Abstract:
Copolymers of ethylene with 10 to 98 percent by weight of conventional comonomers are made by copolymerization in aqueous dispersion, at least a part of the heat of polymerization being removed by evaporation of the ethylene. The vapors are cooled by a cooling medium by heat exchange, in a cooling zone situated above the polymerization vessel and communicating with the latter, the hot vapors being fed to the upper end of the cooling zone, the cooled vapors returning to the polymerization vessel, so that the vapors are cooled by the cooling medium while they are flowing downward.
Abstract:
The invention relates to microcapsules having a wall material composed of optionally crosslinked copolymers comprising olefinically unsaturated monomers containing hydrophilic groups such as an acetylacetate of a mono(meth) acrylate of an aliphatic diol, and olefinically unsaturated monomers containing hydrophobic groups, such as methyl methacrylate, and a process for the manufacture of microcapsules.
Abstract:
In the manufacture of aqueous dispersions of polymers of monoolefinically unsaturated carboxylic acid esters by emulsion copolymerization, polymerization is effected in the presence of a mixture of (a) non-ionic emulsifiers, (b) anionic emulsifiers, (c) a protective colloid based on an N-vinyl pyrrolidone polymer and (d) a hydroxyl-containing protective colloid.
Abstract:
Microcapsule dispersions which have been stabilized with a crosslinked polymer containing carboxyl groups. The physical and chemical properties of the dispersions remain substantially constant while settling and creaming of the dispersed microcapsules are prevented.
Abstract:
HOT-MELT ADHESIVES BASED ON GRAFT POLYMERS IN WHICH A MIXTURE CONSISTING OF STYRENE FOR THE MOST PART AND ESTERS OF ACRYLIC OR METHACYLIC ACID IS POLYMERIZED ONTO A BACKBONE POLYMER CONSISTING A POLYSTYRENE OR A COPOLYMER OF STYRENE AND FOR THE MOST PART ACRYLIC OR METHACRYLIC ESTERS, THE SAID ESTERS BEING DERIVED FROM PRIMARY AND/OR SECONDARY ALKANOLS HAVING 3 TO 12 CARBON ATOMS, ARE VERY STABLE EVEN IN TH MOLTEN STATE, ARE PARTICULARLY TOUGH, AND HAVE AN ESPECIALLY LOW VISCOSITY IN THE MOLTEN STATE.