Fine dispersions of acrylic polymers in water (known as latexes) are used for surface applications, e.g., to produce coatings, paints and adhesives. The polymerization method employed to produce the polymer is generally emulsion polymerization. That is, the monomer (s), a suitable surfactant and a water soluble initiator are combined in water to give polymer particles with diameters typically in the range from 0.05 to Ιμπι dispersed in water.

Flame retardants are required to reduce the flammability of the coatings and paints that are ultimately obtained from the aqueous dispersions described above. One approach to achieve this goal is with the aid of (non-reactive) flame retardants additives, which are included in the aqueous dispersion. However, since the additives are not chemically bonded to the polymer, they are susceptible to separation and migration.

Another approach, which seems to be more desirable, involves the incorporation of bromine-containing units into the polymer chains. This could be achieved with the addition of bromine- containing monomers prior to emulsion polymerization, to enable copolymerization reaction whereby the bromine- containing monomer reacts with the conventional acrylic monomers to produce a copolymer comprising bromine containing repeat units. It was reported in WO 92/04387 that ring- brominated aromatic monomers with vinyl functionality, specifically bromine-substituted styrene, can take part in emulsion polymerization with acrylic monomers to form latex with reduced flammability. Specifically, in WO 92/04387 dibromostyrene was used, apparently owing to its ability to dissolve well in the mixture of acrylic co-monomers. In US 7,932,338 there is illustrated an emulsion polymerization process to produce a copolymer of acrylic monomers and pentabromobenzyl acrylate - again a monomer with aromatically-bound bromine having the structure:

Pentabromobenzyl acrylate is commercially available in a powder form with average particle size of a few microns. According to US 7,932,338, pentabromobenzyl acrylate was first dispersed in water with the aid of dispersing agents; the dispersion was milled and then added slowly to a reactor which was previously charged with a pre-emulsion of the other acrylic monomers. The initiator solution was fed to the reactor and the copolymerization in emulsion was successfully accomplished .

From the above it can be seen that in general, bromine- containing monomers do not easily lend themselves to emulsion polymerization. But we have now found acrylate esters with aliphatically-bound bromine that are well suited to obtain copolymerization products through emulsion polymerization. That is, the invention utilizes liquid bromine-containing acrylate esters having bromine atoms bonded to aliphatic (as opposed to aromatic) carbons. The preferred bromine-containing monomers to be used in this invention have the Formula A:

Formula A

wherein X is an acrylic acid residue -C (0) -CH=CH2 or methacrylic acid residue -C (0) -CCH3=CH2. The individual compounds are therefore: CH2 Br O CH2 Br O CH2

BrCH2— t— CH2—O— 'i— CH-==CH2 BrCH2—A— CH2— O— ϋ— ϋ—Me

CH2 Br CH2 Br

These compounds are chemically named:

3-bromo-2 , 2-bis (bromomethyl ) propyl ester of acrylic acid (i.e., 3-bromo-2 , 2-bis (bromomethyl ) -1-propyl acrylate or trinol acrylate (abbreviated sometimes herein "TA"); and

3-bromo-2 , 2-bis (bromomethyl ) propyl ester of methacrylic acid (i.e., 3-bromo-2 , 2-bis (bromomethyl ) -1-propyl methacrylate or trinol methacrylate (abbreviated herein "TMA") .

The aforementioned bromine-containing acrylate esters are liquids at room temperature; they have boiling points generally above 120°C, for example, above 130°C, e.g., in the range from 130°C-150°C (1 mm Hg) , which would be >250°C at atmospheric pressure. Experimental results reported below indicate that they are readily combinable together with conventional acrylic monomers in emulsion polymerization reaction mixture, to obtain bromine-containing copolymer exhibiting useful properties in coating applications, i.e., reduced flammability and good gloss.

