JP7232045B2 - Composite material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite material having low friction sliding properties and excellent safety.

Conventionally, it has been known that a polymer brush layer composed of a plurality of polymer graft chains exhibits a low coefficient of friction. For example, in Patent Document 1, a polymer graft chain is formed by copolymerizing methyl methacrylate and a monomer copolymerizable therewith on a base material, and such a polymer graft chain is formed by N , N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethylsulfonyl)imide (DEME-TFSI) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMI- A polymer brush layer is disclosed which is swollen with PF ₆ ).

WO2017/171071

According to the technique of Patent Document 1, a polymer brush layer with a low coefficient of friction can be formed, but from the viewpoint of further improving performance, a material with excellent low friction sliding properties is desired.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a composite material having low friction sliding properties and excellent safety.

The inventors of the present invention conducted intensive research to achieve the above object, and found that a composite material obtained by swelling a plurality of polymer chains immobilized on a substrate with a compound containing a specific saccharin anion can achieve the above We have found that the object can be achieved, and have completed the present invention.

（上記一般式（１）中、Ｒ^１～Ｒ^４は、それぞれ独立に、水素原子または置換基を有していてもよい炭素数１～１０のアルキル基を示し、Ｘ^＋は、一価のカチオンを示す。）
〔２〕前記一般式（１）中、Ｘ^＋が、アンモニウムイオンまたはホスホニウムイオンである前記〔１〕に記載の複合材料、
〔３〕前記一般式（１）で表される化合物の融点が１００℃以下である前記〔１〕または〔２〕に記載の複合材料、
〔４〕前記複数の高分子鎖が、基材上に共有結合で固定されたものである前記〔１〕～〔３〕のいずれかに記載の複合材料、
〔５〕前記複数の高分子鎖の分子量分布（Ｍｗ／Ｍｎ）が１．５以下である前記〔４〕に記載の複合材料、
〔６〕前記基材表面の面積に対する、前記複数の高分子鎖の専有面積率が１０％以上である前記〔４〕または〔５〕に記載の複合材料、
〔７〕前記基材上に形成された、前記複数の高分子鎖および前記一般式（１）で表される化合物を含む層の厚みが５００ｎｍ以上である前記〔４〕～〔６〕のいずれかに記載の複合材料、
〔８〕前記複数の高分子鎖が、主鎖となる高分子鎖から分岐したものである前記〔１〕～〔７〕のいずれかに記載の複合材料、ならびに、
〔９〕前記複数の高分子鎖が、架橋構造を形成している前記〔１〕～〔８〕のいずれかに記載の複合材料、
が提供される。 That is, according to the present invention,
[1] A composite material obtained by swelling a plurality of polymer chains fixed to a substrate with a compound represented by the following general formula (1),

(In the above general formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms, and X ⁺ is a monovalent indicates a cation.)
[2] The composite material according to [1] above, wherein X ⁺ is an ammonium ion or a phosphonium ion in the general formula (1);
[3] The composite material according to [1] or [2] above, wherein the compound represented by the general formula (1) has a melting point of 100° C. or lower;
[4] The composite material according to any one of [1] to [3], wherein the plurality of polymer chains are covalently fixed on a substrate;
[5] The composite material according to [4] above, wherein the molecular weight distribution (Mw/Mn) of the plurality of polymer chains is 1.5 or less;
[6] The composite material according to [4] or [5] above, wherein the exclusive area ratio of the plurality of polymer chains to the surface area of the substrate is 10% or more,
[7] Any of the above [4] to [6], wherein the layer formed on the base material and containing the plurality of polymer chains and the compound represented by the general formula (1) has a thickness of 500 nm or more. a composite material according to
[8] The composite material according to any one of [1] to [7], wherein the plurality of polymer chains are branched from a main polymer chain, and
[9] The composite material according to any one of [1] to [8], wherein the plurality of polymer chains form a crosslinked structure,
is provided.

ADVANTAGE OF THE INVENTION According to this invention, the composite material excellent in safety which has low-friction slidability can be provided.

FIG. 1 is a schematic diagram showing an example of the composite material according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing the structure of the branched graft chain-containing polymer according to the third embodiment of the present invention. 3 is ^{a 1} H-NMR chart of N-2-methoxyethyl-N-methylpyrrolidinium saccharinate (MEMP-Sac) synthesized in Synthesis Example 1. FIG. 4 is a ¹ H-NMR chart of Choline-sac synthesized in Synthesis Example 2. FIG. 5 is ^{a 1} H-NMR chart of 1-butyl-3-methylimidazolium saccharinate (BMI-Sac) synthesized in Synthesis Example 3. FIG. 6 is ^{a 1} H-NMR chart of N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium saccharinate (DEME-Sac) synthesized in Synthesis Example 4. FIG. FIG. 7 is a graph showing the results of friction force measurement of Examples 1 and 2 and Comparative Example 1. FIG.

（上記一般式（１）中、Ｒ^１～Ｒ^４は、それぞれ独立に、水素原子または置換基を有していてもよい炭素数１～１０のアルキル基を示し、Ｘ^＋は、一価のカチオンを示す。） The composite material of the present invention is obtained by swelling a plurality of polymer chains fixed to a substrate with a compound represented by the following general formula (1).

(In the above general formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms, and X ⁺ is a monovalent indicates a cation.)

The composite material of the present invention can function as a tribology system material (SRT material) having softness and resilience by having the above configuration.

<First embodiment>
First, a first embodiment of the present invention will be described.
FIG. 1 is a schematic diagram showing a composite material according to a first embodiment of the invention. As shown in FIG. 1, the composite material according to the first embodiment of the present invention comprises a substrate 10 and a polymer brush layer 20 formed on the substrate 10. As shown in FIG.

The base material 10 is not particularly limited, and can be appropriately selected from organic materials, inorganic materials, metal materials, and the like.

For example, materials for forming the base material 10 include:
Polyurethane materials, polyvinyl chloride materials, polystyrene materials, polyolefin materials, PMMA, PET, cellulose acetate, silica, inorganic glass, paper, plastic laminate films, ceramics (alumina ceramics, bioceramics, zirconia-alumina composite ceramics, etc.) composite ceramics, etc.);
Metals (aluminum, zinc, copper, titanium, etc.), metal-deposited paper, silicon, silicon oxide, silicon nitride, polycrystalline silicon, and composites thereof;
Polyolefin (polyethylene, polypropylene, polyisobutylene, ethylene alpha olefin copolymer, etc.), silicone polymer, acrylic polymer (polyacrylonitrile, polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, etc.), fluoropolymer (polytetrafluoroethylene , chlorotrifluoroethylene, fluorinated ethylene-propylene, polyvinyl fluoride, etc.), vinyl polymers (polyvinyl chloride, polyvinyl methyl ether, polystyrene, polyvinyl acetate, polyvinyl ketone, etc.), vinyl monomer-containing copolymers (ABS, etc.) , Natural and synthetic rubber (latex rubber, butadiene-styrene copolymer, polyisoprene, polybutadiene, butadiene-acrylonitrile copolymer, polychloroprene polymer, polyisobutylene rubber, ethylene-propylenediene copolymer, polyisobutylene-isoprene, etc. ), polyurethane (polyether urethane, polyester urethane, polycarbonate urethane, polysiloxane urethane, etc.), polyamide (nylon 6, nylon 66, nylon 10, nylon 11, etc.), polyester, epoxy polymer, cellulose, modified cellulose, and these hydrophobic organic materials such as copolymers;
Hydrophilic acrylic polymers (polyacrylamide, poly-2-hydroxyethyl acrylate, poly-N,N-dimethylacrylamide, polyacrylic acid, polymethacrylic acid, etc.), hydrophilic vinyl polymers (poly-N-vinylpyrrolidone, polyvinyl pyridine, etc.), polymaleic acid, poly-2-hydroxyethyl fumarate, maleic anhydride, polyvinyl alcohol, and hydrophilic organic materials such as copolymers thereof;

The shape of the base material 10 is not particularly limited, and examples thereof include tubes, sheets, fibers, strips, films, plates, foils, membranes, pellets, powders, molded products (extrusion molded products, cast molded products, etc.). is mentioned.

For example, when the composite material according to the first embodiment is used for seal applications, the base material 10 is preferably rubber (for oil seal applications) or inorganic oxide (for mechanical seal applications).
When the composite material according to the first embodiment is used as a bearing, the substrate 10 is preferably metal (SUS, SUJ2, carbon steel, etc.) or resin (polyethylene, etc.).
When the composite material according to the first embodiment is used as a guide (guide mechanism), the base material 10 is preferably metal (SUS, SUJ2, carbon steel, etc.) or resin (polyphenylene sulfide, polytetrafluoroethylene, etc.). .
When the composite material according to the first embodiment is used for a sliding member, the base material 10 includes cast iron, steel, iron such as stainless steel, iron alloys, non-ferrous metals and non-ferrous alloys such as aluminum and copper, and silicon. Wafers, glass, non-metals such as quartz, etc. are preferred.

（上記一般式（１）中、Ｒ^１～Ｒ^４は、それぞれ独立に、水素原子または置換基を有していてもよい炭素数１～１０のアルキル基を示し、Ｘ^＋は、一価のカチオンを示す。） The polymer brush layer 20 is a layer formed by swelling a plurality of polymer chains covalently fixed on a substrate 10 as a substrate with a compound represented by the following general formula (1). . In addition, in the first embodiment, the plurality of polymer chains may be a plurality of polymer graft chains.

(In the above general formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms, and X ⁺ is a monovalent indicates a cation.)

According to the first embodiment, the compound represented by the general formula (1) is used as the swelling agent for swelling the plurality of polymer chains constituting the polymer brush layer 20. The coefficient of friction of the polymer brush layer 20 can be reduced, and the low-friction slidability can be improved. It can be suitably used as a sliding member or sliding material used in moving parts. In addition, the compound represented by the general formula (1) has low toxicity (in particular, low toxicity to the human body), so that excellent safety can be achieved.

