IE42818B1 - Polymeric (2-aryloxyethyl)-phosphates - Google Patents

Abstract

1533790 Polymeric phosphorus compounds BAYER AG 14 May 1976 [21 May 1975] 19969/76 Heading C3R The invention comprises polymers with units of formula where R is an aromatic radical and R1 is clorine or bromine, which are prepared by condensing a tris - ( - 2 - halogenoethyl) - phosphate of formula (R1-CH 2 CH 2 O) 3 PO, with a dialkali metal salt of a bisphenol of formula HO-R-OH. In examples polymers are made by reacting tris(-2-chloroethyl)-phosphate with disodium salts of tetra-bromobisphenol A, tetrachlorobisphenol A, bisphenol A and hydroquinone. The products may be used as flameproofing agents for polymers and in an example one is blended with a copolymer of acrylonitrile, vinylidene chloride, methyl acrylate and methallyl sulphonate.

Description

This invention relates to polymeric (2-aryloxyethyl)phosphates.

More particularly, this invention relates to polymeric (2-aryloxyethyl)-phosphates of tris(2-halogenethyl)-phosphates and bisphenolates, preferably halogenated bisphenolates, and to a process for their production.

Xn principle, halogenated phosphates may be produced by several methods, for example by reacting phosphorus oxychloride with alcohols the radical of which (R-) already LO contains halogen atoms. t P0C1,+x Hal-R-OH+(Hal-R-0) -P(Cl), +xHCl However, the disadvantage of this process lies in the reduced reactivity of the third chlorine atom of the phosphorus oxychloride which only reacts at elevated .5 temperatures, the hydrogen chloride liberated readily resulting in acidolytic splitting of the phosphoric acid trialkyl ester formed, so that alkyl chlorides and phosphoric acid partial esters can be formed as main products (D.

Balarew, Z. anorg. Chem 101, 225 (1917))· In addition, halogen-containing alcohols only react sluggishly.

Accordingly, the method based on transesterification or condensation is generally adopted. 0 (RO) (OR' -Hal)x+XHC1 ( RO ) 3_χΡ- ( OR ’ -Hal) x+xHCL Unfortunately, it is often difficult under the relatively drastic reaction conditions applied (l50-200°C), optionally pressure, cf. US Patent No. 3j787,528; US Patent No. 3,787,529, Japanese Patent NO. 7,332,776, to control the reaction in such a way that uniform products are obtained.

In all these reactions, particular compounds can only be isolated with difficulty.

We have now surprisingly found that the reaction of bisphenolates with (2-halogenethyl)-phosphates in a molar ratio of 1:1 should result in the selective formation of reaction products in which two halogen atoms of the starting material are substituted together with chain formation. In this way, linear polymeric phosphates are formed.

Accordingly, the present invention provides polymeric compounds with the recurring structural unit CH2 T CH2 - o - p - o - ch2 - ch2 0CH2CH2R' in which R' represents chlorine or bromine and R represents an aromatic radical.

The present invention also relates to a process for producing polymeric compounds containing the recurring structural unit ‘ -ch2 - ch2-o - P - 0 - ch2 - ch2 - 0 - R - 0. 0CH2CH2R' in which R and R' are as just defined, wherein tris-(2-halogenethyl)-phosphate is reacted with an alkali metal bisphenolate in a molar ratio of 1:1 in a strongly polar organic solvent at temperatures in the range from 50 to 100°C.

In the context of the invention, halogen in the starting compound tris-(2-halogenethyl)-phosphate is chlorine or bromine.

The aromatic radical R in the general formula is derived from the bisphenolate used. Bisphenols suitable for use in accordance with the invention are in particular halogensubstituted, preferably chlorine- and/or bromine-substituted - 3 43818 bisphenols, for example tetrachlorobisphenol A, tetrahromobisphenol A. In addition to these bisphenols, however, it is also possible to use a number of other bisphenols, for example, hydroquinone, l-bis-(4-hydroxyphenyl)-cyclohexano, h,'ί '-dihydroxy biphenyl, bis-(5-chloro-2-hydroxyphenyl)-methane, 1,l-bis-(4-hydroxyphenyl)-ethane and 1,5dihydroxy naphthalene. In general, suitable bisphenols are those characterised by one of the general formulae (a), (h) or (c): (a) in which It1', R^, R3, R^, which may he the same or different, represent hydrogen, chlorine, bromine or an alkyl radical or (b) in which R1, R2, and R^ are as defined above, and CH I 3 Re represents a direct bond or the atom or radical - CH„, C 3 2 , CH„ 0, S, SOg, CO or NH, or (c) - 4 42818 The average molecular weights of the new compounds are generally in the range from about 7θθ to 10,000, Compounds of lower molecular weights may he obtained by applying mild reaction conditions, whereas compounds of higher molecular weights can be obtained by increasing the reaction temperature to beyond 70°C.

The two reactants are reacted in strongly polar solvents. Particularly preferred strongly polar solvents are dimethyl formamide, dimethyl sulphoxide, dimethyl acetamide and N-methyl pyrrolidone.

A general procedure for preparing the compounds according to the invention is described in the following: The bisphenols used are first converted into the corresponding alkali metal bisphenolates. The concentration of the solution or suspension used amounts to between 10% and 50% by weight, based on phosphorus and bisphenolate compounds. The hisphenolate is preferably introduced first. The phosphate is added dropwise at the reaction temperature which generally is in the range from 50 to 100 °C and preferably in the range from 60 to 70°C. It is of course also possible initially to introduce the phosphorus compound. The reaction time amounts to between 1 and 20 hours and preferably to between 17 and 19 hours. The alkalimetal halide precipitates during the reactions whilst the required polymeric compound remains in solution.

