DE102011005638A1 - Producing a molded body, comprises producing an aqueous dispersion of a polymer A, applying aqueous polymer dispersion A to granular and/or fibrous substrate, and carrying out thermal treatment of treated granular and/or fibrous substrate - Google Patents

Abstract

Producing a molded body, comprises producing an aqueous dispersion of a polymer A (aqueous polymer dispersion A) by free radical initiated aqueous emulsion polymerization of at least one ethylenically unsaturated 3-6C mono- or dicarboxylic acid, at least one ethylenically unsaturated compound comprising at least one oxetanyl group, and at least one other ethylenically unsaturated compound, applying the aqueous polymer dispersion A to a granular and/or fibrous substrate, and subsequently carrying out thermal treatment of the treated granular and/or fibrous substrate at a >= 110[deg] C. Producing a molded body made of granular and/or fibrous shaped substrates, comprises producing an aqueous dispersion of a polymer A (aqueous polymer dispersion A) by free radical initiated aqueous emulsion polymerization of at least one ethylenically unsaturated 3-6C mono- or dicarboxylic acid (monomer A1) (0-15 wt.%), at least one ethylenically unsaturated compound comprising at least one oxetanyl group (monomer A2) (0.1-10 wt.%), and at least one other ethylenically unsaturated compound, which is copolymerizable with the monomers A1 and A2 (A3 monomer) (75-99.8%), applying the aqueous polymer dispersion A to a granular and/or fibrous substrate, and subsequently carrying out thermal treatment of the treated granular and/or fibrous substrate at >= 110[deg] C, where the sum of monomers A1-A3 is 100 wt.%. Independent claims are also included for (1) the molded body obtained by the above mentioned method; and (2) the aqueous polymer dispersion A comprising >= 0.1 and = 5 wt -% of at least one onium salt catalyst, based on the total amount of the polymer A.

Description

The present invention relates to processes for producing a shaped body from granular and / or fibrous substrates, wherein an aqueous dispersion of a polymer A (aqueous polymer dispersion A) prepared by free-radically initiated aqueous emulsion polymerization of 0.1 to 15% by weight at least one ethylenically unsaturated C ₃ - to C ₆ -mono- or dicarboxylic acid (monomer A1), 0.1 to 10% by weight at least one ethylenically unsaturated compound having at least one oxetanyl group (monomer A2), and 75 to 99.8% by weight at least one other ethylenically unsaturated compound which is copolymerizable with the monomers A1 and A2 (monomer A3), wherein the amounts of monomers A1 to A3 add up to 100 wt .-% (total monomer), is applied to the granular and / or fibrous substrate, optionally the treated with the aqueous polymer dispersion A granular and / or fibrous substrate is brought into shape and then the treated granular and / or fibrous substrate is subjected to a thermal treatment step at a temperature ≥ 110 ° C, characterized in that the aqueous polymer dispersion A together with ≥ 0.1 and ≤ 5 wt .-% of at least one onium salt catalyst, based on the Total amount of the polymer A, is applied to the granular and / or fibrous substrate.

Likewise provided by the present invention are moldings which have been prepared by the process according to the invention and specific aqueous polymer dispersions containing at least one onium salt catalyst and the use of these polymer dispersions as binders for granular and / or fibrous substrates.

The solidification of granular and / or fibrous substrates, in particular in sheet-like structures, such as fiber webs, fiberboard, chipboard or papers, etc., often takes place chemically using a polymeric binder. To increase the strength, in particular the wet strength and heat resistance, binders are often used which contain formaldehyde-releasing crosslinkers. But there is the danger of unwanted formaldehyde emission.

To avoid formaldehyde emissions already wound numerous alternatives to the previously known binders proposed. So are from the US-A 4,076,917 Binders known which contain carboxylic acid or carboxylic anhydride-containing polymers and β-hydroxyalkylamides as crosslinking agents. A disadvantage is the relatively complicated production of β-hydroxyalkylamides.

From the EP-A-445578 For example, sheets of particulate materials such as glass fibers are known in which mixtures of high molecular weight polycarboxylic acids and polyhydric alcohols, alkanolamines or polyhydric amines act as binders.

From the EP-A-583086 are formaldehyde-free, aqueous binders for the production of fiber webs, in particular glass fiber webs known. The binders comprise a polycarboxylic acid having at least two carboxylic acid groups and optionally also anhydride groups and a polyol. These binders require a phosphorus-containing reaction accelerator to achieve sufficient strengths of the glass fiber webs. It should be noted that the presence of such a reaction accelerator can only be dispensed with if a highly reactive polyol is used. As highly reactive polyols β-hydroxyalkylamides are mentioned.

The EP-A-651088 describes corresponding binders for substrates made of cellulose fiber. These binders necessarily contain a phosphorus-containing reaction accelerator.

The EP-A-672 920 describes formaldehyde-free binding, impregnating or coating compositions comprising a polymer which is composed of 2 to 100 wt .-% of an ethylenically unsaturated acid or an acid anhydride as a comonomer and enthaften at least one polyol. The polyols are substituted triazine, triazinetrione, benzene or cyclohexyl derivatives, the polyol radicals always being in the 1,3,5-position of the mentioned rings. Despite a high drying temperature, only low wet tensile strengths are achieved with these binders on glass fiber nonwovens.

The DE-A-2214450 describes a copolymer which is composed of 80 to 99% by weight of ethylene and 1 to 20% by weight of maleic anhydride. The copolymer is used, together with a crosslinking agent, in powder form or in dispersion in an aqueous medium for surface coating. As the crosslinking agent, an amino group-containing polyhydric alcohol is used. However, in order to effect cross-linking, it has to be heated up to 300 ° C.

From the US-A 5,143,582 For example, the production of heat-resistant nonwoven materials using a thermosetting, heat-resistant binder is known.

The binder is free of formaldehyde and is obtained by mixing a carboxylic acid group, carboxylic acid anhydride group or carboxylic acid salt group-having polymer and a crosslinking agent. The crosslinker is a β-hydroxyalkylamide or a polymer or copolymer thereof. The crosslinkable with the β-hydroxyalkylamide polymer is, for example, composed of unsaturated mono- or dicarboxylic acids, salts of unsaturated mono- or dicarboxylic acids or unsaturated anhydrides. Self-curing polymers are obtained by copolymerization of the β-hydroxyalkylamides with monomers containing carboxyl groups.

Furthermore, those skilled in the art formaldehyde-free aqueous binder systems based on polycarboxylic acids and polyols or polyamines are common (see, for example EP-A 445578 . EP-A 661305 . EP-A 882074 . EP-A 882093 . EP-A 882094 . EP-A 902796 . EP-A 1005508 . EP-A 1018523 . EP-A 1240205 . EP-A 1448733 . EP-A 1340774 or EP-A 1457245 ).

In a non-prepublished priority application filed with the file number 09169849.8 by the Applicant to the European Patent Office, aqueous polymer dispersions based on polymers containing oxiranyl groups and oxetanyl groups and their use as binders for granular and / or fibrous substrates are described.

The object of the present invention was to provide a process for the production of moldings, starting from granular and / or fibrous substrates, by means of which, compared to the processes of the prior art, moldings, in particular papers with improved wet tensile strength and an improved bursting pressure result ,

Accordingly, the method defined above was found.

The core of the invention is the use of an aqueous polymer dispersion A as a binder for the granular and / or fibrous substrates, which by free-radically initiated aqueous emulsion of 0.1 to 15% by weight at least one ethylenically unsaturated C ₃ - to C ₆ -mono- or dicarboxylic acid (monomer A1), 0.1 to 10% by weight at least one ethylenically unsaturated compound having at least one oxetanyl group (monomer A2), and 75 to 99.8% by weight at least one other ethylenically unsaturated compound which is copolymerizable with the monomers A1 and A2 (monomer A3), wherein the amounts of monomers A1 to A3 add to the total amount of monomers is available.

