JP2012184400A - Fluorine-based graft copolymer and its application - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a graft copolymer which exhibits performance of fluorine characteristics such as water repellency, oil repellency and contamination resistance highly balanced with substrate adhesion, coating film strength and the like, and to provide a coating agent using the same, and a carrier using the coating agent.SOLUTION: The coating agent includes a specific graft copolymer which has a main chain composed of a fluorine-based polymer and 0.7-3.0 meq/g of a polymer having cross-linking functional groups as a side chain. The carrier is coated with the coating agent. In the graft copolymer, the fluorine-based polymer forming the main chain preferably has an 1-10 equivalent amount of cross-linking functional groups per the polymer.

Description

  The present invention relates to a fluorine-based graft copolymer and a coating agent using the same. More specifically, the coating agent comprises a specific fluorine-based graft copolymer, has sufficient substrate adhesion and coating strength, and has good water / oil repellency and stain resistance, and the like, and The present invention relates to a dry electrophotographic carrier having excellent durability and toner contamination resistance.

  Conventionally, a coating agent containing a fluoropolymer has been used as a coating agent that imparts water / oil repellency and stain resistance. As the fluoropolymer, perfluoro (meth) acrylate, Random copolymers with other radical polymerizable monomers are known. Here, in order to obtain high water / oil repellency and stain resistance, it is necessary that the content of perfluoro (meth) acrylate in the copolymer is sufficiently high. When using the coating agent containing, there is a problem that the coating strength and adhesion to the substrate is poor, so in practice the content of perfluoro (meth) acrylate in the copolymer can be increased too much Therefore, the water / oil repellency and the stain resistance have not reached satisfactory levels.

On the other hand, as a means for obtaining a copolymer exhibiting high water / oil repellency and stain resistance while reducing the content of perfluoro (meth) acrylate, a polymer comprising perfluoro (meth) acrylate units is used. A graft copolymer having branches or trunk segments and a paint using the same have been proposed.
For example, Patent Document 1 discloses a graft copolymer having a non-fluorinated polymer as a branch segment and perfluoro (meth) acrylate as an essential polymer component as a trunk segment. Patent Documents 2 and 3 disclose a graft copolymer having a polymer containing perfluoro (meth) acrylate as an essential component as a branch segment, and a coating agent using the same.

In addition, as one of applications in which a coating agent containing a fluoropolymer is used, a coating agent for an electrophotographic carrier can be given.
In electrostatic development such as electrophotography, toner particles adhere to a charged portion of an electrostatic latent image formed on a photoreceptor to form an image. The development methods at this time are roughly classified into wet development methods and dry development methods. In the former, toner particles prepared from a resin such as an acrylic resin or an alkyd resin and a colorant or a polarity control agent in a highly insulating liquid as a developer. Is used.
On the other hand, the dry developer in the latter includes a two-component developer containing a toner and a carrier, and a one-component developer mainly composed of a toner. Among them, a two-component developer has durability and image quality. Is widely used in printers and copiers.

In the two-component developer, the toner particles are charged by mixing and stirring the carrier particles and the toner particles, and the toner particles adhere to the electrostatic latent image on the photoreceptor and are developed. As carrier particles, iron powder, ferrite powder, glass beads, plastic beads, or other core material particles coated with an insulating resin are generally used. However, when used for a long period of time, friction due to peeling or chipping of the coating layer occurs. There may be a phenomenon such as so-called fogging in which the image quality is deteriorated due to destabilization of chargeability and adhesion and solidification of the toner component on the carrier surface. For this reason, the carrier is required to have characteristics such as durability that ensures stable triboelectric charging with the toner for a long period of time and toner contamination resistance.
Various carrier coating agents containing a fluoropolymer having a low surface energy have been studied for the above-mentioned problems. For example, Patent Document 4 discloses a composition containing a polymer comprising a monomer containing a specific fluoromonomer. A carrier formed by coating an object is disclosed. Patent Documents 5 and 6 describe that the use of a carrier coating agent composed of a fluorine-containing resin and a crosslinking agent suppresses peeling of the carrier coating layer and improves durability. Further, Patent Documents 7 and 8 disclose coating agents that have improved durability and toner contamination resistance by using a specific fluorine-based graft copolymer.

JP-A-6-228534 JP-A-9-67417 JP 2000-44635 A Japanese Patent Application Laid-Open No. 61-120169 Japanese Patent Application Laid-Open No. 60-60659 Japanese Patent Laid-Open No. 10-232514 Japanese Patent Laid-Open No. 60-202451 JP-A-2005-315907

  However, in the coating agent using the fluorine-based graft copolymer disclosed in Patent Documents 1 to 3, characteristics due to fluorine such as water repellency / oil repellency and stain resistance, substrate adhesion, coating film strength, etc. There was room for improvement in terms of both compatibility, and the durability was not sufficient.

  Further, regarding the carrier coating agent, the carrier coating agent disclosed in Patent Document 4 is inferior in the strength of the coating layer itself and in the adhesion to the core material, so that the coating layer is scraped and peeled off with use, resulting in durability. Was not enough. In addition, in the carrier coating agents disclosed in Patent Documents 5 and 6, the introduction of a crosslinkable functional group and the formation of a crosslink structure hinder the chargeability and contamination resistance, which are the characteristics of fluorine, resulting in a charge amount as a result. There is a problem that the coating strength cannot be balanced to a high degree. On the other hand, the coating agents for carriers as disclosed in Patent Documents 7 and 8 are also not sufficient in terms of coating strength, and the coating layer has been greatly deteriorated for a long period of time or after high stress.

  The present invention has been made in view of the above-described problems, and exhibits a highly balanced performance of fluorine characteristics such as water repellency / oil repellency and stain resistance, and substrate adhesion and coating film strength. A graft copolymer and a coating agent using the same are provided. It is another object of the present invention to provide a carrier coating agent having both excellent durability and resistance to toner contamination on the carrier surface, and a carrier using the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the use of a coating agent comprising a specific graft copolymer having a main chain composed of a fluorine-based polymer and having a crosslinkable functional group in the side chain. The present invention has been found by finding it effective.

〔式中、Ｒ¹は水素原子またはメチル基、Ｚは水素原子またはフッ素原子、ｍは１〜４のいずれかの整数、ｎは１〜２０のいずれかの整数を示す。〕
〔４〕上記フッ素系グラフト共重合体が、フッ素原子含有単量体、末端に重合性不飽和官能基を有しかつ架橋性官能基を含有するマクロモノマー及びその他の単量体を含む単量体混合物を共重合することにより得られることを特徴とする上記〔１〕〜〔３〕のいずれかに記載のフッ素系グラフト共重合体。
〔５〕上記主鎖を形成する重合体が、該重合体あたり１〜１０個相当量の架橋性官能基を有することを特徴とする上記〔１〕〜〔４〕のいずれかに記載のフッ素系グラフト共重合体。
〔６〕上記主鎖に配される架橋性官能基がω位に架橋性官能基を持つ炭素数１０以上の単量体に由来すること特徴とする上記〔５〕に記載のフッ素系グラフト共重合体。
〔７〕側鎖及び主鎖に配される架橋性官能基が水酸基であることを特徴とする上記〔１〕〜〔６〕のいずれかに記載のフッ素系グラフト共重合体。
〔８〕上記〔１〕〜〔７〕のいずれかに記載のフッ素系グラフト共重合体を含むコーティング剤。
〔９〕上記フッ素系グラフト共重合体に加え、さらに架橋剤を含んでなる上記〔８〕に記載のコーティング剤。
〔１０〕上記〔８〕または〔９〕のいずれかに記載のコーティング剤を用いてなる乾式電子写真用キャリア。 The present invention is as follows.
[1] A fluorine-based graft copolymer having a main chain made of a fluorine-based polymer and having a crosslinkable functional group in a side chain.
[2] The fluorine-based graft copolymer as described in [1] above, wherein the introduction amount of the crosslinkable functional group in the side chain is in the range of 0.7 to 3.0 meq / g.
[3] The fluorine-based monomer according to the above [1] or [2], wherein the monomer constituting the fluorine-based polymer includes a vinyl monomer represented by the following general formula (1): Graft copolymer.

