HK1152028A - Flame retardant halogenated polymer compositions - Google Patents

Description

Halogenated polymer composition flame retardant

Cross Reference to Related Applications

This application claims priority from U.S. provisional application No. 60/926,374, filed on 25/4/2007, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to halogenated polymer composition flame retardants.

Background

Decabromodiphenyl ether (deca) and decabromodiphenyl ethane (deca-DPE) are commercially available materials that are widely used as flame retardant materials for different polymeric resin systems, and have the following structure:

one of the advantages of using deca and deca-DPE in difficult to flame retard polymer resins such as High Impact Polystyrene (HIPS) and polyolefins is that it has a very high bromine concentration (82-83%), which allows for the use of lower amounts of flame retardant in the overall composition, thereby minimizing the adverse effects of the flame retardant on the mechanical properties of the polymer.

Although deca has been commercially successful, efforts have been made to develop alternative halogenated flame retardants with equal or greater efficiency. This is not only due to economic pressure, but also because the development of new flame retardants can reduce the amount of flame retardant used and thereby improve the properties of the polymer. The improvement in properties, such as non-blooming formulations or better mechanical properties, can be achieved by producing polymeric or oligomeric flame retardant compounds. Depending on compatibility, such materials will bond with the matrix resin polymer substrate and thus exhibit a tendency to be less prone to blooming.

A large number of commercially available flame retardants can be considered oligomers or polymers of halogenated monomers. Examples of such monomers include tetrabromobisphenol A (TBBPA) and Dibromostyrene (DBS), which have the following structure:

commercially, TBBPA and DBS are not typically used in monomeric form, but are converted to oligomers or polymers. One class of oligomers is brominated carbonate oligomers based on TBBPA. Available from Chemtura corporation (e.g., Great Lakes BC-52)^TM，Great lakes BC-52HP^TMAnd Great Lakes BC-58^TM) And Teijin Chemical (FireGuard 7500 and FireGuard 8500). These products are mainly used as flame retardants for polycarbonates and polyesters.

Brominated epoxy oligomers based on TBBPA condensates and epichlorohydrin are commercially available from Dainippon Ink and Chemicals asSeries sales, and additional ICL Industrial products (e.g., F-2016 and F-2100) and other suppliers also provide such products. Brominated epoxy oligomers can be used as flame retardants for various thermoplastics, either alone or in combination with other flame retardants.

Another class of brominated polymeric flame retardants based on TBBPA is for example Teijin FG-3000, which is a copolymer of TBBPA and 1, 2-dibromoethane. The aralkyl ethers are useful in ABS and other styrenic polymers. Alternative end groups on the brominated polymer, such as aryl or methoxy groups, have also been known from the material illustrations described in US4,258,175 and US5,530,044. The non-reactive end groups are said to provide thermal stability of the flame retardant.

TBBPA can also be converted with additional difunctional epoxy compounds into many other different kinds of epoxy resin co-oligomers by chain extension reactions, for example, with the diglycidyl ether of bisphenol a. Typical examples of such epoxy resin products are d.e.r manufactured by the dow chemical company.^TM539 or Epon manufactured by Hexion^TM828. These products are mainly used in the production of printed circuit boards.

DBS is manufactured by Chemtura Corporation and is monopoly used, and is available in several different polymeric forms capable of producing poly (bromostyrene) type flame retardants (Great Lakes PDBS-80)^TM，Great LakesPBS-64HW^TMAnd Firemaster CP44-HF^TM) And (5) selling. These materials are homopolymers or copolymers. In addition, similar brominated polystyrene type flame retardants are commercially available from Albemarle Chemical Corporation (R) ((R))HP-3010， HP-7010, and PyroChek 68 PB). All of these polymer products are used for flame retardant thermoplastics such as polyamides and polyesters.

Unfortunately, existing brominated polymeric materials have a major disadvantage in that they have relatively low bromine content, which results in their low effectiveness as flame retardants, thereby often having a negative effect on the desired physical properties of the flame retardant formulations containing them, such as impact strength. For example, considering deca and deca-DPE contain 82-83% bromine, oligomers or polymers based on the above brominated monomers typically contain 52% -68% bromine, depending on the material. Thus in polymer formulations, it is necessary to use significantly more brominated polymeric flame retardant than deca, which often results in a reduction in the mechanical properties of the formulation.

