WO2013085789A1

WO2013085789A1 - Low antimony or antimony trioxide-free flame retarded thermoplastic composition

Info

Publication number: WO2013085789A1
Application number: PCT/US2012/067025
Authority: WO
Inventors: Eyal EDEN; Lior MELAMED; Yaniv HIRSCHSON; Marc LEIFER; Sergei V. Levchik; Garrett SHAWHAN; James Innes
Original assignee: Icl-Ip America Inc.
Priority date: 2011-12-09
Filing date: 2012-11-29
Publication date: 2013-06-13

Abstract

There is provided herein a flame retarded thermoplastic composition comprising: (a) at least one thermoplastic polyester or polyamide; (b) at least one brominated flame retardant; (c) less than about 5 weight percent of at least one antimony synergist based on the total weight of the flame retarded thermoplastic composition; and, (d) at least one calcium borate on inorganic carrier, as well as a method of making a flame retarded article comprising blending components (a)-(d) of the flame retarded thermoplastic composition.

Description

LOW ANTIMONY OR ANTIMONY TRIQXIDE-FREE FLAME

RETARDED THERMOPLASTIC COMPOSITION

This application claims priority to U.S. provisional application number 61/696,974 filed on September 5, 2012 and also to U.S. Provisional application number 61/568,968 filed on December 9, 201 1.

FIELD OF THE INVENTION

The present invention relates to a flame-retarded thermoplastic composition and more particularly to a flame-retarded thermoplastic polyester or polyamide composition and articles made therefrom.

BACKGROUND OF THE INVENTION

Glass reinforced or non-reinforced thermoplastic polyesters and thermoplastic polyamides are used for the production of electronic parts such as connectors, frames, moving parts, transformers, micro motors, amongst others. In most of these applications, the needed flame retardancy is usually provided by a flame retardant system based on a combination of a brominated flame retardant and antimony trioxide, the antimony trioxide functioning as a synergist. But the presence of antimony trioxide in this flame retardant system tends to significantly increase the smoke yield, which is undesirable in that it impairs visibility which may potentially create a problem for evacuation of people in the case of a fire. Furthermore, antimony trioxide has a very high bulk density which increases the specific gravity of molded parts made therefrom. This is especially undesirable in transportation applications such as automotive and aviation applications. Even further, antimony trioxide has significantly increased in price in recent years. Still further, some recently introduced ecolabels require elimination of antimony trioxide from thermoplastic parts.

Although there is a clear need for low antimony trioxide or antimony trioxide free flame retardant plastics, such usually requires a significant increase in the loading of brominated flame retardant. SUMMARY OF THE INVENTION

It has been unexpectedly discovered herein that a combination of a calcium borate on an inorganic carrier and a brominated flame retardant provides a flame retardant additive for thermoplastic polymers, more specifically thermoplastic polyesters and polyamides, which provides flame retardant efficiency adequate to such thermoplastic resins in electrical and electronic applications while mainitaining low levels of antimony trioxide or even without requiring the use of antimony trioxide.

The present invention is directed to a flame retarded thermoplastic composition comprising:

(a) at least one thermoplastic polyester or polyamide;

(b) at least one brominated flame retardant;

(c) less than about 5 weight percent of at least one antimony synergist based on the total weight of the flame retarded thermoplastic composition; and,

(d) at least one calcium borate on inorganic carrier.

Still further, there is provided herein a method of making a flame retarded article comprising:

blending

(a) at least one thermoplastic polymer such as a thermoplastic polyester or polyamide,

(b) at least one brominated flame retardant,

(c) less than about 5 weight perent of at least one antimony trioxide, and

(d) at least one calcium borate on an inorganic filler, and optionally, at least one of a filler, antioxidant, processing aid, and colorant.

DETAILED DESCRIPTION OF THE INVENTION

It will be understood herein that the expression "less than about" with respect to a numerical range can comprise zero as the lower endpoint of the range, or alternatively, the lower endpoint of the range can comprise an amount greater than zero but a value which is less than that amount generally used by those skilled in the art for such a component in a flame retarded thermoplastic. The thermoplastic polyester component used in one embodiment of this invention can be any thermoplastic polyester manufactured by polycondensation polymerization of a glycol component and an acid component.