[Wherein, R ¹ represents a hydrogen atom or a methyl group, Z represents a hydrogen atom or a fluorine atom, m represents an integer of 1 to 4, and n represents an integer of 1 to 20. ]
[4] Monomer containing a fluorine atom-containing monomer, a macromonomer having a polymerizable unsaturated functional group at a terminal and a crosslinkable functional group, and other monomers. The fluorine-based graft copolymer according to any one of the above [1] to [3], which is obtained by copolymerizing a body mixture.
[5] The fluorine according to any one of [1] to [4] above, wherein the polymer forming the main chain has 1 to 10 equivalents of crosslinkable functional groups per polymer. Graft copolymer.
[6] The fluorine-based graft copolymer according to [5], wherein the crosslinkable functional group arranged in the main chain is derived from a monomer having 10 or more carbon atoms having a crosslinkable functional group at the ω position. Polymer.
[7] The fluorine-based graft copolymer according to any one of the above [1] to [6], wherein the crosslinkable functional group arranged on the side chain and the main chain is a hydroxyl group.
[8] A coating agent comprising the fluorine-based graft copolymer according to any one of [1] to [7].
[9] The coating agent according to the above [8], further comprising a crosslinking agent in addition to the fluorine-based graft copolymer.
[10] A dry electrophotographic carrier using the coating agent according to any one of [8] or [9].

Since the fluorine-based graft copolymer of the present invention has a graft structure, it can achieve both good adhesion to various substrates and fluorine characteristics such as water repellency / oil repellency and stain resistance. Useful as. Further, a tough coating layer can be obtained by crosslinking with a crosslinkable functional group arranged in the side chain.
In addition, when the fluorine-based graft copolymer is used as a carrier coating agent, even when used for a long period of time, the coating layer is not scraped or peeled off, ensuring insulation and exhibiting stable triboelectric chargeability. it can. In addition, by placing a fluorine-based segment with low surface energy in the main chain and clearly distinguishing it from the side chain involved in crosslinking, it became possible to effectively show the contamination resistance that is a characteristic of fluorine. . As a result, a carrier coating agent capable of highly balancing durability and toner contamination resistance can be obtained.

The present invention relates to a fluorine-based graft copolymer having a specific structure and a coating agent using the same, and further relates to a carrier coating agent and a carrier using the same.
The present invention will be described in detail below. In the present specification, acrylic acid or methacrylic acid is represented as (meth) acrylic acid.

  The graft copolymer in the present invention comprises a main chain composed of a fluorine-based polymer and a side chain which is a polymer having a crosslinkable functional group. Here, the “fluorine polymer” refers to a polymer containing a fluorine atom, and can be obtained by using a fluorine atom-containing vinyl monomer as a constituent monomer. In addition to this, for example, it can also be obtained by a method of reacting a polymer containing a reactive functional group with a reactive agent containing fluorine, such as reacting a polymer containing a carboxyl group with a fluorine-containing epoxy compound. Among these, a method of obtaining a fluorine-based polymer by using a fluorine atom-containing monomer as a constituent monomer is preferable because the target polymer can be easily obtained with high purity.

〔式中、Ｒ¹は水素原子またはメチル基、Ｚは水素原子またはフッ素原子、ｍは１〜４のいずれかの整数、ｎは１〜２０のいずれかの整数を示す。〕 The fluorine atom-containing vinyl monomer is not particularly limited. For example, trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, heptafluoropropyl (meth) acrylate, nonafluorobutyl (meth) acrylate, undeca (Meth) acryloyl type monomers such as fluoropentyl (meth) acrylate, tridecafluorohexyl (meth) acrylate, pentadecafluoroheptyl (meth) acrylate, and monomers represented by the following general formula (1); Fluoroethylenes such as monofluoroethylene, difluoroethylene, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene; vinylidene fluoride, vinyl fluoride, hexafluoropropylene, etc., but copolymerizability and handling (Meth) acryloyl type monomer is preferable from the easiness, the monomer is more preferably represented by the following general formula (1) in terms of easy availability and cost.

[Wherein, R ¹ represents a hydrogen atom or a methyl group, Z represents a hydrogen atom or a fluorine atom, m represents an integer of 1 to 4, and n represents an integer of 1 to 20. ]

Z in the general formula (1) is preferably a fluorine atom since the characteristics of fluorine are remarkable, and m is preferably 1 or 2 from the viewpoint of availability. About n, the thing of 1-20 can be used, However, When n is small, a fluorine characteristic may not fully be exhibited, When n is too large, the solubility to a solvent and compatibility with another compound may be sufficient. May decrease. From these viewpoints, n = 4 to 10 is preferable, and n = 6 to 8 is more preferable. However, n = 8 is slightly a concern from the viewpoint of compound safety.
Examples of the preferable fluorine atom-containing vinyl monomer described above include, as trade names, Cheminox FAAC-4, Cheminox FAAC-6, Cheminox FAMAC-4, Cheminox FAMAC-6 (manufactured by Unimatec), R-1110, R -1210, R-1420, R-1620, R-5210, R-5410, R-5610, M-1110, M-1210, M-1420, M-1620, M-5210, M-5410, M-5610 (Daikin Co., Ltd.), Light Acrylate FA-108 (manufactured by Kyoeisha Chemical Co., Ltd.), Biscote-3F, Biscote-3FM, Biscote-4F, Biscote-8F, Biscote-8FM (above, Osaka Organic Chemical Industry Co., Ltd.), etc. Is mentioned. Among these, the acrylate type is preferable to the methacrylate type because fluorine characteristics tend to appear and durability tends to be high.
By using the fluorine atom-containing vinyl monomer, a coating agent that gives a coating layer having a low surface energy can be obtained, and it can be excellent in stain resistance.

  The ratio of the fluorine atom-containing vinyl monomer in the monomer mixture constituting the fluoropolymer (main chain) constituting the graft copolymer of the present invention is 30 to the total monomer constituting the main chain. 95 mass% is preferable and 50-80 mass% is still more preferable. When the fluorine atom-containing vinyl monomer is less than 30% by mass, the characteristics of fluorine such as charging performance and toner contamination resistance are not sufficiently exhibited. It may become.

The graft copolymer in the present invention has a side chain composed of a polymer containing a crosslinkable functional group.
The polymer (side chain) containing a crosslinkable functional group can be obtained by using a crosslinkable functional group-containing vinyl monomer as a constituent monomer. Specific examples thereof include hydroxyethyl (meth) acrylate, Ε-caprolactone is added to hydroxyalkyl (meth) acrylate such as 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate, and hydroxyethyl (meth) acrylate. Hydroxyl group-containing monomers such as compounds [for example, trade name Plaxel FM2D, Plaxel FM3, Plaxel FM5, Plaxel FA1DDM, Plaxel FA2D, Plaxel FA10L, etc., manufactured by Daicel Chemical Industries, Ltd.]; (meth) acrylic acid, crotonic acid, malein Carboxylic acids such as acid, maleic anhydride and itaconic acid Group-containing monomer: N-methylol group such as N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide and N-isobutoxymethyl (meth) acrylamide, or N- Examples include alkoxymethyl group-containing compounds; epoxy group-containing monomers such as glycidyl (meth) acrylate.
In addition to the above, after copolymerizing a hydroxyl group-containing unsaturated monomer, a dibasic acid anhydride such as succinic anhydride, maleic anhydride or phthalic anhydride is added to form a carboxyl group as a crosslinkable functional group. It is also possible to introduce groups.
Furthermore, after introducing an epoxy group into the polymer, for example, a carboxylic acid compound having a polymerizable unsaturated bond such as (meth) acrylic acid is added, and the functional group is reacted with the functional group. It is also possible to introduce a polymerizable vinyl group such as a (meth) acryloyl group as a crosslinkable functional group by reacting a compound having both a functional group and a polymerizable vinyl group.
Among the crosslinkable functional groups, a hydroxyl group and a (meth) acryloyl group are preferred, and a hydroxyl group is particularly preferred from the viewpoints of production stability, ease of control of the crosslinking reaction, coating film properties after crosslinking, and the like.

