XSBR polymer composition

Abstract

The present invention relates to a water-dispersible pulverulent composition, and a method for producing the water-dispersible pulverulent composition. The present invention also relates to a pseudo-latex, construction material comprising the water-dispersible pulverulent composition of the pseudo-latex, as well as use of the water-dispersible pulverulent composition or the pseudo-latex in construction material.

Description

[0001] P55553WO_APPL filed_281125.docx

[0002] 1

[0003] XSBR POLYMER COMPOSITION

[0004] The present invention relates to a water-dispersible pulverulent composition, and a method for producing the water-dispersible pulverulent composition. The present invention also relates to a pseudo-latex, construction material comprising the water- dispersible pulverulent composition of the pseudo-latex, as well as use of the water- dispersible pulverulent composition or the pseudo-latex in construction material.

[0005] Background of the invention:

[0006] The addition of aqueous polymer latex to building materials to improve processing and application properties is a common practice. Such effects may include improved adhesion, open time adjustment, improved flexibility, or improved mechanical strength. These latexes are typically produced by the emulsion polymerization process, where the polymer is formed as small particles dispersed in water. In aqueous latex form, the polymer can only be added and incorporated into the building material during mixing with the water (two-component process). By spray drying, usually in the presence of a redispersion aid, the aqueous dispersions can be converted into water-free, redispersible powders that can be added to the building materials in dry form and require only water for mixing (one-component process). By mixing the dry mixture with water and the resulting redispersion of the latex, a building material with all the advantages of polymer modification is obtained.

[0007] A typical process for producing a redispersible powder from a polymer latex is spray drying, where the latex is atomized through a nozzle and dried in a hot air stream. To prevent irreversible film formation of the latex particles, a water-soluble redispersion aid is added to the latex, which separates the particles in the dry state. During redispersion, the redispersion aid dissolves and the latex reforms. This is not always successful. The better the redispersion behavior, the closer the properties of the aqueous latex after redispersion are to those of the aqueous latex before spray drying. The redispersion behavior is determined by the composition of the latex, the choice of redispersion aid and the coordination of the two components.

[0008] EP 0 873 374 B1 describes a water-redispersible powder composition consisting of a water-insoluble, film-forming polymer powder prepared from at least one ethylenically unsaturated monomer and at least one monomer with a carboxyl function, acrylamide or methacrylamide, and at least one amino acid or one of its P55553WO_APPL filed_281125.docx

[0009] 2 salts as a redispersion aid. Although the powders produced in this way usually have good redispersibility, they prove to be incompatible with cement and thus unsuitable for use in cementitious building materials because the polymer particles coagulate in the highly alkaline and calcium ion-rich environment. As a result, the polymer particles agglomerate instead of being finely dispersed in the building material, and the desired positive effect on processing and application properties is lost.

[0010] It is therefore an object of the present invention to provide a redispersible powder with good compatibility with cementitious building materials while providing excellent redispersion behavior.

[0011] Summary of the invention:

[0012] The following clauses summarize some aspects of the present invention.

[0013] According to a first aspect, the present invention relates to a water-dispersible pulverulent composition comprising:

[0014] (a) a polymer obtained by polymerization of a mixture of ethylenically unsaturated monomers comprising:

[0015] (i) an aliphatic conjugated diene;

[0016] (ii) a vinyl aromatic compound;

[0017] (iii) 1 .5 to 10.0 wt.-% of an ethylenically unsaturated carboxylic acid, a salt thereof or a mixture thereof, based on the total weight of ethylenically unsaturated monomers; and

[0018] (iv) an ethylenically unsaturated sulfonic acid, salt thereof, or a mixture thereof, wherein the ethylenically unsaturated sulfonic acid or salt thereof is selected from 2- acrylamido-2-methylpropane sulfonic acid, vinyl sulfonic acid, styrene sulfonic acid or a combination thereof; and

[0019] (b) an amino acid, a salt thereof, or a mixture thereof.

[0020] The conjugated diene (i) may be selected from 1 ,3-butadiene, isoprene, 2,3- dimethyl-1 ,3-butadiene, 2-chloro-1 ,3-butadiene, 1 ,3-pentadiene, 1 ,3-hexadiene, 2,4- hexadiene, 1 ,3-octadiene, 2-methyl-1 ,3-pentadiene, 2, 3-dimethyl-1 ,3-pentadiene, 3, 4-dimethyl-1 ,3-hexadiene, 2, 3-diethyl-1 ,3-butadiene, 4, 5-diethyl-1 ,3-octadiene, 3- butyl-1 ,3-octadiene, 3,7-dimethyl-1 ,3,6-octatriene, 2-methyl-6-methylene-1 ,7- octadiene, 7-methyl-3-methylene-1 ,6-octadiene, 1 ,3,7-octatriene, 2-ethyl-1 ,3- butadiene, 2-amyl-1 ,3-butadiene, 3, 7-dimethyl-1 ,3,7-octatriene, 3,7-dimethyl-1 ,3,6- P55553WO_APPL filed_281125.docx

[0021] 3 octatriene, 3,7,11 -trimethyl-1 ,3,6,10-dodecatetraene, 7,11-dimethyl-3-methylene- 1 ,6,10-dodecatriene, 2,6-dimethyl-2,4,6-octatriene, 2-phenyl-1 ,3-butadiene, 2- methyl-3-isopropyl-1 ,3-butadiene, 1 ,3-cyclohexadiene, myrcene, ocimene, farnesene, or combinations thereof.

[0022] Preferably the conjugated diene (i) may be selected from 1 ,3-butadiene, 2-chloro- 1 ,3-butadiene, isoprene, 1 ,3-pentadiene, 1 ,3-hexadiene, 2,4-hexadiene, or combinations thereof.

[0023] More preferably the conjugated diene monomer may be 1 ,3-butadiene.

[0024] The mixture of ethylenically unsaturated monomers may comprise:

[0025] (i) 15 to 75 wt.-% of the aliphatic conjugated diene, preferably 20 to 70 wt.-%, more preferably 25 to 65 wt.-%, based on the total weight of ethylenically unsaturated monomers.

[0026] The vinyl aromatic compound (ii) may be selected from styrene, alpha-methyl styrene, 4-methyl styrene, alpha-chloro styrene, 4-chloro styrene, divinylbenzene, 4- methoxy-3-methylstyrene, 3,4-dimethyl-alpha-methylstyrene or combinations thereof.

[0027] Preferably the vinyl aromatic compound may be styrene.

[0028] The mixture of ethylenically unsaturated monomers may comprise:

[0029] (ii) 20 to 80 wt.-% of the vinyl aromatic compound, preferably 25 to 75 wt.-%, more preferably 30 to 70 wt.-%, based on the total weight of ethylenically unsaturated monomers.

[0030] The mixture of ethylenically unsaturated monomers may comprises a weight ratio of aliphatic conjugated diene (i) to vinyl aromatic compound (ii) being from 1.0 : 4.0 to 4.0 : 1 .0, preferably from 1.0 : 3.0 to 3.0 : 1 .0, more preferably from 1 .0 : 2.5 to 1.0 : 2.0.

[0031] The ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof (iii) may be selected from (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, vinyl acetic acid, vinyl lactic acid, 2-carboxy ethyl (meth)acrylate, mesaconic acid, glutaconic acid or combinations thereof.

[0032] Preferably the ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof (iii) may be selected from (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid, or combinations thereof. P55553WO_APPL filed_281125.docx

[0033] 4

[0034] The mixture of ethylenically unsaturated monomers may comprise:

[0035] (iii) 2.0 to 8.0 wt.-% of the ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof, preferably 3.0 to 7.0 wt.-%, based on the total weight of ethylenically unsaturated monomers.

[0036] The ethylenically unsaturated sulfonic acid salt (iv) may be a sodium salt, a potassium salt, an ammonium salt or a calcium salt.

[0037] The ethylenically unsaturated sulfonic acid salt (iv) may be a sodium salt.

[0038] The mixture of ethylenically unsaturated monomers may comprise:

[0039] (iv) 0.1 to 8.0 wt.-% of the ethylenically unsaturated sulfonic acid, salt thereof, or mixture thereof, preferably 0.2 to 5.0 wt.-%, more preferably 0.5 to 3.0 wt.-%, based on the total weight of ethylenically unsaturated monomers.

[0040] The mixture of ethylenically unsaturated monomers may comprise:

[0041] (v) 0 to 50 wt.-% of an alkyl ester of (meth)acrylic acid, preferably 0 to 30 wt.-%, more preferably 0 to 20 wt.-%, based on the total weight of ethylenically unsaturated monomers.