The glycol component can contain one or more of the following glycols such as ethylene glycol, trimethylene glycol, 2-methyl-l,3-propane glycol, 1,4-butylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimethanol, or neopentylene glycol.

The acid component can contain one or more of the following acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5- naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenoxyethandicarboxylic acid, p-hydroxy benzoic acid, sebacic acid, adipic acid and polyester-forming derivatives thereof.

Blends of polyesters may also be employed as the thermoplastic polyester in the composition. As indicated earlier, more specific polyesters are poly(ethylene terephthalate), poly (1,3 -trimethylene terephthalate) and poly( 1 ,4-butylene terephthalate). When blends of these more specific components are employed the thermoplastic polyester component can comprise from about 1 to about 99 parts by weight of one polyester and from about 99 to about 1 part by weight of a different polyester based on 100 parts by weight of both components combined.

In a more specific embodiment herein the thermoplastic polyester (a), can be poly( 1 ,4- butylene terephthalate) resin which is obtained by polymerizing a glycol component which is at least 70 mol %, more specifically at least 80 mol %, comprised of 1 ,4-butylene glycol, with an acid component which is at least 70 mol %, more specifically at least 80 mol %, comprised of terephthalic acid, and polyester-forming derivatives.

In another embodiment herein the flame retarded thermoplastic composition can comprise one or a few polyamides.

Suitable polyamide components include at least one of polyamide-6, polyamide-6,6, polyamide-1 1, polyamide-12, polyamide-4,6, polyamide-6, 10 and polyamide-6, 12, as well as polyamides prepared from terephthalic acid and/or isophthalic acid and trimethylhexamethylenediamine; polyamides prepared from adipic acid and m- xylylenediamines; polyamides prepared from adipic acid, azelaic acid, and 2,2-bis-(p- aminocyclohexyl) propane, and polyamides prepared from terephthalic acid and 4,4'- diaminodicyclohexylmethane. Mixtures and/ or copolymers of two or more of the foregoing polyamides or prepolymers thereof, respectively, can also be used herein.

Furthermore, the polyamides may be made by any known method, including the polymerization of a monoamino monocarboxylic acid or a lactam thereof having at least 2 carbon atoms between the amino and carboxylic acid group, of substantially equimolar proportions of a diamine which contains at least 2 carbon atoms between the amino groups and a dicarboxylic acid, or of a monoaminocarboxylic acid or a lactam thereof as defined above, together with substantially equimolar proportions of a diamine and a dicarboxylic acid. The dicarboxylic acid may be used in the form of a functional derivative thereof, for example, a salt, an ester or acid chloride.

In one embodiment herein the polyamide can be selected from the group consisting of polyamide-6; polyamide 6,6; polyamide 1 1 , polyamide 12 and combinations thereof, with the more specific polyamide being at least one of polyamide-6,6 and polyamide 6.

In one embodiment herein the thermoplastic polyester or thermoplastic polyamide (a) herein can be present in an amount of from about 30 to about 90 weight percent based on the total weight of the flame retarded thermoplastic composition.

Brominated flame retardants of the invention (b) include flame retardant compounds of the following formulas:

Decabromodiphenyl oxide sold under the trade name FR-1210

Tetarbromobisphenol A sold under the trade name FR- 1524

Tetrabromobisphenol A bis (2,3-dibromopropyl ether) sold under the trade name

Tris(tribromophenoxy)triazine sold under the trade name

Tris(tribromoneopenyl) phosphate sold under the trade name FR-370

CH₂Br O CH₂Br

I II I

BrCH₂— C— CH₂— O— P— O— CH₂— C— CH₂Br

CH₂Br O CH₂Br

CH₂

BrCH₂— C— CH₂Br

CH₂Br _(V) Brominated polyacrylate sold under the trade name FR-1025

Brominated polystyrene sold under the trade name FR-803P

(VII)

Brominated epoxy polymers sold under the trade name F-2000 series

(VIII)

End capped brominated epoxy polymers sold under the trade name F-3000 series

(IX)

Phenoxy-terminated carbonate oligomer of tetrabromobisphenol A

(XI)

Tetradecabromodiphenoxy benzene

Ethylenebistetrabromophthalimide

Tetrabromobisphenol S bis (2,3-dibromopropyl ether)

Pol -dibromophenylene oxide

2-ethylhexyl tetrabromophthalate ester

In one embodiment herein the brominated flame retardant (b) herein can be present in an amount of from about 5 to about 30 weight percent based on the total weight of the flame retarded thermoplastic composition.

