WO1995021886A1

WO1995021886A1 - Fire retardant plastisol and polymer compositions containing hydrocarbyl polyhaloalkanoates

Info

Publication number: WO1995021886A1
Application number: PCT/GB1995/000117
Authority: WO
Inventors: Ralph Stephen Baddley Jones
Original assignee: Imperial Chemical Industries Plc
Priority date: 1994-02-08
Filing date: 1995-01-23
Publication date: 1995-08-17
Also published as: AU1423395A; GB9402354D0; ZA95603B

Abstract

Fire-resistant plastisols and fire-resistant plasticised polymer compositions, particularly polymer compositions wherein the polymer is derived from a halogen-substituted olefin such as PVC, containing a fire-retardant additive which is a hydrocarbyl polyhaloalkanoate wherein the polyhaloalkanoic acid from which the hydrocarbyl polyhaloalkanoate is derived has at least four carbon atoms and bears at least two halo- substituents, wherein the hydrocarbyl group is preferably aryl and wherein the halo- substituent is preferably chloro-.

Description

FIRE RETARDANT PLASTISOL AND POLYMER COMPOSITIONS CONTAINING HYDROCARBYL POLYHALOALKANOATES

The present invention relates to plastisols and to polymer compositions comprising fire-retardant additives, particularly to plastisols and to polymer compositions comprising polyhaloalkanoate fire-retardant additives, and to hydrocarbyl polyhaloalkanoates for use therein.

Conventional commercially available primary plasticisers for halogen-containing polymers, eg phthalate esters, can be used at high concentrations but ar per se often flammable and consequently tend to render polymeric compositions containing them more flammable, eg plasticised polyvinyl chloride. So-called secondary plasticisers such as chlorinated paraffins are often used commercially to reduce the fiammability of plastics materials, eg polyvinyl chloride (PVC). However, chlorinated paraffins tend to exude from plastic materials, such as PVC, when used alone at higher concentrations. Accordingly, sufficient quantities of certain primary plasticisers, eg phthalates, may be included with the chlorinated paraffin to prevent such exudation. Alternatively, chlorinated paraffins may be used at low concentrations, which are below the optimum concentration for fiammability reduction.

As examples of known fire-retardant plasticisers may be mentioned the fire-retardant plasticisers described in UK 1,389,462, EP 0,319,916 and US 5,118,739.

UK 1,389,462 discloses the preparation of primary fire-retardant plasticisers by the condensation of a phenolic compound with a mixture of substantially straight-chain sulphochlorinated and chlorinated paraffins, typically of 10-18 carbon atoms, containing on average 15-70yow/w chlorine and l-8%w/w sulphur.

EP 0,319,916 discloses the use of certain halogenated 4,4'-bis(phthalimido)diphenyl sulphones as fire-retardant additives and the preparation thereof by the reaction of phthalic anhydride with a halogenated 4,4'-diaminodiphenyl sulphone .

US 5,118,739 describes the use of certain metal salts of polybrominated-sulphonic acids as flame-retardants for poly(phenylene oxide).

"Fire-retardant" and "flame-retardant" are used interchangeably herein. We have now found that hydrocarbyl esters of polyhaloalkanoic acids containing at least four carbon atoms overcome many of the aforementioned disadvantages and can be used as flame-retardant primary plasticisers in certain polymeric compositions with which they are compatible such that fire-resistant plastisols and fire-resistant polymer compositions can be obtained. In particular they afford plasticisation of and have improved compatability with certain polymer compositions and are not unduly volatile. A plastisol is conventionally regarded as a pou able creamy dispersion of finely divided polymer in a liquid plasticiser. For example, a PVC plastisol is defined in "The Technology of Plasticisers", J Kern Sears and Joseph R Darby, John Wiley and Sons Inc., 1982 as " a pourable, creamy dispersion of finely divided PVC in a liquid plasticiser." A PVC plastisol is typically prepared by suspending very fine particles of PVC, prepared by emulsion polymerisation, in a plasticiser. Usually such a plasticiser is liquid at room temperature but we do not exclude the possibility that a solid plasticiser could be used in conjunction with a liquid plasticiser to give a plastisol with the desired flow properties.

When a plastisol is heated the plasticiser migrates into the polymer particles suspended in it which then swell and coalesce. On cooling, a flexible solid product is obtained which is hereinafter referred to for convenience as a "plasticised polymer composition".

According to the first aspect of the present invention there is provided a plastisol and a plasticised polymer composition each comprising an organic polymer and a hydrocarbyl polyhaloalkanoate wherein the polyhaloalkanoic acid from which the hydrocarbyl polyhaloalkanoate is derived contains at least four carbon atoms and bears at least two halo substituents.

The aforementioned "at least four carbon atoms" includes the carbon atom(s) present in the acoyl group(s) of the polyhaloalkanoic acid.

The hydrocarbyl group(s) in the hydrocarbyl polyhaloalkanoate may be inter alia alkyl, aralkyl, alkaryl or preferably cyclic, more preferably aryl. The hydrocarbyl group may bear one or more substituents which do not unduly reduce the fire-retardancy of the hydrocarbyl polyhaloalkanoate, eg chloro-.