[0042] The amino acid, a salt thereof, or combination thereof (b) may comprise a monocarboxylated monoamino acid, a dicarboxy lated monoamino acid, a monocarboxylated diamino acid, or combinations thereof.

[0043] Preferably, the amino acid, a salt thereof (b) may comprise a dicarboxy lated monoamino acid.

[0044] The amino acid, a salt thereof, or mixture thereof (b) may comprise glycine, alanine, leucine, phenylalanine, aspartic acid, glutamic acid, hydroxy glutamic acid, arginine, lysine, histidine, cystine, or combinations thereof.

[0045] Preferably, the amino acid, a salt thereof, of mixture thereof (b) may comprise aspartic acid, glycine, glutamic acid, hydroxy glutamic acid, or combinations thereof.

[0046] The amino acid salt (b) may be a sodium salt, a potassium salt, an ammonium salt or a calcium salt.

[0047] The amino acid salt (b) may be a sodium salt.

[0048] The water-dispersible pulverulent composition preferably comprises divalent metal ions. The divalent metal ions can in particular comprise alkaline earth metal ions P55553WO_APPL filed_281125.docx

[0049] 5 such as calcium ions, magnesium ions or a mixture or combination thereof, preferably calcium ions. The divalent metal ions, such as alkaline earth cations, can aid in effectively separating polymer particles in the dried powder and promoting redispersibility of the water-dispersible pulverulent composition. Divalent metal ions can be incorporated into the composition for example as a water-soluble alkaline metal salt. Alkaline earth cations can in particular be incorporated into the composition by addition of an alkaline earth hydroxide, such as preferably calcium hydroxide, as described in more detail below in the context of the method for producing the water-dispersible pulverulent composition. The divalent metal ions, such as alkaline earth metal ions, if used, can for example be present in the water- dispersible pulverulent composition in an amount of from 0.01 wt.% to 6 wt.%, such as 0.1 wt.-% to 4 wt.-%, or 0.3 wt.-% to 3 wt.-%, the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

[0050] The water-dispersible pulverulent composition may comprise: 75 to 95 wt.-% of the polymer (a); and

[0051] 3 to 20 wt.-% of the amino acid, a salt thereof, or a mixture thereof (b); the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

[0052] The water-dispersible pulverulent composition may comprise:

[0053] (c) an inorganic filler selected from silica, calcium carbonate, dolomite, kaolin, talcum, barium sulfate, titanium oxide, calcium sulfoaluminate, or combinations thereof.

[0054] The water-dispersible pulverulent composition may comprise:

[0055] 2 to 20 wt.-% of the inorganic filler (c); the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

[0056] According to a second aspect, the present invention relates to a method for producing the water-dispersible pulverulent composition as defined above, comprising:

[0057] (I) polymerizing the mixture of ethylenically unsaturated monomers by emulsion polymerization in an aqueous medium to form a polymer (a) dispersion,

[0058] (II) adding the amino acid, a salt thereof, or a mixture thereof after the polymerization to the polymer (a) dispersion; and

[0059] (III) removing water from the polymer (a) dispersion. P55553WO_APPL filed_281125.docx

[0060] 6

[0061] Removing water from the polymer (a) dispersion may be by spray drying.

[0062] According to the second aspect, the method as described above may comprise: adding an alkaline earth hydroxide and / or an alkali hydroxide to the aqueous medium before removing the water in step (III). Addition of an alkaline earth hydroxide can further promote redispersibility of the dried pulverulent composition, particularly when the amino acid component (b) can form water-soluble salts with the alkaline earth hydroxide.

[0063] According to the second aspect, the method may comprise: (IV) adding the inorganic filler (c) during removing the water in step (III).

[0064] In a third aspect, the present invention relates to a pseudo-latex obtained by redispersing the water-dispersible pulverulent composition according to the first aspect or obtained by the method according to the second aspect in water.

[0065] In a fourth aspect, the present invention relates to a construction material comprising the water-dispersible pulverulent composition according to the first aspect or obtained by the method according to the second aspect or the pseudo-latex according to the third aspect.

[0066] Preferably, the construction material is a cement composition.

[0067] In a fifth aspect, the present invention relates to use of the water-dispersible pulverulent composition according to the first aspect or obtained by the method according to the second aspect or the pseudo-latex according to the third aspect in construction materials, preferably cement compositions.

[0068] Detailed description of the invention:

[0069] The present invention relates to a water-dispersible pulverulent composition specifically useful in construction materials. The water-dispersible pulverulent composition comprises (a) a polymer obtained by polymerization of a mixture of ethylenically unsaturated monomers comprising (i) an aliphatic conjugated diene; (ii) a vinyl aromatic compound; (iii) 1 .5 to 10.0 wt.-% of an ethylenically unsaturated carboxylic acid, a salt thereof or a mixture thereof, based on the total weight of ethylenically unsaturated monomers; and (iv) an ethylenically unsaturated sulfonic acid, salt thereof, or a mixture thereof, wherein the ethylenically unsaturated sulfonic acid or salt thereof is selected from 2-acrylamido-2-methylpropane sulfonic acid, P55553WO_APPL filed_281125.docx

[0070] 7 vinyl sulfonic acid, styrene sulfonic acid or a combination thereof. The water- dispersible pulverulent composition comprises (b) an amino acid, a salt thereof, or a mixture thereof.

[0071] According to the present invention, the conjugated diene (i) may be selected from

[0072] 1 .3-butadiene, isoprene, 2,3-dimethyl-1 ,3-butadiene, 2-chloro-1 ,3-butadiene,

[0073] 1 .3-pentadiene, 1 ,3-hexadiene, 2,4-hexadiene, 1 ,3-octadiene, 2-methyl-1 ,3- pentadiene, 2, 3-dimethyl-1 ,3-pentadiene, 3, 4-dimethyl-1 ,3-hexadiene, 2,3-diethyl-

[0074] 1 .3-butadiene, 4, 5-diethyl-1 ,3-octadiene, 3-butyl-1 ,3-octadiene, 3,7-dimethyl-1 ,3,6- octatriene, 2-methyl-6-methylene-1 ,7-octadiene, 7-methyl-3-methylene-1 ,6- octadiene, 1 ,3,7-octatriene, 2-ethyl-1 ,3-butadiene, 2-amyl-1 ,3-butadiene, 3,7- dimethyl-1 ,3,7-octatriene, 3,7-dimethyl-1 ,3,6-octatriene, 3,7,11 -trimethyl-1 ,3,6,10- dodecatetraene, 7, 11 -dimethyl-3-methylene-1 ,6, 10-dodecatriene, 2,6-dimethyl-2,4,6- octatriene, 2-phenyl-1 ,3-butadiene, 2-methyl-3-isopropyl-1 ,3-butadiene,

[0075] 1 .3-cyclohexadiene, myrcene, ocimene, farnesene, or combinations thereof. The conjugated diene (i) may be selected from 1 ,3-butadiene, 2-chloro-1 ,3-butadiene, isoprene, 1 ,3-pentadiene, 1 ,3-hexadiene, 2,4-hexadiene, or combinations thereof. The conjugated diene (i) may be 1 ,3-butadiene.

[0076] The mixture of ethylenically unsaturated monomers may comprise (i) at least 15 wt.- %, such as at least 20 wt.-%, or at least 25 wt.-% of the aliphatic conjugated diene, based on the total weight of ethylenically unsaturated monomers. The mixture of ethylenically unsaturated monomers may comprise (i) 75 wt.-% or less, such as 70 wt.-% or less, or 65 wt.-% or less of the aliphatic conjugated diene, based on the total weight of ethylenically unsaturated monomers. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the mixture of ethylenically unsaturated monomers may comprise (i) 15 to 75 wt.-%, preferably 20 to 70 wt.-%, more preferably 25 to 65 wt.-% of the aliphatic conjugated diene, based on the total weight of ethylenically unsaturated monomers.

