index. In the latter case, they act as plasticizers in the nanoscale oligourea particles and lead to increased elasticity without significantly affecting the hardness. Thus, the polyurethane-polyurea coatings of the invention have a complex morphology consisting of nanoscale oligoureas that organize via intermolecular forces in larger domains and aggregated domains up to several microns in size, as AFM studies have shown.

The polyurethane-polyurea coatings according to the invention have a high elasticity and high strength at an unusually high Shore D hardness. Thus, they are highly suitable for applications for which polyurethanes or polyureas have not been available as coatings, z. As for coatings on metals that are sandable. The combination of very high hardness and high elasticity makes the polyurethane-polyurea coatings of the invention a new Materiaiklasse that was not previously available.

By the implementation of the defined OND polyols with di- and / or polyisocyanates hard elastic coatings with at least two discrete glass transition regions, once between -55 and -35 ⁰ C and on the other hand between +80 and +190 ⁰ C, which are characterized by a high hardness (Shore D hardness preferably between 45 and 85) by an unusually high elasticity (elongation at break, usually between 3 and 20%).

The elastomers show a multiphase structure (AFM) ₁ wherein the one (hard) phase in the form of discrete disc-shaped structures, which store themselves in a chain-like manner, is formed and in the resulting cavities, the soft elastic phase is incorporated. This hitherto unobserved structure leads to the special properties of the products according to the invention.

Particularly preferred are polyurethane-polyurea coatings which have free primary amino groups in the nanoparticles. This has the great advantage that they can determine the hardness by the formation of polyurea depending on the application of the coating.

Depending on the application more or less of the reactive Oiigoharnstoffe be used in the coatings in order to adjust the hardness of the coatings, their elasticity, but also their resistance to media.

They can preferably be used as coatings in the field of water systems. These include e.g. Tanks, basins, swimming pools, wastewater treatment plants, occupancy basins, ship coatings inside and outside, bilge coatings, etc. Furthermore, they are e.g. suitable as coatings on concrete surfaces, buildings and manholes (for example subway shafts).

In a specific embodiment of the process according to the invention, polyurethane-polyurea coatings are prepared from a solvolyzate of a cold-forming flexible foam (prepared by the solvolysis of the cold-forming flexible foam with a mixture of diethylene glycol and dipropylene glycol in the presence of di-n-butylamine with the abovementioned composition) and p-MDI, which are mixed at a preferred isocyanate index of 70 to 105. If this OND polyol is reacted with p-MDI at various isocyanate indices, polyurea-polyurea coatings having the following values of mechanical properties are obtained:

The change in the amount of nanosize oligoureas is a further parameter for adjusting the properties of the polyurethane-polyurea coatings according to the invention. In the following table such properties are listed, if the conditions otherwise remain constant in the OND polyol; the polyurethane-polyurea coatings were prepared at an isocyanate index of 75:

Ausführungsbeispsele

example 1

a) Preparation of the formulated OND polvols

In a 6 l glass reactor with central Feststoffdosierung, reflux condenser, nitrogen inlet and magnetic stir bar, which is operated by a magnetic stirrer in combination with an electric heating bath, and temperature sensors (PtI OO) with electronic control are 675 g dipropylene glycol, 675 g Diethylengiykol and 210 g Di -n-butylamine. The mixture is heated to 170 ⁰ C. At this temperature 2650 g of a PUR cold forming flexible foam in the form of flakes of 3 to 8 cm in size are added within 103 minutes. During the addition, a nitrogen flow of 10 l / h is maintained. The temperature of the reaction mixture is slowly increased to 210 ⁰ C. After completion of the addition, stirring is continued for a further 30 minutes at 210.degree. Thereafter, the reaction mixture is filled and degassed at 120 ⁰ C and 1 Torr for 60 minutes. It will continue to be used in this form. The hydroxyl number is 344 mg KOH / g, the amine value 57 mg KOH / g, the viscosity 3520 mPas (25 ° C). b) Production of the polyurethane-polyurea coating

In a two-component casting machine on the A side, the OND polyo produced under a)! and filled in on the B-side p-MDi. The mixing ratio is adjusted to 1, 37: 1, which corresponds to an isocyanate index of 80. Using a static mixing head, the mixture is applied directly to a siliconized release paper in a Mathis-LabCoater® in front of a knife blade. The knife blade is slowly pulled over the release paper at a distance of 0.2 mm. It is obtained a coating of 0.2 mm, which is cured at 80 ⁰ C for 60 minutes. Thereafter, a polyurethane-polyurea coating having a Shore D hardness of 71, a tensile strength of 35 MPa, an elongation at break of 6% and an E modulus of 2130 MPa.

