JP2016182690A - Surface-modified substrate, polymer-coated substrate, and production method of them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for producing a polymer-coated substrate having a graft polymer layer on the surface by using a surface-modified substrate having a polymerization initiator group introduced into the surface.SOLUTION: In a production method of a polymer-coated substrate, various modification of a substrate surface becomes possible by using tannin, and a polymerization initiator group can be introduced into tannin because tannin has many hydroxy groups, thus a monomer can be polymerized from the polymerization initiator group introduced into tannin, to thereby form a graft polymer layer on the substrate surface.SELECTED DRAWING: None

Description

  The present invention relates to a surface-modified substrate and a polymer-coated substrate. The present invention can be applied not only to a material having a smooth surface such as a film and a sheet but also to a porous material. In particular, the surface of the porous membrane or reverse osmosis membrane can be easily coated with the graft polymer layer.

  As a method for modifying the surface of the substrate, a method of coating a polymer on the surface of the substrate, a method of treating with a plasma or corona, a method of introducing a polymerization initiating group on the surface, and a method of graft polymerization have been proposed. The method of coating the polymer is simple and widely used, but the coating polymer is easily peeled off from the substrate, and it has been difficult to stably maintain the function for a long period of time. In addition, plasma treatment and corona treatment require a large-scale apparatus, and have a drawback that the substrate is easily damaged during the treatment. On the other hand, the method of introducing a polymerization initiating group on the surface and graft polymerization is an excellent modification method because it has excellent long-term stability and there is no damage to the base material. In contrast, it requires a complicated introduction reaction.

  Tannin is a plant-derived polyphenol and includes a wide variety of compounds such as hydrolyzed and condensed types. Due to this diverse chemical structure, tannin can be adsorbed on various substrates and imparts various functions to the substrate. For example, Patent Document 1 discloses that immobilized polymer tannin is produced by adsorbing polymer tannin to hydrophobic resin particles and further cross-linking, and using it as a protein adsorbent for brewing, a water purification treatment agent, and a wastewater treatment agent. Have been described. Patent Document 2 describes adsorbing pentaploid tannin to a polysulfone membrane to impart hydrophilicity, and Patent Document 3 describes adsorbing hydrolyzable tannin to a reverse osmosis membrane to improve ion blocking performance. Has been. Furthermore, Patent Document 4 describes that lychee peel-derived polyphenol is adsorbed onto a polyvinylidene fluoride (hereinafter abbreviated as PVDF) porous film to improve hydrophilicity.

  As described above, tannin has excellent adsorption characteristics to various substrates and can functionalize the substrate surface by a simple method, but the functions to be imparted are limited, and it is desired to impart a wide range of functions. It was.

JP 7-24313 A JP-A-5-301036 JP 2006-223963 A JP 2012-254404 A

  An object of the present invention is to produce and provide a surface-modified base material by simply introducing a polymerization initiating group on the surface of the base material without selecting the type of the base material. Another object of the present invention is to produce and provide a polymer-coated substrate having a graft polymer layer on the surface using a surface-modified substrate having a polymerization initiation group introduced on the surface.

  In order to achieve the above object, as a result of intensive studies by the present inventors, it is possible to modify the surface of the substrate without selecting the type of the substrate by using tannin. Utilizing the fact that a polymerization initiating group can be easily introduced because it has a hydroxyl group, the monomer can be polymerized from the polymerization initiating group introduced into tannin. Further, the present inventor has found that a graft polymer layer can be further formed on the surface of the substrate, and has completed the present invention.

That is, the present invention
[1] A surface-modified base material having a tannin layer into which a polymerization initiating group is introduced on the base material surface.
[2] A method for producing a surface-modified substrate, comprising producing a surface-modified substrate through at least the following two steps.
(1) A step of producing tannin introduced with a polymerization initiating group by reacting tannin, a polymerization initiating group and a compound having a functional group that reacts with a hydroxyl group of tannin.
(2) A step of bringing the base material into contact with the tannin introduced with the polymerization initiating group to form a tannin layer with the polymerization initiating group introduced on the surface of the base material.
[3] A substrate coated with a graft polymer layer formed by polymerizing monomers starting from a polymerization initiating group of the tannin layer.
[4] The monomer according to [3] is a monomer having a functional group selected from an alkoxyalkyl group, an alkoxypolyoxyethylene group, a phosphobetaine group, a sulfobetaine group, and a carboxybetaine group and a vinyl group. A polymer-coated substrate characterized by
[5] A surface-modified base material in which a tannin layer having a polymerization initiating group introduced is formed on the surface of the base material, and is coated with a graft polymer layer by monomer polymerization starting from the polymerization initiator group. A method for producing a polymer-coated substrate.

Hereinafter, embodiments for carrying out the present invention will be described in detail.
The surface-modified base material of the present invention comprises a base material and a tannin layer containing a polymerization initiating group formed on the base material surface.

  The material of the base material used in the present invention is not particularly limited, and metals such as aluminum, iron, stainless steel, titanium, gold, platinum, silver, and copper; silica, alumina, zirconia, titania, silicon nitride, silicon, glass, Inorganic materials such as carbon fiber; polyethylene, polypropylene, polyvinyl chloride, polystyrene, polybutadiene, polymethyl methacrylate, polyacrylonitrile, polyvinyl alcohol, polyacrylamide, cellulose acetate, PVDF, polytetrafluoroethylene, polysulfone, polyethersulfone, polyphenylene sulfide , Polyether ether ketone, polycarbonate, polyacetal, polyester, polyamide, polyurethane, epoxy resin, phenol resin, unsaturated polyester, and the like. Among them, polyamide, polystyrene, PVDF, metal and the like are suitable as a coating base material because they easily adsorb the tannin layer into which the polymerization initiating group is introduced.

