WO1990000165A1

WO1990000165A1 - Flame retardant higher alkyl bisphenoxy alkanes and their application to abs polymer systems

Info

Publication number: WO1990000165A1
Application number: PCT/US1989/002796
Authority: WO
Inventors: Enrico J. Termine; Nicolai A. Favstritsky; Dennis M. Borden
Original assignee: Great Lakes Chemical Corporation
Priority date: 1988-06-30
Filing date: 1989-06-29
Publication date: 1990-01-11
Also published as: EP0388445A1; KR900701715A; JPH03503419A; EP0388445A4; CA1317603C

Abstract

Halogenated unsymmetrical higher alkyl bisphenoxy alkanes have utility as non-blooming flame retardant agents. In particular, halogenated unsymmetrical higher alkyl bisphenoxy alkanes along with an enhancing agent may be used to render an ABS resin flame retardant.

Description

FLAME RETARDANT HIGHER ALKYL BISPHENOXY ALKANES

AND THEIR APPLICATION TO ABS POLYMER SYSTEMS

BACKGROUND OF THE INVENTION

Field Of The Invention. The present invention relates to a plastic additive composition and more particularly to a plastic additive composition

comprising halogenated unsymmetrical higher alkyl bisphenoxy alkanes. In addition, this invention relates to a nonblooming flame retardant ABS resin composition incorporating the halogenated unsymmetrical higher bisphenoxy alkanes.

Description Of The Prior Art. Traditionally, plastic additive compositions are an important class of industrial materials. Plastic additives are used to enhance or modify the properties of commercially available polymers. The use of plastic additives allows a relatively small number of commercially available polymers to be tailored to a myriad of uses. Those skilled in the art will know that the selection of an application of a specific plastic additive is unpredictable at best. Therefore, additive manufacturers must take a sophisticated approach and offer a range of products to achieve the desired result.

Plastic additive compositions can be used as plasticizers, flame retardants, flow modifiers, or impact modifiers in resin systems, heat transfer fluids, or hydraulic fluids. One important use of plastic additive compositions is as flame retardant agents in resin systems. Most flame retardant agents, although efficient in their function of retarding the rate of combustion in a resin system, have a tendency to affect adversely one or more key properties of the resin. For example, many flame retardant additives tend to reduce the impact strength of the resin; to migrate from the resin composition, resulting in a phenomena known as "bloom"; to

volatilize from the resin composition; to plasticize the resin composition adversely, and therefore lower the heat deflection temperature; or to degrade when exposed to indoor or outdoor light.

It is, therefore, essential that flame retardant agents be specifically tailored to the resin system so that in addition to their role as flame retardants, they will also enhance the desirable characteristics of the resin composition. Those skilled in the art well know that the selection of such an application specific flame retardant is unpredictable at best. Moreover, even if a given agent may exhibit utility in a particular resin system, there is no guarantee that this agent will have any use at all with other resins. One type of resin used in the formulation of a flame retardant is acrylonitrile-butadiene-styrene ("ABS") resin. Some of the properties of typical ABS resins are described on pages 1-68 of Harper's Handbook of Plastics and Elastomers published by McGraw-Hill Book Company in 1975.

ABS thermoplastics offer a good balance of

physical and mechanical properties such as good abuse resistance, heat resistance, moldability, stain

resistance, chemical resistance and surface hardness. Typically, ABS thermoplastics are used in. a wide variety of applications because of their properties and moderate costs. For example, ABS thermoplastics are used by telephone equipment, electronic, and automotive manufacturers who require materials of high impact strength.

A number of flame retardants have been described for ABS resins in the art. For example, the following materials have all been used in various ABS systems: bis(tribromophenoxy)-ethane, bis(pentabromophenoxy)-ethane, octabromodiphenyl oxide, decabromodiphenyl oxide, tetrabromobisphenol-A, bis(tribromophenoxy-ethyl)-tetra bromobisphenol A ether. Among the prior art specifically dealing with flame retarding ABS resins are U.S. Patent No. 4,016,139; and U.S. Patent No. 4,567,218, and the references cited therein. The foregoing flame retardant agents for ABS plastics have not been entirely satisfactory because of problems of bloom, thermal migration, heat instability, ultraviolet light instability; discoloration, or adverse effects on properties such as impact strength and flowability.

Many applications of ABS resins with flame

retardant agents require that certain key properties be maintained. Examples of key properties include impact strength, light stability and retention of surface aesthetic properties. In particular, manufacturers of computer housings desire a thermoplastic ABS resin which is flame retardant, light stable, and resistant to bloom.

It is well known in the art to use various bromine containing compounds as flame retardant agents. The compositions obtained using these various bromine containing compounds have a tendency to change color on exposure to light, to develop a reduction in surface gloss, and to form deposits of flame retardant agents on the polymer surface.

