Aliphatic resin

Polyfunctional aliphatic resins have exhibited high reactivity and degrees of cure with amines but problems of toxicity have diminished their usehilness and commercial interest. SoHd epoxy resins can be prepared by the taffy process or the advancement process. 

Another major area of use is in the field of adhesives. The main attractions of the material are the absence of a need for mastication, easy solvation of the polymer, which is supplied in a crumb form, the production of low-viscosity solutions and high joint strength. In conjunction with aromatic resins they are used for contact adhesives whilst with aliphatic resin additives they are used for permanently tacky pressure-sensitive adhesives. In addition to being applied from solution they may be applied as a hot melt. 

Those which contain a ring sturcture as well as an epoxide group in the molecule—the cyclic aliphatic resins. 

Compared with standard diglycidyl ether resins, the liquid cyclic aliphatic resins are paler in colour and have a much lower viscosity. Whereas in general the cyclic aliphatic resins react more slowly with amines, there is less difference with acid anhydrides. Table 26.7 provides data illustrating this point. 

Table26.7 Some properties of cyclic aliphatic resins...

Because of their low viscosity the liquid cyclic aliphatic resins find use in injection moulding and extrusion techniques, as used for glass-reinforced laminates. They are also very useful diluents for the standard glycidyl ether resins. 

The structure of aliphatic resins is difficult to determine as they contain straight-... 

A more quantitative estimation of compatibility can be obtained with the solvent cloud point test. The solvent cloud point is based on the idea that resins will be compatible with elastomers of similar chemical nature. Thus aliphatic resins will be effective tackifiers for aliphatic elastomers, such as natural rubber, while aromatic solvents are needed for aromatic elastomers, such as SBR. Solvent cloud point tests are carried out in three solvent systems which represent aliphatic, aromatic, or polar systems [16j ... 

An electric conductive rubber base containing carbon black is laminated with an electric conductive cover layer of phosphoric acid ester plasticizer and other ionic surfactants to prepare antistatic mats, where the covers have colors other than black. It is also reported that alkyl acid phosphates act as color stabilizer for rubber. Small amounts of phosphate esters are helpful in restoring reclaimed rubber to a workable viscosity [284,290]. Esters of phosphoric acid are used in the production of UV-stable and flame-retarded alkylbenzenesulfonate copolymer compositions containing aliphatic resins and showing a high-impact strength... 

Two types of epoxy resins are formed by this process (1) cycloaliphatic resins and (2) aliphatic resins. Of the many structures that can be synthesized by this process, the cycloaliphatic diepoxies offer the most interesting combination of properties. However, the aliphatic epoxy resins have the greatest utilization in epoxy adhesive formulation. 

DGEBA is the most commonly used epoxy in adhesive formulations. Although they may range from very simple, low molecular weight, primarily aliphatic resins to more complex, multifunctional, primarily aromatic materials. A wide choice of curing agents is available, in common with other applications. Schmidt and... 

Preparation of piperidine derivates required the conversion of the auxiliary s amine into an imine function. Subsequent Lewis acid promoted Mannich-Michael reaction with Danishefsky s diene gave aliphatic, resin-bound dehydropiperidi-nones 5. After cleavage, the yields of the obtained enaminones 6 ranged between 13 and 90% (Scheme 12.4). The diastereomeric ratios varied from 78 22 to 99 1. The authors reported that aliphatic substituted enaminones were formed with lower diastereoselectivity than aromatic products. 

Aromatic Radical Anion + White Oil + 0 ---------- Acids (aliphatic) + Resins... 

Other important uses are adhesives and coatings. A wide variety of resins, plasticizers, fillers, and other ingredients commonly used in adhesives and coatings can be used with styrene-diene-styrene triblock copolymers. With these ingredients properties such as tack, stiflfiiess, softening temperatures, and cohesive strength can be varied over a wide range. With aliphatic resin additives the block copolymers are used for permanently tacky pressure-sensitive adhesives, and in conjunction with aromatic resins they are used for contact adhesives. The copolymers can be compounded into these adhesives by solution or hot-melt techniques. 

Acyclic aliphatic resins differ from cyclic aliphatic resins in that the basic structure of the molecules in the former is a long chain, whereas the latter, as shown, contains ring structures. Two types of acyclic aliphatic epoxies are commercially available, namely, epoxidized diene polymers and epoxidized oils. 

Petroleum resins are a by-product of oil refining. Like hydrocarbon resins, a range of grades are produced. Aliphatic resins, which contain oligomers of isoprene, tend to be used as tackifiers, whereas aromatic resins, which also contain high levels of dicyclopentadiene, tend to be classed more as reinforcing systems. 

Chem. Descrip. Aliphatic resin, stabilized with 0.05% antioxidant (tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane) Uses Tackifier in pressure-sensitive and hot-melt systems, pkg. adhesives, coatings... 

Alternatively, photosensitive epoxy SU-8 can be used as both the core and cladding layer. The refractive index of SU-8 can be reduced by mixing it with at least 2.7 % (by weight) liquid aliphatic epoxy resin DER 353TM from Dow Plastics [13]. The SU-8/aliphatic resin mixture was measured to have n=. 590 at 2 = 633 nm, as opposed to = 1.595 for the unmodified SU-8. The... 

---