摘要:
A process for production of an assembly including several silicone elements crosslinked by polyaddition of ≡Si—H units onto ≡Si-alkenyl (preferably ≡Si-vinyl) units, the elements adhering to one another without detracting from their mechanical properties. The process includes: (I) forming (1st coating) a silicone element (i) with a liquid silicone preparation (i) containing polyorganosiloxanes (POS) A with ≡Si-vinyl units, (POS) B with ≡Si—H units, a platinum catalyst C; (II) crosslinking so that (i) has a surface density SD of unreacted, residual vinyl, per nm2, of 0.0100≧SD≧0.0040; (III) optionally repeating steps (I) and (II) n times to give n elements (i) that adhere to one another; (IV) forming (2nd coating) a silicone element (ii) with a liquid silicone preparation (ii) of the same type as described above; (v) crosslinking to give crosslinked (ii) that adheres to (i).
摘要:
The invention concerns a silicone composition crosslinkable into elastomer by hydrosilylation, in the presence of carbene-based metal catalysts. The invention aims at providing a composition of that type, stable over long periods at room temperature (one day to several months), without loss of its characteristic of being heat-curable by hydrosilylation and without generating secondary isomerization or coloring reactions. The invention is characterised in that the composition comprises: a polyorganovinylsiloxane(polydimethyl)(methylvinyl) siloxane; a polyorganohydrogenosiloxane; a platinum catalyst formed by a complex of formula C3 and optionally an acetylene crosslinking inhibitor, optionally a siliceous filler. The invention also concerns novel hydrosilylation catalysts of the metal complex type of formula C3 above. The life span of the potted single-constituent compositions of the invention is significantly increased
摘要:
A process for increasing the surface tension (“wettability”) of a silicone element crosslinked by polyaddition from a liquid composition containing one or more α, ω-dimethylvinylpolydimethylsiloxanes (PDMS), one or more poly(dimethyl) (methylhydrogenosiloxy)-α,ω-dimethylhydrogenosiloxanes, and a platinum crosslinking catalyst. The silicone surface is treated with a homogeneous atmospheric plasma using a plasma spraying apparatus having a rotating head with one or more plasma nozzles that are offset relative to the axis of rotation, each one being capable of generating a plasma jet whose axis is parallel to said axis of rotation. The articles to which the invention relate include composites of flexible substrate (e.g. textile)/silicone coating. Application: adhesive bonding of silicone surfaces crosslinked by ≡Si—H/≡Si-vinyl polyaddition.
摘要:
The invention relates to adhesive silicone elastomer compositions which can be crosslinked by polyaddition. The composition, crosslinkable by polyaddition (hydrosilylation), comprises: α/ at least one polyorganosiloxane (POS) bearing ethylenic and/or acetylenic unsaturations [POS with≡Si-(unsaturated) units]; β/ at least one polyorganosiloxane (POS) with ≡Si—H units; γ/ a catalytic combination comprising γ.1 at least one metallic catalyst (preferably platinum based), γ.2 and at least one crosslinking inhibitor; δ/ a filler; ε/ at least one adhesion promoter; ρ/ at least one POS resin; λ/ at least one thermal resistance agent; and φ/ optionally at least one other functional additive. Methods of making and using the subject composition are also described.
摘要:
A process for production of an assembly including several silicone elements crosslinked by polyaddition of ≡Si—H units onto ≡Si-alkenyl (preferably ≡Si-vinyl) units, the elements adhering to one another without detracting from their mechanical properties. The process includes: (I) forming (1st coating) a silicone element (i) with a liquid silicone preparation (i) containing polyorganosiloxanes (POS) A with ≡Si-vinyl units, (POS) B with ≡Si—H units, a platinum catalyst C; (II) crosslinking so that (i) has a surface density SD of unreacted, residual vinyl, per nm2, of 0.0100≧SD≧0.0040; (III) optionally repeating steps (I) and (II) n times to give n elements (i) that adhere to one another; (IV) forming (2nd coating) a silicone element (ii) with a liquid silicone preparation (ii) of the same type as described above; (v) crosslinking to give crosslinked (ii) that adheres to (i).
摘要:
Process for the continuous coating of a strip of paper or of a textile support using a silicone composition, comprising at least one POS A containing SiVi or SiOR groups, a POS B containing SiH groups and a catalyst C (for hydrosilylation or for dehydrogeno-condensation) and not corresponding to an LTC/FC silicone system, the said process comprising the following steps: step 1 in which conditions for homogeneously mixing the constituents A, B and C are used such that the homogeneity obtained is reflected by a DSC signature comprising a Gaussian peak for which the peak end temperature T3 is in the range from a value above 110° C. to 200° C., the said conditions making use of means for very precisely metering the constituents, means for premixing the constituents other than C and means for homogeneously mixing C with the premix(es) prepared; step 2 of conveying the homogeneous mixture to the coating site; step 3 of coating the support with the homogeneous mixture; and step 4 of crosslinking, in particular with thermal means.
摘要:
A silicone composition and the uses thereof, particularly as a coating on an airbag for protecting the occupant of a vehicle in the event of a collision, are disclosed. The aim is to provide a silicone composition suitable for coating onto the inner surface of the airbag while significantly reducing the weight of the resulting coating layer to form a protective coating having enhanced high-temperature, mechanical and substrate-adhesion properties. Said aim is achieved in that the composition is free of reinforcing mineral fillers and consists of a mixture of (1) at least one polyorganosiloxane with alkenyl groups bound to the silicon; (2) at least one polyorganosiloxane with hydrogen atoms bound to the silicon; (3) a cross-linking catalyst; (4) an adhesion promoter comprising (4.1) at least one alkoxylated organosilane, (4.2) at least one epoxy-functional organosilicon compound, and (4.3) at least one metal chelate and/or metal alkoxide wherein the metal is selected from the group which consists of Ti, Zr, Ge, Li, Mn, Fe, Al and Mg; (5) at least one polyorganosiloxane resin; and (6) optionally at least one cross-linking inhibitor.
摘要:
Single-component silicone elastomer compositions (SEA) are crosslinkable by polyaddition into self-adhesive state, contain at least one polyorganosiloxane (POS) including sites of ethylenic and/or acetylenic unsaturation {POS containing units ═Si— [unsaturation]}; at least one polyorganosiloxane (POS) containing units ═Si—H; a catalytic system including at least one metal catalyst and at least one crosslinking inhibitor; a filler; at least one adhesion promoter; optionally, at least one POS resin; optionally, at least one thermal resistance agent; and, optionally, at least one other functional additive, and are useful for gluing, assembling, sealing, e.g., joints, coatings, electrical, electronic and automobile engineering parts.
摘要:
The invention relates to a process for the adhesive bonding of fibrous supports using a silicone elastomer which is thermosetted by radical crosslinking using at least one peroxide. The silicone elastomer is inserted between the supports over at least a portion of the region of overlap of the supports, where the supports are held in contact in the region of overlap in an manner that prevents trapping of air at the interface between the supports. The supports containing the silicone elastomer are heated while in intimate contact to allow the adhesive bonding of the supports by crosslinking of the adhesive.
摘要:
The general field of the invention is that of airbags. The invention relates to a process for improving the tear strength and the combing strength of coated fabrics intended for uses in the field of inflatable bags using a silicone composition comprising an additive containing a polyorganosiloxane resin (V) and a calcium carbonate. After coating the composition onto the fabric supports and curing, the coated supports not only have optimum adhesion and crease resistance properties, but also have good properties in terms of combing strength and tear strength.