DE10159782A1 - Particulate binding agent agglomerate, useful for the production of surface coating compositions, contains a natural or synthetic polysaccharide and a synthetic polymer - Google Patents

Abstract

A particulate binding agent agglomerate contains a natural or synthetic polysaccharide and a synthetic polymer whereby 5 wt.% aqueous solutions or dispersions of the particles having a particle diameter above or below the average particle size (D50) have viscosities after a dissolution time of 1 hour or less, that are within 20% of each other. A particulate binding agent agglomerate (I) containing (A) at least one natural or synthetic polysaccharide and (B) a synthetic polymer whereby a 5 wt.% aqueous solution or dispersion of the particles having a particle diameter above the average particle size (D50) and an aqueous solution or dispersion of the particles having a particle diameter below the average particle size (D50) have viscosities after a dissolution time of 1 hour or less, that are within 20% of each other. An Independent claim is included for a process for the production of the agglomerate (I) comprising components (A) and (B) by setting out at a pressure of greater than 10 kN or rolling force of at least 2 kN/cm followed by comminution.

Description

The present invention relates to a particulate binder agglomerate, at least containing a natural or synthetic polysaccharide and a synthetic polymer, wherein a 5 wt .-% aqueous solution or dispersion of Particles with an average particle size interval (Tm) Particle diameter and an aqueous dispersion of the particles with a below one average particle size interval (Tm) lying after a particle diameter Dissolution time of 1 hour or less each have a viscosity that is less than 20% deviates from the other viscosity. Furthermore, the present concerns Invention a method for producing such particulate Binder agglomerates and their use.

Binder that is a natural or synthetic polysaccharide and a synthetic Contain polymer are essentially known. Such binder mixtures are used for gluing, solidifying or sealing. Specific examples of such Applications include paste, dispersion adhesives, primers for mineral substrates and the like. The above binders, in particular their powdery formulations are used especially for the production of the above Products used when preparing the products at the application site simple mixing with water possible and particularly feasible by the user and is desired. The use of such binders in the manufacture of adhesives is particularly preferred when the type of use of the adhesives is the use of self-prepared adhesives. The use of such Binder usually saves transport costs because the weight of the water is eliminated. Such binders are often used for the surface coating of a substrate Paper or other coverings used. A particularly common use Such binders are wallpaper paste that is used in the decorative coating of Walls or ceilings can be used indoors.

If such binders are put into a form suitable for use by the user are required to meet a number of requirements, on the one hand the manageability of the binders and on the other hand one possible constant product quality with regard to both the binder itself and the relate to products that can be produced from such binders. Such requirements relate in particular to the portionability with constant product quality within the individual portions, the dust-free when using, for example when portioning of the binder and the dissolution behavior of the binder. Often such tend Binder namely for clumping when stirred into water, whereby either unacceptably long periods of time are required to remove the lump or the Lumps don't dissolve at all. When using such a lump containing product, however, there are disadvantages with regard to optical or malfunction. For example, if a wallpaper paste has such lumps, This can be particularly the case when gluing smooth, unstructured wallpapers Disruptions in the surface structure come.

Furthermore, the quickest possible use of one with the help of the mentioned Binder obtained product requested. Here, in particular, one is possible rapid solubility or dispersibility combined with the fastest possible Viscosity build-up of the product was important, despite the fastest possible Viscosity build-up still a lump-free dissolution or dispersion of the binder should take place.

It is often also required to portion the binders as simply as possible in order to if necessary, to be able to prepare product quantities that only a certain one Require a fraction of a commercial package volume of the binders. At such portioning, however, requires that all of the package volume removed portions have a largely identical composition, so that one identical in terms of different servings and portions Product quality after the manufacture of the product by the user results.  

The constituents present in the abovementioned binders, namely at least one natural or synthetic polysaccharide and at least one synthetic Polymer tend to differ within the binder mixtures due to different Particle size and different density and surface structure of the particles Segregation. If the user now has a portion of such Binder mixtures is made, so different portions of one unmixed binder mixture have different compositions that Lead products with different application properties. However, this is undesirable, since the user also has a portioning of the binders should achieve consistent and reliable product quality.

In addition, such segregated binder compositions usually have a high proportion of dust-forming components that the user Production of the end product can be perceived as disturbing. Furthermore lead such Ingredients already when filling the binder compositions in one Packaging for a high level of dust, which is either expensive measures Avoid dust or require an increased dust load with the filling of persons involved in the binder.

Various measures have been proposed in the past, the above To avoid problems.

