Polyurethane composition comprising polycarboxylate ether

Abstract

The present invention relates to a process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises at least one polyol (P1) and at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises at least one polyisocyanate (IC). The present invention also relates to a two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), and a polyurethane composition obtained or obtainable by a process according to the invention. Furthermore, the present invention relates to the use of said polyurethane composition as adhesive, sealant, a foam or coating.

Description

[0001] Polyurethane composition comprising polycarboxylate ether

[0002] The present invention relates to a process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises at least one polyol (P1) and at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises at least one polyisocyanate (IC). The present invention also relates to a two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), and a polyurethane composition obtained or obtainable by a process according to the invention. Furthermore, the present invention relates to the use of said polyurethane composition as adhesive, sealant, foam or coating.

[0003] Polyurethanes with high content of fillers are known for different applications. The amount of filler often results in high viscosity of the reactive compositions and makes it difficult to apply the polyurethane composition.

[0004] It is known from the state of the art that by adding polycarboxylate ethers (PCEs) to the otherwise unchanged composition of the cementitious or gypsum material, an improved fluidity and workability of the material is achieved. Recently, it has been demonstrated that these PCEs can also be used in non-aqueous systems, such as for dispersing fillers in a resin containing polyols. For example, WC2014072200A1 discloses curable epoxy resin compositions containing at least one epoxy resin having on average more than one epoxide group per molecule, at least one inorganic filler and at least one polycarboxylate ether, wherein the inorganic filler is coated with the polycarboxylate ether.

[0005] However, in polyurethane compositions different fillers are used depending on the application, including functional fillers to adjust the properties of the resulting polyurethane. For these applications, it is necessary to provide a composition which can be used in combination with different fillers without the need to pretreat the fillers used. It was an object of the present invention to provide compositions for the preparation of polyurethanes which can be easily adapted for the use of different fillers.

[0006] According to the present invention, this object has been achieved by a process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises

[0007] (a1 ) at least one polyol (P1 )

[0008] (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises

[0009] (b1) at least one polyisocyanate (IC). It has been surprisingly found that polycarboxylate ethers (PCE) can be incorporated in the isocyanate reactive component without affecting the reactivity of the component. Even small amounts of the polycarboxylate ether (PCE) resulted in a significant improvement of the workability of the respective composition. It has surprisingly been found that the polycarboxylate ether (PCE) have a high solubility within the A-component and that the adhesion I mechanical properties of the resulting polyurethane are not significantly influenced by the presence of the polycarboxylate ether (PCE) in the composition.

[0010] The polyisocyanate reactive component (A) comprises at least one polyol (P1) and at least one polycarboxylate ether (PCE) and may comprise further components, such as for example fillers and additives.

[0011] The amount of polycarboxylate ether (PCE) in the component (A) may vary. Preferably, the polycarboxylate ether (PCE) is present in the component in an amount in the range of 0.1 to 20 % by weight based on the weight of component (A), preferably in an amount in the range of 0.1 to 5 % by weight based on the weight of component (A), in particular in an amount in the range of 0.1 to 2 % by weight based on the weight of the A component.

[0012] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A).

[0013] The isocyanate reactive component (A) comprises at least one polyol and at least one polycarboxylate ether (PCE).

[0014] Suitable polyols for the preparation of polyurethanes are in principle known to the person skilled in the art. It is possible to use, as polyols (P1), any of the known compounds having at least two hydrogen atoms reactive toward isocyanates, for example those with functionality from 2 to 8 and with number-average molar mass from 62 to 15000 g / mol. Polyols preferably comprise polymeric compounds with at least two hydrogen atoms reactive towards isocyanate. Polymeric compounds with at least two hydrogen atoms reactive towards isocyanate usually have a functionality from 2 to 8 and number-average molar mass from 200 to 15000 g / mol. By way of example it is possible to use compounds selected from the group of the polyether polyols, fatty acid based polyols, polybutadiene based polyols, polyester polyols, and mixtures thereof as polymeric compounds with at least two hydrogen atoms reactive towards isocyanate.

[0015] Polyetherpolyols are by way of example produced from epoxides; for example, propylene oxide and / or ethylene oxide, or from tetrahydrofuran, with starter compounds exhibiting hydrogen-activity containing 1 to 8, preferably 2 to 6 and more preferably 2 to 4 reactive hydrogen atoms bound, or a starter molecule mixture which contains 1 .5 to 8, preferably 1 .8 to 6 and more preferably 1 .9 to 3.5 reactive hydrogen atoms bound in the presence of catalysts. As starter molecules for example aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, for example sucrose, sorbitol or mannitol can be applied. Preferred starter molecules are aliphatic alcohols having 2 to 6, preferably 2 to 4 alcohol groups, aliphatic amines and water. In a preferred embodiment polyetherols comprise molecules produced from starter molecules selected from the group, consisting of aliphatic alcohols having 2 to 6, preferably 2 to 4 alcohol groups, aliphatic amines and water, more preferred from the group consisting of aliphatic alcohols having 2 to 4 alcohol groups and water. In a preferred embodiment, polyetherols consist of molecules produced from starter molecules selected from the group, consisting of aliphatic alcohols having 2 to 6, preferably 2 to 4 alcohol groups, aliphatic amines and water. According to the present invention aliphatic alcohols are not only compounds where the alcohol group is bound to an aliphatic carbon atom but a compound free of aromatic structures. If mixtures of starter molecules with different functionalities are used, fractional functionalities can be obtained. Influences on the functionality, for example through side reactions, are not considered in the nominal functionality. Examples for suitable catalysts are basic catalysts and double-metal cyanide catalysts, as described by way of example in PCT / EP2005 / 010124, EP 90444, or WO 05 / 090440.

[0016] Polyesterpolyols are by way of example produced from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxylated polyacetals, and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are mentioned by way of example in " Polyurethane Handbook, 2ndedition 1993, editor Guether Oertel, Carl Hanser Verlag Munich, Chapter chapter 3.1.

[0017] In a particularly preferred embodiment of the present invention, component comprises polyetherols, and more preferably comprises no polyesterpolyols. In an especially preferred embodiment component consists of polyetherols.

[0018] In a preferred embodiment, the polymeric compounds with at least two hydrogen atoms reactive towards isocyanate comprises at least one polyether polyol obtainable by reacting at least one starter molecule, selected from the group consisting of aliphatic alcohols having 2 to 6, preferably 2 to 4 and more preferred 2 to 3 alcohol groups, aliphatic amines, water and mixtures comprising a combination of at least two thereof, with alkylene oxides. In one preferred embodiment the polyetherpolyolcomprises a polyetherpolyol obtainable by reacting at least one starter molecule having a functionality of 2, selected from aliphatic alcohols, water and a combination of at least one aliphatic alcohol and water, with alkylene oxide wherein the alkylene oxides comprise preferably at least 70 mol-%, more preferred at least 85 mol-% and especially preferred 100 mol.-% propylene oxide, and having a hydroxyl value of preferably 50 to 500 mg KOH / g, more preferred 100 to 400 mg KOH / g and especially preferred 200 to 300 mg KOH / g. In a more preferred embodiment, the polyetherpolyol comprises in addition to the polyetherpolyol a polyetherpolyol (a1a1b) obtainable by reacting at least one starter molecule having a functionality of 3, preferably at least one aliphatic alcohol having a functionality of 3, with alkylene oxide wherein the alkylene oxides comprise preferably at least 50 mol-%, more preferred at least 70 mol-% and especially at least 80 mol-% propylene oxide, and having a hydroxyl value of preferably 20 to 200 mg KOH / g, more preferred 25 to 100 mg KOH / g and especially preferred 30 to 50 mg KOH / g. Preferably polyetherols and are used in a mass ratio of 5:1 to 1:3, more preferred 3:1 to 1 :2 and especially preferred 2:1 to 1 :1.5. In a preferred embodiment, polymeric compounds with at least two hydrogen atoms reactive towards isocyanate comprises at least 80 % by weight, more preferred by at least 90 % by weight and especially preferred by 100 % by weight, each based on the total amount of polymeric compounds with at least two hydrogen atoms reactive towards isocyanate, of polyetherols, selected from the group, consisting of polyetherpolyols and polyetherpolyols and mixtures thereof.

