WO2023142101A1

WO2023142101A1 - Three component composition for the manufacture of polyurethane cementitious hybrid flooring or coating with improved workability

Info

Publication number: WO2023142101A1
Application number: PCT/CN2022/075160
Authority: WO
Inventors: Hu ZHANG; Wenjie Wang; Sihui YANG; Qi Wang
Original assignee: Sika Technology Ag
Priority date: 2022-01-30
Filing date: 2022-01-30
Publication date: 2023-08-03

Abstract

The present invention relates to a three-component composition consisting of a polyol component (A) comprising a polyol P1a with an average molecular weight of 800 to 30'000 g/mol, a reaction product RP of at least one mono-functional epoxy component ME selected from the list consisting of monoglycidyl ethers and monoglycidyl esters with at least one alkanolamine AM, and water; and a polyisocyanate component (B) comprising methylene diphenyl diisocyanate (MDI); and a powder component (C) comprising cement and one or more aggregates. Said three-component composition has improved workability and a prolonged open time.

Description

Three component composition for the manufacture of polyurethane cementitious hybrid flooring or coating with improved workability

Technical field

The invention relates to a three-component composition for the manufacture of polyurethane cementitious hybrid flooring or coating, a method for the manufacture of the flooring or coating with the three-component composition and the flooring or coating obtainable by the method.

Background of the invention

Polyurethane (PU) cementitious hybrid systems are known for the preparation of coating and flooring products which have outstanding mechanical properties. Such PU hybrids are typically composed of a polyol component, a polyisocyanate component and a component containing powder component containing aggregates.

Polyurethane cementitious hybrid systems are complex systems wherein during curing of the precursor components two main reactions occur, namely the reaction of polyols and polyisocyanates to form the polyurethane and the reaction of cement and water which is generally called hydration. Upon hydration, the cement hardens to a solid material. The hydration is usually affected in the presence of aggregates such as sand or gravel so that the aggregate particles are bound together by the cement material to obtain mortar or concrete.

The polyol component typically comprises high molecular weight polyols, low molecular weight polyols, plasticizers and water.

WO 2014174093 mentions low molecular weight polyols to be di-or polyhydric alcohols, e.g., with a molecular weight of less than 250 g/mol.

JP 2018203577 A mentioned the low molecular polyol to be alkylene oxide addition products of (poly) amines or a transesterification product of an alkylene oxide addition of (poly) amine and polyester polyol. The advantage of the use these polyols instead of the regular low molecular polyols in the PU hybrids can improve workability and prolong the open time. However, the synthesis of such polyols requires high temperature and pressure and are therefore expensive and burdensome to produce.

Summary of the invention

Therefore, the object of the present invention is to provide a composition for polyurethane cementitious hybrid systems with improved workability and a prolonged open time.

Surprisingly, this object could be achieved by using a three-component composition comprising

- a polyol component comprising

- at least one polyol P1a with an average molecular weight of 800 to 30’000 g/mol, preferably 850 to 20’000 g/mol, more preferably 900 to 10’000 g/mol, and

- a reaction product RP of at least one mono-functional epoxy component ME selected from the list consisting of monoglycidyl ethers and monoglycidyl esters with at least one alkanolamine AM, and

- water; and

- a polyisocyanate component comprising methylene diphenyl diisocyanate (MDI) ; and

- a powder component comprising cement, preferably calcium hydroxide, and one or more aggregates.

The inventive three-component composition can be used as self-levelling or self smoothing screed or mortar

In addition, the characteristics as to workability, open time, mechanical properties such as in particular compressive strength, are outstanding.

The system of the invention is particularly suited as a polyurethane cementitious hybrid self-levelling screed with heavy duty demands for flooring, especially industrial flooring.

Detailed description of the invention

Substance names beginning with "poly" , such as e.g. polyol or polyisocyanate, designate substances which formally contain, per molecule, two or more of the functional groups occurring in their names.

The term "open time" is understood to mean the duration of processability when the components are mixed with each other. The end of the open time is usually associated with viscosity increase of the composition such that processing of the composition is no longer possible.

The average molecular weight is understood to mean the number average molecular weight, as determined using conventional methods, preferably by gel permeation-chromatography (GPC) using polystyrene as standard (Mw) , styrene-divinylbenzene gel with porosity of 100 Angstrom, 1000 Angstrom and 10000 Angstrom as the column and tetrahydrofuran as a solvent, at 35℃.

The compressive strength is determined according to EN 13892-2 (DIN EN 196-1) after 1d, 7d and 28d of curing at 23℃/50%relative humidity.

The term average functionality in this document describes the average number of functional groups on a given molecule. For, e.g., a polyisocyanate, a functionality of 2 would describe a polyisocyanate molecule with in average 2 isocyanate groups per molecule.

