Abstract: The present invention provides a cheap handsfree unit which can prevent the howling phenomenon and reduce the input sound from the loud-speaker into the microphone in both the analog and digital modes. A reception side comprises a signal level adjusting circuit constituted by a switch circuit and attenuators, and a transmission side comprises a signal level adjusting circuit constituted by a switch circuit and attenuators, to introduce the attenuation of 15 dB or 30 dB in response to the analog or digital mode. A voice switch is constituted so that the analog reception signal and the analog transmission signal are rectified respectively by rectifiers, the levels of both signals are compared by a comparator, and either switch or switch having a higher input signal level becomes conductive as a result of the comparison. The attenuation is introduced on the basis of the communication mode, only to either the analog reception signal or analog transmission signal having a smaller signal intensity.

Abstract: A composite film, comprising a base film and an adhesive layer on one or both sides of the base film, the composite film having a thickness of T (.mu.m), the base film having an edge tearing strength of R (kg/20mm), the adhesive layer having a total thickness of A, the base film having a thickness of B, T being related to R by a numerical formula R>0.6T-8 when T.ltoreq.60, or by a numerical formula R.gtoreq.28 when T>60, and A/B being 0.5 to 1.4.

Abstract: A printing-plate dust removing apparatus includes a guide rail 12 provided in parallel with a plate cylinder 1; a slider 13 moving along the guide rail 12; a holder 18 supported by the slider 13; a moving member 19 supported by the holder 18, the moving member 19 having a plurality of dust removing blades 28; and a driving gear for shifting the moving member 19 intermittently. A driving shaft 38 of the driving gear is connected with a driven shaft 27 through coupling members 41 and 42. Interlocking claws 41A and 42A of the coupling members are set so that the coupling members are engaged with each other at a standby position of the dust removing blades. Also, the holder 119 and the slider 113 are connected with each other by wedge members 138 and 144 so that the wedge members are firmly engaged with each other by a clamping bolt 147 and a holder plate 140.

Abstract: A hot-melt adhesive comprising a special polyamideimide or polyamide is excellent in heat resistance and adhesive strength and usable for providing substrates for printed circuit boards.

Abstract: An impact modifier obtained by emulsion polymerizing acrylic monomer(s), etc., in the presence of a conjugated diene rubber to give a graft rubber polymer, or obtained by polymerizing acrylic monomer(s) and the like ethylenically unsaturated monomers in the presence of the graft rubber polymer, is effective for improving impact resistance and weathering resistance of molded articles obtained from thermoplastic resin compositions containing such an impact modifier.

Abstract: A solvent-soluble polyimide obtained from an exo-form dicarboxylic acid anhydride with an aromatic diamine, e.g. 2,2,-bis[4-(4-aminophenoxy)phenyl]propane is improved in film-forming properties and transparency, and particularly suitable for producing an orientation controlling film in a liquid crystal display device.

Abstract: A toner for developing latent electrostatic images is disclosed, which comprises (a) thermofusible base particles A having a softening point of 80.degree. C. or less, a flow starting temperature of 110.degree. C. or less, and an average particle size of 5 to 25 .mu.m, and (b) small particles B comprising as the main component an organic polymeric material having a softening point at least 5.degree. C. higher than the softening point of the base particles A and no practical softening point, and an average particle size ranging from 0.1 .mu.m or more, but not more than 1/4 of the average particle size of the base particles A, which small particles B are embedded in the surface of the base particles A so as to cover the surface of the base particles A to a depth of less than the particle size of the small particles B.

Abstract: A catalytic combustion device has a fuel supply means communicated with a fuel supply source, an air supply passage communicated with an air supply source, a premixing chamber for mixing together fuel supplied from the fuel supply means and combustion air supplied from the air supply passage to form a fuel-air mixture, a catalyst installed in a combustion chamber to cause oxidation reaction of the fuel-air mixture supplied thereto, thereby effecting catalytic combustion, and an exhaust passage for discharging combustion gas from the catalyst in the combustion chamber.

Abstract: This invention relates to a color toner for electrophotography containing a coloring agent and a binder resin as the main components, said coloring agent comprising at least one of the anthraquinone derivatives expressed by the following general formula (I), ##STR1## wherein R.sup.1 represents hydrogen or an alkyl group having at least 6 carbon atoms and R.sup.2 represents hydrogen, an alkyl group having at least 6 carbon atoms or phenyl group.

Abstract: This invention relates to a toner for developing an electrostatic latent image, which contains a coloring agent, a binder resin and a charge controlling agent as the main components, said charge controlling agent being a metal salt of salicylic acid or derivatives.