Example 2 a) Preparation of the Formulated OND Polvol

It is prepared as in Example 1a) an OND polyol, but instead of the 675 g of diethylene glycol 405 g of polyethylene glycol! used. The OND polyol has a hydroxy number of 284 mg KOH / g, an amine value of 59 mg KOH / g, and a viscosity of 5950 mPas (25 ° C).

b) Production of the polyurethane-polyurea coating

A polyurethane-polyurea coating is prepared as in Example 1b), but with a mixing ratio of 1.64: 1, which corresponds to an isocyanate index of 90. This gives a polyurethane-polyurea coating with a Shore D hardness of 76, a tensile strength of 31 MPa, an elongation at break of 8% and an E-modu! from 1540 MPa.

Example 3 a) Preparation of the Formulated OND Polvol

It is prepared as in Example 1a) an OND polyol, but instead of the 675 g of diethylene glycol 810 g of diethylene glycol are used. The OND polyol has a hydroxy number of 330 mg KOH / g, an amine value of 55 mg KOH / g, and a viscosity of 3250 mPas (25 ° C).

b) preparation of the polyurethane-polyurea coating;

A polyurethane-polyurea coating is prepared as in Example 1 b), but with a mixing ratio of 1.27: 1, which corresponds to an isocyanate index of 100. A polyurethane-polyurea coating having a Shore D hardness of 74, a tensile strength of 45 MPa, an elongation at break of 7% and an E modulus of 1980 MPa is obtained. Example 4 a) Preparation of the Formulated OND Polvols

It is prepared as in Example 1a) an OND polyol, but instead of 210 g of di-n-butylamine 215 g dipropylenetriamine are used. The OND polyol has a hydroxyl number of 333 mg KOH / g, an amine value of 58 mg KOH / g, and a viscosity of 3900 mPas (25 ° C).

b) Preparation of the polyurethane-polvurea coating

A polyurethane-polyurea coating is prepared as in Example 1b), but with a mixing ratio of 1.41: 1, which corresponds to an isocyanate index of 80. A polyurethane-polyurea coating having a Shore D hardness of 75, a tensile strength of 47 MPa, an elongation at break of 4% and an E modulus of 2180 MPa is obtained.

Claims

claims

1. A process for the preparation of elastic polyurethane-polyurea coatings, characterized in that one

Oligourea nanodispersion poiyols (OND polyols) comprising a polyether alcohol in which nanoscale, amino-functional oligourea molecules are dispersed, with di- and / or polyisocyanates, wherein the mixing ratio is adjusted so that it has an isocyanate index of 50 to 125, calculated as the sum of the hydroxyl and amino groups.

2. The method according to claim 1, characterized in that the OND polyol

Polyether alcohols in which 0.1 to 28 wt .-% nanoscale oligourea molecules having a particle size of 10 to 1000 nm are dispersed, having at least two free amine functions as primary and / or secondary amino groups and a ratio of hydroxyl groups to the amino groups (OH : NCO) of 20: 1 to 2: 1, wherein the OND polyol is reacted with the di- and / or polyisocyanates, if necessary in the presence of fillers and additives, and the Shore D hardness in a range above 30 on the Isocyanate index is controlled.

3. The method according to claim 1 or 2, characterized in that the amine functions are present as primary amino groups.

4. The method according to any one of claims 1 to 3, characterized in that the hardness over the amount of OND polyol and / or the amount of oligurea in the range above the Shore D hardness of 30 is controlled.

5. The method according to any one of claims 1 to 4, characterized in that the hardness is controlled by the isocyanate index in the range of Shore D 30 to 80.

6. The method according to any one of claims 1 to 5, characterized in that the hardness is controlled by the proportion of oligoureas between 0.25 and 23 wt -% in the OND polyol component of the coating between Shore D 30 to 80, wherein the amount of Polyetheraikohoien against 100% taking into account the additives.

7. The method according to any one of claims 1 to 6, characterized in that OND polyols are used, the 35 to 65 wt .-% polyether alcohols having a molecular weight of 1000 to 8000 and a hydroxyl functionality between 1, 9 and 3.0 and if necessary From 0 to 30% by weight of ethylene oxides, in which the a-m impunctional nanoscale oligourea compositions are present in a content of 0.25 to 25% by weight, and 10 to 40% by weight of short-chain glycols.

8. The method according to any one of claims 1 to 7, characterized in that OND polyols are used which are prepared by reacting elastic polyurethanes, preferably flexible polyurethane foams with mixtures of diols or mixtures of dioxins and triols having an ethylene oxide content of 20 to 50 wt .-% be prepared in the presence of di- or polyamines at temperatures of 150 to 250 ° C.

