Polymers can be prepared from monomers comprising laurolactam, by a process including a. Beckmann rearrangement of cyclododecanone oxime to give laurolactam in the presence of a Beckmann rearrangement catalyst, b. removal of impurities from the laurolactam to obtain purified laurolactam, and c. polymerization of monomers comprising purified laurolactam. For avoidance of discolouration or yellowing under ageing conditions, prior to the polymerization, polycyclic substances containing 24 carbon atoms and at least one heteroatom selected from oxygen and nitrogen and having a molar mass between 300 and 380 g/mol are limited to 500 ppm, based on laurolactam.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

Disclosed herein is an efficient, economical, industrially advantageous, straight-through process for the preparation of cyclic amides, also referred as lactams, in substantially pure form and high yield, from the corresponding cyclic ketones and a hydroxylammonium salt, using a combination of amphoteric metal oxide or amphoteric masked metal oxide and a base.

Disclosed herein is an efficient, economical, industrially advantageous, straight-through process for the preparation of cyclic amides, also referred as lactams, in substantially pure form and high yield, from the corresponding cyclic ketones and a hydroxylammonium salt, using a combination of amphoteric metal oxide or amphoteric masked metal oxide and a base.

A power supply device, a photochemical reaction device and method in which the power supply device is used, and a lactam production method in which the photochemical reaction method is used, the power supply device being characterized by having a control circuit for controlling the current from a power supply source, a cooling means capable of cooling the surroundings by channeling a refrigerant, a heat transfer means connecting the cooling means and the control circuit to each other, and an insulating means interposed between and in contact with the heat transfer means and the control circuit. It is possible to prevent an excessive increase in temperature of the control circuit, stably maintain the function of the control circuit, and extend the lifespan of electric and electronic components mounted on the control circuit. Applying this power supply device makes it possible to build a high-output and high-integration type LED light source device, and operate the light source device in a stable manner over a long period.

A power supply device, a photochemical reaction device and method in which the power supply device is used, and a lactam production method in which the photochemical reaction method is used, the power supply device being characterized by having a control circuit for controlling the current from a power supply source, a cooling means capable of cooling the surroundings by channeling a refrigerant, a heat transfer means connecting the cooling means and the control circuit to each other, and an insulating means interposed between and in contact with the heat transfer means and the control circuit. It is possible to prevent an excessive increase in temperature of the control circuit, stably maintain the function of the control circuit, and extend the lifespan of electric and electronic components mounted on the control circuit. Applying this power supply device makes it possible to build a high-output and high-integration type LED light source device, and operate the light source device in a stable manner over a long period.

The present invention relates to a process for the preparation of an isomer-enriched mixture of 3S- and 3R-caranone from 3-carane epoxide, a 3S-caranone obtained therefrom, a process for the production of 3S-caranlactam from 3-carene, a process for the production of 3R-caranlactam from 3-carene, a 3S-caranoxime, a 3S-caranlactam, a 3S-polycaranamide, a 3R-polycaranamide, a 3S/3R-co-polycaranamide, a 3S-caranlactam-laurolactam co-polycaranamide, a 3R-caranlactam-laurolactam co-polycaranamide, a 3S-caranlactam-3R-caranlactam-laurolactam co-polycaranamide, a 3S-caranlactam-caprolactam co-polycaranamide, a 3R-caranlactam-caprolactam co-polycaranamide, as well as a 3S/3R-caranlactam-caprolactam co-polycaranamide.

Disclosed herein is an efficient, economical, industrially advantageous, straight-through process for the preparation of cyclic amides, also referred as lactams, in substantially pure form and high yield, from the corresponding cyclic ketones and a hydroxylammonium salt, using a combination of amphoteric metal oxide or amphoteric masked metal oxide and a base.

The present invention provides a continuous process for producing ammonium sulfate crystals, wherein said process comprises: (a) feeding to a first group of crystallization sections, which crystallization sections are heat integrated in series, a first aqueous ammonium sulfate solution that contains one or more impurities; (b) feeding to a second group of crystallization sections, which crystallization sections are heat integrated in series, a second aqueous ammonium sulfate solution that contains one or more impurities; (c) crystallizing ammonium sulfate crystals in each crystallization section respectively from each of said solutions of ammonium sulfate that contain one or more impurities; (d) purging a fraction of the ammonium sulfate solution that contains one or more impurities from each of said crystallization sections; and (e) discharging ammonium sulfate crystals from each crystallization section, characterized in that: (i) both the first group of crystallization sections and the second group of crystallization sections are together heat integrated in one series of crystallization sections; wherein the first group of crystallization sections operates at higher temperature than the second group of crystallization sections; and (ii) the composition of the first aqueous ammonium sulfate solution that contains one or more impurities is different to the composition of the second aqueous ammonium sulfate solution that contains one or more impurities. Further provided is apparatus suitable for producing ammonium sulfate crystals.