Other reasons may also affect the impact of the flame retardant on the final properties of the formed resin. The reasons include thermal stability of the flame retardant and compatibility with the host resin. In the case of relatively stable other properties, the bromine content, and thus the amount of flame retardant added, has a major effect on the performance of the overall composition.

To meet the need for flame retardant materials that do not affect the mechanical properties of the target resins, we have now developed a family of aryl ether oligomer materials that can be considered halogenated, especially brominated. In particular, we have found that the use of the halogenated aryl ether oligomers allows resins such as HIPS and polyolefins to have excellent mechanical properties, and that the materials also allow engineering thermoplastics such as polyamides and polyesters to have perfect properties. The halogen content of the aryl ether oligomers can be higher than that of the currently marketed oligomers or polymers, which has a positive effect on the mechanical properties of the composition. It has also been found that even with low levels of halogenation, the mechanical properties of the compositions are within acceptable ranges.

Japanese unexamined patent application publication No. 2-129,137 discloses a flame retardant polymer composition wherein the polymer is blended with a halogenated bis (4-phenoxyphenyl) ether represented by the general formula [ I ],

wherein X is a halogen atom, a and d are numbers of 1 to 5, and b and c are numbers of 1 to 4. However, the flame retardant obtained by bromination of the above bis (4-phenoxyphenyl) ether is a discrete compound, not an oligomeric material formed by polymerization of an aromatic ether monomer. In contrast, in the present invention, it is considered that the use of a material having a distribution in the form of an oligomer can improve its performance as a flame retardant.

In the literature entitled "Synthesis and Stationary Phase Properties of Bromo phenyl ethers", Journal of Chromatography, 267(1983), page 293-. Likewise, the ethers also appear as discrete compounds, without oligomeric distribution, and although the above products are said to have utility in the separation of organic compounds, no mention is made that they may be used as flame retardants.

SUMMARY

In one aspect, the present invention provides a halogenated aryl ether oligomer formed by halogenating an aryl ether oligomer.

Conveniently, the halogenated aryl ether oligomer has a halogen content of 50 to 83 wt%, such as 65 to 80 wt% of the oligomer. Typically, the halogen is bromine.

Suitably, the halogenated aryl ether oligomer comprises on average at least 3 aromatic groups, typically at least 5 aromatic rings. Typically, the molecular weight of the halogenated oligomer is at most 1,000,000 daltons.

In one embodiment, the halogenated aryl ether oligomer comprises repeating monomer units of:

wherein R is a hydrogen atom or an alkyl group, especially C₁-C₄Alkyl, Hal is a halogen atom, typically bromine, m is at least 1, n is from 0 to 3 and x is at least 2, such as from 3 to 100,000, for example from 5 to 20.

In another aspect, the present invention provides a flame retardant polymer composition comprising (a) a flammable macromolecular material; and (b) a halogenated aryl ether oligomer-type flame retardant formed from the halogenation of an aryl ether oligomer.

In yet another aspect, the present invention provides a flame retardant polymer composition comprising (a) a flammable macromolecular material; and (b) a halogenated aryl ether oligomer-type flame retardant formed by halogenation of an aryl ether oligomer, wherein the halogenated aryl ether oligomer comprises repeating monomer units of:

wherein R is a hydrogen atom or an alkyl group, especially C₁-C₄Alkyl, Hal is a halogen atom, typically bromine, m is at least 1, n is from 0 to 3 and x is at least 2, such as from 3 to 100,000, for example from 5 to 20.

Suitably, the above halogenated aryl ether oligomer further comprises terminal groups each independently comprising an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a hydrogen atom, a halogen or a hydroxyl group.

In yet another aspect, the present invention provides a flame retardant polymer composition comprising (a) a flammable macromolecular material; and (b) a halogenated aryl ether flame retardant of the formula:

wherein each R is¹Independently selected from hydrogen, hydroxy, halogen and alkyl, each R²Independently selected from hydrogen, hydroxy, halogen and alkyl, provided that at least one R²And usually at least one R¹Is halogen, typically bromine, n is 5, m is 4 and x is 1 to 10, such as 2 to 6.

