JP6229989B2 - Surface modification method and surface modification material - Google Patents

Description

The present invention relates to a surface modification method and a surface modification materials.

  Polymer brushes are known as materials that can provide a variety of superior surface properties associated with a wide range of industrial fields. Recently, application as a surface exhibiting oil repellency in water has also been proposed.

  In Non-Patent Document 1, poly (2-hydroxyethyl methacrylate) having a surface of 11- (2-bromoisobutyryloxy) undecylthio group is introduced into an inert gas using an ATRP method in an inert gas. A method of introducing a polymer brush is disclosed.

  On the other hand, as an ATRP method for generating an ATRP catalyst by reducing a metal salt for an ATRP catalyst using a reducing agent, an AGEN (Activator Generated by Electron Transfer) ATRP method and an ARGET (Activator Regenerated by Electron Transfer) method are known. (For example, see Patent Documents 1 and 2).

Macromolecules 2002, 35, 1175-1179, “Functionalization of Surfaces by Water-Accelerated Atom-Transfer Radical Polymerization of Hydroxyethyl Methacrylate and Subsequent Derivatization”

WO2007 / 025310 WO2008 / 021500

  However, there is a problem that a polymer brush excellent in oil repellency after being immersed in water having a predetermined pH cannot be easily introduced.

  In the methods disclosed in Patent Documents 1 and 2, it is necessary to remove oxygen from the polymerization system. Further, the concentration of the monomer in the polymerization solution needs to be 10% by volume or more. Furthermore, it is necessary to add an organic solvent such as DMF, which has a large environmental load, to the polymerization solution.

One aspect of the present invention is a surface modification method in which a polymer brush having excellent oil repellency after being immersed in water having a predetermined pH can be easily introduced on a solid surface in view of the problems of the above-described conventional technology. Law can be provided.

One aspect of the present invention, the surface of the solid, the step of introducing an amino group, by reacting solid and 2-bromo-2-methylpropionic acid derivatives which have an amino group is introduced to the surface, the surface of said solid And introducing a 2-bromoisobutyryl group into the surface, and a solid having the 2-bromoisobutyryl group introduced on the surface thereof in the air, water-soluble monomer, water, metal salt for ATRP catalyst, for ATRP catalyst Dipping in a polymerization solution containing a ligand and a reducing agent, and using an AGET ATRP method or an ARGET ATRP method to polymerize the water-soluble monomer to introduce a polymer brush onto the solid surface, The water-soluble monomer includes (meth) acrylic acid, 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 1,2-diethylene (meth) acrylate. Roxyethyl, 2-hydroxyethyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphorylcholine, [2- (meth) acryloyloxyethyl] dimethyl (3-sulfopropyl) ammonium hydroxide, (meth) acrylamide, N- 2-dimethylaminoethyl (meth) acrylamide, N-2-diethylaminoethyl (meth) acrylamide, N-1,2-dihydroxyethyl (meth) acrylamide or N-2-hydroxyethyl (meth) acrylamide.

One aspect of the present invention, the surface of the solid, the step of introducing an amino group, by reacting solid and 2-bromo-2-methylpropionic acid derivatives which have an amino group is introduced to the surface, the surface of said solid Introducing a 2-bromoisobutyryl group into the surface, and a solid in which the 2-bromoisobutyryl group is introduced on the surface, in the air, water-soluble monomer, water, metal salt for ATRP catalyst, for ATRP catalyst Applying a polymer solution containing a ligand and a reducing agent, and introducing a polymer brush onto the solid surface by polymerizing the water-soluble monomer using the AGET ATRP method or the ARGET ATRP method, Water-soluble monomers are (meth) acrylic acid, (meth) acrylic acid 2-dimethylaminoethyl, (meth) acrylic acid 2-diethylaminoethyl, (meth) acrylic acid 1,2-dihydride. Xylethyl, 2-hydroxyethyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphorylcholine, [2- (meth) acryloyloxyethyl] dimethyl (3-sulfopropyl) ammonium hydroxide, (meth) acrylamide, N- 2-dimethylaminoethyl (meth) acrylamide, N-2-diethylaminoethyl (meth) acrylamide, N-1,2-dihydroxyethyl (meth) acrylamide or N-2-hydroxyethyl (meth) acrylamide.

