CA1065884A - Polymerizable compounds containing tribromomethyl groups - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE: New Compounds containing tribrom-methyl groups, of the general formula

Description

1~16~8~

QqZo 3~97~;;
POLYMERIZABLE COMPOUNDS CONTAINING TRIBROMO~ETHYL GROUPS :
The invention relates to ethylen;cally unsaturated compounds containing tribromomethyl groups, which may be used as monomers .:
for the manu~acture of homopolymers and copolymersO
German Published Application 2,252,908 de~cribes the manu-~acture of polymer~ o~ the 132,2,2-tetrachloroethyl ester of a¢rylic acidO However~ it has not hitherto proved possible to manu-facture vinyl compound~g containing tribromomethyl groups, in suf~icient purity ~or polymerization Furthermore, in most cases :~`
high molecular weight materials were not obtainable hitherto ~rom :
the con~entional compounds of this type 9 ~ince the power~ul chain transfer action o~ the bromine atom~ in the kribromomethyl ~roups resulted in compounds of relatively low molecular weightO
It is an object o~ the present ;nvention to provide compounds, containing tribromomethyl groups, which can be used ~or the manu-~acture o~ homopolymer~ and copolymersO It is a further object of the învention that the compounds containing tribromomethyl groups should be capable o~ ~imple and economical manufacture, in very high yield and great purityO

5~4 We have found that this object is aehieved by ethylenically unsatured compounds, containing tribromomethyl groups, of the general formula ..

' R -C~=C .
COO-C~l~cBr3 in which X is chlorine or bromine, R is hydrogen or methyl and is hydrogen or a ~roup of the formula -COO-CHX-CBr3.
Preferred compounds are the l-chloro-2,2,2-tribromo-methyl esters and the 1,2,2,2-tetrabromoethyl esters of acrylic acid, methacrylic acid, maleic acid and fumaric acid.
The compounds according to the invention can be manufactured by reacting the eorresponding acid chlorides or acid bromides with equivalent amounts of tribromoacetaldehyde.
The acid chlorides and bromides have -the general formula R2 -CH=CR-CX
O :
wherein X is chlorine or bromine, R is hydrogen or methyl and ~
R is hydrogen or -COX. The reaction is carried out in the .~ .
presenee of from 0.1 to 10 per cent by weight of a Lewis acid, preferably AlBr3 or ~eBr3, at from 0 to 80C, generally with reac-tion times of from 1 to 10 hours, preferably from 2 to 3 hours.
The reaction is carried out without solvents or, with particular advantage, in a solution, of about 50 per cent strencJth, in an inert aliphatic, cye:Loaliphatie or aromatie solvent, ecJ. hexane mixtures, oetane mixtures, eyelohexane or toluene. To achieve both good yield and high purity of the compounds according to the invention it is desirable to add from 0.1 to 10 per cent by weight of magnesium oxide to the reaetion mixture, or extract the reaction mixture with aqueous sodium bicarbonate solution, prior to -the distillation. The compounds according to the invention are colorless oily liquids which ean be distilled without decomposition at the reduced pressure generated by a difEusion pump, and can thus be

- 2 -~ ~ 6 5~ ~ ~ oOzO 30,987 obtained ;n a pure ~orm I~ attempts are made to manu~acture the compounds according to the invention, containing tribromomethyl groups3 under the process conditions described in German Published Application 2,252,908, the products are only obtained in very low yield and in most cases, in insuf~icient purityO It was not foreseeable ~hat it would be possible to manu~acture these compounds in the -desired purity and in satis~actory yield by using the process conditions according to the invention~ It is equally surprisin~ :
that the compounds according to the invention can be polymerized to high molecular we;ght substances, ;n spite o~ the known chain transfer e~fect and regulating e~fect of the bromine atoms in the tribromomethyl groupsO To obtain the high molecular weight substances, the compounds containing -CBr3 groups are polymerized, if desired to~ether with other olefinically unsaturated monomers, in accordance with the conventional rules ~or the free radical polymerizakion o~ vinyl monomersO
Suitable ole~inically unsaturated comonomers are olefins, such as ethylene~ butadiene, isoprene~ styrene and substituted 2G styrenes, such as ~-methylstyreneg p~chlorostyrene and p-methyl-styrene, acrylic acid esters and methacrylic acid esters derived ~rom alcohols of 1 to 18 carbon atoms, preferably of 1 to 8 carbon atoms, ~or example acrylic or methacrylic acid esters of methanol, ethanol, butanol or ethylcyclohexanol, acrylamide and methacryl-amide and the corresponding N substituted amides, such as N-methylol-acrylamide 9 N-methylolmethacrylamide and their ethers3 such as N-methylolacrylamide butyl ether and N-methylolmethacrylamide methyl ether, acrylonitrile and methacrylonitrile, vinyl esters, such as vinyl acetate and vinyl propionate, vinyl ethers, such a~

methyl vinyl ether, ethyl vinyl ether or alkyl vinyl ethers wherein alkyl is of 3 to 6 carbon atoms, and also fumaric3 maleic acid or itaconic acid and esters and anhydrides o~ these acidsO