Suitably, the flammable macromolecular material (a) is a thermoplastic polymer, such as polystyrene, poly (acrylonitrile-butadiene-styrene), polycarbonate, polyolefin, polyester and/or polyamide.

In one embodiment, the flammable macromolecular material (a) is polystyrene and the amount of flame retardant haloaryl ether oligomer in the composition is 5 to 25 wt%, such as 10 to 20 wt%.

In another embodiment, the flammable macromolecular material (a) is polypropylene and the amount of flame retardant haloaryl ether oligomer in the composition is from 20 to 50 wt%, such as from 25 to 40 wt%.

In another embodiment, the flammable macromolecular material (a) is polyethylene and the amount of flame retardant haloaryl ether oligomer in the composition is from 5 to 35 wt%, such as from 20 to 30 wt%.

In another embodiment, the flammable macromolecular material (a) is a polyamide or polyester and the amount of flame retardant haloaryl ether oligomer in the composition is 5 to 25 wt%, such as 10 to 20 wt%.

Alternatively, the flammable macromolecular material (a) is a thermosetting polymer, such as an epoxy resin, an unsaturated polyester, a polyurethane and/or a rubber.

Detailed Description

The present invention describes a halogenated aryl ether oligomer formed by halogenating, especially brominating, an aryl ether oligomer, and its use as a flame retardant for flammable macromolecular polymeric materials. Suitable macromolecular polymers include thermoplastic polymers such as polystyrene, poly (acrylonitrile-butadiene-styrene), polycarbonate, polyolefins, polyesters and polyamides; and thermosetting polymers such as epoxy resins, unsaturated polyesters, polyurethanes, and rubbers.

The term "oligomer" as referred to herein refers to a compound formed by oligomerization of one or more monomers comprising repeating units derived from the monomers, regardless of the number of repeating units. Since the arylene ether precursors used to produce flame retardants are derived from oligomerization, the precursors and the halogenated products typically have a molecular weight distribution. In particular, the oligomer typically contains at least 3 aromatic rings, typically at least 5 aromatic rings, and the halogenated oligomer has an average molecular weight of up to 1,000,000 daltons.

Representatively, the halogenated aryl ether polymers of the present application comprise repeating monomer units of:

wherein R is hydrogen or alkyl, especially C₁-C₄Alkyl, Hal is halogen, m is at least 1, n is 0 to 3, x is at least 2, such as 3 to 100,000, for example 5 to 20. The halogen may be fluorine, chlorine, bromine and/or iodine, especially bromine. Typically the halogenated aryl ether oligomer further comprises end groups each independently comprising alkyl, alkoxy, aryl, aryloxy, hydrogen, halogen or hydroxy.

In one embodiment, the halogenated aryl ether oligomer flame retardant has the formula:

wherein each R is¹Independently selected from hydrogen, hydroxy, halogen and alkyl, each R²Independently selected from hydrogen, hydroxy, halogen and alkyl, provided that at least one R²Is halogen, typically bromine, n is 5, m is 4, and x is 1 to 100,000, e.g., 3 to 20.

Typically, the halogen content of the haloaryl ether oligomers herein will be in the range of from 50 to 83 wt%, such as from 65 to 80 wt% of the oligomer.

In another embodiment, the flame retardant for use herein comprises a halogenated aryl ether having the structure:

wherein each R is¹Independently selected from hydrogen, hydroxy, halogen and alkyl, each R²Independently selected from hydrogen, hydroxy, halogen and alkyl, provided that at least one R²And usually at least one R¹Is halogen, typically bromine, n is 5, m is 4 and x is 1 to 10, e.g. 2 to 6. In this embodiment, the halogenated aryl ether may have an oligomeric distribution or may be a discrete compound.

The flame retardants of the present application are prepared by halogenation, especially bromination, of a polyarylether precursor which may be formed by oligomerization of a hydroxyhaloaryl material such as bromophenol, or by reaction of a dihaloaryl material such as dibromobenzene with a dihydroxyaryl material such as resorcinol by ether synthesis such as Ullmann ether synthesis. In this process, the reactants are heated to reflux, typically at a temperature of 125 ℃ to 200 ℃, using a polar organic solvent, such as N, N-dimethylformamide or benzophenone, in the presence of a strong base and a copper-containing catalyst. A representative example of the Ullmann ether synthesis reaction is disclosed by Laskoski et al in the following references: "Oligomeric Cyanate Ester Resins: application of a Modified Ullmann Synthesis in the Preparation of thermoplastic Polymers ", Journal of Polymer Science: part A: polymer Chemistry, Vol.44, (2006), 4559-.

