WO2011067316A1

WO2011067316A1 - Method for producing a polymer dispersion

Info

Publication number: WO2011067316A1
Application number: PCT/EP2010/068698
Authority: WO
Inventors: Uwe Hartnagel; Armin Alteheld
Original assignee: Basf Se
Priority date: 2009-12-04
Filing date: 2010-12-02
Publication date: 2011-06-09
Also published as: EP2507300A1

Abstract

The invention relates to a method for producing a dispersion of polymer particles in an ionic liquid.

Description

The present invention relates to a process for preparing a dispersion of polymer particles in an ionic liquid (ionic polymer dispersion), which comprises adding and removing an aqueous dispersion of polymer particles (aqueous polymer dispersion) with an ionic liquid the resulting mixture of water is separated.

The invention likewise relates to the use of this ionic polymer dispersion in various fields of application, in particular in the field of torque transmission and impact absorption. In the present invention, the following prior art is assumed.

WO 2004/7881 1 discloses the use of ionic liquids in the preparation of block or graft polymers by coupling reactions of the corresponding reactive components.

The object of the present invention was to provide a process for the preparation of novel polymer dispersions and the novel polymer dispersions themselves. The object was achieved by the provision of the method defined at the outset.

According to the invention, aqueous polymer dispersions are used. Aqueous polymer dispersions are well known. These are fluid systems which contain a disperse phase of dispersed polymer beads as a disperse phase in an aqueous dispersion medium consisting of a plurality of intertwined polymer chains, the so-called polymer particles. The average diameter of the polymer particles is generally in the range from 10 to 1000 nm, often from 50 to 500 nm or from 80 to 300 nm. The polymer solids content of the aqueous polymer dispersions is generally from 10 to 70% by weight.

Aqueous polymer dispersions are accessible in particular by free-radically initiated aqueous emulsion polymerization of ethylenically unsaturated monomers. This method has been described many times and is therefore well known to the person skilled in the art [cf. for example, Encyclopedia of Polymer Science and Engineering, Vol. 8, pp. 659-677, John Wiley & Sons, Inc., 1987; DC Blackley, Emulsion Polymerization, pp. 155-465, Applied Science Publishers, Ltd., Essex, 1975; DC Blackley, Polymer Latices, 2nd Edition, Vol. 1, pp. 33-415, Chapman & Hall, 1997; H. Warson, The Applications of Synthetic Resin Emulsions, pages 49 to 244, Ernest Benn, Ltd., London, 1972; J. Piirma, Emulsion Polymerization, pages 1 to 287, Academic Press, 1982; F. Hölscher, dispersions of synthetic high polymers, pages 1 to 160, Springer-Verlag, Berlin, 1969 and the patent DE-A 40 03 422]. The free-radically initiated aqueous emulsion polymerization is usually carried out by dispersing the ethylenically unsaturated monomers, generally with the concomitant use of radical chain transfer agents and dispersing aids, such as emulsifiers and / or protective colloids, in aqueous medium and polymerizing them by means of at least one water-soluble free-radical polymerization initiator. Frequently, the residual contents of unreacted ethylenically unsaturated monomers in the resulting aqueous polymer dispersions are also chemical and / or physical methods known to the person skilled in the art [see, for example, EP-A 771328, DE-A 19624299, DE-A 19621027, DE-A 19741 184, DE-A 19741 187, DE-A 19805122, DE-A 19828183, DE-A 19839199, DE-A 19840586 and 198471 15], the polymerizate solids content is adjusted by dilution or concentration to a desired value or the aqueous polymer dispersion other customary additives, such as, for example, bactericidal, foaming or viscosity-modifying additives, are added. In addition to these so-called primary aqueous polymer dispersions knows the

Professional even so-called secondary aqueous polymer dispersions. These are understood to mean those aqueous polymer dispersions whose preparation produces the polymer outside the aqueous dispersing medium, for example in solution of a suitable non-aqueous solvent. This solution is then transferred into the aqueous dispersing medium and the solvent is separated, generally by distillation, with dispersion.