[0077] According to the present invention, the vinyl aromatic compound (ii) may be selected from styrene, alpha-methyl styrene, 4-methyl styrene, alpha-chloro styrene, 4-chloro styrene, divinylbenzene, 4-methoxy-3-methylstyrene, 3,4-dimethyl-alpha- methylstyrene or combinations thereof. The vinyl aromatic compound may be styrene. P55553WO_APPL filed_281125.docx

[0078] 8

[0079] The mixture of ethylenically unsaturated monomers may comprise (ii) at least 20 wt.- %, such as at least 25 wt.-%, or at least 30 wt.-% of the vinyl aromatic compound, based on the total weight of ethylenically unsaturated monomers. The mixture of ethylenically unsaturated monomers may comprise (ii) 80 wt.-% or less, such as 75 wt.-% or less, or 70 wt.-% or less of the vinyl aromatic compound, based on the total weight of ethylenically unsaturated monomers. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the mixture of ethylenically unsaturated monomers may comprise (ii) 20 to 80 wt.-%, preferably 25 to 75 wt.-%, more preferably 30 to 70 wt.-% of the vinyl aromatic compound, based on the total weight of ethylenically unsaturated monomers.

[0080] According to the present invention, the mixture of ethylenically unsaturated monomers may comprise a weight ratio of aliphatic conjugated diene (i) to vinyl aromatic compound (ii) being at least 1 .0 : 4.0, such as at least 1 .0 : 3.0, or at least 1 .0 : 2.5. The mixture of ethylenically unsaturated monomers may comprise a weight ratio of aliphatic conjugated diene (i) to vinyl aromatic compound (ii) being 4.0 : 1 .0 or less, such as 3.0 : 1 .0 or less, or 1.0 : 2.0 or less. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the mixture of ethylenically unsaturated monomers may comprise a weight ratio of aliphatic conjugated diene (i) to vinyl aromatic compound (ii) being from 1 .0 : 4.0 to 4.0 : 1 .0, preferably from 1 .0 : 3.0 to 3.0 : 1 .0, more preferably from 1 .0 : 2.5 to 1.0 : 2.0.

[0081] According to the present invention, the ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof (iii) may be selected from (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, vinyl acetic acid, vinyl lactic acid, 2-carboxy ethyl (meth)acrylate, mesaconic acid, glutaconic acid or combinations thereof. The ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof (iii) may be selected from (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid, or combinations thereof.

[0082] According to the present invention, the water-dispersible pulverulent composition comprises (iii) 1 .5 to 10.0 wt.-% of an ethylenically unsaturated carboxylic acid, a salt thereof or a mixture thereof, based on the total weight of ethylenically unsaturated monomers. The water-dispersible pulverulent composition may comprise (iii) 2.0 to P55553WO_APPL filed_281125.docx

[0083] 9

[0084] 8.0 wt.-%, preferably 3.0 to 7.0 wt.-% of the ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof, based on the total weight of ethylenically unsaturated monomers.

[0085] According to the present invention, the (iii) ethylenically unsaturated carboxylic acid salt may be an alkali metal salt, alkaline earth metal salt, an ammonium salt, or a combination thereof. The ethylenically unsaturated carboxylic acid salt (iii) may be a sodium salt, a potassium salt, an ammonium salt, or a combination thereof.

[0086] The mixture of ethylenically unsaturated monomers may comprise (iv) at least 0.1 wt.-%, such as at least 0.2 wt.-%, or at least 0.5 wt.-% of the ethylenically unsaturated sulfonic acid, salt thereof, or mixture thereof, based on the total weight of ethylenically unsaturated monomers. The mixture of ethylenically unsaturated monomers may comprise (iv) 8.0 wt.-% or less, such as 5.0 wt.-% or less, or 3.0 wt.- % or less of the ethylenically unsaturated sulfonic acid, salt thereof, or mixture thereof, based on the total weight of ethylenically unsaturated monomers. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the mixture of ethylenically unsaturated monomers may comprise (iv) 0.1 to 8.0 wt.-%, preferably 0.2 to 5.0 wt.- %, more preferably 0.5 to 3.0 wt.-% of the ethylenically unsaturated sulfonic acid, salt thereof, or mixture thereof, based on the total weight of ethylenically unsaturated monomers.

[0087] The mixture of ethylenically unsaturated monomers may comprise an ethylenically unsaturated sulfonic acid salt (iv). The ethylenically unsaturated sulfonic acid salt (iv) may be an alkali metal salt, alkaline earth metal salt, an ammonium salt, or a combination thereof. The ethylenically unsaturated sulfonic acid salt (iv) may be a sodium salt, a potassium salt, an ammonium salt, a calcium salt, or a combination thereof.

[0088] According to the present invention, the mixture of ethylenically unsaturated monomers may comprise (v) an alkyl ester of (meth)acrylic acid. The mixture of ethylenically unsaturated monomers may comprise (iv) 50 wt.-% or less, such as 30 wt.-% or less, or 20 wt.-% or less of the alkyl ester of (meth)acrylic acid, based on the total weight of ethylenically unsaturated monomers. P55553WO_APPL filed_281125.docx

[0089] 10

[0090] The alkyl ester of (meth)acrylic acid (v) may be selected from C1-C10 alkyl (meth)acrylate, preferably Ci-Cs-alkyl (meth)acrylates. Examples of such (meth)acrylate monomers include n-butyl acrylate, isobutyl acrylate, ethyl acrylate, hexyl acrylate, tert-butyl acrylate, 2-ethyl-hexyl acrylate, isooctyl acrylate, 4-methyl- 2-pentyl acrylate, 2-methylbutyl acrylate, isobornyl acrylate, methyl methacrylate, butyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate and cetyl methacrylate. Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and combinations thereof are preferred.

[0091] The monomer mixture according to the present invention optionally may further comprise an ethylenically unsaturated monomer co-polymerizable with and different from monomers (i) to (v). The ethylenically unsaturated monomer co-polymerizable with and different from monomers (i) to (v) can be included in the mixture of ethylenically unsaturated monomers in amounts of 50 wt.-% or less, such as 30 wt.- % or less, or 20 wt.-%, based on the total weight of ethylenically unsaturated monomers.

[0092] The monomer mixture according to the present invention may comprise an unsaturated aliphatic nitrile monomer which contain from 2 to 4 carbon atoms in a linear or branched arrangement, which may be substituted either by acetyl or additional nitrile groups. Such nitrile monomers include acrylonitrile, methacrylonitrile, alpha-cyanoethyl acrylonitrile, fumaronitrile or combinations thereof, with acrylonitrile being most preferred.

[0093] The monomer mixture according to the present invention may comprise a hydroxyalkyl ester of an ethylenically unsaturated acid. Such a hydroxyalkyl ester of an ethylenically unsaturated acid may include hydroxyalkyl acrylate and methacrylate monomers which are based on ethylene oxide, propylene oxide and higher alkylene oxides or mixtures thereof. Examples are hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate and hydroxyethylcaprolactone acrylate.

[0094] The monomer mixture according to the present invention may comprise an ethylenically unsaturated compound bearing a primary or secondary amino group. P55553WO_APPL filed_281125.docx

[0095] 11

[0096] Such ethylenically unsaturated compound bearing a primary or secondary amino group may include (meth)acrylamide, 2-amino ethyl (meth)acrylate hydrochloride, 2- amino ethyl (meth)acrylamide hydrochloride, N-ethyl (meth)acrylamide, N-(3-amino propyl) (meth)acrylamide hydrochloride, N-hydroxyethyl (meth)acrylamide, N-3- (dimethylamino) propyl (meth)acrylamide, [3-(methacryloylamino)propyl] trimethylammonium, N-[tris(hydroxymethyl) methyl] (meth)acrylamide, N- phenylacrylamide, alkylacrylamide, methacrylamide polyethylene glycol) amine hydrochloride, or combinations thereof.

[0097] The water-dispersible pulverulent composition comprises an amino acid, a salt thereof, or a mixture thereof. According to the present invention, the amino acid, a salt thereof, or mixture thereof (b) may comprise a monocarboxy lated monoamino acid, a dicarboxylated monoamino acid, a monocarboxylated diamino acid, or combinations thereof. Preferably, the amino acid, a salt thereof, or mixture thereof (b) comprises a dicarboxylated monoamino acid.

[0098] The monocarboxylated monoamino acids may be selected from glycine, alanine, leucine, phenylalanine, or combinations thereof. The dicarboxylated monoamino acids may be selected from aspartic acid, glutamic acid, hydroxyglutamic acid, or combinations thereof. The monocarboxylated diamino acids may be selected from arginine, lysine, histidine, cystine, or combinations thereof.

[0099] According to the present invention, the amino acid, a salt thereof, or mixture thereof (b) may comprise glycine, alanine, leucine, phenylalanine, aspartic acid, glutamic acid, hydroxy glutamic acid, arginine, lysine, histidine, cystine, or combinations thereof. Preferably, the amino acid, a salt thereof, or mixture thereof (b) comprises aspartic acid, glycine, glutamic acid, hydroxy glutamic acid, or combinations thereof.