Where the hydrocarbyl group in the hydrocarbyl polyhaloalkanoate is an aryl group as examples thereof may be mentioned inter alia fused polycyclic aromatic rings, eg 2-naphthyl; polyaryls, eg biphenyl; heterocyclic rings, eg 2-, 3- or 4-pyridyl; or preferably a mono-cyclic aryl, more preferably phenyl. We have found that phenyl esters of polyhaloalkanoic acids are more compatible with polymer compositions and more thermally stable than linear alkyl esters of the same polyhaloalkanoic acids.

Where the hydrocarbyl group in the hydrocarbyl polyhaloalkanoate comprises an aryl group the aryl group may bear substituents such as alkyl, eg C,.₈; halo, eg Br, Cl, or F; or alkyl-sulphonyl or alkyl-sulphonyloxy, which substituents do not unduly reduce the flame-retardancy of the hydrocarbyl polyhaloalkanoate.

Where the hydrocarbyl group in the hydrocarbyl polyhaloalkanoate is an alkyl group it may be linear, branched or cyclic and typically contains between 1 and 20 carbon atoms. Where the hydrocarbyl group in the hydrocarbyl polyhaloalkanoate is an alkyl group it may bear substituents such as a halo-alkyl group, eg CC1₃-; a halo-acyl group, eg CCI₃CO-; a halo-acyloxy group, eg CCl₃COO-; an aryloxy substituent, eg phenyloxyethyl; or a short chain polyalkylene oxide residue, eg PEG or PPG of MW up to about 400. The polyhaloalkanoic acid from which the hydrocarbyl polyhaloalkanoate is derived may be cyclic, branched or preferably linear; typically it contains 4-20 carbon atoms, preferably between 8 and 14 carbon atoms and more preferably about 10 carbon atoms. Whereas the specific length of the alkane chain in the polyhaloalkanoic acid is not critical it will be chosen such that it exerts a plasticising effect on the polymer composition in which it is used.

The halo substituents in the hydrocarbyl polyhaloalkanoate may be bromo, fluoro or preferably chloro for better fire-retardancy. We do not exclude the possibility that the hydrocarbyl polyhaloalkanoate may bear different halogen substituents.

The halo substituents in the hydrocarbyl polyhaloalkanoate may be geminal, ie on the same carbon atom, or on adjacent or alternating carbon atoms or randomly disposed along the alkane chain of the polyhaloalkanoic acid. Preferably at least one and more preferably two halo substituents are on the carbon atom adjacent the carbonyl group of the polyhaloalkanoate. We have found surprisingly that hydrocarbyl polyhaloalkanoates wherein the carbon atom adjacent the carbonyl group bears two halo atoms, preferably two chlorine atoms, are more thermally stable and have a higher fire-retardancy than similar hydrocarbyl polyhaloalkanoates wherein the halo substituents are randomly distributed along the polyhaloalkanoate chain. Furthermore, we have found that polyhaloalkanoates wherein the carbon atom adjacent the carbonyl group bears two halo atoms, and plastisols prepared therefrom, have lower viscosities than similar hydrocarbyl polyhaloalkanoates wherein the halo substituents are randomly distributed along the polyhaloalkanoate chain. Typically, there are between two and m halo substituents on the polyhaloalkanoic acid residue in the hydrocarbyl polyhaloalkanoate where "m" is the number of carbon atoms excluding the acoyl carbon atom in the polyhaloalkanoic acid. Preferably, for availability and balance of properties, eg fire-retardancy, viscosity and compatability, there are three halo substituents on the polyhaloalkanoic acid residue. We do not exclude the possibility that the hydrocarbyl polyhaloalkanoate may contain more than one ester group, eg 2-6, although 1-3 ester groups are preferred. Where the hydrocarbyl polyhaloalkanoate contains more than one ester group, it will be appreciated that (i) the hydrocarbyl group may be derived from a polyhydroxy compound, eg trimethylol propane, sorbitol, catechol, bis-phenol-A or glycerol, and/or (ii) the alkanoate group may be derived from a polybasic polyhalocarboxylic acid, eg a polyhaloglutaric acid, a dihalosuccininc acid or a trihalocitric acid.

Preferably the hydrocarbyl polyhaloalkanoate of which the plastisol or polymer composition according to the first aspect of the present invention is comprised has the General Formula C_nH_2ft+,CHXCH₂CX₂COO - A I wherein

A is a hydrocarbyl group, eg an alkyl group, or preferably a cycloalkyl group, eg cyclohexyl, or more preferably an aryl group, particularly more preferably phenyl; X is bromo, fluoro or preferably chloro; and n is between 0 and 20, preferably 2-15, more preferably 4-10.

