Patents by Inventor Hansjoerg Vollmann

Hansjoerg Vollmann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5057398
    Abstract: A photopolymerizable composition that contains a polymeric binder, a polymerizable compound and photoinitiator combination comprising an N-heterocyclic compound and a halogen compound corresponding to one of the folowing formulas I and II ##STR1## in which X.sup.1 stands for chlorine or bromine,X.sup.2 and X.sup.3 are identical or different and denote X.sup.1, hydrogen or alkyl groups,Y and Z are identical or different and denote X.sup.1, hydrogen, CN or (A).sub.n --(B).sub.n --D,A is a phenylene group,n is 0 or 1,B is CO or SO.sub.2,D is R, OR, NHR, NH.sub.2, NR.sub.2 or CX.sup.1 X.sup.2 X.sup.3,R is an alkyl, cycloalkyl, aryl or heteroyl radical,W is a five or six-membered heterocyclic ring having from 1 to 3 heteroatoms, which optionally carries substituents and optionally a fused aromatic ring, andm is 1 or 2,is distinguished by an improved light sensitivity.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: October 15, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hans-Dieter Frommeld, Hansjoerg Vollmann
  • Patent number: 4594305
    Abstract: A liquid developer and a charge control substance for developing positively charged electrostatic charge images. The developer comprises an electrically insulating carrier liquid having a high resistance and a low dielectric constant and which contains a pigment or dye, a resinous binder, the charge control substance and conventional additives in dispersion or solution. The charge control substance is a negative-controlling graft copolymer soluble in an aliphatic hydrocarbon and is obtained by grafting a carboxylic acid N-alkenylamide onto polymers soluble in aliphatic hydrocarbons used as the carrier liquid. The carboxylic acid N-alkenylamide is a compound of the formula: ##STR1## in which R is hydrogen or C.sub.1 -C.sub.3 alkyl,R.sub.1 is hydrogen or C.sub.1 -C.sub.20 alkyl, andR.sub.2 is C.sub.2 -C.sub.4 alkenyl.
    Type: Grant
    Filed: June 12, 1985
    Date of Patent: June 10, 1986
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hansjoerg Vollmann, Heinz Herrmann