摘要:
The invention relates to a new three-part process, which can also be employed on a large industrial scale, for the preparation of polyurea lubricating greases, which is characterised(a) in that polyureas which carry oleophilic groups are prepared by reaction of diisocyanates with amines either in the absence of a solvent on a reaction screw at 80.degree.-120.degree. C., preferably at 85.degree.-95.degree. C., (variant A) or in a toluene medium at 20.degree.-80.degree. C., preferably at 30.degree.-60.degree. C., (variant B),(b) in that, after complete reaction, the polyureas prepared according to (a) are ground in the solid, dry state to give powders (at least 70% by weight of the powder having particle sizes of about 100-400.mu.) and(c) in that the ground crude product, after being made into a "paste" (wetted) at elevated temperature in the base oil employed (10-30 minutes at 140.degree.-180.degree. C.) and cooled again to room temperature, is processed to a grease by complete homogenisation--if appropriate in several passes--in a high-pressure homogeniser under a pressure of 400-1,500 bar (spontaneous heating occurring up to about 100.degree. C.),greases having readily reproducible and essentially the same properties as in the case of the previously customary in situ manufacture being produced.
摘要:
This invention relates to reinforced thermoplastic moulding compositions prepared from biodegradable polymers, for example aliphatic or polyester amides, aliphatic polyester urethanes, and to the use thereof for the production of mouldings and to the mouldings, wherein the reinforcing materials are selected from wood flour, fibres of natural origin, minerals of natural origin, cellulose and cellulose derivatives.
摘要:
The object of the present invention is the production of thermoplastically workable copolymers capable of being composted, characterized in that they consist of partially crystalline soft segments formed from aliphatic esters and also of amorphous hard segments and that the proportion of soft segments amounts to 70% to 95% by weight.
摘要:
Thermoplastic starch compositions formed by converting native starch or starch derivatives into thermoplastic starch by at least one hydrophobic biodegradable polymer that functions as a plasticizer for starch. The hydrophobic biodegradable polymer may be a polymer selected from the following list: an aliphatic polyester, a copolyester with aliphatic and aromatic blocks, a polyester amide, a polyester urethane, a polyethylene oxide polymer and/or a polyglycol, and/or mixtures of these. When the starch, such as in particular native starch or derivatives thereof, is mixed in the melt with the hydrophobic biodegradable polymer as a plasticizer or swelling agent, to homogenize the mixture, the water content is reduced to less than about 5% by weight based on the weight of the mixture.
摘要:
Polyether ester amides having high water vapor permeability are disclosed. The amides which are prepared simply and reliably, crystallize quickly, are biodegradable and/or compostable, and are suitable in the manufacture of films by extrusion.
摘要:
For converting native starch or starch derivatives into thermoplastic starch, added to the starch is at least one hydrophobic biodegradable polymer. This hydrophobic biodegradable polymer, which serves as a plasticizer or swelling agent, may be a polymer selected from the following list: an aliphatic polyester, a copolyester with aliphatic and aromatic blocks, a polyester amide, a polyester urethane, a polyethylene oxide polymer and/or a polyglycol, and/or mixtures of these. When the starch, such as in particular native starch or derivatives thereof, is mixed in the melt with the hydrophobic biodegradable polymer as a plasticizer or swelling agent, to homogenize the mixture, the water content is reduced to
摘要:
This invention relates to reinforced thermoplastic moulding compositions prepared from biodegradable polymers, for example aliphatic or polyester amides, aliphatic polyester urethanes, and to the use thereof for the production of mouldings and to the mouldings, wherein the reinforcing materials are selected from wood flour, fibres of natural origin, minerals of natural origin, cellulose and cellulose derivatives.