Title (en)

PROCESS FOR PRODUCING POLYOXYMETHYLENE POLYMERS HAVING INTERMEDIATE CHAIN LENGTH

Title (de)

VERFAHREN ZUR HERSTELLUNG VON POLYOXYMETHYLEN-POLYMEREN MIT MITTLERER KETTENLÄNGE

Title (fr)

PROCÉDÉ DE PRÉPARATION DE POLYMÈRES DE POLYOXYMÉTHYLÈNE DE LONGUEUR DE CHAÎNE INTERMÉDIAIRE

Publication

EP 3883979 A1 20210929 (DE)

Application

EP 19804731 A 20191120

Priority

• EP 18207740 A 20181122
• EP 2019081903 W 20191120

Abstract (en)

[origin: WO2020104512A1] A process for producing polyoxymethylene polymers comprises the reaction of aqueous formaldehyde solution with an aqueous solution of a base, wherein A) a starter solution comprising formaldehyde is initially charged and B) an aqueous formaldehyde solution and a base are added to the starter solution to obtain a reaction mixture. The starter solution in step A) has a temperature of ≥ 40°C to ≤ 46°C and the additions of the solutions in step B) are performed at a temperature of the reaction mixture of ≥ 40°C to ≤ 46°C. The base is an alkali metal hydroxide and/or an alkaline earth metal hydroxide and the molar ratio of formaldehyde to base is ≥ 55:1 to ≤ 90:1 based on the total amounts of formaldehyde and base employed in the process. The base in step B) is added in aqueous solution.

IPC 8 full level

C08G 2/08 (2006.01); C08G 2/06 (2006.01); C08G 2/18 (2006.01)

CPC (source: EP US)

C08G 2/06 (2013.01 - EP US); C08G 2/08 (2013.01 - EP US); C08G 2/18 (2013.01 - EP)

Citation (search report)

See references of WO 2020104512A1

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA ME

DOCDB simple family (publication)

EP 3656796 A1 20200527; CN 113272348 A 20210817; EP 3883979 A1 20210929; US 2022002467 A1 20220106; WO 2020104512 A1 20200528

DOCDB simple family (application)

EP 18207740 A 20181122; CN 201980071663 A 20191120; EP 19804731 A 20191120; EP 2019081903 W 20191120; US 201917292606 A 20191120