Process for producing polymers by means of photoinitiators in suspension

Abstract

The invention relates to the production of a polymer in suspension in the presence of at least one photoinitiator and at least one initiator containing peroxide groups.

Description

[0001] P001 01228- A

[0002] - 1 -

[0003] Method for the production of polymers using photoinitiators in

[0004] The invention relates to the production of a polymer in suspension in the presence of at least one photoinitiator and at least one initiator containing peroxide groups.

[0005] It is known that polymers can be produced from, for example, vinylaromatic compounds such as styrene, together with crosslinking agents such as divinylbenzene, by means of suspension polymerization.

[0006] In suspension polymerization, a monomer phase containing a monomer-soluble initiator is dispersed into droplets in a phase that is essentially immiscible with the monomer and then cured by increasing the temperature. The immiscible phase is typically an aqueous phase that may contain additives such as salts, dispersants, protective colloids, or other water-soluble organic compounds and is also referred to as the continuous phase. A mixture of selected, water-insoluble monomers and dissolved additives and initiators then forms the dispersed phase.

[0007] In addition to gel-like polymers, macroporous polymers can also be produced in suspension polymerization by using porogens such as high-boiling aliphatic hydrocarbons, alcohols, ethers, nitro compounds or esters.

[0008] It is also known that photoinitiators, under the influence of light of certain wavelengths, can initiate radical polymerizations in the presence of mono- and multi-ethylene unsaturated compounds.

[0009] WO-A-2022218327 describes the photoinitiator-induced emulsion polymerization of mono- and multiethylene unsaturated compounds in the presence of light of suitable wavelengths. The emulsion polymers can be produced in both gel and porous forms.

[0010] WO-A-2007144118 describes the precipitation polymerization of mono- and multi-ethylene unsaturated compounds, preferably divinylbenzene, in an organic P001 01228- A

[0011] - 2 - solvents via photopolymerization. The described pearl polymers have a diameter of 0.5-50 pm.

[0012] Esen et al. (Esen C., Antonietti M., Kumru B., J App! Polym Sei. 2021; 138:e50879) describe a process for the light-induced suspension polymerization of styrene and divinylbenzene in the presence of a diphenylphosphine oxide photoinitiator to crosslinked poly(styrene-codivinylbenzene) bead polymers.

[0013] EP-A-0964002 discloses a process for producing gel-like pearl polymers with a reduced proportion of soluble polymers. To reduce the soluble content, a peroxy ester is used as an initiator in this process.

[0014] DE-A-10121163 describes the production of heterodisperse polymers using peroxy compounds as initiators, which are functionalized using the phthalimide process and converted to chelate resins.

[0015] US patent A-20090176897 discloses a jetting process for the production of monodisperse pearl polymers. In this process, peroxide compounds and azo compounds are used as initiators.

[0016] DE-A-19852667 describes a seed-feed manufacturing process for gel-like, monodisperse pearl polymers in which peroxy esters are used as initiators.

[0017] The state of the art shows that the described processes for producing spherical polymers in emulsion or suspension still do not exhibit completely satisfactory yields and conversions per unit of time.

[0018] In view of the known state of the art, there remains a need for a process that can produce polymers in suspension in high yields and high conversions per time.

[0019] It has now been surprisingly found that polymers from mono- and multi-ethylene unsaturated compounds can be prepared in suspension in high yields and conversions per time in the presence of at least one initiator of formula (I) and in the presence of at least one peroxide-containing initiator of formula (II). P001 01228- A

[0020] The invention therefore relates to a process for the production of a polymer in which at least one monoethylene unsaturated compound and at least one multiethylene unsaturated compound are reacted in the presence of at least one initiator of formula (I) where R 1 = H or a Ci- to Cn-alkyl, cyclopentyl, cyclohexyl or an unsubstituted C6-C 24 -Aryl is or a C6-C 24 -Aryl substituted by one or more halogens, Ci- to C13-alkyl groups, C2- to Cio-alkenyl groups or saturated or unsaturated Ci- to C13-alkoxy groups, and wherein R2 , R 6 , R 7 and R 11 can be the same or different and are independently Ci- to C-alkyl or Ci- to C-alkoxy; R 3 , R 4 , R 5 , R 8 , R 9 and R 10 may be the same or different and are independently hydrogen, Ci- to C-alkyl, C2- to Cio-alkenyl or saturated or unsaturated Ci- to C13-alkoxy or halogen and in the presence of at least one initiator of formula (II) where R 12 and R 13 can be the same or different and independent of each other C1- to Cis-alkyl, Ci- to Ci8-alkylcarbonyl, Ci- to Ci8-alkyldicarbonyl, Ci- to Ci8-alkoxycarbonyl, C6-C 24 -aryl, cyclopentyl or cyclohexyl, which may be independently substituted by Ci- to C-alkyl or C2- to Cio-alkenyl or by one or more halogens or R 12 and R 13can be achieved by combining formula (III) P001 01228- A

[0021] - 4 - be substituted, where R 14 = Ci- to Ci8-alkyl, Ci- to Ci8-alkylcarbonyl, Ci- to Ci8-alkoxycarbonyl, C6-C 24 -Aryl, cyclopentyl or cyclohexyl, which may be independently substituted by Ci- to C-alkyl, C2- to Cio-alkenyl or by one or more halogens, are reacted in the presence of water and in the presence of at least one dispersant.

[0022] R 1 is preferably hydrogen or a C3-Ci3-alkyl or a C6-C 24 -Aryl, which may be substituted with C1-C4 alkyl groups. R is particularly preferred. 1 n-Hexyl, n-Neptyl, n-Octyl, n-Undecanyl, n-Dodecanyl, n-Pentyl, 2,4-Dimethylpentyl, 2,4,4-Trimethylpentyl, Phenyl, or Benzyl. R is particularly preferred. 1 phenyl or 2,4,4-trimethylpentyl.

[0023] R 2 , R 6 , R 7 and R11 can be the same or different and are independently of each other preferably Ci- to C4-alkyl and Ci- to C4-alkoxy, particularly preferably methyl, ethyl, n-propyl, isopropyl, methoxy, ethoxy or propoxy, and even more preferably methyl and methoxy. R 3 , R 4 , R 5 , R 8 , R 9 and R 10 can be the same or different and are independently of each other preferably Ci- to C6-alkyl, Ci- to C6-alkoxy and water substance and particularly preferably methyl, ethyl, methoxy, ethoxy and hydrogen.