As examples of organic polymers of which the plastisol and the plasticised polymer composition according to the present invention may be comprised may be mentioned inter alia elastomers, eg natural rubber, butadiene/styrene copolymers, polyurethanes, polysulphides; thermoset resins, eg unsaturated polyesters, epoxy resins; and thermoplastics, eg polyamides, acrylic resins, preferably halogen-containing polyolefins and more preferably chlorine-containing polyolefins, eg PVC. Where the plastisol or plasticised polymer composition according to the present invention comprises a chlorine-containing polymer it may be a homopolymer or a copolymer containing at least 5%w/w chlorine. Where the chlorine-containing polymer is a copolymer it preferably contains more than 20% and more preferably more than 40% w/w chlorine. As examples of such polymers may be mentioned inter alia poly-vinyl chloride, chlorinated polyethylene, poly-vinylidene chloride, vinyl chloride/vinyl acetate copolymer, vinyl chloride acrylic ester copolymers and polymer blends, eg PVC/rubber blends.

Sufficient hydrocarbyl polyhaloalkanoate is mixed with a polymer to afford a plastisol from which a plasticised polymer composition according to the present invention having the desired flexibility and flame-retardency may be obtained after suitable processing of the plastisol, ie heat treatment. It will be appreciated that the plasticiser softens the polymer and modifies certain other properties, eg tensile strength. The amount of the hydrocarbyl polyhaloalkanoate needed to confer fire-retardancy to the polymer composition will be determined by the skilled man by simple experiment. For example, where the plasticised polymer composition according to the present invention comprises PVC it typically comprises at least about 10 parts by weight of the hydrocarbyl polyhaloalkanoate per 100 parts by weight of PVC.

It will be appreciated that the hydrocarbyl polyhaloalkanoate of which the plastisol according to the present invention is comprised will be (a) sufficiently involatile such that evaporation thereof from the plastisol during processing is not excessive and (b) sufficiently thermally stable such that it does not decompose to an undesirable extent during processing of the plastisol.

It will be appreciated that the hydrocarbyl polyhaloalkanoate of which the plasticised polymer composition according to the present invention is comprised will be (a) sufficiently involatile such that the properties of an article prepared from the polymer composition are not unduly changed during its useful working life by evaporation of the hydrocarbyl polyhaloalkanoate therefrom and (b) sufficiently thermally stable such that it does not decompose to an undesirable extent during the useful working life of an article prepared from the plasticised polymer composition. The plastisol and lasticised polymer composition according to the present invention may also contain further components, eg heat stabiliser, light stabiliser, anti-oxidant, filler, pigment, lubricant, fungicide or other components used in the art.

As far as we are aware, certain hydrocarbyl polyhaloalkanoates falling within the definition as set out hereinbefore are themselves new and inventive substances.

Accordingly, there is provided according to a further aspect of the present invention a hydrocarbyl polyhaloalkanoate having utility as a fire-retardant additive in a plastisol or plasticised polymer composition as defined hereinbefore with the proviso that the hydrocarbyl polyhaloalkanoate does not have the General Formula Cl-(-CHCl-CH₂-)_x-CCl₂-CO-OR II wherein x = 1-3 and R = Me, Ph or CH₂CH₂OH

Hydrocarbyl polyhaloalkanoates for use in plastisols and plasticised polymer compositions according to the present invention may conveniently be prepared by a process which comprises the steps of: A. reacting an olefin, preferably a terminal or alpha olefin, with (a) an acoyl halide or (b) a carbon tetrahalide/CO mixture;

B. halogenating the product from Step A, at least where the acoyl halide does not bear a halo-substituent; and

C. reacting the product from Step A or B with a hydroxy-hydrocarbyl compound.

By "olefin" we mean an unsaturated hydrocarbon bearing a C - C double bond.

Preferably the acoyl halide used in Step A bears at least one halo substituent, for example trichloroacetyl chloride.

In Step A the molar ratio of acoyl chloride to olefin is preferably at least about 2:1.

Step A is carried out at elevated temperature, typically at about 100°C and preferably in the presence of a peroxide, eg benzoyl peroxide. Alternatively, the reaction may be carried out in the presence of dichloro tris(triphenylphosphine) ruthenium (II) (Nakano et al, Chem. Letters, 1982, pp 1255-1258) or copper (I) chloride (Martin et al, Helv. Chim. Acta, 1980, 63, 1947) In Step B the alkanoyl chloride may be halogenated at elevated temperature,typically between 80-120°C and, particularly where it is being chlorinated, under long-wavelength UV irradiation.

In Step C, esterification may be carried out under suitable conditions known to the skilled man or which he may find by simple experiment. For example, (i) where the hydroxyhydrocarbyl compound is a phenol, the polyhaoalkanoyl chloride is typically added slowly to an aqueous solution of the phenol at low temperature, eg 3°C to -3^PC; and (ii) where the hydroxyhydrocarbyl compound is a hydroxy-alkane, eg cyclohexanol, it is typically added slowly to the polyhaloalkanoyl halide at about 5-20°C and reaction continued for up to a few hours.

Whereas the hydrocarbyl polyhaloalkanoates used in the present invention are primarily fire-retardant primary plasticisers for halogenated polymers, particularly PVC, they may be used as fire-retardant additives for other polymers, eg polyurethanes or plysulphides, and may also be used as arc-extinguishing fluids or extreme-pressure lubricant additives.

