Process for producing solid state polycarboxylate ether copolymers, solid state polycarboxylate ether copolymers produced thereby, and mineral binder compositions containing same

Abstract

The present invention relates to a process for producing solid state polycarboxylate ether copolymers, the solid state polycarboxylate ether copolymers produced thereby, and mineral binder compositions comprising the same, the process comprising the steps of providing a first type of monomer, treating the first type of monomer with an acid, providing a second type of monomer, copolymerizing the acid-treated first type of monomer with the second type of monomer to obtain a copolymer that is a polycarboxylate ether, and converting the copolymer thus obtained to a solid state.

Description

[Technical field]

[0001] The present invention relates to a process for producing solid polycarboxylate ether copolymers, said solid polycarboxylate ether copolymers having low amounts of double bond isomers. Specifically, the polycarboxylate ether copolymers of the present invention are prepared from the alkoxylation products of alcohols having terminal C-C double bonds and low contents of regioisomers in which the double bonds are shifted. The present invention also relates to such solid polycarboxylate ether copolymers and mineral binder compositions comprising same. [Background technology]

[0002] Dispersants are used in the construction industry as plasticizers or water reducers for mineral binders and / or mineral binder compositions, such as concrete, mortar, cement, gypsum, and lime. As dispersants, organic polymers are generally used. Such organic polymers are added to the mixing water or to the binder or binder composition as solids. In this way, it is possible to advantageously change both the consistency of the binder composition during processing and the properties of the hardened state. The selection and dosage of a suitable dispersant depends in particular on the specific composition, the processing technique, and the intended use of the binder or binder composition.

[0003] In practice, superplasticizers of the polycarboxylate ether copolymer (PCE) type are often used as mineral binders or dispersants for mineral binder compositions, for example to improve the flow behavior of the mineral binder composition. The use of polycarboxylate ether copolymers in the solid state is especially required when it is intended to prepare a mineral binder composition in a ready-mix form. Examples of such ready-mix mineral binder compositions are dry mortars or ready-mix gypsum compositions, which are often supplied in paper bags.

[0004] PCEs based on alkoxylation products of ethylenically unsaturated carboxylic acids and ethylenically unsaturated alcohols, particularly alkoxylated allyl alcohol, methallyl alcohol, and / or isoprenyl alcohol, are particularly useful in many embodiments. Such PCEs are described, for example, in EP 1437330 (Nippon Shokubai Co., Ltd.).

[0005] Polycarboxylate ether copolymers in the solid state are also known, for example from WO 00 / 47533 (SKW), U.S. Pat. No. 7,030,178 (Kao Corporation), WO 2006 / 133933 (Degussa Construction Polymers), and WO 2006 / 129883 (Nippon Shokubai Co., Ltd.).

[0006] EP 2152771 (Nippon Shokubai Co., Ltd.) and EP 2465836 (Nippon Shokubai Co., Ltd.) teach that an increase in the content of double bond-shifted regioisomers in the alkoxylation products of methallyl alcohol or isoprenyl alcohol reduces the plasticizing effect of copolymers prepared from acrylic acid and the respective alkoxylated alcohol in cementitious mixtures. In other words, for good plasticizing effect of polycarboxylate ethers in cementitious mixtures, it is desirable to control and / or reduce the content of double bond-shifted regioisomers in the constituent monomers. This also applies to polycarboxylate ether copolymers in the solid state.

[0007] EP 2152771 and EP 2465836 teach that lowering the reaction temperature of the alkoxylation reaction of methallyl alcohol or isoprenyl alcohol reduces the presence of each double bond-shifted regioisomer.However, lowering the reaction temperature is not always desirable, especially when a fast reaction is required.In addition, after the alkoxylation reaction is completed, it may be desirable to further reduce the content of double bond-shifted regioisomer in the alkoxylation product of ethylenically unsaturated alcohol.Double bond-shifted regioisomer is also referred to as double bond isomer within the context of the present invention.

[0008] Thus, there exists a need for solid state polycarboxylate ether copolymers useful as dispersants for mineral binder compositions, said solid state polycarboxylate ether copolymers having low amounts of double bond shifted regioisomers. There also exists a need for a process for the preparation of solid state polycarboxylate ether copolymers having reduced content of double bond shifted regioisomers. Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide a process for the production of solid state polycarboxylate ether copolymers based on the alkoxylation products of alcohols having terminal CC double bonds and minor amounts of regioisomers with shifted double bonds and / or minor amounts of structural units derived from such regioisomers. It is also an object of the present invention to provide such solid state polycarboxylate ether copolymers. It is a further object of the present invention to provide mineral binder compositions comprising such solid state polycarboxylate ether copolymers. [Means for solving the problem]

[0010] Surprisingly, it has been found that the double bond isomers of the alkoxylation products of alcohols having terminal CC double bonds can be significantly reduced by acid treatment of the respective alkoxylated alcohols, which is particularly true for the alkoxylation products of methallyl alcohol or isoprenyl alcohol, in which the double bond is shifted.

[0011] Therefore, the object of the present invention can be solved by a process according to claim 1. Further aspects of the invention are subject matter of the independent claims.

[0012] The process of the present invention is particularly efficient in reducing the double bond isomers of the alkoxylation products of alcohols having terminal CC double bonds. Such double bond isomers can be specifically reduced to very low levels, for example, less than 10 wt%, preferably less than 5 wt%, more preferably less than 1 wt%, even more preferably less than 0.5 wt%, especially less than 0.01 wt%. Without wishing to be bound by theory, it is believed that the reduction is due to the protonation of the shifted double bonds with subsequent cleavage of the polyether chains by water. At the same time, the amount of alkoxylation products of alcohols with loss of terminal CC double bonds is negligible. Moreover, the process of the present invention is simple and can be easily and inexpensively implemented in existing production facilities for the production of polycarboxylate ether copolymers.

