(JP2735463-B2)      A soln. of a low temp.-vulcanising carborane siloxane adhesive (I) is applied to the surface of a substrate and the solvent is allowed to evaporate to form a film of (I) on the surface. This is then brought into contact with the surface of a second substrate, opt. similarly coated, and the two surfaces are bonded together by application of heat and opt. pressure.    Alternatively, the adhesive film is formed on the surface of a third substrate from which it is removed and placed between the first and second substrates for bonding.    (I) comprises a polycarborane siloxane polymer (II) having vinyl gps. attached to 3-30 (pref. about 5)% of the carborane gps. in its backbone; a silane curing agent (III) contg. two terminal-SiH gps.; a hydrosilation catalyst (IV) comprising a complex of Pt, Pd or Rh; and solvent. A substrate having its surface coated with a film of (I) is also claimed.    (II) is pref. the reaction prod. of carborane bisdimethylsilanol (IIa) of formula HOSi(CH3)2(C-B10H10-C) Si(CH3)2OH, a dimethylbisureidosilane of formula (IIb) with R = Me, a cpd. (IIb) with R = Ph, and a cpd. (IIb) with R = vinyl, all ultra-purified. The method of prepn. is described in US Application 807,364. The resulting (II) has formula -(Si(CH3)2(C-B10H10-C) -Si(CH3)2-O-SiR(CH3)-O)n-; pref. R = Me:Ph:Vi = 63:32:5%. 7 Cpds. (III) are claimed; those contg. carborane gps. are pref. and esp. m-carboranebis (2-hydridotetramethyl-trisiloxane (IIIa) of formula HSi(CH3)2(OSi(CH3)2)n -(C-B10H10-C)-(Si(CH3)2O)n Si(CH3)2H with n = 1, and also the analogous novel cpd. with n = 2. (III) is used at molar proportion corresp. to 85-95% of the Vi gps. in (II). (IV) is selected from conventional cpds., used at a level equiv. to 5-75 ppm metal w.r.t. (II). Most pref. are Pt/siloxane complexes (4 claimed) and esp. Pt cyclovinylmethylsiloxane (IVa). The solvent is chlorobenzene (CB), benzene, toluene or CHCl3.    USE/ADVANTAGE -   Opt. the coated part(s) may be stored at low temp. (below -10 deg.C) for a long period of time prior to the bonding process. The adhesive is esp. used for bonding a solar cell cover glass to a solar cell (claimed), and for bonding such solar cells to an underlying substrate. The adhesive is capable of withstanding the harsh environment of space for long periods, and also the cyclic high temps. (250-350 deg.C) used to anneal the new high efficiency gallium arsenide solar cells to restore damage caused by high energy electron bombardment in space.    (JP2768890-B2)      A soln. of a low temp.-vulcanising carborane siloxane adhesive (I) is applied to the surface of a substrate and the solvent is allowed to evaporate to form a film of (I) on the surface. This is then brought into contact with the surface of a second substrate, opt. similarly coated, and the two surfaces are bonded together by application of heat and opt. pressure.    Alternatively, the adhesive film is formed on the surface of a third substrate from which it is removed and placed between the first and second substrates for bonding.    (I) comprises a polycarborane siloxane polymer (II) having vinyl gps. attached to 3-30 (pref. about 5)% of the carborane gps. in its backbone; a silane curing agent (III) contg. two terminal-SiH gps.; a hydrosilation catalyst (IV) comprising a complex of Pt, Pd or Rh; and solvent. A substrate having its surface coated with a film of (I) is also claimed.    (II) is pref. the reaction prod. of carborane bisdimethylsilanol (IIa) of formula HOSi(CH3)2(C-B10H10-C) Si(CH3)2OH, a dimethylbisureidosilane of formula (IIb) with R = Me, a cpd. (IIb) with R = Ph, and a cpd. (IIb) with R = vinyl, all ultra-purified. The method of prepn. is described in US Application 807,364. The resulting (II) has formula -(Si(CH3)2(C-B10H10-C) -Si(CH3)2-O-SiR(CH3)-O)n-; pref. R = Me:Ph:Vi = 63:32:5%. 7 Cpds. (III) are claimed; those contg. carborane gps. are pref. and esp. m-carboranebis (2-hydridotetramethyl-trisiloxane (IIIa) of formula HSi(CH3)2(OSi(CH3)2)n -(C-B10H10-C)-(Si(CH3)2O)n Si(CH3)2H with n = 1, and also the analogous novel cpd. with n = 2. (III) is used at molar proportion corresp. to 85-95% of the Vi gps. in (II). (IV) is selected from conventional cpds., used at a level equiv. to 5-75 ppm metal w.r.t. (II). Most pref. are Pt/siloxane complexes (4 claimed) and esp. Pt cyclovinylmethylsiloxane (IVa). The solvent is chlorobenzene (CB), benzene, toluene or CHCl3.    USE/ADVANTAGE -   Opt. the coated part(s) may be stored at low temp. (below -10 deg.C) for a long period of time prior to the bonding process. The adhesive is esp. used for bonding a solar cell cover glass to a solar cell (claimed), and for bonding such solar cells to an underlying substrate. The adhesive is capable of withstanding the harsh environment of space for long periods, and also the cyclic high temps. (250-350 deg.C) used to anneal the new high efficiency gallium arsenide solar cells to restore damage caused by high energy electron bombardment in space.