（上記一般式（２）中、Ｘ^＋は、上記一般式（１）と同様である。） In the general formula (1), R ¹ to R ⁴ are each independently a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom or a substituent. It is an alkyl group having 1 to 5 carbon atoms which may be present, and all of R ¹ to R ⁴ are preferably hydrogen atoms. Specifically, compounds represented by the following general formula (2) are particularly preferred.

(In general formula (2) above, X ⁺ is the same as in general formula (1) above.)

The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, and examples thereof include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl and isobutyl. group, s-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group etc. Examples of substituents include halogen atoms such as a fluorine atom, a chlorine atom and a bromine atom; alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group and an isopropoxy group; a nitro group; .

Further, in the general formula (1), X ⁺ is a monovalent cation, and the monovalent cation is not particularly limited. Ammonium ions or phosphonium ions are preferable from the viewpoint that they can be made more excellent, and ammonium ions represented by the following general formulas (3) to (6) or phosphonium ions represented by the following general formula (7) is more preferred.

In the general formula (3), R ⁵ to R ⁸ each independently represent an alkyl group having 1 to 4 carbon atoms, —(CH ₂ ) _m —OR ⁹ (R ⁹ is a methyl group or an ethyl group; , m is 1 or 2.) or an alkyl alcohol group having 1 to 4 carbon atoms represented by —(CH ₂ ) _n —OH (n is an integer of 1 to 4) is.

The alkyl group having 1 to 4 carbon atoms may be linear, branched or cyclic, and may be methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl or s-butyl. group, isobutyl group, t-butyl group, cyclobutyl group and the like. Among these, an alkyl group having 1 to 3 carbon atoms is preferable, a linear alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group or an ethyl group is more preferable. Specific examples of the alkoxyalkyl group represented by —(CH ₂ ) _m —OR ⁹ include methoxymethyl group, ethoxymethyl group, methoxyethyl group, ethoxyethyl group and the like. Ethoxyethyl groups are preferred. In addition, the alkyl alcohol group having 1 to 4 carbon atoms represented by —(CH ₂ ) _n —OH (n is an integer of 1 to 4) includes a hydroxymethyl group, a 2-hydroxyethyl group, and a 2-hydroxypropyl group. group, 3-hydroxypropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group, etc. Among these, 2-hydroxyethyl group is preferred.

In general formula (4) above, R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 4 carbon atoms, —(CH ₂ ) _m —OR ⁹ (R ⁹ is a methyl group or an ethyl group; , m is 1 or 2.) or an alkyl alcohol group having 1 to 4 carbon atoms represented by —(CH ₂ ) _n —OH (n is an integer of 1 to 4) and specific examples thereof include those exemplified for R ⁵ to R ⁸ above. Also, R ¹⁰ and R ¹¹ may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded.

In the above general formula (5), R ¹² and R ¹³ each independently represent an alkyl group having 1 to 12 carbon atoms, —(CH ₂ ) _m —OR ⁹ (R ⁹ is a methyl group or an ethyl group; , m is 1 or 2.) or an alkyl alcohol group having 1 to 4 carbon atoms represented by —(CH ₂ ) _n —OH (n is an integer of 1 to 4) is. The alkyl group having 1 to 12 carbon atoms may be linear, branched or cyclic, and may be methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl or s-butyl. group, isobutyl group, t-butyl group, cyclobutyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n- dodecyl group, cyclopentyl group, cyclohexyl group and the like. Specific examples of the alkoxyalkyl group represented by -(CH ₂ ) _m -OR ⁹ and the alkyl alcohol group having 1 to 4 carbon atoms represented by -(CH ₂ ) _n -OH include the above R ⁵ to R ⁸ Those exemplified in are mentioned. R ¹² and R ¹³ are preferably alkyl groups having 1 to 12 carbon atoms, R ¹² and R ¹³ are alkyl groups having 1 to 12 carbon atoms, and R ¹² and R ¹³ may be different. More preferably, it is an alkyl group having 1 to 12 carbon atoms, and it is even more preferable that R ¹³ is an alkyl group having a larger number of carbon atoms than R ¹² , R ¹² is a methyl group, R ¹³ is an ethyl group, n-propyl group and n-butyl group are even more preferred, and it is particularly preferred that R ¹² is a methyl group and R ¹³ is an n-butyl group.

In general formula (6) above, R ¹⁴ is an alkyl group having 1 to 8 carbon atoms, —(CH ₂ ) _m —OR ⁹ (R ⁹ is a methyl group or an ethyl group, and m is 1 or 2. ), or an alkyl alcohol group having 1 to 4 carbon atoms represented by —(CH ₂ ) _n —OH (n is an integer of 1 to 4). The alkyl group having 1 to 8 carbon atoms may be linear, branched or cyclic, and may be methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl or s-butyl. group, isobutyl group, t-butyl group, cyclobutyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, cyclopentyl group, cyclohexyl group and the like. Specific examples of the alkoxyalkyl group represented by -(CH ₂ ) _m -OR ⁹ and the alkyl alcohol group having 1 to 4 carbon atoms represented by -(CH ₂ ) _n -OH include the above R ⁵ to Those exemplified for R ⁸ can be mentioned.

In the general formula (7), R ¹⁵ to R ¹⁷ are alkyl groups having 1 to 12 carbon atoms, and the alkyl groups having 1 to 12 carbon atoms may be linear, branched or cyclic, Each group exemplified as specific examples of the alkyl group having 1 to 4 carbon atoms, and n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group and the like. R ¹⁸ is an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl represented by —(CH ₂ ) _m —OR ⁹ (R ⁹ is a methyl group or an ethyl group, and m is 1 or 2); is the base. The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and may be any of the groups listed above as specific examples of the alkyl group having 1 to 12 carbon atoms, an n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group and the like. Specific examples of the alkoxyalkyl group represented by —(CH ₂ ) _m —OR ⁹ include those exemplified for R ⁵ to R ⁸ above. As the phosphonium ion represented by the general formula (7), R ¹⁵ to R ¹⁷ are selected from the viewpoint that the friction coefficient of the polymer brush layer 20 can be further reduced and the low-friction slidability can be improved. and R ¹⁸ are groups having different carbon atoms, R ¹⁵ to R ¹⁷ are preferably alkyl groups having 1 to 8 carbon atoms, and R ¹⁸ is preferably a group having 9 to 20 carbon atoms. is an alkyl group. In this case, R ¹⁵ to R ¹⁷ may be the same groups or different groups.

In the first embodiment, among the ammonium ions and phosphonium ions, ammonium ions are preferable from the viewpoint that the coefficient of friction of the polymer brush layer 20 can be further reduced and the low-friction slidability can be improved. , the ammonium ions represented by the general formula (3), the general formula (4), and the general formula (5) are more preferable. Further, among the ammonium ions represented by the above general formula (3), the ammonium ions represented by the following general formulas (8) and (9) are more preferable, and the ammonium ions represented by the above general formula (4) Among them, an ammonium ion represented by the following general formula (10) is more preferable.

In general formula (8) above, R ⁵ to R ⁷ , R ⁹ and m are the same as in general formula (3) above, and R ⁵ to R ⁷ are each independently a methyl group or an ethyl group. and particularly preferably R ⁵ is a methyl group and R ⁶ and R ⁷ are an ethyl group, or R ⁵ and R ⁶ are a methyl group and R ⁷ is an ethyl group. R ⁹ is a methyl group or an ethyl group, particularly preferably a methyl group. Moreover, m is 1 or 2, and 2 is particularly preferable.

In general formula (9) above, R ⁵ to R ⁷ and n are the same as in general formula (3) above, and R ⁵ to R ⁷ are each independently preferably a methyl group or an ethyl group, It is particularly preferred that all of R ⁵ to R ⁷ are methyl groups. Moreover, n is preferably 1 or 2, and particularly preferably 2.

In general formula (10), R ¹⁰ and m are the same as in general formula (4), and R ¹⁰ is preferably a methyl group or an ethyl group, particularly preferably a methyl group. R ⁹ is a methyl group or an ethyl group, particularly preferably a methyl group. Moreover, m is 1 or 2, and 2 is particularly preferable.

The melting point of the compound represented by the general formula (1) is not particularly limited, and varies depending on the type of the monovalent cation represented by X ⁺ . The temperature is preferably 100° C. or lower, more preferably 50° C. or lower, and still more preferably 25° C. or lower, from the viewpoint that slidability can be improved. In addition, when the compound represented by the general formula (1) has a melting point of 100° C. or less, it corresponds to an ionic liquid. Here, the ionic liquid is a salt composed only of ions and generally has a melting point of 100° C. or lower.

The method for producing the compound represented by the general ^formula (1) is not particularly limited. It can be produced by obtaining an ion or a halide of a phosphonium ion and mixing the corresponding saccharin derivative or a salt of the saccharin derivative.

Then, in the first embodiment, the polymer brush layer 20 shown in FIG. can be formed by introducing a plurality of polymer chains by and then swelling the plurality of polymer chains with the compound represented by the general formula (1). In this case, the compounds represented by the general formula (1) may be used singly or in combination of two or more. Further, as a swelling agent, in addition to the compound represented by the general formula (1), other media may be used in combination. Examples include ionic liquids other than the compounds that are used, water, organic solvents, and the like. The amount of the other medium to be used may be set as appropriate within a range that does not impair the effects of the present invention.

In the surface-initiated living radical polymerization method, a polymer chain is formed by introducing a polymerization initiating group onto the surface of the substrate 10, which serves as the starting point of the polymer chain, and performing living radical polymerization using the polymerization initiating group as the starting point. For example, the methods described in JP-A-2009-59659 and JP-A-2010-218984 can be applied.

