Silicone heat-curable

Hydrosilation inhibitors, in paper release coating fabrication, 22 591-592 Hydrosilation silicone, heat-curable, 10 5 Hydrosilylation. See also Silylation monoallyl derivatives, 2 242 products of, 22 552-554 Hydrosorbic acid, physical properties, 5 31t Hydrostatic cooker, 12 81 Hydrostatic lubrication, 15 212 Hydrosulfide salts, oxidation of, 23 633 Hydrosulfite bleaching, 21 50, 52 of recycled pulps, 21 52 Hydrosulfite-induced reductive-cleavage, 9 439-140... 

Keohan FL, Lewis LN (1985) Heat curable silicone polyimide rubber compositions containing cyclometallized platinum phosphite compounds. US Patent 4634610 A... 

Chem. Descrip. Silicone polymer sol n. in toluene and IPA Uses Film-former, conformal coating, encapsulant tor electronic components, for elec, insulation and protection against moisture Features Produces clear elastomeric tilm with exc. heat stability and flexibility, providing protection from moisture, weathering, and vibration ready-to-use prod. flexible over wide temp, range good release props. heat curable... 

F. Dong, S. Diao, D. Ma, S. Zhang, S. Peng, Preparation and characterization of 3-chlo-ropropyl polysiloxane-based heat-curable silicone rubber using polyamidoamine den-drimers as cross-linkers. Reactive and Pimctional Polymers, ISSN 1381-5148 96 (November 2015) 14—20. http //dx.doi.Org/10.1016/j.reactfimctpolym.2015.09.005. 

Heat curable silicone (either elastomer or gel) has become an attractive device encapsulant. This heat curable silicone gel tends to have a slightly higher thermal... 

SURFACE DEFECTS AND MICROSTRUCTURE OF HEAT CURABLE SILICONE ELASTOMERS... 

Heat-curable rubber (HeR) These are typically silicon rubber compounded with catalyst, color, and additives mixed and milled into siloxane polymers. HCRs are often used in molded parts for high-temperature service or in applications that utilize their chemical and weathering resistance, but also see applications as seals and gaskets. 

A third generation of products is currently emerging in the silicone industry. These are heat-curable liquid materials specifically designed for the automated production of moulded parts and supported extrusions. This technology is described later in some detail and could represent a significant advance in processing during the next decade. 

For the purpose of this chapter we will not discuss the applications and technology of the RTV liquid materials as this generally falls outside the scope of rubber industry practice. Developments in the physics and chemistry of silicone elastomers has been covered in great detail elsewhere and recently reviewed by Warrick et al In this chapter an up-to-date treatment of compounding, processing and application technology relating to the commercially available heat curable products will be presented. 

Silicone and fluorosilicone elastomers that require heat for crosslinking generally use some form of peroxide as the curing agent. Non-peroxide addition cure systems are extremely efficient at high temperatures, but are normally only used in heat curable liquid systems (Section 5). 

The use of heat curable liquid silicone rubbers to manufacture a range of supported extrusions and moulded parts is a recent innovation in the development of silicone elastomer processing. For some years, addition cured RTV silicones have been available as heat curable liquid materials, but have never been widely used in this way for a number of reasons ... 

The new UV curable silicones afford an attractive alternative to standard heat activated materials for integrated circuit protection where high speed automated fabrication and assembly processes are desired. Additionally, the photosensitivity of these materials present other convenient processing opportunities. 

Typical physical properties obtainable with UV cured silicones are provided In Table I. Incorporation of reactive unsaturation into the silicone polymer backbone In combination with a photosensitization system provided the photocure capability. Properties of a standard heat-cured encapsulant developed for use on semiconductor devices, Dow Corning HIPEC R-6103, are provided for comparative purposes. Clearly, introduction of a photocrosslinking mechanism into a siloxane type composition has afforded the desired result. The one-part, solventless, UV curable silicone composition cured rapidly upon exposure to UV radiation, providing a cured composition which has retained the typical properties that make silicones so attractive for protection of semiconductor devices. 

Chem. Descrip. Silicone-modified EPDM elastomer Uses EPDM for automotive applies, such as radiator and heater hose, ignition cable, spark plug boots, and for appliance wire, molded elec, goods, rolls for copiers, laminating, coil coating Features General-purpose elastomer with optimum heat resistance peroxide-curable... 

With all of the aforementioned variables, hundreds of Pt-curable silicone products are available including heat-cured rubber, liquid injection moldable products and release coatings. There are also many curable products based on chemistry other than platinum condensation cure RTV, peroxide-cured and UV-cured epoxy silicones. With other functional groups and/or molecular weights, even more products are... 

Ultraviolet curing UV curing adhesives use ultraviolet light to initiate curing. This allows a permanent bond to develop without any need for heating. UV curable adhesives use various chemical systems, which include acrylics and acrylates, epoxies, polyurethanes (PUR), polyesters, silicones, vinyl and vinyl esters Aaylics are the most common components of UV curable adhesives. 

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