Antimony synergist (c) (e.g., antimony trioxide) if used herein shows a synergistic effect with the brominated flame retardant and can serve to further improve the flame retardancy of polyesters and polyamides when it is compounded.

The proportion of antimony synergist (c) which is appropriate when one antimony atom exists based on every two to five bromine atoms of the brominated flame retardant. When the proportion is smaller than one antimony atom on every five bromine atoms the effect of antimony synergist is negligible. On the other hand, once the proportion is larger than one antimony atom on every two bromine atoms, an increase in the effect can no longer be expected even by further increase of antimony synergist proportion and the obtained polyester or polyamide composition is inferior in mechanical properties and moldability such as flowability.

In addition to antimony trioxide, some other examples of antimony syngergist (c) can be antimony pentaoxide or sodium antimonate. The average particle size of antimony synergist (c) is specifically from 0.5 to 5 μιη. Antimony synergist (c) may be surface-treated with an epoxy compound, silane compound, isocyanate compound, titanate compound, or the like as required. Antimony synergist (c) can be used as a powder or as a masterbatch compounded in a carrier resin. Typically a masterbatch contains 50-80 wt. % pre-dispersed antimony syngerist (c) such as the non-limiting example of antimony trioxide. Use of a masterbach impoves safety of the operation eliminating the handling of hazardous powder and improves dispersion of antimony synergist (c) in the polyester or polyamide.

In one non-limiting embodiment the antimony synergist (c) can be present in an amount of less than 5 weight percent based on the total weight of the flame retarded thermoplastic composition, and in a further embodiment can have a lower endpoint range amount of zero or a lower endpoint range amount of 0.001 weight percent, more specifically a lower endpoint range amount of 0.01 weight percent, even more specifically a lower endpoint range amount of 0.1 weight percent or a lower endpoint range amount of 0.5 weight percent with said a lower endpoint range amounts being based on the total weight of the flame retarded thermoplastic composition.

The calcium borate on an inorganic carrier (d), which is used herein, can in one embodiment be manufactured by the reaction of lime with boric acid in the presence of an inorganic carrier, in a water suspension, with subsequent drying, milling and sieving. The calcium borate on an inorganic carrier can comprise any known inorganic filler material as the inorganic carrier. Some non-limiting examples of inorganic filler material which may function as the inorganic carrier are alumina trihydrate, natural calcium carbonate, precipitated calcium carbonate, calcium sulphate, carbon black, carbon fibers, clay, cristobalite, diatomaceous earth, dolomite, feldspar, graphite, glass beads, glass fibers, kaolin, magnesium carbonate, magnesium hydroxide, metal powders or fibers, mica muscouite, mica phlogopite, natural silica, synthetic silica, nepheline-syenite, kaolin, talc, whiskers, wollastonite, and combinations thereof.

In one non-limiting embodiment the inorganic carrier for the calcium borate is wollastonite. More specifically, the calcium borate on an inorganic carrier (e.g. wollastonite) is such that the particles of calcium borate on an inorganic carrier (e.g wollastonite) have a mean particle size (d₅o) of from about 1 micron to about 15 microns and 99 weight percent of the total amount of particles of calcium borate on an inorganic carrier have a diameter (d₉₉) of less than about 50 microns, and more specifically, a d$ of from about 2 microns to about 10 microns and a d₉₉ of less than about 25 microns. In one embodiment, calcium borate on an inorganic carrier contains from about 20 to about 80 weight percent of wollastonite and from about 20 to about 80 weight percent of calcium borate, provided that the total weight percent of calcium borate and the total amount of inorganic carrier is equal to 100 weight percent.

In another embodiment the inorganic carrier is synthetic calcium silicate having a d₅o of from about 0.5 microns to about 3 microns. Such calcium silicates are available for example from Evonik, Europe or Shreji, China.

