Method for preparing block copolymer

Abstract

The invention relates to a method for preparing a block copolymer, comprising polymerizing in an aqueous medium under reversible-addition-fragmentation chain transfer polymerization conditions: a) polymerizing a first monomer composition to prepare a first polymer block, the first monomer composition comprises 0.0-40.0 mol% of methacrylic acid and at least 50.0 mol% of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20 DEG C, said polymerizable ethylenically unsaturated monomers being selected from the group consisting of monomers having an ether group and monomers having a hydroxyl group; and b) polymerizing a second monomer composition comprising at least 60.0% by weight of one or more polymerizable ethylenically unsaturated monomers having a water solubility of less than 50 g / l at 20 DEG C to produce a second polymer block.

Description

[0001] The present invention relates to a method for preparing a block copolymer, a block copolymer comprising a first block and a second block, the use of the block copolymer as a dispersant for solid particles, a method for dispersing solid particles, and a coating composition.

[0002] US 8658741 B describes a process for the preparation of block copolymers. The process comprises in a first step the preparation of a homopolymer of butyl acrylate in an organic solvent. In a second step, a second polymer block is prepared from 4-vinylpyridine. In a third step, the butyl ester groups are partially transesterified with polyethylene glycol monomethyl ether. The disadvantage of this process is that it comprises an additional transesterification step, which requires additional time and energy. The resulting butanol must be distilled off. In addition, the polymerization process is carried out in an organic solvent. If an aqueous polymer solution is desired, the organic solvent must be removed by distillation.

[0003] US 10280101 B relates to water-soluble chain transfer agents. The document describes water-soluble RAFT agents which can be used for controlled polymerization of water-soluble monomers directly in water. Water-soluble block copolymers are expected to be obtained. Polyethylene glycol monoacrylate and polyethylene glycol monomethacrylate are mentioned as suitable water-soluble monomers.

[0004] Zhang et al. describe the synthesis of poly(methacrylic acid-co-poly(ethylene oxide) methyl ether methacrylate)-block-polystyrene amphiphilic block copolymers by a one-pot method via RAFT-mediated free radical emulsion polymerization in Macromolecules 2011, 44, pp. 7584-7593.

[0005] There is a need for a simple process for preparing block copolymers in aqueous media that avoids solvent removal operations and that provides block copolymers that are suitable as dispersants for solid particles, in particular for pigment and filler particles.

[0006] The present invention provides a method for preparing a block copolymer, comprising carrying out the following polymerization in an aqueous medium under reversible-addition-fragmentation chain transfer polymerization conditions:

[0007] a) polymerizing a first monomer composition to prepare a first polymer block, the first monomer composition comprising 0.0-40.0 mol % of methacrylic acid and at least 50.0 mol % of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C., the polymerizable ethylenically unsaturated monomers being selected from monomers having an ether group and monomers having a hydroxyl group; and

[0008] b) polymerizing a second monomer composition to prepare a second polymer block, the second monomer composition comprising at least 60.0 wt % of one or more polymerizable ethylenically unsaturated monomers having a water solubility of less than 50 g / l at 20°C.

[0009] The method of the present invention obtains block copolymers which are very suitable as dispersants for solid particles, in particular for pigment and filler particles. In order to provide an aqueous block copolymer solution or emulsion, the method does not require either an ester exchange step or a solvent distillation step. In addition, the method can be carried out at a mild temperature. Therefore, the method is simple, requires less energy, does not generate waste, and is thus environmentally sustainable.

[0010] The method of the present invention obtains a block copolymer. The block copolymer comprises at least two different polymer blocks or segments connected to each other. The first polymer block and at least one second polymer block have different monomer compositions. Each polymer block may comprise one or more than one type of repeating unit. Therefore, each polymer block may be prepared from a single type of monomer, or from two or more types of monomers. In some embodiments, the block copolymer consists of a first block and a second block. In a further embodiment, the first block and the second block are interconnected by an intermediate polymer segment, wherein the monomer composition gradually changes from the composition of the first polymer block to the composition of the second polymer block. In a further embodiment, the block copolymer comprises a third polymer block, which may be located between the first block and the second block. Alternatively, the third polymer block may be an end block adjacent to the first polymer block or the second polymer block.

[0011] The method of the present invention is carried out in an aqueous medium. The aqueous medium is usually a continuous aqueous phase. The continuous aqueous phase usually has a water content in the range of 40.0-100.0 wt %, preferably 50.0-100.0 wt %, more preferably 60.0-100.0 wt %. If necessary, the aqueous phase may contain a water-miscible organic solvent, the content of which is suitably 0.0-30.0 wt %, preferably 0.0-20.0 wt %, more preferably 0.0-10.0 wt %, calculated based on the amount of water present in the aqueous phase.

[0012] In the method of the present invention, monomers are polymerized under reversible addition-fragmentation chain transfer polymerization conditions. Reversible addition-fragmentation chain transfer or RAFT polymerization is one of several types of reversible-deactivated free radical polymerization. This polymerization uses a chain transfer agent in the form of a thiocarbonyl-thio compound or a similar compound, thereby providing control of molecular weight and polydispersity index during free radical polymerization. RAFT polymerization is one of several living or controlled radical polymerization techniques, other techniques are, for example, atom transfer radical polymerization (ATRP) and nitroxide-mediated polymerization (NMP). RAFT polymerization uses thiocarbonyl-thio compounds to regulate polymerization via a reversible chain transfer method, and the thiocarbonyl-thio compounds are, for example, trithiocarbonates, dithioesters, thiocarbamates and xanthates.

[0013] In step a) of the process of the present invention, a first monomer composition is polymerized to prepare a first polymer block. The first monomer composition comprises one or more polymerizable ethylenically unsaturated monomers.

[0014] Ethylenically unsaturated monomers suitable for forming the first block in the block copolymer are generally selected from acrylates, methacrylates, acrylamides and / or methacrylamides. The term "(meth)acryloyl" herein refers to both methacryloyl and acryl. The same applies to the term "(meth)acrylate", which similarly refers to both methacrylate and acrylate.

[0015] Methacrylates are preferred over acrylates.

[0016] It has been found that the presence of a large amount of carboxylic acid functional monomers can reduce the performance of the block copolymer, especially when the block copolymer is used as a dispersant for solid particles. Therefore, the content of methacrylic acid in the first monomer composition does not exceed 40.0 mole %, based on the total amount of ethylenically unsaturated monomers in the first monomer composition.

[0017] Thus, the first monomer composition comprises methacrylic acid in an amount of 0.0-40.0 mol %.In a preferred embodiment, the first monomer composition comprises methacrylic acid in an amount of 0.0-25.0 mol %, even more preferably 0.0-15.0 mol %, most preferably 0.0-7.0 mol %.

[0018] The first monomer composition comprises at least 50 mol% of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C. and selected from monomers having ether groups and monomers having hydroxyl groups. In a preferred embodiment, the first monomer composition comprises 70-100 mol%, more preferably 80-100 mol% or even 90-100 mol% of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C. In all cases, the mol% is calculated based on the total amount of ethylenically unsaturated monomers in the first monomer composition.

[0019] In a further preferred embodiment, the first monomer composition comprises at least 60 wt % of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C., based on the total weight of the monomers in the first monomer composition. Typically, the first monomer composition comprises 60-100 wt %, preferably 80-100 wt %, of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C.