The polymer for forming the polymer chain may be either a hydrophobic polymer or a hydrophilic polymer, and the hydrophilic polymer may be prepared using a hydrophilic monomer. It may be prepared by preparing a polymer using monomers and then introducing a hydrophilic group into this polymer. In addition, the polymer chain may be a homopolymer of one type of monomer or a copolymer of two or more types of monomers. Any of gradient copolymerization and the like may be used.

The monomer used for forming the polymer chain is not particularly limited, but a monomer having at least one addition-polymerizable double bond is preferred. Preferred examples of the monofunctional monomer having one addition-polymerizable double bond include (meth)acrylic acid-based monomers and styrene-based monomers.

Examples of monomers used to form the polymer chain include (meth)acrylic acid-based monomers, styrene-based monomers, monofunctional monomers having one addition-polymerizable double bond, hydrophobic monomers, hydrophilic monomers, Examples thereof include monomers having a carboxyl group or a group that can be easily converted to a carboxyl group in the side chain.

Specific examples of (meth)acrylic acid-based monomers include:
(meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate;
heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate;
2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, stearyl (meth)acrylate , glycidyl (meth)acrylate, 3-ethyl-3-(meth)acryloyloxymethyloxetane;
2-(meth)acryloyloxyethyl isocyanate, (meth)acrylate-2-aminoethyl, 2-(2-bromopropionyloxy)ethyl (meth)acrylate, 2-(2-bromoisobutyryloxy)ethyl (meth) acrylate;
1-(meth)acryloxy-2-phenyl-2-(2,2,6,6-tetramethyl-1-piperidinyloxy)ethane, 1-(4-((4-(meth)acryloxy)ethoxyethyl) ) phenylethoxy)piperidine, γ-(methacryloyloxypropyl)trimethoxysilane;
3-(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yl) Propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptaisobutyl-pentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octa Siloxane-1-yl)propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.1 ^{3,9.1 5,15} .1 ^7,13 ]octasiloxane-1-yl)propyl (meth)acrylate;
3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yl) Propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octa Siloxane-1-yl)propyl (meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.1 ^{3,9.1 5,15} .1 ^7,13 ]octasiloxane-1-yloxy)dimethylsilyl]propyl (meth)acrylate;
3-[(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yloxy ) dimethylsilyl]propyl (meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.1 ^{3,9.1 5,15} . 1 ^7,13 ]octasiloxane-1-yloxy)dimethylsilyl]propyl (meth)acrylate;
3-[(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yloxy ) dimethylsilyl]propyl (meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.1 ^{3,9.1 5,15.1 7,13} ]octasiloxane-1-yloxy)dimethylsilyl]propyl (meth)acrylate;
(Meth)acrylic acid ethylene oxide adduct, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutyl ethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, trifluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate;
2-perfluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate; .

Specific examples of styrene-based monomers include
Styrene, vinyltoluene, α-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, m-chloromethylstyrene, o-aminostyrene, p-styrenechlorosulfonic acid, styrenesulfonic acid and its salts, vinylphenylmethyldithio carbamate, 2-(2-bromopropionyloxy)styrene, 2-(2-bromoisobutyryloxy)styrene;
1-(2-((4-vinylphenyl)methoxy)-1-phenylethoxy)-2,2,6,6-tetramethylpiperidine, 1-(4-vinylphenyl)-3,5,7,9, 11,13,15-heptaethylpentacyclo[9.5.1.1 ^3,9 . ^15,15 . 1 ^7,13 ]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 ^3,9 . ^15,15 . 1 ^7,13 ]octasiloxane;
1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.1 ^3,9 . ^15,15 . 1 ^7,13 ]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 ^3,9 . ^15,15 . 1 ^7,13 ]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.1 ^3,9 . ^15,15 . 1 ^7,13 ]octasiloxane;
3-(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yl) Ethylstyrene, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1 -yl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ] octasiloxane-1-yl)ethylstyrene;
3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yl) Ethylstyrene, 3-(3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1 -yl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octa siloxane-1-yloxy)dimethylsilyl)ethylstyrene;
3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yloxy) dimethylsilyl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ] octasiloxane-1-yloxy)dimethylsilyl)ethylstyrene;
3-((3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ]octasiloxane-1-yloxy )dimethylsilyl)ethylstyrene, 3-((3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.1 ^3,9 .1 ^5,15 .1 ^7,13 ] octasiloxane-1-yloxy)dimethylsilyl)ethylstyrene; and the like.

Specific examples of monofunctional monomers having one addition-polymerizable double bond include:
Fluorine-containing vinyl monomers (perfluoroethylene, perfluoropropylene, vinylidene fluoride, etc.), silicon-containing vinyl monomers (vinyltrimethoxysilane, vinyltriethoxysilane, etc.), maleic anhydride, maleic acid, maleic acid monoalkyl esters and dialkyls esters, fumaric acid, mono- and dialkyl esters of fumaric acid;
Maleimide-based monomers (maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide, etc.);
Nitrile group-containing monomers (acrylonitrile, methacrylonitrile, etc.), amide group-containing monomers (acrylamide, methacrylamide, etc.), vinyl ester monomers (vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, etc.) ;
Olefins (ethylene, propylene, etc.), conjugated diene monomers (butadiene, isoprene, etc.), vinyl halides (vinyl chloride, etc.), vinylidene halides (vinylidene chloride, etc.), allyl halides (allyl chloride, etc.);
allyl alcohol, vinylpyrrolidone, vinylpyridine, N-vinylcarbazole, methylvinylketone, vinylisocyanate;
Further, the monofunctional monomer having one addition polymerizable double bond includes one polymerizable double bond in one molecule, and the main chain is styrene, (meth)acrylic acid ester, Macromonomers and the like derived from siloxanes and the like can also be used.

Specific examples of hydrophobic monomers include
Acrylic acid esters (alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl acrylate, hexafluoroisopropyl acrylate; aryl acrylates such as phenyl acrylate; aryl alkyl acrylates such as benzyl acrylate; methoxymethyl acrylate, etc. alkoxyalkyl acrylate, etc.);
Methacrylic acid esters (alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, hexafluoroisopropyl methacrylate; aryl methacrylates such as phenyl methacrylate; arylalkyl methacrylates such as benzyl methacrylate; methoxymethyl methacrylate, etc. alkoxyalkyl methacrylate, etc.);
fumaric acid ester (dimethyl fumarate, diethyl fumarate, alkyl ester of fumaric acid such as diallyl fumarate, etc.), maleic acid ester (alkyl ester of maleic acid such as dimethyl maleate, diethyl maleate, diallyl maleate, etc.);
Itaconic acid esters (such as alkyl esters of itaconic acid), crotonic acid esters (such as alkyl esters of crotonic acid), methyl vinyl ether, ethoxyethyl vinyl ether, vinyl acetate, vinyl propionate, vinyl benzoate, styrene;
Alkyl styrene, vinyl chloride, vinyl methyl ketone, vinyl stearate, vinyl alkyl ether;

Specific examples of hydrophilic monomers include
hydroxy-substituted alkyl acrylates (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, polyethoxyethyl acrylate, polyethoxypropyl acrylate, etc.);
hydroxy-substituted alkyl methacrylates (2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl methacrylate, 2,3-dihydroxypropyl methacrylate, polyethoxyethyl methacrylate, polyethoxypropyl methacrylate, etc.);
acrylamide, N-alkylacrylamide (N-methylacrylamide, N,N-dimethylacrylamide, etc.), N-alkylmethacrylamide (N-methylmethacrylamide, etc.);
polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, alkoxypolyethyleneglycol acrylate, alkoxypolyethyleneglycol methacrylate, phenoxypolyethyleneglycol acrylate, phenoxypolyethyleneglycol methacrylate, 2-glucosyloxyethyl methacrylate;
acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid, methacrylamide, allyl alcohol, N-vinylpyrrolidone, N,N-dimethylaminoethyl acrylate;

Specific examples of monomers having a carboxyl group or a group that can be easily converted to a carboxyl base in the side chain include:
1-methoxyethyl acrylate, 1-ethoxyethyl acrylate, 1-propoxyethyl acrylate, 1-(1-methylethoxy)ethyl acrylate, 1-butoxyethyl acrylate, 1-(2-methylpropoxy)ethyl acrylate, 1-(2 - ethylhexoxy) ethyl acrylate;
pyranyl acrylate, 1-methoxyethyl methacrylate, 1-ethoxyethyl methacrylate, 1-propoxyethyl methacrylate, 1-(1-methylethoxy)ethyl methacrylate, 1-butoxyethyl methacrylate, 1-(2-methyl propoxy)ethyl methacrylate, 1-(2-ethylhexoxy)ethyl methacrylate;
pyranyl methacrylate, di-1-methoxyethyl maleate, di-1-ethoxyethyl maleate, di-1-propoxyethyl maleate, di-1-(1-methylethoxy)ethyl maleate, di-1-butoxyethyl Malate, di-1-(2-methylpropoxy)ethyl maleate, dipyranyl maleate; and the like.

The monomers used for forming the polymer chains described above may be used singly or in combination of two or more.

Further, the monomer used for forming the polymer chain has excellent affinity with the compound represented by the general formula (1) described above, can further reduce the coefficient of friction of the polymer brush layer 20, and has low friction sliding property. It is preferable to use a monomer having an ionic dissociation group (especially a monomer having an ionic dissociation group and a reactive double bond group) because it can make the composition more excellent. By using a monomer having an ionic dissociation group, the polymer chain obtained by polymerization can have an ionic dissociation group. As the monomer for forming the polymer chain, in addition to the monomer having an ionic dissociation group, a monomer copolymerizable therewith (for example, each of the monomers described above) may be used. Monomers having such an ionic dissociative group are not particularly limited, but include, for example, compounds represented by the following general formula (11).

