Toray Industries, Inc.

Koji Nakatsuji

Masahiro Kimura

Hiroki Minehara

Tsuyoshi Hamada

Jun Okabe

Takao Sasaki

Masakazu Koiwa

Hiroki Tomioka

Hiroaki Tanaka

Ryoma Miyamoto

Kentaro Takagi

Hiroo Takabatake

Takafumi Ogawa

Harutoki Shimura

Masaki Higashi

Yoshie Marutani

Shinya Shimoda

Kiyohiko Takaya

Kenji Saito

The present invention relates to a damage inspection method for a reverse osmosis membrane, in which at least one of: presence or absence of physical damage; and a degree of physical damage in a reverse osmosis membrane is inspected based on presence or absence of a stained area on at least a permeate side of a stained membrane obtained by supplying a water-to-be-treated including a staining agent to the reverse osmosis membrane to stain the reverse osmosis membrane.

Method for inspecting damage in reverse osmosis membrane

The present invention relates to a composite semipermeable membrane including: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, in which the separation functional layer includes: a crosslinked polyamide; and a hydrophilic polymer which is a polymer of a monomer having an ethylenically unsaturated group, and a surface of the separation functional layer has a ratio of the number of oxygen atoms to the number of nitrogen atoms (O/N ratio), both determined by X-ray photoelectron spectrometry, of 1.5-10, and a standard deviation of the O/N ratio of 0.15 or larger.

Composite semipermeable membrane and method for producing composite semipermeable membrane

An object of the present invention is to provide a separation membrane having high permeability and selective removability of divalent/monovalent ions. The separation membrane of the present invention includes a supporting membrane and a separation functional layer formed on the supporting membrane, in which the separation functional layer contains a polymerized product of a polyfunctional amine with a polyfunctional acid halide, the polyfunctional amine contains a polyfunctional aliphatic amine as a main component, the separation functional layer has a hollow protuberant structure, and the separation functional layer has a relative surface area of 1.1-10.0.

Separation membrane, separation membrane element, water purifier, and method for producing separation membrane

This composite semipermeable membrane is provided with: a porous supporting membrane that comprises a base and a porous supporting layer; and a separating function layer that is provided on the porous supporting layer. With respect to this composite semipermeable membrane, the standard deviation of pore radius of the separating function layer as determined by positron annihilation lifetime measurement is 0.025 nm or less.

An object of the present invention is to provide a composite semipermeable membrane which has a high permeation rate and high salt removal performance and is excellent in terms of performance stability during long-term operation. The composite semipermeable membrane of the present invention includes: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, the separation functional layer includes a crosslinked polyamide and a hydrophilic polymer having an acidic group, and in the separation functional layer, a ratio of (molar equivalent of amino groups)/(molar equivalent of amide groups) is 0.18 or less.

Composite semipermeable membrane and method for producing same

A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 &#x3bc;m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/&#x3bc;m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

Composite semipermeable membrane

The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 &#x3bc;m and includes a portion where a degree of cyclization (I/I) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

Solvent-resistant separation membrane

Disclosed herein are a composite semipermerable membrane and a method for producing the same. The composite semipermeable membrane comprises a microporous support membrane and a separation functional layer provided on the microporous support membrane, wherein the separation functional layer contains a condensation product produced by condensation of at least one selected from the group consisting of ions of trialkoxysilanes each having an imidazolium group and a conjugated base of a polymer having at least one acidic group. The composite semipermeable membrane achieves excellent selective separation of divalent ions over monovalent ions, and is suitable for use in various water treatment fields such as seawater desalination and drinking water production.

Composite semipermeable membrane and method for producing the same

Disclosed is a composite semipermeable membrane, which comprises a separation functional layer on a microporous support, and in which the separation functional layer is made of a condensation product of a polymer that has acidic groups and a trialkoxysilane groups having an imidazolium structure in side chains. The composite semipermeable membrane has excellent selective separation performance for divalent ions over monovalent ions, while exhibiting excellent long-term durability. Also disclosed is a method for producing the composite semipermeable membrane. The composite semipermeable membrane is suitable for uses in various water treatment fields such as the desalination of seawater and the production of drinking water. In addition, the composite semipermeable membrane does not deteriorate as much as conventional composite semipermeable membrane even in cases where the membrane is sterilized by having chlorine-containing raw water permeate therethrough continuously or intermittently.

There is provided a composite semipermeable membrane that shows a high salt removal ratio and high performance in rejecting boron that is not dissociated in the neutral region. The composite semipermeable membrane is produced by a process that includes forming a separating functional polyamide layer on a porous substrate film, while using an organic solvent solution containing a specific cyclic aliphatic compound or a specific aromatic compound such that a polyamide molecule that forms the separating functional polyamide layer has a partial structure composed of 'a cyclic aliphatic group or an aromatic group having at least two specific substituents, at least one of which contains a heteroatom bond and a carbonyl group at the &#x3b2; or &#x3b3; position'.

Composite semipermeable membranes, methods for production thereof and uses thereof

A composite semipermeable membrane, which comprises a separating functional layer comprising a reactant of polyfunctional amine with polyfunctional acid halide, wherein a water-soluble organic material is in contact with the separating functional layer, and the separating functional layer has a boron removal ratio of 95% or more, when seawater at 25&#xb0; C. having a pH of 6.5, a boron concentration of 5 ppm and a TDS concentration of 3.5% by weight is permeated under an operation pressure of 5.5 MPa.

Composite semipermeable membrane, production process thereof, and element, fluid separation equipment and treatment method for boron-containing water using the same

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Ehime, Japan

Koji Nakatsuji