. .: . , .. : ~ .... :

~65~8~ oOz~ 303987 It is also possible simultaneously to copolymerize 2 or more of the above compounds with the compounds containing tribromomethyl groups.
To manu~acture the copolymers, the proportion of compounds, containing tribromomethyl groups, in the monomer mixture may vary within wide limits, egO ~rom 1 to 99 per cent by weight and especially from 10 to 90 per cent by weightO
Conventional in;tiators whlch form free rad;cals are used to initiate the polymerizationO Examples o~ suitable initiators are hydrogen peroxide, organic hydroperoxldes and peroxides, egO caproyl peroxide, lauroyl peroxlde, tertOobutyl-perbenzoatesg :~
dicumyl peroxideg p~menthane hydroperoxide and cumene hydroPer-oxide as well as aliphatic azo compounds which decompose ;nto free radicals under the polymerization conditions, such as 2,2'-azo bis~2,4-dimethylvaleronitrlle, 2,2~ azo-bis-iso-butyronitrile and analogous azonitriles, ~uch as are listed, egO, in J0 Hine, "Reaktivitat und Meohanismus in der organischen Chemie", published by Georg Thieme, Stuttgart (1960), page 412, as well as conventional Redox catalyst systems, egO the systems compri~ing pota~sium persulfate or ammonium persul~ate and ascorbic acidS sodium bi~ul~ate or iron II salts Furthermore~ the chelates o~ transition metals ~nown to form free radicals may be u~ed, particularly those in which the metal has an unusual valency, eg. chelates Or mangane~e (III), cobalt-(III), copper (II) and cerium-(IV)0 In general, 1,3-di-carbonyl compound5 are used to ~orm the chelatesO Examples of the chelates are manganese-(III) acetylacetonate and the cobalt-(III) chelate of ethyl acetoacetate~
In general~ from 0005 to 5 per csnt by weight, based on

3 monomer, o~ the initiators are usedO The optimum amount, and the most effective initiatorg may readily be establ;shed by experiments~
The polymerization can be carried out in bulk, but is advan-~ 4 --- ;
~58~4 o~z. 30~897 ~
tageously carr;ed out in the presence of æolvents or diluentsO
Examples of very suitable ~olvents or diluents are alcohols, egO methanol, ethanolg propanol or butanol, ketones, e~0 methyl ethyl ketone or methyl propyl ketone, ethersg egO tetrahydro- ~ :
furan or dioxane9 allphatlc3 cycloaliphatic or aromatic hydro-carbons, egO heptane, hexane, cyclohexane or benzene, and ~orm- :
amide and dimethyl~ormamideO In many cases it ls particularly advantageous to use water as the diluent0 The suspension polymerization3 solution polymerization or emulsion polymerization processes conventionally used with other monomers are also applicable to the compounds contain;ng tribromo-methyl groupsO The assistants which may be used in the polymerization process, egO buffersg d;spersin~ agents, nrotective collo;ds and the like, are also the .same as those used in conventional processes0 The polymerization may be carried out w;th;n a broad tempera-ture range, ~rom about 0 to 150C, pre~erably ~rom 50 to ~20Co In general, the polymerization is carried out under atmospheric pressure, but lower or higher pressures, egO up to 3,000 atmospheres, -may also be u~edO When using low-boiling comonomers, in particular, superatmospheric pressures are used to ensure an adequate concen-20 tration o~ the comonomer in the reaction mixture, The copolymerization of the unsaturated compounds w;th ethyleneor butadiene can advantageously be carried out in emulsion by introducing the copolymerizable monomers into an aqueous soap emuls;on which conta;ns an ;n;t;ator, a buf~er system and, if appropr;ate, a protective colloid3 and carrying out the poly-merization at superatmospheric pressure0 The copolymerization with acrylic acid esters is suitably carried out in aromat;c or aliphatic hydrocarbons under the condit;ons known for the oly-merizat;on of acrylic acid esters~ ; :

