GB2282819A

GB2282819A - Crosslinkable and crosslinked polyphenylene oxide compositions

Info

Publication number: GB2282819A
Application number: GB9420250A
Authority: GB
Inventors: Sr Raymond T Leibfried
Original assignee: Hercules LLC
Current assignee: Hercules LLC
Priority date: 1993-10-13
Filing date: 1994-10-07
Publication date: 1995-04-19
Anticipated expiration: 2014-10-07
Also published as: DE4436675A1; JP3629048B2; JPH07173384A; DE4436675B4; GB9420250D0; GB2282819B

Description

2282819 1 CROSSLINKABLE AND CROSSLINKED POLYPHENYLENE OXIDE COMPOSITIONS

The present invention relates to novel crosslinkable and crosslinked polyphenylene oxide compositions, and to processes for preparing these compositions.

The preparation of aromatic polyethers - by means of redox polymerization of 2,6-dimethylphenol, in the presence of a copper-amine complex as a catalyst - is taught in H.-_Y '89, U.S. Patent No. 3,262,892, HAY' 505, U. S. Patent No. 3,378,505, and HAY '466, U.S. Patent No. 3,432,466. This reaction yields high molecular weight polyphenyleneoxide (PPO).

Glass filled PPO has been injection molded to provi:e excellent strength and stability in molded parts for -.-ar-c-us applications where electrical resistance is recpi _4 red. Tlie 4 1 ve modulus of th pcl-,ner:.s n3u=- 4 S Lens and compressi 4 ne'er ,g _ _ _ S SU eq,.;a -ha-- of other eng. - a C pclysculfcne and polycarbonate (2.6:3Pa, T h e- d I e- -r I ccn-c:-.an cf PPO is 2.58 at 60 Hz, and --he dissipa_on fac!:cr 4s low, ai: 0.00035 (60 Hz). The 24 hour water absorpt-ion is 14 4se low, at 0.06%, while the volume resisti-,-ity i X' kew s 1 1 1:Z 2. 5 10' ohm -cm - thereby making the overall properties very suitable for electrical applications.

The heat and chemical resistance of PPO can be impro77ed, for applications in composites and electronic components, by crosslinking the PPO, and thus converting it into a thermoset material. The crosslinking of unsaturated PPO derivatives, by means of free radical cures, has been described in Japanese Patent Publications Nos. 4-91160, 491161, 3-45649, 2-208355, 2-233,239, 4-91110, and 2-1203157.

PERCEC et al., U.S. Patent 4,871,K6, discloses polvarylene pol-lethers with te-rminal reactive vinyl groups, hydrosilatable with a,wdihydrcpoly(dialk.,lsiloxane), to form thermally crosslinkable, thermoplastic linear triblock oligomers with -7inyl chain ends. SHEA et al., U.S. Patent No. 4,814,3192, discloses silic-one-pol'yarylene ether block copol,,,mers made by reaction betwe-en amine-terminated polydiorganos-iloxanes and anhydr'Lde functionalized polvarylene ethers. SJTo-,T 7T. S.

et a!., Patent 5,204,438, discloses the oxidative coupling of 2,6-disubstituted Phenol's with phenol-siloxane macr-zrr.-ers, to 1 --h.-ermcniastic s i I i cone -po lvpheny' ene ether graFt-- -CZDC"-.-M. =rS J.S. Patent Z d-scizses hiock re-par-e-a from reacting p---'- Iyphe-y-en- segmer.

P--L-,----rcTar.csi1oY.ane segments are -han ta:-'rmina-d .-.Ith amine groups.

A It - 3 is The present invention pertains, _,_ one embodiment, to a crosslinkable composition comprising a silicon compound and a pol-_-phenylene oxide. The silicon compound has at least two hydrosilation reactive -=SiH groups, and the polyphenylene oxide has at least two hydrosilation reacti7e unsaturated carbon-carbon bonds; further, at least one,:)f the silicon compound and the polyphenylene oxide, has more than two hydrosilation reactive sites.

In another embodiment, the present invention pertains to a crosslinkable composition comprising a polyene, a silicon compound, and a polyphenylene oxide. The silicon compound has at least two hydrosilation reactive -=SiH groups, the polyene has at least two hydrosilation reacti-.7-e carboncarbon double bonds, and the polyphenylene oxide has at least one hydrosilation reactive unsaturated carboncarbon bond; further, at least one of the polyene, silicon compound, and polyphenylene oxide has more than two hvdrosilation reactive sites.

In yet a further embodiment, the present in-,rention pertains to a crosslinkable composition comprising a cr:ss'inkable organosilicon prepolymer, and a -xlcle- ha-.--'r.g at: least one hydrcsilati-)n react4%,= unsa:ura-_:--_, --ar-=-carbon bond. The crosslinkable organz)si-i= r-po.11-yiner may comprise the hydrosilation react.= pr-_Iuc b-1 - - I cf the polyene and silicon compound, as discussed above.

j is The invention additionally pertains to crosslinked compositions comprising the hydrosilation reaction products of the foregoing crosslinkable compositions - and to processes tLor preparing these crosslinked compositions, comprising effecting hydrosilation, of the reactants comprising the crosslinkable compositions. As yet another embodiment, the invention pertains to articles of manufacture comprising the crosslinked compositions of the invention - in the form of electronic components, and reinforced composite articles.

The term Ilpolyenell, as used herein, refers to molecules having at least two carbon-carbon double bonds.

The term Ilprepolymerll, as used herein, refers to any liquid or solid hydrosilation crosslinkable composition that has been partially cured, but has not been cured up to or beyond its gel point (gel point is the point at which a material will no longer flow when heated, and is no longer soluble in organic solvents); typically having 5% to 60% of the available =-SiH groups reacted.

The term Ilcrosslinkedll, as used herein, encompasses a state of less than full crosslinking; in this regard, crosslinked compositions include compositions which retain unreacted crosslinkable sites - e.g., with respect to hydrosilation, unreacted hydrosilation reactive =-SiH groups, and unreacted hydrosilation reactive unsaturated carboncarbon bonds. The crosslinking reaction, as discussed - 5 _O herein, encompasses hydrosilation, i.e., the reaction cf hydrosilation reactive -=SiH groups and hydrosilation reacti---e unsaturated carbon- carbon bonds.

s used herein, the terms, "aliphatic", "cycloaliphatic", and "aromatic" unless stated otherwise are understood as including the alkyl, cycloalkyl, and aryl groups, respectively. Further, "aliphatic", "cycloaliphatic", and "aromatic" are understood as including both nonsubstituted aliphatic, cycloaliphatic, and aroma,ic groups, and substituted aliphatic, cycloaliphatic, and aromatic groups, with the latter referring to the aliphatic, cycloaliphatic, and aromatic portion bearing additional substituents, besides the carbon and hydrogen.

The term "silicon compound", as used herein, encompasses organosilicon compounds, containing carbon, in addition to the silicon.

The vinyl substituted benzyl radicals, as discussed herein, are those of the general fcrmula:

1 \/ ....,t:h the position of the -.?.in,,11 g=up Jndic:at-4ng that be present on any open position of the iDhen,;! ring.

it --an The pol-jenes suitable for the -in-,r_--nti,3n include those ha-,Ting at least two hydrosilation reacti-,,-e carbon-carbon double bonds. ---mong such polvene-s are the polyeyclic pol-2enes, including those as disclosed in LEIBFRIED '779, U.S. Patent No. 4,900,779, LEIBFFIE-11 1731, U.S. Patent No.

4, 9 02, -1,3 1, BA RD et al. '3 6 0, U. 51. Patent 11o. 5, 0 0 8, 3) 6,0, and LEIBFRIED '809, U.S.

Patent 11o. 5,013,80-9.

Particular polycyclic pol:,;,enes are polycyclic hydrocarbon compounds ha-,Ting at 1.-:-ast two non-aromatic carbon-carbon double bonds in their rings. Exemplary compounds include cycl)pentadit---n.-=:-7-Jgomers (e.g., dic-,,c-'--pentadi--:ne (DCPD), tr4L--".--'Dnentadiene, and tetrac,,,clopentadi.ane, bic-,,cl--heptadien;-= Ii.e., norbrnadi4c-,n;-,, and its Diels--,'Ld.--r.,ith -:;cl,3-pentadiene (e.g., dimer-hanohexalil,,dr-cnaphthalene,,, A n,:rb.::,rnad--ne dimer, hexah.:drena::h--halene, and subst'Ltuted of any of these, e.g., methyl J,-,,"c:' -pentad' Two or more pelyenes can te "I-- -- - ienes. - - -L- - u-d in combination.

s; a Z-'JcDn compounds of the- includ;:-- these- -- - -.1. - - - - - - 2 5 and prepc with t-,.o or h-dr:,,crz--n atoms bound e- part 4 cularly, -,,7i'--h a-- z 7 least two hydrosilation reactive =-SiH groups. Two or more suitable silicon compounds can be used in combination; particularly, one or more such cyclic polysiloxanes, and.fcr one or more such tetrasilo)cysilanes, and/or one or more such linear polysiloxanes, and/or one or more such polyfuncti:)nasilanes, and/or one or more such polycarbosilanes, may be employed.

