阅读说明：本技术 调色剂 (Toner and image forming apparatus ) 是由 河村政志 丰田隆之 大久保显治 下田卓 于 2020-04-24 设计创作，主要内容包括：本发明涉及调色剂。一种调色剂,其包括调色剂颗粒,所述调色剂颗粒包括调色剂核颗粒和覆盖所述调色剂核颗粒表面的有机硅聚合物,所述有机硅聚合物具有由R<Sup>4</Sup>-SiO<Sub>3/2</Sub>(R<Sup>4</Sup>各自独立地表示具有1至6个碳原子的烷基或苯基)表示的结构,所述调色剂核颗粒包含在其分子内具有取代或未取代的甲硅烷基的树脂A,所述取代的甲硅烷基的取代基为选自由具有1个以上碳原子的烷基、具有1个以上碳原子的烷氧基、羟基、卤素原子和具有6个以上碳原子的芳基组成的组中的至少一种,所述树脂A中的硅原子的含量为0.02至10.00质量％,并且所述有机硅聚合物中的硅原子的含量为30至50质量％。(The present invention relates to a toner. A toner comprising toner particles including a toner core particle and a silicone polymer covering a surface of the toner core particle, the silicone polymer having a structure represented by R 4 ‑SiO 3/2 (R 4 Each independently represents an alkyl group having 1 to 6 carbon atoms or a phenyl group), the toner core particle containing a resin a having a substituted or unsubstituted silyl group in its molecule, the substituent of the substituted silyl group being selected from the group consisting of an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, a hydroxyl group, a halogen atom, andat least one member selected from the group consisting of aryl groups having 6 or more carbon atoms, the content of silicon atoms in the resin A is 0.02 to 10.00 mass%, and the content of silicon atoms in the silicone polymer is 30 to 50 mass%.)

1. A toner comprising toner particles, characterized in that

The toner particles comprise

A toner core particle; and

a silicone polymer covering a surface of the toner core particle,

the silicone polymer has a structure represented by the following formula (A),

the toner core particle contains a resin a,

R⁴-SiO_3/2…(A)

wherein R is⁴Each independently represents an alkyl group having 1 to 6 carbon atoms or a phenyl group,

the resin A has a substituted or unsubstituted silyl group in its molecule,

the substituent of the substituted silyl group is at least one selected from the group consisting of an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, a hydroxyl group, a halogen atom, and an aryl group having 6 or more carbon atoms,

the content of silicon atoms in the resin A is 0.02 to 10.00 mass%, and

the content of silicon atoms in the silicone polymer is 30 to 50 mass%.

2. The toner according to claim 1, wherein the resin a has a structure represented by the following formula (1):

wherein, P¹Represents a polymer moiety, L¹Represents a single bond or a divalent linking group, and R¹To R³Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, an aryl group having 6 or more carbon atoms, or a hydroxyl group, m represents a positive integer, and when m is 2 or more, a plurality of L' s ¹Each being the same or different, a plurality of R¹Each being the same or different, a plurality of R²Each being the same or different, and a plurality of R³Each of which may be the same or different.

3. The toner according to claim 2, wherein R in the formula (1)¹To R³At least one of them represents an alkoxy group having 1 or more carbon atoms or a hydroxyl group.

4. The toner according to claim 2 or 3, wherein R in the formula (1)¹To R³Each independently represents an alkoxy group having 1 or more carbon atoms or a hydroxyl group.

5. The toner according to claim 2 or 3, wherein P in the formula (1)¹Represents a polyester moiety or a styrene acrylic moietyA bit.

6. The toner according to claim 2 or 3, wherein P in the formula (1)¹Represents a polyester site.

7. The toner according to claim 1 or 2, wherein the resin a has a weight average molecular weight of 3,000 to 100,000.

8. The toner according to claim 1 or 2, wherein of tetrahydrofuran insoluble matter in the toner particles²⁹The ratio of the peak area of the structure represented by the formula (A) to the total peak area of the silicone polymer in Si-NMR measurement is 30% to 100%.

9. The toner according to claim 8, wherein of tetrahydrofuran insoluble matter in the toner particles ²⁹The ratio of the peak area of the structure represented by the formula (A) to the total peak area of the silicone polymer in Si-NMR measurement is 50% to 90%.

10. The toner according to claim 1 or 2, wherein R in the formula (a)⁴Represents an alkyl group having 1 to 3 carbon atoms.

Technical Field

The present disclosure relates to a toner for developing an electrostatic image (electrostatic latent image) used in an image forming method such as electrophotography and electrostatic printing.

Background

The electrophotographic method is a printing method including the following processes, and a general example is given below.

First, a photosensitive member using a photoconductive substance is uniformly charged, and an electrostatic latent image is formed by exposure. Next, the toner charged by friction with a charging member such as a blade carrier is developed on the photosensitive member. Finally, after the toner image is transferred to a medium such as paper, the toner image is fixed on the medium by heating, pressing, or the like. The toner remaining on the photosensitive member after transfer is removed by a cleaning member as needed. By going through this series of steps again, printing can be continuously performed.

In the above process, almost all the steps involve the toner. Therefore, it is required to improve various characteristics of the toner such as fluidity, charging performance, and thermal properties (heat-resistant storage stability and fixing property). First, control of toner charging characteristics is important to obtain a printed product with good image quality. Specifically, the toner charging characteristics are the rapidity of charging by friction (charge rising performance), the magnitude of the amount of charge generated by friction, and the stability with respect to temperature and humidity. Among such charging characteristics, improvement in the charge amount of the toner is important for establishing an electrophotographic process.

In order to increase the charge amount of the toner, an external additive (for example, inorganic particles such as silica, titanium oxide, and alumina) is often attached or fixed to the surface of the toner particles.

However, the external additive easily contaminates various parts inside the developing tank and is difficult to use. Further, in recent years, the mechanical speed and the lifetime of the machine are improved, and it becomes even more difficult to achieve both an increase in the amount of electrification and prevention of contamination of parts. Under such circumstances, it is desired to establish a technique capable of improving the charge amount of toner and at the same time preventing contamination of the members.

A technique without using an external additive has been developed as an example of a method for solving these problems. Specifically, a method of coating an alkoxysilane polymer on the surface of toner particles by using a sol-gel method is known.

Japanese patent application publication No.2013-120251 discloses a toner in which the surface of toner particles is coated with a tetraalkoxysilane polymer, thereby solving the problem of detachment or burial of the conventional external additive.

Japanese patent application laid-open No. h09-269611 discloses a toner in which the surface of a toner core particle composed of a polyvinyl-based thermoplastic resin having a dialkoxysilyl group is coated with a dialkoxysilane polymer, thereby preventing hot offset during toner fixing.

Japanese patent application publication No.2018-194837 discloses a toner in which the surface of toner particles is coated with a trialkoxysilane polymer as a main component, thereby improving the abrasion resistance caused by a developing unit.

Disclosure of Invention

It was found that the method described in japanese patent application laid-open No.2013-120251 had an insufficient charge amount. This is considered to be caused by charge leakage occurring on the toner surface. This will be described in detail below.

The coating layer on the surface of the toner particles in the method described in japanese patent application laid-open No.2013-120251 mainly contains silica. However, depending on the conditions, the polymerization of tetraalkoxysilanes may not be sufficient for complete conversion to silica, and a large number of silanol groups may be present. It is considered that the charge leakage is caused by the high hygroscopicity of the silanol group which lowers the resistance value of the toner.

Further, it was found that the method described in japanese patent application laid-open No.2013-120251 is also insufficient in preventing contamination of parts. The reason for this is considered to be that, as described above, since the proportion of complete conversion to silica is small and the crosslinked network of siloxane bonds is small, the coating layer becomes brittle.

It has further been found that the method described in Japanese patent application laid-open No. H09-269611 also has an insufficient toner charge amount. It is also considered that this is caused by charge leakage occurring on the toner surface. This will be described in detail below.

The coating layer on the surface of the toner particles in the method described in japanese patent application laid-open No. h09-269611 mainly contains a polydimethylsiloxane compound. Since the polydimethylsiloxane compound has high flexibility, it is estimated that the generated electric charge is difficult to hold in place. As a result, it is considered that charge leakage occurs.

In addition, it was found that the method described in Japanese patent application laid-open No. H09-269611 is insufficient in preventing contamination of parts. The reason for this is considered to be that many free components exist and that the free components easily adhere to the component.

Details are explained below. Japanese patent application laid-open No. h09-269611 discloses that polydimethylsiloxane is covalently bonded through a bifunctional silane-containing resin contained in toner particles, but the proportion of polydimethylsiloxane covalently bonded to the surfaces of the toner particles is small. Therefore, it is considered that the number of free components increases, and the free components easily adhere to the member.

