Self-curing ceramicizable polysiloxanes

Claim 2

A polysiloxane having the formula: ##STR3## wherein: R' is an alkyl group having 1 to 4 carbon atoms; R" is hydrogen, a vinyl group or an alkyl group having 1 to 4 atoms; x has a value of from 1 to 2; y has a value of from 0 to 1; z has a value of from 0 or 1; with the proviso that x+y is 2, x+z is 2, y and z each has an average value of at least 0.75; and a and b each has an average value from 2 to 100.

Claim 3

A polysiloxane according to claim 1 wherein y is 1 and z is 1.

Claim 4

A polysiloxane according to claim 2 wherein the ratio of a to b is about 0.5:1 to 1:0.5.

Claim 5

A polysiloxane according to claim 3 wherein the ratio of a to b is about 0.75:1 to 1:0.75.

Claim 6

A polysiloxane according to claim 4 wherein the ratio of a to b is about 1:1.

Claim 7

A polysiloxane according to claim 3, wherein R' is methyl.

Claim 8

A polysiloxane according to claim 6, wherein one R" is a hydrogen in each endblocking unit.

Claim 9

A polysiloxane according to claim 6, wherein R" is a methyl group.

Claim 10

A polysiloxane according to claim 6, wherein one R" is a vinyl group in each endblocking unit.

Claim 11

A polysiloxane according to claim 6, wherein x, y, and z are each 1.

Claim 12

A polysiloxane according to claim 2 wherein a+b is about 4 to 100.

Claim 13

A polysiloxane according to claim 5, wherein R' is methyl; one R" is hydrogen or a vinyl group in each endblocking unit; x, y, and z are each 1; a+b is about 4 to 50; and the ratio of a to b is about 1:1.

Claim 14

A polysiloxane according to claim 12, wherein a+b is 10 to 50.

Claim 15

A process for the preparation of a polysiloxane having the formula: ##STR4## wherein: R' is an alkyl group having 1 to 4 carbon atoms; R" is hydrogen, a vinyl group or an alkyl group having 1 to 4 atoms; x has a value of from 1 to 2; y has a value of from 0 to 1; z has a value of from 0 to 1; with the proviso that x+y must equal 2, x+z must equal 2, y and z each has an average value of at least 0.75; and a and b each has a value from 2 to 100 which process comprises (1) reacting in the presence of a sulfonic acid catalyst with agitation at ambient or higher temperature and pressure at least one siloxane selected from (i) cyclic siloxanes selected from the group consisting of (OSiR'H).sub.c, (OSiR'CH═CH.sub.2).sub.c, (OSiR'.sub.2).sub.d, (OSiR'H).sub.e (OSiR'CH═CH.sub.2).sub.f, (OSiR'.sub.2).sub.e (OSiR'H).sub.f, and (OSiR'.sub.2).sub.e (OSiR'CH═CH.sub.2).sub.f wherein c and d are positive integers ranging from 3 to 10 and c and f are positive integers and e+f equals e or d; with at least one siloxane selected from group (ii) or group (iii); wherein group (ii) consists of endblocking disiloxanes of the formula: R".sub.3 SiOSiR".sub.3 and wherein group (iii) consists of linear siloxanes selected from the group consisting of R".sub.3 Si(OSiR'H).sub.g OSiR".sub.3, R".sub.3 Si(OSiR'CH═CH.sub.2).sub.g OSiR".sub.3, and R".sub.3 Si(OSiR'.sub.2).sub.g OSiR".sub.3 wherein g is a positive integer ranging from 1 to 100; and wherein in groups (i), (ii) and (iii) R' is an alkyl group having from 1 to 4 carbon atoms and R is hydrogen, an alkyl group having 1 to 4 carbon atoms, or vinyl group; (2) neutralizing the catalyst; and (3) vacuum stripping the polysiloxane.