[0020] The polymerizable ethylenically unsaturated monomer in the first monomer composition has a single polymerizable ethylenically unsaturated group. If necessary, a small amount of monomers with two or more polymerizable ethylenically unsaturated groups can be present in the first monomer composition. The amount of this monomer can be 0.0-3.0 mol %, based on the total amount of the ethylenically unsaturated monomers in the first monomer composition.

[0021] Suitable monomers having a water solubility of more than 500 g / l at 20° C. are monomers having ether groups and monomers having hydroxyl groups. Monomers having a plurality of acyclic ether groups are very suitable, for example ether groups obtained by ring-opening polymerization of alkylene oxides, especially ethylene oxide and propylene oxide.

[0022] The example of very suitable monomer is the monomethacrylate of polyethylene glycol or the monomethacrylate of polyethylene glycol monoether.Suitable monoethers include methyl ether, ethyl ether, propyl ether and butyl ether.Polyethylene glycol suitably has 2-100 ethylene oxide polymerization units, preferably 3-50 ethylene oxide polymerization units, more preferably 3-20 ethylene oxide polymerization units.In some embodiments, the number of ethylene oxide polymerization units is in the scope of 4-15.

[0023] Other suitable monomers having a water solubility of greater than 500 g / l at 20° C. are hydroxy-functional monomers such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

[0024] The second monomer composition comprises at least 60 wt% of one or more polymerizable ethylenically unsaturated monomers having a water solubility of less than 50 g / l at 20° C. The wt% is calculated based on the total weight of the polymerizable ethylenically unsaturated monomers in the second monomer composition. In a preferred embodiment, the second monomer composition comprises 70-100 wt%, more preferably 80-100 wt% or even 90-100 wt% of one or more polymerizable ethylenically unsaturated monomers having a water solubility of less than 50 g / l at 20° C.

[0025] Examples of suitable monomers having a water solubility of less than 50 g / l at 20° C. are (meth)acrylates of linear, branched or alicyclic alcohols having 1 to 22, preferably 1 to 12, more preferably 1 to 8 and most preferably 1 to 6 carbon atoms, for example methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, isobutyl (meth)acrylate, isopentyl (meth)acrylate, lauryl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, behenyl (meth)acrylate, isodecyl (meth)acrylate, 2-propylheptyl (meth)acrylate, 3,5,5-trimethyl-1-hexyl (meth)acrylate, 1,2-dimethyl-2-propen ... acrylate, 2-propylheptyl(meth)acrylate, 2-isopropyl-5-methyl-hexyl(meth)acrylate, tridecyl(meth)acrylate, heptadecyl(meth)acrylate, heneicosyl(meth)acrylate and isobornyl(meth)acrylate; and aryl(meth)acrylates, the aromatic ring of which contains 5 to 12, preferably 6 to 10, carbon atoms without possible additional substituents, such as phenyl acrylate; and aralkyl(meth)acrylates, the aralkyl containing 6 to 11, preferably 7 to 11, carbon atoms without possible additional substituents on the aryl group, such as benzyl methacrylate; the aryl radical in the aryl(meth)acrylates and aralkyl(meth)acrylates can in each case be unsubstituted or substituted four times, such as 4-methylphenyl methacrylate. In a preferred embodiment, the second monomer composition comprises or consists of a polymerizable vinylaromatic compound.

[0026] In a particularly preferred embodiment, the second monomer composition comprises at least one of 4-vinylpyridine, 2-vinylpyridine, and styrene.

[0027] The polymerizable ethylenically unsaturated monomer in the second monomer composition usually has a single polymerizable ethylenically unsaturated group. If necessary, a small amount of monomers with two or more polymerizable ethylenically unsaturated groups can be present in the second monomer composition. The amount of this monomer can be 0.0-3.0 mole %, based on the total amount of the ethylenically unsaturated monomers in the second monomer composition.

[0028] The weight ratio between the polymerizable ethylenically unsaturated monomer in the first monomer composition and the polymerizable ethylenically unsaturated monomer in the second monomer composition is generally in the range of 50:50 to 95:5, preferably in the range of 70:30 to 95:5, and even more preferably in the range of 75:25 to 95:5.

[0029] In a preferred embodiment, the block copolymer prepared according to the process of the present invention has a number average molecular weight Mn in the range of 5000-30000 g / mol, more preferably in the range of 8000-20000 g / mol.

[0030] It is further preferred that the block copolymer has a polydispersity index in the range of 1.1 to 2.0, preferably 1.1 to 1.8. The polydispersity index is the quotient of weight average molecular weight Mw / number average molecular weight Mn.

[0031] The number average molecular weight Mn and the weight average molecular weight Mw are suitably determined by gel permeation chromatography using polystyrene as calibration standard and tetrahydrofuran as diluent.

[0032] As described above, the method of the present invention comprises polymerizing under reversible-addition-fragmentation chain transfer polymerization conditions in an aqueous medium. This method is generally referred to as RAFT polymerization, which involves degenerative-transfer radical polymerization, wherein the activation and deactivation of the chain involve a degenerative chain transfer process, which occurs via a two-step addition-fragmentation mechanism.

[0033] To effect reversible-addition-fragmentation chain transfer polymerization, the process is suitably carried out in the presence of:

[0034] i) a free radical generator having a water solubility of greater than 10 g / l at a temperature of 20°C; and

[0035] ii) A chain transfer agent having a thiocarbonyl-thio group represented by the formula (I) -C(=S)-S-.

[0036] Suitable examples of free radical generators are compounds with peroxide groups or azo groups which can decompose under conditions that form free radicals. Persulfates are also suitable, such as potassium persulfate and ammonium persulfate. In order to achieve the desired water solubility, the free radical generator may also contain one or more carboxylic acid groups or salts thereof. Examples of suitable free radical generators include 4,4'-azobis(4-cyanovaleric acid) or its salts, (2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] tetrahydrate), (2,2'-azobis(2-methylpropionamidine) dihydrochloride), 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2-cyano-2-butane), dimethyl 2,2'-azobisdimethylisobutyrate, 4,4'-azobis(4-cyanovaleric acid), 1, 1′-Azobis(cyclohexanecarbonitrile), 2-(tert-butylazo)-2-cyanopropane, 2,2'-azobis[2-methyl-N-(l,l)-bis(hydroxymethyl)-2-hydroxyethyl]propionamide, 2,2'-azobis[2-methyl-N-hydroxyethyl)]-propionamide, 2,2'-azobis(N,N'-dimethyleneisobutylamidine) dihydrochloride, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(N,N'-di-methyleneisobutylamine ), 2,2'-azobis(2-methyl-N-[l,l-bis(hydroxymethyl)-2-hydroxyethyl]propionamide), 2,2'-azobis(2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(isobutyramide) dehydrate, 2,2'-azobis(2,2,4-trimethylpentane), 2,2'-azo-bis(2-methylpropane), tert-peroxyacetic acid tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxybenzoate, tert-butyl peroxyoctanoate, tert-butyl peroxyneodecanoate, tert-butyl peroxyisobutyrate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, dicumyl peroxide, dibenzoyl peroxide, dilauroyl peroxide, potassium peroxydisulfate, ammonium peroxydisulfate, di-tert-butyl hyponitrite, and dicumyl hyponitrite.

[0037] In order to achieve reversible addition-fragmentation chain transfer polymerization, the method is preferably carried out in the presence of a chain transfer agent having a thiocarbonyl-thio group represented by the formula (I)-C(=S)-S-.

