JPH10337454A - Reverse osmotic multipie membrane and reverse osmosis treatment of water using the same - Google Patents
Reverse osmotic multipie membrane and reverse osmosis treatment of water using the sameInfo
- Publication number
- JPH10337454A JPH10337454A JP10089671A JP8967198A JPH10337454A JP H10337454 A JPH10337454 A JP H10337454A JP 10089671 A JP10089671 A JP 10089671A JP 8967198 A JP8967198 A JP 8967198A JP H10337454 A JPH10337454 A JP H10337454A
- Authority
- JP
- Japan
- Prior art keywords
- reverse osmosis
- composite membrane
- osmosis composite
- water
- active layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
- Removal Of Specific Substances (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、液状混合物の成分
を選択的に分離するための逆浸透複合膜の性能安定性、
耐汚染性等の膜性能の向上に関するものである。さらに
詳しくは、逆浸透複合膜上に有機重合体薄膜を備えた、
高塩阻止率、高耐塩素殺菌剤性、及び、高耐汚染性等を
有する逆浸透複合膜とこれを用いた水の逆浸透処理方法
に関する。The present invention relates to the performance stability of a reverse osmosis composite membrane for selectively separating components of a liquid mixture,
The present invention relates to improvement of film performance such as stain resistance. More specifically, with an organic polymer thin film on a reverse osmosis composite membrane,
The present invention relates to a reverse osmosis composite membrane having a high salt rejection rate, a high resistance to chlorine disinfectants, a high resistance to contamination and the like, and a reverse osmosis treatment method for water using the same.
【０００２】かかる逆浸透複合膜は、超純水の製造、か
ん水の脱塩等に好適であり、また染色排水や電着塗料排
水、生活排水等の公害発生原因である汚水等から、その
中に含まれる汚染源あるいは有効物質を除去回収して排
水のクローズ化に寄与することができる。特に、透過水
量の低下を招く種々膜汚染物質、例えば界面活性剤、鉄
などの遷移金属成分が含まれる水質に対しても長期間安
定して運転することが可能である。Such a reverse osmosis composite membrane is suitable for production of ultrapure water, desalination of brackish water, and the like, and is useful for removing polluted water such as dyeing wastewater, electrodeposition paint wastewater, domestic wastewater, etc. It can contribute to the closure of wastewater by removing and collecting the polluting source or effective substance contained in the wastewater. In particular, it is possible to operate stably for a long period of time even for water quality containing various membrane contaminants causing a decrease in the amount of permeated water, for example, a surfactant and a transition metal component such as iron.
【０００３】[0003]
【従来の技術】工業的に利用されている逆浸透膜には、
酢酸セルロースから作った非対称膜として、例えば、米
国特許第3133132号明細書や米国特許第3133137号明細書
に記載されたロブ型の膜がある。一方、非対称逆浸透膜
とは構造の異なる逆浸透膜として、微孔性支持膜上に実
質的に選択分離性を有する活性な薄膜を形成してなる逆
浸透複合膜が知られている。BACKGROUND ART Reverse osmosis membranes used industrially include:
As an asymmetric membrane made of cellulose acetate, for example, there is a lob type membrane described in US Pat. No. 3,133,132 or US Pat. No. 3,133,137. On the other hand, as a reverse osmosis membrane having a structure different from that of an asymmetric reverse osmosis membrane, a reverse osmosis composite membrane formed by forming an active thin film having substantially selective separation on a microporous support membrane is known.
【０００４】現在、かかる逆浸透複合膜として、多官能
芳香族アミンと多官能芳香族酸ハロゲン化物との界面重
合によって得られるポリアミドからなる薄膜が支持膜上
に形成されたものが多く知られている（例えば、特開昭
55-147106号公報、特開昭62-121603号公報、特開昭63−
218208号公報、特開平2-187135号公報等）。又、多官能
芳香族アミンと多官能脂環式酸ハロゲン化物との界面重
合によって得られるポリアミドからなる薄膜が、支持膜
上に形成されたものも知られている（例えば、特開昭61
-42308号公報等）。更に、逆浸透膜を後処理する方法も
種々開示されている。例えば、保護層として種々の有機
重合体を用いる例も開示されている（例えば、特開昭51
-13388号公報、特開昭53-16372号公報、特開昭62−1971
05号公報、特公平7-90152号公報など）。[0004] At present, as such a reverse osmosis composite membrane, a membrane in which a thin film made of a polyamide obtained by interfacial polymerization of a polyfunctional aromatic amine and a polyfunctional aromatic acid halide is formed on a support film is widely known. (For example,
JP-A-55-147106, JP-A-62-121603, JP-A-63-121
218208, JP-A-2-187135, etc.). Further, a thin film made of a polyamide obtained by interfacial polymerization of a polyfunctional aromatic amine and a polyfunctional alicyclic acid halide formed on a support film is also known (for example, Japanese Patent Application Laid-Open No.
No. -42308). Further, various methods for post-treating the reverse osmosis membrane have been disclosed. For example, an example in which various organic polymers are used as a protective layer is disclosed (for example, Japanese Patent Application Laid-Open No.
-13388, JP-A-53-16372, JP-A-62-1971
No. 05, Japanese Patent Publication No. 7-90152, etc.).
【０００５】近年、下水に代表されるような種々の界面
活性剤等の汚染物質を含む水処理への逆浸透膜の応用が
期待されているが、この場合、高い逆浸透膜性能（高塩
阻止性能・高透水性能）に加え、透水量を長期間保持す
るために高い耐汚染性が必要になる。これらの２つの要
求を満たすためには上記逆浸透膜や従来の後処理法等で
は不十分であり、さらに高性能な逆浸透複合膜が求めら
れている。汚染機構の一つとして、膜の荷電状態が挙げ
られる。例えば、多官能芳香族アミンと多官能脂環式酸
ハロゲン化物との界面重合によって得られる架橋ポリア
ミド型逆浸透膜は残存カルボン酸の影響で表面は負荷電
を有している。この負荷電を有する膜面に例えばカチオ
ン性汚染物質等が吸着して透水量の低下をもたらす。従
って、荷電的に中性であり、かつ高透水性能・高塩阻止
性能を併せ持つ膜が必要とされる。In recent years, the application of reverse osmosis membranes to water treatment containing contaminants such as various surfactants represented by sewage is expected. In this case, high reverse osmosis membrane performance (high salt In addition to blocking performance and high water permeability, high contamination resistance is required to maintain the water permeability for a long period of time. In order to satisfy these two requirements, the reverse osmosis membrane and the conventional post-treatment method are not sufficient, and a higher performance reverse osmosis composite membrane is required. One of the contamination mechanisms is the charge state of the membrane. For example, a crosslinked polyamide type reverse osmosis membrane obtained by interfacial polymerization of a polyfunctional aromatic amine and a polyfunctional alicyclic acid halide has a negative charge on the surface due to the influence of the residual carboxylic acid. For example, a cationic contaminant or the like is adsorbed on the negatively charged membrane surface, resulting in a decrease in water permeability. Therefore, there is a need for a membrane that is neutral in terms of charge and has both high water permeability and high salt rejection.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、高塩阻止
率、高透水性と高耐汚染性を併せ有し、低圧で実用性の
ある脱塩を可能にする逆浸透複合膜及びこれを用いた水
の逆浸透処理方法を提供することを目的とする。SUMMARY OF THE INVENTION The present invention relates to a reverse osmosis composite membrane which has both high salt rejection, high water permeability and high stain resistance, enables practical desalination at a low pressure, and a reverse osmosis composite membrane. It is an object of the present invention to provide a method for reverse osmosis treatment of used water.
