EP0276285A1

EP0276285A1 - A shaped article formed from a blend of a poly(aryl ether) and a polycarbonate

Info

Publication number: EP0276285A1
Application number: EP87905140A
Authority: EP
Inventors: Barry Lee Dickinson
Original assignee: BP Corp North America Inc
Current assignee: BP Corp North America Inc
Priority date: 1986-08-07
Filing date: 1987-07-30
Publication date: 1988-08-03
Also published as: JP2527986B2; JPH01500442A; WO1988000886A1; EP0276285A4; CA1290829C

Abstract

Un assemblage de conducteur électrique utilisé dans des commutateurs, des connecteurs, des contacteurs, des relais et autres comprend une coquille de composition polymère pour réduire sensiblement au minimum un allumage d'arc à courant élevé et un allumage de fils chauds, cette coquille comprenant une résine de poly(aryle éther) et une résine de polycarbonate aromatique, et un noyau métallique électriquement conducteur s'étendant au moins partiellement au travers de ladite coquille.An electrical conductor assembly used in switches, connectors, contactors, relays and the like includes a shell of polymeric composition to substantially minimize high current arc ignition and hot wire ignition, which shell includes a poly (aryl ether) resin and an aromatic polycarbonate resin, and an electrically conductive metal core extending at least partially through said shell.

Description

A SHAPED ARTICLE FORMED FROM A BLEND OF A

POLY(ARYL ETHER) AND A POLYCARBONATE

FIELD OF THE INVENTION This invention is directed to a shaped article forme from a blend of a poly(aryl ether) resin and an aromatic polycarbonate resin. The article has improved electrical properties as compared to an article fabricated from the individual components. More particularly, this invention relates to an electrical conductor assembly for use in switches, connectors, contactors, relays, and the like comprising a polymeric composition shell for substantially minimizing high current arc ignition and hot wire ignition, said composition shell comprising a poly(aryl ether) resin and an aromatic polycarbonate resin; and an electrical conductive metal core extending at least par- tially through said shell.

BACKGROUND OF THE INVENTION Articles molded from polysulfone or polycarbonate individually have relatively poor flammability character- istics and thus require the addition of flame retardant additives in order to meet UL-94 flammability require¬ ments. Also, articles molded from polysulfone or polycar¬ bonate do not have acceptable electrical properties for certain applications. Blends of polyarylethers and polycarbonates are known from U.S. Patent No. 3,365,517. The patent states that as a result of this blend, polycarbonate polymers are ren¬ dered more resistant to environmental stress crazing and cracking and their heat distortion temperatures are increased, and that thermoplastic polyarylene polyethers are rendered more resistant to thermal stress embrittle- ment.

However, this patent does not disclose or suggest that blends of poly(aryl ether) resins and polycarbonate resins can be used to form shaped articles which have improved electrical properties such as hot wire ignition and high current arc ignition properties. ϋ.S. Patent Application Serial No. 773,113 filed Sep¬ tember 6, 1985 in the name of B. L. Dickinson et al, titled "A Shaped Article Formed From A Blend Of A Poly(aryl ether) And A Polycarbonate and/or A Polyary- late", and assigned to the same assignee as this invention, describes a shaped article having a tensile strength as measured by ASTM D-1822 after 80 cycles of steam sterilization at 270°F of >50 ft.-lbs./in formed from a blend comprising a poly(aryl ether) resin, an aro¬ matic polycarbonate resin and/or a polyarylate resin.

However, this application does not disclose an arti¬ cle formed from a blend of a poly(aryl ether) and a poly¬ carbonate having improved electrical properties, particularly improved hot wire ignition and high current arc ignition properties.

THE INVENTION This invention is directed to a shaped article formed by injection molding, extruding, thermoforming or blow molding a blend of a poly(aryl ether) resin and an aro¬ matic polycarbonate resin. The article has improved elec¬ trical properties, particularly hot wire ignition and high current arc ignition properties. More particularly, this invention relates to an elec¬ trical conductor assembly for use in switches, connectors, contactors, relays, and the like comprising a flame resistant composition shell for substantially minimizing high current arc ignition and hot wire ignition, said com- position shell comprising a poly(aryl ether) resin and an aromatic polycarbonate resin; and an electrical conductive metal core extending at least partially through said shell.

