Resins illuminating formulations

Many investigators have studied the effect of binders and their percentages on the efficiency of illuminating formulations. In general, the luminosity and luminous efficiency increase to a maximum at =4—6% of the binder and thereafter decrease. It has also been reported that binders with high oxygen content, such as unsaturated polyesters and epoxy resins, improve the efficiency... 

With the advancement of polymer chemistry, a wide range of polymers are now available for use as binders for HEMs. The extensive use of polymers such as unsaturated polyesters, epoxy resins, epoxy-PS blends and VAARs as binders for illuminating formulations has been reported in the literature. The chemistry of unsaturated polyesters and epoxy resins has already been discussed in Chapter 4 on propellants. Some salient features of liquid PS and its blends with epoxy resin and VAARs are given in this section. 

Epoxy-Liquid Polysulfide Blends Epoxy resins in combination with liquid PSs appear to possess many added advantages as the elastomeric PS segments in epoxy chains impart permanent flexibility [18]. Epoxy-liquid PS blends have been reported as binders for Army illuminating formulations [8]. Similarly, novolac epoxy-liquid PS blends have been reported for inhibition of composite propellants [19]. 

For some applications, a refractive index is important. A match between the particle size of some barium grades and the refractive index of matrix material allows the formulation of products with desirable optical properties. A series of synthetic barium sulfates is produced by Sachtleben Chemie which have particle sizes between 4 and 10 pm. If the particle size of these barium sulfates is well coordinated with the refractive index of the matrix polymer, semi-opacity combined with translucency results. This permits the foimulation of a light disperser in lampshades or in illuminated advertising displays. The coirect particle size can be calculated from the equation d = (lOOn - 141)/2, where n is the refractive index of the resin and d the particle size of barium sulfate. 

Obviously Douda felt that a silicone resin binder was the right approach to a high illumination flare compn, for he next patented a formulation (Ref 11) Similar to the successful one de veloped during his earlier investigation. In his... 

Unsaturated Polyester Systems. Coatings in the furniture industry rely heavily upon resin formulations containing unsaturated polyesters, styrene, and photoinitiator (3,4,13,43,44). The imsaturated polyesters are synthesized using step-growth polymerization (see Polyesters, Unsaturated). Upon illumination, the carbon-carbon double bond in the imsaturated polyester and st5Tene copolymerize to form a cross-linked network (eq. 6). Equation 6 shows a generalized reaction scheme for an imsaturated polyester system. 

---