[0024] In another embodiment of the invention, R 1 Phenyl or 2,4,4-trimethylpentyl and independently of that R 7 , R 9 and R 11 Methyl or methoxy and regardless of that R 2 , R 4 , R 6 Methyl or methoxy and regardless of that R 3 , R 5 , R 8 and R 10 Methyl or hydrogen.

[0025] In another embodiment of the invention, R 1 Phenyl and R 2 , R 4 , R 6 , R 7 , R 9 and R 11 Methyl and R 3 , R 5 , R 8 and R 10 Hydrogen.

[0026] In another embodiment of the invention, R 1 2,4,4-Trimethylpentyl and R 2 , R 4 , R 6 , R 7 , R 9 and R 11 Methyl and R 3 , R 5 , R 8 and R 10 Hydrogen.

[0027] R 12 and R 13 are independently of each other preferably Ci-C6-alkyl, cyclohexyl, cyclopentyl, Ci-Ci8-alkylcarbonyl, Ci- to Ci8-alkyldicarbonyl, Ci-Ci8-alkoxycarbonyl or P001 01228- A

[0028] - 5 -

[0029] C6-Ci8-aryl, which may be substituted with Ci-C4 alkyl groups or with one or more halogens. R is particularly preferred. 12 and R13 Cyclohexyl, phenyl, benzyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, methyl, ethyl, n-propyl, n-butyl, i-butyl, or t-butyl are independent of one another. R is particularly preferred. 12 and R 13 independently of one another phenyl, cyclohexyl, t-butyl, C6-Ci2-alkylcarbonyl, C6-Ci2-alkyldicarbonyl, Ce-Ci2-alkoxycarbonyl or cyclohexoxycarbonyl. In a further preferred embodiment of the invention, R 12 and R 13 even.

[0030] R 14 is preferably C6-C 24 -Aryl, Ci- to C6-alkyl or Ci- to C8-alkylcarbonyl. R 14 Phenyl, cyclohexyl, t-butyl, or C6-Ci2-alkylcarbonyl are particularly preferred. In a further preferred embodiment of the invention, R 12 and R 14 even.

[0031] Within the scope of the invention, Ci to Cis-alkyl or Ci to Ci8-alkoxy represents a straight-chain or branched alkyl or alkoxy residue with 1 to 18 (Ci-Cis), preferably 1 to 13 (C1-C13), and particularly preferably 3 to 13 (C3-C13) carbon atoms. By way of example, alkyl represents methyl, ethyl, n-propyl, isopropyl, n-, i-, s-, or t-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neo-pentyl, 1-ethylpropyl, n-hexyl, n-heptyl, n-octyl, n-decyl, and n-dodecyl. Preferably, alkyl represents methyl, ethyl, n-propyl, isopropyl, n-, i-, s- or t-butyl, n-hexyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neo-pentyl, 1-ethylpropyl, n-undecanyl, n-dodecanyl, 2,5-dimethylhexanediyl, 2-ethylhexanyl and 1,1-dimethyl-1-propyl. Particularly preferably, alkyl represents methyl, n-propyl, isopropyl, n-, i-, s- or t-butyl, n-pentyl, n-hexyl, n-undecanyl, n-dodecanyl, 2,5-dimethylhexanediyl and 1,1-dimethyl-1-propyl.By way of example and preferably, alkoxy stands for methoxy, ethoxy, n-propoxy, 1-propenoxy, isopropoxy, n-, i-, s- or t-butoxy, n-pentoxy, 1-penten-5-oxy, n-hexoxy.

[0032] Within the scope of the invention, C2-Cio.Alkenyl represents a straight-chain, cyclic, or branched alkenyl group with 2 to 10 (C2-C10), preferably with 2 to 6 (C2-C6) carbon atoms. By way of example, and preferably, alkenyl represents vinyl, allyl, isopropenyl, and n-but-2-en-1-yl.

[0033] Ce-C 24 -Aryl, within the scope of the invention, represents an aromatic residue with 6 to 24 framework carbon atoms, in which none, one, two or three framework carbon atoms per cycle, but at least one framework carbon atom in the entire molecule, are sub- P001 01228- A

[0034] - 6 - may be substituted, but preferably for a carbocyclic aromatic residue with 6 to 24 framework carbon atoms.

[0035] Preferred examples of Cs-C24 aryl are phenyl, naphthyl, phenanthrenyl, anthracenyl or fluorenyl; examples of heteroaromatic C6-C24 aryl in which one, two or three framework carbon atoms per cycle, but at least one framework carbon atom in the entire molecule, may be substituted by heteroatoms selected from the group nitrogen, sulfur or oxygen, are pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, thienyl, furyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl or isoxazolyl, indolizinyl, indolyl, benzo[b]thienyl, benzo[b]furyl, indazolyl, quinolyl, isoquinolyl, naphthyridinyl, quinazolinyl, benzofuranyl or dibenzofuranyl. Particularly preferably, C6-C24-aryl represents a phenyl ring, which may optionally be substituted by two or three methyl, methoxy, ethyl, ethoxy or propyl groups or propoxy.Even more preferred is C6-C24-aryl, a phenyl group or a phenyl group which may be substituted by one, two or three methyl groups or methoxy groups.

[0036] Within the scope of the invention, Ci- to Cis-alkylcarbonyl represents a straight-chain or branched Ci- to Cis-alkyl residue according to the above definition, which is substituted by a carbon yl group.

[0037] Ci- to cis-alkylcarbonyl, by way of example and preferably, represents methanalyl, ethanalyl, propanalyl, butanalyl, pentanalyl, hexanalyl, heptanalyl, octanalyl, nonanalyl, decanalyl, undecanalyl and dodecanalyl.

[0038] Within the scope of the invention, Ci- to C-alkyldicarbonyl represents a straight-chain or branched Ci- to Cis-alkyl residue according to the above definition, which is substituted by two carbon yl groups.

[0039] Ci- to cis-alkyldicarbonyl can be exemplified and preferably represent methanediadiyl, ethanediadiyl, propanediadiyl, butanediadiyl, pentanediadiyl, hexanediadiyl, heptanediadiyl, octanediadiyl, nonanediadiyl, decanediadiyl, undecanediadiyl, dodecanediadiyl and 1,9-nonanediadiyl.

[0040] Within the scope of the invention, Ci- to Cis-alkoxycarbonyl represents a straight-chain, cyclic, or branched Ci- to Cis-alkoxy residue as defined above, substituted by a carbonyl group. Cyclic Ci- to Cis-alkoxycarbonyl P001 01228- A

[0041] - 7 - is understood, for example and preferably, as cyclopentoxycarbonyl, cyclohexoxycarbonyl, cycloheptoxycarbonyl and cyclooctoxycarbonyl.