[0038] In order to regulate the polymerization via reversible chain transfer, examples of suitable chain transfer agents include dithioesters, thiocarbamates, trithiocarbonates and xanthates. Specific examples of suitable chain transfer agents include 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid, 3-((((1-carboxyethyl)thio)thiocarbonyl)-thio)propanoic acid, 2-(((dodecylthio)thiocarbonyl)thio)propanoic acid, 2-(butylthiothiocarbonylthio)propanoic acid, 4-cyano-4-(phenylthiocarbonylthio)pentanoic acid, 4-cyano-4-(phenylthiocarbonylthio)pentanoic acid, 2-(dodecylthiocarbonylthio)-2-methylpropanoic acid, 4-cyano-4-(phenylthiocarbonylthio)pentanoic acid, and 4-((((2-carboxyethyl)thio)-thiocarbonyl)thio)-4-cyanopentanoic acid.

[0039] During the process of the present invention, foam may form due to the stirring or agitation of the aqueous medium and the presence of organic components. Therefore, the process of the present invention is preferably carried out in the presence of a defoamer. Defoamers prevent or reduce the formation of foam, or promote the decomposition of foam. Suitable defoamers are silicone-based defoamers, as well as silicone-free defoamers. Examples of silicone-free defoamers are hydrocarbon-based defoamers, such as C 4 -C 30 A mixture of aliphatic or aromatic hydrocarbons. Mixtures and combinations of different types of defoamers may also be used. Defoamers are generally used in low amounts sufficient to effectively prevent or substantially reduce the formation of foam. The amount of defoamer or defoamer combination is generally in the range of 0.1-2.5 wt % based on the weight of the monomers used in the present invention.

[0040] The reversible-addition-fragmentation chain transfer polymerization is suitably carried out at a temperature in the range of 35-100° C., preferably 50-95° C. and atmospheric pressure for a time sufficient to substantially completely polymerize the polymerizable ethylenically unsaturated monomers. Typically, the polymerization time is 30 minutes to 300 minutes for each polymer block to be prepared. The polymerization is carried out in a suitable reactor equipped with a control device, a metering device and an agitator. In the first polymerization step, the first monomer composition is polymerized. The first monomer composition can be added to the reactor in one or more metering steps, or can be metered into the reactor continuously during the polymerization process. The initiator and the chain transfer agent can be added to the reactor simultaneously with the monomer composition or separately therefrom. When the first monomer mixture completes the polymerization reaction, the polymerization of the second monomer composition is similarly carried out.

[0041] In some embodiments, the method of the present invention consists of the following steps: polymerizing the first monomer composition and the second monomer composition as described above. This obtains a block copolymer consisting of a first block and a second block. In some embodiments, the second block is polymerized directly after the first block is obtained, for example in the same reactor. If desired, the second block can also be prepared at a later stage, for example after the first block is stored, in the same reactor or in a different reactor.

[0042] In other embodiments, the method of the present invention includes a third step, wherein a third monomer composition is added to prepare the third block after the second block is obtained. The third monomer composition generally comprises one or more polymerizable ethylenically unsaturated monomers. When the second monomer composition comprises at least one of 4-vinylpyridine and 2-vinylpyridine, the third monomer preferably comprises at least one of styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene and β-methylstyrene. Other examples of monomers suitable for the third block are benzyl methacrylate, methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate and hydroxypropyl methacrylate. The amount of monomers in the third monomer composition is generally within the range of 2-30% by weight, calculated based on the amount of monomers in the second monomer composition. It is found that the use of the third monomer composition can significantly reduce the amount of residual free monomers in the block copolymer.

[0043] The method of the present invention obtains a composition comprising a block copolymer in an aqueous medium, wherein the block copolymer is dissolved or dispersed. In many cases, the aqueous composition can be used for other purposes, as described below. If necessary, the amount of water can be adjusted for a specific purpose. In some cases, the amount of water can be reduced by distillation, thereby adjusting the water content to a level suitable for a specific application. If necessary, most of the water can be removed by distillation, thereby obtaining a block copolymer with a water content of 0-10% by weight, calculated based on the weight of the block copolymer.

[0044] The present invention also relates to a block copolymer obtainable by the process of the present invention. The block copolymer is a block copolymer comprising the following blocks:

[0045] a) a first block comprising polymerized units of one or more polymerizable ethylenically unsaturated monomers, wherein the first block comprises 0.0-40.0 mol % of polymerized units of methacrylic acid and at least 50.0 mol % of polymerized units of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C. and selected from monomers having an ether group and monomers having a hydroxyl group; and

[0046] b) a second block comprising polymerized units of one or more polymerizable ethylenically unsaturated monomers, wherein the second block comprises at least 60.0 wt. % of polymerized units of one or more polymerizable ethylenically unsaturated monomers having a water solubility at 20° C. of less than 50 g / l.

[0047] In typical embodiments of the polymer, the weight ratio between the first block and the second block is in the range of 50:50 to 95:5, preferably in the range of 70:30 to 95:5, even more preferably in the range of 75:25 to 95:5.

[0048] Additionally, the embodiments described above with respect to the process of the present invention also apply analogously to the polymers of the present invention with respect to monomer types and monomer compositions.

[0049] As mentioned above, the process of the invention obtains the block copolymer in an aqueous medium. Therefore, the present invention also relates to an aqueous composition comprising water and the block copolymer of the invention.

[0050] The present invention also relates to the use of the above-mentioned block copolymer or the block copolymer prepared as an additive, preferably as a wetting and dispersing agent for solid particles, preferably for coatings, paints, plastics, pigment pastes, sealants, cosmetics, adhesives, casting compounds, fillers, battery applications, oil and gas field applications, caulking compounds, inks and printing dyes. Block copolymers can be used as dispersing additives for conductive carbon-based materials. Examples of suitable conductive carbon-based materials include carbon black, carbon nanotubes, graphite, carbon fiber, graphene, fullerene and mixtures thereof. Preferred carbon-based materials are carbon black, graphene and carbon nanotubes. These dispersed conductive carbon-based materials can be suitably included in electrode slurries or electrode pastes for rechargeable batteries. The term "battery" covers a single electrochemical cell containing an electrode, a separator and an electrolyte, as well as a cell assembly or a cell assembly.

[0051] The invention furthermore relates to the use of the block copolymers or aqueous compositions according to the invention as wetting agents or dispersants for solid particles.

[0052] The present invention also relates to a method for dispersing solid particles in a dispersion medium, comprising the following steps:

[0053] i) providing a block copolymer or an aqueous composition according to the invention,

[0054] ii) providing solid particles,

[0055] iii) providing an aqueous dispersion medium or using water in an aqueous composition as a dispersion medium,

[0056] iv) mixing the components provided in steps i) to iii) in any suitable order and applying shear forces.

[0057] The block copolymers of the invention are used, for example, as aluminum passivators, dispersants, dispersion stabilizers, surfactants or wetting agents, and can be used, for example, in pigmented and / or filled products, such as pigment concentrates or pastes, coating compositions, sealants, plastics, ceramics, cosmetics, adhesives, casting compounds, caulking compounds, inks and / or printing inks. Preferred pigment concentrates are those that can be mixed with suitable paint systems to obtain colored paints.