[0013] The solid polycarboxylate ether copolymers obtained by the process of the present invention can be used as dispersants for mineral binder compositions. In particular, the solid polycarboxylate ether copolymers obtained by the process of the present invention are useful for increasing the flowability of mineral binder compositions with a given amount of water present. The solid polycarboxylate ether copolymers obtained by the process of the present invention are also useful in reducing the amount of water required to achieve a desired flowability of a given mineral binder composition. Finally, the solid polycarboxylate ether copolymers obtained by the process of the present invention are useful for reducing bleeding from mineral binder compositions.

[0014] Preferred embodiments of the invention are the subject matter of the dependent claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In a first aspect, the present invention relates to a process for producing a polycarboxylate ether copolymer in a solid state, said process comprising: a) General structure (I) [ka] (In the formula, R a is H or methyl, AO is a C2-C12 oxyalkylene group, x=0, 1, (n = 2 to 350) providing a first type of monomer having b) treating the first type of monomer provided in step a) with an acid; c) General structure (II) [ka] (In the formula, R u , R V are, independently of each other, H or methyl, R w is H or COOM, where M is H, an alkali metal, an alkaline earth metal, or an ammonium ion, or where R w is COOM, and adjacent COOM groups may form a ring. providing at least one second type of monomer having d) copolymerizing the monomer obtained in step b) with the monomer provided in step c) to obtain a copolymer which is a polycarboxylate ether; e) converting the copolymer obtained in step d) into a solid state; Including, However, in steps a) and / or b) and / or d) a liquid, preferably water, is added.

[0016] According to a preferred embodiment, in the above formula (I), R a is methyl, AO is an oxyethylene group or an oxypropylene group, x=0 or 1, and n=2 to 350. It is especially preferred that the first type of monomer provided in step a) is an ethoxylated methallyl alcohol, or an ethoxylated isoprenyl alcohol, or a propoxylated methallyl alcohol, or a propoxylated isoprenyl alcohol.

[0017] Preferred monomers of the second type provided in step c) having the general structure (II) are acrylic acid, methacrylic acid, maleic acid, or any of these with an alkali metal, alkaline earth metal, or ammonium salt, or maleic anhydride. Mixtures of any of these monomers are also possible.

[0018] The first type of monomer having the general structure (I) can be produced by the reaction of an unsaturated alcohol with an alkylene oxide. For example, either methallyl alcohol or isoprenyl alcohol can be reacted with ethylene oxide to produce ethoxylated methallyl alcohol or ethoxylated isoprenyl alcohol. An alkaline catalyst is required for the reaction. The alkaline catalyst can be, for example, potassium hydroxide, sodium hydride, sodium methylate, or butyl lithium. Typically, such alkoxylation reactions are carried out at elevated temperatures, for example, at temperatures between 60 and 150°C.

[0019] According to an embodiment, a first type of monomer having the general structure (I) is produced by the reaction of an unsaturated alcohol with an alkylene oxide in the presence of an alkaline catalyst, preferably sodium methylate, and at a reaction temperature of 60-150°C.

[0020] Typically, the first type of monomer of general structure (I) and provided in step a) contains a double bond shifted regioisomer as an impurity. This impurity may be formed during the alkoxylation reaction which produces the monomer of general structure (I). Within the context of the present invention, the term impurity always relates to the double bond shifted regioisomer. The double bond shifted regioisomer can be represented by the following general structure (III): [ka] (In the formula, R a is H or methyl, AO is a C2-C12 oxyalkylene group, x=0, 1, (n = 2 to 350) has.

[0021] Of course, the impurity R of general structure (III) a , AO, x, and n are each R of the monomer of general structure (I) containing the impurity. a , AO, x, and n.

[0022] Thus, according to an embodiment, in the process of the invention, the first type of monomer having general structure (I) provided in step a) is a monomer having general structure (III) [ka] (In the formula, R a , AO, x, and n are as defined for general structure (I). Contains impurities.

[0023] Within the context of the present invention, general structures (I) and (III) are intended to encompass both the respective cis and trans isomers, i.e., monomers of general structure (I) as well as impurities of general structure (III) contain double bonds that are either in the cis-configuration or in the trans-configuration or in a mixture of cis- and trans-configurations.

[0024] The amount of impurities of general structure (III) present in the monomers of general structure (I) is typically 0.01 to 10 wt%, based on the total dry weight of the monomers of general structure (I). However, it can also be lower or higher. The amount of impurities of general structure (III) present in the monomers of general structure (I) is reduced by step b) of the process of the invention. In step b) of the process of the invention, it is possible to reduce the amount of impurities of general structure (III) present in the monomers of general structure (I) to 10 wt% or less, preferably 5 wt% or less, more preferably 1 wt% or less, even more preferably 0.5 wt% or less, in particular 0.01 wt% or less, in particular less than 0.01 wt%, in each case based on the total dry weight of the monomers of the first type of general structure (I). Reduction to 0 wt% means, within the context of the present invention, that the content is reduced below the lowest detection limit of the detection method used.

[0025] The content of impurity of general structure (III) present in monomer of general structure (I) can be measured by HPLC. Any suitable HPLC method known to those skilled in the art can be used within the context of the present invention. The preferred HPLC protocol is as follows: stationary phase: Shiseido Fine Chemicals column MGII 100 Å, 5 μm, 10 mm (ID) × 250 mm, mobile phase: mixture of acetonitrile and water (volume basis 45:55), sample preparation: 10% sample solution in eluent, mode: 100 μL sample injection, measurement flow rate 1.0 mL / min, column temperature 40 ° C, detector: Waters 2414 RI detector, analysis software: Empower 2 by Waters.

[0026] Another method for determining the content of impurities of general structure (III) present in monomers of general structure (I) is 1 H-NMR.