The methods described in Japanese patent application laid-open Nos. 2018-194837 were found to have higher toner charge amounts than the methods described in Japanese patent application laid-open Nos. 2013-120251 and H09-269611. The reason for this is considered to be that the charge leakage occurring on the toner surface as described above is prevented. This will be described in detail below.

The trialkoxysilane polymer as the main component of the coating layer of the toner particles described in japanese patent application laid-open No.2018-194837 has higher hydrophobicity than tetraalkoxysilane polymer and is harder than polydimethylsiloxane polymer. This is obviously the reason for preventing the charge leakage as described above.

However, it was found that in the high-speed processing, the charge amount is not sufficient even if the charge leakage occurring on the toner surface can be prevented.

Further, it was found that the method described in Japanese patent application laid-open No.2018-194837 prevented the contamination of parts as compared with the methods described in Japanese patent application laid-open Nos. 2013-120251 and H09-269611. The reason for this is considered to be that the abrasion resistance is improved by using a silicone polymer having a predetermined mohs hardness.

However, it was found that the charge amount was insufficient for the foregoing reasons. Therefore, in order to secure a sufficient charge amount, the use of an external additive such as hydrotalcite particles has been studied, but it is difficult to prevent the contamination of parts by the external additive.

As described above, there is a trade-off relationship between improving the toner charging performance and preventing contamination of the members, and it is difficult to solve the problem with the prior art.

The present disclosure provides a toner that solves the problems of the related art. That is, the present disclosure provides a toner that can achieve both an improvement in the charge amount of the toner and prevention of contamination of the member.

The present disclosure is a toner comprising toner particles, wherein

The toner particles comprise

A toner core particle; and

A silicone polymer covering the surface of the toner core particle,

the silicone polymer has a structure represented by the following formula (a),

R⁴-SiO_3/2…(A)

wherein R is⁴Each independently represents an alkyl group having 1 to 6 carbon atoms or a phenyl group,

the toner core particle contains the resin a,

the resin a has a substituted or unsubstituted silyl group in its molecule,

the substituent of the substituted silyl group is at least one selected from the group consisting of an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, a hydroxyl group, a halogen atom, and an aryl group having 6 or more carbon atoms,

the content of silicon atoms in the resin A is 0.02 to 10.00 mass%, and

the content of silicon atoms in the silicone polymer is 30 to 50 mass%.

According to the present disclosure, it is possible to provide a toner that can achieve both an improvement in the charge amount of the toner and prevention of contamination of components.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

Fig. 1 is a schematic view of a faraday cage.

Detailed Description

Unless otherwise specified, the description of "XX above and YY below" and "XX to YY" denoting a numerical range is intended to include the lower and upper limits as endpoints.

The inventors of the present disclosure have intensively studied to solve the above-described problems of the related art, and as a result, found that both improvement of the charge amount of the toner and prevention of contamination of the member can be achieved by adopting the following configuration.

Specifically, the toner is a toner comprising toner particles, wherein

The toner particles comprise

A toner core particle; and

a silicone polymer covering the surface of the toner core particle,

the silicone polymer has a structure represented by the following formula (a),

the toner core particle contains the resin a,

R⁴-SiO_3/2…(A)

wherein R is⁴Each independently represents an alkyl group having 1 to 6 carbon atoms or a phenyl group,

the resin a has a substituted or unsubstituted silyl group in its molecule,

the substituent of the substituted silyl group is at least one selected from the group consisting of an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, a hydroxyl group, a halogen atom, and an aryl group having 6 or more carbon atoms,

the content of silicon atoms in the resin A is 0.02 to 10.00 mass%, and

the content of silicon atoms in the silicone polymer is 30 to 50 mass%.

The present inventors speculate that the following mechanism greatly increases the charge amount and can prevent the contamination of the members, as compared with the conventional toner.

First, a mechanism of increasing the charge amount will be described.

Toner charging is a phenomenon in which electric charge is imparted to a toner surface by friction between the toner surface and a charging member such as a charging roller, a charging blade, and a carrier. At this time, in the case where the electrical resistance of the toner surface is high, the charge is maintained on the toner surface, so that the toner can be charged. However, electric charge can be imparted only to the rubbed portion, and thus the charge amount is low.

Meanwhile, when the resistance of the toner surface is low, a phenomenon (charge leakage) occurs in which charges are transferred and escape at the toner surface. As a result, the charge amount decreases.

Specifically, the conventional toners described in japanese patent application laid-open nos. 2013-120251 and H09-269611 have a low charge amount due to large charge leakage on the toner surface.

In contrast, the conventional toner described in japanese patent application laid-open No.2018-194837 has small charge leakage on the toner surface, and, although insufficient, the charge amount is increased. However, since the generated electric charges remain on the toner surface and the electric charges on the toner surface are instantly saturated, the charge amount is insufficient in the high-speed processing.

Therefore, in the case of conventional toners, a high charge amount cannot be achieved due to the relationship between frictional charging on the toner surface and charge leakage.

Meanwhile, in the toner of the present disclosure, it is considered that a high charge amount can be achieved because the electric charge on the toner surface is diffused to the inside of the toner core particles, and the entire toner particles can be charged.

The diffusion of the electric charge into the interior of the toner core particle is caused by the resin a inside the toner core particle.

Specifically, the silyl group in the resin a is easily negatively charged. Meanwhile, the sites other than the silyl group in the resin a tend to be positively charged. Therefore, charge transfer occurs between the structure represented by formula (a) contained in the silicone polymer covering the surface of the toner core particle and the silyl group of the resin a inside the toner core particle. As a result, electric charge is transported from the toner surface to the inside of the toner core.

The transfer of the charge reduces the charge on the toner surface, so that the toner surface can be further charged by friction, and as a result, the toner can be highly charged.

Next, a mechanism of preventing contamination of the components will be described.

Although the coating film of the silicone polymer in the toner described in japanese patent application laid-open No.2018-194837 is hard and has high abrasion resistance, it was found that the adhesion of the coating film to the toner core particles is insufficient and parts are contaminated when a large amount of printed matter is printed.

In contrast, in the present disclosure, by having the resin a present in the toner core particle, the contamination of the parts can be prevented. The present inventors believe that this is because the polarity of the resin a in the toner core particle and the polarity of the silicone polymer are close to each other, thereby improving the adherence between the toner core particle and the silicone polymer.

As described hereinabove, by coating the toner core particles containing the resin a with the silicone polymer having the structure represented by formula (a), it is possible for the first time to achieve both an increase in the charge amount and prevention of contamination of the member, which are conventional problems.

Hereinafter, the constitutional requirements of the present disclosure will be described in detail.

< resin A >

The toner core particle contains a resin a. The resin a (i) has a substituted or unsubstituted silyl group in its molecule, and the substituent of the (ii) substituted silyl group is at least one selected from the group consisting of an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, a hydroxyl group, a halogen atom, and an aryl group having 6 or more carbon atoms.

The number of carbon atoms in the alkyl group is preferably 1 to 20, and more preferably 1 to 4.

The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 4, further preferably 1 to 3, and particularly preferably 1 or 2.

The number of carbon atoms in the aryl group is preferably 6 to 14, and more preferably 6 to 10.

The resin a is not limited as long as the above conditions (i) and (ii) are satisfied. Examples of the resin a include resins having a chemically bonded silane coupling agent or the like, polymers of organosilicon compounds, and hybrid resins thereof. More specific examples include resins obtained by modifying polyester resins, vinyl resins, polycarbonate resins, polyurethane resins, phenol resins, epoxy resins, polyolefin resins, or styrene acrylic resins with a silane coupling agent and/or silicone oil or the like.

The content of silicon atoms in the resin a is 0.02 to 10.00 mass%. Within this range, the adherence between the toner core particles and the silicone polymer can be improved while allowing electric charge to be transported inside the toner core, so that both an increase in the charge amount and prevention of contamination of the member can be achieved.

The content of silicon atoms in the resin a is preferably 0.10 to 5.00 mass%, and more preferably 0.15 to 2.00 mass%.

The content of the silicon atom in the resin a can be controlled by adjusting the amount of the silicon compound used in the production of the resin a.

Further, the content of the resin a in the toner core particle is preferably 0.1 to 100.0 mass%, and more preferably 0.3 to 30.0 mass%.

The resin a preferably has a structure represented by the following formula (1).

Wherein, P¹Represents a polymer moiety, L¹Represents a single bond or a divalent linking group, and R¹To R³Each independently represents a hydrogen atom, a halogen atom, orAn alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, an aryl group having 6 or more carbon atoms, or a hydroxyl group, m represents a positive integer, and when m is 2 or more, a plurality of L' s¹A plurality of R, which may be the same or different from each other¹A plurality of R, which may be the same or different from each other²May each be the same or different, and a plurality of R³Each may be the same or different.