In one embodiment herein the calcium borate on inorganic carrier (d) herein can be present in an amount of from about 1 to about 10 weight percent based on the total weight of the flame retarded thermoplastic composition.

In addition, to components (a)-(d) of the flame retarded thermoplastic composition, some additional optional components may include at least one of an inorganic filler, an impact modifier, a heat stabilizer, an antioxidant, a processing aid, a colorant, an antidripping agent, a lubricant, and other additives enhancing physical properties of the resin.

An inorganic filler may be added to the flame retarded thermoplastic composition for the purpose of reducing the molding shrinkage coefficient and linear expansion coefficient of a resultant molded article and improving high and low heat shock property, and various fillers in the form of fiber or non-fiber (e.g., powder, plate) may be used depending on the desired article. Some examples of fibrous filler, which are types of inorganic filler, may be those such as, glass fiber, glass fiber having a non-circular cross section such as flat fiber, carbon fiber, silica fiber, silica- alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and further, metal fibrous substances such as stainless, aluminum, titanium, copper and brass. Particularly, the typical fibrous filler is glass fiber or carbon fiber. On the other hand, the inorganic filler may be a powdery filler, such as carbon black, silica, quartz powder, glass bead, glass powder, calcium silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, metal oxides such as iron oxide, titanium oxide, zinc oxide and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and in addition, silicon carbide, silicon nitride, boron nitride and various metal powders. Another example of inorganic filler may be plate-like filler such as, mica, glass flake and various metal foils. These inorganic fillers can be used alone or in combination of two or more. When these inorganic fillers are used, they are desirably treated previously with a sizing agent or surface treatment agent, if necessary. In one non-limiting embodiment, the inorganic filler can be different than the inorganic carrier employed in component (d) herein.

The amount of the inorganic filler in the flame retarded thermoplastic composition may be from about 1 to about 50% by weight, specifically from about 10 to about 45% by weight, and most specifically from about 20 to about 40% by weight. When a lower amount of inorganic filler than the noted ranges is employed, the effect for improving heat shock resistance is low, and when a higher amount of inorganic filler than that noted is employed, molding work becomes difficult.

The flame retarded thermoplastic composition may also further comprise impact modifiers such as elastomers and core-shell polymers. These elastomers can be thermoplastic elastomers, which can be melt-mixed with thermoplastic polyester resin (a) because they are solids having rubber-like elasticity at normal temperature, but heating them decreases the viscosity thereof. The specific thermoplastic elastomer used is not particularly restricted, and olefin-, styrene-, polyester-, polyamide-and urethane-based elastomers may be used as non- limiting examples.

A core shell polymer is a core shell type graft copolymer having a multi-layer structure and preferably in which a rubber layer having an average particle size of 1.0 μιη or less is wrapped with a vitreous resin. The rubber layer of the core shell type copolymer has an average particle size of 1.0 μπι or less, and more specifically from 0.2 to 0.6 μπι. If the average particle size of the rubber layer is over 1. 0 μηι, the effect for improving impact resistance property may be insufficient. As the rubber layer of this core shell type copolymer, those obtained by copolymerization/graft copolymerization of at least one of a silicon-based, diene-based or acrylic elastomer can be used. The amount of the impact modifier in the flame retarded thermoplastic composition may be from about 1 to about 10 % by weight based on the total weight of the flame retarded thermoplastic composition. In one specific embodiment herein the flame retarded theromplastic composition can comprise:

(a) at least one thermoplastic polyester or polyamide;

(b) at least one brominated epoxy polymer;

(d) a calcium borate on an inorganic carrier; and,

wherein the flame retarded thermoplastic composition is in the absence of antimony trioxide.

Other optional ingredients typically employed in non-limiting amounts of less than 10 percent by weight of the flame retarded thermoplastic composition, specifically less than 5 percent by weight, include the non-limiting examples such as at least one of an inorganic filler, an impact modifier, a heat stabilizer, an antioxidant, a processing aid, a colorant, an antidripping agent, a lubricant, and other additives enhancing physical properties of the resin. Conventional stabilizer additives may be specifically utilized in amounts from 0.01 to 5 percent by weight of the total weight of the flame retarded thermoplastic composition and can include specific examples such as hindered phenols and antioxidants.

