摘要:
The incandescent lamp, which uses a carbon cycle process, is equipped with a luminous body which, together with a fill, is introduced in a vacuum-tight manner into a bulb, the luminous body including a metal carbide, the melting point of which is above that of tungsten. The distance between the luminous body and the wall of the bulb is less than 18 mm, with a first cycle process, which is attributed to the carbon, being effected by the use of carbon and hydrogen as fill additive, and a second cycle process, which is attributed to the metal, being effected by the use of halogen.
摘要:
The incandescent lamp, which uses a carbon cycle process, is equipped with a luminous body which, together with a fill, is introduced in a vacuum-tight manner into a bulb, the luminous body including a metal carbide, the melting point of which is above that of tungsten. The distance between the luminous body and the wall of the bulb is less than 18 mm, with a first cycle process, which is attributed to the carbon, being effected by the use of carbon and hydrogen as fill additive, and a second cycle process, which is attributed to the metal, being effected by the use of halogen.
摘要:
A high pressure discharge lamp has a ceramic discharge vessel (8), whose s are closed with plugs (11). The metallic feedthrough, or a main part of it, has a thermal coefficient of expansion which is smaller than the coefficient of the ceramic. The current feedthrough is gas-tightly sintered directly into the plug.
摘要:
Azeotropic compositions made up of from about 60 to about 78% by weight of 1,1,1,3,3-pentafluoropropane and from about 22 to about 40% by weight of tetramethylsilane have been found to be particularly useful as blowing agents for the production of polyurethane foams.
摘要:
An azeotropic composition made up of from about 73 to about 87% by weight of 1,1,1,4,4,4-hexafluorobutane and from about 13 to about 27% by weight of n-pentane is used as a blowing agent in a process for the production of polyurethane foams.
摘要:
The present invention relates to polyurethanes with softening temperatures above 80.degree. C. which are NCO-free, which are reactive via masked isocyanates, which are essentially linear and extensively pre-lengthened, and their preparation. The polyurethanes can be used as powders which can be processed like thermoplastics and post-cured.
摘要:
This invention relates to novel polyisocyanate compositions, to a process for these polyisocyanate compositions, to a process for the production of cold cure flexible molded foams wherein this novel polyisocyanate composition comprises the polyisocyanate component, and to the cold cure flexible molded foams produced by this process. The novel polyisocyanate compositions of the present invention are characterized by an NCO group content of more than about 15%, (preferably from about 20% to less than about 33%, more preferably from about 25% to about 32%), and comprising: (1) from about 70 to 99% by weight of a polymethylene poly(phenyl isocyanate) having an NCO group content of from about 30 to about 33%, and a monomer content of from about 40% to about 90% by weight and (2) from about 1 to about 30% by weight of a prepolymer of diphenylmethane diisocyanate having an NCO group content of from about 2% to about 20%, and comprising the reaction product of: (a) diphenylmethane diisocyanate; and (b) a polyether polyol.
摘要:
Azeotropic compositions made up of (a) from about 4 to about 50% by weight 1,3-dioxolane and (b) one compound selected from (1) about 75 to about 96% by weight cyclopentane, (2) about 60 to about 79% by weight 2-methyl pentane, (3) about 59 to about 77% by weight 3-methyl pentane, and (4) about 50 to about 69% by weight n-hexane in which the sum of the weight percent of (a) plus weight percent of (b) is approximately 100 percent are used as blowing agents in the production of polyurethane/polyurea foams.
摘要:
A device for producing rigid plastic pipes of an approximately cylindrical shape, contains an extruder and a calibrating station following in the direction of production, which has calibrating tools to calibrate the outside diameter of the already partly hardened pipe. The calibrating tools bear against the outside wall of the pipe, lamellae serving as calibrating tools being respectively connected to spindles, which, for adaptation to different outside diameters of pipes that are to be calibrated, being adjustable in a radial direction perpendicular to the axis of the calibrating device and feed axis of the pipe that is to be extruded.
摘要:
Azeotropic compositions made up of from about 60 to about 78% by weight of 1,1,1,3,3-pentafluoropropane and from about 22 to about 40% by weight of tetramethylsilane have been found to be particularly useful as blowing agents for the production of polyurethane foams.