[0058] Thus, the block copolymers can be used, for example, in the production or processing of paints, coatings, inks and printing dyes, for example for inkjet printing, paper coatings, inks for leather and textiles, pastes, pigment concentrates, ceramics, adhesives and sealants, casting compounds, plastics and cosmetic preparations, in particular when they contain solids such as pigments and / or fillers or fibrous materials.

[0059] The block copolymers can also be used, for example, in the production of casting compounds, potting materials, PVC plastisols, gel coatings, polymer cements, circuit boards, industrial paints, wood and household paints, automotive paints and enamels, (anti-fouling) marine paints, anti-corrosion paints, coatings for cans and coils, or painting and architectural paints.

[0060] Typically, the product containing the block copolymer and pigment and / or filler is a paint, or a pigment concentrate for use in a coating composition.

[0061] Therefore, the present invention also relates to a coating composition comprising:

[0062] a) solid particles,

[0063] b) a block copolymer according to the invention, and

[0064] c) Film-forming binders.

[0065] In a preferred embodiment, the coating composition is an aqueous composition comprising a continuous aqueous phase.

[0066] The pigments used may be those known to those skilled in the art. Examples of suitable pigments include mono-, di-, tri- and polyazo pigments, oxazines, dioxazines, thiazine pigments, diketopyrrolopyrroles, phthalocyanines, ultramarines and other metal complex pigments, indigoid pigments, diphenylmethane pigments, triaryl pigments, xanthene pigments, acridine pigments, quinacridone pigments, methine pigments, anthraquinones, pyranthrone, perylene pigments and other polycyclic carbonyl pigments, carbon black pigments and / or pigments based on carbon black, for example graphite.

[0067] Useful pigments may be inorganic pigments, for example zinc, titanium dioxide, zinc oxide, zinc sulfide, zinc phosphate, barium sulfate, lithophone, iron oxide, ultramarine, manganese phosphate, cobalt aluminate, cobalt stannate, cobalt zincate, antimony oxide, antimony sulfide, chromium oxide, zinc chromate, mixed metal oxides based on nickel, bismuth, vanadium, molybdenum, cadmium, titanium, zinc, manganese, cobalt, iron, chromium, antimony, magnesium, aluminum (for example nickel titanium yellow, bismuth vanadate molybdate yellow or chrome titanium yellow).

[0068] Inorganic pigments can be magnetic pigments based on pure iron, iron oxide and chromium oxide or mixed oxides, metallic effect pigments of aluminum, zinc, copper or brass, and pearlescent pigments or fluorescent and phosphorescent pigments. Other examples include nanoscale organic or inorganic solids having a particle size of less than 100 nm in at least one dimension, such as specific types of carbon black or other allotropes of carbon, such as single-walled CNTs, multi-walled CNTs and graphene. The particle size is determined, for example, by transmission electron microscopy, analytical ultracentrifugation or light scattering.

[0069] Mention may also be made of particles consisting of metal oxides and / or hydroxides, or semimetallic oxides and / or hydroxides, and particles consisting of mixed metal oxides and / or hydroxides, and / or semimetallic oxides and / or hydroxides. For example, oxides and / or hydroxides of aluminum, silicon, zinc, titanium, etc. can be used to produce such very finely divided solids.

[0070] When the corresponding product, in particular the coating composition, contains fillers, the fillers are, for example, fillers known to the person skilled in the art. Examples of pulverulent or fibrous fillers are, for example, those consisting of pulverulent or fibrous particles of aluminum oxide, aluminum hydroxide, silicon dioxide, diatomaceous earth, siliceous earth, quartz, silica gel, talc, kaolin, mica, perlite, feldspar, slate powder, calcium sulfate, barium sulfate, calcium carbonate, calcite, dolomite, glass or carbon. The fibers used can be organic and / or inorganic and also serve as reinforcing materials.

[0071] Flame retardants, such as aluminum hydroxide or magnesium hydroxide, and matting agents, such as silica, can also be well dispersed and stabilized using the block copolymers of the invention.

[0072] The block copolymers of the present invention can also be used for the surface treatment of fibers or particles, such as pigments or fillers, to improve their processing properties or compatibility.

[0073] Depending on the field of application, the block copolymers according to the invention are used in such an amount that the end product for further use advantageously contains the block copolymers according to the invention in a proportion of 0.01 to 10.00% by weight, based on the total amount of the corresponding product. However, even greater amounts are possible. Based on the solid particles to be dispersed, for example pigments, the block copolymers according to the invention are preferably used in an amount of 0.50 to 100.00% by weight.

[0074] When using difficult to stabilize solids, the amount of block copolymers of the present invention can be significantly higher. The concentration of the required block copolymer generally depends on the specific surface area of ​​the solid to be dispersed. In general, the stabilization of inorganic pigments usually requires less dispersant than when stabilizing organic pigments, because organic pigments tend to have a higher specific surface area, and thus require a larger amount of dispersant. The typical dosage of block copolymers for inorganic pigments is 1-30% by weight, and the dosage for organic pigments is 10-50% by weight, each calculated based on the solid to be dispersed, especially the pigment. In the case of very finely divided pigments, such as certain carbon blacks, it is necessary to add an amount of 30-90% or more. Criteria for sufficient pigment stabilization can include, for example, the gloss and transparency of the coating composition, or the degree of floating.

[0075] Dispersion of the solids can take place as a result of grinding a single solid or simultaneously grinding a mixture of pigments, with best results generally being achieved in the case of grinding a single solid.

[0076] Those products in which the block copolymers according to the invention are ultimately to develop their effect, in particular coating compositions and / or lacquers, may contain organic polymers as binders.

[0077] Examples of water-based coating compositions include cathodic or anodic electrodeposition paints, for example for automobile bodies. Other examples include plaster, silicate paints, emulsion paints, water-based paints based on water-dilutable alkyd resins, alkyd emulsions, hybrid systems, two-component systems, dispersions of polyurethanes and acrylates. Both one-component systems and two-component systems are possible, wherein in the case of two-component systems, generally speaking, polyisocyanates, melamine resins and / or polyamide resins are present in the second component as typical crosslinking agents known to those skilled in the art.

[0078] "Water-based" is understood to mean that the coating composition contains predominantly water as solvent. Water-based coating compositions contain in particular not more than 20% by weight of organic solvents, based on the total amount of solvents present in the coating composition.

[0079] The coating composition may contain other ingredients such as photoinitiators, defoamers, wetting agents, film-forming additives such as cellulose derivatives (e.g. cellulose nitrate, cellulose acetate, cellulose acetobutyrate), reactive diluents, flow control agents, dispersants and / or rheology control additives.

[0080] The pigment concentrates and coating compositions which are preferred as products of the invention are prepared by methods known in the art, for example by adding the individual components of the coating composition stepwise in customary mixing apparatuses, such as stirred vessels or dissolvers, while stirring and mixing. Example

[0081] abbreviation:

[0082] 4VP 4-vinylpyridine

[0083] ACVA 4,4'-azobis(4-cyanovaleric acid)

[0084] CVDT 4-Cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid

[0085] Polydispersity index Mw / Mn

[0086] DMAE Dimethylaminoethanol

[0087] HEMA (Hydroxyethyl) Methacrylate

[0088] Mc Black value dependent on hue

[0089] MMA Methyl Methacrylate

[0090] Mn Number average molecular weight (measured by GPC)

[0091] PEGMA(xyz) poly(ethylene oxide) methyl ether methacrylate, having a number average molecular weight of xyz g / mol

[0092] PM Propylene glycol monomethyl ether

[0093] ACVA stock solution

[0094] 1 g ACVA (3.6 mmol), 640 mg DMAE (7.1 mmol) and 98.36 g water were mixed and stirred until these raw materials were completely dissolved.