Further, there is also provided herein a molded part comprising a thermoplastic polymer, glass fiber, a brominated flame retardant, less than about 5 weight percent of antimony trioxide, calcium borate on an inorganic carrier, and optionally, at least one of an inorganic filler, an impact modifier, a heat stabilizer, an antioxidant, a processing aid, a colorant, an antidripping agent, a lubricant, and other additives enhancing physical properties of the resin.

In one embodiment herein the flame retarded thermoplastic composition comprises thermoplastic polyester or polyamide (a) in an amount of from about 30 to about 90 weight percent; brominated flame retardant (b) in an amount of from about 5 to about 30 weight percent; antimony synergist (c) in an amount less than about 3 weight percent and calcium borate on an inorganic carrier (d) in an amount of from 1 to about 10 weight percent all said weight percents being based on the total weight of the flame retarded thermoplastic composition.

In a more specific embodiment, the flame retarded thermoplastic composition comprises thermoplastic polyester or polyamide (a) in an amount of from about 40 to about 90 weight percent; brominated flame retardant (b) in an amount of from about 5 to about 30 weight percent; antimony synergist (c) in an amount less than about 3 weight percent; calcium borate on an inorganic carrier (d) in an amount of from 1 to about 10; and, inorganic filler in an amount of from about 10 to about 35 weight percent said weight percent all said weight percents being based on the total weight of the flame retarded thermoplastic composition.

These amounts of flame retardant additives (a), (b), (c), (d) and inorganic filler in the flame retarded thermoplastic composition are flame retardant effective amounts thereof.

The flame retarded thermoplastic composition herein can have a flame retardancy classification of one or more of V-2, V-l, V-0 and 5VA according to UL-94 protocol. In one embodiment the flame retarded thermoplastic composition can have a flame retardancy of at least V-l or V-0.

The method of blending the contents of the flame retarded thermoplastic composition herein is not critical and can be carried out by conventional techniques. One convenient method comprises blending the polyester or polyamide (a) and other ingredients (b), (c) and (d) in powder or granular form, extruding the blend and compounding the extruded blend into pellets or other suitable shapes.

Although it is not essential, best results are obtained if the ingredients are compounded, pelletized and then molded. Compounding can be carried out in conventional equipment. For example, after carefully predrying the polyester or polyamide resin (a), other ingredients (b), (c) (if present) and (d), and, optionally, other additives and/or reinforcements, a single screw extruder is fed with a dry blend of the flame retarded thermoplastic composition, the screw employed having a long transition section to insure proper melting. On the other hand, a twin screw extrusion machine e.g., a ZE25 with L/D=32 ex Berstorff extruder can be fed with resins and additives at the feed port and have reinforcement fed down of the stream. In either case, a generally suitable machine temperature will be from about 220° to about 320° C.

The compounded flame retarded thermoplastic composition can be extruded and cut or chopped into conventional granules, pellets, etc. by standard techniques. The flame retarded thermoplastic composition can be molded in any equipment conventionally used for thermoplastic compositions. For example, good results can be obtained in an injection molding machine, e.g. of the Arburg 320S Allrounder 500-150 type, at conventional temperatures, e.g., from 230 to 320°C. If necessary, depending on the molding properties of the polyester or polyamide (a), the amount of additives and/or reinforcing filler and the rate of crystallization of the polyester or polyamide component (a), those skilled in the art will be able to make the conventional adjustments in molding cycles to accommodate the composition.

In another embodiment herein there is provided a molded article comprising the flame retarded thermoplastic composition, specifically where the molded article is made by injection molding the flame retarded thermoplastic composition. In one embodiment herein the molded article can be an electronic component, specifically an injection molded electronic component.

The flame retarded thermoplastic composition herein is useful, for example, in the production of electronic components, such as for example, connectors, frames, moving parts, transformers and micromotors, and the like.

In a specific embodiment herein there is provided an injection molded component, e.g., an electronic component, comprising PBT (a), glass fiber, and a flame retardant additive composition, which composition comprises brominated polyacrylate (b), optionally, antimony trioxide (c) and calcium borate on wollastonite carrier (d).