The bromination of poly (arylene ether) with bromine is readily carried out in the presence of a Lewis acid catalyst such as aluminum chloride. The weight ratio of bromine to oligomer used in the bromination reaction is typically from 1: 1 to 100: 1, for example from 3: 1 to 20: 1, depending on the amount of bromine to be introduced into the arylene ether oligomer. The final brominated arylene ether oligomer typically contains at least one, and typically 2 to 4, bromine atoms per arylene ether repeat unit of the oligomer.

Alternatively, bromine chloride may be used as a brominating agent in the same process to produce the desired product. In this case, small amounts of organically bound chlorine may also be present, but its presence does not detract from the properties of the final flame retardant.

The resulting halogenated aryl ether oligomers are useful as flame retardants for a variety of different polymeric resin systems due to their good thermal stability and higher halogen content relative to known flame retardant polymers such as brominated polystyrene. Typically, the halogenated aryl ether oligomers are used as flame retardants for thermoplastic polymers, such as polystyrene, High Impact Polystyrene (HIPS), poly (acrylonitrile-butadiene-styrene) (ABS), Polycarbonate (PC), PC-ABS blends, polyolefins, polyesters and/or polyamides. Using the above polymers, the halogenated oligomer content in the polymer formulation required to meet the V-0 standard when subjected to flammability testing by underwriters laboratories is generally as follows:

useful range of polymer preferred range

Polystyrene 5-25 wt% 10-20 wt%

20-50 wt% of polypropylene and 25-40 wt%

Polyethylene 5-35 wt% 20-30 wt%

Polyamide 5-25 wt% 10-20 wt%

Polyester 5-25 wt% 10-20 wt%

The halogenated aryl ether oligomers may also be used in thermosetting polymers such as epoxy resins, unsaturated polyesters, polyurethanes and/or rubbers. When the base polymer is a thermosetting polymer, the flammability reducing oligomer is suitably present in an amount of from 5 wt% to 35 wt%, for example from 10 wt% to 25 wt%.

Typical uses for polymer compositions comprising the halogenated aryl ether oligomers of the present application as flame retardants include automotive molding elements, adhesives and sealants, fabric back coatings, wire and cable claddings, and electronic and electrical product housings, components and connectors, among others. Typical uses for the flame retardants of the present application in the building and construction areas include self-extinguishing composite films, wire and cable coatings, back coatings for carpets and fabrics including wallpaper, wood and other natural fiber filled members, waterproofing materials including waterproofing membranes, waterproofing composites, and binders used in composite compositions. In general consumer products, the flame retardants of the present application can be used in the formulation of household electrical components, homes, and attended and unattended appliance articles requiring flame retardancy.

The invention will now be described in more detail by way of the following non-limiting examples.

Examples 1 to 7: bromination of aryl ether resins

500g of a polyarylether resin (Santovac OS-124) was dissolved in a solution containing 6.5g of AlCl₃A solution of the catalyst in 1L of dichloroethane was formed and bromine (3176g, 19.87mol) was added. Santovac OS-124 is an arylene ether resin comprising five meta-linked aromatic rings, used to simulate an oligomeric material. After completion of the reaction, the brominated resin was isolated to give 2013.6g of a light-colored paste powder. The resulting material was analyzed to have a bromine content of 75.7%, a mass loss of 5% at 420 ℃ as shown by TGA analysis, and a glass transition temperature (Tg) of 154 ℃ as shown by Differential Scanning Calorimeter (DSC) analysis.

Several other materials were prepared using similar methods to give brominated arylene ether materials with different bromine contents or ring attachment modes, as shown in table 1. It can be seen that the bromine content affects the measured glass transition temperature and the melting temperature range of the product.

