MTQ/polysiloxane hybrid resins, method of making the same, and coating/potting compositions containing the same

Claim 2

A polysiloxane of the general formula: wherein: A is an acrylic-functional end group; R₁ and R₂ are each independently selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, haloalkyl, (meth)acryloxyalkyl, and (meth)acryloxyalkenyl; B is a multifunctional cross-linked polysiloxane moiety having a plurality of pendant hydroxy groups and comprising a multiplicity of monofunctional siloxane units (M), trifunctional siloxane units (T), tetrafunctional siloxane units (Q) wherein: p has a value of 0.5 when the associated oxygen atom is bonded to another silicon atom, and a value of 1 when the associated oxygen atom is bonded to other than a silicon atom, with the proviso that at least one p in each T and Q unit has a value of 0.5; each R is independently selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, haloalkyl, (meth)acryloxyalkyl, and (meth)acryloxyalkenyl; the concentration ratio of M units to the sum of T and Q units, M/(T+Q), in the cross-linked polysiloxane moiety is from about 0.55 to about 0.75; and n is 2 to 1000.

Claim 3

A polysiloxane according to Claim 1, wherein A is selected from the group consisting of: wherein R₃ is H or alkyl.

Claim 4

A polysiloxane according to Claim 1 or 2, wherein M/(T+Q) is from about 0.60 to about 0.70.

Claim 5

A polysiloxane according to any of Claims 1 to 3, wherein the concentration of acrylic functionality is from about 0.60 to about 1.40 meq/gm solid of the polysiloxane.

Claim 6

A polysiloxane according to any of Claims 1 to 4, wherein said linear polydiorganosiloxane chains are joined to (meth)acrylic functional end groups selected from the group consisting of (meth)acryloxyalkyl and (meth)acryloxyalkenyl.

Claim 7

A UV curable composition comprising a polysiloxane according to any of Claims 1 to 5 and a photoinitiatingly effective amount of a UV photoinitiator.

Claim 10

A process according to Claim 7, wherein the mole ratio of M units to the sum of T units and Q units, M/(T+Q), in said MTQ/silicone hybrid resin is from about 0.55 to about 0.75.

Claim 11

A process according to Claim 7 or 8, wherein (meth)acrylate concentration in said MTQ/silicone hybrid resin is from about 0.28 meq/gram about 2.54 meq/gram of said hybrid resin.

Claim 12

A process according to any of Claims 7 to 9, wherein (meth)acrylate concentration in said MTQ/silicone hybrid resin is from about 0.60 meq/gram to about 1.4 meq/gram of said hybrid resin.

Claim 13

A process according to any of Claims 7 to 10, wherein the reaction of said MTQ resin and said linear polydiorganosiloxane is carried out for sufficient time and under sufficient conditions to react a majority of hydroxyl functional groups of said MTQ resin.

Claim 14

A polysiloxane comprising a linear polydiorganosiloxane chain joined at one end thereof to an acrylic-functional end group, and joined at its other end to a cross-linked polysiloxane moiety comprising a multiplicity of monofunctional siloxane units (M), trifunctional siloxane units (T), and tetrafunctional siloxane unit (Q), wherein: the concentration ratio of M units to the sum of T units and Q units, M/(T+Q), in the polysiloxane moiety is from about 0.55 to about 0.75; the number of siloxy repeating units in the linear diorganopolysiloxane chain is from 2 to 1000; said polysiloxane moiety is formed as an MTQ reaction product having T and Q hydroxyl functionally, by reaction of M, T, and Q silane reactants, the MTQ reaction product being reacted with a linear polydiorganosiloxane having said acrylic-functional end group at one end thereof and at its other end a functional group which is reactive with said hydroxy functionally, to join said linear polydiorganosiloxane chain to said MTQ reaction product; and the polysiloxane comprises silanol groups in said polysiloxane moiety in sufficient quantity relative to the number of acrylic-functional end groups present to render the polysiloxane self-curable by exposure to UV radiation in the presence of a photoinitiator.

Claim 15

A polysiloxane comprising a linear polydiorganosiloxane chain joined at one end thereof to an acrylic-functional end group, and joined at its other end to a cross-linked polysiloxane moiety comprising a multiplicity of monofunctional siloxane units (M), trifunctional siloxane units (T), and tetrafunctional siloxane unit (Q), wherein: the concentration ratio of M units to the sum of T units and Q units, M/(T+Q), in the polysiloxane moiety is from about 0.55 to about 0.75; the number of siloxy repeating units in the linear diorganopolysiloxane chain is from 2 to 1000; said polysiloxane moiety is formed as an MTQ reaction product having T and Q hydroxyl functionally, by reaction of M, T, and Q silane reactants, the MTQ reaction product being reacted with a linear polydiorganosiloxane having said acrylic-functional end group at one end thereof and at its other end a functional group which is reactive with said hydroxy functionally, to join said linear polydiorganosiloxane chain to said MTQ reaction product; and the polysiloxane comprises silanol groups in said polysiloxane moiety in sufficient quantity relative to the number of acrylic-functional end groups present to render the polysiloxane self-curable by exposure to UV radiation in the presence of a photoinitiator.

Claim 16

A polysiloxane according to Claim 12 wherein the acrylic functional end group is selected from the group consisting of (meth) acryloxyalkyl and (meth)acryloxyalkenyl.

Claim 17

A polysiloxane according to Claims 12 and 13, wherein said linear polydiorganosiloxane chains are joined to (meth)acrylic functional end groups selected from the group consisting of (meth) acryloxyalkyl and (meth)acryloxyalkenyl.

Claim 18

A UV curable composition comprising a polysiloxane according to any of Claims 12 to 14 and an effective amount of UV photoinitiator.

Claim 19

A UV curable composition according to Claim 15, wherein the linear polydiorganosiloxane chain is a linear polydimethylsiloxane chain of from 2 to 1000 repeating units