JP2020045427A - Production method of polymer and production method of surface-modified substrate - Google Patents

Abstract

To provide a production method of a polymer which uses an easily obtainable material and can provide a high molecular weight (meth)acrylic polymer which has hitherto been difficult to obtain, while under relatively mild conditions without requiring rigorous management of polymerization conditions.SOLUTION: Provided is a method for producing a polymer, comprising a step of polymerizing a (meth)acrylic monomer in the coexistence of an initiator compound having an initiator group represented by a general formula (1) or (2) and a halogenated quaternary ammonium salt, etc., under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60°C or higher to form a (meth)acrylic polymer of a number average molecular weight of 100,000 to 10,000,000. In the formulas, X represents a chlorine atom, etc.; Y represents O or NH; Rto Rrepresent alkyl groups, etc.; and "*" represents a bond position.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a high molecular weight polymer ((meth) acrylic acid-based polymer) and a method for producing a surface-modified base material.

  In recent years, a so-called "dense polymer brush", which is grafted onto a substrate at a high density by using a living radical polymerization technique developed in the 1990s, has been studied. In this concentrated polymer brush, the polymer chains are grafted on the substrate at a high density at intervals of 1 to 4 nm. The surface of the base material can be modified with such a concentrated polymer brush to impart characteristics such as low friction, protein adsorption suppression, size exclusion, hydrophilicity, and water repellency (for example, Patent Documents 1 and 2). , Non-Patent Documents 1 to 3).

JP 2008-133434 A JP 2010-261001 A

Adv. Polym. Sci. , 2006, 197, 1-45. J. Am. Chem. Soc. , 2005, 127, 15843-15847 Polym. Chem. , 2012, 3, 148-153

  Most of the conventional concentrated polymer brushes are manufactured by an atom transfer radical polymerization method. The atom transfer radical polymerization method is a kind of living radical polymerization method, in which an initiator such as halogen is introduced onto a substrate, and a redox reaction using a metal complex such as copper or ruthenium as a catalyst is a polymerization method. However, in the atom transfer radical polymerization method, it takes time to remove heavy metals such as copper used. In addition, there is a concern that the use of heavy metals imposes a burden on the environment. Furthermore, the atom transfer radical polymerization method is a rather complicated method, for example, it is necessary to purify monomers and materials and it is necessary to strictly control polymerization conditions such as oxygen concentration.

  The present invention has been made in view of such problems of the prior art, and it is an object of the present invention to use readily available materials and to require strict control of polymerization conditions. It is an object of the present invention to provide a method for producing a polymer capable of obtaining a high-molecular-weight (meth) acrylic acid-based polymer, which has been conventionally difficult even under relatively mild conditions. Further, an object of the present invention is to use easily available materials, and to use a relatively mild condition without requiring strict control of polymerization conditions. An object of the present invention is to provide a method for producing a surface-modified base material on which a polymer layer of a sufficient thickness made of a (meth) acrylic acid-based polymer having a molecular weight is formed.

That is, according to the present invention, a method for producing a polymer described below is provided.
[1] Polystyrene which is obtained by polymerizing a (meth) acrylic acid-based monomer in the presence of a starting compound and a salt under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60 ° C. or more, and measuring by gel permeation chromatography A step of forming a (meth) acrylic acid-based polymer having a converted number average molecular weight of 100,000 to 10,000,000, wherein the starting compound is represented by the following general formula (1) or (2) A polymer having an initiating group, wherein the salt is at least one selected from the group consisting of quaternary ammonium halide salts, quaternary phosphonium halide salts, and alkali metal halide salts.

（前記一般式（１）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｒ₁は、水素原子、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、Ｒ₂は、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、「＊」は結合位置を示す）

(In the general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom, and R ₁ represents a hydrogen atom, an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or Represents an amide group, R ₂ represents an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or an amide group, and “*” represents a bonding position)

（前記一般式（２）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｙは、Ｏ又はＮＨを示し、Ｒ₃は、水素原子、アルキル基、アリール基、又はアシル基を示し、Ｒ₄は、アルキル基、アリール基、又はアシル基を示し、「＊」は結合位置を示す）

(In the general formula (2), X represents a chlorine atom, a bromine atom, or an iodine atom, Y represents O or NH, and R ₃ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group. R ₄ represents an alkyl group, an aryl group, or an acyl group, and “*” represents a bonding position)

[2] In at least one organic solvent selected from the group consisting of alcohol solvents, glycol solvents, amide solvents, ether solvents, sulfoxide solvents, urea solvents, and ionic liquids, the boiling point of the organic solvent or lower The method for producing a polymer according to [1], wherein the (meth) acrylic acid-based monomer is polymerized under the following temperature conditions.
[3] The above-mentioned [1] or [2], wherein the salt is at least one selected from the group consisting of quaternary ammonium iodide, quaternary phosphonium iodide, and alkali metal iodide. A method for producing a polymer.
[4] The method for producing a polymer according to any one of [1] to [3], wherein the (meth) acrylic acid-based polymer having a molecular weight distribution (weight average molecular weight / number average molecular weight) of 1.8 or less is obtained.