[0100] The water-dispersible pulverulent composition preferably comprises an amino acid salt.

[0101] According to the present invention, the (b) amino acid salt may be an alkali metal salt, alkaline earth metal salt, an ammonium salt, or a combination thereof. The amino acid salt (b) may be a sodium salt, a potassium salt, an ammonium salt, a calcium salt, or a combination thereof.

[0102] The water-dispersible pulverulent composition of the present invention may comprise at least 75 wt.-%, such as 80 wt.-% of the polymer (a). The water-dispersible P55553WO_APPL filed_281125.docx

[0103] 12 pulverulent composition of the present invention may comprise 95 wt.-% or less, such as 92 wt.-% of the polymer (a). A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the water-dispersible pulverulent composition of the present invention may comprise 75 to 95 wt.-%, preferably 75 to 92 wt.-% of the polymer (a). The water-dispersible pulverulent composition of the present invention may comprise 80 to 95 wt.-%, preferably 80 to 92 wt.-% of the polymer (a). The wt.-% is based on the total weight of the water-dispersible pulverulent composition.

[0104] The water-dispersible pulverulent composition of the present invention may comprise at least 3 wt.-%, such as 5 wt.-% of the amino acid, a salt thereof, or a combination thereof (b). The water-dispersible pulverulent composition of the present invention may comprise 20 wt.-% or less, such as 18 wt.-% of the amino acid, a salt thereof, or a combination thereof (b). A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the water-dispersible pulverulent composition of the present invention may comprise 3 to 20 wt.-%, preferably 3 to 18 wt.-% of the amino acid, a salt thereof, or a combination thereof (b). The water-dispersible pulverulent composition of the present invention may comprise 5 to 20 wt.-%, preferably 5 to 18 wt.-% of the amino acid, a salt thereof, or a combination thereof (b). The wt.-% is based on the total weight of the water-dispersible pulverulent composition.

[0105] According to the present invention, the water-dispersible pulverulent composition may comprise 80 to 95 wt.-% of the polymer (a); and 5 to 20 wt.-% of the amino acid, a salt thereof, or a combination thereof (b); the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

[0106] The water-dispersible pulverulent composition may comprise further components. According to the present invention, the water-dispersible pulverulent composition may comprise 75 to 95 wt.-% of the polymer (a); and 3 to 20 wt.-% of the amino acid, a salt thereof, or a combination thereof (b); the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

[0107] As set forth above, the water-dispersible pulverulent composition can preferably comprise divalent metal ions. The divalent metal ions can in particular comprise alkaline earth metal ions such as calcium ions, magnesium ions or a mixture or P55553WO_APPL filed_281125.docx

[0108] 13 combination thereof, preferably calcium ions. The divalent metal ions, such as alkaline earth cations, can aid in effectively separating polymer particles in the dried powder and promoting redispersibility of the water-dispersible pulverulent composition. Divalent metal ions can be incorporated into the composition for example as a water-soluble alkaline metal salt, such as a hydroxide. Alkaline earth cations can in particular be incorporated into the composition by addition of an alkaline earth hydroxide, such as preferably calcium hydroxide, as described in more detail herein in the context of the method for producing the water-dispersible pulverulent composition. The divalent metal ions, such as alkaline earth metal ions, if used, can for example be present in the water-dispersible pulverulent composition in an amount of 0.01 wt.% or more, such as 0.1 wt.-% or more, or 0.3 wt.-% or more, or 0.5 wt.-% or more. The water-dispersible pulverulent composition may comprise 6 wt.-% or less, such as 5 wt.-% or less, or 4 wt.-% or less, or 3 wt.-% or less, or 2 wt.- % or less, of the divalent metal ions, such as alkaline earth metal ions. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the water-dispersible pulverulent composition of the present invention may comprise for example from 0.01 wt.-% to 6 wt.%, such as 0.1 wt.-% to 4 wt.-%, or 0.3 wt-% to 3 wt.-%, or 0.5 wt.-% to 2 wt.-%, of divalent metal ions, such as alkaline earth metal ions. The wt.-% is based on the total weight of the water-dispersible pulverulent composition.

[0109] The water-dispersible pulverulent composition of the present invention may comprise (c) an inorganic filler. The inorganic filler may reduce the agglomeration of the polymer (a) in the water-dispersible pulverulent composition. Typically, the inorganic filler has a particle size (Dv50) of from 1 to 20 pm, preferably from 1 to 10 pm. The particle size (Dv50) may be determined by laser diffraction with a laser diffractometer instrument, such as Mastersizer 3000+ (Malvern Pananalytical (UK)). The inorganic filler may have low solubility, preferably no solubility in water.

[0110] The inorganic filler may be selected from silica, colloidal silica gel, microsilica, fumed silica, precipitated silica that may optionally have been hydrophobized, calcium carbonate, magnesium carbonate, Ca / Mg carbonate, dolomite, kaolin, talcum, barium sulfate, calcium sulfate, magnesium sulfate, titanium oxide, calcium sulfoaluminate, bentonite, quartz sand, quartz flour, kieselguhr, clay, magnesium hydrosilicate, calcium hydrosilicate, mica, xonolite, or combinations thereof. P55553WO_APPL filed_281125.docx

[0111] 14

[0112] Preferably, the inorganic filler may be selected from silica, calcium carbonate, dolomite, kaolin, talcum, barium sulfate, titanium oxide, calcium sulfoaluminate, or combinations thereof.

[0113] The water-dispersible pulverulent composition of the present invention may comprise at least 2 wt.-%, such as 4 wt.-% of the inorganic filler (c). The water-dispersible pulverulent composition of the present invention may comprise 20 wt.-% or less, such as 18 wt.-% of the inorganic filler (c). A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the water-dispersible pulverulent composition of the present invention may comprise 2 to 20 wt.-%, preferably 4 to 18 wt.-% of the inorganic filler (c). The wt.-% is based on the total weight of the water-dispersible pulverulent composition.

[0114] Method for the preparation of the water-dispersible pulverulent composition

[0115] The present invention relates to a method for producing the water-dispersible pulverulent composition as defined above, which comprises (I) polymerizing the mixture of ethylenically unsaturated monomers by emulsion polymerization as described above in an aqueous medium to form a polymer (a) dispersion, (II) adding the amino acid, a salt thereof, or mixture thereof after the polymerization to the polymer (a) dispersion; and (III) removing water from the polymer (a) dispersion.

[0116] The polymer (a) according to the present invention can be made by any emulsion polymerization process known to a person skilled in the art, provided that the monomer mixture as herein defined is employed.

[0117] In the emulsion polymerization for preparing the polymer (a) of the present invention, a seed dispersion may be employed. Any seed particles as known to the person skilled in the art can be used.

[0118] The seed particles are preferably present in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of total ethylenically unsaturated monomers employed in the polymer. The lower limit of the amount of seed particles therefore can be 0.01 , 0.05, 0.1 , 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 , 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 , 2.2, 2.3, 2.4, or 2.5 parts by weight. The upper limit of the amount can be 10, 9, 8, 7, 6, 5.5, 5, 4.5, 4, 3.8, 3.6, 3.4, 3.3, 3.2, 3.1 or 3 parts by weight. A person skilled in the art will P55553WO_APPL filed_281125.docx

[0119] 15 understand that any range formed by any of the explicitly disclosed lower limits and upper limits is explicitly encompassed in the present specification.

[0120] The process for the preparation of the above-described polymer (a) can be performed at temperatures of from 0 to 130 °C, preferably of from 0 to 100 °C, particularly preferably of from 20 to 95 °C, very particularly preferably of from 40 to 90 °C, in the presence of no or one or more emulsifiers, no or one or more protective colloids and one or more initiators. The temperature includes all values and subvalues therebetween, especially including 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120 and 125 °C.