[0027] The amount of impurity of general structure (III) present in monomer of general structure (I) in wt% can be determined by HPLC or 1 It can be calculated from the results of H-NMR measurements.

[0028] According to an embodiment, in the process of the invention, in step b), the content of impurities of general structure (III) in the first type of monomer of general structure (I) is reduced to 10 wt. % or less, preferably 5 wt. % or less, more preferably 1 wt. % or less, even more preferably 0.5 wt. % or less, in particular 0.01 wt. % or less, in particular less than 0.01 wt. %, in each case based on the total dry weight of the first type of monomer of general structure (I).

[0029] It is possible to carry out step b) of the process of the present invention substantially. This means that the monomer of general structure (I) can be treated without the presence of any solvent or other auxiliary materials. For example, the monomer of general structure (I) can be heated above its softening or melting point and then treated with an acid.

[0030] However, it is preferred to carry out step b) of the process of the present invention in solution or dispersion, preferably in solution. It is particularly preferred to dissolve the monomer of general structure (I) in a liquid, preferably in water, before or during step b). Then, in such a solution in a liquid, preferably in water, an acid treatment is carried out. This allows a particularly efficient reaction.

[0031] According to an embodiment, in the process of the present invention, the acid used in step b) has a pKa value of less than or equal to 4.5, preferably less than or equal to 2, more preferably less than or equal to 0.

[0032] The acid can be a mineral acid, an organic acid, or a mixture thereof.

[0033] According to an embodiment, the acid used in step b) is selected from the group consisting of hydrohalic acids, preferably hydrochloric acid or hydrobromic acid, perchloric acid, chloric acid, iodic acid, sulfuric acid, sulfonic acids, preferably methanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid or para-toluenesulfonic acid, nitric acid, nitrous acid, phosphoric acid, oxalic acid, chloroacetic acid, trifluoroacetic acid, citric acid, formic acid, lactic acid, ascorbic acid, benzoic acid, picric acid, maleic acid, acrylic acid, or acidic ion exchange resins or acidic silicates, such as H-zeolites. Mixtures of two or more of any of these acids are also possible.

[0034] According to an embodiment, the acid can be used in liquid form. The liquid form can be a pure acid in liquid form or a solution or dispersion of the acid in a liquid, especially in water. Preferred acids in liquid form are hydrochloric acid in water, phosphoric acid in water, sulfuric acid in water, maleic acid in water, oxalic acid, formic acid, and acrylic acid. According to another embodiment, the acid can also be in solid form. The use of a solid acid can be advantageous because its removal from the mixture containing the monomer of general structure (I) is simple. The solid acid can be a pure acid in solid form under the reaction conditions of the process of the invention. The solid acid can also be an acid attached to a solid support or an acid adsorbed on a solid support. Suitable solid support materials include polystyrene, polyethylene glycol, polyacrylate, cellulose, silica, glass, and sheet silicates. Preferred acids in solid form are solid support-supported para-toluenesulfonic acid, citric acid, maleic acid, and H-zeolite. Mixtures of two or more of any of these acids are also possible.

[0035] When step b) of the process of the invention is carried out in a solution or dispersion in water, the pH during the treatment with acid is preferably below 3.5, preferably below 3.0, more preferably below 2.5, especially below 2.0.

[0036] In step b) of the process of the present invention, it is generally preferred to add an acid to the monomer of general structure (I). The addition of the acid can be by any conventional means. For example, it is possible to add the acid for treatment to the monomer of general structure (I) in a storage tank, a container, or a reaction vessel. According to an embodiment, in step b) of the present invention, the acid is provided as an aqueous solution, the monomer of general structure (I) is dissolved or dispersed in the aqueous acid thus prepared, and then the acid treatment is carried out. According to another embodiment, in step b) of the present invention, the monomer of general structure (I) is dissolved or dispersed in water, the acid is added to the obtained solution or dispersion, and then the acid treatment is carried out.

[0037] Step b) of the process of the invention can be carried out with or without stirring. The process of the invention is preferably carried out with stirring. Stirring means stirring of the monomer of general structure (I) for a defined reaction time before, during and / or after the addition of the acid. The duration of the acid treatment is not particularly limited. According to an embodiment, the treatment of the monomer of general structure (I) with the acid is carried out for a duration of 5 min to 24 h, preferably 10 min to 12 h, in particular 20 min to 90 min. It is possible to carry out step b) in a wide temperature range, in particular at elevated temperature. However, it is preferred to carry out step b) at a temperature of 15 to 100° C., preferably 20 to 60° C. and at a pressure of 1013 mbar. It is also possible to carry out the acid treatment at reduced pressure. According to an embodiment, step b) is carried out at a temperature of 15 to 100° C., preferably 20 to 60° C. and at a pressure of approximately 1013 mbar.

[0038] The acid used in the treatment in step b) is preferably neutralized or partially neutralized after the treatment. Neutralization can be carried out, for example, with a strong base such as NaOH. The process of the invention can therefore additionally comprise a step b1) of neutralization of the acid used in the treatment in step b).

[0039] The process of the present invention comprises a step d) of copolymerizing the monomer obtained in step b) with the monomer provided in step c) to obtain a copolymer, which is a polycarboxylate ether. Suitable conditions for producing polycarboxylate ethers by copolymerization are known to those skilled in the art and are described, for example, in EP 1437330 (Examples 1-1 to 3-3) or EP 1103570 (Examples 1-1 to 1-13).

[0040] In a particularly preferred embodiment of the present invention, the monomer mixture copolymerized in step d) of the present invention is a mixture of at least one, preferably one, of ethoxylated methallyl alcohol or ethoxylated isoprenyl alcohol or propoxylated methallyl alcohol or propoxylated isoprenyl alcohol and at least one of acrylic acid, methacrylic acid, maleic acid, or the alkali metal, alkaline earth metal or ammonium salt of any of these, or maleic anhydride.