For example, EP-B 0 541 526 describes free-flowing, quick-opening Dry powder with adhesive character, a process for their production and their Use. The publication describes that so-called special paste to a batch Have binders that due to different particle size and density Separation and tendency to dust when stirring in water. To Avoiding this effect are suggested in the publication dry powder, the have a grain structure in which the at least predominant portion of the granular dry matter has closed cores of a non-ionic cellulose ether, which comprises a shell of a redispersion polymer and adheres to it are connected. The production of such dry powder takes place in that nonionic cellulose ether as powder or aqueous powder slurry with a aqueous polymer dispersion intimately mixed, the aqueous phase on a Temperature above the cloud point of the non-ionic cellulose ethers used is kept and the aqueous mixture thus obtained in compliance certain temperature conditions is subjected to spray drying. The result The products obtained have average particle diameters in the range from about 50 to about 500 µm. The high technical outlay for the described has a disadvantage here Process and the limitation of the upper limit for the achievable particle size to about 1-2 mm out.

WO 99/03945 relates to agglomerates for the production of an aqueous binder system which contain at least one hydrophilic disintegrant which is insoluble in water and generates a swelling pressure. To produce the substances mentioned, the starting compounds are used as powders or agglomerates with a grain size of 0.01 to 3 mm and then shaped to form the agglomerate using pressure. The agglomerate is formed by pressing, for example stamping presses or roller presses. The pressure applied should be less than 10 kN / cm ² . Subsequent grinding of the agglomerates thus obtained does not take place. However, the procedure described and the binder agglomerates described have various disadvantages. For example, the yield of good grain is generally not entirely satisfactory in the process described. In addition, the components separated with a sieve often have a mixing ratio which differs from the originally used composition, so that these parts can no longer be easily returned to the production process. Furthermore, the individual agglomerates usually have to be individually packaged to prevent abrasion.

WO 97/27258 relates to a porous molded part for producing an aqueous one Binder system. The porous molded part described preferably has a cylindrical shape with porous edges. First, however, is the manufacture of the Molded parts are very complex due to the use of microwave technology, on the other hand no molded parts with a particle size are described in the publication, which in range from about 0.01 to about 10 mm. The use of larger molded parts,  especially the tablets described in the publication, but comes across some Consumers on reservations.

EP-B 0 311 873 describes a method for producing a paste base suitable dry product in the form of flakes or granules. The production of the described dry product is carried out by heating a 30 to 80 wt .-% water contained mixture of a cellulose ether, a starch derivative and one in water dispersible or water-soluble polymers in a thin layer on surfaces Heat to 80 to 200 ° C. For example, roller drying is described in the product is dried on a heated roller without pressure. Has a disadvantage also in the process described here that the bulk densities obtained are low, which means additional expenditure on packaging. Beyond that do not increase the proportion of methyl cellulose arbitrarily, as the proportion of Methylcellulose the bulk weight is greatly reduced.

There has therefore been a need for binder agglomerates that are good Portionability, a particularly low dust content, an excellent Solubility and one over all particle sizes of the binder agglomerates have consistent quality and composition.

The object of the present invention was therefore such Binder agglomerates, a process for their preparation and their use for To make available. The object of the invention is achieved by a particulate Binder agglomerate, a process for its production and its use, as described in the text below.

The present invention thus relates to a particulate Binder agglomerate, at least containing a natural or synthetic Polysaccharide and a synthetic polymer, with a 5 wt .-% aqueous solution or dispersion of the particles with a particle size above the average (D50) lying particle diameter and an aqueous dispersion of the particles with a particle diameter below the average particle size (D50) after a  Dissolution time of 1 hour or less each have a viscosity that is less than 20% deviates from the other viscosity.

A "binder agglomerate" is used in the context of the present invention more or less porous, sufficiently firm for practical use cohesive collection of powdery substances understood. Such Agglomerates can be irregularly shaped particles, so they don't have to have regular geometric shape, but can rather be uneven or even have jagged surfaces. As agglomerates are within the scope of the present However, the invention also refers to those particles which have a regular shape with planes or have rounded surfaces.

The binder agglomerates according to the invention contain substances that are suitable for production own aqueous binder systems. Under an aqueous binder system are solutions or dispersions to understand that are used for gluing, sealing, solidifying or are generally suitable for surface treatment. Specific examples of such Solutions or dispersions are paste, dispersion adhesive, primer for mineral substrates and the like.

The particulate binder agglomerates according to the invention must be obtained a ready-to-use product, for example a paste, one Dispersion adhesive, a sealant or a primer for mineral Substrates first mixed with a suitable amount of water by the user means dissolved or dispersed in it.

The particulate binder agglomerates according to the invention have in the context of present invention preferably a size of at least about 0.01 and at most about 50 mm, for example about 0.05 to about 20 mm. As part of a preferred In one embodiment of the present invention, the agglomerates have a particle size from about 0.1 to about 8 or about 0.4 to about 6 mm. For certain applications can both the upper and the lower limit, for example by suitable Sieving process, to be set to intermediate values of the limits mentioned. So can for example the lower limit for the minimum particle size of the invention  Binder agglomerates are about 0.5, 0.8, 1.2, 1.5, 2.0, 2.5 or 3 mm. The Upper limit for the particle size of the binder agglomerates according to the invention can for example 5.5, 5, 4.5, 4, 3.5 or 3.2 mm.