[0019] In a further preferred embodiment of the invention the polymeric compounds with at least two hydrogen atoms reactive towards isocyanate comprises at least one fatty acid-based polyol. Suitable fatty acid-based polyols are preferably those having a hydroxyl value of greater than 50 to less than 500 mg KOH I g, more preferably 100 to 300 mg KOH I g and in particular 100 to 200 mg KOH I g, and a functionality of at least 2. Unless otherwise noted, the OH value is determined according to DIN 53240 in the context of the present invention. The OH functionality of the fatty acid-based polyols is preferably in the range of 2 to 3. Particularly preferably, the OH functionality of the fatty acidbased polyols is 2.3 to 3 and most preferably 2.6 to 3.

[0020] A fatty acid-based polyol may be a fat, oil, fatty acid or fatty acid derivative or obtained from the aforementioned compounds by physical or chemical modification. Fat-based polyols according to the above definition are known in the art per se or can be obtained by methods known per se.

[0021] Suitable fat-based polyol are, for example, vegetable oils or derivatives thereof. As a fat-based polyol can also be used generally known fatty acids, preferably natural fatty acids, particularly preferably vegetable fatty acids, in particular unsaturated vegetable fatty acids, and derivatives thereof such as the esters with mono-, di- and I or trialcohols, provided that the further properties in terms of molecular weight and OH functionality are met.

[0022] As fat-based polyol, however, for example, ring-opened epoxidized or oxidized fatty acid compounds and I or adducts of fatty acid compounds and alkylene oxides can be used. Hydroxylated fatty acids and I or hydroxylated fatty acid derivatives are preferred, which are obtainable by the aforementioned methods.

[0023] The adducts of OH-functional fat-based compounds, for example castor oil or hydroxylated vegetable oils, and alkylene oxides can be prepared by generally known alkoxyl ation of the compounds with, for example, ethylene oxide, propylene oxide and / or butylene oxide at temperatures of 80 to 130 °C and pressures of 0.1 to 1 MPa, optionally in the presence of customary catalysts such as alkali metal hydroxides or alkali metal alcoholates.

[0024] As fat-based polyol, hydroxylated fatty acid compounds based on rapeseed oil, soybean oil, rapeseed oil, olive oil and I or sunflower oil and I or those based on oleic and I or linoleic acid can also be used. As fat-based polyols, polyols based on hydroxylated soybean oil are particularly suitable. Also preferred are triglycerides of fatty acids having an OH functionality of 2 to 3. Particularly preferred are the triglyceride of ricinoleic acid, optionally in a mixture with triglycerides containing other natural fatty acids, for example linoleic acid and I or palmitic acid. Suitable are for example mixtures comprising two or more polyols, for example polyols selected from polypropylene glycols and polyethylene glycols, in particular mixtures comprising one or more polyols selected from polypropylene glycols and polyethylene glycols with a molecular weight of less than 500 g / mol.

[0025] Unless otherwise noted, Gel Permeation Chromatography (GPC) measurements were performed in accordance with DIN EN ISO 13885-1, to determine he molecular weight of the polyols. This methodology is specifically designed to accurately determine the molecular weight distribution of polymers, with a particular emphasis on the calibration process. The calibration is conducted using homologous standards that correspond to the nature of the polyols being analyzed. For this purpose, a range of calibration standards is available, including poly(tetrahydrofuran) (PTHF), polyethylene glycol (PEG), polypropylene glycol (PPG), poly(methyl methacrylate) (PMMA), polystyrene (PS), and poly (butylene adipate). This selection of standards ensures a robust and reliable framework for the measurement of molecular weight, allowing for accurate comparisons and assessments of the polymer samples. The GPC technique provides insights into the molecular weight averages, including number-average molecular weight (Mn) and weightaverage molecular weight (Mw), which are crucial for understanding the material properties and performance of the polymers in various applications.

[0026] Besides polymeric compounds having at least two hydrogen atoms reactive towards isocyanate, the component (A) preferably comprises chain extenders and / or crosslinking agents.

[0027] Chain extenders used here can be compounds of molar mass less than 200 g / mol, preferably less than 150 g / mol and more preferred 62 to 150 g / mol, which have two groups reactive toward isocyanates as for example -SH or NH2- groups and preferably OH-groups. According to the present invention, if chain extenders are used, they are preferably used in an amount of 0.1 to 20 wt.-%, more preferred 1 to 10 wt.-% and especially preferred 1 to 5 wt.-%, each based on the total weight of components. As chain extenders, use may be made of the chain extenders known in the production of polyurethanes. These are preferably low-molecular-weight compounds having two functional groups reactive toward isocyanates, for example monoethylene glycol, diethylene glycol, 1,2-propane diol, 1,3-propane diol, 1,4-butane diol, 1,3-butane diol, 1,5-pentane diol, 1,6-hexane diol, neopentyl glycol, tetraethylene glycol, dipropylene glycol, cyclohexane diol and aliphatic or aromatic amine based chain extenders as aliphatic or aromatic diamines like ethylene diamine, triethylene diamine and / or diethyl toluene diamine. In a preferred embodiment the chain extender is selected from the group, consisting of monoethylene glycol, diethylene glycol, dipropylene glycol, 1,2-propane diol, 1,3 propane diol, 1,4 butane diol, 1,6 hexane diol or mixtures thereof. Other possible low-molecular-weight chain extenders are mentioned by way of example in "Polyurethane Handbook”, Carl Hanser Verlag, 2ndedition 1994, chapter 3.2 and 3.3.2.

[0028] In addition to chain extenders or instead of chain extenders, crosslinking agents may be added to the mixture. As crosslinking agents used in the invention are compounds of molar mass less than 200 g / mol preferably less than 150 g / mol which have at least three groups reactive toward isocyanates. Examples for crosslinking agents are glycerine, trimethylolpropane, pentaerythritol and triethanolamine, in a preferred embodiment glycerine is used as crosslinking agent. Other possible low-molecular-weight crosslinking agents are mentioned by way of example in "Polyurethane Handbook”, Carl Hanser Verlag, 2ndedition 1994, chapter 3.2 and 3.3.2. According to the present invention, if chain extenders and / or crosslinking agents are used, they are used in an amount of 0.1 to 10 wt.-%, preferably 0.5-10 and especially preferred ably 1 to 5 wt.-%, each based on the total weight of components.

[0029] Catalysts greatly accelerate the reaction of the polyols with the polyisocyanates. As catalysts any catalyst known in the field of polyurethane catalysts may be used. These comprise basic amine catalysts and metal-based catalysts. In a preferred embodiment the catalysts comprise incorporable amine catalysts. In a further preferred embodiment the catalysts comprise delayed action catalysts. Delayed action catalysts are well known in the art and provide a long open time of the reaction mixture at room temperature and a fast curing at elevated temperatures. Examples for delayed action catalysts are metal based catalysts.

[0030] Incorporable amine catalysts have at least one, preferably from 1 to 8, and particularly preferably from 1 to 2, groups reactive toward isocyanates, for example primary amine groups, secondary amine groups, hydroxy groups, amides, or urea groups, preferably primary amine groups, secondary amine groups, or hydroxy groups. Incorporable amine catalysts are used mostly for the production of low-emission polyurethanes which are in particular used in the auto- mobile-interior sector. These catalysts are known and are described by way of example in EP 1888664. These comprise compounds which preferably comprise, alongside the group(s) reactive toward isocyanates, one or more tertiary amino groups. It is preferable that at least one tertiary amino groups of the incorporable catalysts bear at least two aliphatic hydrocarbon moieties, preferably having from 1 to 10 carbon atoms per moiety, particularly preferably having from 1 to 6 carbon atoms per moiety. It is particularly preferable that the tertiary amino groups bear two moieties selected mutually independently from methyl and ethyl moiety, and bear another organic moiety.