According to the invention, it is particularly advantageous to use those aqueous polymer dispersions whose polymerizate particles

From 50 to 99.9% by weight of esters of acrylic and / or methacrylic acid with alkanols and / or styrene having from 1 to 12 carbon atoms, or

From 50 to 99.9% by weight of styrene and / or butadiene, or

From 50 to 99.9% by weight of vinyl chloride and / or vinylidene chloride, or

40 to 99.9 wt .-% vinyl acetate, vinyl propionate, vinyl ester of Versatiesäure, vinyl esters of long-chain fatty acids and / or ethylene in polymerized form. According to the invention, it is particularly advantageous to use those aqueous polymer dispersions whose polymers are too

0.1 to 5 wt .-% at least one 3 to 6 C-atoms

having α, β-monoethylenic

unsaturated mono- and / or dicarboxylic acid

and / or their amide and

50 to 99.9 wt .-% of at least one ester of acrylic and / or

Methacrylic acid with 1 to 12 C atoms

having alkanols and / or styrene, or

0.1 to 5 wt .-% at least one 3 to 6 C-atoms

having α, β-monoethylenic

unsaturated mono- and / or dicarboxylic acid

and / or their amide and

From 50 to 99.9% by weight of styrene and / or butadiene,

or

0.1 to 5 wt .-% at least one 3 to 6 C-atoms

having α, β-monoethylenic

unsaturated mono- and / or dicarboxylic acid

and / or their amide and

From 50 to 99.9% by weight of vinyl chloride and / or vinylidene chloride,

or

0.1 to 5 wt .-% at least one 3 to 6 C-atoms

having α, β-monoethylenic

unsaturated mono- and / or dicarboxylic acid

and / or their amide and

From 40 to 99.9% by weight of vinyl acetate, vinyl propionate, vinyl ester of versatic acid,

Vinyl esters of long-chain fatty acids and / or ethylene in polymerized form.

In addition to the abovementioned aqueous polymer dispersions, those aqueous polymer dispersions which have dilatant properties are particularly advantageously used according to the invention. The skilled person understands by dilatant properties, when an aqueous polymer dispersion under the action of shear forces has a significant increase in viscosity, without there being a measurable time dependence. That is, dilatant dispersions are characterized by ideally constant shear rate, the so-called critical Shear rate, characterized by a steep increase in shear stress. This described shear thickening is reversible and isothermal.

Aqueous polymer dispersions having dilatant properties are described, for example, in EP-A 43464, in particular Examples 1 to 3, EP-A 400416, in particular Examples 1 to 9, DE-A 3433085, in particular Examples A to D and DE-A 19757669, in particular examples 1 to 30, which are to be considered as expressly incorporated herein by reference. According to the invention, preference is given to using those aqueous polymer dispersions whose glass transition temperature is> -90 and <180 ° C., in particular> -70 and <120 ° C. and advantageously> -20 and <90 ° C. By glass transition temperature (Tg) is meant the glass transition temperature limit to which it tends to increase in molecular weight according to G. Kanig (Kolloid-Zeitschrift & Zeitschrift fur Polymere, vol. 190, page 1, equation 1). The glass transition temperature is determined by the DSC method (differential scanning calorimetry, 20 K / min, midpoint measurement, DIN 53 765).

Fox (TG Fox, Bull. Am. 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 are 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 constructed polymers in degrees Kelvin. The Tg values for the homopolymers of most monomers are known and are listed, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th ed., Vol. A21, page 169, Verlag Chemie, Weinheim, 1992; Other sources of glass transition temperatures of homopolymers include, for example, J. Brandrup, EH Immergut, Polymer Handbook, Ist Ed., J. Wiley, New York, 1966; 2nd Ed. J. Wiley, New York, 1975 and 3rd Ed. J. Wiley, New York, 1989. The average diameter of the polymer particles present in the aqueous polymer dispersions which can be used according to the invention is generally in the range from 10 to 1000 nm, often 50 to 500 nm or 80 to 300 nm. Furthermore, the solids contents are according to the invention usable aqueous usually> 10 and <70 wt .-%, advantageously> 30 and <70 wt .-% and particularly advantageously> 40 and <60 wt .-%. In a corresponding manner, the aqueous polymer dispersions usable according to the invention contain> 30 and <90% by weight, advantageously> 30 and <70% by weight and particularly advantageously> 40 and <60% by weight of water. Here are the Solids contents or the water contents determined by a defined amount (about 0.8 g) of the aqueous polymer dispersion is dried at 130 ° C to constant weight. From the resulting weight loss, the solids content or the water content can be determined.