The term "particle size" in the context of the present invention relates to actual size of the individual binder agglomerate particles according to the invention. Each the binder agglomerate particles have a specific process Distribution of particle sizes within a certain range. If the Binder agglomerate particles according to the invention for example by a suitable Molding processes are made in a substantially same size, so the particle size distribution may be narrow, for example about 10% or about 5% differ by an average particle size (D50). If the invention Binder agglomerate particles, for example, by grinding a precompacted Binder agglomerate are produced, the particle size distribution can be clearly be wider, for example about 1000% or about 500% around a certain average the particle size distribution deviate. So an inventive Binder agglomerate, for example, particles in a size of about 0.4 to about 6 mm or about 1.2 to 3 mm.

The mean particle size D50 of the binder particles means in the context of present text the particle size in which 50% of the particles have a larger size Diameter than D50 and 50% of the particles a smaller diameter than D50 exhibit.

The measurement of the average particle size (D50) is generally carried out by the Principle of light scattering particle size analyzers from Coulter, for example Coulter laser diffractometer.

In practice, however, determining the D50 value is often a hindrance. It gets more frequent a size determination by sieve fractionation of the particles into several fractions used, instead of a value D50 depending on the number of Sieve fractions result in different size intervals. For every size interval the ratio by weight of the particles lying within this interval to the total weight of the measured particles. The first and last interval naturally have only one interval limit and are only up or down by the largest or smallest particle actually present in the particle mixture limited. In the context of the present invention, a value Tm is now the average Particle size interval defined. To determine Tm at least three Sieve fractions are present, the fraction with the smallest particle size and the Fraction with the largest particle size in each case at least 2% by weight of the total Must have particles. With an odd number of sieve fractions, for example fractions 1, 2 and 3, the numerically middle fraction (in Example: Fraction 2) set as Tm. If the number of factions is even, For example, fractions 1, 2, 3 and 4, Tm is determined as a single value, namely as the size at which a separation of fraction 2 and fraction 3 took place.

When determining Tm, the procedure is preferably such that the proportion of Particles each with a value below and above Tm at least about 3, 4 or 5% by weight or more, for example more than about 10, 15, 20, 25 or 30 wt .-% is. If with a large number of fractionation sieves worked for this purpose, for example, several successive or non-successive lower fractions and several summarize successive or non-successive upper fractions.

The particle size distribution of the binder agglomerates according to the invention can vary the production can be set to a certain value by suitable processes. A particularly suitable method is sieving the agglomerate particles. As part of a preferred embodiment after the manufacture of the Binder agglomerate particles particles with a size of less than about 0.1 mm, preferably less than 0.2, 0.3 or 0.4 mm sorted out by sieving.

The binder agglomerates according to the invention have due to their composition and their manufacturing process the advantage that fractions of different Particle sizes are essentially identical or at least so similar Have composition that individual fractions with a certain  Particle size is identical or at least identical in its application properties have almost identical profile.

To check whether an identical or at least almost identical Application profile is present, the determination is within the scope of the present invention the viscosity of a 5 wt .-% aqueous solution or dispersion of a particular Fraction with a certain particle size or a mixture of different Fractions of different particle sizes were used. The invention Binder agglomerates are characterized by the fact that a 5% by weight aqueous solution or dispersion of the particles with an above an average particle size interval (Tm) lying particle diameter and a 5 wt .-% aqueous solution or Dispersion of the particles with a below the mean particle size interval (Tm) lying particle diameter after a dissolution time of 1 h or less each have a viscosity that is less than 20% of the other viscosity deviates.

In the context of a preferred embodiment of the present invention, the Binder agglomerates according to the invention with a further refinement the division of the size fractions is also only slightly different Viscosity on. So it is preferred, for example, if the Binder agglomerates according to the invention in three, four, five, six or more fractions each with a different particle size distribution, a 5% by weight aqueous solution or dispersion of the particles the above requirements with regard to the Deviation in viscosity met. It is particularly preferred if the Viscosity deviation less than about 15%, for example less than about 10 or is less than about 5%. The similar or identical viscosities of each Fractions of different particle sizes are preferably already after one Dissolution time less than 50 minutes or less than 30 minutes or less than 10 minutes on.

The viscosity of the individual fractions is determined according to Brookfield RVT, 20 rpm, 20 ° C measured. The choice of a spindle suitable for the viscosity range to be measured is known to the expert.