[0031] Suitable metal based catalysts comprise organometallic compounds, preferably organotin compounds, such as tin(ll) salts of organic carboxylic acids, e.g. tin(ll) acetate, tin(ll) octoate, tin(ll) ethylhexoate, and tin(ll) laurate, and the dial- kyltin(IV) salts of organic carboxylic acids, e.g. dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate, and also bismuth carboxylates, such as bismuth(lll) neodecanoate, bismuth 2-ethylhexanoate, and bismuth octanoate, or a mixture thereof. The organometallic compounds can be used alone or in combination with strongly basic amines. A preferred metal based catalyst is dioctyltin diacetate. In a particularly preferred embodiment, catalysts used comprise or consist of at least one metal based catalysts.

[0032] Catalysts can by way of example be used at a concentration of from 0.001 to 5% by weight, in particular from 0.05 to 2% by weight, as catalyst or, respectively, catalyst combination, based on the weight of component.

[0033] Preferably to the isocyanate reactive component (A) no blowing agent as for example water is added. Preferably, component (A) is free of water. In a more preferred embodiment the isocyanate reactive component (A) comprises a water scavenger. Generally, all water scavengers known in the field of polyurethanes are suitable. The isocyanate component (B) comprises at least one polyisocyanate (IC). Suitable polyisocyanates are in principle known to the person skilled in the art.

[0034] According to the invention, the polyisocyanate composition may also comprise two or more polyisocyanates. These may be unmodified or modified, wherein by a modification, the reaction of these isocyanates to isocyanate-termi- nated polyisocyanate prepolymer and I or the reaction to biuret, allophanat, uretdione, and I or isocyanurate-contain- ing isocyanates, preferably allophanate and I or isocyanurate containing isocyanates as well as their prepolymers is understood. These isocyanates can be used individually or in mixtures. Isocyanates used with preference are aliphatic, cycloaliphatic, araliphatic and / or aromatic isocyanates, more preferably tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene 1 ,5-diisocyanate, 2-ethylbutylene 1 ,4-diisocyanate, pentamethylene 1 ,5-diisocyanate, butylene 1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclo- hexane (isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane and / or 1,3-bis(isocyanatomethyl)cy- clohexane (HXDI), paraphenylene 2,4-diisocyanate (PPDI), tetramethylenexylene 2,4-diisocyanate (TMXDI), dicyclohexylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate (H12 MDI), hexamethylene 1,6-diisocyanate (HDI), cyclohexane 1,4- diisocyanate, 1 -methylcyclohexane 2,4- and / or 2,6-diisocyanate, diphenylmethane 2,2'-, 2,4'- and / or 4,4'-diisocya- nate (MDI), naphthylene 1 ,5-diisocyanate (NDI), tolylene 2,4- and / or 2,6-diisocyanate (TDI), diphenylmethane diisocyanate, 3,3,‘-dimethyl-4,4‘-diisocyanato-diphenyl (TODI), dimethyldiphenyl 3,3'-diisocyanate, diphenylethane 1,2- diisocyanate and / or phenylene diisocyanate or prepolymers of these isocyanates and polyols or isocyanates and iso- cyanate-reactive components.

[0035] Particular preference is given to diphenylmethane 4,4'-diisocyanate (MDI), paraphenylene 2,4-diisocyanate (PPDI), naphthylene 1 ,5-diisocyanate (NDI), 3,3,‘-dimethyl-4,4‘-diisocyanato-diphenyl (TODI) , and linear aliphatic diisocyanates such as for example pentamethylene-1,5-diisocyanate, hexamethylene 1,6-diisocyanate.

[0036] Isocyanate reactive component (A) and isocyanate component (B) are preferably mixed at temperatures of 5 to 60 °C, more preferred 10 to 50 °C and especially preferred 15 to 35 °C at an isocyanate index in the range of 70 to 150, preferably 80 to 130, more preferably 90 to 120, more preferred 95 to 115 and especially preferred 100 to 110 to form a reaction mixture and the reaction mixture is allowed to cure to form the thermal conductive polyurethane adhesive.

[0037] The polyurethane composition according to the present invention may be a compact material or a foam, for example an adhesive, a sealing, a foam or a coating.

[0038] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

[0039] In the context of the present invention, the amount of the filler and also the chemical nature of the filler may vary in broad ranges. Suitable fillers may be selected from metals, metal oxides, metal nitrides, or metal hydroxides. Suitable fillers may for example be fillers with a thermal conductivity of greater than 2 W / mK, preferably greater than 14 W / mK, determined according to ASTM D5470 or ISO 22007".

[0040] Suitable fillers also include talcs, clays, silicas, calcium carbonates, graphites, glass, carbon black, plastic powders such as ABS; glass fibers or other ceramics, or polymers such as polyamide, propylene or recycled polyurethane foam.

[0041] Suitable fillers may also be inorganic fillers selected from silicon compounds such as silica, silicates and precipitated and fumed silica; metal oxides such as titanium dioxide, iron oxide, alumina, zinc oxide and magnesium oxide; metal carbonates such as calcium carbonate or dolomite; metal sulfates such as calcium sulfate (gypsum) and barium sulfate; metal hydroxides such as aluminum hydroxide, nitrides or carbides, clay minerals such as kaolin, fly ash, cement, glass and ceramic materials.

[0042] It is for example possible that the filler is added to the polyurethane composition as a flame retardant. Suitable fillers may for example be selected from melamine, phosphorous containing flame retardants, or metal hydroxides such as aluminum hydroxide and magnesium hydroxide.

[0043] The fillers used according to the invention may be of any particle size, for example from 0.1 m to 300 pm, in particular between 1 pm and 200 pm. In a particularly preferred embodiment, the inorganic fillers are finely divided fillers, or the fillers have a proportion of finely divided fillers, which is preferably added during production as a finely divided filler fraction. Finely divided fillers are in particular fillers with absolute particle sizes less than 60 pm. Finely divided fillers are in particular fillers having an average particle size of less than 50 pm, less than 30 pm or less than 10 pm. Here, the particle size of the finely divided fillers can be at least 0.5 pm, at least 1 pm or at least 2 pm. Preferably, the finely divided fillers have particle sizes from 0.5 to 60 pm, in particular between 1-30 pm. In a preferred embodiment of the invention a mixture of different fillers and / or fractions of the same filler are / is used, which have different particle sizes. For example, a mixture of finely divided fillers with absolute particle sizes less than 60 pm and coarser fillers with absolute particle sizes of more than 60 pm can be used. The filler may have a monomodal, bimodal, trimodal or multimodal size distribution, preferably a bimodal or trimodal size distribution

[0044] According to the present invention, also mixtures of different fillers or fillers having different particle size distribution may be used.

[0045] Particle sizes, such as D10, D50 and D90 values and particle size distributions of powders and powdery materials can be measured, using a wide variety of measurement methods known per se to the person skilled in the art, for example via sieve analyses according to DIN 66165-2:2016-08, sedimentation or light scattering, e.g. laser diffraction in accordance with DIN ISO 13321 :2004-10. Particle size can be measured by dispersing the powder in a suitable solvent and to perform laser diffraction in accordance with ISO 13320:2009 or dynamic light scattering in accordance with ISO 22412:2008.

[0046] The particle size distribution can be reported as intensity distribution, volume distribution, surface distribution or numerical distribution. In the present case, given particle sizes of the fillers are determined by dispersing the powder in 2-isopropanol using laser diffraction in accordance with ISO 13320:2009.

[0047] The filler may be added in suitable amounts depending on the nature of the filler and the application. Suitable amounts may for example be in the range of from 40 to 95 % by weight, preferably in the range of from 70 to 95 % by weight, based on the weight of the polyurethane composition.

[0048] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein component (A) comprises at least one filler in an amount of from 40 to 95 % by weight.