The term workability encompasses many interrelated terms such as flowability, consistency, mobility, pumpability, plasticity, compactability, stability, and finishibility. These terms are usually of qualitative type. Herein, workability refers to flow/consistency which is determined at 23℃/50%relative humidity using the cone as described in DIN EN 1015-3, but without tamping the material. 1 kg of material (at 23℃/50%relative humidity) is used, 30 sec Component A; 1 min A+B 400 U/min, and 2 min, A+B+C to 700 U/min. The cone is set on the glass sheet, filled to the rim, lifted and the diameter of the resulting circle is determined after 5 min.

The composition of the invention consists of at least three individual components, which are stored separately in order to avoid spontaneous reaction, and are combined when a polyurethane cementitious hybrid flooring or coating is to be prepared. The components may be assembled together as a package. The at least three components are a polyol component (A) , a polyisocyanate component (B) and a powder component (C) which are also simply referred to as component (A) , component (B) , and component (C) , respectively, which are described in the following.

Polyol component (A)

The polyol component (A) comprises at least one polyol P1a with an average molecular weight of 800 to 30’000 g/mol.

Examples of suitable polyols P1a are polyoxyalkylenepolyols, also referred to as "polyetherpolyols" , polyesterpolyols, polycarbonatepolyols, poly (meth) acrylate polyols, polyhydrocarbon-polyols, polyhydroxy-functional acrylonitrile/butadiene copolymers and mixtures thereof, in particular diols thereof, and mixtures thereof.

Examples of polyetherpolyols are polyoxyethylenepolyols, polyoxypropylenepolyols and polyoxybutylenepolyols, in particular polyoxyethylenediols, polyoxypropylenediols, polyoxybutylenediols, polyoxyethylenetriols and polyoxypropylenetriols. Polyoxyalkylenediols or polyoxyalkylenetriols having a degree of unsaturation of less than 0.02 meq/g and having an average molecular weight in the range from 1000 to 30’000 g/mol and polyoxyethylenediols, polyoxyethylenetriols, polyoxypropylenediols and polyoxypropylenetriols having an average molecular weight of from 800 to 8’000 g/mol are appropriate.

Further examples of polyetherpolyols are so-called ethylene oxide-terminated ("EO-endcapped" , ethylene oxide-end-capped) polyoxypropylenepolyols, styrene-acrylonitrile-grafted polyetherpolyols, e.g.

from Elastogran GmbH, Germany.

Particularly preferred polyols P1a to be used in the present invention are polyhydroxy-functional fats and/or oils, for example natural fats and/or oils, such as castor oil, or polyols obtained by chemical modification of natural fats and/or oils, so-called oleochemical polyols. Castor oil is particularly preferred.

Examples of chemically modified natural fats and/or oils are polyols obtained from epoxypolyesters or epoxypolyethers obtained, for example, by epoxidation of unsaturated oils, by subsequent ring opening with carboxylic acids or alcohols, polyols obtained by hydroformylation and hydrogenation of unsaturated oils, or polyols which are obtained from natural fats and/or oils by degradation processes, such as alcoholysis or ozonolysis, and subsequent chemical linkage, for example by transesterification or dimerization, of the degradation products thus obtained or derivatives thereof. Also suitable are polyols obtained by polyoxyalkylation of natural oils, such as castor oil, for example available under the trade name Lupranol

by Elastogran GmbH, Germany. Suitable degradation products of natural fats and/or oils are in particular fatty acids and fatty alcohols and fatty acid esters, in particular the methyl esters (FAME) , which can be derivatized, for example, by hydroformylation and hydrogenation to give hydroxy-fatty acid esters.

The polyols P1a mentioned above usually have a relatively high molecular weight of between 800 and 30’000 g/mol, preferably between 850 and 20’000 g/mol, more preferably between 900 and 10’000 g/mol, and preferably an average OH functionality in the range from 1.6 to 3.

In a preferred embodiment component (A) contains said polyol P1a with an amount of 20 to 75%, preferably 25 to 70%, more preferably 30 to 60%, most preferably 30 to 50%by weight, based on the total weight of component (A) .

The polyol component (A) comprises a reaction product RP of at least one mono-functional epoxy component ME selected from the list consisting of monoglycidyl ethers and monoglycidyl esters with at least one alkanolamine AM.

It was surpisingly found that said reactions products RP lead to flawless appearances and high values in the compressive strength in the cured compositions. Further, the compositions displayed a sufficiently long open time and good workability. In contrast, compositions containing unreacted monoglycidyl ethers significant lower values in compressive strength and occasional surface defects in the cured compositions. Small crosslinking polyols like triethylene glycol led to inferior workability of the composition and occasional surface defects in the cured compositions. This can be seen for example in the comparison of Ex. 1-Ex. 6 with Ref. 1-4. in table 1.