[0042] By way of example and preferably Ci- to Cis-alkoxycarbonyl stands for methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, 1-propenoxycarbonyl, isopropoxycarbonyl, n-, i-, s- or t-butoxycarbonyl, n-pentoxycarbonyl, 1-penten-5-oxycarbonyl and n-hexoxy carbonyl and cyclohexoxycarbonyl.

[0043] Halogen preferably represents fluorine, chlorine, bromine, or iodine. Chlorine is particularly preferred as a halogen.

[0044] Initiators of Formula (I)

[0045] Initiators of formula (I) are preferably bis-acylphosphine oxides, which are commercially available e.g. under the brand name Icagure®, such as Irgacure 819 (bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide) from BASF AG, Frankfurt am Main).

[0046] Preferably, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide or bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and mixtures of these compounds are used as initiators of formula (I).

[0047] Initiators of formula (I) are also referred to as photoinitiators, since they are preferably activated by irradiation with UV light. In a further embodiment of the invention, other photoinitiators, such as Norrish type (II) initiators or α-hydroxyketone derivatives, can also be used in the process according to the invention. A Norrish type II initiator is a photoinitiator that is activated by actinic radiation and forms free radicals by hydrogen abstraction from a second compound, which becomes the actual initiating free radical. This second compound is referred to as a polymerization synergist or co-initiator. Other photoinitiators that can be used include, for example, and preferably, 2-hydroxy-2-methyl-1-phenyl-propan-1-one or 1-hydroxycyclohexyl phenyl ketone, or mixtures of these initiators.

[0048] Initiators of formula (I) and 2-hydroxy-2-methyl-1-phenyl-propan-1-one or 1-hydroxy-cyclohexyl-phenyl-ketone are available as a mixture, among others, as Irgacure 1700 (a 25% mixture of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide with 2-hydroxy-2-methyl-1-phenyl-propan-1-one), Irgacure 1800 (a 25% mixture of bis(2,6- P001 01228- A

[0049] - 8-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide with 1-hydroxycyclohexyl phenyl ketone), Irgacure 1850 (a 50% mixture of bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide with 1-hydroxycyclohexyl phenyl ketone), Irgacure 1870 (a 70% mixture of bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide with 1-hydroxycyclohexyl phenyl ketone), Irgacure 149 (a 5% mixture of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide with 2-hydroxy-2-methyl-1-phenylpropan-1-one), Irgacure 2022 (a 20% mixture of bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide with 2-hydroxy-2-methyl-1-phenylketone), Irgacure 2100 (a mixture of bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide with 2,4,6-trimethyl-benzoyl-phenylphosphinic acid ethyl ester), Irgacure 819 (bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide) from BASF AG, Frankfurt am Main, commercially available.

[0050] Initiators of Formula (II)

[0051] Initiators of formula (II) are selected peroxy esters. Preferably, the initiators of formula (II) are dibenzoyl peroxide, dilauroyl peroxide, bis(p-chlorobenzoyl) peroxide, dicyclohexyl peroxydicarbonate, tert-butyl peroctoate, tert-butyl peroxy-2-ethylhexanoate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-amyl peroxy-2-ethylhexane, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyoctoate, tert-butyl peroxyneodecanoate, tert-butyl peroxy-2-ethylhexanoate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-amyl peroxy-2-ethylhexane, tert-amyl peroxyneodecanoate. tert-Amylperoxypivalate, tert-Amylperoxyoctoate, tert-Amylperoxy-2-ethylhexanoate, 2,5-Bis(2-ethylhexanolyperoxy)-2,5-dimethylhexane, 2,5-Dipivaloyl-2,5-dimethylhexane (CAS number 78-63-7), 2,5-Bis(2-neodecanoylperoxy)-2,5-dimethylhexane, Di-tert-butylperoxyazelate or Di-tert-amylperoxyazelate or mixtures of these compounds are used.

[0052] Particularly preferred is the use of dibenzoyl peroxide and tert-butyl peroxy-2-ethyl hexanoate or mixtures of these compounds as the initiator of formula (II). Most preferred is the use of tert-butyl peroxy-2-ethyl hexanoate as the initiator of formula (II).

[0053] In the process according to the invention, at least one monoethylene unsaturated compound and at least one multiethylene unsaturated compound are used. P001 01228- A

[0054] - 9 -

[0055] However, it is also possible to use mixtures of two or more monoethylene unsaturated compounds and mixtures of two or more multiethylene unsaturated compounds.

[0056] Monoethylene unsaturated compounds (monomers) within the meaning of the invention are compounds that have one radically polymerizable C=C double bond per molecule. Preferred compounds of this type include aromatic, monoethylene unsaturated compounds, such as vinyl and vinylidene derivatives of benzene and naphthalene, preferably vinylnaphthalene, vinyltoluene, ethylstyrene, oc-methylstyrene, chlorostyrenes, chloromethylstyrene, and preferably styrene, as well as non-aromatic vinyl and vinylidene compounds, preferably acrylic acid, methacrylic acid, acrylic acid Ci-Cs alkyl esters, methacrylic acid Ci-C8 alkyl esters, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, and vinyl acetate. Preferably, the non-aromatic monoethylene unsaturated compounds are present in subordinate amounts, preferably in amounts of 0.1 to 50 wt.%, particularly preferably 0.5 to 20 wt.%.-%, based on aromatic monoethylene unsaturated compounds, is used. Preferably, only aromatic, monoethylene unsaturated compounds are used.

[0057] The monoethylene unsaturated compounds are preferably used in amounts > 50 wt. %, based on the mixture of monoethylene and multiethylene unsaturated compounds, particularly preferably from 80 wt. %, to 99 wt. %, very preferably 88 wt. %, to 98 wt. %, and even more preferably 90 wt. %, to 96 wt. %, based on the mixture of monoethylene and multiethylene unsaturated compounds.

[0058] As aromatic, monoethylene unsaturated compounds within the meaning of the present invention, styrene, vinyltoluene, ethylstyrene, α-methylstyrene, chlorostyrene, or chloromethylstyrene are preferably used in the process according to the invention.

[0059] Styrene or mixtures of styrene with the aforementioned monomers, preferably with ethylstyrene, are particularly preferred.