After the alkali metal halide precipitated has been filtered off under suction, the polymeric (2-aryloxyethyl)-phosphate is obtained hy concentrating the filtrate, the required product accumulating in powder form. The polymers have molecular weights of from about 700 to 10,000. The quantity of alkali metal halide isolated corresponds to the calculated quantity. - 5 42818 To obtain linear chain products, it is important that the reaction temperature should not be allowed to rise appreciably above 100°C because otherwise crosslinking reactions occur. The crosslinked product precipitates from the solution, whilst the linear compounds are soluble in the solvents used as reaction medium.

Optimum polymerisation results are obtained by reacting the two reactants in a molar ratio of 1:1. However, minor deviations from this ratio are acceptable.

The new compounds are eminently suitable for use as flameproofing agents for polymers, for example, polyacrylonitrile and polyesters. Compounds with a molecular weight of from 800 to 3000 have proved to be particularly effective in this respect.

The Invention is illustrated by the following Examples.

EXAMPLE 1 Reaction of the disodium salt of tetra-bromobisphenol A with tris-(2-chloroethyl)-phosphate in a molar ratio of 1:1. 148 parts by weight of the disodium salt of tetrabromobisphenol A in 250 parts by weight of dimethyl formamide were stirred at 60°C with 71.5 parts by weight of tris-(2chloroethyl)-phosphate. The reaction ceased after 17 hours. After the salt residue had been filtered off and the solvent distilled off in vacuo, the reaction product was washed with water and ligroin, leaving 156 parts by weight (82%) of a pale yellow powder melting at 61 to 70°C.

EXAMPLE 2 Reaction of the disodium salt of tetra-chlorobisphenol A with tris-(2-chloroethyl)-phosphate in a molar ratio of 102.5 parts by weight of the disodium salt of tetra- 6 1:1 chlorobisphenol A in 250 parts by weight of dimethyl formamide were stirred at 60°C with 71·5 parts hy weight of tris-(2-chloroethyl)-phosphate. The reaction ceased after 17 hours. After the salt residue has been filtered off and :.ho solvent distilled off in vacuo the reaction product was washed with water and ligroin, leaving 123 parts by weight (H7%) of a light-coloured brittle mass melting at 75 to 86°C. EXAMPLE 5 Reaction of the disodium salt of bisphenol A with tris10 (2-chloroethyl)-phosphate in a molar ratio of 1:1 parts by weight of the disodium salt of bisphenol A in 250 parts by weight of dimethyl formamide were stirred at 60°C with 71.5 parts hy weight of tris-(2-chloroethyl)phosphate. The reaction ceased after 20 hours. Working up in the usual way gave 86 parts by weight (78%) of a greyyellow powder melting at 68 to 77°C.

EXAMPLE k Reaction of the disodium salt of hydroquinone with tris(2-ch1oroethyl)-phosphate in a molar ratio of 1:1 71.5 parts by weight of tris-(2-chloroethyl)-phosphate were added at 65°C to 39 parts by weight of the disodium salt of hydroquinone in 200 parts hy weight of dimethyl sulphoxide. After 19 hours, working up in' the usual way gives 65 parts hy weight of a grey powder melting at 93 to' 107°C.

EXAMPLE 5 The compound of Example 1 was added in a quantity of 15%, based on the total mixture of a modacrylic polymer (56% of acrylonitrile, 38% of vinylidene chloride, 5% of methyl acrylate, 1% of methallyl sulphonate). Filaments produced therefrom were knitted up into a test specimen for the burning test - 7 42818 defined in DIN 50 906.

The following results were obtained: Burning time sec. iiiel.3 see.

Assessment: Length burnt cm max 35 cm 0.5 0.5 0.5 the material was self-extinguished according to DIN 53 906 Burning time sec. incl. 15 sec.

Oxygen test n = °2 Og [1] + Ng Cl] n = 28.1

Claims (8)

CLAIMS:

1. A polymeric compound containing the recurring structural uni t Ϋ η _.CII„ - CII,, - 0 - P - 0 - CH 2 - CHg - 0 - R - 0.,. 0CH 2 CH 2 R> in which R' represents chlorine or bromine; and R represents an aromatic radical.

2. A compound as claimed in Claim 1 with a molecular weight of from 700 to 10,000.

3. A process for the production of a polymeric compound containing the recurring structural unit defined in Claim 1, wherein a tris-(2-halogenethyl)-phosphate is reacted with an alkali metal bisphenolate in a molar ratio of 1:1 in a strongly polar solvent at a temperature of from 50 to 100°C.

4. A process as claimed in Claim 3, wherein the solvent is formamide, dimethyl sulphoxide, dimethyl acetamide or N-methylpyrrolidone.

5. A process as claimed in Claim 3 or 4, wherein the reaction is carried out at a temperature of from 60 to 70°C.

6. A process for the production of a polymeric compound as claimel in Ciain 1 substantially as herein described with reference to any of the specific Examples.

7. A polymeric compound when produced by a process as claimed in any of Claims 3 to 6,

8. A flameproof agent comprising at least one polymeric compound as claimed in any of Claims 1, 2 and 7 together with an adjuvant therefor.