Preferably, the alkanolamine AM is a primary alkanolamine. It is further preferred, if the alkanolamine AM is a monoamine.

More preferably, the alkanolamine AM is selected from the list consisting of ethanolamine, diglycolamine, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2- methyl-2- (methylamino) -1-propanol, 2-amino-2-ethyl-1, 3-propane-diol and tris (hydroxymethyl) aminomethane, more preferably 2-amino-2-methyl-1-propanol and 2-methyl-2- (methylamino) -1-propanol, most preferably 2-amino-2-methyl-1-propanol.

The mono-functional epoxy component ME are selected from the list consisting of monoglycidyl ethers and monoglycidyl esters.

Preferred monoglycidyl ethers are selected from the list consisting of mono-functional aliphatic glycidyl ethers and mono-functional aromatic glycidyl ethers.

Preferred mono-functional aliphatic glycidyl ethers are selected from the list consisting of alky C ₈-C ₁₀ glycidyl ether (Heloxy 7) , alky C ₁₂-C ₁₄ glycidyl ether (Heloxy 8) , butylglycidyl ether (Heloxy 61) and 2-ethylhexylglycidyl ether (Heloxy 116) , preferably alky C ₁₂-C ₁₄ glycidyl ether.

It was surpisingly found that reactions products RP based on alky C12-C14 glycidyl ether lead to flawless appearances in the cured compositions and longer open time and good workability. This can be seen for example in the comparison of Ex. 1 and Ex. 4 with Ex. 2 and Ex. 3, Ex. 5 and Ex. 6 respectively.

Such mono-functional aliphatic glycidyl ethers are commercially available for example as Heloxy 7 Heloxy 8, Heloxy 61 and Heloxy 116 from Momentive.

Preferred mono-functional aromatic glycidyl ethers are selected from the list consisting of o-cresyl glycidyl ether (HELOXY 62) , nonylphenol glycidyl ether (HELOXY 64) and para-tertbutylphenol glycidyl ether (HELOXY 65) , preferably o-cresyl glycidyl ether.

Such mono-functional aromatic glycidyl ethers are commercially available for example as Heloxy 62 Heloxy 64 and Heloxy 65 from Momentive.

Preferably, the monoglycidyl ester is a reaction product of an alpha-branched monocarboxylic acid with epihalohydrin, especially epiclorohydrin. More preferably, the monoglycidyl ester is neodecanoic acid glycidyl ester.

Neodecanoic acid glycidyl ester is commercially available as Cardura E10P from Momentive.

Preferably, the reaction product RP of at least one mono-functional epoxy component ME selected from the list consisting of monoglycidyl ethers and monoglycidyl esters with at least one alkanolamine AM is prepared by contacting the at least one mono-functional epoxy component ME with the at least one alkanolamine AM, wherein the molar ratio of the HN-groups to the epoxy groups are in the range of 0.5 –1.5, preferably 0.8 –1.2, more preferably 0.9 –1.1. Preferably, the contacting the at least one mono-functional epoxy component ME with the at least one alkanolamine AM is performed at a temperature of 50 –110 ℃, preferably a temperature of 70 –90 ℃, for 0.5 –4 hours, preferably 1 –3 hours.

It is further preferred if the reaction product RP is present in an amount of 2 -10 wt. -%, preferably 3 -7 wt. -%, based on the total weight of the polyol component. Such an amount is advantageous with respect to the appearance of the applied material. An amount of less than 2 wt. -%leads to a poor appearance of the applied material. An amount of more than 10 wt. -%has the disadvantage of too short open times and low values for compressive strength.

It is further preferred if the weight ratio between the polyols P1a and the product RP (P1a /RP) is between 3 -15, preferably 7 -11.

Ratios higher than 15, higher than 11 respectively, lead to inferior results with respect to appearance, especially pinhole formation, and reduced workability. Ratios lower than 3, lower than 7 respectively, lead to an uneven distribution of the sand and reduced compressive strength values.

The polyol component (A) might further comprise polyols P1b that are low molecular weight di-or polyhydric alcohols, with a molecular weight of 48 to 800 g/mol. Examples thereof are C2 to C12 alkyl diols, such as 1, 2-ethanediol ( (mono) ethylene glycol) , 1, 2-and 1, 3-propanediol, neopentylglycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols (such as 1, 2-, 1, 3-, and 1, 4-butandediol) , pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1, 3-and 1, 4-cyclohexanedimethanol, hydrogenated bisphenol A, dimeric fatty alcohols, 1, 1, 1-trimethylolethane, 1, 1, 1-trimethylolpropane, glycerol, pentaerythritol, sugar alcohols, such as xylitol, sorbitol or mannitol, sugars, such as sucrose, other alcohols having a higher functionality, low molecular weight alkoxylation products of the abovementioned di-and polyhydric alcohols, and mixtures thereof.