Anderson, et al., U.S. Patent No. 3,876,612 disclose ABS plastic compositions containing

symmetrical bisphenoxy flame retardants. The

compositions of the flame retardants are depicted by the following formula:

where Z is bromine or chlorine; m and m' are integers having a value of 1-5; and i and i' are integers having a value of 0-2; A is a cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl,

halo-phenyl, benzyl or halo-benzyl group; and R is chosen from the following group:

(a) CH₂— CH(OH)— CH₂

(b) CH₂— CH(CH₂OH)— CH₂

(c) (CH₂)_w— O— (CH₂)_w

where w = 1-6

where X-H, Cl.Br

n=4

(e) CH₂— C(O)— CH₂

where S = satutated

ring

Anderson, et. al., '612 does not disclose the use of an unsymmetrical higher alkyl bisphenoxy alkane as a flame retardant agent for the disclosed ABS resin.

U.S. Patent No. 3,883,479 issued to Anderson, .et al., discloses plastic compositions containing ABS and symmetrical bisphenoxy compounds. The bisphenoxy compounds have the formula:

wherein Z is bromine, m and m' are integers having a value of 1-4, i and i' are integers having a value of 1 or 2. The alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms. A is to be selected from the group consisting of cyano, nitro, lower alkoxy, lower alkyl (defined as CH₃, C₂H₅, C₃H₇ or C₄H₉), fluorine, dialkylamino, phenyl,

halo-phenyl, benzyl or halo-benzyl group. Anderson, et al., '479, do not disclose the use of an unsymmetrical higher alkyl bisphenoxy alkane as a flame retardant agent.

Anderson, et al., U.S. Patent No. 3,892,710 disclose ABS plastic compositions containing

symmetrical halogenated alkyl flame retardants. The flame retardants have the formula:

where Z is bromine or chlorine; m and m' are integers having a value of 1-5. i and i' are integers having a value of 0 to 2, M and M' are each independent and are from the group consisting of oxygen, nitrogen or sulfur as long as both m and m' are not oxygen. A is chosen from the group consisting of cyano, nitro, lower alkoxy, lower alkyl, fluorine, diakylamino, phenyl, halo-phenyl, benzyl or halo-benzyl group. Anderson, et al., '710's disclosure on halogenated aryl flame retardants fails to suggest usage of an unsymmetrical higher alkyl bisphenoxy alkane.

In U.S. Patent No. 3,971,758, Anderson, et al., disclose an ABS plastic composition containing

symmetrical bisphenoxy flame retardant compounds. The compositions of the flame retardants have the formula:

where Z is bromine or chlorine; m and m' are integers having a value of 1 to 5; i and i' are integers having a value of 0 to 2; HBCA is a halo-branched alkylene group having from 1 to 6 carbon atoms; and A is cyano, nitro, lower alkoxy, lower alkyl (C₁-C₄), fluorine, dialkylamino, phenyl, halo-phenyl, benzyl or

halo-benzyl group. Again, Anderson, et al., '758 fail to disclose usage of an unsymmetrical higher alkyl bisphenoxy alkane as a flame retardant agent.

Anderson, et al ., U.S. Patent No. 4,016,137, describe plastic compositions containing ABS and symmetrical bisphenoxy flame retardant compounds, which have the following formula:

where Z is bromine, m and m' are integers having a value between 1 and 5 and the alkylene is a straight or branched alkylene group containing 1 to 6 carbon atoms.

This reference again fails to suggest usage of an unsymmetrical higher alkyl bisphenoxy alkane as a flame retardant.

Anderson, et al., U.S. Patent No. 4,016,139 disclose a composition containing an ABS polymer, a symmetrical bisphenoxy flame retardant and a flame retardant enhancing agent. The bisphenoxy flame retardant has the following formula:

wherein Z is bromine, m and m' are integers having a value of 1 to 5 so that the total bromine atom content ranges from 6 to 10 atoms, and T is a straight chain or branched chain carbon group having 1 to 4 carbon atoms. There is a lack of disclosure of an unsymmetrical higher alkyl bisphenoxy alkane compound in Anderson, et al., '139.

Anderson, et al., U.S. Patent No. 4,051,105, disclose a plastic composition. The plastic

composition contains an ABS polymer and a symmetrical bisphenoxy compound having the formula:

where Z is bromine, m is an integer having a value of 1 to 5, and m' is an integer having a value of 0 to 4, i is an integer having a value of 0 to 2, and i' is an integer having a value of 1 to 5. The alkylene is a straight or branched chain alkylene group having from 1 to 6 carbon atoms and A is chlorine. Clearly there is no disclosure of unsymmetrical higher alkyl bisphenoxy compound in Anderson, et al, '105.

In overview, the bromine containing compounds for ABS resins described by the Anderson, et al., patents disclose the usage of symmetrical bisphenoxy alkane compounds containing nuclear aromatic bromination, alkylation and various other substitutions. The use of these symmetrical bisphenoxy alkane compounds has not been entirely satisfactory in the ABS systems. In particular, the symmetrical bisphenoxy compounds such as bis(tribromophenoxy)-ethane tend to bloom or migrate to the polymer surface in ABS systems.