The plastisol or plasticised polymer composition according to the present invention can be formed into articles by conventional polymer-forming techniques, eg injection moulding, extrusion, spread-coating, calendering, slush moulding and blow-moulding techniques. As examples of uses of plasticised polymer compositions according to the present invention may be mentioned inter alia conveyor belts, electric-cable coating and flooring.

The present invention is further illustrated by reference to the following Examples which illustrate, by way of example only, certain aspects of the present invention.

In the Examples: A) The viscosity of the hydrocarbyl polyhaloalkanoate was measured at 25°C using a calibrated glass viscometer; and

B) The viscosity of the plastisol or plasticised polymer composition was measured by allowing a sample thereof to stand at 23 °C for one hour after mixing as is hereinafter more fully described, then placing it in a 75 ml beaker. A Brookfield DV II viscometer, fitted with a number 4 spindle, was lowered into the sample. The RPM was set to 0.5, the motor was started and the viscosity was taken after 2 minutes. With the motor running, the RPM was altered to 1, and a reading was taken after 28 sees; further readings were taken at other RPM settings, 28 seconds after the setting was altered, up to 100 RPM. EXAMPLE 1

This Example

chloride (TCDC) for use in the preparation of hydrocarbyl polyhaloalkanoates which are useful in plastisols and plasticised polymer compositions according to the present invention.

Oct-1-ene (102.7g, 0.915moles) and trichloroacetyl chloride (502g; 2.76 moles) were charged to a three-necked round-bottomed flask fitted with a nitrogen inlet, thermometer and condenser. The flask was flushed with dry nitrogen and heated to 110°C in an oil bath while the contents thereof were stirred magnetically. Dried benzoyl peroxide (4.45g, 0.0184 moles) was added to the flask in the quantities and at the time-intervals shown in Table 1.

TABLE 1

Addition Number Quantity Time

(8) (mins)

1 0.7 0

2 0.65 30

3 0.6 60

4 0.6 120

5 0.55 150

6 0.5 180

7 0.45 210

8 0.4 240

After the addition of the benzoyl peroxide was complete, the reaction mixture was stirred at 110°C for 1 hour and then cooled. Analysis of the reaction mixture by 60MHz Η NMR indicated that 81.5% of the oct-1-ene had been converted intoTCDC. Unreacted oct-1-ene and trichloroacetyl chloride were removed from the reaction mixture by distillation under reduced pressure and the residue was distilled at 106-110°C/lmm Hg to afford TCDC (158.9g; 59% yield based on the oct-1-ene charge and 72.5% yield based on the oct-1-ene converted). EXAMPLE 2

This Example illustrates the preparation of 2,2,4-trichlordodecanoyl chloride (TCDDC) for use in the preparation of hydrocarbyl polyhaloalkanoates useful in plastisols and plasticised polymer compositions according to the present invention. Dec-1-ene (13.47g, 0.096moles) and trichloroacetyl chloride (69.85g; 0.384 moles) were charged to a three-necked round-bottomed flask fitted with a nitrogen inlet, thermometer and condenser. The flask was flushed with dry nitrogen for 10 minutes and the contents were then heated under reflux.

Trichloroacetyl chloride (496.87g; 2.73 moles), dec-1-ene (202.5 lg; 1.44 moles) and dried benzoyl peroxide (6.46g) were dissolved in a dropping funnel and degassed by sparging with nitrogen. The resulting solution was added dropwise to the refluxing mixture over 16 hours.

Excess (396.58g) trichloroacetyl chloride and dec-1-ene was removed by distillation at reduced pressure and TCDDC (302.1 lg) was collected by distillation at 134°C-142°C, pressure 0.1 Torr, as a pale yellow oily liquid. It was characterised by infra-red spectroscopy and 1H NMR (500MHz). EXAMPLE 3

This Example illustrates the preparation of 2,2,4-trichlorhexadecanoyl chloride (TCHDC) for use in the preparation of hydrocarbyl polyhaloalkanoates useful in plastisols and plasticised polymer compositions according to the present invention.

Tetradec-1-ene (192.26g; 0.797moles) and trichloroacetyl chloride (284g; 1.562 moles) were charged to a 1 litre flask. The contents of the flask were sparged with nitrogen for 10 minutes and it was then heated in an oil bath to 120°C.

Benzoyl peroxide (5.43g), dissolved in trichloroacetyl chloride (90ml, 146.6g, 0.806 moles), was degassed by sparging with nitrogen for 10 minutes and added dropwise over 16 hours to the reaction mixture, at a reaction temperature of 120°C.