[0095] Example 1

[0096] A monomer composition of PEGMA 550 and water (1:1 vol) was prepared and degassed with nitrogen purge for 1 hour. For the polymerization of the first block, 1.35 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (3.34 mmol), 46.9 mg ACVA (167 μmol), 262 mg DMAE (2.94 mmol), 530 mg BYK-011 (defoamer), 34.1 mL water and 21.2 g of a monomer composition (containing 11.1 g PEGMA 550 and 10.1 g water) was added to a 250 mL four-necked round bottom flask equipped with a CPG stirrer, internal thermometer, bubble counter and diaphragm. The batch was degassed with nitrogen purge for 1 hour and heated to 70°C. When this temperature was reached, 49.6 g of the monomer composition (containing 25.9 g PEGMA 550 and 23.7 g water) was pumped into the flask over 1.5 minutes using a syringe pump. The reaction solution was stirred for another 2.5 hours and then cooled (Mn: 12.1 kg / mol, ).

[0097] For the polymerization of the second block, 2.38 mL of 4-vinylpyridine (2.35 g, 22.4 mmol), 2.58 mL of styrene (2.33 g, 22.4 mmol) and 6.32 mL of ACVA stock solution (10 g / L) were added to the flask. The batch was degassed with nitrogen purge for 1 hour before the reaction. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 2 hours (Mn: 16.2 kg / mol, ).

[0098] Example 2

[0099] A monomer composition of PEGMA 550 and water (1:1 vol) was prepared and degassed with nitrogen purge for 1 hour. For the polymerization of the first block, 1.35 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (3.34 mmol), 46.9 mg ACVA (167 μmol), 262 mg DMAE (2.94 mmol), 530 mg BYK-011 (defoamer), 34.1 mL water and 21.2 g of a monomer composition (containing 11.1 g PEGMA 550 and 10.1 g water) was added to a 250 mL four-necked round bottom flask equipped with a CPG stirrer, internal thermometer, bubble counter and diaphragm. The batch was degassed with nitrogen purge for 1 hour and heated to 70°C. When this temperature was reached, 49.6 g of the monomer composition (containing 25.9 g PEGMA 550 and 23.7 g water) was pumped into the flask over 1.5 minutes using a syringe pump. The reaction solution was stirred for another 2.5 hours and then cooled (Mn: 12.1 kg / mol, ).

[0100] For the polymerization of the second block, 7.27 mL of 2-vinylpyridine (7.05 g, 67.0 mmol) and 6.32 mL of ACVA stock solution (10 g / L) were added to the flask. Prior to the reaction, the batch was degassed by purging with nitrogen for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour, and at 80° C. for 2 hours (conversion: 98%; Mn: 16.2 kg / mol; Mp: 17.6 kg / mol; ).

[0101] Example 3

[0102] A monomer composition of PEGMA 550 and water (1:1 vol) was prepared and degassed with nitrogen purge for 1 hour. For the polymerization of the first block, 1.35 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (3.34 mmol), 46.9 mg ACVA (167 μmol), 262 mg DMAE (2.94 mmol), 530 mg BYK-011 (defoamer), 34.1 mL water and 21.2 g of a monomer composition (containing 11.1 g PEGMA 550 and 10.1 g water) was added to a 250 mL four-necked round bottom flask equipped with a CPG stirrer, internal thermometer, bubble counter and diaphragm. The batch was degassed with nitrogen purge for 1 hour and heated to 70°C. When this temperature was reached, 49.6 g of the monomer composition (containing 25.9 g PEGMA 550 and 23.7 g water) was pumped into the flask over 1.5 minutes using a syringe pump. The reaction solution was stirred for another 2.5 hours and then cooled (Mn: 12.1 kg / mol, ).

[0103] For the polymerization of the second block, 3.85 mL of styrene (3.50 g, 33.6 mmol) and 6.32 mL of ACVA stock solution (10 g / L) were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour, and at 80° C. for 2 hours.

[0104] Example 4

[0105] 0.8 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (1.98 mmol), 32.7 g (59.5 mmol) of PEGMA 550, 0.23 g (2.6 mmol) of DMAE, 3.1 g of ACVA stock solution, 51 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed for 1 hour with nitrogen purge. After 1 hour, the mixture was heated to 70° C. After 1 hour at 70° C., 0.66 g (6.6 mmol) of MMA and 0.5 g of ACVA stock solution were added three times at intervals of 30 minutes over 1.5 hours. After the addition of MMA, the reaction was carried out at 70° C. for 3 hours.

[0106] For the polymerization of the second block, 4.17 g (39.6 mmol) of 4-VP and 5.55 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0107] Example 5

[0108] 0.82 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (2.03 mmol), 22.34 g (0.04 mol) of PEGMA 550, 11.58 g (0.012 mol) of PEGMA 950, 0.24 g (2.64 mmol) of DMAE, 2.85 g of ACVA stock solution, 51.42 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed with nitrogen purge for 1 hour. After 1 hour, the mixture was heated to 70° C. When the temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0109] For the polymerization of the second block, 4.27 g (41 mmol) of 4-VP and 5.69 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0110] Example 6

[0111] 0.76 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (1.88 mmol), 31.06 g (56.5 mmol) of PEGMA 550, 0.22 g (2.45 mmol) of DMAE, 2.64 g of ACVA stock solution, 50.3 g of water and 450 mg of BYK-011 (defoamer) were added to a flask, stirred, and degassed with nitrogen purge for 1 hour. After 1 hour, the mixture was heated to 70° C. After 1 hour at 70° C., 1.26 g (12.6 mmol) of MMA and 0.5 g of ACVA stock solution were added three times at 30 minute intervals over 1.5 hours. After the addition of MMA, the reaction was continued at 70° C. for 3 hours.

[0112] For the polymerization of the second block, 3.96 g (37.7 mmol) of 4-VP and 5.28 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0113] Example 7

[0114] 1.22 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (3.0 mmol), 21.15 g (60.4 mmol) of PEGMA 350, 10.58 g (30.2 mmol) of polypropylene glycol monomethacrylate having an Mn of 350 g / mol, 0.5 g (5.6 mmol) of DMAE, 6.2 g of ACVA stock solution, 44.7 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed with nitrogen purging for 1 hour. After 1 hour, the mixture was heated to 70° C. When this temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0115] For the polymerization of the second block, 6.35 g (60 mmol) of 4-VP and 8.47 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0116] Example 8

[0117] 0.9 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (2.22 mmol), 36 g (37.9 mmol) of PEGMA 950, 0.26 g (2.9 mmol) of DMAE, 3.1 g of ACVA stock solution, 48.5 g of water and 450 mg of BYK-011 (defoaming agent) were added to the flask, stirred, and degassed with nitrogen purge for 1 hour. After 1 hour, the mixture was heated to 70° C. When the temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0118] For the polymerization of the second block, 4.69 g (45 mmol) of 4-VP and 6.25 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0119] Example 9

