Abstract: A pellicle having a reflection-preventing function comprised of a transparent polyvinyl acetal film and a reflection-preventing film formed on at least one surface of the polyvinyl acetal film. The reflection-preventing film is made of a copolymer of a perfluoroalkyl acrylate or methacrylate with a hydroxyalkyl acrylate or methacrylate having (i) a hydroxyalkyl group having 2-3 OH groups on the terminal or side chain and 3-5 carbon atoms, (ii) a hydroxyalkyl group having an OH group on the terminal or side chain and 2-4 carbon atoms, or (iii) a fluorine-containing hydroxyalkyl group having an OH group on the terminal or side chain and 4-12 carbon atoms.

Abstract: A photoresist composition comprising:a resin soluble in an aqueous alkaline solution, having units of an aliphatic cyclic hydrocarbon main frame and units derived from maleic anhydride and/or units derived from a maleimide; anda photosensitive agent in a sufficient amount to promote or hinder the solubility of said resin in an aqueous alkaline solution upon exposure to active radiation so as to create a substantial difference in the solubility as between an exposed portion and a non-exposed portion and to form a positive or negative image by subsequent development with an aqueous alkaline solution.

Abstract: A polyacrylic acid ester derivative having repeating units represented by the formula: ##STR1## (wherein R and R' independently represent a hydrogen atom or a methyl group, R.sub.1 represents a C.sub.1 -C.sub.4 linear or branched alkyl group, A represents a structural unit derived from a group copolymerizable with an acrylic acid ester, and l, m and n are, respectively, from 0.04 to 1.0, from 0 to 0.96 and from 0 to 0.5 in this order, provided that their sum is 1, and when m is not higher than 0.2, n is a number of not higher than 0.01) and having a molecular weight of from about 5,000 to about 1,000,000, is capable of being molded, and is useful as an optical material.

Abstract: A positive resist composition comprising an aromatic group-containing alkali-soluble resin and a compound having an ammonium salt as skeleton, as the main components.

Abstract: A pellicle film comprised of a resin prepared by reducing a polyvinyl acetal of the formula: ##STR1## wherein R is a C1-3 alkyl group and the vinyl acetate content "y/(x+y+z)" is not larger than 0.1 and the degree of acetalization "z/(x+y+z)" is at least 0.6. This pellicle film exhibits a reduced UV absorption in the vicinity of 365 nm and is durable against irradiation with UV rays, especially i-line of a mercury arc light.

Abstract: An ultrafiltration membrane formed of a polyvinyl formal resin having a recurring unit represented by the general formula (I), and a process for producing this ultrafiltration membrane: ##STR1## wherein n is 550 to 950.

Abstract: Positive resist patterns prepared by using a derivative of polyacrylic acid esters containing halogen expressed by the following general formula for the resist material; ##STR1## (where A is a structural unit which is derived from monomers having a copolymerable double bond, and X is either a halogen atom or a methyl group. m is a positive integer, n is 0 or a positive integer, n/m is 0 to 2 and m+n are 20 to 20,000. Y.sub.1 to Y.sub.5 are a fluorine or hydrogen atom and at least one of them is a fluorine atom).

Abstract: A process for preparing an anion exchange membrane, which comprises subjecting a carboxylate membrane made of a copolymer having repeating units of the formula: ##STR1## wherein X is F or CF.sub.3, l is an integer of from 0 to 5, m is 0 or 1, n is an integer of from 1 to 5, and p/q is from 4 to 16, and R is an alkyl group, to an acid or base treatment, and then introducing anion exchange groups thereinto.

Abstract: Halogen-containing polyacrylate derivatives having the formula: ##STR1## wherein A is a structural unit derived from a copolymeriazable monomer having a double bond; R is ##STR2## wherein each of R.sub.1 and R.sub.2 is a hydrogen atom or a fluorinated methyl group, provided R.sub.1 and R.sub.2 are not hydrogen atoms at the same time, and R.sub.3 is a hydrogen atom or a lower alkyl group; X is a halogen atom or a methyl group; and m is a positive integer, n is 0 or a positive integer, and n/m from 0 to 2, preferably from 0 to 1 are disclosed.Also disclosed are methods for forming a resist pattern by using the halogen-containing polyacrylate derivatives as a resist material.

Abstract: A method for recovering acids from an aqueous solution of a mixture of the acids and metal salts by dialysis, characterized in that a fluorinated anion exchange membrane made of a copolymer having repeating units of the formula: ##STR1## wherein X is F or CF.sub.3, l is an integer of from 0 to 5, m is 0 or 1, n is an integer of from 1 to 5, p/q is from 2 to 16, and Y is a quaternary ammonium group, is used as a dialysis membrane.

