Wacker Chemie Ag

Frank Sandmeyer

Georg Loessel

Herbert Barthel

Torsten Gottschalk-Gaudig

Marko Prasse

Arvid Kuhn

Young-Hyuk Joo

Hyun-Kwan Yang

Hans-Peter Weitzel

Richard Weidner

James Greene

Daniel Calimente

Enno Funk

Amitabha Mitra

Bernd-Josef Bachmeier

Oliver Minge

Amanda Andrews

Sarah Burke

Christoph Schosser

Daniel Hwang

Georg Lössel

Sebastian Knör

Markus Winterer

Claudia Katharina Hahn

Vanessa Koch

An aqueous dispersion along with methods for producing and uses for the same. Where the aqueous dispersion includes crosslinkable reactive silicone organic copolymers of ethylenically unsaturated monomers and of ethylenically functionalized silicone polymers and is obtainable by means of radically initiated miniemulsion polymerization in an aqueous medium.

Crosslinkable reactive silicone organic copolymers dispersions

Storage stable organopolysiloxane gels, preparable in commercial quantities are prepared by the hydrosilylation reaction of a silicone resin containing a hydrosilyatable group, a short chain Si&#x2014;H-functional silicone, and a long chain Si&#x2014;H-functional silicone.

Process for preparing organopolysiloane gels

Unique compositions containing organopolysiloxanes having both silicon-bonded hydrogen and aliphatically unsaturated groups exhibit robust processing characteristics and provide coatings or encapsulations of high transparency which can withstand numerous temperature cycles without failure.

Siloxane resin compositions

Aqueous dispersions of copolymers of ethylenically unsaturated monomers and silicone resins bearing functional groups which are free radically polymerizable are prepared by forming an aqueous miniemulsion of the silicone resin dissolved in an ethylenically unsaturated monomer, the miniemulsion having a Ddroplet size &#x3c;350 nm, and polymerizing using a free radical polymerization initiator.

Organocopolymer dispersions

Addition curable silicone resin compositions have excellent processing characteristics, and can be used to encapsulate electrical and electronic devices.

Multistep continuous and semicontinuous hydrolysis and condensation of chlorosilanes with alcohol containing minimal water in a column in a first step to form a silicone resin intermediate, followed by further condensation provides silicone resins in reproducible fashion substantially free of hydrogen chloride, without reactor gelatin.

Process for preparing organopolysiloxanes

Highly condensed silicon resins are obtained by a three step continuous procedure without the use of organic solvent, by preliminarily forming a partial alkoxylate by reacting a chlorosilane with alcohol containing no or a minimal amount of water, feeding the partial alkoxylate to a reaction column to form a silicone resin of low degree of condensation, and further condensing the silicone resin intermediate thus formed to produce a silicone resin product.

Method for producing organopolysiloxanes

Addition-crosslinkable silicone resin compositions containing a branched organopolysiloxane bearing each of Si&#x2014;H groups, alkenyl groups, and aryl groups, and also containing blocks of linear organopolysiloxane free of Si&#x2014;H and alkenyl groups with a chain length of at least three siloxy groups, and further bearing at least one aryl group, serve as excellent potting compositions for electronic devices, particularly LEDs, with high refractive index and optical transmittance, and wide processing latitude.

Silicone resin composition for optical semiconductors

Silicone resins with a weight average molecular weight of at least 5000 g/mol and polydispersity of &#x2266;65 are prepared by hydrolyzing and condensing:

Production of high-molecular-weight silicone resins

Particles with a structural surface which are useful to produce abrasion resistant self-cleaning surfaces contain particulate solid particles having a superstructured overlayer of fine particles. The particles may be prepared by polymerizing a polymerizable siloxane, silane, or mixture thereof in a Pickering emulsion.

Particles with structured surface

The invention provides copolymers of ethylenically unsaturated monomers and of ethylenically functionalized nanoparticles in the form of their aqueous polymer dispersions or water-redispersible polymer powders, obtainable by means of free-radically initiated polymerization in an aqueous medium and, if desired, subsequent drying of the resultant polymer dispersion, of A) one or more monomers from the group consisting of vinyl esters, (meth)acrylic esters, vinylaromatics, olef ins, 1,3-dienes, vinyl ethers and vinyl halides and, if desired, further monomers copolymerizable therewith, in the presence of B) at least one particle P having an average diameter of &#x2266;1000 nm, which is functionalized with ethylenically unsaturated, free-radically polymerizable groups, characterized in that B2) particles P used are one or more from the group of metal oxides and semimetal oxides, and/or B2) particles P used are silicone resins composed of repeating units of the general formula [RSiO] (II), where for at least 20 mol % of the respective silicone resin p+z=0, 1 or 3, and where B1) and B2) are each functionalized with one or more &#x3b1;-organosilanes of the general formula (RO)(R)Si&#x2014;(CR)&#x2014;X (I), where X is a radical having 2 to 20 hydrocarbon atoms and containing an ethylenically unsaturated group.

Growing community of inventors

Burgkirchen, Germany

Frank Sandmeyer