Suitable such silicon compounds include those disclosed in LEIBFRIED '779, LEIBFRIED '731, and LEIBFRIED '809, and BARD et al. '360, and in COWAN, U.S. Patent No. 4,87",82,D, LEIBFRIED '134, U.S. Patent No-5,077,134, LAMCREAUX '4322, U.S. Patent No. 3,197,432, LAMOREAUX '433, U.S. Patent No. 3,197,433, and LAMOREAUX '936, U.S. Patent No. 3,438,9356. Suitable such polycarbosilanes include those disclosed 4n W '390, U.S. Patent No. 5,130,390, 'w%'EBER et al.

9EBER et al. '916, U.S. Patent No. 5,169,916, WEBER et al. '792, U.S. Patent No. 5,171,792, and WEBER et al. '810, U.S. Paent 11c, 5,i-11,810.

Appropriate cyclic polysiloxanes include those ha-,--4-,a the general formula:

z -. C 5 9 It wherein R, which can be the same or different, is hydrogen, or a saturated, substituted, or unsubstituted alkyl or alk,.xy radical, or a subst-ltute-d or unsubstituted arGmatic or arylox-lr radical, n is an integer from 2 to about '10, and R is hydrogen on at least two of the silicon atoms in the molecule.

The m=-thylh,,-drocycl.,,sil(,-7.anes (also referred to herein as lw2ICS), and mixtures thereof, are suitable such cyclic polysiloxanes. Examples include, e.g., tetraocti,l cyclotetrasilloxane, and hexame--.m-','1 c-.,clotetrasiloxane; tetra- and pentamethyleyel,5t=-c-rasi-l-c.--,.an-:--s; tetra, penta, hexa- and hepta-methyleyclop--lnlEiasilxanes; tetra-, penta- and hc-xameth-71-c-j,clohexasilexan.--s, tetraethyl c:lcltetrasiL-',--.-,7.anes, and tetraphenyl c-.,clotetrasiJloxanes.

Preferred are 1,3,1-,7-t,:--t--ramc-t-h-,lc-,-clo-c-trasiloxane, 13 ),5,-,,9-pentameth,ll-cyclopc-n--as49.1oxane, and J or blends thereof.

The sili-con compound may ---mcr-Jse a plurality of - 1; ica J - S pe c i f In a majorJt of :7as;--s. at is use-JA is a a number 2f - -1 -, -in purer -4-Grms, 1 J as 'L ow as l 1 ----u l a r 1 g h t near as h=ptairLeth-.1'trJsi,:xant--, - 9 octamethyltetrasiloxane, etc. One suitable commercial mixture is Huls M8830 MHCS, available from Huls America, formerly Petrarch, Bristol, PA.

The tetrasiloxysilanes are represented by the general formula:

p 1 3: -- 0 - 5 1 - p 1 R wherein R is as defined above, and is hydrogen on at least two silicon atoms in the molecule.

Examples include, e.g., tetrakisdimethyl-siloxysilan-,-,,j tetrakisdiphenylsiloxysilane, and tetrak-'sdieth:,,1 slioxysilane.

Appropriate linear polysiloxanes include those ha-.--ng the general formula:

Q p - 1 - 10 d ', 7herein R, which can be the same or ifferent. is hydrogen, or a substituted cr unsubstituted saturated alkyl radical, 1 or a substituted or unsubsti-tuted phenyl radical, at least two R's are hydrogen, and m is an integer -o about 10 t 1000.

-en c=tain rr.)r amounts of -The linear polysiloxanes branc.-ied pa-1-.,siloxanes as JLmpurities. Includ amcng such branched polysiloxanes are those ha-7ing the a -.ral f ormula:

1 z -.-' z-r=4n R and m are as defined abo-.-e -"er l--ar - - - - -1. --- p!-.-s-lexa.nes, and n _Js an intege-r.'-z)m about 3 to 1 ---C,. t'm.:: R's in h,= r-, n such branched - - - 1 pcl-.-sL--.-.-.anz-s, at least are Jn r - s - a re iloxanes - e.g., am,,,unt branched polys; ecru 4 be c,:,nsidered as _ --alent to linear pol-,,sLl:xanes, and to be considered as within the scope cf llnear polysiloxanes, for the purposes of this invention.

Further as to linear polysiloxanes of the invention, suitable such linear polysiloxanes include the linear, short chain -=SiH terminated polysiloxanes having the general formula:

1 p C -- 5 0 S p R p 9 wherein n is 0 to 1000 and R is alkyl or ar-;1, preferabl.j methyl or phenyl, as disclosed in LEIBFRIED '134 and LEIBFRIED 1809.

Lhese linear, short chain -=SiH terminated polysiloxanes impart flexibility to the cured =positions, and can be used to produce elastomers. As examples of such polysiloxanes, disiloxanes, trisiloxanes, and other short siloxane oligomers, such as hexamethyltrisiloxane, are useful to lower.-iscosity, particuliarlly for transfer operations where low viscosity is most desirah-.-:--.

Yet additional suitable linear pol-7sJL.",oxan.-=s are llnear pol,. 1(organohydrosiloxanes), ha...ing the general formula:

1 1 1 1 1 Q ' (Z 3 c - 12 FI where-in R is a substituted or unsubstituted sradical or a substituted or unsubstituted phe-r 1--0%, or about ISIA, or mc-)re and 1%, or about 1%, to 155%, to 50%, or about 50%, of the R's terably 5%, or about pre4L are hydrogen, and m is an integer from or about 5, t3 1.300, or about 1000, or 3, or about 3, to 100, or about 100, and preferably 5, or about 5, to 100, or about 105, and the about 60.

maxmum -,-alue of m is most pre._rabl-. Exemplary linear polr(organoh-., dr.-,sil2xan:--s)inc'-ude: trimz--th,,,lsiloxy-termina-ed th-;lsi lox..terminated me- t hy -, s i Io- x- ---d y-terminate:1 -- t:!-. -.. - s i = an eme t hy 1 hy d r c s - -I -- - a n e- 7: p -- -'-.-.nt= --, -xanemeth-,,1h-.,dr,:-s '--.-.ane silo,,c-.,terminat.:-d L. - z -iratc-d alkyl radical, j 13 - trimethylsiloxy-terminated methylcyanopropyl-siloxanemethylhydrosiloxane copolymer, trimethylsilo.cy-terminaued 3,3,3trifluoropropy1methylsiloxane methylhvdrosiloxane copolymer, trimethylsiloxy-term-inated 3-aminopropylmethyl siloxane- methylhydrosiloxane copolymer, trimethylsiloxy-terminated 2-phenylethylmethyl siloxane-me+,hylhydrosiloxane copolymer, and trimethylsiloxy-terminated 2-(4-methylph--iyleL-hylmethyl-siloxane- methylhydrosiloxane copo--/mer Poly(organohydrosiloxanes) which may be used include those as disclosed in COWAN.

Suitable polyfunctional silanes of the invention include the aliphatic, cycloaliphatic, and aromatic polyfunctional silanes, having the general formula:

is 1 1 1 j z 1 z ---- c 1 - 11 L z 14 - wherein R' is a substituted or unsubstituted aliphatic, cycloaliphatic, or aromatic radical, and R, which can be th same or different, is hydrogen or a C,, radical, and at least two R's are hydrogen on the molecule, and n is an integer of 2-4. Of the foregoing, preferred aliphatic and cycloaliphatic groups are those having 2-22 carbon atoms, and preferred aromatic groups are those having 6-12 carbon atoms.

Exemplary polyfunctional silanes are 1,4bis(dimethylsilyl)benzene, 4,4bis(dimethylsilyl)diphenyl ether; 1,2-bis(dimetolsilyl)ethane, 1, 6bis(methylsilyl)hexane, bis(methylsilyl)diisopropylbenzene, tris(dimetolsilyl)cyclohexane, and tristdimethylsilyl)benzene. of these, the disilanes - i.e., 1,4bis(dimethylsilyl)benzene, 4,4'bisfdimethylsilyl)diphenyl ether, i,2-bis(dimethylsilyl)ethane, 1,6bistmethylsilyl)hexane, and bis(methylsilyl)-diisopropylbenzene - are preferred.

Suitable polycarbosilanes of the invention include A saturated and unsaturated polycarbosi:anes having the 1 f irmula:

1 1 1 -R -5 - 1 j R m wherein R' which can be the same or different, is a substituted or unsubstituted aliphatic or aromatic radical, and F, which can be the same or different, is hydrogen, or substituted or unsubstituted alkyl or aryl radical, and at least two R's are hydrogen, and m is an integer of 5 or greater.