Typically, the metal core comprises a metal conductor imbedded in said shell and said shell comprises a substan¬ tially rigid housing for abuttingly engaging and support- ing said core, and, in many cases, said core comprises a pin.

The articles of this invention can be fabricated by the steps of: (1) forming a support member comprising a poly(aryl ether) resin and an aromatic polycarbonate resin; and (2) positioning an electrical conductor in proximity to said support member.

An article molded from the blend of poly(aryl ether) resin and aromatic polycarbonate has a High Current Arc Ignition as measured by U-746A-43.1 of greater than about 200 arcs and a Hot Wire Ignition as measured by D-3784 of greater than 100 seconds.

The Shaped Articles

The shaped articles into which the blend of poly(aryl ether) resin and aromatic polycarbonate resin and/or poly- arylate resin can be formed include any articles which require^'high electrical properties such as hot wire ignition and high current arc ignition properties.

The Poly(aryl ether) resin

The poly(aryl ether) resin suitable for blending with the polycarbonate resin and/or polyarylate resin is a linear, thermoplastic polyarylene polyether containing recurring units of the following formula:

-O-E-O-E^•- wherein E is the residuum of a dihydric phenol, and E* is the residuum of a benzenoid compound having an inert electron withdrawing group in at least one of the posi¬ tions ortho and para to the valence bonds; both of said residua are valently bonded to the ether oxygens through aromatic carbon atoms. Such aromatic polyethers are included within the class of polyarylene polyester resins described in, for example, U.S. Patents 3,264,536 and

4,175,175. It is preferred that the dihydric phenol be a weakly acidic dinuclear phenol such as, for example, the dihydroxyl diphenyl alkanes or the nuclear halogenated derivatives thereof, such as, for example, the 2,2-bis(4- hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)2-phenyl ethane ,bis(4-hydroxyphenyl)methane, or their chlorinated derivatives containing one or two chlorines on each aro¬ matic ring. Other materials also termed appropriately bisphenols are also highly valuable and preferred. These materials are the bisphenols of a symmetrical or unsymmet- rical joining group, as

O

It for example, ether oxygen (-0-) _r carbonyl (-C-), O

II sulfone (-S-), or hydrocarbon residue in which the

O two phenolic nuclei are joined to the same or different carbon atoms of the residue.

Such dinuclear phenols can be characterized as having the structure:

HO(Ar-R₂ -Ar₁)OH

wherein Ar and Ar, are aromatic groups preferably a phen- ylene group, R-. and R*-. can be the same or different inert substituent groups such as alkyl groups having from 1 to 4 carbon atoms, aryl, halogen atoms, i.e., fluorine, chlo¬ rine, bromine or iodine, or alkoxyl radicals having from 1 to 4 carbon atoms, the c's are independently integers having a value of from 0 to 4, inclusive, and R~ is repre¬ sentative of a bond between aromatic carbon atoms as in dihydroxyl-diphenyl, or is a divalent radical, O

II including for example, radicals such as -C-, -0-, -S-, -SO-, -S-S-, -S0₂, and divalent hydrocarbon radicals such as alkylene, alkylidene, cycloalkylene, cycloalkylidene, or the halogen, alkyl, aryl or like substituted alkylene, alkylidene and cycloaliphatic radicals as well as aromatic radicals and rings fused to both Ar groups. Examples of specific dihydric polynuclear phenols include among others: the bis-(hydroxyphenol) alkanes such as

2,2-bis-(4-hydroxyphenyl)propane,

2,4'-dihydroxydiphenylmethane, bis-(2-hydroxyphenyl)methane, bis-(4-hydroxyphenylJmethane, bis(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)methane,