【０００７】[0007]
【課題を解決するための手段】前記目的を達成するた
め、本発明の逆浸透複合膜は、スポンジ層とその表面の
分離活性層を含む逆浸透複合膜であって、前記分離活性
層内に電気的に中性の有機物及び有機重合体から選ばれ
る少なくとも一つの物質を存在させるか、または前記分
離活性層の表面に電気的に中性の有機物及び有機重合体
から選ばれる少なくとも一つの物質を被覆させており、
かつ前記少なくとも一つの物質を存在している層または
前記表面被覆前の分離活性層の比表面積が２以上１００
０以下であることを特徴とする。本発明において、分離
活性層とスキン層とは同義である。前記において比表面
積とは、次の式で定義される。 スキン層の比表面積＝（スキン層の表面積）／（支持体
の表面積） 前記スキン層の表面積は、供給液と接触する側の表面の
面積を表している。支持体の表面積は、スキン層の下の
スポンジ層が接触している、例えばポリスルホンのよう
な支持膜の表面積を示している。前記スキン層の比表面
積が２以上であるということは、支持膜の表面が比較的
平らで、スキン層の表面が凸凹であったり、皺が入って
いるような場合に実現する。前記表面積及び比表面積を
求める測定方法は、一般的な測定方法、例えば表面積測
定装置、比表面積測定装置、走査型電子顕微鏡、透過型
電子顕微鏡、または原子間力顕微鏡などがある。In order to achieve the above object, a reverse osmosis composite membrane of the present invention is a reverse osmosis composite membrane including a sponge layer and a separation active layer on the surface thereof, wherein At least one substance selected from an electrically neutral organic substance and an organic polymer is present, or at least one substance selected from an electrically neutral organic substance and an organic polymer on the surface of the separation active layer. Have been coated,
And the specific surface area of the layer containing the at least one substance or the separation active layer before the surface coating is 2 or more and 100 or more.
0 or less. In the present invention, the separation active layer and the skin layer are synonymous. In the above, the specific surface area is defined by the following equation. Specific surface area of skin layer = (surface area of skin layer) / (surface area of support) The surface area of the skin layer represents the surface area on the side that comes into contact with the supply liquid. The surface area of the support indicates the surface area of the support membrane, such as polysulfone, with which the sponge layer below the skin layer is in contact. The fact that the specific surface area of the skin layer is 2 or more is realized when the surface of the support film is relatively flat and the surface of the skin layer is uneven or wrinkled. The measuring method for obtaining the surface area and the specific surface area includes a general measuring method, for example, a surface area measuring device, a specific surface area measuring device, a scanning electron microscope, a transmission electron microscope, or an atomic force microscope.
【０００８】前記逆浸透複合膜においては、前記少なく
とも一つの物質を存在している層または前記表面被覆前
の分離活性層の比表面積が３以上５００以下であること
が好ましい。３未満であると十分な透水性が得られず、
５００を超えるとスキン層強度が低下する。In the reverse osmosis composite membrane, the specific surface area of the layer in which the at least one substance is present or the separation active layer before the surface coating is preferably 3 or more and 500 or less. If it is less than 3, sufficient water permeability cannot be obtained,
If it exceeds 500, the strength of the skin layer decreases.
【０００９】また前記逆浸透複合膜においては、前記表
面被覆後の分離活性層の比表面積が、表面被覆前の分離
活性層の比表面積の９０％以下に減少していることが好
ましく、さらに好ましくは６０％以下に減少しているこ
とである。減少率が９０％を超える場合は、十分に表面
被覆されていないことに該当し、長期の安定した耐汚染
性を有する運転が損なわれる。In the reverse osmosis composite membrane, it is preferable that the specific surface area of the separation active layer after the surface coating is reduced to 90% or less of the specific surface area of the separation active layer before the surface coating. Is reduced to 60% or less. When the reduction rate exceeds 90%, it means that the surface is not sufficiently coated, and a long-term operation having stable stain resistance is impaired.
【００１０】また前記逆浸透複合膜においては、電気的
に中性の有機物及び有機重合体から選ばれる少なくとも
一つの物質が、非イオン系の親水基を有する有機物又は
有機重合体であることが好ましい。電気的に中性が好ま
しいのは、膜に対する水中に存在している荷電基を有す
る膜汚染物質の電気的な吸着を抑制するからである。ま
た非イオン系の親水基（例えば−ＯＨ基）を有すると、
前記電気的に中性という特性に加えて、膜汚染物質が疎
水性基を有する場合、膜での疎水性相互作用による吸着
を抑制するからである。In the reverse osmosis composite membrane, at least one substance selected from an electrically neutral organic substance and an organic polymer is preferably an organic substance or an organic polymer having a nonionic hydrophilic group. . Electric neutrality is preferred because it suppresses the electrical adsorption of membrane contaminants having charged groups present in water on the membrane. Further, when it has a nonionic hydrophilic group (for example, -OH group),
This is because, when the film contaminant has a hydrophobic group in addition to the above-described electrically neutral property, adsorption due to hydrophobic interaction in the film is suppressed.
【００１１】また前記逆浸透複合膜においては、非イオ
ン系の親水基を有する有機物又は有機重合体が、２５℃
の水に対し不溶性であり、８０℃の水に対し可溶性であ
るポリビニルアルコールであることが好ましい。このよ
うなポリビニルアルコールは、膜汚染物質の吸着を抑制
する作用が高い。逆に、８０℃を超える温度の水に対し
ても不溶であるポリビニルアルコールは、アルコール基
の数が少ないため、膜汚染物質の吸着を抑制できない傾
向となる。また前記逆浸透複合膜においては、ポリビニ
ルアルコールのケン化度は９５％以上であることが好ま
しい。アルコール基を十分に確保できるからである。[0011] In the reverse osmosis composite membrane, an organic substance or an organic polymer having a nonionic hydrophilic group is kept at 25 ° C.
It is preferably a polyvinyl alcohol which is insoluble in water and soluble in water at 80 ° C. Such polyvinyl alcohol has a high effect of suppressing the adsorption of film contaminants. Conversely, polyvinyl alcohol, which is insoluble in water at a temperature exceeding 80 ° C., tends to be unable to suppress the adsorption of membrane contaminants because the number of alcohol groups is small. Further, in the reverse osmosis composite membrane, the saponification degree of polyvinyl alcohol is preferably 95% or more. This is because an alcohol group can be sufficiently secured.
【００１２】また前記逆浸透複合膜においては、前記分
離活性層の表面に被覆した電気的に中性の有機物及び有
機重合体から選ばれる少なくとも一つの物質が、非イオ
ン系の親水基を有する有機物又は有機重合体であり、か
つその厚さが、０．００１〜１μｍの範囲であることが
好ましい。厚さが１μｍを超えると被膜処理後の透水性
の低下が大きく、０．００１μｍ未満では均一な被覆処
理が困難となる。In the reverse osmosis composite membrane, at least one substance selected from an electrically neutral organic substance and an organic polymer coated on the surface of the separation active layer is an organic substance having a nonionic hydrophilic group. Alternatively, it is preferably an organic polymer and its thickness is in the range of 0.001 to 1 μm. When the thickness exceeds 1 μm, the water permeability after the coating treatment is greatly reduced, and when the thickness is less than 0.001 μm, uniform coating treatment becomes difficult.
【００１３】また前記逆浸透複合膜においては、圧力
７．５kgf/cm2、温度２５℃、供給液５００ｐｐｍのＮ
ａＣｌ溶液の条件下での逆浸透試験において、その透水
量が０．６［ｍ3／ｍ2／日］以上であることが好まし
い。被覆処理後の透水量を十分に確保するためである。In the reverse osmosis composite membrane, the pressure is 7.5 kgf / cm 2 , the temperature is 25 ° C., and the feed liquid is 500 ppm N.
In a reverse osmosis test under conditions of an aCl solution, the water permeability is preferably 0.6 [m 3 / m 2 / day] or more. This is for ensuring a sufficient water permeability after the coating treatment.
【００１４】また前記逆浸透複合膜においては、逆浸透
複合膜が、１５圧力kgf/cm2、温度２５℃、供給液１５
００ｐｐｍのＮａＣｌ溶液の条件下での逆浸透試験にお
いて、その透水量が０．６［ｍ3／ｍ2／日］以上である
ことが好ましい。実用レベルでの透水量を十分に確保す
るために好ましい。In the reverse osmosis composite membrane, the reverse osmosis composite membrane has a pressure of 15 kgf / cm 2 , a temperature of 25 ° C.,
In a reverse osmosis test under the condition of a 00 ppm NaCl solution, the water permeability is preferably 0.6 [m 3 / m 2 / day] or more. It is preferable to ensure sufficient water permeability at a practical level.
