Abstract: After applying a metal film on a surface of a substrate, the metal film is patterned in such a manner that the surface of the substrate is exposed in a pattern that corresponds to the pattern of the required indented portion. Then, the substrate is immersed in an etchant which etches the substrate selectively to form the indented portion in the surface of the substrate using the metal film as a mask.The method makes it possible to define the depth and the pattern of an indented portion where a magnetic transducer is provided with a high degree of accuracy, to prevent a reduction in pattern accuracy due to re-adhering and to advance industrial productivity.

Abstract: A coating protective film which comprises a substrate, which is made of a colored polyolefin film and has a maximum per cent transmission of ultraviolet within a wavelength range of 190 to 370 nm of not more than 10%, and a pressure sensitive adhesive layer, which is made of a pressure sensitive adhesive containing as the main component at least one of polyisobutylene, butyl rubber and polybutene, satisfies the requirements for weatherability of protective pressure sensitive adhesive film which is temporarily attached to finished automobiles for the purposes of protection of automotive coating during transfer and storage, and is also so excellent in peelability as not to pollute the coating on the automobiles.

Abstract: A radiation curable pressure sensitive adhesive composition comprising:(A) 100 parts by weight of a hydrogenated polybutadiene liquid oligomer which has one or more ethylenically unsaturated terminal radicals in its molecule and in which 70% or more of intramolecular carbon-carbon double bonds has been hydrogenated;(B) from 0.2 to 20 parts by weight of a chain transfer agent; and(C) from 0.001 to 1.0 parts by weight of a thermal polymerization inhibitor selected from metal complexes of N-nitrosophenylhydroxylamine;has an excellent storage stability and curing property and can provide pressure sensitive adhesive tapes which have excellent heat resistance and weatherability and are suitably used as surface protecting films.

Abstract: A radiation curable pressure-sensitive adhesive composition comprising a liquid oligomer having one or more acrylic double bonds in its molecule, a chain transfer agent and an aliphatic polar monomer having a carboxyl group can give an adhesive tape excellent in rubber-like properties, high in cohesive force and good in adhesiveness at low temperatures.

Abstract: A radiation curable adhesive composition comprising a liquid oligomer, a chain transfer agent, and an N-methyl compound can give a surface protective film which is slightly influenced in adhesive strength with the lapse of time, and excellent in weather resistance and heat resistance.

Abstract: A radiation curable pressure-sensitive adhesive composition comprising 100 parts by weight of a liquid oligomer having one or more acrylic unsaturated double bonds in its molecule, 0.2 to 20 parts by weight of a thiol compound and 0.5 to 30 parts by weight of acrylic monomer has high cohesion and is excellent in adhesiveness.

Abstract: In a process for producing a radiation curable pressure sensitive adhesive tape, when a quaternary ammonium salt is coated on a substrate as an undercoating before the coating of an adhesive composition comprising a liquid oligomer and a thiol compound, the resulting adhesive tape has good adhesive strength and higher cohesion with no unpleasant odor of the thiol compound.

Abstract: A radiation curable coating media can be cured without using a laminating material prepared otherwise by running a continuous belt-like supporter so as to contact a back side of a portion of the substrate with a front side of a portion of the substrate coated with a coating media to form a laminated portion, wherein curing of the coating media is conducted by irradiation with a radiation in the absence of oxygen.