[0120] 0.91 g of 2-(((dodecylthio)thiocarbonyl)thio)propionic acid (2.6 mmol), 30.98 g (64.5 mmol) of methoxypolyethylene monoacrylate having an Mn of 400 g / mol, 3.62 g (12.9 mmol) of butyl acrylate, 0.26 g (2.9 mmol) of DMAE, 3.31 g of ACVA stock solution, 47.47 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed with nitrogen purging for 1 hour. After 1 hour, the mixture was heated to 70° C. When this temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0121] For the polymerization of the second block, 5.43 g (52 mmol) of 4-VP and 7.24 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0122] Example 10

[0123] Prepare a monomer composition of PEGMA 550 and water (1:1 vol) and degas with nitrogen purge for 1 hour. For the polymerization of the first block, 1.35g 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (3.34mmol), 46.9mg ACVA (167μmol), 262mg DMAE (2.94mmol), 530mg BYK-011 (defoamer), 34.1mL water and 21.3g of this monomer composition are added to a 250mL four-necked round-bottom flask equipped with a CPG stirrer, an internal thermometer, a bubble counter and a diaphragm. The batch is degassed with nitrogen purge for 1 hour and heated to 70°C. When the temperature is reached, 49.6g of this monomer composition is pumped into the flask in 1.5 minutes using a syringe pump. The reaction solution is stirred for another 2.5 hours and then cooled (Mn: 12.1kg / mol, ).

[0124] For the polymerization of the second block, 3.55 mL of 4VP (3.52 g, 33.4 mmol) and 9.36 mL of ACVA stock solution (10 g / L) were added to the flask. The batch was degassed with nitrogen purge for 1 hour before the reaction. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 2 hours (Mn: 13.1 kg / mol, ).

[0125] Embodiment 11

[0126] A monomer composition was prepared from a mixture of PEGMA 550 and HEMA (2:1 molar ratio) and diluted with water (50 vol% water). 1.20 g 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (2.97 mmol), 41.7 mg ACVA (149 μmol), 233 mg DMAE (2.62 mmol), 529 mg BYK-011 (defoamer) and 33.9 mL water were added to a flask (CVDT / ACVA / monomer molar ratio was 1:0.05:30). 21.1 g of this monomer composition was added to the flask and 49.3 g (Mn: 14.4 kg / mol, The reaction was carried out at 65°C for 1.5 hours and at 70°C for 2.5 hours.

[0127] For the polymerization of the second block, 6.32 mL of 4VP (6.25 g, 59.4 mmol) and 8.32 mL of ACVA stock solution (10 g / L) were added to the flask, and the reaction was carried out at 65° C. for 1 hour, 70° C. for 1 hour, and 80° C. for 2 hours (Mn: 16.4 kg / mol, ).

[0128] Example 12

[0129] 0.3 g of 2,2'-[thiocarbonyldi(thio)]di[2-methylpropionic acid] (1.05 mmol), 34.71 g (63 mmol) of PEGMA 550, 0.26 g (2.9 mmol) of DMAE, 4.42 g of ACVA stock solution, 46.7 g of water and 450 mg of BYK-011 (defoaming agent) were added to the flask, stirred, and degassed with nitrogen purge for 1 hour. After 1 hour, the mixture was heated to 70° C. When the temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0130] For the polymerization of the second block, 4.42 g (42 mmol) of 4-VP and 8.84 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0131] Embodiment 13

[0132] For the polymerization of the first block, 900 mg of 4-cyano-4-(((dodecylthio)thiocarbonyl)-thio)pentanoic acid (2.23 mmol), 31.2 mg of ACVA (111 μmol), 36.8 g of PEGMA 550 (66.9 mmol), 175 mg of DMAE (1.96 mmol), 106 mg of BYK-011 (defoamer), 51.1 g of water and 17.0 g of propylene glycol methyl ether (PM) were added to a 250 mL four-necked round bottom flask equipped with a CPG stirrer, an internal thermometer, a bubble counter and a septum. The reaction solution was degassed by purging with nitrogen for 1 hour. The reaction was carried out at 65° C. for 1.5 h and at 70° C. for 2.5 h (Mn: 15.4 kg / mol, ).

[0133] For the polymerization of the second block, 4.75 mL of 4VP (4.69 g, 44.6 mmol) and 6.25 mL of ACVA stock solution (10 g / l) and 1.52 g of PM were added to the flask. After degassing for 1 hour, the reaction was carried out at 65° C. for 1 hour, 70° C. for 1 hour and 80° C. for 2 hours (Mn: 17.3 kg / mol, ).

[0134] Embodiment 14

[0135] The aqueous product of Example 10 was heated to 80°C and water was distilled off under reduced pressure. The resulting product was very viscous and had an amber color.

[0136] Embodiment 15

[0137] 0.84 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (2.08 mmol), 34.33 g (62.4 mmol) of PEGMA 550, 0.24 g (2.7 mmol) of DMAE, 0.054 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 59 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed with nitrogen purge for 1 hour. After 1 hour, the mixture was heated to 70° C. When the temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0138] For the polymerization of the second block, 4.38 g (42 mmol) of 4-VP and 0.07 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride were added to the flask. Prior to the reaction, the batch was degassed by purging with nitrogen for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0139] Example 16

[0140] 0.66 g (1.64 mmol) of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid, 14.7 g (26.7 mmol) of PEGMA 550, 0.19 g (2.1 mmol) of DMAE, 2 g of ACVA stock solution, 55 g of water and 470 mg of BYK-011 (defoamer) were added to a flask, stirred and degassed for 1 hour by purging with nitrogen. After 1 hour, the mixture was heated to 70° C. After 1 hour at 70° C., a mixture of 7.3 g (13.3 mmol) of PEGMA 550 and 10.46 g (73.6 mmol) of butyl methacrylate was metered in over 90 minutes. At the same time, 2 g of ACVA stock solution were metered in over 90 minutes. After metering in the monomers, the reaction was carried out at 70° C. for 3 hours.

[0141] For the polymerization of the second block, 5.16 g (49 mmol) of 4-VP and 5.16 g of ACVA stock solution were added to the flask. Prior to the reaction, the batch was degassed with nitrogen purge for 1 hour. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 3 hours.

[0142] Embodiment 17

[0143] For the polymerization of the first block, 0.85 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)-thio)pentanoic acid (2.1 mmol), 34.74 g (63.2 mmol) of PEGMA 350, 0.24 g (2.75 mmol) of DMAE, 2.95 g of ACVA stock solution, 50 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed with nitrogen purging for 1 hour. After 1 hour, the mixture was heated to 70° C. When this temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0144] For the polymerization of the second block, 3.32 g (31.6 mmol) of 4-VP and 5.9 g of ACVA stock solution were added to the flask. The process was degassed with nitrogen for 1 hour before the reaction. The reaction was carried out at 65°C for 1 hour, at 70°C for 1 hour and at 80°C for 3-4 hours.

[0145] For the polymerization of the third block, 1.09 g (10.5 mmol) of styrene and 2.5 g of ACVA stock solution were metered in over 90 minutes. During the reaction, the process was further degassed with nitrogen. After 1 hour of metered addition, the reaction was post-initiated with 1 g of ACVA stock solution. The reaction was carried out at 80° C. for 2 hours (Mn: 16.0 kg / mol, ).

[0146] By introducing the third block, the residual 4-vinylpyridine monomer was reduced from 600 ppm to 30 ppm.