The implementation of free-radically initiated emulsion polymerizations of ethylenically unsaturated monomers in an aqueous medium has often been described above and is therefore sufficiently known to the person skilled in the art [cf. For this Emulsion Polymerization in Encyclopaedia of Polymer Science and Engineering, Vol. 8, p. 659 et seq. (1987) ; DC Blackley, in High Polymer Latices, Vol. 1, pp. 35 ff. (1966) ; H. Warson, The Applications of Synthetic Resin Emulsions, Chapter 5, pages 246 ff. (1972) ; D. Diederich, Chemistry in our time 24, pages 135 to 142 (1990) ; Emulsion Polymerization, Interscience Publishers, New York (1965) ; DE-A 40 03 422 and Dispersions of Synthetic High Polymers, F. Hölscher, Springer-Verlag, Berlin (1969) ]. The free-radically initiated aqueous emulsion polymerization reactions are usually carried out in such a way that the ethylenically unsaturated monomers are dispersed in the aqueous medium in the form of monomer droplets and polymerized by means of a free-radical polymerization initiator with the concomitant use of dispersing aids. From this procedure, the present inventive method differs only by the use of specific monomers A1 to A3.

The monomers A1 used are ethylenically unsaturated, in particular α, β-monoethylenically unsaturated C ₃ - to C ₆ -mono- or dicarboxylic acids, where α, β-monoethylenically unsaturated C ₃ - and C ₄ -mono- and C ₄ - to C ₆ -Dicarboxylic acids are preferred. Examples of monomers A1 are acrylic acid, methacrylic acid, ethylacrylic acid, allylacetic acid, crotonic acid, vinylacetic acid, maleic acid, fumaric acid, itaconic acid, methylmaleic acid, methylenemalonic acid, dimethylacrylic acid and / or 1,2,3,6-tetrahydrophthalic acid and the ammonium, sodium or potassium salts called the aforementioned acids. Of course, the C ₄ - to C ₆ -dicarboxylic acids according to the invention also the anhydrides derived therefrom, such as maleic anhydride, and / or methylmaleic anhydride considered as belonging. However, particularly preferred are acrylic acid and / or methacrylic acid.

The amount of the monomers A1 in the preparation of the aqueous polymer dispersant A is 0.1 to 15 wt .-%, preferably 0.5 to 10 wt .-% and particularly preferably 1 to 7 wt .-%, each based on the total amount of monomers.

As monomers A2 ethylenic, especially α, β-monoethylenically unsaturated compounds are used which have at least one oxetanyl group, in particular vinyloxetane, allyloxetane, 3-ethyl-3-methacryloxymethyloxetan, 3-ethyl-3-methacryloxymethyloxetan, 3-ethyl-3 acryloxymethyloxetane, 3-methyl-3-methacryloxymethyloxetane, 3-methyl-3-acryloxymethyloxetane, 3-ethyl-3-acrylpoly (ethyleneoxy) methyloxetane and / or 3-ethyl-3-methacrylpoly (ethyleneoxy) methyloxetane (each having 1 to 10, preferably 1 to 5 and in particular 2 to 4 ethyleneoxy groups [-CH ₂ CH ₂ -O-]). Particularly preferred are 3-ethyl-3-methacryloxymethyloxetane, 3-ethyl-3-methacryloxymethyloxetane, 3-ethyl-3-acryloxymethyloxetane, 3-methyl-3-methacryloxymethyloxetane, 3-methyl-3-acryloxymethyloxetane, 3-ethyl-3 acrylpoly (ethyleneoxy) methytoxetane and / or 3-ethyl-3-methacrylpoly (ethyleneoxy) methyloxetane (each having 2 to 4 ethyleneoxy groups), with 3-ethyl-3-methacryloxymethyloxetane being particularly preferred.

The amount of the monomers A2 in the preparation of the aqueous polymer dispersant A is 0.1 to 10 wt .-%, preferably 0.5 to 7 wt .-% and particularly preferably 1 to 5 wt .-%, each based on the total amount of monomers.

Suitable monomers A3 are, in principle, all ethylenically unsaturated compounds which differ from the monomers A1 and A2 but are readily copolymerizable with them in a straightforward manner, for example vinylaromatic monomers, such as styrene, α-methylstyrene, o-chlorostyrene or vinyltoluenes, Vinyl halides, such as vinyl chloride or vinylidene chloride, esters of vinyl alcohol and 1 to 18 carbon atoms monocarboxylic acids, such as vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl laurate and vinyl stearate, esters of preferably 3 to 6 carbon atoms having α, β-monoethylenic unsaturated mono- and dicarboxylic acids, in particular acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, having generally from 1 to 12, preferably 1 to 8 and in particular 1 to 4 carbon atoms alkanols, such as acrylic acid and Methacrylsäuremethyl-, -ethyl , n-butyl, iso-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and 2-ethylhexyl ester, dimethyl fumarate and dimethyl maleate or di-n-butyl nitrile, nitriles of α, β-monoethylenically unsaturated carboxylic acids, such as acrylonitrile, methacrylonitrile, fumaronitrile, malononitrile, and C _4-8 conjugated dienes, such as 1,3-butadiene ( Butadiene) and isoprene. The monomers mentioned generally form the main monomers which, based on the total amount of monomers A3, account for ≥80% by weight, preferably ≥85% by weight and more preferably ≥90% by weight, or even the total amount of monomers A3 form. As a rule, these monomers have only a moderate to low solubility in water under standard conditions [20 ° C., 1 atm (absolute)].

Monomers A3, which have an increased water solubility under the abovementioned conditions, are those which either have at least one sulfonic acid group and / or their corresponding anion or at least one amido, amino, ureido or N-heterocyclic group and / or their nitrogen containing protonated or alkylated ammonium derivatives. Examples which may be mentioned are vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid and its water-soluble salts and N-vinylpyrrolidone, 2-vinylpyridine, 4-vinylpyridine, 2-vinylimidazole, 2- (N, N-dimethylamino) ethyl acrylate, 2- (N , N-dimethylamino) ethyl methacrylate, 2- (N, N-diethylamino) ethyl acrylate, 2- (N, N-diethylamino) ethyl methacrylate, 2- (N-tert-butylamino) ethyl methacrylate, N- (3-N ', N '-Dimethylaminopropyl) methacrylamide and 2- (1-imidazolin-2-onyl) ethyl methacrylate and the amides of the monomers A1, but acrylamide and / or methacrylamide are particularly preferred. In the normal case, the abovementioned water-soluble monomers A3 are used only as modifying monomers in amounts of ≥ 0.1 and ≦ 10% by weight, preferably ≦ 5% by weight and more preferably ≦ 3% by weight, based in each case on the total amount of monomers A3, used.

Monomers A3, which usually increase the internal strength of the films of a polymer matrix, usually have at least two non-conjugated ethylenically unsaturated double bonds. Examples include two vinyl radicals containing monomers, two vinylidene radicals having monomers and two alkenyl radicals having monomers. Particularly advantageous are the diesters of dihydric alcohols with α, β-monoethylenically unsaturated monocarboxylic acids, among which acrylic and methacrylic acid are preferred. Examples of such two non-conjugated ethylenically unsaturated double bonds monomers are alkylene glycol diacrylates and dimethacrylates such as ethylene glycol diacrylate, 1,2-propylene glycol diacrylate, 1,3-propylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate and ethylene glycol dimethacrylate, 1,2- Propylene glycol dimethacrylate, 1,3-propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate and divinylbenzene, vinyl methacrylate, vinyl acrylate, allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, methylenebisacrylamide, cyclopentadienyl acrylate, triallyl cyanurate or triallyl isocyanurate. Frequently, the above-mentioned crosslinking monomers A3 are used in amounts of ≦ 10 to% by weight, but preferably in amounts of ≦ 3% by weight, in each case based on the total amount of monomers A3. However, particularly preferred, no such crosslinking monomers A3 are used.