Exemplary polycarbosilanes are poly (1-mezhyl-lsil-apent-3-ene), poly (1phenyl-l-silapent-')-ene), poly silapent-3-ene), poly (1-methyl-Isilaindane), poly (Iphenvl-l-silaindane), poly (1-phenyl-l-silabutane), poly (I rl-j-S4 mel:hyl-l-silabutane) and poly (1-meth- -L-'a-1--,-lidene 1, 11 -pheny leene 1.

:he prolypheny'Lene oxides of he -4=ention include at least one hydrosiiati= re-act-4-.-e cart'--M-carl---n b--nd. In this recrard, carbon- carbon unsaiura!:-:--d and r-r-ple bonds; cf t:hese, 1 1 - b--nds enc=pass th- the:- b::njs ar.-- These h-,,drosila-Lion reacti-,,c-, unsaturated carbon-carbjn bGnd- bearing polyphenylene oxides can have a high molecular 1 1 L;:

weight, so that the basic thermoplastic properties of the pc,l--,mer are largel-,, maintained. There is no upper limit on such molecular weight, except as it affects the solubilitv of the po':imer. In this regard, abc-,-e a certain mclecular weight - which mav be different for each pG1:1Tner - the pol-imer will become insoluble and;cr -jery -jiscous, and so will become difficult t, carry out the crosslinking reactions. zl--cordingl:j, it 4S preferable that the molecular weight, of the pol-phen:jl-n..--- e-3mponent, be beow this - L - 1 - -L 1 0 1 1 imi t.

The of unsalt--uratJL,--n characterizing the ffeets the properties of the oxide also a:

thermoplastic pol.,,ner, and can be adjusted, to aid in pr-=si-:-r-.r4j-ng properties are desired.

Specificali_ -Ln is the present i=ention, higher degrees of substitut-J--n lead, to easier processing and greater f--orrpatibi'Lit:j with the crgan,:,s-J"L'--cn csmpounds; the unsaturated pol-.-h-ln,.llen.,-:- i-i - retain the desirable- Properties and absorption of the start-ing pl.,-ph4---riylene exide 17 - R CH22 R C2R R C H 2 2 0 0- 0 OP L J R CH22 P C H 2 R p CH R R wherein R, which can be the same of different, is hydrogen, or a -CH.CH=CH -CH - CH=MC (0) -, or 2 1 2C=CH, CH,=CHC(O)-, CH3 CH=CH2 -CH2 -(a radical, and n is an integer of 5 or greater; and j 2 R J'I 0 U 1 1,2 2 R 0 R p - H, P, 2 -. 2 Z wherein R and n are as defined abo-je, n can be the same r different, and Q is a multi-ring aromatic residue.

With reference to the latter of the two above-indicated formulae, the multi-ring aromatic residue Q preferably - 18 comprises the residue of a diaryl, e.g., a diphenolic, compound. Such residues may include a 1! 1, 1 i of these, res.dues ha-j;-ng the 4-',:,rmula cz p - 19 \- __y CH3 where Y is SO, or -C, are partIcularly preferred. 1 CH3 Suitable starting materials, for preparing the unsaturated, h-, rdrosilation reactive carbon-carbon bondbearing polyphenylene oxides of the invention, encompass both homopolymer and copolymer polyphenylene oxides; in this context, the copolymers are understood as including both those polymers incorporating two different monomeric unils, as well as polymers incorporating three or more different monomeric units, e.g., terpolymers, etc.; such copolymers are further understood as encompassing polyphenylene oxides' including both different aromatic and different nonaromaic monomeric units.

--able monomeric units, for preparLng the Suit 4 4 p3l-J-Pheny-lene oxide starting materLa-s of n-'uding those as disclosed in.2,..S. Hay,.1. Pcly.

P-, il,_.7nerizat ion by C3upl=!I.

_xida!:_'3n cf 2,6-DisubstItuted Phen-_'s, " and 'n No. 546, 1-0. t.m rz) n g t- su i t a L- 1,E dimethyl pheno'L, l-methyl-6-.:--t-h,';.phe.no, 2methy',.-- isopropylphenol, Z,6-diethylphenol, --met--hyl-:')-ch'-orophg---ncl.

the in-,-ent-')n, -G - ) -me thyl - 2-methy"L-6-bromophenol, -methyl-6-methoxyphenol, '6-pherrylphenol, -1methyl-6-(thi,,-methoxymeth,1)phenol, 2methyl-6-ia-phenyleth-rl)phenol, 2, 6bis(thiomethoxymethyl)phenol, 2-phen,JI-62 -thyl-6-(methylthiophenol), 2(thiometho:cZmethyl) phenol,.-m--pheiryl-6-(methylthi-o')pheno'L, and 2,6diphenylphenol.

Homopoiy.mers and copolymers, of the requisite monomeric units, are suitable as the polyphenylene oxide starting materials. 03ne means for preparing these polymers is by 2 redox polymerization, as disclosed in IH.Z',Y '89, ILLY '505, and HAY '466.

The homopolymeric starting materials may include poly(2,6-dimethyl-1,4phen7ylene oxides), of the formula j - 21 wherein n is at least about 5. These polymers may be prepared by the indicated redox polymerization, of 2,6 dimethyl phenol.

Where comonomers having two aryl hydroxyls particularly, phenolic hydroxyls, such as tetramethylbisphenol - are used for preparing the polyphenylene oxide starting materials, polymers having free hydroxyl groups at both ends of the polymer chains, can be prepared. A benefit of comonomers, whether or not they contain one or more aryl hydroxyls, is that they decrease the crystallinity of the resulting polymers and::hus ir-.,pro-.-e their solubility and processabi-ity. Comonomers CC.-,L--a. ning two phenolic groups can be included, in preparation c-f the polyphenylene oxide starting materials, to obtain copolyMers ha,:ing the general formula: 1 1 bo -1 L . 3 wherein n, -which can be the same or different, is 5 or greater, and Q is the residue deri-7ed from the comonomer containing two phenolic groups. Diphenolic compounds which may be employed for this purpose include 2,6- naphthalene diol, 4,4'-dihydrox7ybipherryl, bisphenol A, bisphenol B, p, p'-dihydrox7ydiphen-ylsulfone, p,p'-dihydroxydiphenylketone, and p,p'dihydroxydiphen-ylether.

The polyphenylene oxides of the invention can be prepared by metallating polyphen-ylene oxide starting material - then adding radicals, containing hydrosilation reactive, carbon-carbon unsaturated bonds, at the metallated sites, by reaction with compounds supplying such radicals.

Metallation can be effected according to the procedures taught in CHALK and HAY, Journal of Pol-nner Science A-1, .'olume 7, pages 691-705 (1969), and in HAY '144, U.S. Patent No. 3,402,144; CHALK and and I-L'--Y '144.

In this regard, a mixtur.-= of side chain and aryl ring lithiation can be provided by metallation with bUtyl'L4thium thyl side chain and in tetrahydro'Luran; particularly, met phenyl ring lithiation, of pol-."1,6-dimeth-il-1,4-phen-ilene ether, can thusly be readil-, pro-:ided, in this manner. The lene 4 amJ. -'-,-.h--um 11j,N,N N -tetrametlhyleth% -dine complex of butyl lat4 - t i -.' -.-en- ca.- be used for the metal Lon reaz on in other s-L %_s.

Me'tallatic,n can be confined, or at least eSsentiallv conf4ned, to side chains of the polyphenylene oxide particularly, to the methyl sid chains, where -poly(22,,,)- - /2 3 dimethyl-1,4-phenylene ether) is employed - by using the sodium or potassium metallating agents.

The metallated polyphenylene oxides can be modified by reaction with organic halides, characterized by the requisite hydrosilation reactive, unsaturated carbon-carbon - ive, bonds, to obtain the corresponding hydrosilation react unsaturated carbon- carbon bond-bearing polyphenylene oxides of the invention. Accordingly, where the metallated polyphenylene oxides feature a mixture of side chain and aryl ring lithiation, the thusly mod4fied polyphenylene oxides will have a mixture of side chain unsaturation and aryl ring unsaturation. Correspondingly, where the metallation is confined essentially to side chains, the hydrosilation reactive unsaturated carbon-carbon bonds will consist essentially of side chain unsaturation.

Suitable compounds, for reacting at the metallated sites to provide the requisite hydrosilation reacti-.-e, carbon-carbon unsaturated bondcontaining radicals, includ4-allyl, proparayl, acrylyl, crotyl, and vinyl substituted benzyl halides; these, of course, pr3-.-ide al1yl, proparayl, acr -.11, and.,in, l subs-- -u--ed benz,.,l rad-4 - crot ca's, c"--j respecti-:ely.;,mong the halides which ma,. be Mp __ he chlorides, bromides, and icd_4des. The reac,_4-_n ma-_: effected according to the procedures disclosed in Japan.-=-se Patent Publications Nos. 1-113425, 1696228, 1-69629, 1- 113426, 2-233757, 2-233759, 3-2171--d718, and 21-2232260.

