Abstract: A thrust bearing includes: a top foil formed of top foil pieces which face a thrust collar; a back foil formed of back foil pieces which support the top foil pieces; and a base plate including support areas which support the back foil pieces. A support area includes an inclined surface defined by a first boundary line and by a second boundary line disposed on a trailing side of the first boundary line in the rotational direction of the thrust collar. The height of the inclined surface gradually increases from the first boundary line to the second boundary line. In addition, a back foil piece is disposed within the inclined surface which is formed continuously from the first boundary line to the second boundary line.

Abstract: A thrust bearing includes: a top foil formed of top foil pieces which face a thrust collar; a back foil formed of back foil pieces which support the top foil pieces; and a base plate including support areas which support the back foil pieces. A support area includes an inclined surface defined by a first boundary line and by a second boundary line disposed on a trailing side of the first boundary line in the rotational direction of the thrust collar. The height of the inclined surface gradually increases from the first boundary line to the second boundary line. In addition, a back foil piece is disposed within the inclined surface which is formed continuously from the first boundary line to the second boundary line.

Abstract: A process for the stabilization of an aqueous acrylamide solution is described which includes adding at least one compound selected from water-soluble monocarboxylic acid salts having at least two carbon atoms to an aqueous solution of acrylamide in an amount of from 20 to 5,000 ppm as acid per acrylamide. According to the present invention, a high purity aqueous acrylamide solution which is markedly stable, even under an iron surface-contacting condition, without causing problems such as the polymerization of acrylamide can be provided by adding a water-soluble monocarboxylic acid salt having at least two carbon atoms.

Abstract: A radical-curing polyvinyl alcohol derivative is disclosed, which is obtained by reacting an anion-modified polyvinyl alcohol prepared by saponification of a copolymer comprising vinyl acetate and an unsaturated carboxylic acid and/or a derivative thereof with a glycidyl-containing vinyl compound in water or in a mixed solvent of water and a lower alcohol under acidic conditions, and which is useful as an image-forming material which is curable upon light irradiation and developable with water.

Abstract: The invention relates to a process for producing a powder of a cationic polymer by spreading on a moveable carrier a layer of an aqueous solution of a vinyl monomer, carrying out continuous polymerization followed by peeling off hydrous polymer from the carrier in a hot state, and cutting said hydrous polymer in a hot state by a shearing stress.

Abstract: A process for preparing a cationic polymer which comprises polymerizing a monomer mixture containing acrylamide and a cationic alkenyl monomer represented by the general formula: ##STR1## wherein R.sup.1 represents H or CH.sub.3 ; R.sup.2 and R.sup.3 represent independently CH.sub.3 or C.sub.2 H.sub.5 ; R.sup.4 represents H, CH.sub.3, C.sub.2 H.sub.5 or a benzyl group; A represents --OC.sub.n H.sub.2n -- (wherein n=2 or 3), ##STR2## or --NC.sub.n H.sub.2n -- (wherein n=2 or 3); and X.sup.- represents Cl.sup.-, Br.sup.-, I.sup.-, CH.sub.3 SO.sub.4.sup.-, C.sub.2 H.sub.5 SO.sub.4.sup.-, 1/2SO.sub.4.sup.-- or CH.sub.3 COO.sup.-, in the form of a sheet in an aqueous medium, characterized in that the composition ratio of acrylamide/cationic alkenyl monomer is within the range of 95/5 to 5/95, and the polymerization is carried out in the presence of a phosphite. The polymers obtained according to this process are free from insolubles produced under the influence of oxygen.

Abstract: When an alkaline substance is added to and mixed with aggregates of the mutually adhering blobs of a hydrogel of an acrylamide polymer, (1) a mixing tank in which the portion to be contacted with the hydrogel of an acrylamide polymer is made of a chromium-plated material is used, and (2) to said hydrogel aggregates is added at least one compound represented by the general formulae: ##STR1## wherein R.sub.1 is a residue obtained by removing two OH groups from a saturated dihydric alcohol having 2 to 4 carbon atoms, and R.sub.2 is a residue obtained by removing three OH groups from a saturated trihydric alcohol having 3 to 6 carbon atoms, and having an average molecular weight of 500 to 5,000, whereby the hydrolysis of the acrylamide polymer can be achieved at a high efficiency while preventing the mutual adhesion of the hydrogel aggregates and also reducing the adhesion of the aggregates to the interior surface of the mixing tank to such an extent that there is substantially no problem of adhesion.

Abstract: In the production of a dried acrylamide polymer by polymerizing, in an aqueous medium, acrylamide alone or a monomer mixture comprising 50 mole % or more of acrylamide and at least one monomer copolymerizable therewith with a radical initiator, and then drying the resulting hydrous acrylamide polymer, the allowing of 2-mercaptobenzimidazole to be present in the drying step or a step prior thereto enables the dried acrylamide polymer having a high molecular weight and a good dissolvability in water to be obtained.