It is essential to the process that the aqueous dispersion of polymer particles (aqueous polymerizate dispersion) is mixed with an ionic liquid and water is separated off from the resulting mixture. In the context of this document, an ionic liquid is understood as meaning salts (compounds of cations and anions) which at normal pressure (1 atm absolute) have a melting point of less than 200 ° C., preferably less than 150 ° C., more preferably less than 100 ° C., and most preferably own less than 80 ° C. With particular advantage, the ionic liquids according to the invention have a melting point> -80 and <80 ° C and particularly advantageously> -45 and <60 ° C.

In a particularly preferred embodiment, the ionic liquids are liquid under normal conditions (1 atm absolute, 21 ° C). Preferred ionic liquids contain an organic compound as a cation (organic cation). Depending on the valence of the anion, the ionic liquid may contain other cations, including metal cations, in addition to the organic cation.

The cations of particularly preferred ionic liquids are exclusively an organic cation or, in the case of polyvalent anions, a mixture of different organic cations.

Suitable organic cations are, in particular, organic compounds containing heteroatoms, such as nitrogen, sulfur, oxygen or phosphorus; In particular, the organic cations are compounds having an ammonium group (ammonium cations), an oxonium group (oxonium cations), a sulfonium group (sulfonium cations) or a phosphonium group (phosphonium cations).

In a particular embodiment, the organic cation of the ionic liquids are ammonium cations, including non-aromatic compounds having a localized positive charge on the nitrogen atom, for example, tetra-nitrogen (quaternary ammonium) compounds or trivalent nitrogen compounds wherein a bond is a double bond, or aromatic compounds with delocalized positive charge and at least one, preferably one or two nitrogen atoms in the aromatic ring system are understood. Preferred organic cations are quaternary ammonium cations having preferably three or four aliphatic substituents, particularly preferably C 1 to C 12 alkyl groups, on the nitrogen atom, which may optionally be substituted by hydroxyl groups.

Particularly preferred are organic cations containing a heterocyclic ring system having one or two nitrogen atoms as a constituent of the ring system. Suitable compounds are monocyclic, bicyclic, aromatic or non-aromatic ring systems. Called e.g. bicyclic systems, as described in WO 2008/043837. The bicyclic systems of WO 2008/043837 are diazabicyclo derivatives, preferably of a 7- and a 6-membered ring, which contain an amidinium group; in particular the 1,8,8-diazabicyclo (5.4.0) undec-7-enium cation is mentioned. Very particularly preferred organic cations comprise a five- or six-membered heterocyclic ring system having one or two nitrogen atoms as part of the ring system.

Examples of suitable organic cations are pyridinium cations, pyridinium cations, pyrimidinium cations, pyrazinium cations, imidazolium cations, pyrazolium cations, pyrazolinium cations, imidazolinium cations, thiazolium cations, triazolium cations. Cations, pyrrolidinium cations and imidazolidinium cations. These cations are listed, for example, in WO 2005/1 13702. Insofar as it is necessary for a positive charge on the nitrogen atom or in the aromatic ring system, the nitrogen atoms are in each case by an organic group having generally not more than 20 C-atoms, preferably a hydrocarbon group, in particular a C to Ci6-alkyl group, in particular a C to C10, more preferably a substituted C to C ₄ alkyl. The carbon atoms of the ring system can also be substituted by organic groups having generally not more than 20 C atoms, preferably a hydrocarbon group, in particular a C to C 16 -alkyl group, in particular a C to C 10, particularly preferably a C to C ₄ -alkyl groups , Particularly preferred ammonium cations are quaternary ammonium cations, imidazolium cations, pyrimidinium cations and pyrazolium cations.

Very particular preference is given to imidazolium cations, in particular those as listed in formula I below.

The ionic liquids may contain inorganic or organic anions. Such anions are listed, for example, in the above-mentioned WO 03/029329, WO 2007/076979, WO 2006/000197 and WO 2007/128268.

