Abstract: A particular size measuring apparatus uses laser light and monochrome beams of different wavelengths to measure a wide range of particle sizes. The monochrome beams are obtained from a lamp source and are changed in wavelength by a group of band-pass filters, whereby different ranges of particle sizes can be measured for the respective single wavelengths and thus the range of particle sizes capable of being measured can be expanded.

Abstract: A multi-layer molded article including a thermoplastic resin body having a plurality of ribs and/or bosses on one side and a layer of a foam which is laminated on the side of the thermoplastic resin body having ribs and/or bosses is produced by a press molding method. The method involves the steps of supplying a foam between upper and lower halves of a mold, one of which has plurality of slits and/or holes corresponding to the ribs and/or bosses to be formed, supplying a quantity of a plasticized thermoplastic resin melt between the already supplied foam and the half of the mold not having any slit or hole, moving at least one half of the mold during supplying the thermoplastic resin or just after completion of supply of the thermoplastic resin to press mold the thermoplastic resin so that the plasticized thermoplastic resin breaks at least a part of areas of the foam on the slits and/or holes of the half of the mold to flow into the slits and/or holes and to form the ribs and/or bosses.

Abstract: A vibration-damping material consisting of two metal plates and a vibration-damping layer of thermoplastic resin interposed between the two metal plates, in which said thermoplastic resin has a percentage of wlongation at 20.degree. C. of 30% or more, preferably 50% or more, a peak temperature of dissipation factor (tan .delta.) in the range of -50.degree. C. to 130.degree. C., and a bonding strength toward the metal plates of 3 kg/cm or more as determined by 180.degree.-peeling test at 20.degree. C.

Abstract: An optical disk is provided which comprises two sheets of substrates; or two sheets of substrate and a reinforcing plate or a reinforcing rim; or one sheet of substrate and a reinforcing plate; which are bonded to form an integrated body having a spacer interposed therebetween, said spacer being made of elastomeric foam having a specific gravity of not more than 1.5 and an expansion ratio of not less than 1.5 as the material of the said spacer. This optical disk has a high adaptability of the drive and exhibits a high reliability, i.e. excellent vibration restricting performance, thereby being possible to provide a stable and highly accurate information processing.

Abstract: A vibration-damping material with excellent workability consisting of two metal plates and a vibration-damping layer of a thermoplastic resin interposed between the two metal plates, in which the vibration-damping layer of a thermoplastic resin consists of a film as a middle layer and a polyolefin type resin (B) provided on both sides of the film as an upper and lower layer, the film as the middle layer being composed of (1) at least one resin (A) selected from the group consisting of polyolefin type resins and ionomer resins each having a modulus of elasticity in shear at 20.degree. C. of 3.times.10.sup.9 to 1.times.10.sup.7 dyne/cm.sup.2, a percentage of elongation at 20.degree. C. of 50% or above and a peak temperature of dissipation factor (tan .delta.) of -120.degree. C. to 80.degree. C. or (2) a resin mixture of the resin (A) and a synthetic rubber having a percentage of elongation at 20.degree. C. of 100% or above and a peak temperature of dissipation factor (tan .delta.) of -120.degree. to 50.degree.