Further, according to the present invention, there is provided the following method for producing a surface-modified base material.
[5] a step of subjecting the substrate to a surface treatment with a treating agent having a starting group represented by the following general formula (1) or (2) and an alkoxysilyl group to obtain a treated substrate; A (meth) acrylic acid-based monomer is polymerized under pressure and at a temperature of 60 ° C. or more in the coexistence of the treated substrate and the salt, and the number average molecular weight in terms of polystyrene measured by gel permeation chromatography is 100. Forming a (meth) acrylic acid-based polymer of 2,000 to 10,000,000, and arranging a polymer layer having a thickness of 100 nm or more containing the (meth) acrylic acid-based polymer on the surface of the treated substrate. And a method for producing a surface-modified substrate.

（前記一般式（１）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｒ₁は、水素原子、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、Ｒ₂は、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、「＊」は結合位置を示す）

(In the general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom, and R ₁ represents a hydrogen atom, an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or Represents an amide group, R ₂ represents an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or an amide group, and “*” represents a bonding position)

（前記一般式（２）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｙは、Ｏ又はＮＨを示し、Ｒ₃は、水素原子、アルキル基、アリール基、又はアシル基を示し、Ｒ₄は、アルキル基、アリール基、又はアシル基を示し、「＊」は結合位置を示す）

(In the general formula (2), X represents a chlorine atom, a bromine atom, or an iodine atom, Y represents O or NH, and R ₃ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group. R ₄ represents an alkyl group, an aryl group, or an acyl group, and “*” represents a bonding position)

  According to the present invention, it is possible to use a readily available material, and to use a relatively high-molecular-weight (meta) polymer which is relatively mild without requiring strict control of polymerization conditions. A method for producing a polymer capable of obtaining an acrylic acid-based polymer can be provided. Further, according to the present invention, it is possible to use a readily available material, and to use a relatively high-molecular-weight ( It is possible to provide a method for producing a surface-modified base material on which a polymer layer made of a (meth) acrylic acid-based polymer having a sufficient thickness is formed. That is, by using the method for producing a polymer of the present invention, a substrate such as a part or a member having various properties imparted to its surface can be produced.

<Production method of polymer>
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. The method for producing a polymer of the present invention comprises polymerizing a (meth) acrylic acid-based monomer in the presence of a starting compound and a salt under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60 ° C. or more, and the gel permeation chromatography A step (polymerization step) of forming a (meth) acrylic acid-based polymer having a number average molecular weight in terms of polystyrene of 100,000 to 10,000,000 as measured by chromatography.

(Polymerization step)
In the polymerization step, the polymerization is performed under a pressure of 100 to 1,000 MPa, preferably 200 to 800 MPa, and more preferably 300 to 600 MPa. Specifically, the polymerization is performed while uniformly applying pressure to the entire polymerization vessel containing the (meth) acrylic acid-based monomer via a medium such as water. By performing radical polymerization in a state where pressure is applied, a termination reaction can be suppressed, and a higher molecular weight (meth) acrylic acid-based polymer can be formed. If the pressure is less than 100 MPa, it is not possible to obtain a desired high molecular weight polymer. On the other hand, it is difficult to prepare a container or a device capable of withstanding a pressure of more than 1,000 MPa, which is not practical.

  As the polymerization container, it is preferable to use a container that can be hermetically sealed and can withstand high pressure. Further, since pressure needs to be transmitted to the inside of the container, it is preferable to use a container having a portion that is deformed by pressure, such as a plastic soft portion or an elastic portion. Specifically, various containers such as a polyethylene bottle, a plastic bottle, a retort pouch, and a blister container can be used. Further, a container made of a heat-resistant material that is not easily deformed at the temperature during polymerization is preferable. Further, a container made of a material which is hardly attacked by a polymerization solvent or the like and has properties such as chemical resistance and solvent resistance is preferable. Examples of the material constituting the polymerization container include polyolefin-based resins, fluorine-based resins, polyester-based resins, polyamide-based resins, and engineering plastics. At the time of polymerization, it is preferable to prevent gas from entering the polymerization vessel as much as possible. For example, it is preferable to charge the polymerization solution to 90% or more of the capacity of the polymerization vessel.

In the polymerization step, the polymerization is carried out at a temperature of 60 ° C. or higher, preferably 70 ° C. or higher. The polymerization is preferably carried out at a temperature of 200 ° C. or lower, more preferably 120 ° C. or lower.
In the polymerization step, the halogen in the specific starting group is eliminated as a radical, and the polymerization proceeds from the eliminated site (carbon radical). For this reason, it is necessary to set a predetermined temperature condition in order for the reaction with the salt to proceed when the halogen radical is eliminated.

(Starting compound)
The starting compound is a compound having a starting group represented by the following general formula (1) or (2). Polymerization starts from the starting group of the starting compound. Specifically, X in the general formula (1) or (2) is eliminated as a radical, and a monomer is inserted into the generated carbon radical to polymerize. This forms a polymer terminated by an initiator.