The particulate binder agglomerates according to the invention contain at least a natural or synthetic polysaccharide. As natural or synthetic Polysaccharides are, for example, starch or cellulose and their suitable processes available, substituted on one or more OH groups Derivatives.

All starch types such as are suitable as starch or as the basis of the starch derivatives Potato starch, corn starch, wheat starch, rice starch, milo starch, tapioca starch or Mixtures of two or more of the above strengths and the like. As part of a preferred embodiment of the present invention are starch or Starch derivatives based on potato or corn starch or their mixtures are used.

The starch should be water-soluble, possibly at least water-swellable. In particular is modified starch suitable in the context of the present invention, wherein a appropriate modification due to physical or minor chemical effects comes about. Specific examples of such starch derivatives are partially degraded Strength and swelling strength.

The starch derivatives should in particular be water-soluble or at least water-swellable. In this connection, starch esters or starch ethers are particularly suitable all carboxylated or alkoxylated starches. As carboxylated or alkoxylated starches all appropriately modified natural ones already mentioned are suitable Starch types. Usable starch derivatives have a degree of carboxylation of about 0.1 to about 2.0 or a degree of alkoxylation from about 0.05 to about 1.5. Suitable Starch derivatives can also be crosslinked with difunctional compounds, such as them are known for example from EP-B 0 311 873 (page 3, line 49 to page 4, line 5).

In addition to natural cellulose, cellulose compounds are particularly suitable Cellulose ether. Carboxymethyl cellulose (CMC), for example, are suitable, Carboxymethylmethyl cellulose (CMMC), ethyl cellulose (EC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), hydroxybutyl cellulose (HBC), Hydroxybutylmethyl cellulose (HBMC), hydroxyethyl cellulose (HEC), Hydroxyethylcarboxymethylcellulose (HECMC), Hydroxyethylethylcellulose (HEEC), Hydroxypropyl cellulose (HPC), hydropropyl carboxymethyl cellulose (HPCMC), Hydroxypropylmethylcellulose (HPMC), hydroxyethylmethylcellulose (HEMC), Methylhydroxyethyl cellulose (MHEC), methyl hydroxyethyl propyl cellulose (MHEPC), Methyl cellulose (MC) and propyl cellulose (PC), with carboxymethyl cellulose, Methyl cellulose, methyl hydroxy cellulose and methyl hydroxypropyl cellulose as well Mixtures of two or more of them, as well as the alkali salts of the CMC and the light ethoxylated MC or mixtures of two or more of the compounds mentioned.

The cellulose derivatives mentioned can be slightly cross-linked so that they are at a pH out of 8 are soluble and the solution is delayed in water. Networking can for example in a known manner by glyoxal addition.

In addition to the described polysaccharides and their derivatives, a Binder agglomerate according to the invention or at least one synthetic polymer.

Such synthetic polymers are used, for example, to increase the adhesive strength or to improve the water resistance of one using one of one Binder agglomerate product of the invention obtained end product to guarantee. Suitable synthetic polymers in the context of the present Invention, in particular, redispersible dispersion powder of fully synthetic Polymers (base polymers). Basically, these are homo- and Copolymers of vinyl alcohol, vinyl esters, styrene, acrylic acid esters and vinyl chloride.

Vinyl ester polymers which are suitable as the base polymer are, for example, vinyl acetate homopolymers, copolymers of vinyl acetate with ethylene and / or vinyl chloride and / or further vinyl esters such as vinyl laurate, vinyl versatic acid, vinyl pivalate or esters of maleic acid or fumaric acid or copolymers of two or more of the monomers of vinyl or homopolymer mentioned of saturated C _3-8 alkyl carboxylic acids or their copolymers with ethylene, vinyl chloride or other vinyl esters.

The above-mentioned acrylic acid esters, methacrylic acid esters or styrene polymers conduct derive from the polymerization of styrene or esters of acrylic acid or methacrylic acid. Esters of acrylic acid or methacrylic acid are preferably esters with straight-chain or branched or cyclic aliphatic alcohols with 1 to 20 C- Atoms used. Other styrenic polymers can be copolymers, for example of styrene with one or more other monomers. Are suitable for example styrene-butadiene copolymers. As vinyl chloride polymers are Suitable vinyl chloride-ethylene copolymers.

In the context of the present invention, vinyl acetate homopolymers, vinyl acetate-ethylene copolymers or copolymers of vinyl esters of saturated C _3-8 alkylcarboxylic acids and ethylene with an ethylene content of 1 to about 40% by weight of ethylene and 0 to about 40 are preferred as the redispersion powder % By weight of further vinyl esters from the group of the vinyl esters of saturated C _3-8 -alkylcarboxylic acids or vinyl chloride or mixtures of two or more thereof, styrene acrylates such as styrene-butyl acrylate or styrene-ethylhexyl acrylate with a styrene content of 1 to about 70% by weight used. These redispersing polymers are usually produced by spray drying polymer dispersions in spray towers.