After adding a crosslinking agent as described later to the graft copolymer having a crosslinkable functional group introduced in the side chain, if necessary, it is crosslinked by applying energy such as heat or active energy rays to obtain a tough coating layer. Therefore, even when used for a long period of time, the coating layer will not be scraped or peeled off, and a highly durable coating film can be obtained.
Here, introduction of a crosslinkable functional group into the side chain of the graft copolymer is important for solving the problems of the present invention. If the amount of crosslinkable functional groups necessary for imparting durability is introduced into the main chain, the orientation of the fluorine segments arranged in the main chain to the coating layer surface is hindered. (Oil repellency, charging performance, toner contamination resistance, etc.) are impaired, making it difficult to achieve both durability and durability. In the present invention, a fluorine-based polymer for exhibiting fluorine characteristics and a cross-linkable functional group-containing polymer for ensuring durability are used as a graft copolymer in which a main chain and a side chain are separately arranged, respectively. It is presumed that both the characteristics and durability by this have become possible.

The amount of the crosslinkable functional group introduced into the side chain polymer is preferably in the range of 0.7 to 3.0 meq / g, and more preferably in the range of 1.0 to 2.5 meq / g. When the introduction amount of the crosslinkable functional group is less than 0.7 meq / g, the durability of the coating agent is not sufficient, and when it exceeds 3.0 meq / g, the surface of the coating layer is easily contaminated.
The amount introduced is determined from the monomer charge ratio.

The polymer forming the side chain preferably has a glass transition temperature (hereinafter referred to as “Tg”) of the side chain of 30 ° C. or higher, and more preferably 60 ° C. or higher. When Tg is less than 30 ° C., the coating layer becomes soft and toner contamination resistance may deteriorate.
The Tg of the polymer forming the side chain can be measured by a differential scanning calorimeter (DSC), and each single weight described in “POLYMER HANDBOOK 4th edition” (published by John Wiley & Sons, Inc.). You may use the value calculated | required by the calculation shown to the following formula | equation (1) based on Tg of coalescence.

上記の式中、
Ｔｇ：重合体のＴｇ
Ｗ（ａ）：重合体における単量体（ａ）からなる構造単位の重量分率
Ｗ（ｂ）：重合体における単量体（ｂ）からなる構造単位の重量分率
Ｗ（ｃ）：重合体における単量体（ｃ）からなる構造単位の重量分率
Ｔｇ（ａ）：単量体（ａ）の単独重合体のガラス転移温度
Ｔｇ（ｂ）：単量体（ｂ）の単独重合体のガラス転移温度
Ｔｇ（ｃ）：単量体（ｃ）の単独重合体のガラス転移温度

In the above formula,
Tg: Tg of polymer
W (a): Weight fraction of structural unit composed of monomer (a) in polymer W (b): Weight fraction of structural unit composed of monomer (b) in polymer W (c): Heavy Weight fraction of structural unit consisting of monomer (c) in coalescence Tg (a): Glass transition temperature of homopolymer of monomer (a) Tg (b): Homopolymer of monomer (b) Glass transition temperature of Tg (c): Glass transition temperature of homopolymer of monomer (c)

Examples of other monomers constituting the polymer forming the side chain include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( (Meth) acrylic acid alkyl esters such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, octadecyl (meth) acrylate; styrene, α-methylstyrene and Examples thereof include styrene derivatives such as p-methylstyrene; (meth) acrylonitrile; (meth) acrylamide and the like, and one or more of them can be used.
Among these, the use of methyl methacrylate and / or isobornyl methacrylate is preferable because the Tg of the entire side chain is high, and particularly methyl methacrylate is preferable because a tough coating layer can be obtained.

  The weight average molecular weight (hereinafter referred to as “Mw”) of the polymer forming the side chain is preferably 3,000 to 20,000, more preferably 5,000 to 10,000. When Mw is less than 3,000, the adhesion and fluorine characteristics tend to be inferior, and when it exceeds 20,000, the durability of the coating layer may be inferior. This is presumably due to an increase in the polymer having only the main chain component having no graft structure.

The graft copolymer of the present invention comprises a main chain composed of a fluoropolymer as described above and a side chain which is a polymer having a crosslinkable functional group, and the ratio of the main chain to the side chain is 10 to 10 for the main chain. The side chain is preferably 30 to 90% by mass with respect to 70% by mass, more preferably the main chain is 15 to 60% by mass and the side chain is 40 to 85% by mass, and still more preferably the main chain. The side chain is 50 to 80% by mass with respect to 20 to 50% by mass.
When the main chain is less than 10% by mass (side chain exceeds 90% by mass), the fluorine characteristics tend to be impaired, and when the main chain exceeds 70% by mass (side chain is less than 30% by mass), coating The adhesion and durability of the layer may be inferior.

  The Mw of the graft copolymer is preferably 10,000 to 100,000, more preferably 15,000 to 50,000. When the Mw is less than 10,000, the coating layer is inferior in strength, so that the durability is insufficient. When the Mw is greater than 100,000, the viscosity of the solution is increased and the coating suitability may be insufficient. For example, when used as a carrier coating agent, it is necessary to reduce the viscosity of the coating agent using a large amount of a diluting solvent in order to uniformly apply to the carrier surface. If the application is not uniform, the coating layer is likely to be contaminated with toner or the like.

  There is no particular limitation on the method for producing the graft copolymer, and any method can be used as long as it can produce a graft copolymer having a fluoropolymer as a main chain and a polymer having a crosslinkable functional group as a side chain. It may be manufactured.

As a manufacturing method of the above-mentioned graft copolymer, for example,
(I) Graft copolymerization by copolymerizing a monomer mixture containing a fluorine atom-containing vinyl monomer in the presence of a macromonomer having a polymerizable unsaturated functional group at the terminal and containing a crosslinkable functional group Method for obtaining coalescence (macromonomer method);
(Ii) A monomer mixture having a polymerization initiating group such as an azo group or a peroxide group in the polymer segment and containing a crosslinkable functional group-containing monomer in the presence of a polymer containing a fluorine atom. A method of obtaining a graft copolymer by copolymerization.
(Iii) A method of obtaining a graft copolymer by reacting a polymer containing a functional group with one or more polymers having a functional group capable of reacting with the functional group.

Among the above-described production methods, the macromonomer method (i) is preferable from the viewpoint that the graft copolymer can be produced efficiently.
In addition, the terminal polymerizable unsaturated functional group in the macromonomer is preferably a (meth) acryloyl group or a styryl group from the viewpoint of copolymerizability, and among them, a (meth) acryloyl group is particularly preferable.