[0041] According to an embodiment, maleic acid and acrylic acid may be used as the acid in step b) and as the second monomer provided in step c) of the process of the invention. However, it is preferred that the second monomer provided in step c) is different from the acid used in step b).

[0042] Thus, according to an embodiment, the present invention also relates to a process for the production of polycarboxylate ether copolymers in solid state, said process comprising the steps of: a) General structure (I) [ka] (In the formula, R a is H or methyl, AO is a C2-C12 oxyalkylene group, x=0, 1, (n = 2 to 350) providing a first type of monomer having b) reacting the first type of monomer provided in step a) with the monomer of general structure (II) [ka] (In the formula, R u , R V is H, R w is H or COOM, where M is H, an alkali metal, an alkaline earth metal, or an ammonium ion, or where R w is COOM, and adjacent COOM groups may form a ring. and treating with an acid having d) copolymerizing the monomer mixture obtained in step b) to obtain a copolymer which is a polycarboxylate ether; e) converting the copolymer obtained in step d) into a solid state; Including, With the proviso that in steps a) and / or b) and / or d) a liquid, preferably water, is added, and with the proviso that the first type of monomer having the general structure (I) provided in step a) is converted to a monomer having the general structure (III) [ka] (In the formula, R a , AO, x, and n are as defined for general structure (I). Contains impurities of R a , AO, x, and n are as defined for the general structure.

[0043] In the process of the present invention, it is necessary to add a liquid, preferably water, in steps a) and / or b) and / or d). A liquid, preferably water, can be added in step a) to provide a solution or dispersion of a first type of monomer having general structure (I). A liquid, preferably water, can alternatively or additionally be added in step b), for example as a solution or dispersion of an acid. A liquid, preferably water, can alternatively or additionally be added in step d).

[0044] According to a particularly preferred embodiment, water is added in step a) to provide a solution or dispersion of the first type of monomer having the general structure (I), and additional water is added in step d) before the copolymerization starts. There is no specific restriction regarding the amount of liquid, preferably water, added in steps a) and / or b) and / or d). However, it may be preferred to adjust the amount of liquid, preferably water, so that the polycarboxylate ether copolymer obtained in step d) has a ratio of at least 20 wt%, more preferably at least 40 wt%, up to a maximum of 75 wt%, each based on the total weight of the mixture obtained in step d).

[0045] According to an embodiment, the polycarboxylate ether copolymer is obtained in step d) as a solution or dispersion in water in a ratio of 20-75 wt. %, preferably 40-60 wt. % of the polycarboxylate ether copolymer.

[0046] The copolymer obtained in step d) of the process of the invention is converted into a solid state in step e).

[0047] Within the context of the present invention, the term "solid state" means that the material is in a solid physical state at 20° C. and 1013 mbar. Thus, a polycarboxylate ether copolymer in the solid state is a polycarboxylate ether copolymer that is solid at 20° C. and 1013 mbar. In other words, a polycarboxylate ether copolymer in the solid state has a softening or melting point of >20° C. at 1013 mbar.

[0048] Typically, the solid polycarboxylate ether copolymer is in powder or flake form.

[0049] According to an embodiment, in step e) of the process of the invention, the copolymer obtained in step d) is converted into a solid state by spray drying, oven drying, vacuum drying, fluidized bed drying, dielectric drying, supercritical drying or freeze drying, preferably by spray drying. Additional chemical drying agents can be used.

[0050] A particularly preferred method for use in step e) is spray drying. Spray drying is a known method for producing a dry powder from a liquid in combination with rapid drying of the solution by spraying. Drying can be carried out using hot gas, preferably hot air or hot nitrogen. The hot gas can be blown in the same direction as the sprayed liquid. The hot gas can equally be blown in the opposite direction to the sprayed liquid. The liquid is dispersed by a spray nozzle or atomizer, the inlet of which is preferably located in the upper part of the spray tower. The dry powder can be separated from the hot gas by means of a cyclone.

[0051] According to an embodiment, the pH of the aqueous solution of polycarboxylate ether copolymer is adjusted to >7, preferably >9, especially >10, before spray drying. Such pH of the aqueous solution of polycarboxylate ether copolymer used for spray drying results in a finer particle size of the polycarboxylate ether copolymer in the solid state and a powder with less tendency to caking. According to an embodiment, the pH of the aqueous solution of polycarboxylate ether copolymer is adjusted according to the number n of repeating units -[AO]-. As the number n increases, the pH increases to prevent stickiness and caking during spray drying. According to an embodiment, the pH is adjusted by addition of an oxide or hydroxide of an alkali metal, an alkaline earth metal, or a mixture thereof. Preferably, the pH of the aqueous solution of polycarboxylate ether copolymer is adjusted by addition of NaOH, KOH, MgO, Mg(OH)2, CaO, or Ca(OH)2, most preferably Ca(OH)2.

[0052] Preferably, the aqueous solution of polycarboxylate ether copolymer is preheated before entering the spray dryer. If no gas is used for drying, the polycarboxylate ether copolymer solution can be introduced into the spray dryer at a pressure of 0.2-40 MPa. If gas is used for drying, the polycarboxylate ether copolymer solution can be introduced into the spray dryer at ambient pressure. Preferably, drying is carried out with hot air or hot nitrogen, preferably the gas is blown in the same direction as the spray liquid. Spray drying can be carried out at an inlet temperature of 90-300°C, preferably 100-200°C, more preferably 110-150°C, especially 110-120°C. A lower inlet temperature has the advantage of less energy consumption and less tendency to degradation of the PCE type copolymer. The outlet temperature can be 55-200°C, preferably 60-150°C, more preferably 65-100°C.