2i - 24 is As yet further means for obtaining the hydrosilation reacti,je, unsaturated carbon-carbon bond-bearing polypherrene oxide of the i=ention, 2, - dia'lylphenol can A- L - 0 -L be polymerized to obtain the homopolymer, or can be copol:imerized, with 22,6 dimeth-jlphenol as the comonomer, to obtain the copolymer, using the redox polymerization procedures as disclosed in HAY '892, IIAZ' 505, and HAY '466.

Yet further hydrosilation reacti-.,e, unsaturated carbon- carbon bond-bearing polyphenyle'ne oxides of the in-jention are those wherein the radicals supplying the unsaturatin-n are added only - or at least -=ssent4a!1:1, or substantially only - at the hydroxyl groups of the pol-,7pheriylene 3xdes.

In this manner, there can be pro-.7ided polyphenylene oxides of the invention, with only two hydrosillation react-'L-.'- unsaturated carbon-carbon bonds - one- on each of two terminal radicals, attached at opposing ends of the polymer chain; further, there can be po'-i-nhen-l,len4--- oxides - L- - - ch- in-ention, with on- onh-:.dros4'ar-ion reacti-.-e - - _L.Z - - ---L unsaturated carbon-carbon bond.

lhe- indicated two unsaturate-d group-bearing oxides can be the- pc h n..

Starting rra-t-.-=-r4Ia-ls, partiz.u-ar--.. the -ee h-;dr,:,x-,-1 groups -ar-----u-ar.,.-:, phiz---'1- h a.. i ng L- - groups - at both ends the p,:)'-.-mer chaJ-s.

--- - - 1 -L - ---1 Correspondingly, the single unsa--urat.-:-d grGup-bearing polyphenylene oxides can be obtained from the pGI-,,pnen-,--,ene - 25 oxide starting materials having one such free hydrcx-.-l group, e.g., at one chain end; such monohydroxy Polymers include the poly(2,6-dimethyl-1, 4-phenylene oxides), resulting from homopolymerization of 2,6- dimethylphenol.

The hydroxylated polyphenylene oxides can be suitably reacted with the requisite unsaturated halides - e.g., including those as specified herein - in accordance with the procedures as set forth in PERCEC et al. '816, and in Japanese Patent Publication No. 2-233760.

Hydrosilation catalyst can be included, with crosslinkable compositions, such as blends, of the invention, for effecting the cure - specifically, including the crosslinking - thereof, and thereby obtaining the final, cured - or crosslinked - product. For instance, this catalyst facilitates the hydrosilation reaction, where theri, are -=SiH groups and carboncarbon double bonds available therefor, and conditions are otherwise suitable for supporting hydrosilation; with this hydrosilation reaction, crosslinking is effected.

The hydrosilation catalyst, where employed, may be ded in an amount of about 5-60 ppm, based on the t:,a_ weight- '_-f:he crosslinkable composition.

"he hydrosilation catalysts include metal salts and complexes of Group VIII elements. The hydrosilation catalysts may contain platinum (e.g., PtCl., dibenzonitrile platinum dichloride, platinum on carbon, dichloro(1, 2- 26 - 0 cyclooctadiene) platinum (II) [(COD)PtCl.], available from Strem Chemicals, Inc., Newbur-iport, M7k, etc.). one such platinum catalyst.., 7hich is suitable, in terms of both reactivity and cost, is chloroplatinic acid (H.PtCl,.6H.0); also appropriate are the platinum complex of divin7yltetramethyldi-siloxane, available as PC075 from Huls America, and the platinum-containing catalysts PC072 (a platinum divinyl complex) and PC085, also available from Huls America. One catalyst is a complex of chloroplatinic acid and dicyclopentadiene, as disclosed, for instance, in LEIBFRIED '779, and in BARD et al. '360. A second catalyst is the indicated (COD)PtCl- Also suitable, as hydrosilation catalysts for crosslinkable blends of the invention, are those as disclosed in CRIVELLO et al., "Nove Platinum-Containing Initiators for Ring-opening Pol:linerizations", Journal of Pol=er Science: Part P,,_)l..ner Chemistry, Vol.29, pages 1853-1863 (1991).

j The crosslinkable compositions of the invention can be pro.-ided in the form of blends, of,..he indi-.-idual corr,n,:)nents. The crossl-nkab'Le blends can be prepared by any suitable means, such as con-,-4---nt-,--, nal mixina --f the c 0 mp 2, r. e- n t S.

The crosslinking reactJL.,---n can be carried out either i solution or neat, and by any suitable means which will support the hydrosilation reaction. The temperatures used for the crosslinking reaction are not critical, and depend is no in part on the identity of the components and presence or absence of solvent; generally, temperatures as low as room temperature can be used. Aiternatively, crosslinking can be effected thermally; in this regard, heating to as high as 2500C may be necessary, to maximize the glass transition temperature of the crosslinked composition.

Particularly with regard to molding applications, for the crosslinkahle or crosslinked compositions, the neat polymers are warmed, injected into a mold, and then heated to form the cured part. A catalyst retardant such as diethylenetriamine is required during this molding operation. The thermosetting formulations can be cured at various temperatures normally, 30-400C above the glass transition temperature required in the cured coating. The thermally promoted cure with a platinum hydrosilationcatalyst can be started at 1000C or higher where a gel can be formed in minutes. If curing is effected at 250-C, for 1 two hours, a glass transition temperature of around 200C is developed in the coating.

In a first embodiment, the crosslinkable compositi= comprises hydrosilation catalyst and the reactants, i.e., including the silicon compound and polyphenylene oxide. These reactants are suitably blended, then subjected tc a suitable crosslinking procedure, until the crosslinked product is achieved.

-,8 - 0 In this first embodiment, the silicon compound has at least two hydrosilation reacti"7e -=SiH groups, and the polyphenylene oxide has at least two hydrosilation reactive unsaturated carbon-carbon bonds; furthermore, at least one of the silicon compound and the pc!-jpheir, 71ene oxide has more than two hydrosilation reacti-7e sites. The crosslinking procedure is conducted so as to effect hydrosilation of such silicon compound and polyphenylene oxide, and thereby pro-7ide their crosslinking.

In a second embodiment, the crosslinkable composition includes a polyene ha-iing at least two hydrosilation rea---.i-.,e carbon-carbon double bonds, besides pGlyphen-;lene oxide, and the indicated h-7drosilation catalyst and silicon compound. Because the pol,eene has at least two hydros41ation reactive sites, the polyphenylene oxide does; not also require two such sites, for the requisite crosslinking to be effected; sriecifJ-all-,,, pol-jpherilrlene oxides with only one hydrosilation reacti-je unsaturated carbon-carbon bond, as well as those t-t.c or more, ma-, be emplG,7ed.

z:cord4Lngly, in this sz--c--n.' the p:xlde has at --n.-:

unsat,jra---:-d zarbon-carbi:n bc-nd....,th the first er, _li ir -und, at least one GJ. tIhe s- C2n p -ne, and polyphenylene oxide has m,re than t...,,o hydrosilation reacti-je sites, in order to support crsslinking; i 5 - Z crosslinking can conducted, in the same manner as for first embodiment.

In yet a third embodiment, the crosslinkable composition comprises a prepolymer preferably, a crosslinkable prepolymer, and more preferably, a crosslinkable organosilicon prepol:rner - and a polyphenyllene oxide, having at least one hydrosilation reacti-ie unsaturated carbon-carbon bond; in a particularly preferreJ embodiment, polyene and silicon compound are provided to thecrosslinkable composition in the form of the indicated crosslinkable organosilicon prepol:qner, which has been prepared by hydrosilation, from reactants comprising such polyene and silicon compound. This crosslinkable composition, including the hydrosilation catalyst, and such prepolymer, as well as polyphenylene oxide, is likewise subjected to the crosslinking procedure.

The same hydrosilation catalysts pre,.--Jous-'-.- d-Jsc,-ss----d are likewise appropriate for use in preparation of the prepol.mer. For those of such catalysts which are P'a-nu.T.

catalysts, catalyst concentrations of about t2. a---,,1- --%n the we -ht -- f j5%..,eiaht of platinum, based.n,3n:,,m-rs, ma-,- be used.

"t regard to this third embediment, .--h -- -he crosslinkable composition contains a suff- t amount, of the hydrosilation catalyst used in its preparation, to effect crosslinking of the composition, the- 2 0.

the crosslinked comnosition of the invention can be obtained without requiring further addition of hydrosilation catalyst. Alternatively, ilnecessary, the crosslinkable composition can be provided with additional h-ydrosilation catalyst.

The crosslinkable organosilicon prepolymers suitable for the invention include those prepolymers as disclosed in LEIEFRIED 1779, LEIBFRIED '731, LEIBFRIED '134, BARD et al.'360, and CO'.I.L27. The crossl-Lnkable prepolymers suitable for the invention also include those prepGlymers as disclosed in BARD et al.'3103, U.S. Patent No. 5,068,303, BURITIER '048, U.S. Patent No. 5,0'215,048, BURITILER '735, U.S. Patent No. 5,118,735, BAR17,;M et al. '979, U.S. Patent No.