[0060] A polystyrene-divinylbenzene copolymer is particularly preferred as the polymer produced in the process according to the invention. P001 01228- A

[0061] - 10 -

[0062] Multiethylene unsaturated compounds are compounds containing two or more, preferably two to four, radically polymerizable C=C double bonds per molecule. Aromatic multiethylene unsaturated compounds preferably include divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene, triallyl cyanurate, triallyl isocyanurate, and trivinylnaphthalene. Non-aromatic multiethylene unsaturated compounds preferably include diethylene glycol divinyl ether, octadiene-1,7, hexadiene-1,5, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate, and methylene N,N'-bisacrylamide. Divinylbenzene is particularly preferred as a multiethylene unsaturated compound. For most applications, commercially available divinylbenzene grades containing ethylvinylbenzene isomers are sufficient.

[0063] Preferred aromatic, multiethylene unsaturated compounds according to the present invention are divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene, triallyl cyanurate, triallyl isocyanurate, or trivinyl naphthalene. Divinylbenzene is particularly preferred.

[0064] The multiethylene unsaturated compounds are preferably used in amounts of 1-20 wt.%, particularly preferably 2-12 wt.%, and especially preferably 4-10 wt.%, based on the amount of monoethylene unsaturated compounds. The type of multiethylene unsaturated compounds (crosslinkers) is selected with regard to the subsequent use of the polymer.

[0065] The initiators of formula (I) are preferably used in amounts of 0.01 to 10 wt.%, particularly preferably 0.01 to 5 wt.%, based on the monomer mixture.

[0066] The initiators of formula (II) are preferably used in amounts of 0.01 to 10 wt.%, particularly preferably 0.01 to 5 wt.%, based on the monomer mixture.

[0067] Preferably, the initiators of formula (I) are used in a ratio of 100:1 to 1:100, particularly preferably in a ratio of 15:1 to 1:1, based on their weight quantities, to the initiators of formula (II). P001 01228- A

[0068] - 11 -

[0069] Macroporous or gel-like polymers can be produced. Gel-like polymers are preferred; "gel-like" in the context of the invention preferably means that the polymers have a BET surface area of ​​< 2 m². 2 exhibit / g.

[0070] The optional production of macroporous polymers is achieved by adding at least one porogen to the monoethylene unsaturated and multiethylene unsaturated compounds during polymerization to create a macroporous structure in the polymer. Organic substances that dissolve poorly in the monoethylene unsaturated compounds but swell poorly in the polymer (precipitating agents for polymers) are particularly suitable as porogens; examples include aliphatic hydrocarbons. Particularly preferred porogens are hexane, dextane, isooctane, isododecane, pentamethylheptane, methyl ethyl ketone, butanol, and octanol, and their isomers. Isododecane is especially preferred as a porogen.

[0071] Polymers with a BET surface area of ​​10 to 100 m² are preferably considered macroporous polymers. 2 / G.

[0072] Porogens are preferably used in an amount of 25 wt.% to 45 wt.% based on the amount of organic phase.

[0073] The scope of the invention includes all the above and the following general or preferred residual definitions, parameters and explanations among themselves, i.e. also between the respective areas and preferred areas in any combination.

[0074] Suitable dispersing agents include natural or synthetic water-soluble polymers, preferably gelatin, starch, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, or copolymers of (meth)acrylic acid and (meth)acrylic acid esters and hydroxyalkyl methylcelluloses, such as preferably hydroxypropyl methylcellulose and hydroxyethyl methylcellulose or mixtures thereof. Hydroxypropyl methylcellulose is particularly preferred. The amount of dispersing agent used is preferably 0.05 to 10 wt.% based on the aqueous phase, and particularly preferably 0.1 to 5 wt.%. P001 01228- A

[0075] - 12 -

[0076] Manufacturing

[0077] The polymers are produced according to general methods known to those skilled in the art using suspension polymerization.

[0078] The organic phase preferably comprises substantially the monomers, at least one initiator of formula (I) and formula (II), and optionally at least one porogen. The aqueous phase preferably comprises substantially water, at least one buffer substance, and at least one dispersant. "Substantially" within the meaning of this application means at least 95 wt.%.

[0079] Due to the fact that the dispersing agents alter the solubility of the compounds and that the monomer droplets are present and react in boundary phase regions, a more precise quantitative delimitation of the phases cannot be made.

[0080] The ratio of the organic phase to the aqueous phase is preferably 3:1 to 1:3, more preferably 2:1 to 1:2. In a particularly preferred embodiment of the invention, the weight ratio of the organic phase to the aqueous phase is 1.3:1 to 1:1.3.

[0081] Low stirring speeds are preferably used, which are sufficient to keep the suspended monomer droplets in suspension and to facilitate the removal of the heat of polymerization. Various types of stirrers can be used for this purpose. Axial-acting grid stirrers are particularly suitable.

[0082] In a preferred embodiment, the polymerization can be carried out in the presence of a buffer system. Buffer systems that adjust the pH of the aqueous phase prior to polymerization to a value between 6 and 14, preferably between 8 and 12, are preferred. Under these conditions, dispersants with carboxylic acid groups are present wholly or partially as salts. This favorably influences the effect of the dispersants. Particularly suitable buffer systems contain phosphate or borate salts. For the purposes of this invention, the terms phosphate and borate also include the condensation products of the ortho forms of the corresponding acids and salts. The concentration of phosphate or borate in the aqueous phase is preferably 0.5–500 mmol / l, and particularly preferably 2.5–100 mmol / l. P001 01228- A

[0083] - 13 -

[0084] The volume ratio of monomer droplets to aqueous phase is preferably 1 : 0.75 to 1 : 20, particularly preferably 1 : 1 to 1 : 6. This applies regardless of whether heterodisperse or monodisperse polymers are being produced.

[0085] For the method according to the invention, a light source is preferably used that emits light within a wavelength range of at least 100 to 450 nm, particularly preferably from 300 nm to 380 nm. The light source used should have a sufficiently high luminous intensity, preferably at least 8–12 W. Higher power levels of 100–1000 W are particularly preferred. A UV lamp is preferably used as the light source.

[0086] The irradiation time of the monomer mixture depends on the type of monomer mixture and the initiator concentration. If a monomer mixture consisting of both mono- and multi-ethylene unsaturated compounds is selected, the irradiation time is preferably 1 to 10 hours, and particularly preferably 2 to 4 hours. If a porogen is added to the monomer mixture consisting of both mono- and multi-ethylene unsaturated compounds, the irradiation time is preferably 1.5 to 15 hours. The polymerization temperature depends on the decomposition temperature of the initiator of formula (II) used. It is preferably from 50°C to 180°C, particularly preferably from 55°C to 130°C, and even more preferably from 90°C to 100°C. The polymerization after heating preferably lasts 1.5 to 6 hours.It has proven effective to use a temperature program in which the polymerization is started at a low temperature, preferably 60°C, and the reaction temperature is increased as the polymerization progresses.