Suitable anions are, in particular, those from the group of halides and halogen-containing compounds of the formulas:

F ^", Cf, Bf, T, BF ₄ PF _^6", AICU ^", Al ₂ Cl _7, ^AI3CI10", AlBr _4, FeCu ^{^"BCU",} SbF ₆ ^", AsF _6, ZnCIs, SnCIs, CuCl _2, CF3SO3 , (CF ₃ S0 ₃ ) ₂ N, CF ₃ CO ₂ , CC ₃ CO 2, CN, SCN, OCN, NO ₂ , NO ₃ , N (CN), the group of sulfates, sulfites and sulfonates of the general formulas:

S0 ₄ ² , HSO4 ^" , SO3 ² , HSO3, R ^a OS0 ₃ , R ^a S0 ₃ , the group of phosphates of the general formulas:

PO4 ^{3 "} , HPO4 ^2" , H2PO4 ^" , R ^a P0 ₄ ² HR ^a P0 ₄ , R ^a R ^b P0 _{4 of} the group of phosphonates and phosphinates of the general formula:

R ^a HP0 ₃ , R ^a R ^b P0 ₂ , R ^a R ^b P0 ₃ ; the group of phosphites of the general formulas:

PO3 ^3, HPO 3 ^2, H2PO ^3, R ^a ₃ P0 ^2, R ^a HP0 ^3, R ^a R ^b P0 ^3; the group of phosphonites and phosphinites of the general formula:

R ^a R P0 ₂ , R ^a HP0 ₂ , R ^a R ^b PO, R ^a HPO; the group of carboxylates of the general formulas:

R ^a COO; the group of borates of the general formulas:

BO3 ³ , HBO3 ² , H2BO3, R ^a R B0 ₃ , R ^a HB0 ₃ , R ^a B0 ₃ ² , B (OR ^a ) (OR) (OR ^c ) (OR ^d ),

the group of boronates of the general formulas:

R ^a B0 ₂ ² , R ^a R ^b BO; the group of carbonates and carbonic esters of the general formulas:

the group of silicates and silicic acid esters of the general formulas:

Si0 ₄ ⁴ HS1O4 ³ H2S1O4 ² H3S1O4 ^" , R ^a Si0 ₄ ³ R ^a R Si0 ₄ ² R ^a RR ^c Si0 ₄ HR ^a Si0 ₄ ² H ₂ R ^a Si0 ₄ HR ^a R Si0 ₄ the group of the alkyl or aryl silane salts of the general formulas:

R ^a Si0 ₃ ³ R ^a R ^b Si0 ₂ ² R ^a R ^b R ^c SiO, R ^a R ^b Si0 ₃ ^{2 of} the group of carboxylic acid imides, bis (sulfonyl) imides and sulfonylimides of the general formulas:

the group of methides of the general formula:

SO ₂ -R ^a

R ^b -O ₂ S SO ₂ -R ^c

the group of alkoxides and aryloxides of the general formulas:

the group of halometalates of the general formula

[M _r Hal _t ] ^s

where M is a metal and shark is fluorine, chlorine, bromine or iodine, r and t are integer positive numbers and indicate the stoichiometry of the complex and s is an integer positive number indicating the charge of the complex; the group of sulfides, hydrogen sulfides, polysulfides, hydrogen polysulfides and thiolates of the general formulas:

S ^{2 "} , HS ^" , [Sv] ^{2 ~} , [HSv] ^" , [R ^a Sr,

where v is a whole positive number from 2 to 10; and the group of complex metal ions such as Fe (CN) ₆ ³ , Fe (CN) ₆ ⁴ , MnO ₄ , Fe (CO) ₄ .

In the above anions, R ^a , R ^b , R ^c and R ^d are each independently

Hydrogen, C 1 -C 30 -alkyl and their aryl, heteroaryl, cycloalkyl, halogen, hydroxy, amino, carboxy, formyl, -O-, -CO-, -CO-O- or -CO- N <substituted components such as methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl (Isobutyl), 2-methyl-2-propyl (tert-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl 2-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl, 1-hexyl,

2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4- Methyl 2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3-dimethyl-1 - butyl, 2-ethyl-1-butyl,

2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, Henicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, triacontyl, phenylmethyl (benzyl), diphenylmethyl, triphenylmethyl, 2-phenylethyl, 3-phenylpropyl, cyclopentylmethyl, 2-cyclopentylethyl, 3