The polyols P1b mentioned above usually have a relatively low molecular weight, for instance, an average molecular weight of from 48 to 800 g/mol, preferably 60 to 600 g/mol, more preferably 60 to 400 g/mol, most preferably 60 to 300 g/mol and an average OH functionality in the range of 1.6 to 6, preferably 2 to 5, more preferably 2 to 4. Especially preferred polyols P1b are ethylene glycol or triethylene glycol.

Preferably, the polyol component contains less than 5%by weight, preferably less than 2%by weight, preferably less than 1%by weight, preferably less than 0.1 %by weight, based on the total weight of component (A) , of the above polyols P1b. Most preferably, the polyol component is free of polyols P1b.

Component (A) furthermore comprises water, in a preferred embodiment with an amount of 20 to 40%, preferably 22 to 35%, more preferably 24 to 30%by weight, based on the total weight of component (A) , and/or wherein the weight ratio of water to RP is in the range of 0.8 to 40, preferably 1.6 to 20, more preferably 2 to 6, and/or wherein the weight ratio of water in component (A) to hydraulic binder in component (C) is in the range of 0.1 to 0.7. Preferably all those conditions are met simultaneously.

Apart from the at least one polyol P1a, the reaction product RP and water, component (A) may contain further additives. Such additives are commonly used, if desired, and typically known to the persons skilled in the art of polyurethanes. Examples of optional additives are plasticizers, pigments, adhesion promoters, such as silanes, e.g. epoxysilanes, (meth) acrylatosilanes and alkylsilanes, stabilizers against heat, light, and UV radiation, thixotropic agents, flow improving additives, flame retardants, surface active agents such as defoamers, wetting agents, flow control agents, deaerating agents, biocides and emulsifiers.

Preferably used optional additives for component (A) are one or more plasticizers, preferably selected from the list consisting of as benzoates, preferably benzoate esters, phthalates, preferably benzylbutyl phthalate, citric acid esters, preferably acetyltributyl citrate, stearates, preferably ethylene oxide modified stearates, laurates, preferably propyleneglycol laurates, and diisopropylbenzene, most preferably benzoates.

In a preferred embodiment, component (A) comprises 10 to 30%, preferably 15 to 25%by weight of a plasticizer, based on the total weight of component (A) .

Other suitable additives include pigments, such as inorganic and organic pigments, e.g.

and

defoamers, such as solvent silicon free and polyorganosiloxane, e.g.

and

and emulsifiers such as calcium hydroxide and calcium oxide.

While component (A) can be prepared without an emulsifier, the addition of an emulsifier may be suitable since the emulsifier increases stability of component (A) when the emulsion is prepared. A suitable emulsifier is calcium hydroxide. The content of the emulsifier, preferably calcium hydroxide, in component (A) may be up to 0.5%by weight, preferably in the range of 0.01 to 0.5%by weight based on the total weight of component (A) .

Polyisocyanate component (B)

The polyisocyanate component (B) comprises methylene diphenyl diisocyanate (MDI) . In the following methylene diphenyl diisocyanate is abbreviated as “MDI” as usual.

Said comprised MDI is preferably an MDI product with an average NCO functionality of at least 2.5.

A plurality of different MDI product grades is available. MDI products can be classified into monomeric MDI (MMDI) also referred to as pure MDI and polymeric MDI (PMDI) also referred to as technical MDI. Such MDI products are commercially available. The MDI product is preferably monomeric MDI or polymeric MDI or a mixture of monomeric MDI and polymeric MDI.

There exist three isomers of MDI, namely 4, 4'-methylene diphenyl diisocyanate (4, 4'-MDI) , 2, 4'-methylene diphenyl diisocyanate (2, 4'-MDI) , and 2, 2'-methylene diphenyl diisocyanate (2, 2'-MDI) .

It should be mentioned that polymeric MDI is a common designation for MDI products including a mixture of MDI isomers or a single isomer and oligomeric species as outlined above and explained in more detail below. The term "polymeric" in polymeric MDI does not necessarily mean that polymeric MDI contains common polymers of MDI.

Monomeric MDI or pure MDI is an MDI product of a single MDI isomer or isomer mixtures of two or three MDI isomers. The isomeric ratio of MDI isomers can vary in wide ranges. For instance, 4, 4'-MDI is a colorless to yellowish solid having a melting point of 39.5℃. Commercial monomeric MDI is often a mixture of 4, 4'-MDI, 2, 4'-MDI and typically very low levels of 2, 2'-MDI.

