Abstract: Hot melt adhesive compositions are disclosed containing the reaction product of a resin linear organosiloxane block copolymer and an organosilane capping agent containing hydrolyzable groups.

Abstract: Amphiphilic organosiloxane block copolymers and methods for making them are disclosed. The compositions incorporate an amphiphilic “linear” segment with a “resinous” segment. For example, a polyether (A) modified PDMS (B) with (AB)n architecture and polydiorganosiloxane with Si—H end-groups can be reacted with a phenyl silsesquioxane resin bearing vinyl functionality to form an amphiphilic resin-linear copolymer.

Abstract: An organosiloxane block copolymer includes 65 to 90 mol % of diorganosiloxane units having the formula R12-SiO2/2 (I). These diorganosiloxane units are arranged in linear blocks which have an average of from 10 to 400 diorganosiloxane units per linear block. The organosiloxane block copolymer also includes 10 to 35 mol % of siloxane units that have the average formula R2x(OR3)ySiO(4-x-y)/2 (II). The siloxane units are arranged in nonlinear blocks having at least 2 siloxane units per nonlinear block wherein 0.5?x?1.5 and 0?y?1. In addition, each R1 is independently a C1 to C10 hydrocarbyl, each R2 is independently an aryl or C4 to C10 hydrocarbyl, at least 50 mol % of R2 are aryl, and each R3 is independently R1 or H. Moreover, the organosiloxane block copolymer has a light transmittance of at least 95%.

Abstract: Curable compositions of “resin-linear” organosiloxane block copolymers comprising a metal ligand complex are disclosed. The addition of a metal ligand complex to compositions of certain resin-linear organosiloxane block copolymers results in curable compositions having faster cure rates, and improved mechanical strength and/or thermal stability over similar compositions without the metal ligand complex.

Abstract: Curable compositions of resin-linear organosiloxane block copolymers having improved shelf stability are disclosed. A stabilizer compound is added to the resin-linear organosiloxane block copolymer which increases the temperatures needed to effect final cure of the compositions. In other embodiments, the present disclosure provides curable compositions of resin linear organosiloxane block copolymers having improved physical properties, such as improved toughness.

Abstract: A process for preparing resin-linear organosiloxane block copolymers is disclosed. The process involves an initial hydrosilylation reaction to link a linear organosiloxane block with a resin organosiloxane portion to form the resin-linear block copolymer. The resulting resin-linear organosiloxane block copolymer is further crosslinked to provide copolymer compositions that are useful as coatings for various electronics and lighting components.

Abstract: Optical assemblies comprising an optical device and a composition comprising a resin-linear organosiloxane block copolymer are disclosed. In some embodiments, the organosiloxane block copolymers has a weight average molecular weight of at least 20,000 g/mole and includes 40 to 90 mole percent disiloxy units of the formula [R12SiO2/2] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R12SiO2/2] per linear block, 10 to 60 mole percent trisiloxy units of the formula [R2—SiO3/2] arranged in non-linear blocks each having a weight average molecular weight of at least 500 g/mol, and 0.5 to 25 mole percent silanol groups. R1 is independently a C1 to C30 hydrocarbyl and R2 is independently a C1 to C20 hydrocarbyl. At least 30% of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains. Each linear block is linked to at least one non-linear block.

Abstract: A light guide has a transmission of greater than 90 percent, a refractive index greater than 1.4, and less than 10 haze percent. The light guide also includes an organosiloxane block copolymer having a weight average molecular weight of at least 20,000 g/mole. The organosiloxane block copolymer includes 40 to 90 mole percent disiloxy units of the formula [R12SiO2/2] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R12SiO2/2] per linear block, 10 to 60 mole percent trisiloxy units of the formula [R2SiO3/2] arranged in non-linear blocks each having a weight average molecular weight of at least 500 g/mol, and 0.5 to 25 mole percent silanol groups [?SiOH]. R1 is independently a C1 to C30 hydrocarbyl and R2 is independently a C1 to C20 hydrocarbyl. Moreover, at least 30% of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains.

Abstract: A process is disclosed for preparing a resin-linear organosiloxane block copolymer. The resin-linear organosiloxanes block copolymers prepared by the disclosed process may provide optically solid compositions which may be considered as “reprocessable”.

Abstract: A process is disclosed for preparing a resin-linear organosiloxane block copolymer by reacting a linear organosiloxane and an organosiloxane resin to form a resin-linear organosiloxane block copolymer. The resulting resin-linear organosiloxane block copolymer is then crosslinked to increase the average molecular weight of the resin-linear organosiloxane block copolymer. The resin-linear organosiloxanes block copolymers prepared by the disclosed process may provide solid, optically clear compositions which may be considered as “reprocessable.

