Silane-based adhesion promoters

Silane-Based Adhesion Promotion (Oxide Alternative Treatments). The silane-based process is an alternative to the copper oxide process. Silane can be used to bond epoxy to other materials. One end of the silane molecule bonds to the epoxy. If the other end of the molecule is modified to bond to the secondary material, the silane can serve as a bridge, greatly enhancing adhesion. It is commonly used in this mode to enhance the adhesion of epoxy to glass. It can be also used to enhance the adhesion of epoxy to copper. 

ToF-SIMS chemical imaging (often in conjunction with iXPS) also plays a role in the analysis of the interphase region of fully fabricated glass fibre composites, particularly interaction of silane based adhesion promoters with the resin matrix. ToF-SIMS is profitably used in the packaging industry (adhesives) and food industry (contamination of contents by the packaging). The technique allows examining phase-separation of blends in the surface [822]. 

Zircoaluminates are predominantly inorganic (50-75 wt%) metal organic adhesion promoters in contrast to the silanes (< 50%). As such, they are highly polar and do not dissolve appreciably or disperse easily in resin/solvent-based media. Thus, the user must employ a high shear mixer (Cowles in paint manufacture, Banbury in rubber manufacture) to achieve as fine and homogeneous a dispersion of ZA as possible within a given system. 

The hardener portion (Part B) may also be mixed with fillers, diluents, solvents, and other additives. Fillers may be mixed in the resin portion alone or partly in the resin and partly in the hardener portion. Adhesion promoters such as Dow Corning A-180 silane may also be added to enhance the adhesion of the filler particles to the resin or hardener. Examples include several electrically conductive epoxy formulations that were used to evaluate their electrical stability on non-noble metal surfaces. The base epoxy resin was the diglycidylether of bisphenol-F (DGEBF, equivalent wt. = 170 g). Methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and 4-methylphthalic anhydride were evaluated as curing agents with 4-methylimidazole as a catalyst. The manufacturing procedure was ... 

Sealant adhesion is improved by the incorporation of additives. Typical phenolic resin additives are Methylon AP-108, Durez 16674, Bakelite BRL 2741, and Resinox 468. Epoxies are also good adhesion promoters. Silanes (e.g., A-187 and A-189) are known to increase adhesion. Table 1 lists five types of sealant formulations suggested by Panek that are useful in several end applications [10]. Generally, the integral fuel tank polysulfide sealant consists of two parts 9 parts by weight of sealant base components mixed with 1 part by weight of accelerator. A typical composition is shown in Table 2. 

Properties Wh. milky liq. sp.gr. = 1.08 vise. < 100 mPa s pH 5-6 Aerosil K328 [Degussa/Aerosil Silanes Degussa AG/Aerosil Silanes] Chem. Descrip. Fumed silica aq. disp. based on Aerosil MOX 80 CAS 112945-52-5 EINECS/ELINCS 231-545-4 Uses Reinforcing agent, adhesion promoter, antislip agent, stabilizer, and surf, tackiness reducer in nat. and syn. latex, paints/coatings, adhesives, paper and cardboard, aq. emulsions, etc. 

Chem. Descrip. Methyl trimethoxy silane CAS 1185-55-3 EINECS/ELINCS 214-685-0 Uses Pigment and filler treatment in solv. and water-based systems primer reduces pigment separation and floating improves disp. adhesion promoter... 

EVA, adhesives adhesion promoter for solv., water-based, solventless, and povwJ. coaling systems pigment treatment copolymerized with styrene in formation of sol-gel composites RegiiaUxy SARA 313 reportable Manuf./Distrib. AP Resources Aldrich Fluka GelesI Sigma Trade Names Dow Coming Z-6030 Silane PC4100 Silane SilquesI A-174... 

One of the most frequent procedures in the formulation of adhesives is the addition of adhesion promoters. Of these, silanes are by far the most frequently used. The silanes form a multi-membered family of chemicals. Numerous publications have described aspects of silane chemistry and the applications of silanes [15-18]. Although many silanes are readily available, in many industrial formulations of adhesives the most frequently used of these are the primary amine and diamine versions because of their relatively low cost. However, these do not necessarily produce optimum benefits in adhesion for all applications. Guidelines for the selection of silanes best suited for specific applications would therefore be useful. These should be based on a fundamental understanding of the manner in which silane compounds affect the interface and interphase in adhesively bonded systems. The... 

A strong correlation has been shown to exist between initial bond strengths displayed by polymer and glass surfaces bonded by PU adhesives containing a variety of silane adhesion promoters and the acid-base interaction at substrate/adhesive interfaces. 

Ceramic brackets are used for aesthetic reasons, and they are commonly treated with Silane adhesion promoters, either a vinyl silane, typically methacryloxypropy-Itrimethoxysilane, coupling agent or a micro-crystalline roughened base to enhance mechanical retention. 

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