It may be appropriate if the Binder agglomerates according to the invention two or more of the synthetic mentioned Contain polymers.

In the context of a further preferred embodiment of the present invention are mixtures of a homopolymer and a polymer particles Copolymer used. Those already mentioned above are suitable as homopolymers Homopolymers, but especially homopolymers of vinyl esters, preferably polyvinyl acetate. The above-mentioned are also copolymers Copolymers suitable. In a preferred embodiment, the mentioned mixtures of two or more polymer particles, however, copolymers of Ethylene and vinyl acetate, vinyl acetate and vinyl versatate or terpolymers, in particular Ethylene-vinyl acetate-acrylate terpolymers used.  

The proportion of homopolymers in such mixtures of polymer particles is preferably at least about 20% by weight, but preferably 40% by weight or more, for example at least about 50% by weight. Suitable mixing ratios of Homopolymers and copolymers are, for example, about 75:25 or about 80:20.

The binder agglomerates according to the invention can be used in addition to those mentioned Ingredients, namely at least one natural or synthetic polysaccharide and contain at least one synthetic polymer still further additives.

Suitable additives are, for example, compounds which cause an alkalization of the Dissolving the water-soluble preparations that can be produced according to the invention cause. These include, for example, ammonium, alkali and / or Alkaline earth metal hydroxides, the water-soluble, preferably powdered Alkali metal silicates (water glass), especially sodium or potassium water glass as well Ammonia and amines or basic salts and neutral salts, which differ from strong and derive weak acids. These include, for example, the alkali salts of carbonic acid or the carboxylic acids or the tertiary phosphates. The salts are also suitable, especially the alkali salts of organic acids such as sodium formate, sodium acetate or Sodium citrate. The compounds mentioned can be used alone or as a mixture of two or more of them are used.

If within the scope of the dissolution of the water-soluble preparations according to the invention if an alkalization is to take place, then the proportion of the abovementioned additives is the total binder agglomerates according to the invention generally about 0.1 to about 2% by weight.

Wetting agents and preservatives, consistency formers and additional components with adhesive properties such as dextrins, ionogenic cellulose ethers or other aqueous polymer preparations or mixtures of two or more of the additives mentioned are also suitable as additives. Auxiliaries such as anti-caking agents, for example rutile (TiO ₂ ), chalk, lime powder, precipitated silica, pyrogenic silica, zeolites, bentonites, gypsum or anhydrite are also suitable as additives.

Binder agglomerates according to the invention contain, for example, up to about 20% by weight such additives.

A binder agglomerate according to the invention may also contain additives. Particularly suitable additives are water-soluble nonionic polymers from the group of the polyvinylpyrrolidones, vinylpyrrolidone / vinyl ester copolymers, water-soluble amphoteric polymers from the group of the alkyl acrylamide / acrylic acid copolymers, alkyl acrylamide / methacrylic acid copolymers, alkylacrylamide / methyl metharylic acid / acrylamide copolymers (meth) acrylic acid copolymers, alkyl acrylamide / methacrylic acid / alkylaminoalkyl (meth) acrylic acid copolymers, alkyl acrylamide / methyl methacrylic acid / alkylaminoalkyl (meth) acrylic acid copolymers, alkyl acrylamide / alkyl methacrylate / alkylaminoethyl methacrylate / alkyl methacrylate copolymers, copolymers of unsaturated carboxylic acids, unsaturated carboxylic acids, optionally further ionic or nonionic monomers, water-soluble zwitterionic polymers from the group of acrylamidoalkyltrialkylammonium chloride / acrylic acid copolymers and their alkali and ammonium salts, acrylamidoalkyltrialkylammoni umchloride / methacrylic acid copolymers and their alkali and ammonium salts, methacroylethylbetaine / methacrylate copolymers, water-soluble anionic polymers from the group of vinyl acetate / crotonic acid copolymers, vinylpyrrolidone / vinyl acrylate copolymers, acrylic acid / ethyl acrylate / N-tert-butyl acrylamide, Graft polymers of vinyl esters, esters of acrylic acid or methacrylic acid, alone or in a mixture, copolymerized with crotonic acid, acrylic acid or methacrylic acid with polyalkylene oxides and / or polyalkylene glycols, grafted and crosslinked copolymers from the copolymerization of at least one monomer of the nonionic type, at least one monomer of the ionic type Type, of polyethylene glycol and a crosslinking agent obtained by copolymerization of at least one monomer of each of the following three groups, esters of unsaturated alcohols and short-chain saturated carboxylic acids and / or esters of short-chain saturated alcohols and unsaturated carboxylic acids, unsaturated gte carboxylic acids, esters of long-chain carboxylic acids and unsaturated alcohols and / or esters from the carboxylic acids of the group with saturated or unsaturated, straight-chain or branched C _8-18 alcohols, terpolymers of crotonic acid, vinyl acetate and an allyl or methallyl ester, tetra and pentapolymers Crotonic acid or allyloxyacetic acid, vinyl acetate or vinyl propionate, branched allyl or methallyl esters, vinyl ethers, vinyl esters or straight-chain allyl or methallyl esters, crotonic acid copolymers with one or more monomers from the group consisting of ethylene, vinylbenzene, vinylmethylether, acrylamide, and their water-soluble solvent from saline , Crotonic acid and vinyl esters of a saturated aliphatic monocarboxylic acid branched in the α-, β- or γ-position, water-soluble cationic polymers from the group of the quaternized cellulose derivatives, polysiloxanes with quaternary groups, cationic guar derivatives, polymeric dimethyldiallylammonium salts and their copolymers with esters and amides of acrylic acid and methacrylic acid, copolymers of vinylpyrrolidone with quaternized derivatives of dialkylaminoacrylate and methacrylate, vinylpyrrolidone-methoimidazolinium chloride copolymers, quaternized polyvinyl alcohol, specified under the INCI names Polyquaternium 18, Polyquaternium 27, and Polyquaternium 27 .