[0049] According to the present invention, component (A) comprises at least one polycarboxylate ether (PCE). Suitable polycarboxylate ethers are in principle known as dispersing agents for gypsum and cement. Polycarboxylate ethers are comb polymers with a main chain having carboxy groups, and side chains typically comprising ether groups. The polycarboxylate ethers usually have side chains with polyether groups, in particular based on polyethylene glycol and / or polypropylene glycol. According to the invention, the term "polycarboxylate ether” refers to compounds which have ether groups, wherein they may have other groups, in particular ester and amide groups. According to the invention, mixtures of different polycarboxylate ethers can be used.

[0050] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a derivative or a salt thereof and / or at least one methacrylic acid moiety or a derivative or a salt thereof.

[0051] Preferably, the polycarboxylate ether has side chains which are attached to a main chain via ester, amide and / or ether groups. The main chain preferably has at least one acid moiety or a salt thereof, which is preferably an acrylic acid moiety and / or a methacrylic acid moiety. The polycarboxylate ether may be produced by esterification and / or amidation of a polycarboxylic acid or a salt or anhydride thereof.

[0052] An acid moiety is usually introduced into the polymer by performing the polymerization in the presence of a corresponding acid monomer, which is usually unsaturated, or a salt or anhydride thereof. Suitable acid monomers are in particular a-unsaturated mono- or dicarboxylic acids, in particular, acrylic acid, methacrylic acid, maleic anhydride, maleic acid, itaconic acid, crotonic acid or fumaric acid.

[0053] In a preferred embodiment of the invention, the polycarboxylate ether comprises: a) at least one acid moiety (AM) of the general formula I): wherein each R1, R2 and R3 independently of one another represents H, — COOM, — CH2 COOM or an alkyl group having 1 to 5 carbon atoms, each R4 independently of one another represents —COOM, — CH2 COOM, — SO2 —CM, — 0— PO(OM)2 and / or -PO(OM)2 ; or wherein R3 together with R4 forms a —CO— O—CO— ring; wherein M represents H, an alkali metal, an alkaline earth metal, ammonium, an ammonium cation, an organic ammonium compound, or mixtures thereof; with the proviso that overall a single one or two of R1 , R2 , R3 and R4 is / are acid groups, wherein the acid moiety (AM) is preferably an acrylic acid moiety or a salt thereof and / or a methacrylic acid moiety or a salt thereof; and b) at least one structural moiety (SM1) of formula (II); wherein

[0054] R1 independently of one another represents H or CH3 .

[0055] R2 independently of one another represents an ether group -0-(CH2)n-0-, ester group —00—0— or an amide group — CO— NH— ;, with n representing a value between 1 and 10, R3 independently of one another represents a C2 -C6 alkylene group, in particular an ethylene or propylene group,

[0056] R4 independently of one another represents H, a C1 -C12 alkyl or cycloalkyl radical, a C7 -C20 alkylaryl or aralkyl radical, or a substituted or unsubstituted aryl radical, or a monovalent organic radical having 1 to 30 carbon atoms, which optionally comprises heteroatoms, and x independently of one another represents a value between 3 and 250, preferably between 5 and 150.

[0057] The at least one acid moiety (AM), in particular the at least one acrylic acid moiety and / or the at least one methacrylic acid moiety may be partially or completely neutralized. The acid moiety (AM) may be present as free acid or as a salt or partial salt or anhydride, where the term "salt” here and below, in addition to the classical salts such as are obtained by neutralization with a base, also comprises complex-chemical compounds between metal ions and the carboxylate or carboxyl groups as ligands. The classical salts are obtained in particular by neutralization with sodium hydroxide, calcium hydroxide, magnesium hydroxide, ammonium hydroxide or an amine.

[0058] Typically, the main chain of the polycarboxylate ether is a linear copolymer wherein said structural moiety (SM1) is a component of said linear copolymer.

[0059] The structural moiety (SM1) of formula (I) may be an ester or an amide depending on the selection of the group R2. Here, a polycarboxylate ether may contain both ester and amide groups.

[0060] In a preferred embodiment of the invention, the polycarboxylate ether has at least one structural moiety (SM1) of formula (I) where R1 is H, and at least one structural moiety (SM1) of formula (I) where R1 is CH3, wherein R2 is preferably an ester group. That is, in a preferred polycarboxylate ether a part of the structural moieties (SM1) represents polyoxyalkylene acrylate moieties, and another part of the structural moieties (SM1) represent polyoxyalkylene methacrylate moieties.

[0061] In a preferred embodiment, — (R3 O)x — represents a C2 to C4 polyoxyalkylene group, in particular a polyoxyethylene group or polyoxypropylene group or mixtures of oxyethylene and oxypropylene moieties in any order such as random, alternating or blockwise.

[0062] R4 is preferably not H, and particularly preferably is a methyl radical.

[0063] In a preferred embodiment of the invention, the polycarboxylate ether has a proportion of ethylene oxide moieties of at least 30 mol %, preferably 50 to 100 mol %, in particular 80 to 100 mol % of the total number of all (R3 O)x moieties. Particularly preferably ethylene oxide and propylene oxide moieties are present in the polycarboxylate ether. In a preferred embodiment of the invention, the polycarboxylate ether has at least one further structural moiety (SM2), which is different from the acid moiety (AM) and the structural moiety (SM1), and which is selected from an ether, ester, amide or imide moiety, an acid moiety selected from carboxylic acid, sulfonic acid, phosphonic acid, phosphoric acid esters, carbonylamidomethyl propanesulfonic acid and salts thereof, or a polyoxyalkylene oxycarbonyl, polyoxyalkylene aminocarbonyl, polyoxyalkylene oxyalkyl, polyoxyalkylenoxy, hydroxyethyloxycarbonyl, acetoxy, phenyl, or N-pyrrolidonyl group. Preferably, the additional structural moiety (SM2) comprises polyoxyalkylene groups, preferably polyoxyethylene groups, polyoxypropylene groups or mixtures thereof. For example, the structural moiety (SM2) may be an ester moiety which is produced by reaction of a mono- or dicarboxylic acid with an alkyl alcohol, in particular a C6 -C20 alkyl alcohol.

[0064] The polycarboxylate ether may be a combination of different structural moieties of the respective acid moiety (AM) and structural moieties (SM1) and optionally (SM2). For example, several acid moieties (AM) which are not at all or completely neutralized, may be present in the polycarboxylate ether as a mixture. Alternatively, several different ester and / or amide moieties (SM1) as a mixture may be present in the polycarboxylate ether, for example, several ester moieties (SM1) having different substituents R3 . Preferred is, for example, the joint use of polyoxyalkylenes, in particular polyoxyethylene with polyoxypropylene, or the joined use of polyoxyalkylenes, in particular polyoxyethylene, of different molecular weight.

[0065] In a preferred embodiment of the invention, the polycarboxylate ether comprises a) 5 to 95 mol %, preferably 10 to 80 mol %, particularly preferably 20 to 60 mol % acid moieties (AM), in particular acrylic acid moieties and / or methacrylic acid moieties; b) 5 to 50 mol %, preferably 10 to 40 mol % structural moiety (SM1); and c) 0 to 30 mol %, preferably 0 to 15, in particular 0 to 5 mol % structural moiety (SM2), each based on the total number of monomeric moieties in the main chain of the polycarboxylate ether.

[0066] The sequence of the individual structural moieties (AM), (SM1), and (SM2) in the polycarboxylate ether may be alternating, statistical, blockwise or random.

[0067] According to a further embodiment, the polycarboxylate ether is a copolymer which is obtainable by polymerizing a mixture of monomers comprising

[0068] (V) at least one ethy lenically unsaturated monomer which comprises at least one radical from the series of carboxylic acid, carboxylic salt, carboxylic ester, carboxylic amide, carboxylic anhydride, and carboxylic imide and (VI) at least one ethy lenically unsaturated monomer comprising a polyether group, the polyether group being represented preferably by the structural unit (I).