1,1-bis-(4-hydroxy-phenyl)ethane,

1,2-bis-(4-hydroxyphenyl)ethane, l,l-bis-(4-hydroxy-2-chlorophenyl)ethane,

1,1-bis-(3-methyl-4-hydroxyphenyl)propane,

1,3-bis-(3-methyl-4-hydroxyphenyl)propane, 2,2-bis-(3-phenyl-4-hydroxyphenyl)propane,

2,2-bis-(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis-(2-isopropyl-4-hydroxyphenyl)propane,

2,2-bis-(4-hydroxy-naphthyl)propane,

2,2-bis-(4-hydroxyphenyl)pen ane,

3,3-bis-(4-hydroxyphenyl)pen ane, 2,2-bis-(4-hydroxyphenyl)heptane, bis-(4-hydroxyphenyl)phenylmethane,

2,2-bis-(4-hydroxyphenyl)-1-phenyl-propane,

2,2-bis-(4-hydroxyphenyl)1,1,1,3,3,3,-hexafluoropropane, and the like; di(hydroxyphenyl)sulfones such as bis-(4-hydroxyphen- yl)sulfone, 2,4'-dihydroxydiphenyl sulfone, 5-chloro-

2,4'-dihydroxydiphenyl sulfone,

5'-chloro-4,4'-dihydroxydiphenyl sulfone, and the like; di(hydroxyphenyl)ethers such as bis-(4-hydroxyphenyl)ether, the 4,3'-, 4,2'-2,2'-2,3-,dihydroxyphenyl ethers, 4,4'-dihydroxyl-2,6-dimethyldiphenyl ether,bis-(4-hydroxy-3-isobutylphenyl)ether, bis-(4-hydroxy-3-isopropylphenyl)ether, bis-(4-hydroxy-3-chlorophenyl)ether, bis-(4-hydroxy-3-fluorophenyl)ether, bis-{4-hydroxy-3-bromophenyl)ether, bis-(4-hydroxynaphthyl)ether, bis-(4-hydroxy-3-chloronaphthyl)ether, and 4,4'-dihydroxyl-3,6-dimethoxydiphenyl ether.

As herein used the E* term defined as being the "residuum of the dihydric phenol" of course refers to the residue of the dihydric phenol after the removal of the two aromatic hydroxyl groups. Thus as is readily seen these polyarylene polyethers contain recurring groups of the residuum of the dihydric phenol and the residuum of the benzenoid compound bonded through aromatic ether oxygen atom.

Any dihalobenzenoid or dinitrobenzenoid compound of mixtures thereof can be employed in this invention which compound or compounds has the two halogens or nitro-groups bonded to benzene rings having an electron withdrawing group in at least one of the positions ortho and para to the halogen or nitro group. The dihalobenzenoid or dini¬ trobenzenoid compound can be either mononuclear where the halogens or nitro groups are attached to the same benzen- oid rings or polynuclear where they are attached to dif¬ ferent benzenoid rings, as long as there is an activating electron withdrawing group in the ortho or para position of that benzenoid nuclear. Fluorine and chlorine substi¬ tuted benzenoid reactants are preferred; the fluorine co - pounds for fast reactivity and the chlorine compounds for their inexpensiveness. Fluorine substituted benzenoid compounds are most preferred, particularly when there is a trace of water present in the polymerization reaction system. However, this water content should be maintained below about 1% and preferably below 0.5% for best results. An electron withdrawing group can be employed as the activator group in these compounds. It should be, of course, inert under the reaction conditions, but otherwise its structure is not critical. Preferred are the strong activating O

II groups such as the sulfone group (-S-) bonding two

halogen or nitro substituted benzenoid nuclei as in the 4,4'-dichlorodiphenyl sulfone and .4,4'-difluorodiphenyl sulfone, although such other strong withdrawing groups hereinafter mentioned can also be used with equal ease. The more powerful of the electron withdrawing groups give the fastest reactions and hence are preferred. It is further preferred that the ring contain no electron sup¬ plying groups on the same benzenoid nucleus as the halogen or nitro group; however, the presence of other groups on the nucleus or in the residuum of the compound can be tol¬ erated.