The additives mentioned can be used in an amount of from about 2 to about 10% by weight Binder agglomerates according to the invention are present.

The binder agglomerates according to the invention are notable for particularly good and rapid solubility in water. Another advantage of the binder agglomerates according to the invention is that the binder agglomerates according to the invention have an essentially identical composition and thus an essentially identical product quality over substantially the entire fraction of binder agglomerates in individual sections with a certain particle size. The binders according to the invention can be produced by a process described in more detail in the context of the text below. It is essential that the substances forming the binder agglomerate are exposed to a pressure of more than 10 kN / cm ² and then comminuted.

The present invention therefore also relates to a process for producing a binder agglomerate, in which a composition containing at least a natural or synthetic polysaccharide and a synthetic polymer is exposed to a pressure of more than 10 kN / cm ² and then comminuted.

The process according to the invention includes shaping the constituents of the binder agglomerate according to the invention under pressure and then comminuting them. In this way, binder agglomerates with an essentially arbitrary average particle size can be obtained, which can be adjusted depending on the area of application by a suitable choice of the type of comminution. In this context it is surprising that the use of high pressures of more than 10 kN / cm ² leads to binder agglomerates which have a rapid solubility combined with a rapid build-up of viscosity.

In the context of a preferred embodiment of the present invention, the binder agglomerates according to the invention are exposed in the context of the method according to the invention at a pressure of up to about 150 kN / cm ² , in particular a pressure of up to 100 kN / cm ² . A particularly suitable pressure range is, for example, approximately 30 to approximately 80, in particular approximately 40 to approximately 70 or 60 kN / cm ² .

The method according to the invention is used in a preferred embodiment of the present invention carried out by means of roller grain compacting. The at the Roll compaction adjacent printing area is not exactly known, therefore in In this case, the roller contact force is specified. To different roller widths Account is taken of the specific contact pressure. The specific Roller contact force corresponds to the actual contact force divided by the width of the Roller or working width, d. that is, the width on which material is compacted.

The pressures required in the process according to the invention are for example with a specific roller contact pressure of approximately 2 to approximately 150 kN, in particular from about 5 or about 7 to about 80 kN. A particularly suitable one The range for the specific roller contact pressure is, for example, about 10 to about 50, especially about 15 to about 40 or about 20 to about 30 kN.

In the context of the inventive method, the components of Binder agglomerates, namely at least one natural or synthetic Polysaccharide and at least one synthetic polysaccharide and at least one synthetic polymer used in a particulate state. Here it has turned out to be preferred for the method according to the invention if at least 10 % By weight of the natural or synthetic polysaccharide particles and at least 10 % By weight of the polymer particles have a size of about 0.1 to about 0.5 mm. in the A further preferred embodiment of the present invention should at least 20, at least 30, at least 40 or at least 50% by weight of the Polysaccharide particles or the polymer particles or both have a size that is within the specified range. In a further embodiment of the In the present invention, the proportion of polymer particles or polysaccharide particles or both, which is within the range, even above the range Values are, for example up to 60, 70, 80 or 90% by weight or above.

Within the scope of a further embodiment of the present invention Polysaccharideparticles or polymer particles used, one of the above Weight percentages within a particle size range of 0.1 to 0.4 mm or 0.1 to 0.3 mm or 0.1 to 0.2 mm.

A particularly suitable example is a methylhydroxyethyl cellulose which is in the range from 0.125 mm to 0.2 mm a proportion of about 45 to about 75% by weight of all particles having. Suitable redispersion powders are, for example, those which are one of the Corresponding particle size distribution of the polysaccharide particles Have particle size distribution. Redispersion powders which are particularly suitable Range from 0.1 to 0.2 mm, a proportion of at least 40 wt .-%, preferably more than 50% by weight or more than 60% by weight.