In general formula (11) above, R ¹⁹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ²⁰ to R ²² represent alkyl groups having 1 to 5 carbon atoms. R ²⁰ to R ²² may contain one or more heteroatoms selected from an oxygen atom, a sulfur atom and a fluorine atom, and R ²⁰ to R ²² are bonded to each other and together with the nitrogen atom to which they are bonded, the ring may be formed. Also, Z ⁻ represents a monovalent anion. In general formula (11) above, k represents an integer of 1-10, and j represents an integer of 1-5.

In the above general formula (11), the monovalent anion represented by Z ⁻ is not particularly limited, but BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , AlCl ₄ ⁻ , NbF ₆ ⁻ , Anions such as HSO ₄ ⁻ , ClO ₄ ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , CF ₃ CO ₂ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , saccharinate, etc. These may be used alone, or two or more may be used in combination. BF ₄ ^- , PF ₆ ^- , (CF ₃ SO ₂ ) ₂ N ^- , CF ₃ SO ₃ ^- , or CF ₃ CO ₂ ^- is more preferable. Moreover, from the viewpoint of affinity for the compound represented by the general formula (1), saccharinate is more preferable.

Among the compounds represented by the general formula (11), from the viewpoint that the effect of reducing the coefficient of friction of the polymer brush layer 20 is greater, the compounds represented by the following general formulas (12) to (19) are particularly preferred. It can be used preferably. In addition, these can be used individually by 1 type or in combination of 2 or more types.

In general formulas (12) to (19) above, R ¹⁹ , R ²⁰ , Z ⁻ , k and j are the same as in general formula (11) above.

Further, when the polymerization is performed by the surface-initiated living radical polymerization method, the polymerization initiating group to be introduced onto the surface of the base material 10 is not particularly limited as long as it can initiate polymerization. Groups and the like are preferred.

The polymerization initiation group is physically or chemically bonded to the surface of the substrate 10 from the viewpoint of controllability of the graft density and the primary structure (molecular weight, molecular weight distribution, monomer arrangement pattern) of the grafted polymer chain. is preferred.

Methods for introducing (bonding) the polymerization initiation group to the surface of the substrate 10 include a chemical adsorption method, a Langmuir-Blodgett (LB) method, and the like.

For example, when a silicon wafer is used as the substrate 10, 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane is immobilized on the surface of the silicon wafer by chemical bonding of a chlorosulfonyl group (polymerization initiation group). , 2-(4-chlorosulfonylphenyl)ethyltrichlorosilane or the like is used to react with the oxide layer on the surface of the silicon wafer.

Further, when introducing a polymerization initiation group for surface-initiated living radical polymerization to the surface of the base material 10, the polymerization initiation group and a group having bonding property to the base material or a group having affinity for the base material are provided. It is preferable to use a surface treatment agent containing a polymerization initiation group. Such a polymerization initiation group-containing surface treatment agent may be a low-molecular-weight compound or a high-molecular-weight compound.

The surface treatment agent containing a polymerization initiating group is not particularly limited, but a compound having a group capable of bonding to the substrate 10 and a radical generating group is preferable. Initiating group-containing surface treating agents, that is, TEMPO-based, ATRP-based, RAFT-based, and RTCP-based polymerization initiating group-containing surface treating agents can be used. Among these, TEMPO-based, RAFT-based, and RTCP-based polymerization initiation group-containing surface treatment agents are more preferable. Among TEMPO-based surface treating agents containing a polymerization initiating group, DEPN-based surface treating agents containing a polymerization initiating group are particularly preferred. Examples of groups that can be bonded to the substrate 10 include -SiCl ₃ , -Si(CH ₃ )Cl ₂ , -Si(CH ₃ ) ₂ Cl, and -Si(OR) ₃ (in these formulas, R represents methyl, ethyl, propyl or butyl.) and the like. Alternatively, the polymerization initiation group-containing surface treatment agent is described in WO 2006/087839, (2-bromo-2-methyl)propionyloxyhexyltriethoxysilane (BHE), (2-bromo-2 -methyl)propionyloxypropyltriethoxysilane (BPE) and the like can also be used.

Further, from the viewpoint of adjusting the graft density, a silane coupling agent containing no polymerization initiation group (for example, a commonly used alkylsilane coupling agent) may be used in combination with the polymerization initiation group-containing surface treatment agent. good.

The graft density can be freely changed by adjusting the ratio of the polymerization initiation group-containing surface treatment agent and the silane coupling agent containing no polymerization initiation group. In introducing the polymerization initiation group to the surface of the base material 10, the LB method or the vapor phase adsorption method may be adopted from the viewpoints of the uniformity of the polymerization initiation group to be introduced and the controllability of the graft density of the polymerization initiation group. is also possible.

In the LB method, first, a film-forming material is dissolved in a suitable solvent (eg, chloroform, benzene, etc.). Next, after spreading a small amount of this solution on a clean liquid surface, preferably a pure water surface, the solvent is allowed to evaporate or diffuse into the adjacent aqueous phase, resulting in a low density film-forming molecule on the water surface. to form a film of

The diaphragm is then typically mechanically swept over the water surface to compress the membrane by reducing the surface area of the water surface over which the membrane-forming molecules are deployed, thereby increasing the density and forming a dense monolayer on the water surface. get

Next, under appropriate conditions, while maintaining a constant surface density of the molecules that make up the monomolecular film on the water surface, the substrate on which the monomolecular layer is to be deposited is immersed or pulled up in a direction across the monomolecular film on the water surface. transfers the monomolecular film on the water surface onto the substrate 10 and deposits a monolayer on the substrate.

For details and specific examples of the LB method, see Kiyonari Fukuda et al., New Experimental Chemistry Course, Volume 18 (Interface and Colloid), Chapter 6, (1977) Maruzen, Edited by Kiyonari Fukuda, Michio Sugi and Hiroyuki Sasabe, LB Membrane and Electronics, (1986) CMC", "Yoshio Ishii, Practical Techniques for Producing Good LB Films, (1989) Kyoritsu Shuppan".

Then, a polymerization initiation group is introduced into the surface of the base material 10 by using the above-described method of using the polymerization initiation group-containing surface treatment agent, and then the base material 10 introduced with the polymerization initiation group is coated with the above-described monomer. By immersing the substrate 10 in the polymerization reaction solution and heating as necessary, polymer chains containing the above-described monomers as polymerization units can be formed on the surface of the substrate 10 . In addition to the monomers described above, the polymerization reaction solution can contain various components necessary for the polymerization reaction, such as various radical initiators and solvents.

In the first embodiment, the polymer chains formed on the surface of the base material 10 are formed with a graft density such that the exclusive area ratio (occupancy rate per polymer cross-sectional area) with respect to the surface area of the base material 10 is 10% or more. preferably 15% or more, and still more preferably 20% or more. The graft density can be calculated from, for example, the absolute value of the number average molecular weight (Mn) of graft chains, the amount of grafted polymer, and the surface area of substrate 10 . Further, the exclusive area ratio in the polymer brush layer 20 can be calculated by obtaining the cross-sectional area from the length of the repeating unit in the stretched form of the polymer and the bulk density of the polymer, and multiplying the cross-sectional area by the graft density. The occupied area ratio means the ratio of the surface of the base material 10 occupied by the graft points (the first monomer) (100% in close packing, no more grafting is possible).

In addition, the graft density per unit area of the polymer chains is preferably 0.02 chains/nm ² or more, more preferably 0.04 chains/nm ² or more, still more preferably 0.06 chains/nm ² or more, particularly It is preferably 0.08 chains/nm2 ^or more.

The graft density of the polymer chain can be determined, for example, according to the method described in Macromolecules, 31, 5934-5936 (1998), Macromolecules, 33, 5608-5612 (2000), Macromolecules, 38, 2137-2142 (2005), etc. can be measured. Specifically, the graft density (chains/nm ² ) can be obtained by measuring the graft amount (W) and the number average molecular weight (Mn) of the grafted chains and using the following formula.
Graft density (chain/nm ² ) = W (g/nm ² )/M n x (Avogadro's number)
(In the formula, W represents the amount of grafting and Mn represents the number average molecular weight.)

When the base material 10 is a flat substrate such as a silicon wafer, the graft amount (W) is obtained by measuring the dry film thickness, that is, the dry film thickness of the grafted polymer chain layer by ellipsometry. , can be obtained by calculating the graft amount per unit area using the density of the bulk film. Alternatively, when the base material 10 is silica particles or the like, it can be measured by infrared absorption spectrometry (IR), thermogravimetric loss measurement (TG), elemental analysis measurement, or the like.

The number average molecular weight (Mn) of the polymer chains constituting the polymer brush layer 20 is preferably 500 to 10,000,000, more preferably 100,000 to 10,000,000. In addition, the molecular weight distribution (Mw/Mn) of the polymer chains forming the polymer brush layer 20 can further reduce the friction coefficient of the polymer brush layer 20, and from the viewpoint of making the polymer brush layer 20 more excellent in low-friction slidability, It is preferably close to 1, preferably 1.5 or less, more preferably 1.3 or less, still more preferably 1.25 or less, even more preferably 1.2 or less, particularly preferably 1.15 or less. is. The number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) of the polymer chains are obtained, for example, by cutting out the polymer chains from the base material 10 by hydrofluoric acid treatment and subjecting the cut polymer chains to gel permeation. A method of measuring with a value converted to polyethylene oxide by a chromatographic method can be mentioned. Alternatively, assuming that the free polymer generated during polymerization has the same molecular weight as the polymer chain introduced into the base material 10, the free polymer is subjected to gel permeation chromatography, and the number average A method of measuring the molecular weight (Mn) and the molecular weight distribution (Mw/Mn) and using them as they are may be adopted.

The average molecular chain length L _p (that is, the polymer brush length) of the polymer chains constituting the polymer brush layer 20 is preferably 10 nm or more, and from a practical point of view, it should be in the range of 10 to 1000 nm. is more preferred. If the average molecular chain length _Lp of the polymer chain is too short, the sliding properties may become insufficient. Also, the average molecular chain length _Lp of the polymer chain can be adjusted by, for example, the type of monomers constituting the polymer chain, polymerization conditions, and the like.