The activating group can be basically either of two types:

(a) monovalent groups that activate one or more hal- ogens or nitro groups on the same ring such as another nitro or halo group, phenylsulfone, or alkylsulfone, cyano, trifluoromethyl, nitroso, and hetero nitrogen, as in pyridine. (b) divalent groups which can activate displacement of halogens on two different rings,

O

II such as the sulfone group -S-; the carbonyl group

II o

O H

II I

-C-; the vinylene group -C=C-; the sulfoxide group

H

o

II

-S-; the azo group -N=N-; the saturated fluorocarbon

CF₃

I groups -C-, ~CF_ -CF-CF--; organic phosphine

I CF₃

O

II oxides -P-:

^R3

where R₃ is a hydrocarbon group, and the ethylidene group A-C-A where A can be

-C- hydrogen or halogen. If desired, the polymers may be made with mixtures of two or more dihalobenzenoid or dinitrobenzenoid compounds. Thus, the E* residuum of the benzenoid compounds in the polymer structure may be the same or different.

It is also seen that as used herein, the E' term defined as being the "residuum of the benzenoid compound" refers to the aromatic or benzenoid residue of the com¬ pound after the removal of the halogen atom or nitro group on the benzenoid nucleus.

The poly(aryl ether) resins of this invention are prepared by methods well-known in the art as for instance the substantially equimolar one-step reaction of a double alkali metal salt of dihydric phenol with a dihalobenzen- oid compound in the presence of specific liquid organic sulfoxide or sulfone solvents under substantially anhy¬ drous conditions. Catalysts are not necessary for this reaction.

The polymers may also be prepared in a two-step proc- ess in which a dihydric phenol is first converted _irι situ in the primary reaction solvent to the alkali metal salt of the reaction with the alkali metal, the alkali metal hydride, alkali metal hydroxide, alkali metal alkoxide or the alkali metal alkyl compounds. Preferably, the alkali metal hydroxide is employed. After removing the water which is present or formed, in order to secure substan¬ tially anhydrous conditions, the dialkali metal salts of the dihydric phenol are admixed and reacted with about stoichiometric quantities of the dihalobenzenoid or dini- trobenzenoid compound.

Additionally, the poly(aryl ether) resins may be pre¬ pared by the procedure described in, for example, U.S. Patent 4,176,222 in which a substantially equimolar mix¬ ture of at least one bisphenol and at least one dihaloben- zenoid are heated at a temperature of from about 100° to about 400°C with a mixture of sodium carbonate or bicarbo- nate and a second alkali metal carbonate or bicarbonate having a higher atomic number than that of sodium.

Further, the pol (aryl ether) resins may be prepared by the procedure described in Canadian Patent 847,963 wherein the bisphenol and dihalobenzenoid compound are heated in the presence of potassium carbonate using a high boiling solvent such as diphenylsulfone.

Preferred poly(aryl ether) resins of this invention are those prepared using the dihydric polynuclear phenols of the following four types, including the derivatives thereof which are substituted with inert substituent groups

in which the R. groups represent independently hydrogen, lower alkyl, aryl and the halogen substituted groups thereof, which can be the same or different;

and substituted derivatives thereof. -li¬

lt is also contemplated in this invention to use a mixture of two or more different dihydric phenols to accomplish the same ends as above. Thus when referred to above the -E- residuum in the polymer structure can actu¬ ally be the same or different aromatic residua.

The poly(aryl ether)s have a reduced viscosity of from about 0.35 to about 1.5 as measured in an appropriate solvent at an appropriate temperature depending on the particular poly(aryl ether), such as in methylene chloride at 25°C.