[0053] The aqueous solution of polycarboxylate ether copolymer can be introduced into the spray dryer by any means known to those skilled in the art, such as a nozzle, an atomizer, a centrifuge, etc. Any spray dryer known to those skilled in the art is suitable for producing the polycarboxylate ether copolymer in a solid state. The size of the spray dryer can be selected according to the intended throughput.

[0054] Additives such as anti-caking agents and / or antioxidants that stabilize the powder against thermo-oxidative degradation and autoignition can be added before or during spray drying. Suitable anti-caking agents can be any known to those skilled in the art. Examples of anti-caking agents include powdered cellulose, magnesium stearate, calcium carbonate, dolomite, clay, kaolin, vermiculite, bentonite, talc, slag, fly ash, silicates or aluminosilicates, and silicon dioxide, such as fumed silica, precipitated silica, silica gel, or silica sol. Suitable antioxidants can be any known to those skilled in the art. Examples of antioxidants are disclosed, for example, in WO 00 / 17263 and include alkylated monophenols, alkylated hydroquinones, alkylidene-bisphenols, hydroxylated benzyls, phenol-thiodiphenyl ethers, acylaminophenols, phenolic esters, and phenolic amides.

[0055] According to an embodiment, any such additives may be added prior to the spray drying process, which may result in increased performance of such additives. The additives may be added to the aqueous solution of polycarboxylate ether copolymer prior to spray drying. During the spray drying process, one or more additives may also be added, for example, via separate feed nozzles.

[0056] The resulting solid polycarboxylate ether copolymer may be sieved to remove any small agglomerates that may potentially be formed.

[0057] The spray drying process can be carried out continuously or discontinuously.

[0058] Step e) of the process of the invention can also be a step of oven drying and / or vacuum drying and / or fluidized bed drying. Such step e) can be carried out in a drum dryer or belt dryer. In a preferred embodiment, the polycarboxylate ether copolymer prepared in step d) is converted to a solid state in step e) by oven drying and / or vacuum drying at a temperature between 20 and 180° C. The pressure can be normal pressure. However, it is also possible to carry out step e) at reduced pressure, for example at a pressure below 900 mbar, preferably below 500 mbar. Lower pressures allow a faster process and / or a reduction in the required temperature. When step e) is carried out by oven drying and / or vacuum drying, it is particularly preferred to carry out step e) at 20 to 180° C. and a pressure below 100 mbar.

[0059] The process of the invention may comprise an additional step f) of granulation of the polycarboxylate ether copolymer in the solid state. Such optional step f) may be carried out by crushing and / or grinding. Suitable mills include hammer mills, colloid mills, corundum mills, ball mills, planetary mills, impact mills, tube mills, rotor mills, disc mills, cutting mills, vibratory mills, jet mills, pin mills, drum mills, vertical mills, vortex mills or roller mills. It may be particularly convenient to carry out the granulation in a cryogenic mill. The granulation, especially the grinding, may thus be carried out at temperatures between -196°C and +80°C.

[0060] In another aspect, the present invention relates to polycarboxylate ether copolymers in solid state obtainable by the process described above.

[0061] The term "solid state" is defined above.

[0062] Such copolymers include a) General formula (IV) [ka] Repeating units M-1 and b) General formula (V) [ka] Repeating unit M-2 of (In the formula, R u , R V are, independently of each other, H or methyl, R w is H or COOM, where M is H, an alkali metal, an alkaline earth metal, or an ammonium ion, or where R w is COOM, and adjacent COOM groups may form a ring; R a is H or methyl, AO is a C2-C12 oxyalkylene group, x=0, 1, (n = 2 to 350) comprising or consisting essentially of And the molar ratio of repeating unit M1 to repeating unit M-2 in the copolymer is 90:10 to 10:90.

[0063] The repeat units M-1 and / or M-2 can be arranged statistically randomly or block-wise or a mixture of random and block-wise, eg, gradient-wise, along the backbone of the copolymer.

[0064] According to an embodiment, the polycarboxylate ether copolymers in the solid state of the invention do contain not more than 10 wt.%, preferably not more than 5 wt.%, more preferably not more than 1 wt.%, even more preferably not more than 0.5 wt.%, especially not more than 0.01 wt.%, and in particular less than 0.01 wt.%, in each case based on the total dry weight of said polycarboxylate ether copolymer in the solid state, of impurities of general structure (III) or any repeat units derived from such impurities of general structure (III).

[0065] According to a preferred embodiment of the present invention, the polycarboxylate ether copolymer in the solid state is a powder. However, the polycarboxylate ether copolymer in the solid state can also be in the form of flakes, granulates, shaped blocks, tablets, etc. The powder can be converted into another solid form, for example by pressing.

[0066] The solid state polycarboxylate ether copolymers of the present invention are readily dispersible or soluble in water.

[0067] The solid polycarboxylate ether copolymers of the present invention can be used as dispersants for mineral binder compositions. In particular, the solid polycarboxylate ether copolymers of the present invention are useful in reducing the amount of water required to achieve a desired flowability of a given mineral binder composition. The solid polycarboxylate ether copolymers of the present invention are also useful in reducing bleeding from mineral binder compositions. Finally, the solid polycarboxylate ether copolymers of the present invention are useful in increasing the flowability of mineral binder compositions with a given amount of water present.

[0068] In yet another aspect, the present invention relates to a mineral binder composition comprising at least one mineral binder and a solid polycarboxylate ether copolymer, said solid polycarboxylate ether copolymer being as described above.

[0069] Within the context of the present invention, a "mineral binder composition" is a composition comprising at least one mineral binder. The term "mineral binder" means in particular a binder chosen from cement, calcium sulfate, lime, pozzolans, latent hydraulic binders, or mixtures thereof.