[0121] Initiators which can be used when carrying out the present invention may include water-soluble and / or oil-soluble initiators which are effective for the purposes of the polymerization. Representative initiators are well known in the technical area and include, for example: azo compounds (such as, for example, AIBN, AMBN and cyanovaleric acid) and inorganic peroxy compounds, such as hydrogen peroxide, sodium, potassium and ammonium peroxydisulfate, peroxycarbonates and peroxyborates, as well as organic peroxy compounds, such as alkyl hydroperoxides, dialkyl peroxides, acyl hydroperoxides, and diacyl peroxides, as well as esters, such as tert-butyl perbenzoate and combinations of inorganic and organic initiators. Suitable initiators may be selected from 2,3-dimethyl-2,3-diphenylbutane, tert-butyl hydroperoxide, tert-amyl hydroperoxide, cumyl hydroperoxide, 1 , 1 ,3,3- tetramethylbutyl hydroperoxide, isopropylcumyl hydroperoxide, p-menthane hydroperoxide, 2,5-di(tert-butylperoxy)-2,5-dimethyl-3-hexyne, 3,6,9-triethyl-3,6,9- trimethyl-1 ,4,7-triperoxonane, di(tert-butyl)peroxide, 2, 5-dimethyl-2, 5-di(tert- butylperoxy)hexane, di(tert-butylperoxy-isopropyl)benzene, tert-butyl cumyl peroxide, di-(tert-amyl)-peroxide, dicumyl peroxide, butyl 4,4-di(tert-butylperoxy)valerate, tertbutylperoxybenzoate, 2,2-di(tert-butylperoxy)butane, tert-amyl peroxy-benzoate, tert- butylperoxy-acetate, tert-butylperoxy-(2-ethylhexyl)carbonate, tert-butylperoxy isopropyl carbonate, tert-butyl peroxy-3,5,5-trimethyl-hexanoate, 1 , 1 -di(tert- butylperoxy)cyclohexane, tert-amyl peroxyacetate, tert-amylperoxy-(2- ethylhexyl)carbonate, 1 , 1 -di(tert-butylperoxy)-3,5,5-trimethylcyclohexane, 1 , 1 -d i(tert- amylperoxy)cyclohexane, tert-butyl-monoperoxy-maleate,

[0122] 1 ,1 ’-azodi(hexahydrobenzonitrile), tert-butyl peroxy-isobutyrate, tert-butyl peroxydiethylacetate, tert-butyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, P55553WO_APPL filed_281125.docx

[0123] 16 tert-amyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide,

[0124] 1 ,1 ,3,3-tetramethylbutyl peroxy-2 -ethylhexanoate, ammonium peroxodisulfate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 2,2’-azodi(2-methylbutyronitrile), 2,2’-azodi(isobutyronitrile), didecanoyl peroxide, potassium persulfate, dilauroyl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, tert-amyl peroxypivalate, tert-butyl peroxyneoheptanoate, 1 ,1 ,3,3-tetramethylbutyl peroxypivalate, tert-butyl peroxypivalate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, di(2- ethylhexyl) peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, tert-butyl peroxyneodecanoate, di-sec-butyl peroxydicarbonate, tert-amyl peroxyneodecanoate, cumyl peroxyneoheptanoate, di(3-methoxybutyl) peroxydicarbonate, 1 ,1 ,3,3-tetramethylbutyl peroxyneodecanoate, cumyl peroxyneodecanoate, di isobutyryl peroxide, and mixture thereof.

[0125] The initiator may be used in a sufficient amount to initiate the polymerization reaction at a desired rate. In general, an amount of initiator of from 0.01 to 5 wt.-%, preferably of from 0.1 to 4 wt.-%, based on the total weight of monomers in the monomer mixture, is sufficient. The amount of initiator is most preferably of from 0.01 to 2 wt.-%, based on the total weight of monomers in the monomer mixture. The amount of initiator includes all values and sub-values therebetween, especially including 0.01 , 0.1 , 0.5, 1 , 1 .5, 2, 2.5, 3, 4 and 4.5 wt.-%, based on the total weight of monomers in the monomer mixture.

[0126] The above-mentioned inorganic and organic peroxy compounds may also be used alone or in combination with one or more suitable reducing agents, as is well known in the art. Examples of such reducing agents may include sulfur dioxide, alkali metal disulfites, alkali metal and ammonium hydrogen sulfites, thiosulfates, dithionites and formaldehyde sulfoxylates, as well as hydroxylamine hydrochloride, hydrazine sulfate, iron (II) sulfate, cuprous naphthanate, glucose, sulfonic acid compounds such as sodium methane sulfonate, amine compounds such as dimethylaniline and ascorbic acid. The quantity of the reducing agent is preferably 0.03 to 10 parts by weight per part by weight of the polymerization initiator.

[0127] Surfactants or emulsifiers which are suitable for stabilizing the polymer may include those conventional surface-active agents for polymerization processes. The P55553WO_APPL filed_281125.docx

[0128] 17 surfactant or surfactants can be added to the aqueous phase and / or the monomer phase. An effective amount of surfactant in a seed process is the amount which was chosen for supporting the stabilization of the particle as a colloid, the minimization of contact between the particles and the prevention of coagulation. In a non-seeded process, an effective amount of surfactant is the amount which was chosen for determining the particle size.

[0129] The surfactant may include an anionic surfactant, a cationic surfactant, a nonionic surfactant or combinations thereof.

[0130] Suitable examples of a nonionic surfactant are araliphatic or aliphatic nonionic surfactants, such as ethoxylated mono-, di- and tri-alkylphenols (EO level: 3 to 50, alkyl moiety: C4-C10), ethoxylates of long-chain alcohols (EO level: 3 to 100, alkyl moiety: Cs-Cse), and polyethylene oxide (EO)Zpolypropylene oxide (PO) homo- and copolymers. These may comprise the alkylene oxide units copolymerized in random distribution or in the form of blocks. Very suitable examples are EO / PO block copolymers. Ethoxylates of long-chain alkanols (alkyl moiety C1-C30, average degree of ethoxylation 5 to 100) or ethoxylated monoalkylphenols are used preferably as non-ionic surfactants. Ethoxylates of long-chain alkanols having a linear C12 -C20 alkyl moiety and an average degree of ethoxylation of 10 to 50, are used even more preferably as non-ionic surfactants.

[0131] Suitable examples of an anionic surfactant are alkali metal and ammonium salts of alkyl sulfates (alkyl moiety: C8-C22), of sulfuric monoesters of ethoxylated alkanols (EO level: 2 to 50, alkyl moiety: C12-C18) and ethoxylated alkylphenols (EO level: 3 to 50, alkyl moiety: C4-C9), of alkylsulfonic acids (alkyl moiety: C12-C18) and of alkylarylsulfonic acids (alkyl moiety: C4-C6). Further suitable examples of an anionic surfactant are bis(phenylsulfonic acid) ethers and the alkali metal or ammonium salts thereof which bear a C4 -C24 alkyl group on one or both aromatic rings. These compounds are generally known, for example from U.S. Pat. No. 4,269,749 A, and commercially available, for example as Dowfax® 2A1 (Dow Chemical Company).

[0132] Suitable examples of a cationic surfactant are quaternary ammonium halides, such as trimethylcetylammonium chloride, methyltrioctylammonium chloride, benzyltriethylammonium chloride or quaternary compounds of N-C6-C20- alkylpyridines, -morpholines or -imidazoles, such as N-laurylpyridinium chloride. P55553WO_APPL filed_281125.docx

[0133] 18

[0134] The surfactant may also include a reactive surfactant. The term "reactive surfactant" refers to any surfactant that has the ability to react with the monomer, such as, for example, by formation of a covalent bond. Typically, the reaction between the reactive surfactant and the polymer surface is sufficiently strong to prevent separation and migration therebetween.

[0135] Like non-reactive surfactants, reactive surfactants are molecules that typically have a hydrophobic segment, such as alkyl, and a hydrophilic segment(s) such as an ionic salt group and / or poly(oxyethylene) groups (ethoxy hydrophobicity). The hydrophobic segment preferentially absorbs onto the surface of the polymer during and following particle polymerization. The hydrophilic group extends into the normally aqueous solution phase and thereby provides a steric barrier against particle coagulation. Unlike their non-reactive counterparts, reactive surfactants contain a reactive group, typically an alkenyl group, on the hydrophobic segment that is capable of covalently bonding to the latex surface. The ionic groups may be anionic or cationic. Suitable anionic functional groups include, for example, sulfonate, phosphonate, and carboxylate ions. Suitable cationic functional groups include, for example, ammonium ions. The hydrophilicity of nonionic reactive surfactants is typically that provided by poly(oxyethylene) groups.

[0136] The type and the amount of the surfactant is governed typically by the number of particles, their size and their composition. Typically, the surfactant is used in amounts of from 0 to 20 wt.-%, preferably from 0 to 10 wt.-%, more preferably from 0 to 5 wt.-%, based on the total weight of the monomers in the monomer mixture. The amount of surfactant includes all values and sub-values therebetween, especially including 0, 0.1 , 0.5, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, and 19 wt.-%, based on the total weight of the monomer in the monomer mixture. The polymerization may be conducted without using surfactants.