[0087] Preferably, in the process according to the invention, the reaction mixture is irradiated with light of 100 to 450 nm in a first step and then the temperature is increased in a second step.

[0088] The total polymerization time, including irradiation time and polymerization time with heating, is preferably 3 to 9 hours.

[0089] In the production of the polymers in the process according to the invention, the aqueous phase can, in a further preferred embodiment, contain a dissolved polymerization inhibitor. In this case, both inorganic and organic substances are suitable as inhibitors. Preferred inorganic inhibitors are transition metal salts, such as copper(II) chloride, copper(II) sulfate, iron(III) chloride, P001 01228- A

[0090] - 14 -

[0091] Iron(II) sulfate, manganese(II) chloride, and inorganic nitrogen compounds, particularly preferably hydroxylamine, hydrazine, sodium nitrite, and potassium nitrite, salts of phosphorous acid such as sodium hydrogen phosphite, and sulfur-containing compounds such as sodium dithionite, sodium thiosulfate, sodium sulfite, sodium bisulfite, sodium thiocyanate, and ammonium thiocyanate. Examples of organic inhibitors are phenolic compounds such as hydroquinone, hydroquinone monomethyl ether, resorcinol, catechol, tert-butylcatechol, pyrogallol, and condensation products of phenols with aldehydes. Other preferred organic inhibitors are organic nitrogen-containing compounds.Particularly preferred are hydroxylamine derivatives such as N,N-diethylhydroxylamine, N-isopropylhydroxylamine, as well as sulfonated or carboxylated N-alkylhydroxylamine or N,N-dialkylhydroxylamine derivatives, hydrazine derivatives such as preferably N,N-hydrazinodioacetic acid, nitroso compounds such as preferably N-nitrosophenylhydroxylamine, N-nitrosophenylhydroxylamine ammonium salt or N-nitrosophenylhydroxylamine aluminum salt.

[0092] The concentration of the inhibitor is preferably 5 - 1000 ppm (based on the aqueous phase), particularly preferably 10 - 500 ppm, most preferably 10 - 250 ppm.

[0093] Preferably, no polymerization inhibitor is used in the process according to the invention.

[0094] After polymerization, the polymer is isolated using standard methods, such as filtration or decantation, and washed if necessary.

[0095] In a preferred embodiment of the invention, water and the buffer substances, such as phosphates and / or borates, and the dispersant are initially provided. Then, the compounds that will be substantially in the organic phase, comprising the monoethylene unsaturated compounds, the polyethylene unsaturated compounds, and the compounds of formula (I) and the compounds of formula (II), are added. However, the addition can also be carried out by adding the compounds that will be substantially in the aqueous phase to those that will be substantially in the organic phase. Furthermore, a mixture comprising the monoethylene unsaturated compounds, the polyethylene unsaturated compounds, and the compounds of formula (I) and the compounds of formula (II) is preferred. P001 01228- A

[0096] - 15 - and add it to the aqueous mixture. The mixture is preferably irradiated with light while stirring. Preferably, this light has a wavelength between 100 nm and 450 nm. Preferably, the irradiation is carried out for a period of 2 to 4 hours. The irradiation starts the polymerization with the initiator (I). Afterwards, the mixture is heated for a period of preferably 30 to 90 minutes. Preferably, the mixture is then heated for a period of 1.5 to 6 hours at a temperature of preferably 90 °C to 100 °C. The polymer is then isolated by a method known to those skilled in the art, preferably by filtration or decantation and washing with water.

[0097] The polymers preferably have a mean diameter of 300 pm to 1100 pm. Particularly preferably, the polymers have a mean diameter of 400 pm to 800 pm.

[0098] A preferred embodiment of the invention is a process for producing a polymer in which at least one monoethylene unsaturated compound from the group consisting of vinylnaphthalene, vinyltoluene, ethylstyrene, oc-methylstyrene, chlorostyrenes, chloromethylstyrene, styrene, acrylic acid, methacrylic acid, acrylic acid Ci-Cs alkyl esters, methacrylic acid Ci-C8 alkyl esters, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride and vinyl acetate is used in an amount > 50 wt.% based on the monomer mixture, and at least one multiethylene unsaturated compound from the group consisting of divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene, triallyl cyanurate, triallyl isocyanurate, trivinylnaphthalene, diethylene glycol divinyl ether, octadiene-1,7, hexadiene-1,5, ethylene glycol dimethacrylate, Triethylene glycol dimethacrylate, trimethylol propane trimethacrylate, allyl methacrylate and methylene N,N'-bisacrylamide in an amount of 1 to 20 wt.% based on the monomer mixture in the presence of at least one initiator of formula (I) P001 01228- A.

[0099] - 16 - where R 1 = H or a Ci- to Cn-alkyl, cyclopentyl, cyclohexyl or an unsubstituted C6-C 24 -Aryl is or a C6-C 24 -Aryl substituted by one or more halogens, Ci- to C13-alkyl groups, C2- to Cio-alkenyl groups or saturated or unsaturated Ci- to C13-alkoxy groups, and wherein R 2 , R 6 , R 7 and R 11 can be the same or different and are independently Ci- to C-alkyl or Ci- to C-alkoxy; R 3 , R 4 , R 5 , R 8 , R 9 and R 10may be the same or different and independently of one another hydrogen, Ci- to C-alkyl, C2- to Cio-alkenyl or saturated or unsaturated Ci- to C13-alkoxy or halogen are present in amounts of 0.01 to 10 wt% based on the monomer mixture and in the presence of at least one initiator of formula (II) where R 12 and R 13 can be the same or different and independently of each other C1- to Cis-alkyl, Ci- to Ci8-alkylcarbonyl, Ci- to Ci8-alkyldicarbonyl, Ci- to Ci8-alkoxycarbonyl, C8-C 24 -aryl, cyclopentyl or cyclohexyl, which may be independently substituted by Ci- to C-alkyl or C2- to Cio-alkenyl or by one or more halogens or R 12 and R 13 can be achieved by combining formula (III) be substituted, where R 14 = Ci- to Cn-alkyl, Ci- to Cn-alkylcarbonyl, Ci- to Ci8-alkoxycarbonyl, C6-C 24-Aryl, cyclopentyl or cyclohexyl, which independently of each other P001 01228- A

[0100] - 17 - may be substituted by Ci- to C-alkyl, C2- to Cio-alkenyl or by one or more halogens, in amounts of 0.01 to 10 wt.%, based on the monomer mixture, in the presence of at least one dispersing agent in amounts of 0.05 to 10 wt.% based on the aqueous phase in the presence of water, wherein the ratio of the organic phase to the aqueous phase is 3 : 1 to 1 : 3.

