External additive particles and toner

Abstract

To provide an external additive particle that can obtain a toner that can have excellent fluidity, and can have excellent flow maintaining property when long-time image output is performed and excellent density stability in a low humidity environment.SOLUTION: An external additive particle includes a polymer having sulfur atoms and nitrogen atoms. The polymer has a vinyl polymer part and a siloxane part. The ratio of the number of silicon atoms constituting the external additive particle to the total of the numbers of carbon atoms, oxygen atoms, and the silicon atoms constituting the external additive particle is 4.0% or more and 25.0% or less. When X-ray photoelectron spectroscopic analysis is performed on a surface of the external additive particle, with respect to the total of the numbers of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms, the ratio of the number of nitrogen atoms is 0.40% or more and 2.50% or less, and the ratio of the number of sulfur atoms is 0.05% or more and 0.25% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a toner used in an electrophotographic image forming apparatus. [Background technology]

[0002] In recent years, there has been a demand for even higher speeds and higher image quality in image forming apparatuses using electrophotography. In response to these demands, toners that have stress resistance that allows them to withstand long periods of friction in developing devices and that have excellent fluidity and developability in order to obtain high image quality even in high-speed printing have been studied.

[0003] Patent Document 1 discloses that the fluidity and the like of a toner can be improved by incorporating a toner additive having an organic polymer skeleton and a polysiloxane skeleton into the toner. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-202071 Summary of the Invention [Problem to be solved by the invention]

[0005] As a result of the inventors' investigation of the toner described in Patent Document 1, they recognized that further improvements are needed in terms of the change in toner fluidity over time when image output is performed for a long period of time, and the stability of image density when image output is performed in a low-humidity environment.

[0006] One aspect of the present disclosure is to provide external additive particles that can be used to obtain a toner that has excellent fluidity, excellent fluidity retention even when image output is performed for a long period of time, and excellent concentration stability in a low-humidity environment. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, there is provided an external additive particle including a polymer having sulfur atoms and nitrogen atoms, the polymer has a vinyl polymer portion and a siloxane portion; the ratio of the number of silicon atoms constituting the external additive particles to the total number of carbon atoms, oxygen atoms, and silicon atoms constituting the external additive particles is 4.0% or more and 25.0% or less; When X-ray photoelectron spectroscopy is performed on the surface of the external additive particle, the number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms is The ratio of the number of nitrogen atoms is 0.40% or more and 2.50% or less, The ratio of the number of sulfur atoms is 0.05% or more and 0.25% or less. The present invention provides an external additive particle characterized by the above. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, it is possible to provide a toner that can have excellent fluidity, excellent fluidity maintenance even when image output is performed for a long period of time, and excellent density stability in a low-humidity environment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Unless otherwise specified, the expressions "xx or more and xx or less" and "xx to xx" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0010] In the present disclosure, the (alkyl)amino group refers to an amino group, a monoalkylamino group, or a dialkylamino group, in which the alkyl preferably has 1 to 6 carbon atoms.

[0011] In this disclosure, SiO N / 2This means that, of the four valences of a silicon atom, N are bonded to oxygen atoms, and each of the N oxygen atoms is bonded to Si. In other words, each of the N oxygen atoms is treated as a unit in which a siloxane bond (Si-O-Si) is formed.

[0012] As a result of extensive research, the present inventors have found that a toner to which external additive particles having the above-mentioned constituent requirements have been externally added can have excellent fluidity and excellent fluidity maintaining properties. Each of the constituent requirements will be described in detail below.

[0013] <Sulfur atoms in the surface region of external additive particles> The polymer according to the present disclosure contains sulfur atoms, and when X-ray photoelectron spectroscopy is performed on the surface of the external additive particles, the ratio of the number of sulfur atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms is 0.05% or more and 0.25% or less. That is, sulfur atoms are present in the surface region of the external additive particles. The present inventors have discovered that when the polymer contains sulfur atoms and when sulfur atoms are present in the surface region of the external additive particles, a toner with excellent fluidity retention properties is more easily obtained. The reason for the improved fluidity retention properties is unclear, but the present inventors speculate as follows.