[0070] According to an embodiment, the mineral binder composition of the invention is characterized in that said mineral binder is selected from cement, calcium sulfate, lime, pozzolana, latent hydraulic materials or mixtures thereof, preferably calcium sulfate or mixtures comprising calcium sulfate.

[0071] The cements are, inter alia, Portland cements of type CEM I, II, III, IV or V (according to standard EN 197-1), calcium aluminate cements (according to standard EN 14647:2006-01) and calcium sulphoaluminate cements. Naturally, cements produced in accordance with relevant alternative standards, for example relevant ASTM or Chinese standards, are likewise suitable.

[0072] Calcium sulfate is intended to include natural gypsum, REA gypsum, calcium sulfate dihydrate, alpha and beta calcium sulfate hemihydrate, and / or anhydrite.

[0073] According to a preferred embodiment, the mineral binder composition of the invention is characterized in that the calcium sulfate is selected from natural gypsum, REA gypsum, anhydrite, α-calcium sulfate hemihydrate, β-calcium sulfate hemihydrate, calcium sulfate dihydrate, or mixtures thereof.

[0074] The term "lime" is intended to encompass natural hydraulic lime, blended lime, hydraulic lime, and aerated lime as described in standard EN459-1:2015.

[0075] The pozzolans and latent hydraulic materials are preferably selected from the group consisting of clays, calcined clays, especially metakaolin, slag, kiln dust, microsilica, fly ash, pyrogenic silica, precipitated silica, silica fume, sodocalcic glass, borocalcic glass, zeolites, rice husk ash, calcined oil shale, and natural pozzolans such as pumice and tulace.

[0076] Besides at least one mineral binder and the polycarboxylate ether copolymer in solid state, the mineral binder composition of the present invention also typically comprises an inert material, such as aggregates, especially gravel and / or sand, and / or fillers, such as limestone or quartz flour. Further additives, such as accelerators, retarders, thickeners, defoamers, pigments, fibers, water retention agents, biocides, may additionally be present. Water may additionally be present.

[0077] According to some embodiments, the mineral binder composition of the present invention comprises (based on the total dry weight of the mineral binder composition unless otherwise specified): a) at least 25 wt. % of a mineral binder, the mineral binder comprising 5-100 wt. % calcium sulfate (based on the total weight of the dry mineral binder); b) 0.01-10 wt. %, preferably 0.1-2 wt. %, of the polycarboxylate ether copolymer described above in solid state; c) optionally 30 to 74.99 wt. % aggregates and / or fillers; d) optionally further additives; e) optionally water; Includes. EXAMPLES

[0078] A-Generation example A.1-Measurement method The HPLC measurements were performed using a column MGII 100 Å, 5 μm, 10 mm (ID) × 250 mm manufactured by Shiseido Fine Chemicals. The eluent was a mixture of acetonitrile and water (volume basis 45:55). The sample to be measured was a 10% solution in the eluent. 100 μL of sample was injected and the measurement was performed at a column temperature of 40 °C and a flow rate of 1.0 mL / min. The detector used was a Waters 2414 RI detector. The analysis software was Empower 2 by Waters Sampling. In general, the compound I of general formula (II) has a longer retention time compared to the alkoxylated alcohol A of general formula (I).

[0079] The content of compound I of general formula (II) is represented by the following formula: c I =[SA I / (SA I +SA A )] x 100 It can be calculated from the surface area ratio of the chromatogram by using the formula: I = content of compound I of general formula (II), SA I = surface area of ​​compound I of general formula (II), SA A = surface area of ​​alkoxylated alcohol A of general formula (I).

[0080] A. Preparation of 2.0-HPEG solution 1 An aqueous solution of methallyl-started polyethylene oxide (HPEG with molecular mass Mw=4000 g / mol) was prepared by dissolving 220 g of HPEG in 220 g of water. The pH was adjusted to 2.0 by adding aqueous HCl (10 N). The resulting solution was stirred at 25° C. for 8 h and then the pH was adjusted to 4.5 with 1 M NaOH to produce HPEG solution 1. The content of isomers (isomethallyl isomers of HPEG) in HPEG solution 1 as well as in the HPEG used as starting material (as a 50% solution in water) was measured by HPLC as described above. In the HPLC chromatogram of HPEG solution 1, no isomers could be detected (0 wt% isomer). The HPEG used as starting material had an isomer content of 10 wt%. The isomer content was thus reduced by the acid treatment.

[0081] Preparation of A.2.1-HPEG solution 2 An aqueous HPEG solution was prepared as in Example A.2.0, except that HCl (10 N) was used to adjust the pH to 1.0 and stirring was carried out at 50° C. After 20 minutes, the resulting HPEG solution 2 was isomer free (0 wt % isomer as determined by HPLC).

[0082] A.2.2 Preparation of HPEG solution 3 An aqueous HPEG solution was prepared as in Example A.2.0, except that H2SO4 (7.5 N) was used to adjust the pH to 1.0 and stirring was carried out at 50° C. After 20 minutes, the resulting HPEG solution 3 was isomer free (0 wt % isomer as determined by HPLC).

[0083] Preparation of A.2.3-HPEG solution 4 An aqueous HPEG solution was prepared as in Example A.2.0, except that HNO3 (10 N) was used to adjust the pH to 1.0 and stirring was carried out at 50° C. After 80 minutes, the resulting HPEG solution 4 was isomer free (0 wt % isomer as determined by HPLC).

[0084] A.2. Preparation of 4-HPEG solution 5 An aqueous HPEG solution was prepared as in Example A.2.0, except that a mixture of H2SO4 (7.5N) and p-toluenesulfonic acid (1:2 ratio by weight) was used to adjust the pH to 1.4, and stirring was carried out at 50° C. After 50 minutes, the resulting HPEG solution 5 was isomer free (0 wt % isomer as determined by HPLC).