Abstract: A halogen-containing polyacrylate derivative having the formula: ##STR1## wherein A is a structural unit derived from a copolymerizable monomer having a double bond; R is ##STR2## wherein each of R.sub.1 and R.sub.2 is a hydrogen atom or a fluorinated methyl group, provided R.sub.1 and R.sub.2 are not hydrogen atoms at the same time, and R.sub.3 is a hydrogen atom or a lower alkyl group; X is a halogen atom or a methyl group; and m is a positive integer, n is 0 or a positive integer, and n/m is from 0 to 2, preferably from 0 to 1.

Abstract: A cation exchange membrane manufacturing method in which a film of a blend which consists of a perfluoro carbon polymer having a group transformable into a sulfonic acid group and a perfluoro carbon polymer having a group transformable into a carboxylic acid group or a film of a copolymer which consists of a perfluoro carbon monomer having a group transformable into a sulfonic acid group and a perfluoro carbon monomer having a group transformable into a carboxylic acid group and another film of a perfluoro carbon polymer having a group transformable into a carboxylic acid group are joined together. Following that, the group transformable into a carboxylic acid group and the group transformable into a sulfonic acid group are transformed respectively into the carboxylic acid group and the sulfonic acid group.

Abstract: A fluorocarbon anion exchanger which is composed of a fluorocarbon polymer comprising a perfluorocarbon main chain and a pendant chain attached to the main chain, characterized in that the pendant chainhas a terminal group represented by the formula: ##STR1##

Abstract: A process for the preparation of chlorinated polyvinyl aromatic compound is described, comprising the steps of: (1) in an aromatic organic solvent, forming a solution of an aromatic compound represented by formula (I): ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 is selected from hydrogen and an alkyl groups containing from 1 to 6 carbon atoms, and R.sup.4 and R.sup.5, or R.sup.5 and R.sup.6 can together form a ring by ##STR2## wherein each of R.sup.7, R.sup.8, R.sup.9, and R.sup.10 is selected from hydrogen and an alkyl group containing from 1 to 6 carbon atoms, and n has an average value of from 50 to 30,000; and (2) subjecting the solution to electrolysis reaction in the pressure of an aqueous solution containing chloride ions.

Abstract: A fluorocarbon polymer comprising a perfluorocarbon main chain and a pendant chain attached to the main chain, characterized in that the pendant chain has a quaternary ammonium type terminal group.

Abstract: A method of producing a cation-exchange membrane having roughed surface which is characterized in mixing silica powder with water to give a suspended or pasty mixture, supporting the resultant mixture on art paper or filter paper, drying the mixture to form silica powder layer, adhering with heating and pressing the silica powder layer on surface of membrane composed of perfluorocarbon polymer, and removing the silica powder layer formed on the surface of said membrane with caustic alkali aqueous solution.

Abstract: A cation-exchange membrane for electrolyzing an aqueous solution of an alkali metal halide in the manufacture of an alkali hydroxide and a halogen. The membrane comprises one layer which occupies 5 to 30% of the total thickness of the membrane and has carboxylic acid groups; another layer which occupies 5 to 30% of the membrane thickness and has weakly acidic groups, the weakly acidic groups occupying 10 to 60% of the total exchange group capacity of the layer; and a further layer which has sulfonic acid groups occupying the middle portion of the membrane.

Abstract: Characteristics of a cation exchange membrane used for an electrolysis of an alkali metal chloride are recovered by immersing the perfluorocarbon type cation exchange membrane in an organic solvent having a water miscibility and a boiling point of higher than 120.degree. C. in 760 mmHg; holding the immersed membrane between a pair of smooth plates and heating at 40.degree. C. to 180.degree. C.; treating the heat-treated membrane in hydrochloric acid and then, immersing it in an aqueous solution of sodium hydroxide and the organic solvent is preferably ethyleneglycol, propyleneglycol, isopropyleneglycol butanediol, pentanediol, hexanediol, glycerin or polyethyleneglycol.

Abstract: An improved method for electrolyzing alkali metal halide. Electrolysis is carried out by supplying an aqueous solution of a halide of alkali metal into an anode chamber partitioned by a cation-exchange membrane and water into a cathode chamber to obtain halogen from the anode chamber and hydrogen and alkali hydroxide from the cathode chamber. The cation-exchange membrane is a fluorocarbon polymer membrane which is prepared by arranging one side thereof to have a cation exchange group concentration lower by 10 to 30% within a depth range of 1 to 100.mu. than that of the other side. The anode chamber is prepared with this side of the membrane which has the lower cation exchange group concentration arranged to face the anode chamber. By this arrangement, a high purity alkali hydroxide can be manufactured at a high rate of decomposition of halide of alkali metal and at a high current efficiency.

Abstract: An alkali metal hydroxide and hydrogen in a cathode compartment and chlorine in an anode compartment by feeding an aqueous solution of an alkali metal chloride in said anode compartment which is partitioned from said cathode compartment with a cation exchange membrane made of a fluorinated polymer is produced under a condition that a temperature of said anode compartment is kept at lower than a temperature of said cathode compartment in said electrolysis.