52 422, 9 7 9, 1817, U.S. Patent No. 5,171,817, BAPTTUM et al. and LEIBFRIED '498, U.S. Patent No. 51,196,498, and in U.S. 'j Application Serial No. 593,168, filed October 5, 1990.

14 --mers are Preferred c-rosslinkable organosii Lcon prepol, those comprising:

'a) at least one polyene ha-.ring at least two 4 -carbon double bo.h%dros lation reactive carbon Ids; and "b) at least one sil'Lcon c-_mnound, ha-.-ing at least hydrosilation reactive -=SiH groups, and comprising at 'Least one member selected from the group consisting or p,:',ysl!Gxanes, tetras ilox-;si llantes, and linear PCI'I'S-.1Loxanes; wherein at least one of the at least one polyene and the at least one silicon compound has more than two hydrosilation reactive sites. Most preferably, the at least one silicon compound has three or more hydrosilation reactive -=SiH groups.

Suitable polyenes and silicon compounds, for such prepolymers, include those as discussed herein.

Where the crosslinkable prepolymers, of the invention, are the indicated crosslinkable organosilicon prepolymers i.e., comprising at least one polyene, and one or more one cyclic polysiloxanes, and/or tetrasiloxysilanes, and ';or linear polysiloxanes, as discussed at length above - the ratio of total hydrosilation reactive carbon-carbon double bonds, contributed thereto by the at least one polyene, to hydrosilation reactive -=SiH groups, contributed thereto by the at least one silicon compound, is preferably regulated according to the intended function of these prepolymers. I Specifically, the prepolymer is formulated for hydrosilation reaction with the polyphenylene oxide; where the polyphenylene oxide provides two or more hydrosilaticn reactive sites, it will participate in the crosslinking, by -.-irtue of such hydrosilation. Because the hydrosilatJon reacti7:e sites of the poi,.-phenylene oxide are u.- saturatz-7i car' ton-carbon bonds, the prepolymer must prc-.-Ide suffficient hydrzsilation reactive =SiH groups for reaction and the relative proportion of hydrosilation reactive sites, contributed by polyene and silicon compound, is determine-d accordingly.

1 1) j - In -,,iew of Is the foregoing, the prepolymer composition ma. L j have at least a slight excess of hydrosilation reacti,7e =SiH groups o,. rer hydrosilation reactive carbon-carbon double bonds; this ratio is preferably in the range of 1.1:1 or larger. Higher molecular weight pol:, rphenylene oxides can be employed - e.g., crosslinked, -,,ith on!-,; a slight excess of ITjdrosilation reactive ESiH groups available.

Further as to crosslinkable organosilicon prepolymers of the in-,-er.tion, included among such prepol:lmers are the crosslinkable linear pol. i(organch,;drosiloxane) prepol:,ners, comprising linear poly(organoh:; drosiloxane) with hydrosilation reacti-je =_SiH groups ha-,-ing been reacted with polyene - preferably, polyc-jelJ- polyene. Suitable polyenes, such as polyc-jclic polyenes, include thosa as discussed herein.

In these cross.linkable linear p3lyz-,rgan-,h-,,dr,--,.s-1--xanc-) prep,:. 1j.-,-mers, preferably, 5% to 90% - more preferably, at 1 -G%, and, most pref-erabl.,-, -3% -1-G 0% - =4 such least =ac: -ed hydrosilation reactive =-SiH groups ha-.?.e jjeen thusly re -,P.-i-,h pc- -,_..-enc-. Apprcpriate linear f -r i--r;-=iDcl-,-mers, aren these b:,th ti-le g;---ni-z-rall. fzrmula, and the j:r-,,anh..-drosi':y.anes,, being pc.!-. '--lraani--h-.--"4res-'---:.-.an4--s, as can be prepared utilizing the procedures and including, but not limited te, precess steps and.--a-l-a-'--.-sts, as set - h he- crosslinkable of is 0 forth in LEIBFRIED 1779, LEIBFRIED 1731, LEIBFIRIED '14, BARD et al.'360, BARD et al.'303, BUFVIER '048, BUR.NIER '735, COWAN, BARNUM et a!. '979, and BARNUM et al. '817, and in U.S. Patent No. 5,340,644. The reactions for forming the prepolymer, can be promoted thermally, or by the addition of a hydrosilation catalyst or radical generators such as peroxides and azo compounds.

One approach for preparing, as the crosslinkable prepolymer of the invention, a crosslinkable organosilicon prepolymer as previously discussed, is simply to mix the correct relative ratios of components - i. e., including the polyene, silicon compound, and hydrosilation catalyst and bring the mixture to a temperal=e at which the reaction is initiated. Proper temperature conditions are thereafter maintained, to drive the reaction to the degree of completion requisite for obtaining the desired prepolymer.

In this regard, reaction conditions utilized are those which are requisite for obtaining a prepolymer, within the meaning of the term as defined herein - i.e., such polymer being partially cured, but not cured up to or beyond its point; for instance, the mixture of the components is maintained at about 3F to 80'C., several hours, h-&n - where - interrupted at the point. the requisite pr3porticn z---t a,-ailable hydrosilation reacti-.-e =-SiH groups ha-,Te been reacted - preferably, 5% to 60% thereof. More preferabi-,, this polymerization is effected so that, 30% to 60%, and 1 most preferably, 30% to 50%, of a-ia-4lable hydrosilation reacti-.?.e -=SiH groups ha-7e been reacted.

The indicated preparation of prepolymer can be conducted as a two stage procedure; in such instance, the polyene used, in ultimate preparation of the prepolymer, is itself first prepared in the same manner as the prepolymer.

in this regard, such polyene is obtained by heating a mixture of hydrosilation catalyst, silicon compound, and initial polyene - those polyenes discussed herein being suitable as such initial pcl-.,--ne - to effect- the hydrosilation reaction; more spec if ical 1"_,r, the p,:)-':io-=-ne can be prepared in the manner as set frth in LE1BFRIED '134 and LE-MFRIED '809.

it is noted that besides being suit-able in this two ]_ 5 stage procedure - i.e., for preparation of the pri-=-,po'L,_,,mer oi the third embodiment of the present -in-jent-i--%n - this pc.!,-,,en.-::-, s "kewise suitable, as the polvent- for crosslinkable cor..n7,s-it:-ons of the in-,rention where the pre-pollymer is not i.e., in the second embodiment.

_U For preparation of this the an-- p r 2 p -- rt s c- f - - - that there 'c a large --f carbon-carbon dc5ubl=- C---.Js h il at i G n - c, rati., of h-.-drosilation react.7C- carb--n-carbGn double irJ-al ncl-.;ene, to iFI grGups c.- silicon compound, is between about 2:1 and about 10:1. Excess initial polyene which remains after this reaction removed by any suitable method, such as conventicnal stripping - e.g., by distillation under vacuum.

In the resulting polyene, the ratio of total hydrosilation reactive carbon-carbon double bonds, contributed thereto by the initial polyene, to hydrosilat-L3.-, reactive =-SiH groups, contributed thereto b-i the silicon compound, is preferably at least 1.8:1, or at least about 1.8:1; more preferably, it is greater than 1.8:1, or great.-:-r than about 1.8:1. Still more preferably, this ratio is greater than 1.8:1, or about 1.8:1, and up to 2.2:1, or about 2.21:1; most preferably, it is greater than 1. 8:1, or about 1.8:1, and up to 2.0:1, or about -1.0:1.

In the formation of this resulting polyene, the hydrosilation reactive sSiH groups, which have been contributed thereto by the silicon compound, are full-Y, cr at!---ast substantiall,,,, fully, reacted with the h-,drosilation-reacti7.-e carbon-carbon double bonds w.-.ich 1-a-.-EI ik---, :4 se been contributed b-,, the ini tial pol,.ene. subs- -ial--,, f,:11v" means =ext, "a:: leas, L ant - r T.-- r e, o f t h e a S 4;. H a r 2 u p s h a b- e e n r e- a C -s t--, such hvdrosilaticn-reac_-.-e carbon-c-art-n j_-.=_=- b3nds contr- lbuted by the initial polvene, thcse which ha',---not been thusly reacted, with the indicated -=SiH groups, ar.-a-.-ailable for further hydrosilation. The resulting polyene 1 3 6, -is accordingly pro-,,-ided with at least two h-7drosilation- reactive carbon-carbon double bonds.

Of th, jL hydros latJ-,n react'-re carben-carbon double I i - -1. -.1.

bonds thusly contributed, but not reacted -,..it-h the =-SiH groups, such hydrosilation carbon-carbon double bonds which are part of the thusl-.'reacted initial polyene which, in turn, is now part:--f the resulting pol-,,ren-= accordinal-.- be a-,-ailable for reaction with hydrosilation fur-:,r s4L"---n compound, in. the r.--acti-.re ESiH groups e., - - he second stage of the indicated stage pr:eedure. This second s--aje is preparati= -,4 he cr-sslinkalk-l- r, and can be conducted - with such resulting polvene, and s-ch further silic.on compound - in the manner for preparing lir-.Lkable organosilicon prepc-IL.-.-WLer, as pre-ii3usly c--c,ss L- A 4 -io cf total As t, such two stage prepclymer, the rat.