Excess trichloroacetyl chloride and excess tetradecene were removed by vacuum distillation and the residual pale yellow liquid was TCHDC (336.12g; 98% yield). EXAMPLE 4 This Example illustrates the preparation of 2,2,4-trichlorooctanoyl chloride

(TCOC) for use in the preparation of hydrocarbyl polyhaloalkanoates useful in plastisols and plasticised polymer compositions according to the present invention. The procedure used in Example 3 was repeated except that trichloroacetyl chloride (478.19g; 2.63mol) and hex-1-ene (150g; 1.78 moles) were charged to the reaction flask and benzoyl peroxide (4.35g) dissolved in trichloroacetyl chloride (80g; 0.44moles) was added over 9 hours at a reflux temperature between 70°C and 120°C. Excess trichloroacetyl chloride and excess hex-1-ene were removed by distillation at reduced pressure and the residue was vacuum distilled yielding TCOC (388g; 82% yield). EXAMPLE 5-7

These Examples illustrate the preparation of further chlorinated alkanoyl chlorides for use in the preparation of hydrocarbyl polyhaloalkanoates useful in plastisols and plasticised polymer compositions according to the present invention. General Method

Nitrogen at 0.4 litres/min was passed through a sintered glass gas-dispersion tube into an alkanoyl chloride in a Pyrex glass chlorination vessel for 30 minutes to de-aerate the alkanoyl chloride.

The temperature of the alkanoyl chloride was raised to 90°C (Examples 5 and 6) or 82°C (Example 7) by a water bath and the flask was irradiated with a 500W long-wave UV light. Chlorine gas was charged to the reaction mixture through the dispersion tube at 0.4 litres/min. The temperature of the reaction mixture was kept between 90°C and 105°C by air cooling (Examples 5 and 6) or between 82°C and 120°C by a cold-water bath (Example 7).

After reaction, the chlorinated alkanoyl chloride was sparged with nitrogen for 30 minutes at 0.8 litre/min or 0.6 litre/min until the off-gases did not test acidic using moistened pH indicator paper. The products were characterised by infra-red spectroscopy and 1H NMR

(500MHz).

From the weight gain of the alkanoyl chloride the average number of chlorine atoms introduced per alkanoyl chloride molecule was calculated. The results are shown in Table 2. TABLE 2

It will be appreciated that whereas the alkane chains in both TCDC prepared Example 1 and in the chlorinated decanoyl chloride (CDC) prepared in Example 7 contain approximately the same number of Cl atoms, ie 3, the chlorine atoms in the chain of TCDC are disposed at specific C atoms, ie 2,2 and 4, while the chlorine atoms in the CDC prepared in Example 7 are dispersed randomly along the chain. EXAMPLES 8-12

These Examples illustrate phenyl polyhaloalkanoates for use in plastisols and polymer compositions according to the present invention. General Method

Phenol was dissolved in a solution of sodium hydroxide in water in a 250ml three-necked round-bottomed flask. The phenol solution was degassed by sparging with nitrogen.

In Examples 8-11, the phenol solution was cooled to 2°C using an ice bath and alkanoyl chloride was added thereto at a rate such that the temperature of the reaction mixture remained between 2°C and 3°C. In Example 12, the phenol solution was cooled to -1°C before the alkanoyl chloride was added. The alkanoyl chloride was added at a rate to maintain the temperature of the reaction mixture between -1°C and -5°C and towards the end of the addition was lowered to -10°C.

A thick white precipitate formed.

When addition was complete, the ice bath was removed and the reaction mixture was stirred until the temperature thereof rose to ambient temperature. The reaction mixture was poured onto ice (Examples 8-11) or water was added thereto (Example 12) and the lower organic product layer was removed. The organic layer was washed with 2% sodium hydroxide solution (200ml x 2) and then with water until the washings were neutral.The product was dried under reduced pressure, at ambient temperature initially, then at 30-40°C (Examples 8-11) or 50-60°C (Example 12).

The specific reaction conditions are shown in Table 3.

TABLE 3

Example Phenol Aqueous NaOH Acoyl Chloride Yield

No. (g) (g)

NaOH Water Name Weight (%)

(g) (ml) (g)

8 42.7 17.27 70 TCDC 120 124.65 (87)

9 81.62 33.12 154 CTCDC 256.03 289.0 (95.9)

10 69.11 28.04 132 TCDDC 215.08 240 (95)

11 85.42 34.66 161 CTCDDC 280 304 (93)

12 66.8 27.1 111 CDC 190 210 (92)

TCDC:Pr epared in Ex ample 1

CTCDC: 5

TCDDC: 2

CTCDDC 6 CDC: 7

The product from Example 8, phenyl 2,2,4-trichlorodecanoate (PTCD), was a clear colourless oil (124.65g; 87% yield based on TCDC).

The product from Example 12, phenyl ester of chlorinated decanoic acid (PCD) was a slightly yellow oil.

The products from Examples 8-12 were characterised by Fourier Transform Infra-Red Spectroscopy (FTIR), IH NMR (500 MHz) and elemental analysis. The results of the elemental analysis are shown in Table 4. TABLE 4

Example C H Cl

No. (% w/w) (% w/w) (% w/w)

Found Calc. Found Calc. Found Calc.