Claim 16

A process for the preparation of a polysiloxane having the formula: ##STR4## wherein: R' is an alkyl group having 1 to 4 carbon atoms; R" is hydrogen, a vinyl group or an alkyl group having 1 to 4 atoms; x has a value of from 1 to 2; y has a value of from 0 to 1; z has a value of from 0 to 1; with the proviso that x+y must equal 2, x+z must equal 2, y and z each has an average value of at least 0.75; and a and b each has a value from 2 to 100 which process comprises (1) reacting in the presence of a sulfonic acid catalyst with agitation at ambient or higher temperature and pressure at least one siloxane selected from (i) cyclic siloxanes selected from the group consisting of (OSiR'H).sub.c, (OSiR'CH═CH.sub.2).sub.c, (OSiR'.sub.2).sub.d, (OSiR'H).sub.e (OSiR'CH═CH.sub.2).sub.f, (OSiR'.sub.2).sub.e (OSiR'H).sub.f, and (OSiR'.sub.2).sub.e (OSiR'CH═CH.sub.2).sub.f wherein c and d are positive integers ranging from 3 to 10 and c and f are positive integers and e+f equals e or d; with at least one siloxane selected from group (ii) or group (iii); wherein group (ii) consists of endblocking disiloxanes of the formula: R".sub.3 SiOSiR".sub.3 and wherein group (iii) consists of linear siloxanes selected from the group consisting of R".sub.3 Si(OSiR'H).sub.g OSiR".sub.3, R".sub.3 Si(OSiR'CH═CH.sub.2).sub.g OSiR".sub.3, and R".sub.3 Si(OSiR'.sub.2).sub.g OSiR".sub.3 wherein g is a positive integer ranging from 1 to 100; and wherein in groups (i), (ii) and (iii) R' is an alkyl group having from 1 to 4 carbon atoms and R is hydrogen, an alkyl group having 1 to 4 carbon atoms, or vinyl group; (2) neutralizing the catalyst; and (3) vacuum stripping the polysiloxane.

Claim 17

A process according to claim 14 wherein y is 1 and z is 1.

Claim 18

A process according to claim 15 wherein the sulfonic acid catalyst is trifluoromethanesulfonic acid.

Claim 19

A process according to claim 16 wherein the endblocking disiloxane is selected from the group consisting of ((CH.sub.3).sub.3 Si).sub.2 O (CH.sub.2 ═CH(CH.sub.3).sub.2 Si).sub.2 O and (H(CH.sub.3).sub.2 Si).sub.2 O.

Claim 20

A process according to claim 16 wherein the cyclic siloxane is selected from the group consisting of (OSi(CH.sub.3)H).sub.c (OSi(CH.sub.3)CH═CH.sub.2).sub.c and (Si(CH.sub.3)H)e(OSi(CH.sub.3)CH═CH.sub.2).sub.f.

Claim 21

A process according to claim 16 wherein the linear siloxane is selected from the group consisting of (CH.sub.3).sub.3 Si(OSi(CH.sub.3)H).sub.g OSi(CH.sub.3).sub.3 H(CH.sub.3).sub.2 Si(OSi(CH.sub.3)H).sub.g OSi(CH.sub.3).sub.2 H (CH.sub.3).sub.3 Si(OSi(CH.sub.3)CH═CH.sub.2).sub.g OSi(CH.sub.3).sub.3 H(CH.sub.3).sub.2 Si(OSi(CH.sub.3)CH═CH.sub.2).sub.g OSi(CH.sub.3).sub.2 H CH.sub.2 ═CHSi(CH.sub.3).sub.2 (OSi(CH.sub.3)H).sub.g OSi(CH.sub.3).sub.2 CH═CH.sub.2 and CH.sub.2 ═CH(CH.sub.3).sub.2 Si(OSi(CH.sub.3)CH═CH.sub.2).sub.g OSi(CH.sub.3).sub.2 CH═CH.sub.2.

Claim 22

A process according to claim 14 wherein the temperature ranges from about 25° to 100° C.

Claim 23

A process according to claim 20 wherein the catalyst is present in an amount ranging from about 0.02 to about 5 percent by weight based on the total weight of (i), (ii) and (iii).

Claim 24

A process according to claim 16 wherein the catalyst is neutralized by the addition of from about 0.04 to 10 weight percent based on the total weight of (i), (ii) and (iii) of an inorganic salt selected from the group consisting of sodium carbonate and sodium bicarbonate.

Claim 25

A process according to claim 16 wherein from about 0.5 to 5 times the equivalent weight of a solvent selected from the group consisting of acetonitrile, dimethylsulfoxide, and hexamethylphosphoramide is added to the catalyst.

Claim 26

A process according to claim 21 wherein the catalyst is neutralized by the addition of from about 0.04 to 10 weight percent of allyltrimethylsilane or hexamethyldisilazane based on the total weight of (i), (ii) and (iii).

Claim 27

A process according to claim 24 wherein the catalyst is neutralized by the addition of allyltrimethylsilane and vacuum stripped.

Claim 28

A process according to claim 24 wherein the ratio of a to b is about 1:1.

Claim 29

A process according to claim 24, wherein R' and R" are methyl groups.

Claim 30

A process according to claim 24, wherein R' is methyl; one R" in each endblocking unit is hydrogen or a vinyl group; x, y, and z are each 1; a+b is about 4 to 50; and the ratio of a to b is about 1:1.

Claim 31

A process according to claim 23 wherein R' is methyl; R" is methyl; x, y and z are each 1; a+b is about 4 to 50; the ratio of a to b is about 1:1; the solvent is acetonitrile; the catalyst is neutralized by the addition of 0.04 to 10 weight percent allyltrimethylsilane and vacuum stripped.