The preferred poly(aryl ether)s have repeating units of the formula:

The Aromatic Polycarbonate

The thermoplastic aromatic polycarbonate resins that can be employed herein are homopolymers and copolymers and mixtures thereof, which have an intrinsic viscosity of from about 0.4 to about 1.0 dl./g. as measured in methy- lene chloride at 25°C. The polycarbonates are prepared by reacting a dihydric phenol with a carbonate precursor. Typical of some of the dihydric phenols that may be employed are bisphenol-A, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 4,4-bis(4-hy- droxyphenyl)heptane, 2,2-(3,5,3'-5'tetrabromo-4,4'dihy¬ droxydiphenyl)propane, (3,3'dichloro-4,4' ihydroxydiphenyl)methane, and the like. Other dihydric phenols of the bisphenol type are described in, for example, U.S. Patents 2,999,835, 3,028,365 and 3,334,154. It is, of course, possible to employ two or more dif¬ ferent dihydric phenols or a copolymer of a dihydric phenol with a glycol or with hydroxy or acid terminated polyesters.

The carbonate precursor may be either a carbonyl halide, a carbonate ester, or a haloformate. The carbonyl halides which can be employed herein are carbonyl bromide, carbonyl chloride and mixtures thereof. Typical of the carbonate esters which may be employed herein are diphenyl carbonate, di-(halophenyl)carbonates, such as di-(chloro- phenyl)carbonate or di-(bromophenyl)carbonate, etc., di- (alkylphenyl)carbonates such as di(toly)carbonate, di(naphthyl)carbonate, di(chloronaphthyl)carbonate, etc. or mixtures thereof. The haloformates suitable for use herein include bis-haloformate of dihydric phenols for example, bischloroformates of bisphenol-A, of hydroqui- none, etc. or glycols for example, bishaloformates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc. While other carbonate precursors will be apparent to those .skilled in the art, carbonyl chloride, also known as phosgene, is preferred.

The aromatic polycarbonate polymers may be prepared by methods well-known in the art by using phosgene or a haloformate and by employing a molecular weight regulator, an acid acceptor and a catalyst. The molecular weight regulators which can be employed in carrying out the proc¬ ess include monohydric phenols, such as phenol, para-ter- tiary-butylphenol, para-bromophenol, primary and secondary amines, etc. Preferably, a phenol is employed as the molecular weight regulator. A suitable acid acceptor may be either an organic or an inorganic acid acceptor. A suitable organic acid acceptor is a tertiary amine and includes materials, such as pyridine, triethylamine, dimethylaniline, tributyla- mine, etc. The inorganic acid acceptor may be one which can be either a hydroxide, a carbonate, a bicarbonate, or a phosphate of an alkali or alkaline earth metal.

The catalysts which are employed herein can be any of the suitable catalysts that aid the polymerization of, for example, bisphenol-A with phosgene. Suitable catalysts include tertiary amines, such as triethylamine, tripropy- lamine, N,N-dimethylaniline, quaternary ammonium com¬ pounds, such as tetraethylammonium bromide, cetyl triethyl ammonium bromide, tetra-n-heptylammonium iodide, and qua¬ ternary phosphoniu compounds, such as n-butyltriphenyl- phosphonium bromide and methyl-triphenyl phosphonium bromide.

The polycarbonates can be prepared in a one-phase (homogeneous solution) or a two-phase (interfacial) system when phosgene, or a haloformate are used. Bulk reactions are possible when the diarylcarbonate precursors are used. Also, aromatic polyester carbonates may be used. These are described in, for example, U.S. Patent 3,169,121. The preferred polyester carbonate results from the condensation of phosgene, terephthaloyl chloride, iso- phthaloyl chloride with bisphenol-A and a small amount of p-tertbutylphenol.

The polymeric portion of the shell contains from about 30 to about 80, preferably from about 35 to about 70 wt. percent of the poly(aryl ether) and from about 70 to about 20, preferably from about 65 to about 30 wt. per- cent of the aromatic polycarbonate, or combinations thereof.

Other Additives

Other additives which may be used in combination with the blends include mineral fillers such as carbonates including chalk, calcite and dolomite; silicates including mica, talc, wollastonite; silicon dioxide; glass spheres; glass powders; aluminum; clay; quartz; and the like. Additional additives include fibers such as glass fibers and carbon fibers; pigments, such as titanium dioxide; thermal stabilizers such as zinc oxide; ultraviolet light stabilizers, plasticizers, and the like.