Advantageously used in the preparation of the aqueous polymer dispersant A as monomers A3 are those monomers or monomer mixtures which are added to From 50 to 100% by weight Esters of acrylic and / or methacrylic acid having alkanols having 1 to 12 carbon atoms, or From 50 to 100% by weight Styrene and / or butadiene, or From 50 to 100% by weight Vinyl chloride and / or vinylidene chloride, or From 50 to 100% by weight Vinyl acetate and / or vinyl propionate contain.

Preferred main monomers A3 are styrene, n-butyl acrylate, methyl methacrylate, tert-butyl acrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, 2-propylheptyl acrylate and / or 2-ethylhexyl acrylate.

In the preparation of the aqueous Polymerisatdispersison A, the total amount of monomers A3 with particular advantage 0.1 to 10 wt .-% of acrylamide and / or methacrylamide and 90 to 99.9 wt .-% of styrene, n-butyl acrylate, methyl methacrylate and or 2-ethylhexyl acrylate.

Use advantageously in the preparation of the aqueous polymer dispersion A. 0.5 to 10% by weight at least one monomer A1 0.5 to 7% by weight at least one monomer A2 and 83 to 99% by weight at least one monomer A3 and especially advantageous 1 to 7% by weight at least one monomer A1 1 to 5% by weight at least one monomer A2 and 88 to 98% by weight at least one monomer A3 used.

According to the invention, in the preparation of the aqueous polymer dispersion A, the total amount of the monomers A1 to A3 in the aqueous reaction medium before initiation of the polymerization reaction are presented. However, it is also possible, if appropriate, to initially introduce only a partial amount of the monomers A1 to A3 in the aqueous reaction medium prior to initiation of the polymerization reaction and then, after initiation of the polymerization under polymerization conditions during the free radical emulsion polymerization according to the invention, the total amount or the remaining amount remaining in accordance with the consumption continuously Constant or changing flow rates or discontinuous admit. In this case, the metering of the monomers A1 to A3 can be carried out as separate individual streams, as inhomogeneous or homogeneous (part) mixtures or as a monomer emulsion. Advantageously, the monomers A1 to A3 in the form of a monomer mixture, in particular in the form of an aqueous monomer emulsion.

In the preparation of the aqueous polymer dispersion A dispersants are also used, which had dispersed both the monomer droplets, as well as the polymerizate particles formed in the aqueous medium and thus ensure the stability of the aqueous polymer dispersion produced. Suitable dispersing agents are both the protective colloids commonly used to carry out free-radical aqueous emulsion polymerizations and emulsifiers.

Suitable protective colloids are, for example, polyvinyl alcohols, polyalkylene glycols, alkali metal salts of polyacrylic acids and polymethacrylic acids, gelatin derivatives or acrylic acid, methacrylic acid, maleic anhydride, 2-acrylamido-2-methylpropanesulfonic acid and / or 4-styrenesulfonic acid-containing copolymers and their alkali metal salts but also N-vinylpyrolidone, N-vinylcaprolactam, N-vinylcarbazole, 1-vinylimidazole, 2-vinylimidazole, 2-vinylpyridine, 4-vinylpyridine, acrylamide, methacrylamide, amines group-bearing acrylates, methacrylates, acrylamides and / or methacrylamides containing homo- and copolymers. A detailed description of other suitable protective colloids can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular Materials, Georg-Thieme-Verlag, Stuttgart, 1961, pages 411-420 ,

Of course, mixtures of protective colloids and / or emulsifiers can be used. Frequently, dispersants used are exclusively emulsifiers whose relative molecular weights, in contrast to the protective colloids, are usually below 1000. They may be anionic, cationic or nonionic in nature. Of course, in the case of the use of mixtures of surfactants, the individual components must be compatible with each other, which can be checked in case of doubt by hand on fewer preliminary tests. In general, anionic emulsifiers are compatible with each other and with nonionic emulsifiers. The same applies to cationic emulsifiers, while anionic and cationic emulsifiers are usually incompatible with each other. An overview of suitable emulsifiers can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular Materials, Georg-Thieme-Verlag, Stuttgart, 1961, pages 192 to 208 ,

In accordance with the invention, however, emulsifiers are used in particular as dispersing aids.

Common nonionic emulsifiers are z. B. ethoxylated mono-, di- and tri-alkylphenols (EO degree: 3 to 50, alkyl radical: C ₄ to C ₁₂ ) and ethoxylated fatty alcohols (EO degree: 3 to 80, alkyl radical: C ₈ to C ₃₆ ). Examples are the Lutensol ^® A grades (C ₁₂ C ₇₄ fatty alcohol ethoxylates, EO units: 3 to 8), Lutensol ^® AO-marks (C ₁₃ C ₁₅ -Oxoalkoholethoxylate, EO units: 3 to 30), Lutensol ^® AT-marks (C ₁₆ C ₁₈ fatty alcohol EO 11 to 80), Lutensol ^® ON brands (C ₁₀ -Oxoalkoholethoxylate, EO units: 3 to 11) (and the Lutensol ^® tO brands C ₁₃ - Oxo alcohol ethoxylates, EO grade: 3 to 20) from BASF SE.

Usual anionic emulsifiers are z. B. Alkali metal and ammonium salts of alkyl sulfates (alkyl: C ₈ to C ₁₂ ), of sulfuric monoesters of ethoxylated alkanols (EO degree: 4 to 30, alkyl: C ₁₂ to C ₁₈ ) and ethoxylated alkylphenols (EO degree: 3 to 50 , Alkyl radical: C ₄ to C ₁₂ ), of alkylsulfonic acids (alkyl radical: C ₁₂ to C ₁₈ ) and of alkylarylsulfonic acids (alkyl radical: C ₉ to C ₁₈ ).

worin R¹ und R² H-Atome oder C₄- bis C₂₄-Alkyl bedeuten und nicht gleichzeitig H-Atome sind, und M¹ und M² Alkalimetallionen und/oder Ammoniumionen sein können, als geeignet erwiesen. In der allgemeinen Formel (I) bedeuten R¹ und R² bevorzugt lineare oder verzweigte Alkylreste mit 6 bis 18 C-Atomen, insbesondere mit 6, 12 und 16 C-Atomen oder Wasserstoff, wobei R¹ und R² nicht beide gleichzeitig H-Atome sind. M¹ und M² sind bevorzugt Natrium, Kalium oder Ammonium, wobei Natrium besonders bevorzugt ist. Besonders vorteilhaft sind Verbindungen (I), in denen M¹ und M² Natrium, R¹ ein verzweigter Alkylrest mit 12 C-Atomen und R² ein H-Atom oder R¹ ist. Häufig werden technische Gemische verwendet, die einen Anteil von 50 bis 90 Gew.-% des monoalkylierten Produktes aufweisen, wie beispielsweise Dowfax^® 2A1 (Marke der Dow Chemical Company). Die Verbindungen (I) sind allgemein bekannt, z. B. aus US-A 4269749 , und im Handel erhältlich.Further anionic emulsifiers further compounds of the general formula (I)

wherein R ¹ and R ^{2 are} H atoms or C ₄ - to C ₂₄ alkyl and are not H atoms at the same time, and M ¹ and M ^{2 may be} alkali metal ions and / or ammonium ions have been found suitable. In the general formula (I), R ¹ and R ^{2 are} preferably linear or branched alkyl radicals having 6 to 18 C atoms, in particular having 6, 12 and 16 C atoms or hydrogen, where R ¹ and R ^{2 are} not both simultaneously H and Atoms are. M ¹ and M ² are preferably sodium, potassium or ammonium, with sodium being particularly preferred. Particularly advantageous compounds (I) are those in which M ¹ and M ^{2 are} sodium, R ^{1 is} a branched alkyl radical having 12 C atoms and R ^{2 is} an H- Atom or R ¹ is. Frequently, technical mixtures are used which have a proportion of 50 to 90 wt .-% of the monoalkylated product, such as Dowfax ^® 2A1 (trademark of the Dow Chemical Company). The compounds (I) are well known, for. B. off US-A 4269749 , and commercially available.