Cyclopentylpropyl, cyclohexylmethyl, 2-cyclohexylethyl, 3-cyclohexylpropyl, methoxy, ethoxy, formyl, acetyl or _Cq F2 (qa) + (1-b) H2a + b with q <30, 0 <a <q and b = 0 or 1 (for example CF ₃ , C ₂ F ₅ , CH ₂ CH ₂ -C ( _q -2) F ₂ ( _q -2) ₊ i, C ₆ Fi ₃ , C ₈ Fi ₇ , C10F21, C12F25); C 3 -C 12 -cycloalkyl and their aryl, heteroaryl, cycloalkyl, halogen, hydroxy, amino, carboxy, formyl, -O-, -CO- or -CO-O-substituted components, such as cyclopentyl , 2-methyl-1-cyclopentyl, 3-methyl-1-cyclopentyl, cyclohexyl, 2-methyl-1-cyclohexyl, 3-methyl-1-cyclohexyl, 4-methyl-1-cyclohexyl or C _q F2 ( _q-a ) - (1 -b) H2a-b with q <30, 0 <a <q and b = 0 or 1;

C 2 -C 30 -alkenyl and their aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, -O-, -CO- or -CO-O-substituted components, such as, for example 2 -Propenyl, 3-butenyl, cis-2-butenyl, trans-2-butenyl or _Cq F2 ( _q - _a ) - (1-b) H2a-b with q <30, 0 <a <q and b = 0 or 1;

C 3 -C 12 -cycloalkenyl and their aryl, heteroaryl, cycloalkyl, halogen, hydroxy, amino, carboxy, formyl, -O-, -CO- or -CO-O-substituted components, such as 3, for example Cyclopentenyl, 2-cyclohexenyl, 3-cyclohexenyl, 2,5-cyclohexadienyl or C _q F ₂ ( _q -a) -3 (1-b) H ₂ a-3b with q <30, 0 <a <q and b = 0 or 1;

Aryl or heteroaryl having 2 to 30 carbon atoms and their alkyl, aryl, heteroaryl, cycloalkyl, halogen, hydroxy, amino, carboxy, formyl, -O-, -CO- or -CO-O- substituted components such as phenyl, 2-methylphenyl (2-tolyl),

3-Methyl-phenyl (3-tolyl), 4-methyl-phenyl, 2-ethyl-phenyl, 3-ethyl-phenyl, 4-ethyl-phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl , 2,5-dimethyl-phenyl, 2,6-dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 4-phenyl-phenyl, 1-naphthyl, 2-naphthyl, 1 -pyrrolyl , 2-pyrrolyl, 3-pyrrolyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl or C6F ( _5-a ) Ha with 0 <a <5; or two radicals an unsaturated, saturated or aromatic, optionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles and optionally substituted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups interrupted ring.

In the above anions R ^a, R ^b, R ^c and R ^d preferably independently of one another each represent a hydrogen atom or a d- to Ci2-alkyl group.

As anions are mentioned z. B. chloride; Bromide; iodide; thiocyanate; Hexafluorophosphate; trifluoromethanesulfonate; methane; the carboxylates, in particular formate; Acetate; mandelate; Nitrate; Nitrite; trifluoroacetate; Sulfate; Bisulfate; Methyl sulfate; ethyl sulfate; 1-propyl sulfate; 1-butyl sulfate; 1 -hexyl sulfate; 1-octyl sulfate; Phosphate; dihydrogen phosphate; Hydrogen phosphate; Ci-C4-dialkyl; propionate; Tetrachloroaluminate; AI2CI7-; chlorozincate; Chloroferrat; imide, bis (trifluoromethylsulfonyl);

Bis (pentafluoroethylsulfonyl) imide; Bis (methylsulfonyl) imide; Bis (p-tolylsulfonyl) imide; Tris (trifluoromethylsulfonyl) methide; Bis (pentafluoroethylsulfonyl) methide; p-tolylsulfonate; tetracarbonylcobaltate; Dimethylenglykolmonomethylethersulfat; oleate; stearate; acrylate; methacrylate; maleate; hydrogen citrate; vinylphosphonate;

Bis (pentafluoroethyl) phosphinate; Borates such as bis [salicylato (2 -)] borate, bis [oxalato (2-)] borate, bis [1,2-benzenediolato (2 -) - 0,0 '] borate, tetracyano borate, tetrafluoroborate; Dicyanamide; Tris (pentafluoroethyl) trifluorophosphate; Tris (heptafluoropropyl) trifluorophosphate, cyclic aryl phosphates such as catechol phosphate (C6H ₄ O 2) P (0) 0 and chlorocobaltate.