Fabrication

The blends, and one or more optional additives are generally compounded in an extruder. The compounding is carried out at temperatures of from about 200°C to about 400°C. The compounded material may be pelletized by con¬ ventional techniques.

The compounded material may be shaped into the desired article by conventional molding techniques such as by injection molding, compression molding, thermoforming, or blow molding.

The forming comprises mixing said poly(aryl ether) resin and said aromatic polycarbonate resin and molding said polymeric mixture of poly(aryl ether) resin and aromatic polycarbonate resin. Molding also includes soli¬ difying and curing the resin. The electrical conductor can be embedded in the polymeric mixture before said mold¬ ing or solidification and curing. If desired, the polym- eric mixture can be poured about said conductor prior to said molding or the electrical conductor can be positioned adjacent to support member after said molding. The mold¬ ing step itself can include abuttingly engaging the con¬ ductor against the support member or annularly surrounding the conductor with said support member. The assembly can be fabricated into at least part of a switch, relay, con¬ nector, contactor, etc. EXAMPLES

The following examples serve to give specific illus¬ trations of the practice of this invention but they are not intended in any way to _^limit the scope of this invention.

The following designations used in the Examples have the following meaning:

Polysulfone: A polymer having the following repeat- ing unit:

This polymer has a reduced viscosity of 0.47 dl/g as measured in chloroform (O.lg/lOOml) at 25°C (Udel P-1700 polysulfone sold by Union Carbide Corp.).

Polycarbonate: an aromatic bisphenol-A polycarbonate having a reduced viscosity of 0.64 dl/g as measured in chloroform at 25°C. (Lexan 104 sold by General Electric

Co. )

EXAMPLES The Polycarbonate and the Polysulfone and one percent titanium dioxide were injection molded in a Newbury

Injection molding machine at 270°-290°C into test speci¬ mens (0.125 inch thick, 0.5 inch wide tensile and flexure bars) and tested according to the ASTM procedures described in Tables 1 to 4. TABLE 1

(50/50 PSF/PC + 1% Ti0₂)

TEST DESCRIPTION ASTM Test Results Method

GENERAL Density D-792 76.7 lbs/ft"

Water Absorption (24 hours) D-570-63 0.20%

MECHANICAL Tensile

Modulus D-638-72 350,000 psi Strength ' Yield D-638-72 9,500 psi

Elongation § Yield D-638-72 5-6%

Strength @ Break D-638-72 8,300 psi

Elongation § Break D-638-72 100%

Flexural Modulus D-790-71 381,000 psi

Strength D-790-71 14,100 psi

IMPACT

Tensile Impact D-1822 130 ft-lbs/in' Notched Izod, 1/8" D-256-73(A) 1.6 ft-lbs/in

THERMAL

Heat Deflection

Temperature

1/4" 264 psi D-648-70 300°F

Coefficient of Linear

Expansion D-696-70 5.7xl0^*5 in/in-

Melt Flow

44 psi § 320°C (608°F) D-1238-73 13 gm/10 min. TABLE 1 (cont) (50/50 PSF/PC + 1% Ti0₂)

TEST DESCRIPTION ASTM Test Results Method

ELECTRICAL

Dielectric Strength,

1/8" ST D-149-75 500 V/mil Volume Resistivity,

1/8" (500V, 23C) D-257 6.0x10 oh Arc Resistance D-495 130 sec

Dielectric Constant @ D-150-74 60³ HZ 3.12

10' HZ 3.1

10 HZ 3.5

Dissipation Factor § D-150-74 60³ HZ 0.0027 10⁶ HZ 0.001

10 HZ 0.007 Hot Wire Ignition D-3874 103 sec High Current Arc

Ignition UL 746A-43, .1 200 + arcs High Voltage Arc

Tracking UL 746A-25. .1 1.6 in/min Comparative Tracking

Index D-3638 175 volts

FABRICATION

Mold Shrinkage 0.0066 in/in TABLE 2

(60/40 PC/PSF + 1% Ti0₂)