In principle, suitable cationic emulsifiers are generally C ₆ -C ₁₈ -alkyl, -alkylaryl or heterocyclic radical-containing primary, secondary, tertiary or quaternary ammonium salts, alkanolammonium salts, pyridinium salts, imidazolinium salts, oxazolinium salts, morpholinium salts, thiazolinium salts and salts of amine oxides , Quinolinium salts, isoquinolinium salts, tropylium salts, sulfonium salts and phosphonium salts. Examples include dodecylammonium acetate or the corresponding sulfate, the sulfates or acetates of the various 2- (N, N, N-trimethylammonium) ethylparaffinsäureester, N-Cetylpyridiniumsulfat, N-Laurylpyridiniumsulfat and N-cetyl-N, N, N-trimethylammonium sulfate, N- Dodecyl-N, N, N-trimethylammonium sulfate, N-octyl-N, N, N-trimethylammonium sulfate, N, N-distearyl-N, N-dimethylammonium sulfate and the gemini surfactant N, N '- (lauryldimethyl) ethylenediamine disulfate, ethoxylated tallow fatty alkyl -N-methyl ammonium sulfate and ethoxylated oleylamine (for example Uniperol.RTM ^® AC from. BASF SE, about 11 ethylene oxide units). Numerous other examples can be found in H. Stache, Tensid Paperback, Carl-Hanser-Verlag, Munich, Vienna, 1981 and in McCutcheon's, Emulsifiers & Detergents, MC Publishing Company, Glen Rock, 1989 , It is favorable if the anionic counter groups are as low as possible nucleophilic, such as perchlorate, sulfate, phosphate, nitrate and carboxylates, such as acetate, trifluoroacetate, trichloroacetate, propionate, oxalate, citrate, benzoate, as well as conjugated anions of organosulfonic acids, such as methyl sulfonate , Trifluoromethylsulfonate and para-toluenesulfonate, furthermore tetrafluoroborate, tetraphenylborate, tetrakis (pentafluorophenyl) borate, tetrakis [bis (3,5-trifluoromethyl) phenyl] borate, hexafluorophosphate, hexafluoroarsenate or hexafluoroantimonate.

The anionic and / or nonionic emulsifiers preferably used as dispersing agents are advantageously used in a total amount of ≥ 0.005 and ≦ 10% by weight, preferably ≥ 0.01 and ≦ 5% by weight, in particular ≥ 0.1 and ≦ 3% by weight. %, in each case based on the total amount of monomers used.

The total amount of the protective colloids used as dispersing agents in addition to or instead of the emulsifiers is often ≥ 0.1 and ≦ 10% by weight and frequently ≥ 0.2 and ≦ 7% by weight, in each case based on the total monomers.

However, preference is given to using anionic and / or nonionic emulsifiers and particularly preferably anionic emulsifiers as sole dispersing aids.

In the preparation of the aqueous polymer dispersion A, the total amount of the dispersing aid in the aqueous reaction medium before initiation of the polymerization reaction can be presented. However, it is also possible, if appropriate, to initially introduce only a subset of the dispersing agent in the aqueous reaction medium prior to initiation of the polymerization reaction and then to add continuously or discontinuously under polymerization conditions during the free-radical emulsion polymerization according to the invention the total amount or any remaining amount of the dispersing aid. Preferably, the addition of the main or the total amount of dispersing aid takes place in the form of an aqueous monomer emulsion.

In the preparation of the aqueous polymer dispersion A, the free-radically initiated aqueous emulsion polymerization is initiated by means of a free-radical polymerization initiator (free-radical initiator). In principle, these can be both peroxides and azo compounds. Of course, redox initiator systems come into consideration. As peroxides may in principle inorganic peroxides, such as hydrogen peroxide or peroxodisulfates, such as the mono- or di-alkali metal or ammonium salts of peroxodisulfuric, such as their mono- and di-sodium, potassium or ammonium salts or organic peroxides, such as alkyl hydroperoxides, for example tert-butyl, p-menthyl or cumyl hydroperoxide, as well as dialkyl or diarylperoxides, such as di-tert-butyl or di-cumyl peroxide are used. The azo compounds are essentially 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile) and 2,2'-azobis (amidinopropyl) dihydrochloride (AIBA, corresponding to V-50 from Wako Chemicals). Use. Suitable oxidizing agents for redox initiator systems are essentially the abovementioned peroxides. Suitable reducing agents may be sulfur compounds having a low oxidation state, such as alkali metal sulfites, for example potassium and / or sodium sulfite, alkali hydrogen sulfites, for example potassium and / or sodium bisulfite, alkali metal metabisulfites, for example potassium and / or sodium metabisulfite, formaldehyde sulfoxylates, for example potassium and / or sodium formaldehyde sulfoxylate, Alkali salts, especially potassium and / or sodium salts, aliphatic sulfinic acids and alkali metal hydrogen sulfides, such as, for example, potassium and / or sodium hydrosulfide, salts of polyvalent metals, such as iron (II) sulfate, iron (II) ammonium sulfate, iron (II) phosphate, endiols, such as dihydroxymaleic acid, benzoin and / or ascorbic acid and reducing saccharides, such as sorbose, glucose, fructose and / or dihydroxyacetone used. In general, the amount of the radical initiator used, based on the total amount of monomers, 0.01 to 5 wt .-%, preferably 0.1 to 3 wt .-% and particularly preferably 0.2 to 1.5 wt .-%.

In the preparation of the aqueous polymer dispersion A, the total amount of the radical initiator in the aqueous reaction medium before initiation of the polymerization reaction can be submitted. However, it is also possible, if appropriate, to initially introduce only a subset of the free radical initiator in the aqueous reaction medium prior to initiation of the polymerization reaction and then to add continuously or discontinuously under polymerization conditions during the free radical emulsion polymerization according to the invention the total amount or any residual amount remaining in accordance with the consumption.

Initiation of the polymerization reaction is understood to mean the start of the polymerization reaction of the monomers present in the polymerization vessel after radical formation of the radical initiator. In this case, the initiation of the polymerization reaction by adding radical initiator to the aqueous polymerization mixture in the polymerization vessel can be carried out under polymerization conditions. However, it is also possible that a partial or total amount of the radical initiator is added to the aqueous polymerization mixture containing the monomers present in the polymerization vessel under conditions which are not suitable for initiating a polymerization reaction, for example at low temperature, and polymerization conditions are subsequently set in the aqueous polymerization mixture , Polymerization conditions are to be understood as meaning in general those temperatures and pressures under which the free-radically initiated aqueous emulsion polymerization proceeds at a sufficient rate of polymerization. They are dependent, in particular, on the radical initiator used. The type and amount of the radical initiator, the polymerization temperature and the polymerization pressure are advantageously selected so that the free-radical initiator has a half-life of <3 hours, more preferably <1 hour and most preferably <30 minutes, and there are always enough starting radicals available to effect the polymerization reaction to initiate and maintain.

The reaction temperature for the free-radical aqueous emulsion polymerization is the entire range from 0 to 170 ° C into consideration. In this case, temperatures of 50 to 120 ° C, often 60 to 110 ° C and often 70 to 100 ° C are usually applied. The free-radical aqueous emulsion polymerization according to the invention can be carried out at a pressure of less than or equal to 1 atm [1.013 bar (absolute), atmospheric pressure], such that the polymerization temperature can exceed 100 ° C. and can be up to 170 ° C. In the presence of gaseous monomers A or monomers A having a low boiling point, polymerization is preferably carried out under elevated pressure in the process according to the invention. The pressure can be 1,2, 1,5, 2, 5, 10, 15 bar (absolute) or even higher values. If emulsion polymerizations are carried out under reduced pressure, pressures of 950 mbar, often 900 mbar and often 850 mbar (absolute) are set. The free-radical aqueous emulsion polymerization according to the invention is advantageously carried out at 1 atm or in overpressure up to 20 bar with exclusion of oxygen, in particular under an inert gas atmosphere, for example under nitrogen or argon.