Accordingly, a primary object of this invention is to provide new unsymmetrical higher alkyl halogenated bisphenoxy alkanes.

Another object of the invention is to provide halogenated unsymmetrical higher alkyl bisphenoxy alkanes having utility as flame retardant agents.

Yet another object of the invention is to provide halogenated unsymmetrical higher alkyl bisphenoxy alkanes having utility as non-blooming flame

retardants.

An additional object of the present invention is to provide an agent capable of flame retarding ABS resin compositions without exhibiting problems of bloom, heat or light instability or any of the other disadvantages of the prior art ABS flame retardant agents.

A further object is to provide flame retardant ABS resin compositions that exhibit the desired level of flame retardancy without suffering any deterioration of physical properties. Yet a further object is to utilize halogenated unsymmetrical higher alkyl bisphenoxy alkane as flame retardant agents for ABS resins.

SUMMARY OF THE INVENTION

The foregoing and other objects, advantages and features of this invention may be achieved with new compositions of matter comprising halogenated

unsymmetrical higher alkyl bisphenoxy alkanes.

Preferably the bisphenoxy alkane used in accordance with this invention is a brominated unsymmetrical higher alkyl bisphenoxy ethane. The preferred

brominated bisphenoxy ethane contains between 40 and 70 percent by weight of bromine. In addition, the invention contemplates incorporating an effective amount of halogenated unsymmetrical higher alkyl bisphenoxy alkane and an enhancing agent into a normally combustible ABS resin to obtain a flame retardant ABS resin composition. The compositions of this invention preferably comprise about 50 to 90 percent ABS thermoplastic resin, about 5 to 30 percent halogenated unsymmetrical higher alkyl bisphenoxy alkane and about 0.1 to 15 percent enhancing agent, all by weight of the composition.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with this invention, new halogenated unsymmetrical higher alkyl bisphenoxy compounds have been discovered. The novel compositions of this invention are distinguished from the known bisphenoxy compositions by improved properties. The novel

compositions are stable to light and heat, have good flame retardant properties, and, most importantly, compositions incorporating the novel compounds do not bloom.

The novel compositions of matter are halogenated unsymmetrical higher alkyl bisphenoxy alkanes of the following formula:

wherein X is bromine or chlorine; z is an integer from 2 to 4; R₁ is an alkyl ranging from methyl (CH₃) to dodecyl (C₁₂H₂₅); n is 0, 1 , or 2; Y i s 0, 1 , or 2; R₂ is an alkyl selected from the group consisting of sec-butyl, (sec C₄H₉), pentyl (C₄H₁₁) hexyl (C₆H₁₃), heptyl (C₇H₁₅), octyl (C₈H₁₇), nonyl (C₉H₁₉), decyl

(C₁₀H₂₁), undecyl (C₁₁H₂₃) and dodecyl (C₁₂H₂₅). R₃ is a straight or branched alkylene group from methyl (CH₃) to dodecyl (C₁₂H₂₅) such as cyclohexane for example; and if n is 1, R₁ is not R₂. The novel composition of matter contains some minor amounts of symmetrical halogenated higher alkyl bisphenoxy alkanes. The minor amounts in the composition do not effect the utility of the composition as a non-blooming flame retardant agent. When X is bromine, the bromine content should be between approximately 40 percent and 70 percent by weight. Especially preferred bisphenoxy compounds, for example, are those compounds where x is 3, z is 2, and n is zero. In these most preferred compounds X is bromine, R₂ is either octyl (C₈H₁₇) or nonyl (C₉H₁₉) and R₃ is ethylene.

The preferred novel plastic additive compositions, brominated bisphenoxy ethanes are prepared in a

two-step synthesis from brominated phenols and

dihalogenated ethanes. The synthesis follows standard Williamson ether synthesis techniques, shown below without substitution:

wherein X and Y are independently bromine or chlorine. The preferred method of synthesis is to react the phenate salt containing the least alkyl content with a large excess of 1,2-dibromoethane (>4 moles/mole phenate) in a polar, high-boiling solvent such as propylene glycol. The excess dibromoethane is then preferably removed by distillation before reacting the intermediate with the second phenate salt.

The compounds listed in Table 1 are examples of compounds synthesized by the preferred synthesis method. The list is not intended to be exhaustive or to limit the scope of the invention. The brominated alkyl phenols were produced from commercially available alkyl phenols using techniques known in the art.