In another specific embodiment herein there is provided an injection molded component, e.g., an electronic components, comprising PBT (a), glass fiber, and a flame retardant additive composition, which composition comprises end-capped brominated epoxy polymer (b), optionally antimony trioxide (c) and calcium borate on wollastonite carrier (d).

Even in another specific embodiment herein there is provided an injection molded component, e.g., an electronic component, such as a injection molded electronic component, wherein the injection molded component can comprise polyamide 6.6 (a), glass fiber, and a flame retardant additive composition, which composition comprises brominated polystyrene (b), optionally antimony trioxide (c) and calcium borate on wollastonite carrier (d).

Even in another specific embodiment herein there is provided an injection molded component, e.g., an electronic component, comprising polyamide 6.6 (a), glass fiber, and a flame retardant additive composition, which composition comprises brominated polyacrylate (b), optionally antimony trioxide (c) and calcium borate on wollastonite carrier (d).

Even in another specific embodiment herein there is provided an injection molded component, e.g., an electronic component, comprising polyamide 6.6 (a), glass fiber, and a flame retardant additive composition, which composition comprises brominated epoxy polymer (b), optionally antimony trioxide (c) and calcium borate on wollastonite carrier (d).

Even in another specific embodiment herein there is provided an injection molded component, e.g., an electronic component, comprising polyamide 6.6 (a), glass fiber, and a flame retardant additive composition, which composition comprises brominated epoxy polymer (b), and calcium borate on wollastonite carrier (d).

Even in another specific embodiment herein there is provided an injection molded component, e.g., an electronic component, comprising polyamide 6 (a), glass fiber, and a flame retardant additive composition, which composition comprises brominated polyacrylate (b), optionally antimony trioxide (c) and calcium borate on wollastonite carrier (d).

Even in another specific embodiment herein there is provided an injection molded component, e.g., an electronic component, comprising polyamide 6 (a), glass fiber, and a flame retardant additive composition, which composition comprises end-capped brominated epoxy polymer (b), optionally antimony trioxide (c) and calcium borate on wollastonite carrier (d).

In another embodiment there is provided a flame retarded article, e.g., an electronic component, specifically an injection molded electronic component, as described herein, made by the above-described method. The following examples are used to illustrate the present invention.

EXAMPLES

In order to prepare samples of flame retarded glass reinforced polybutylene terephthalate (PBT) or polyamide 6.6 or polyamide 6 that illustrate the invention, the following procedures have been used.

Materials.

ai - Poly(butylenes terephthalate), PBT Celanex 2500 ex. Ticona

a₂ - Polyamide 6.6, Akulon S 223D ex. DSM

a₃ - Polyamide 6, Plustek PB 145 ex. PolyRam

bi - Poly(pentabromobenzyl acrylate), FR-1025 ex. ICL-IP

b₂ - Brominated polystyrene, FR-803P ex. ICL-IP

b₃ - Brominated epoxy polymer Mw = 41,000, F-2400 ex. ICL-IP

b₄ - End-capped brominated epoxy polymer Mw = 15,000, F-3100 ex. ICL-IP

c - Master batch 80% antimony trioxide, universal grade, AO M-0112 ex. Kafrit

d - Calcium borate on wollasonite carrier, FR-1 120 ex. ICL-IP

Filler - Glass fiber, GF Chop Vantage 3660 ex. PPG

Antidripping agent - poly(tetrafluoroethylene), PTFE, Hostaflon 2711 ex. Dyneon

Antioxidant - Nitrogen-containing hindered phenol, Irganox Bl 171 or Irganox 1010 ex. Ciba Lubricant - N,N ⁵ -ethylene bisstearamide, Acrawax C ex. Lonza

Lubricant - Calcium stearate, reagent grade ex. Aldrich

Compounding

Polymers pellets of the chosen thermoplastic polyester or thermoplastic polyamide were dried in vacuum oven over night at 80°C. The polymers pellets, antimony trioxide, FR-1 120 and lubricants and stabilizers were weighted on a semi analytical scale with consequent manual mixing in plastic bags. The mixtures were introduced into the main feeding port of the extruder via feeder N°l . FR-1025, FR-803P, F-2400 and F-3100 were introduced into the main feeding port of the extruder via feeder N°2.