R in the formula (1)¹To R³At least one of them preferably represents an alkoxy group having 1 or more carbon atoms or a hydroxyl group. More preferably, R in formula (1)¹To R³Each independently represents an alkoxy group having 1 or more carbon atoms or a hydroxyl group.

In the above substituents, the alkyl group preferably has 1 to 20 carbon atoms, and more preferably 1 to 4 carbon atoms. The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 4, further preferably 1 to 3, and particularly preferably 1 or 2. Further, the number of carbon atoms in the aryl group is preferably 6 to 14, and more preferably 6 to 10.

When R in the formula (1)¹To R³When at least one of them represents an alkoxy group having 1 or more carbon atoms or a hydroxyl group, the structure represented by formula (1) has a Si — O-bond.

The toner core particles having Si-O-bonds have increased affinity for Si-O-bonds in the silicone polymer on the surface of the toner particles. As a result, the efficiency of charge transport to the inside of the toner core is increased, the charge amount is further increased, and the adhesion between the toner core particles and the silicone polymer is further improved.

Further, by improving the adherence between the toner core particles and the silicone polymer, the resistance to thermal deformation is increased, and the heat-resistant storage stability of the toner is also improved.

For the purpose of converting R in the formula (1)¹To R³May be converted to a hydroxyl group, wherein R may be¹To R³The resin a in which one or more of them are alkoxy groups is hydrolyzed, thereby converting the alkoxy groups into hydroxyl groups.

Any hydrolysis method may be used and examples thereof are described below.

Wherein R in formula (1)¹To R³The resin a in which at least one of them is an alkoxy group is dissolved or suspended in an appropriate solvent (which may be a polymerizable monomer), and the pH is adjusted to an acidic value with an acid or a base, followed by hydrolysis.

In addition, hydrolysis may be caused during production of the toner particles.

For P in formula (1)¹There are no particular restrictions, and examples thereof include polyester sites, vinyl sites, styrene acrylic sites, polyurethane sites, polycarbonate sites, phenolic resin sites, polyolefin sites, and the like.

Among them, P is preferable from the viewpoint of charge rising property¹Including polyester moieties or styrene acrylic moieties. For example, a hybrid site of polyester and styrene acrylic may be used. More preferably, P¹Denotes a polyester site or a styrene acrylic site, and a polyester site is particularly preferable.

The reason is considered as follows. Due to the silicon atom and P in the resin represented by formula (1)¹The ester bond in (b) is subjected to charge transfer therebetween, and the charge generated by triboelectric charging on the toner surface is diffused into the entire toner. Due to this diffusion, not only the surface of the toner but also the inside of the toner can contribute to charging, thereby improving the charge rising performance.

The weight average molecular weight (Mw) of the resin a is preferably 3,000 to 100,000, and more preferably 3,000 to 30,000, from the viewpoint of charge rising property and storage stability. The Mw of the resin a may be controlled by various methods depending on the kind of the resin included. For example, when the polyester resin is contained, the control can be performed by adjusting the input ratio of the diol and the dicarboxylic acid as the monomers thereof or adjusting the polymerization time. In the case of containing a styrene acrylic resin, it can be controlled by adjusting the ratio of a vinyl monomer as a monomer thereof to a polymerization initiator or adjusting the reaction temperature.

The polyester resin is not particularly limited, but is preferably a condensate of a diol and a dicarboxylic acid. For example, a polyester resin having a structure represented by the following formula (6) and at least one structure (a variety of structures may be selected) selected from the group consisting of structures represented by the following formulae (7) to (9) is preferable. Another example is a polyester resin having a structure represented by the following formula (10).

Wherein R is⁹Represents an alkylene group, an alkenylene group or an arylene group; r¹⁰Represents alkylene or phenylene; r¹⁸Represents an ethylene group or a propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 2 to 10; r¹¹Represents an alkylene group or an alkenylene group.

For R in formula (6)⁹Examples of the alkylene group (preferably having 1 to 12 carbon atoms) include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a hexamethylene group, a neopentylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a 1, 3-cyclopentylene group, a 1, 3-cyclohexylene group and a 1, 4-cyclohexylene group.

For R in formula (6)⁹Examples of the alkenylene group (preferably having 1 to 4 carbon atoms) include vinylene, propenylene and 2-butenylene.

For R in formula (6)⁹Examples of the arylene group (preferably having 6 to 12 carbon atoms) include 1, 4-phenylene, 1, 3-phenylene, 1, 2-phenylene, 2, 6-naphthylene, 2, 7-naphthylene and 4,4' -biphenylene.

R in the formula (6)⁹May be substituted by a substituent. In this case, examples of the substituent include a methyl group, a halogen atom, a carboxyl group, a trifluoromethyl group, and a combination thereof.

For R in formula (7)¹⁰Examples of the alkylene group (preferably having 1 to 12 carbon atoms) include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a hexamethylene group, a neopentylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a 1, 3-cyclopentylene group, a 1, 3-cyclohexylene group and a 1, 4-cyclohexylene group.

For R in formula (7)¹⁰Examples of the phenylene group include a 1, 4-phenylene group, a 1, 3-phenylene group and a 1, 2-phenylene group.

R in the formula (7)¹⁰May be substituted by a substituent. In this case, examples of the substituent include a methyl group, an alkoxy group, a hydroxyl group, a halogen atom, and a combination thereof.

For R in formula (10)¹¹Examples of the alkylene group (preferably having 1 to 12 carbon atoms) include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a hexamethylene group, a neopentylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group and a 1, 4-cyclohexylene group.

For R in formula (10) ¹¹Examples of the alkenylene group (preferably having 1 to 40 carbon atoms) include a vinylene group, a propenylene group, a butenylene group, a butadienylene group, a pentenylene group, a hexenylene group, a hexadienylene group, a heptenylene group, an octenylene group, a decenylene group, an octadecenylene group, an eicosenylene group and a triacontenylene group. These alkenylene groups may have any of linear, branched, and cyclic structures. Further, the double bond may be in any position as long as at least one double bond is present.

R in the formula (10)¹¹May be substituted by a substituent. In this case, examples of the substituent that may be used for the substitution include an alkyl group, an alkoxy group, a hydroxyl group, a halogen atom, and a combination thereof.

The vinyl-based resin is not particularly limited, and known resins can be used. For example, the following monomers can be used.

Styrenic monomers such as styrene and its derivatives, for example, o-methylstyrene, m-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3, 4-dichlorostyrene, p-ethylstyrene, 2, 4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n-dodecylstyrene.

Acrylic esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate.

Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

Alpha-methylene aliphatic monocarboxylic acid esters containing an amino group such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; and vinyl monomers containing a nitrogen atom, for example, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

Unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenylsuccinic acid, fumaric acid, and mesaconic acid; α, β -unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid; vinyl monomers containing carboxyl groups, such as anhydrides of these acids.

When the compound containing a carboxyl group includes a vinyl-based resin, a method of containing a carboxyl group in the vinyl-based resin is not particularly limited, and a known method may be used. For example, vinyl monomers containing a carboxyl group such as acrylic acid and methacrylic acid are preferably used.

The vinyl-based resin is preferably a polymer of at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters, a styrenic monomer, and a vinyl-based monomer containing a carboxyl group.

L in formula (1)¹Examples of the divalent linking group represented include, but are not limited to, structures represented by the following formulae (2) to (5).

R in the formula (2)⁵Represents a single bond, alkylene or arylene. (. sup.) represents P in the formula (1)¹And (×) represents a binding site to a silicon atom in formula (1). R in the formula (3)⁶Represents a single bond, alkylene or arylene. (. sup.) represents P in the formula (1)¹And (×) represents a binding site to a silicon atom in formula (1). R in the formulae (4) and (5)⁷And R⁸Each independently represents an alkylene group, an arylene group or an oxyalkylene group. (. sup.) represents P in the formula (1)¹And (×) represents a binding site to a silicon atom in formula (1).

The structure represented by formula (2) is a divalent linking group containing an amide bond.

The linking group may be formed, for example, by reacting a carboxyl group in the resin with an aminosilane.

The aminosilane is not particularly limited, and examples thereof include γ -aminopropyltriethoxysilane, γ -aminopropyltrimethoxysilane, N- β - (aminoethyl) γ -aminopropylmethyldimethoxysilane, N-phenyl γ -aminopropyltriethoxysilane, N-phenyl γ -aminopropyltrimethoxysilane, N- β - (aminoethyl) γ -aminopropyltriethoxysilane, N-6- (aminohexyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethylsilane, 3-aminopropylsilane and the like.

To R⁵The alkylene group (preferably having 1 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an alkylene group containing an-NH-group.

To R⁵The arylene group (preferably having 6 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an arylene group containing a hetero atom.