Table 1

TGA, °C % Br

Compound Z Y R₁ n R ₂ 5& 25% 50% Theory Found

A 3 2 - - 0 C₉H₁₉ 315 365 389 54.4 54.1

B '' 2 - - '' C₈H₁₇ 302 353 376 55.4 55.5

C '' 2 - - '' C₅H₁₁ 309 358 382 58.9 58.7

D '' 2 - - '' C₁₂H₂₅ 336 386 408 51.4 51.3

E '' 2 CH₃ 2 C₈H₁₇ 315 358 379 53.3 53.8

G 4 2 CH3 1 C₅H₁₉ 328 382 408 57.9 57.6

H 4 2 CH₃ 1 C₁₂H₂₅ 363 411 429 55.1 56.1

I 5 2 - - 0 C₉H₁₉ 361 409 426 62.6 62.0

M 3 2 - - 0 Sec 313 363 387 60 59.5

C₄H₉ The halogenated unsymmetrical higher alkyl bisphenoxy alkanes can be used individually or in conjunction with other additives in plastics formulations. When the preferred brominated

bisphenoxy ethane is used in a plastic formulation, it should be employed in amounts of 0.5 to 30 percent by weight of plastic formulation. The most preferred weight percent of brominated bisphenoxy ethane in the plastic formulation is 5 percent to 20 percent.

This invention also encompasses use of

unsymmetrical bisphenoxy compounds in an ABS resin.

Halogenated unsymmetrical higher alkyl

bisphenoxy alkanes are useful in the preparation of non-blooming flame retardant ABS resins. The novel compositions of this invention are distinguished from known flame retardant ABS compositions by improved properties.

Preferred novel flame retardant ABS

compositions may be prepared by admixing from about 50% to about 90% by weight thermoplastic ABS resin; from about 5% to about 30% by weight halogented unsymmetrical higher alkyl bisphenoxy alkane compounds; from about 0.1% to about 15% by weight enhancing agent, where the percentages are based on the total weight of the resulting admixture of these three components. Most desirably, the compositions of this invention comprise about 60 to 90% ABS resin; about 10 to 30% halogenated unsymmetrical higher alkyl bisphenoxy alkane compound; and about 2 to 10% enhancing agent.

The ABS resin may be any thermoplastic resin formed by blending a styrene/acrylonitrile copolymer with butadiene-based rubber, or by grafting

butadiene-based rubber with styrene/acrylonitrile chains ; or by copolymerizing styrene , acrylonitrile and butadiene monomers . Thus , substantially any suitable acrylonitri le-butadiene-styrene composition may be used, containing each component of the terpolymer in substantially any proportion. The ABS may contain or may be substantially free of other additives such as stabilizers , plasticizers , dyes , pigments , fillers and the like .

The preferred plastic composition additives in the preparation of non-blooming flame retardant ABS resins are all unsymmetrical , that i s R₁ is not R₂ where n is 1 . The preferred additives in accordance with this invention include :

1-(tribromophenoxy) -2-(dibrotnononyIphenoxy)-ethane;

1-(-tribromophenoxy)-2-(dibromooctylphenoxy)-ethane;

1-(tribromophenoxy) -2-(dibromopentyIphenoxy) -ethane;

1-(tribromophenoxy)-2-(dibromododecyIphenoxy)-ethane;

1-(tetrabromomethyIphenoxy)-2-(dibromooctylphenoxy)-ethane;

1-(tetrabromomethylphenoxy)-2-(dibromononyIphenoxy) -ethane; or 1-(pentabromophenoxy)-2-(dibromononyIphenoxy) -ethane. The ABS flame retardant compositions of this invention also desirably incorporate one or more

enhancing agents. Enhancing agents useful in

accordance with this invention comprise the oxides and halides of groups IV-A and V-A of the periodic table; organic or inorganic compounds of

phosphorous, nitrogen, boron or sulfur; and oxides and halides of, for example, zinc, magnesium and

titanium, all as disclosed in U.S. Patent No. 4,016,139, Preferred enhancing agents in accordance with this invention are the oxides of antimony, arsenic and bismuth, with the oxides of antimony being

especially preferred. Antimony trioxide is the most preferred enhancing agent used in the compositions of this invention. As noted, the enhancing agent is supplied at the level of about 0.1-15 percent by

weight. Preferably, the enhancing agent is used at a level of about 2-10 percent by weight.

The scope of the present invention includes the incorporation of other additives in the composition so far as to produce a particular end result. Such additives include, without limitation, heat

stabilizers, light stabilizers, plasticizers,

pigments, preservatives, ultraviolet light

stabilizers, fillers, antioxidants, antistatic

agents and other materials well known to those

skilled in the art, for example, as described in Modern Plastics Encyclopedia, Vol. _.63_., No. 10A, McGraw-Hill, Inc. (1986).

The following preparations and examples are given to illustrate the invention and should not be construed as limiting its scope. All parts are by weight.

Example 1

Step I. 2,4,6-Tribromophenol (856 grams, 2.6 moles), phenol (6 grams), sodium carbonate (180 grams, 1.7 moles) and propylene glycol (1036 grams) are combined in a five-liter reactor equipped with a mechanical stirrer. The mixture is brought to 100ºC with agitation and held for one hour.