Abstract: A curable resin formulation based on the modification of cyanate esters with silsesquioxane resins is provided for use in forming a cured composite structure or layer. More specifically, a resin formulation that generally comprises a silsesquioxane resin component having an equivalent weight of aromatic hydroxyl groups that is greater than 500 and less than 2,000 grams per mole of aromatic hydroxyl groups; a cyanate ester component; and optionally a catalyst is described. In this resin formulation, the silsesquioxane resin component is present in an amount greater than 10 wt. % of the total solids content of the resin formulation. The resin composite layer formed therefrom exhibits a glass transition temperature that is greater than or equal to 185° C., wherein this glass transition temperature decreases by less than or equal to 40% upon exposure to water at an elevated temperature for a predetermined amount of time.

Abstract: Resin-linear organosiloxane block copolymers combined with linear or resin organopolysiloxane components are disclosed. In some embodiments, the combination of resin-linear organosiloxane block copolymers with linear or resin organopolysiloxane components provides compositions having improved physical properties, such as improved toughness and flow behavior.

Abstract: A method for controlling morphology of a silicone organic block copolymer includes adding an MQ resin to the silicone organic block copolymer and annealing. The method is useful for forming thin films, which are useful in electronic device fabrication. The method is also useful for forming adhesives, release coatings, and reversible elastomers.

Abstract: Amphiphilic organosiloxane block copolymers and methods for making them are disclosed. The compositions incorporate an amphiphilic “linear” segment with a “resinous” segment. For example, a polyether (A) modified PDMS (B) with (AB)n architecture and polydiorganosiloxane with Si—H end-groups can be reacted with a phenyl silsesquioxane resin bearing vinyl functionality to form an amphiphilic resin-linear copolymer.

Abstract: Organosiloxane block copolymers, curable compositions, and solid compositions derived from these block copolymers are disclosed. The organosiloxane block copolymers comprise: 40 to 90 mole percent disiloxy units of the formula [R12—SiO2/2] 10 to 60 mole percent trisiloxy units of the formula [R2SiO3/2] 0.5 to 35 mole percent silanol groups [?SiOH] where R1 is independently a C1 to C30 hydrocarbyl, R2 is independently a C1 to C20 hydrocarbyl, wherein; the disiloxy units [R12SiO2/2] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R12SiO2/2] per linear block, the trisiloxy units [R2SiO3/2] are arranged in non-linear blocks having a molecular weight of at least 500 g/mol, and at least 30% of the non-linear blocks are crosslinked with each other, each linear block is linked to at least one non-linear block, and the organosiloxane block copolymer has a molecular weight (Mw) of at least 20,000 g/mole.

Abstract: A light guide has a transmission of greater than 90 percent, a refractive index greater than 1.4, and less than 10 haze percent. The light guide also includes an organosiloxane block copolymer having a weight average molecular weight of at least 20,000 g/mole. The organosiloxane block copolymer includes 40 to 90 mole percent disiloxy units of the formula [R12SiO2/2] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R12SiO2/2] per linear block, 10 to 60 mole percent trisiloxy units of the formula [R2SiO3/2] arranged in non-linear blocks each having a weight average molecular weight of at least 500 g/mol, and 0.5 to 25 mole percent silanol groups [?SiOH]. R1 is independently a C1 to C30 hydrocarbyl and R2 is independently a C1 to C20 hydrocarbyl. Moreover, at least 30% of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains.

Abstract: Hot melt adhesive compositions are disclosed containing the reaction product of a resin linear organosiloxane block copolymer and an organosilane capping agent containing hydrolyzable groups.

Abstract: Curable compositions of resin-linear organosiloxane block copolymers having improved shelf stability are disclosed. A stabilizer compound is added to the resin-linear organosiloxane block copolymer which increases the temperatures needed to effect final cure of the compositions. In other embodiments, the present disclosure provides curable compositions of resin linear organosiloxane block copolymers having improved physical properties, such as improved toughness.

Abstract: A process is disclosed for preparing a resin-linear organosiloxane block copolymer by reacting a silanol terminated linear organosiloxane and an organosiloxane resin containing hydrolyzable groups to form a resin-linear organosiloxane block copolymer. The resulting resin-linear organosiloxane block copolymer is then crosslinked to sufficiently increase the average molecular weight of the resin-ituted organosiloxane block copolymer by at least 50%. The resin-linear organosiloxanes block copolymers prepared by the disclosed process may provide optically solid compositions which may be considered as “reprocessable.

Abstract: Optical assemblies comprising an optical device and a composition comprising a resin-linear organosiloxane block copolymer are disclosed. In some embodiments, the organosiloxane block copolymers has a weight average molecular weight of at least 20,000 g/mole and includes 40 to 90 mole percent disiloxy units of the formula [R12SiO2/2] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R12SiO2/2] per linear block, 10 to 60 mole percent trisiloxy units of the formula [R2—SiO3/2] arranged in non-linear blocks each having a weight average molecular weight of at least 500 g/mol, and 0.5 to 25 mole percent silanol groups. R1 is independently a C1 to C30 hydrocarbyl and R2 is independently a C1 to C20 hydrocarbyl. At least 30% of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains. Each linear block is linked to at least one non-linear block.