The structure represented by formula (3) is a divalent linking group containing a urethane bond.

The linking group may be formed, for example, by reacting a hydroxyl group in the resin with an isocyanate silane.

The isocyanate silane is not particularly limited, and examples thereof include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropyldimethylmethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, and 3-isocyanatopropyldimethylethoxysilane and the like.

To R⁶The alkylene group (preferably having 1 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an alkylene group containing an-NH-group.

To R⁶The arylene group (preferably having 6 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an arylene group containing a hetero atom.

The structure represented by formula (4) or (5) is a divalent linking group containing a bond to an ester bond in the resin.

The linking group is formed by, for example, an epoxysilane insertion reaction.

The term "epoxysilane insertion reaction" refers to a reaction including the step of an insertion reaction of an epoxy group of an epoxysilane into an ester bond contained in the main chain in a resin. Further, the term "insertion reaction" as used herein is described as "insertion reaction of an ester bond of an epoxy compound into a polymer chain" in "Journal of Synthetic Organic Chemistry, Japan" (volume 49, No. 3, page 218, 1991).

The reaction mechanism of the epoxysilane insertion reaction can be represented by the following scheme.

In the above figures, D and E represent constituent parts of a resin, and F represents a constituent part of an epoxy compound.

In the ring opening of the epoxy group in the figure, two compounds are formed due to α -scission and β -scission. In both cases, a compound in which an epoxy group is inserted into an ester bond in the resin, in other words, a compound in which a constituent portion of the epoxy compound other than the epoxy site is grafted to the resin is obtained.

The epoxysilane is not particularly limited and may be, for example, β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ -glycidoxypropyltrimethoxysilane, γ -glycidoxypropylmethyldiethoxysilane, and the like.

To R⁷And R⁸The alkylene group (preferably having 1 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an alkylene group containing an-NH-group.

To R⁷And R⁸The arylene group (preferably having 6 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an arylene group containing a hetero atom.

To R⁷And R⁸The oxyalkylene group (preferably having 1 to 12 carbon atoms) in (b) is not particularly limited, and may be, for example, an oxyalkylene group containing an-NH-group.

< Silicone Polymer having a Structure represented by formula (A) >

The silicone polymer has at least a structure represented by the following formula (a).

R⁴-SiO_3/2…(A)

Wherein R is⁴Each independently represents an alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms) or a phenyl group.

One of four valence electrons of the Si atom in the structure represented by formula (A) participates in R⁴And the remaining three participate in the bond with the O atom. The O atom forms a state in which both valences are bonded to Si, that is, a siloxane bond (Si-O-Si). Regarding Si atoms and O atoms as those in the silicone polymer, since there are three O atoms for two Si atoms, it is expressed as-SiO_3/2。

The silicone polymer having the structure represented by formula (a) has high hardness because the concentration of siloxane bonds contained in the structure is close to that of silicon dioxide (SiO)₂) The concentration of (c). In addition, due to the bonding of R⁴Therefore, the structure has strong hydrophobicity. For these reasons, charge leakage on the toner surface can be prevented, and therefore the toner of the present disclosure has more excellent toner than conventional tonersHigh charge amount.

The composition of the silicone polymer having the structure represented by formula (a) may be controlled so that the hardness and hydrophobicity of the silicone polymer fall within desired ranges. Specifically, the control can be performed by changing: the type and amount of organosilicon compound used in the production of the silicone polymer, as well as the reaction temperature, reaction time, reaction solvent, and pH of hydrolysis, addition polymerization, and condensation polymerization during the formation of the silicone polymer.

The content of silicon atoms in the silicone polymer thus obtained is 30 to 50 mass%, and preferably 33 to 40 mass%. The content of silicon atoms in the silicone polymer can be controlled by: a method of performing polycondensation by changing the kind of the organosilicon compound at the time of production, a method of performing polycondensation of a mixture of different kinds of organosilicon polymers adjusted in a mixing ratio, or a method of performing polycondensation after (or while) adjusting the temperature or pH.

Further, of tetrahydrofuran-insoluble matter in toner particles²⁹In the Si-NMR measurement, the ratio of the peak area of the structure represented by the formula (a) to the total peak area of the silicone polymer is preferably 30% to 100%. Further, in order to greatly increase the charge amount and significantly prevent the contamination of the parts, the proportion of the peak area of the structure represented by formula (a) is more preferably 50% to 100%, and even more preferably 50% to 90%. The proportion of the peak area of the structure represented by formula (a) can be controlled by: a method of performing polycondensation by changing the kind of the organosilicon compound at the time of production, a method of performing polycondensation of a mixture of different kinds of organosilicon polymers adjusted in a mixing ratio, or a method of performing polycondensation after (or while) adjusting the temperature or pH.

In the silicone polymer having a structure represented by formula (a), R in formula (a) is from the viewpoint of setting the hardness and hydrophobicity of the silicone polymer within appropriate ranges⁴Preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R⁴More preferably a hydrocarbon group having 1 to 3 carbon atoms. From the viewpoint of charge retention, R⁴More preferably methyl or ethyl, and particularly preferably methyl.

< method for producing Silicone Polymer having Structure represented by formula (A) >

The silicone polymer is not particularly limited, but is preferably a polycondensate of an organosilicon compound (trifunctional silane) having a structure represented by the following formula (11).

Wherein R is¹⁴Having the formula (A) with R⁴The same meaning is used.

Wherein R is¹⁵To R¹⁷Each independently represents a halogen atom, a hydroxyl group, an acetoxy group, or an alkoxy group (hereinafter, these are collectively referred to as reactive groups). These reactive groups undergo hydrolysis, addition polymerization, and polycondensation to form a crosslinked structure, whereby contamination of the parts can be further prevented.

From the viewpoint of mild hydrolyzability at room temperature and deposition and coating properties on the toner particle surface¹⁵To R¹⁷Preferably each independently an alkoxy group having 1 to 3 carbon atoms, and more preferably a methoxy group or an ethoxy group. R ¹⁵To R¹⁷Can be controlled by varying the reaction temperature, reaction time, reaction solvent and pH.

The trifunctional silanes may be used individually or in combination of a plurality thereof in order to obtain the silicone polymer.

Specific examples of trifunctional silanes are listed below.

Trifunctional methylsilanes, for example methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxysilane, methylmethoxyethoxysilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxysilane, methyldiacetoxyloxyethoxysilane, methylacethoxydiethoxysilane, methyltrimethoxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, and methyldiethoxyhydroxysilane.

Trifunctional silanes, such as ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrisilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrisilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltrisilane, butyltrisacetoxysilane, butyltrisiloxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltrisiloxysilane, and hexyltrisilolane.

Trifunctional phenylsilanes, such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrimethoxysilane.

Further, a silicone polymer obtained by using the following compound in combination with a trifunctional silane may be used to such an extent that the effects of the present disclosure are not impaired.

An organosilicon compound having four reactive groups in one molecule (tetrafunctional silane), an organosilicon compound having two reactive groups in one molecule (difunctional silane), an organosilicon compound having one reactive group in one molecule (monofunctional silane), and wherein R⁴The above trifunctional silane having a substituent. Specific examples of these compounds are listed below.

Dimethyldimethoxysilane, dimethyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane.

Trifunctional vinylsilanes, for example vinyltriisocyanate silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, and vinyldiethoxymethylsilane.

Further, the content of the silicone polymer in the toner particles is preferably 0.1 to 20.0 mass%, and more preferably 1.0 to 10.0 mass%.

When the content of the silicone polymer is 0.1% by mass or more, the occurrence of contamination and fogging of parts can be prevented. In the case where the amount is 20.0 mass% or less, it is possible to make the occurrence of overcharging unlikely. The content of silicone polymer can be controlled by varying: the type and amount of organosilicon compound used in the production of the silicone polymer, the method used to produce the toner particles in forming the silicone polymer, as well as the reaction temperature, reaction time, reaction solvent, and pH.

The method for producing the silicone polymer is exemplified by the following method, but is not limited thereto.

First, core particles of a toner containing a binder resin and a colorant as needed are produced and dispersed in an aqueous medium to obtain a core particle dispersion liquid. Next, an organosilicon compound is added to the core particle dispersion liquid and condensation polymerization is performed to form an organosilicon polymer covering the surface of the toner core particles.

As a method of adding the organosilicon compound, the organosilicon compound may be added as it is. Alternatively, it may be added after being mixed with the aqueous medium in advance and hydrolyzed.

The organosilicon compound undergoes a polycondensation reaction after hydrolysis. The pH most suitable for the hydrolysis reaction may be different from the pH most suitable for the polycondensation reaction. Therefore, the reaction can be efficiently performed by mixing the organosilicon compound and the aqueous medium in advance, hydrolyzing the mixture at a pH suitable for the hydrolysis reaction, and then performing polycondensation of the organosilicon compound at a pH optimum for the polycondensation reaction.