[0101] A particularly preferred embodiment of the invention is a process for producing a polymer in which at least one monoethylene unsaturated compound from the group consisting of styrene, vinyltoluene, ethylstyrene, α-methylstyrene, chlorostyrene, or chloromethylstyrene is added in an amount > 50 wt.% based on the monomer mixture, and at least one multiethylene unsaturated compound from the group consisting of divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene, triallyl cyanurate, triallyl isocyanurate, or trivinylnaphthalene is added in an amount of 1 to 20 wt.% based on the monomer mixture, in the presence of at least one initiator of formula (I) where R 1 = H or a Ci- to Ci8-alkyl, cyclopentyl, cyclohexyl or an unsubstituted C6-C 24 -Aryl is or a C6-C 24 -Aryl containing one or more halogens, Ci- to C- - P001 01228- A

[0102] - 18 -

[0103] Alkyl groups, C2- to Cio-alkenyl groups or saturated or unsaturated Ci- to C-alkoxy groups are substituted, and wherein R 2 , R 6 , R 7 and R 11 can be the same or different and are independently Ci- to Cn-alkyl or Ci- to Cn-alkoxy; R 3 , R 4 , R 5 , R 8 , R 9 and R 10 may be the same or different and independently contain hydrogen, Ci- to C-alkyl, C2- to Oo-alkenyl or saturated or unsaturated Ci- to C13-alkoxy or halogen in amounts of 0.01 to 10 wt% based on the monomer mixture and in the presence of at least one initiator of formula (II) where R 12 and R 13may be the same or different and are independently C1- to Cis-alkyl, Ci- to Ci8-alkylcarbonyl, Ci- to Ci8-alkyldicarbonyl, Ci- to Ci8-alkoxycarbonyl, C8-C24-aryl, cyclopentyl or cyclohexyl, which may be independently substituted by Ci- to C-alkyl or C2- to Cn-alkenyl or by one or more halogens or R 12 and R 13 can be achieved by combining formula (III) be substituted, where R 14 = Ci- to C-alkyl, Ci- to Cn-alkylcarbonyl, Ci- to Ci8-alkoxycarbonyl, C8-C24-aryl, cyclopentyl or cyclohexyl, which may be independently substituted by Ci- to C-alkyl, C2- to Cn-alkenyl or by one or more halogens, in amounts of 0.01 to 10 wt.%, based on the monomer mixture, in the presence of at least one dispersant in amounts of 0.05 to 10 wt.%, based on the aqueous phase. P001 01228- A

[0104] - 19 - in the presence of water, wherein the ratio of the organic phase to the aqueous phase is 3 : 1 to 1 : 3.

[0105] The polymers produced according to the inventive process can be manufactured in heterodisperse or monodisperse form. Preferably, monodisperse polymers are produced using the inventive process.

[0106] In the present application, substances are referred to as monodisperse if at least 90% by volume or mass of the particles have a diameter that lies within the interval with a width of + / - 10% of the most frequent diameter around the most frequent diameter.

[0107] For example, for a fabric with a most common diameter of 0.5 mm, at least 90% by volume or mass lies within a size interval between 0.45 mm and 0.55 mm; for a fabric with a most common diameter of 0.7 mm, at least 90% by volume or mass lies within a size interval between 0.77 mm and 0.63 mm.

[0108] The production of monodisperse polymers using the jetting principle is known from the prior art and is described, for example, in US-A 4 444 961 and EP-A 0 046 535.

[0109] The monodisperse polymers are preferably produced using the jetting principle.

[0110] Preferably, the monomer droplets for the production of monodisperse polymers are encapsulated using coacervas and / or complex coacervas. Polyamides, and especially gelatin, are preferably used as coacervas in accordance with the invention. Complex coacervas in accordance with the invention are primarily combinations of polyamides with synthetic polyelectrolytes. Suitable synthetic polyelectrolytes are copolymers with incorporated units of, for example, maleic acid, acrylic acid, methacrylic acid, acrylamide, and methacrylamide. Acrylic acid and acrylamide are particularly preferred. Gelatin-containing capsules can be cured with conventional curing agents, such as formaldehyde or glutaraldehyde. The encapsulation of monomer droplets with gelatin, gelatin-containing coacervas, and gelatin-containing complex coacervas is described in EP-A P001 01228-A.

[0111] - 20 -

[0112] The process is described in detail in 0 046 535. The methods for encapsulation with synthetic polymers are known. The preferred method is interfacial condensation, in which a reactive component dissolved in the monomer droplet (in particular an isocyanate or an acid chloride) is reacted with a second reactive component dissolved in the aqueous phase (in particular an amine). Although the previously described method for forming encapsulated monomer droplets can also be used in the process according to the invention, it was surprisingly found that encapsulation with a coacervate or a complex coacervate is not necessary.

[0113] Therefore, coacervates and / or complex coacervates are preferably not used in the process according to the invention. Gelatin is particularly preferably not used as a coacervate.

[0114] Preferably, the polymerization in the production of monodisperse particles is carried out by first irradiation with UV light and then an increase in temperature. In a further embodiment of the invention, the irradiation with UV light takes place in a separate container. The reaction mixture is then preferably transferred to a further container in which the heating takes place. In the first container, the polymerization occurs essentially by the activation of the initiators of formula (I), and in the second container essentially by the activation of the initiators of formula (II).

[0115] In a preferred embodiment according to the invention, polyvinyl alcohol is used as a dispersing agent in the production of monodisperse polymers. Preferably, both initiators of formula (I) and (II) are added to the monomers. Preferably, the monomer mixture is then bubbled by atomization with a droplet generator. Preferably, irradiation with UV light then follows.

[0116] The polymers are preferably used for the production of ion exchangers. The polymers can be functionalized to cation or anion exchangers and chelating resins by known processes such as sulfonation, chloromethylation, or amidomethylation using phthalimide and saponification, and by further reaction of the chloromethylated or saponified intermediates with alkylamines.