  There are no particular restrictions on the shape of the substrate and the surface shape of the substrate, and various shapes of substrates such as plates, sheets, films, thin films, nets, cloths, particles, powders, tubes, and fibers are used. Can do. Further, the surface shape may be embossed, wavy, line & space, etc., but is not particularly limited. Moreover, a porous body can also be used as a base material, and it can use in shapes, such as a dice form, a sheet form, a flat film form, a tube form, a hollow fiber, and a nonwoven fabric. Preferred porous bodies include flat membrane porous bodies and hollow fiber porous bodies. In particular, porous bodies used as microfiltration membranes and ultrafiltration membranes are preferably used in the present invention.

  The microfiltration membrane referred to here is a porous membrane having a pore size of about 0.05 to 10 μm, and the material is an organic polymer such as polyethylene, polypropylene, PVDF, polytetrafluoroethylene, polycarbonate, cellulose, or alumina. Ceramics are used. On the other hand, the ultrafiltration membrane is a porous membrane having a pore size of about 2 to 50 nm, and the material is polyacrylonitrile, polyvinyl chloride-polyacrylonitrile copolymer, polysulfone, polyethersulfone, PVDF, aromatic polyamide, Organic polymers such as polyimide and cellulose acetate and ceramics such as alumina are used.

  The porous structure of the ultrafiltration membrane has an asymmetric membrane structure in which the porous structure differs between the dense layer on the surface and the internal support layer, whereas the microfiltration membrane has a uniform porous structure. Furthermore, a base material in which the above shape is combined may be used, and a composite film in which a porous film and a non-porous thin film are combined, such as a reverse osmosis film, is also preferably used in the present invention. A reverse osmosis membrane having a composite membrane structure has a structure in which a porous support layer (ultrafiltration membrane) made of polysulfone and a nonporous thin film having a function of separating water and ions made of a crosslinked aromatic polyamide are combined. ing.

  The tannin used in the present invention is a water-soluble compound that is derived from plants and reacts with proteins, alkaloids, metal ions and strongly binds to form a hardly soluble salt, and has a complex fragrance having many phenolic hydroxyl groups. Group compounds. Tannins are classified into hydrolyzed tannins and condensed tannins based on the difference in chemical structure, and any of them is preferably used in the present invention. Hydrolyzable tannin is suitably used when the substrate is hydrophilic, and condensed tannin is preferably used when the substrate is hydrophobic.

  In the present invention, the hydrolyzable tannin is hydrolyzed to polyhydric phenol and polyhydric alcohol by acid, alkali, or enzyme. When polyhydric phenol is gallic acid, gallotannin is used. When ellagic acid is used, ellagitannin is used. It can be illustrated. Furthermore, examples of gallotannins include pentaploid tannins and gallic tannins, and examples of ellagitannins include geraniin, but are not limited thereto.

  On the other hand, condensed tannin has a structure in which a compound having a flavanol skeleton is polymerized and does not undergo hydrolysis. Specific examples of condensed tannin include, but are not limited to, catechin, epicatechin, proanthocyanidins, and polymers thereof.

  The polymerization initiating group used in the present invention may be either an ionic polymerization initiating group or a radical polymerization initiating group as long as it is a functional group that initiates polymerization, and the polymerization type is not limited. Although there is no particular limitation in the present invention, radical polymerization is preferred as the polymerization mode because of the wide application range of the monomers and easy operation. The polymerization initiating group is also preferably a radical polymerization initiating group. Furthermore, since a surface graft layer having a high uniformity and a high graft density can be formed, controlled radical polymerization is preferred as a polymerization mode, and therefore, a controlled radical polymerization initiating group is more preferably used as the polymerization initiating group.

  Examples of the polymerization initiating group include peroxides, azo compounds, organometallic compounds, Lewis acids, dormant species, and the like. Hereinafter, the polymerization initiating group in the controlled radical polymerization will be described in more detail. When a polymerization method via nitroxide (hereinafter abbreviated as NMP) is used for surface graft polymerization, the polymerization initiating group to be introduced is nitroxide. When using a styrene derivative as a monomer, NMP is suitable as a polymerization method. For example, by reacting 1- (2,2,6,6-tetramethylpiperidinyl-1-oxy) -2- (dimethylchlorosilyloctyloxy) ethylbenzene with tannin, the nitroxyl group which is a polymerization initiating group is converted to tannin. Can be introduced. When an atom transfer radical polymerization method (hereinafter abbreviated as ATRP) is used, the polymerization initiating group to be introduced is an organic halogen compound. Examples of the introduction method include a method of reacting 2-bromoisobutyric acid bromide with tannin and introducing a polymerization initiating group into tannin, but this is not restrictive.