The aqueous reaction medium may in principle also in minor amounts (<5 wt .-%) include water-soluble organic solvents such as methanol, ethanol, isopropanol, butanols, pentanols, but also acetone, etc. However, the preparation of the aqueous polymer dispersion A is preferably carried out in the absence of such solvents.

In addition to the abovementioned components, it is also possible optionally to use free-radical chain transfer compounds in the preparation of the aqueous polymer dispersion A in order to reduce or control the molecular weight of the polymers A obtainable by the polymerization. These are essentially aliphatic and / or araliphatic halogen compounds, such as n-butyl chloride, n-butyl bromide, n-butyl iodide, methylene chloride, ethylene dichloride, chloroform, bromoform, bromotrichloromethane, Dibromdichlormethan, carbon tetrachloride, carbon tetrabromide, benzyl chloride, benzyl bromide, organic thio compounds such as primary , secondary or tertiary aliphatic thiols such as ethanethiol, n-propanethiol, 2-propanethiol, n-butanethiol, 2-butanethiol, 2-methyl-2-propanethiol, n-pentanethiol, 2-pentanethiol, 3-pentanethiol, 2-methyl -2-butanethiol, 3-methyl-2-butanethiol, n-hexanethiol, 2-hexanethiol, 3-hexanethiol, 2-methyl-2-pentanethiol, 3-methyl-2-pentanethiol, 4-methyl-2-pentanethiol, 2 Methyl-3-pentanethiol, 3-methyl-3-pentanethiol, 2-ethylbutanethiol, 2-ethyl-2-butanethiol, n-heptanethiol and its isomeric compounds, n-octanethiol and its isomeric compounds, n-nonanethiol and its isomeric compounds , n-Decanethiol and its isomeric compound n-undecanethiol and its isomeric compounds, n-dodecanethiol and its isomeric compounds, n-tridecanethiol and its isomeric compounds, substituted thiols such as Hydroxyethanthiol, aromatic thiols, such as benzenethiol, ortho-, meta- or para-Methylbenzolthiol, and all other im Polymer Handbook 3rd Edition, 1989, J. Brandcup and EH Immergut, John Wiley & Sons, Section II, pages 133-141 Sulfur compounds described, but also aliphatic and / or aromatic aldehydes, such as acetaldehyde, propionaldehyde and / or benzaldehyde, unsaturated fatty acids such as oleic acid, dienes with non-conjugated double bonds, such as divinylmethane or vinylcydohexane or hydrocarbons with easily abstractable hydrogen atoms, such as toluene, for Commitment. However, it is also possible to use mixtures of non-interfering radical-chain-transferring compounds mentioned above.

The total amount of radical chain-transferring compounds optionally used in the preparation of the aqueous polymer dispersion A, based on the total amount of monomers, is generally ≦ 5% by weight, often ≦ 3% by weight and frequently ≦ 1% by weight.

It is advantageous if a partial or total amount of the radical chain transferring compound optionally used is fed to the reaction medium before the initiation of the free-radical polymerization. In addition, a partial or total amount of the radical chain transferring compound may advantageously also be added to the aqueous reaction medium together with the monomers A1 to A3 during the polymerization.

The polymers A obtainable by free-radically initiated aqueous emulsion polymerization can in principle have glass transition temperatures Tg in the range of ≥ -70 and ≦ 150 ° C. The monomers A1 to A3 are advantageously selected such that the resulting polymers A have a glass transition temperature Tg in the range of ≥ -10 and ≦ 130 ° C. and particularly advantageously in the range ≥ 10 and ≦ 100 ° C. Under glass transition temperature Tg is in the context of this document, the midpoint temperature after ASTM D 3418-82 understood as determined by differential thermal analysis (DSC) [cf. also Ullmann's Encydopedia of Industrial Chemistry, page 169, Verlag Chemie, Weinheim, 1992 and Zosel in paint and varnish, 82, pages 125 to 134, 1976 ].

After Fox ( TG Fox, Bull. Phys. Soc. 1956 [Ser. II] 1, page 123 and according to Ullmann's Encyclopedia of Industrial Chemistry, Vol. 19, page 18, 4th edition, Verlag Chemie, Weinheim, 1980 ) applies to the glass transition temperature of at most weakly crosslinked copolymers in a good approximation: 1 / Tg = x1 / Tg1 + x2 / Tg2 + ... xn / Tgn, where x1, x2, ... xn the mass fractions of the monomers 1, 2, ... n and Tg1, Tg2, ... Tgn the glass transition temperatures of each of only one of the monomers 1, 2, ... n built polymers in Degrees Kelvin mean. The glass transition temperatures of these homopolymers of most ethylenically unsaturated monomers are known (or can be determined experimentally in a simple manner known per se) and, for example, in US Pat J. Brandrup, EH Immergut, Polymer Handbook 1st Ed. J. Wiley, New York, 1966, 2nd ed. J. Wiley, New York, 1975 and 3rd Ed. J. Wiley, New York, 1989 , as in Ullmann's Encyclopedia of Industrial Chemistry, page 169, Verlag Chemie, Weinheim, 1992 listed.

Advantageously, the free-radically initiated aqueous emulsion polymerization in the presence of a polymer seed, for example in the presence of 0.01 to 3 wt .-%, often from 0.02 to 2 wt .-% and often from 0.04 to 1.5 wt. -% of a polymer seed, in each case based on the total amount of monomers, carried out.

A polymer seed is used in particular if the particle size of the polymer particles to be produced by means of a free-radically aqueous emulsion polymerization is to be adjusted in a targeted manner (see, for example, for this US-A 2520959 and US-A 3397165 ).

In particular, a polymer seed is used whose polymer seed particles have a narrow particle size distribution and weight-average diameters Dw ≦ 100 nm, frequently ≥ 5 nm to ≦ 50 nm and often ≥ 15 nm to ≦ 35 nm. The determination of the weight-average particle diameter is known to the person skilled in the art and is carried out, for example, by the method of the analytical ultracentrifuge. Weight-average particle diameter in this document is understood to mean the weight-average Dw50 value determined by the method of the analytical ultracentrifuge (cf. See SE Harding et al., Analytical Ultracentrifugation in Biochemistry and Polymer Science, Royal Society of Chemistry, Cambridge, Great Britain 1992 . Chapter 10, Analysis of Polymer Dispersions with Eight-Cell AUC Multiplexers: High Resolution Particle Size Distribution and Density Gradient Techniques, W. Mächtle, pp. 147-175 ).

A narrow particle size distribution should be understood within the scope of this document if the ratio of the weight-average particle diameter Dw50 determined by the analytical ultracentrifuge method and the number-average particle diameter DN50 [Dw50 / DN50] <2.0, preferably <1.5 and particularly preferably <1, 2 or <1.1.

Usually, the polymer seed is used in the form of an aqueous polymer dispersion. The aforementioned amounts are based on the polymer solids content of the aqueous polymer seed dispersion.

If a polymer seed is used, it is advantageous to use a foreign polymer seed. In contrast to a so-called in situ polymer seed, which is prepared before the actual emulsion polymerization in the reaction vessel and which generally has the same monomeric composition as the polymer prepared by the subsequent free-radically initiated aqueous emulsion polymerization, a polymer seed is understood to mean a polymer seed, which was prepared in a separate reaction step and the monomeric composition of which is different from the polymer prepared by the free-radically initiated aqueous emulsion polymerization, which means nothing else than that for the preparation of Fremdpolymersaat and for preparing the aqueous polymer dispersion different monomers or monomer mixtures of different composition be used. The preparation of a foreign polymer seed is familiar to the person skilled in the art and is usually carried out by initially charging a relatively small amount of monomers and a relatively large amount of emulsifiers in a reaction vessel and adding a sufficient amount of polymerization initiator at reaction temperature.

According to the invention, a foreign metal seed having a glass transition temperature ≥ 50 ° C., frequently ≥ 60 ° C. or ≥ 70 ° C. and often ≥ 80 ° C. or ≥ 90 ° C. is preferably used. Particularly preferred is a polystyrene or polymethyl methacrylate polymer seed.