[0014] Sulfur, a period 3 element, has a larger principal quantum number than period 2 elements such as carbon, resulting in a smaller energy difference between atomic orbitals and greater orbital hybridization. Therefore, the orbitals are more likely to be distorted by external electrostatic fields. That is, the polarizability of sulfur atoms is relatively high, and polarized portions are more likely to generate electrostatic interactions with the outside. Even when sulfur atoms are covalently bonded to highly electronegative atoms such as oxygen atoms, polarization also occurs in the bond between the sulfur atom and the oxygen atom, and the polarized portions are more likely to generate electrostatic interactions with the outside. Furthermore, the presence of polarized portions in the surface regions of external additive particles is thought to facilitate strong interactions with portions capable of electrostatic interaction present on the toner particle surface, making it more difficult for the external additive particles to detach from the toner particle surface. The inventors believe that this will result in a toner that exhibits excellent fluidity retention, even when image output is performed for extended periods of time.

[0015] The present inventors believe that the atomic ratio of sulfur atoms within the above range facilitates appropriate control of the interaction between the surface of the toner particles and the external additive particles. The atomic ratio of sulfur atoms is preferably 0.10% or more and 0.20% or less.

[0016] Examples of sulfur atoms in the moiety that easily induces electrostatic interaction include sulfo groups (-SO3H) and sulfate groups (-OSO3H), as well as their sodium and potassium salts. Therefore, the polymer according to the present disclosure is preferably a polymer having at least one functional group selected from the group consisting of -SO3H, -SO3Na, -SO3K, -OSO3H, -OSO3Na, and -OSO3K. Furthermore, the sulfur atoms detected when X-ray photoelectron spectroscopy is performed on the surface of the external additive particles are preferably sulfur atoms contained in at least one functional group selected from the group consisting of -SO3H, -SO3Na, -SO3K, -OSO3H, -OSO3Na, and -OSO3K.

[0017] Examples of methods for incorporating sulfo groups or salts thereof into the surface regions of polymers and external additive particles according to the present disclosure include a method using a radically polymerizable sulfonate, such as sodium p-styrenesulfonate, as a polymer material, as described below. Additionally, examples of methods for incorporating sulfate groups or salts thereof into the surfaces of polymers and external additives according to the present disclosure include a method using a persulfate, such as potassium peroxodisulfate, as a radical polymerization initiator. When potassium peroxodisulfate is used as a radically polymerizable initiator during polymer production, -OSOK or -OSOH is introduced at the terminal of the polymer, and a sulfur atom is introduced into the produced polymer.

[0018] <Nitrogen atoms in the surface region of external additive particles> The polymer according to the present disclosure contains nitrogen atoms, and when X-ray photoelectron spectroscopy is performed on the surface of the external additive particles, the ratio of the number of nitrogen atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms is 0.40% or more and 2.50% or less. That is, nitrogen atoms are present in the surface region of the external additive particles. The ratio of the number of nitrogen atoms is preferably 1.00% or more and preferably 2.00% or less. The present inventors have discovered that by using a toner containing external additive particles in which the polymer contains nitrogen atoms and the nitrogen atoms in the surface region are present in the above ratio range, the density of the output image is more likely to be stabilized in a low-humidity environment. The reason for the improved density stability of the output image is unclear, but the present inventors speculate as follows.

[0019] In the process of toner charge acquisition through frictional charging, negative charges tend to accumulate in the toner due to the influence of negatively chargeable functional groups present on the surfaces of external additive particles and toner particles. When nitrogen atoms are present in the surface region of external additive particles, compounds containing nitrogen atoms tend to act as bases and acquire positive charges by accepting hydrogen ions, making it difficult for excessive accumulation of negative charges to occur in the toner as a whole. As a result, the toner is less likely to be excessively charged, and the inventors believe that this makes it easier to obtain toners that exhibit less variation in image density even in low-humidity environments.

[0020] The present inventors also believe that when the ratio of the number of nitrogen atoms is within the above range, the balance between the positive charge amount and the negative charge amount in the surface region of the external additive particle can be easily controlled appropriately. Furthermore, since this balance is considered to be more appropriate and excellent image density stability is easily obtained, when X-ray photoelectron spectroscopy is performed on the surface of the external additive particle, the ratio of the number of nitrogen atoms to the number of sulfur atoms is preferably 2.0 or more. It is more preferably 7.0 or more, and even more preferably 8.0 or more. There is no particular upper limit, but it is preferably 20.0 or less, preferably 10.0 or less, and even more preferably 9.0 or less. Furthermore, the nitrogen atoms detected when X-ray photoelectron spectroscopy is performed on the surface of the external additive particle are preferably nitrogen atoms contained in the polymer according to the present disclosure.