[0069] The copolymers in accordance with the present invention contain at least two monomer units. It may, however, also be advantageous to use copolymers having three or more monomer units.

[0070] In one preferred embodiment, the ethy lenically unsaturated monomer (V) is represented by at least one of the following general formulae from the group of (Va), (Vb), and (Vc):

[0071] In the monocarboxylic or dicarboxylic acid derivative (Va) and in the monomer (Vb) present in cyclic form, where Z = 0 (acid anhydride) or NR16 (acid imide), R7 and R8 independently of one another are hydrogen or an aliphatic hydrocarbon radical having 1 to 20 carbons, preferably a methyl group. B is H, -COOMa, -CO-O(CqH2qO)r-R9, -CO- NH-(CqH2qO)r-R9.

[0072] M is hydrogen, a mono- or di- or trivalent metal cation, preferably sodium, potassium, calcium or magnesium ion, or else ammonium or an organic amine radical, and a = 1 / 3, 1 / 2 or 1, according to whether M is a mono-, di- or trivalent cation. Organic amine radicals used are preferably substituted ammonium groups which derive from primary, secondary or tertiary C1-20 alkylamines, 01-20 alkanolamines, 05-8 cycloalkylamines, and 06 14 arylamines. Examples of the corresponding amines are methylamine, dimethylamine, trimethylamine, ethanolamine, diethanolamine, triethanolamine, methyldiethanolamine, cyclohexylamine, dicyclohexylamine, phenylamine, diphenylamine in the protonated (ammonium) form.

[0073] R9 is hydrogen, an aliphatic hydrocarbon radical having 1 to 20 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an aryl radical having 6 to 14 carbons, this radical optionally being substituted as well, q = 2, 3 or 4 and r = 0 to 200, preferably 1 to 150. The aliphatic hydrocarbons here may be linear or branched and also saturated or unsaturated. Preferred cycloalkyl radicals are cyclopentyl or cyclohexyl radicals, and preferred aryl radicals are phenyl or naphthyl radicals, which in particular may also be substituted by hydroxyl, carboxyl or sulfonic acid groups. Furthermore, Z is 0 or NR16, where R16 independently of each occurrence is identical or different and is represented by a branched or unbranched C1 to C10 alkyl radical, C5 to C8 cycloalkyl radical, aryl radical, heteroaryl radical or H.

[0074] The following formula represents the monomer (Vc):

[0075] In this formula, R10 and R11 independently of one another are hydrogen or aliphatic hydrocarbon radical having 1 to 20 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an optionally substituted aryl radical having 6 to 14 carbons.

[0076] Furthermore, R12 is identical or different and is represented by (CnH2n)-SO3H with n = 0, 1, 2, 3 or 4, (CnH2n)-OH with n = 0, 1, 2, 3 or 4; (CnH2n)-PO3H2 with n = 0, 1, 2, 3 or 4, (CnH2n)-OPO3H2 with n= 0, 1, 2, 3 or 4, (C6H4)- SO3H, (C6H4)-PO3H2, (C6H4)-OPO3H2 and (CnH2n)-NR14b with n = 0, 1, 2, 3 or 4 and b by 2 or 3.

[0077] R13 is H, -COOMa, -CO-O(CqH2qO)r-R9, -CO-NH-(CqH2qO)r-R9, where Ma, R9, q and r possess the definitions stated above.

[0078] R14 is hydrogen, an aliphatic hydrocarbon radical having 1 to 10 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an optionally substituted aryl radical having 6 to 14 carbons.

[0079] Furthermore, Q is identical or different and is represented by NH, NR15 or O, where R15 is an aliphatic hydrocarbon radical having 1 to 10 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons or an optionally substituted aryl radical having 6 to 14 carbons.

[0080] In one particularly preferred embodiment, the ethylenically unsaturated monomer (VI) is represented by the following general formulae (Via) in which all the radicals having the definitions above. In a further-preferred embodiment, the ethy lenically unsaturated monomer (VI) is represented by the following general formulae (Vlb) where

[0081] R1, R2, R3 independently of one another, identically or differently, are H, CH3,

[0082] R4 is linear or branched C1 -C30 alkylene,

[0083] R5, R6independently of one another, identically or differently, are H, C1-C20 alkyl, C3-C15 cycloalkyl, aryl, -CH2-O- C1-C20 alkyl, CH2-O-C2-C20 alkenyl, and R5 and R6 may also together form a C3-C6 alkylene, R7 independently at each occurrence, identically or differently, is H, C1-C4 alkyl,

[0084] R8 is C1-C22 alkyl, C2-C22 alkenyl, and n independently at each occurrence, is identical or different and is an integer from 2 to 200.

[0085] In particular, the copolymer has an average molar weight (Mw) of between 5,000 and 150,000 g / mol, more preferably 10,000 to 80,000 g / mol, and very preferably 15,000 to 60,000 g / mol, as determined by gel permeation chromatography.

[0086] The polymers are analyzed for average molar mass and conversion by means of size exclusion chromatography (column combinations: Shodex OH-Pak SB 804 HQ and OH-Pak SB 802.5 HQ from Showa Denko, Japan; eluent: 80 vol% aqueous solution of HCO2NH4 (0.05 mol / l) and 20 vol-% MeOH; injection volume 100 l; flow rate 0.5 ml / min).

[0087] The preparation of the comb polymers which comprise the structural units (V) and (VI) is carried out in a conventional way, for example by free-radical polymerization. It is, for example, described in EP0894811, EP1851256, EP2463314, EP0753488.

[0088] The polycarboxylate ether preferably has an average molecular weight Mn in the range of 1000 to 100,000 g / mol, preferably 2000 to 70,000 g / mol, particularly preferably 5000 to 50,000 g / mol.

[0089] The polycarboxylate ethers may be produced by the polymer-analogous reaction. The polymer-analogous reaction has the advantage that by varying the amount, type and ratio of alcohols and amines, polycarboxylate ethers with very different and advantageous structures and properties can be obtained from polycarboxylic acids. The different properties are typically obtained by different distributions of the side chains in the polymer.

[0090] Polymer-analogous reactions are known per se and are described, for example, in WO97 / 35814A1, WO95 / 09821A2, DE 100 15 135 A1 , EP 1138697 A1 , EP 1348729 A1 , and W02005 / 090416 A1. Details about the polymer-analogous reaction are disclosed, for example, in EP 1 138 697 B1 on page 7, line 20 to page 8, line 50, and in the examples included, or in EP 1 061 089 B1 on page 4, line 54 to page 5, line 38 and in the examples.

[0091] The polymer used according to the invention may be produced also by a free radical polymerization reaction, wherein the copolymer is obtained from corresponding ethy lenically unsaturated acid, ester and amide monomers in the presence of a free radical generator. The route via free radical polymerization is the method most commonly used in the prior art.

[0092] Depending on the reaction conditions, the polycarboxylate ether may be used as a reaction product, which, in addition to the polycarboxylate ether, contains free compounds of the starting materials, in particular free monohydroxy compounds such as unilaterally end group-capped polyoxyalkylene, in particular free methoxy-polyoxyethylene.

[0093] However, PCEs which are synthesized by aqueous radical polymerization and converted into PCE powder by drying. In the drying process, additional drying additives may be incorporated, such as stabilizers to enhance the thermo- oxidative stability of polymer powders, as for example described in EP1124892B1 . Drying may for example be effected by drum drying, lyophylization, flash drying or spray drying, often are not fully satisfactory in reactive (adhesive) systems, since a lot of water has to be removed due to the process, resulting in residual moisture and antiblocking agents (ABA) from the drying and powder processing steps, which adversely affect the properties in the application system. In a thermally conductive adhesive system, conventional PCE powder introduces limestone flour, silica, talc or kaolin (as ABA), which have significantly lower thermal conductivity than the thermally conductive (TC) fillers normally used (AI(OH)3, AI2O3, BN, graphene, carbon black, etc.). This reduces thermal conductivity and at the same time, more inorganic fillers must be dispersed. The latter can lead to higher viscosities and mechanical weakening of the adhesive matrix. In other highly filled systems, the ABA of the PCE may be incompatible with the particle size distribution (resulting in rheological effects) for the application or with the existing filler concept. Residual moisture leads to bubble formation (CO2 development) in PU systems when reacting with isocyanates. Alternatively, water can react with the electrophilic reactive groups of an adhesive system (in competition with the desired nucleophiles) in general. Therefore, the residual moisture can lead to a reduced shelf life and / or a weakening of the PU matrix.

