Mitsubishi Chemical Industries Limited

Mitsubishi Kasei Corporation

Kyoritsu Yuki Co., Ltd.

Mitsubishi Chemical Corporation

Shigeru Sawayama

Kohichi Satoh

Mitsuaki Shiraga

Takaharu Itagaki

Yoshikazu Murao

Shin-ichi Sato

Toshiaki Sakakihara

Yasuharu Mori

Masato Nakajima

Kenji Mori

Yukino Yamada

Hiroyshi Okada

Takashi Nishikaji

Yukino Nagai

Kenzo Watanabe

Kenzoh Watanabe

Osamu Kamada

Disclosed herein is an N-vinylformamide composition comprising 250 ppm by weight or less of formic acid based on N-vinylformamide. According to the invention, the purity and polymerizing activity of N-vinylformamide are preserved for a long time.

N-vinylformamide compositions

There is provided a lactam ring-containing polymer comprising: 20 to 100 molar % of a structural unit represented by the general formula (1); 0 to 70 molar % of a structural unit represented by the general formula (2); and 0 to 70 molar % of a structural unit represented by the general formula (3) and/or a structural unit represented by the general formula (4): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each represents a hydrogen atom or a methyl group, and X represents COOR.sup.4 and/or CONR.sup.5 R.sup.6 in which R.sup.4, R.sup.5 and R.sup.6 each represents a hydrogen atom or a C1-C4 alkyl. The polymer is excellent in heat resistance and is expected to be used for resin modifiers, polymeric additives for petroleum tertiary recovery, and other various applications.

Lactam ring containing polymer

An acrylic fiber has 99.9 to 85 mol % of acrylonitrile units, and 0.1 to 15 mol % of N-vinylcarboxylic acid amide units, wherein the latter unit may be modified. The fiber is excellent, e.g., in dyeing property and hygroscopicity, and can be readily converted into a functional fiber.

Acrylic fiber and process for producing the same

Disclosed herein is a paper-making additive.comprising a specified cationic polymer having an amidine structure. The cationic polymer additive for paper-making according to the present invention has 20 to 90% by mole of units represented by the formula (1) and/or (2): ##STR1## wherein R.sup.1 and R.sup.2 independently denote a hydrogen atom or a methyl group, and X- denotes an anion; and has a reduced viscosity of 0.1 to 10 dl/g as measured in a 1N saline solution of 0.1 g/dl at 25.degree. C. The additives are excellent in improving paper or pulp properties, such as freeness, filler retention and paper strength.

Paper-making additives comprising cationic polymers

The present invention relates to a method for sizing of paper by using a particular vinylamine polymer as a size-fixing aid. By the use of the vinylamine polymer as a size-fixing aid, it has become possible to obtain a paper having superior sizing properties by papermaking at a pH around neutrality using a hitherto known acidic sizing agents without using a neutral sizing agent. The method of the present invention further has effects that operating efficiency of papermaking is greatly improved since contaminations of a papermaking machine due to a neutral agent can be avoided, and therefore, the prices of paper can be greatly lowered. The present method has further advantages when it is applied under acidic papermaking condition of a pH of less than 5.5. In such a condition, the addition amount of alum can be decreased and the life of a papermaking machine can be prolonged. In spite of a small amount of alum added, a considerably good sizing effect can be obtained by the present method.

Method for sizing of paper

Disclosed herein is a flocculating agent comprising a specified cationic polymer having an amidine structure. The cationic polymer flocculating agents according to the present invention have 20 to 90% by mole of a repeating amidine unit represented by the formula (1) and/or (2): ##STR1## The agents have a reduced viscosity of 0.1 to 10 dl/g as measured in a 1N saline solution of 0.1 g/dl at 25.degree. C. The agents have a remarkably excellent performance as flocculating agents, in particular for organic sludge.

Cationic polymer flocculating agents

Disclosed herein is a vinylamine copolymer having the structural units represented by the following formulas (I), (II), (III), (IV) and (V): ##STR1## wherein x.sup..crclbar. represents an anion or hydroxyl ion, R represents a hydrogen atom or a methyl group, M.sup..sym. represents a hydrogen ion or a monovalent cation, in which the molar fraction of the structural unit (I) is 5 to 85% by mole, the molar fraction of the structural unit (II) is 2 to 85% by mole, the molar fraction of the structural unit (III) is 5 to 80% by mole, the molar fraction of the structural unit (IV) is 0 to 40% by mole, all of said molar fractions being based on the vinylamine copolymer, and the molar fraction of the structural unit (V) is 0 to 8% by mole which is based on the total content of the structural units (III), (IV), and (V), a flocculating agent and a paper strength increasing agent using the vinylamine copolymer, and a process for producing the vinylamine copolymer.

