One of the purposes of the present invention is to provide an SiH group-containing polysiloxane emulsion composition having a less risk of expansion of a container due to the dehydrogenation reaction with time during storage, causing less deterioration in its performance, and having an excellent shelf life. Another purpose of the present invention is to provide an addition-curable silicone emulsion composition comprising the aforesaid emulsion composition and having excellent curability. Another purpose is to provide a cured film obtained by curing the aforesaid addition-curable silicone emulsion composition and having excellent light releasability from an adhesive. The present invention provides an emulsion composition comprising components (A), (B), (C) and (E): 100 parts by mass of (A) organohydrogenpolysiloxane having at least two hydrogen atoms each bonded to a silicon atom (i.e., SiH group) in one molecule, 0.1 to 20 parts by mass of (B) a nonionic surfactant, 0.01 to 50 parts by mass of (C) a buffer solution having a pH in a range of 4.0 to 6.0 at 25° C., and 30 to 10000 parts by mass of (E) water.

The present invention provides a new method by which polymers can be modified. The present invention provides a method for modifying a polymer including the step of: irradiating a reaction system containing a polymer with light to react the reaction system in a presence of a compound radical, wherein the compound radical is a radical containing one element selected from the group consisting of Group 15 elements and Group 16 elements, and a Group 17 element.

A polymeric liquid material formed of molecular building blocks of core-shell type architecture, wherein each building block consists of a hyperbranched polysiloxane core and a functional siloxane shell peripherally attached thereto, the material comprising bridging oxygen moieties (Si—O—Si), hydrolysable alkoxy moieties (Si—O—R) and organofunctional moieties (R′—Si—) and (R.sub.1-S1-R.sub.2) and less than 0.5 mass percent hydroxy moieties (Si—OH). The core has a degree of polymerization DP.sub.core in the range of 1.3 to 2.7, the shell is formed of R′-substituted siloxane moieties and has a degree of polymerization DP.sub.shell in the range of 0.3 to 2.5. At least 75 atomic percent of all Si atoms in the core are bonded exclusively to alkoxy or bridging oxygens, the remainder each being bonded to 3 oxygens and 1 carbon. The total Si to free hydrolysable alkoxy molar ratio in the material is 1:1.25 to 1:2.75, and the material has a viscosity in the range of 10-100,000 cP. A method for preparing the polymeric liquid material relies on first forming the hyper-branched polysiloxane core followed by a build-up of the functional siloxane shell. To do so, a reaction scheme based on adding stoichiometric amounts of acetic anhydride in a water-free environment is exploited.

A composite article and a method for insulating an appliance are disclosed. In general, the appliance is selected from the group of major, domestic or household appliances (e.g. ovens, stoves, ranges, etc.). The appliance has a first surface that defines a heating cavity, and a second surface opposite the first surface. The composite article comprises a backing layer spaced from the first surface, and an insulating layer sandwiched between the second surface and the backing layer. The insulating layer reduces heat transfer from the heating cavity to the backing layer (e.g. during use of the appliance). The insulating layer comprises a foamed silicone. The foamed silicone can be one formed via a hydrosilylation-curable silicone composition, a condensation-curable silicone composition, or a combination thereof. The insulating layer may comprise a foamed room-temperature-vulcanizing (RTV) silicone. The backing layer comprises a foamed polyurethane (PUR), a foamed polyisocyanurate (PIR), or a foamed PUR/PIR hybrid.

A composition for forming a foamed silicone elastomer is disclosed. The composition comprises: A) an organopolysiloxane having at least two silicon-bonded ethylenically unsaturated groups per molecule; B) an organohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; C) a hydrosilylation catalyst; D) a chemical blowing agent; and E) a physical blowing agent. The hydrosilylation catalyst C) is present in a catalytically effective amount. The chemical blowing agent D) has at least one hydroxyl (OH) group, and is present in an amount to provide a OH content >0 and <500 parts per million (ppm). The physical blowing agent E) undergoes a phase change from a liquid to a gaseous state during exposure to atmospheric pressure and a temperature ≥0° C. The blowing agents D) and E) are different from one another. A foamed silicone elastomer, and methods of forming the composition and foamed silicone elastomer are also disclosed.

A composition for a low refractive film, said composition comprising 10 parts by weight of a polysiloxane and 3 to 150 parts by weight of a volatile hydroxyalkylsilane. Based on the polysiloxane composition, films can be produced having a porous polysiloxane network and exhibiting a low refractive index of 1.4 or less and dielectric constant of 1.5 or less.

A liquid resin composition may include a base resin (A) in an amount of 100 parts by weight, a chemical foaming agent (B) in an amount of 2 parts by weight or more and 100 parts by weight or less, and water (C) in an amount of 1 part by weight or more and 30 parts by weight or less. The base resin may be a polymer that includes a hydrolyzable group bonded to a silicon atom, at least one reactive silicon group that is capable of being crosslinked by forming a siloxane bond, and a main chain that is constituted by an oxyalkylene-based monomer unit. The chemical foaming agent (B) may include a bicarbonate (B-1) and an acidic compound (B-2) having an acid dissociation constant pKa of 3.0 or less.

The present disclosure provides porous carbon-heteroatom-silicon inorganic/organic homogenous copolymeric hybrid materials, methods for their preparation, and uses thereof, e.g., as chromatographic separations materials. The present disclosure also provides methods of preparing porous inorganic/organic homogenous copolymeric hybrid materials, comprising two or more repeat units, comprising (a) preparing a polyoligomeric siloxane (POS) by partial condensation of tetraalkoxysilane, adding a heterocyclic silane, and further reacting the heterocyclic silane with the POS to thereby prepare a porous inorganic/organic homogenous copolymeric hybrid material, comprising a carbon-heteroatom-silicon functionality or (b) partially condensing an organic olefin, an alkenyl functionalized silane, an alkoxysilane, or a heterocyclic silane, or mixtures thereof, adding a heterocyclic silane, and further reacting the heterocyclic silane with the partially condensed polymer to thereby prepare a porous inorganic/organic homogenous copolymeric hybrid material comprising a carbon-heteroatom-silicon functionality.

Curable organopolysiloxane compositions contain (A) organopolysiloxane resins consisting of units of the formula

R.sub.aR.sup.1.sub.b(OR.sup.2).sub.cSiO.sub.(4-a-b-c)/2   (I),

with the proviso that in formula (I) the sum of a+b+c≤3, in at least one unit of the formula (I) b=1, in at least 50% of the units of the formula (I) a+b=1 and in at most 10% of the units of the formula (I) a+b=3, based in each case on all siloxane units of the formula (I) in organopolysiloxane resin (A), (B) organic compounds having at least one unit of the formula

CR.sup.3.sub.2═CR.sup.3—CO—Z—  d(II), (C) initiators, (D) fillers and (K) amines,
wherein the radicals and indices have the definition specified in claim 1. When coarse and fine grained fillers are employed, the composition can be used to mold artificial stone.

The present invention provides: porous spherical silicone rubber particles which have high light scattering performance; porous silicone composite particles; and a method for producing these particles. The porous spherical silicone rubber particles have pores inside the particles or in the surfaces of the particles.