[0021] Since an (alkyl)amino group is considered to be a preferred embodiment of the nitrogen atom, the polymer according to the present disclosure preferably contains an (alkyl)amino group. The (alkyl)amino group is more preferably at least one of an amino group and a monoalkylamino group. Furthermore, the nitrogen atom detected when X-ray photoelectron spectroscopy is performed on the surface of the external additive particle is preferably a sulfur atom contained in the (alkyl)amino group.

[0022] A method for incorporating an (alkyl)amino group into the polymer according to the present disclosure includes, for example, reacting an amine compound described below with a polymer having a vinyl polymer portion and a siloxane portion to bond the polymer with the amine compound.

[0023] The nitrogen atom contained in the polymer may be a trialkylammonium group, that is, the polymer according to the present disclosure may contain a trialkylammonium group.

[0024] <Polymer having a vinyl polymer moiety and a siloxane moiety> The polymers according to the present disclosure have a vinyl polymer portion and a siloxane portion.

[0025] The vinyl polymer portion in the polymer is an organic polymer portion formed by polymerizing a vinyl-based polymerizable monomer. The presence of the vinyl polymer portion in the polymer contained in the external additive particles is thought to increase affinity with the resin constituting the toner particles, making it difficult for the external additive particles to separate from the toner particles.

[0026] Furthermore, the polymer contained in the external additive particles contains not only a vinyl polymer portion but also a siloxane portion, which makes the external additive particles containing the polymer according to the present disclosure likely to have sufficient mechanical strength and be resistant to plastic deformation, and therefore the toner to which the external additive particles are externally added can have excellent fluidity.

[0027] As one aspect of the polymer according to the present disclosure, it is preferable that the polymer is a polymer in which vinyl polymer chains are crosslinked by siloxane bonds. It is considered that when the external additive particles contain this polymer, the mechanical strength of the external additive particles is likely to be increased and plastic deformation is unlikely to occur. Similarly, as one aspect of the polymer according to the present disclosure, it is preferable that the polymer is a polymer having a structure in which molecular chains of vinyl polymers are bonded via siloxane bonds.

[0028] Particles having only a polysiloxane skeleton, such as silica particles, have high mechanical strength but low affinity with the resin that constitutes the toner particles, and the fluidity of the toner tends to decrease when images are output for a long period of time.

[0029] Furthermore, particles having only an organic polymer skeleton, such as polymethyl methacrylate particles, have low mechanical strength, and therefore, when used as external additive particles, they are likely to undergo plastic deformation or breakage due to mechanical impact in a developing machine, etc. As a result, the toner tends to adhere to various components, making it difficult to obtain a toner having excellent fluidity and flow retention.

[0030] The method for obtaining the polymer according to the present disclosure can be exemplified by the method of carrying out vinyl polymerization using a vinyl polymerization monomer that contains silicon atom bonded with hydrolyzable group such as methoxy group, and then carrying out hydrolysis of this hydrolyzable group and polycondensation reaction to form siloxane bond.In this method, vinyl polymerization is carried out first to form a vinyl polymer chain, and then hydrolysis and polycondensation are carried out to form siloxane bond in this polymer or between these polymers, so that the polymer that vinyl polymer chain is crosslinked by siloxane bond can be obtained.

[0031] Furthermore, the content of the polymer according to the present disclosure relative to the mass of the external additive particles is preferably 60.0 mass% or more, more preferably 70.0 mass% or more, more preferably 80.0 mass% or more, and even more preferably 90.0 mass% or more.

[0032] <The ratio of the number of silicon atoms to the total number of carbon atoms, oxygen atoms, and silicon atoms> The ratio of the number of silicon atoms constituting the external additive particles to the total number of carbon atoms, oxygen atoms, and silicon atoms constituting the external additive particles is 4.0% or more and 25.0% or less.

[0033] The present inventors believe that the ratio of the number of silicon atoms constituting the external additive particles to the total number of carbon atoms, oxygen atoms, and silicon atoms constituting the external additive particles is an indicator of how many siloxane moieties are present in the external additive particles.