【００１５】また前記逆浸透複合膜においては、逆浸透
複合膜が、芳香族系ポリアミドで形成されていることが
好ましい。ここで芳香族系ポリアミドとは、酸成分及び
アミン成分から選ばれる少なくとも一つの成分が芳香族
を含むものをいう。好ましい芳香族系ポリアミドは、酸
成分及びアミン成分がともに芳香族を含む全芳香族系ポ
リアミドである。このような芳香族系ポリアミドは、高
い透水性と高い塩阻止率を保持できる。In the reverse osmosis composite membrane, it is preferable that the reverse osmosis composite membrane is formed of an aromatic polyamide. Here, the aromatic polyamide refers to a polyamide in which at least one component selected from an acid component and an amine component contains an aromatic component. Preferred aromatic polyamides are wholly aromatic polyamides in which both the acid component and the amine component contain aromatics. Such an aromatic polyamide can maintain high water permeability and high salt rejection.
【００１６】次に本発明の水の逆浸透処理方法は、スポ
ンジ層とその表面の分離活性層を含む逆浸透複合膜であ
って、前記分離活性層内に電気的に中性の有機物及び有
機重合体から選ばれる少なくとも一つの物質を存在させ
るか、または前記分離活性層の表面に電気的に中性の有
機物及び有機重合体から選ばれる少なくとも一つの物質
を被覆させており、かつ前記少なくとも一つの物質を存
在している層または前記表面被覆前の分離活性層の比表
面積が２以上１０００以下である逆浸透複合膜を原水に
接触させて逆浸透処理を行うことを特徴とする。Next, a reverse osmosis treatment method for water according to the present invention is directed to a reverse osmosis composite membrane including a sponge layer and a separation active layer on the surface thereof, wherein an electrically neutral organic substance and an organic substance are contained in the separation active layer. At least one substance selected from polymers is present, or the surface of the separation active layer is coated with at least one substance selected from an electrically neutral organic substance and an organic polymer; The reverse osmosis treatment is performed by bringing a layer in which two substances exist or a reverse osmosis composite membrane having a specific surface area of 2 or more and 1000 or less of the separation active layer before surface coating into contact with raw water.
【００１７】前記方法においては、逆浸透複合膜は、供
給する原水として、界面活性剤を含有する水を処理する
のにも有用である。従来の逆浸透複合膜では、界面活性
剤が膜に吸着してしまい、安定した性能が得られなかっ
たのに対して、本発明の逆浸透複合膜を用いると、界面
活性剤の膜への吸着が抑制されるので、分離性能の低下
が無く安定して界面活性剤含有水を逆浸透処理できる。
また前記方法においては、界面活性剤の含有量は０．０
１ppm 〜２０wt%の範囲であることが好ましい。本発明
の処理方法においては、界面活性剤の含有量はいかなる
範囲であっても使用できるが、界面活性剤の含有量が
０．０１ppm 以上２０wt% 以下の範囲であると、本発明
の表面電位の特性を十分発揮できる。In the above method, the reverse osmosis composite membrane is also useful for treating water containing a surfactant as raw water to be supplied. In the conventional reverse osmosis composite membrane, the surfactant was adsorbed to the membrane, and stable performance was not obtained. On the other hand, when the reverse osmosis composite membrane of the present invention was used, the surfactant was applied to the membrane. Since the adsorption is suppressed, the surfactant-containing water can be subjected to reverse osmosis treatment stably without a decrease in separation performance.
Further, in the above method, the content of the surfactant is 0.0
Preferably, it is in the range of 1 ppm to 20 wt%. In the treatment method of the present invention, the surfactant content can be used in any range, but if the surfactant content is in the range of 0.01 ppm to 20 wt%, the surface potential of the present invention is reduced. Characteristics can be fully exhibited.
【００１８】また前記方法においては、逆浸透複合膜
は、供給する原水として、遷移金属成分を含む水を処理
するのにも有用である。従来の逆浸透複合膜では、遷移
金属成分が膜に吸着してしまい、安定した性能が得られ
なかったのに対して、本発明の逆浸透複合膜を用いる
と、遷移金属成分の膜への吸着が抑制されるので、分離
性能の低下が無く安定して遷移金属成分含有水を逆浸透
処理できる。また前記方法においては、遷移金属成分が
鉄であることが好ましい。鉄成分の吸着を十分に抑制で
きる特性を本発明の逆浸透膜は有するからである。また
前記方法においては、遷移金属成分の含有量は０．０１
ppm 〜２０wt%の範囲であることが好ましい。本発明の
処理方法においては、遷移金属成分の含有量はいかなる
範囲であっても使用できるが、遷移金属成分の含有量が
０．０１ppm以上２０wt%以下の範囲であると、本発明の
表面電位の特性を十分発揮できる。In the above method, the reverse osmosis composite membrane is also useful for treating water containing a transition metal component as raw water to be supplied. In the conventional reverse osmosis composite membrane, the transition metal component was adsorbed on the membrane, and stable performance was not obtained.On the other hand, when the reverse osmosis composite membrane of the present invention was used, the transition metal component Since the adsorption is suppressed, the water containing the transition metal component can be subjected to reverse osmosis treatment stably without a decrease in separation performance. In the above method, the transition metal component is preferably iron. This is because the reverse osmosis membrane of the present invention has a property capable of sufficiently suppressing the adsorption of the iron component. In the above method, the content of the transition metal component is 0.01%.
It is preferably in the range from ppm to 20 wt%. In the treatment method of the present invention, the content of the transition metal component can be used in any range, but when the content of the transition metal component is in the range of 0.01 ppm to 20 wt%, the surface potential of the present invention is reduced. Characteristics can be fully exhibited.
【００１９】本発明方法において、ＴＯＣ（total orga
nic carbon）が２０〜３０ｐｐｍという高濃度の汚染物
質（界面活性剤を含む）を含む原水を処理する場合で
も、フラックス(Flux)の低下はみられない。すなわち、
実用的な水処理ができる。これに対して従来技術ではフ
ラックスの低下がみられ、実用的な水処理はできなかっ
た。以上説明した通り、本発明の逆浸透膜及びこれを用
いた逆浸透処理方法によれば、高塩阻止率、高透水性と
高耐汚染性を併せ有し、低圧で実用性のある脱塩ができ
る。In the method of the present invention, TOC (total orga)
Even when treating raw water containing a high concentration of contaminants (including surfactants) of 20 to 30 ppm (nic carbon), no reduction in flux is observed. That is,
Practical water treatment is possible. On the other hand, in the prior art, the flux was reduced, and practical water treatment could not be performed. As described above, according to the reverse osmosis membrane of the present invention and the reverse osmosis treatment method using the same, a high salt rejection rate, a high water permeability and a high contamination resistance, and a low-pressure and practical desalination Can be.
