Provided is a process for preparing polythiols by preparing a sulfhydration reaction medium, simultaneously carrying out radical sulfhydration reaction of at least one polyene and acid-catalyzed sulfhydration reaction of the polyene and recovering a mixture including at least two polythiols. Also provided is a mixture of polythiols obtained from the process described herein.

Disclosed herein are systems and processes involving the catalyzed cleavage reaction of dimethyl sulfide to methyl mercaptan. The catalyzed cleavage reaction can be a standalone system or process, or can be integrated with a methyl mercaptan production plant.

Disclosed herein are systems and processes involving the catalyzed cleavage reaction of dimethyl sulfide to methyl mercaptan. The catalyzed cleavage reaction can be a standalone system or process, or can be integrated with a methyl mercaptan production plant.

The present invention relates to a novel polyol or polythiol having three or more functional groups, a preparation method there for, and an optical body manufactured therefrom. Especially, the present invention relates to a poly(thio)urethane-based resin and an optical body, such as lenses, manufactured using the resin, wherein the poly(thio)urethane-based resin is prepared by obtaining a novel polyol and then combining a polythiol, which is prepared from the obtained polyol, with a polyiso(thio)cyanate.

The present invention relates to a novel polyol or polythiol having three or more functional groups, a preparation method there for, and an optical body manufactured therefrom. Especially, the present invention relates to a poly(thio)urethane-based resin and an optical body, such as lenses, manufactured using the resin, wherein the poly(thio)urethane-based resin is prepared by obtaining a novel polyol and then combining a polythiol, which is prepared from the obtained polyol, with a polyiso(thio)cyanate.

The invention relates to a process for the co-production of alkyl mercaptan and of dialkyl disulfide, comprising the following successive steps: a) reaction of a C.sub.1-C.sub.4 alcohol in the presence of hydrogen sulfide (H.sub.2S) to form a stream (M) comprising an alkyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purification of the stream (M) to obtain a stream (N) enriched in alkyl mercaptan, c) recovery of a first portion of the stream (N) including the alkyl mercaptan purified in step b), d) oxidation with sulfur of the second portion of the stream (N) of alkyl mercaptan, to form a stream (O) comprising a dialkyl disulfide, hydrogen sulfide, and possibly unreacted alkyl mercaptan, e) purification of the stream (O) to separate, on the one hand, the enriched dialkyl disulfide and, on the other hand, the hydrogen sulfide and possibly the alkyl mercaptan that has not reacted in step d), f) recycling of the hydrogen sulfide and possibly of the alkyl mercaptan isolated in step e) into the stream (M) obtained from step a), g) recovery of the dialkyl disulfide isolated in step e).

The invention relates to a process for the co-production of alkyl mercaptan and of dialkyl disulfide, comprising the following successive steps: a) reaction of a C.sub.1-C.sub.4 alcohol in the presence of hydrogen sulfide (H.sub.2S) to form a stream (M) comprising an alkyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purification of the stream (M) to obtain a stream (N) enriched in alkyl mercaptan, c) recovery of a first portion of the stream (N) including the alkyl mercaptan purified in step b), d) oxidation with sulfur of the second portion of the stream (N) of alkyl mercaptan, to form a stream (O) comprising a dialkyl disulfide, hydrogen sulfide, and possibly unreacted alkyl mercaptan, e) purification of the stream (O) to separate, on the one hand, the enriched dialkyl disulfide and, on the other hand, the hydrogen sulfide and possibly the alkyl mercaptan that has not reacted in step d), f) recycling of the hydrogen sulfide and possibly of the alkyl mercaptan isolated in step e) into the stream (M) obtained from step a), g) recovery of the dialkyl disulfide isolated in step e).

The present invention relates to a process for drying methyl mercaptan, notably by azeotropic distillation, comprising the following steps: 1) a stream (A) comprising methyl mercaptan and water is introduced into a distillation column (1); 2) said stream (A) is distilled in said column (1); 3) the distillate (B) is recovered in gaseous form, preferably at the top of the column; 4) the distillate (B) is condensed, preferably in a condenser (2), so as to obtain a condensate (C) in liquid form; 5) said condensate (C) is separated, preferably using a decanter (3), so as to obtain two separate liquid phases: an aqueous phase (D); and an organic phase (E) comprising methyl mercaptan; 6) all or part of the organic phase (E) is optionally introduced into the distillation column (1) as reflux; and 7) a stream (F) comprising the dried methyl mercaptan is recovered, preferably at the bottom of column (1).

The present invention also relates to processes for producing methyl mercaptan comprising said drying process.

The present invention relates to a process for drying methyl mercaptan, notably by azeotropic distillation, comprising the following steps: 1) a stream (A) comprising methyl mercaptan and water is introduced into a distillation column (1); 2) said stream (A) is distilled in said column (1); 3) the distillate (B) is recovered in gaseous form, preferably at the top of the column; 4) the distillate (B) is condensed, preferably in a condenser (2), so as to obtain a condensate (C) in liquid form; 5) said condensate (C) is separated, preferably using a decanter (3), so as to obtain two separate liquid phases: an aqueous phase (D); and an organic phase (E) comprising methyl mercaptan; 6) all or part of the organic phase (E) is optionally introduced into the distillation column (1) as reflux; and 7) a stream (F) comprising the dried methyl mercaptan is recovered, preferably at the bottom of column (1).

The present invention also relates to processes for producing methyl mercaptan comprising said drying process.

The present invention discloses processes for producing a thiol compound or a sulfide compound from an olefin compound. Diphenylamine or a phenol compound can be used to increase the rate of conversion of the olefin compound to the thiol compound or the sulfide compound.