[0034] When the above ratio is 4.0% or more, the siloxane moiety is sufficiently present in the external additive particles, which is thought to make the external additive particles less susceptible to plastic deformation, thereby making it easier to obtain a toner with excellent fluidity. Furthermore, when the above ratio is 25.0% or less, the amount of siloxane moiety in the external additive particles is less likely to become excessive, which is thought to make the external additive particles less likely to separate from the toner particles, thereby making it easier to obtain a toner with excellent fluidity retention. Therefore, the ratio is 25.0% or less, preferably 20.0% or less, more preferably 15.0% or less, and even more preferably 10.0% or less. That is, the above ratio is more preferably 4.0% or more and 10.0% or less. Furthermore, it is more preferably 8.0% or less.

[0035] Furthermore, since a toner having excellent fluidity retention is easily obtained, the ratio of the number of carbon atoms constituting the external additive particles to the number of silicon atoms constituting the external additive particles is preferably 6.5 or more. More preferably, it is 7.5 or more, and even more preferably, it is 13.5 or more. There is no particular upper limit, but from the viewpoint of toner fluidity, it is preferably 20.0 or less. More preferably, it is 17.0 or less.

[0036] The above-mentioned ratio of the number of atoms can be controlled by adjusting the type and amount of the monomer unit containing a silicon atom and the type and amount of the monomer unit not containing a silicon atom when producing the polymer contained in the external additive particles. In addition, when producing the polymer contained in the external additive particles, the above-mentioned range of the ratio of the number of atoms can also be easily satisfied by performing a radical polymerization reaction followed by a hydrolysis reaction and a polycondensation reaction. Details will be described later.

[0037] <Monomer units in polymer> The polymer preferably contains a monomer unit represented by the following formula (1), since the ratio of carbon atoms, oxygen atoms, and silicon atoms is likely to fall within the above range and the effects of the present disclosure are likely to be obtained. [ka] (In formula (1), R 1 is an alkylene group having 1 to 10 carbon atoms, and R' is a hydrogen atom or a methyl group.

[0038] In addition, as one embodiment of the polymer according to the present disclosure having a sulfur atom, it is preferable that the polymer has a monomer unit represented by the following formula (S):

[0039] [ka]

[0040] (In formula (S), R S1 ~R S4 are each independently a hydrogen atom or a methyl group, and X is a hydrogen atom or an alkali metal atom. When the polymer contains the above-mentioned monomer unit, the polymer according to the present disclosure contains sulfur atoms, which facilitate the presence of sulfur atoms on the surface of the external additive particles, thereby improving the fluidity retention of the toner to which the external additive particles containing the polymer are added. Examples of the alkali metal atom in the formula (S) include Na and K. Furthermore, the position of -SO3X in the formula (S) is preferably para-position relative to -CH2-CH- in the formula (S). Furthermore, R S1 ~R S4 is preferably a hydrogen atom.

[0041] <Proportion of T units in external additive particles> The polysiloxane portion contained in the external additive particles may contain the following four units. M unit, which is a unit in which one silicon atom is bonded to one oxygen atom D unit, which is a unit in which one silicon atom is bonded to two oxygen atoms T unit, which is a unit in which one silicon atom is bonded to three oxygen atoms Q unit, which is a unit in which one silicon atom is bonded to four oxygen atoms The ratio of these units is: 29 This can be determined from the integral value in Si-NMR measurements.

[0042] Regarding the external additive particles according to the present disclosure 29 When Si-NMR measurement is performed, it is preferable that the following formula (P1) is satisfied. Integral value in T units / {(Integral value in M units) + (Integral value in D units) + (Integral value in T units) + (Integral value in Q units)} ≥ 60% (P1) By satisfying the above formula (P1), it is believed that the polysiloxane portion in the external additive particles is likely to have a portion having a three-dimensional bond. The inventors believe that this makes it easier for the external additive particles to have sufficient mechanical strength and to become external additive particles that are less susceptible to plastic deformation. The value of formula (P1) is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more.

[0043] <Proportion of T0 to T3 units in T units in external additive particles> The T units contained in the polysiloxane portion of the external additive particles are in one of the following states: T0 unit, T1 unit, T2 unit, and T3 unit. A Tn unit (n = 0, 1, 2, 3) refers to a state in which n of the three oxygen atoms bonded to a silicon atom constituting a T unit are bonded to another silicon atom, and the ratio of these is 29 This can be determined from the integral value in Si-NMR measurements.