The total amount of foreign polymer seed can be presented in the polymerization vessel. However, it is also possible to introduce only a subset of the foreign polymer seed in the polymerization vessel and to add the remaining amount during the polymerization together with the monomers A1 to A3. If necessary, however, it is also possible to add the total amount of polymer seed in the course of the polymerization. Preferably, the total amount of Fremdpolymersaat is submitted before initiation of the polymerization in the polymerization.

The aqueous polymer dispersions A obtainable by the free-radically initiated aqueous emulsion polymerization usually have a polymer solids content of ≥ 10 and ≦ 70% by weight, frequently ≥ 20 and ≦ 65% by weight and often ≥ 25 and ≦ 60% by weight, based in each case to the aqueous polymer dispersion, on. The quasi-elastic light scattering ( ISO standard 13 321 ) determined number average particle diameter (cumulant z-average) is usually between 10 and 2000 nm, often between 20 and 1000 nm and often between 100 and 700 nm and 100 to 400 nm.

Frequently, in the aqueous polymer dispersions A obtained, the residual contents of unreacted monomers and other low-boiling compounds are also subject to chemical and / or physical methods which are likewise known to the person skilled in the art [see, for example EP-A 771328 . DE-A 19624299 . DE-A 19621027 . DE-A 19741184 . DE-A 19741187 . DE-A 19805122 . DE-A 19828183 . DE-A 19839199 . DE-A 19840586 and 19847115 ] lowered.

In addition to their use as binders for granular and / or fibrous substrates, the aqueous polymer dispersions A can in principle also be used to prepare adhesives, sealants, plastic plasters, paper coating slips, paints and coating compositions for organic substrates, such as leather or textile materials, and for modifying mineral binders be used.

However, the aqueous polymer dispersions A are advantageously suitable for use as binders for granular and / or fibrous substrates. With particular advantage, the abovementioned aqueous polymer dispersions A can therefore be used for the production of moldings from granular and / or fibrous substrates.

Granular and / or fibrous substrates are familiar to the person skilled in the art. For example, these are wood chips, wood fibers, cellulose fibers, textile fibers, plastic fibers, glass fibers, mineral fibers or natural fibers such as jute, flax, hemp or sisal, but also cork chips, sand and others Organic or inorganic natural and / or synthetic granular and / or fibrous compounds whose longest extent in the case of granular substrates ≤ 10 mm, preferably ≤ 5 mm and in particular ≤ 2 mm. Of course, the term substrate according to the invention should also include the fiber webs obtainable from fibers, such as so-called mechanically consolidated or chemically pre-bonded nonwoven fabrics and advantageously mechanically consolidated or chemically pre-bonded papers (especially base papers and glued papers) as well as particularly advantageous also porous filter papers with.

As a base paper is in the context of this document after DIN 6730 (August 1985) flat, consisting essentially of fibers predominantly of vegetable origin existing material, which is formed by dewatering a fibrous slurry containing various auxiliaries on a screen, wherein the resulting fiber felt is then compressed and dried. Examples of excipients which are known to the person skilled in the art are fillers, dyes, pigments, binders, optical brighteners, retention aids, wetting agents, defoamers, preservatives, slimicides, plasticizers, antiblocking agents, antistatic agents, water repellents, etc. Depending on the basis weight of the sheet material obtained, one also speaks of base paper (basis weight ≤ 225 g / m ² ) or of raw board (basis weight> 225 g / m ² ). In addition, the term "cardboard" is also common, which comprises a basis weight of about 150 to 600 g / m ² both base paper grades and raw paperboard. For the sake of simplicity, the term "base paper" will be understood to include both base paper, raw board and cardboard.

Frequently, raw paper surfaces are treated with sizing agents, which essentially influence the absorbency and thus the writing or printability of the raw paper. The papers treated in this way are called "glued papers". Corresponding methods and the type and amounts of the corresponding sizing agents are familiar to the person skilled in the art.

Frequently, the base paper or glued paper is refined by the so-called brushing, or transferred to the finished form of use. The term "coating of paper" is understood to mean the one- or two-sided coating of the paper with an aqueous coating material consisting essentially of pigments / fillers and binders. Depending on the type of coating composition, the layer thickness to be achieved or the type of paper to be produced, use is made of different coating methods, for example the roller, doctor blade, air brush or cast coating method known to the person skilled in the art, which is followed by a drying step. The papers treated in this way are called "coated papers".

The aqueous polymer dispersions A are particularly advantageously suitable as a formaldehyde-free binder system for the abovementioned fibers or fiber webs or papers formed therefrom. With particular advantage, the aqueous polymer dispersions A are used as sole or as an additional binder or binder component for the reinforcement of base paper and for sized paper, but in particular for filter paper.

The inventive method for producing a shaped body from a granular and / or fibrous substrate is such that the aqueous polymer dispersion A or a binder formulation containing them is applied to the granular and / or fibrous substrate, for example by spraying, knife coating or impregnation, then optionally granulated and / or fibrous substrate treated with the aqueous polymer dispersion A is brought into shape and then the treated granular and / or fibrous substrate is subjected to a thermal treatment step at a temperature ≥ 110 ° C, is essential to the invention that the aqueous polymer dispersion A together with ≥ 0.1 and ≤ 5 wt .-% of at least one onium salt catalyst, based on the total amount of the polymer A, is applied to the granular and / or fibrous substrate.

In the context of this document, onium salt catalysts are generally C ₁ -C ₁₈ -alkyl- or C ₇ -C ₁₈ -alkylaryl-containing quaternary ammonium salts, phosphonium salts, alkanolammonium salts, morpholinium salts and on nitrogen with C ₁ - to C ₁₈ -alkyl - or C ₇ - to C ₁₈ -alkylaryl substituted or protonated pyridinium salts, imidazolinium salts, oxazolinium salts, thiazolinium salts, quinolinium salts, isoquinolinium salts. It is advantageous if the anionic counter groups are as low as possible nucleophilic, such as perchlorate, sulfate, phosphate, nitrate, carboxylate, such as acetate, trifluoroacetate, trichloroacetate, propionate, oxalate, citrate, benzoate, halide, such as chloride and bromide and conjugated Anions of organosulfonic acids, such as methylsulfonate, trifluoromethylsulfonate and para-toluenesulfonate, furthermore tetrafluoroborate, tetraphenylborate, tetrakis (pentafluorophenyl) borate, tetrakis [bis (3,5-trifluoromethyl) phenylborate, hexafluorophosphate, hexafluoroarsenate or hexafluoroantimonate. Examples of suitable onium salt catalysts are: the sulfates or acetates of various 2- (N, N, N-trimethylammonium) ethyl paraffinic acid ester, N-cetylpyridinium sulfate, N-laurylpyridinium sulfate and N-cetyl-N, N, N-trimethylammonium sulfate, N-dodecyl-N, N, N-trimethylammonium sulfate, N-octyl N, N, N-trimethlyammonium sulfate, N, N-distearyl-N, N-dimethylammonium sulfate and the gemini surfactant N, N '- (lauryldimethyl) ethylenediamine disulfate, and also tetrabutylammonium bromide, tetraethylammonium bromide, tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, pyridinium chloride and / or N-alkylpyridinium chloride, in particular N-methylpyridinium chloride and N-ethylpyridinium chloride. Tetrabutylammonium bromide, tetraethylammonium bromide, tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, N-methylpyridinium chloride, N-ethylpyridinium chloride and / or pyridinium chloride are particularly advantageously used as onium salt catalysts.

According to the invention, the amount of onium salt catalyst is ≥ 0.1 and ≦ 5% by weight, advantageously ≥ 0.1 and ≦ 3% by weight, and particularly advantageously ≥ 0.5 and ≦ 2.5% by weight, in each case based on the total amount of the polymer A.