Particularly preferred anions are those from the group of alkyl sulfates R ^a OS0 ₃ ,

wherein R ^{a is} a C to C 12 -alkyl group, preferably a C to C 6 -alkyl group, the alkylsulfonates R ^a S0 ₃ ,

wherein R ^{a is} a C 1 to C 12 alkyl group, preferably a C 1 to C 6 alkyl group, of the halgenides, in particular chloride and bromide and the pseudohalides, such as thiocyanate, dicyanamide, the carboxylates R ^a COO,

wherein R ^{a is} a C 2 -C 20 -alkyl group, preferably a C 1 -C 4 -alkyl group, in particular acetate, which is phosphates, in particular the dialkyl phosphates of the formula R ^a R ^b P0 ₄ , wherein R ^a and R ^b independently of one another represent a C 1 to C ₆ alkyl group; in particular, R ^a and R ^{b are} the same alkyl group, which may be mentioned dimethyl phosphate and diethyl phosphate and the phosphonates, especially the Monoalkylphosphonsäureester

of the formula R ^a R ^b P03, wherein R ^a and R ^b independently of one another represent a C 1 - to C 6 -alkyl group.

Very particularly preferred anions are chloride, bromide, hydrogensulfate, tetrachloroaluminate, thiocyanate, dicyanamide, methylsulfate, ethylsulfate, methanesulfonate, formate, acetate, dimethyl phosphate, diethyl phosphate, p-tolylsulfonate, tetrafluoroborate and hexafluorophosphate, methylmethylphosphonate and methylphosphonate.

Particularly preferred ionic liquids are imidazolium salts of the following formula I:

wherein

R ¹ and R ^{3 are} an organic radical having 1 to 20 C atoms,

R ² , R ⁴ , and R ⁵ stand for an H atom or an organic radical having 1 to 20 C atoms,

X stands for an anion and

n is 1, 2 or 3.

In formula I, R ¹ and R ^{3 are} preferably independently an organic radical having 1 to 10 C atoms. In particular, R ¹ and R ^{3 are} an aliphatic radical, in particular an aliphatic radical without further heteroatoms, for. For example, an alkyl group. Particularly preferably, R ¹ and R ³ independently of one another represent a C 1 to C 10 or a C 1 to C ₄ alkyl group.

In formula I, R ² , R ⁴ and R ^{5 are} preferably independently an H atom or an organic radical having 1 to 10 C atoms. Particularly preferably, R ² , R ⁴ and R ⁵ independently of one another represent an H atom or an alkyl group, in particular R ² , R ⁴ and R ⁵ independently of one another are an H atom or a C ¹ - to C ₄ -alkyl group. Most preferably, R ² , R ⁴ and R ^{5 are} each an H atom.

X is an anion, preferably one of the abovementioned anions, more preferably chloride, methanesulfonate, thiocyanate, methylsulfate, ethylsulfate and / or acetate. n is preferably 1. Particularly preferred ionic liquids consist exclusively of an organic cation having one of the above anions.

The molecular weight of the ionic liquids is preferably less than 2000 g / mol, more preferably less than 1500 g / mol, more preferably less than 1000 g / mol, and most preferably less than 750 g / mol. In a particular embodiment, the molecular weight is between 100 and 750 g / mol and between 100 and 500 g / mol.

According to the invention, the preferred ionic liquid is 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium methanesulfonate, 1-ethyl-3-methylimidazolium thiocyanate, 1-ethyl-3-methylimidazolium ethylsufate, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl 3-methylimidazolium chloride and / or 1 - ethyl-3-methylimidazoliumacetat used. According to the invention, the aqueous dispersion of polymenate per 100 parts by weight of polymer particles> 40 and <9900 parts by weight, advantageously> 45 and <3000 parts by weight and particularly advantageously> 50 and <300 parts by weight of ionic liquid are added. The manner in which the ionic liquid is added to the aqueous polymer dispersion is generally not critical and can be carried out batchwise in one or more portions or continuously with constant or varying flow rates. It is advantageous if the ionic liquid is added to the aqueous polymer dispersion under homogeneous mixing, for example by means of customary stirrers, static and / or dynamic mixing devices. It is essential that the ionic liquid is chosen so that the ionic liquid and the aqueous polymer dispersion do not influence negatively, for example by coagulation or precipitation of the polymer, which can be tested in doubt by those skilled in the art by means of a few routine experiments. From the mixture obtained, consisting of the ionic liquid and the aqueous polymer dispersion, water is added in a manner known to those skilled in the art, for example with continuous mixing, by means of a rotary evaporator, falling film evaporator, freeze-drying apparatus and / or a simple distillation bridge separated, advantageously at a temperature of the mixture in the range> -20 and <100 ° C and in particular in the range> 30 and <90 ° C. In particular, the removal of water advantageously takes place at a pressure <1 atm (absolute), with pressures in the range> 0.1 and <700 mbar (absolute) or> 10 and <500 mbar (absolute) being particularly preferred.