  In addition, when a methacrylic acid ester is used as a monomer, ATRP is suitable and the graft polymerization method is used, but this is not restrictive. When graft polymerization is performed by a reversible addition-cleavage chain transfer polymerization method (hereinafter abbreviated as RAFT), an initiating group to be introduced is a thiocarbonylthio group. As an example of the introduction method, there is a method in which 4-cyano-4-[(dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid chloride is reacted with tannin to introduce a polymerization initiating group into tannin. When acrylic acid ester or methacrylic acid ester is used as a monomer, RAFT is a suitable polymerization method, but is not limited thereto.

  1-30 nm is preferable and, as for the thickness of the tannin layer in which the polymerization initiation group formed in the base-material surface of this invention was introduce | transduced, 1-10 nm is especially preferable. If the thickness of the tannin layer is less than 1 nm, the amount of polymerization initiation group introduced to the substrate surface is reduced, which is not preferable. If the thickness of the tannin layer exceeds 30 nm, graft polymerization proceeds from the inside of the tannin layer. This is not preferable because the tannin layer peels frequently.

The method for producing a surface-modified substrate of the present invention is characterized by producing a surface-modified substrate through at least the following two steps. (1) A step of producing tannin introduced with a polymerization initiating group by reacting tannin, a polymerization initiating group and a compound having a functional group that reacts with a hydroxyl group of tannin.
(2) A step of bringing the base material into contact with the tannin introduced with the polymerization initiating group to form a tannin layer with the polymerization initiating group introduced on the surface of the base material.

  The process (1) will be described below.

  As the functional group that reacts with the hydroxyl group of tannin, it is necessary to select a functional group that can react with the hydroxyl group under mild conditions such that the polymerization initiation group does not change. For example, a carboxyl group, an acid halide group, an acid anhydride group Sulfonyl chloride group, epoxy group, isocyanate group, silyl halide group and the like. Specific examples of the compound having a functional group that reacts with the polymerization initiation group and the hydroxyl group of tannin include 4,4′-azobis (4-cyanovaleric acid), 1- (2,2,6,6-tetramethylpi Peridinyl-1-oxy) -2- (dimethylchlorosilyloctyloxy) ethylbenzene, 1- (2,2,6,6-tetramethylpiperidinyl-1-oxy) -2- (trichlorosilyloctyloxy) ethylbenzene 2-bromoisobutyric acid, 2-bromoisobutyric acid bromide, 2-iodoisobutyric acid bromide, 2-bromoisopropionic acid, 2-bromoisopropionic acid bromide, 2- (4-chlorosulfonylphenyl) ethyldimethylchlorosilane, 2- (4 -Chlorosulfonylphenyl) ethyltrichlorosilane, 4-cyano-4-[(dodecylsulfanylthiocarbo L) sulfanyl] pentanoic acid, 4-cyano-4-[(dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid chloride, 2- (dodecylthiocarbonothioylthio) -2-methylpropionic acid, 2- (dodecylthiocarbonothio) And oilthio) -2-methylpropionic acid chloride, 4-cyano-4- (phenylcarbonothioylthio) pentanoic acid, 4-cyano-4- (phenylcarbonothioylthio) pentanoic acid chloride, and the like.

  The reaction of a compound having a functional group that reacts with tannin and a polymerization initiating group and a hydroxyl group of tannin may be performed by mixing both, but in order to allow the reaction to proceed quantitatively under mild conditions, dicyclohexyl which is generally used A condensing agent such as carbodiimide or carbonyldiimidazole, or a base such as pyridine or triethylamine acting as a catalyst or an acid trapping agent may be added.

  0-60 degreeC of reaction temperature is preferable, More preferably, it is 0-30 degreeC. The reaction time is not particularly limited as long as the time during which the reaction proceeds quantitatively, and can usually be set in the range of 10 minutes to 24 hours.

  Solvent used in the reaction is required to dissolve tannin, a compound having a functional group that reacts with the polymerization initiation group and the hydroxyl group of tannin, and the reaction product so as not to inhibit the reaction and not to dissolve or swell the substrate. It is. Preferred solvents include amide solvents such as N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and 2-pyrrolidone; tetramethylurea, N, N Urea solvents such as' -dimethylpropylene urea, 1,3-dimethyl-2-imidazolidinone, 2-imidazolidinone; dimethyl sulfoxide, acetonitrile and the like.

  There is no restriction | limiting in particular in the density | concentration of the tannin in the case of reaction, What is necessary is just to select suitably in 0.01 to 10% of range. The charging ratio of tannin and the compound having a functional group that reacts with a polymerization initiating group and a hydroxyl group of tannin is 0.1 to 3 mol with respect to 1 mol of hydroxyl group of tannin.

  The product after the reaction may be once isolated and used in the next step (2), or may be used in the step (2) in a solution state without isolation.

Next, the process (2) will be described.
The solvent for bringing the base material into contact with the tannin introduced with the polymerization initiating group is not particularly limited as long as it is a solvent that can dissolve the tannin with the polymerization initiating group introduced and does not damage the base material. Specifically, water, methanol, ethanol, propanol, ethylene glycol, tetramethylene glycol, acetone, 2-butanone, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, butyl acetate, tetrahydrofuran, dioxane and the like can be mentioned. There is no restriction | limiting in particular in the density | concentration at the time of making the tannin into which the polymerization initiating group was introduce | transduced, It can set in 0.01 to 50% of range. The contact time between the substrate and the tannin into which the polymerization initiating group has been introduced can be selected from a wide range because it varies greatly depending on the type of solvent, the tannin concentration, and the temperature at the time of contact. Can be set by range. Moreover, there is no restriction | limiting also in both contact temperature, It can select arbitrarily from the range of 10-50 degreeC.