In the first embodiment, the method for swelling the plurality of polymer chains formed on the substrate 10 with the compound represented by the general formula (1) is not particularly limited. A method in which the compound represented by the general formula (1) is dropped or applied onto the plurality of polymer chains formed in the above, and then left to stand, or a method in which the base material 10 having the plurality of polymer chains formed thereon is used as described above. A method of immersing in a compound represented by general formula (1) can be used. In this case, when the compound represented by the general formula (1) is an ionic liquid, dropping, coating, or immersion can be performed without using a solvent.

The thickness of the polymer brush layer 20 formed according to the first embodiment is preferably 500 nm or more from the viewpoint that the coefficient of friction of the polymer brush layer 20 can be further reduced and the low-friction slidability can be further improved. is 700 nm or more, more preferably 800 nm or more, and still more preferably 1,000 nm or more. Although the upper limit of the thickness of the polymer brush layer 20 is not particularly limited, it is usually 20 μm or less.

In the above description, a method of obtaining a plurality of polymer chains formed on the base material 10 and then swelling the obtained plurality of polymer chains with the compound represented by the general formula (1) is used. As an example, when an ionic liquid is used as the compound represented by the general formula (1), the base material 10 is formed by a surface-initiated living radical polymerization method using a monomer having an ionic dissociation group. When forming a plurality of polymer chains thereon, a method of performing polymerization using the compound represented by the general formula (1) as a polymerization solvent may be employed. Here, when an ionic liquid is used in the polymerization system, the viscosity of the solution at the initial stage of polymerization may become relatively high during the polymerization, so there is a problem that it is difficult to form the desired polymer chains. By using a combination of a monomer having an ionic dissociative group and a compound represented by the above general formula (1) as an ionic liquid, the monomer having an ionic dissociative group is obtained due to their high compatibility. can proceed satisfactorily, whereby a desired polymer chain can be formed relatively easily. Therefore, according to such a method, the polymer brush layer 20 can be formed with high productivity.

<Second embodiment>
Next, a second embodiment of the invention will be described.
The composite material according to the second embodiment has the same configuration as that of the first embodiment except that the plurality of polymer chains constituting the polymer brush layer 20 shown in FIG. 1 form a crosslinked network structure. It is a thing. That is, in the second embodiment, a plurality of polymer chains covalently fixed on the substrate 10 as a substrate form a crosslinked network structure, and such a crosslinked network structure is formed. The polymer brush layer 20 is formed by swelling the polymer chains with the compound represented by the general formula (1). Also in the second embodiment, the plurality of polymer chains may be a plurality of polymer graft chains.

The polymer chains forming the crosslinked network structure that constitute the polymer brush layer 20 are not particularly limited. A double network gel that forms an interpenetrating network structure is preferred. Here, the term "interpenetrating network structure" means that polymers having two or more crosslinked network structures are physically entangled by entering each other's network structure, resulting in the formation of multiple network structures inside. A structure or state in which In addition, the double network gel according to the second embodiment is formed of not only two types of polymer networks, but also three types of polymer networks, or more types of polymer networks. can be any of the The double network gel according to the second embodiment may further contain a linear polymer to form a semi-interpenetrating network structure.

The two or more types of polymer networks for forming the double network gel are not particularly limited. From the point of view of being able to enhance the polymer network (A) formed from unsaturated monomers having groups that can be not) in combination with a polymer network (B) formed from unsaturated monomers.

A positively or negatively charged polymer network (A) formed from unsaturated monomers having groups that can be positively or negatively charged (hereinafter referred to as "polymer network (A)" as appropriate). The unsaturated monomer having a group to obtain is not particularly limited, but includes unsaturated monomers having an acidic group (e.g., carboxyl group, phosphoric acid group and sulfonic acid group) or basic group (e.g., amino group). .

Specific examples of unsaturated monomers having groups that can be positively or negatively charged include:
(Meth)acrylic acid (meaning acrylic acid and/or methacrylic acid; hereinafter the same), (anhydrous) maleic acid, maleic acid monoalkyl ester, fumaric acid, fumaric acid monoalkyl ester, crotonic acid, itaconic acid, itaconic acid carboxyl group-containing vinyl monomers such as acid monoalkyl esters, itaconic acid glycol monoethers, citraconic acid, citraconic acid monoalkyl esters, cinnamic acid, and salts thereof;
sulfopropyl (meth)acrylate, 2-hydroxy-3-(meth)acryloxypropylsulfonic acid, 2-(meth)acryloylamino-2,2-dimethylethanesulfonic acid, 2-(meth)acryloyloxyethanesulfonic acid, 3-(meth)acryloyloxy-2-hydroxypropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid and other sulfonic acid group-containing vinyl monomers, and salts thereof;
Phosphate group-containing vinyl monomers such as 2-hydroxyethyl acryloyl phosphate, and salts thereof;
amino group-containing vinyl monomers such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate; and the like.
These monomers may be used singly or in combination of two or more.

Further, a polymer network (B) formed from electrically neutral unsaturated monomers (having no positively or negatively charged groups) (hereinafter referred to as "polymer network (B)" as appropriate). Electrically neutral unsaturated monomers for forming include dimethylsiloxane, styrene, acrylamide, methylenebisacrylamide, trimethylpropane trimethacrylate, vinylpyridine, styrene, methyl methacrylate, fluorine-containing unsaturated monomers ( Examples include trifluoroethyl acrylate (TFE)), hydroxyethyl acrylate, vinyl acetate, triethylene glycol dimethacrylate, and the like. These monomers may be used singly or in combination of two or more.

In the second embodiment, from the viewpoint that the strength of the double network gel can be appropriately increased when swollen with the compound represented by the general formula (1), the double network gel has a molecular weight between cross-linking points of is preferably a combination of a polymer network with a relatively large molecular weight and a polymer network with a relatively small molecular weight between cross-linking points. From this point of view, the polymer network (C) formed from the compound represented by the general formula (11) mentioned in the first embodiment and the compound other than the compound represented by the general formula (11) It is preferable that it is a combination with a polymer network (D) that is used.

The compound represented by the general formula (11) used to form the polymer network (C) is represented by the general formulas (12) to (19) as in the first embodiment. Compounds can be particularly preferably used, and these can be used singly or in combination of two or more.

Moreover, the monomer for forming the polymer network (D) is not particularly limited, and examples thereof include electrically neutral unsaturated monomers used for forming the polymer network (B) described above.

A method for forming the polymer brush layer 20 on the substrate 10 when the plurality of polymer chains formed on the substrate 10 is a double network gel is not particularly limited, but the method described below can be mentioned. be done. In the following description, two types of polymer networks are used to form the double network gel, and an ionic liquid is used as the compound represented by the general formula (1).

First, a compound for introducing a substituent capable of reacting with the radical active species is reacted with the surface of the substrate 10 to the surface of the substrate 10, and a substituent capable of reacting with the radical active species is formed on the surface of the substrate 10. introduce a group. The compound for introducing the substituent capable of reacting with the radical active species is not particularly limited, but preferably includes a compound containing a substituent capable of reacting with the radical active species and an alkoxysilyl group.

Compounds containing substituents and alkoxysilyl groups capable of reacting with radical active species are not particularly limited, but N,N-bis(3-(trimethoxysilyl)propyl)methacrylamide, N,N-bis(3 -(trimethoxysilyl)propyl)acrylamide, N,N-bis((methyldimethoxysilyl)propyl) alkoxysilyl group-containing amide compounds having unsaturated bonds such as methacrylamide; 3-(trimethoxysilyl)propyl methacrylate, Alkoxy such as 3-(triethoxysilyl)propyl methacrylate, 3-[tri(methoxyethoxy)silyl]propyl methacrylate, 3-(methyldimethoxysilyl)propyl methacrylate, 3-(methyldiethoxysilyl)propyl methacrylate, etc. silyl group-containing acrylate compounds; and the like.

The method of reacting the surface of the base material 10 with a compound containing a substituent and an alkoxysilyl group capable of reacting with a radically active species is not particularly limited. and immersing the substrate 10, which has been subjected to hydrophilization treatment, in a solution containing a compound containing a substituent and an alkoxysilyl group that can react with radical active species, thereby reacting them, and the like. . The hydrophilization treatment method is not particularly limited, but includes a plasma etching treatment method and the like.

The reaction temperature at this time is not particularly limited, but is preferably 20 to 50° C., and the reaction time is 6 to 48 hours.

Next, separately from the above, a gel (hereinafter referred to as "first polymer network gel”) is prepared. The method for producing the first polymer network gel is not particularly limited, but a solution containing a monomer for forming the first polymer network gel, a cross-linking agent, and the compound represented by the general formula (1) is prepared. , can be prepared by polymerizing and cross-linking this solution.

The cross-linking agent is not particularly limited as long as it can form a cross-linked structure. Examples include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. , divinylbenzene and methylenebisacrylamide.

Next, a monomer for forming the remaining polymer network (hereinafter referred to as "second polymer network") of the two types of polymer networks in the first polymer network gel obtained above, and a cross-linking agent is impregnated into the first polymer network gel, thereby preparing a monomer-containing first polymer network gel. In this case, the solution impregnated into the first polymer network gel may further contain the compound represented by the general formula (1).

The method for impregnating the first polymer network gel with the solution containing the monomer for forming the second polymer network and the cross-linking agent is not particularly limited. A method of immersing a network gel and the like can be mentioned. As the cross-linking agent, those mentioned above can be used in the same manner.

Next, the monomer-containing first polymer network gel obtained as described above is brought into contact with the base material 10 having a substituent capable of reacting with the radical active species introduced to the surface thereof, and reacted while they are in contact. Thereby, the second polymer network is formed by the second polymer network-forming monomer contained in the monomer-containing first polymer network gel, and the second polymer network-forming monomer is introduced onto the substrate 10. By allowing the reaction between the radical active species and the reactive substituent to proceed at the same time, the polymer chain composed of the double network gel is swollen with the compound represented by the above general formula (1) on the base material 10. A coated polymer brush layer 20 can be formed.