[0147] Embodiment 18

[0148] Prepare a monomer composition of PEGMA 550 and water (1:1 vol) and degas with nitrogen purge for 1 hour. For the polymerization of the first block, 1.8g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)pentanoic acid (4.45mmol), 62.4mg ACVA (222μmol), 520mg DMAE (5.8mmol), 900mg BYK-011 (defoamer), 18mL water and 21.3g of this monomer composition are added to a 250mL four-necked round-bottom flask equipped with a CPG stirrer, an internal thermometer, a bubble counter and a diaphragm. The batch is degassed with nitrogen purge for 1 hour and heated to 70°C. When this temperature is reached, 49.6g of this monomer composition is pumped into the flask in 1.5 minutes using a syringe pump. The reaction solution is stirred for another 2.5 hours and then cooled (Mn: 12.1kg / mol, ).

[0149] For the polymerization of the second block, 3.55 mL of 4VP (3.52 g, 33.4 mmol) and 9.36 mL of ACVA stock solution (10 g / L) were added to the flask. The batch was degassed with nitrogen purge for 1 hour before the reaction. The reaction was carried out at 65° C. for 1 hour, at 70° C. for 1 hour and at 80° C. for 2 hours (Mn: 13.1 kg / mol, ).

[0150] Embodiment 19

[0151] For the polymerization of the first block, 0.83 g of 4-cyano-4-(((dodecylthio)thiocarbonyl)thio)-pentanoic acid (2.06 mmol), 33.92 g (61.7 mmol) of PEGMA 550, 0.24 g (2.7 mmol) of DMAE, 2.88 g of ACVA stock solution, 43 g of water and 450 mg of BYK-011 (defoaming agent) were added to a flask, stirred, and degassed with nitrogen purging for 1 hour. After 1 hour, the mixture was heated to 70° C. When this temperature was reached, the reaction was carried out at 70° C. for 5 hours.

[0152] For the polymerization of the second block, 3.24 g (30.8 mmol) of 4-VP and 7.01 g of ACVA stock solution were added to the flask. The batch was degassed with nitrogen for 1 hour before the reaction. The reaction was carried out at 65°C for 1 hour, at 70°C for 1 hour and at 80°C for 3-4 hours.

[0153] For the polymerization of the third block, 1.81 g (10.3 mmol) of benzyl methacrylate and 7.01 g of ACVA stock solution were added. The reaction was carried out at 80°C for 2 hours (Mn: 15.7 kg / mol, ).

[0154] By introducing the third block, the residual 4-vinylpyridine monomer was reduced from 500 ppm to 35 ppm.

[0155] Comparative Example 1

[0156] Comparative Example 1 is a copolymer of butyl acrylate and 4-vinylpyridine, which is transesterified with methoxypolyethylene glycol, see Example A3 of US Pat. No. 8,658,741B.

[0157] Application test

[0158] Stabilizing Pigments in Waterborne Coating Compositions Raven 5000 Ultra III Powder

[0159] The grind type is a pigment paste without an aqueous binder.

[0160] Pigment Raven 5000 Ultra III Powder is Black 7 pigment from BIRLA CARBON.

[0161] The water-based adhesive system is acrylic copolymer Setaqua 6801 and 6802 from ALLNEX.

[0162] Formulating Clear Basecoats for OEM Coatings:

[0163]

[0164] The first four components were placed in a beaker and mixed, and then the last three components were added and further mixed.

[0165] A pigment paste was prepared with an addition amount of 70% active substance, based on the pigment.

[0166] Preparation of pigment paste black

[0167]

[0168] The dispersion vessel is a 100 mL wide neck glass bottle with a screw cap. All components are weighed in and mixed with 1 mm glass beads in a 1:1 weight ratio.

[0169] The closed glass bottle was clamped and shaken in a LAU disperser at level 3 dispersion cooling for 180 minutes.

[0170] The resulting pigment paste was then separated from the glass beads by sieving using a 210 μm filter into a 175 mL beaker.

[0171] Stir with a spatula to determine the viscosity of the pigment paste.

[0172] The pigment paste was adjusted to pH 8 to 9 using DMEA 50%.

[0173] A mixture with a pigment content of 1.5% by weight was prepared and shaken for 2 minutes.

[0174] Mix the ingredients:

[0175]

[0176] The mixture was left overnight and then coated onto a PE film using a film applicator and a 120 μm spiral rubber roller.

[0177] After a 15 minute flash off time the mixture was dried in a convection oven at 80°C for 15 minutes.

[0178] The clearcoat was coated onto the black basecoat, dried at room temperature for 5 minutes, and dried in a convection oven at 120°C for 20 minutes.

[0179] The jetness of the coating system is measured with a color spectrophotometer BYK-Gardner Spectro-Guide Gloss-45 / 0 and expressed as MC, MY and dM values. These values ​​should be as high as possible.

[0180] MC MY dM Comparative Example 1 312 305 7 Example 1 315 305 10 Example 2 317 305 12 Example 4 317 305 12 Example 5 322 310 12 Example 8 315 305 10 Example 10 322 310 12

[0181] Application Example - Inkjet

[0182] To evaluate the effectiveness of the polymers of the present invention as pigment dispersants, tests were conducted on different inkjet mill bases.

[0183] Application Example 1: Aqueous Dispersion

[0184] As a first step, an aqueous pigment dispersion with two different pigments was prepared using Pigment Red 150 (Fuji Fast Carmine 522-1D) and Pigment Blue 15:3 (PVFast Blue BG). The components shown in Table 1 were combined in a 100 mL glass bottle and then dispersed in a Lau disperser with 100 g of zirconium oxide beads (0.5 mm) to form a pigment concentrate (using cooling level 3, shaking for 16 hours).

[0185]

[0186] Table 1: Composition of the pigment concentrates. BYK-019 is a siloxane defoamer from BYK-Chemie GmbH; Fuji Fast Carmine 522-1D is an organic red pigment from Fuji Pigment Co. Ltd, with the color index Pigment Red 150; PV Fast Blue BG is a phthalocyanine pigment from Clariant, with the color index Pigment Blue 15:3.

[0187] The particle size of the pigment concentrates was determined directly after grinding and after storage (2 weeks at 60° C.). The particle size values ​​for the pigment concentrates using the polymer of Example 10 (according to the invention) and the polymer of Comparative Example 1 are listed below in Tables 2 and 3. The particle size was determined by dynamic laser scattering (NanoPlus DLS).

[0188]

[0189] Table 2: Particle size values ​​for pigment concentrate Fuji Fast Carmine 522-1D (PR150) sample.

[0190] The samples of the present invention showed better particle size reduction effect than the comparative examples.

[0191]

[0192] Table 3: Particle size values ​​for pigment concentrate PV Fast Blue BG (PB15:3).

[0193] The product of the present invention also improves the particle size and stability of PB15:3.

[0194] Application Example 2: Eco-solvent dispersion

[0195] As a second step, a solvent-based pigment dispersion with an organic pigment was prepared in diethylene glycol diethyl ether (DEGDEE) using Pigment Red 146 (Permanent Carmine FBB02). The components shown in Table 4 were combined in a 100 mL glass bottle and then dispersed in a Lau disperser with 100 g of zirconium oxide beads (0.5 mm) to form a pigment concentrate (using cooling level 3, shaking for 16 hours).

[0196]

[0197] Table 4: Composition of the pigment concentrate. DEGDEE is diethylene glycol diethyl ether; Permanent Carmine FBB02 is an organic red pigment from Clariant with the color index Pigment Red 146.