  By selecting these conditions, the thickness of the tannin layer on the substrate surface can be controlled. In addition, the thickness of the tannin layer preferable in this invention is 1-30 nm, More preferably, it is 1-10 nm.

  Next, the polymer is polymerized starting from the polymerization initiating group fixed to the surface-modified base material, thereby forming a graft polymer layer and obtaining a polymer-coated material. The monomer used in the present invention is not particularly limited as long as it is a monomer that can be polymerized in various polymerization formats such as ionic polymerization and radical polymerization. Specific examples of the monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, Methoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, 2- (meth) acryloyloxyethyl phosphorylcholine, [2-((meth) acryloyloxy) ethyl] dimethyl (3- Sulfopropyl) ammonium hydroxide, dimethylaminoethyl (meth) acrylate, [2-((meth) acryloyloxy) ethyl] -N, N, N-trimethylammonium chloride, 2-sulfoethyl (meth) acrylate, N- (Meta) a (Meth) acrylic acid esters such as liloyloxyethyl-N, N-dimethylammonium-α-N-methylcarboxybetaine, (meth) acrylic acid 2-perfluoroalkylethyl; (meth) acrylic acid; (meth) acrylamide N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methyl-N-ethyl (meth) acrylamide, N, N-di (hydroxyethyl) (Meth) acrylamide derivatives such as (meth) acrylamide; styrene, styrene sulfonic acid, lithium styrene sulfonate, sodium styrene sulfonate, ammonium styrene sulfonate, ethyl styrene sulfonate, methyl styrene, chlorostyrene, butoxy styrene, acetoxy Styrene, such as styrene, (1-ethoxyethoxy) styrene, vinylbenzoic acid, butyl vinylbenzoate, dimethylaminostyrene, N, N-dimethylaminomethylstyrene, vinylbenzyl chloride, vinylbenzyltrimethylammonium chloride, vinylpyridine; acetic acid Vinyl esters such as vinyl and vinyl propionate; vinyl ethers such as propyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, ethylhexyl vinyl ether and hydroxyalkyl vinyl ether; dienes such as butadiene, isoprene and chloroprene; vinyl chloride, vinylidene chloride and vinylidene fluoride , Vinyl halides such as tetrafluoroethylene; α-olefins such as ethylene, propylene, 1-butene and isobutene; Data) acrylonitrile, and the like.

  Among these, methoxyethyl (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, 2- (meth) acryloyloxyethyl phosphorylcholine, [2-((meth) acryloyloxy) ethyl] dimethyl (3-sulfopropyl) ) Alkoxyalkyl groups such as ammonium hydroxide, N- (meth) acryloyloxyethyl-N, N-dimethylammonium-α-N-methylcarboxybetaine, alkoxypolyoxyethylene groups, phosphobetaine groups, sulfobetaine groups, carboxybetaines It is preferable to form a graft polymer layer using a monomer having a group because the obtained polymer-coated substrate has a protein non-adsorption property. A substrate having protein non-adsorbing properties is excellent in biocompatibility and exhibits antithrombogenicity and is effective in suppressing biofouling, and therefore can be used in a wide range of applications.

The thickness of the graft polymer layer in the polymer-coated substrate of the present invention is 3 to 300 nm, although the optimum value varies depending on the application. When the thickness of the graft polymer layer is less than 3 nm, the function derived from the graft polymer layer is not sufficiently exhibited, and the characteristics of the substrate cannot be completely shielded. On the other hand, when the thickness of the graft polymer layer exceeds 300 nm, the function derived from the graft polymer layer is saturated, so that even if the thickness is further increased, a remarkable effect cannot be obtained. Further, the graft density of the graft polymer layer can be increased to 0.1 to 0.7 / nm ² by using the method of the present invention, and the function derived from the graft polymer layer is further emphasized. Can do. When the graft density is less than 0.1 / nm ² , the function derived from the graft polymer layer is not sufficiently exhibited, which is not preferable. On the other hand, when the graft density exceeds 0.7 / nm ² , diffusion to the growth terminal becomes insufficient depending on the type of the monomer, and the graft chain length varies, which is not preferable.

  The method for producing a polymer-coated substrate according to the present invention comprises contacting a monomer with a surface-modified substrate on which a tannin layer having a polymerization initiating group introduced is formed on the substrate surface, and maintaining the monomer under polymerization conditions. Features. The conditions under which the monomer is polymerized vary greatly depending on the polymerization mode, but the polymerization temperature can be appropriately selected from 0 to 120 ° C. and the polymerization time from 1 minute to 72 hours. A solvent may not be used, but if used, a solvent that dissolves the monomer, does not inhibit the polymerization reaction, and does not dissolve or swell the substrate is selected. Preferred solvents include water, alcohols such as methanol, ethanol, propanol, tetramethylene glycol, ethylene glycol, and trifluoroethanol; ketones such as acetone, 2-butanone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, isopropyl acetate, and butyl acetate. Carboxylic acid esters such as ethyl propionate; ethers such as tetrahydrofuran, dioxane and anisole; aliphatic hydrocarbons such as hexane, heptane, octane and decane; aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene; formamide, N Amide solvents such as N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 2-pyrrolidone; , N'- dimethylpropyleneurea, 1,3-dimethyl-2-imidazolidinone, 2-urea-based solvents imidazolidinone; dimethyl sulfoxide, acetonitrile and the like. A mixed solvent obtained by mixing two or more of the above solvents is also preferably used.