8 52.1 54.6 6.2 6.02 29.1 30.3

9 50.74 50.26 5.54 5.3 34.9 36.1

10 54.74 56.9 6.57 6.64 24.3 28

11 55.26 54.46 6.56 6.22 30.1 31.3

12 54.32 54.1 6.2 5.9 30.2 31

Certain physical properties of the phenyl esters prepared in Examples 8-12 were measured as hereinbefore described and the results are shown in Table 5.

TABLE 5

Example No. Viscosity Density

(cp) (g/cm³)

8 48.9 1.17

9 249.4 1.25

10 52 1.18

11 97.4 1.17

12 978 1.23

CT1 57.5 1.17

CT1 : Comparative Test using Reofos 50, a commercially available, phosphate ester, flame-retardant plasticiser.

EXAMPLE 13

This Example illustrates a cyclohexyl polyhaloalkanoate for use in plastisols and plasticised polymer compositions according to the present invention.

Cyclohexanol (59.63g; 0.595 moles) was added dropwise with stirring under nitrogen to TCDC (150g; 0.510 moles) in a 500ml flask at 10°C while the temperature was maintained between 10 and 15°C. After addition was complete, the mixture was stirred for a further two hours at 10°C. Excess cyclohexanol was removed by steam distillation, 100ml steam distillate was collected. The residue was dried by heating in an oil bath at 140°C while nitrogen was bubbled through it. A yellow oily liquid was obtained which was clarified by filtration through a bed of silaceous filter aid and yielded cyclohexyl 2,2,4-trichlorodecanoate (147.6g; 80.9%w/w) EXAMPLE 14

This Example illustrates a further phenyl polyhaloalkanoate for use in plastisols and plasticised polymer compositions according to the present invention.

TCHDC (62.75g; 0.166 moles), prepared in Example 3, phenol (17.18g; 0.183 moles) and diethyl ether ( 50 ml) in a 250 ml 3-necked flask were cooled to -10°C using an ice-salt bath and were sparged with nitrigen for 10 minutes.

Pyridine (15.75g, 0.199 moles) was added dropwise over 30 minutes with stirring while the reaction remperature was maintained at 10-20°C. After addition was complete, stirring was continued for 2 hours at 10°C. The reaction mixture was washed with 1M HC1 ( 100ml x2), 1 % NaOH (500ml x

2) and 0.5% NaCl (100ml x 2). Excess ether was removed at 70°C/15 Torr on a Rotavac and the residue was dried at 60°C/0.1 Torr for 2 hours.

The structure of the product, phenyl 2,2,4-trichlorohexadecanoate, was confirmed by infra-red and IH nmr analysis. EXAMPLE 15

This Example illustrates a hydrocarbyl polyhaloalkanoate containing two ester groups for use in plastisols and plasticised polymer compositions according to the present invention.

A solution of TCOC (120g; 0.45mol), prepared in Example 4, and catechol (24.8g; 0.225 moles) in diethyl ether (235ml) in a 1-litre 3-necked flask was degassed by sparging with nitrogen for 15 minutes and then cooled to 16°C using an ice-bath. Pyridine (39.2g, 0.496 moles) was added to the reaction mixture with stirring over 100 minutes while the reaction temperature was maintained at 16-21°C.

The reaction mixture was stirred overnight and then washed with water (200ml x 3). The ether was removed from the washed reaction mixture on a rotary evaporator, the residual pyridine was removed by azeotroping with toluene and the residual toluene removed by azeotroping with industrial methylated spirit. The residue was further purified by recrystallisation to yield 135g of colourless crystals.

IH nmr(500MHz) of the crystals confirmed that the material was catechol bis(2,2,4-trichlorooctanoate). EXAMPLE 16-21

These examples illustrate plastisols according to the present invention. General Method

A plastisol was prepared by mixing all the dry components and half of the liquid components shown in Table 6 in a Casberg Blender, evacuating the blender, stirring the mixture for ten minutes, releasing the vacuum, then scraping the mixture back to the stirrer blades. The rest of the liquid components were added, the blender was evacuated and the mixture was stirred for a further two minutes. The vacuum was released, the mixture was scraped down to the stirrer blades, the blender re-evacuated and stirring continued for a further eight minutes.

In a Comparative Test (CT2) a mixture of a commercially available flame-retardant plasticiser, Reofos 50, and a commercially available secondary plasticiser, Cereclor (RTM) S45 was used instead of a hydrocarbyl polychloroalkanoate.

The formulations used are shown in Table 6.

TABLE 6

Ex. No. P72 214 SF4 SbO NP6 R5O S45 DOP HPCA phr phr phr phr phr phr phr phr phr

16-21 100 5 28 5 7 0 0 30 90

CT2 100 5 28 5 7 75 15 30 0

P72 : Corvic(RTM)P72/755 (ex ICI) is a grade of PVC suitable for formulating plastisols;

214 : Irgablend 214 is a blend of stabilisers containing epoxidised vegetable oils and tin based stabilisers;

SF4 : An alumina trihydrate filler;

SbO : Antimony oxide, a flame retardant synergist known in the art;

NP6 : NP6 is an antistatic agent;

R50 : Reofos 50 is a commercially available, phosphate ester, flame-retardant plasticiser;

S45 : Cereclor(RTM) S45 (ex ICI) is a chlorinated paraffin secondary plasticiser;

DOP : Di-(2-ethyl hexyl) phthalate is a plasticiser known in the art; and

HPCA . : Hydrocarbyl polychloroalkanoate.

