Sealant butyl

Table 7. One-Part Solvent-Releasing Butyl Sealant Formulation ...

Adhesives and Sealants. Various grades of chloriaated paraffins are used as nonvolatile iaert fire-retardant plasticizers and modifying resias ia adhesives and sealants (3). They find wide appHcation ia polysulfide, polyurethane, acryUc, and butyl sealants for use ia building and constmction. The low volatihty high chlorine types are also employed ia sealants for double- and triple-glazed wiadows. 

One-part solvent-releasing butyl sealant formulation, 22 43t One-part urethane sealants, 22 36-37 One-pass clarifier, 22 61 One-photon absorption, 77 455 One-pot oxidation polymerization, 23 713 One-stage separation plants, 75 840 One-step cameras/processors, 79 276-278 One-step Ziegler process, 77 715-718 One-way memory, of shape-memory alloys, 22 341, 345-346... 

Reactive fibers, 9 486-489 Reactive flame retardants, 11 474-479 brominated, ll 475-477t Reactive gases, 13 456 Reactive groups, types of, 9 178 Reactive hot melt butyl sealants, 22 44 Reactive hot melt polyurethanes, 22 37-38 Reactive hot melt silicones, 22 35 Reactive ion-beam etching (RIBE), 22 184 Reactive ion etching (RIE), 20 278 22 183 of lotus effect surfaces, 22 120 Reactive lead alloys, 14 779 Reactive liquid metal infiltration process, 16 168... 

Solvent-releasing acrylic sealants, 22 43 Solvent-releasing butyl sealants, 22 43-44 Solvent resistance, of polycarbonates, 79 799-801... 

Bulyk. Butyl-based materials are sold in the form of preformed tapes, thermoplastic hot melts, and one-part solvent-releasing sealants. Butyl polymers are made by the copolymerization of 97-98 mol % isobutylene with 2-3% isoprene. Another butyl-based polymer, polyisobutylene, is produced by the polymerization of isobutylene. Formulations of butyl-based sealants also include plasticizer, filler, and lackifier resins. Poly butenes are common plasticizers for butyl sealants. Solvents, such as mineral spirits, are used for the one-part solvent-releasing formulations. As the solvent leaves the typical one-part butyl, the sealant hardens and loses its elastomeric ability. This limits the use of solvents to low movement applications where durability is not of high concern. 

Thermo-SeaL DHJB. Fuller] Hot butyl sealant... 

The new steel panels used in vehicles are not as heavy as in older cars but, being thinner, are not as strong. The use of PU windshield adhesive/sealants to replace the traditional butyl sealants has enabled the windshield to become a structural part of the vehicle because it supports the roof. OEM adhesives are typically one-component moisture-cured urethanes that take several hours to cure and give bonds with tensile shear strengths of 5-8 MPa. The products are pigmented black to give resistance to UV. After-market adhesives... 

Special materials used in butyl sealants or as primers to obtain bonds of PIB-based products to specific substrates such as glass are various organic silanes. An example is an epoxy silane... 

Poly isobutylene, PIB, is a homopolymer of high molecular weight. The butyl elastomers are copolymers of isobutylene with sufficient isoprene (0.5-2.5%) to permit crosslinking. Most butyl compositions are one-component, e.g., tapes or liquid gun-grade caulks. They may be modified with plasticizers such as polybutene, or tackifiers and fillers such as calcium carbonate and fibrous talc. Two-component, curing butyl sealants are also available. 

Two-Component Sealants.Two-component butyl sealants are room temperature vulcanized materials. Low in moisture vapor transmission and easy working because of low molecular weight and semi-liquid form, these sealants are filled with calcium carbonate and titanium dioxide, plasticized with polybutene, and may be modified with epoxy and silane adhesion promoters. The cure system is p-qui-none dioxime activated with a peroxide. 

Medium movement sealants show versatility. Latex sealants offer compatibility with latex paint in that they are suitable for coating and provide ease of cleanup. This allows them to be used as an interior sealant under paint finishes. Butyl sealants have good adhesion to most surfaces and good resistance to water. This leads to their use in such places as door thresholds, flashing, metal and vinyl siding, and duct end pipe penetrations. 

Kutch, E. F., Hot Melt Butyl Sealant Provides High Adhesion Properties, Adhesives Age, 33 (Aug. 1973). 

Scheinbart, E. L., and Callan, J. E., A Systems Design Approach for Butyl Sealant Tape Manufacturing, Adhesives Age, 17 (March 1973). 

Concrete pipe seals - Butyl sealant tapes and neoprene rubber are frequently used as concrete pipe seals. The neoprene seals have very good chemical resistance. 

Newton, M.V. et al, 1986, "Butyl Sealants Formulating, Developing, Processing", ibid, pp 25-75. 

Kilchesty, AA., 1986, "Oleo Resinous and Oil-Base Caulking Compounds", ibid, pp 13-23. Newton, M.V. et al, 1986, "Butyl Sealants Formulating, Developing, Processing", ibid, pp 25-75. 

Butyl sealants are also formulated to be hot melt applied. These materials are formulated with high levels of tackifier and yield a solid sealant in rod or pellet or bulk form. The application temperature is about 180 °C. This type of sealant has been used to manufacture insulated glass where the high impermeability of poly(isobutylene) can be put to use. 

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