It h-,,dr,s4L.';.a---':)n reacti-,-e -arbor.-carb--ln bends, c.:nt-ribu,-;---d thereto by such resulting p,:1-,.-:-ne, to - Z h-i-dres--1at.Gn 7atal-.-st aria P-.,-ene are mixed and heated i f_= a Ths 37 - complex and the poly(organohydrosiloxane) are thereafter combined, and, as with respect to the previously discussed organosilicon prepolymer, suitable reaction conditions are utilized to obtain the requisite prepolymer.

Particularly, the reaction mixture is heated to about 400 to 800C.; as previously discussed with reference to preparation of the organosilicon crosslinkable prepolymer, the reaction temperature is thusly maintained for several hours, then interrupted at the point where the requ_4site proportion of available hydrosilation reactive =-SiH groups have been reacted - preferably, for this poly(organohydrosiloxane) prepolymer, 5% to 60% thereof. More preferably, the polymerization is effected so that 30% to 60%, of such available hydrosilation reactive =-SiH groups, have been reacted.

As to the immediately following discussion, concerning suitable pclycyclic polyenes for obtaining the requisite poly(organohydrosiloxane) prepolymer, from the indicated lower temperature reaction, such discussion is provided : this matter at the according to the best understanding of -o limit the sc-_P4-present. This discussion is not intended t of the invention.

SpecifIcally, so that the requisite pcl-,-organ3h-.---=s-41oxane) prepolymer, preferably being flowabIe and heatcurable, can be obtained from such lower temperature reaction, even though the ratio of hydrosilation reacti-I-e 1 carbon-carbon double bonds to h-:drr--,sila7-i,:)n reacti,.?,e -=SiH groups is otherwise suitable for obtaining the crosslinked polymer, it appears that an appropriate polye-iclic polyene is required; suitable such pc-'ycyclic p-,1.-ien----s are those ha-jing chemically distinguishable h-7drosL-ation reacti-ie carbon-carbon double bonds, i.e., one such bond being more reacti-ie during hydrosilation than the other. These pol:jc,,,cl,c polvenes include, for example, c:jclopo=ntadienz- - -L - - -1. - - - oligomers such as di:--yelopentadiene and cyclopentadiene trimer, and methyl dic,-,,clopentad-J--ne.

Crosslinking, for the third embodiment, can be conducte-d according to the same- conditions as utilized for the first and second embodiments.

Yet further components, other than those pre-,-iGusly SP.=Cf-44--d, may be included in the in-.,ention; such component ma,17 be r-r:5---ided to the crosslinkable c---mpcsiti,:,ns of the in-.-.-:-ntion, and or, where a is em-o-'.o7=-d, in pre-naratl-,-:n of such _rrepol-,,mc-r, depending upon the prop=-r--s of the components and Further aS tc -omponents, it is that thz--!=-- are I- J, 7: 7 C For instance, what is identi -5, in LEE. ED '4,.'S, as the at least one second --,cmpound, lis a sui-Ea-l-'L;---- such - 39 __0 -5 additional component. This compcnent is particularly noted as one which can be provided to curable blends of the invention as a starting material, and/or employed in preparation of prepolymer.

Other yet additional further components include reaction rate modifiers, as disclosed in U.S. Patent No. 5,340,644.

Still additional further components include flame retardants, as disclosed in U.S. Patent No. 5,298,536.

As yet further examples of additional components, carbon black, carbon (graphite), quartz, aramid, and other polymeric fibers may be included in the curable blends of the invention; these materials are wetted very well by the liquid prepolymers of the invention, making them excellent matrix materials. Fiber can be in non-woven, unidirectional, woven, fabric, etc., form; suitable fibers and prepregs include those as discussed in BARD '360.

Additives such as fillers and pigments are also read-4-1 incorporated. Vermiculite, mica, wollastonite, calc4um carbonate, sand, silica, fumed silica, fused silica, ceramic beads, hollow glass, glass spheres, glass beads, ar--=d glass, waste glass and other mineral -Lllers are fillers which can be incorporated. Fillers as ri:-4nforcement cr as fillers and extenders to reduce cost of the molded product; glass spheres, in particular, are useful for preparing low density composites. Fillers ca i - 40 r also be used for other reasons, such as viscosity modification. F-illers can he present in amounts up to abcut 15% by weight cf the crosslinkable compositions of the invention, and in e-:en higher amounts, i.e., up to about 95% by weight, when glass fibers are not used.

In this regard, especial!y useful reinforcing fillers are spherical particles of fused silica, -Nhich can be included up to about 95% by weight. Heat conducting ceramic fillers can be used up to about 90% by weight; these are 4 useful in electronLC encapsulants, to remo-ie heat from electron 4 c de- iices.

Stabilizers (anti-oxidants, antiozonants, thermal and light stabilizers) are useful to maintain storage stability cf the monomers, prepclymers, and polymers, in crosslinka'le compositions of the invention, and thermal oxidati-ie stability, of the crosslinked products.:mong the preferred stab_41.1.zers are radical sca-.7-engers such as hindered phen-_,1s in cDrrd:inaticn with other stab-'-'-'z-_:rs. EsDeciallv useful exarr-,ples include bis(1,2,-',6,tD-pc--nl-ameth-,,1-4-riperidin:,"-,- as -.inu-:41.n1 1'4 Cita- zeicr-Y C--rp, te- r t - propionate; a-.?.ai'lable as ilaugard!! 76) from Uniroyal Chemical Co., M Z iS, -- -per, t ame t hy 1 - 4 -p ip e r i J ny 1 Middlebur_ CT) and bis(1,2,2,- sebacate) (available as Tinuvin' 765 from Ciba-Geigy Corp.). Stabilizers are generally used in an amount of about 0.5% to about 3.0%, based on the weight of the prepolymer of the curable blend. Generally, the stabilizers can be employed as disclosed in BURNIER '048, and in BUFDIER 1735.

One or more elastomers can also be added, preferably prior to crosslinking, to improve toughness, by incorporating elastomeric domains into the composition. Preferred are hydrocarbon elastomers having a molecular weight of less than 100,000 and low molecular weight siloxane elastomers. Exemplary hydrocarbon elastomers are low molecular weight ethylene-propylene-diene terpolymers, low molecular weight butyl rubber, partially hydrogenated low molecular weight polyisoprene or natural rubber, and partially hydrogenated i low molecular weight polybutadiene or styrene-butadiene copolymers. Exemplary siloxane rubbers include low molecular weight vinyl or SiH terminated polvdimethyl diphenyl siloxane copolymers. Preferred are low molecular weight ethylene-propylenedicyclopentadiene and --h%,leneprop,-,lene-ethvlidenenorbornene polymers having a molecular we'ght of 5500 to 7000. Most preferred is Trilene 65 e'astomer (available from Uniroyal Chemical Co.,,. The elastomer or elastomers are generally used in an amount of '10%, preferably 3 to 12%, and most preferably 5 to 0.5 to. 10%, by weight of the total composition; higher levels may i 0 _ 0 4 1211 - be useful in some applications. Generally, elastomers can be employed as disclosed in B-APITLI1 et al. '979 and BAP11M et al. '21117.

Generally as to the relati-7e proportions and different types of components used in preparing the crosslinkable and crosslinked compositions of the in-7entJon, these can be determined without undue experimentation, by those of ordinary skill in the art, according to a -jariety of factors. Such factors include, but are not limited to, the compatibility of such components, whether they will react with one another, and - they react with one t 4 another - the stoichicme--r-,, c,." the reac Lons which occur; still additional faetcrs concern the properties desired 4n the curable blend and cured p=duct.

i-n this regard, one set:,iE: propGr-icns to consider is the rat) of hydrosilation reacti-.-.= carbcn-carbor. double -c hydrosilation rc-act-J-.7--1 -- 1 timately bonds, t = H groups, u.

c,:,;ntirJ.buted from pol,Iene present) and the silicon compound, Jn preparing the. cirp-,sitJDns ef the in-jenticn - 1 -.f he pr pc.l -mer, or t the final,:rossl.Jnk;--d pr--duct. This rat-"- Js preferably In _. c --his ratio is in the range of 0.8:11, or about 43 - 0.8:1, to 1.2:1, or about 1.2:1. Most preferably, this ratio is 1:1.1, or slightly larger.

