摘要:
Chiral nematic polyesters comprise as alcohol component chiral diol structural units and as acid component dicarboxylic acid residues comprising mesogenic groups. The polyesters are particularly suitable for surface coating.
摘要:
Method for bonding of anchoring bolts in boreholes, in which an anchoring bolt is pushed with a rotary motion into a twin-chamber cartridge, one compartment of which is filled with a polyisocyanate component and the other one with a hydroxyl component, prepolymer from the conversion of polyisocyanates with one or several difunctional polyols of the molecular weight range 800-5000, preferably 1600-3000, being used as polyisocyanate component.
摘要:
For consolidation of geological formations and artificial beds of rock, earth, and coal by means of foaming and hardening polyisocyanate/polyol blends, diols with secondary hydroxyl functions of the OH number range 150-1000 are used as diol component. Preferably a crude polyisocyanate blend (MDI) obtained by phosgenation of aniline/formaldehyde condensates which at ambient temperature assumes a liquid state, and the liquid prepolymers of said crude MDI are used as isocyanate components.
摘要:
A method of and an adhesive cartridge for securing an anchor or the like in a bore hole or the like. The cartridge comprises an outer tube and an inner tube within this outer tube. Between the inner and outer tube is a mass of synthetic-resin material and filler. The inner tube is filled with a hardener capable of reacting with the synthetic-resin to form a mass capable of holding the rock anchor or the like in the borehole. At least the outer tube is made of an elastomeric polymer with which is mixed a filler that renders the outer tube completely opaque. The inner tube may also be extruded simultaneously with the outer tube of the same synthetic-resin material. It is also possible otherwise to partition the interiors of the outer tube, or to provide the one component in the outer tube directly in contact with the other component but unmixed therewith.
摘要:
Waterglass solutions are mixed with polyisocyanates and these emulsions are then left to harden in the formations. Introduction of the mixture into the formations which are required to be consolidated, e.g. deposits of coal, is mainly carried out by forcing the mixture under pressure into bore-holes in the formations. According to one variation of the process, the components of the mixture are introduced into the multi-chamber cartridges which are introduced into the bore-holes and then destroyed as the components are mixed. Certain additives such as accelerators, blowing agents, polyols, stabilizers and/or thixotropic agents are advantageous for the quality of the composite masses formed by hardening of the mixture.
摘要:
An object extends into a passage and defines a clearance space with the inner wall of the passage. A hardenable, foamable synthetic resin in flowable state is admitted into the clearance space. Upon hardening and foaming of the synthetic resin, the object is sealingly secured in the passage by the synthetic resin. In a preferred application, the passage is one provided in a coal mine and the object is a hose line for the purpose of suppressing dust. The synthetic resin is advantageously polyurethane including a polyhydroxyl component which contains a polyetherglycol having a hydroxyl number of 300 to 350 and a polyetherglycol having a hydroxyl number of 450 to 500. The polyetherglycol components respectively constitute 80 to 90 parts and 10 to 20 parts of the polyhydroxyl component. The polyhydroxyl component preferably includes a filler in an amount such that the weight of the latter at least equals that of the polyhydroxyl component.
摘要:
Process for isolating aqueous brine layers in underground gas-storage caverns which comprises injecting into the said cavern a liquid polyurethane-resin-forming composition that is hardenable by reaction with water which, upon hardening, forms a resinous barrier between the brine and the gas-storage space thereabove that is essentially impervious to water vapor. The liquid hardenable polyurethane-resin-forming composition comprises a polyol and a polyisocyanate of an aromatic hydrocarbon.
摘要:
A laser match honing system and method are provided for processing one of a pair of mechanically matching components (1, 2) having matching portions (12, 22, 16, 26) that will be fitted with each other. A dimension of the matching portion (12, 16) of the first component (1) is measured and is then used for calculating the desired dimension of the corresponding matching portion (22, 26) of the second component (2). An actual dimension of the matching portion (22, 26) of the second component (2) is also measured. Then, the matching portion (22, 26) of the second component (2) is honed by laser beam in the condition that the actual dimension is not equal to the desired dimension.
摘要:
In a frictionally locking elastic rail attachment for track systems, which attachment has a clamping element (11) which is made of elastic material, in particular of hardened steel, is embodied in the manner of a clamp with torsional limbs and is attached in the mounted state by means of a holding device and an attachment armature (13) which penetrates the latter vertically, on a sleeper body (3), in particular a concrete sleeper, and applies a clamping force which holds the rail (1) in position—the rail being arranged on the sleeper body with the intermediate connection of a rail supporting plate (6), the rail supporting plate (6) is embodied in one piece with through-bores, provided at both of its ends, for the holder housings (10) having attachment armatures, in such a way that, on the one hand, the clamping elements (11) are held in a positive locking fashion and, on the other hand, the holder housings (10) and, associated therewith, the clamping elements (11) are prestressed by the rail (1) which is inserted with its rail foot (2) between the holder housings (10).