The viscosities of the plastisols are shown in Table 7.

TABLE 7

Example No. Source of HPCA Plastisol Viscosity fire-retardant (cP at 20rρm)

(Example No.)

16 8 910

17 9 2,610

18 10 940

19 11 1,490

20 13 1,000

21 12 3,690

CT2 1,230

HPCA : Hydrocarbyl polychloroalkanoate.

CT2: Comparative Test

EXAMPLES 22-27

These Examples illustrate plasticised polymer compositions according to the present invention.

The plastisols prepared in Examples 16-21 were converted into plasticised polymer compositions by heat treatment under the conditions described in the following General Method. General Method

The plastisol was spread on waxed paper into a film 0.8mm thick. The film was heated in a Werner Mathis oven, preheated to 160°C, at 160°C with internal air circulation for 2 minutes. It was removed from the oven and allowed to cool. The cooled cured film was removed from the paper and cut into strips of a size appropriate to a template mould. The strips were stacked in the template mould until the desired thickness was obtained, ie thickness of the mould; sheets of polyester film were placed at the top and bottom of the mould to facilitate release from the mould.

The template was placed in a Moore press pre-heated to 160°C. Where the samples were 1.27mm thick the faces of the press were brought into contact with the top and bottom of the mould for 5 minutes, then the maximum pressure of the press was applied at 160°C for 2 minutes; where the samples were thicker than 1.27mm the faces of the press were brought into contact with the top and bottom of the mould for 10 minutes, then the maximum pressure of the press was applied at 160°C for 5 minutes.

The press was allowed to cool under pressure to 25°C. The pressure was released and the samples were removed from the template and were cut into the appropriate size and shape for the following tests.

A) The limiting oxygen index (LOI) of the plasticised polymer composition was measured by burning strips (15cm x 6mm x 3mm) thereof in an atmosphere of nitrogen and oxygen and determining the minimum percentage oxygen by volume required to sustain combustion of the strip for 3 minutes;

B) British Standard Softness (BSS) was determined by measuring the depth of penetration of a ball-ended plunger of diameter 2.38mm into a disc-shaped sample (10.2mm thick) of the plasticised polymer composition relative to a small foot resting on the surface of the disc which had been aged for seven days prior to testing. An initial load (30g) was applied to the plunger for 5 seconds then a final load (565g) was applied for 30 seconds. Penetration of the plunger was read from a gauge calibrated in units of 0.01mm, which corresponds to British Standard Softness. During the loading period the equipment was gently vibrated to overcome any friction;

C) Shore A, a hardness measurement, of the plasticised polymer composition was determined using a Shore A Hardness Tester working to BS2782 (1990): The Testing of

Plastics;

D) Ultimate tensile strength (UTS) and elongation to break (EB) of the plasticised polymer composition were measured on dumbell-shaped samples, cut from pressed film using a standard cutter, on a Houndsfield Tensometer working on BS 2782 (1970): The Testing of PLastics; and

E) Cold flex temperature (CFT) of the plasticised polymer composition was measured using the method of Clash and Berg [Ind. Eng. Chem. (1942), 34, 1218] working to BS2782 (1990): The Testing of Plastics.

The results obtained from Tests (A) - (E) are shown in Table 8. TABLE 8

Example Source of BSS SH LOI UTS EB CFT

No. plastisol (mPa) (%) (°C)

(Example

No.)

22 16 107.8 48.6 27 12.57 509 -39

23 17 96 52.6 29 13.3 346 -34.5

24 18 130.7 50.7 26 12.7 496 -44.1

25 19 100.5 51.6 27.5 13.5 271 -41.2

26 20 99.3 50.4 26 13.6 307 -45.5

27 21 98.3 50.2 28 13.6 308 -32.7

CT3 CT2 113.3 47 27.5 12.45 439 -35

BSS :British standard softne ss;

SH : Shore Hardness A;

LOI :Limiting oxygen index

UTS :Ultimate tensile strengl th;

EB :Elongation to break;

CFT :Cold flex temperature;

CT3 ^•.Comparative Test.

From Tables 7 and 8 it can be seen that plastisols and plasticised polymer compositions according to the present invention have properties that are at least as good as, and that certain important properties, namely plastisol viscosity and cold flex temperature, are better than plastisols and polymer compositions based on the same polymer but containing a commercially available fire retardant. EXAMPLES 28-29

These Examples illustrate further plastisols and plasticised polymer compositions according to the present invention.

