US4777205A — Electrically conductive compositions

Claim 1

Independent Claim 69 words

An electrically conductive curable organopolysiloxane composition comprising (1) an organopolysiloxane capable of being cross-linked, (2) a cross-linking agent which reacts with the organopolysiloxane (1) to form an elastomer, (3) silver coated mica particles in an amount of from 120 to 200 parts by weight per 100 parts by weight of organopolysiloxane (1) and (4) a sufficient amount of carbon black to prevent the composition from separating into two phases.

Claim 2

Dependent Claim 69 words

An electrically conductive curable organopolysiloxane composition comprising (1) an organopolysiloxane capable of being cross-linked, (2) a cross-linking agent which reacts with the organopolysiloxane (1) to form an elastomer, (3) silver coated mica particles in an amount of from 120 to 200 parts by weight per 100 parts by weight of organopolysiloxane (1) and (4) a sufficient amount of carbon black to prevent the composition from separating into two phases.

Claim 3

Dependent Claim 61 words

The composition of claim 1, wherein the organopolysiloxane (1) is represented by the formula R.sup.1 (SiR.sub.2 O).sub.x SiR.sub.2 R.sup.1 where R is selected from the group consisting of monovalent hydrocarbon radicals and substituted monovalent hydrocarbon radicals having from 1 to 18 carbon atoms, R 1 is a hydroxyl group and x is an integer having a value of at least 10.

Claim 4

Dependent Claim 61 words

The composition of claim 2, wherein R 1 is a hydroxyl group and the cross-linking agent is a silane of the formula R.sub.a SiX.sub.4-a where R is selected from the group consisting of a monovalent hydrocarbon radical and a halogenated monovalent hydrocarbon radical having from 1 to 18 carbon atoms, X is a hydrolyzable group and a is 0 or 1.

Claim 5

Dependent Claim 136 words

The composition of claim 2, wherein R 1 is a hydroxyl group and the cross-linking agent is selected from the group consisting of a polyalkoxysilane of the formula (R.sup.3 O).sub.n SiR.sub.4-n.sup.2 and a polyalkoxysiloxane, in which the silicon atoms are linked through ═ 13 Si--O--Si 13 ═ linkages and the remaining valences of the silicon atoms are satisfied by (R 2 ) and (R 3 O) radicals, where R 2 is selected from the group consisting of a monovalent hydrocarbon radical having from 1 to 10 carbon atoms and a halogenated monovalent hydrocarbon radical having from 1 to 10 carbon atoms, R 3 is a monovalent hydrocarbon radical having from 1 to 10 carbon atoms, n is 3 or 4, and the composition further contains a metallic salt of an organic carboxylic acid as a catalyst.

Claim 6

Dependent Claim 13 words

The composition of claim 4, wherein the catalyst is an organic tin compound.

Claim 7

Dependent Claim 21 words

The composition of claim 1, wherein the carbon black has a surface area of from 40 to 1500 m 2 /g.

Claim 8

Dependent Claim 13 words

The composition of claim 2, wherein the organopolysiloxane (1) is a hydroxyl-terminated polydimethylsiloxane.

Claim 9

Dependent Claim 30 words

The composition of claim 1, wherein the carbon black is present in an amount of from 1 to 8 parts by weight per 100 parts by weight of organopolysiloxane (1).

Claim 10

Dependent Claim 51 words

The composition of claim 1, wherein the composition contains carbon black in an amount of from 2 to 6 parts by weight per 100 parts by weight of organopolysiloxane (1) and graphite in an amount of from 0 to 5 parts by weight per 100 parts by weight of organopolysiloxane (1).

Claim 11

Dependent Claim 44 words

The composition of claim 3, wherein the cross-linking agent has an average of more than two hydrolyzable groups per molecule, selected from the group consisting of hydrocarbonoxy groups, substituted hydrocarbonoxy groups, acyloxy groups, amino groups, oximo groups, aminoxy groups, acylamino groups and phosphato groups.

Claim 12

Dependent Claim 115 words

The composition of claim 1, wherein the organopolysiloxane (1) is represented by the formula R.sup.1 (SiR.sub.2 O).sub.x SiR.sub.2 R.sup.1 where R is selected from the group consisting of monovalent hydrocarbon radicals and substituted monovalent hydrocarbon radicals having from 1 to 18 carbon atoms, R 1 is a monovalent hydrocarbon raicals having aliphatic unsaturation and the cross-linking agent is an organohydrogenpolysiloxane of the formula ##STR2## where R 4 is selected from the group consisting of hydrogen, monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals having from 1 to 18 carbon atoms in which at least two of the R 4 groups are hydrogen and m is 1, 2 or 3 and further contains a platinum catalyst.

Claim 13

Dependent Claim 69 words

The composition of claim 1, wherein the organopolysiloxane (1) is represented by the formula R.sup.1 (SiR.sub.2 O).sub.x SiR.sub.2 R.sup.1 where R is selected from the group consisting of monovalent hydrocarbon radicals and substituted monovalent hydrocarbon radicals having from 1 to 18 carbon atoms, R 1 is selected from the group consisting of a monovalent hydrocarbon and, monovalent hydrocarbon radical having aliphatic unsaturation and the cross-linking agent is a peroxide.

Claim 14

Independent Claim 117 words

A method for preparing a silicone elastomer having electrically conductive properties which comprises mixing (1) an organopolysiloxane having terminal hydroxyl groups with (2) a silicon compound having an average or more than two silicon-bonded hydrolyzable groups per molecule which is capable of reacting with organopolysiloxane (1), (3) silver coated mica particles in an amount of from about 120 to 200 parts by weight per 100 parts by weight of organopolysiloxane (1), in which the mica particles contain at least 50 percent by weight of silver based on the weight of mica, and (4) a sufficient amount of carbon black to prevent the composition from separating into two phases, and thereafter exposing the resultant composition to atmospheric moisture.

Claim 15

Independent Claim 117 words

A method for preparing a silicone elastomer having electrically conductive properties which comprises mixing (1) an organopolysiloxane having terminal hydroxyl groups with (2) a silicon compound having an average or more than two silicon-bonded hydrolyzable groups per molecule which is capable of reacting with organopolysiloxane (1), (3) silver coated mica particles in an amount of from about 120 to 200 parts by weight per 100 parts by weight of organopolysiloxane (1), in which the mica particles contain at least 50 percent by weight of silver based on the weight of mica, and (4) a sufficient amount of carbon black to prevent the composition from separating into two phases, and thereafter exposing the resultant composition to atmospheric moisture.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-10-11	1992-04-11	1992-10-11	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-10-11	1996-04-11	1996-10-11	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-10-11	2000-04-11	2000-10-11	$7700.00	Window Closed / Lapsed

Electrically conductive compositions

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