9. The method according to any one of claims 1 to 8, characterized in that OND polyols are used which have a composition as follows:

40 to 60% by weight of one or more long-chain polyetheric alcohols containing 0 to 21% by weight of ethylene oxide and having a hydroxyl functionality f _0H = 2.00 to 3.00,

- 10 to 22 wt .-% of a short-chain, oligomeric ethylene glycol

From 10 to 22% by weight of a short-chain, oligomeric propylene glycol,

From 2 to 28% by weight of oligoureas in dispersed form,

0.1 to 3% by weight of additives, e.g. Catalysts, stabilizers, wherein the OND polyols have a hydroxyl number between 120 and 400 mg KOH / g and an amine number between 10 and 100 mg KOH / g and the nanoscale oligoureas have a particle size of 20 to 400 nm.

10. The method according to any one of claims 1 to 7, characterized in that OND polyols are used which constitute a Solvolysat a cold forming soft foam (HR foam), which by mixing the soft KaItformschaumstoffes - during or after solvolysis - with 5 to 60 wt .-% of one or more polyether diols and / or triols in the presence of a tertiary amine is prepared as a catalyst and optionally further additives.

11. The method according to any one of claims 1 to 7 and 10, characterized in that OND polyols are used, which represent a Solvolysat a cold forming soft foam, which consists of

10-20% by weight of diethylene glycol,

10 to 20% by weight of dipropylene glycol and / or butane-1, 4-diol,

5% to 20% by weight of oligoureas,

0.1 to 1.0% by weight of tertiary amine catalyst,

- 0.05 - 0.2 wt .-% organotin compounds.

12. The method according to claim 11, characterized in that the OND polyol is a product which is formed by solvolysis of the cold mold flexible foam with a mixture of diethyl and Dipropylengiykol in the presence of di-n-butylamine and has the following composition:

49.1% by weight of polyether alcohol with 13% by weight of ethylene oxide endblock,

15.5% by weight of diethylene glycol,

15.5% by weight of dipropylene glycol,

18.7% by weight of oligoureas,

1.0% by weight of tertiary amine catalyst,

- 0.2 wt .-% organotin compounds, and a total content of ethylene oxide blocks of 21, 4%.

13. The method according to any one of claims 1 to 12, characterized in that the OND polyol comprises polyether alcohols in which the nanoscale oligurea molecules having a particle size of 20 to 400 nm are dispersed.

14. The method according to any one of claims 1 to 13, characterized in that the di- and / or polyisocyanates used are selected from aromatic, cycloaliphatic or aliphatic diisocyanates, preferably selected from 4,4'-diphenylmethane diisocyanate (MDI) and other position isomers of this isocyanate , 2,4- and / or 2,6-tolylene diisocyanate (TDI) or isomer mixtures, xylylene diisocyanate (XDl) or 1,5-naphthylene diisocyanate (NDi) ₁ whose technical products or polymeric products, preferably polymeric MDI (p-MDl) , or bis (4-isocyanatocyclohexyl) methane, isophorone diisocyanate or 1,4-cyclohexyl diisocyanate, or hexane-1,6-diisocyanate (HDI).

15. The method according to any one of claims 1 to 14, characterized in that the di- and / or polyisocyanates used are MDI, p-MDS and bis (4-isocyanatatocyclohexyl) methane.

16. The method according to any one of claims 1 to 15, characterized in that the used OND polyol is a sovolysate of a cold foamed flexible foam according to any one of claims 10 or 11 and the di- and / or polyisocyanate used is pMDl, which is in a isocyanate index of 70 to 105 and processed during the reaction under molding.

17. Elastic polyurethane-polyurea coating based on OND polyols with 0.1 to 28 wt.% Nanoscale, amino-functional oligourea molecules, prepared by a process according to one of claims 1 to 16 with a Shore D hardness> 30, preferably from 50 to 90.

18. Use of elastic polyurethane Poiyharnstoff coatings according to claim 1 to 17 as coatings for water systems, concrete surfaces, buildings and shafts.

19. Process according to claim 11, characterized in that the OND polyol is a product obtained by solvolysis of a poly (urethane resin) based on one or more polyether alcohols, water, catalysts and one or more di- and / or polyisocyanates is formed with a mixture of diethylene glycol and dipropylene glycol in the presence of di-n-butylamine and has the following composition:

15.5% by weight of diethylene glycol,

15.5% by weight of dipropylene glycol,

18.7% by weight of oligoureas,

1.0% by weight of tertiary amine catalyst,

20. The method according to claim 19, characterized in that the poly (urethane urea) used by the ratio of hydroxyl groups of the Polyetheralkohoie and the water is set between 1: 1 and 1:20 in its chain length of Oligohamstoffe.

21. Process according to claim 19 or 20, characterized in that the particle size of the oligoureas in the OND polyol is controlled by the ratio of hydroxyl groups of the polyether alcohols and of the water.

22. The method according to any one of claims 1 to 21, characterized in that is controlled by the use of polyTHF, polybutadiene, polycaprolactone and the ratio of the OH groups of the polyols and the water, the particle size of the oligoureas in targeted OND polyols.