1,2-Dibromoethane (1950 grams, 10.4 moles) is added to the reactor all at once. The temperature is returned to 100ºC and held for an additional three hours with high agitation. Without allowing the reaction mixture to cool, agitation is discontinued, the phases are allowed to separate. Methanol (6 liters) is placed in a 12-liter reactor with

mechanical stirrer. With the methanol being

vigorously agitated, the lower phase from the

5-liter reactor is added to the methanol while keeping the lower phase warm enough to avoid

solidification before the addition is complete. The resulting methanol slurry is filtered to recover the product (β-bromoethyl-2,4,6- tribromophenyl ether, Compound Q). After drying in a vacuum oven at room temperature, 995 grams (87% of theory) of product

with greater than 98% purity and less than one

percent 1,2-bis(tribromophenoxy)-ethane are

obtained.

Step II. Dibromononylphenol (860 grams, 2.25 moles), phenol (5 grams), sodium carbonate (127

grams, 1.2 moles) and propylene glycol (2100 grams) are combined in a 5-liter reactor with mechanical stirrer. The mixture is heated slowly to 150ºC with agitation. Compound Q (995 grams, 2.25 moles) is added to the reaction portion-wise over one hour at 150ºC with vigorous agitation. The temperature and agitation are maintained for an additional four

hours. With the agitation off, the reaction is

allowed to cool. The upper phase is decanted and

the lower phase is dissolved in methylene chloride

(1 liter). After washing with dilute hydrochloric acid, the solvent is distilled, and volatile

components are removed using a wiped film evaporator at 200ºC and 1.0 torr vacuum. The product, Compound A, weighs 1530 grams (92.5%) of theory. Combined

yield for the two steps is about 80% of theory.

Example 2

Step I. Dibromononylphenol (2270 grams, 6.0

moles), phenol (16 grams), sodium carbonate (382

grams, 3.6 moles) and propylene glycol (3700 grams) are combined in a 12- liter reactor equipped with a mechanical stirrer and a Dean-Stark trap. The mixture is slowly heated to 100ºC (30-60 minutes) with agitation and held at 100ºC for one hour. 1,2-Dibromoethane (4410 grams, 24.0 moles) is added to the reactor all at once. With vigorous agitation the mixture is heated to 130ºC and held for four hours. After cooling the reaction to 90-95ºC, water (300 grams) is added and the mixture heated to reflux (~95ºC). The

dibromoethane and water azeotrope is collected in the Dean-Stark trap. The dibromoethane is removed and the water returned to the reactor until no

additional dibromoethane is recovered. The water is then also removed. If during the azeotropic

distillation the pH of the water becomes acidic, the situation is corrected by adding additional sodium carbonate to the reaction mixture.

Step II. 2,4,6-Tribromophenol (1985 grams, 6.0 moles), phenol (14 grams), sodium carbonate (382

grams, 3.6 moles) and propylene glycol (2500 grams) are combined in a 5-liter reactor equipped with a mechanical stirrer. The mixture is heated slowly to 100ºC (30-60 minutes) and held for one hour with

agitation. The reaction mixture from Step I is

heated to 145ºC, and the contents of the 5-liter

reactor are added to it. After returning the

temperature to 145ºC, the mixture is held at 145ºC with vigorous agitation for four hours. With the stirrer off, the reactor is cooled to 35ºC and the upper phase decanted. The lower phase is dissolved in methylene chloride (2.5 liter). After washing with dilute hydrochloric acid, the solvent is

distilled, and volatile components are removed using a wiped film evaporator at 200ºC and 1.0 torr

vacuum. The product, Compound A, weighs 3,480

grams, which is approximately 79% of its theoretical yield.

Example 3

Step I. Dibromononylphenol (983 grams, 2.6 moles), sodium carbonate (180 grams, 1.7 moles), 1,2-dibromoethane (1950 grams, 10.4 moles),

tris(2-(2-methoxyethoxy)ethyl) amine or TDA-1 (84 grams) are combined in a 3-liter reactor equipped with a mechanical stirrer and Dean-Stark trap. The mixture is heated to 130ºC and held for four hours. After cooling, the mixture is filtered, and the excess dibromoethane is removed using a wiped film evaporator at 100ºC and 20 torr vacuum.

Step II. The product from Step I which is predominantly 3-bromoethyl-dibromononylphenyl ether and TDA-1 is combined with 2,4, 6-tribromophenol (860 grams, 2.6 moles) and sodium carbonate (180 grams, 1.7 moles) in a 3-liter reactor equipped with mechanical stirrer and Dean-Stark trap. The mixture is heated to 130ºC and held for five hours. Methylene

chloride (2 liters) is placed in a 5-liter reactor equipped with mechanical stirrer and reflux condenser. The still-hot product in the 3-liter reactor is slowly added to the methylene chloride. This mixture is then washed with diluted

hydrochloric acid. After distilling the methylene chloride, volatile components are removed using a wiped film evaporator at 200ºC and 1.0 torr vacuum. The product, Compound A, weighs 1,410 grams which is approximately 74% of its theoretical yield.