< Binder resin >

The resin contained in the toner core particle may be only the resin a, or may contain a binder resin as needed.

When the toner core particle contains a binder resin, the content of the resin a is preferably 0.1 to 20.0 parts by mass, and more preferably 0.3 to 5.0 parts by mass, relative to 100 parts by mass of the binder resin.

The binder resin is not particularly limited, and conventionally known binder resins may be used. For example, vinyl resins, polyester resins and the like are preferable. The following resins and polymers may be exemplified as the vinyl-based resin, the polyester resin, and other binder resins.

Homopolymers of styrene and its substituted products, such as polystyrene and polyvinyltoluene;

styrenic copolymers, such as styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-vinyl acetate copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-vinyl acetate copolymer, styrene-, Styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers;

Polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, and aromatic petroleum resin.

These binder resins may be used alone or as a mixture of plural kinds thereof.

The binder resin preferably contains a carboxyl group from the viewpoint of charging performance, and is preferably a resin produced using a polymerizable monomer containing a carboxyl group. Specific examples of the carboxyl group-containing polymerizable monomer include, for example, the following polymerizable monomers, but are not limited thereto.

Alpha-alkyl or beta-alkyl derivatives of (meth) acrylic acid, such as alpha-ethacrylic acid and crotonic acid; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid; and unsaturated dicarboxylic acid monoester derivatives such as monoacryloxyethyl succinate, monomethacryloxyethyl succinate, monoacryloxyethyl phthalate, and monomethacryloxyethyl phthalate.

As the polyester resin, those obtained by polycondensation of the carboxylic acid component and the alcohol component listed below can be used.

Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexane dicarboxylic acid, and trimellitic acid.

Examples of the alcohol component include bisphenol a, hydrogenated bisphenol, ethylene oxide adduct of bisphenol a, propylene oxide adduct of bisphenol a, glycerin, trimethylolpropane and pentaerythritol.

Further, the polyester resin may be a urea group-containing polyester resin. It is preferable that the carboxyl group present at the terminal end of the polyester resin or the like is not blocked.

The binder resin may have a polymerizable functional group for the purpose of improving the change in viscosity of the toner at high temperature. Examples of the polymerizable functional group include a vinyl group, an isocyanate group, an epoxy group, an amino group, a carboxyl group, and a hydroxyl group.

< crosslinking agent >

In order to control the molecular weight of the binder resin, a crosslinking agent may be added during polymerization of the polymerizable monomer.

For example, the following compounds may be used as the crosslinking agent, but these examples are not limitative.

Ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1, 3-butanediol diacrylate, 1, 4-butanediol diacrylate, 1, 5-pentanediol diacrylate, 1, 6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, the respective diacrylates of polyethylene glycol #200, #400, #600, dipropylene glycol diacrylate, polypropylene glycol diacrylate and polyester diacrylate (MANDA, manufactured by Nippon Kayaku co., ltd.), and a substance that changes the above acrylate into methacrylate.

The amount of the crosslinking agent to be added is preferably 0.001 parts by mass to 15.0 parts by mass based on 100 parts by mass of the polymerizable monomer.

< Release agent >

The toner core particle may contain wax.

For example, the following waxes may be used, but these examples are not limiting.

Esters of monohydric alcohols with aliphatic monocarboxylic acids or esters of monocarboxylic acids with aliphatic monohydric alcohols, such as behenate, stearyl stearate and palmityl palmitate; esters of dihydric alcohols with aliphatic monocarboxylic acids or esters of dihydric carboxylic acids with aliphatic monohydric alcohols, such as dibehenate sebacate and hexanediol dibehenate; esters of trihydric alcohols with aliphatic monocarboxylic acids or of tribasic carboxylic acids with aliphatic monohydric alcohols, such as glyceryl tribehenate; esters of tetrahydric alcohols with aliphatic monocarboxylic acids or esters of tetrahydric carboxylic acids with aliphatic monohydric alcohols, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; esters of hexahydric alcohols with aliphatic monocarboxylic acids or esters of hexahydric carboxylic acids with aliphatic monohydric alcohols, such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate; esters of polyhydric alcohols with aliphatic monocarboxylic acids or esters of polyhydric carboxylic acids with aliphatic monohydric alcohols, for example polyglycerol behenate; natural ester waxes such as carnauba wax and rice wax; petroleum-based waxes and their derivatives, such as paraffin wax, microcrystalline wax, and vaseline; hydrocarbon waxes obtained by the fischer-tropsch process and derivatives thereof; polyolefin waxes and derivatives thereof, such as polyethylene wax and polypropylene wax; a higher aliphatic alcohol; fatty acids such as stearic acid and palmitic acid; and amide waxes.

The content of the wax in the toner particles is preferably 0.5 to 20.0 mass%.

< coloring agent >

The toner core particle may contain a colorant. The colorant is not particularly limited, and for example, the following known colorants can be used.

Examples of the yellow pigment include yellow iron oxides such as navel orange yellow, naphthol yellow S, hansa yellow G, hansa yellow 10G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake, condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples are shown below.

Pigment yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168 and 180.

Examples of orange pigments are shown below.

Permanent Orange GTR, pyrazolone Orange, warken Orange (Vulcan Orange), benzidine Orange G, indanthrene bright Orange RK, and indanthrene bright Orange GK.

Examples of Red pigments include indian Red, such as permanent Red 4R, lithol Red, pyrazolone Red, malachite Red calcium salt (Watching Red calcium salt), lake Red C, lake Red D, brilliant carmine 6B, brilliant carmine 3B, eosin lake, rhodamine lake B, alizarin lake and like condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples are shown below.

C.i. pigment red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254.

Examples of the blue pigment include copper phthalocyanine compounds and derivatives thereof such as alkali blue lake, victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, fast sky blue, indanthrene blue BG, and the like; an anthraquinone compound; and basic dye lake compounds and the like. Specific examples are shown below.

C.i. pigment blue 1, 7, 15:1, 15:2, 15:3, 15:4, 60, 62 and 66.

Examples of violet pigments include fast violet B and methyl violet lake.

Examples of green pigments include pigment green B, malachite green lake and finally Yellow green g (final Yellow greeng).

Examples of the white pigment include zinc white, titanium oxide, antimony white, and zinc sulfide.

Examples of the black pigment include carbon black, aniline black, nonmagnetic ferrite, magnetite, and those toned black using the above-described yellow-based colorant, red-based colorant, and blue-based colorant.

These colorants may be used alone or as a mixture of plural kinds thereof. These colorants can be used in the form of solid solutions.

If necessary, the toner may be surface-treated with a substance that does not inhibit polymerization.

The content of the colorant in the toner particles is preferably 3.0% by mass to 15.0% by mass.

< Charge control agent >

The toner core particle may contain a charge control agent. The charge control agent is not particularly limited, and a known charge control agent can be used. In particular, a charge control agent which has a high charging speed and can stably maintain a constant charging amount is preferable. Further, in the case of producing the toner core particles by a direct polymerization method, a charge control agent having low polymerization inhibitory property and substantially free of a substance soluble in an aqueous medium is particularly preferable.

An example of a charge control agent that controls toner particles to be negatively chargeable is shown below.

Organometallic compounds and chelate compounds, exemplified by monoazo metal compounds, acetylacetone metal compounds, and metal compounds of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, hydroxycarboxylic acids, and dicarboxylic acid systems. Other examples include aromatic hydroxycarboxylic acids, aromatic mono-and polycarboxylic acids, and metal salts, anhydrides, esters thereof, and phenol derivatives such as bisphenols, and the like. Further, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, and calixarenes may be mentioned.

Meanwhile, an example of a charge control agent that controls toner particles to be positively charged is shown below.

Nigrosine modifications such as nigrosine and fatty acid metal salts; a guanidine compound; an imidazole compound; quaternary ammonium salts such as tributylbenzyl-1-hydroxy-4-naphthalenesulfonic acid ammonium salt and tetrabutyltetrafluoroboric acid ammonium salt, onium salts such as phosphonium salts as analogs thereof, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (examples of lake converting agents include phosphotungstic acid, phosphomolybdic acid, phosphomolybdotungstic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, and the like); metal salts of higher fatty acids; and a resin-based charge control agent.

These charge control agents may be used alone or in combination of plural kinds thereof. The content of these charge control agents in the toner particles is preferably 0.01 to 10 mass%.

< external additive >

The toner particles may be used as they are as a toner, but in order to improve fluidity, charging performance, cleanability, and the like, a fluidizing agent or a cleaning assistant, or the like, which is a so-called external additive, may be added to obtain a toner.