[0137] The polymer (a) of the present invention may further comprise protective colloids. The protective colloids may comprise polyvinyl alcohol, vinyl alcohol-ethylene copolymer, silanol-modified polyvinyl alcohol, cellulose derivatives, such as methylcellulose, ethylcellulose, hydroxycellulose and carboxycellulose, chitin, chitosan, starches, polyethylene glycol, polypropylene glycol, polyvinyl ether, gelatin, casein, cyclodextrin, and combinations thereof. The protective colloids may stabilize the polymer latex in addition or instead of the surfactants as described above. The P55553WO_APPL filed_281125.docx

[0138] 19 protective colloids may be present during the polymerization or post-added. Typical quantities are 1 to 15 parts by weight, based on 100 parts by weight of the polymer latex.

[0139] Furthermore, it may be advantageous to use chain transfer agents (regulators) in the emulsion polymerization. Typical agents are, for example, organic sulfur compounds, such as thioesters, 2-mercaptoethanol, 3-mercaptopropionic acid, iso-octyl-3- mercaptopropionat, butyl-3-mercaptopriopionat, and C1-C12 alkyl mercaptans, n-dodecylmercaptan and t-dodecylmercaptan being preferred. The quantity of chain transfer agents, if present, is usually 0.01-3.0 wt.-%, preferably 0.05-2.0 wt.-%, based on the total weight of the monomer mixture.

[0140] The solid content of the polymer (a) dispersion after step (I) may be at least 30 wt.- %, such as at least 40 wt.-%, or at least 45 wt.-%. The solid content of the polymer (a) dispersion after step (I) may be 65 wt.-% or less, such as 60 wt.-% or less, or 55 wt.-% or less. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the solid content of the polymer (a) dispersion after step (I) may be in the range of from 30 to 65 wt.-%, preferably 40 to 60 wt.-%, more preferably 45 to 55 wt.-%.

[0141] The particle size of the polymer (a) may be in the range of from 10 to 500 nm, preferably 50 to 300, and more preferably 100 to 250 nm. According to the present invention, the particles of the polymer (a) may have a mono-, bi- or multi-modal particle size distributions. The particle size and the particle size distribution of the polymer (a) may be determined by dynamic light scattering with a dynamic light scattering instrument, such as Zetasizer nano S (Malvern Instruments (UK)), using the z-average diameter.

[0142] The pH of the polymer (a) dispersion, in particular before removing of water in step (III) may be in the range of from 3 to 9, preferably from 3 to 7, more preferably from 3.5 to 6.

[0143] The removing of water from the polymer (a) dispersion may be achieved by fluidized- bed drying, freeze drying or spray drying. Preferably, the removing of water is achieved by spray drying. Spray drying may be carried out in customary spray dryers, and atomization may be achieved by means of single-fluid, two-fluid or multifluid nozzles or by means of a rotary disk. The outlet temperature is generally P55553WO_APPL filed_281125.docx

[0144] 20 set in the range of from 45 °C to 120 °C, preferably from 60 °C to 90 °C. The aqueous polymer dispersion may be dried by spay drying after addition of a spraying aid, such as protective colloids.

[0145] Suitable spraying aids are polyvinyl alcohols; polyvinylpyrrolidones; polysaccharides in water-soluble form, i.e. starches such as amylose and amylopectin, celluloses and their carboxym ethyl, methyl, hydroxyethyl and hydroxypropyl derivatives; proteins such as casein or caseinate, soya protein, gelatin; lignosulfonates; synthetic polymers such as poly(meth)acrylic acid, copolymers of (meth)acrylates with carboxyl-functional comonomer units, poly(meth)acrylamide, polyvinylsulfonic acids and their water-soluble copolymers; melamine-formaldehyde sulfonates, naphthalene-formaldehyde sulfonates, styrene-maleic acid and vinyl ether-maleic acid copolymers, preferably polyvinyl alcohols. If added, the spraying aids may be added to the aqueous polymer (a) dispersion of the present invention in an amount of from 3 to 30 wt.-%, such as 5 to 20 wt.-%, based on the total weight of the solids content of the aqueous polymer (a) dispersion.

[0146] The viscosity of the aqueous polymer (a) dispersion of the present invention to be dried by spray-drying may have a viscosity at 23 °C of less than 2000 mPa s, preferably of less than 1000 mPa s, more preferably of less than 600 mPa s. The viscosity can be measured according to ASTM D-3236 using a Brookfield Model RVT viscometer (commercially available from Brookfield Engineering Laboratories, Inc. (USA)) at 50 revolutions per minute using spindle 2 at 23 °C.

[0147] According to the present invention, the method for producing the water-dispersible pulverulent composition as defined above further may comprise adding an alkaline earth hydroxide and / or an alkali hydroxide to the aqueous medium before removing the water in step (III). The alkaline earth hydroxide may comprise magnesium hydroxide, calcium hydroxide, or combinations thereof. Preferably, the alkaline earth hydroxide comprises calcium hydroxide. The alkali hydroxide may comprise lithium hydroxide, sodium hydroxide, potassium hydroxide, caesium hydroxide, or combinations thereof. Preferably, the alkali hydroxide comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof. More preferably, the alkali hydroxide comprises sodium hydroxide. By the addition of the alkaline earth hydroxide and / or an alkali hydroxide the pH of the aqueous medium can be increased, e.g. to the alkaline region, such as a pH in a range from 8 to 11 , or 9 to P55553WO_APPL filed_281125.docx

[0148] 21

[0149] 10. Divalent alkaline earth cations can moreover aid in effectively separating polymer particles in the dried powder and promoting redispersibility. According to a preferred practice of the invention thus an alkaline earth hydroxide, such as preferably calcium hydroxide, is added to the aqueous medium before removing the water in step (III). The alkaline earth hydroxide, such as calcium hydroxide, can in particular be added in an approximately stoichiometric amount for neutralization of carboxylic acid groups of the amino acid component, for example in an amount such that the ratio of equivalents of amino acid molecules to the equivalents of alkaline earth hydroxide (two basic hydroxide groups per alkaline earth hydroxide unit) is from 1 :2 to 2:1 , such as from 1.5:1 to 1 :1.5, or from 1.2:1 to 1 :1.2, or from 1.1 :1 to 1 :1.1. Alkali hydroxide, such as sodium hydroxide, may be used in addition to the alkaline earth hydroxide, for example to adjust the pH to the alkaline region, as described above.

[0150] The alkaline earth hydroxide and / or the alkali hydroxide may be added to the aqueous medium in an amount of at least 0.01 wt.-%, such as at least 0.05 wt.-%, based on the total solids content of the aqueous polymer (a) dispersion. The alkaline earth hydroxide and / or the alkali hydroxide may be added to the aqueous medium in an amount of 3.0 wt.-% or less, such as 2.0 wt.-% or less, based on the total solids content of the aqueous polymer (a) dispersion. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the alkaline earth hydroxide and / or the alkali hydroxide may be added to the aqueous medium in an amount of from 0.01 wt.-% to 3.0 wt.-%, preferably from 0.05 wt.-% to 2.0 wt.-%, based on the total solids content of the aqueous polymer (a) dispersion.

[0151] According to the present invention, the method for producing the water-dispersible pulverulent composition as defined above may further comprise (IV) adding inorganic filler (c) as described above to the composition comprising the polymer (a) and the amino acid, salt thereof, or mixture thereof (b).

[0152] The inorganic filler (c) may be added to the polymer (a) dispersion before removing the water in step (III). The inorganic filler (c) may be added to the polymer (a) dispersion during removing the water in step (III). The inorganic filler (c) may be added to the polymer (a) dispersion after removing the water in step (III). Preferably, the inorganic filler (c) is added to the polymer (a) dispersion during removing the water in step (III). P55553WO_APPL filed_281125.docx

[0153] 22

[0154] Pseudo-latex and construction materials

[0155] The water-dispersible pulverulent composition as defined above or obtained by the method as defined above are stable on storage and may be readily dispersible in water in the form a pseudo-latex and may be used directly in powder form or in pseudo-latex form in all the fields of application known for latices, especially in construction materials.

[0156] The present invention relates to a pseudo-latex obtained by redispersing the water- dispersible pulverulent composition as defined above or obtained by the method for producing the water-dispersible pulverulent composition as defined above in water.

