The present invention concerns a method for preparing 1,3,5-trioxane by trimerization of formaldehyde in the presence of methanesulfonic acid. The invention also concerns the use of at least one catalyst comprising methanesulfonic acid for the trimerization of formaldehyde into 1,3,5-trioxane.

The present invention provides a trioxane composition which comprises trioxane as a main component, an antioxidant, and at least one alkaline organic compound selected from the group consisting of an amine compound having an alcoholic hydroxy group in the molecule thereof, a thiocarbamate compound, and an organophosphorus compound, wherein the amount of the alkaline organic compound contained is 0.01 to 10 ppm, based on the trioxane, and wherein the trioxane composition is a liquid.

The present invention provides a trioxane composition which comprises trioxane as a main component, an antioxidant, and at least one alkaline organic compound selected from the group consisting of an amine compound having an alcoholic hydroxy group in the molecule thereof, a thiocarbamate compound, and an organophosphorus compound, wherein the amount of the alkaline organic compound contained is 0.01 to 10 ppm, based on the trioxane, and wherein the trioxane composition is a liquid.

The present invention provides a trioxane composition which comprises trioxane as a main component, an antioxidant, and at least one alkaline organic compound selected from the group consisting of an amine compound having an alcoholic hydroxy group in the molecule thereof, a thiocarbamate compound, and an organophosphorus compound, wherein the amount of the alkaline organic compound contained is 0.01 to 10 ppm, based on the trioxane, and wherein the trioxane composition is a liquid.

The present invention provides a trioxane composition which comprises trioxane as a main component, an antioxidant, and at least one alkaline organic compound selected from the group consisting of an amine compound having an alcoholic hydroxy group in the molecule thereof, a thiocarbamate compound, and an organophosphorus compound, wherein the amount of the alkaline organic compound contained is 0.01 to 10 ppm, based on the trioxane, and wherein the trioxane composition is a liquid.

A method for producing trioxane or methylal is provided in which the decrease in the intended reaction activity is suppressed and the volume change of the styrene-based resin is suppressed even over prolonged use. A method for producing trioxane or methylal includes the step of producing trioxane or methylal by reacting formaldehyde in the presence of a styrene-based resin having electron withdrawing groups. A solid-state .sup.13C-NMR spectrum of the styrene-based resin has Peak 1 having a peak top in the range of 32 to 57 ppm and Peak 2 having a peak top in the range of 120 to 137 ppm. The area ratio (A1/A2) of the area A1 of Peak 1 to the area A2 of Peak 2 is 1.00 to 1.40.

A method for producing trioxane or methylal is provided in which the decrease in the intended reaction activity is suppressed and the volume change of the styrene-based resin is suppressed even over prolonged use. A method for producing trioxane or methylal includes the step of producing trioxane or methylal by reacting formaldehyde in the presence of a styrene-based resin having electron withdrawing groups. A solid-state .sup.13C-NMR spectrum of the styrene-based resin has Peak 1 having a peak top in the range of 32 to 57 ppm and Peak 2 having a peak top in the range of 120 to 137 ppm. The area ratio (A1/A2) of the area A1 of Peak 1 to the area A2 of Peak 2 is 1.00 to 1.40.

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) formaldehyde source, b) an aprotic compound and c) a catalyst; and ii) converting the formaldehyde source into cyclic acetals.

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) formaldehyde source, b) an aprotic compound and c) a catalyst; and ii) converting the formaldehyde source into cyclic acetals.

Disclosed is a method of producing trioxane, including: (A) preparing trioxane from a high-concentration formaldehyde aqueous solution in the presence of an acid catalyst; (B) distilling a mixture including trioxane; (C) liquefying the distilled gas mixture; (D) mixing the liquefied liquid mixture with an extraction solvent and separating the mixture into an aqueous phase and a solvent phase; (E) distilling the solvent phase to give trioxane, and mixing the aqueous phase with the extraction solvent to give a mixture, which is then separated into an aqueous phase and a solvent phase; and (F) discharging the aqueous phase separated in (E) out of the system, and recirculating the solvent phase so as to be reused in (D) and (E).