Abstract: The invention relates to a vacuum coating installation comprising a container (9) in which is disposed the material (10) to be vaporized, for example SiO. The vaporization of the material (10) herein takes place by means of an electron beam gun (11) or by means of a vaporization oven. Opposing the surface of the material to be vaporized (10) is provided a synthetic film (5) to be coated which is transported further by means of a transport arrangement (4, 6, 22 to 27). Into the space between the material (10) to be vaporized and the material (5) to be coated a microwave is irradiated from an horn antenna (13).

Abstract: A diazotype heat development recording medium of the present invention has excellent shelf life and heat sensitivity. The medium comprises a support and a recording layer which is formed on said support and which comprises a diazo compound, a coupler, an acid stabilizer, a thermal developer, and a polymeric binder. The thermal developer is a salt of an organic or inorganic acid having a primary dissociation constant of 2.times.10.sup.-1 to 1.times.10.sup.-4 and an alkyl-substituted guanidine represented by the general formula: ##STR1## (wherein at least one of R1 and R2 is an alkyl group of C.sub.8 to C.sub.24, and the other of R1 and R2 is a hydrogen atom or an alkyl group of C.sub.1 or more).