TABLE 1

Examples	Oligomer type(a)	Bromine%	Tg，℃ (DSC)	Visible melting range,. deg.C
					1	5-chamber	75.7	154	177-211
2	5-chamber	65.5	77.0	87-109
					3	5-chamber	74.7	150.8	160-183
4	5-chamber	80.0	192.1	204-221
					5	6-compartment	74.8	160.5	184-198

6	3-pair	72.6	85.3	185-241
					7	4-pair	70.8	130.5	168-196

a) Naming principle: 5-m means that all of the 5 aromatic rings are linked by a meta bond

Example 8: synthesis of polyarylether by resorcinol and 1, 4-dibromobenzene

A reaction flask was charged with resorcinol (15.0g, 0.137mol), 1, 4-dibromobenzene (32.3g, 0.137mol), N, N-dimethylformamide (205g, 2.58mol), toluene (20g, 0.22mol), and a 50% KOH solution prepared by dissolving 90% KOH (17.05g, 0.274mol) in deionized water. Typically, the base is added in an amount of 1.8 to 2.2 moles per mole of resorcinol. The reaction mixture was heated to reflux to azeotropically remove water. After removal of the theoretical amount of water, most of the toluene was stripped from the reaction flask with a final vessel temperature of 148-150 ℃. The reaction was then cooled to-120 ℃ and CuI (0.52g, 0.00274mol) and 1, 10-phenanthroline (0.74g, 0.0041mol) were added simultaneously under a stream of diazo gas. The reaction flask was filled with nitrogen, and the reaction was heated to reflux for 24 hours (-150-. The organic phase was stripped to give a viscous resin product residue in 92% isolated yield. GPC analysis showed that the product had a molecular weight (Mw) of 605 and a polydispersity (Pd) of 1.97.

The Mw range of the different reaction products obtained by this method was 600-3100 according to GPC analysis.

Example 9: synthesis of polyarylethers from 3-bromophenol in DMF/toluene

3-bromophenol (100g, 0.58mol), toluene (700g) and 50% KOH (72g, 0.58mol) were charged to a standard reaction flask, the reaction was heated to reflux to azeotropically remove water, and an additional 540g of toluene was stripped from the reaction flask. The flask contents were cooled to 100 ℃ and DMF (467g), CuI (0.22g, 0.0012mol) and 1, 10-phenanthroline (0.31g, 0.0017mol) were added. Again heated to reflux. Excess toluene was stripped until the temperature reached 140 ℃ and then bromobenzene (4.55g, 0.029mol) was added. When the reaction was complete, the product was worked up to give a viscous amber resin in 93.1% yield. The molecular weight Mw of the product polymer was 2270 by GPC analysis.

Example 10: synthesis of polyarylether by using benzophenone as solvent and 4-bromophenol

A reaction flask was charged with 4-bromophenol (232.5g, 1.34mol), benzophenone (1435g, 8.04mol) and toluene (900g, 1.34 mol). With N₂The flask was purged and heated to less than 100 ℃ to dissolve the benzophenone. 90% KOH (83.5g, 1.34mol) was dissolved in 83.5g deionized water to make a 50% KOH solution, which was added to the flask over 5min and the reaction was heated to reflux with azeotropic removal of water and toluene was also distilled off. Bromobenzene (10.5g, 0.07mol) and a solution of CuCl (1.33g, 0.0134mol) in pyridine (90g, 0.134mol) were added and the reaction temperature was maintained at 204 ℃ for 5 h. The reaction was cooled and worked up to give 165.7g of a light brown solid in 65% yield. Analyzed by GPC (THF solvent system), Mw 1790 and Pd 1.70 (not all materials soluble).

The molecular weight was analyzed again a second time based on DSC, since it was not completely soluble in the solvent used for GPC measurement. A series of para-aryl ether compounds containing 3, 4, 5 rings respectively are analyzed by DSC, and the melting points are found to conform to the equation of a straight line. Diphenyl ether was included in the analysis, again following the expected straight line. Melting point data for compounds containing para-aromatic rings (2-5) are as follows: 26, 75.6, 108.2, 147.4 ℃. This line is used to estimate the number of aromatic groups on the polymer prepared, which gives only a rough estimate of the molecular weight. By this method, the number of aromatic rings is predicted to be 8.