Accordingly, one aspect of the invention is a process for preparing an aqueous dispersion of bromine-containing copolymer suitable for surface applications, comprising: combining in water, together with one or more surfactants, the following monomers

A) at least one aliphatic bromine-containing acrylic monomer which is liquid at room temperature; and

B) at least one (non-halogenated) acrylic monomer; and copolymerizing said monomers in emulsion in the presence of water-soluble initiator under heating to obtain particles of a bromine-containing copolymer dispersed in water.

Most preferred are monomers selected from the group consisting of:

CH2 Br CH2Br 0 CH2

BrCH2 t— CH2 CH2 BrCH2- Me

CH2 Br !:H2Br

Formula Al Formula A2

The brominated (meth) acrylate ester of Formulas Al and A2 required as starting materials for this invention can be prepared by reacting aliphatic-bromine containing alcohol, e.g., tribromoneopentyl alcohol:

CH2 Br

BrCH2— t— CH2— OH

CH2 Br

with acrylic or methacrylic acid under conditions known in the art. The esterification reaction takes place in a solvent or a mixture of solvents, with the aid of a catalyst, generally in the presence of a polymerization inhibitor to prevent premature polymerization of the monomer. The crude liquid monomer is recovered using conventional techniques and can be purified. Further information including full preparative procedures can be found in US 3,165,502, US 3,480,600, WO 2011/045780 and US 2012/0203028, where the bromine-containing acrylate esters were purified by chromatography. The concentration of the aforementioned bromine-containing monomer in the reaction mixture is between 5 and 50 by weight, e.g., between 20 and 40 (based on the total weight of the dispersed polymerizable emulsion after the addition of all ingredients) . Other useful liquid brominated acrylate esters have the followin formula:

wherein X is selected from an acrylic acid residue -C(0)-CH=CH2 and methacrylic acid residue -C (0) -CCH3=CH2 (one X may be hydrogen but generally both X moieties contain the (meth) acrylate functionality) . These esters (named herein didinol diacrylate or methacrylate ) are obtainable from the corresponding di-alcohol:

by esterification with acrylic or methacrylic acid.

Preferred (non-halogenated) acrylic compounds for use as co- monomers are acrylates and methacrylates (the salts and esters of acrylic acid and methacrylic acid, respectively) , especially of Formula B:

Formula B wherein Ri is H or methyl and R2 is (optionally-substituted) alkyl, that is, preferably alkyl acrylate and alkyl methacr late of Formulas Bl and B2 respectively:

Formula B2

wherein R2 is an alkyl group such as linear or branched C1-C10, preferably C1-C5 alkyl, e.g., methyl, ethyl, propyl (e.g., n- propyl) and butyl (e.g., n-butyl), wherein the alkyl group may be substituted, e.g., with one or more hydroxyl groups, and mixtures thereof. Especially preferred co-monomers are ethyl acrylate, n-butyl acrylate and methylmethacrylate . The parent acid - acrylic acid or methacrylic acid - may also be used in small amounts. The total concentration of the acrylic monomers in the reaction mixture is between 10% and 70% by weight, e.g., between 20% and 50% (based on the total weight of the dispersed polymerizable emulsion after the addition of all ingredients) . It should be noted that when monomers of Formulas Bl and B2 are both added to the reaction mixture, then R2 is independently chosen. Additional acrylic monomers to be specifically named include acrylamide, acrylonitrile , 2- ethyl hexyl acrylate, tricyclodecanedimethanol diacrylate (available as SR833S from Sartomer) , ethoxylated ( 4 ) - pentaerythritoltetraacrylate (available as SR494 from Sartomer) ] .

Regarding the surfactants (the terms "surfactants", "surface active agents", "emulsifiers", "dispersants", "dispersing agents" are used herein interchangeably) , it should be noted that the surfactants of choice should be able to stabilize the starting emulsion composition containing the individual co- monomers, enable efficient copolymerization reaction and stabilize the copolymer aqueous dispersion product. To this end, a combination comprising at least one anionic dispersing agent and at least one nonionic dispersing agent is employed.