  The graft copolymer of the present invention is composed of a main chain made of a fluoropolymer and side chains made of a polymer having a crosslinkable functional group. By being this structure, it can be set as the coating agent for carriers which shows the stability at the time of manufacture, and the characteristic of a fluorine sufficiently. On the other hand, in the case of a graft copolymer having a crosslinkable functional group as the main chain and a fluoropolymer as a side chain, the production stability may not be sufficient. Problems such as liquid separation are likely to occur due to the low compatibility between the resin and the acrylic resin.

The fluorine-based polymer constituting the main chain of the graft copolymer of the present invention may have 1 to 10 equivalent crosslinkable functional groups (hereinafter referred to as the average number of functional groups in the main chain) per the polymer (main chain). It is preferable to have 2 to 6 equivalents. By introducing the above-mentioned amount of functional groups into the main chain, the durability of the coating layer is further improved.
As described above, various known methods can be adopted for producing the graft copolymer of the present invention. In any method, a polymer having only a main chain component (fluorine-based linear polymer) having no graft structure is used. A small amount is produced. The fluorine-based linear polymer does not have sufficient toughness when formed into a coating film, and may be detached from the coating layer when used for a long period of time. By introducing the above-mentioned amount of crosslinkable functional groups into the main chain within a range that does not impair the fluorine characteristics, the fluorine-based linear polymer also has a small amount of crosslinkable functional groups and is bonded to the matrix component in the coating layer. It is estimated that the durability is improved.

ここで、各記号の意味は以下の通り。
Ｆ_m：主鎖中の平均官能基数
Ｗ_m：グラフトポリマー製造時に使用した架橋性官能基含有単量体（マクロモノマーを 除く）の質量
Ｍ_m：上記架橋性官能基含有単量体の分子量
Ｗ_GP：グラフトポリマーを構成する全単量体の質量（マクロモノマーを含む）
Ｍｎ_GP：グラフトポリマーの数平均分子量 The average number of functional groups (F _m ) in the main chain is obtained as a calculated value by the following formula (2).

Here, the meaning of each symbol is as follows.
F _m : Average number of functional groups in the main chain W _m : Mass of the crosslinkable functional group-containing monomer (excluding the macromonomer) used in the production of the graft polymer M _m : Molecular weight of the crosslinkable functional group-containing monomer W _GP : Mass of all monomers composing the graft polymer (including macromonomer)
Mn _GP : Number average molecular weight of graft polymer

  The durability is further improved when the average number of functional groups in the main chain is 1 or more. On the other hand, if the number exceeds 10, the characteristics of fluorine may be hindered, and there is a concern that the water / oil repellency, charging performance, toner contamination resistance, and the like are lowered.

The crosslinkable functional group introduced into the main chain may be the same functional group as the functional group introduced into the side chain described above, but the same type of functional group as the crosslinkable functional group introduced into the side chain. Is preferably introduced. When the type of the crosslinkable functional group introduced into the main chain and the side chain is different, it may be necessary to add a crosslinking agent corresponding to each type, and the operation becomes complicated.
Further, as in the case of the side chain, a hydroxyl group, a carboxyl group, and a (meth) acryloyl group are preferred from the viewpoints of production stability, ease of control of the crosslinking reaction, coating film physical properties after crosslinking, etc. preferable.

The crosslinkable functional group introduced into the main chain is preferably derived from a monomer having 10 or more carbon atoms having a crosslinkable functional group at the ω position. For example, a compound obtained by adding ε-caprolactone to hydroxyethyl (meth) acrylate corresponds to this, and specific examples include, for example, Plaxel FA1DDM, Plaxel FA2D, Plaxel FA3D, Plaxel FA10L, Plaxel FM3D, Plaxel FM3 and Plaxel FM5 ( All of them are manufactured by Daicel Corporation). Other than these, polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and (meth) acrylates of polyethylene / polypropylene block bodies, ω-carboxy-polycaprolactone mono (Meth) acrylate (for example, trade name “Aronix M-5300” manufactured by Toagosei Co., Ltd.) and the like can be used, and one or more of these can be used.
When a crosslinkable functional group is introduced into the main chain by these compounds, it is preferable because a cross-linking point exists at a position away from the main chain and the surface orientation of the fluorine segment is relatively difficult to be disturbed.

Among the monomers having 10 or more carbon atoms having a crosslinkable functional group at the ω position, a compound obtained by adding ε-caprolactone to hydroxyethyl (meth) acrylate having a structure derived from caprolactone in the molecule, and ω-Carboxy-polycaprolactone mono (meth) acrylate is preferred because it provides better water / oil repellency and durability. Furthermore, ω-carboxy-polycaprolactone mono (meth) acrylate whose functional group is a hydroxyl group is more preferable.
The polymerizable unsaturated group is preferably an acrylate type in terms of good friction durability and stain resistance.

The fluorine-based polymer constituting the main chain of the graft copolymer of the present invention is not limited to the above-mentioned fluorine atom-containing vinyl monomer and crosslinkable functional group. Can be copolymerized.
Examples of the copolymerizable vinyl monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, and ( (Meth) acrylic acid alkyl esters such as isobornyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, octadecyl (meth) acrylate; styrene such as styrene, α-methylstyrene and p-methylstyrene Derivatives; (meth) acrylonitrile; aminoalkyl (meth) acrylamides such as (meth) acrylamide, dimethylaminomethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylamide and the like.
Among the above, methyl (meth) acrylate, isobornyl (meth) acrylate and styrene derivatives are preferable in terms of improving the toughness of the coating layer.

As described above, in the coating agent of the present invention, a crosslinking agent can be further used in addition to the graft copolymer, if necessary. The cross-linking agent to be used is not particularly limited as long as it can cross-link with the introduced cross-linkable functional group, but examples thereof include epoxy-based, isocyanate-based, amino resin-based, hydrazide-based, carbodiimide-based, and oxazoline-based crosslinking agents. One kind or two or more kinds selected can be used. Among these, an isocyanate-based crosslinking agent is preferable from the viewpoint of reactivity and ease of control. The addition amount of the crosslinking agent is preferably used in the range of 0.1 to 10 equivalents, more preferably 0.2 to 5 equivalents, and still more preferably 0.1 to 10 equivalents relative to the amount of the crosslinking functional group of the graft copolymer. 5 to 2 equivalents.
The crosslinking reaction can be carried out under heating conditions of, for example, about 80 to 200 ° C., but is appropriately set according to the type of the crosslinkable functional group and the crosslinking agent used.

A variety of isocyanate crosslinking agents can be used as long as they have two or more isocyanate groups in the molecule. Specific examples thereof include p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, Range isocyanate, 4,4'-diphenylene diisocyanate, 1,5-octylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,4- Cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, diphenylmethane diiso Aneto, 1,4-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate and carbodiimide-modified 4,4'-diphenylmethane diisocyanate.
Among these, aliphatic isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate are preferable from the viewpoint of stain resistance of the coating layer.

  Epoxy crosslinking agents can also be used without particular limitation as long as they are compounds having two or more epoxy groups in the molecule. Specific examples include bisphenol type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol Z type epoxy resins and hydrogenated bisphenol type epoxy resins; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl Ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, diglycidylamine, N, N, N ′, N′-tetraglycidyl- Examples thereof include m-xylenediamine and 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane.

  Examples of the amino resin-based crosslinking agent include alkyl etherified melamine, alkyl etherified urea resin and alkyl etherified benzoguanamine. Among these, as the alkyl etherified melamine, a completely alkyl etherified melamine such as hexamethoxymethylol melamine or hexabutoxymethylol melamine or a partially alkyl etherified melamine having an alkyl etherification degree of 5 or less can be used. In addition, multimers such as alkyl etherified melamine dimers and trimers can also be used.