Examples 11 and 12: bromination of aryl ethers by 4-bromophenol polymerization

A reaction flask was charged with 100.0g of the polyphenylene ether obtained in example 10, 600ml of chloroform and 10.2g of aluminum chloride. The resulting slurry was heated to reflux (60 ℃ C.) and 1202.8g of dry bromine were added over 6h under reflux. The reaction was maintained at reflux temperature for 2h and treated to give a solid precipitate. The polymerization product (223.2g) was obtained as a brown solid with the following analytical data: 68.8% OBr, melting range 230-.

The above bromination process was repeated to obtain brominated arylene ether oligomer materials having different bromine contents, as shown in Table 2.

Examples 12 to 14: bromination of aryl ethers by 3-bromophenol polymerization

The scale-up reaction of example 9 was carried out using bromobenzene and 3-bromophenol at a molar ratio of 0.20, and the product was found by GPC analysis to have a lower molecular weight of 700 Mw. A reaction flask was charged with 108.2g of the polyarylether, 1000ml chloroform and 10.8g aluminum chloride. The resulting slurry was heated to reflux (60 deg.C), maintained at reflux and 1044.1g of dry bromine were added over 8 h. The reaction was kept at reflux temperature for 1h and treated to give a solid precipitate. The polymer (319.9g) was obtained as a brown solid with the following analytical data: 70.2% OBr with a melting range of 141-161 ℃ and a DSC test showing a glass transition temperature (Tg) of 117 ℃. The properties thereof are shown in table 2.

The above bromination procedure was repeated to obtain brominated arylene ether oligomer materials having different bromine contents, as shown in Table 2.

Comparing the results in table 2, it can be seen that by varying the stereo structure (meta, para) of the oligomer, oligomers with different glass transition temperatures and visible melting ranges can be prepared. Mixed oligomers containing meta and para linkages can also be prepared by using the appropriate reactants and ratios in the reaction.

TABLE 2

Examples	Oligomer type	GPC (Mw)(a)	% bromine	Tg，℃ (DSC)	Melting range, deg.C
						11	Alignment of	1790	68.8	＞240	230-313
12	Alignment of	1700	58.7	＞240	216-293
						13	Meta position	700	70.2	117	141-161
14	Meta position	1020	64.1	123	141-164

a) GPC analysis was performed on the oligomers prior to bromination. The alignment samples were only partially soluble.

Example 15: compounding of brominated arylene ether oligomer and High Impact Polystyrene (HIPS) resin

The brominated arylene ether oligomers produced in examples 1-4 (Table 1) were each mixed with a HIPS (high impact polystyrene) resin composition containing an antimony oxide (ATO) synergist using a twin screw extruder having a barrel temperature of 200 ℃ and 220 ℃. For comparison, similar compositions were made using deta and deta-DPE as flame retardants. The resulting composition was injection molded into test bars and the test results are shown in table 3. The mechanical properties and MFI tests were performed according to the usual ASTM methods. The glass transition temperatures of the brominated arylene ether oligomers were all below the resin formulation temperature, indicating that the oligomers are melt-miscible in the system. It is noted that deca and deca-DPE are not melt-mixable and are used only as filler materials. The data show a correlation, somewhat predictable, between the Melt Flow Index (MFI) of the combined material and the Tg of the flame retardant used. It is also reasonable that the vicat softening point is not affected by the type of flame retardant used, except for the samples with lower Tg temperatures.

TABLE 3

The surprising result is impact data. The arylene ether oligomer system exhibited a significant improvement in impact resistance when compared to the two control samples. Good mechanical properties are obtained despite the use of a wide range of Tg. This may be due to an increase in resin-flame retardant compatibility, or the domain size of the flame retardant material in the test bar, or some other factor. These data indicate that the properties of the final composition can be optimized by adjusting the glass transition temperature of the FR oligomer. This is not feasible with low molecular bromides, since they are generally high melting solids.

