摘要:
The present invention refers to the use of screens comprising at least two layers of different mesh or pore size in a cellulose powder preparation method as well as to said method, wherein grinding the cellulose pulp and sieving the obtained particles can be carried out on-line.
摘要:
A thermoplastic molding composition suitable for the preparation of foam is disclosed. The composition comprises a thermoplastic resinous component and a foaming agent which includes A) (i) 0.01 to 4.8% alumina hydrate (aluminum hydroxide) in combination with (ii) 0.01 to 4.8% of an acidic additive or B) 0.01 to 4.8% of the reaction product of said (i) and said (ii), the percentages being relative to the weight of the composition to be foamed. The invention is based on the finding that the foaming of the composition does not lead to any significant reduction in molecular weight of the resinous component or to troublesome discoloration of the foam, even during its re-extrusion.
摘要:
A process for the preparation of multinuclear phenols alkylated in the nucleus, wherein bisphenol A is reacted with a phenyl alkenyl compound in the presence of a catalytic quantity of aluminium phenolate and resols obtained from said alkylated phenols.
摘要:
A method of foaming thermoplastic aromatic polycarbonates is disclosed. Accordingly, a polycarbonate resin is mixed with 0.01 to 10%, the percent being relative to the total weight of polycarbonate resin and polysaccharide, of a particular polysaccharide and the mixture then processed thermoplastically without the application of negative pressure in an extruder, at temperatures of 180.degree. C. to 320.degree. C., or in an injection molding machine, at temperatures of 190.degree. C. to 330.degree. C., to obtain foamed molded articles.
摘要:
A process for the preparation of resol resins by reacting bisphenol A with 1.2 to 1.8 moles of formaldehyde in the presence of n-butanol or isobutanol and in the presence of a tri-alkali metal phosphate as a catalyst, and their use, optionally combined with epoxy resins, for the preparation of deep-drawable, sterilizable and chemically resistant lacquer films.
摘要:
An alkyd resin stoving lacquer with decreased loss of reactive diluent yields outstandingly hard coatings if a reactive diluent mixture comprising a lactam and a hydroxyl compound is used.
摘要:
A freeze dryer for the freeze drying of, for example, comestible products such as fruit juices and coffee, comprises a sublimation chamber having a heating plate upon which the products are disposed and an ice condenser spaced from the heating plate and upon which the moisture driven out of the product sublimes in the form of ice. According to the invention between the heating place and the ice condenser a heat pump is disposed so that the heat transferred to the ice condenser is returned via the heat pump to the heating plate.
摘要:
Stoving lacquer systems having a high solids content contain a binder consisting of carboxyl and hydroxyl group-containing polyester or alkyd resin including an .epsilon.-caprolactone as a "reactive diluent", and an aminoplast resin as a cross-linking agent.
摘要:
The throughput of a reactor for producing alkali cellulose and/or a cellulose derivative can be increased by using a granulated cellulose-based material for the preparation of alkali cellulose and/or a cellulose derivative. Cellulose derivatives of essentially the same quality can be produced as in known processes wherein powdered cellulose-based material is used for alkalization and derivatization.
摘要:
The present invention relates to thermoplastic foams in which .beta.-ketocarboxylic acids, .beta.-ketocarboxylic acid esters or tert.-butyl esters of organic acids are used as the foaming agents.