Polymeric MDI is an MDI product including oligomeric species in addition to MDI isomers. Thus, polymeric MDI contains a single MDI isomer or isomer mixtures of two or three MDI isomers, the balance being oligomeric species. Polymeric MDI tends to have isocyanate functionalities of higher than 2. The isomeric ratio as well as the amount of oligomeric species can vary in wide ranges in these products. For instance, polymeric MDI may typically contain about 30 to 80%by weight of MDI isomers, the balance being said oligomeric species. As in the case of monomeric MDI, the MDI isomers are often a mixture of 4, 4'-MDI, 2, 4'-MDI and very low levels of 2, 2'-MDI. Polymeric MDI is typically a brown or dark amber liquid product at room temperature (23℃) .

The oligomeric species are oligomers having a NCO functionality of 3 or higher. The oligomeric species are a result of the synthesis process and can be represented by the following formula

wherein n is 1 to 4 and higher. The amount of the homologues generally decreases with increasing chain length. The total content of homologues with n higher than 4 is generally not very high.

A wide variety of polymeric MDI grades is available with varying characteristics as to the number, type and content of isomers and oligomeric species, isomeric ratio, and weight distribution of the oligomeric homologues. These characteristics depend on type and conditions of synthesis and purification procedures. Moreover, the characteristics can be adjusted, e.g., by mixing different MDI product grades according to the needs of the customer.

MDI products including monomeric MDI and polymeric MDI are commercially available, e.g.

and

from Dow,

from BASF,

88 or

5003 from Bayer, or

from Huntsman.

The MDI product may be momomeric MDI or polymeric MDI, wherein polymeric MDI is generally preferred. The total content of MDI isomers in polymeric MDI may vary. The polymeric MDI (PMDI) used may contain e.g. 55 to 65 %by weight and preferably 35 to 45 %by weight of MDI isomers (4, 4'-MDI and optionally 2, 4'-MDI and/or 2, 2'-MDI) , based on the total weight of the MDI product, the balance being said oligomeric species.

Apart from MDI, component (B) may contain at least one polyurethane prepolymer which can be formed by adding at least one polyol P2, a molecule with one or more hydroxyl groups that are reactive with isocyanates, to the MDI and leaving it react for a certain amount of time, preferably with elevated temperature. Suitable conditions include, e.g. 12 h at 40 ℃. The polyol is added in amounts of between 1%and 30 %, preferably between 5%and 25 %, more preferably between 10%and 20%, based on the total weight of component (B) . This sub-stoichiometric addition leads to a partial reaction of the MDI product with the polyol, forming polyurethane-prepolymers.

Suitable polyols P2 are essentially the same as the polyols P1a used in component (A) . Preferred are polyoxyalkylenepolyols, also referred to as "polyetherpolyols" , polyesterpolyols, polyoxyethylenediols, polyoxyethylenetriols, polyoxypropylenediols and polyoxypropylenetriols having an average molecular weight of from 400 to 8’000 g/mol. Especially preferred are blends of natural polyols such as castor oil with polyoxyalkylenpolyols, blends with keton resins, mixtures thereof, and the like.

Powder component (C)

Component (C) is a powder comprising at least one hydraulic binder, preferably cement. In a preferred embodiment, cement is used as hydraulic binder. As cement, any conventional cement type or a mixture of two or more conventional cement types may be used, for example, cements classified according to DIN EN 197-1: Portland cement (CEM I) , Portland composite cement (CEM II) , blast furnace cement (CEM III) , pozzolanic cement (CEM IV) and composite cement (CEM V) . These main types are divided into 27 subtypes, known to those skilled in the art. Of course, cements produced in accordance with another standard, such as according to ASTM Standard or Indian Standard are also suitable.

Portland cement is the most common type of cement and appropriate for the present invention. A preferred type of cement is white cement, such a white cement I-52, 5. or 42,5 R. White cement is a Portland cement with a low iron oxide content. It is similar to ordinary, gray Portland cement except for its high degree of whiteness.

Apart from cement, also other hydraulic binders, such as fly ash or slag may be used in the present invention.

Component (C) preferably further comprises a calcium compound selected from calcium hydroxide and/or calcium oxide. Calcium hydroxide is also known as hydrated lime, calcium oxide is also known as burnt lime. Calcium hydroxide and calcium oxide can each be purchased as a white powder. The calcium compound selected from calcium hydroxide and/or calcium oxide may play an important role in the composition by controlling workability and by avoiding blister formation. It is generally preferred to use either calcium hydroxide or calcium oxide, but a mixture of calcium hydroxide and calcium oxide can also be used.

In addition, component (C) comprises in preferred embodiments one or more aggregates. Aggregates are chemically inert, solid particulate materials. Aggregates come in various shapes, sizes, and materials ranging from fine particles of sand to large, coarse rocks. Examples of suitable aggregates are sand, such as silica sand, gravel, and crushed stone, slag, calcined flint, lightweight aggregates as clay, bentonite, pumice, perlite, and vermiculite. Sand, in particular silica sand, is preferably used to reach the workability expected and to obtain a smooth surface.

