Abstract: Provided is a block polymer including two or more polymer block As each having a value ? of 0.20 or less and a functional group F containing at least one element selected from a group consisting of nitrogen, silicon, oxygen, and sulfur in a part or all of terminals of the two or more polymer block As, in which the block polymer has a value ? of 0.75 or more, when p, q, r and s are defined as a component proportion (molar proportion) of a structural unit represented by Formula (1), a component proportion of a structural unit represented by Formula (2), a component proportion of a structural unit represented by Formula (3), and a component proportion of a structural unit represented by Formula (4), in the polymer, respectively.

Abstract: There is provided a polymer composition using which a molded product having excellent balance between rigidity, wear resistance, viscoelastic properties, and heat resistance can be obtained. A polymer composition according to the disclosure includes (A) a conjugated diene rubber (where, a polymer corresponding to the following component (B) is excluded); and (B) a hydrogenated product of a polymer that satisfies the following (1) to (3), which is a polymer in which 80% or more of structural units derived from butadiene are hydrogenated: (1) being a copolymer of a conjugated diene compound containing butadiene and an aromatic vinyl compound, (2) including a polybutadiene block having a vinyl group content of 20% or less, and (3) including a block composed of a conjugated diene compound and an aromatic vinyl compound.

Abstract: A method includes steps of: expressing changes of velocity components of a paper material at an exit of a slice lip by using a mathematical model, wherein the changes of velocity components are caused by manipulating an edge flow adjustment means (or a side bleed adjustment means) of a headbox when supplying the paper material on a wire; without changing a velocity component of a flow of the paper material in the mathematical model, setting the mathematical model based on an assumption in which a velocity component orthogonally crossing a flow direction of the paper material is proportionally changed by changes of an edge flow (or a side bleed) of a certain response width from the exit of the slice lip; and conducting a forecasting calculation of changes of a fiber orientation profile in a cross direction by using the mathematical model.

Abstract: A method includes steps of: expressing changes of velocity components of a paper material at an exit of a slice lip by using a mathematical model, wherein the changes of velocity components are caused by manipulating an edge flow adjustment means (or a side bleed adjustment means) of a headbox when supplying the paper material on a wire; without changing a velocity component of a flow of the paper material in the mathematical model, setting the mathematical model based on an assumption in which a velocity component orthogonally crossing a flow direction of the paper material is proportionally changed by changes of an edge flow (or a side bleed) of a certain response width from the exit of the slice lip; and conducting a forecasting calculation of changes of a fiber orientation profile in a cross direction by using the mathematical model.

Abstract: A high-strength and highly wet-heat-resistant polyvinyl-alcohol-based fiber--in which the crosslinking agent has hardly been oxidized by the heat at the drawing time upon preparation of the fiber, the crosslinking agent has not exhaled so much at the time of dry heat drawing, and the crosslinking agent has penetrated even inside of the fiber so that not only the surface but also the inside of the fiber has sufficiently been crosslinked--can be obtained by the steps of: preparing a polyvinyl-alcohl-based fiber by spinning the polyvinyl-alcohol-based solution, wet drawing the fiber, applying an acetalization compound of an aliphatic dialdehyde having at least 6 carbon atoms to the fiber, subjecting the fiber which contains above compound to dry heat drawing to a total draw ratio of at least 15, and then crosslinking the drawn filament with an acid under mild crosslinking treatment conditions.

Abstract: Provided are high-performance polyvinyl alcohol fibers having excellent resistances to hot water and dry heat as well as excellent strength and elastic modulus. The fibers are produced from a highly syndiotactic polyvinyl alcohol containing units from vinyl pivalate in an appropriate amount, which renders it possible to draw the highly crystalline fiber in a high drawing ratio of at least 16.

Abstract: High-strength polyvinyl alcohol fiber is provided by extruding a polyvinyl alcohol dope solution through a spinneret into a coagulating bath, the spinneret being located such that substantially only its dope-extruding surface contacts the coagulating bath. This process can produce stably and at a low cost polyvinyl alcohol fibers with excellent strength.

Abstract: Provided are a polyvinyl alcohol fiber having a specific higher order structure, obtained by having the orientation and arrangement of molecular chains forming the fiber which comprises a crystalline region and an amorphous region lie in specific ranges to thereby making the fiber have a break-ing temperature in hot water of at least 125.degree. C., or further at least 130.degree. C. and be excellent in abrasion resistance, while maintaining the tenacity and the modulus of the fiber at high levels; and a process for producing the same.