Abstract: The object of the present invention is to produce a polymer, which is free from the troubles of the coloration and the decrease in the mechanical properties of molded articles (films, etc.), crosslinkage failure, migration (stain) or the like, by the living radical polymerization method wherein the content of impurities consisting of a transition metal and its ligand employed as a polymerization activator is reduced. A process for producing a polymer is described, comprising: a) the step of performing a polymerization reaction by using a monomer, a transition metal and its ligand and a polymerization initiator to form a polymer; and b) the step of eliminating the transition metal and its ligand contained in the polymer under the condition of a viscosity of 100 Pa·s or below, wherein the step b comprises: b1) the former step of eliminating the transition metal and its ligand insoluble in the polymer; and b2) the latter step of eliminating the transition metal and its ligand dissolved in the polymer.

Abstract: A pressure-sensitive adhesive composition having well-balanced pressure-sensitive adhesive force and cohesive force without causing any safety or economy problems, a process for the preparation of the same and pressure-sensitive adhesive sheets using the same are disclosed. The pressure-sensitive adhesive composition comprises a crosslinked polymer obtained by crosslinking a block copolymer comprising at least two of a styrene-based polymer block A and an acrylic polymer block B having a structural unit represented by the general formula (1):—[CH2═C(R1)COOR2]— wherein R1 represents a hydrogen atom or methyl group, and R2 represents a C2-14 alkyl group, bonded each other, such as A-B or B-A type block copolymer and A-B-A type block copolymer.

Abstract: An ultraviolet crosslinking pressure-sensitive adhesive composition showing good pressure-sensitive adhesive characteristics is obtained by using a block copolymer of styrenic polymer component and acrylic polymer component. The pressure-sensitive adhesive composition is produced by conducting living radical polymerization of styrenic monomer and acrylic monomer in a proper order in the presence of a transition metal and its ligand using a polymerization initiator to obtain a block copolymer (a) wherein at least one styrenic polymer block A and at least one acrylic polymer block B are bound to each other and mixing it with a trichloromethyl group-containing triazine derivative (b) or, alternatively, to obtain a block copolymer (a) which contains carboxyl precursor groups in the acrylic polymer block B, and converting the precursor groups to carboxyl groups, before or after mixing with the component (b), by heat-treating in the presence of an acid catalyst.

Abstract: The object of the present invention is to produce a polymer, which is free from the troubles of the coloration and the decrease in the mechanical properties of molded articles (films, etc.), crosslinkage failure, migration (stain) or the like, by the living radical polymerization method wherein the content of impurities consisting of a transition metal and its ligand employed as a polymerization activator is reduced. A process for producing a polymer is described, comprising: a) the step of performing a polymerization reaction by using a monomer, a transition metal and its ligand and a polymerization initiator to form a polymer; and b) the step of eliminating the transition metal and its ligand contained in the polymer under the condition of a viscosity of 100 Pa•s or below, wherein the step b comprises: b1) the former step of eliminating the transition metal and its ligand insoluble in the polymer; and b2) the latter step of eliminating the transition metal and its ligand dissolved in the polymer.

Abstract: A method for removing a resist pattern formed on a semiconductor wafer, and a curable pressure-sensitive adhesive, adhesive sheets and an apparatus used for the method. The resist-removing method comprising adhering an adhesive tape on an upper surface of a resist pattern formed on an article and peeling off the resist pattern together with the adhesive tape; the curable pressure-sensitive adhesive constituting the adhesive tape, comprising a pressure-sensitive adhesive polymer containing a non-volatile compound having at least one unsaturated double bond in the molecule and having a good affinity with a resist material to be removed; the adhesive sheet comprising a film substrate having formed thereon the curable pressure-sensitive adhesive; and the resist-removing apparatus comprising a means for press-adhering the adhesive tape, a tape-peeling means, and a substrate-washing means.

Abstract: A method for removing a resist pattern formed on a semiconductor wafer, and a curable pressure-sensitive adhesive, adhesive sheets and an apparatus used for the method. The resist-removing method comprising adhering an adhesive tape on an upper surface of a resist pattern formed on an article and peeling off the resist pattern together with the adhesive tape; the curable pressure-sensitive adhesive constituting the adhesive tape, comprising a pressure-sensitive adhesive polymer containing a non-volatile compound having at least one unsaturated double bond in the molecule and having a good affinity with a resist material to be removed; the adhesive sheet comprising a film substrate having formed thereon the curable pressure-sensitive adhesive; and the resist-removing apparatus comprising a means for press-adhering the adhesive tape, a tape-peeling means, and a substrate-washing means.

Abstract: A pressure-sensitive adhesive and adhesive sheets using the pressure-sensitive adhesive are disclosed. The pressure-sensitive adhesive comprising (a) from 50 to 84% by weight of an acrylic monomer, (b) from 15 to 28% by weight of an N,N-di-substituted (meth)acrylamide, (c) from 1 to 10% by weight of a monomer having an acid group, and (d) from 0 to 25% by weight of other monomer copolmerizable with the components (a) to (c).

Abstract: A vibration-damping pressure-sensitive adhesive composition containing a crosslinked structure of a copolymer comprising (A) from 75 to 92% by weight of a main monomer comprising an alkyl (meth)acrylate containing from 8 to 12 carbon atoms in the alkyl moiety thereof and (B) from 8 to 25% by weight of a carboxyl-containing monomer whose homopolymer has a glass transition temperature of 50.degree. C. or more, said crosslinked structure having a solvent-insoluble content of 80% by weight or more and a weight loss of 3% by weight or less on heating at 120.degree. C. for 240 hours, and said composition having a T-peel strength of 400 g/20 mm-width or more from a SUS plate and a loss factor of 0.05 or more at 60.degree. C. in the vicinity of 1 kHz as determined by a half-value width method. The composition exhibits satisfactory heat resistance against long-term use in high temperatures as well as satisfactory adhesion to various parts at room temperature.

Abstract: A pressure-sensitive adhesive composition containing as a polymer component an addition-polymerization polymer of an acryl-based polymer having sticking properties at room temperature and one or more ethylenically unsaturated monomers capable of forming a homo- or co-polymer having a glass transition point of at least 273.degree. K.; the addition-polymerization polymer is prepared by polymerizing one or more ethylenically unsaturated monomers in the presence of the acryl-based polymer; the present pressure-sensitive adhesive composition has high adhesive strength and cohesive strength.

Abstract: A water-soluble pressure-sensitive adhesive composition is described containing a polymerization product obtained by the solution polymerization of a water-soluble ethylenically unsaturated monomer in the presence of an alcoholic plasticizer having a molecular weight of less than about 3,000 and which is a liquid at room temperature, selected from the group consisting of polyether polyols and polyhydric alcohols, wherein the polymerization product contains as a polymer component at least an addition copolymer of the water-soluble ethylenically unsaturated monomer and the alcoholic plasticizer.

Abstract: An antibacterial and antifungal material comprising a polymer containing carboxyl groups in an amount of at least about 0.008 milliequivalent per gram of the polymer and antibacterial and antifungal metallic ions ionically bonded to the carboxyl groups in an amount of at least about 0.0009 millimole per gram of the polymer.