Dow Corning Corporation

Therese M Bauman

Chi-long Lee

James A Rabe

Alan L Freiberg

Todd S Klenk

John E Dietlein

David J Huebner

An apparatus for preparing foams exhibiting a uniformly small cell size, a minimum number of ruptured cell walls and a smooth surface from foamable curable compositions comprises means to transport the ingredients of a foamable, curable composition to the input of a static mixer in which the ingredients of the composition are blended to homogeneity prior to being extruded into an exit zone and through an exit orifice. The length to diameter ratio of the mixing zone and the diameter of the exit orifice are within specified ranges.

Apparatus for blending and dispensing foamable, curable organosiloxane

Apparatus and method for blending and dispensing foamable, curable

A foam mixer-applicator for mixing a two-part foamable composition includes a mixing head having a mixing chamber for impingement mixing of the two component parts of the foamable composition, which are supplied to the mixing chamber in a pre-pressurized state. The mixing head is sealingly connected to a dispensing head having a foaming chamber of a substantially greater capacity than the mixing chamber and an outlet port for discharging the foam composition after foaming and acquiring a higher, yet flowable viscosity. A pneumatic plunger system pushes the foamed composition through an outlet port of the dispensing housing onto a substrate.

Foam mixer-applicator with foaming chamber and method of using

This invention describes a method of producing a silicone elastomer from an emulsion. When the ingredients are mixed together, the resulting latex can be used immediately. Removing the water from the latex results in a silicone elastomer. The method combines (A) an anionically stabilized, hydroxyl endblocked polydiorganosiloxane, present as an emulsion of dispersed particles in water, the emulsion having a pH of greater than 9, (B) dialkyltindicarboxylate, (C) alkylorthosilicate, (D) colloidal silica, and optionally (E) water, admixing (A) and (B) only in the presence of (C) to produce a dispersion of the ingredients in water. The ingredients can be distributed into a two-part system for storage. One embodiment includes fibers, lauryl alcohol, or a mixture of both in the emulsion; then forms an open-cell, elastomeric foam by forming a froth from the emulsion and removing the water from the froth.

Method of producing a silicone water-based elastomer

A method of producing an emulsion of crosslinked polydiorganosiloxane admixes hydroxyl endblocked polydiorganosiloxane, alkoxy silicone compound, anionic emulsifying agent, and water. The mixture is homogenized, then the emulsion is admixed with surface active anionic catalyst. Maintaining the catalyzed emulsion, having a pH of less than 5, at room temperature allows the ingredients to react to raise the molecular weight of the polydiorganosiloxane and to crosslink the polymer. The reaction is halted by adding sufficient base to raise the pH to greater than 7. The resultant latex yields an elastomer upon removal of the water. When colloidal silica is also added to the mixture before homogenization, the final latex yields a reinforced elastomer upon removal of the water.

Method of producing aqueous latex of crosslinked polydiorganosiloxane

This invention relates to a method of producing silicone elastomeric foam of low density. The method mixes polydiorganosiloxanes having hydroxyl endblocking or vinyl endblocking or mixtures of both along with water to react with silicon hydride in the presence of platinum catalyst to release hydrogen gas to create a froth which cures to a foam. The combination of ingredients allows the manufacture of silicone foam having different combinations of properties than those obtained from previous methods. Embodiments of the invention also make use of specific profoamers and specific alcohols to further modify the properties of the foams produced. The method of this invention yields a low cost, low density, silicone elastomeric foam having physical properties which enable it to be used in cushioning and sealing applications.

Water-blown silicone foam

A method of producing elastomeric silicone foams from a two-part system is disclosed. The method mixes the ingredients then allows a froth to form and cure at ambient temperature to an elastomeric silicone foam. The method mixes a vinyl-containing polydiorganosiloxane (1), a hydroxylated polydiorganosiloxane (2), a platinum catalyst (3), an organohydrogensiloxane (4) and a profoamer (5). The profoamer is a resinous, benzene-soluble organosiloxane copolymer consisting essentially of SiO.sub.4/2 units, silicone bonded hydroxyl groups, (CH.sub.3).sub.3 SiO.sub.1/2 units, and fluorine-containing units. An embodiment of the method includes a liquified blowing agent and stores the mixture under superatmospheric pressure, forming a foam by releasing the mixture to atmospheric pressure. Another embodiment includes an alcohol in the mixture to provide a foam of lower density. when lauryl alcohol is used and the alcohol is mixed with (1), (3), and (5) before (2) is admixed, the foam has a Bashore resiliency of less than 20.

Method of producing elastomeric silicone foam

A method of producing elastomeric silicone foams from a two-part system is disclosed. The method mixes the ingredients then allows a froth to form and cure at ambient temperature to an elastomeric silicone foam. The method mixes a vinyl-containing polydiorganosiloxane (1), a hydroxylated polydiorganosiloxane (2), a platinum catalyst (3), an organohydrogensiloxane (4) and a profoamer (5). The profoamer is a resinous, benzene-soluble organosiloxane copolymer consisting essentially of SiO.sub.4/2 units, silicone bonded hydroxyl groups, (CH.sub.3).sub.3 SiO.sub.1/2 units, and fluorine-containing units. An embodiment of the method includes a liquified blowing agent and stores the mixture under superatmospheric pressure, forming a foam by releasing the mixture to atmospheric pressure. Another embodiment includes an alcohol in the mixture to provide a foam of lower density. When lauryl alcohol is used and the alcohol is mixed with (1), (3), and (5) before (2) is admixed, the foam has a Bashore resiliency of less than 20.

This invention discloses a method of controlling the relative physical properties of foams such as density and compressibility or density and Bashore resiliency for compositions which consist essentially of triorganosiloxy endblocked polydiorganosiloxane having at least two vinyl radicals, platinum catalyst, organohydrogensiloxane, and hydroxyl endblocked polydiorganoisiloxane. The relative values of the physical properties are adjusted by the addition of varying amounts of organic alcohol having from 3 to 12 carbon atoms to the composition.

Lower density silicone elastomeric foam

A composition useful in producing an open-cell, elastomeric silicone foam combines a silicone oil-in-water emulsion, which forms an elastomer upon removal of the water, with an aerosol propellant. When the composition is discharged to atmospheric pressure, a froth is formed. Removing water from the froth yields an open-cell foam. The froth is stabilized by surfactants, thickeners, or froth stabilizers selected from fibers or lauryl alcohol.

Silicone foam, water-based, aerosol composition

Moisture curable, foamable compositions that do not slump appreciably in the uncured state when applied on a vertical surface, consist essentially of an RTV elastomeric composition, from 10 to 50 weight percent of a liquified blowing agent and less than 12 weight percent finely divided filler. The RTV elastomeric composition comprises the product obtained by mixing at least two moisture curable polydiorganosiloxanes with an effective amount of a moisture reactive crosslinker. A graft copolymer derived from a liquid polydiorganosiloxane and an ethylenically unsaturated organic monomer constitutes from 5 to 80 weight percent of the polydiorganosiloxanes.

Growing community of inventors

Midland, MI, United States of America

Therese M Bauman