（前記一般式（１）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｒ₁は、水素原子、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、Ｒ₂は、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、「＊」は結合位置を示す）

(In the general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom, and R ₁ represents a hydrogen atom, an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or Represents an amide group, R ₂ represents an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or an amide group, and “*” represents a bonding position)

In the general formula (1), the carbon atom to which X is bonded is a tertiary carbon atom or a quaternary carbon atom. Preferably, at least one of R ₁ and R ₂ is a group other than an alkyl group. That is, when at least one of R ₁ and R ₂ is an electron-donating group other than an alkyl group, X is easily eliminated. Above all, it is more preferable that X is bonded to a quaternary carbon atom to generate a radical.

（前記一般式（２）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｙは、Ｏ又はＮＨを示し、Ｒ₃は、水素原子、アルキル基、アリール基、又はアシル基を示し、Ｒ₄は、アルキル基、アリール基、又はアシル基を示し、「＊」は結合位置を示す）

(In the general formula (2), X represents a chlorine atom, a bromine atom, or an iodine atom, Y represents O or NH, and R ₃ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group. R ₄ represents an alkyl group, an aryl group, or an acyl group, and “*” represents a bonding position)

In the general formula (2), the carbon atom to which X is bonded is a tertiary carbon atom or a quaternary carbon atom. Since the ester group or the amide group is an electron donating group, both R ₃ and R ₄ may be alkyl groups. Further, it is more preferable that X is bonded to a quaternary carbon atom to generate a radical.

  As the starting compound, a commercially available compound can be used, or a synthesized compound can be used. The initiator compound can be obtained, for example, by reacting iodine with an azo radical polymerization initiator such as azobisisobutyronitrile or dimethyl azobisisobutyrate.

(salt)
The salt is at least one selected from the group consisting of quaternary ammonium halide salts, quaternary phosphonium halide salts, and alkali metal halide salts. X (halogen) in the starting group is eliminated as a radical, and a monomer is inserted into a carbon radical generated with the elimination of X, whereby polymerization proceeds. At this time, the coexistence of a specific salt causes the extraction of halogen radicals or the exchange of halogens, and the polymerization of the monomer proceeds from the generated carbon radicals to form a polymer.

  Examples of the quaternary ammonium halide salt include benzyltrimethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetraoctylammonium iodide, nonylpyridinium chloride, choline chloride and the like. Examples of the halogenated quaternary phosphonium salt include tetraphenylphosphonium chloride, methyltributylphosphonium bromide, tetrabutylphosphonium iodide and the like. Examples of the alkali metal halide include lithium bromide and potassium iodide.

  As the salt, it is preferable to use an iodide salt. By using an iodide salt, living radical polymerization proceeds, and a polymer having a narrower molecular weight distribution can be obtained. Further, it is preferable to use a salt that can be dissolved in a polymerization solution such as a quaternary ammonium iodide salt, a quaternary phosphonium iodide salt, and an alkali metal iodide salt, and it is preferable to use a quaternary ammonium iodide salt. More preferred. Examples of the quaternary ammonium iodide include benzyltetrabutylammonium iodide, tetrabutylammonium iodide, tetraoctylammonium iodide, dodecyltrimethylammonium iodide, octadecyltrimethylammonium iodide, trioctadecylmethylammonium iodide, and the like. Can be mentioned.

  From the viewpoint of increasing the activity and obtaining a polymer having a higher concentration and a higher molecular weight, the amount of the salt with respect to the starting group is preferably at least equimolar, more preferably at least 10 moles, and more preferably at least 100 moles. Is also good.

((Meth) acrylic acid monomer)
As the (meth) acrylic acid-based monomer, a conventionally known (meth) acrylic acid-based monomer can be used. The “(meth) acrylic acid-based monomer” in this specification includes (meth) acrylic acid in addition to (meth) acrylic acid ester.

  Examples of the (meth) acrylic acid-based monomer include (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and tert-butyl (meth). Acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, cyclodecyl (meth) ) Acrylic, tricyclodecyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate and other alkyl and cycloalkyl (meth) acrylate monomers ;

  Hydroxyalkyl (meth) acrylate monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2,3-dihydroxypropyl (meth) acrylate;

  Methoxyethoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monomethyl ether (meth) acrylate, glycidyl (meth) acrylate, 3-ethyloxetanyl (meth) acrylate, 2, Oxyalkyl (meth) acrylate monomers such as 2-dimethyl-1,3-dioxolan-4-methanol (meth) acrylate and glucosyloxyethyl (meth) acrylate;

  N, N'-dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, benzyldimethylammoniumethyl (meth) acrylate, trimethylethylchloride (meth) acrylate, dimethylammonium Amino, ammonium alkyl (meth) acrylate monomers such as bistrifluoromethaneamide salt of ethyl (meth) acrylate and 2- (meth) acryloyloxyethyl phosphorylcholine;

  Fluorine atom-containing (meth) acrylate monomers such as 2,2,2-trifluoroethyl (meth) acrylate, 2-perfluorobutylethyl (meth) acrylate, and 2-perfluorooctylethyl (meth) acrylate; terminals of polydimethylsiloxane Silicon polymer-based macromonomers such as (meth) acrylate; highly reactive monomers such as ethyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilyl, and (meth) acryloyloxyethyl isocyanate; Can be.