[0157] The water-dispersible pulverulent composition as defined above or obtained by the method as defined above may be redispersed by stirring at room temperature, i.e. , 20 to 25 °C. The water-dispersible pulverulent composition as defined above or obtained by the method as defined above may be fully redispersible in water. As used herein, the term “fully redispersible” is understood to refer to a pulverulent composition in accordance with the invention which, after addition of an appropriate amount of water, makes it possible to obtain a pseudo-latex whose particle size is substantially identical to the particle size of the latex particles present in the starting dispersion. They are therefore of excellent wettability with water and of spontaneous, rapid and complete redispersion by redispersing this powder in deionized water or in CaCl2 solution (1 M). The particle size distribution of the pseudo-latex obtained by redispersing this pulverulent composition in water may be similar, preferably almost identical to that of the starting latex. The particle size and particle size distribution may be determined by dynamic light scattering with a dynamic light scattering instrument, such as Zetasizer nano S (Malvern Instruments (UK)), using the z- average diameter.

[0158] The present invention further relates to a construction material comprising the water- dispersible pulverulent composition as defined above or obtained by the method for producing the water-dispersible pulverulent composition as defined above, or the pseudo-latex according as defined above. The construction material may be a concrete composition, cement composition, mortar composition, or plaster composition. Preferably, the construction material may be a cement composition. P55553WO_APPL filed_281125.docx

[0159] 23

[0160] Furthermore, the present invention relates to use of water-dispersible pulverulent composition as defined above or obtained by the method for producing the water- dispersible pulverulent composition as defined above, or the pseudo-latex according as defined above in construction materials. The construction material may be a concrete composition, cement composition, mortar composition, or plaster composition. Preferably, the construction material may be a cement composition.

[0161] The water-dispersible pulverulent compositions of the invention or the pseudo-latex derived therefrom can also be used in all the other fields of application of latices, more particularly in the field of adhesives, paper coatings and paints.

[0162] EXAMPLES:

[0163] The following examples are intended to further illustrate the present invention but are not intended to limit the scope of the present invention in any way.

[0164] The following abbreviations are used in the Examples:

[0165] AMPS = 2-acrylamido-2-methylpropane sulfonic acid NaVS = sodium salt of vinyl sulfonic acid

[0166] NaStS = sodium salt of styrene sulfonic acid

[0167] NaMAS = sodium salt of methallyl sulfonic acid

[0168] NaAHPS = sodium 1 -allyloxy-2-hydroxypropanesulfonate

[0169] NaGI = Sodium glutamate

[0170] Gly = Glycine

[0171] In the following all parts and percentages are based on weight unless otherwise specified.

[0172] Preparation of XS BR latexes

[0173] The polymer latex compositions used in the examples and comparative examples were produced by a free radical emulsion polymerization process carried out in a pressure resistant stainless-steel reactor with 5 L volume connected to a cryostat enabling temperature control of the double-wall reactor jacket.

[0174] The initial charge in the reactor was composed of 66 pphm (parts by weight based on 100 parts of total monomer weight) deionized water and 0.4 pphm polystyrene seed with an average particle size of 35 nm. After heating the initial charge to 85 °C under continuous agitation using a three-layered cross beam stirrer the P55553WO_APPL filed_281125.docx

[0175] 24 polymerization reaction was initiated by starting a feed of a 5 % (w / w) sodium persulfate solution (1 pphm). The temperature was maintained constant at 85 °C.

[0176] 2 min after starting the persulfate feed the monomers (monomers and quantities as listed in Table 1 ), 0.6 pphm of the chain transfer agent tert-dodecyl mercaptan (premixed with styrene) and a 6.5 % (w / w) aqueous solution of an anionic surfactant (0.5 pphm of a lauryl ether sulfate with 7 ethoxylate units) were added to the reactor at a constant feed rate over a period of five hours. Thereafter, a post activation feed with 0.25 pphm sodium persulfate solution to reduce the residual monomers was started and continued for one hour at a batch temperature of 90 °C. After completed sodium persulfate addition the batch was kept at 90 °C for further 30 min and agitated continuously. The product was then let cool down to ambient temperature and the pH adjusted to 5 using a 10 % aqueous sodium hydroxide solution.

[0177] The crude batch was transferred to a 5 L round bottom glass flask and the flask placed in a water batch held constantly at 75 °C. Volatile substances were removed from the batch by applying a mild vacuum and constant agitation. Evaporated water was replaced from time to time to prevent the batch from becoming too viscous. After 10 h of degassing the total solids content of the final latex was adjusted to 52 % (w / w) and the pH to 5.5 with some drops of 10 % aqueous sodium hydroxide solution. Finally, the latex was sieved over a filter cloth with 50 pm mesh width.

[0178] The particle sizes of the example latexes were between 200 and 220 nm, determined by dynamic light scattering with a dynamic light scattering instrument Zetasizer nano S (Malvern Instruments (UK)).

[0179] Preparation and Evaluation of Precursors for Spray Drying

[0180] Sodium glutamate as redispersing aid:

[0181] 4.2 parts by weight of sodium glutamate were slowly added to 85 parts by weight of the prepared latex while stirring and incorporated for 15 min. Subsequently, 5.8 parts by weight of lime milk (20 % (w / w) calcium hydroxide suspended in water) were added in small portions while stirring, followed by 4.4 parts of water and finally, 0.6 parts by weight of 50 % sodium hydroxide solution were added.

[0182] Glycine as redispersing aid: P55553WO_APPL filed_281125.docx

[0183] 25

[0184] 2.3 parts by weight of glycine were slowly added to 88 parts by weight of the prepared latex while stirring and incorporated for 15 min. Subsequently, 5.6 parts by weight of lime milk (20 % (w / w) calcium hydroxide suspended in water) were added in small portions while stirring, followed by 3.5 parts of water and finally, 0.6 parts by weight of 50 % sodium hydroxide solution were added.

[0185] Suitable latices form thin, pumpable, and sprayable precursors with the original total solids content. The evaluation of sprayability criterion in this case was: "yes." In cases where the precursor becomes highly viscous or even solid during mixing or shortly thereafter, the latex is deemed unsuitable as it cannot be sprayed. Evaluation of sprayability criterion: "no."

[0186] Production of Redispersible Powders and Their Evaluation for Redispersibility

[0187] The latices prepared for spray drying as described above (precursor for spray drying) were dried into powder using a laboratory spray dryer from GEA Niro equipped with an atomizer with a rotary wheel. The precursor feed was 4 kg / h, resulting in 2 kg / h of powder. The inlet temperature of the air flow was 130 °C and the outlet temperature was 80 °C. Kaolin (Blankalite 78, SOKA) and silica (Sipernat D17, Evonik) were fed into the top of the tower such that the dried powder had a kaolin content of 9.5 wt.-% and a silica content of 0.5 wt.-%.

[0188] To evaluate the redispersibility, 1 part by weight of powder was mixed with 3 parts by weight of water in a beaker, and the mixture was homogenized for 15 minutes using a dissolver disc at 2000 revolutions per minute. The redispersed latex was then left to stand for 3 hours. If the redispersed latex remained homogeneous and showed no sedimentation of polymer coagulate apart from the mineral components, the redispersibility criterion of the redispersed latex was rated as "yes." If the redispersed latex was poorly wetted by the water and separation occurred after 3 hours, such as a distinct white sediment or even clarification of the upper liquid layer, the redispersibility criterion of the redispersed latex was rated as "no."

[0189] Stability Test of Redispersible Powders in Cement

[0190] 100 g of Portland cement CEM I 42.5 R (Heidelberger), 30 g of water, and 10 g of redispersible powder were mixed in a flat aluminum dish for one minute with a wooden spatula and visually evaluated immediately and after 30 minutes. The cement stability criterion was rated as "yes" if the cement mixture showed a moist- P55553WO_APPL filed_281125.docx

[0191] 26 glossy appearance and a low to moderately viscous flowability immediately and after 30 min. If the cement appeared dry-matte and crumbly immediately or after 30 min and had a highly pasty consistency up to high stiffness, the cement stability criterion was rated as "no." Below are the polymer compositions and the evaluation of performance criteria:

[0192] Table 1 : Examples 1 to 9 P55553WO_APPL filed_281125.docx

[0193] 27

[0194] Table 2: Examples 10 to 18

Claims

P55553WO_APPL filed_281125.docx28CLAIMS1 . A water-dispersible pulverulent composition comprising:(a) a polymer obtained by polymerization of a mixture of ethylenically unsaturated monomers comprising:(i) an aliphatic conjugated diene;(ii) a vinyl aromatic compound;(iii) 1 .5 to 10.0 wt.-% of an ethylenically unsaturated carboxylic acid, a salt thereof or a mixture thereof, based on the total weight of ethylenically unsaturated monomers; and(iv) an ethylenically unsaturated sulfonic acid, salt thereof, or a mixture thereof, wherein the ethylenically unsaturated sulfonic acid or salt thereof is selected from 2-acrylamido-2-methylpropane sulfonic acid, vinyl sulfonic acid, styrene sulfonic acid or a combination thereof; and(b) an amino acid, a salt thereof, or a mixture thereof.