Example 16: compounding of brominated arylene ether oligomer and High Impact Polystyrene (HIPS) resin

The brominated arylene ether oligomers produced in example 12 (Table 2) were respectively mixed with HIPS (high impact polystyrene) resin compositions containing antimony oxide synergists using a twin-screw extruder having a barrel temperature of 200 ℃ and 220 ℃ and the resulting compositions were injection molded into test bars, and the test results are shown in Table 4. Two of these flame retardant oligomer materials have Tg temperatures below the compounding temperature and the two Tg temperatures data somewhat above the compounding temperature. Since the two materials cannot be melt mixed thereafter, a relatively low melt flow index can be expected. Interestingly, these samples based on para-arylene ether had reduced impact resistance, while the samples based on meta-arylene ether had better impact resistance. This may be affected by differences in the type of flame retardant and resin compatibility, or how the materials in the composition bond when cooled, or some other factor.

TABLE 4

Example 17: mixing bromoaryl ether oligomers in High Impact Polystyrene (HIPS) resins

Since some of the compositions of examples 15 and 16 actually have higher impact resistance than the compositions using standard deca as a flame retardant, a study was conducted to use the flame retardant of example 1 and reduce the amount of impact modifier (kraton d1101), and the results are shown in fig. 5. Studies have shown that the impact modifier can be reduced or even eliminated in HIPS compositions, resulting as good (or close) to deca control compositions, and thus there is still room for improvement in the properties of the compositions.

TABLE 5

Number of composition	17-A	17-B	17-C	17-D
					FR	Deca	Example 1	Example 1	Example 1
FR，％Br	83	73.1	73.1	73.1
					FR Tg，℃	NA	148	148	148
Composition comprising a metal oxide and a metal oxide
					Polystyrene resin	77.3	75.9	78.4	80.9
FR	14.0	15.4	15.4	15.4
					ATO	3.5	3.5	3.5	3.5
Anox PP-18	0.2	0.2	0.2	0.2
					Kraton D1101	5.0	5.0	2.5	0
Test results
					MFI(g/10min)	9.7	12.5	14.3	15.5
Vicat point, deg.C	96.2	99.3	99.1	98.6
					Izod impact Strength (ft-lb/in)	2.1	2.6	2.2	1.8

UL-94(1/16”)

V-0

V-0

V-0

V-0

Example 18: compounding bromoaryl ether oligomers in polyamides

The brominated arylene ether oligomers shown in table 1 were mixed with a glass reinforced PA66 resin containing an antimony oxide synergist. These compositions were molded into test bars and the test results are shown in table 6. This set of data is for flame retardant of an aromatic ether oligomer with commercially available brominated polystyrene (Saytex)^TMHP-3010) were compared. The results show that the efficiency of the aryl ether oligomer is higher, reaching the V-0 standard at 13.3% and the strong V-0 standard at 16% in the composition, whereas 20% is required with the HP-3010 material. The data also show that the mechanical properties of the composition are also improved, with about a 20% increase in elongation, although the tensile strength is about the same.

TABLE 6

a) Scale-up test of example 2; and (3) analysis: m.p.96-113 deg.C, Br% 63.0%

To determine whether the improvement in flame retardant efficiency is a result of the increased bromine content, or is related to the structure of the oligomer, samples with lower bromine content were also tested. The results show that the composition still achieved a level above the V-0 standard using the same amount of inhibitor in the composition as the brominated polystyrene material containing 68% bromine (i.e., a lower total bromine content). This indicates that the structure is associated with an increase in the efficiency of the flame retardant.

Example 19: mixing different flame retardants in polypropylene

A similar composition was prepared by mixing the brominated arylene ether oligomer of example 3 with a Profax6323 polypropylene homopolymer containing an antimony oxide synergist, as a comparison, using deca and deca-DPE as flame retardants. The test bars were injection molded using a twin screw extruder with a barrel temperature of about 200 ℃ and the test results are shown in Table 7.

TABLE 7

Number of composition	19-A	19-B	19-C	19-D
					Profax6323PP homopolymer (%)	100	59	55.8	59
Deca(％)		35
					Brominated polyarylether example 3 (%)			38.2
Deca-BDE(％)				35
					ATO(％)		6	6	6
					UL-94 rating		V-0	V-0	V-0
MFI(g/10min)	12.4	11.2	47.4	12.1
					HDT(℃)， 264psi	84	112	120	117

The results show a significant improvement in melt flow characteristics and a slight increase in Heat Deflection Temperature (HDT) of the oligomeric flame retardant product as compared to the control samples made with deta and deta-DPE.