Examples of the external additive include inorganic oxide fine particles such as silica fine particles, alumina fine particles, titanium oxide fine particles, and the like; inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles; and inorganic titanic acid compound fine particles such as strontium titanate, zinc titanate, and the like; and the like. These may be used alone or in combination of plural kinds thereof.

These inorganic fine particles are preferably subjected to a gloss treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid or silicone oil, or the like, thereby improving heat-resistant storage properties and environmental stability. The BET specific surface area of the external additive is preferably 10m²G to 450m²/g。

The BET specific surface area is determined by a low-temperature gas adsorption method based on a dynamic constant pressure method according to the BET method (preferably, BET multipoint method). For example, the BET specific surface area (m) was calculated by adsorbing nitrogen gas on the surface of the sample and measuring by the BET multipoint method using a specific surface area measuring apparatus (trade name: GEMINI 2375 version 5.0, manufactured by Shimadzu corporation)²/g)。

The total amount of these various external additives is preferably 0.05 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the toner particles. Various external additives may be used in combination.

< developer >

The toner may be used as a magnetic or non-magnetic one-component developer, but may also be mixed with a carrier and used as a two-component developer.

As the carrier, magnetic particles composed of conventionally known materials such as, for example, metals such as iron, ferrite, magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Among them, ferrite particles are preferable. Further, as the carrier, a coated carrier obtained by coating the surface of the magnetic particles with a coating agent such as a resin, or a resin dispersion type carrier obtained by dispersing magnetic fine powder in a binder resin, or the like can be used.

The volume average particle diameter of the carrier is preferably 15 μm to 100 μm, and more preferably 25 μm to 80 μm.

< Process for producing toner particles >

Known methods may be used to produce toner particles. Therefore, a kneading and pulverizing method or a wet production method can be used. From the viewpoint of obtaining uniform particle diameter and shape controllability, the wet production method is preferable. The wet production method may be exemplified by a suspension polymerization method, a dissolution suspension method, an emulsion polymerization aggregation method, an emulsion aggregation method, and the like.

Here, the suspension polymerization method will be described.

The suspension polymerization method may include a step of preparing a polymerizable monomer composition by uniformly dissolving or dispersing the resin a and other additives such as a polymerizable monomer and a colorant for forming a binder resin as needed by using a dispersing machine such as a ball mill or an ultrasonic dispersing machine (a step of preparing a polymerizable monomer composition). At this time, a polyfunctional monomer, a chain transfer agent, a wax as a release agent, a charge control agent, a plasticizer, and the like may be appropriately added as needed.

Preferred examples of the polymerizable monomer in the suspension polymerization method include the following vinyl-based polymerizable monomers.

Styrene; styrene derivatives such as α -methylstyrene, β -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2, 4-dimethylstyrene, p-n-butylstyrene, p-t-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, and the like; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethylphosphate ethyl acrylate, diethylphosphate ethyl acrylate, dibutylphosphate ethyl acrylate, and 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, ethyl diethyl phosphate methacrylate, and ethyl dibutyl phosphate methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, and vinyl formate, and the like; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether and the like; vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

The suspension polymerization process may comprise the steps of: the polymerizable monomer composition is put into a previously prepared aqueous medium, and droplets composed of the polymerizable monomer composition are formed into a desired toner particle size using a stirrer or a disperser having a high shearing force (a granulating step).

The aqueous medium in the granulating step preferably contains a dispersion stabilizer in order to control the particle size of the toner particles, sharpen the particle size distribution, and prevent coalescence of the toner particles during production. Dispersion stabilizers are generally classified into high molecules exhibiting repulsive force due to steric hindrance and poorly water-soluble inorganic compounds stabilizing dispersion by means of electrostatic repulsive force. It is preferable to use fine particles of the poorly water-soluble inorganic compound because they are dissolved by an acid or a base, and therefore, can be dissolved and easily removed by washing with an acid or a base after polymerization.

A dispersion stabilizer comprising a poorly water-soluble inorganic compound of any one of magnesium, calcium, barium, zinc, aluminum, and phosphorus can be preferably used. More preferably, any one of magnesium, calcium, aluminum and phosphorus is contained. Specific examples are listed below.

Sodium phosphate, magnesium phosphate, tricalcium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, calcium chloride, and hydroxyapatite.

For example, organic compounds such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch may be used in combination with the dispersion stabilizer.

These dispersion stabilizers are preferably used in an amount of 0.01 to 2.00 parts by mass based on 100 parts by mass of the polymerizable monomer.

In addition, in order to miniaturize these dispersion stabilizers, a surfactant may be used in combination in an amount of 0.001 to 0.1 parts by mass relative to 100 parts by mass of the polymerizable monomer. Specifically, commercially available nonionic surfactants, commercially available anionic surfactants, and commercially available cationic surfactants can be used. For example, sodium lauryl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate, and the like are preferably used.

In the suspension polymerization method, it is preferable to set the temperature to 50 ℃ to 90 ℃, and polymerize the polymerizable monomer contained in the polymerizable monomer composition to obtain the toner base particle dispersion liquid (polymerization step). The polymerization step may be performed after the granulation step, or may be performed simultaneously with the granulation step.

In the polymerization step, it is preferable to perform a stirring operation so that the temperature distribution in the vessel becomes uniform. The addition of the polymerization initiator can be carried out at any timing and for a desired time. Further, the temperature may be increased in the latter half of the polymerization reaction to obtain a desired molecular weight distribution, and in order to remove unreacted polymerizable monomers, by-products, and the like from the system, a part of the aqueous medium may be distilled off in the latter half of the reaction or after the completion of the reaction by a distillation operation. The distillation operation may be carried out under normal pressure or reduced pressure.

As the polymerization initiator to be used for the suspension polymerization method, an oil-soluble initiator is generally used. Examples of which are shown below.

Azo compounds, such as 2,2 '-azobisisobutyronitrile, 2' -azobis-2, 4-dimethylvaleronitrile, 1 '-azobis (cyclohexane-1-carbonitrile), 2' -azobis-4-methoxy-2, 4-dimethylvaleronitrile; and peroxide-based initiators such as acetyl cyclohexyl sulfonyl peroxide, diisopropyl peroxycarbonate, decanoyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide, tert-butyl peroxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxypivalate, and cumene hydroperoxide.

Water-soluble initiators may be used in combination as a polymerization initiator as needed, and examples thereof are listed below.

Ammonium persulfate, potassium persulfate, 2 '-azobis (N, N' -dimethyleneisobutyramidine) hydrochloride, 2 '-azobis (2-amidinopropane) hydrochloride, azobis (isobutylamidine) hydrochloride, sodium 2,2' -azobisisobutyronitrile sulfonate, ferrous sulfate, or hydrogen peroxide.

These polymerization initiators may be used alone or in combination of plural kinds thereof. In order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor, and the like may be further used in combination.

In the case where the toner core particles are formed in the aqueous medium in the step of coating the surfaces of the toner core particles with the silicone polymer, the surface layer may be formed by adding the hydrolysis liquid of the silicone compound while performing the polymerization step or the like in the aqueous medium as described above. Further, the surface layer may be formed by using a dispersion of the polymerized toner particles as a core particle dispersion and adding a hydrolysis liquid of an organic silicon compound.

Further, in a method not using an aqueous medium, such as a kneading pulverization method, the surface layer may be formed by dispersing the obtained toner particles in an aqueous medium to be used as a core particle dispersion liquid and adding a hydrolysis liquid of an organic silicon compound as described above.

The weight average particle diameter of the toner particles is preferably 3.0 μm to 10.0 μm from the viewpoint of obtaining a high-definition and high-resolution image. The weight average particle diameter of the toner can be measured by a pore resistance method. For example, the measurement can be performed using "Coulter multisizer 3" (manufactured by Beckman Coulter, Inc.). The toner particle dispersion thus obtained is subjected to a filtration step for solid-liquid separation of the toner particles from the aqueous medium.

The solid-liquid separation for obtaining toner particles from the obtained toner particle dispersion liquid may be performed by a general filtration method, and thereafter, it is preferable to further perform washing by repulping or washing with washing water or the like, thereby removing foreign matters that may not be completely removed from the surface of the toner particles. After sufficient washing, solid-liquid separation was performed again to obtain a toner cake. Thereafter, the particles are dried by a known drying means, and, as necessary, a group of particles having a particle diameter outside a predetermined range is separated by classification, thereby obtaining toner particles. The group of particles having a particle diameter outside the predetermined range separated at this time can be recycled, thereby improving the final yield.

The method for measuring each physical property value is described below.

< method for producing tetrahydrofuran-insoluble matter of toner particles (extraction of Silicone Polymer) >

First, in the case where the surface of the toner particles is treated with an external additive or the like, the external additive is removed by the following method to obtain toner particles.