According to one aspect of the present invention, it is possible to provide the surface of the solid, the surface modifying how that can be easily introduced into the polymer brushes with excellent oil repellency after immersion in water of a given pH .

It is a figure which shows the relationship of the thickness of the polymer brush with respect to the superposition | polymerization time of Example 1-1. It is a SEM photograph of the section of the polymer brush of Example 1-1. It is a figure which shows the relationship of the thickness of the polymer brush with respect to the polymerization time of Example 1-1, 1-2. 6 is a graph showing the relationship of the thickness of a polymer brush with respect to the polymerization time of Comparative Example 1. FIG. The relationship of the thickness of the polymer brush with respect to the density | concentration of ascorbic acid in the polymerization liquid of Examples 3-1 to 3-7 is shown.

  Next, the form for implementing this invention is demonstrated with drawing.

  The surface modification method comprises a step of introducing an amino group or a hydroxyl group on the surface of a solid, a reaction of a solid having an amino group or a hydroxyl group introduced on the surface with a 2-bromo-2-methylpropionic acid derivative, A step of introducing a 2-bromoisobutyryl group on the surface of the solid, and a solid having the 2-bromoisobutyryl group introduced on the surface thereof, in the air, water-soluble monomer, water, metal salt for ATRP catalyst, ATRP It has the process of introduce | transducing a polymer brush on the surface of a solid by immersing in the polymerization liquid containing the ligand for a catalyst, and a reducing agent, and polymerizing a water-soluble monomer using AGET ATRP method or ARGET ATRP method. For this reason, a polymer brush can be simply introduced on the solid surface.

  Water-soluble monomers are (meth) acrylic acid, (meth) acrylic acid 2-dimethylaminoethyl, (meth) acrylic acid 2-diethylaminoethyl, (meth) acrylic acid 1,2-dihydroxyethyl, (meth) acrylic acid 2 -Hydroxyethyl, 2- (meth) acryloyloxyethyl phosphorylcholine, [2- (meth) acryloyloxyethyl] dimethyl (3-sulfopropyl) ammonium hydroxide, (meth) acrylamide, N-2-dimethylaminoethyl (meth) Acrylamide, N-2-diethylaminoethyl (meth) acrylamide, N-1,2-dihydroxyethyl (meth) acrylamide or N-2-hydroxyethyl (meth) acrylamide. For this reason, the polymer brush excellent in oil repellency after being immersed in the water of predetermined | prescribed pH can be formed.

  The concentration of the water-soluble monomer in the polymerization solution is preferably 1 to 50% by volume, and more preferably 5 to 45% by volume. When the concentration of the water-soluble monomer in the polymerization solution is 1% by volume or more, the cost can be reduced, and when it is 50% by volume or less, the environmental load can be reduced.

  Although it does not specifically limit as solid, A metal, a metal oxide, an alloy, a semiconductor, ceramics, glass, etc. are mentioned.

  The shape of the solid surface is not particularly limited, and examples thereof include a flat surface, a curved surface, an uneven surface, and a porous surface.

  At this time, since the polymerization solution contains water, the water-soluble monomer can be polymerized in a short time at room temperature, and a thick polymer brush can be introduced on the solid surface.

  The polymerization liquid may further contain an organic solvent that is miscible with water.

  Although it does not specifically limit as an organic solvent which can be mixed with water, Ethanol etc. are mentioned.

  The metal salt for ATRP catalyst is not particularly limited as long as it can be reduced by a reducing agent contained in the polymerization solution after being oxidized or not, but copper (I) chloride, copper (II) chloride , Copper (I) bromide, copper (II) bromide, titanium (II) chloride, titanium (III) chloride, titanium (IV) chloride, titanium (IV) bromide, iron (II) chloride, iron chloride (III) ), Iron (II) bromide, iron (III) bromide, cobalt (II) chloride, cobalt (II) bromide, nickel (II) chloride, nickel (II) bromide, molybdenum (III) chloride, molybdenum chloride (V), ruthenium (III) chloride, etc. are mentioned.