Particularly suitable representatives of the above-mentioned polymer and polysaccharide types are, for example, methyl hydroxyethyl cellulose MHEC 6000 PR (manufacturer: Henkel KGaA, Düsseldorf) and the redispersible powder ELOTEX HM 100 (manufacturer: company Elotex).

In the context of a further preferred embodiment, the inventive method as polymer particles, a mixture of two or more various polymer particles used. It is preferably the mixture from polymer particles around a mixture of homopolymer particles and Copolymer particles, suitable homopolymers and copolymers already mentioned above in Were mentioned within the framework of the present text. As part of another preferred Embodiment is the proportion of homopolymer in mixtures of such Polymer particles at least about 20 wt .-%.

Polysaccharides which have the following grain size distribution are, for example, used in the process according to the invention:

<0.8 mm maximum 0.2% <0.4 mm 30 ± 5% <0.2 mm 55 ± 5% <0.1 mm 10 ± 5% <0.1 mm 5 ± 3%

A methylhydroxyethyl cellulose with the following particle size distribution is also suitable:

<0.2 mm 20% <0.25 mm 45-75%

Suitable redispersible powders have, for example, a particle size distribution as follows:

<0.4 mm 0.3-0.7% <0.2 mm 5-18% <0.1 mm 50-75% <0.1 mm 15-40%

The percentages relate to the weight of the particles.

In the process according to the invention, the particulate polysaccharides and particulate synthetic polymers are exposed to a pressure which is greater than 10 kN / cm ² . This can be done, for example, by introducing appropriate portions of a mixture leading to the binder agglomerate according to the invention into a suitable press, for example a stamp press.

In a preferred embodiment of the present invention, the However, the method according to the invention with a roller press, in particular one Smooth roller press. This becomes one of the invention Binder agglomerate material mixture continuously pressed by means of rollers and then to the desired one with the help of suitable grinding equipment Grind particle size. In this case, the above applies to the roller press force and the values specified specific roll press force.

To carry out the method according to the invention, for example the BEPEX Pharmaceutical compactor L 200/50 P and the sieve mill FC 200 are suitable.

Binder agglomerate particles produced by the process according to the invention have, for example, the following particle size distribution (data in% by weight):

10-20% <2.5 mm 30-50% <1.6 mm 20-30% <1 mm 5-15% <0.8 mm 4-12% <0.4 mm 0.1-3% <0.4 mm

The binder agglomerates produced by the process according to the invention have excellent solubility and rapid viscosity build-up. The present invention therefore also relates to a particulate Binder agglomerate, which was produced by a method according to the invention.

The binder agglomerates according to the invention are suitable, as already in the context of described text, for the production of surface coating agents.

As surface coating agents in the context of the present invention in particular paste, dispersion adhesive, primers and the like.

The binder agglomerates according to the invention quickly give one with water lump-free aqueous solution or dispersion. With such a solution or dispersion it is preferably a paste, i.e. an adhesive in the form of a aqueous swelling product, which is already at a relatively low solids concentration forms highly viscous, non-stringy mass. These pastes are particularly suitable for gluing wallpaper and other wall coverings. With the help of the invention Binder agglomerates can also be made from other aqueous adhesives. The Binder agglomerates are - with the appropriate composition - also suitable for Production of lump-free primers for mineral substrates such as plaster, Screed or concrete on walls, ceilings and floors. Such a solidified surface is in usually then coated, for example with paint, a filler or with an adhesive. Also aqueous adhesives for textile or ceramic coverings from Floors, walls and ceilings can easily be lump-free with the help of Produce binder agglomerates according to the invention.

For example, to make a paste:

First, the agglomerates according to the invention are introduced with stirring Given water. Then, if necessary, continue stirring until the Agglomerates have dissolved and a viscosity corresponding to the planned application have trained.

The application concentration of the binders according to the invention is for example about 1 to about 50% by weight, in particular about 1 to about 10% by weight. For a paste application are, for example, application concentrations of about 1 to about 10% by weight is suitable, for powder adhesives about 10 to about 20% by weight.

Compared to a paste that comes directly from the powdery, originally used Fabrics was produced, shows with the help of the invention Binder agglomerates produced paste virtually no change in important properties such as viscosity, wet tack and dry tack. Compared to a conventional, powdered binder composition However, binder agglomerate according to the invention has many advantages. For example handling of the binder agglomerates according to the invention without dust formation and thus possible without annoying the user. In addition, the Binder agglomerates according to the invention are simply portioned, the individual portions of an essentially identical quality with regard to the Have application properties.

The invention is explained in more detail below by examples.