  In the method for producing a polymer of the present invention, a (meth) acrylic acid-based monomer having a carboxy group or a highly reactive group can be used as it is without protecting the carboxy group or the highly reactive group. In the conventional atom transfer radical polymerization method, a metal complex of a polyamine is used as a catalyst. However, when an acid component such as a monomer having a carboxy group coexists, the metal complex serving as a catalyst is broken, so that the polymerization reaction does not proceed. On the other hand, in the method for producing a polymer of the present invention, a polymerization reaction proceeds without protecting a functional group such as a carboxy group or a phosphate group.

  The molecular weight of the resulting polymer can be controlled to some extent by setting the ratio of the initiator to the (meth) acrylic acid-based monomer. For example, assuming that polymerization is performed using 5,000 moles of a monomer having a molecular weight of 100 with respect to 1 mole of the starting compound, a polymer having a theoretical molecular weight of “1 × 100 × 5,000 = 500,000” is formed. . That is, the molecular weight of the obtained monomer can be calculated from the formula [1 mol of starting compound × molecular weight of monomer × molar ratio of starting compound to monomer].

(Organic solvent)
In the polymerization step, it is preferable to polymerize the (meth) acrylic acid-based monomer in an organic solvent. Above all, by polymerizing in a solvent capable of dissolving the formed polymer, the polymer does not solidify and can be easily handled. From the viewpoint of industrial and productive safety, it is preferable to polymerize the (meth) acrylic acid-based monomer under a temperature condition equal to or lower than the boiling point of the organic solvent.

  As the organic solvent, a conventionally known solvent for polymerization can be used. Among them, it is preferable to use at least one organic solvent selected from the group consisting of alcohol solvents, glycol solvents, amide solvents, ether solvents, sulfoxide solvents, urea solvents, and ionic liquids. Since these organic solvents have high polarity, the above-mentioned salts can be dissolved. Furthermore, it is preferable to use these organic solvents having a high polarity since the halogen exchange rate can be further increased.

  Examples of the alcohol solvent include isopropanol, butanol, hexanol and the like. Examples of glycol solvents include ethylene glycol, propylene glycol, poly (n = 2 or more) ethylene glycol monomethyl ether, poly (n = 2 or more) ethylene glycol monobutyl ether, poly (n = 2 or more) propylene glycol monomethyl ether, propylene Examples thereof include glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monomethyl ether acetate. Examples of the amide solvent include dimethylformamide, dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, 3-methoxy-N, N-dimethylpropanamide, and 3-butoxy-N, N-dimethylpropanamide. .

  Examples of the ether solvent include diethylene glycol dimethyl ether and diethylene glycol diethyl ether. Examples of the sulfoxide-based solvent include sulfolane and dimethyl sulfoxide. Examples of the urea-based solvent include tetramethylurea and dimethylimidazolidinone. Examples of the ionic liquid include ethyl (3-methoxypropyl) dimethylammonium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylimidazolium tetrafluoroborate, and N, N-diethyl-N-methyl-N-2- Methoxyethyl ammonium bis (trifluoromethanesulfonyl) imide and the like can be mentioned. Among these organic solvents, it is preferable to use an organic solvent that is difficult to volatilize because it is difficult to expand during polymerization, and it is preferable to use an organic solvent having a boiling point of 150 ° C. or higher.

((Meth) acrylic acid polymer)
The (meth) acrylic acid-based polymer produced by the method for producing a polymer of the present invention has a number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) of 100,000 to 10,000. 000, preferably 300,000 to 8,000,000, and more preferably 500,000 to 5,000,000. That is, according to the method for producing a polymer of the present invention, it is possible to easily produce a high molecular weight (meth) acrylic acid-based polymer which is difficult to produce by ordinary solution polymerization or the like. It is considered that this is because the termination reaction is suppressed and the growth reaction is promoted by polymerization under high pressure conditions. The (meth) acrylic acid-based polymer having Mn of less than 100,000 can be produced by another polymerization method (solution polymerization method, bulk polymerization method, emulsion polymerization method, etc.). On the other hand, it is substantially difficult to produce a (meth) acrylic acid-based polymer having Mn of more than 10,000,000.

  The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn) = PDI) of the (meth) acrylic acid-based polymer produced by the method for producing a polymer of the present invention is preferably 1.8 or less. , More preferably 1.4 or less.

  Since the (meth) acrylic acid-based polymer produced by the method for producing a polymer of the present invention has a high molecular weight, for example, a coating agent for forming a coating layer having excellent durability, and a molding raw material for various molded articles Useful as

<Production method of surface modified base material>
The method for producing a surface-modified base material of the present invention comprises subjecting the base material to a surface treatment with a treatment agent having an initiator group represented by the following general formula (1) or (2) and an alkoxysilyl group. The step of obtaining (pretreatment step) and polymerizing the (meth) acrylic acid-based monomer in the presence of a treatment substrate and a salt under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60 ° C. or more, and gel permeation A (meth) acrylic acid-based polymer having a polystyrene-equivalent number average molecular weight of 100,000 to 10,000,000 as measured by chromatography is formed, and the surface of the treated substrate contains the (meth) acrylic acid-based polymer. And disposing a polymer layer having a thickness of 100 nm or more (polymerization step). That is, the method for producing a surface-modified substrate of the present invention comprises modifying the surface of the substrate using the above-described method for producing a polymer, and forming a polymer layer having a predetermined thickness on the surface of the substrate. This is a method for obtaining a surface-modified base material.