  The molar ratio of the catalyst metal salt to the water-soluble monomer is preferably 0.004 to 0.03.

  Although it does not specifically limit as a ligand for ATRP catalysts, 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-t-butyl-2,2 ' -Bipyridyl, 4,4'-dinonyl-2,2'-bipyridyl, N-butyl-2-pyridylmethanimine, N-octyl-2-pyridylmethanimine, N-dodecyl-N- (2-pyridylmethylene) amine N-octadecyl-N- (2-pyridylmethylene) amine, N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine, tris (2-pyridylmethyl) amine, 1,1,4, 7,10,10-hexamethyltriethylenetetramine, tris (2-dimethylaminoethyl) amine, 1,4,8,11-tetraazacyclotetradecane, 1,4,8,11-tetra Chill -1,4,8,11- tetraazacyclotetradecane, N, N, N ', N'- tetrakis (2-pyridylmethyl) ethylenediamine, and the like.

  The molar ratio of the ATRP catalyst ligand to the ATRP catalyst metal salt is 0.50 to 1.5.

  Although it does not specifically limit as a reducing agent, Ascorbic acid, glucose, di-n-butyltin bis (2-ethylhexanoate) etc. are mentioned. Among them, ascorbic acid is preferable because it has a small environmental load and exhibits a strong reducing action.

  The molar ratio of the reducing agent to the metal salt for ATRP catalyst is preferably from 0.30 to 50, and more preferably from 7 to 31. When the molar ratio of the reducing agent to the metal salt for ATRP catalyst is 0.30 or more, the decrease in the concentration of the metal salt for ATRP catalyst (for example, copper (I) chloride) as a reductant in the polymerization system is suppressed. The polymerization termination reaction can be suppressed by being 50 or less.

  The method for introducing an amino group or hydroxyl group on the surface of the solid is not particularly limited, and examples thereof include a method for treating the surface of the solid with a silane coupling agent having an amino group or a hydroxyl group.

  Although it does not specifically limit as a silane coupling agent which has an amino group, 3-aminopropyl triethoxysilane etc. are mentioned.

  Although it does not specifically limit as a silane coupling agent which has a hydroxyl group, Hydroxymethyltriethoxysilane etc. are mentioned.

  The 2-bromo-2-methylpropionic acid derivative is not particularly limited, but 2-bromoisobutyryl bromide, 2-bromoisobutyryl chloride, 2-bromoisobutyryl iodide, 2-bromo-2-methyl Examples include methyl propionate, ethyl 2-bromo-2-methylpropionate, and propyl 2-bromo-2-methylpropionate.

  As a method for introducing a 2-bromoisobutyryl group on the surface of a solid other than the above, 3- (2-bromoisobutyrylamino) propyltrialkoxysilane or 3- (2-bromoisobutyryloxy) propyltri A method of chemical vapor deposition of an alkoxysilane on a solid surface, comprising 3- (2-bromoisobutyrylamino) propyltrialkoxysilane or 3- (2-bromoisobutyryloxy) propyltrialkoxysilane, Accordingly, a method of applying a sol-gel solution further containing tetraalkoxysilane to a solid surface can be used.

  A method for applying the sol-gel solution is not particularly limited, and examples thereof include a spin coating method, a spray coating method, and a dip coating method.

  Although it does not specifically limit as an alkoxy group in alkoxysilane, A methyl group, an ethyl group, a propyl group, etc. are mentioned.

  Instead of immersing the solid having 2-bromoisobutyryl group introduced on the surface in the polymerization solution, the polymerization solution may be applied to the solid having 2-bromoisobutyryl group introduced on the surface.

  In this case, the polymerization liquid may further contain a thickener. Thereby, the repelling of a polymerization liquid can be prevented and a polymerization liquid can be uniformly apply | coated to the surface of a solid.

  Although it does not specifically limit as a thickener, Polyvinyl alcohol etc. are mentioned.

  The method for applying the polymerization solution is not particularly limited, and examples thereof include a method for applying the polymerization solution using a brush or a brush, and a method for dropping the polymerization solution using a dropper.