[0117] The invention therefore also includes a process step in which the polymers produced according to the invention are processed by known methods, such as sulfonation P001 01228- A

[0118] - 21 - or chloromethylation or amidomethylation and saponification and functionalized by further reaction of the chloromethylated or saponified intermediates with alkylamines to form cation or anion exchangers and chelating resins.

[0119] The foregoing invention enables the production of polymers in high yields and conversions per unit of time. This is particularly relevant in the context of suspension polymerization, which is used in the production of polymers for ion exchangers. Suspension polymerization is characterized by a high ratio of aqueous to organic phases during the reaction.

[0120] Furthermore, it was found that monodisperse polymers can be produced without the addition of encapsulation material, such as coacervas or complex coacervas, and that the production of monodisperse polymers for ion exchanger manufacturing can therefore be more cost-effective and environmentally friendly.

[0121] P001 01228- A

[0122] - 22 -

[0123] methods

[0124] Determination of the effective particle size of the pearl polymer

[0125] Determination of the effective particle size of the pearl polymer by measurement using

[0126] Camsizer X2. The Camsizer measurement method is based on the principle of dynamic image analysis (ISO 13322-2). The effective grain size is measured using a sample of approximately 25 ml.

[0127] Determination of the mean diameter of the polymer particles (pearl polymer)

[0128] The mean particle diameter is determined by laser diffraction according to ISO 13320-1.

[0129] P001 01228- A

[0130] - 23 -

[0131] Examples

[0132] Example 1

[0133] (Inventive example initiator of formula (I) and formula (II))

[0134] In a quartz glass reactor, a solution of hydroxypropylmethylcellulose (Methocel F4M / K100 solution (0.29 g, 0.15 wt% based on the aqueous phase)) and K2HPO4 (0.20 g, 0.001 mol, 0.15 wt% based on the aqueous phase) is placed in deionized water (182 ml) (pH = 8.3). A nitrogen flow of 20 l / h is introduced into the vessel. To this aqueous phase, a mixture of styrene (145.65 g, 1.4 mol), divinylbenzene (15.07 g, 0.12 mol), and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (1.66 g, 0.004 mol, 1 wt% based on the monomer mixture, CAS: 162881-26-7) (initiator of formula (I)), as well as tert-butyl peroxy-2-ethylhexanoate (0.8 g, 0.004 mol, 0.5 wt% based on the monomer mixture, CAS: 3006-82-4) (initiator of formula (II)) is added. The weight ratio of the aqueous phase to the organic phase was 1.22. It is first stirred for 20 minutes and then irradiated with light of wavelength 365 nm for 180 minutes using a UV lamp.The reaction mixture is then heated to 95 °C for one hour and this temperature is maintained for four hours. The total polymerization time is eight hours. The reaction mixture is cooled and the product is isolated. The yields and particle sizes (mean diameter) are given in Table 1.

[0135] Comparative example 1

[0136] (Only UV initiator of formula (I) not according to the invention)

[0137] In a quartz glass reactor, a solution of hydroxypropylmethylcellulose (Methocel F4M / K100 solution) (0.29 g, 0.15% based on the aqueous phase) and K2HPO4 (0.20 g, 0.1% based on the aqueous phase) is placed in deionized water (182 mL) (pH value = 8.3). A nitrogen flow of 20 l / h is introduced into the vessel. To this aqueous phase, a mixture of styrene (145.65 g, 1.4 mol), divinylbenzene (15.07 g, 0.12 mol), and bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide (2.49 g, 0.006 mol, 1.5 wt% based on the monomer mixture, CAS: 162881-26-7) (initiator of formula (I)) is added. The mixture is stirred for 20 min and then irradiated with light at a wavelength of 365 nm for 480 min using a UV lamp. The reaction mixture is P001 01228-A

[0138] - 24 - cooled and the product isolated. The yields and particle sizes (mean diameter) are given in Table 1.

[0139] Comparative example 2

[0140] (Only thermal initiator of formula (II) not according to invention) In a glass reactor, a solution of hydroxypropylmethylcellulose (Methocel F4M / K100 solution (non-ionic cellulose ether)) (0.29 g, 0.15% based on the aqueous phase) and K2HPO4 (0.2 g, 0.1% based on the aqueous phase) is placed in deionized water (182 mL) (pH = 8.3). A nitrogen stream of 20 l / h is introduced into the vessel. To this aqueous phase, a mixture of styrene (145.65 g, 1.4 mol), divinylbenzene (15.07 g, 0.12 mol), and tert-butyl peroxy-2-ethylhexanoate (2.41 g, 0.011 mol, 1.5 wt% based on the monomer mixture) is added. The mixture is first stirred and then heated to 66 °C for 90 min and held at this temperature for 4 h. Subsequently, the reaction mixture is heated to 95 °C for 30 min and held at 95 °C for 2 h. The reaction mixture is then cooled and the product isolated.The yields and grain sizes (mean diameter) are given in Table 1.

[0141] P001 01228- A

[0142] - 25 -

[0143] Table 1: Overview of yields

[0144] * The product exhibits strong clumping and is unsuitable as a polymer for the production of an ion exchanger. Table 2: Overview of the composition of the monomer mixture and the amounts of initiator used.

[0145] BAPO = Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0146] The claimed process enables the production of polymers in high yields and high throughputs per unit of time. P001 01228- A

[0147] - 26 -

[0148] Example 2

[0149] (Example according to the invention: Production of a monodisperse polymer with the initiators (I) and (II))

[0150] To produce directly atomized capsule mass, a polyvinyl alcohol mixture is prepared from deionized water (998 g) and polyvinyl alcohol (Mowiol 40-88) (2 g). The polyvinyl alcohol solution is stirred for 1 hour at 90 °C.

[0151] In addition to the polyvinyl alcohol solution, a monomer mixture is prepared. The monomers, consisting of styrene (316.6 g, 3.04 mol), divinybenzene (32.4 g, 0.25 mol), bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide (3.4 g, 0.008 mol), and tert-butyl peroxy-2-ethylhexanoate (Trigonox 21S (1.1 g, 0.005 mol)), are stirred together. The monomer mixture is then aerated by atomization using a droplet generator with a hole size of 100 pm, with a flow rate of 1.63 mL / min for the aqueous phase and 1.4 mL / min for the organic phase.

[0152] The total throughput of the capsule mass is then the sum of the monomer and polyvinyl alcohol feeds. The produced capsule mass is transferred to an apparatus for direct irradiation with UV light from a UV lamp and irradiated there for approximately 5 minutes with light at a wavelength of 365 nm. Direct irradiation with UV light eliminates the need for the formation of a co-cervical shell. The capsule mass is sufficiently stabilized by the UV light irradiation.