[0085] A.2. Preparation of 5-HPEG solution 6 An aqueous HPEG solution was prepared as in Example A.2.0, except that acrylic acid was used in an amount to adjust the pH to 4.2 and stirring was carried out at 50° C. The amount of isomers in the resulting HPEG solution 6 was 50% of the original amount within 3.5 days.

[0086] A.2. Preparation of 6-HPEG solution 7 An aqueous HPEG solution was prepared as in Example A.2.0, except that maleic acid was used in an amount to adjust the pH to 2.0 and stirring was carried out at 50° C. After 8 hours, the resulting HPEG solution 7 was isomer free (0 wt % isomer as determined by HPLC).

[0087] A. Preparation of 3-polycarboxylate polymer PC1 A glass reactor equipped with a thermometer, stirrer, dropping funnel, and reflux condenser was charged with 480 g of HPEG solution 1 prepared as described above. To it, a mixture of 3 g hydrogen peroxide (35%) and 7 g water, a mixture of 51 g acrylic acid and 55 g water, and a mixture of 2 g sodium hydroxymethanesulfinate and 11 g water were added in parallel over a period of 60 minutes. Then, the temperature was increased to 65° C. and maintained for 60 minutes to complete the polymerization reaction. Polymer PC1 was obtained in an aqueous solution.

[0088] A. Preparation of 4-polycarboxylate polymers PC2 to PC7 Polycarboxylate polymer PC2 was prepared similarly to PC1 in Example A.3, except that HPEG solution 2 was used.

[0089] Polycarboxylate polymer PC3 was prepared similarly to PC1 in Example A.3, except that HPEG solution 3 was used.

[0090] Polycarboxylate polymer PC4 was prepared similarly to PC1 in Example A.3, except that HPEG solution 4 was used.

[0091] Polycarboxylate polymer PC5 was prepared similarly to PC1 in Example A.3, except that HPEG solution 5 was used.

[0092] Polycarboxylate polymer PC6 was prepared similarly to PC1 in Example A.3, except that HPEG solution 6 was used.

[0093] Polycarboxylate polymer PC7 was prepared similarly to PC1 in Example A.3, except that HPEG solution 7 was used.

[0094] A. Preparation of 5-polycarboxylate polymer powder PP1 Polymer powder PP1 was prepared by adding 3 g Ca(OH)2, 68 g water, and 3 g fumed silica (Aerosil® 150 from Evonik) to 200 g PC1. The resulting suspension had a pH of approximately 13. The resulting suspension was dried in a laboratory spray dryer of the type Mini Spray Dryer B-290 (Buchi AG, Switzerland). Spray drying was performed by inserting the suspension at the nozzle of the head of the spray dryer. Compressed air flowing in the same direction as the sprayed material was used at a flow rate of 600 L / h and a pressure of 0.5 MPa. The inlet temperature was 120° C. The dosing speed was adjusted so that the outlet temperature reached 65-70° C. A cyclotron was used to separate the exiting powder from the air stream. This powder is the polycarboxylate polymer powder PP1 according to the invention.

[0095] A. Preparation of 6-polycarboxylate polymer powders PP2 to PP7 Polycarboxylate polymer powder PP2 was prepared similarly to PP1 in Example A.4, except that PC2 was used.

[0096] Polycarboxylate polymer powder PP3 was prepared similarly to PP1 in Example A.4, except that PC3 was used.

[0097] Polycarboxylate polymer powder PP4 was prepared similarly to PP1 in Example A.4, except that PC4 was used.

[0098] Polycarboxylate polymer powder PP5 was prepared similarly to PP1 in example A.4, except that PC5 was used.

[0099] Polycarboxylate polymer powder PP6 was prepared similarly to PP1 in example A.4, except that PC6 was used.

[0100] Polycarboxylate polymer powder PP7 was prepared similarly to PP1 in Example A.4, except that PC7 was used.

[0101] B-Mineral Binder Test B.1-Measurement method The flow was tested using a mini-cone with a diameter of 50 mm and a height of 51 mm. The mini-cone was filled with the respective gypsum slurry and the diameter of the formed gypsum cake was measured as soon as no further flow was observed. The diameter in mm was called the flow.

[0102] The setting start and setting end were determined using the knife cut method and thumb pressure method according to DIN EN13279-2:2014-03. The setting start is the time when the cut edge no longer converges after knife cutting the gypsum plaster cake. The setting end is the time when water no longer escapes from the plaster cake when a pressure of approximately 5 kg is applied by pressing with a thumb. Alternatively, the setting start and setting end can also be determined by a Vicat needle device according to DIN EN13279-2:2014-03.

[0103] The slump flow was measured after the times shown in the table below in accordance with standard EN 12350-5 with the only exception that a cone with a bottom diameter of 50 mm was used.

[0104] The compressive strength was measured on 4x4x16 cm prisms after the times indicated in the table below according to standard EN 12190. The curing of the prisms was as follows: 24 h curing in the mould at 20°C / 65% rh, followed by demoulding and curing for 48 h in a sealed plastic bag at 20°C, followed by 25 days at 20°C / 65% rh.

[0105] B.2 - Example 1 199.6 g of β-calcium sulfate hemihydrate, 0.4 g calcium sulfate dihydrate, and each of the polycarboxylate ethers shown in Table 1 below at 0.22 solids were thoroughly mixed until visually uniform (except for Example 1-1, where no PCE was added). Water was added to the mixture in an amount to achieve a calcium sulfate to water weight ratio of 0.69. Table 1 below shows the results.

[0106] [Table 1]

[0107] The results in Table 1 show that the solid polycarboxylate ethers of the present invention significantly increase the flow of the gypsum slurry with a given amount of water, while at the same time increasing the end setting time acceptable for practical applications.