【００２０】[0020]
【発明の実施の形態】本発明の表面ζ電位の制御法とし
ては特に限定されないが、逆浸透複合膜表面を電気的に
中性の、より好ましくは非イオン系の親水基を有する有
機物及び有機重合体から選ばれる少なくとも一つの物質
により処理することが好適である。かかる電気的に中性
の有機物及び有機重合体から選ばれる少なくとも一つの
物質とは、カチオン性基とアニオン性基を共に有する有
機物又は有機重合体であり、これらは、共重合体、ブレ
ンド体として調製される。なお、前記の「カチオン性基
とアニオン性基を共に有する」とは、１つの分子であれ
ば、カチオン性基とアニオン性基とを１つの分子内に共
存する物質をいう。その結果、相互に電気的に相殺し合
うために中性となる。また、複数分子のブレンド体や組
成物の場合は、混合した結果、カチオン性基の総計とア
ニオン性基の総計がほぼ同一となって、相互に電気的に
相殺し合うために中性となる。したがって、ブレンド体
や組成物の場合は、系全体で中性であればよい。かかる
非イオン系の親水性基とは、例えば下記式（化１〜４）
に代表されるものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for controlling the surface ζ potential of the present invention is not particularly limited, but it is preferable that the surface of the reverse osmosis composite membrane is electrically neutral, more preferably an organic substance having a nonionic hydrophilic group and an organic substance. It is preferable to treat with at least one substance selected from polymers. The at least one substance selected from such electrically neutral organic substances and organic polymers is an organic substance or organic polymer having both a cationic group and an anionic group, and these are copolymers and blends. Prepared. The term “having both a cationic group and an anionic group” refers to a substance in which a cationic group and an anionic group coexist in one molecule if it is a single molecule. As a result, they become neutral because they mutually cancel each other out electrically. In addition, in the case of a blend or composition of a plurality of molecules, as a result of mixing, the total of the cationic groups and the total of the anionic groups become substantially the same, and neutral because they mutually cancel each other out electrically. . Therefore, in the case of a blend or a composition, it suffices if the entire system is neutral. Such a nonionic hydrophilic group is represented by, for example, the following formula (Chemical Formulas 1 to 4)
It is represented by
【００２１】[0021]
【化１】ＨＯ−HO-
【００２２】[0022]
【化２】 Embedded image
【００２３】[0023]
【化３】−ＣＯＮＨ2 −## STR3 ## -CONH 2-
【００２４】[0024]
【化４】−ＣＨ2 ＣＨ2 ＯＲ− （ただし、ＲはＣ1-4 のアルキル基を示す。）Embedded image —CH 2 CH 2 OR— (where R represents a C 1-4 alkyl group)
【００２５】これら非イオン系の親水性基を有する有機
物としては、トリエチレングリコール、ジエチレングリ
コール等のオリゴマーがあり、また非イオン系の親水性
基を有する有機重合体としては、ポリビニルアルコー
ル、ケン化ポリエチレン−酢酸ビニル共重合体、ポリビ
ニルピロリドン、ヒドロキシプロピルセルロース、ポリ
エチレングリコール等の非イオン系の親水性基を持つビ
ニル系重合体、非イオン系の親水性基を有する縮合系重
合体、または非イオン系の親水性基を有する付加系重合
体等から選ばれるものである。より好ましい有機重合体
は２５℃において水不溶性であり、且つ、熱水に可溶な
非イオン系の親水性基を有する有機重合体、例えば、ポ
リビニルアルコールが用いられる。Examples of the organic substance having a nonionic hydrophilic group include oligomers such as triethylene glycol and diethylene glycol, and examples of the organic polymer having a nonionic hydrophilic group include polyvinyl alcohol and saponified polyethylene. A vinyl polymer having a nonionic hydrophilic group such as a vinyl acetate copolymer, polyvinylpyrrolidone, hydroxypropylcellulose, or polyethylene glycol, a condensation polymer having a nonionic hydrophilic group, or a nonionic polymer Selected from addition polymers having a hydrophilic group. A more preferred organic polymer is a water-insoluble organic polymer having a nonionic hydrophilic group soluble in hot water at 25 ° C., for example, polyvinyl alcohol.
【００２６】ポリビニルアルコールを用いる場合、ケン
化度が９５％以上、より好ましくはケン化度９９〜１０
０％の範囲である。この場合、ポリビニルアルコールは
分子鎖間水素結合により２５℃では水不溶性になるが、
８０℃の水には可溶である。これらの条件を満たすこと
は、処理水と接する膜表面での−ＯＨ基が多いことに起
因し親水性の増加により、汚染物質に対する耐性が高く
なり、又、表面処理に伴う透過水量の低下も抑制され、
非常に良好な膜性能を付加することができるため好適で
ある。When polyvinyl alcohol is used, the degree of saponification is 95% or more, and more preferably, the degree of saponification is 99 to 10.
The range is 0%. In this case, polyvinyl alcohol becomes water-insoluble at 25 ° C. due to intermolecular hydrogen bonding,
It is soluble in water at 80 ° C. Satisfying these conditions is due to the increase in hydrophilicity due to the large number of -OH groups on the membrane surface in contact with the treated water, thereby increasing the resistance to contaminants, and also reducing the amount of permeated water due to the surface treatment. Restrained,
This is preferable because very good film performance can be added.
【００２７】以下に上記有機物又は有機重合体による逆
浸透複合膜の表面処理の具体的制御法を以下に示す。用
いる逆浸透複合膜は特に限定されないが、ポリアミド
系、ポリウレア系等の界面重合法により製膜されたもの
がある。これらの膜は従来の公知の方法等によって、容
易に得ることができる。例えば、多孔性ポリスルホン支
持膜を用い、メタフェニレンジアミン、ピペラジン、ポ
リエチレンイミン等の反応性アミノ基を有するモノマー
又はポリマーの水溶液を前記多孔性ポリスルホン支持膜
の少なくとも片面に塗布した後、トリメシン酸クロライ
ド、イソフタル酸クロライド等の多官能酸クロライド、
またはトリレンジイソシアネート等の多官能イソシアネ
ート、又はこれらの混合物のヘキサン等の溶媒と接触さ
せることで、多孔性ポリスルホン支持膜上で界面重合を
行なわせ脱塩性能を有する薄膜を形成させ逆浸透複合膜
とすることができる。The specific control method of the surface treatment of the reverse osmosis composite membrane with the organic substance or the organic polymer will be described below. The reverse osmosis composite membrane to be used is not particularly limited, and there is a polyamide-based, polyurea-based or the like formed by an interfacial polymerization method. These films can be easily obtained by a conventionally known method or the like. For example, using a porous polysulfone support membrane, metaphenylene diamine, piperazine, after applying an aqueous solution of a monomer or polymer having a reactive amino group such as polyethyleneimine to at least one surface of the porous polysulfone support membrane, trimesic acid chloride, Polyfunctional acid chlorides such as isophthalic acid chloride,
Alternatively, by contacting a polyfunctional isocyanate such as tolylene diisocyanate, or a mixture of these with a solvent such as hexane, an interfacial polymerization is performed on the porous polysulfone support membrane to form a thin film having desalination performance, and a reverse osmosis composite membrane is formed. It can be.
【００２８】これら逆浸透複合膜のスキン層の比表面積
は高い透水性を有するために、２以上１０００以下であ
ることが好ましく、３以上５００以下であることがさら
に好ましい。前記比表面積が２未満であると、後に説明
する表面被覆処理後に十分な透水量が得られなくなり、
また１０００を超えると均質な表面被覆処理が行えなく
なる。さらに３以上５００以下であると、得られる逆浸
透複合膜の性能は、操作圧力７．５kgf/cm2で、温度２
５℃、塩化ナトリウム５００ｐｐｍを含有するｐＨ６．
５の水溶液を１時間透過させた後の透過流束が０．６
［ｍ3／ｍ2／日］以上となり、表面被覆処理により透過
性能が低下しても実用上問題のない逆浸透複合膜を得る
ことができる。The specific surface area of the skin layer of the reverse osmosis composite membrane is preferably 2 or more and 1000 or less, more preferably 3 or more and 500 or less in order to have high water permeability. When the specific surface area is less than 2, a sufficient water permeability cannot be obtained after the surface coating treatment described later,
On the other hand, if it exceeds 1,000, uniform surface coating cannot be performed. Further, when it is 3 or more and 500 or less, the performance of the obtained reverse osmosis composite membrane is as follows: operating pressure 7.5 kgf / cm 2 , temperature 2
5 ° C., pH 6.0 containing 500 ppm of sodium chloride.
Permeate flux after permeating the aqueous solution of No. 5 for 1 hour is 0.6
[M 3 / m 2 / day] or more, and it is possible to obtain a reverse osmosis composite membrane having practically no problem even if the permeability is reduced by the surface coating treatment.