Example 4

Step I. 2,4,6-Tribromophenol (1,160 grams, 3.5 moles), lithium hydroxide monohydrate (7.5 grams), and ethylene glycol (2000 grams) are combined in a 5-liter reactor equipped with mechanical stirrer and subsurface gas inlet tube. The mixture is heated to 120ºC and ethylene oxide is introduced subsurface at a rate of three to four grams per minute with vigorous stirring. The pH of the reaction mixture is monitored with dampened pH indicator paper.

After approximately one hour, depending on the rate of ethylene oxide addition, the pH will change from slightly acidic to strongly basic. At this point, the ethylene oxide addition is discontinued.

Between 180 grams and 200 grams of ethylene oxide will have been used. When the reaction has cooled below 100ºC, water (750 grams) is added. With the temperature at or still slightly above 70ºC, the heavy slurry is filtered on a laboratory filtering centrifuge and washed on the filter cloth with 70ºC water (10 liter). The product is dried in a forced draft oven at 80ºC to constant weight. The product, β-hydroxyethyl-2,4,6- tribromophenyl ether, weighs 1190 grams, which is approximately 91% of the theoretical yield.

Step II. Product from Step I (940 grams, 2.5 moles), and pyridine (3 liters) are combined in a 5-liter reactor equipped with mechanical stirrer. After cooling the mixture to <5ºC, benzenesulfonyl chloride (883 grams, 5 moles) is added dropwise over one hour while keeping the temperature at <5ºC. The mixture is allowed to slowly warm to room

temperature after stirring for 16 hours at <5ºC. After filtering off the solids formed, the mixture is slowly added to a 12-liter reactor half-full with an ice/water slurry with vigorous agitation. The product is recovered by filtration and dried in a vacuum oven to constant weight. The product,

2-(2,4,6-tribromophenoxy)- ethyl benzene-sulfonate weighs 1,210 grams which is about 94% of the

theoretical yield.

Step III. Same as Step II of Example 1 except β-(2,4,6-tribromophenoxy)-ethyl benzenesulfonate (1,160 grams, 2.25 moles) is used in place of

Compound Q. The product, Compound A, weighs 1540 grams which is 93% of theory. Combined yield of the three steps is approximately 79% of its theoretical yield. Example 5

A flame retardant composition was prepared by blending 20.0 parts halogenated unsymmetrical higher alkyl bisphenoxy alkane (Compound A); 69.0 parts ABS resin, which is available from Borg-Warner

Corporation as CYCOLAC GSM 1000; 5.0 parts

chlorinated polyethylene, which is available from The Dow Chemical Company as TYRIN CPE-4213S; 5.0 parts antimony trioxide, which is available from M & T Chemical Company as THERMOGUARD S; 0.5 parts stabilizer, which is available from Ciba Geigy

Corporation as TINUVIN 770; and 0.5 parts

antioxidant, which is available from Ciba Geigy Corporation as Irganox 1076.

Compound A is 1-(tribromophenoxy)- 2-(dibromononyIphenoxy)-ethane, a halogenated unsymmetrical higher alkyl bisphenoxy alkane

prepared in accordance with Example 1.

The resultant mixture was blended in a

prep-center bowl (Model R6, C.W. Brabender

Instruments, Inc., S. Hackensack, NJ) at 200ºC until a homogeneous mass developed. The admixture was cooled, ground into chips, and molded into test specimens. The chips were injection molded in a one-ounce injection molder (Model HI-30 RS, Newbury Industries, Inc., Newbury, OH). Conditions for injection molding are given in Table II. The resulting mixture had a bromine content of 10.8% by weight. TABLE I I

INJECTION MOLDING MACHINE PARAMETERS Stock Temperature 430ºF

Mold Temperature 100ºF

Initial Ram Pressure 1900 psi

Secondary Ram Pressure 1000 psi

Total Injection Time 5 sec

Cycle Time 25 sec

Bloom observations were made on molded test plaques which were aged at 70ºC for at least 2 to 6 weeks. Periodic visual inspections were used to detect the presence of deposits on the specimen

surface.