The glass fibers were fed by feeder N°3 to the 5-th section of the extruder via lateral feeder. Compounding was performed in a twin screw co-rotating L/D=32 ex Berstorff ZE25. The extruded strands were cooled in water tray and pelletized by cutting.

PBT based compositions were compounded at 220-270°C

Polyamide 6.6 based compositions were compounded at 250-280°C

Polyamide 6 based compositions were compounded at 220-265°C

The obtained pellets were dried in a circulating air oven over night at 80°C.

Injection molding.

Test specimens were prepared by injection molding in Allrounder 500-150 ex. Arburg. PBT based compositions from the compounding step were molded at 230-265°C

Polyamide 6.6 based compositions from the compounding step were molded at 250-285°C Polyamide 6 based compositions from the compounding step were molded at 230-250°C

Test methods.

Before testing specimens were conditioned at 23°C for 168 hours.

Vertical flammability test - UL-94 V protocol, specimen thickness 0.4, 0.8 and 1.6 mm.

Heat distortion temperature, HDT - ASTM D648, load 1820 kPa, DDT/VICAT Plus Davenport ex. Lloyd Instruments.

Tensile properties- ASTMD638, Zwick/Roell Z010 material testing machine.

Notched Izod impact - ASTM D256, Zwick 5102 pendulum impact tester.

Melt volume index, MVI and melt flow index, MFI - ASTM D1238, Meltflixer 2000, ex.

Thermo Hake

Glow wire ignition test, GWIT - CEI EN 60695-2-13/11, PTL Dr. Grabenhorst apparatus.

Comparative tracking index, CTI - IEC 601 12, Trackvis 6266/000 ex. Ceast

Results

Composition and tests results for PBT compositions are presented in Table 1.

As it is shown, reference formulations (comparative examples 1 and 6) contain 8 wt.% Br and 5,7 wt. % antimony trioxide. In FR-1025 based formulations 50 wt% replacement of the total amount of antimony trioxide with FR-1 120 was achieved without lost of V-0 rating at 0.8 mm and 75 wt % replacement of the total amount of antimony trioxide with FR-1 120 was achieved without lost of V-0 rating at at 1.6 mm. In F-3100 based formulations 75 wt % replacement of the total amount of antimony trioxide with FR-1120 was achieved without lost of V-0 rating at both 0.8 mm and 1.6 mm.

Compositions and test results for polyamide 6.6 are presented in Table 2.

As it is shown, reference formulations (comparative examples 1 1, 16, 21 and 26) contain 13 wt. % Br and 5.0 wt. % antimony trioxide. In FR-803P based formulations 25wt.% replacement of the total amount of antimony trioxide with FR-1120 was achieved without lost of V-0 rating at 0.4 mm and 50 wt. % replacement of the total amount of antimony trioxide with FR-1 120 was achieved without lost of V-0 rating at 0.8 mm. In FR-1025 based formulations 75 wt.% replacement of the total amount of antimony trioxide with FR-1 120 was achieved without lost of V-0 rating at both 0.4 mm and 0.8 mm. In FR-2400 based formulations 75 wt.% replacement of the total amount of antimony trioxide with FR-1 120 was achieved without lost of V-0 rating at both 0.4 mm and 0.8 mm. In F-3100 based formulations 75 wt. % replacement of the total amount of antimony trioxide with FR-1120 was achieved without lost of V-0 rating at 0.4 mm and 100 wt.% replacement of the total amount of antimony trioxide with FR-1 120 was achieved without lost of V-0 rating at 0.8 mm.

Compositions and test results for polyamide 6 are presented in Table 3.

As it is shown, reference formulations (comparative examples 31 and 36) contain 10 wt. % Br and 6.3 wt. % antimony trioxide. In both FR-1025 and F-3100 based formulations 75 wt.% replacement of the total amount of antimony trioxide with FR-1120 was achieved without lost of V-0 rating at 1.6 mm.

TABLE 1. Flammability performance and physical properties of flame retardant PBT

TABLE 2 Flammability performance and physical properties of flame retardant Nylon 6.6

TABLE 2 (continuation) Flammability performance and physical properties of flame retardant polyamide 6.6.

TABLE 3 Flammability performance and physical properties of flame retardant poiyamide 6.