As an anionic dispersing agent, a sulfonate or sulfate, in the form of alkali, alkaline earth or ammonium salt could be used, e.g., alkyl aryl-based, such as alkyl aryl sulfonic acid or alkyl aryl sulfonate. For example, ammonium salt of poly aryl phenyl ether sulphate can be used, available commercially as Soprophor® from Rhodia Chemical Company. Other suitable anionic dispersing agents are the sodium salt of alkyl naphthalene sulfonate formaldehyde condensate, available from Akzo Nobel; sodium lauryl sulfate, available from Mosselman and sodium di (2-ethylhexyl) sulfosuccinate, which is commercially available from Clariant GmbH.

Suitable non-ionic dispersing agents for use in the present invention are known in the art and are commercially available. For example, emulsion of a structured acrylate copolymer available commercially from DisperBIK® from BIK Chemical Company. Other suitable non-ionic dispersing agents are secondary alcohol ethoxylate, available from Dow; EO/PO block co-polymer, available from KLK OLEO and polyoxyethylene Copolymerisable, which is commercially available from Croda.

The anionic and nonionic dispersing agents are used at varying weight concentrations, each at a concentration in the range from 1% to 5% by weight, e.g., between 2% to 3% (based on the total weight of the dispersed polymerizable emulsion after the addition of all ingredients) . Regarding the initiator, a free radical initiator which exhibits good solubility in the aqueous phase is used. By the term "water-soluble initiator" is meant an initiator with solubility in water at 20°C of at least 1 g/liter, e.g., at least 20 g/liter, and even more specifically, at least 200 g/liter. To this end, water soluble persulfate salts are especially preferred. Utilizable persulfates include potassium persulfate (27g/l at 20°C), sodium persulfate (238g/l at 20°C) and ammonium persulfate (228g/l at 20°C) . Water soluble peroxides and hydroperoxides, as described in J. Org. Chem 60 (16), p. 5341-5345 (1995), can also be used. Water soluble free radical initiators operative in the present invention may be also selected from the class of Redox initiators, namely, a pair of initiators consisting of water soluble oxidant (e.g., a persulfate salt) in combination with a water soluble reductant (metabisulfite salt) . Other useful thermal initiators may be selected from the group of water-soluble azo compounds, such as 2 , 2 ' -azobis- ( 2-amidinopropane*HCl ) . The initiator loading is preferably between 1 to 10% w/w based on the monomers, preferably about 2 to 7%, e.g. about 5%.

It should be noted that a third type of monomers - one or more vinyl aromatic monomers - may be added to the reaction mixture to take part in the emulsion copolymerization, such as, styrene or styrene-based monomers, e.g., an alkyl-substituted styrene. Such secondary monomer (s) can be added to the reaction mixture in an amount of up to 20 % by weight, for example, 3-13%, e.g., about 10% (based on the total weight of the dispersed polymerizable emulsion after the addition of all ingredients) . Preferred vinyl aromatic monomers have the Formula C: Formula C wherein m is 3, 4 or 5, the ring substituent R3 is selected from the group consisting of alkyl (such as methyl and ethyl), vinyl and bromine; and R4 is hydrogen or methyl. For example, m may be 5; in other embodiments, m is 3 or 4 and R3 is alkyl or vinyl .

A poly-functional (either acrylic or non acrylic) bromine- containing liquid monomer can also be added to the reaction mixture, that is, a monomer having two reactive groups, to impart a small degree of crosslinking by joining chains together. Useful poly-functional monomers are bromine- containing diacrylic monomers obtainable for example from brominated epoxy compounds. For example, tetrabromobisphenol A diglycidyl ether, also known as 2 , 2-Bis [ 4- ( glycidyloxy) -3 , 5- dibromophenyl ] -propane, commercially available from ICL-IP as F2200™, may be reacted with an acrylic acid or a methacrylic acid in presence of a polymerization inhibitor, e.g. 4- methoxyphenol or butylatedhydroxytoluene, to furnish, e.g. di- (meth) -acrylated-F2200. The reaction is conducted in a suitable solvent, e. g. in an aromatic hydrocarbon, such as in toluene, or a halogenated hydrocarbon, such as chlorobenzene, at elevated temperatures, e.g. at reflux. Upon cooling and workup, the organic phase may be dried over suitable drying agent, e.g. sodium sulfate or magnesium sulfate, and evaporated to provide the bromine-containing poly-functional acrylic monomer of Formula D:

The compound of Formula D is recovered from the synthesis described below under Preparation 1 as viscous oil. The compound of Formula D and its use in emulsion polymerization form additional aspects of the invention. It can be added to the reaction mixture in an amount of up to 8 % by weight, for example 3 to 7, e.g., around 5% (based on the total weight of the dispersed polymerizable emulsion after the addition of all ingredients) . Another useful poly-functional bromine- containing liquid monomer which could serve the purpose of crosslinking is the aforementioned didinol diacrylate or methacrylate .

To summarize, the co-monomers A, B, C and D are preferably employed in the following proportions:

Table 1

The emulsion copolymerization according to the invention may be accomplished via a one-step process where all ingredients are charged into the reaction vessel or via a two-step process, with a formation of an initiator-free emulsion (also named herein as ' pre-emulsion ' ) in the first step, followed by the step of emulsion polymerization induced by the addition of the initiator and heating (named herein 'polymerizable emulsion ' ) . For example, one variant of the process of the invention comprises charging a reaction vessel with water and surfactant ( s ) , adding the co-monomers to obtain an emulsion, feeding this pre-emulsion to a polymerization reactor previously charged with water and adding the initiator under stirring. In a preferred embodiment, the process comprises concurrently adding the emulsion and an aqueous solution of the initiator to the reactor via two separate feed streams, at a fairly slow feed rate, e.g., during not less than 3 hours, for example, not less than 5 hours. The temperature of the reaction may be from 60°C to 100°C, inclusive, more preferably 70°C to 90°C, inclusive, more preferably 85°C. Upon completion of the addition, the reaction mixture is stirred for an additional period of time, optionally filtered to remove large copolymer particles thereby obtaining the aqueous dispersion product. The pH may be corrected by the addition of a base and auxiliary ingredients may be added to obtain a finished formulation suitable for use for surface application (e.g., dispersing agents which may be the same or different than previously used in the emulsion polymerization process, rheology modifiers, thickeners, etc.) .

Another aspect of the invention is a copolymer obtainable by the emulsion polymerization, wherein the copolymer comprises:

A) a first type of repeat unit derived from aliphatic bromine- containing acrylic monomer, e.g., aliphatic bromine-containing (meth) acrylate, that is, an ester of acrylic acid or methacrylic acid with aliphatic bromine-containing alcohols, and

B) a second type of repeat unit derived from (non-halogenated) acrylate monomer or a methacrylate monomer. More specifically, the invention provides an aqueous dispersion comprising particles of the aforesaid copolymer. The preferred copolymer comprises:

a first repeat unit selected from the group consisting of romine-containing structural units of Formulas Al or A2 ;

Al A2 a second repeat unit selected from the group consisting of alkyl acrylate of Formula Bl and alkyl methacrylate of Formula B2 :

wherein R2 is as previously defined. Preferably, R2 is an alkyl group such as linear or branched C1-C10, preferably C1-C5 alkyl, e.g., methyl, ethyl, propyl (e.g., n-prpoyl) and butyl (e.g., n-butyl), wherein the alkyl group may be substituted, e.g., with one or more hydroxyl groups. In Formulas Bl and B2, R2 is more preferably selected from methyl, ethyl and n-butyl.

The copolymer may further comprise a third type of monomer unit : wherein m, R3 and R4 are as previously defined for the corresponding monomer of Formula C.

Chains of the copolymer may be joined by a structural unit corresponding to the monomer of Formula D.