（前記一般式（１）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｒ₁は、水素原子、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、Ｒ₂は、アルキル基、アリール基、シアノ基、アシル基、カルボキシ基、エステル基、又はアミド基を示し、「＊」は結合位置を示す）

(In the general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom, and R ₁ represents a hydrogen atom, an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or Represents an amide group, R ₂ represents an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or an amide group, and “*” represents a bonding position)

（前記一般式（２）中、Ｘは、塩素原子、臭素原子、又はヨウ素原子を示し、Ｙは、Ｏ又はＮＨを示し、Ｒ₃は、水素原子、アルキル基、アリール基、又はアシル基を示し、Ｒ₄は、アルキル基、アリール基、又はアシル基を示し、「＊」は結合位置を示す）

(In the general formula (2), X represents a chlorine atom, a bromine atom, or an iodine atom, Y represents O or NH, and R ₃ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group. R ₄ represents an alkyl group, an aryl group, or an acyl group, and “*” represents a bonding position)

(Base material)
Substrates include silicon substrates; glass substrates; plate-like and film-like substrates such as metals, ceramics, alumina, silicon carbide, boron nitride, ITO films, plastic plates, and plastic films; fibers such as glass fibers and carbon fibers Substrate and the like. Further, a filler-like base material such as a pigment, silica, and magnetic powder can be used.

(Processing agent)
In the pretreatment step, the base material is surface-treated with a treating agent having a starting group represented by the general formula (1) or (2) and an alkoxysilyl group. Thus, a treated base material having a predetermined starting group bonded to the surface of the base material can be obtained. Examples of the alkoxysilyl group include a methoxydimethylsilyl group, an ethoxydimethylsilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, a trimethoxysilyl group, a triethoxysilyl group, and a chloromethoxymethylsilyl group. Further, specific examples of the treating agent having a predetermined starting group and an alkoxysilyl group include compounds represented by the following formulas (3) to (7).

  Further, a monomer component containing a monomer represented by the following formula (8) and a monomer having an alkoxysilyl group such as (meth) acryloyloxypropyltrimethylsilyl and (meth) acryloyloxypropyltriethoxysilyl is polymerized. A polymer (polymer type treating agent) obtained by the above method can also be used as a treating agent. Further, such a polymer used as a treating agent may be a polymer having a structure such as polyester, polyurethane, or polyamide, or a polymer having a structure such as a random structure, a block structure, a graft structure, a star structure, or a particle. It may be.

  Before the surface treatment with the treating agent, the substrate may be pretreated. Pre-treatment includes silane coupling treatment, silica treatment, alumina treatment, silica-alumina treatment, zirconia treatment, UV irradiation, plasma irradiation, electron beam irradiation, radiation irradiation, surface cleaning such as ozone oxidation, activation, and functional groups. Processing such as giving can be given.

  The treating agent is a compound having an alkoxysilyl group. Therefore, the surface of the base material can be treated with a treating agent by a conventionally known silane coupling treatment method such as a dry treatment method or a wet treatment method. The dry treatment method is a method in which a treatment agent dissolved as is or dissolved in a low boiling point solvent or the like is applied to the surface of a substrate by spraying or the like, and then dried. The wet processing method is a method in which a substrate is immersed in a solution of a processing agent and then dried. In the case of the above-mentioned polymer type treating agent, a base material can be flattened by forming a thick layer by a technique such as dipping, coater, or spin coating.

(Polymerization step)
In the polymerization step, the (meth) acrylic acid-based monomer is polymerized in the same manner as in the polymerization step in the above-described polymer production method. That is, the (meth) acrylic acid-based monomer is polymerized under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60 ° C. or more in the presence of a treatment substrate and a salt. Thereby, a (meth) acrylic acid-based polymer is formed, and a surface-modified base material having a polymer layer disposed on the surface of the treated base material can be obtained.

  The pressure conditions and temperature conditions at the time of polymerization are the same as the pressure conditions and temperature conditions in the above-mentioned polymer production method, including suitable conditions. The monomers used and salts coexisting during polymerization are also the same as the monomers and salts used in the above-described polymer production method, including suitable ones.

  As described above, since polymerization is performed under predetermined pressure and temperature conditions, a high-molecular-weight (meth) acrylic acid-based polymer is formed. Therefore, a polymer layer having a thickness of 100 nm or more, preferably 200 nm or more, more preferably 500 nm or more can be formed. Also, unlike a general polymer coating layer, the polymer layer is formed of a polymer grafted from an initiator group bonded to the substrate surface. For this reason, it is expected that the polymer layer constituting the surface-modified base material produced by the production method of the present invention will exhibit properties different from those of a general polymer coating layer. Furthermore, since the polymer layer is formed by a polymer that is densely extended in the vertical direction from the substrate surface, characteristics such as low friction, protein adsorption suppression, size exclusion, hydrophilicity, and water repellency are more remarkable. It is expected to be used in

  Since the reactivity of the starting group is uniform, the molecular weight of the above-mentioned polymer produced using the predetermined starting compound having the starting group and the polymer layer formed using the predetermined treating agent having the starting group are formed. The molecular weights of the polymers are considered to be substantially the same. For this reason, the molecular weight of the polymer constituting the polymer layer formed on the surface of the base material was confirmed by measuring the molecular weight of the polymer generated in the polymerization step of the method for producing the surface-modified base material of the present invention by GPC or the like. can do.