  Although there is no restriction | limiting in particular in the composition ratio of a monomer and a solvent, It is preferable to select within the range of 0-5000 weight part of solvent with respect to 100 weight part of monomers.

  According to the present invention, a polymerization initiating group can be introduced into various substrates by a simple operation, and a polymer-coated substrate obtained by graft polymerization of various monomers starting from the polymerization initiating group can be obtained. For example, methoxyethyl (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, 2- (meth) acryloyloxyethyl phosphorylcholine, [2-((meth) acryloyloxy) ethyl] dimethyl (3-sulfopropyl) ammonium hydroxy , N- (meth) acryloyloxyethyl-N, N-dimethylammonium-α-N-methylcarboxybetaine and other alkoxyalkyl groups, alkoxypolyoxyethylene groups, phosphobetaine groups, sulfobetaine groups, carboxybetaine groups If a monomer having a functional group is selected and graft polymerization is performed, a polymer-coated substrate having a protein non-adsorption property can be produced.

  Since such polymer-coated substrates have biocompatibility and antithrombotic properties, medical devices such as artificial dialysis devices, cardiopulmonary devices, and plasma separators; infusion bottles, infusion bags, tissue regeneration repair materials, and adhesion prevention materials , Wound dressings, contact lenses, intraocular lenses, artificial blood vessels, catheters, stents, drug delivery carriers, cell culture substrates and other medical materials; microfiltration membranes used for the separation and purification of foods such as dairy products It can be used for filtration membranes and reverse osmosis membranes. Furthermore, since the polymer-coated substrate can suppress biofilm formation and biofouling, it can be used as a microfiltration membrane or ultrafiltration membrane used in water purification treatment, sewage / wastewater treatment, seawater desalination or pure water. It can be suitably used as a reverse osmosis membrane used for production applications and the like.

  If a fluorine-containing monomer such as 2-perfluoroalkylethyl (meth) acrylate is used as the monomer, a polymer-coated substrate excellent in water repellency, non-adhesiveness and antifouling property can be provided. On the other hand, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, 2- (meth) acryloyloxyethyl phosphorylcholine, [2-((meth) acryloyloxy) ethyl] as monomers Dimethyl (3-sulfopropyl) ammonium hydroxide, N- (meth) acryloyloxyethyl-N, N-dimethylammonium-α-N-methylcarboxybetaine, dimethylaminoethyl (meth) acrylate, [2-((meta ) Acryloyloxy) ethyl] -N, N, N-trimethylammonium chloride, 2-sulfoethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylamide, styrene sulfonic acid, lithium styrene sulfonate Beam, sodium styrene sulfonate, ammonium styrene sulfonate, vinyl benzoate, if a hydrophilic monomer such as vinylbenzyl trimethyl ammonium chloride, high hydrophilicity, can provide excellent polymer coated substrate adhesiveness.

  Among the above monomers, when a monomer having a quaternary ammonium group such as [2-((meth) acryloyloxy) ethyl] -N, N, N-trimethylammonium chloride is used, the polymer coated substrate is not only hydrophilic. Antibacterial properties can be imparted. Among the above monomers, polyethylene glycol (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, [2-((meth) acryloyloxy) ethyl] -N, N, N-trimethylammonium chloride, vinylbenzyltrimethylammonium When a monomer having a polyether or ion exchange group such as chloride, 2-sulfoethyl (meth) acrylate, styrene sulfonic acid, lithium styrene sulfonate, sodium styrene sulfonate or ammonium styrene sulfonate is used, the polymer coated substrate becomes hydrophilic. In addition to the properties, ion conductivity can be imparted.

  In addition, if a monomer having a long-chain alkyl group such as octyl (meth) acrylate is used as a monomer, a polymer-coated substrate having excellent sliding properties can be provided, and the use of tannin has an affinity for living organisms and the environment. Is advantageous in that the load can be reduced.

It is an ESCA O1s spectrum of (A) base material of Example 1. It is an ESCA O1s spectrum of (B) surface modification base material of Example 1. 2 is an ESCA O1s spectrum of (C) the polymer-coated substrate of Example 1. It is an ESCA O1s spectrum of (A) base material of Example 3. It is an ESCA O1s spectrum of (B) surface modification base material of Example 3. It is an ESCA O1s spectrum of the polymer-coated substrate of Example 3 (C). 6 is a SEM image of a PVDF porous membrane used as a substrate in Example 5. 6 is a schematic diagram of a reverse osmosis membrane used as a base material in Example 6. FIG. It is an ESCA wide scan spectrum of the base material of (A) in Example 6. It is an ESCA wide scan spectrum of the polymer coating base material of (B) of Example 6.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
Base material: Para-aramid film (production of polymerization initiation group-introduced tannin)
Hydrolyzable tannin (manufactured by Wako Pure Chemical Industries, molecular weight 1500, 21 hydroxyl groups per tannin molecule) 0.4 g was dissolved in 20 ml of DMF under a nitrogen stream, 0.46 g of triethylamine was added, and the mixture was ice-cooled. A solution prepared by dissolving 1.06 g of 2-bromoisobutyric acid bromide in 10 ml of DMF was dropped into the tannin solution, reacted at 0 ° C. for 2 hours, then warmed to room temperature and reacted for 3 hours. After the reaction, a part of the reaction solution was taken out and dropped into water to collect a precipitate. When ¹ H-NMR of the recovered product was measured, the methyl group proton in the bromoisobutyric acid ester was detected at 2.1 ppm, so that the introduction of the bromoisobutyric acid ester group, which is a polymerization initiating group, was confirmed to tannin. Similarly, from TOF-MS measurement, a fragment of m / z = 74 corresponding to the acyl group of bromoisobutyrate was detected, and introduction of a polymerization initiating group into tannin could be confirmed.

