Abstract: Disclosed are a block-graft copolymer comprising a polymer block having a repetitive unit represented by General Formula: ##STR1## wherein A represents an organopolysiloxane chain, a polyalkylene oxide chain, a polyalkylene-imine chain, a polyacrylate chain or a polyacryloyl chain,and a process for producing the same. This block-graft copolymer can have various performances such as an oxygen enrichment performance, an ion concentration property, a capability of forming a complex with a metal salt and a biocompatibility, depending on the kind of graft polymer chains.

Abstract: A graft copolymer having a plurality of polymer side chains is disclosed. The starting backbone polymer is a homopolymer or copolymer of a styrene derivative having a pendant vinylidene group on the benzene ring. The graft copolymer may be produced by metallizing said backbone polymer with an alkali metal and then polymerizing an ethylenically unsaturated monomer in the presence of the metallized polymer as an anionic polymerization initiator.

Abstract: Disclosed are a block-graft copolymer comprising a polymer block having a repeating unit represented by General Formula (I): ##STR1## wherein A is a side chain and represents an organopolisiloxane chain, a polyacrylate chain, a polymethacrylate chain, polydiene chain, etc.and a process for producing the same. This block-graft copolymer can have various performances such as oxygen enrichment performance, biocompatibility, depending on the kind of side chains.

Abstract: A scanning electron microscope includes a heater coil which is arranged around a sample, an electron beam which is radiated when the sample is heated, and a secondary electron generated from the sample which is attracted to a photo multiplier. In this electron microscope, a shield plate is provided having an extracting hole for extracting the secondary electron outside of the heat coil in such a manner that the extracting hole is aligned with a light axis of the electron beam. The shield plate is connected to a power source which supplies a variable voltage so that a desired voltage can be applied to the shield plate so as to shield thermal electrons.

Abstract: The invention provides a novel polymeric compound having crosslinkability by irradiation with actinic rays, e.g. ultraviolet light, and useful as a polymeric base ingredient of a negative type photoresist composition with high sensitivity and resistance against dry etching. The polymer is obtained by the anionic living polymerization of a vinylsilyl group-containing styrene derivative of the formulaCH.sub.2 .dbd.CH--C.sub.6 H.sub.4 --CH.sub.2).sub.n SiR.sub.2 --CH.dbd.CH.sub.2,in which R is a monovalent hydrocarbon group, e.g. methyl and phenyl, and n is an integer of 0 to 3, in a specific solvent in the presence of a specific polymerization initiator so that the polymerization takes place only at the styrenic vinyl groups leaving the silicon-bonded vinyl groups unpolymerized. Quite unexpectedly, the polymer has a very uniform monodisperse distribution of the molecular weight.

Abstract: A process for producing an alkenylsilyl group-containing polymer compound, comprising polymerizing a vinyl monomer compound containing an alkenylsilyl group-containing styrene compound represented by General Formula (I): ##STR1## wherein R.sup.1 represents hydrogen atom, methyl group or ethyl group; R.sup.2 and R.sup.3 may be the same or different and each represent an alkyl group having 1 to 3 carbon atoms or phenyl group; and n is an integer of 0 to 4, by using an organic metallic compound as an initiator, wherein the polymerization is carried out in the presence of N-methylpyrrolidine.There can be obtained a monodisperse alkenylsilyl group-containing high molecular compound in which only the unsaturated bond in the styrene moiety of the compound of Formula (I) has been predominantly polymerized.

Abstract: The negative-working photoresist composition of the invention comprises, as the polymeric constituent thereof, a polymeric compound obtained by the anionic living polymerization of a vinylphenyl substituted-vinyl dimethyl silane compound represented by the general formulaCH.sub.2 .dbd.CH--C.sub.6 H.sub.4 --SiMe.sub.2 --CR.sup.1 .dbd.CR.sup.2 R.sup.3,in which Me is a methyl group and R.sup.1, R.sup.2 and R.sup.3 are each a hydrogen atom, methyl group or ethyl group, at least one of the R.sup.1, R.sup.2 and R.sup.3 being not a hydrogen atom, to cause the polymerization only at the styrenic double bond, the other double bond in the same molecule remaining unpolymerized. By virtue of the high density of the double bonds in the polymer molecules, the photoresist composition is highly sensitive to irradiation with actinic rays and capable of giving a patterned photoresist layer having excellent resolving power and resistance against dry etching.

Abstract: This is a method for separating or purifying an amino acid from a mixture including other substance such as an inorganic salt other than the amino acid and/or a mutual mixture of amino acids including the amino acid by means of piezo-dialysis employing an amphoteric ion exchange membrane. This membrane is made from a ternary block copolymer having a molecular structure of straight chain in which first macro-molecule with a cation exchange group, second macromolecule with an anion exchange group and third macromolecule without ion exchange group are linked together.

Abstract: A method for purifying and concentrating organic matters by employing an amphoteric ion-exchange membrane which is made of a ternary block copolymer consisting of a macromolecule poly A.sup.- having cation-exchange group, a macromolecule poly B.sup.+ having anion-exchange group and a macromolecule poly C having no ion-exchange group and allows sodium chloride to permeate at a concentration not lower than 100% of that in the starting aqueous solution when a pressure of 50 kg/cm.sup.2 is given to the starting aqueous solution of sodium chloride of 0.01 g/dl and by allowing inorganic salts to permeate selectively from an aqueous solution of the organic compounds containing the inorganic salts with giving an increased pressure thereto.

Abstract: An amphoteric ion exchanger constituted by linking (1) first macromolecular chain A.sup.- having cation exchange groups, (2) second macromolecular chain B.sup.+ having anion exchange groups and (3) third macromolecular chain C having no ion exchange group into a straight chain to have a linking mode of the first chain and the second chain being separated from each other by the third chain.

Abstract: A pattern formation with a negative type resist comprises forming a thin film made of a resist on a board and irradiating light or radiation; developing and etching the product. The resist is a diene polymer obtained by a living polymerization in the presence of an organometallic compound or a cyclic polymer thereof.

Abstract: A fine work process comprises forming a thin film made of a radiation sensitive polymer on a board; irradiating radiation; developing and etching the product. The radiation sensitive polymer comprises at least 10 wt. % of a polymer having repeat units: ##STR1## wherein R and R' respectively represent hydrogen atom or an alkyl group and n is an integer of number of substituent groups.

Abstract: A ternary block copolymer and a method for manufacturing it. The copolymer has a molecular structure consisting of a macro-molecule having a cation exchange group, a macro-molecule having an anion exchange group and another macro-molecule which does not have any ion exchange group. These macro-molecules are linked together into a straight chain.

Abstract: In the polymerization of an anionically polymerizable monomer using a polymerization system comprising a monomer and a polymerization solvent wherein an organometallic compound polymerization initiator, soluble in said polymerization system and having the formula:MeR.sub.xwherein Me is a metal selected from the group consisting of Groups I and II of the Periodic Table; R represents an alkyl or aryl group, or an aliphatic or aromatic hydrocarbon residue; and the integer x is 1 or 2; is added to said system, the improvement which comprises adding said organometallic compound as a solution comprising said organometallic compound dissolved in a high viscosity solvent having a viscosity higher than 1 cp at room temperature, and which dissolves slowly in said polymerization system.