  The solid surface to which the polymerization solution is applied may be covered with a coating material. Thereby, the polymerization liquid can be uniformly distributed over the entire surface of the solid.

  Although it does not specifically limit as a coating material, A filter paper, a film, etc. are mentioned.

  The surface of the surface modifying material is modified by the surface modifying method described above.

  The thickness of the polymer brush of the surface modifying material is preferably 4 to 700 nm.

The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of n-hexadecane of the surface modifying material after being immersed in an acid aqueous solution having a pH of 2 is preferably 150 ° or more.

The contact angle hysteresis θ _A -θ _{R with} respect to n-hexadecane of the surface modifying material after being immersed in an acid aqueous solution having a pH of 2 is preferably 10 ° or less, and more preferably 5 ° or less. For this reason, oil droplets can be slid down at an inclination angle of 5 ° or less (referred to as sliding angle), and a surface modifying material having excellent oil repellency (droplet removal ability and antifouling property) can be obtained.

When the surface modifying material is immersed in an acid aqueous solution or a base aqueous solution having different pHs, the advancing contact angle (θ _A ), receding contact angle (θ _R ), contact angle hysteresis (θ _A −θ _R ) and sliding angle with respect to the oil droplets are immersed. Changes. The pH responsiveness of this surface modifying material functions repeatedly.

n- of the surface modification material after being immersed in an acid aqueous solution having a pH of 2 with respect to the contact angle hysteresis θ _A -θ _R of the surface modification material after being immersed in an aqueous base solution having a pH of 10 with respect to n-hexadecane. The ratio of the contact angle hysteresis θ _A -θ _{R to} hexadecane is preferably 0.1 or less, and more preferably 0.05 or less. For this reason, the change in oil repellency due to the change in pH of the water to be immersed is large.

  The surface modifying material can be applied to lubrication treatment, antibacterial treatment, antifouling treatment, super water / oil repellent treatment, stimulus-responsive surface and the like.

[Preparation of pretreatment substrate]
A 1 cm × 1 cm silicon substrate was ultrasonically cleaned in ethanol for 5 minutes and then dried in a nitrogen stream. Next, after ozone cleaning at 1 × 10 ³ Pa for 30 minutes, together with about 100 μL of 3-aminopropyltriethoxysilane (APTES), put it in a sealed Teflon (registered trademark) container and heat treatment at 100 ° C. for 60 minutes. did. As a result, silanol groups present on the surface of the silicon substrate and the triethoxysilyl group of APTES were dehydrated and condensed to introduce amino groups on the surface of the silicon substrate. Further, excess APTES adsorbed on the silicon substrate was rinsed with toluene and then dried in a nitrogen stream. Next, the silicon substrate into which the amino group was introduced was immersed in a 0.1 M 1,4-dioxane solution of 2-bromoisobutyryl bromide (BIBB) as an ATRP initiator overnight. -A bromoisobutyryl group was introduced to obtain a pretreated substrate.

[Example 1-1]
A polymer brush of poly (2- (dimethylamino) ethyl methacrylate) (PDMAEMA) was introduced on the surface of the pretreated substrate using the AGET ATRP method. Specifically, 2-dimethylaminoethyl methacrylate (DMAEMA) 8 mL, water 7 mL, copper (II) chloride 16 mg and N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine 50 μL in 20 mL After putting in a glass bottle, 20 μL of a 1 mg / mL aqueous solution of ascorbic acid was added and stirred for about 2 minutes to obtain a polymerization solution. Next, after prepolymerizing the substrate by immersing the pretreated substrate in the polymerization solution, the glass bottle was sealed with a screw cap made of PTFE. At this time, since the polymerization solution was not degassed, the glass bottle contained about 4 mL of air. Furthermore, after superposing | polymerizing under room temperature (23-28 degreeC), without stirring, the glass substrate in which the polymer brush was introduce | transduced was taken out from the glass bottle, and it rinsed sufficiently with water, and obtained the surface modification board | substrate.

  FIG. 1 shows the relationship of the thickness of the polymer brush to the polymerization time.