When the crosslinkable functional group is a polymerizable vinyl group, an active energy ray-curable coating agent can be obtained by adding a photopolymerization initiator as necessary.
In the case of blending a photopolymerization initiator, the photopolymerization initiator includes benzoin and its alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones, acylphosphine oxides, and α-diketones. Among these, benzophenones and thioxanthones are preferred because of their high polymerization rate. The amount of the photopolymerization initiator used is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the graft copolymer of the present invention.
Moreover, in order to improve the sensitivity by an active energy ray, a photosensitizer can also be used together. Examples of the photosensitizer include benzoic acid and amine photosensitizers, and these may be used in combination of two or more.

  Examples of active energy rays include visible light, ultraviolet rays, X-rays, and electron beams, and ultraviolet rays are preferably used because inexpensive devices can be used. Examples of the light source when using ultraviolet rays include ultra-high pressure, high pressure, medium pressure or low pressure mercury lamp, metal halide lamp, xenon lamp, electrodeless discharge lamp, carbon arc lamp, and the like.

The coating agent of the present invention may further contain a fluorine-free binder component capable of forming a coating layer alone. As the binder to be blended, various known general-purpose polymers and oligomers can be used, and it is particularly preferable to blend an acrylic polymer having the same kind of crosslinkable functional group as the graft copolymer of the present invention.
As a compounding quantity, it is preferable to make the compounding quantity of a binder component into 5 (solid content) or less with respect to the weight 1 (solid content) of a graft copolymer, and it is more preferable to set it as 2 or less. When the blending amount of the binder component exceeds 5, the fluorine concentration in the coating layer becomes thin, so that the fluorine characteristics are impaired.

  The coating agent of the present invention can be blended with silica, titanium oxide or the like for the purpose of improving the coating film strength and adjusting the deposition efficiency, as long as the properties of fluorine and the durability of the coating layer are not impaired.

By coating the surface of the carrier with the coating agent thus obtained, it can be suitably used as a carrier in electrophotography, electrostatic printing and the like.
Examples of the carrier core material include iron powder, ferrite powder, glass beads, and plastic beads. The particle diameter of the core material is desirably 20 to 70 μm, and the shape may be spherical or non-spherical.

  The coating agent of the present invention is coated on the surface of the core material of the carrier in the range of 0.05 to 20 μm, preferably 0.1 to 5 μm. In this case, a conventionally known coating method can be employed. For example, a coating layer is formed on the surface of the carrier core using a spray dryer, fluidized bed, heating type kneader, etc., and then heated, irradiated with active energy rays or left as it is. Thus, the carrier of the present invention is obtained.

Hereinafter, the present invention will be specifically described based on examples. In the following description, “part” means part by mass, and “%” means mass%.
Further, the macromonomer, graft copolymer, coating agent and carrier obtained in each example were evaluated by measuring the following physical properties and properties.
(1) Characteristics of Macromonomer and Graft Copolymer a) About 1 g of solid content measurement sample is weighed (a), and then the residue after drying for 30 minutes in an air dryer 155 ° C. is measured (b). It was calculated from the following formula. A weighing bottle was used for the measurement. Other operations were in accordance with JIS K 0067-1992 (chemical product weight loss and residue test method).
[Solid content (%)] = (b / a) × 100

b) Molecular weight After a sample was dissolved in tetrahydrofuran (hereinafter referred to as “THF”) to prepare a solution having a concentration of 0.2%, 100 μL of the solution was added to a column (manufactured by Tosoh Corporation, “TSK-GEL MULTIPIORE HXL-M” ( 4)), and was measured by gel permeation chromatography (GPC method) in which THF was passed through the column at a flow rate of 1.0 mL / min at a column temperature of 40 ° C. to elute the components adsorbed on the column. The number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated from a calibration curve prepared in advance using polystyrene having a known molecular weight as a standard substance.

c) Tg
Using a differential scanning calorimeter “DSC5200” (manufactured by Seiko Instruments Inc.), Tg was measured under a nitrogen atmosphere under a temperature rising rate of 20 ° C./min. The sample amount used for the measurement was 5 to 10 mg.

(2) Characteristics of Coating Agent a) Contact Angle Using an automatic contact angle measuring device “OCA-20” (manufactured by Dataphysics), the contact angles of pure water and n-hexadecane with respect to each test coating film sample were measured.
After that, a nylon scrubber is put on the coating film sample, and a 50-round reciprocating friction test is performed by applying a load of 2 kg with a rubbing tester (manufactured by Daiei Kagaku Seiki Seisakusho, Gakushin type dyeing friction fastness tester). Similarly, contact angles of pure water and n-hexadecane were measured. Further, [contact angle after test / contact angle before test] was calculated as an index of friction durability.

b) Pencil hardness A pencil scratch test was carried out according to JIS K 5600-5-4 (scratch hardness (pencil method)) for each test paint film sample, and the maximum hardness at which the paint film was not damaged was measured.

c) Adhesiveness For each test film sample, a cross-cut peel test was performed according to JIS K 5600-5-6 (adhesiveness (cross-cut method)), and the number of pieces not peeled in 25 cross-cut pieces Was recorded.

d) Magic stain resistance A line was drawn with black magic ink on each test sample, and the ink was wiped off with a paper towel after 1 hour. The ease of ink wiping at that time was evaluated according to the following criteria.
◎: It can be wiped off with light force, and no trace remains ○: It can be wiped off with a little strong force, but a slight trace remains △: It can be wiped off with a strong force, but there is an obvious trace Remaining ×: Can hardly be wiped off

e) Powder contamination resistance Two test coating sample plates were prepared, carbon powder (Mitsubishi Chemical Co., Ltd., trade name “MA100”) was sandwiched between the sample plates, and rubbed with a certain force. . Thereafter, the carbon powder was wiped off with a paper towel, and the ease of wiping was evaluated according to the following criteria.
○: Completely wiped off △: Traces remain after wiping off: Marks of carbon powder can be clearly confirmed after wiping off

f) Weather resistance The coating film samples for each test were subjected to a weather resistance test for 100 hours using a metalling weather meter “DAIPLA METAL WEATHER KU-R5NCI-A” (manufactured by Daipura Wintes). Thereafter, the surface of the coating film was observed and evaluated according to the following criteria.
○: No difference in appearance compared to before the test △: The gloss of the coating film surface is lower than before the test ×: Concavities and convexities or peeling are confirmed on the coating film

(3) Characteristics of carrier a) Charge amount of toner 98 parts of a carrier having a coating layer and 2 parts of a commercially available toner (manufactured by Kyocera Mita Co., Ltd., KM-C2630 magenta toner, polyester series) are stirred and mixed in a tumbler mixer for 1 hour. Thus, an initial developer was produced. The toner was extracted from this, and the charge amount was measured by a Toshiba blow-off charge amount measuring device TB-200, which was defined as the initial toner charge amount.
Further, as a forced deterioration test, 100 g of a carrier having a coating layer was put in a 200 mL glass container, and shaken with a paint conditioner (manufactured by RED DEVIL) for 12 hours. 98 parts of the carrier after this forced deterioration and 2 parts of a commercially available toner (manufactured by Kyocera Mita Co., Ltd., KM-C2630 magenta toner, polyester) are combined with a tumbler mixer for 1 hour to produce a developer after forced deterioration. did. The toner was extracted from this, and the charge amount was measured by a Toshiba blow-off charge amount measuring device TB-200, which was defined as the toner charge amount after forced deterioration.