2. The water-dispersible pulverulent composition according to claim 1 , wherein the conjugated diene (i) is selected from 1 ,3-butadiene, isoprene,2.3-dimethyl-1 ,3-butadiene, 2-chloro-1 ,3-butadiene, 1 ,3-pentadiene, 1 ,3- hexadiene, 2,4-hexadiene, 1 ,3-octadiene, 2-methyl-1 ,3-pentadiene, 2,3- dimethyl-1 ,3-pentadiene, 3,4-dimethyl-1 ,3-hexadiene, 2, 3-diethyl-1 ,3- butadiene, 4, 5-diethyl-1 ,3-octadiene, 3-butyl-1 ,3-octadiene, 3,7-dimethyl- 1 ,3,6-octatriene, 2-methyl-6-methylene-1 ,7-octadiene, 7-methyl-3- methylene-1 ,6-octadiene, 1 ,3,7-octatriene, 2-ethyl-1 ,3-butadiene, 2-amyl-1 .3-butadiene, 3,7-dimethyl-1 ,3,7- octatriene, 3,7-dimethyl-1 ,3,6-octatriene, 3,7,11 - trimethy 1-1 ,3,6, 10-dodecatetraene, 7, 11 -dimethyl-3-methylene-1 ,6,10-dodecatriene, 2,6-dimethyl-2,4,6-octatriene, 2-phenyl-1 ,3-butadiene, 2-methyl-3-isopropyl-1 ,3-butadiene, 1 ,3-cyclohexadiene, myrcene, ocimene, farnesene, or combinations thereof; preferably 1 ,3-butadiene, 2-chloro-1 ,3-butadiene, isoprene, 1 ,3-pentadiene,1 .3-hexadiene, 2,4-hexadiene, or combinations thereof; more preferably the conjugated diene monomer is 1 ,3-butadiene; and / or wherein the vinyl aromatic compound (ii) is selected from styrene, alpha-P55553WO_APPL filed_281125.docx29 methyl styrene, 4-methyl styrene, alpha-chloro styrene, 4-chloro styrene, divinylbenzene, 4-methoxy-3-methylstyrene, 3,4-dimethyl-alpha- methylstyrene or combinations thereof, preferably the vinyl aromatic compound is styrene.

3. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the mixture of ethylenically unsaturated monomers comprises:(i) 15 to 75 wt.-% of the aliphatic conjugated diene, preferably 20 to 70 wt.-%, more preferably 25 to 65 wt.-%, based on the total weight of ethylenically unsaturated monomers.

4. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the mixture of ethylenically unsaturated monomers comprises:(ii) 20 to 80 wt.-% of the vinyl aromatic compound, preferably 25 to 75 wt.-%, more preferably 30 to 70 wt.-%, based on the total weight of ethylenically unsaturated monomers.

5. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the mixture of ethylenically unsaturated monomers comprises a weight ratio of aliphatic conjugated diene (i) to vinyl aromatic compound (ii) being from 1 .0:4.0 to 4.0:1 .0, preferably from1 .0:3.0 to 3.0:1 .0, more preferably from 1 .0:2.5 to 1 .0:2.0.

6. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof (iii) is selected from (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, vinyl acetic acid, vinyl lactic acid, 2-carboxy ethyl (meth)acrylate, mesaconic acid, glutaconic acid or combinations thereof, preferably from (meth)acrylic acid, itaconic acid, fumaric acid, maleic acid, or combinations thereof.P55553WO_APPL filed_281125.docx307. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the mixture of ethylenically unsaturated monomers comprises:(iii) 2.0 to 8.0 wt.-% of the ethylenically unsaturated carboxylic acid, salt thereof, or mixture thereof, preferably 3.0 to 7.0 wt.-%, based on the total weight of ethylenically unsaturated monomers.

8. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the ethylenically unsaturated sulfonic acid salt(iv) is a sodium salt.

9. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the mixture of ethylenically unsaturated monomers comprises:(iv) 0.1 to 8.0 wt.-% of the ethylenically unsaturated sulfonic acid, salt thereof, or mixture thereof, preferably 0.2 to 5.0 wt.-%, more preferably 0.5 to 3.0 wt.-%, based on the total weight of ethylenically unsaturated monomers.

10. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the mixture of ethylenically unsaturated monomers comprises:(v) 0 to 50 wt.-% of an alkyl ester of (meth)acrylic acid, preferably 0 to 30 wt.-%, more preferably 0 to 20 wt.-%, based on the total weight of ethylenically unsaturated monomers.11 . The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the amino acid, a salt thereof, or a mixture thereof (b) comprises a monocarboxylated monoamino acid, a dicarboxylated monoamino acid, a monocarboxylated diamino acid, or combinations thereof, preferably a dicarboxylated monoamino acid.

12. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the amino acid, a salt thereof, or mixture thereofP55553WO_APPL filed_281125.docx31(b) comprises glycine, alanine, leucine, phenylalanine, aspartic acid, glutamic acid, hydroxy glutamic acid, arginine, lysine, histidine, cystine, or combinations thereof, preferably aspartic acid, glycine, glutamic acid, hydroxy glutamic acid, or combinations thereof.

13. The water-dispersible pulverulent composition according to any one of the preceding claims, wherein the amino acid salt (b) is a sodium salt.

14. The water-dispersible pulverulent composition according to any of the preceding claims, comprising:75 to 95 wt.-% of the polymer (a); and3 to 20 wt.-% of the amino acid, a salt thereof, or a mixture thereof (b); the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

15. The water-dispersible pulverulent composition according to any of the preceding claims, comprising divalent metal ions, preferably alkaline earth metal ions such as calcium ions, magnesium ions or a mixture or combination thereof, more preferably calcium ions.

16. The water-dispersible pulverulent composition according to claim 15, comprising 0.01 wt.-% to 6 wt.-%, of the divalent metal ions, the wt.-% being based on the total weight of the water-dispersible pulverulent composition17. The water-dispersible pulverulent composition according to any one of the preceding claims, comprising:(c) an inorganic filler selected from silica, calcium carbonate, dolomite, kaolin, talcum, barium sulfate, titanium oxide, calcium sulfoaluminate, or combinations thereof.

18. The water-dispersible pulverulent composition according to claim 17, comprising:P55553WO_APPL filed_281125.docx322 to 20 wt.-% of the inorganic filler (c); the wt.-% being based on the total weight of the water-dispersible pulverulent composition.

19. A method for producing the water-dispersible pulverulent composition as defined in any one of the preceding claims, comprising:(I) polymerizing the mixture of ethylenically unsaturated monomers by emulsion polymerization in an aqueous medium to form a polymer (a) dispersion,(II) adding the amino acid, a salt thereof, or mixture thereof (b) after the polymerization to the polymer (a) dispersion, and optionally adding an alkaline earth hydroxide and / or an alkali hydroxide to the aqueous medium before removing the water in step (III); and(III) removing water from the polymer (a) dispersion, preferably by spray drying.

20. The method according to claim 19, comprising adding an alkaline earth hydroxide, preferably calcium hydroxide to the aqueous medium before removing the water in step (III), wherein the alkaline earth hydroxide, such as calcium hydroxide, is preferably added in an amount such that the ratio of equivalents of amino acid molecules to the equivalents of alkaline earth hydroxide is from 1 :2 to 2:1 .21 . The method according to claim 19 or 20, comprising:(IV) adding an inorganic filler (c) during removing the water in step (III).

22. A pseudo-latex obtained by redispersing the water-dispersible pulverulent composition according to any one of claims 1 to 18 or obtained by the method according to any one of claims 19 to 21 in water.

23. A construction material, preferably a cementitious composition comprising the water-dispersible pulverulent composition according to any one of claims 1 to 18 or obtained by the method according to any one of claims 19 to 21 ; or the pseudo-latex according to claim 22.

Images