摘要:
A production process for heat-expanded microspheres comprising the step of providing a gaseous fluid containing heat-expandable microspheres, which comprise shell of thermoplastic resin and a blowing agent encapsulated therein having a boiling point not higher than the softening point of the thermoplastic resin and have an average particle size from 1 to 100 μm, feeding the gaseous fluid through a gas-introducing tube having a dispersion nozzle on its outlet and being fixed inside a hot gas flow, and emitting a jet of the gaseous fluid through the dispersion nozzle; a step wherein the gaseous fluid is collided on a collision plate fixed under the dispersion nozzle so as to disperse the heat-expandable microspheres in the hot gas flow; and a step wherein the dispersed heat-expandable microspheres are heated in the hot gas flow at a temperature not lower than their expansion initiating temperature and thus expanded. The production process results in minimum difference in the variation coefficient of particle size distribution between the microspheres before and after heat-expansion, slight ratio of raw microspheres and slightly expanded microspheres contained in resultant heat-expanded microspheres, and suppressed formation of aggregated microspheres.
摘要:
Heat-expandable microspheres include a shell of thermoplastic resin and a blowing agent encapsulated therein having a boiling point not higher than the softening point of the thermoplastic resin, have a maximum expanding ratio not lower than 50 times, and are thermally expanded into hollow particulates having a repeated-compression durability not lower than 75 percent. The method of producing the heat-expandable microspheres includes the steps of dispersing an oily mixture containing a polymerizable component and the blowing agent in an aqueous dispersing medium containing a specific water-soluble compound and polymerizing the polymerizable component contained in the oily mixture.
摘要:
The present invention provides thermo-expansive microspheres comprising thermoplastic resinous shell and a blowing agent being encapsulated in the shell, the blowing agent which is a fluorine-containing C2-10 compound having ether linkage, being free of chlorine and bromine atoms and gasifying at a temperature not higher than the softening point of the thermoplastic resin; and also provides the production and application processes thereof. The thermo-expansive microspheres have preferably an average particle size ranging from 1 to 100 μm and a CV, or coefficient of variation, of particle size distribution being 30% or less, and a retaining ratio of blowing agent encapsulated being 90% or more. The thermo-expansive microspheres have low environmental loading and superior flame-retardant or flame-resistant performance, and have particle sizes distributing in narrow ranges. Those thermo-expansive microspheres and foamed hollow microspheres are suitable for applying to fire-proof paints, flame-retardant or flame-resistant thermo-insulating materials, flame-retardant or flame-resistant lightweight fillers, and flame-retardant or flame-resistant lightweight molded products, in addition to the conventional application field.
摘要:
In a record player for playing a record disk on which video information is recorded, the player body is equipped with a turntable having a diameter smaller than the information-recorded surface part of the record disk, on which the record disk is pressed at its central part, and the pick-up has access from below to the information-recorded surface part of the record disk extending outwardly of the turntable surface.
摘要:
A jitter correcting system is provided in a video reproducing apparatus for reproducing a composite video signal of a given standard television system to be connected to a monitor television receiver including an automatic frequency control for a horizontal oscillator, comprising a circuit for phase modulating the horizontal synchronizing signal of the reproduced composite video signal, by the amount associated with the phase difference between the composite video signal to be applied to the picture tube of the monitor television receiver and the output signal of the automatic frequency control of the monitor television receiver, for providing a modified composite video signal a phase modulated horizontal synchronizing signal. The system further comprises a circuit for generating a pseudo video composite signal including vertical and horizontal synchronizing signals and a marking signal in the video signal phase region wherein the horizontal synchronizing signal has been phase shifted as compared with that of the standard television system of the video reproducing apparatus for applying the said pseudo composite video signal through the jitter correcting system to the monitor television receiver, whereby the phase modulating circuit can be adjusted while observing the marking indication caused by the marking signal appearing on the screen of the picture tube.
摘要:
A video information reproduction circuitry for use in a video disc player of a type utilizing a combination of a scanning transducer and a flexible foil-type disc record having at least one surface formed with a spirally extending information-carrier groove in which the scanning transducer is slidingly engaged during reproduction of video information, is provided with a drop-out compensation circuit for substantially avoiding a possibility of color streaks and black and white dots, which may otherwise occur on a picture tube.
摘要:
A plasma display device is provided with a chassis supporting a PDP on its front surface, circuit boards located within a specific region of the back surface of the chassis, a back cover including an edge portion covering the outside of the specific region of the back surface of the chassis and a projecting portion accommodating the plurality of the circuit boards, and a fan arranged inside a space defined by the projecting portion. The peripheral wall of the projecting portion is provided with a plurality of air inlets and a plurality of air outlets.
摘要:
The present invention provides a temperature-indicating sheet which, when exposed to temperatures higher than the prescribed temperature in temperature-control for the common low-temperature preserved goods, changes in color according to the exposure temperature and time. This object is attained by arranging one component which melts at the prescribed temperature and a substance which irreversibly changes in color in contact with said component through a membrane permeable to the component. The sheet of the present invention comprises a component which melts at the prescribed temperature, a substance which changes in color in contact with the component and a membrane permeable to the molten component, said component being included in microcapsules which can be broken by outer pressure at a temperature used, and in which the component and the substance are arranged at the opposite sides with respect to the membrane.
摘要:
The present invention provides a process for preparing an ester comprising the step of reacting a carboxylic acid and an alcohol in the presence of an esterifying catalyst comprising at least one compound having the formula:O.dbd.M(RCOO).sub.2 wherein M represents Sn or Zn and R represents a saturated or unsaturated hydrocarbon group having 1-21 carbon atoms with or without side chains. According to the present process, substantially equal equivalents of the alcohol and the acid can be reacted completely. In addition, the present invention further provides a purification process to eliminate the catalyst from a homogeneous reaction system completely.
摘要:
An automatic record feeding device particularly advantageous for use in association with a flexible foil-type video disc record used by a video disc player. The record feeding device includes a transfer roll having at least one escapement recess or notch formed in the outer peripheral surface thereof, and a back-up guide cooperative with the transfer roll to hold the disc record between it and the transfer roll during transfer of the disc record from one position to another.