b) Charge retention rate Calculated based on the following formula.
[Charge retention rate (%)] = ([Toner charge amount after forced deterioration] / [Initial toner charge amount]) × 100

c) Toner stain resistance The carrier was extracted from the developer after initial and forced deterioration, observed with a scanning electron microscope (JSM-6330F manufactured by JEOL), and evaluated based on the following criteria.
◎: Contamination such as toner adhering to the coating layer on the carrier is hardly recognized ○: Contamination such as toner adhering to the coating layer on the carrier is observed in a small amount Δ: Toner adhering to the coating layer on the carrier A considerable amount of contamination is observed ×: The coating layer on the carrier is severely contaminated with toner deposits, etc.

d) Peeling of coating layer The carrier after forced deterioration was observed with a scanning electron microscope (JSM-6330F manufactured by JEOL) and evaluated based on the following criteria.
○: No peeling of the coating layer on the carrier is observed Δ: A small amount of peeling of the coating layer on the carrier is observed ×: Many peeling of the coating layer on the carrier is observed

e) Fluorine concentration change The carrier after initial and forced deterioration is uniformly deposited on the carbon tape, and the fluorescent X-ray analyzer ZSX-100e type (manufactured by Rigaku, X-ray source: Rh target 30 kV × 80 mA, spectral crystal: RX- 35) was used to compare the fluorine peak intensities of the two and evaluated based on the following criteria.
○: Fluorine peak intensity after forced deterioration is 90% or more before forced deterioration △: Fluorine peak intensity after forced deterioration is 60% or more and less than 90% before forced deterioration ×: Fluorine peak intensity after forced deterioration is forced Less than 60% before degradation-: Almost no fluorine peak is observed from the beginning

<Manufacture of macromonomer>
Synthesis Example 1: Production of Macromonomer A 2-hydroxyethyl methacrylate (hereinafter referred to as “HEMA”) as a monomer in a glass flask equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas inlet tube and a thermometer. 25 parts and 75 parts of methyl methacrylate (hereinafter referred to as “MMA”), 2.5 parts of 3-mercaptopropionic acid (hereinafter referred to as “MPA”) as a chain transfer agent, and butyl acetate (hereinafter referred to as “BAC” as a polymerization solvent). 80 parts), and heated and stirred at 90 ° C. under a nitrogen stream. In a separate container, 1.0 part of 2,2′-azobis (2-methylbutyronitrile) (manufactured by Nippon Finechem Co., Ltd., trade name “ABN-E”) is added and dissolved in 20 parts of BAC to prepare a polymerization initiator solution. The polymerization initiator solution was dropped into the flask over 3 hours while adjusting and maintaining the solution in the flask at 90 ° C. Furthermore, the polymerization was completed by continuing heating and stirring for 3 hours to obtain a polymer having a carboxyl group at one end.
The nitrogen stream was switched to air bubbling, and subsequently 0.02 part of methoxyphenol, 1.0 part of tetrabutylammonium bromide and 3.5 parts of glycidyl methacrylate (hereinafter referred to as “GMA”) were added to the same flask at 110 ° C. After heating for 8 hours, the mixture was cooled to room temperature, and BAC was added to adjust the solid content to 50% to obtain a BAC solution of macromonomer A having a methacryloyl group at one end.
When the molecular weight of the obtained macromonomer A was measured, it was number average molecular weight (Mn) = 3,900 and weight average molecular weight (Mw) = 7,100. Further, this macromonomer A had a hydroxyl group equivalent to 1.81 meq / g as a crosslinkable functional group, and the calculated Tg was 88 ° C.

Synthesis Examples 2 to 6: Production of Macromonomer B to F The same procedure as in Synthesis Example 1 was performed except that the monomer, chain transfer agent, and GMA were used as shown in Table 1, and the BAC solution of macromonomer B to F was used. Got.
It shows in Table 1 about the physical-property value of obtained macromonomer BF.

Synthesis Example 7 Production of Macromonomer G The same operation as in Synthesis Example 1 except that after adding GMA in Synthesis Example 1 and heating at 110 ° C. for 8 hours, 19 parts of succinic anhydride was further added and heated for 3 hours. A BAC solution of macromonomer G having a methacryloyl group at one end and a carboxyl group as a crosslinkable functional group was obtained.
The physical property values of the obtained macromonomer G are shown in Table 1.

Synthesis Example 8 Production of Macromonomer H N-butoxymethylmethacrylamide (manufactured by MRC Unitech Co., Ltd.) as a monomer in a glass flask equipped with a stirrer, dropping funnel, reflux condenser, nitrogen gas inlet tube and thermometer Name “NBMM” 25 parts and MMA 75 parts, chain transfer agent 2.5 parts MPA, polymerization solvent 80 parts BAC 80 parts and heated and stirred at 80 ° C. under nitrogen flow. -1.0 part of azobis (2,4′-dimethylvaleronitrile) (trade name “V-65”, manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved to prepare a polymerization initiator solution. The polymerization initiator solution was dropped into the flask over 3 hours while maintaining the temperature at 3 ° C. The polymerization was completed by continuing heating and stirring for 3 hours, and a carboxyl group was present at one end. To obtain a polymer.
Switch the nitrogen stream to air bubbling, then add 0.02 part of methoxyphenol, 1.0 part of tetrabutylammonium bromide, 3.5 parts of GMA in the same flask and heat at 90 ° C. for 20 hours, then cool to room temperature, A BAC solution of macromonomer H having a methacryloyl group at one end and an N-butyrol group as a crosslinkable functional group was obtained by adding BAC to adjust the solid content to 50%.
The physical property values of the resulting macromonomer H are shown in Table 1.

Synthesis Example 9 Production of Macromonomer I In a glass flask equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas introduction tube and a thermometer, 25 parts of GMA and 75 parts of MMA as monomers, and 2-mercapto as a chain transfer agent 2.0 parts of ethanol (hereinafter referred to as “MTG”) and 80 parts of BAC as a polymerization solvent were charged and heated and stirred at 90 ° C. in a nitrogen stream. Add 1.0 part of ABN-E to 20 parts of BAC in a separate container and dissolve it to prepare a polymerization initiator solution. The polymerization initiator solution is dropped into the flask over 3 hours while keeping the solution in the flask at 90 ° C. did. Furthermore, the polymerization was completed by continuing heating and stirring for 3 hours to obtain a polymer having a hydroxyl group at one end.
The nitrogen stream was switched to air bubbling, and subsequently 0.02 part of methoxyphenol, 0.01 part of dioctyltin dilaurate (manufactured by Nitto Kasei Co., Ltd., trade name “Neostan U-810”), 2-isocyanatoethyl methacrylate By adding 4.0 parts (made by Showa Denko Co., Ltd., trade name “Karenz MOI”), heating at 110 ° C. for 3 hours, cooling to room temperature, adding BAC to adjust the solid content to 50%, A BAC solution of macromonomer I having a methacryloyl group at the end and an epoxy group as a functional group was obtained.
The physical property values of the obtained macromonomer I are shown in Table 1.

Synthesis Example 10: Production of Macromonomer J The same procedure as in Synthesis Example 1 was performed except that the monomer, chain transfer agent and GMA were used as shown in Table 1, and a methacryloyl group at one end had a crosslinkable functional group. A BAC solution of macromonomer J having no slag was obtained.
The physical property values of the obtained macromonomer J are shown in Table 1.