[0108] B.3 - Example 2 Dry mortars were prepared consisting of 35 wt% ternary binder system consisting of 69 parts by weight of CEM I52.5R, 26 parts by weight of calcium aluminate cement, and 5 parts by weight of anhydrite, 40 wt% of Sand F33, 21.9 wt% of fine limestone filler, 0.7 wt% of hydrated lime, 0.15 wt% of tartaric acid, 0.04 wt% of lithium carbonate, and 2.2 wt% of further additives (redispersible polymer powder, defoamer, thickener). To this dry mortar, 0.4 g of each polycarboxylate ether in solid state shown in Table 2 below was added to each 100 g of dry mortar (except for Example 2-1, where no PCE was added at all). Water was then added in an amount to achieve a powder to water weight ratio of 0.23, and the mixture was mixed for 2 minutes with a Hobart mixer at speed #1. Table 2 below shows the results.

[0109] [Table 2]

Claims

1. 1. A process for producing a solid state polycarboxylate ether copolymer, said process comprising: (a) General structure (I) 【Chemistry 1】 (In the formula, R ａ is H or methyl, AO is a C2-C12 oxyalkylene group; x=0, 1, n = 2 to 350) providing a first type of monomer having: (b) treating the first type of monomer provided in step (a) with an acid; (c) General structure (II) 【Chemistry 2】 providing a second type of monomer having (In the formula, R ｕ , R Ｖ are, independently of each other, H or methyl, R ｗ is H or COOM, where M is H, an alkali metal, an alkaline earth metal, or an ammonium ion, or where R ｗ is COOM, and adjacent COOM groups may form a ring. (d) copolymerizing the monomers obtained in step (b) with the monomers provided in step (c) to obtain a copolymer which is a polycarboxylate ether; (e) converting the copolymer obtained in step (d) into a solid state; Including, A production process wherein in steps (a) and / or (b) and / or (d) a liquid, preferably water, is added.

2. 2. The process according to claim 1, characterized in that in step (d) the copolymer which is polycarboxylate ether is obtained as a solution or dispersion in water in a ratio of the copolymer which is polycarboxylate ether of 20 to 75 wt %, preferably 40 to 60 wt %.

3. 3. The process according to claim 1 or 2, characterized in that in step (e) the copolymer obtained in step (d) is converted into a solid state by spray drying, oven drying, vacuum drying, fluidized bed drying, dielectric drying, supercritical drying or freeze drying, preferably by spray drying.

4. The first type of monomer having general structure (I) provided in step (a) is a monomer having general structure (III): 【Transformation 3】 (In the formula, R ａ , AO, x, and n are as defined above with respect to general structure (I).

3. The process according to claim 1 or 2, characterized in that it contains impurities of

5. 5. The process according to claim 4, characterized in that in step (b) the content of said impurity of general structure (III) in said first type of monomer of general structure (I) is reduced to 10 wt % or less, preferably 5 wt % or less, more preferably 1 wt % or less, even more preferably 0.5 wt % or less, especially 0.01 wt % or less, in particular less than 0.01 wt %, in each case based on the total dry weight of said first type of monomer of general structure (I).

6. 3. The process according to claim 1 or 2, characterized in that the acid used in step (b) has a pKa value of 4.5 or less, preferably 2 or less, more preferably 0 or less.

7. 3. The process according to claim 1 or 2, characterized in that the acid used in step (b) is selected from the group consisting of a hydrohalic acid, preferably hydrochloric acid or hydrobromic acid, perchloric acid, chloric acid, iodic acid, sulfuric acid, a sulfonic acid, preferably methanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, or para-toluenesulfonic acid, nitric acid, nitrous acid, phosphoric acid, oxalic acid, chloroacetic acid, trifluoroacetic acid, citric acid, formic acid, lactic acid, ascorbic acid, benzoic acid, picric acid, maleic acid, acrylic acid, or a mixture of two or more of these acids.

8. 3. The process according to claim 1 or 2, characterized in that step (b) is carried out at a temperature of 15 to 100°C, preferably 20 to 60°C, and at a pressure of about 1013 mbar.

9. A polycarboxylate ether copolymer in solid form obtainable by the process of claim 1 or 2.

10. 10. The solid state polycarboxylate ether copolymer of claim 9, characterized in that it contains impurities of general structure (III) or repeat units derived from such impurities of general structure (III) in an amount of 10 wt % or less, preferably 5 wt % or less, more preferably 1 wt % or less, even more preferably 0.5 wt % or less, especially 0.01 wt % or less, and especially less than 0.01 wt %, in each case based on the total dry weight of the solid state polycarboxylate ether copolymer.

11. 10. A mineral binder composition comprising at least one mineral binder and a solid polycarboxylate ether copolymer, wherein the solid polycarboxylate ether copolymer is as defined in claim 9.

12. 12. Mineral binder composition according to claim 11, characterized in that the mineral binder is selected from cement, calcium sulfate, lime, pozzolana, latent hydraulic materials or mixtures thereof, preferably calcium sulfate or mixtures containing calcium sulfate.

13. 13. The mineral binder composition according to claim 12, wherein the calcium sulfate is selected from natural gypsum, REA gypsum, anhydrous gypsum, α-calcium sulfate hemihydrate, β-calcium sulfate hemihydrate, calcium sulfate dihydrate, or mixtures thereof.

14. The mineral binder composition comprises (based on the total dry weight of the mineral binder composition unless otherwise specified): (a) at least 25 wt. % mineral binder, the mineral binder comprising 5 to 100 wt. % calcium sulfate (based on the total dry weight of the mineral binder); (b) 0.01 to 10 wt %, preferably 0.1 to 2 wt %, of the polycarboxylate ether copolymer of claim 9 in a solid state; (c) optionally, 30 to 74.99 wt. % aggregate and / or filler; (d) optionally, further additives, and (e) optionally, water; 12. The mineral binder composition of claim 11, comprising:

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