[0044] From the viewpoint of mechanical strength of external additive particles, 29 When Si-NMR measurement is performed, it is preferable that the following formula (P2) is satisfied. {(Integral value in T0 units) + (Integral value in T1 units)} / {(Integral value in T0 units) + (Integral value in T1 units) + (Integral value in T2 units) + (Integral value in T3 units)} ≤ 0.1 (P2) In addition, from the viewpoint of flexibility and elasticity of the external additive particles, 29 When Si-NMR measurement is performed, it is preferable that the following formula (P3) is satisfied. Integral value in T2 units / {(Integral value in T0 units) + (Integral value in T1 units) + (Integral value in T2 units) + (Integral value in T3 units)} ≥ 0.35 (P3) The present inventors believe that satisfying the above formula (P3), i.e., containing a sufficient amount of T2 units in the polysiloxane portion of the external additive particles, increases the flexibility and elasticity of the external additive particles, making it difficult for the external additive particles to be embedded in the toner particles even after continuous image output, and reducing the occurrence of variations in image density caused by the embedded external additive particles.

[0045] Furthermore, from the viewpoint of flexibility and elasticity of the external additive particles, 29 When Si-NMR measurement is performed, it is preferable that the integral value of the T2 unit relative to the integral value of the T3 unit is 1 or more.

[0046] the above 29 The integral values in the Si-NMR measurement can be controlled by the type and amount of the silicon atom-containing monomer unit when producing the polymer contained in the external additive particles. The integral value of the T2 unit can also be controlled by adjusting the reaction pH when producing the polymer contained in the external additive particles.

[0047] <D50 of external additive particles> In order to ensure that the external additive particles have an appropriate volume average particle size, when the 50% particle size based on the volume distribution of the external additive particles is defined as D50, the D50 is preferably 50 nm or more and 200 nm or less.

[0048] <Method for producing external additive particles> In the production of external additive particles, it is preferable to carry out a radical polymerization reaction using a compound containing a radical polymerizable group and a hydrolyzable group that forms a siloxane bond by hydrolysis and polycondensation, and then carry out a hydrolysis reaction and a polycondensation reaction to obtain condensate particles.Furthermore, it is preferable to react the polycondensate particles with an amine compound having a silyl group to which a hydrolyzable group is bonded.Specific examples of the amine compound will be described later.

[0049] By carrying out the radical polymerization reaction first, the main skeleton of the polymer contained in the external additive particles becomes a vinyl polymer moiety, which is thought to increase the affinity with the resin that constitutes the toner, and therefore the fluidity of the toner to which the external additive particles have been added tends to increase.

[0050] Furthermore, it is preferable to include a radically polymerizable sulfonate in the monomer raw material for the radical polymerization reaction, or to use a persulfate as a radical polymerization initiator, since this allows sulfur atoms to be incorporated into the surface regions of the polymer and toner particles according to the present disclosure.

[0051] That is, as one aspect of the present disclosure, a method for producing external additive particles containing a polymer is preferably provided, the method for producing external additive particles being characterized by having step (i-1), step (ii), and step (iii) or step (i-2), step (ii), and step (iii).

[0052] (i-1) a step of radically polymerizing a monomer raw material containing a radically polymerizable sulfonate and a compound represented by the following formula (2) to obtain a polymer having a hydrolyzable group in the formula (2): (i-2) a step of radically polymerizing a monomer raw material containing a compound represented by the following formula (2) using a persulfate as a radical polymerization initiator to obtain a polymer having a hydrolyzable group in the formula (2): (ii) a step of hydrolyzing the hydrolyzable groups in the polymer obtained in the step (i-1) or the step (i-2) and polycondensing the hydrolyzable groups to obtain polycondensate particles; (iii) A step of reacting particles of the polycondensate with an amine compound having a silyl group to which a hydrolyzable group is bonded to obtain particles containing a polymer in which the polycondensate and the amine compound are bonded via a siloxane bond. R 5 m Six 4-m ···(2) (In formula (2), X is a hydrolyzable group, and m is an integer of 1 to 3, When m=1, R 5 is a radical polymerizable group having 1 to 20 carbon atoms, When m=2~3, multiple R 5 At least one R 5 is a radical polymerizable group having 1 to 20 carbon atoms, and other R is not a radical polymerizable group. 5 are each independently an alkyl group having 1 to 20 carbon atoms. R in equation (2) 5 The number of carbon atoms in the group is preferably 1 to 15, and more preferably 1 to 10. Furthermore, m is preferably 1 or 2, and more preferably 1.