Example 1 (comparative example)

80% MHEC 6000 PR and 20% polyvinyl acetate (HM 100, Elotex) became one Dusting, segregating paste product with a bulk density of approx. 420 to 440 g / l produced. The powder was then placed in water at a temperature of 20 ° C stirred in and the increase in viscosity measured.

Viscosity build-up

3 min 2250 mPa.s 10 min 6500 mPa.s 60 min 9000 mPa.s (final viscosity)

Example 2

80% MHEC 6000 PR and 20% polyvinyl acetate (HM 100, Elotex) became one Dusting, segregating paste product with a bulk density of approx. 420 to 440 g / l produced.

This paste product was then in a pharmaceutical compactor L 200/50 P (company Hosokawa Bepex) compacted and then using an FC 200 sieve mill  crushed. The pharmaceutical compactor had smooth rollers with a working width of 5 cm, the applied roll press force was 100 kN, the specific roll press force was 10 kN. The sieve fractionation in the sieve mill was set to 0.5-3.25 mm. It 70% good grain was obtained. The Gutkorn presented itself as a portionable, dust-free agglomerate with a bulk density of about 400 g / l. The product dropped Mix well in water. Stir in the measurement of the viscosity build-up after in water at a temperature of 20 ° C was as follows:

Viscosity build-up

3 min 2000 mPa.s 10 min 6000 mPa.s 60 min 9000 mPa.s (final viscosity)

Example 3

A dusty, non-portionable paste product with a bulk density of approximately 440 g / l was produced from 80% MHEC 6000 PR and 18% polyvinyl acetate (HM 100, Elotex) and 2% PEG 4000. This paste product was then compacted in the pharmaceutical compactor, as described above, at a roller pressing force of 100 kN / cm ² and a specific roller pressing force of 20 kN. Sieve fractionation was carried out for the range 0.6 - 4 mm. The yield was about 72% of good grain. A portionable, dust-free agglomerate with a bulk density of about 425 g / l was obtained, which could be easily mixed in water without lumps. The measurement of the viscosity build-up after stirring into water at a temperature of 20 ° C was as follows:

Viscosity build-up

3 min 2000 mPa.s 10 min 6000 mPa.s 60 min 9000 mPa.s (final viscosity)

Claims (16)

1. Particulate binder agglomerate, at least containing a natural one or synthetic polysaccharide and a synthetic polymer, a 5 % By weight aqueous solution or dispersion of the particles with an above average particle size (D50) lying particle diameter and an aqueous Solution or dispersion of the particles with a below the middle Particle size (D50) lies after a dissolution time of 1 h or less each have a viscosity that is less than 20% deviates from the other viscosity. 2. Binder agglomerate according to claim 1, characterized in that at least 50% of the particles have a diameter of more than 0.5 mm. 3. binder agglomerate according to claim 1 or 2, characterized in that the Viscosity deviation is less than 10%. 4. Binder agglomerate according to one of claims 1 to 3, characterized characterized in that it contains at least one additive. 5. Binder agglomerate according to one of claims 1 to 4, characterized characterized in that it has at least one polysaccharide as a polysaccharide Contains cellulose base. 6. A process for producing a binder agglomerate, in which a Composition containing at least one natural or synthetic Polysaccharide and at least one synthetic polymer at a pressure of more than 10 kN or a specific roller pressure of 2 kN / cm or exposed more and then crushed.   7. The method according to claim 6, characterized in that the natural or synthetic polysaccharide and the synthetic polymer are particulate. 8. The method according to claim 6 or 7, characterized in that at least 10th % By weight of the polysaccharide particles and at least 10% by weight of the Polymer particles have a size of 0.1 to 0.5 mm. 9. The method according to any one of claims 6 to 8, characterized in that at least 20% by weight of the polysaccharide particles and at least 20% by weight of the Polymer particles have a size of 0.1 to 0.5 mm. 10. The method according to any one of claims 6 to 9, characterized in that as Polymer particles used a mixture of two or more polymers becomes. 11. The method according to any one of claims 6 to 10, characterized in that as Polymer particles a mixture of a homopolymer and a Copolymer is used. 12. The method according to any one of claims 6 to 11, characterized in that as Polymer particles a mixture of a homopolymer and a Copolymer is used, the proportion of homopolymer is at least 20% by weight 13. The method according to any one of claims 6 to 12, characterized in that the Pressure is exerted by a roller. 14. The method according to any one of claims 6 to 13, characterized in that the composition is subjected to a pressure of more than 30 kN / cm ² or a specific roller pressure of at least 5 kN / cm. 15. Particulate binder aggregate, produced by a method according to one of claims 6 to 14. 16. Use of a binder aggregate according to one of claims 1 to 5 or a composition prepared according to one of claims 6 to 14 for Manufacture of surface coatings.