Thus, specifically provided herein are copolymers of acrylate with mixtures of brominated acrylates (bromine-containing acrylic monomers) . For example, provided herein is a copolymer of acrylate with 3-bromo-2 , 2-bis (bromomethyl ) -1-propyl acrylate (trinol acrylate (TA) ) and optionally 2,2-Bis[4- ( glycidyloxy) -3, 5-dibromophenyl] propanediacrylate (F2200- diacrylate) . Such copolymers form an aspect of the invention.

The copolymer is preferably provided in an aqueous dispersion, that is, the copolymer is dispersed in water with the aid of surfactants/dispersants . The solid content of the aqueous dispersion may vary from 5 to 60 % by weight, e.g., from 30 to 55 % by weight, more specifically from 45 to 50%. The solid content is determined after night exposure at room temperature, followed by drying for 2h at 80°C in a vacuum oven .

The concentration of the dispersing agent (s) in the aqueous dispersion is from 2 to 20 % by weight, e.g., from 5 to 10 % relative to the solid copolymer. Thus, in compositions according to the invention the copolymer of the invention is usually combined with a surfactant or combinations of surfactants, more preferably a combination of an anionic and a non-ionic surfactant, as described above.

The bromine-containing copolymer of the invention is characterized in having bromine content of at least about 1% (w/w percentage) . According to one embodiment the bromine- containing copolymer of the invention has bromine content of 1-55%, inclusive, according to another embodiment the bromine content is between 2 and 40%, inclusive, and according to another embodiment the concentration of bromine is not less than 6%, e.g., 6-20%, inclusive. Bromine content of the dry film obtained from the dispersion is measured by the Parr Bomb method, involving the decomposition of bromine-containing organic compound to give bromides, followed by potentiometric titration .

The particle size distribution as measured by laser diffraction (e.g., Malvern master sizer 3000) is characterized by ϋ9ο<1.0μπι. For example, the particles may possess a particle size distribution characterized by 0.01<Dio≤0.6 and/or 0.3<D ₅ o≤0.7 and/or 0.5<D ₉ o≤l .0 μπι.

The aqueous dispersions of bromine-containing acrylic copolymers are useful in various surface applications, e.g., coatings and paints. Prior to application, auxiliary additives may be incorporated in the aqueous dispersion, e.g., plasticizers, dyes, pigments, wetting and dispersing agents; ultraviolet (UV) absorbers; UV light stabilizers; defoaming and antifoaming agents, preservatives, fillers, solvents, coalescing agents, rheology modifiers, cross linkers, hardeners, curing agents and more, to obtain formulations for surface application. The resultant coatings and paints exhibit good flame retardancy and other useful properties, such as high gloss and abrasion resistance. The glass transition temperature (Tg) of the copolymers of the invention may vary in a broad range, with non tacky/sticky paints and coatings being easily obtainable upon adjusting the Tg, e.g., to be above 10°C (by suitably proportioning the bromine-containing and bromine-free monomers), for example, above 14°C.

Accordingly, another aspect is the use of a composition comprising the aqueous dispersion of the invention for surface applications. A coating formulation or a paint formulation comprising the copolymers of the invention and a method of applying same onto surfaces to form coatings and paints constitute additional aspects of the invention.

Examples

Methods

Testing methods

Description of the analytical methods and chemical/physical testing methods that were used in testing of the compositions according to the invention are provided in Table 2.

Table 2

The above methods are shortly described herein:

PSD - The test is conducted in water at 1500 rpm speed adding 3 drops of sample to the testing vessel. The result is the average of three runs.

Gloss - micro-Tri-gloss by BYK is measuring the gloss using three degrees - 20°, 60° and 85°. The equipment is being placed on the substrate and the measurement is taken.

%Br - Thermal decomposition of the sample by Parr Bomb method in the presence of sodium peroxide and sucrose. Potentiometric titration of bromide ions by Metrohm equipment.