From the mixture obtained, consisting of the ionic liquid and the aqueous polymer dispersion, according to the invention at least> 50% by weight, advantageously> 70% by weight and in particular advantageously> 90% by weight, of the total amount of water contained in the mixture is removed. Often, the entire amount of water is separated. However, it may be advantageous in embodiments of the invention if not the entire amount of water, but only> 93 and <99 wt .-% of the total amount of water is separated. This may be the case, for example, if the pure ionic liquid is not liquid at room temperature. It is essential that small amounts of water greatly reduce the melting temperature of the ionic liquid, so that it is liquid in the desired temperature range. It may also be possible that residual amounts of water are difficult or only with a high expenditure of time and energy can be removed from the resulting dispersion, so that it may be more economical to leave them in the resulting dispersion. In addition to the aqueous and nonaqueous components of the aqueous polymer dispersions and the ionic liquids, the ionic polymer dispersions according to the invention may additionally contain further customary additives, such as, for example, fillers, for example calcium carbonate, talc, dolomite and precipitated silica, pigments, for example titanium dioxide, pigment dispersants, rheology additives , Preservatives, defoamers and / or biocides.

The ionic polymer dispersions obtainable according to the invention are mechanically stable and therefore storage-stable for many months. They can be used, for example, for the production of adhesives, sealants, plastic plasters, paper coating slips, fiber webs, coating compositions and impact modifiers, and for the consolidation of sand, textile finishing, leather finishing, or for the modification of mineral binders and plastics.

It is also important that when an aqueous polymer dispersion having dilatant properties is used, the ionic polymer dispersion obtainable therefrom generally also has dilatant properties. Advantageously, these ionic polymer dispersions with dilatants Properties as a medium for transmitting torques, for example in vibration dampers, speed limiter or hydraulic clutches and shock absorption, for example as a filling in shock absorbers, especially in the automotive industry, but also in sports shoes and hiking boots or as a cushion in ski shoes and as a filling in orthopedic pillows , In addition, the ionic polymer dispersions can be used as non-flammable hydraulic fluids, lubricants or cleaning agents.

The following non-limiting examples are intended to illustrate the invention.

EXAMPLES a) Preparation of an Aqueous Polymer Dispersion In a 2 liter polymerization reactor with paddle stirrer and

Heating / cooling device 300 g of deionized water were heated to 85 ° C under a nitrogen atmosphere. While stirring, 102 g of feed 1 and 14.0 g of feed 2 were added at this temperature. After 15 minutes, the remaining amounts of feed 1 and feed 2 were fed simultaneously via separate feeds continuously with constant flow rates within two hours to the polymerization mixture.

Feed 1 was an aqueous emulsion prepared from 96.3 g of deionized water, 5.6 g of sodium alkyl sulfonate, 37.5 g of ethoxylated isooctylphenol (with an average of 25 ethylene oxide (emulsifier K30 ^® from Bayer AG.) Emulsifier 825 ^® from BASF SE ), 150 g of methacrylamide, 15.0 g of maleic acid, 488 g of styrene and 225 g of tert-butyl acrylate.

Feed 2 was a solution of 135 g of deionized water and 5.3 g of a 7.5% strength by weight aqueous solution of potassium peroxodisulfate.

After the end of the feeds 1 and 2 was stirred for a further 60 minutes at 85 ° C and the reaction mixture then cooled to room temperature (20 to 25 ° C). The aqueous polymer dispersion obtained had a solids content of 55% by weight. The average particle diameter was determined to be 210 nm.