From the thickness L of the polymer layer, the number average molecular weight Mn of the polymer chains, and the density d of the polymer chains, the number of polymer chains per unit area (polymer formation density, unit: nm / nm ² ) can be calculated. The polymer formation density in the polymer layer constituting the surface-modified base material produced by the production method of the present invention is preferably at least 0.05 / nm ² , more preferably 0.1 to 0.7 / nm ^2. nm ² . The higher the polymer formation density, the more effectively the properties such as high elasticity, ultra-low friction, and size exclusion effect are exhibited.

The polymer formation density σ is represented by the following formula (X). In the following formula (X), N _A represents Avogadro's number.
_{σ = dLN A Mn ··· (X} )

  The thickness L of the polymer layer can be measured using, for example, an ellipsometer, an electron microscope, an atomic force microscope, or the like. The density d of the polymer chain can be measured by, for example, a method according to JIS K 7112: 1999, in addition to the density described in a conventionally known document.

  ADVANTAGE OF THE INVENTION According to the manufacturing method of this invention, the surface-modified base material which remarkably improved the surface characteristic of the base material can be manufactured easily. Therefore, the production method of the present invention is useful as a method for producing various base materials used in various fields such as medical members, electronic materials, display materials, semiconductor materials, mechanical parts, sliding members, and battery materials. It is.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the Examples and Comparative Examples, “parts” and “%” are based on mass unless otherwise specified.

<Production of polymer>
(Example 1)
In a glass sample bottle, 0.002 parts of 2-cyano-2-iodopropane (CP-I), 0.7388 parts of tetrabutylammonium iodide (TBAI), 20.0 parts of methyl methacrylate (MMA), And 20.0 parts of 3-methoxy-N, N-dimethylpropanamide (MDPA). The contents were stirred and the TBAI was dissolved and homogenized. After blowing nitrogen gas, the contents were transferred to a resin sample bottle and sealed. The sample bottle sealed by winding a film around the lid was placed in an aluminum laminate bag, and air was released to seal.

  The aluminum laminate bag was placed in a high-pressure device (product name “PV-400 series”, manufactured by Shin Corporation) containing water as a pressurizing medium, heated to 80 ° C., pressurized to 400 MPa, and polymerized for 4 hours. . A part of the highly viscous polymer solution in the sample bottle was sampled, and the number average molecular weight (Mn) in terms of polystyrene of the polymer measured by GPC using THF as a developing solvent was 785,000, and PDI (Mw / Mn ) Was 1.56. The polymerization rate calculated from the residual amount of MMA measured by gas chromatography (GC) was 64.3%.

(Comparative Example 1)
Polymerization was carried out in the same manner as in Example 1 except that no pressure was applied, to obtain a slightly viscous polymer solution. Mn of the obtained polymer was 39,000 and PDI was 1.12. Further, the polymerization rate was 15.0%.

(Example 2)
Example 1 was repeated except that 0.002 part of ethyl bromoisobutyrate (EBIB) was used instead of CP-I and 0.645 part of tetrabutylammonium bromide (TBAB) was used instead of TBAI. Polymerization resulted in a polymer solution. Mn of the obtained polymer was 1,230,000, and PDI was 3.25. The conversion was 71.2%. By using a bromide salt instead of an iodide salt, a polymer having a higher molecular weight distribution but a higher molecular weight can be obtained in a high yield.

(Example 3)
Except that 0.001 part of EBIB, 0.593 part of tetraoctyl ammonium iodide (TOAI), 20 parts of MMA and 10 parts of MDPA were used, polymerization was carried out in the same manner as in Example 1 described above, and a polymer solution having almost no fluidity was used. I got Mn of the obtained polymer was 2,420,000, and PDI was 1.78. Further, the polymerization rate was 65.0%. By using bromide as the starting compound and using an iodide salt, it is possible to obtain a polymer having a narrower molecular weight distribution and a higher molecular weight.

(Example 4)
Polymerization was conducted in the same manner as in Example 3 except that 35.2 parts of benzyl methacrylate (BzMA) was used instead of MMA, 0.369 parts of TBAI was used instead of TOAI, and the polymerization time was 6 hours. Thus, a polymer solution was obtained. Mn of the obtained polymer was 3,530,000, and PDI was 1.49. The conversion was 71.1%.

(Example 5)
The above procedure was followed except that 25.4 parts of lauryl methacrylate (LMA) was used in place of BzMA and 25.4 parts of 3-butoxy-N, N-dimethylpropanamide (BDPA) was used in place of MDPA. Polymerization was carried out in the same manner as in Example 4 to obtain a polymer solution. The Mn of the obtained polymer was 450,000 and the PDI was 1.23. The conversion was 51.2%.