As to the specified most preferred range of 1:1.1, or slightly larger, considerations stated with respect to the preferred hydrosilation site ratios, for the crosslinkable prepolymers, are likewise of general applicability. There must be sufficient hydrosilation reactive =SiH groups, available for reaction with the hydrosilation reacti-je unsaturated carbon-carbon bonds of the polyphenylene oxide; accordingly, at least a slight excess of the -=SiH groups is preferred. Also as noted, with respect to the discussion of hydrosilation site ratios for the crosslinkable prepolymers, the suitability of higher molecular weight polyphenylene oxides for crosslinking, where only a slight excess of hydrosilation reactive =SiH groups are available, is likewise of general applicability.

Particularly as to the amount of polyphenylene oxide, relative to the other components, this amount is not critical. The minimum amount of hydrosilation react-J-,-e components to be used, other than po'L-_, rphenylen-=- oxide, is that which will still permit crosslinking to be th,s amount being about 1% by weight of the c-omposit-'n; a22cr.d-Jngly, up to about 99% by weight pol-,-phen...Ie--may be employed. The maximum amount, of components ot-her than polyphenylene oxide, is that which will maintain the desirable properties afforded to the composition, by the j 44 presence of the polyphenylene oxide; this amount is about f the composition, consequently providing 40% 60% by weight o., by,,, eight, as being the minimum amount of polyphenylene oxide preferably to be present.

The compositions of this invention can be coated, molded, or compounded to make useful fabricated forms. Coating inorganic, glass, or metal under ambient cond 4 tions can provide corrosion protection for costly assemblies. The low polarity compositions pro-,ride cDhesi-ie and adhesiie coatings with very low propensity for the absorption of atmospheric moisture. This and the low d _4 electric constants make them excellent protective coatings and encapsulants for sensitive electronic parts.

The compositions of this invention may be used for impregnating reinforcements, to obtain reinfcrced composite; articles; further, they may be coated onto fibers to make composite laminates, and fabricated into useful structures. The fluid compositions will coat glass, aramide or carbon fibers as fillaments, mats -,r cloth and can be partially cured to pro-.,Ide forms which aree eass-41y processed intz, laminate-s or other compos ite- f Drms, such as pr inte-J c ir-, I-ari s--s-ra--s.

I- - r ':, J -z The -mpssit-J=.s can 4 _:

be -_.t di'-:-S C M rJimtruded or molded parts directly. Typical ly, glass non-woven mats or cloth are placed in the mold and --h-fluid composition is injected tc, 'Lill the moId, and cured in - place, to make the finished molded part. In the rimtrusion applications, glass or fiber roving is pulled through a die where the fluid polymer formulation is injected under pressure and cured thermally to make a rigid rod out of the roving before it leaves the heat zone of the rimtruder barrel. Rods, beams or other composite constructions can he made continuously by this process.

The invention is illustrated by the following Examples, which are provided for the purpose of representation, and are not to be construed as limiting the scope of the invention. Unless stated otherwise, all percentages, parts, etc. are by weight.

Examnle 1 PreTDaration of Polyphenylene Oxide Havina Two Hydrox,,,l is Groups, One on Either End of Polvmer (PPO-20H) - a,G)bis,'2,6-dimeth,;liDhenol)-pol,;(2,6-dimeth,,,1-1,4-)hen-.-lene oxide, 3 To a solution of 4-dimethylaminopyridine (28g, 0. mol) in 740 ml of methanol and 100 ml of water was added cuprous chloride (7.2g, 0.113 mol). AI'lir was passed through the reaction mixture for 15 min. A solution of te-t-ram=--th.;lbisphenol-A (66.24g, 0.23-1 mol) and 2,C- -1 1 1 in 1200 ml f -met.--.-'Lphenol (113.71g, 0.9'13 mol, .... as ad--e-d tc the reaction mixture. AJLr was passed The preci he reacion mixture for 18 hours. pitated pc-'-.-.ller was filtered and air dried at room temperature. Purification was carried out by precipitating a chloroform 46 - 1 j L solution of the crude polymer in 2.4 1 of methanol containing 40 ml of concentrated hydrochloric acid. The pale vello!a precipitate formed was collected and washed ivith methanol thor,ughly to give.178 g of the PPO- 20H. Prenaration of Pol-n)henyiene Oxide Having Two Hydrosilation Peacti'- e Carbon-l"arbon Unsaturaled Bonds, One on Eji-ther End of -Polymer, from the PPO---(,'jH - Bis-yinvlbenzvlether, of the PPO-20H (PPQ-2.TB1 To a solution of the PPO-2'1JH 1100g, 0.09 equi-Talents of OH;, in 800 ml of chloroform, was added 50% aqueous sodium hydroxide (10.8g, 0.135 mol) dropwise. -Lfter addition of tetrabutylammonium hydrogen sulfate (3.4g, 0. 01 mcl) and 300 t 4 ml of water, the color of the reac.on mixture turned to yellow- green from dark b='.%7n. M4xture of m,p-vinylbenzyl chloride f25g, 0.16 mol) was added to the react4on mixture and stirring was continued for 18 hours. Thin-laver 20H starting chrc,matography analysis showed that the PPO- material had disappeared. The organic layer was separated I of from. the aqueous layer and precipitated in 4.0 me-th.ansi. The- formed precipitate was collected, -dashed th mg-±hanoL d under -,-acuum.-1 1-211.1p. ±h= PrDduct sh3-.-.ed a clear prctcn sr-!:.

= -5.Z5 pprr, 55.-5 ppm ani p,-,-m ':zr Ether Terminated - -B) - - pp:-Z", with GMCS, anj tadiene, UsincT a-Plat-j.,,ijr-, H-,,drsilati-n Catal-.-st 1 47 - 3 An amount of the PPO-2VB (0.31g) was added to 0.58g dicyclopentadiene (8. 717 meq olefins) and 0.618g of toluene. To tt-his solution was added 0. 55g methylhvdrocyclosiloxanes and 0.08g of chloroplatinic acid complexed with DCPD (1123 ppm Pt in dicyclopentadiene) to give 59 ppm Pt in the crosslinking formulation.

The formulation gelled after stirring at room temperature for 72 hours. The formulation produced a clear, compatible gel in 3 minutes and 15 seconds at 154-,-". Exam-ple 2 Preliaration of Pol-;(2,6-dimeth.;1-1,4--, henviene:)xides PPO Catalyst was prepared by dissolving 1.23g of CuEr, in 15 ml of methanol. This solution was then transferred to a flask containing 1350 ml toluene and 32117g dibutylamine. The mixture was stirred vigorously while air was introduced; at a rate if 3.7 li'min near the bottom of the flask. A s1 iin cf -110g of 2,6-dimethylphenol dissol-7ed in 21 GLut- L'J g c f t,-luene was added over a period of 15 min while stirring and air flow continued. The reaction was stopped after 9 hcur-z - 1 Izzy e.-J-'ng the air flow and by addition cf 2.00 ml c. _% aa-.i--us a:etic acid. The organi: la...o--r..,as separa::.:--- anJ "1 1 methanol precpi, p=red into mI of - -ate the ...-h,'-h -...,as then dried under.-acuum at JI -hain All,.,lation cf the PP3 Six grams (6g) of the poly('-,6-dimeth:jl-1,4phen,-.,,;--.-.e 250 ml of dry toluene, and -.-g -,f s,.d-um cxide) is added to.

- 48 is added and dispersed by heating the mixture at for minutes. cocling to room tempe-rature, 6g of 1- chlorchexane is added. The re-action mixt-ure is heated 1zo 65-C for 1 hr, and 3.8g of all-,-1 chIcride is added. The toluene sclution is gradually added tc) 750 ml of methanol to precipitate the polymer. The is redissol-lred in -50 ml of toluene ande.xtracted 3 t.m;-:--s -,,,,ith 25,3 ml portions of water. The pol=er is by adding the -toluene solution tc, 150 mi --,f methawl. The pre-cipitated polymer is z dried under -,-acuum.