Vinylamine copolymer, flocculating agent and paper strength increasing

Disclosed herein are an N-vinylformamide copolymer having the structural units represented by the following formulas (I) and (II): ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group and R.sub.2 represents an alkyl group of 1 to 4 carbon atoms, in which the molar ratio between the structural units (I) and (II) is from 20:80 to 95:5, and a process for producing the N-vinylformamide copolymer.

Vinylamine copolymer and process for producing same

Disclosed herein is a vinylamine copolymer having the structural units represented by the following formulas (I), (II), (III), (IV) and (V): ##STR1## wherein X.sup..crclbar. represents an anion or hydroxyl ion, R represents a hydrogen atom or a methyl group, M.sup..sym. represents a hydrogen ion or a monovalent cation, in which the molar fraction of the structural unit (I) is 5 to 85% by mole, the molar fraction of the structural unit (II) is 2 to 85% by mole, the molar fraction of the structural unit (III) is 5 to 80% by mole, the molar fraction of the structural unit (IV) is 0 to 40% by mole, all of said molar fractions being based on the vinylamine copolymer and the molar fraction of the structural unit (V) is 0 to 8% by mole which is based on the total content of the structural units (III), (IV) and (V), a flocculating agent and a paper strength increasing agent using the vinylamine copolymer, and a process for producing the vinylamine copolymer.

Vinylamine copolymer, flocculating agent etc.

Disclosed herein is a process for preparing a water-soluble polymer, which comprises granulating a hydrous gel-like polymer obtained by polymerizing N-vinylformamide in the form of an aqueous solution of which a monomer concentration is 20 to 60% by weight, dispersing the formed polymer particles in methanol and contacting them with an aqueous solution of ammonium salt of a monovalent acid in an amount of 1 to 200% by mole based on the formamide groups in said polymer, thereby partially modifying the formamide groups in the polymer.

Process for preparing water-soluble polymer

Disclosed herein is a vinylamine copolymer having the structural units represented by the general formulae (I), (II) and (III): ##STR1## (wherein X represents an anion or hydroxyl ion) ##STR2## (wherein R.sup.1 represents hydrogen atom or a methyl group, R.sup.2 represents hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R.sup.3 represents an alkyl group having 1 to 4 carbon atoms or an oxoalkyl group having 4 to 8 carbon atoms) in which the molar fraction of the structural unit (I) is 5 to 85% by mole, the molar fraction of the structural unit (II) is 5 to 85% by mole, and the molar fraction of the structural unit (III) is 90 to 5% by mole, a flocculating agent, a drainage aid and a paper strength increasing agent using such vinylamine copolymer, and a process for producing such vinylamine copolymer.

Vinylamine copolymer, flocculating agent using the same, and process for

Disclosed herein are a coagulant for minute mineral particles in suspension, comprising a copolymer of 0.5 to 10 mol % of 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof, 40 to 99.5 mol % of N-hydroxymethylacrylamide and 0 to 59.5 mol % of acrylamide and showing a reduced viscosity of 10 to 30 dl/g in an aqueous 1N solution of sodium chloride at a temperature of 25.degree. C. and a concentration of the copolymer of 0.1 g/dl therein, and a method for coagulating the minute mineral particles in a suspension, comprising adding the coagulant a neutral waste water.

Coagulant for minute mineral particles in suspension and method for

Disclosed herein is a process for producing N-substituted formamide represented by the formula: ##STR1## wherein R represents a hydrogen atom or a residual radical of a primary or secondary alcohol, comprising the steps of reacting formamide with acetaldehyde in the presence of a basic catalyst and if required, further reacting the thus formed product, N-(.alpha.-hydroxyethyl)formamide, with a primary or secondary alcohol in the presence of an acid catalyst.

Process for producing N-substituted formamides

Disclosed is a process for preparing a water-soluble bead polymer by dispersing drops of an aqueous solution of water-soluble vinyl monomer in a dispersing medium in the presence of a dispersion stabilizer, and polymerizing the monomer by using monomer selected from the following A and B (a) a compound of the general formula I ##STR1## wherein R.sup.1 is hydrogen or methyl, R.sup.2 and R.sup.3 may be the same or different and each is linear or branched alkyl of from 1 to 4 carbon atoms, R.sup.4 is hydrogen, linear or branched alkyl of from 1 to 8 carbon atoms, hydroxy alkyl of from 1 to 4 carbon atoms, or benzyl, Y is alkylene or hydroxyalkylene each of from 2 to 4 carbon atoms, and X.sup.- is an anion, or (B) a mixture of the compound of the formula I and a water-soluble vinyl monomer copolymerizable with the compound (I), and a cellulose ester or a cellulose ether insoluble in water but soluble in the dispersing medium is used as the dispersion stabilizer.

Process for preparing bead polymers

An aqueous gel of a water-soluble polymer containing units of a quaternary ammonium salt of an alkylacrylate or a methacrylate is dehydrated by adding at least one salt of a divalent metal and a strong acid to said gel and then dehydrating said gel.

Growing community of inventors

Yokohama, Japan

Shigeru Sawayama