(Example 6)
Polymerization was carried out in the same manner as in Example 3 except that 25.6 parts of butyl acrylate (BA) was used instead of MMA, 25.6 parts of BDPA was used instead of MDPA, and the polymerization temperature was 130 ° C. Thus, a relatively viscous polymer solution was obtained. Mn of the obtained polymer was 1,030,000 and PDI was 1.89. The conversion was 30.0%.

(Example 7)
A high-viscosity polymer solution was obtained by polymerizing in the same manner as in Example 3 except that the pressure was increased to 100 MPa using a high-pressure processing device (trade name: Marugoto Extract) manufactured by Toyo Kogyo Co., Ltd. Was. Mn of the obtained polymer was 278,000 and PDI was 1.92. Further, the polymerization rate was 45.5%.

(Example 8)
N, N-Diethyl-N-methyl-N-2-methoxyethylammonium bis (trifluoromethanesulfonyl) was used in place of MDPA, and the polymerization time was 2 hours, except that the polymerization time was 2 hours. Polymerization resulted in a polymer solution. Mn of the obtained polymer was 2,600,000, and PDI was 1.58. Further, the polymerization rate was 35.0%.

(Example 9)
Polymerization was performed in the same manner as in Example 2 except that butyl acetate was used instead of MDPA to obtain a polymer solution. The Mn of the obtained polymer was 120,000 and the PDI was 1.23. Further, the polymerization rate was 7.5%.

<Production of surface-modified base material (1)>
(Example 10)
After a 1 cm × 1 cm silicon substrate was ultrasonically cleaned with isopropyl alcohol, the substrate was irradiated with UV ozone using a chip cleaner (manufactured by Bioforce Nanoscience) to form hydroxyl groups on the surface of the silicon substrate and activated. The activated silicon substrate was immersed in a container containing 100 parts of ethanol, 10 parts of a 28% aqueous ammonia solution, and 1 part of 2-bromo-2-methylpropionyloxypropyltrimethoxysilane (BPM) for 12 hours. The removed silicon substrate was dried at 80 ° C. for 10 minutes using a dryer.

  The silicon substrate was placed in a plastic container with a lid containing 20 parts of MMA, 0.593 parts of TOAI, 0.001 part of EBAI, and 20 parts of MDPA. The covered plastic container was placed in a high-pressure device, heated to 80 ° C., and pressurized to 400 MPa to polymerize for 6 hours to obtain a surface-modified base material having a polymer layer formed on the surface of a silicon substrate. The Mn of the polymer in the highly viscous polymer solution formed in the plastic container was 720,000, and the PDI was 1.86. The resulting polymer is a polymer formed from free initiator groups. Since a free initiation group exists on the surface of the silicon substrate, the polymer layer formed on the surface of the silicon substrate is also made of the same polymer. The film thickness of the polymer layer measured using ellipsometry (trade name “EC-400”, manufactured by JA Woollam) was 380 nm.

(Example 11)
A surface having a polymer layer formed on the surface of a silicon substrate in the same manner as in Example 10 except that 1 part of 2-iodo-2-methylpropionyloxyhexyltriethoxysilane (HIE) was used instead of BPM. A modified substrate was obtained. The Mn of the resulting polymer was 860,000 and the PDI was 1.33. The thickness of the formed polymer layer was 490 nm.

(Example 12)
Using a high-pressure processing device (trade name “Dr. Chef”) manufactured by Kobe Steel, heated to 80 ° C., pressurized to 600 MPa, and polymerized for 4 hours in the same manner as in Example 11 described above. Thus, a surface-modified base material having a polymer layer formed on the surface of a silicon substrate was obtained. The Mn of the resulting polymer was 1,300,000 and the PDI was 1.66. The thickness of the formed polymer layer was 680 nm.

<Synthesis of starting compound>
(Synthesis example 1)
100 parts of propylene glycol monomethyl ether acetate (PGMAc) was charged into a reactor equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube, heated to 80 ° C., and blown with nitrogen gas. In a separate container, 50 parts of 2- (2-bromoisobutyryloxy) ethyl methacrylate (BBEM), 50 parts of methacryloyloxypropyltriethoxysilyl (MOPS), and 1.5 parts of azobisisobutyronitrile (AIBN) 1.5 And stirred to prepare a uniform monomer mixture. After half of the monomer mixture was added to the reactor, the remainder was added dropwise over 2 hours, and then polymerized for 8 hours to obtain a polymer solution. The solid content measured by sampling a part of the polymer liquid was 49.2%, and it was confirmed that most of the monomers were polymerized. The Mn of the polymer in the polymer liquid was 18,900, and the PDI was 3.11. PGMAc was added to and diluted with the obtained polymer solution to obtain a starting polymer 1 solution having a solid content of 15%. The starting group polymer 1 in the starting group polymer 1 solution is a polymer type treating agent having a predetermined starting group and an alkoxysilyl group.