(Manufacture of surface modified substrates)
A para-aramid film (Mitotron manufactured by Toray Industries, Inc., 12 μm thick) was cut into a 60 mm square and immersed in 180 ml of methanol under a nitrogen stream. To this was added a DMF solution of the above polymerization initiation group-introduced tannin, immersed for 24 hours at room temperature, the film was taken out, washed with methanol, and dried under reduced pressure at 40 ° C. The surface of the obtained aramid film was analyzed by ESCA. The surface composition of the unmodified aramid film is C = 81.8%, N = 6.2%, O = 6.7%, Cl = 5.2%, O / N is 1.1 and bromine is not detected In contrast, the surface composition of the modified aramid film is as follows: C = 75.4%, N = 6.2%, O = 11.8%, Cl = 2.8%, O / N is 1.9. Bromine was also detected at 0.4%. The Ois peaks before and after the modification are shown in FIGS. 1 to 3, and the tannin modification reduces the carbonyl oxygen peak (531.3 eV) in the amide carbonyl derived from the base material and the ether oxygen in the tannin derived ester. The peak (533.0 eV) increased. From these facts, it can be seen that the surface of the aramid film is modified with a polymerization initiating group introduced tannin. The contact angle measured by bringing bubbles into contact with the substrate in water (hereinafter abbreviated as “water contact angle. 180 ° −expressed by bubble contact angle. The smaller value indicates hydrophilicity”) is an unmodified aramid. The film was 84 °, the tannin-modified aramid film was 38 °, and the surface was hydrophilized by the tannin modification.

(Manufacture of polymer-coated substrate)
60 ml of poly (ethylene glycol) methyl ether methacrylate (manufactured by Aldrich, molecular weight 300, hereinafter abbreviated as PEGMA), 36 ml of pure water, and 24 ml of methanol were mixed and sufficiently purged with nitrogen. Cupric bromide 9.4 mg, bipyridyl 65.6 mg, and ascorbic acid 740 mg were added here, and it stirred under nitrogen to make a uniform solution. The polymerization initiation group-introduced tannin-modified aramid film was immersed in this solution, and graft polymerization was performed at 30 ° C. for 6 hours. After completion of the polymerization, the film was washed with methanol and water in that order and dried under reduced pressure at 45 ° C. When the surface of the obtained aramid film was analyzed by ESCA, the surface composition of the unmodified aramid film was C = 81.8%, N = 6.2%, O = 6.7%, Cl = 5.2%. The surface composition of the aramid film after graft polymerization was C = 76.4%, N = 4.6%, O = 14.8%, Cl = 2. 8%, O / N increased to 3.2. Moreover, although the Ois peak after graft polymerization is shown in FIGS. 1 to 3, the peak of carbonyl oxygen (531.3 eV) in the amide carbonyl derived from the substrate is reduced by graft polymerization, and the ether in the ester derived from the graft polymer. The oxygen peak (533.0 eV) increased. From these facts, it can be seen that the aramid film surface is coated with the PEGMA graft polymer. In addition, the underwater contact angle of the aramid film after graft polymerization was 30 °, which was lower than the underwater contact angle of 84 ° for the unmodified aramid film and the underwater contact angle of 38 ° for the tannin-modified aramid film. Hydrophilicity could be imparted to the aramid film by graft polymerization of PEGMA.

Example 2
Base material: Meta-aramid thin film (Production of polymerization initiation group-introduced tannin)
In the same manner as in Example 1, a DMF solution of polymerization initiation group-introduced tannin was produced.

(Manufacture of surface modified substrates)
Poly [N, N ′-(1,3-phenylene) isophthalamide] (manufactured by Aldrich) was dissolved by heating in N-cyclohexyl-pyrrolidone to prepare a 0.02% solution. This solution was dropped on a QCM sensor chip, coated with a spin coater at 4000 rpm, and dried under reduced pressure at 120 ° C. It was 7 nm when the film thickness of the obtained meta-type aramid thin film was measured with the ellipsometer. This sensor chip was immersed in 180 ml of methanol under a nitrogen stream, and a DMF solution of polymerization initiation group-introduced tannin prepared by the same method as in Example 1 was added thereto. After immersion for 24 hours at room temperature, the sensor chip was taken out and methanol was added. And dried under reduced pressure at 40 ° C. The thickness of the tannin layer formed on the meta-aramid thin film measured by an ellipsometer was 2 nm.