  From FIG. 1, it can be seen that the thickness of the polymer brush increases linearly at about 2 nm / min after an incubation period of about 30 minutes and reaches 300 nm about 200 minutes after the start of polymerization. The linear increase in the thickness of the polymer brush indicates that the polymerization is controlled at a high level and that bromo or chloro groups are retained at the ends of the growing polymer chain. After the thickness of the polymer brush reached 300 nm, the increase in the thickness of the polymer brush became gradual. This is considered to be because the number of growing polymer chains is decreased by decreasing the bromo group or chloro group at the terminal of the growing polymer chain. As a result, the thickness of the polymer brush reached 670 nm after 1380 minutes from the start of polymerization.

  The thickness of the polymer brush was measured using an ellipsometer.

  In FIG. 2, the SEM photograph of the cross section of a polymer brush is shown.

  From FIG. 2, it can be seen that the polymer brush is smooth and homogeneous.

[Example 1-2]
Except for changing the addition amount of 1 mg / mL aqueous solution of copper (II) chloride, N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine and ascorbic acid to 8 mg, 25 μL and 10 μL, respectively. A surface-modified substrate was obtained in the same manner as Example 1-1.

  In FIG. 3, the relationship of the thickness of the polymer brush with respect to the polymerization time of Example 1-1, 1-2 is shown.

  From FIG. 3, in Example 1-2 in which the addition amounts of copper (II) chloride, pentamethyldiethylenetriamine, and ascorbic acid are half of those in Example 1-1, the incubation period is from about 30 minutes to about 0.1 minutes in Example 1-1. It turns out that it increases in 80 minutes. This is considered to be because the rate at which oxygen that inhibits the polymerization reaction is removed from the polymerization system is slowed by the oxidation of Cu (I) to Cu (II). In Example 1-1, the polymer brush rapidly grows about 30 minutes after the start of polymerization, whereas in Example 1-2, the polymer brush is about 160 minutes after the start of polymerization. Grows rapidly. This is because the growth rate of the polymer brush is proportional to [Cu (I)] / [Cu (II)] in the polymerization system. In Example 1-2, since the amount of Cu (I) in the polymerization system is small after 80 minutes from the start of polymerization, the growth of the polymer brush is slow. On the other hand, 120 minutes after the start of the polymerization, the amount of [Cu (I)] / [Cu (II)] in the polymerization system increases, so the growth of the polymer brush becomes faster and the polymerization starts. About 160 minutes after the removal, almost all oxygen is removed from the polymerization system, and [Cu (I)] / [Cu (II)] in the polymerization system becomes maximum and becomes constant.

[Example 2]
A polymer brush of poly (2- (diethylamino) ethyl methacrylate) (PDEAEMA) was introduced on the surface of the pretreated substrate using the ARGET ATRP method. Specifically, 2-diethylaminoethyl methacrylate (DEAEMA) 8 mL, water 3 mL, ethanol 4 mL, copper (II) chloride 2.8 mg and N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine 5 μL was placed in a 20 mL glass bottle. Next, 1 mL of a 1 mg / mL aqueous solution of ascorbic acid was added and stirred for about 2 minutes to obtain a polymerization solution. Next, after prepolymerizing the substrate by immersing the pretreated substrate in the polymerization solution, the glass bottle was sealed with a screw cap made of PTFE. At this time, since the polymerization solution was not degassed, the glass bottle contained about 4 mL of air. Furthermore, after superposing | polymerizing at room temperature (23-28 degreeC) for 24 hours, without stirring, the glass substrate in which the polymer brush was introduce | transduced was taken out from the glass bottle, and it rinsed enough with water, and obtained the surface modification board | substrate. . The polymer brush introduced into the surface treatment substrate had a thickness of 70 nm.