PreiDaratien of the Crosslinkal:-e raanesilicGn Pre-pG1,,-mer, fr,3m anj (MHCS:DCPZ Int:3 a bottle are ad-di-=,d.:,g of silcxanes Huls America, of and 0.759 ef a soluticyn acid in p-Enta.-dien.=-- ( 0. 1L59 C-PA, 10Cg D12PID, he-ated at 1-:,r I hr) react 4::n mixture- is st -Jrr4--5 at Ur.t-;'L eassential, T I., -5 G 1,71,11R ana7L.-.,s-is.

cr--- ss I inkabl is, organcs ilicen ymer,;. -!g c f the a'm--'L..'lated PPC, j - J - p- num catal-stHuIs 49 I 1.0 0 America), and 0.4 mg of tetramethylethylenediamine. A 0.2 mil coating of this solution is spun onto a glass plate and heated gradually to 250'C, to give a hard, clear, non-polar coating with excellent electrical properties (low dielectri:: constant, low dissipation factor, high resistance). Exami:)le 3 Aryl Ring and Side Chain Allylation of r,31v(2,6- dimethvl1,4--nhenvlene oxide) Butyl lithium (8.3 ml of 1.6 M solution in hexane) and i.Ijg of tetramethylethylenediamine are added to 370g of benzene. Eight grams (8g) of poly(2,6-dimethyl-1,4phenylene oxide) is added to the solution and stirred at 25"C for 24 hours. The resulting lithiated polymer is reacted with l.Ig of allyl chloride at 25"C by stirring for 1 hr. The resulting polymer is precipitated from the solution by gradual addition to 1 1 of methanol. For purification, the polymer is redissolved in 250 ml of toluene, and the resulting solution is extracted with thra-25D ml porticns of water. The polymer is reprecipitatej 'ntc methanol and dried under vacuum. - -SSI 4 -king the Ring and Side Chain -.1.11ylat-d PP-_ - r- - -S=' -le '2rcranosi'4-on - r -_:.nka L__ - -lated PPC The ar.1 rina and side chain all -;f crossi4nkable organosilicon prepol-, "Mer, pro:-pcare-, acccrdance with the procedure as set forth in Example 2, are dissol-:ed in lOg of tetrahydrofuran; 0.04g of PC0722 platinu:-.. ccmplex, and 0.3 mg of tetramethylethylenediamine, are added j - so to this solution. Mil coat4 0. 3 ing cf the solutLon, spun onto a silicon wafer and cured at 200-C for -1 hours, is hard _C -'_ t4 eS and clear, with exce-11ent el=-t-ical proper r 4 FinalLy, although the in-:en Lon has been described with reference tD par t4 cular means, materials, and embodiments, it should he noted that the in-.-ention is not limited to the 4 particulars disclosed, and e-:-:tends to all equi-.ralents within 4 the claims. the scope -..

51 - 1. A crosslinkable composition comprising:

(a) a silicon compound having at least two hydrosilation reactive =-SiH groups; and (b) a polyphenylene oxide having at least two hydrosilation reactive unsaturated carbon-carbon bonds; wherein at least one of the silicon compound and the polyphenylene oxide has more than two hydrosilation reactive sites.

n. The crosslinkable composition of claim comprising a hydrosilation catalyst.

further 1 3. The crosslinkable composition of claim 1, w.l,ere-n the silicon compound comprises a member selected f-rem group consisting of (a) crosslinkable orga.-.2silicon prepl-.1-,ers, lation reactJ- --,mpr-s ng the hydrosi. ---n crduct --f ri-aca.----z =prising the following:

(i) a polyene ha,.--Jng at 'Least two hydrosilation reactive carboncarbon double bonds; and (ii) a silicon compound, having at least tg2 h-.,.drosilation reactive - =SiH groups, and comprising at least - S.) one member selected from the group cons4St;ng of cyc polysiloxanes, tetrasilo=,-silanes, and linear pol-7siloxanes; lic wherein at least one of the polyene and the silicon compound has more than two hydrosilation reactije sites (b) cyclic pol-,-sil-,xanes; (c) linear polysiloxanes; (d) tetrasiloxysilanes; (e) polycarbosilanes; and (f) polyfunctional silanes.

4. The crosslinkable cor-,,z,sitJLon of claim 3, wherein the silicon compound comprises a cyclic polysiloxane ha-jing formula:

the If - z - 1 z - / ' \1 a can be the same- t:r JJ---- subst-tuted, a'kox-,, radical, or a substituted or unsu--sti-J--ur-ed aror.-,a.JJ.-- 53 or arylo.wy radical, n is an integer from _) to about 20, and R is hydrogen on at least two of the silicon atoms.

5. The crosslinkable composition of claim 3, wherein the silicon compound comprises a linear pclysiloxane having the formula:

i R ( R) 3 5 ' - 0 - 5 0-- 5 1 r R) 3 H wherein R, which can be the same or different, is hydrogen, or a substituted or unsubstituted saturated alkyl radical,; or a substituted or unsubstituted phenyl radical, at least two R's are hydrogen, and m is an integer from about: 0 1000.

of claim 3, where' 6. The crossl"Lnkable compos t -- s-J-11-- -- he __M compound comprises a ti:---rasiloxysilane ha-.-.inj the f--,rmula:

54 4 wherein R, which can be the same or different, is h--,dr-,gen, or a saturated, subs+t---Jtut--=id, or unsubstituted alkyl or alkox.; radical, Gr a subs ti tuted or unsubst-itute-d ar---.Tat---- or ar-l,lcx:; radicall, and is c.-. at least twG silicon atoms in the molecule.

7. The c_rosslinkable of claim 3, -,,,her-=-i4n the compound comprises a pG!ycarbcs-4lan--- selected from the g=up consisting of saturated and unsaturated polycarbos i lanes ha-.-ing the frmula:

j ,her;--'Ln R',..hich can be the same cr J s a t-4,- -a,--a' subst-ituted or unsubst-'tut----d a-'i-,,hat4i--- -,r aroma i_ and R, which can be the same or different, is hydrogen, or a substituted or unsubstituted alkyl or aryl radical, and at least two R's are hydrogen, and m is an integer of at least, 5.

8. The cross 14 nkable composition of claim 3, wherein the silicon compound comprises a polyfunctional silane selected from the group consisting of aliphatic, cYcloaiiphatic, and aromatic polyfunctional silanes ha,.7ing the formula:

1 R 1 R -5 1 1 i:

1 i 1 wherein R' is a substituted or unsubstituted aliphatic, aliphatic, or aromatic radical, and P., which can be- same- or clif feerent, is hydrogen cr a J c a, -, alk.1 ra at le:-ast- two R's are hydrogen, and n is an integer --f- an _ 2-,.

9. The crosslinkable composition of claim 1, gher--2aJL,- the polyphenylene oxide comprises a member selected from the i 0 6 - group consisting of homopol:lrrLer and c:Dp3Iymer pol-,Tjherrr-'ene oxides.

10. The crosslinkable composition of claim 9, wherein the polyphenylene oxide comprises a member selected from the group consisting of:

(a) polyphenylene oxides haT7ing the formula:

(D -. z - 1 1 j - n)-- "(D 1 1 (D:

wherein R, which can be the same or different, is h-,..drcTen, a-H,C- -H MC - I-"=' -, -CH,C-aCH, or and n.

1 is an integer =f at least- S; and b) polyphenylene exides ha-,-Jng the -formula:

- 57 C 2 3 C H 2 R C H 2 0 R -CH2R R -2 R C H 2 R R H 2 2 R C rH2 wherein R and n are as defined above, n can be the same or different, and Q is a multi-ring aromatic residue.

11. The crosslinkable composition of claim 10, where-n Q is the residue of a diphenolic compound.

12. The crosslinkable composition of claim 11, wherein Q comprises a member selected from the group consisting of j MOO - - CO:

-Cv-a- :; r rp - 1 1 1 i3.

T.he crosslinkable composition of claim 9,...,herein the polyphenylene oxide has h,dr- -:e silation reacti unsaturated carbon-carbcn bonds, and further comprises a radical c.ntain-L-ng --ne opposing ends, each terminate, - of the two hydrosilai--,n unsaturated carb,n-carl----,n b::nds.

1 1 - --:t.

1 1 j Lhe cross-Linkable comr,,:s.r--4on of claim 9, the a least two hydrosilation r;-:-act-4-jc- unsaturated carbin- carben -'---,nds consist essentialll.;:,f side chain unsaturation.

crosslinkable cf:--!aim 9, two h-,-dr--;s-4la-.-4rn Z zrssj".-nkabli= IL 5 A) a pol-yene ha-,--J-n.g at Ileast t-;:G h,;drcs-lation c:arbcn-carbon double bonds; 59 -- n j (b) a silicon compound, having at least two hydrosilation reactive =-SiH groups, and comprising at least one member selected from the group consisting of cyclic polysiloxanes, tetrasiloxysilanes, and linear polysiloxanes; and (c) a polyphenylene oxide having at least one hydrosilation reactive unsaturated carbon-carbon bond.

wherein at least one of the polyene, silicon compound, and polyphenylene oxide has more than two hydrosilation reactive sites.

17. A crosslinkable composition comprising:

(a) a crosslinkable organosilicon prepolymer, comprising the hydrosilation reaction product of reactants comprising the following:

(i) a polyene having at least two hydrosilation reactive carbon-carbon double bonds; and (ii) a silicon compound, having at least tw hydrosilation reactive =-SiH groups, and comprising at least one member selected from the group consisting of cyclic poL',-,,siloxanes, tetras iloxysilanes, and linear wherein at least one of the pol,,ene and the siliccn comnound has more than two hydrDsilat-'on sites; and (b) a polyphenylene oxide having at least cne hydrosilation reactive unsaturated carbon-carbon bond.

1 18. A crosslinked composition comprising the hydrosilation product of the crosslinkable composition of an-,r of the preceding claims.

Claims

19. An article of manufacture comprising the crosslinked composition of

Claim 18, wherein the article of manufacture comprises a member selected from -the group consisting of an electronic component comprising the crosslinked composition and an electronic component coated or encapsulated with -the crosslinked composition.

20. A crosslinkable or crosslinked composition substantially as hereinbefore described and/or exemplified.

1