According to the invention, the aqueous polymer dispersion A is applied to the granular and / or fibrous substrate together with the onium salt catalyst. In this context, the term "together in this context means that both the aqueous polymer dispersion A and the onium salt catalyst were applied uniformly and homogeneously distributed onto the granular and / or fibrous substrate before the thermal treatment step. According to the invention, it is therefore possible that first at least a partial amount of the aqueous polymer dispersion A is homogeneously and uniformly applied to the granular and / or fibrous substrate and then any remaining amount of the aqueous polymer A and the total amount of the onium salt catalyst, optionally in the form of a aqueous solution is uniformly and homogeneously applied to the pretreated substrate. However, it is also possible first to apply at least a partial amount of the onium salt catalyst, if appropriate in the form of an aqueous solution, homogeneously and uniformly to the granular and / or fibrous substrate and then the remaining amount of the onium salt catalyst and the total amount of the aqueous polymer dispersion, if any A, evenly and homogeneously applied to the pretreated substrate. Advantageously, however, the total amount of the onium salt catalyst of the aqueous Polymeriasatdispersion A is added and homogeneously mixed and then applied this homogeneous aqueous polymer dispersion A / onium salt catalyst mixture on the granular and / or fibrous substrate, which is why according to the invention an aqueous polymer dispersion A, prepared by free-radically initiated aqueous emulsion polymerization of 0.1 to 15% by weight at least one monomer A1, 0.1 to 10% by weight at least one monomer A2, and 75 to 99.8% by weight at least one monomer A3, wherein the amounts of monomers A1 to A3 add up to 100% by weight, containing ≥ 0.1 and ≦ 5% by weight of at least one onium salt catalyst, based on the total amount of the polymer A, and their use as binders for granular and / or or fibrous substrates is particularly preferred.

It is important, however, that if the aqueous polymer dispersion A was prepared in the presence of cationic emulsifiers which correspond in their amount and structure to the onium salt catalysts used according to the invention, the aqueous polymer dispersion A when applied to the granular and / or fibrous substrates in usually no further onium salt catalyst has to be added.

In accordance with the invention, the aqueous polymer dispersion A may also be admixed with other customary auxiliaries customary to the person skilled in the art, such as fillers, dyes, pigments, optical brighteners, retention aids, wetting agents, defoamers, preservatives, slimicides, plasticizers, antiblocking agents, antistatics, water repellents, etc ,

The amount of aqueous polymer dispersion A or of an aqueous binder formulation containing these applied to the granular and / or fibrous substrate is selected so that, per 100 g of granular and / or fibrous substrate, ≥ 1 g and ≦ 100 g, preferably ≥ 1 g and ≦ 50 g and in particular preferably ≥ 5 g and ≤ 30 g of polymer A (calculated as solid) are applied. The technique of application (impregnation) is familiar to the person skilled in the art and takes place, for example, by impregnation, knife coating or by spraying the granular and / or fibrous substrates.

After application of the aqueous polymer dispersion A and the onium salt catalyst, the granular and / or fibrous substrate is optionally brought into the desired shape, for example by introduction into a heatable press or mold. Thereafter, the shaped treated (impregnated) granular and / or fibrous substrate is dried and cured in a manner known to those skilled in the art.

According to the invention, the curing of the optionally shaped impregnated granular and / or fibrous substrate takes place at a temperature ≥ 110 ° C. The curing is advantageously carried out at a temperature ≥ 110 ° C. and ≦ 250 ° C., preferably at a temperature ≥ 130 ° C. and ≦ 220 ° C., and particularly preferably at a temperature ≥ 150 and ≦ 200 ° C.

The moldings obtainable by the process according to the invention, in particular non-woven fabrics or papers, have advantageous properties, in particular improved tear strength or increased bursting pressure, in comparison to the moldings of the prior art.

The invention will be illustrated by the following non-limiting examples.

Examples

a) Preparation of the oxetanylgruppenhaltigen monomers

3-Ethyl-3-methacryloxymethyloxetane (II) was prepared according to A. El-ghayoury, C. Boukaftane, B. de Ruiter, R. van der Linde; J. Polym. Sci. Part A: Polym. Chem. 41, 2003, pages 469 to 475 produced.

b) Preparation of the aqueous polymer dispersions

example 1

In a equipped with stirrer, thermometer, reflux condenser and metering 5 I polymerization vessel was at 20 to 25 ° C (room temperature) and under nitrogen atmosphere at atmospheric pressure (1 atm absolute), a mixture consisting of 576 g of deionized water and 22.5 g of an aqueous Polystyrene seed latex (33% strength by weight, particle diameter 30 nm).

Feed 1 consisted of a homogeneous emulsion prepared from 328 g of deionized water, 40 g of a 3% strength by weight aqueous sodium pyrophosphate solution, 5.3 g of a 45% strength by weight aqueous solution of a C ₁₂ -C ₁₄ -alkyldiphenyl ether-disulfonic acid solution. sodium salt (Dowfax ^® 2A1), 43 g of a 28 wt .-% aqueous solution of sodium lauryl ether sulphate (Texapon ^® NSO Cognis GmbH), 58.8 g acrylic acid, 149.6 g of a 15 wt .-% aqueous solution of Methacrylamide, 53.7 g of 3-ethyl-3-methacryloxymethyloxetane (II), 582 g of styrene and 487 g of n-butyl acrylate.

Feed 2 consisted of 67 g of a 7 wt .-% aqueous solution of sodium peroxydisulfate.

The original was heated to 91 ° C. with stirring and nitrogen atmosphere. Subsequently, while maintaining this temperature, 18 g of feed 2 were added within 2 minutes and the original was stirred for 5 minutes. Subsequently, at the same time starting from feed 1 within 135 minutes and the remainder of feed 2 within 140 minutes continuously metered in with constant flow rates.

After completion of the feeds was polymerized for a further 15 minutes at 91 ° C and then cooled, the resulting aqueous polymer dispersion to 70 ° C. At this temperature, starting simultaneously 24.0 g of a 10 wt .-% aqueous tert-butyl hydroperoxide solution and 28.9 g of a 13.3 wt .-% aqueous solution of acetone bisulfite (molar 1: 1 addition product of Acetone and sodium hydrogen sulfite) within 60 minutes with constant flow rates metered. After completion of the dosages the aqueous polymer dispersion was cooled to room temperature. The aqueous polymer dispersion obtained at room temperature were 4.8 g Acticid ^® MV (1.5% wt .- aqueous biocide from Thor GmbH) as a biocide and 494 g of a 5 wt .-% aqueous tetrabutylammonium bromide solution as an onium salt catalyst added and then the aqueous polymer dispersion filtered through 120 micron filter. The aqueous polymer dispersion obtained had a solids content of 50.3% by weight. The number average particle size was determined to be 210 nm and the Tg to 40 ° C.

The solids contents were generally determined by drying a defined amount of the aqueous polymer dispersion (about 0.8 g) with the aid of moisture meter HR73 from Mettler Toledo at a temperature of 130 ° C. to constant weight.

The number average particle diameter of the latex particles was determined by dynamic light scattering (DLS) on a 0.005 to 0.01 weight percent aqueous dispersion at 23 ° C. by means of Autosizer IIC from Malvern Instruments, England. The mean diameter of the cumulant evaluation (cumulant z-average) of the measured autocorrelation function ( ISO standard 13321 ).

The glass transition temperature was determined using a differential calorimeter from Mettler Toledo. The heating rate was 10 K / min. The evaluation was carried out by means of the software Star Version 9.01.

Comparative Example C1

The preparation of Comparative Example C1 was carried out analogously to Example 1, with the difference that no aqueous solution of tetrabutylammonium bromide was added.

Comparative Example V2

Comparative Example C2 was prepared analogously to Example 1, with the difference that 40.0 g of glycidyl methacrylate were used instead of 53.7 g of 3-ethyl-3-methacryloxymethyloxetane (II).

The aqueous polymer dispersion obtained had a solids content of 49.6% by weight. The number average particle size was determined to be 180 nm and the Tg to 40 ° C.

c) application tests

Commercially available cellulose raw paper for the production of automotive air filters with a basis weight of 107 g / m ^{2 was} used for the performance tests. The paper sheets had a size of 21.0 × 29.7 cm [DIN A4] with the longitudinal direction of the machine direction corresponded.