Dry abrasion (ASTM D2486)- 2000 cycles of brushing are applied on coated plywood using a nylon bristle brush inside the abrasion scrub tester (BYK catalog number 5005) . The measurement is based on visual inspection. Cold liquid resistance (BS EN 12720) - wine, coffee, tea, water, oil and vinegar were applied separately on painted plywood for 24h following with gentle wiping. A visual inspection was done with internal grading the stains on the board (5 - no change; 4 - minor change; 3 - moderate change; 2- significant change; 1 - strong change) .

NFPA 701 test method #1 - This is a standard method of fire tests for flame propagation of textiles and films, used as a small scale flammability test as indication for flame retarded coatings. In this test, a hanging test specimen (coated plywood) is exposed to flame for 45 seconds. The delta between the time after the flame is automatically shut-down and the subtract flame is self-extinguished is the reported time. Fail result is reported if water must be applied on the burning sample in order to extinguish it.

Example 1

General procedure for linear acrylate polymer emulsion

Step 1: pre-emulsion preparation

To water (60 ml) were added 7.5 g of Poly (oxy-1 , 2-ethanediyl ) , a-sulfo-ω- [ tris ( 1-phenylethyl ) phenoxy ammonium (Soprophor® 4D/384) and 7.5g of DisperBYK2010® (commercially available mixture of undisclosed dispersants, available from BYK, ALTANA group), at room temperature. When a clear solution was obtained the following acrylates were slowly added using separate dropping funnels (over 2 hours) : 69.3 g of butylacrylate (BA) , 54 g of methylmethacrylate (MMA) , 1.56 g of acrylic acid (AA) and 31.2 g of 3-bromo-2 , 2- bis (bromomethyl ) -1-propyl acrylate ( Trinolacrylate ( TA) ) . At the end of the addition, the emulsion was stirred for another 3 hours and then left to stand without stirring for at least 3 hours. Upon phase separation, if any, the white milky pre- emulsion solution was used as it in the next step. Step 2: emulsion polymerization

A 1-L reactor was loaded with 60mL of water. The solution was heated to 85°C and then the pre-emulsion prepared in step 1 was slowly added by dropping funnel. The catalyst, ammonium persulfate ( 0.6 g in 9 ml of water), was added via a separate funnel for 5-6 hours in such a way that the end of the addition of the acrylates and the catalyst occurred at the same time. The reaction mixture was stirred for another 1 hour at 85°C then cooled to room temperature. The pH was corrected to 7 by the addition of NH4OH (other base may also be used) . The mixture was filtered on fabric to remove large particles of polymers. A final white milky product was obtained and tested for application.

Analysis was performed using the methods set out in Table 2. The following results were obtained:

Tests on dispersion - Solid content: 50.8%.

PSD (um) = Dio:0.43; D ₅₀ : 0.5; D ₉₀ :0.59; D99: 0.66;

Tests on dry dispersion film (see Example 5) - %Br: 11.5%

Tg: 11.52°C

Example 2

General procedure for cross-linked acrylate polymer

The procedure of Example 1 was repeated, with the following, composition of co-monomers being used: 75 g BA; 62.4 g MMA; 1.56g acrylic acid; 15.6 g trinol acrylate (TA) , and 1.56g of F2200-dicrylate with a total volume of water of 165mL. A final white milky product was obtained and tested for application.

Analysis was performed using the methods set out in Table 2. The following results were obtained: Tests on dispersion - Solid content: 49.5%.

PSD (um) = Dio :0.38 ; D ₅₀ : 0.46; D ₉₀ :0.55; D ₉₉ : 0.59

Tests on dry dispersion film (see Example 5) - Tg: 14.6°C

Example 3

General procedure for styrene acrylate copolymer

The procedure of Example 1 was repeated, with the following composition of co-monomers being used: 74.5g BA; 47g styrene and 13.5g TA, with a total volume of water of 165mL. A final white milky product was obtained and tested for application.

Analysis was performed using the methods set out in Table 2. The following results were obtained:

Test on dispersion- Solid content: 41.5%.