[0153] The reaction mixture is then transferred to a second reactor, heated to 95°C within one hour, and held at 95°C for 4 hours. In this example, 223.72 g of product (approximately 97% yield) were isolated.

Claims

P001 01228- A Patent claims 1. A process for the production of a polymer, characterized in that at least one monoethylene unsaturated compound and at least one multiethylene unsaturated compound are reacted in the presence of at least one initiator of formula (I) where R 1 = H or a Ci- to Cis-alkyl, cyclopentyl, cyclohexyl or an unsubstituted C6-C24-aryl or a C6-C24-aryl substituted by one or more halogens, Ci- to C-alkyl groups, C2- to Cio-alkenyl groups or saturated or unsaturated Ci- to C-alkoxy groups, and wherein R 2 , R 6 , R 7 and R 11 can be the same or different and are independently Ci- to C-alkyl or Ci- to C-13-alkoxy; R 3 , R 4 , R 5 , R 8 , R 9 and R 10may be the same or different and are independently hydrogen, Ci- to C-alkyl, C2- to Cio-alkenyl or saturated or unsaturated Ci- to C13-alkoxy or halogen and in the presence of at least one initiator of formula (II) where R 12 and R 13 can be the same or different and independently Ci to Ci8-alkyl, Ci to Ci8-alkylcarbonyl, Ci to Ci8-alkyldicarbonyl, Ci to Ci8-alkoxycarbonyl, C6-C24-aryl, cyclopentyl or P001 01228- A - 28 - cyclohexyl compounds can be independently substituted by Ci- to C-alkyl or C2- to Cio-alkenyl or by one or more halogens, or R 12 and R 13 can be achieved by combining formula (III) be substituted, where R 14 = Ci- to C-alkyl, Ci- to Ci8-alkylcarbonyl, Ci- to Cis-alkoxycarbonyl, Ce-C 24-Aryl, cyclopentyl or cyclohexyl, which may be independently substituted by Ci- to C-alkyl, C2- to Cio-alkenyl or by one or more halogens, are reacted in the presence of water and in the presence of at least one dispersant.

2. A process for producing a polymer according to claim 1, characterized in that styrene, vinyltoluene, ethylstyrene, α-methylstyrene, chlorostyrene or chloromethylstyrene or mixtures of these compounds are used as monoethylene unsaturated compounds.

3. A process for producing a polymer according to claim 1 or 2, characterized in that divinyl benzene, divinyltoluene, trivinylbenzene, divinylnaphthalene or trivinylnaphthalene or mixtures of these compounds are used as the multiethylene unsaturated compound.

4. A process for producing a polymer according to one or more of claims 1 to 3, characterized in that in formula (I) R 1 = C3-Ci3. Alkyl or a C6-C 24 -Aryl, which may be substituted with Ci-C4 alkyl groups and R 2 , R 6 , R 7 and R 11 can be the same or different and are independently Ci- to C4-alkyl or Ci- to C4-alkoxy and R 3 , R 4 , R 5 , R 8 , R 9 and R 10 They can be the same or different and are independently Ci- to C6-alkyl, Ci- to C6-alkoxy or hydrogen. P001 01228- A - 29 - 5. A process for producing a polymer according to one or more of claims 1 to 4, characterized in that in formula (II) R 12 and R 13are independent of each other Ci-C6-alkyl, cyclohexyl, cyclopentyl, C1-C18-alkylcarbonyl, Ci- to Ci8-alkyldicarbonyl, Ci-Ci8-alkoxycarbonyl or C6-Ci8-aryl, which is substituted with Ci-C4-alkyl groups or by one or more halogens.

6. A process for producing a polymer according to one or more of claims 1 to 5, characterized in that in formula (III) R 14 = Ci- to C6-alkyl or Ci- to C8-alkylcarbonyl.

7. A process for producing a polymer according to one or more of claims 1 to 6, characterized in that the initiators of formula (I) are bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide or bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide and mixtures of these compounds.

8. Method for producing a polymer according to one or more of the Claims 1 to 7, characterized in that the initiators of formula (II) are dibenzoyl peroxide, dilauroyl peroxide, bis(p-chlorobenzoyl) peroxide, dicyclohexyl peroxydicarbonate, tert-butyl peroctoate, tert-butyl peroxy-2-ethyl hexanoate, 2,5-bis(2-ethylhexanoyl peroxy)-2,5-dimethylhexane, tert-amyl peroxy-2-ethylhexane, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyoctoate, tert-butyl peroxy -Butylperoxyneodecanoate, tert-butylperoxy-2-ethyl-hexanoate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-amylperoxy-2-etylhexane, tert-amylperoxyneodecanoate, tert-amylperoxypivalate, tert- Amyl peroxyoctoate, tert-amylperoxy-2-ethylhexanoate, 2,5-bis(2-ethylhexanolyperoxy)-2,5-dimethylhexane, 2,5-dipivaloyl-2,5-dimethylhexane (CAS number 78-63-7) or 2,5-bis(2-neodecanoylperoxy)-2,5-dimethylhexane or mixtures of these compounds.

9. A process for producing a polymer according to one or more of claims 1 to 8, characterized in that hydroxy- is used as a dispersing agent. P001 01228- A - 30 - propylmethylcellulose or hydroxyethylmethylcellulose or mixtures of these compounds are used.

10. A method for producing a polymer according to one or more of claims 1 to 9, characterized in that the weight ratio of the organic phase to the aqueous phase is 3 : 1 to 1 :

3.

11. A process for producing a polymer according to one or more of claims 1 to 10, characterized in that the initiator of formula (I) is used in an amount of 0.01 to 10 wt.%, preferably 0.01 to 5 wt.%, based on the monomer mixture.

12. A method for producing a polymer according to one or more of claims 1 to 11, characterized in that the initiators of formula (I) are used in a ratio of 15 : 1 to 1 : 1 to the initiators of formula (II) based on their weight amounts.

13. A method for producing a polymer according to one or more of claims 1 to 12, characterized in that the reaction mixture is irradiated with light within a wavelength range of 100 to 450 nm.

14. A method for producing a polymer according to one or more of claims 1 to 13, characterized in that the reaction mixture is irradiated with light within a wavelength range of 100 to 450 nm and that the reaction mixture is then heated to 55 °C to 130 °C.

15. A method for producing a polymer according to one or more of claims 1 to 13, wherein the production relates to polystyrene-divinylbenzene copolymers.

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