The grain size of the aggregates is preferably rather small, e.g. less than 2 mm The aggregate may have, for instance, a grain size in the range of 0.06 to 2 mm, wherein sand, in particular silica sand, having a grain size in the range of 0.1 to 1 mm is particularly preferred. For instance, sand having a grain size ranging from 0.3 to 0.8 mm or from 0.1 to 0.5 mm can be advantageously used in the present invention. The grain size range can be determined, e.g. by sieve analysis.

The use of aggregates depends largely on the desired application. Especially for highly self-levelling products or very thin coating applications, omitting aggregates completely may be advantageous. The skilled artisan is able to adjust the type and amount of aggregates to the desired workability properties and end-use of the product.

Component (C) may optionally comprise one or more additives which are commonly used, if desired, and typically known to the persons skilled in the art of cement applications. Examples of suitable additives, which may be optionally used in component (C) , are superplastizicers such as polycarboxylate ethers (PCE) ; mineral oil, fibres such as cellulose fibres, and inorganic or organic pigments.

Suitable proportions for the three component composition

By adjusting the proportions of the ingredients within the components and between the components as well in a suitable manner, the improvements of the present invention can be significantly enhanced. Such suitable proportions are described in the following. The ingredients indicated refer to the ingredients in the particular component as discussed above. Ratios referring to ingredients in different components relate to suitable or correct proportions of each component according to operating instructions, i.e. to the mixing ratios to be used for mixing the three components and, in use to the mixture of the three components prepared.

The three component composition of the invention is in one preferred embodiment containing aggregates formulated such that the following proportions are satisfied:

a) the content of water is in the range of 3.5 to 5 %by weight, preferably in the range of 4.1 to 4.6 %by weight,

b) the content of MDI product is in the range of 12 to 16%by weight, preferably in the range of 13 to 15 %by weight, and

c) the content of hydraulic binder is in the range of 8 to 15 %by weight, preferably in the range of 10 to 13 %by weight, based on the total weight of component (A) , component (B) and component (C) .

Differences in the amount of water can influence not only the finished surface of the product but also the physical properties such as compression strength, workability and open time. Therefore, the proportion of water with respect to the other ingredients is to be determined carefully.

The content of the calcium compound selected from calcium hydroxide and/or calcium oxide may be, e.g., in the range of 3.5 to 7.5 %by weight, preferably in the range of 4.5 to 6.5%by weight, based on the total weight of component (A) , component (B) and component (C) .

Component (A) is preferably formulated such that the water content is in the range of 20 to 40 %by weight, preferably 22 to 35 %by weight, and in particular 24 to 30 %by weight, and/or the content of polyol P1a is in the range of 20 to 75 %by weight, preferably 25 to 70 %by weight, more preferably 30 to 60 %by weight, most preferably 35 to 50 %by weight, and the content of polyol P1b is in the range of 1 to 25 %by weight, preferably 2 to 20 %by weight, more preferably 5 to 20 %by weight, most preferably 5 to 15 %by weight, each based on the total weight of component (A) .

The molar ratio of polyol hydroxyl groups in component (A) to MDI isocyanate groups in component (B) is preferably in the range of from 0.1 to 0.4.

In one preferred embodiment, component (C) is formulated such that at least one, preferably all, of the following conditions is fulfilled, each based on the total weight of component (C) :

a) the cement content is in the range of 10 to 30%by weight, preferably 15 to 20 %by weight,

b) the content of calcium compound selected from calcium hydroxide and/or calcium oxide is in the range of 4 to 12 %by weight, preferably 6 to 10 %by weight,

c) the aggregates content, preferably sand, is in the range of 60 to 80 %by weight, preferably 65 to 75 %by weight.

As to the mixing ratio of components (A) , (B) and (C) , the weight ratio of component (A) to component (B) is preferably in the range of 0.7 to 1.4, and more preferably in the range of 0.9 to 1.2.

The weight ratio of components (A+B) to component (C) is preferably in the range of 0.3 to 0.6, and more preferably in the range of 0.4 to 0.5, wherein components (A+B) represent the combined weight of component (A) and component (B) .

Method for the manufacture of a polyurethane cementitious hybrid flooring or coating

The three component composition of the invention is suitable to prepare a polyurethane cementitious hybrid flooring or coating. The method comprises

a) mixing polyol component (A) and polyisocyanate component (B) ,

b) adding the powder component (C) to the mixture of polyol component (A) and polyisocyanate component (B) and mixing, to obtain a mixed material,

c) applying the mixed material to a substrate,

d) optionally smoothing the applied mixed material, and

e) curing the applied mixed material, to obtain the polyurethane cementitious hybrid flooring or coating.

