Abstract:
Curable adhesive compositions comprise combinations of organosiloxane MQ resins and liquid polyorganosiloxanes of specified viscosity and functionality. The compositions are substantially free of unreactive materials and are applied in the molten state. Depending upon the concentration of reactive groups on the resin and polyorganosiloxane, the compositions may also include a silane containing an average of more than two hydrolyzable groups per molecule. Preferred compositions develop excellent adhesion to a variety of organic and metallic substrates during curing under ambient conditions.
Abstract:
A silicone pressure-sensitive adhesive composition having high adhesion and tack while having a high percentage of adhesive failure when peeled from substrates is disclosed, said composition consisting essentially of(A) 50 to 80 parts by weight of an MQ organopolysiloxane resin;(B) 20 to 50 parts by weight of a polydiorganosiloxane having at least 3 alkenyl groups in its molecule, with the proviso that the alkenyl group content of said polydiorganosiloxane is 0.1 to 4 mole percent, the total amount of components (A) and (B) being 100 parts by weight;(C) an organohydrogenpolysiloxane crosslinking agent having, on average, at least 3 SiH groups per molecule, the amount of said organohydrogenpolysiloxane being sufficient to provide a molar ratio of said SiH groups of component (C) to said alkenyl groups of component (B) in the range of 0.1 to
Abstract:
There is disclosed a pressure-sensitive adhesive composition based on a silicone resin and a polydiorganosiloxane polymer wherein the resin component has a number average molecular weight of about 950 to 1,600 and consists essentially of triorganosiloxy (M) units and silicate (Q) units wherein the molar ratio M/Q is in the range 1.1/1 to 1.4/1, inclusive. The adhesives of the invention exhibit improved adhesion to low energy substrates such as polyethylene and polytetrafluoroethylene.
Abstract:
There is disclosed the use of a quaternary ammonium salt of an alkoxysilane as a dispersant for magnetic pigment particles in the preparation of magnetic recording media. The dispersant of the present invention can bind to the pigment particles and may be substituted for conventional phosphate ester dispersants which are incapable of binding to the pigment and tend to migrate to the surface of such media, thereby adversely affecting recording media performance.
Abstract:
This disclosure relates to a method for imparting durable press characteristics to textile fabrics containing cellulosic fibers. The fabric is impregnated with a homogeneous composition comprising a volatile liquid carrier and certain methoxylated, phenyl-substituted fluid organosilicon polymers, and is subsequently heated to effect crosslinking of the fluid organosilicon polymers.
Abstract:
A plasticized polyvinyl chloride composition consisting essentially of polyvinyl chloride resin and a polysiloxane fluid containing at least 10 mole percent of 3-chloropropyl functional siloxane units is described. The compositions have increased flexibility and reduced tendency to exude silicone to the surface.
Abstract:
A dielectric enhancement fluid composition having at least one organoalkoxysilane and an acid catalyst having a pKA less than about 2.1 and a method for using the composition to enhance the dielectric properties of an electrical cable having a central stranded conductor encased in a polymeric insulation and having an interstitial void volume in the region of the conductor, the method comprising at least partially filling the interstitial void volume of the cable with the composition. The fluid composition may further include an organometallic catalyst and a corrosion inhibitor.
Abstract:
An improved method for imparting excellent long-term dielectric performance to an in-service electrical cable section having a stranded conductor surrounded by a conductor shield encased in a polymeric insulation and having an interstitial void volume in the region of the conductor, the cable section having an average operating temperature T. The method comprising injecting a dielectric enhancement fluid composition into the interstitial void volume, the composition comprising at least one component selected from: (1) a water-reactive material selected from an organosilane monomer, the above organosilane monomer wherein at least one of the water-reactive groups has been substituted with a condensable silanol group, an oligomer oligomer of the above organosilane monomer, or a co-oligomer of the above organosilane monomer, the organosilane monomer having a diffusion coefficient at least about 15 times greater than the diffusion coefficient of its corresponding tetramer; (2) a water-reactive material similar to (1) having at least one group attached to silicon comprising 7 to about 20 —CH2— units; (3) a non-water-reactive organic material which has a diffusion coefficient of less than about 10−9 cm2/sec and an equilibrium concentration of at least about 0.005 gm/cm3 in the polymeric insulation, the above mentioned diffusion coefficients and equilibrium concentration being determined at temperature T; or (4) an organic compound having an equilibrium concentration in the polymeric insulation at 55° C. which is less than 2.25 times the equilibrium concentration at 22° C.
Abstract:
A composition comprising a polyolefin and an additive selected from cyclic siloxanes containing at least one aromatic group attached to silicon; linear siloxanes containing at least one aromatic group and a silanol content greater than 0.4 weight percent, and linear siloxanes containing at least one aromatic group and having a functional group convertible to a silanol content of greater than 0.4 weight percent by ambient hydrolysis conditions.
Abstract:
Phenyl containing siloxane fluids are added to transparent thermoplastic polymers to give transparent thermoplastics having improved internal lubrication. For example, PhSi(OMe).sub.3 is equilibrated with (Me.sub.2 SiO).sub.x to give a fluid containing 28 percent by weight phenyl radicals, a PhSiO.sub.3 /2 to Me.sub.2 SiO ratio of 0.72 and an OMe to Si ratio of 0.78. This fluid was added to polystyrene in amount of 1 percent by weight to give a transparent plastic which exhibits no bleed and had excellent surface lubricity.