[Comparative Example 1]
A polymer brush of poly (sodium methacrylate) was introduced on the surface of the pretreatment substrate using the AGET ATRP method. Specifically, 3 g of sodium methacrylate, 4.6 mL of water, 8 mg of copper (II) chloride, and 25 μL of N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine were placed in a 20 mL glass bottle. Then, 10 μL of a 1 mg / mL aqueous solution of ascorbic acid was added and stirred for about 2 minutes to obtain a polymerization solution. Next, after prepolymerizing the substrate by immersing the pretreated substrate in the polymerization solution, the glass bottle was sealed with a screw cap made of PTFE. At this time, since the polymerization solution was not degassed, the glass bottle contained about 4 mL of air. Furthermore, after superposing | polymerizing under room temperature (23-28 degreeC), without stirring, the glass substrate in which the polymer brush was introduce | transduced was taken out from the glass bottle, and it rinsed sufficiently with water, and obtained the surface modification board | substrate.

  FIG. 4 shows the relationship between the polymer brush thickness and the polymerization time.

  From FIG. 4 it can be seen that the thickness of the polymer brush increases without the incubation period, but reaches 150 nm 1320 minutes after the start of polymerization.

  Next, the oil repellency after immersing the surface-modified substrates of Examples 1-1 and 2 and Comparative Example 1 in water having a predetermined pH was evaluated. At this time, a substrate into which a polymer brush having a thickness of 20 nm was introduced as the surface modified substrate of Example 1-1, and a polymer brush having a thickness of 29 nm was used as the surface modified substrate of Example 2. Was used, and as the surface modified substrate of Comparative Example 1, a substrate into which a polymer brush having a thickness of 87 nm was introduced was used.

[Oil repellency after immersion in water at a predetermined pH]
After immersing the surface-modified substrate in an aqueous acid solution having a pH of 2 or an aqueous base solution having a pH of 10, the automatic contact angle meter DM-501Hi (manufactured by Kyowa Interface Science Co., Ltd.) is used to move forward with respect to 3 μL of n-hexadecane. Contact angle θ _A and receding contact angle θ _R were measured at 25 ° C. Next, the formula θ _A −θ _R
From the above, the contact angle hysteresis Δθ was calculated.

  Table 1 shows the evaluation results of oil repellency after immersion in the acid aqueous solution having a pH of 2 or the base aqueous solution having a pH of 10 of the surface-modified substrates of Examples 1-1 and 2 and Comparative Example 1.

なお、ΔｐＨは、ｐＨの変化よるθ_Ａ及びθ_Ｒの変化を意味する。

ΔpH means a change in θ _A and θ _R due to a change in pH.

  From Table 1, since the surface modified substrates of Examples 1-1 and 2 have a contact angle hysteresis Δθ with respect to n-hexadecane after being immersed in an acid aqueous solution having a pH of 2, respectively, 4 ° and 8 °, Oil drops can be slid down at an inclination angle of 5 ° or less (referred to as sliding angle), and the oil repellency (droplet removal ability and antifouling property) is excellent.

  The surface modified substrates of Examples 1-1 and 2 were immersed in an acid aqueous solution having a pH of 2 with respect to the contact angle hysteresis Δθ with respect to n-hexadecane after being immersed in a basic aqueous solution having a pH of 10. Since the ratio of the contact angle hysteresis Δθ to n-hexadecane is 0.04 and 0.08, respectively, the change in oil repellency due to the change in the pH of the immersion water is large.

  On the other hand, the surface modified substrate of Comparative Example 1 is n after being immersed in an aqueous acid solution having a pH of 2 with respect to the contact angle hysteresis Δθ for n-hexadecane after being immersed in an aqueous base solution having a pH of 10. -Since the ratio of the contact angle hysteresis Δθ to hexadecane is 9, the change in oil repellency due to the change in the pH of the water to be immersed is small.

[Example 3-1]
A polymer brush of poly (2- (dimethylamino) ethyl methacrylate) (PDMAEMA) was introduced onto the surface of the pretreated substrate using the ARGET ATRP method. Specifically, 2-dimethylaminoethyl methacrylate (DMAEMA) 0.8 mL, water 15.2 mL, copper (II) chloride 2.8 mg and N, N, N ′, N ″, N ′ ″-penta After putting 5 μL of methyldiethylenetriamine in a 20 mL glass bottle, 1 mg of ascorbic acid was added and stirred for about 2 minutes to obtain a polymerization solution.