The aqueous polymer dispersions obtained according to Example 1 and Comparative Examples C1 and C2 were diluted at room temperature with deionized water to a solids content of 10% by weight. Thereafter, the cellulose base papers were impregnated with the aqueous polymer dispersions according to Example 1 and Comparative Examples and excess aqueous Polymerisatdispersion by means of a hand shortage (horizontally arranged stainless steel rollers [length 46 cm, diameter 6 cm], driven by hand crank) with a gap width of 0.2 mm stripped. In this case, a wet application of 210 g / m ² (corresponding to 21 g / m ² binder calculated as a solid) was set.

Thereafter, the impregnated filter papers were dried for 24 hours at 23 ° C and 50% relative humidity in a conditioning room and then cured for 15 sec at 200 ° C in a Mathis furnace at maximum hot air flow and then cooled to room temperature.

The determination of the tensile strength [wet] was carried out with a tensile testing machine from Zwick Roell AG

Before the test, test specimens (web width: 6 mm, land length: 34 mm, clamping area: 25 mm, overall length: 115 mm) were punched out in the machine direction and in the transverse direction to the machine direction of the paper. Thereafter, the specimens for 15 hours at 23 ° C and 50% rel. Humidity stored in the climatic room. (Bayer AG sodium alkanesulfonate having an average chain length of 15 C) dipped and then blotted excess emulsifier with a dry cotton cloth Thereafter, the specimens were incubated at room temperature for 2 minutes in a 2 wt .-% aqueous solution of emulsifier ^® strength K30. Immediately thereafter, the wet test specimens were clamped in the tensile testing machine so that the clamping length was 70 mm. The measurement of the tensile strength [wet] was carried out at a withdrawal speed of 50 mm / min. In each case 5 individual measurements were carried out. The measured values listed in Table 1 represent the average of these 5 individual measurements.

The determination of the bursting pressure [wet] was carried out with a strength testing machine from Zwick Roell AG using the test module bursting pressure according to ISO 2758 , Before the test, 20 cm x 15 cm were punched out of the test strip impregnated filter papers, these strength for 2 minutes in a 2 wt .-% aqueous solution of emulsifier immersed ^® K30 and thereafter blotted excess emulsifier with a dry cotton cloth. Subsequently, the test strips were stretched over the circular elastic membrane of the test module. To determine the bursting pressure [wet], the membrane was then bulged together with the test strip by means of a hydraulic fluid until the test strip burst. The maximum applied pressure was the bursting pressure. In each case 2 individual measurements were carried out. The measured values also shown in Table 1 represent the mean value of these two individual measurements. Table 1: Results of the application-related tests Example / Comparative Example 1 V1 V2 Tear force [wet] (N / mm ² ) - Machine direction 1.6 1.0 1.0 - Transverse direction 1.0 0.7 0.7 Bursting pressure [wet] (kPa) 82 55 59

It is clearly evident from the results that when the aqueous polymer dispersion A according to the invention containing an onium salt catalyst as binder was used, significantly higher values were obtained with regard to the breaking force [wet] and the bursting pressure [wet] than in the corresponding comparative experiments, in which either the onium salt catalyst was omitted (V1) or an oxiranylgruppenhaltiges monomer instead of a oxetanylgruppenhaltigen monomer (V2) was used.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4076917 A [0004]
• EP 445578 A [0005, 0012]
• EP 583086A [0006]
• EP 651088 A [0007]
• EP 672920 A [0008]
• DE 2214450 A [0009]
• US 5143582A [0010]
• EP 661305 A [0012]
• EP 882074A [0012]
• EP 882093 A [0012]
• EP 882094A [0012]
• EP 902796A [0012]
• EP 1005508A [0012]
• EP 1018523 A [0012]
• EP 1240205A [0012]
• EP 1448733 A [0012]
• EP 1340774A [0012]
• EP 1457245 A [0012]
• DE 4003422 A [0017]
• US 4269749A [0036]
• US 2520959 A [0053]
• US Pat. No. 3,397,165 A [0053]
• EP 771328A [0061]
• DE 19624299 A [0061]
• DE 19621027 A [0061]
• DE 19741184A [0061]
• DE 19741187A [0061]
• DE 19805122 A [0061]
• DE 19828183 A [0061]
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• DE 19847115 A [0061]

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Claims (10)

A process for producing a shaped body from granular and / or fibrous substrates, wherein an aqueous dispersion of a polymer A (aqueous polymer dispersion A), prepared by free-radically initiated aqueous emulsion of 0.1 to 15% by weight at least one ethylenically unsaturated C ₃ - to C ₆ -mono- or dicarboxylic acid (monomer A1), 0.1 to 10% by weight at least one ethylenically unsaturated compound having at least one oxetanyl group (monomer A2), and 75 to 99.8% by weight at least one other ethylenically unsaturated compound which is copolymerizable with the monomers A1 and A2 (monomer A3), wherein the amounts of monomers A1 to A3 add up to 100 wt .-% (total monomer), is applied to the granular and / or fibrous substrate, optionally the treated with the aqueous polymer dispersion A granular and / or fibrous substrate is brought into shape and then the treated granular and / or fibrous substrate is subjected to a thermal treatment step at a temperature ≥ 110 ° C, characterized in that the aqueous polymer dispersion A together with ≥ 0.1 and ≤ 5 wt .-% of at least one onium salt catalyst, based on the Total amount of the polymer A, is applied to the granular and / or fibrous substrate. A method according to claim 1, characterized in that for the preparation of the polymer A 1 to 7% by weight at least one monomer A1 1 to 5% by weight at least one monomer A2 and 88 to 98% by weight at least one monomer A3 be used. Method according to one of claims 1 or 2, characterized in that the total amount of the monomers A3 0.1 to 10 wt .-% of acrylamide and / or methacrylamide and 90 to 99.9 wt .-% of styrene, n-butyl acrylate, Methyl methacrylate and / or 2-ethylhexyl acrylate contains. Method according to one of claims 1 to 3, characterized in that acrylic acid and / or methacrylic acid as the monomer A1, 3-ethyl-3-methacryloxymethyloxetan, 3-ethyl-3-methacryloxymethyloxetan, 3-ethyl-3-acryloxymethyloxetan, 3-methyl 3-Methacryloxymethyloxetan, 3-methyl-3-acryloxymethyloxetan, 3-ethyl-3-acrylpoly (ethlenoxy) methyloxetane and / or 3-ethyl-3-methacrylpoly (ethyleneoxy) methyloxetane be used as the monomer A2. Method according to one of claims 1 to 4, characterized in that the monomers A1 to A3 are selected in type and amounts such that the polymer A obtained has a glass transition temperature Tg ≥ 10 and ≤ 100 ° C. Method according to one of claims 1 to 5, characterized in that the amount of aqueous polymer dispersion A is chosen so that per 100 g of granular and / or fibrous substrate ≥ 1 g and ≤ 100 g of polymer A are applied. Shaped body obtainable by a process according to one of claims 1 to 6. Aqueous polymer dispersion A, prepared by free-radically initiated aqueous emulsion polymerization of 0.1 to 15% by weight at least one monomer A1, 0.1 to 10% by weight at least one monomer A2, and 75 to 99.8% by weight at least one monomer A3, wherein the amounts of monomers A1 to A3 add up to 100% by weight, containing ≥ 0.1 and ≦ 5% by weight of at least one onium salt catalyst, based on the total amount of the polymer A. Use of an aqueous polymer dispersion A according to claim 8 as a binder for granular and / or fibrous substrates. A process according to any one of claims 1 to 6, aqueous polymer dispersion A according to claim 8 and use according to claim 9, characterized in that the onium salt catalyst used is tetrabutylammonium bromide, tetraethylammonium bromide, tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, N-methylpyridinium chloride, N-ethylpyridinium chloride and / or pyridinium chloride ,