(Manufacture of polymer-coated substrate)
Example 1 except that 96.8 mg of tris [2- (dimethylamino) ethyl] amine was used instead of 65.6 mg of bipyridyl and a meta-aramid thin film clothing sensor chip was used instead of the para-aramid film. In the same manner as above, PEGMA was graft-polymerized onto a meta-aramid thin film-coated sensor chip whose surface was modified with a polymerization-initiating group-introduced tannin. The thickness of the graft polymer layer measured with an ellipsometer was 5 nm. The amount of protein adsorbed to the obtained graft polymer-coated sensor chip was evaluated by QCM method using albumin as the protein. As a result, the protein adsorption amount to the meta-aramid thin film-coated sensor chip was 230 ng / cm ² whereas the protein adsorption amount to the graft polymer-coated sensor chip was 30 ng / cm ² , which was a very small value. . By coating the meta-aramid thin film with PEGMA graft polymer, it was possible to impart protein non-adsorption properties to the meta-aramid thin film.

Example 3
Base material: Meta-aramid paper (Manufacture of tannin with polymerization initiation group introduced)
In the same manner as in Example 1, a DMF solution of polymerization initiation group-introduced tannin was produced.

(Manufacture of surface modified substrates)
Meta aramid paper (Dupont Teijin Advanced Paper Nomex paper, thickness 50 μm) was cut into a 50 mm square, and the surface of the aramid paper was modified with polymerization initiation group-introduced tannin in the same manner as in Example 1, and surface analysis was performed by ESCA. . The surface composition of the unmodified aramid paper was C = 86%, N = 7%, O = 6%, and O / N was 0.9, whereas the surface composition of the modified aramid paper was C = 80%, N = 4%, O = 15%, O / N increased to 7.5, and bromine was also detected at 0.7%. Moreover, although Ois peaks before and after modification are shown in FIGS. 4 to 6, the peak of carbonyl oxygen (531.7 eV) in the amide carbonyl derived from the substrate is reduced by the tannin modification, and the ether oxygen in the tannin-derived ester is reduced. The peak (533.3 eV) increased. From these, it can be seen that the surface of the aramid paper is modified with a polymerization initiation group-introduced tannin. The underwater contact angles were 71 ° for unmodified aramid paper and 42 ° for tannin-modified aramid paper, and the surface was hydrophilized by tannin modification.

(Manufacture of polymer-coated substrate)
PEGMA was graft-polymerized on the above-described polymerization initiation group-introduced tannin-modified meta-aramid paper in the same manner as in Example 1 except that meta-aramid paper was used in place of the para-aramid film. When the surface of the obtained meta-aramid paper was analyzed by ESCA, the surface composition of the unmodified aramid paper was C = 86%, N = 7%, O = 6%, and O / N was 0.9. On the other hand, the surface composition of the aramid paper after graft polymerization increased to C = 78%, N = 2%, O = 20%, and O / N to 10. Moreover, although the Ois peak after graft polymerization is shown in FIGS. 4 to 6, the peak of carbonyl oxygen (531.7 eV) in the amide carbonyl derived from the substrate is reduced by graft polymerization, and the ether oxygen in the ester derived from the graft polymer. Peak (533.3 eV) increased. From these, it can be seen that the aramid paper surface is coated with PEGMA graft polymer. In addition, the underwater contact angle of the aramid paper after graft polymerization was 28 °, which was significantly lower than the underwater contact angle 71 ° of the unmodified aramid paper and the underwater contact angle 42 ° of the tannin-modified aramid paper. Hydrophilicity could be imparted to the aramid paper by graft polymerization of PEGMA.

Example 4
Substrate: PVDF thin film (production of polymerization initiation group-introduced tannin)
A DMF solution of a polymerization initiating group-introduced tannin was produced in the same manner as in Example 1 except that condensed tannin (good tanned tannin) was used instead of hydrolyzed tannin.

(Manufacture of surface modified substrates)
PVDF (manufactured by Aldrich, number average molecular weight 71,000, hereinafter abbreviated as PVDF) was dissolved in DMF by heating to prepare a 2% solution. This solution was dropped on a QCM sensor chip, coated with a spin coater at 4000 rpm, and dried under reduced pressure at 120 ° C. It was 25 nm when the film thickness of the obtained PVDF thin film was measured with the ellipsometer. This sensor chip is immersed in 180 ml of methanol under a nitrogen stream, and the DMF solution of the above-mentioned polymerization initiation group-introduced tannin is added to the sensor chip. did. The thickness of the tannin layer formed on the PVDF thin film measured by an ellipsometer was 3 nm. The underwater contact angle was 77 ° for the unmodified PVDF thin film and 40 ° for the tannin modified PVDF thin film, and the surface was hydrophilized by the tannin modification.

(Manufacture of polymer-coated substrate)
In the same manner as in Example 2 except that a PVDF thin film-coated sensor chip was used instead of the meta-aramid thin film-coated sensor chip, the PVDF thin film-coated sensor chip surface-modified with the above polymerization initiation group-introduced tannin was used. PEGMA was grafted. The thickness of the graft polymer layer measured by an ellipsometer was 13 nm. The amount of protein adsorbed to the obtained graft polymer-coated sensor chip was evaluated by QCM method using albumin as a protein. As a result, the protein adsorption amount to the PVDF thin film-coated sensor chip was 396 ng / cm ² , whereas the protein adsorption amount to the graft polymer-coated sensor chip was a very small value of 45 ng / cm ² . By coating the PVDF thin film with the PEGMA graft polymer, the protein non-adsorption property could be imparted to the PVDF thin film. In addition, the underwater contact angle of the PVDF thin film-coated sensor chip after graft polymerization was 33 °, which was greatly lower than the underwater contact angle of 77 ° of the PVDF thin film-coated sensor chip. By graft polymerization of PEGMA, not only protein non-adsorption property but also hydrophilicity could be imparted to the PVDF thin film.