Abstract: In the production of a dried acrylamide polymer by polymerizing, in an aqueous medium, acrylamide alone or a monomer mixture comprising 50 mole % or more of acrylamide and at least one monomer copolymerizable therewith with a radical initiator, and then drying the resulting hydrous acrylamide polymer, the allowing of at least one of the following compounds [I], [II] and [III] to be present in the drying step or a step prior thereto enables the dried acrylamide polymer having a high molecular weight and a good dissolvability in water to be obtained:[I] a non-polymerizable compound having in its molecule at least one group represented by the formula, ##STR1## wherein R.sub.1 is H or an alkyl group having up to 4 carbon atoms, [II] a compound represented by the formula, R.sub.2 --S--C.sub.n H.sub.2n X wherein n is an integer of 1 to 8, R.sub.2 is an alkyl group, an aryl group or --C.sub.n H.sub.2n X, in which X is --OH, --COOH (or its salt), --CN or --CONH.sub.

Abstract: A process for producing a cationic polymer, which comprises polymerizing a vinyl monomer represented by the general formula, ##STR1## wherein R.sub.1 represents --H or --CH.sub.3, R.sub.2 represents --CH.sub.2 CH.sub.2 -- or ##STR2## R.sub.3 and R.sub.4 represent --CH.sub.3 or --CH.sub.2 CH.sub.3, R.sub.5 represents --C.sub.n H.sub.2n+1, in which n is an integer of 0 to 4, ##STR3## or --CH.sub.2 COOH, and X.sup.- represents Cl.sup.-, CH.sub.3 SO.sub.4.sup.-, CH.sub.3 SO.sub.3.sup.-, or 1/2 SO.sub.4.sup.--, either alone or in admixture with up to 25% by weight, based on the total weight of the monomers, of other copolymerizable vinyl monomers in the presence of 7 to 18% by weight, based on the weight of the polymerization system, of water and, if necessary, choline chloride by use of a polymerization initiator and elevating the temperature, in the final polymerization stage, to 110.degree. to 150.degree. C.

Abstract: A method for producing a water-soluble cationic polymer by polymerizing, in the presence of water, a high concentration of (a) at least one vinyl monomer represented by the following general formula (I)ch.sub.2 .dbd.cr.sub.1 coor.sub.2 n.sup..sym. r.sub.3 r.sub.4 r.sub.5 x.sup..crclbar. (i)wherein R.sub.1 is --H or --CH.sub.3 ; R.sub.2 is --CH.sub.2 CH.sub.2 -- or --CH.sub.2 CH(OH)CH.sub.2 --; R.sub.3 and R.sub.4, which may be the same or different, each is --CH.sub.3 or --CH.sub.2 CH.sub.3 ; R.sub.5 is --C.sub.n H.sub.2n+1 where n is 0 or an integer of 1 to 4, --CH.sub.2 C.sub.6 H.sub.5, or --CH.sub.2 COOH; and X is Cl.sup.-, Br.sup.-, 1/2SO.sub.4.sup.-- or CH.sub.3 SO.sub.4.sup.

Abstract: In a process for producing a water-soluble polymer in an easily grindable glassy state by subjecting to aqueous solution polymerization a mixture comprising a monomer composed mainly of a vinyl monomer represented by the general formula (I): ##STR1## and water in an amount of 7 to 18% by weight based on the total weight of the monomer and water, a water-soluble salt in a powdery form is added to and dispersed in the polymerization system and the polymerization is carried out in the state that the powdery salt is dispersed, whereby a water-soluble polymer excellent in flocculating action and dissolving workability is obtained.

Abstract: A method of reducing the adhesiveness of a water-soluble hydrogel-like polymer obtainable by aqueous solution polymerization of acrylamide or a monomeric mixture consisting mainly of acrylamide in a high monomer concentraton using polyethylene glycol. Where the hydrogel-like polymer has already been formed, the adhesiveness of the polymer can be reduced by merely applying polyethylene glycol to the surface of the polymer. Where it is desired to obtain a hydrogel-like polymer whose adhesiveness has been reduced, a very simple method of performing the polymerization in the presence of polyethylene glycol can be used to achieve the desired objective.

Abstract: A process for producing a partially hydrolyzed polyacrylamide which has a high molecular weight and high water solubility and can be suitably used as a flocculant for water treatment and a size for paper manufacture comprising polymerizing an aqueous solution of an acrylamide monomer in the presence of an alkali metal hydroxide such as sodium hydroxide and boric acid, whereby a partial hydrolysis of the polymer formed is also conducted substantially simultaneously with the polymerization. In an additional embodiment, a maturing of the polyacrylamide produced can be conducted by continuing to heat the polymer solution to increase the hydrolysis percentage.