EXAMPLES 6-11

Flame retardant compositions were prepared

using the method of Example 5, except that Compound A was replaced by bisphenoxy alkanes Compound B,

Compound C, Compound D, Compound E, Compound G, and Compound I, respectively in proportion so as to maintain a 10.8 percent by weight bromine concentration in the resulting polymer composition. The identity for these compounds are listed in Table III. TABLE III

A 1-(Tribromophenoxy)-2-(dibromononyIphenoxy)-ethane

B 1-(Tribromophenoxy)-2-(dibromooctyIphenoxy)-ethane

C 1-(Tribromophenoxy)-2-(dibromopentylphenoxy-ethane

D 1- (Tribromophenoxy)-2-(dibromododecyIphenoxy)-ethane E 1-(TetrabromomethyIphenoxy)-2-(dibromooctyIphenoxy)-ethane F bis-(DibromononyIphenoxy)-ethane

G 1-(Tetrabroraomethylphenoxy)-2-(dibromononyIphenoxy)-ethane I 1-(Pentabromophenoxy)-2-(dibromononylphenoxy)-ethane

J bis-(Tribromophenoxy)-ethane

K bis-(Tetrabromomethylphenoxy)-methane

L bis-(Tribromophenoxy)-decane

COMPARATIVE EXAMPLE 1-4

Flame retardant compositions were prepared using the method of Example 5 , except that Compound A was replaced by Compound J, Compound F, Compound K, and Compound L, respectively in a proportion so as to maintain a 10.8 percent by weight bromine concentration in the resulting polymer composition. Identity for these Compounds J, F, K, and L are listed in Table III.

Flame retardancy and physical properties of the various injected molded samples obtained from

Examples 5-11 are reported in Table IV which identifies the test procedures employed, all of which are well known to those skilled in the art. TABLE IV

Example Notched Heat Flamma Tensile Elonga Flexural Flexural

Izod Debility Strength tion Strength Modulus ft- flee UL-94 psi % psi 10¹⁵ psi 1b/in tion ASTM ASTM ASTM ASTM

ASTM ºF D-638 D-790 D-790 DD--779900

D-256 ASTM

D-648

5 4.2 156 V-O 4800 40 7900 2.60

6 3.9 153 V-O 5100 37 8400 2.80

7 4.1 151 V-O 5500 21 9100 3.00

8 3.4 156 V-O 4500 36 7400 2.50

9 3.7 156 V-O 5200 ≥30 8000 2.80

10 4.6 156 V-O 4900 50 8100 2.70

11 4.9 158 V-O 5100 55 8400 2.80

Comp 1 2.5 151 V-O 5400 12 9400 3.20

Comp 2 3.8 140 V-O 3300 4 3600 1.90

Comp 3

Comp 4 4.0 150 V-O 4800 52 8300 3.09

Example Melt HardBloom Light Yellowness Yellowness

Flow ness 70 ºC Stability Index Index g/10 R- (See Delta E initial 300 hrs min Scale text) ASTM ASTM ASTM

ASTM ASTM ASTM ASTM ASTM

D-1238 D-785 D-2565 D-1925 D-1925

5 2.2 80 No 1.0 16.7 18.6

6 2.0 84 No 0.7 16.6 18.1

7 3.4 86 No

8 2.3 73 No 1.3 17.2 20.0

9 2.0 73 No 0.2 16.2 16.4

10 2.3 84 No 3.8 17.0 25.2

11 1.8 85 No 6.0 17.0 30.0 Comp 1 2.1 93 Yes 0.9 16.4 17. 7

Comp 2 - - 36 Yes 0.3 17.6 17.8

Comp 3 Yes

Comp 4 1.6 75 Yes 0.2 Table IV shows the results of the experimental evaluations of various test specimens and may be summarized as follows.

Example 5 illustrates a flame retardant ABS formulation incorporating halogenated unsymmetrical higher alkyl bisphenoxy alkane in accordance with this invention. A flammability rating of V-O was achieved, and bloom was not observed.

Comparative Examples 1-4 show that prior art symmetrical bisphenoxy compound, when used in V-O formulation, migrate (bloom) from ABS resin.

Examples 6-11 illustrate flame retardant formulations incorporating other halogenated

unsymmetrical higher alkyl bisphenoxy alkanes within the scope of this invention.

It is especially important to note that ABS resins incorporating halogenated unsymmetrical higher alkyl bisphenoxy alkanes of this invention do not bloom whereas symmetrical bisphenoxy alkanes do bloom or tend to migrate from the resin

compositions. It is to be noted that ABS resins incorporating the halogenated unsymmetrical higher alkyl bisphenoxy alkanes of this invention exhibit excellent resistance to light instability, to thermal migration of flame retarding agents, and have improved physical properties, such as impact strength and tensile elongation.

EXAMPLES 12-14

Flame retardant compositions were prepared using the method of Example 5, except that Compound A was partially replaced by Compound J in proportion as specified in Table V, so as to maintain a constant weight of bromine-containing flame retardant.

COMPARATIVE EXAMPLES 5-6

A flame retardant composition was prepared using the method of Example 5, except that Compound A was replaced by Compound J in proportion as specified in Table V.