[0198] The viscosity and particle size of the pigment concentrates were measured directly after grinding and after storage (2 weeks at 60° C.). The viscosity and particle size values ​​of the pigment concentrates using the polymer of Example 14 (according to the invention) and the polymer of Comparative Example 1 are listed in Table 5 below. The viscosity and particle size of the pigment concentrates were measured using an Anton Paar rheometer (25 mm Φ, 1°, 25° C.) at 100 s -1 The viscosity was measured at a shear rate of 1.5 Å. The particle size was measured by dynamic laser scattering (NanoPlus DLS).

[0199]

[0200] Table 5: Viscosity and particle size values ​​for samples of pigment concentrate Permanent Carmine FBB02 (PR146).

[0201] The samples of the present invention showed a better viscosity reducing effect than the comparative examples.

[0202] Application Example 3: UV Curable Dispersion

[0203] As a third step, a UV-based pigment dispersion containing organic pigments was prepared using Pigment Yellow 155 (Inkjet Yellow 4GC), Pigment Red 122 (Fastogen SuperMagenta RG) and Pigment Blue 15:4 (Heliogen Blue D7110F) in a 1:1 mixture of PONPGDA / DPGDA. The components shown in Table 6 were combined in a 100 mL glass bottle and then dispersed in a Lau disperser with 100 g of zirconium oxide beads (0.5 mm) to form a pigment concentrate (using cooling level 3, shaking for 16 hours).

[0204]

[0205] Table 6: Composition of pigment concentrates. PONPGDA is propoxylated 2-neopentyl glycol diacrylate, DPGDA is dipropylene glycol diacrylate, Inkjet Yellow 4GC is an organic yellow pigment from Heubach (formerly Clariant) with the color index "Pigment Yellow 155", Fastogen Super Magenta RG is an organic magenta pigment from DIC with the color index "Pigment Red 122", Heliogen Blue D7110F is an organic cyan pigment from DIC (formerly BASF) with the color index "Pigment Blue 15:4".

[0206] The viscosity and particle size of these pigment concentrates were measured directly after grinding. The viscosity and particle size values ​​of the pigment concentrates using the polymers of the invention and the polymers of Comparative Example 1 are listed in Tables 7, 8 and 9 below. Anton Paar rheometer (25 mm Φ, 1°, 25° C.) was used for 100 s -1 The viscosity was measured at a shear rate of 1.5 Å. The particle size was measured by dynamic laser scattering (NanoPlus DLS).

[0207] <![CDATA[Within 100 s -1 , mPa]]> Particle size (D50, nm) Polymer samples Pigment concentrate PY155 Pigment concentrate PY155 Comparative Example 1 62.0 169 Example 10 49.0 162

[0208] Table 7: Viscosity and particle size values ​​for samples of pigment concentrate Inkjet Yellow 4GC (PY155) The samples of the invention show a better viscosity reduction effect than the comparative examples.

[0209] <![CDATA[At 100 s -1 Below, mPa]]> Particle size (D50, nm) Polymer samples Pigment concentrate PR122 Pigment concentrate PR122 Comparative Example 1 73.8 180 Embodiment 18 41.9 157

[0210] Table 8: Viscosity and particle size values ​​for samples of pigment concentrate Fastogen Super Magenta RG (PR122) The samples of the invention show better viscosity and particle size reduction than the comparative examples.

[0211] <![CDATA[At 100 s -1 under, mPa]]> Particle size (D50, nm) Polymer samples Pigment concentrate PB15:4 Pigment concentrate PB15:4 Comparative Example 1 86.0 130 Example 10 65.9 125

[0212] Table 9: Viscosity and particle size values ​​of pigment concentrate Heliogen Blue D7110F (PB15:4) samples The samples of the invention show better viscosity and particle size reduction effect than the comparative examples.

Claims

1. A method for preparing a block copolymer, comprising carrying out the following polymerization in an aqueous medium under reversible-addition-fragmentation chain transfer polymerization conditions: a) polymerizing a first monomer composition to prepare a first polymer block, the first monomer composition comprising 0.0-40.0 mol % of methacrylic acid and at least 50.0 mol % of one or more polymerizable ethylenically unsaturated monomers having a water solubility of greater than 500 g / l at 20° C., the polymerizable ethylenically unsaturated monomers being selected from monomers having an ether group and monomers having a hydroxyl group; and b) polymerizing a second monomer composition to prepare a second polymer block, the second monomer composition comprising at least 60.0 wt % of one or more polymerizable ethylenically unsaturated monomers having a water solubility of less than 50 g / l at 20°C.

2. The method of claim 1, wherein the first monomer composition comprises 0.0-25.0 mol% of methacrylic acid.

3. The method according to claim 1 or 2, wherein the block copolymer has a number average molecular weight in the range of 5000-30000 g / mol.

4. The method of any one of the preceding claims, wherein the second monomer composition comprises at least one of 4-vinylpyridine, 2-vinylpyridine, and styrene.

5. The method according to any one of the preceding claims, further comprising the step of adding a third monomer composition after the second block is prepared to prepare a third block.

6. The process according to any one of the preceding claims, wherein the process is carried out in the presence of a defoaming agent.

7. The method of any one of the preceding claims, wherein the first monomer composition comprises at least 60.0 wt% of one or more polymerizable ethylenically unsaturated monomers having a water solubility greater than 500 g / l at 20°C.

8. The method according to any one of the preceding claims, wherein the method is carried out in the presence of: i) a free radical generator having a water solubility of greater than 10 g / l at a temperature of 20°C; and ii) A chain transfer agent having a thiocarbonyl-thio group represented by the formula (I) -C(=S)-S-.

9. A block copolymer comprising: a) a first block comprising polymerized units of one or more polymerizable ethylenically unsaturated monomers, wherein the first block comprises 0.0-40.0 mol % of polymerized units of methacrylic acid and at least 50.0 mol % of polymerized units of one or more polymerizable ethylenically unsaturated monomers having a solubility in water at 20° C. greater than 500 g / l and selected from monomers having an ether group and monomers having a hydroxyl group; and b) a second block comprising polymerized units of one or more polymerizable ethylenically unsaturated monomers, wherein the second block comprises at least 60.0 wt. % of polymerized units of one or more polymerizable ethylenically unsaturated monomers having a water solubility at 20° C. of less than 50 g / l. 10 . The block copolymer according to claim 9 , wherein a weight ratio between the first block and the second block is in the range of 50:50 to 95:

5. The block copolymer according to claim 10 , wherein the block copolymer comprises a third block.

12. An aqueous composition comprising water and a block copolymer according to any one of claims 9 to 11.

13. Use of the block copolymer according to any one of claims 9 to 11 or the aqueous composition according to claim 12 as a dispersant for solid particles.

14. The use according to claim 13, wherein the solid particles comprise at least one of pigment particles and filler particles.

15. A method for dispersing solid particles in a dispersion medium, comprising the following steps: i) providing a block copolymer according to any one of claims 9 to 11 or an aqueous composition according to claim 12, ii) providing solid particles, iii) providing an aqueous dispersion medium or using water in an aqueous composition according to claim 9 as a dispersion medium, iv) mixing the components provided in steps i) to iii) in any suitable order and applying shear forces.

16. A coating composition comprising: a) solid particles, b) a block copolymer according to any one of claims 9 to 11, and c) Film-forming binders.

17. The coating composition of claim 16, wherein the composition is an aqueous composition comprising a continuous aqueous phase.

Images