Abstract: The present invention relates to a high clarity water sensitive carboxylated nitrile rubber composition which is particularly useful in making photopolymer formulations for printing plates utilized in flexographic printing applications. The present invention more specifically discloses a high clarity water sensitive carboxylated nitrile rubber composition which is comprised of (a) a carboxylated nitrile rubber which is comprised of repeat units which are derived from about 30 weight percent to about 60 weight percent 1,3-butadiene, from about 30 weight percent to about 50 weight percent acrylonitrile, and from about 10 weight percent to about 20 weight percent methacrylic acid, and (b) from about 1 to about 10 phr of at least one organic acid which contains at least three carboxyl groups. The carboxylated nitrile rubber of this invention will typically have a Mooney ML-4 viscosity of less than about 80.

Abstract: The present invention relates to a high clarity water-sensitive carboxylated nitrile rubber composition which is particularly useful in making photopolymer formulations for printing plates utilized in flexographic printing applications. The present invention more specifically discloses a high clarity water-sensitive carboxylated nitrile rubber composition which is comprised of (a) a carboxylated nitrile rubber which is comprised of repeat units which are derived from about 33 weight percent to about 77 weight percent 1,3-butadiene, from about 15 weight percent to about 45 weight percent acrylonitrile and from about 8 weight percent to about 22 weight percent methacrylic acid and (b) from about 1 to about 10 phr of at least one organic acid which contains at least three carboxyl groups. The carboxylated nitrile rubber of this invention will typically have a Mooney ML-4 viscosity of less than about 80 and a volume swell of greater than 40 percent.

Abstract: The present invention relates to a high clarity water sensitive carboxylated nitrile rubber composition which is particularly useful in making photopolymer formulations for printing plates utilized in flexographic printing applications. The present invention more specifically discloses a high clarity water sensitive carboxylated nitrile rubber composition which is comprised of (a) a carboxylated nitrile rubber which is comprised of repeat units which are derived from about 30 weight percent to about 60 weight percent 1,3-butadiene, from about 30 weight percent to about 50 weight percent acrylonitrile, and from about 10 weight percent to about 20 weight percent methacrylic acid, and (b) from about 1 to about 10 phr of at least one organic acid which contains at least three carboxyl groups. The carboxylated nitrile rubber of this invention will typically have a Mooney ML-4 viscosity of less than about 80.

Abstract: Nitrile rubber can be synthesized by copolymerizing acrylonitrile and 1,3-butadiene in an aqueous emulsion. After these monomers have been polymerized, it is, of course, necessary to recover the polymer from the aqueous emulsion.

Abstract: By utilizing the process of the present invention, a free-flowing crumb rubber composition can be easily prepared on a commercial scale. This invention more specifically discloses a process for preparing a free-flowing crumb rubber composition which comprises the steps of:(1) adding a wax emulsion to a latex of a rubbery polymer to produce a latex which contains the wax, wherein the wax has a melting point which is within the range of about 40.degree. C. to about 175.degree. C.;(2) agitating the latex which contains the wax in a manner whereby the wax is distributed throughout the latex;(3) coagulating the latex which contains the wax to produce a slurry of wax coated crumb rubber in water;(4) recovering the wax-coated crumb rubber from the water in the slurry; and(5) drying the wax-coated rubbery polymer in a hot air medium under forced motion to produce the free-flowing crumb rubber composition, wherein the hot air medium is at a temperature which is within the range of about 20.degree. C. to about 99.

Abstract: A magnetic differential pressure indicator is provided for detecting and indicating a pressure differential thereacross that is greater than a predetermined value in a fluid system. A thermal lockout effective even at high internal fluid pressures prevents false actuation of the magnetic indicating means at low temperatures due to increased viscosity of the system fluid.