Also in the second embodiment, as in the first embodiment described above, the swelling agent for swelling the polymer chains forming the crosslinked network structure, which constitutes the polymer brush layer 20, is represented by the above general formula (1). Since the compound represented by the formula is used, the coefficient of friction of the polymer brush layer 20 can be reduced, excellent low-friction slidability can be achieved, and excellent safety can be achieved. be.

<Third Embodiment>
Next, a third embodiment of the invention will be described.
FIG. 2 shows a branched polymer forming a composite material according to the third embodiment of the present invention. As shown in FIG. 2, a branched polymer 30 according to the third embodiment comprises a linear main chain (a linear polymer chain serving as a main chain) 31 as a substrate, and a plurality of polymer graft chains. The (side chain) 32 has a branched structure, and the composite material according to the third embodiment is such that such a branched polymer 30 is swollen with the compound represented by the general formula (1). consists of The branched polymer 30 has a shape like a bottle brush (a cleaning brush for cleaning a container having a bottle structure).

The branched polymer 30 has a branched polymer structure in which a plurality of side chains 32 are branched from the linear main chain 31 as described above. It is composed of a plurality of repeating units containing carbon atoms and hydrogen atoms linked together.

The number average degree of polymerization of the main chain 31 is preferably 10-10,000, more preferably 10-1,000, still more preferably 10-100. By setting the number average degree of polymerization of the main chain 31 within the above range, it is possible to further improve the low-friction slidability in the case of swelling with the compound represented by the general formula (1) to form a composite material. can. The number average degree of polymerization of the main chain 31 is not particularly limited, but the number average molecular weight of the main chain precursor before introducing the side chain 32 is measured, and the measured number average molecular weight is divided by the monomer unit molecular weight. can be found at

The side chain 32 may be linear, or may have a branched structure or a crosslinked structure. The number average degree of polymerization of the side chains 32 is preferably 1-1,00, more preferably 1-50, and even more preferably 5-20. By setting the number-average degree of polymerization of the side chains 32 within the above range, it is possible to further improve the low-friction slidability in the case of swelling with the compound represented by the general formula (1) to form a composite material. can. The method for measuring the number average degree of polymerization of the side chain is not particularly limited. A small amount of an agent (for example, an organic compound having a halogen-substituted carbon group) is added to simultaneously synthesize a free polymer having a repeating structure common to the polymer chain of the side chain 32, and the free polymer is measured. The obtained number average degree of polymerization can be used as the number average degree of polymerization of the side chain 32 .

The number average molecular weight (Mn) of the entire branched polymer 30 including the main chain 31 and side chains 32 is preferably 1,000 to 10,000,000, more preferably 1,000 to 1,000,000. , more preferably 5,000 to 500,000. By setting the number-average molecular weight of the entire branched polymer 30 within the above range, the low-friction slidability can be further enhanced in the case of swelling with the compound represented by the general formula (1) to form a composite material. can be done. The number average molecular weight of the branched polymer 30 as a whole can be measured by a gel permeation chromatography method in terms of polystyrene.

The density of side chains branched from the main chain is the number per 1 nm of main chain path length (chain/nm), preferably 1 chain/nm or more, more preferably 2 chains/nm or more, and still more preferably 3 chains. /nm or more. Here, the density of side chains can be determined from the graft efficiency.

As the branched polymer 30 used in the third embodiment, as shown in FIG. 2, any structure may be used as long as it has a structure in which a plurality of side chains 32 are branched from a linear main chain 31 as a substrate. Although not limited, it is preferably a compound represented by the following general formula (20).

In general formula (20) above, R ²⁰ and R ²¹ each independently represent a hydrogen atom or a methyl group, R ²² represents an alkyl group having 1 to 10 carbon atoms, and R ²³ and R ²⁴ are A terminal group composed of an atom or an atomic group, and includes a hydrogen atom, an azide group, a fragment of a polymerization initiation group, a polymerization control group, and the like. Further, Q ¹ represents -O- or -NH-, Q ² represents a divalent organic group, h is 10 to 10,000, and Polymer A represents a polymer chain. In the compound represented by the above general formula (20), the parenthesized repeating structural unit having h of repeating units corresponds to the main chain 31 of the branched polymer 30, and Polymer A corresponds to the branched polymer 30. corresponds to the side chain 32 of That is, in the compound represented by the above general formula (20), a main compound having a repeating unit number h is formed via a predetermined organic group from the carbon atom to which R ²⁰ is bonded to the carbon atom to which Polymer A is bonded. It has a configuration in which a plurality of side chains 32 represented by Polymer A are linked to a chain 31 . In the above general formula (20), Polymer A may be introduced into all the repeating units constituting the compound represented by the above general formula (20), or may be introduced into only some of the repeating units. may be When Polymer A is introduced into only a part of the repeating units constituting the compound represented by the general formula (20), the terminal of the side chain of the repeating unit into which Polymer A is not introduced is a hydrogen atom. It may be one in which the polymerization initiation group remains, or one in which the hydrogen atom or the polymerization initiation group is replaced with another atom or atomic group.

Q ² is a divalent organic group and is an alkylene group having 1 to 18 carbon atoms or an oxyalkylene group having 1 to 10 carbon atoms (R ²⁵ O) (R ²⁵ represents an alkylene group having 1 to 18 carbon atoms). ), a linked structure in which a plurality of oxyalkylene groups are linked, or at least one of these organic groups (alkylene group having 1 to 18 carbon atoms, oxyalkylene group having 1 to 10 carbon atoms, and linked structure of oxyalkylene group) A divalent organic group consisting of a combination of two groups and the like can be mentioned. Here, the alkylene group of the alkylene group and the oxyalkylene group may be linear or branched, and may have a cyclic structure. Specific examples of the alkylene group include ethylene group, propylene group, butylene group and cyclohexylene group. The alkylene group of this alkylene group and oxyalkylene group may be substituted with a substituent. Examples of substituents include alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 40 carbon atoms, and heteroaryl groups having 3 to 40 carbon atoms, and these substituents are further substituted with substituents. good too.

In general formula (20) above, Polymer A preferably has a structural unit derived from a (meth)acrylic acid-based monomer. (Meth) acrylic acid-based monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate. , t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate ) acrylate, lauryl (meth)acrylate, tetradecyl (meth)acrylate, octadecyl (meth)acrylate, behenyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate , isobornyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, cyclodecyl (meth)acrylate, cyclodecylmethyl (meth)acrylate, tricyclodecyl (meth)acrylate, benzyl (meth)acrylate, dicyclopentenyloxyethyl (meth) (cyclo)alkyl (meth)acrylates such as acrylate and dicyclopentanyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and naphthyl (meth)acrylate; alkenyl (meth)acrylates such as allyl (meth)acrylate; ) acrylates; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (poly)ethylene glycol mono(meth)acrylate; (poly)ethylene glycol monomethyl ether (meth) Glycol monoalkyl ethers such as acrylates, (poly)ethylene glycol monoethyl ether (meth)acrylate, (poly)ethylene glycol monolauryl ether (meth)acrylate, (poly)propylene glycol monomethyl ether (meth)acrylate, etc. ) acrylate; (meth)acrylic acid, mono-2-((meth)acryloyloxy)ethyl phthalate, mono-2-((meth)acryloyloxy)ethyl succinate, mono-2-((meth)acryloyloxy) hexahydrophthalate ) ethyl, mono-2-((meth)acryloyloxy)ethyl trimellitate, etc. carboxy group-containing (meth)acrylates; (meth)acrylates containing acid groups other than carboxy groups such as (meth)acryloyloxyethyl phosphate and (meth)acryloyloxyethylsulfonic acid; dimethylaminoethyl (meth) Amino group-containing (meth)acrylates such as acrylates, diethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate; (meth)acrylates having a quaternary ammonium base such as chlorotrimethylammonium ethyl (meth)acrylate; (Meth)acryloyloxyethyl isocyanate and 2-(2-isocyanatoethoxy)ethyl (meth)acrylate containing isocyanate group blocked with ε-caprolactone, methylethylketone oxime (MEK oxime), pyrazole, etc. (meta) Acrylates; cyclic (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate; halogen-containing (meth)acrylates such as octafluorooctyl (meth)acrylate and tetrafluoroethyl (meth)acrylate; 2-(4-benzoxy-3- UV-absorbing (meth)acrylates such as hydroxyphenoxy)ethyl (meth)acrylate, 2-(2′-hydroxy-5-(meth)acryloyloxyethylphenyl)-2H-benzotriazole; trimethoxysilyl groups and dimethyl Examples include silicon-containing (meth)acrylates having silicone chains. A macromonomer obtained by introducing a (meth)acrylic group to one end of an oligomer obtained by polymerizing these monomers can also be used.

Polymer A may be a homopolymer, a copolymer having a random structure, or a copolymer having a block structure.

上記一般式（２１）、（２２）において、Ｒ^２０、Ｒ^２１、Ｒ^２２、Ｒ^２３、Ｒ^２４、Ｑ^１、Ｑ^２、ｈは、上記一般式（２０）と同様である。 The compound represented by the general formula (20) is, for example, a polymer (initiating group-containing polymer) of a monomer represented by the following general formula (21), from a compound represented by the following general formula (22) Polymer A can be obtained by using a carbon radical generated by elimination of the group represented by T ¹ as an active site and grafting a polymer chain therefrom to generate Polymer A. Here, a compound represented by the following general formula (22) containing a polymerization initiating group (T ¹ ) (a polymer before introducing Polymer A) is referred to as an "initiating group-containing polymer", and the polymerization initiating group Radicals generated by the reaction of are sometimes referred to as "active sites".