【００２９】このような逆浸透複合膜に、前記有機物又
は有機重合体の溶液を塗布し、その後に乾燥させて最終
的な表面荷電が制御された逆浸透複合膜を得る。これら
非イオン系の親水性基を有する有機物又は有機重合体は
逆浸透複合膜の活性薄膜層にダメージを与えることの少
ない溶媒、水、低級アルコール、ハロゲン化炭化水素、
脂肪族炭化水素、アセトン、アセトニトリル、及び、こ
れらの少なくとも２種の混合溶液等に溶解させ用いられ
る。これら溶媒の内、好適には、メタノール、エタノー
ル、プロパノール、ブタノールなどの脂肪族アルコー
ル、エチレンクロルヒドリン等のハロゲン化脂肪族アル
コール、メトキシメタノール、メトキシエタノール、及
び、これら低級アルコールの少なくとも一種と水の混合
溶媒を挙げることができる。混合溶媒の場合、水に対す
る低級アルコールの比率は特に限定されないが、好まし
くは、水の比率が０％〜９０％であることが好ましい。
又、水を溶媒として用いる場合は膜との濡れ性を良くす
ることを目的に界面活性剤を添加することも好適であ
る。The solution of the organic substance or the organic polymer is applied to such a reverse osmosis composite membrane, and then dried to obtain a final reverse osmosis composite membrane having a controlled surface charge. Organic substances or organic polymers having these nonionic hydrophilic groups are solvents that do not damage the active thin film layer of the reverse osmosis composite membrane, water, lower alcohols, halogenated hydrocarbons,
It is used by dissolving it in an aliphatic hydrocarbon, acetone, acetonitrile, or a mixed solution of at least two of them. Among these solvents, preferably, aliphatic alcohols such as methanol, ethanol, propanol and butanol, halogenated aliphatic alcohols such as ethylene chlorohydrin, methoxymethanol, methoxyethanol, and at least one of these lower alcohols and water Can be mentioned. In the case of a mixed solvent, the ratio of the lower alcohol to water is not particularly limited, but preferably, the ratio of water is preferably 0% to 90%.
When water is used as the solvent, it is also preferable to add a surfactant for the purpose of improving the wettability with the film.
【００３０】上記溶媒を用いて調製される前記の有機物
又は有機重合体の濃度は０．０１〜２０重量％、好まし
くは、０．０５〜５重量％の範囲が好適である。塗布方
法は特に限定されないが、ディッピング法、転写法、噴
霧法等が好適に用いられる。塗布後の乾燥手段及び乾燥
温度も特に限定されないが、２０℃〜２００℃、好まし
くは５０℃〜１５０℃の範囲が好適である。The concentration of the above-mentioned organic substance or organic polymer prepared using the above-mentioned solvent is in the range of 0.01 to 20% by weight, preferably 0.05 to 5% by weight. The coating method is not particularly limited, but a dipping method, a transfer method, a spraying method and the like are preferably used. The drying means and the drying temperature after coating are not particularly limited either, but are preferably in the range of 20C to 200C, preferably in the range of 50C to 150C.
【００３１】このようにして逆浸透複合膜上に得られた
薄膜の厚みは、０．００１〜１μｍ、好ましくは０．０
０５〜０．５μｍ程度の厚みが、塗布による透水量の低
下を抑制する上で好適である。膜厚の制御法は特に限定
されないが、溶液濃度等で制御することができる。The thickness of the thin film thus obtained on the reverse osmosis composite membrane is 0.001 to 1 μm, preferably 0.01 to 1 μm.
A thickness of about 0.5 to 0.5 μm is suitable for suppressing a decrease in water permeability due to coating. The method for controlling the film thickness is not particularly limited, but can be controlled by the solution concentration or the like.
【００３２】さらに、逆浸透複合膜の表面制御法とし
て、前述の有機物又は有機重合体を前述の反応性アミノ
基を有するモノマー又はポリマーの水溶液、酸クロライ
ド、またはイソシアネートの例えばヘキサン溶液に混合
し、前記の手法に従い逆浸透複合膜を製膜することで表
面荷電を制御することも可能である。この際、前記有機
重合体の溶解性を与えるために、前記低級アルコールを
有機重合体を添加する上記の少なくとも一方の溶液に加
えることも好適である。Further, as a method for controlling the surface of the reverse osmosis composite membrane, the above-mentioned organic substance or organic polymer is mixed with an aqueous solution of the above-mentioned monomer or polymer having a reactive amino group, acid chloride, or isocyanate, for example, in a hexane solution. It is also possible to control the surface charge by forming a reverse osmosis composite membrane according to the method described above. At this time, in order to impart the solubility of the organic polymer, it is also preferable to add the lower alcohol to at least one of the above solutions to which the organic polymer is added.
【００３３】用いる逆浸透複合膜性能は特に限定されな
いが、圧力７．５ｋｇｆ／ｃｍ2 、温度２５℃、供給液
５００ｐｐｍのＮａＣｌの条件下での逆浸透試験におい
て、その透水量が０．６［ｍ3／ｍ2／日］以上であるこ
とが、有機物又は有機重合体にて処理した後の逆浸透複
合膜の透水性を高く保持する上で好ましい。又、有機
物、又は有機重合体にて処理した後の逆浸透複合膜の透
水性は特に限定されないが、実際の使用を考慮すると、
圧力１５ｋｇｆ／ｃｍ2 、温度２５℃、供給液１５００
ｐｐｍのＮａＣｌ溶液の条件下での逆浸透試験におい
て、その透水量が０．６［ｍ3／ｍ2／日］以上であるこ
とが好ましい。The performance of the reverse osmosis composite membrane to be used is not particularly limited, but in a reverse osmosis test under the conditions of a pressure of 7.5 kgf / cm 2 , a temperature of 25 ° C., and a supply liquid of 500 ppm of NaCl, the water permeability is 0.6 [ m 3 / m 2 / day] or more in order to maintain high water permeability of the reverse osmosis composite membrane after treatment with an organic substance or an organic polymer. Further, the water permeability of the reverse osmosis composite membrane after treatment with an organic substance or an organic polymer is not particularly limited, but in consideration of actual use,
Pressure 15 kgf / cm 2 , temperature 25 ° C, supply liquid 1500
In a reverse osmosis test under the condition of a NaCl solution of ppm, the water permeability is preferably 0.6 [m 3 / m 2 / day] or more.
【００３４】更に、得られた非イオン系の親水性基を有
する水不溶性の有機重合体を表層、または分離活性層内
に有する逆浸透複合膜の透水量は、圧力１５ｋｇｆ／ｃ
ｍ2、温度２５℃、供給液１５００ｐｐｍのＮａＣｌ溶
液の条件下でその透水量が０．１［ｍ3／ｍ2／日］以
上、好ましくは０．６［ｍ3／ｍ2／日］以上であること
が実際の運転上好適である。Further, the reverse osmosis composite membrane having the obtained water-insoluble organic polymer having a nonionic hydrophilic group in the surface layer or in the separation active layer has a water permeability of 15 kgf / c.
The water permeability is 0.1 [m 3 / m 2 / day] or more, preferably 0.6 [m 3 / m 2 / day] or more under the conditions of m 2 , temperature of 25 ° C., and 1500 ppm NaCl solution of the supply liquid. Is preferable in actual operation.
【００３５】次に図面を用いて本発明の一実施形態を説
明する。図１〜２は本発明の一実施形態の概略断面図で
ある。図１は多孔質層１の上に分離活性層（スキン層）
２が存在し、その表層にポリビニルアルコールからなる
薄膜３が存在している。図２は多孔質層１の上に、ポリ
ビニルアルコール成分４と分離活性層（スキン層）５が
相分離状態で存在している層（部分）を示す。ポリビニ
ルアルコール成分は薄膜状態でなくても良い。本発明に
おいては、前記図１と図２の状態を組み合わせたもので
あっても良い。Next, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 are schematic sectional views of one embodiment of the present invention. FIG. 1 shows a separation active layer (skin layer) on the porous layer 1
2 and a thin film 3 made of polyvinyl alcohol is present on the surface layer. FIG. 2 shows a layer (portion) in which a polyvinyl alcohol component 4 and a separation active layer (skin layer) 5 exist on the porous layer 1 in a phase-separated state. The polyvinyl alcohol component need not be in a thin film state. In the present invention, a combination of the states shown in FIGS. 1 and 2 may be used.
