Low void composites with high Tg polyimide matrices are prepared from stoichiometrically unbalanced precursors.

1. Phenolic resin compositions suitable for the manufacture of phenolic prepreg mats, according to which the compositions employed for impregnating the fibre mats consist of phenolformaldehyde resins of the resole type, fillers, pigments and hardening agents, characterized in that these compositions contain an additive consisting of at least 20% by weight of an alkali or alkaline-earth metal metab...

To produce a cellulosic article, a cellulosic amine oxide solution is pressed through a nozzle or through a slit, then passed through an air slit and finally coagulated in a precipitation bath. According to the invention, it is not stretched in the air gap, i.e. the ratio of discharge rate to hole emergence rate is at most 1; only the coagulated cellulose is stretched or deep-drawn.

PURPOSE:To produce a wire with a superconductive characteristic and without no defect such as of swelling by interposing in a composite billet any one of material selected from metal elements of the fourth and fifth group in the periodic table of Mendelejeff and these alloy and the like, over the whole length in the longitudinal direction. CONSTITUTION:Raw material for oxide superconductive body s...

PURPOSE:To efficiently produce an excellent tape-shaped oxide superconductor by a coat metal layer on a superconductor layer by the use of molten metal having a lower melting point than the melting starting temperature of an oxide superconductor constituting an oxide superconducting layer. CONSTITUTION:A metal sheet-shaped body 10 is made to run in one direction at a constant speed, then a specifi...

The rate at which diamond is deposited by chemical vapor deposition on a substrate is increased by the presence of an expediting metal such as molybdenum in the surface of a wall exposed to the chemical vapor deposition.

Cement based casting compositions are formulated in which the sand and aggregate in conventional concrete are replaced by a low density mineral of particle size suitable for its intended use, together with other additives to ensure that the finished castings possess adequate flexural strength. The light weight and high thermal insulation of such castings can be further enhanced by design features ...

A method for testing physical integrity of production tubing (20) and production casing (16) in a gas-lift well includes the steps disposing a sealing tool (48) in the production tubing to obtain a seal at a desired location; applying a predetermined test pressure to the interior space of the production tubing; monitoring the test pressure applied for a pressure drop; and monitoring flow from the ...

Polypropylene microporous films characterized by having a porosity of 30-35%, an average pore size of 200-2800 Angstroms, a permeation coefficient for nitrogen of 1-5 x 10<-3> ml/cm sec atm and a tensile strength of greater than 60 MPA in all directions within the film plane are prepared by the consecutive steps of biaxial stretching a non-porous starting film of high beta -crystal content and he...

A warehouse control apparatus (1) is disclosed which includes a CPU (2) which directs storage in disk drives (5) of data including vacant time and actual storage times for storage locations on racks of a warehouse. A map of the warehouse is stored in the disk drives (5) and the CPU (2) generates a list of storage locations for incoming pallets. A storage location is eligible if it is vacant and if...

A mat comprises a substantially uniform thickness aggregation of irregularily shaped filament loops lying against each other so as to be substantially upright when the plane of the mat is horizontal, the loops in the surface of the aggregation being bent and fused to one another. The loops may be coated with a plastisol made of the same material as the filament. It may be used as a door or floor m...

LA INVENCION SE REFIERE A UN PROCEDIMIENTO PARA OBTENCION DE PLACAS DE YESO REFORZADAS DE YESO (-SEMIHIDRATO), SI ES CASO MATERIALES DE REFUERZO, PREFERENTEMENTE PARTICULAS DE CELULOSA, EN MEZCLA CON POLIISOCIANATOS PARA LA FABRICACION DE PLACAS DE YESO Y/O INTRODUCCION DE POLIISOCIANATOS SOBRE LA SUPERFICIE DE LAS PLACAS DE YESO. LA INVENCION SE REFIERE TAMBIEN A PLACAS DE YESO (-SEMIHIDRATO) MOD...

UN METODO DE PRODUCCION DE UNA PIEZA DE ESPUMA EXTRUIDA DE POLIMERO AROMATICO ALQUENILICO CON UN TAMAÑO CELULAR MEDIO DE 0,05 MM A 3,5 MM, UNA DENSIDAD DE 1,0 LBS/ PIE 3 (16 KG/M3) A 5 LBS/PIE 3 (80 KG/CM3) UN ESPESOR DE SECCION TRANSVERSAL MINIMO DE 0,5 PULGADAS (1,3 CM) Y UN AREA DE SECCION TRANSVERSAL MINIMA DE 8 PULGADAS 2 (52 CM2) COMPRENDE LAS ETAPAS DESCRITAS EN LA INVENCION.; A method for ...

LOS POLIMERIZADOS EXPANSIBLES, AUTOEXTINGUIBLES, DE ESTIRENO, SE OBTIENEN POR EXTRUSION DE UNA MEZCLA A BASE DE POLIMERIZADO DE ESTIRENO, UN AGENTE DE EXPANSION, UNA COMBINACION ORGANICA DE BROMO Y DICUMIL COMO SINERGISTICO, SIENDO ENFRIADAS LAS BARRAS DE UN MODO LO SUFICIENTEMENTE RAPIDO PARA NO FORMAR ESPUMA Y MIENTRAS QUE EN SU INTERIOR AUN CONSERVAN PLASTICIDAD, SE SOMETEN A DEFORMACION POR ME...

Injection of gas into a bed of solids contained in a hopper is compartmentalized to allow independent control of gas to be vented upward and gas and solids to be discharged.

The invention relates to a process for the production of a laminate structure comprising two cover layers based on unsaturated polyester and fibrous material sandwiching a layer with a relatively low density based on unsaturated polyester by applying the core layer to a first cover layer, and is characterized in that the core layer consists of fibrous material covered with a film of unsaturated po...

There is disclosed the use of matrix-antidegradants in rubber and a process for the production of matrix-antidegradants. More specifically, this invention is directed to microparticles of vulcanized rubber containing high levels of para-phenylenediamine type antiozonants which have a particle diameter of 100 microns or less. The matrix-antidegradant or microparticles prepared according to this inv...

Spinnable and formable solutions of polyamideimides and process for their preparation. They contain 5 to 30% of a polyamideimide in a solvent mixture comprising 40-80% by weight of gamma -butyrolactone and 20-60% of an aprotic amide solvent. They are obtained by reaction, in gamma -butyrolactone as a polycondensation solvent, of a diisocyanate, of an aromatic acid anhydride, optionally of a...

A portable apparatus 10 to aid in assessing the cost of repairing damaged vehicles, said apparatus 10 including a body 11 which receives a digitising pad 20 and a computer 21. The pad 20 and computer 21 are operatively associated so that signals generated by the pad 20 are received by the computer 21, which computer 21 then stores information indicative of those signals. Applied to the pad 20 is a...

A composite material, suitable for use in a power transmission belt, having a rubber matrix and a plurality of short staple reinforcing fibers therein of methaphenyleneiso-phthalamide coated with one of a rubber latex and a rubber paste. The invention is also directed to a method of forming the composite material.