A plastisol was prepared using the procedure described in Examples 16-21 using the formulations shown in Table 9 instead of the formulations shown in Table 6. TABLE 9

Example P72 214 SF4 SbO NP6 R5O S45 CBTCO

No. phr phr phr phr phr phr phr

28 100 5 28 5 7 - 35 65

CT4 100 5 28 5 7 65 35 -

CBTCO: Catechol bis(2,2,4-trichlorooctanoate) prepared in Example 15.

P72, 214, SF4, SbO, NP6, R5O and S45 have the meanings hereinbefore ascribed to them.

The plastisol prepared in Example 28 was found to have a viscosity of 474 poise at 20rpm; the viscosity of R50 was found to be 39.5 poise at 20rpm.

The pastisol prepared in Example 28 was converted into a plasticised polymer composition, under the conditions described in the General Method in Examples 22-27. and the plasticised polymer composition was tested according to aforementioned Tests (A) -(E). The results are shown in Table 10.

TABLE 10

Example Source of BSS SH LOI UTS EB CFT

No. plastisol (mPa) (%) (°C) (Example No.)

29 28 ^• 62 65.8 32.5 15.6 212 -13.5 CT5 CT4 73.4 59.7 29 14.8 181 -22.9

BSS, SH, LOI, UTS, EB and CFT have the meanings hereinbefore ascribed to them.

EXAMPLE 30

This Example illustrates a plastisol and a plasticised polymer composition according to the present invention comprising a polysulphide resin.

A portion (10g) of a cure paste [prepared from manganese (iv) oxide (10g), phenyl 2,2,4-trichlorodecanoate (lOg), 97% tetramethylthiuram disulphide (O.lg), N,N-diphenylguanidine powder (O.lg) and Aerosil 200, ex Degussa (O.lg)] was mixed into a mixture of a polysulphide polymer, LP2C ex Morton International (100g), and fire-retardant, phenyl 2,2,4-trichlorodecanoate (20g). The resulting mixture was allowed to cure for a week at room temperature on a metal foil lid.

Touch-testing indicated that the fire-retardant had not exuded from the resulting plasticised polymer composition.

Claims

1. A plastisol or plasticised polymer composition comprising an organic polymer and a hydrocarbyl polyhaloalkanoate wherein the polyhaloalkanoic acid from which the hydrocarbyl polyhaloalkanoate is derived contains at least four carbon atoms and bears at least two halo- substituents.

2. A plastisol or plasticised polymer composition as claimed in Claim 1 wherein the hydrocarbyl group in the hydrocarbyl polyhaloalkanoate is a cyclic hydrocarbyl group.

3. A plastisol or plasticised polymer composition as claimed in Claim 2 wherein the cyclic hydrocarbyl group is an aryl group.

4. A plastisol or plasticised polymer composition as claimed in Claim 3 wherein the aryl group is a monocyclic aryl group.

5. A plastisol or plasticised polymer composition as claimed in any of the preceeding claims wherein the polyhaloalkanoic acid from which the hydrocarbyl polyhaloalkanoate is derived contains 8-14 carbon atoms.

6. A plastisol or plasticised polymer composition as claimed in any of the preceeding claims wherein at least one of the halo- substuents in the hydrocarbyl polyhaloalkanoate is chloro-.

7. A plastisol or plasticised polymer composition as claimed in any of the preceeding claims wherein the carbon atom adjacent the carbonyl group in the polyhaloalkanoic acid residue in the hydrocarbyl polyalkanoate bears at least one of the halo- substituents.

8. A plastisol or plasticised polymer composition as as claimed in any of the preceeding claims wherein the polyhaloalkanoic acid residue in the hydrocarbyl polyhaloalkanoate bears three halo- substituents.

9. A plastisol or plasticised polymer composition as claimed in any of the preceeding claims wherein the hydrocarbyl polyhaloalkanoate contains a plurality of ester groups.

10. A plastisol or plasticised polymer composition as claimed in any of the preceeding claims wherein the hydrocarbyl polyhaloalkanoate has the General Formula

C_nH_2n+1CHXCH₂CX₂COO - A wherein A is a hydrocarbyl group, X is a halo- substituent and n is between 0 to 20.

11. A plastisol or plasticised polymer composition as claimed in any of the preceeding claims wherein the organic polymer is a halogen-containing polyolefin.

12. A plastisol or plasticised polymer composition as claimed in Claim 11 wherein the halogen-containing polyolefin contains more than 20% w/w chlorine.

13. A plastisol or plasticised polymer composition as claimed in Claim 12 wherein the halogen-containing polyolefin is PVC.

14. A plastisol or plasticised polymer composition as claimed in Claim 13 comprising at least 10 parts by weight hydrocarbyl polyhaloalkanoate per 100 parts by weight PVC.

15. A hydrocarbyl polyhaloalkanoate having utility as a fire-retardant additive in a plastisol or plasticised polymer composition as defined in any of the preceeding claims with the proviso that the hydrocarbyl polyhaloalkanoate does not have the general formula Cl-(-CHCl-CH₂-)_x-CCl₂-CO-OR wherein x = 1-3 and R = Me, Ph or CH,CH₂OH

16. An article prepared from a plasticised polymeric composition as claimed in any of Claims 1-14.