TEST DESCRIPTION ASTM Test Results Method

GENERAL Density D-792 76.7 lbs/ft^"

Water Absorption (24 hours) D-570-63 0.20%

MECHANICAL Tensile

Modulus D-638-72 343,000 psi Strength @ Yield D-638-72 9,400 psi

Elongation § Yield D-638-72 5-6%

Strength g.Break D-638-72 8,100 psi

Elongation g Break D-638-72 90%

Flexural Modulus D-790-71 372,000 psi

Strength D-790-71 13,800 psi

IMPACT

Tensile Impact D-1822 104 ft-lbs/in' Notched Izod, 1/8" D-256-73(A) 1.9 ft-lbs/in

THERMAL

Heat Deflection

Temperature

1/4" 264 psi D-648-70 289°F Coefficient of Linear

Expansion D-696-70 5.7x10 ,-5 in/in- Melt Flow

44 psi g 320°C (608°F) D-1238-73 15.0 gm/1'0 min. TABLE 2 (cont) (60/40 PC/PSF + 1% Ti0₂)

TEST DESCRIPTION ASTM Test Results Method

ELECTRICAL

Dielectric Strength,

1/8" ST D-149-75 470 V/mil

Volume Resistivity,

1/8" (500V, 23C) D-257 3.0x10 ohm-i

Arc Resistance D-495 140 sec

Dielectric Constant g D-150-74

60 HZ 3.07

10³ HZ 3.08

10⁶ HZ 3.16

Dissipation Factor g D-150-74

60 HZ 0.0072

10³ HZ 0.0077

10⁶ HZ 0.0068

FABRICATION

Mold Shrinkage 0.0064 in/in

TABLE 3

(10% GLASS FILLED 50 PSF/50 PC)

TEST DESCRIPTION ASTM Test Results Method

GENERAL Density D-792 81.7 lbs/ff Water Absorption D-570-63 0.18%

MECHANICAL

Tensile Modulus D-638-72 493,000 psi

Strength g Yield D-638-72 10,400 psi Elongation g Yield D-638-72 4.2% Strength g Break D-638-72 10,400 psi Elongation g Break D-638-72 7.0%

Flexural Modulus D-790-71 521,000 psi Strength D-790-71 17,300 psi

IMPACT

Tensile Impact D-1822 33 ft-lbs/in' Notched Izod, 1/8" D-256-73(A) 1.6 ft-lbs/in

THERMAL

Heat Deflection

Temperature

1/4" 264 psi D-648-70 306°F

Coefficient of Linear

-5

Expansion D-696-70 4.4x10 in/in-

Melt Flow

44 psi g 320°C (608°F) D-1238-73 14 gm/10 min. TABLE 3 (cont) (10% GLASS FILLED 50 PSF/50 PC)

TEST DESCRIPTION ASTM Test Results Method

ELECTRICAL

Dielectric Strength,

1/8" ST D-149-75 465 V/mil Volume Resistivity,

1/8" (500V, 23C) D-257 5.9x10 oh -i Arc Resistance D-495 134 sec Dielectric Constant g D-150-74

60 HZ 3.2

10³ HZ 3.2

10⁶ HZ 3.24

Dissipation Factor g D-150-74

60 HZ 0.0018

10³ HZ 0.0012

10⁶ HZ 0.006 Hot Wire Ignition D-3874 79 sec High Current Arc

Ignition UL 746A-43, .1 48 arcs High Voltage Arc

Tracking UL 746A-25. .1 3.3 in/min Comparative Tracking

Index D-3638 140 volts

FABRICATION

Mold Shrinkage 0.0040 in/in TABLE 4 FLAMMABILITY & ELECTRICAL PROPERTIES (1/8" Specimens)

Comparative Data on

ASTM (50/50 Resin Components

Test PSF/PC + Poly- Poly¬

Method 1% TiO„) carbonate sulfone

Flammability UL-94 V-O - 1/8" V-O - 1/4" V-0 - 1/4"

Hot Wire Ignition D-3784 103 40 63 (sees)

