Teijin Limited

Noriaki Sasaki

Shigeyoshi Hara

Takeyuki Kawaguchi

Hiroyoshi Minematsu

Yutaka Taketani

Akihiro Aoki

Yuzuru Hayashi

Keizo Shimada

Hiroshi Mera

Michio Yamamoto

Tsutomu Kiriyama

Kenji Ishimaru

Yoshitaka Sakamoto

A method for treating synthetic pulp particles, which includes treating a slurry of synthetic pulp particles having a Schopper-Riegler freeness of more than 30.degree.SR by a concentration provided with a rotary filter bed to lower the freeness not more than 30.degree.SR, water-washing the synthetic pulp particles in the state where the freeness is not more than 30.degree.SR, and dispersing the synthetic pulp particles in water to restore the freeness to more than 30.degree.SR.

Method for treating synthetic pulp particles, and pulp particles

A cake of synthetic fibrid, which is formed by pressing to hydroextract a slurry of synthetic fibrid, pulverizing the compression product, and compressing the pulverization product again to solidity it in the form of a plate-like cake.

Cake of synthetic fibrid

An aromatic copolyamide comprising recurring units (A) of the formula (I), (B) of the formula (II) and (C) of the formula (III): ##STR1## wherein in (I), (II) and (III), Ar.sub.1 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented meta; Ar.sub.2 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented coaxially or in parallel to each other and radicals of the formula (IV): ##STR2## wherein Y.sub.1 and Y.sub.2 are independently ##STR3## and; X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 respectively are independently --NH-- and --CO-- radicals, connected to each other to form an amide bond (--NHCO-- or --CHNH--), and the molar proportions of said recurring units (A), (B), and (C) fall within a quadrilateral defined by the co-ordinates P, Q, R and S or on a twice-turned line defined by the co-ordinates Q, R, S and P:

Aromatic copolyamide containing 3,4'-diphenylene moiety

An aromatic copolyamide comprising recurring units (A) of the formula (I), (B) of the formula (II) and (C) of the formula (III): ##STR1## wherein in (I), (II) and (III) Ar.sub.1 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented meta; Ar.sub.2 is phenylene, naphthylene or biphenylene radicals, each having two valence bonds oriented coaxially or in parallel to each other and radicals of the formula (IV): ##STR2## wherein Y.sub.1 and Y.sub.2 are independently; ##STR3## and; X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 respectively are independently --NH-- and --CO-- radicals, connected to each other to form an amide bond (--NHCO-- or --CHNH--), and the molar proportions of said recurring units (A), (B) and (C) fall within a quadrilateral defined by the co-ordinates P, Q, R and S or on a twice-turned line defined by the co-ordinates Q,R,S, and P:

Aromatic copolyamide containing 3,4'-diamino diphenylene moiety

A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of a microporous substrate, the polymeric material being prepared by crosslinking a soluble polymer containing at least 30 mole % of a recurring unit of the formula ##STR1## wherein all symbols are as defined herein, and having at least 0.5 milliequivalent, per gram of said polymer, of an amino group containing 1 or 2 active hydrogen atoms, with a polyfunctional compound containing at least two functional groups capable of reacting with the amino group having 1 or 2 active hydrogen atoms; and a process for preparing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Semipermeable composite membrane

A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of a microporous substrate, said polymeric material being prepared by crosslinking a soluble polymer containing at least 30 mole % of a recurring unit of the formula ##STR1## wherein all symbols are as defined in claim 1, and having at least 0.2 milliequivalent, per gram of said polymer, of an amino group containing 1 or 2 active hydrogen atoms, with a polyfunctional compound containing at least two functional groups capable of reacting with the amino group having 1 or 2 active hydrogen atoms; and a process for preparing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of the microporous substrate, said polymeric material being prepared by interfacial crosslinking of a polymer containing a recurring unit of the formula ##STR1## wherein each of R.sub.1 and R.sub.2 represents a hydrogen atom or a methyl group, and W.sub.1 represents a direct bonding or a sulfonyl group (--SO.sub.2 --), with a polyfunctional compound containing at least two functional groups selected from acid halide, sulfonyl halide, isocyanate, N-haloformyl, haloformate and acid anhydride groups; and a process for producing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Growing community of inventors

Iwakuni, Japan

Noriaki Sasaki