Details of the compounds used in Table 1 are shown below.
HEMA: 2-hydroxyethyl methacrylate NBMM: Nn-butoxymethyl methacrylamide GMA: glycidyl methacrylate MMA: methyl methacrylate EHMA: 2-ethylhexyl methacrylate MPA: 3-mercaptopropionic acid MTG: 2-mercaptoethanol Karenz MOI: 2-isocyanate Natoethyl methacrylate (made by Showa Denko)

<Production of graft copolymer>
Production Example 1: Production of Graft Copolymer A1 To a glass flask equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas inlet tube and a thermometer, 120 parts of the BAC solution of macromonomer A obtained above ( 60 parts as a solid content), 30 parts perfluorohexyl acrylate (product name “Cheminox FAAC-6”, manufactured by Unimatec Co., Ltd.), ε-caprolactone 2 mol adduct of 2-hydroxyethyl acrylate (product name “Placcel FA2D” manufactured by Daicel) “) And 10 parts of methyl isobutyl ketone (hereinafter referred to as“ MIBK ”) were charged, and the mixture was heated and stirred at 90 ° C. under a nitrogen stream. In a separate container, 2.2 parts of ABN-E is added to 20 parts of BAC and dissolved to prepare a polymerization initiator solution, and this polymerization initiator solution is dropped into the flask over 3 hours while maintaining the solution in the flask at 90 ° C. did. Further, the polymerization was completed by continuing the heating and stirring for 3 hours to obtain a graft copolymer A1.
When the molecular weight of the obtained graft copolymer A1 was measured, the number-average molecular weight (Mn) = 13,000 and the weight-average molecular weight (Mw) = 27,000. The graft copolymer 1 also has a hydroxyl group equivalent to 0.73 meq / g as a crosslinkable functional group in the main chain.

Production Examples 2 to 8 and 10 to 28: Production of Graft Copolymers A2 to A8 and A10 to A28 Tables 2-1 to 2-4 show monomers constituting the main chain and macromonomers serving as side chains. The same operations as in Production Example 1 were carried out except that they were used in the same manner to obtain graft copolymers A2 to A8 and A10 to A28.
The physical properties of the obtained graft copolymers A2 to A8 and A10 to A28 are shown in Tables 2-1 to 2-4.

Production Example 9 Production of Graft Copolymer A9 To a glass flask equipped with a stirrer, dropping funnel, reflux condenser, nitrogen gas inlet tube and thermometer, 120 parts of the BAC solution of Macromonomer I obtained above ( 60 parts as solids), 30 parts of Cheminox FAAC6, 7 parts of GMA, 3 parts of MMA and 70 parts of MIBK were charged and heated and stirred at 90 ° C. under a nitrogen stream. In a separate container, 2.2 parts of ABN-E is added to 20 parts of BAC and dissolved to prepare a polymerization initiator solution, and this polymerization initiator solution is dropped into the flask over 3 hours while maintaining the solution in the flask at 90 ° C. did. The polymerization was completed by continuing heating and stirring for 3 hours.
By switching the nitrogen stream to air bubbling, 0.05 parts of methoxyphenol, 0.5 parts of tetrabutylammonium bromide and 11.5 parts of acrylic acid were added to the same flask and heated at 90 ° C. for 12 hours. A graft copolymer A9 having an acryloyl group in the chain and main chain was obtained.
The physical property values of the obtained graft copolymer A9 are shown in Table 2-1.

Details of the compounds used in Tables 2-1 to 2-4 are shown below.
FAAC-6: Perfluorohexyl ethyl acrylate
(Product name "Cheminox FAAC6" manufactured by Unimatec)
FAMAC-6: Perfluorohexyl ethyl methacrylate
(Product name "Cheminox FAMAC6" manufactured by Unimatec)
FAAC-4: Perfluorobutyl ethyl acrylate
(Product name “Cheminox FAAC4” manufactured by Unimatec)
FA-108: Perfluorooctyl ethyl acrylate
(Kyoeisha Chemical Co., Ltd., trade name “Light Acrylate FA-108”)
3FM: trifluoromethyl methyl methacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name “Biscoat-3FM”)
HEA: 2-hydroxyethyl acrylate HEMA: 2-hydroxyethyl methacrylate M5300: ω-carboxy-polycaprolactone (n≈2) monoacrylate
(Product name "Aronix M-5300", manufactured by Toagosei Co., Ltd.)
AA: Acrylic acid NBMA: Nn-Butoxymethylacrylamide GMA: Glycidyl methacrylate FA1DDM: 1 mol caprolactone adduct of HEA
(Daicel Chemical Co., Ltd., trade name "Placcel FA1DDM")
FA2D: 2 mol of caprolactone adduct of HEA
(Product name "Placcel FA2D" manufactured by Daicel Chemical Industries, Ltd.)
FA3D: 3 mol of caprolactone adduct of HEA
(Daicel Chemical Industries, trade name "Placcel FA3D")
AE-200: Polyethylene glycol monoacrylate
(Manufactured by NOF Corporation, trade name "Blemmer AE-200")
MMA: Methyl methacrylate

Comparative Production Examples 1 to 8: Production of Copolymers B1 to B8 The same operations as in Production Example 1 were carried out except that the monomers and macromonomers were used as shown in Table 3, and (linear) copolymers B1 to B4 were used. In addition, (graft) copolymers B5 to B8 were obtained.
It shows in Table 3 about the physical-property value of obtained copolymer B1-B8.

Example 1
100 parts by weight of the graft copolymer A1 obtained in Production Example 1 and 27.3 parts of coronate HX (manufactured by Nippon Polyurethane Co., Ltd., an isocyanate-based crosslinking agent) as a crosslinking agent (the amount of crosslinking functional groups of the graft copolymer) And 0.01 part of Neostan U-810 (vs. 100 ppm of graft polymer) as a curing accelerating catalyst were mixed and diluted with methyl ethyl ketone so as to have a solid content of 10% to prepare a coating solution.
This coating solution was applied to bar coater no. 12 was applied onto an allodin-treated aluminum test plate “A5052P” (manufactured by TP Giken Co., Ltd.), and then dried and crosslinked at 120 ° C. for 30 minutes with a draft dryer to obtain a test coating sample A1.
Table 5-1 and Table 5-2 show the results of various characteristics evaluations of the coating agent with respect to the coating film sample A1.

Further, the coating liquid is coated on a surface of 5 kg of Cu-Zn ferrite powder having an average particle size of 35 μm by a fluidized bed type coating apparatus, and further heated and dried at 150 ° C. for 1 hour to have a coating layer having a thickness of 2 μm. Carrier A1 was obtained.
With respect to this carrier A1, the toner charge amount and the like were measured. The results are shown in Table 6.
Further, 98 parts of this carrier A1 and 2 parts of a commercially available toner (manufactured by Kyocera Mita, KM-C2630 magenta toner, polyester type) are stirred and mixed in a tumbler mixer for 1 hour to produce a developer. The charge amount was measured and found to be 30.2 μc / g. Further, as a forced deterioration test, 100 g of carrier A1 (without toner) was put in a 200 mL glass container and shaken with a paint conditioner (manufactured by RED DEVIL) for 12 hours. 98 parts of carrier A1 after forced deterioration and 2 parts of commercially available toner (manufactured by Kyocera Mita Co., Ltd., KM-C2630 magenta toner, polyester type) are combined for 1 hour with a tumbler mixer to produce a developer. The charge amount was measured and found to be 29.8 μc / g. In addition, the results are shown in Table 6 together with the results of resistance to toner contamination, peeling of the coating layer, and changes in fluorine concentration.

Examples 2-7, 10-28
A coating film sample and a carrier were obtained by the same operation as in Example 1 except that the copolymer, the crosslinking agent, and the curing accelerator were used as shown in Table 4.
The evaluation results of each coating film sample are shown in Tables 5-1 and 5-2, and the evaluation results of each carrier are shown in Table 6.

Example 8
Coating film sample A8 and carrier A8 were obtained by the same operation as in Example 1 except that the copolymer and the curing accelerator were used as shown in Table 4.
The evaluation results of the coating film sample A8 are shown in Tables 5-1 and 5-2, and the evaluation result of the carrier A8 is shown in Table 6.