Examples o~ the uses o~ the polymers, ;~ appropriate mixed with other plastics, egO wlth polyethylene, polypropylene or co-polymers of ethylene and vinyl acetate3 are the manufacture o~
~ 5 -1 ~ 6 5~ ~ ~ oOzO 30,897 moldings, coatings or adhesivesO Such products are flameproo~0 Because of their surf'ace~active properties, the polymers manu-factured accordi.ng to the invention may also be used, inter alia~
for flnishing paper and text;les, and permit further secondary react;ons to take place via the trlbromomethyl groupsO
In the Examples, parts and percentages are by weight. The K values are a measure of the mean molecular we;ght and were determlned in 1 per cent strength solut;on in dimethylformamlde ~:~
by the method o~ H~ Fikentscher, described in 7'Cellulosechemie"
13, (1932), page 580 1 part of anhydrous iron-III chloride Is added caref'ully in portions~ in the course of 10 minutes, to 90~5 parts of acrylic acid chloride) 28i parts of tribromoacetaldeh~de and 200 parts of benzeneO The heat of reaction is conducted away by cooling with ice so that the temperature in the reaction vessel does not exceed 70Cô The mixture is then stlrred for 4 hours at 70C~ after which 2 parts of magnesium chloride are addedO The benzene solution is concentrated and the res;due is distilled at f'rom Ool to 002 mm Hg and from 77 to 81C through a 20 cm column (containing 5 mm Raschig rings)0 265 parts of the 1-chloro-292,2-tribromoethyl ester o~ acrylic acid are obtained, corresponding to a y;eld of 7104%.
The product contains 6404% of bromine (theoret1.cal content 64~6%)o EXAMPI~ 2 lOoO parts of the ester CH2=CH-C00-CHC1-CBr3, manufactured in Example 1, in ~0 parks of benzene and Ool part o~ azobisiso-butyronitrile are heated at 60C f'or ll hours under nitrogen, whilst stirringO Af`ter stripp;ng off the benzene, washing the residue with methanol and drying~ 900 parts of a polymer are obtainedg which has a K value of' 9206, a glass transition temperature T~
of ~63C and a refractive index nDof 1052930 ~OG5884 OOZ 30,897 EXAMP~ES 3 T0 13 2503 parts Or aluminum bromide are added ln the course of 10 minutes~ at 0C~ to 10405: parts of methacryllc acid chloride, the equimolar amount o~ tribromoacetaldehyde and 200 parts of benzeneO The temperature rises to 10C, and the mixture is cooled with iceO 300 parts o~ benzene are then added and the reaction solution is stirred ~or 6 hours and then heated to 30C, and worked .
up analogously to Example lo The l~chlor-2,292-tribromoethyl ester o~ methacrylic acid ls obtained in 4504 per cent yieldO The product contains 6201% o~ bromine (theoretical content 6203%)o 10This ester and ethyl acrylate are mixed ;n the rat;os shown in Table 19 and after addition of 001% of azobislsobutyronitrile each mixture is heated, in the presence of 100 parts o~ benzene3 .
at 70C for 2 hour~0 After removing the benzene ;n a rotary evap-orator, the copolymers are dried for 10 ho~rs in a vacuum drying oven at 60C and 12 mm H~o The results are ~hown in Table lo ~ABLE 1 :;

NoO Ethyl -CBr deri- Conver~ion K value Proportion o~
acrylate 3 the bromine deri- :
part~ vative % vative in the part~ copolymer9 ln %
by weight - .
3 9o9 Ool 9Q00 7605 loO

4 905 005 8605 8605 L~o5 9oO loO 8700 8300 80 ~
6 835 105 8700 81~oo 1401 9 600 l~oO 9200 8805 3704 500 500 9405 88,o 4407 13 1,0 900 9905 90,0 8100 ~ 7 -. ~ ; . .

LQ~,58~`
OOZO 3098q7 EXAMPLES 14 TO 17 -:
If the procedure descrlbed in Example lO is ~ollowed but ~ ~:
one of the compounds shown below is used as the -CBr3 compound, ~:~
the results shown in Table 2 are obtai.nedO .

NoO K value TG C Type , 76 i~ 88 CH2 = C - COO - CHBr - CBr3 4 3 ~ 5 + 2 6 CH = CH
COOR COO ~ CHCl~C Br - R :~
16 34 ~ 33 ROOC
CH = CH
COOCHCl - CBr3 17 78 + 7005 CH2 = CH - COOCHBr - CBr3 I~ the procedure described in Example 2 is ~ollowed but in add~tion one or more comonomers are used, the results shown below are obtained (Table 3)~ -~ABLE 3 NoO K value T~ C Comonomers Type Amount 18 34 ~68 styrene 1~ parts 19 43 ~ 88 styrene/70 parts acrylic acid 20 par~s - 11 n-butyl 10 parts acrylate 21 69 ~ 64 acrylo- 5 parts n;trile ' ' ' ', ~ .

Claims (2)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Compounds containing tribromomethyl groups, of the general formula in which X is chlorine or bromine, R is hydrogen or methyl and R1 is hydrogen or a group of the formula -COO-CHX-CBr3.

2. A process for the manufacture of the compounds containing tribromomethyl groups as defined in claim 1, wherein unsaturated acid halides of the general formula R2-CH=CR-COX
in which X is chlorine or bromine, R is hydrogen or methyl and R2 is hydrogen or -COX, are reacted with equivalent amounts of tribromoacetaldehyde in the presence of Lewis acids at from 0 to 80°C.