Claims

1. A flame retarded thermoplastic composition comprising:

(a) at least one thermoplastic polyester or polyamide;

(b) at least one brominated flame retardant;

(d) at least one calcium borate on inorganic carrier.

2. The flame retarded thermoplastic composition of Claim 1 , wherein thermoplastic polyester is at least one of poly(l,4-butylene terephthalate), poly(l,3-trimethyle terephthalate) and poly(ethylene terephthalate).

3. The flam retarded thermoplastic composition of Claim 1 wherein the thermoplastic polyester is at least one of polybutylene terephthalate and polyethylene terephthalate.

4. The flame retardant thermoplastic composition of Claim 1 , wherein thermoplastic polyamide is selected from the group consisting of polyamide 6,6, polyamide 6, polyamide 11, polyamide 12, polyamide 4,6, polyamide 6,10, polyamide 6,12 and mixtures thereof.

5. The flame retarded thermoplastic composition of Claim 1, wherein brominated flame retardant is at least one compound selected from the group consisting of decabromodiphenyl oxide, tetarbromobisphenol A, tetrabromobisphenol A bis (2,3-dibromopropyl ether), tris(tribromophenoxy)triazine, tris(tribromoneopenyl) phosphate, brominated polyacrylate, brominated polystyrene, brominated epoxy polymers, end capped brominated epoxy polymers, phenoxy-terminated carbonate oligomer, decabromodiphenylethane,

tetradecabromodiphenoxybenzene, ethylenebistetrabromophthalimide, tetrabromobisphenol S bis (2,3-dibromopropyl ether), poly-dibromophenylene oxide, 2-ethylhexyl tetrabromophthalate ester or bis (tribromophenoxy) ethane.

6. The flame retarded thermoplastic composition of Claim 1 , wherein the antimony synergist is antimony trioxide

7. The flame retarded thermoplastic composition of Claim 1, wherein the inorganic carrier is wollastonite.

8. The flame retarded thermoplastic composition of Claim 1 further comprising a filler.

9. The flame retarded thermoplastic composition of Claim 8 wherein the filler is glass fiber.

10. The flame retarded thermoplastic composition of Claim 1 further comprising an impact modifier.

1 1. The flame retarded thermoplastic composition of Claim 1 further comprising a heat stabilizer and/or an antioxidant.

12. The flame retarded thermoplastic composition of Claim 1 further comprising a lubricant.

13. The flame retarded thermoplastic composition of Claim 1 wherein the thermoplastic polyester or polyamide (a) is present in an amount of from about 30 to about 90 weight percent; the brominated flame retardant (b) is present in an amount of from about 5 to about 30 weight percent; the antimony synergist (c) is present in an amount of less than about 3 weight percent; and, the calcium borate on an inorganic carrier (d) is present in an amount of from 1 to about 10 weight percent of the flame retarded thermoplastic composition.

14. The flame retarded thermoplastic composition of Claim 1 wherein the thermoplastic polyester or polyamide (a) is present in an amount of from about 40 to about 90 weight percent; the brominated flame retardant (b) is present in an amount of from about 5 to about 30 weight percent; the antimony synergist (c) is present in an amount of less than about 3 weight percent; the calcium borate on an inorganic carrier (d) is present in an amount of from 1 to about 10; and, the inorganic filler is present in an amount of from about 10 to about 35 weight percent of the flame retarded thermoplastic composition.

15. A molded article comprising the flame retarded thermoplastic composition of Claim 1.

16. The molded article of Claim 15 wherein the molded article is an electronic component.

17. The molded article of Claim 16 wherein the electronic component is an injection molded electronic component.

18. A method of making a flame retarded thermoplastic article comprising:

blending

(a) at least one thermoplastic polyester or polyamide;

(b) at least one brominated flame retardant;

(c) less than about 5 weight percent of at least one antimony synergist;

(d) at least one calcium borate on an inorganic carrier; and, optionally, at least one of an inorganic filler, an impact modifier, an antioxidant, a heat stabilizer and a lubricant.

19. A flame retarded article made by the method of Claim 18.

20.. The flame retarded article of Claim 19 wherein the article is an electronic component.

21. The flame retarded article of Claim 20 wherein the electronic component is an injection molded electronic component.