In general formulas (21) and (22) above, R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ , Q ¹ , Q ² and h are the same as in general formula (20) above.

The monomer represented by the general formula (21) is, for example, a reaction of a (meth)acrylate having a hydroxyl group (hereinafter referred to as "monomer (a)" and an acid component (hereinafter referred to as "acid component (b)"). can be synthesized by

Among the monomers (a), examples of the compound that produces a monomer in which Q ¹ in the general formula (21) is —O— include 2-hydroxyethyl (meth)acrylate and 2-(meth)acrylate. Hydroxypropyl, 3-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2-hydroxy-3-chloropropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, ( hydroxycyclohexyl meth)acrylate, polyethylene glycol (meth)acrylate monoester, propylene glycol (meth)acrylate monoester, ethylene propylene glycol (meth)acrylate and the like.
Among the monomers (a), examples of compounds that produce monomers in which Q ¹ in the general formula (21) is —NH— include hydroxyethyl (meth)acrylamide; (meth)acrylic acid and (meth)acryl A monomer obtained by reacting an acid halide such as an acid chloride with a compound having an amino group and one or more hydroxyl groups, and the like.
Examples of acid component (b) include 2-chloropropionic acid, 2-bromopropionic acid, 2-chloro-2-methyl-propionic acid, 2-bromo-2-methyl-propionic acid and the like. Moreover, these acid halides, acid anhydrides, etc. can also be used as an acid component (b).

The compound represented by the general formula (22) can also be obtained by reacting the polymer of the monomer (a) with the acid component (b).

As the branched polymer 30, instead of the compound represented by the general formula (20), the above acid component ( It is also possible to use a product obtained by reacting b) and then reacting this with Polymer A.

Further, in the third embodiment, as the branched polymer 30, a plurality of branched polymers 30 forming a crosslinked structure may be used, or the plurality of branched polymers 30 may be composed of ionic bonds, Those bonded to each other by hydrogen bonding, hydrophobic interaction, or the like may be used. Alternatively, a base material or filler is used, a polymerization initiating group is introduced to the surface of the base material or filler, and a polymerization reaction is performed on the base material or in a state containing the filler to obtain a branched polymer. 30 may be on a substrate or composited with a filler.

The composite material according to the third embodiment can be obtained by swelling the branched polymer 30 with the compound represented by the general formula (1). The method for swelling the branched polymer 30 with the compound represented by the general formula (1) is not particularly limited, but for example, the compound represented by the general formula (1) is added dropwise to the branched polymer 30. Alternatively, a method of coating and then allowing to stand, a method of immersing the branched polymer 30 in the compound represented by the general formula (1), and the like can be used. In this case, when the compound represented by the general formula (1) is an ionic liquid, dropping, coating, or immersion can be performed without using a solvent.

Also in the third embodiment, as in the first embodiment described above, the compound represented by the general formula (1) is used as the swelling agent for swelling the branched polymer 30, so that low friction It is excellent in slidability and can realize excellent safety.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

<Synthesis Example 1>
1.51 parts by mass of pyrrolidine (manufactured by Wako Pure Chemical Industries, Ltd.) and 1.00 parts by mass of 2-methoxyethyl chloride (manufactured by Kanto Chemical Co., Ltd.) were mixed and reacted for 1 hour under reflux. After the reaction, the reaction solution was separated into two layers, but the lower layer was solidified after standing to cool for a while. Next, only the upper layer was recovered by decantation and purified by distillation under reduced pressure to obtain 0.96 parts by mass of the target N-2-methoxyethylpyrrolidine (boiling point 76° C./vapor pressure 45 mmHg) (yield 70 %).

Ten times the volume of tetrahydrofuran (THF) was added to 1.00 parts by mass of the obtained N-2-methoxyethylpyrrolidine, and methyl iodide (Wako Pure Chemical Industries, Ltd.) was added under ice cooling in an ice bath. 1.22 parts by mass were added. After a while after adding methyl iodide, a white solid precipitated. After 30 minutes, the ice bath was removed and the mixture was stirred overnight at room temperature. Thereafter, the reaction solution was filtered under reduced pressure, the precipitated white solid was separated by filtration, and recrystallization was performed using a mixed solvent system of acetonitrile-tetrahydrofuran to obtain 1.71 parts by mass of N-2-methoxyethyl-N-methylpyrrolidinium iodide. was obtained (81% yield).

Then, 2.00 parts by weight of deionized water was added to 1.00 parts by weight of the obtained N-2-methoxyethyl-N-methylpyrrolidinium iodide to dissolve it. Separately, a strongly basic ion-exchange resin "ORLITE DS-2" (Organo Co., Ltd., exchange capacity 1.4 meq/ml, OH type) was thoroughly washed until the washing liquid showed neutrality, and N-2-methoxyethyl- An amount equivalent to 2.5 moles of N-methylpyrrolidinium iodide was placed in a plastic container and charged. After 6 to 7 hours, the mixture was filtered using a Kiriyama funnel to remove the ion exchange resin. Next, a freshly washed strongly basic ion-exchange resin "ORLITE DS-2" was added to the filtrate in an amount equivalent to 2.5 times the molar amount of the starting material, left overnight, and then filtered with a Kiriyama funnel. Then, the ion exchange resin was filtered off to obtain a solution in which most of the salt was converted from chloride salt to hydroxide. Furthermore, the filtrate is passed through a column filled with a strongly basic ion exchange resin "ORLITE DS-2" (equivalent to 5 times the molar amount of the raw material) at a space velocity SV = 1 to obtain a hydroxide for neutralization reaction. An aqueous solution was obtained.

0.61 part by weight of saccharin (a.k.a. o-Sulfobenzimide, Tokyo Kasei Kogyo Co., Ltd.) was added to the obtained aqueous hydroxide solution and dissolved by stirring. After that, saccharin was added little by little while checking the pH with pH test paper, and mixing was finished when the pH test paper indicated pH7. Next, after most of the water was distilled off from this aqueous solution with an evaporator, the vacuum was further vacuumed for 3 hours or more using a vacuum pump at 45° C. (using an oil bath) to obtain the desired product, N-2-methoxyethyl-. 1.11 parts by weight of N-methylpyrrolidinium saccharinate (MEMP-Sac, compound represented by the following formula (23)) (yield 92%) was obtained as a colorless transparent liquid (melting point: -1°C). ^{A 1} H-NMR chart (solvent: heavy chloroform) is shown in FIG.

<Synthesis Example 2>
1.00 parts by mass of choline chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 7.00 parts by mass of methanol (manufactured by Sanyo Chemical Co., Ltd.) was added with saccharin sodium dihydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) ) was added and stirred overnight. Next, methanol is distilled off using a rotary evaporator, 70.0 parts by mass of acetonitrile (manufactured by Kanto Kagaku Co., Ltd.) is added to the residue, and the insoluble matter is removed by filtration under reduced pressure using a Kiriyama funnel. The filtrate was rotary evaporated to remove solvent. Next, 70.0 parts by mass of isopropanol (manufactured by Kanto Kagaku Co., Ltd.) is added to the residue, filtered under reduced pressure using a Kiriyama funnel, and then filtered under reduced pressure using a membrane filter to remove insoluble matter. did The solvent was distilled off from the resulting filtrate using a rotary evaporator, and the vacuum was further drawn using a vacuum pump at 45° C. (using an oil bath) for 3 hours or longer to obtain the target choline saccharinate (Choline- sac, a compound represented by the following formula (24)) was obtained as a white solid (melting point: 69°C (literature value)) at 2.05 parts by mass (quantitative yield). ^{A 1} H-NMR chart (solvent: heavy chloroform) is shown in FIG.

<Synthesis Example 3>
34.4 parts by mass of 1-butyl-3-methylimidazolium chloride (manufactured by Toyo Gosei Kogyo Co., Ltd.) was dissolved in 100 parts by mass of methanol. 48.2 parts by mass of saccharin sodium dihydrate (manufactured by Toyo Gosei Kogyo Co., Ltd.) was added to this solution and stirred overnight. Then, methanol is distilled off using a rotary evaporator, 50 parts by mass of acetonitrile (manufactured by Kanto Kagaku Co., Ltd.) is added to the residue, and insoluble matter is removed by filtration under reduced pressure using a Kiriyama funnel. After the acetonitrile was distilled off by using an evaporator, the minimum amount of acetonitrile necessary for dissolving the solid was again added and dissolved. This solution was then filtered under reduced pressure using a membrane filter, and the filtrate was subjected to a rotary evaporator to remove the solvent. Next, the residue is evacuated for 1 hour or more under heating at 110° C. using a vacuum pump, and the desired product, 1-butyl-3-methylimidazolium saccharinate (BMI-Sac, represented by the following formula (25 ) was obtained as a colorless transparent liquid (melting point: -2.6°C) at 63.7 parts by mass (yield: 99%). ^{A 1} H-NMR chart (solvent: heavy chloroform) is shown in FIG.

<Synthesis Example 4>
1.00 parts by weight of diethylamine (manufactured by Kanto Chemical Co., Ltd.) and 1.24 parts by weight of 2-methoxyethyl chloride (manufactured by Kanto Chemical Co., Ltd.) are mixed, and the resulting mixed solution is placed in an autoclave and °C for 24 hours. At this time, the internal pressure was 1.3 kgf/cm ² . After 24 hours, an aqueous solution prepared by dissolving 0.79 parts by weight of potassium hydroxide (manufactured by Katayama Chemical Industry Co., Ltd.) in 2.00 parts by weight of water was added to the mixture of the precipitated crystals and the reaction solution, and the mixture was separated into two layers. The organic layer was separated using a separating funnel. Furthermore, an operation of adding 1.87 parts by weight of methylene chloride (manufactured by Wako Pure Chemical Industries, Ltd.) for extraction was performed twice. The separated organic layers were combined, washed with saturated saline, dried by adding potassium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.), and filtered under reduced pressure. The solvent in the obtained organic layer is distilled off using a rotary evaporator, and the residue is subjected to atmospheric distillation to take a fraction having a boiling point of around 135° C., which is the desired product, N,N-diethyl-N-2-. 0.26 parts by weight of methoxyethylamine (yield 30%) was obtained.

