Benzoyl cyclohexanol

The photoinitiator selected for this study was 1-benzoyl cyclohexanol (Irgacure 184 from Ciba Geigy), a compound known for its high initiation efficiency and the weak coloration of its photoproducts. The multifunctional monomer was an epoxy-diacrylate derivative of bis-phenol A (Ebecryl 605 from UCB). A reactive diluent, tripropyleneglycol diacrylate, had to be introduced in equal amounts, in order to lower the viscosity of the formulation to about 0.3 Pa.s. 

Photoinitiator/Peroxide or Hydroperoxide-Based Systems In these systems where useful effects occur [li], oxygen-centered radicals are generated the mechanism is not clear. In the same way, in the 1-benzoyl-cyclohexanol HAP/benzophenone BP system under air, the radicals that are formed after the a-cleavage of HAP consume oxygen and further allow the generation of a hydroperoxide ROOH whose decomposition is sensitized by BP, and so on. 

Chemical reactions with the radicals formed during the primary processes are also found to be responsible for synergistic effects, e.g. in a combination of 1 and 1 -benzoyl cyclohexanol 3. in aerated medium. A possible explanation [23] is based on the decomposition by 1 of the hydroperoxides arising from the oxidation of the radicals generated through cleavage of 3- The weak reactivity of these peroxy radicals compared to alkoxy and hydroxy radicals (Scheme 2) and the concommittant reduction of air inhibition due to the consumption of dissolved oxygen by excited benzophenone can be also invoked to account for the experimental observations. 

In the case of radiation-curable (e.g., UV) adhesives, TLC represents a very useful screening test for the presence of several characteristic photo-initiators, e.g., benzophenone, 2,2 -diethoxyacetophenone, 1-benzoyl-cyclohexanol, and 4,4 -dimethylaminobenzophenone (Michler s ketone). 

Materials. PiPP (18), PsBPP (20), PBPP (39), PTFEP (40), PMPP (41) and PtBPP (42) were prepared according to the literature. Methylmethacrylate (MMAM) and NJ -dimethyl-acrylamide (NNDMAAM) monomers were Aldrich products purified fi-om the stabilizers by vacuum distillation. Maleic anhydride (MA), 9,10-anthraquinone (AQ) and benzoyl peroxide (BPer) were purchased from Aldrich. 1-benzoyl-cyclohexanol (Irgacure 184) (IRG) was a Ciba Geigy product. All these chemical were used as received. The solvents were CErba analytical grade when necessary they were purified or dried with standard techniques (43),... 

Figure 3.84. Voxel obtained by irradiation of a mixed urethane acrylate oligomer and a urethane acrylate monomer in the presence of a mixture of benzoyl cyclohexanol and morpholino phenyl amino ketones at 780 nm using a 150-fs pulsed Ti sapphire mode-locked laser operating at 76 MHz, where light was focused by a 1.4 numerical aperture objective lens (a) scanning electronic microscopic images of the voxel and (b) longitudinal and lateral voxel size as function of the exposure time. (From Ref. [580] with permission of the American Institute of Physics.)...

The carbonyl group contained in the initiators that were used, a mixture of benzoyl cyclohexanol and morpholino phenyl amino ketones (inset of Fig. 13a), exhibits two kinds of triplet states nn and nn. However, according to selection rules of electronic transition, transitions are symmetry forbidden and transition are symmetry allowed. Therefore the... 

Prepn is by reaction of cyclohexanol (with caution ) with a mixt of 75% H202 and 0.01 vol % of coned sulfuric acid at 0°. The mixt is allowed to stand overnight under refrigeration. The 1-hydroxycyclohexyl 1-hydroperoxide formed (see also Vol 3, C598-L) is then esterified with benzoyl chloride in py at 0°. 

Nearly all the adipic acid manufactured, 98%, is made from cyclohexane by oxidation. Air oxidation of cyclohexane with a cobalt or manganese (II) naphthenate or acetate catalyst at 125-160°C and 50-250 psi pressures gives a mixture of cyclohexanone and cyclohexanol. Benzoyl peroxide is another... 

Cyclohexanol and cyclohexanone are made by the air oxidation of cyclohexane (81%) with a cobalt(II) naphthenate or acetate or benzoyl peroxide catalyst at 125-160°C and 50-250 psi. Also used in the manufacture of this mixture is the hydrogenation of phenol at elevated temperatures and pressures, in either the liquid or vapor phase (19%). The ratio of alcohol to ketone varies with the conditions and catalysts. 

Cyclohexene oxide was first prepared by Brunei from o-iodo-cyclohexanol and solid potassium hydroxide.1 It has also been obtained by the oxidation of cyclohexene with benzoyl hydroperoxide.2... 

Under appropriate conditions activated thiazoles are alkylated at the 5-position 2-amino 4-methylthiazole is alkylated in the 5-position by heating with /-butyl alcohol in sulfuric acid (24). Under similar conditions 4-methyl-2-phenylthiazole is alkylated by cyclohexanol. 2-Acetylamino-4-methylthiazole reacts with dimethylamine and formaldehyde to afford the corresponding Mannich base (25). 2-Hydroxy-4-methyIthiazole fails to react when submitted to Friedel-Crafts benzoylation conditions whereas it reacts normally in Gatter-mann and in Reimer-Tiemann formylation reactions yielding the 5-formyl derivative (26). 2,4-Dimethylthiazole undergoes perfluoroalkylation when heated at 200 °C for 8 h in a sealed tube with perfluoropropyl iodide and sodium acetate (27). 

If one allows betaine (73) to react with iV-benzoyl iV-phenylhydra-zine, one obtains iV.-N -dibenzanilidourea (76). The same compound is obtained by heating under reflux with water. A-Benzoyl-A-phenylhydrazinoformic ester (77) is formed using cyclohexanol and ethanol. 

Fischer esterification reaction. Thus, reaction of cyclohexanol with benzoyl chloride is the preferred method for preparing cyclohexyl benzoate. 

FIGURE 8.8 Magnetic field dependence for the photolysis of a series of benzoyl containing molecules in cyclohexanol solution obtained by time-resolved infrared spectroscopy of the carbonyl group of the resulting benzoyl radical. Key 1 = a,a,a-trimethylacetophenone, 2 = 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone, 3 = 1-benzoylcyclohexanol, 4 = 2-hydroxy-2-methy Ipropiophenone, 5 = benzoin, 6 = methyl ether benzoin, 7 = dimethyl ether benzoin, 8 = 2-dimethylamino-2-(4-methyl-benzyl)-l-(4-morpholin-4-yl-phenyl)-butan-l-one. 

Esterifications of benzoic acids with ethanol, N HCl ref. 14, p. 189. Reaction of benzoic acids with cyclohexanol, acid catalyst ref. 16. Reaction of benzoyl chlorides with ethanol ref. 14, p. 189. Reaction of anilines with formic acid ref. 14, p. 190. 

The photoinitiated crosslinking of three ethylene-propylene-diene copolymers (EPDM elastomers) has been investigated in a series of studies > > >9. Commercial EPDM samples were used containing the following dienes ethylidene-norbomene (ENB), dicydopentadiene (DCPB) and hexadiene (HD). The main photoinitiators used were benzoyl-1-cyclohexanol (PI) from Ciba-Geigy and 2,4,6-trimethyl-benzoyl diphenylphosphineoxide (APO) from BASF, which both are photofragmenting (formulas 3 and 4) ... 

---