  Using a dropper, several drops of the polymerization solution were dropped on the pretreated substrate to start polymerization, and then the surface of the pretreated substrate on which the polymerization solution was dropped was coated with Whatman filter paper. Furthermore, after polymerizing at room temperature (23 to 28 ° C.) for 90 minutes, the Whatman filter paper was peeled off and thoroughly rinsed with water to obtain a surface modified substrate.

  When n-hexadecane was dropped onto the surface-modified substrate after the surface-modified substrate was immersed in water, the n-hexadecane droplets were able to move freely on the surface of the surface-modified substrate. From this, it was found that the surface-modified substrate was excellent in oil repellency after being immersed in water.

[Examples 3-2 to 3-7]
A surface modified substrate was obtained in the same manner as in Example 3-1, except that the amount of ascorbic acid added was changed to 2 mg, 10 mg, 20 mg, 30 mg, 40 mg, and 80 mg.

  When n-hexadecane was dropped onto the surface-modified substrate after the surface-modified substrate was immersed in water, the n-hexadecane droplets were able to move freely on the surface of the surface-modified substrate. From this, it was found that the surface-modified substrate was excellent in oil repellency after being immersed in water.

  FIG. 5 shows the relationship of the thickness of the polymer brush with respect to the concentration of ascorbic acid in the polymerization solution.

  The thickness of the polymer brush was measured using an ellipsometer.

  From FIG. 5, it was found that the optimum concentration of ascorbic acid in the polymerization solution was 0.2M (30 mg added). Here, when the concentration of ascorbic acid in the polymerization solution is low, the polymerization rate is slow, but since the polymerization is controlled, it is considered that a polymer brush having a large thickness is introduced. However, when the concentration of ascorbic acid in the polymerization solution is low, the oxygen in the solution oxidizes the regenerated Cu (I), and ascorbic acid is consumed in a short time. It is done. On the other hand, when the concentration of ascorbic acid in the polymerization solution is high, the concentration of polymer radicals in the polymerization system tends to be high, so a stop reaction is likely to occur early in the polymerization, resulting in a decrease in the thickness of the polymer brush. It is done.

[Example 4]
DMAEMA 4.8 mL, water 7.0 mL, copper (II) chloride 8.0 mg, N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine 50 μL and polyvinyl alcohol 0.50 g are placed in a 20 mL glass bottle. Thereafter, 0.01 mg of ascorbic acid was added and stirred for about 2 minutes to obtain a polymerization solution.

  Using the obtained polymerization solution, a surface-modified substrate was obtained in the same manner as in Example 3-1, except that the surface of the pretreated substrate on which the polymerization solution was dropped was not coated with Whatman filter paper. The polymer brush had a thickness of 4-6 nm.

  When n-hexadecane was dropped onto the surface-modified substrate after the surface-modified substrate was immersed in water, the n-hexadecane droplets were able to move freely on the surface of the surface-modified substrate. From this, it was found that the surface-modified substrate was excellent in oil repellency after being immersed in water.

[Example 5]
DMAEMA 0.8 mL, water 15.2 mL, copper (II) chloride 2.8 mg and N, N, N ′, N ″, N ′ ″-pentamethyldiethylenetriamine 5 μL were placed in a 20 mL glass bottle, and then ascorbic acid 20 mg Was added and stirred for about 2 minutes to obtain a polymerization solution.

  A surface-modified substrate was obtained in the same manner as in Example 3-1, except that the obtained polymerization solution was used. The polymer brush had a thickness of 10 nm.

  When n-hexadecane was dropped onto the surface-modified substrate after the surface-modified substrate was immersed in water, the n-hexadecane droplets were able to move freely on the surface of the surface-modified substrate. From this, it was found that the surface-modified substrate was excellent in oil repellency after being immersed in water.

  This international application claims priority based on Japanese Patent Application No. 2014-091865 filed on April 25, 2014 and Japanese Patent Application No. 2014-097191 filed on May 8, 2014 The entire contents of Japanese Patent Application No. 2014-091865 and Japanese Patent Application No. 2014-097191 are incorporated herein by reference.