Then, the N,N-diethyl-N -Methyl-N-(2-methoxyethyl) ammonium saccharinate (DEME-Sac, compound represented by the following formula (26)) 1.12 parts by weight (yield 93%), colorless transparent liquid (melting point: 14 ° C.) ). ^{A 1} H-NMR chart (solvent: heavy chloroform) is shown in FIG.

<Example 1>
0.4 g of 3-((3-(triethoxysilyl)propyl)thio)propyl-2-bromo-2-methylpropanoate (BPTPE) as an immobilized initiator and 20 ml of ethanol were mixed and then , 20 ml of ethanol containing 1.8 g of aqueous ammonia was mixed to prepare an immobilized initiator-containing solution. Then, the silicon substrate was immersed in the immobilized initiator-containing solution prepared above for 18 hours to prepare a silicon substrate having a polymerization initiation group introduced on its surface.

In addition to the above, as a monomer having an ionic dissociation group (ionic liquid monomer), N,N-diethyl-N-(2-methacryloylethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide (DEMM-TFSI) 18 g, ethyl-2-bromo-2-methylpropionate (EBIB) 0.00024 g as a radical initiator, 2,2-bipyridyl 0.020 g as a ligand, CuCl as a copper catalyst 0.0062 g of N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide (DEME-TFSI) as a non-volatile solvent (ionic liquid) 1.97 g to obtain a monomer solution.

Then, the resulting monomer solution was applied to the surface of the silicon substrate having the polymerization initiation group introduced above, and then this was placed in an incubator under an argon atmosphere at 70°C for 32 hours. By heating, atom transfer radical polymerization (ATRP) proceeds to form polymer graft chains on the surface of the silicon substrate, thereby forming a polymer brush layer (poly(DEMM-TFSI) with a thickness of 1 μm on the surface of the silicon substrate. ) was swollen with DEME-TFSI to form a polymer brush layer). The obtained substrate was subjected to ultrasonic cleaning in acetonitrile for 10 minutes, and this was performed three times to clean the polymer solution, and the obtained substrate was dried with nitrogen gas. In addition, when the number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the free polymer jointly obtained in the synthesis system were measured at this time, Mn = 4.66 × 10 ⁵ , Mw=6.36×10 ⁵ , Mw/Mn=1.37. Therefore, it can be said that the polymer graft chains introduced on the surface of the silicon substrate also have the same number average molecular weight and molecular weight distribution. Moreover, the area occupation ratio of the polymer graft chains on the surface of the silicon substrate measured according to the above method was 10% or more.

The number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) of the free polymer were determined by gel permeation chromatography (GPC). For the measurement, Showa Denko Co., Ltd. "Shodex GPC-101" (columns ("Shodex OHpak SB-806M HQ", Showa Denko Co., Ltd.) are connected in series) as a measuring device. A 1:1 (volume ratio) mixture of 0.2 M sodium nitrate aqueous solution and 0.5 M acetonitrile acetate solution was used as an eluent. Moreover, the measurement was performed at 40° C. and the flow rate was 1.0 ml/min. Then, from the obtained measurement results, the number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) of the free polymer were determined using a polyethylene oxide-equivalent calibration curve prepared by Shodex480II.

A friction test was carried out on the ionic liquid type dense polymer brush (ILCPB) obtained above, using glass balls (contact radius 10 mm) as opposing surfaces. N-2-Methoxyethyl-N-methylpyrrolidinium saccharinate (MEMP-Sac) obtained in Synthesis Example 1 was added dropwise to a dried ionic liquid type concentrated polymer brush, and the mixture was allowed to stand overnight at 80°C. A polymer brush layer (thickness: about 2 μm) was formed by swelling the ionic liquid type dense polymer brush by placing it. Subsequently, a glass ball was placed on an ionic liquid type dense polymer brush (polymer brush layer) swollen with N-2-methoxyethyl-N-methylpyrrolidinium saccharinate, and this was measured by a surface property measuring instrument. Frictional force was measured by setting it in "TRIBOGEAR, TYPE38" (manufactured by Shinto Kagaku Co., Ltd.). The measurement conditions were a sliding speed of 10.0 mm/s, a sliding distance of 10 mm, a load of 1.96 to 9.8 N, a test temperature of 24° C., and a test humidity of 25%. Results are shown in Table 1 and FIG.

<Example 2>
A dry ionic liquid type dense polymer brush obtained in the same manner as in Example 1 in a state where the choline-sac obtained in Synthesis Example 2 was heated and melted at 80° C. for 10 minutes. (ILCPB) and allowed to stand overnight at 80° C. to swell the ionic liquid type dense polymer brush to form a polymer brush layer (thickness: about 2 μm). Frictional force was measured in the same manner as in Example 1, except that an ionic liquid type dense polymer brush (polymer brush layer) swollen with choline saccharinate was used. Results are shown in Table 1 and FIG.

<Example 3>
1-Butyl-3-methylimidazolium saccharinate (BMI-Sac) obtained in Synthesis Example 3 was added dropwise to a dry ionic liquid type concentrated polymer brush (ILCPB) obtained in the same manner as in Example 1. Then, the ionic liquid type dense polymer brush was allowed to stand overnight at 80° C. to swell, thereby forming a polymer brush layer (thickness: about 2 μm). Friction force was measured in the same manner as in Example 1, except that an ionic liquid type dense polymer brush (polymer brush layer) swollen with 1-butyl-3-methylimidazolium saccharinate was used. Results are shown in Table 1 and FIG.

<Comparative Example 1>
N-2-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide (MEMP-TFSI, manufactured by Kanto Chemical Co., Ltd., compound represented by the following formula (27)) was added in the same manner as in Example 1. It was added dropwise to the dried ionic liquid type dense polymer brush (ILCPB) obtained in the above, and allowed to stand overnight at 80° C. to swell the ionic liquid type dense polymer brush. Then, friction force measurement was performed in the same manner as in Example 1, except that an ionic liquid type dense polymer brush swollen with N-2-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide was used. gone. Results are shown in Table 1 and FIG.

As shown in Table 1 and FIG. 7, when the ionic liquid type dense polymer brush (ILCPB) was swollen with the compound represented by the general formula (1), N-2-methoxyethyl-N-methyl As compared with the case of swelling with pyrrolidinium bis(trifluoromethanesulfonyl)amide (MEMP-TFSI), the friction coefficient was smaller, resulting in excellent low friction properties. In addition, it can be said that the compound represented by the above general formula (1) is excellent in safety because of its low toxicity.

<Example 4>
The N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium saccharinate (DEME-Sac) obtained in Synthesis Example 4 was combined with the dry ion A polymer brush layer (thickness: about 2 μm) was formed by dropping it onto a liquid-type dense polymer brush (ILCPB) and allowing it to stand overnight at 80° C. to swell the ionic liquid-type dense polymer brush. Then, the same as in Example 1 except that an ionic liquid type dense polymer brush (polymer brush layer) swollen with N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium saccharinate was used. Then, the frictional force measurement was performed. In addition, in Example 4, the frictional force was measured under the condition of a test load of 6.86N. As a result, the coefficient of friction under the test load of 6.86 N was 0.0015. As is clear from this result, the polymer brush layer of Example 4 and the polymer brush layer of Comparative Example 1 Under the condition of 6.86 N, the coefficient of friction was lower than that of 0.0019), and the low friction property was excellent. Moreover, since the polymer brush layer according to Example 4 also uses the compound represented by the general formula (1), it can be said that the polymer brush layer has low toxicity and is excellent in safety.

Claims (9)

A composite material obtained by swelling a plurality of polymer chains fixed to a substrate with a compound represented by the following general formula (1),
The polymer chain comprises a (meth)acrylic acid-based monomer, a styrene-based monomer, a monomer having a carboxyl group in a side chain, a monomer having a group convertible to a carboxyl group in a side chain, and a monomer having an ionic dissociation group. It is formed by polymerizing at least one monomer selected from
A composite material in which the compound represented by the general formula (1) has a melting point of 100° C. or less .

(In the above general formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms, and X ⁺ is a monovalent indicates a cation.) The composite material according to claim 1, wherein X ⁺ in the general formula (1) is an ammonium ion or a phosphonium ion. 3. The composite material according to claim 1, wherein the polymer chain is formed by polymerizing a monomer containing a compound represented by general formula (11).

(In the above general formula (11), R ¹⁹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R. ²⁰ ～R ²² each independently represents an alkyl group having 1 to 5 carbon atoms, and R ²⁰ ～R ²² may contain one or more heteroatoms selected from an oxygen atom, a sulfur atom, and a fluorine atom; ²⁰ ～R ²² may bond with each other to form a ring with the nitrogen atom to which they are bonded. Z. ^- indicates a monovalent anion. k represents an integer of 1-10, and j represents an integer of 1-5. ) 4. The composite material according to any one of claims 1 to 3, wherein the plurality of polymer chains are covalently fixed on a substrate. 5. The composite material according to claim 4, wherein the plurality of polymer chains have a molecular weight distribution (Mw/Mn) of 1.5 or less. 6. The composite material according to claim 4, wherein the exclusive area ratio of the plurality of polymer chains to the surface area of the substrate is 10% or more. The composite material according to any one of claims 4 to 6, wherein the layer formed on the substrate and containing the plurality of polymer chains and the compound represented by the general formula (1) has a thickness of 500 nm or more. . The composite material according to any one of claims 1 to 7, wherein the plurality of polymer chains are polymer graft chains branched from a main polymer chain. The composite material according to any one of claims 1 to 8, wherein the plurality of polymer chains form a crosslinked structure.

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