The present invention relates to polyphosphazenes, polyurethanes based on these polyphosphazenes, methods for their manufacture and hydrogels based on the polyurethanes. The invention further relates to the use of the hydrogels in medical, veterinary and agricultural applications. The terminal ends of the polyphosphazenes bear NCO-reactive hydrogen atoms for reaction with polyisocyanates.

A composition including at least one compound having a perfluoropolyether group and a curable site, wherein in a molecular weight distribution curve in gel permeation chromatography measurement, the following formula is satisfied: M2/M1≤3.5, wherein M1 is a molecular weight at a main peak, and M2 is a molecular weight at 25% intensity of an intensity of the main peak on a higher molecular weight side than M1. Also disclosed is a curable composition containing the composition and a method for producing the curable composition.

Compositions comprising a combination of low molecular weight prepolymers and high molecular weight prepolymers are disclosed. The compositions are used to fabricate elastomeric articles having high tensile strength and high tensile elongation.

A composition including at least one compound having a perfluoropolyether group and a curable site, wherein in a molecular weight distribution curve in gel permeation chromatography measurement, the following formula is satisfied: M2/M1≤3.5, wherein M1 is a molecular weight at a main peak, and M2 is a molecular weight at 25% intensity of an intensity of the main peak on a higher molecular weight side than M1. Also disclosed is a curable composition containing the composition and a method for producing the curable composition.

Curable compositions include at least one organic polymer which contains silane groups and/or isocyanate groups, at least one compound which contains acetal groups and has a molecular weight of at least 280 g/mol, and at least one basic catalyst. The composition is particularly storage-stable and can be readily processed. Using moisture the composition cures rapidly, and with very little residual tackiness, to form a resilient material that has good adhesive and mechanical properties, in particular a high level of malleability and elasticity, is heat resistant and exhibits hardly any odour formation or migration effects. In particular, the composition has very consistent product properties during storage in respect of viscosity, curing rate and odour.

A charging roller for an image forming apparatus is provided, which includes a shaft, an elastic layer disposed around the shaft, and a coating layer formed on the elastic layer, wherein the coating layer includes a urethane resin formed by crosslinking of a polyol mixture with polyisocyanate, and the polyol mixture includes polyester polyol and polyether polyol having 60% by weight or more and 90% by weight or less of an ethylene oxide content.

A charging roller for an image forming apparatus is provided, which includes a shaft, an elastic layer disposed around the shaft, and a coating layer formed on the elastic layer, wherein the coating layer includes a urethane resin formed by crosslinking of a polyol mixture with polyisocyanate, and the polyol mixture includes polyester polyol and polyether polyol having 60% by weight or more and 90% by weight or less of an ethylene oxide content.

Compositions comprising a combination of low molecular weight prepolymers and high molecular weight prepolymers are disclosed. The compositions are used to fabricate elastomeric articles having high tensile strength and high tensile elongation.