A typical layer thickness e.g. ranges from 2 to 6 mm. The application temperature is preferably from about 12 to 35℃. Fast curing in less than 24 h for a wide range of temperatures can be achieved. Application of a top sealer is not required so that one day application is possible.

High compressive strengths can be achieved. The compressive strength of the flooring or coating obtained is preferably at least 40 N/mm ², more preferably in the range of 45 to 55 N/m ², preferably at 23℃/50%relative humidity measured 1 day after application, and preferably at least 50 N/mm ², more preferably at least 58 N/mm ², e.g. in the range of 58 to 68 N/m ², preferably 62 to 65 N/m ² after 28 days.

Three component compositions described herein are especially suitable as a self-levelling system or screed.

The invention is further explained in the following experimental part which, however shall not be construed as limiting the scope of the invention. The proportions and percentage indicated are by weight, unless otherwise stated.

Examples

Raw materials and test methods used for the testing of the respective properties in the examples were as follows:

Raw materials used

Preparation of the reaction product RP1 (based on ME1)

A 1 litre four-necked flask, with stirrer, thermometer, reflux condenser, nitrogen gas inlet, dropping funnel was used. Under nitrogen gas protection, 100 g of ME1 was added into the flask, heated up it to 60 ℃ while stirring. Then, 16.0 g of AM was added dropwise over a time period of 1 hour, controlling the temperature at 70-80 ℃. The reaction was then kept for an additional 2 hours at 80 ℃.

Then, the temperature was decreased to 40 ℃ and the reaction product was filtered and used as reaction product RP1.

Preparation of the reaction product RP2 (based on ME2)

A 1 litre four-necked flask, with stirrer, thermometer, reflux condenser, nitrogen gas inlet, dropping funnel was used. Under nitrogen gas protection, 100 g of ME2 was added into the flask, heated up it to 60 ℃ while stirring. Then, 25.0 g of AM was added dropwise over a time period of 1 hour, controlling the temperature at 70-80 ℃. The reaction was then kept for an additional 2 hours at 80 ℃.

Then, the temperature was decreased to 40 ℃ and the reaction product was filtered and used as reaction product RP2.

Preparation of the reaction product RP3 (based on ME3)

A 1 litre four-necked flask, with stirrer, thermometer, reflux condenser, nitrogen gas inlet, dropping funnel was used. Under nitrogen gas protection, 100 g of ME3 was added into the flask, heated up it to 60 ℃ while stirring. Then, 18.5 g of AM was added dropwise over a time period of 1 hour, controlling the temperature at 70-80 ℃. The reaction was then kept for an additional 2 hours at 80 ℃.

Then, the temperature was decreased to 40 ℃ and the reaction product was filtered and used as reaction product RP3.

According to the information in Table 1, the reference compositions Ref. 1-Ref. 4 and the compositions Ex. 1-Ex. 6 according to the invention were produced by mixing the indicated raw materials and reaction products respectively. The amounts in Table 1 are in parts by weight.

The following measurements were carried out:

Test Methods:

Appearance:

The mixed compositions Ex. 1 –Ex. 6 and Ref. 1 –Ref. 4 were applied on a concrete surface of 0.36 square meters that has been sealed with a polyurethane primer. 4.32kg of mixed composition was poured onto the substrate evenly, then the surface of the applied material was smoothed with a foam roller and the appearance was observed after 24 hours at 25 ℃ and 50%humidity.

The following rating system was used:

good levelling = flat surface and uniform sand distribution

poor levelling = uneven surface and non-uniform sand distribution

pinholes = pinholes visible

no pinholes = no pinholes visible

Workability:

The mixed compositions (mixing time 4 min) Ex. 1 –Ex. 6 and Ref. 1 –Ref. 4 were applied on a concrete surface of 0.36 square meters that has been sealed with a polyurethane primer. 4.32kg of mixed composition was poured onto the substrate evenly, then the material was evenly distributed using a trowel.

The following rating system was used based on the ease of distributing the applied material on the substrate:

thixotropic = material sticks to trowel, difficult to distribute

not thixotropic = material does not (significantly) stick to trowel, easy to distribute

Open time:

The mixed compositions Ex. 1 –Ex. 6 and Ref. 1 –Ref. 4 were applied on a concrete surface of 0.36 square meters that has been sealed with a polyurethane primer. 4.32kg of mixed composition was poured onto the substrate evenly, then the surface of the applied material was smoothed with a foam roller and every minute a line was drawn trough the applied material with a wooden stick. The end of the open time was reached when the drawn line did not disappear/level out but remained visible on the surface of the applied material.

Compressive strength:

The compressive strength was determined according to EN 13892-2 (DIN EN 196-1) after 1d, 7d and 28d of curing at 23℃/50%relative humidity (prism specimen =40mm*40mm*160mm) .