The solids content was 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 (about 2 hours). In each case two measurements were carried out. The specified value represents the average of these measurements. The average particle diameter of the polymer particles was determined by dynamic light scattering on a 0.005 to 0.01 weight percent aqueous dispersion at 23 ° C. by means of an Autosizers NC from Malvern Instruments, England. The mean diameter of the cumulant analysis (cumulant zaverage) of the measured autocorrelation function (ISO standard 13321) is given. b) Preparation of ionic polymer dispersions Example 1

To 100 g of the aqueous polymer dispersion prepared under section a) were added at room temperature with stirring with 45 g of 1-ethyl-3-methylimidazoliumthiocyanat and mixed homogeneously. The water was then removed under reduced pressure by means of a rotary evaporator (bath temperature 80 ° C.). The procedure was such that after reaching a negative pressure of 20 mbar (absolute), the ionic polymer dispersion was left for a further 2 hours under these conditions on a rotary evaporator. Example 2

Example 2 was prepared analogously to Example 1 with the difference that 1-ethyl-3-methylimidazolium methanesulfonate was used instead of 1-ethyl-3-methylimidazolium thiocyanate.

Example 3

Example 3 was prepared analogously to Example 1 with the difference that 1-ethyl-3-methylimidazolium chloride was used instead of 1-ethyl-3-methylimidazolium thiocyanate.

Example 4

The preparation of Example 4 was carried out analogously to Example 1 with the difference that 1 - ethyl-3-methylimidazoliumethylsulfat was used instead of 1-ethyl-3-methylimidazoliumthiocyanat. c) Measurement of the Shear Stress The shear stress of the ionic polymer dispersion obtained according to Example 1 was measured as a function of the shear rate and was determined using a shear-voltage controlled rotational viscometer MCR301 from Physica Messrs. engineering GmbH (double gap geometry DG 26.7, measuring body inside radius: 12.33 mm, outside radius: 13.33 mm, inside diameter measuring cup: 1 1, 913 mm, outside radius: 13.796 mm) at 25 ° C. The procedure was to start with a low shear rate and slowly increase the shear rate to a maximum. From Figure 1 it can be clearly seen that the shear stress is practically constant over a large shear area and then increases abruptly at a shear rate of approx. 18 s ^_1 . In the subsequent lowering of the shear rate, the shear stress also drops abruptly and settles again at further low level at the low constant level. This shear stress behavior is typical of dilatant behavior. In a comparative experiment, the analogous measurement was carried out with 1-ethyl-3-methylimidazoliumthiocyanat alone (ie without Polymerisatteilchen). It showed that the shear stress increases linearly with increasing shear rate and then decreases linearly with decreasing shear rate, which corresponds to the behavior of a Newtonian fluid. The corresponding shear stress values as a function of the increasing shear rate are also shown in Figure 1.

Claims

claims

1 . Process for the preparation of a dispersion of polymer particles in an ionic liquid (ionic polymer dispersion), characterized in that an aqueous dispersion of polymer particles (aqueous polymer dispersion) is mixed with an ionic liquid and water is separated from the resulting mixture.

2. The method according to claim 1, characterized in that the aqueous polymer dispersion contains> 30 and <90 wt .-% of water.

3. The method according to any one of claims 1 or 2, characterized in that per 100 parts by weight of polymer particles> 40 and <9900 parts by weight of ionic liquid are used.

4. The method according to any one of claims 1 to 3, characterized in that> 90 wt .-% of the total amount of water contained in the mixture is separated.

5. The method according to any one of claims 1 to 4, characterized in that the water separation takes place at a pressure <1 atm (absolute).

6. The method according to any one of claims 1 to 5, characterized in that the ionic liquid has a melting point> -45 and <60 ° C.

7. The method according to any one of claims 1 to 6, characterized in that as the ionic liquid 1-ethyl-3-methylimidazoliumchlorid, 1-ethyl-3-methylimidazoliummethansulfonat, 1-ethyl-3-methylimidazoliumthiocyanat, 1 - ethyl-3-methylimidazoliumethylsufat, 1-Butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium chloride and / or 1-ethyl-3-methylimidazolium acetate is used.

8. The method according to any one of claims 1 to 7, characterized in that an aqueous polymer dispersion having dilatant properties is used.

9. ionic polymer dispersion obtainable according to one of claims 1 to 7.

10. Use of an ionic polymer dispersion according to claim 9 for the preparation of adhesives, sealants, plastic plasters, paper coating slips, nonwoven fabrics, coating compositions and impact modifiers, and for the consolidation of sand, textile finishing, leather finishing, or for the modification of mineral binders and plastics.

1 1. Ionic polymer dispersion obtainable according to claim 8.

12. Use of an ionic polymer dispersion according to claim 1 1 as a medium for transmitting torque in vibration dampers, speed limiter or hydraulic couplings and as a filling in shock absorbers.