[0094] In particular in reactive systems, it can be advantageous to use polycarboxylate ethers (PCEs) which are synthesized in the melt phase. This offers a more efficient approach for the use of PCEs in adhesives, since they are water free and also free of anti-blocking agents. This eliminates the need for elaborate drying prior to use and also circumvents the introduction of poorly thermally conductive fillers. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

[0095] It is for example possible to prepare suitable polycarboxylate ethers in a polymerization reaction in the melt starting from methacrylic acid or acrylic acid and a suitable comonomer, i.e. a methacrylate or acrylate with a suitable side chain, for example a polyether side chain.

[0096] The reaction may be carried out at elevated temperature, for example in the range of from 70 to 110°C in the presence of suitable additives and optionally solvents. According to a preferred embodiment, the polycarboxylate ether may be synthesized in a polyol as solvent.

[0097] The reaction may be carried out in the presence of suitable additives, for example in the presence of chain transfer agents, such as for example mercaptoethanol or mercaptopropionic acid.

[0098] Due to the preparation process, the polycarboxylate ether (PCE) prepared in a water-free process without the need of a drying process, and, thus, without the addition of anti blocking agents. The resulting PCE typically has a low water content and can be directly used in a polyol component. Additionally, less drying agent is needed.

[0099] The polycarboxylate ether (PCE) prepared in a water-free process can be advantageously be used in an isocyanate reactive composition for the preparation of polyurethanes. Due to the low water content, polyurethanes may be obtained with improved properties, such as a lower air void content (no CO2 formation due to residual moisture) and a more homogeneous PU matrix.

[0100] According to a further aspect, the present invention is also directed to a two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), each as defined above. With respect to preferred embodiments, reference is made to the disclosure above.

[0101] Furthermore, according to a further aspect, the present invention is also directed to a polyurethane composition obtained or obtainable by a process as disclosed above.

[0102] The polyurethane composition obtained according to the present invention man be used for different applications, for example as an adhesive, a sealant, a foam or a coating. Depending on the chemical nature of the polyurethane and also the filler used, the polyurethane composition may for example be a protective coating, an electrically conductive coating, an electrically non-conductive coating or a thermally conductive coating. According to a further aspect, the present invention is also directed to the use of the polyurethane composition as disclosed above as adhesive, sealant, a foam or coating. The polyurethane composition is suitable for different applications depending on the chemical nature of the polyurethane and also the filler used, in particular in electronic components. The composition according to the present invention preferably has improved (a reduced) squeeze flow (SQF) characteristics. As described by Frauenhofer et al. (Frauenhofer, M., Gormanns, M., Simon, M., Rutters, M., & Fricke, H. Optimized heat dissipation of energy storage systems, adhesion ADHESIVES+ SEALANTS, 17, 12-17 (2020)), for the assembly of the battery, the thermally conductive adhesive typically is applied on the cooling plate. Afterwards, the battery cells I modules are inserted into the adhesive. During this movement, the adhesive is effectively pressed against the surface to be wetted, and great care must be taken not to damage the pressure-sensitive battery cells. Therefore, the flow properties and the resulting pressing forces of the adhesive have to be adjusted to prevent any damage to the battery and the cooling plate. This is even more challenging since the adhesives have a high filler load. It is aimed to formulate adhesives which can be easily compressed also to ensure a good wetting, pumpability, and put less strain on the application equipment. In this regard, the squeeze flow (SQF) is a well-known topic in bonding technology, which occurs when joining substrates. The pressure in the adhesive can increase unexpectedly when squeezing small gap heights. Thus, low SQF pressure forces are desired. The SQF is well accepted to simulate the forces when battery cells I modules are pressed into the adhesive on the cooling plate.

[0103] The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The process of any one of embodiments 1 to 4", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to "The process of any one of embodiments 1, 2, 3 and 4". Further, it is explicitly noted that the following set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and, thus, suitably supports, but does not represent the claims of the present invention.

[0104] 1 . A process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises (a1) at least one polyol (P1 ) (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises

[0105] (b1) at least one polyisocyanate (IC).

[0106] 2. The process according to embodiment 1, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A). 3. The process according to any one of embodiments 1 or 2, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

[0107] 4. The process according to any one of embodiments 1 to 3, wherein component (A) comprises at least one filler in an amount of from 50 to 95 %.

[0108] 5. The process according to any one of embodiments 1 to 4, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof.

[0109] 6. The process according to any one of embodiments 1 to 5, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

[0110] 7. A two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), each as defined in any of the embodiments 1 to 6.

[0111] 8. A two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), wherein the polyisocyanate reactive component (A) comprises

[0112] (a1) at least one polyol (P1)

[0113] (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises

[0114] (b1) at least one polyisocyanate (IC).

[0115] 9. The two component polyurethane adhesive composition according to embodiment 8, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A).

[0116] 10. The two component polyurethane adhesive composition according to any one of embodiments 8 or 9, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

[0117] 11 . The two component polyurethane adhesive composition according to any one of embodiments 8 to 10, wherein component (A) comprises at least one filler in an amount of from 50 to 95 %.

[0118] 12. The two component polyurethane adhesive composition according to any one of embodiments 8 to 11, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof.

[0119] 13. The two component polyurethane adhesive composition according to any one of embodiments 8 to 12, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

[0120] 14. A polyurethane composition obtained or obtainable by a process according to any one of embodiments 1 to 6.

[0121] 15. A polyurethane composition obtained or obtainable by a process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises

[0122] (a1) at least one polyol (P1)

[0123] (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises

[0124] (b1) at least one polyisocyanate (IC).

[0125] 16. The polyurethane composition according to embodiment 15, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A).

[0126] 17. The polyurethane composition according to any one of embodiments 15 or 16, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

[0127] 18. The polyurethane composition according to any one of embodiments 15 to 17, wherein component (A) comprises at least one filler in an amount of from 50 to 95 %.

[0128] 19. The polyurethane composition according to any one of embodiments 15 to 18, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof.

[0129] 20. The polyurethane composition according to any one of embodiments 15 to 19, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

[0130] 21 . Use of the polyurethane composition according to any one of embodiments 14 to 20 as adhesive, sealant, a foam or coating. 22. A process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises

[0131] (a1) at least one polyol (P1) (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises

[0132] (b1) at least one polyisocyanate (IC).

[0133] 23. The process according to embodiment 22, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A).

[0134] 24. The process according to any one of embodiments 22 or 23, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

[0135] 25. The process according to any one of embodiments 22 to 24, wherein component (A) comprises at least one filler in an amount of from 50 to 95 %.

[0136] 26. The process according to any one of embodiments 22 to 25, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof.

[0137] 27. The process according to any one of embodiments 22 to 26, wherein component (A) is free of water.

[0138] 28. The process according to any one of embodiments 22 to 27, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

[0139] 29. A two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), each as defined in any of the embodiments 22 to 28.