【００３６】[0036]
【実施例】以下に実施例を挙げて本発明を説明するが、
本発明はこれらの実施例に何ら限定されるものではな
い。EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples.
【実施例１】ｍ−フェニレンジアミン３．０重量％と、
ラウリル硫酸ナトリウム０．１５重量％とを含む水溶液
にトリエチルアミンを３．０重量％、カンファースルホ
ン酸を６．０重量％、イソプロピルアルコールを５．０
重量％を含有した水溶液を微多孔性ポリスルホン支持膜
に数秒塗布し接触させた後、余分の水溶液を除去して上
記支持膜上に上記水溶液の層を形成した。EXAMPLE 1 3.0% by weight of m-phenylenediamine and
An aqueous solution containing 0.15% by weight of sodium lauryl sulfate contains 3.0% by weight of triethylamine, 6.0% by weight of camphorsulfonic acid, and 5.0% of isopropyl alcohol.
After the aqueous solution containing the weight% was applied to the microporous polysulfone support membrane for several seconds and brought into contact, the excess aqueous solution was removed to form a layer of the aqueous solution on the support membrane.
【００３７】次に、かかる支持膜の表面に、トリメシン
酸クロライドを０．２０重量％、イソプロピルアルコー
ルを０．０５重量％を含むＩＰ１０１６（出光化学
（株）製イソパラフィン系炭化水素油）溶液を塗布し接
触させた。その後、１２０℃の熱風乾燥機の中で３分保
持して支持体上にスキン層を形成させ逆浸透複合膜を得
た。得られた逆浸透複合膜を十分に洗浄し、膜性能を評
価し、乾燥後透過型電子顕微鏡で断面を観察し、スキン
層の比表面積を測定した。膜性能を表１に示す。スキン
層の比表面積は４．３であった。Next, an IP1016 (isoparaffinic hydrocarbon oil manufactured by Idemitsu Chemical Co., Ltd.) solution containing 0.20% by weight of trimesic acid chloride and 0.05% by weight of isopropyl alcohol is applied to the surface of the supporting film. And contacted. Then, it was kept in a hot air dryer at 120 ° C. for 3 minutes to form a skin layer on the support to obtain a reverse osmosis composite membrane. The obtained reverse osmosis composite membrane was sufficiently washed, the membrane performance was evaluated, and after drying, the cross section was observed with a transmission electron microscope to measure the specific surface area of the skin layer. Table 1 shows the film performance. The specific surface area of the skin layer was 4.3.
【００３８】同様にして得られた逆浸透複合膜表面に、
０．２５重量％のケン化度９９．５％のポリビニルアル
コール（平均重合度ｎ＝２，６００）溶液（イソプロピ
ルアルコール／水＝３／７）を塗布した後、１００℃で
５分間乾燥し、再度同溶液を塗布して１３０℃で５分間
乾燥し、平均厚さが約０．１μｍの均質なポリビニルア
ルコール（ＰＶＡ）被膜を形成し、本発明の逆浸透複合
膜を得た。スキン層の比表面積は２．０であり、ＰＶＡ
被覆処理前の比表面積の４７％に減少していた。また、
得られた複合逆浸透膜表層の部分は概略図１に示す断面
構造であった。得られたＰＶＡ被膜を有する逆浸透複合
膜を、１５００ｐｐｍの塩化ナトリウムを含む水溶液を
用いて１５ｋｇｆ／ｃｍ2 の圧力で評価した時の膜性能
を表１に示す。On the reverse osmosis composite membrane surface obtained in the same manner,
After applying a solution (isopropyl alcohol / water = 3/7) of polyvinyl alcohol (average degree of polymerization n = 2,600) having a saponification degree of 0.25% by weight and drying at 100 ° C. for 5 minutes, The same solution was applied again and dried at 130 ° C. for 5 minutes to form a homogeneous polyvinyl alcohol (PVA) film having an average thickness of about 0.1 μm, thereby obtaining a reverse osmosis composite membrane of the present invention. The specific surface area of the skin layer is 2.0 and PVA
It was reduced to 47% of the specific surface area before the coating treatment. Also,
The surface portion of the obtained composite reverse osmosis membrane had a sectional structure schematically shown in FIG. Table 1 shows the membrane performance when the obtained reverse osmosis composite membrane having a PVA coating was evaluated at a pressure of 15 kgf / cm 2 using an aqueous solution containing 1500 ppm of sodium chloride.
【００３９】[0039]
【表１】 [Table 1]
【００４０】スキン層の比表面積は２．０であった（対
処理前比表面積４７％）。 前記で得られた逆浸透複合膜を平膜セルにセットし、工
業用水を用いて耐汚染性の評価を行った。前記工業用水
を１５ｋｇｆ／ｃｍ2 の圧力で、逆浸透複合膜を透過さ
せる連続運転における５分後と２８時間後の連続運転テ
ストの透過水量（１５ｋｇｆ／ｃｍ2 の圧力で評価）を
比較した。結果を後記の表２に示す。The specific surface area of the skin layer was 2.0 (specific surface area before treatment: 47%). The reverse osmosis composite membrane obtained above was set in a flat membrane cell, and the pollution resistance was evaluated using industrial water. The industrial water at a pressure of 15 kgf / cm 2, were compared permeate flow rate of continuous operation test after 5 minutes and after 28 hours in continuous operation for transmitting a reverse osmosis membrane (evaluated at a pressure of 15kgf / cm 2). The results are shown in Table 2 below.
【００４１】[0041]
【比較例１】ポリビニルアルコールによる表面被膜処理
前の逆浸透複合膜を用いて、上記実施例１と同様の測定
を行った。結果を表２に示す。Comparative Example 1 The same measurement as in Example 1 was performed using the reverse osmosis composite membrane before the surface coating treatment with polyvinyl alcohol. Table 2 shows the results.
【００４２】[0042]
【表２】 [Table 2]
【００４３】以上の実施例１、比較例１から明らかな通
り、本実施例品はケン化度９９．５％のＰＶＡ薄層を形
成させることで、高いフラックス保持率を有し、フラッ
クスの安定性が向上していることが確認できた。As is clear from the above Example 1 and Comparative Example 1, the product of this example has a high flux retention rate and a stable flux by forming a thin PVA layer having a saponification degree of 99.5%. It was confirmed that the property was improved.
【００４４】[0044]
【実施例２】実施例１と同様にして界面重縮合による逆
浸透複合膜を製造した後、ケン化度９９．５％のポリビ
ニルアルコール（ＰＶＡ）を同様の方法にてスキン層の
表面に平均厚さ：約０．１μｍでコーティングした。前
記で得られた逆浸透複合膜を平膜セルにセットし、工業
用水（鉄分１．０ｐｐｍを含む水溶液）を用いて耐汚染
性の評価を行った。前記工業用水を５μｍのＭＦ（マイ
クロフィルトレーション）フィルターで濾過処理した水
を１５ｋｇｆ／ｃｍ2 の圧力で、５分後と２８時間後の
加圧循環テストにて透過水量（１５ｋｇｆ／ｃｍ2 の圧
力で評価）を比較した。結果を後記の表３に示す。Example 2 After producing a reverse osmosis composite membrane by interfacial polycondensation in the same manner as in Example 1, polyvinyl alcohol (PVA) having a saponification degree of 99.5% was averaged on the surface of the skin layer in the same manner. Thickness: about 0.1 μm was coated. The reverse osmosis composite membrane obtained above was set in a flat membrane cell, and the pollution resistance was evaluated using industrial water (aqueous solution containing 1.0 ppm of iron). The industrial water was filtered through a 5 μm MF (microfiltration) filter and the permeated water (15 kgf / cm 2 ) was subjected to a pressurized circulation test at a pressure of 15 kgf / cm 2 and after 5 minutes and 28 hours. (Evaluated by pressure). The results are shown in Table 3 below.
【００４５】[0045]
【比較例２】ポリビニルアルコールによる表面被膜処理
前の逆浸透複合膜を用いて、上記実施例２と同様の測定
を行った。結果を表３に示す。Comparative Example 2 Using a reverse osmosis composite membrane before surface coating treatment with polyvinyl alcohol, the same measurement as in Example 2 was performed. Table 3 shows the results.