TABLE V

BROMINE-CONTAINING COMPOUND , pbw

EXAMPLE COMPOUND A COMPOUND J BLOOM

5 20.0 0.0 NO

12 19.0 1.0 NO

13 18.0 2.0 NO

14 16.0 4.0 NO

COMP 5 0.0 20.0 YES

COMP 6 0.0 1.0 YES Table V shows the results of experimental evaluation of the various test specimens and may be summarized as follows:

Use of the halogenated unsymmetrical higher alkyl bisphenoxy alkanes of this invention in ABS resin formulations also suppresses bloom. In the case of bis(tribromophenoxy)-ethane (Compound J), severe bloom was noted in high (Comparative

Example 5) and low (Comparative Example 6) loading levels. Examples 12-14 show no evidence of bloom in compositions comprising mixtures of the agents of this invention with bis(tribromophenoxy)-ethane (Compound J). Thus, the presence of Compound A retards or suppresses the blooming that would otherwise occur due to the presence of

bis(tribromophenoxy)-ethane (Compound J).

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and without departing from the spirit and scope thereof can make various changes and modifications of the invention to adopt to its various usages and conditions.

Claims

1. A halogenated unsymmetrical higher alkyl bisphenoxy alkane of the structure

wherein X is bromine or chlorine; R₁ is straight or branched alkyl from methyl to dodecyl (C₁ to C₁₂); z is an integer from 2 to 5; n is 0, 1. or 2; R₂ is straight or branched alkyl selected from the group consisting of sec-butyl, (sec C₄H₉), pentyl (C₅H₁₁), hexyl (C₆H₁₃), heptyl (C₇H₁₅), octyl (C₈H₁₇), nonyl (C₉H₁₉), decyl (C₁₀H₂₁), undecyl (C₁₁H₂₃) and dodecyl (C₁₂H₂₅); y is 0, 1, or 2; R₃ is a straight or branched alkylene group from methyl to docedyl (C₁ to C₁₂); and if n is 1, R₁ is not R₂.

2. A composition as claimed in claim 1 wherein X is bromine.

3. A composition as claimed in claim 2 wherein R₂ is octyl (C₈H₁₇).

4. A composition as claimed in claim 2 wherein R₂ is nonyl (C₉H₁₉).

5. A composition as claimed in claim 4 wherein R₃ is ethylene.

6. A halogenated unsymmetrical higher alkyl 10 bisphenoxy alkane of the structure:

7. A halogenated unsymmetrical higher alkyl bisphenoxy alkane of the structure:

8. A halogenated unsymmetrical higher alkyl bisphenoxy alkane of the structure:

9. A non-blooming flame retardant acrylonitrile- butadiene-styrene resin composition comprising: a normally flammable acrylonitrile-butadiene-styrene resin; as a flame retardant agent, an effective amount of

halogenated unsymmetrical higher alkyl bisphenoxy alkane to render the composition flame retardant; and a flame retardant enhancing agent.

10. A composition as claimed in claim 1 wherein the halogenated unsymmetrical higher alkyl

bisphenoxy alkane is a compound of the structure:

wherein X is bromine or chlorine; R₁ is straight or branched alkyl from C₁ to C₁₂; z is an integer from 2 to 5; n is O, 1, or 2; R₂ is straight or branched alkyl selected from the groups consisting of sec-butyl (sec C₄H₉), pentyl (C₅H₁₁), hexyl (C₆H₁₃), heptyl (C₇H₁₅), octyl (C₈H₁₇), nonyl (C₉H₁₉), decyl (C₁₀H₂₁), undecyl (C₁₁H₂₃) and dodecyl (C₁₂H₂₅); y is O, 1, or 2; R₃ is straight or branched alkylene from C₁ to C₁₂; and if n is 1, R₁ is not R₂.

11. A composition, as claimed in claim 9, wherein the composition comprises about 50 to about 90 percent acrylonitrile-butadiene-styrene resin, about 5 to about 30 percent halogenated

unsymmetrical higher alkyl bisphenoxy alkane and about 0.1 to about 15 percent enhancing agent , all by weight of the flame retardant ABS composition.

12 . A composition, as claimed in claim 9 wherein the enhancing agent is selected from the group consisting of the oxides and halides of groups IV-A and V-A of the periodic table ; organic or inorganic compounds of phosphorous , nitrogen, boron or sulfur ; or oxides and halides of zinc , magnesium and titanium.

13 . A composition as claimed in claim 9 , wherein the enhancing agent is antimony trioxide .

14. A composition as claimed in claim 9 , wherein the halogenated unsymmetrical higher alkyl bisphenoxy alkane is selected from the group consisting of:

1-(tribromophenoxy) -2-(dibromononyIphenoxy) -ethane;

1-(tribromophenoxy) -2-(dibromooctyIphenoxy) -ethane;

1-(tribromophenoxy) -2-(dibromopentyIphenoxy)-ethane;

1-(tribromophenoxy)-2-(dibromododecylphenoxy)-ethane;

1-(tetrabromofflethyIphenoxy)-2-(dibromooctyIphenoxy)-ethane; 1-(tetrabronotnethyIphenoxy)-2-(dibromσnonyIphenoxy)-ethane; 1-(pentabromophenoxy)-2-(dibromononyIphenoxy)-ethane.