[0053] After the radical polymerization reaction, the hydrolysis reaction of the hydrolyzable group in the formula (2) and the polycondensation reaction are carried out, thereby obtaining external additive particles containing a polymer in which a vinyl polymer is crosslinked by a siloxane bond. Furthermore, by carrying out hydrolysis and polycondensation after the molecular chain of the vinyl polymer is formed, it is easy to obtain a polymer in which the ratio of the number of silicon atoms constituting the external additive particles is controlled as described above. Furthermore, it is thought that by carrying out the hydrolysis reaction and the polycondensation reaction later, sulfur atoms and nitrogen atoms are easily contained in the surface region of the external additive particles.

[0054] In the particles of the polycondensate obtained in the above step (ii), hydrolyzable groups (particularly hydroxyl groups) bonded to silicon atoms remain.In step (iii), a siloxane bond is formed between the silicon atom bonded to the hydrolyzable group and the silyl group in the amine compound to which the hydrolyzable group is bonded, thereby bonding the polycondensate to the amine compound.That is, it is preferable that the particles of the polycondensate have hydrolyzable groups.

[0055] The silyl group is preferably bonded to three hydrolyzable groups. The silyl group bonded to the hydrolyzable groups is preferably a silyl group bonded to an alkoxy group, i.e., an alkoxysilyl group.

[0056] The hydrolyzable group according to the present disclosure refers to a functional group that is converted to a hydroxy group when hydrolyzed while bonded to a silicon atom, or a hydroxy group. Examples include at least one selected from the group consisting of a hydroxy group, a fluoro group, a chloro group, a bromo group, an iodo group, an alkoxy group, and an acyloxy group. A structure in which such a hydrolyzable group is bonded to a silicon atom is easily hydrolyzed by water, and subsequent polycondensation reactions are likely to occur, making it easy to form a siloxane bond. Preferred examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group, and preferred examples of the acyloxy group include an acetoxy group. More preferred examples of the hydrolyzable group according to the present disclosure include a hydroxy group, a methoxy group, an ethoxy group, a propoxy group, and an acetoxy group, and even more preferred examples are a methoxy group and an ethoxy group.

[0057] The radically polymerizable group refers to a substituent having a radically reactive double bond in its structure, such as a vinyl group, an acryloxyalkyl group, or a methacryloxyalkyl group.

[0058] The radically polymerizable sulfonate is an organic sulfonate compound having the radically polymerizable group described above in the compound.

[0059] Examples of radical polymerizable sulfonates include sodium p-styrenesulfonate, potassium p-styrenesulfonate, lithium p-styrenesulfonate, magnesium p-styrenesulfonate, calcium p-styrenesulfonate, ammonium p-styrenesulfonate, sodium vinylsulfonate, potassium vinylsulfonate, lithium vinylsulfonate, magnesium vinylsulfonate, calcium vinylsulfonate, ammonium vinylsulfonate, etc. These radical polymerizable sulfonates may be used alone or in combination of two or more.

[0060] Examples of persulfates used as radical polymerization initiators include the following:

[0061] Potassium persulfate, sodium persulfate, ammonium persulfate, etc. These persulfates may be used alone or in combination of two or more.

[0062] From the viewpoint of toner fluidity maintenance, the radical polymerizable sulfonate is preferably 0.4 to 5.0% by mass, more preferably 0.7 to 1.0% by mass, based on the total mass of the monomer raw materials. From the viewpoint of toner fluidity, the compound represented by formula (2) is preferably 50 to 80% by mass, more preferably 60 to 75% by mass, based on the total mass of the monomer raw materials.

[0063] <Radical polymerization reaction (step (i-1), step (i-2))> The radical polymerization reaction method is preferably an emulsion polymerization method. The emulsion polymerization method is a polymerization method in which a medium such as water, a monomer that is poorly soluble in the medium, and an emulsifier (surfactant) or an ionic comonomer are mixed, and a polymerization initiator that is soluble in the medium is added thereto. The emulsion polymerization method is preferably a soap-free emulsion polymerization method in which polymerization is performed without using a surfactant. The present inventors believe that this is because the soap-free emulsion polymerization method prevents the surfactant from remaining on the surface of the external additive particles, making it easier to control the affinity between the toner particles and the external additive particles.

[0064] Specific examples of the compound represented by the above formula (2), that is, the monomer containing both a radically polymerizable group and a hydrolyzable group, include the following.

