| abstract |
The present invention relates to compositions of spherical microparticles composed of a wall material and at least one cavity containing a gas and/or a liquid which contain pores at their surface, wherein the spherical microparticles have an average particle diameter of 10 - 600 µm and wherein at least 80% of those microparticles whose particle diameters deviate from the average particle diameter of the microparticles of the composition by not more than 20% each have on average at least 10 pores whose diameter is in the range from 1/5000 to 1/5 of the average particle diameter and furthermore the diameter of these pores is at least 20 nm, wherein the wall material consists of a composition containing at least one aliphatic-aromatic polyester and at least one additional polymer, wherein the additional polymen is selected from the group consisting of polyhydroxy fatty acids, poly(p-dioxanones), polyanhydrides, polyester amides, polysaccharides and proteins. The invention also relates to a process for the production and use thereof. |