PSD (um) = Dio :0.3 ; D ₅₀ : 0.36; D ₉₀ :0.42 ; D ₉₉ : 0.56

Tests on dry dispersion film (see Example 5) - Tg: -2.87°C

Example 4

Comparative example - copolymer without brominated monomer

The procedure of Example 1 was repeated, with the following composition being used: 83.4 g BA; 71 g MMA, 1.56g acrylic acid with a total volume of water of 165 mL . A final white milky product was obtained and tested for application.

Analysis was performed using the methods set out in Table 2. The following results were obtained:

Test on dispersion- Solid content: 48.3%.

PSD (um) = Dio :0.42 ; D ₅₀ : 0.51; D ₉₀ :0.60; D ₉₉ : 0.67

Tests on dry dispersion film (see Example 5) - Tg: 2.7°C

Example 5

Copolymer dispersion formulations and surface applications

Finished formulations for coatings were generally prepared by mixing acrylic dispersions obtained in the Examples 1 or 2, with an additional dispersing agent and a rheology modifier, as set out in the Table 3 below.

Table 3

All dispersions or formulations afforded thin-film products. Generally, the dispersion was applied on drawdown card (byko- chart Opacity, BYK) using automatic film applicator (byko- drive, BYK) with a knife at 120 μπι clearance (Applicator Frame, BYK) , and dried at room temperature (RT) .

The formulations were applied on different panels, depend on the required test (scrub test panel, glass panel, steel panel etc.) with a knife at 300 μπι clearance (Film casting knife, BYK), and dried at RT .

Formulations on wood were applied to provide three layers by a hand brush (around 100 g/m2 coverage) . Example 6 (comparative) and 7 to 10 (of the invention) Preparation of copolymer dispersions, finished formulations, films obtained and properties thereof

In the next set of Examples, dispersions were prepared by emulsion polymerization according to the procedure described in Examples 1 and 2. The compositions set out in Table 4 are expressed as weight % relative to the final dispersion. The following abbreviations are used in Table 4: TA - trinol acrylate; TMA -trinol methacrylate ; BA- n-butyl acrylate ; MMA-methyl methacrylate; AA-acrylic acid; FDA- monomer of Formula D; SI- anionic surfactant Soprophor® 4D/384; S2- nonionic surfactant BYK2010.

Table 4

Finished formulations were prepared from each of the dispersions set out in Table 4 by adding extra dispersing agent and a rheology modifier, as described in Example 5.

Properties of interest were determined for the dispersions of Table 4; films obtained from the dispersions and films obtained from the finished formulations (applied onto a wood surface; the coating consists of three layers) . The results are set out in Table 5. Table 5

Incorporation of liquid brominated acryl monomer in emulsion polymerization resulted is forming a stable dispersion with a desired particle size distribution, that is, ϋ90<1.0μπι, more specifically 0.32<Dio≤0.55 and/or 0.42<D ₅ o≤0.64 and/or 0.54<D ₉₀ ≤0.74.

Incorporation of bromine in acrylic copolymer chains reduces the flammability of the coating and increases gloss from semi gloss film to high gloss (at the 60° angle, the value measured is above 70 and at the 20° angle, the value measured is higher than 30° ) .

Preparation 1

Preparation of F2200-diacrylate

Tetrabromobisphenol A diglycidyl ether (F2200® from ICL) (32.8 g, 0.05 moles) and 0.3 g of butylatedhydroxytoluene (BHT) were dissolved in 120 mL of toluene, and the solution was heated to reflux. The acrylic acid (10.8g, 0.15 moles) was then added dropwise. The reaction was heated for 8 hours until complete disappearance of the starting material. The reaction mixture was cooled to room temperature and was washed twice with aqueous bicarbonate solution and further with water. The organic phase was separated and dried with sodium sulfate. After filtration, the solvent was evaporated in vacuo to give the product as very viscous oil. The product is