【００４６】[0046]
【表３】 [Table 3]
【００４７】以上の実施例２、比較例２から明らかな通
り、本実施例品はケン化度９９．５％のＰＶＡ薄層を形
成させることで、高いフラックス保持率を有し、フラッ
クスの安定性が向上していることが確認できた。また評
価後、水洗浄して膜面の分析をした結果、比較例２の膜
面には鉄成分の吸着が確認されたのに対して、実施例２
の膜面には鉄成分がほとんど検出されなかった。もちろ
ん鉄成分は実施例２の逆浸透複合膜を透過もせず、付着
もなく、濃縮水側へ流れていた。As is clear from the above Example 2 and Comparative Example 2, the product of this example has a high flux retention rate and a stable flux by forming a PVA thin layer having a saponification degree of 99.5%. It was confirmed that the property was improved. After the evaluation, the membrane was washed with water and the film surface was analyzed. As a result, adsorption of iron component was confirmed on the film surface of Comparative Example 2.
Almost no iron component was detected on the film surface. Of course, the iron component did not permeate through the reverse osmosis composite membrane of Example 2 and flowed to the concentrated water without adhesion.
【００４８】[0048]
【実施例３】実施例１と同様にして界面重縮合による逆
浸透複合膜を製造した後、ケン化度９９．５％のポリビ
ニルアルコール（ＰＶＡ）を同様に被覆処理した。前記
で得られた逆浸透複合膜を平膜セルにセットし、耐汚染
性の評価として、界面活性剤含有の生活排水を用いてＦ
ｌｕｘ低下を測定した。前記界面活性剤を含む生活排水
を５μｍのＭＦ（マイクロフィルトレーション）フィル
ターで濾過処理した水を１５ｋｇｆ／ｃｍ2 の圧力で、
開始時と１４日後の加圧循環テストの透過水量（１５ｋ
ｇｆ／ｃｍ2 の圧力で評価）を比較した。結果を後記の
表４に示す。Example 3 A reverse osmosis composite membrane was produced by interfacial polycondensation in the same manner as in Example 1, and polyvinyl alcohol (PVA) having a saponification degree of 99.5% was similarly coated. The reverse osmosis composite membrane obtained above was set in a flat membrane cell, and as a stain resistance evaluation, F was measured using household wastewater containing a surfactant.
Lux reduction was measured. The water obtained by filtering the domestic wastewater containing the surfactant through a 5 μm MF (microfiltration) filter is applied at a pressure of 15 kgf / cm 2 .
The amount of permeated water (15k
gf / cm 2 ). The results are shown in Table 4 below.
【００４９】[0049]
【比較例３】実施例３記載のＰＶＡ層形成前の膜、すな
わちＰＶＡ被覆のない膜の測定を実施した。結果を表４
に示した。Comparative Example 3 A film before the formation of the PVA layer described in Example 3, that is, a film having no PVA coating was measured. Table 4 shows the results
It was shown to.
【００５０】[0050]
【表４】 [Table 4]
【００５１】[0051]
【実施例４】ｍ−フェニレンジアミンを３．０重量％、
ラウリル硫酸ナトリウムを０．１５重量％を含む水溶液
に、トリエチルアミンを３．０重量％、カンファースル
ホン酸を６．０重量％、イソプロピルアルコールを５．
０重量％を加えた。前記水溶液組成物に、ケン化度９９
％のポリビニルアルコール（ＰＶＡ）を０．５重量％加
えた。前記ＰＶＡは８０℃の水にて溶解し添加した。こ
の溶液組成物を微多孔性ポリスルホン支持膜に塗布し、
数秒間接触させた後、余分の水溶液を除去して支持膜上
に前記水溶液組成物の層を形成した。Example 4 3.0% by weight of m-phenylenediamine,
In an aqueous solution containing 0.15% by weight of sodium lauryl sulfate, 3.0% by weight of triethylamine, 6.0% by weight of camphorsulfonic acid, and 5.0% of isopropyl alcohol.
0% by weight was added. A saponification degree of 99 was added to the aqueous solution composition.
% Polyvinyl alcohol (PVA) was added at 0.5% by weight. The PVA was dissolved in water at 80 ° C. and added. Applying the solution composition to a microporous polysulfone support membrane,
After contacting for a few seconds, the excess aqueous solution was removed to form a layer of the aqueous solution composition on the support film.
【００５２】次に、前記支持膜の表面に、トリメシン酸
クロライドを０．２０重量％、イソプロピルアルコール
を０．０５重量％を含むＩＰ１０１６（出光化学（株）
製イソパラフィン系炭化水素油）溶液を塗布し接触させ
た。その後、１２０℃の熱風乾燥機の中で３分保持して
支持体上にスキン層を形成させ複合逆浸透膜を得た。得
られた複合逆浸透膜を充分に洗浄し、膜性能を評価し、
乾燥後透過型電子顕微鏡にて該複合逆浸透膜の断面を観
察しスキン層の比表面積を測定した。膜性能を表５に示
す。スキン層の比表面積は３．５であった。また、得ら
れた複合逆浸透膜表層の部分は、概略図２に示す断面構
造であった。Next, IP1016 (Idemitsu Chemical Co., Ltd.) containing 0.20% by weight of trimesic acid chloride and 0.05% by weight of isopropyl alcohol was provided on the surface of the support film.
(Isoparaffin-based hydrocarbon oil) solution was applied and brought into contact. Then, it was kept in a hot air dryer at 120 ° C. for 3 minutes to form a skin layer on the support to obtain a composite reverse osmosis membrane. Wash the obtained composite reverse osmosis membrane sufficiently, evaluate the membrane performance,
After drying, the cross section of the composite reverse osmosis membrane was observed with a transmission electron microscope, and the specific surface area of the skin layer was measured. Table 5 shows the film performance. The specific surface area of the skin layer was 3.5. Further, the surface portion of the obtained composite reverse osmosis membrane had a sectional structure schematically shown in FIG.
【００５３】[0053]
【表５】 [Table 5]
【００５４】得られた平膜を実施例１と同様に工業用水
を用いて評価した。結果を表６に示す。The obtained flat membrane was evaluated in the same manner as in Example 1 using industrial water. Table 6 shows the results.
【００５５】[0055]
【表６】 [Table 6]
【００５６】以上説明したとおり、本実施例によれば、
ＰＶＡ薄層を形成させることで、耐汚染性を向上させる
ことができた。また、高塩阻止率、高透水性も併せ有
し、比較的低圧で実用性のある脱塩を可能にする逆浸透
複合膜とすることができた。As described above, according to the present embodiment,
By forming a PVA thin layer, contamination resistance could be improved. In addition, it was possible to obtain a reverse osmosis composite membrane having both a high salt rejection rate and a high water permeability, and enabling practical desalination at a relatively low pressure.
【００５７】[0057]
【発明の効果】以上説明したとおり、本発明の逆浸透複
合膜によれば、高塩阻止率、高透水性と高耐汚染性を併
せ有し、比較的低圧で実用性のある脱塩を可能にする逆
浸透複合膜を実現できた。さらに界面活性剤または遷移
金属成分を含む原水を使用して逆浸透処理しても、逆浸
透複合膜の性能は大きく低下しなかった。As described above, according to the reverse osmosis composite membrane of the present invention, desalination which has both high salt rejection, high water permeability and high stain resistance and is practically usable at a relatively low pressure. The realized reverse osmosis composite membrane was realized. Furthermore, the reverse osmosis treatment using raw water containing a surfactant or a transition metal component did not significantly reduce the performance of the reverse osmosis composite membrane.
【図１】本発明の一実施形態の逆浸透複合膜表面部分の
概略断面図である。FIG. 1 is a schematic sectional view of a reverse osmosis composite membrane surface portion according to an embodiment of the present invention.
【図２】本発明の別の実施形態の逆浸透複合膜表面部分
の概略断面図である。FIG. 2 is a schematic cross-sectional view of a reverse osmosis composite membrane surface portion according to another embodiment of the present invention.
