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  • 1
    Electronic Resource
    Electronic Resource
    Chemical Aspects of Offset Printing (1994)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 336 (1994), S. 377-389 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the last ten years, offset printing has achieved the broadest application on the printing market due to its inherent advantages. Light sensitive offset plates for contact UV exposure are mainly used at present. The chemistry of these plates are based on the photoreactions of quinone diazides, diazo resins and radical photopolymers. For the further development of offset printing plates the improvement of the light sensitivity and extension of spectral sensitivity to the visible range is a market-driven requirement to realize transfer of computer stored informations by laser. For this requirement electrophotographic systems, systems based on silver halides and photoinduced polymerizations are most important. New literature data dealing with these systems in relation to printing plates are summarized.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19943360502
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  • 2
    Electronic Resource
    Electronic Resource
    Lichtinitiierte polymer- und polymerisationsreaktionen, 10Teil 9: cf.21.. Photoinduzierte zersetzung von diareniodonium- und triarensulfoniumsalzen durch kaliumtrisoxalatoferrat (1983)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 2409-2419 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to elucidate kinetics and mechanism of photoinitiation processes based on potassium trioxalatoferrate(III) (K3[Fe(cx)3])/ onium compounds/acrylamide (AA) interactions, photolysis and stationary photopolymerization were carried out. Diphenyliodonium chloride (Ph2I⊕Cl⊖) and triphenylsulfonium tetrafluoroborate (Ph3S⊕BF⊖4) were used as onium compounds. These compunds react with photolytically formed ·CO⊖2 radicals by an electron transfer mechanism. The resulting phenyl radicals were detected by spin trapping with nitrosodurene. The quantum yield of the decomposition of onium salts, φIn, depends both on their reduction potentials and concentrations. Thus, an efficient redox reaction between ·CO⊖2 radical and Ph3S⊕BF⊖4 is impossible because the former reacts faster with the Fe(III) complex. The ratio between rate constants of these competitive reactions (onium compound/Fe(III)) are 0,1 (Ph2I⊕Cl⊖) and 4 · 10-4 (Ph3S⊕BF⊖4). Only with the system K3[Fe(ox)3]/Ph2I⊕Cl⊖/AA a radically induced photopolymerization was observed. Both the rate and the quantum yield (φBr) depend on the Ph2I⊕Cl⊖ concentration. A correlation between φBr and √φIn was found.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1983.021841202
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  • 3
    Electronic Resource
    Electronic Resource
    Saturated polyesters as emulsifiers for emulsion copolymerization of unsaturated polyester resins with styrene (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 83-92 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Intramolecularly crosslinked macromolecules (ICM) from unsaturated polyesters (UP) and styrene, respectively from technical divinylbenzene (t-DVB), were prepared by emulsion copolymerization (ECP). Saturated polyesters of different compositions and molar masses between 1200 and 2400 were used as emulsifiers (ESP). The influence of molar mass and structure at various concentrations of the ESP on yield, number and diameter of the ICM and their composition was studied. For comparison, also sodium dodecyl sulfate (SDS) was used as emulsifier.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900110
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  • 4
    Electronic Resource
    Electronic Resource
    Lichtinitiierte polymer- und polymerisationsreaktionen, 26Teil 25: cf.27.. Elektrophile ringöffnungsreaktionen zwischen glycidylethern und ketonen oder aldehyden initiiert durch photoinitiatorsysteme (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 187-197 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: By the irradiation of benzoin derivatives in the presence of arene diazonium salts or aryl iodonium salts cationic species are formed, which initiate ring-opening reactions of 2,3-epoxy-propyl (glycidyl) ethers in the presence of ketones or aldehydes. 1,3-Dioxolane formation dominates over homopolyaddition reactions of glycidyl ethers. This method forms dioxolane in satisfactory preparative yields. The quantum yields of disappearance of phenyl glycidyl ether in acetone (ΦPGE) were measured in dependence of some system parameters. By the photolysis of benzil dimethyl ketal more catalytic species are produced as in the case of benzoin isopropyl ether or α-phenylbenzoin. The ΦPGE values for diazonium salts are higher than for iodonium salts, with triphenylsulfonium salts the reaction failed. With the anions of iodonium salts the following sequence for ΦPGE is observed: SbF6- 〉 PF6- ≫ SbCl6- = BF4- = 0. Because the key step of the catalyst formation is an electron transfer reaction between radicals produced by the photolysis and the onium ions, the concentration of the salts influences ΦPGE. Phenyl glycidyl ether reacts more rapidly than 2,2-bis(4-hydroxyphenyl)trimethylene diglycidyl ether and isobutyl glycidyl ether.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021870118
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  • 5
    Electronic Resource
    Electronic Resource
    Emulsifying properties of saturated polyestersDedicated to Prof. Dr. G. Manecke on the occasion of his 70th birthday (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 2933-2946 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Saturated emulsifying polyesters (EPE's) with terminal carboxyl groups were prepared by melt condensation from 1,6-hexanediol, 1,4-butanediol, phthalic acid, and adipic acid. The EPE's were characterized by molar mass, acid number, and hydroxyl number. Micelle formation of the EPE in the neutralized state was studied. The critical micelle concentration of the EPE is influenced by chain structure, chain length, temperature, and presence of electrolyte. A monomer mixture of styrene/unsaturated polyester (1 : 1 by wt.) was solubilized with different EPE's. On addition of NaHCO3 and NaCl the monomer mixture is optimally solubilized at a distinct concentration of electrolyte. At the optimal electrolyte concentration the solubilization of the monomer mixture is influenced by chain structure and chain length of the EPE.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021871218
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  • 6
    Electronic Resource
    Electronic Resource
    Dediazoniation of 2,5-di(n-butoxy)-4-morpholino-benzenediazonium tetrafluoroborate sensitized by zinc phthalocyanine tetrasulfomorpholide (ZnPcTSM) in di-n-butyl phthalate (1993)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 335 (1993), S. 449-454 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dediazoniation of 2,5-di-(n-butoxy)-4-morpholino-benzenediazonium tetrafluoroborate (1) sensitized by zinc phthalocyanine tetrasulfomorpholid (ZnPcTSM) is studied in di-n-butylphthalate. The life-time of singlet-excited ZnPcTSM (τs = 3.0 ns) is not decreased by 1 whereas the static fluorescence at 689 nm is quenched. Thus, a ground-state complex is formed, Keq = 1730 M-1 showing an absorption band at 714 nm. A similar complex is formed with mono-n-butylphthalate being present if di-n-butylphthalate was not distilled in a good vacuum (1 torr), Keq = 1545 M-1. The decay of the triplet state in the presence of 1 is adequately treated as a reaction from the triplet-excited ground-state complex. Keq of the ZnPcTSM-diazonium salt complex is also obtained from quantum yields of the sensitized dediazoniation. A rather low intersystem crossing quantum yield of the complex amounting to 0.17 is deduced. ZnPcTSM is also bleached, but much weaker than expected for an oxidative electron transfer.The system works well - even under air - in dibutylphthalate micro droplets in gelatine coated on a PET-base.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19933350510
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