Claims

A three-component composition comprising

- a polyol component (A) comprising

- at least one polyol P1a with an average molecular weight of 800 to 30’000 g/mol, preferably 850 to 20’000 g/mol, more preferably 900 to 10’000 g/mol, and

- a reaction product RP of at least one mono-functional epoxy component ME selected from the list consisting of monoglycidyl ethers and monoglycidyl esters with at least one alkanolamine AM, and

- water; and

- a polyisocyanate component (B) comprising methylene diphenyl diisocyanate (MDI) ; and

- a powder component (C) comprising cement, preferably calcium hydroxide, and one or more aggregates.
The three-component composition of claim 1, wherein the alkanolamine AM preferably selected from the list consisting of ethanolamine, diglycolamine, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-methyl-2- (methylamino) -1-propanol, 2-amino-2-ethyl-1, 3-propane-diol and

tris (hydroxymethyl) aminomethane, more preferably 2-amino-2-methyl-1-propanol and 2-methyl-2- (methylamino) -1-propanol, most preferably 2-amino-2-methyl-1-propanol.
The three-component composition according to any of the proceeding claims, wherein the monoglycidyl ether is selected from the list consisting of alky C ₈-C ₁₀ glycidyl ether, alky C ₁₂-C ₁₄ glycidyl ether, butylglycidyl ether, 2-ethylhexylglycidyl ether, o-cresyl glycidyl ether, nonylphenol glycidyl ether and para-tertbutylphenol glycidyl ether, preferably alky C ₁₂-C ₁₄ glycidyl ether and o-cresyl glycidyl ether.
The three-component composition according to any of the proceeding claims, wherein the monoglycidyl ester is neodecanoic acid glycidyl ester.
The three-component composition according to any of the proceeding claims, wherein the mono-functional epoxy component ME is selected from the list consisting of C ₁₂-C ₁₄ glycidyl ether, o-cresyl glycidyl ether and neodecanoic acid glycidyl ester, preferably alky C ₁₂-C ₁₄ glycidyl ether.
The three-component composition according to any of the proceeding claims, wherein the reaction product RP is present in an amount of 2-10 wt. -%, preferably 3-7 wt. -%, based on the total weight of the polyol component.
The three-component composition according to any of the proceeding claims, wherein the weight ratio between the at least one polyol P1a and the product RP (P1a /RP) is between 3-15, preferably 7-11.
The three-component composition according to any of the proceeding claims, wherein the reaction product RP is prepared by contacting the at least one mono-functional epoxy component ME with the at least one alkanolamine AM, wherein the molar ratio of the HN-groups to the epoxy groups are in the range of 0.5 –1.5, preferably 0.8 –1.2, more preferably 0.9 –1.1 and the contacting is performed at a temperature of 50 –110 ℃, preferably a temperature of 70 –90 ℃, for 0.5 –4 hours, preferably 1 –3 hours.
The three-component composition according to any one of the preceding claims, wherein the at least one polyol P1a is a polyhydroxy-functional natural oil or fat or a polyol obtained by chemical modification of a natural oil or fat, wherein said polyol P1a is preferably castor oil or a chemical modification thereof.
The three-component composition according to any one of the preceding claims, wherein the amount of the at least one polyol P1a is 20 to 75%, preferably 25 to 70%, more preferably 30 to 60%, most preferably 30 to 50%by weight, based on the total weight of the polyol component (A) .
Three component composition according to any one of the preceding claims, wherein the molar ratio of polyol hydroxyl groups in the polyol component (A) to MDI isocyanate groups in the polyisocyanate component (B) is in the range of 0.1 to 0.4.
Three component composition according to any one of the preceding claims, wherein the powder component (C)

a) the cement content is in the range of 10 to 30%by weight, preferably 15 to 20 %by weight,

b) the content of calcium compound selected from calcium hydroxide and/or calcium oxide is in the range of 4 to 12 %by weight, preferably 6 to 10 %by weight,

c) the aggregates content, preferably sand, is in the range of 60 to 80 %by weight, preferably 65 to 75 %by weight,

based on the total weight of the powder component (C) .
Method for the manufacture of a polyurethane cementitious hybrid flooring or coating with a three-component composition according to any of claims 1 to 12, wherein the method comprises

a) mixing polyol component (A) and polyisocyanate component (B) ,

b) adding the powder component (C) to the mixture of polyol component (A) and polyisocyanate component (B) and mixing, to obtain a mixed material,

c) applying the mixed material to a substrate,

d) optionally smoothing the applied mixed material, and

e) curing the applied mixed material, to obtain the polyurethane cementitious hybrid flooring or coating.
Polyurethane cementitious hybrid flooring or coating obtained by mixing and curing a composition according to any of claims 1 to 12 and/or by employing the method according to claim 13.