Claims (12)

Introducing an amino group on the surface of the solid;
Reacting a solid having an amino group introduced on the surface with a 2-bromo-2-methylpropionic acid derivative to introduce a 2-bromoisobutyryl group on the surface of the solid;
The solid having a 2-bromoisobutyryl group introduced on the surface is immersed in a polymerization solution containing a water-soluble monomer, water, a metal salt for ATRP catalyst, a ligand for ATRP catalyst, and a reducing agent in air. Using the AGET ATRP method or the ARGET ATRP method to polymerize the water-soluble monomer to introduce a polymer brush onto the solid surface,
The water-soluble monomer is (meth) acrylic acid, (meth) acrylic acid 2-dimethylaminoethyl, (meth) acrylic acid 2-diethylaminoethyl, (meth) acrylic acid 1,2-dihydroxyethyl, (meth) acrylic acid 2-hydroxyethyl, 2- (meth) acryloyloxyethyl phosphorylcholine, [2- (meth) acryloyloxyethyl] dimethyl (3-sulfopropyl) ammonium hydroxide, (meth) acrylamide, N-2-dimethylaminoethyl (meta ) A surface modification method characterized by being acrylamide, N-2-diethylaminoethyl (meth) acrylamide, N-1,2-dihydroxyethyl (meth) acrylamide or N-2-hydroxyethyl (meth) acrylamide.   2. The surface modification method according to claim 1, wherein the concentration of the water-soluble monomer in the polymerization solution is 1% by volume or more and 50% by volume or less. Surface modification method according to claim 1, the molar ratio before Kikae source agent to the ATRP catalyst metal salt is characterized in that at least 0.30 50 or less. Introducing an amino group on the surface of the solid;
Reacting a solid having an amino group introduced on the surface with a 2-bromo-2-methylpropionic acid derivative to introduce a 2-bromoisobutyryl group on the surface of the solid;
Applying a polymerization solution containing a water-soluble monomer, water, a metal salt for ATRP catalyst, a ligand for ATRP catalyst, and a reducing agent in air to a solid having a 2-bromoisobutyryl group introduced on the surface; Using the AGET ATRP method or the ARGET ATRP method to introduce a polymer brush on the solid surface by polymerizing the water-soluble monomer,
The water-soluble monomer is (meth) acrylic acid, (meth) acrylic acid 2-dimethylaminoethyl, (meth) acrylic acid 2-diethylaminoethyl, (meth) acrylic acid 1,2-dihydroxyethyl, (meth) acrylic acid 2-hydroxyethyl, 2- (meth) acryloyloxyethyl phosphorylcholine, [2- (meth) acryloyloxyethyl] dimethyl (3-sulfopropyl) ammonium hydroxide, (meth) acrylamide, N-2-dimethylaminoethyl (meta A method for surface modification characterized by being acrylamide, N-2-diethylaminoethyl (meth) acrylamide, N-1,2-dihydroxyethyl (meth) acrylamide or N-2-hydroxyethyl (meth) acrylamide.   The surface modification method according to claim 4, wherein the polymerization solution has a concentration of the water-soluble monomer of 1% by volume to 50% by volume. Surface modification method according to claim 4 molar ratio before Kikae source agent to the ATRP catalyst metal salt is characterized in that at least 0.30 50 or less.   The surface modification method according to claim 4, wherein the polymerization solution further includes a thickener.   The surface modification method according to claim 4, wherein a solid surface to which the polymerization solution is applied is coated with a coating material.   A surface-modified material, wherein the surface is modified by the surface-modifying method according to claim 1.   The ratio of the contact angle hysteresis for n-hexadecane after immersion in an acid aqueous solution having a pH of 2 to the contact angle hysteresis for n-hexadecane after immersion in an aqueous base solution having a pH of 10 is 0.1 or less. The surface modifying material according to claim 9.   The surface modification material according to claim 9, wherein the contact angle hysteresis with respect to n-hexadecane after being immersed in an acid aqueous solution having a pH of 2 is 10 ° or less. A surface-modified material, the surface of which is modified by the surface-modifying method according to claim 4 .

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