１ 多孔質層 ２，５ 分離活性層 ３ ポリビニルアルコールからなる薄膜 ４ ポリビニルアルコール成分と分離活性層が相分離状
態で存在している層DESCRIPTION OF SYMBOLS 1 Porous layer 2, 5 Separation active layer 3 Thin film which consists of polyvinyl alcohol 4 Layer in which a polyvinyl alcohol component and a separation active layer exist in phase separation state
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｃ０２Ｆ 1/44 Ｃ０２Ｆ 1/44 Ｄ 1/58 1/58 Ｃ 1/64 1/64 Ｚ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI C02F 1/44 C02F 1/44 D 1/58 1/58 C 1/64 1/64 Z
Claims (16)
む逆浸透複合膜であって、前記分離活性層内に電気的に
中性の有機物及び有機重合体から選ばれる少なくとも一
つの物質を存在させるか、または前記分離活性層の表面
に電気的に中性の有機物及び有機重合体から選ばれる少
なくとも一つの物質を被覆させており、かつ前記少なく
とも一つの物質を存在している層または前記表面被覆前
の分離活性層の比表面積が２以上１０００以下であるこ
とを特徴とする逆浸透複合膜。1. A reverse osmosis composite membrane including a sponge layer and a separation active layer on the surface thereof, wherein at least one substance selected from an electrically neutral organic substance and an organic polymer is present in the separation active layer. Or a layer or surface in which the surface of the separation active layer is coated with at least one substance selected from an electrically neutral organic substance and an organic polymer, and the at least one substance is present. A reverse osmosis composite membrane, wherein the specific surface area of the separation active layer before coating is 2 or more and 1000 or less.
る層または前記表面被覆前の分離活性層の比表面積が３
以上５００以下である請求項１に記載の逆浸透複合膜。2. The layer having at least one substance or the separation active layer before the surface coating has a specific surface area of 3
The reverse osmosis composite membrane according to claim 1, wherein the number is 500 or more and 500 or less.
が、表面被覆前の分離活性層の比表面積の９０％以下に
減少している請求項１に記載の逆浸透複合膜。3. The reverse osmosis composite membrane according to claim 1, wherein the specific surface area of the separation active layer after the surface coating is reduced to 90% or less of the specific surface area of the separation active layer before the surface coating.
ら選ばれる少なくとも一つの物質が、非イオン系の親水
基を有する有機物又は有機重合体である請求項１に記載
の逆浸透複合膜。4. The reverse osmosis composite membrane according to claim 1, wherein at least one substance selected from an electrically neutral organic substance and an organic polymer is an organic substance or an organic polymer having a nonionic hydrophilic group. .
有機重合体が、２５℃の水に対し不溶性であり、８０℃
の水に対し可溶性であるポリビニルアルコールである請
求項４に記載の逆浸透複合膜。5. An organic substance or organic polymer having a nonionic hydrophilic group, which is insoluble in water at 25 ° C.
The reverse osmosis composite membrane according to claim 4, which is a polyvinyl alcohol that is soluble in water.
以上である請求項５に記載の逆浸透複合膜。6. Polyvinyl alcohol having a saponification degree of 95%
The reverse osmosis composite membrane according to claim 5, which is the above.
に中性の有機物及び有機重合体から選ばれる少なくとも
一つの物質が、非イオン系の親水基を有する有機物又は
有機重合体であり、かつその厚さが、０．００１〜１μ
ｍの範囲である請求項１に記載の逆浸透複合膜。7. At least one substance selected from an electrically neutral organic substance and an organic polymer coated on the surface of the separation active layer is an organic substance or an organic polymer having a nonionic hydrophilic group, And the thickness is 0.001 to 1μ
The reverse osmosis composite membrane according to claim 1, wherein the range is m.
ｍ2 、温度２５℃、供給液５００ｐｐｍのＮａＣｌ溶液
の条件下での逆浸透試験において、その透水量が０．６
［ｍ3／ｍ2／日］以上である請求項１に記載の逆浸透複
合膜。8. The reverse osmosis composite membrane has a pressure of 7.5 kgf / c.
In a reverse osmosis test under the conditions of m 2 , a temperature of 25 ° C., and a NaCl solution containing 500 ppm of a feed solution, the water permeability was 0.6
The reverse osmosis composite membrane according to claim 1, which is [m 3 / m 2 / day] or more.
2 、温度２５℃、供給液１５００ｐｐｍのＮａＣｌ溶液
の条件下での逆浸透試験において、その透水量が０．６
［ｍ3／ｍ2／日］以上である請求項１に記載の逆浸透複
合膜。9. The reverse osmosis composite membrane has a pressure of 15 kgf / cm.
2. In a reverse osmosis test under the conditions of a temperature of 25 ° C. and a supply solution of 1500 ppm of NaCl solution, the water permeability was 0.6
The reverse osmosis composite membrane according to claim 1, which is [m 3 / m 2 / day] or more.
で形成されている請求項１に記載の逆浸透複合膜。10. The reverse osmosis composite membrane according to claim 1, wherein the reverse osmosis composite membrane is formed of an aromatic polyamide.
含む逆浸透複合膜であって、前記分離活性層内に電気的
に中性の有機物及び有機重合体から選ばれる少なくとも
一つの物質を存在させるか、または前記分離活性層の表
面に電気的に中性の有機物及び有機重合体から選ばれる
少なくとも一つの物質を被覆させており、かつ前記少な
くとも一つの物質を存在している層または前記表面被覆
前の分離活性層の比表面積が２以上１０００以下である
逆浸透複合膜を原水に接触させて逆浸透処理を行うこと
を特徴とする水の逆浸透処理方法。11. A reverse osmosis composite membrane including a sponge layer and a separation active layer on the surface thereof, wherein at least one substance selected from an electrically neutral organic substance and an organic polymer is present in the separation active layer. Or a layer or surface in which the surface of the separation active layer is coated with at least one substance selected from an electrically neutral organic substance and an organic polymer, and the at least one substance is present. A reverse osmosis treatment method for water, wherein the reverse osmosis treatment is performed by bringing a reverse osmosis composite membrane having a specific surface area of the separation active layer before coating of 2 or more and 1000 or less into contact with raw water.
活性剤含有水である請求項１１に記載の逆浸透処理方
法。12. The reverse osmosis treatment method according to claim 11, wherein the raw water supplied to the reverse osmosis composite membrane is surfactant-containing water.
２０wt%の範囲である請求項１２に記載の逆浸透処理方
法。13. A surfactant content of 0.01 ppm or less.
The reverse osmosis treatment method according to claim 12, wherein the amount is in the range of 20 wt%.
金属成分を含む水である請求項１１に記載の逆浸透処理
方法。14. The reverse osmosis treatment method according to claim 11, wherein the raw water supplied to the reverse osmosis composite membrane is water containing a transition metal component.
記載の逆浸透処理方法。15. The reverse osmosis treatment method according to claim 14, wherein the transition metal component is iron.
〜２０wt%の範囲である請求項１４に記載の逆浸透処理
方法。16. The content of the transition metal component is 0.01 ppm.
The reverse osmosis treatment method according to claim 14, wherein the amount is in the range of 20 wt% to 20 wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10089671A JPH10337454A (en) | 1997-04-10 | 1998-04-02 | Reverse osmotic multipie membrane and reverse osmosis treatment of water using the same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9-92619 | 1997-04-10 | ||
| JP9261997 | 1997-04-10 | ||
| JP10089671A JPH10337454A (en) | 1997-04-10 | 1998-04-02 | Reverse osmotic multipie membrane and reverse osmosis treatment of water using the same |
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| Publication Number | Publication Date |
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| JPH10337454A true JPH10337454A (en) | 1998-12-22 |
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| Application Number | Title | Priority Date | Filing Date |
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| JP10089671A Pending JPH10337454A (en) | 1997-04-10 | 1998-04-02 | Reverse osmotic multipie membrane and reverse osmosis treatment of water using the same |
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| JP (1) | JPH10337454A (en) |
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