[0140] 30. A two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), wherein the polyisocyanate reactive component (A) comprises

[0141] (a1) at least one polyol (P1)

[0142] (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises (b1) at least one polyisocyanate (IC). The two component polyurethane adhesive composition according to embodiment 30, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A). The two component polyurethane adhesive composition according to any one of embodiments 30 to 31 , wherein component (A) comprises at least one filler in an amount of from 50 to 95 %. The two component polyurethane adhesive composition according to any one of embodiments 30 to 32, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof. The two component polyurethane adhesive composition according to any one of embodiments 30 to 33, wherein component (A) is free of water. The two component polyurethane adhesive composition according to any one of embodiments 30 to 34, wherein the polycarboxylate ether (PCE) is prepared in a water-free process. A polyurethane composition obtained or obtainable by a process according to any one of embodiments 22 to 28. A polyurethane composition obtained or obtainable by a process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises

[0143] (a1) at least one polyol (P1)

[0144] (a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises

[0145] (b1) at least one polyisocyanate (IC). The polyurethane composition according to embodiment 37, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A). 39. The polyurethane composition according to any one of embodiments 37 or 38, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

[0146] 40. The polyurethane composition according to any one of embodiments 37 to 39, wherein component (A) comprises at least one filler in an amount of from 50 to 95 %.

[0147] 41 . The polyurethane composition according to any one of embodiments 37 to 40, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof.

[0148] 42. The polyurethane composition according to any one of embodiments 37 to 41 , wherein component (A) is free of water.

[0149] 43. The polyurethane composition according to any one of embodiments 37 to 42, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

[0150] 44. Use of the polyurethane composition according to embodiment 36 or according to any one of embodiments 37 to 43 as adhesive, sealant, a foam or coating.

[0151] The present invention is further illustrated by the following examples.

[0152] EXAMPLES

[0153] Raw materials:

[0154] Polyol 1 : polyethylene glycol homopolymer having a molecular weight of 300 g / mol and an OH-Number of 375 mgKOH / g.

[0155] Polyol 2: polyalkylene glycol obtained by alkoxy lation of glycerine having an OH-Number of 35 mgKOH / g and a propylene oxide content of 80 to 90 % by weight based on the total weight of the alkylene oxide.

[0156] TO filler 1 : alkyl-silane treated aluminium trihydroxide having a particle size D90 of about 100 pm

[0157] TO filler 2: spherical aluminium oxide filler having a particle size D90 of about 20 pm.

[0158] TO filler 3: spherical aluminium oxide filler having a particle size D90 of about 130 pm.

[0159] TO filler 4: aluminium trihydroxide without surface modification having a particle size D90 of about 90 pm.

[0160] Chain extender: 1 ,2-propylene glycol Cross-linker: glycerine (97.7%)

[0161] Drying agent 1 : alkali aluminosilicate

[0162] Drying agent 2: water scavenger for isocyanates (Luna PTSI)

[0163] Catalyst 1 : dioctyltin mercaptide catalyst

[0164] Iso 1 : isocyanurate modified hexamethylene diisocyanate, NCO content 22 wt.-%

[0165] Iso 2: allophanate modified hexamethylene diisocyanate, NCO content 20 wt.-%

[0166] Synthesis of polymers

[0167] PCE1

[0168] 1 .0 moles of MPEG 500 and 0.57 moles of maleic anhydride were added to the reactor. The mixture was then acidified with 2 g of sulfuric acid. Afterwards, the mixture was heated to a temperature of 140 °C and 4.2 g of tert-bu- tylperoxide were slowly added to the reaction mixture over a period of 30 minutes. The reaction mixture was then heated for 2 hours, diluted, and neutralized to a pH of 7. The molecular weight of the resulting polymer was 4000 g / mol, as determined by GPC.

[0169] PCE2

[0170] 100 g of MPEG 200 were melted at 80 °C in a vessel. Thereto, 6.35 g of maleic acid anhydride were added followed by 0.15 g of sodium acetate, and 15 g of water. After cooling the mixture to 16 °C, the pH was adjusted to 4.6. To this mixture, 16 g of hydroxybutylvinylether, 0.02 g of Iron (II) sulfate, and 0.16 g of 2-mercaptoethanol were added. Then 1.48 g of hydrogen peroxide was added. Within 1 h, a 10% solution of Rongalit and a 25% solution of maleic acid anhydride were added to the reaction mixture. The molecular weight of the resulting polymer was 42000 g / mol, as determined by GPC.

[0171] PCE3

[0172] PCE3 is a copolymer of methacrylic acid and methy l-polyethy lene glycol methacrylate ester with 23 ethylene oxide units (EC). The polymer was prepared as follows: 330 g of methacrylate ester were melted at 70 °C under stirring in a 500 ml three-neck flask equipped with a propeller stirrer. The amount of methacrylic acid (70.0 g) and 0.1 g of sodium persulfate were added. The reaction mixture was stirred for 5 hours at 80 °C. The resulting polymer was mixed with 500 ml of water and then neutralized to pH 7 using 50% sodium hydroxide solution. The molecular weight of the resulting polymer was 29000 g / mol, as determined by GPC.

[0173] PCE4

[0174] PCE4 is a copolymer of ethoxylated vinyloxybutanol with a chain length of 131 ethylene oxide units and acrylic acid. The copolymer was prepared as follows: A glass reactor equipped with multiple feed ports, a stirrer, and a dropping funnel was charged with 500 ml of water and 359 g of macromonomer 1 (prepared by ethoxylation of vinyloxybutanol with 131 mol EC) and temperature was maintained at 13 °C. To this, 0.01 g of iron(ll) sulfate heptahydrate and 5.5 g of Briiggolit FF6 were added. Then, 22.28 g of acrylic acid and 5 g of 30% hydrogen peroxide solution were added. The reaction mixture was stirred for 0.5 hours at 25 to 35 °C. After that, it was neutralized to pH 5 using sodium hydroxide solution. The molecular weight determined by GPC was 35000 g / mol.

[0175] PCE5

[0176] PCE5 is a copolymer of ethoxylated vinyloxybutanol with a chain length of 68 ethylene oxide units and acrylic acid. The copolymer was prepared as follows: A glass reactor equipped with multiple feed ports, a stirrer, and a dropping funnel was charged with 500 ml of water and 359 g of macromonomer 1 (prepared by ethoxylation of vinyloxybutanol with 68 mol EO) and temperature was maintained at 13 °C. To this, 0.01 g of iron(ll) sulfate heptahydrate and 5.5 g of Bruggolit FF6 were added. Then, 68.4 g of acrylic acid and 5 g of 30% hydrogen peroxide solution were added. The reaction mixture was stirred for 0.5 hours at 25 to 35 °C. After that, it was neutralized to pH 5 using sodium hydroxide solution. The molecular weight determined by GPC was 25000 g / mol.

[0177] Synthesis of polymers (in melt) mPCE1 to mPCE10

[0178] The reaction vessel was filled with MPEG-Methacrylate and the other solvent / comonomer (other) as specified in Table 1 and then heated to 90 °C. Methacrylic acid and 2-mercaptoethanol were subsequently added. Slowly and gradually, either Azo 044, dissolved in water to obtain a 15% solution, or VAZO V067, dissolved in MPEG 500 (15%), was carefully added to the reaction mixture. Once 7 ml of the vazo solution had been added over a period of 3 hours, the reaction mixture was further heated for an additional hour.

[0179] Table 1: Composition and characteristics of the polymers synthesized in melt. Methods:

[0180] Polymer characterization via GPC

[0181] The average molecular weight Mwof the copolymer of the invention as determined by gel permeation chromatography (GPC) is preferably 1000 to 200 000 g / mol, more preferably 3000 to 80 000 g / mol, and very preferably 3000 to 50 000 g / mol. The polymers were analyzed for average molar mass and conversion by means of size extrusion chromatography (column combinations: OH-Pak SB-G, OH-Pak SB 804 HQ, and OH-Pak SB 802.5 HQ from Sho- dex, Japan; eluent: 80 vol% aqueous solution of HCO2NH4 (0.05 mol / l) and 20 vol% acetonitrile; injection volume 100 l; flow rate 0.5 ml / min). The calibration to determine the average molar mass took place with linear polyethylene glycol standards. As a measure of the conversion, the peak of the copolymer is standardized to a relative height of 1, and the height of the peak of the unreacted macromonomer / PEG-containing oligomer is used as a measure of the residual monomer content.