A total of 160g of sucrose (manufactured by Kishida Chemical co., ltd.) was added to 100mL of ion-exchanged water and dissolved using a hot water bath, thereby preparing a thick sucrose solution. A total of 31g of a thick sucrose solution and 6mL of a 10 mass% aqueous solution of a neutral detergent for precision measuring apparatus cleaning having a pH of 7 containing a nonionic surfactant, an anionic surfactant and an organic builder (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a centrifugal separation tube (capacity 50mL) to prepare a dispersion. To the dispersion, 1.0g of toner was added, and the clumps of toner were loosened with a doctor blade or the like.

The tube was shaken with a shaker at 350spm (number of strokes per minute) for 20 min. The solution thus shaken was transferred to a glass tube for an oscillating rotor (capacity 50mL) and centrifuged in a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3,500rpm for 30 min. By this operation, the exfoliated external additive is separated from the toner particles. It was visually confirmed that the toner was sufficiently separated from the aqueous solution, and the separated toner in the uppermost layer was collected with a blade or the like. The collected toner was filtered with a reduced-pressure filter, and then dried with a dryer for 1 hour or more to obtain toner particles. This operation is performed several times to ensure the required amount.

Next, a Tetrahydrofuran (THF) -insoluble matter of the toner particles was prepared as follows.

A total of 10.0g of the toner particles were weighed, placed in a cylindrical Filter paper (No.84, manufactured by Toyo Filter paper co., ltd.), and charged into a soxhlet extractor. Extraction was performed for 20h using 200mL THF as solvent. Extraction was further carried out for 20h after replacement with 200mL of fresh THF. Finally, extraction was carried out for 20h after replacement with 200mL of fresh THF again (total amount of THF used was 600mL, and total extraction time was 60 h).

The substance obtained by vacuum-drying the filtrate in the cylindrical filter paper at 40 ℃ for several hours was a tetrahydrofuran-insoluble substance. The tetrahydrofuran insoluble matter contains "an organosilicon polymer having a structure represented by the formula (a)".

Further, as necessary, a method involving the same operations as those for removing the external additive may be performed, thereby removing insoluble substances such as pigments from the tetrahydrofuran insoluble substances and separating "a silicone polymer having a structure represented by formula (a)" (using "the tetrahydrofuran insoluble substances" instead of "the toner".

< method for producing tetrahydrofuran-soluble matter of toner particles (removal of resin A) >

The resin a in the toner particles was taken out by separating the extract with Tetrahydrofuran (THF) by means of a solvent gradient elution method. The preparation method is described below.

A total of 10.0g of the toner particles were weighed, placed in a cylindrical Filter paper (No.84, manufactured by Toyo Filter paper co., ltd.), and charged into a soxhlet extractor. Extraction was performed using 200mL of THF as a solvent for 20h, and the solid obtained by removing the solvent from the extract was a THF-soluble substance. Resin a is contained in a THF soluble material. The above operation was carried out several times to obtain the required amount of THF-soluble matter.

Gradient preparative HPLC (LC-20 AP high pressure gradient preparative System manufactured by Shimadzu Corporation, SunAire preparative column manufactured by Waters Co., Ltd.)250mm) was used in the solvent gradient elution method. The column temperature was 30 ℃, the flow rate was 50mL/min, acetonitrile was used as a poor solvent for the mobile phase, and THF was used as a good solvent. As a sample for separation, a solution obtained by dissolving 0.02g of THF soluble substance obtained by extraction in 1.5mL of THF was used. The mobile phase started from a composition of 100% acetonitrile and after 5min of sample injection, the THF ratio increased by 4% per minute and the composition of the mobile phase was 100% THF over 25 min. The components may be separated by drying the fractions obtained. As a result, resin A can be obtained. The content of silicon atoms can be measured by the following methods ¹³C-NMR measurements were made to determine which fraction component was resin A.

< method for measuring the content of silicon atom in resin A or Silicone Polymer >

The measurement of the content of silicon in the resin a or the silicone polymer was performed by using a wavelength dispersion type X-ray fluorescence spectrometer "Axios" (manufactured by PANalytical) and special software "SuperQ version 4.0F" (manufactured by PANalytical) for setting the measurement conditions and analyzing the measurement data. Rh was used as the anode of the X-ray tube, the measurement atmosphere was vacuum, the measurement diameter (collimator mask diameter) was 27mm, and the measurement time was 10 sec. A Proportional Counter (PC) is used for detection when measuring light elements, and a flicker counter (SC) is used for detection when measuring heavy elements.

Pellets obtained by the following method were used as measurement samples: 4g of the resin A, or 4g of the tetrahydrofuran soluble matter obtained by the foregoing production method, or 4g of the silicone polymer, or 4g of the tetrahydrofuran insoluble matter was placed in a dedicated aluminum ring for compression, leveled, pressurized at 20MPa for 60 seconds using a tablet forming compressor "BRE-32" (manufactured by Maekawa Testing Machine Co., Ltd.), and formed to have a thickness of 2mm and a diameter of 39 mm.

Further, with respect to 100 parts by mass of the binder particles [ trade name: spectro Blend, composition: 81.0% by mass of C, 2.9% by mass of O, 13.5% by mass of H, 2.6% by mass of N, and a chemical formula: c₁₉H₃₈ON, form: powder (44 μm); manufactured by Rigaku Corp]0.5 part by mass of SiO was added₂Particles (hydrophobic fumed silica) [ trade name: AEROSILNAX50, specific surface area: 40 +/-10 m²(iv)/g, carbon content: 0.45% to 0.85%; manufactured by Nippon Aerosil co., ltd.), then mixed thoroughly using a coffee mill. Similarly, SiO₂The particles were mixed with the binder particles in a manner of 5.0 parts by mass and 10.0 parts by mass, respectively, and these were used as samples for the calibration curve.

For each sample, pellets for the calibration curve sample were prepared as described above using a tablet forming compressor, and the count rate (unit: cps) of Si — K α rays observed at a diffraction angle (2 θ) ═ 109.08 ° when PET was used for the spectroscopic crystals was measured. At this time, the acceleration voltage and current value of the X-ray generator were set to 24kV and 100mA, respectively. Obtaining calibration curves of a linear function, wherein the obtained X-ray count rates are plotted on the vertical axis and the SiO in the sample for each calibration curve is plotted on the horizontal axis ₂The amount of particles added.

Next, the resin a as an analysis object, or the tetrahydrofuran soluble substance obtained by the foregoing production method, or the silicone polymer, or the tetrahydrofuran insoluble substance is formed into pellets by using the above tablet forming compressor, and the count rate of Si — K α rays thereof is measured. Then, the content of silicon atoms in the resin a, or the tetrahydrofuran soluble substance, or the silicone polymer or the tetrahydrofuran insoluble substance is determined from the above calibration curve.

< method for confirming Structure represented by formula (A) >

The structure represented by formula (a) in the silicone polymer contained in the toner particles was confirmed by the following method.

R in the formula (A)⁴Alkyl of the formula¹³And C-NMR.

(¹³Measurement conditions for C-NMR (solid fraction)

The device comprises the following steps: JNM-ECX500II manufactured by JEOL RESONANCE Co., Ltd

Sample tube:

sample preparation: tetrahydrofuran-insoluble matter obtained by the above-mentioned preparation method, 150mg

Measuring the temperature: at room temperature

Pulse mode: CP/MAS

Measuring the nuclear frequency: 123.25 MHz: (¹³C)

Reference substance: adamantane (external standard: 29.5ppm)

Sample rotation speed: 20kHz

Contact time: 2ms

Delay time: 2s

Cumulative number of times: 2,000 to 8,000 times

According to this method, by means of a compound derived from a methyl group (Si-CH) bonded to a silicon atom₃) Ethyl (Si-C)₂H₅) Propyl group (Si-C)₃H₇) Butyl (Si-C)₄H₉) Pentyl group (Si-C)₅H₁₁) Hexyl (Si-C)₆H₁₃) Or phenyl (Si-C)₆H₅) Confirming the presence or absence of the signal (A) represented by R⁴Alkyl groups as shown.

< method for calculating the ratio of the peak area of the partial structure represented by the formula (A) to the total peak area of the silicone polymer >

Of tetrahydrofuran-insoluble matter of toner particles under the following measurement conditions²⁹Si-NMR (solid) measurement.