Example 9
100 parts of the graft copolymer 9 obtained in Production Example A9 and IRGACURE907 (manufactured by BASF, photopolymerization initiator) are mixed in a solid content, and diluted with methyl ethyl ketone so as to have a solid content of 10% to prepare a coating solution. did. After coating the aluminum test plate and the core material by the same operation as in Example 1, the coating film sample A9 and the carrier A9 were obtained by irradiating with an ultraviolet ray of 500 mJ / cm 2 with an 80 W / cm high-pressure mercury lamp.
The evaluation results of the coating film sample A9 are shown in Tables 5-1 and 5-2, and the evaluation result of the carrier A9 is shown in Table 6.

Example 29
The graft copolymer A1 obtained in Production Example 1 was mixed with 33 parts in solid content and the linear copolymer B1 obtained in Comparative Production Example 1 was mixed with 67 parts in solid content, and this was mixed with Coronate HX ( 27.3 parts (equivalent to the amount of the crosslinkable functional group of the copolymer mixture) and 0.01 part of Neostan U-810 (100 ppm of the copolymer mixture) as a curing accelerating catalyst. The mixture was mixed and diluted with methyl ethyl ketone so as to have a solid content of 10% to prepare a coating solution. A coating film sample A29 and a carrier A29 were obtained by coating the aluminum test plate and the core material with this coating solution in the same manner as in Example 1, followed by heating.
The evaluation results of the coating film sample A29 are shown in Tables 5-1 and 5-2, and the evaluation result of the carrier A29 is shown in Table 6.

Comparative Examples 1, 3-5, 7, 8
A coating film sample and a carrier were obtained by the same operation as in Example 1 except that the copolymer, the crosslinking agent, and the curing accelerator were used as shown in Table 4.
The evaluation results of each coating film sample are shown in Tables 5-1 and 5-2, and the evaluation results of each carrier are shown in Table 6.
Comparative Examples 2 and 6
A coating film sample and a carrier were obtained by the same operation as in Example 1 except that the copolymer was used as shown in Table 4 and the crosslinking agent and the curing accelerator were not used.
The evaluation results of each coating film sample are shown in Tables 5-1 and 5-2, and the evaluation results of each carrier are shown in Table 6.

Details of the compounds used in Table 4 are shown below.
jER828: Epoxy resin, manufactured by Mitsubishi Chemical Corporation DBU: Diazabicycloundecene Catalyst 296-9: Phosphate catalyst, manufactured by Mitsui Cytec

In Examples 1 to 29 using the coating agent containing the graft copolymer according to the present invention, both fluorine properties such as water repellency / oil repellency and stain resistance, and substrate cohesion and coating film strength are compatible. This has a good balance.
Among them, in terms of crosslinkable functional groups, Examples 1 to 6 having a hydroxyl group are more resistant to contamination such as magic stain resistance and powder stain resistance than Examples 7 to 9 having other functional groups. Shows good results. Furthermore, the contact angle is generally high, indicating that it is excellent in terms of water and oil repellency.

Further, as compared with Example 16 having no functional group in the main chain, the other examples in which a crosslinkable functional group was introduced into the main chain had a high contact angle ratio before and after the friction test of n-hexadecane, which was favorable. It was shown to have friction durability.
Further, in Examples 1, 21 and 22 in which the functional group is arranged at a position relatively far from the main chain, compared to Examples 19 and 20 having a functional group at a position close to the main chain, the n-hexadecane contact angle The result shows that the characteristics of fluorine are more effectively shown in terms of resistance to magic and contamination with magic.

  In Examples 1-27 and 29 in which the carrier according to the present invention was evaluated, all exhibited good chargeability and toner contamination resistance. And even after forced deterioration, the performance was not significantly reduced, and a good level was maintained. From the observation of the coating layer by an electron microscope and fluorescent X-ray analysis, it was supported that there was little change due to forced deterioration and excellent durability.

  Comparing the results of Examples 1 to 3 with different amounts of crosslinkable functional groups introduced into the side chain, Examples 1 and 2 having a large amount of functional groups have better durability from the results of electron microscope observation and fluorescent X-ray analysis. It was suggested to have sex.

From a comparison between Example 16 and Example 1 and the like, it can be seen that the durability is further improved by introducing a small amount of a crosslinkable functional group into the main chain. Furthermore, the crosslinkable functional group introduced into the main chain has 10 or more carbon atoms having a crosslinkable functional group at the ω position as compared with Examples 19 and 20 in which the functional group is introduced at a position close to the main chain. It was shown that Examples 21 to 23, which are derived from these monomers, have good resistance to toner contamination despite having the same functional group amount, and exhibit excellent fluorine characteristics.
As for the amount of the crosslinkable functional group introduced into the main chain, the amount of functional group introduced per main chain is 1 to 10 in Example 1 and Example 17, compared to Example 18 where the amount of functional groups is large. In this range, satisfactory results were shown in the toner contamination resistance, and it was confirmed that the characteristics of fluorine can be effectively exhibited.

On the other hand, in Comparative Examples 1 to 4, which are carrier coating agents made of a linear polymer, charging performance and / or toner contamination resistance are not sufficient.
Further, even in a graft polymer having a fluorinated polymer as a main chain, in Comparative Example 6 in which no crosslinkable functional group was introduced, the durability was greatly inferior, and in Comparative Example 7 in which a functional group was introduced only into the main chain According to electron microscope observation and fluorescent X-ray analysis, results with insufficient durability were obtained.
Although Comparative Example 8 is a graft polymer having a crosslinkable functional group in the side chain, fluorine is not introduced into the main chain, and it was confirmed that the charging performance and the toner contamination resistance were poor. .

  The graft copolymer of the present invention is useful as a coating agent having a good balance in terms of coexistence of properties due to fluorine such as water / oil repellency and stain resistance, and substrate adhesion and coating strength. . In particular, it is suitable as a coating agent for peripheral members of a copying machine such as an ink discharge portion of an ink jet printer and a photoreceptor, a rubber roll, a carrier and other internal parts.

Claims (10)

A fluorine-based graft copolymer characterized in that the main chain is made of a fluorine-based polymer and the side chain has a crosslinkable functional group. 2. The fluorine-based graft copolymer according to claim 1, wherein the amount of the crosslinkable functional group introduced into the side chain is in the range of 0.7 to 3.0 meq / g. The fluorine-based graft copolymer according to claim 1 or 2, wherein the monomer constituting the fluorine-based polymer includes a vinyl monomer represented by the following general formula (1).

[Wherein, R ¹ represents a hydrogen atom or a methyl group, Z represents a hydrogen atom or a fluorine atom, m represents an integer of 1 to 4, and n represents an integer of 1 to 20. ] The fluorine-based graft copolymer is a monomer mixture containing a fluorine atom-containing monomer, a macromonomer having a polymerizable unsaturated functional group at a terminal and a crosslinkable functional group, and other monomers. The fluorine-based graft copolymer according to any one of claims 1 to 3, which is obtained by copolymerization. 5. The fluorine-based graft copolymer according to claim 1, wherein the polymer forming the main chain has 1 to 10 equivalents of crosslinkable functional groups per polymer. 6. The fluorine-based graft copolymer according to claim 5, wherein the crosslinkable functional group arranged in the main chain is derived from a monomer having 10 or more carbon atoms having a crosslinkable functional group at the ω position. 7. The fluorine-based graft copolymer according to claim 1, wherein the crosslinkable functional group arranged on the side chain and the main chain is a hydroxyl group. The coating agent containing the fluorine-type graft copolymer in any one of Claims 1-7. The coating agent according to claim 8, further comprising a crosslinking agent in addition to the fluorine-based graft copolymer. A dry electrophotographic carrier using the coating agent according to claim 8.