[0182] Spray-drying of polymers

[0183] For drying the polymers PCE1 to PCE5, a GEA Niro spray dryer of the Mobile Minor type MM-I was used. Drying was carried out using a two-component nozzle at the top of the tower. Nitrogen was used for drying, which was blown in concurrently with the drying material from top to bottom. A first anti-blocking agent (0.5 wt.% of silica powder, based on the total of all components of the final product) was fed into the drying chamber through a nozzle. Drying was carried out with 80 kg / h of drying gas. The temperature of the drying gas at the tower inlet was 220 °C. The inlet speed of the drying material was adjusted so that the outlet temperature of the drying gas at the tower outlet was 100 °C. The powder discharged from the drying tower with the drying gas was separated from the drying gas using a cyclone. After removing the obtained powder from the spray dryer, it was mixed with 4-4.5 wt.-% (based on the total of all components of the final product) of a second anti-blocking agent, which were selected from commercially available anti-blocking agents, namely silica or limestone.

[0184] Preparation of the two-component PU TC adhesive:

[0185] First, the A-component is prepared. When using the dispersing additives, they were dispersed in the PEG component while stirring, and if necessary, heated at 70 °C until a homogeneous mixture or solution was obtained. All liquid components are placed in a Speedmixer cup, followed by the addition of fillers (totaling 100-500 g). This mixture is stirred using a Hauschild Speedmixer at 800 rpm for 1 minute, followed by an additional minute at 1600 rpm. Subsequently, the mixing is continued under vacuum at 800 rpm for 10 minutes.

[0186] Next, the B-component is prepared. All liquid components are placed in a Speedmixer cup, followed by the addition of fillers (totaling 200-500 g). This mixture is stirred using a Hauschild Speedmixer at 800 rpm for 1 minute, followed by an additional minute at 1600 rpm. Subsequently, the mixing is continued under vacuum at 800 rpm for 10 minutes. Afterwards, the A and B components are mixed in a Speedmixer for 10 seconds at 800 rpm and 30 seconds at 1600 rpm, resulting in an index of 115 (disregarding any OH groups from dispersing additives or fillers and disregarding the drying agents). The index defines the equivalent ratio of NCO to OH groups. An index of 115 means that there are 115 isocyanate groups for every 100 OH groups. Immediately after, the squeeze flow is examined. The compositions of the components are listed in Table 2 and in Table 3.

[0187] Squeeze flow:

[0188] To measure the SQF, a rotationally symmetrical cylinder with diameter D is mounted such to be axially movable. The gap between the underside of the cylinder and a plane surface is filled with the thermally conductive adhesive. In tests where the cylinder has been lowered at a linear speed v, the force F(h) occurring during the axial movement of the cylinder and the height of the gap h(t) are simultaneously measured. The movement of the cylinder causes a radial squeezing of the adhesive out of the gap. The maximum hydrostatic pressure in the adhesive occurs on the rotational axis (r=0). The exact parallelism of the cylinder and the plane surface are decisive for the measuring quality, as are the speed control and the very precise measurement of the gap height h(t).

[0189] For the patent experiments, the following measurement setup was used:

[0190] • Test speed: v = 1 mm / s

[0191] • Diameter D of the cylinder = 40 mm; diameter of the plane surface = 60 mm

[0192] • Initial gap of 5 mm was lowered to a final gap of 0.3 mm

[0193] • The SQF force was evaluated at a gap of 0.5 mm

[0194] • Apparatus: Table-top testing machine Zwicki Z2.5 (ZwickRoell) with PC and measurement and control software (testXpert III and testControl II).

[0195] The measurement of the SQF took place at room temperature. The A-component and B-component were measured after production. The measurement of the mixture of A- and B-component took place immediately after mixing.

[0196] Lap shear strength:

[0197] For lap shear strength measurements, the samples are prepared by forming a layer of the adhesive between two 100 mm X 25 mm isopropanol cleaned Al-specimen (5005A) from Rocholl with 2 mm thickness, that overlap to form a bond area of about 12.5 mm X 25 mm. The adhesive layer is 1 .0 mm thick. The adhesive is applied, and the test samples were assembled at room temperature and cured for 6 h at 60 °C and for 7 d at room temperature. The measurement was performed at room temperature with a pulling speed of 5 mm / min and the resulting lab shear strength (LSS) is recorded in MPa.

[0198] The polycarboxylate ethers (PCEs) were tested in a simplified two-component (2c) polyurethane adhesive formulation to better observe the effects of this dispersing agent. Therefore, the use of adhesion promoters, chain extenders, crosslinking agents, and dyes was omitted. Hydroxyl value DIN 53240

[0199] NCO content DIN EN ISO 14896

[0200] Table 2 Composition of component A and the component B of the examples (Ex.) and reference examples (Ref. Ex.).

[0201] Abbreviations: n.m. = not measured; X = not measurable Table 3 Composition of component A and the component B of the examples (Ex.) and reference example (Ref).

[0202] Comparative Example

[0203] When using traditional dispersing additives such as BYK-W 996 or 669 from BYK company, very low paste viscosities (SQF) are also achieved for the A-component and for the mixture of the A- and B-component. However, for fast curing processes, such as when a green strength of 0.25 MPa is required within 60 minutes at room temperature, the organometallic catalyst: 0.15 parts of dioctyltin mercaptide catalyst are added. In comparison to the reference system, a significantly delayed curing process was observed, with the green strength not being achieved even after 80 minutes. Literature cited

[0204] W02014072200A1

[0205] PCT / EP2005 / 010124

[0206] EP 90444

[0207] WO 05 / 090440

[0208] "Polyurethane Handbook”, Carl Hanser Verlag, 2ndedition 1994, chapter 3.2 and 3.3.2.

[0209] EP0894811

[0210] EP1851256

[0211] EP2463314

[0212] EP0753488

[0213] WO97 / 35814A1

[0214] WO95 / 09821A2

[0215] DE 100 15 135 A1

[0216] EP 1138697 A1

[0217] EP 1348729 A1

[0218] WC2005 / 090416 A1

[0219] EP 1 138 697 B1

[0220] EP 1 061 089 B1

[0221] Frauenhofer, M., Gormanns, M., Simon, M., Rutters, M., & Fricke, H. Optimized heat dissipation of energy storage systems, adhesion ADHESIVES+ SEALANTS, 17, 12-17 (2020)

Claims

Claims1 . A process for the production of a polyurethane composition obtained by mixing an isocyanate reactive component (A) and an isocyanate component (B) at an isocyanate index in the range of 70 to 150 to form a reaction mixture and allowing the reaction mixture to cure, wherein the polyisocyanate reactive component (A) comprises(a1) at least one polyol (P1)(a2) at least one polycarboxylate ether (PCE), and the isocyanate component (B) comprises(b1) at least one polyisocyanate (IC).

2. The process according to claim 1, wherein the polycarboxylate ether is present in component (A) in an amount of from 0.1 to 20 % by weight, based on the weight of component (A).

3. The process according to any one of claims 1 or 2, wherein the polyurethane composition is an adhesive, a sealant, a foam or a coating.

4. The process according to any one of claims 1 to 3, wherein component (A) comprises at least one filler in an amount of from 50 to 95 %.

5. The process according to any one of claims 1 to 4, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and / or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and / or at least one methacrylic acid moiety or a salt thereof.

6. The process according to any one of claims 1 to 5, wherein component (A) is free of water.

7. The process according to any one of claims 1 to 6, wherein the polycarboxylate ether (PCE) is prepared in a water-free process.

8. A two component polyurethane adhesive composition comprising an isocyanate reactive component (A) and an isocyanate component (B), each as defined in any of the claims 1 to 7.

9. A polyurethane composition obtained or obtainable by a process according to any one of claims 1 to 7.

10. Use of the polyurethane composition according to claim 9 as adhesive, sealant, a foam or coating.

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