(²⁹Measurement conditions of Si-NMR (solid)

The device comprises the following steps: JNM-ECX500II manufactured by JEOL RESONANCE Co., Ltd

Sample tube:

sample preparation: tetrahydrofuran-insoluble matter of toner particles for NMR measurement, 150mg

Measuring the temperature: at room temperature

Pulse mode: CP/MAS

Measuring the nuclear frequency: 97.38 MHz: (²⁹Si)

Reference substance: DSS (external standard: 1.534ppm)

Sample rotation speed: 10kHz

Contact time: 10ms

Delay time: 2s

Cumulative number of times: 2,000 to 8,000 times

After the above measurement, the plural silane component peaks having different substituents and binding groups in the THF insoluble matter of the toner particles were separated into an X1 structure, an X2 structure, an X3 structure, and an X4 structure in the following figures by curve fitting, and the respective peak areas were calculated.

The structure of X1: (R)_i)(R_j)(R_k)SiO_1/2

The structure of X2: (R)_g)(R_h)Si(O_1/2)₂

The structure of X3: r_mSi(O_1/2)₃

The structure of X4: si (O)_1/2)₄

The structure of X1:

the structure of X2:

the structure of X3:

the structure of X4:

in the above figures, R in the structures of X1 to X3_i、R_j、R_k、R_g、R_hAnd R_mEach independently represents an organic group such as an alkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, an acetoxy group or an alkoxy group bonded to silicon.

Then, the ratio of the X3 structure was calculated, and the ratio of the peak area of the structure represented by formula (a) to the total peak area of the silicone polymer was calculated.

When it is necessary to confirm the structure represented by formula (a) in more detail, it is possible to confirm the structure by¹H-NMR measurement results together with¹³C-NMR and²⁹Si-NMR measurements to identify the structure.

< identification of the Structure represented by formula (1) >

A polymer moiety P in the structure represented by the formula (1)¹Position L¹And site R¹To R³By passing¹H-NMR analysis,¹³C-NMR analysis,²⁹Si-NMR analysis and FT-IR analysis. As an analysis sample, a tetrahydrofuran soluble substance obtained by the above preparation method or an additionally synthesized resin a was used.

At L¹When the amide bond represented by the formula (2) is contained, the amide bond can be bonded to the aromatic hydrocarbon compound¹H-NMR analysis was carried out for identification. Specifically, identification can be performed by a chemical shift value of a proton at an NH site of an amide group, and quantification of the amide group can be performed by calculating an integrated value.

R in the structure represented by formula (1)¹To R³In the case of containing an alkoxy group or a hydroxyl group, the valence of the alkoxy group or the hydroxyl group to the silicon atom may be determined by reaction with (A) or (B) as defined above²⁹Si-NMR (measurement condition of solid) was determined by the same method. As an analysis sample, a tetrahydrofuran soluble substance obtained by the above preparation method or an additionally synthesized resin a was used.

Specifically, the valence can be calculated by calculating the ratio of X1 to X4 structures in the measurement data and calculating the ratio of peak areas derived from alkoxy groups or hydroxyl groups.

< method for measuring weight average molecular weight (Mw) >

The weight average molecular weight (Mw) of the resin was measured by Gel Permeation Chromatography (GPC) in the following manner.

First, the sample was dissolved in Tetrahydrofuran (THF) at room temperature for 24 h. Then, the obtained solution was filtered through a solvent-resistant membrane filter "Mysyori Disc" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution was prepared so that the concentration of the THF-soluble component was about 0.8 mass%. Using this sample solution, measurement was performed under the following conditions.

The device comprises the following steps: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)

Column: 7-column connection of Shodex KF-801, 802, 803, 804, 805, 806 and 807 (manufactured by Showa Denko KK)

Eluent: tetrahydrofuran (THF)

Flow rate: 1.0mL/min

Oven temperature: 40.0 deg.C

Sample injection amount: 0.10mL

In calculating the molecular weight of the sample, a molecular weight calibration curve prepared using a standard polystyrene resin (trade name "TSK standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation) was used.

< method for measuring acid value Av of resin >

The acid number is the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1g of sample. The acid value of the resin was measured according to JIS K0070-1992. Specifically, the acid value was measured according to the following procedure.

(1) Preparation of reagents

A total of 1.0g of phenolphthalein was dissolved in 90mL of ethanol (95 vol%), and ion-exchanged water was added to reach 100mL and a phenolphthalein solution was obtained.

A total of 7g of special grade potassium hydroxide was dissolved in 5mL of water and ethanol (95 vol%) was added to reach 1L. The solution was placed in an alkali-resistant container in such a manner that it was not exposed to carbon dioxide gas or the like and allowed to stand for 3 days, followed by filtration to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution was stored in an alkali-resistant container.

A total of 25mL of 0.1mol/L hydrochloric acid was placed in an Erlenmeyer flask, several drops of phenolphthalein solution were added, titration was performed with potassium hydroxide solution, and the factor of the potassium hydroxide solution was determined from the amount of potassium hydroxide solution required for neutralization. 0.1mol/L hydrochloric acid prepared according to JIS K8001-.

(2) Operation of

(A) Main test

In a 200mL conical flask, 2.0g in total of the pulverized sample was accurately weighed, 100mL of a mixed solution of toluene/ethanol (2:1) was added, and dissolution was performed for 5 hours. Next, several drops of phenolphthalein solution were added as an indicator, and titration was performed using a potassium hydroxide solution. The endpoint of the titration was a light red color of the indicator for about 30 sec.

(B) Blank test

The same titration as in the above procedure was performed except that no sample was used, i.e., only a mixed solution of toluene/ethanol (2:1) was used.

(3) The obtained result was substituted into the following equation to calculate the acid value.

A＝[(C-B)×f×5.61]/S

Here, a: acid value (mg KOH/g), B: amount (ml) of potassium hydroxide solution added in the blank test, C: amount (ml) of potassium hydroxide solution added in the main test, f: factor of potassium hydroxide solution, and S: mass (g) of the sample.

< method for measuring hydroxyl value OHV of resin >

The hydroxyl number is the number of milligrams of potassium hydroxide required to neutralize the acetic acid bound to the hydroxyl groups upon acetylation of a 1g sample. The hydroxyl value of the resin was measured in accordance with JIS K0070-1992. Specifically, the hydroxyl value was measured according to the following procedure.

(1) Preparation of reagents

A total of 25g of special grade acetic anhydride was put into a 100mL volumetric flask, pyridine was added so that the total volume was 100mL, and sufficient shaking was performed to obtain an acetylation reagent. The obtained acetylation reagent was stored in a brown bottle to prevent exposure to moisture, carbon dioxide gas and the like.

A total of 1.0g of phenolphthalein was dissolved in 90mL of ethanol (95 vol%), and ion-exchanged water was added to reach 100mL, thereby obtaining a phenolphthalein solution.

A total of 35g of special grade potassium hydroxide was dissolved in 20mL of water and ethanol (95 vol%) was added to reach 1L. The solution was placed in an alkali-resistant container in such a manner that it was not exposed to carbon dioxide gas or the like and allowed to stand for 3 days, followed by filtration to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution was stored in an alkali-resistant container.

A total of 25mL of 0.5mol/L hydrochloric acid was placed in an Erlenmeyer flask, several drops of phenolphthalein solution were added, titration was performed with potassium hydroxide solution, and the factor of the potassium hydroxide solution was determined from the amount of potassium hydroxide solution required for neutralization. 0.5mol/L hydrochloric acid prepared according to JIS K8001-.

(2) Operation of

(A) Main test

A total of 1.0g of the comminuted sample was accurately weighed in a 200mL round bottom flask and 5.0mL of acetylation reagent was accurately added thereto using a full-scale pipette (w hole pipette). At this time, when the sample was difficult to dissolve in the acetylation reagent, a small amount of special grade toluene was added and dissolved.

A small funnel was placed on the neck of the flask, the flask was immersed in a glycerol bath at about 97 ℃ to about 1cm from the bottom and heated. In this case, in order to prevent the temperature of the neck of the flask from rising due to the heat of the glycerin bath, it is preferable to cover the bottom of the neck of the flask with a thick paper having a round hole.

After 1h, the flask was taken out of the glycerol bath and allowed to cool. After cooling, 1mL of water was added from the funnel and the flask was shaken to hydrolyze the acetic anhydride. The flask was again heated in the glycerol bath for 10min for more complete hydrolysis. After allowing to cool, the funnel and flask walls were washed with 5mL of ethanol.

Several drops of phenolphthalein solution as an indicator were added and titration was performed with potassium hydroxide solution. The endpoint of the titration was when the light red color of the indicator lasted for about 30 sec.

(B) Blank test

The same titration as in the above procedure was performed, except that no sample was used.

(3) The obtained result was substituted into the following equation to calculate a hydroxyl value.

A＝[{(B-C)×28.05×f}/S]+D

Here, a: hydroxyl number (mg KOH/g), B: amount (ml) of potassium hydroxide solution added in the blank test, C: amount (ml) of potassium hydroxide solution added in the main test, f: factor of potassium hydroxide solution, S: mass of sample (g), and D: acid value of the sample (mg KOH/g).