Лако-красочные материалы — производство

The first anaerobic patents mentioned only the polyglycol dimethacrylates with tetraethy — lene glycol dimethacrylate (XV) as the dominant example [7,8]. Neopentylglycol dimetha­crylate (XVI) was first mentioned in a patent assigned to Borden [21]. The use of acrylic or methacrylic acids to improve adhesion to smooth surfaces was mentioned in a patent assigned to Loctite [22]. The use of diallylphthalate (XVII) and diallylphthalate prepoly­mer as comonomers with tetraethylene glycol dimethacrylate was claimed in a patent filed by Kalinowski [23].

A series of polyurethane polyacrylates were prepared by reaction of toluene diisocyanate (XVIII), other isocyanates, and isocyanate-terminated oligomers with hydroxyalkyl methacrylates [24]. These monomers could be tailored to provide the strength and toughness required for some structural adhesive applications. The incorpora­tion of hard and soft segments into the polyurethane backbones provided significant improvements in toughness, cure-through-gap, and cryogenic strength properties [25].

The use of monomethacrylates in anaerobic formulations was disclosed in a patent assigned to Loctite. Specifically mentioned were hydroxyethyl (XIX), hydroxypropyl (XX), cyclohexyl (XXI), tetrahydrofurfuryl (XXII), dimethylaminoethyl (XXIII), and glycidyl methacrylates (XXIV), and cyanoethyl acrylate [26]. Methacrylate esters containing residual carboxylic acid groups were prepared by the reaction of hydroxyethyl methacrylate with phthalic anhydride (XXV), pyromellitic dianhydride (XXVI), and benzophenonetetracarboxylic acid dianhydride (XXVII). The residual acid provided improved adhesion [27,28]. The reaction product of hydroxyalkylmethacrylates with maleic anhydride (XXVIII) also produced monomers with residual acid as well as additional curable unsaturation [29]. The dimethacrylates of the bisglycol esters of dicarboxylic acids were used to formulate anaerobic adhesives. Among the dicarboxylic acids mentioned were phthalic (XXIX), maleic (XXX), fumaric (XXXI), and malonic (XXXII) [30].

Three Bond Company used trimethylolpropane trimethacrylate (XXXIII) [31] and ethoxylated bisphenol A dimethacrylate (XXXIV) [32] in anaerobic formulations. These monomers have some advantages in providing improved heat resistance. At Henkel & Cie. dicyclopentadienyl methacrylate (XXXV) was used in anaerobic formulations with high strength [33]. Rohm and Haas has disclosed the use of dicyclopentenyloxyethyl acrylate (XXXVI) and methacrylate in anaerobic formulations [34]. These monomers provide good cure strength on metal parts that have not been degreased and also have lower odor and volatility than do the corresponding dicyclopentadienyl esters. Silicone methacrylates have been formulated by Dow Corning [35] and Toshiba Silicones [36].

Methacrylate esters have been prepared by the reaction of methacrylic acid with epoxies such as the diglycidyl ethers of bisphenol A (XXXVII) [37]. Methacrylate esters suitable for anaerobic adhesives have also been prepared by the reaction of glycidyl methacrylate (XXXVIII) with a hydroxyl-terminated polyester [38]. The reaction of isocyanatoethyl methacrylate (XXXIX) with polyols resulted in monomers that could be formulated into anaerobic adhesives and sealants [39].