Example 5
Base material: PVDF porous membrane (see FIG. 7)
(Production of polymerization initiation group-introduced tannin)
In the same manner as in Example 4, a DMF solution of polymerization-initiating group-introduced tannin was produced.

(Manufacture of surface modified substrates)
A PVDF porous membrane (Durapore made by Merck Millipore, pore diameter 0.22 μm, microfiltration membrane) was cut into a 50 mm square, and polymerization initiation group-introduced tannin was introduced onto the surface of the PVDF membrane in the same manner as in Example 1. The contact angle in water before and after modification was 62 ° for the PVDF porous membrane before modification and 33 ° for the tannin-modified PVDF membrane, and the porous membrane was hydrophilized by tannin modification.

(Manufacture of polymer-coated substrate)
Example 1 except that 60 ml of 2-methacryloyloxyethyl phosphorylcholine (manufactured by Tokyo Chemical Industry, hereinafter abbreviated as MPC) was used instead of 60 ml of PEGMA, and a PVDF porous membrane was used instead of the para-aramid film. By this method, MPC was graft-polymerized on the above-described polymerization initiation group-introduced tannin-modified PVDF porous membrane. The amount of protein adsorbed on the obtained graft polymer-coated PVDF porous membrane was evaluated by the bicinchoninic acid method using albumin as a protein. As a result, the protein adsorption amount to the unmodified PVDF porous membrane was 56 μg / cm ² , whereas the protein adsorption amount to the graft polymer-coated PVDF porous membrane was 80 ng / cm ² or less, which was a very small value. there were. By coating the PVDF porous membrane with the MPC graft polymer, it was possible to impart protein non-adsorption properties to the PVDF porous membrane. In addition, the underwater contact angle of the PVDF porous membrane after graft polymerization was 20 °, which was significantly lower than 62 ° for the unmodified PVDF porous membrane and 33 ° for the tannin-modified PVDF porous membrane. Hydrophilicity could also be imparted to the PVDF porous membrane by graft polymerization of MPC.

Example 6
Base material: Reverse osmosis membrane (Production of polymerization initiation group-introduced tannin)
In the same manner as in Example 1, a DMF solution of polymerization initiation group-introduced tannin was produced.

(Manufacture of surface modified substrates)
A reverse osmosis membrane (DW Chemical BW-30, polyamide composite membrane, hereinafter abbreviated as RO membrane) was cut into 50 mm squares, and polymerization initiation group-introduced tannin was introduced onto the reverse osmosis membrane surface in the same manner as in Example 1. As shown in FIG. 8, the reverse osmosis membrane used here was a homogeneous layer (t = 0.2 μm) composed of a crosslinked aromatic polyamide, a polysulfone porous layer (t = 45 μm) and a polyester nonwoven fabric (t = 150 μm). ). The underwater contact angles before and after modification were 42 ° for the RO membrane before modification and 49 ° for the tannin-modified RO membrane, and the RO membrane was slightly hydrophobized by tannin modification.

(Manufacture of polymer-coated substrate)
PEGMA was graft-polymerized on the RO membrane surface-modified with the above-described polymerization initiation group-introduced tannin in the same manner as in Example 2 except that an RO membrane was used instead of the meta-aramid thin film-coated sensor chip. The surface of the obtained RO membrane was analyzed by ESCA. 9 to 10 show ESCA wide scan spectra of the unmodified RO film as a base material and the RO film after PEGMA graft polymerization. The surface composition of the unmodified RO membrane was C = 80%, N = 6%, O = 13%, whereas the surface composition of the RO membrane after graft polymerization was C = 80%, N <1%, Since O = 19% and N contained only in the RO membrane of the base material was not observed after the graft polymerization, it can be seen that the RO membrane surface was coated with the PEGMA graft polymer. The underwater contact angle of the RO membrane after graft polymerization was 29 °, which was significantly lower than the underwater contact angle of 42 ° for the unmodified RO membrane and the underwater contact angle of 49 ° for the tannin-modified RO membrane. Hydrophilicity could be imparted to the RO membrane by PEGMA graft polymerization.

Claims (5)

A surface-modified base material having a tannin layer into which a polymerization initiating group has been introduced on the surface of the base material. A method for producing a surface-modified substrate, comprising producing a surface-modified substrate through at least the following two steps.
(1) A step of producing tannin introduced with a polymerization initiating group by reacting tannin, a polymerization initiating group and a compound having a functional group that reacts with a hydroxyl group of tannin.
(2) A step of bringing the base material into contact with the tannin introduced with the polymerization initiating group to form a tannin layer with the polymerization initiating group introduced on the surface of the base material. A substrate coated with a graft polymer layer formed by polymerizing monomers starting from a polymerization initiating group of a tannin layer. The monomer according to claim 3 is a monomer having a functional group selected from an alkoxyalkyl group, an alkoxypolyoxyethylene group, a phosphobetaine group, a sulfobetaine group, and a carboxybetaine group and a vinyl group. A polymer-coated substrate.   A surface-modified base material in which a tannin layer having a polymerization initiating group introduced is formed on the surface of the base material, and a polymer coated with a graft polymer layer by monomer polymerization starting from the polymerization initiator group A method for producing a coated substrate.

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