<Production of surface-modified base material (2)>
(Example 13)
A glass substrate having a size of 3 cm × 3 cm was prepared and activated in the same manner as in Example 10 described above. The solution of the starting group polymer 1 prepared in Synthesis Example 1 was spin-coated on a glass substrate at 2,000 rotations for 30 seconds, and baked at 90 ° C. for 90 seconds and at 180 ° C. for 30 minutes to be cured to form a coating film. The thickness of the coating film measured by ellipsometry was 1.80 μm. Then, a surface-modified base material having a polymer layer formed on the surface of a glass substrate was obtained in the same manner as in Example 10 except that the above-mentioned glass substrate on which a coating film was formed was used. The Mn of the resulting polymer was 790,000 and the PDI was 1.72. The thickness of the polymer layer including the coating film formed with the starting base polymer 1 solution was 2.15 μm. That is, the thickness of the polymer layer formed on the coating film was 350 nm.

(Example 14)
A substrate made of silicon carbide (a disc having a diameter of 2 cm and a thickness of 1.0 mm) was prepared and activated in the same manner as in Example 10 described above. The substrate was immersed in a solution containing 100 parts of ethanol, 1 part of a 28% aqueous ammonia solution, and 10 parts of tetraethoxysilane for 24 hours. The substrate thus taken out was washed with ethanol and dried at 150 ° C. for 10 minutes. A surface modification in which a polymer layer was formed on the surface of a silicon carbide substrate was performed in the same manner as in Example 10 except that the thus prepared substrate was used and the polymerization time was changed to 8 hours. A quality substrate was obtained. The Mn of the resulting polymer was 1,480,000 and the PDI was 1.88. The thickness of the formed polymer layer was 710 nm.

(Example 15)
A metal plate made of SUS402 having a size of 1.5 cm × 1.5 cm was dipped in a 3% -diluted solution of the starting polymer 1 solution prepared in Synthesis Example 1 and then at 90 ° C. for 30 seconds and at 180 ° C. for 20 minutes. It was baked and cured to form a coating film. The film thickness of the formed coating film was 2.6 μm. Then, in the same manner as in Example 10 described above, except that the above-described metal plate on which the coating film was formed was used, LMA was used instead of MMA, and BDPA was used instead of MDPA. A surface-modified base material having a polymer layer formed on the surface of the plate was obtained. The Mn of the resulting polymer was 1,340,000 and the PDI was 1.55. The thickness of the formed polymer layer was 686 nm.

  The method for producing the polymer of the present invention includes, for example, coatings such as paints, inks, and coating agents, films, building materials, automobile members, battery members, medical materials, display materials, and high-molecular-weight polymers used for electronic device parts and the like. It is useful as a method for producing Further, the method for producing a surface-modified base material of the present invention is useful as a method for producing a base material provided with new performance, which is used for various industrial materials.

Claims (5)

A polystyrene-equivalent number determined by polymerizing a (meth) acrylic acid-based monomer in the presence of a starting compound and a salt under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60 ° C. or higher and gel permeation chromatography Forming a (meth) acrylic acid-based polymer having an average molecular weight of 100,000 to 10,000,000,
The starting compound has a starting group represented by the following general formula (1) or (2),
A method for producing a polymer, wherein the salt is at least one selected from the group consisting of quaternary ammonium halide salts, quaternary phosphonium halide salts, and alkali metal halide salts.

(In the general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom, and R ₁ represents a hydrogen atom, an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or Represents an amide group, R ₂ represents an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or an amide group, and “*” represents a bonding position)

(In the general formula (2), X represents a chlorine atom, a bromine atom, or an iodine atom, Y represents O or NH, and R ₃ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group. R ₄ represents an alkyl group, an aryl group, or an acyl group, and “*” represents a bonding position)   In at least one organic solvent selected from the group consisting of alcohol solvents, glycol solvents, amide solvents, ether solvents, sulfoxide solvents, urea solvents, and ionic liquids, at a temperature below the boiling point of the organic solvent. The method for producing a polymer according to claim 1, wherein the (meth) acrylic acid-based monomer is polymerized below.   3. The method according to claim 1, wherein the salt is at least one selected from the group consisting of quaternary ammonium iodide, quaternary phosphonium iodide, and alkali metal iodide. 4.   The method for producing a polymer according to any one of claims 1 to 3, wherein the (meth) acrylic acid-based polymer having a molecular weight distribution (weight average molecular weight / number average molecular weight) of 1.8 or less is obtained. A step of obtaining a treated substrate by surface-treating the substrate with a treating agent having a starting group represented by the following general formula (1) or (2) and an alkoxysilyl group;
The poly (meth) acrylate is obtained by polymerizing a (meth) acrylic acid-based monomer in the presence of the treated substrate and the salt under a pressure condition of 100 to 1,000 MPa and a temperature condition of 60 ° C. or more, and measured by gel permeation chromatography. A (meth) acrylic acid-based polymer having a number average molecular weight of 100,000 to 10,000,000 and containing the (meth) acrylic acid-based polymer on the surface of the treated substrate, having a thickness of 100 nm or more. Placing a polymer layer;
A method for producing a surface-modified substrate having:

(In the general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom, and R ₁ represents a hydrogen atom, an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or Represents an amide group, R ₂ represents an alkyl group, an aryl group, a cyano group, an acyl group, a carboxy group, an ester group, or an amide group, and “*” represents a bonding position)

(In the general formula (2), X represents a chlorine atom, a bromine atom, or an iodine atom, Y represents O or NH, and R ₃ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group. R ₄ represents an alkyl group, an aryl group, or an acyl group, and “*” represents a bonding position)