High Current Arc WL-746A- 200+ 81 14

_*

Ignition (arcs) 43.1

High Voltage Arc UL-746A- 1.6 2.6 Tracking (in/min) 25.1

Comparative D-3638 175 330 135 Tracking Index (volts)

TABLE 4 ( cont )

FLAMMABILITY & ELECTRICAL PROPERTIES

(1/8" Specimens)

(45/45

PSF/PC + 10% Glass-Filled

10% Glass Poly- Poly-

+ 1% TiO^) carbonate sulfone

Flammability UL-94 V-O - 1/8" V-O - 1/8" V-O - 1/8"

Hot Wire Ignition D-3784 79 64 97 (sees)

High Current Arc WL-746A- 48 13 Ignition (arcs) 43.1

High Voltage Arc UL-746A- 3.3 6.9 8.0 Tracking (in/min) 25.1

Comparative D-3638 150 165 Tracking Index (volts)

EXAMPLE 2 The following example illustrates the production of an electrical part according to this invention. The resin compositions are set forth below in Table 5 wherein the polysulfone and polycarbonate are the polymers identified above. The compositions were compounded in a laboratory twin screw extruder and were injection molded into an edge-gated circuit board with many pins forming holes in the part. On cooling, there was no apparent phase sepa¬ ration and undesirable appearance. Metallic conductive pins are inserted into the holes in the parts extending above the surface of the molded boards.

TABLE 5

B

Polysulfone 49.% 47.765% Polycarbonate 49. 47.765 Carbon Black 2. 0.12 Zinc Oxide - 1.5 τio₂ - 1.5 Tan Oxide - 0.95 Oxide — 0.40

Claims

WHAT IS CLAIMED IS:

1. An electrical conductor assembly for use in switches, connectors, contactors, relays, and the like comprising a polymeric composition shell for substantially minimizing high current arc ignition and hot wire ignition, said composition shell comprising a poly(aryl ether) resin and an aromatic polycarbonate resin, and an electrical conductive metal core extending at least par- tially through said shell.

2. The article of Claim 1 wherein said metal core comprises a metal conductor embedded in said shell.

3. The article of Claim 1 wherein said shell com¬ prises a substantially rigid housing for abuttingly engag- ing and supporting said core.

4. The article of Claim 1 wherein said shell com¬ prises an arc-ignition resistance support member having an arc ignition greater than about 200 arcs as measured UL-746A-43.1.

5. The article of Claim 1 wherein said core com¬ prises a pin.

6. The article of Claim 1 wherein said poly(aryl ether) resin comprises a polysulfone resin.

7. An article as defined in Claim 1 wherein the poly(aryl ether) has repeating units of the formula:

8. The article of Claim 1 wherein the polymeric composition shell comprises from about 30 to 80 weight percent of the poly(aryl ether) resin and said aromatic polycarbonate comprises from about 70 to about 20 weight percent.

9. The process for fabricating an electrical con¬ ductor assembly comprising the steps of forming a support member comprising a poly(aryl ether) resin and an aromatic polycarbonate resin; and positioning an electrical conduc¬ tor in proximity to said support member.

10. The process of Claim 9 wherein said forming com- prises mixing said poly(aryl ether) resin and said aro¬ matic polycarbonate resin and molding said mixture.

11. The process of Claim 10 wherein said molding includes solidifying and curing.

12. The process of Claim 10 wherein said electrical conductor is embedded in said mixture before said molding.

13. The process of Claim 10 wherein said electrical conductor is positioned adjacent to said support after said molding.

14. The process of Claim 10 wherein said mixture is poured about said conductor prior to said molding.

15. The process of Claim 9 including abuttingly engaging said conductor against said support member.

16. The process of Claim 9 including annularly sur¬ rounding said conductor with said support member.

17. The process of Claim 9 wherein said assembly is fabricated into at least part of a switch.

18. The process of Claim 10 including forming a relay from said support member and said conductor.

19. The process of Claim 9 wherein said assembly is in association with an electrical contactor.