The composition was also tested for blooming by placing the UL test bars in an oven at 80 ℃. The test bars were pulled in an oven for 24h and after one week, if present, wiped with a black cloth to defrost. Frost is formed by the migration of flame retardants or other additives to the surface, often appearing as a visible dusty material on black cloth. No frost was found on the test bars containing the oligomeric flame retardant combination, whereas frost was present with the other two flame retardant compositions.

Example 20: mixing different flame retardants in low density polyethylene

A similar composition was prepared by mixing the brominated arylene ether oligomer of example 3 with Petrothene NA820000 NT low density polyethylene, using deca and deca-DPE as flame retardants for comparison. The test bars were injection molded using a twin screw extruder with a barrel temperature of about 190 ℃ and the test results are shown in Table 8.

TABLE 8

For this resin system, both MFI and HDT characteristics were improved when using the oligomeric flame retardant compared to the brominated flame retardant control sample. In addition, it was found that the bending resistance was also improved. The blooming test was conducted as described in the previous examples, and the composition containing the oligomeric flame retardant showed trace of blooming, while the composition containing deca showed a large amount of blooming on the test cloth.

While the invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that the modifications made to the invention itself need not be set forth in the context of this application. For that reason, reference should be made to the appended claims in order to determine the true scope of the invention.

Claims (17)

1. A halogenated aryl ether oligomer formed by halogenation of an aryl ether oligomer.

2. The oligomer of claim 1, wherein the halogen content of the halogenated aryl ether oligomer is about 50 to about 90 wt% of the oligomer.

3. The oligomer of claim 1 or 2 comprising an average of at least 3 aromatic rings.

4. An oligomer according to any preceding claim wherein the halogen is bromine.

5. An oligomer according to any preceding claim, wherein the aryl ether oligomer is brominated and comprises at least 5 aromatic rings and has a molecular weight of at most 1,000,000 daltons.

6. The oligomer of any preceding claim, wherein the oligomer comprises repeating monomer units of the structure:

wherein R is hydrogen or alkyl, especially C₁-C₄Alkyl, Hal is halogen, m is at least 1, n is 0-3 and x is at least 2.

7. The oligomer of claim 6 wherein x is from 5 to 20.

8. An oligomer according to claim 6 or 7, characterized in that Hal is bromine.

9. The oligomer of any one of claims 6-8, characterized in that said halogenated aryl ether oligomer also comprises end groups each independently comprising alkyl, alkoxy, aryl, aryloxy, hydrogen, halogen and hydroxyl groups.

10. Use of an oligomer according to any preceding claim as a flame retardant.

11. A flame retardant polymer composition comprising (a) a flammable macromolecular material and (b) a flame retardant comprising a halogenated aryl ether oligomer as defined in any preceding claim.

12. A flame retardant polymer composition comprising (a) a flammable macromolecular material and (b) a halogenated aryl ether having the formula:

wherein each R is¹Independently selected from hydrogen, hydroxy, halogen and alkyl, each R²Independently selected from hydrogen, hydroxy, halogen and alkyl, provided that at least one R²Is halogen, n is 5, m is 4 and x is 1 to 10, preferably 2 to 8.

13. A composition according to claim 11 or 12, wherein the flammable macromolecular material (a) is a thermosetting polymer or a thermoplastic polymer.

14. A composition according to any of claims 11 to 13, wherein the flammable macromolecular material (a) is polystyrene and the halogenated aryl ether oligomer flame retardant is present in the composition in an amount of from 5 to 25 wt%.

15. A composition according to any of claims 11 to 13, wherein the flammable macromolecular material (a) is polypropylene and the halogenated aryl ether oligomer flame retardant is present in the composition in an amount of 20 to 50 wt%.

16. A composition according to any of claims 11 to 13, wherein the flammable macromolecular material (a) is polyethylene and the halogenated aryl ether oligomer flame retardant is present in the composition in an amount of from 5 to 35 wt%.

17. A composition according to any of claims 11 to 13, wherein the flammable macromolecular material (a) is a polyamide or polyester and the halogenated aryl ether oligomer flame retardant is present in the composition in an amount of from 5 to 25 wt%.