[0065] Organotrialkoxysilane compounds such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, 1-hexenyltrimethoxysilane, and 1-octenyltrimethoxysilane, organotriacetoxysilane, bis(γ-acryloxypropyl)dimethoxysilane, bis(γ-methacryloxypropyl)dimethoxysilane, γ-methacryloxypropylethyldimethoxysilane, γ-methacryloxypropylethyldiethoxysilane, and γ-acryloxypropyl Diorganodialkoxysilane compounds such as bis(γ-acryloxypropyl)ethoxysilane, γ-acryloxypropylethyldiethoxysilane, etc.; triorganoalkoxysilane compounds such as tris(γ-acryloxypropyl)methoxysilane, tris(γ-acryloxypropyl)ethoxysilane, tris(γ-methacryloxypropyl)methoxysilane, tris(γ-methacryloxypropyl)ethoxysilane, bis(γ-acryloxypropyl)vinylmethoxysilane, bis(γ-methacryloxypropyl)vinylmethoxysilane, γ-acryloxypropyldiethylmethoxysilane, γ-acryloxypropyldiethylethoxysilane, γ-methacryloxypropyldiethylmethoxysilane, γ-methacryloxypropyldiethylethoxysilane, etc.

[0066] Of the above monomers, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriacetoxysilane are more preferred.

[0067] The compound represented by the above formula (2), that is, the monomer containing both a radically polymerizable group and a hydrolyzable group, is preferably a monomer represented by the following formula (3).

[0068] [ka]

[0069] (In formula (3), R 1 is an alkylene group having 1 to 10 carbon atoms, and R 2 , R 3 , and R 4 are each independently hydrogen, a methyl group, or an ethyl group, and R' is hydrogen or a methyl group. 1 More preferably, it is an alkylene group having 1 to 5 carbon atoms.

[0070] The radical polymerization initiator used in the radical polymerization is not particularly limited, but is preferably at least one compound selected from persulfates, azo compounds, and peroxides, and more preferably persulfates. The amount of the radical polymerization initiator is not particularly limited, but is preferably 0.1 to 10.0 mass% relative to the total mass of the raw material monomers, and more preferably 0.3 to 5.0 mass%. When the amount of the radical polymerization initiator is within the above range, the radical polymerization can proceed sufficiently and the amount of heat generated in the reaction system is less likely to be excessive, which is preferable.

[0071] The temperature during radical polymerization can be appropriately selected depending on the type and amount of the radical polymerization initiator used, and is preferably in the range of 30 to 100°C, more preferably in the range of 50 to 80°C.

[0072] The radical polymerization steps, i.e., steps (i-1) and (i-2) according to the present disclosure, are preferably carried out under conditions of 6.0≦pH≦8.0. More preferably, 6.5≦pH≦7.5. It is believed that when the pH of the reaction system is within the above range, hydrolysis of hydrolyzable groups and polycondensation reactions are less likely to occur during the radical polymerization reaction. It is believed that carrying out hydrolysis and polycondensation reactions after radical polymerization makes it easier for sulfur atoms and nitrogen atoms, which tend to have higher polarity, to be incorporated into the surface region of the external additive particles. Therefore, it is preferable that the radical polymerization reaction be carried out in a buffer solution. The buffer solution is not particularly limited, and any buffer solution exhibiting a near-neutral pH, such as a phosphate buffer solution or an MES buffer solution, may be used.

[0073] Furthermore, in the case of radical polymerization, not only a monomer containing both a radically polymerizable group and a hydrolyzable group but also other monomers having a radically polymerizable group may be used.

[0074] Examples of other monomers include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, unsaturated carboxylic acid esters such as acrylic acid esters, methacrylic acid esters, crotonates, itaconic acid esters, maleates, and fumarates, acrylamides, methacrylamides, aromatic vinyl compounds such as styrene, α-styrene, and divinylbenzene, vinyl esters such as vinyl acetate, and vinyl halide compounds such as vinyl chloride. These monomers may be used alone or in combination. Monomers containing two or more radically polymerizable groups, such as divinylbenzene, trimethylolpropane trimethacrylate, and ethylene glycol dimethacrylate, may also be used.

[0075] <Hydrolysis reaction and polycondensation reaction (step (ii))> The methods for the hydrolysis and polycondensation reactions are not particularly limited. Preferably, an emulsion containing particles obtained by radical polymerization is subjected to hydrolysis and polycondensation by adding a catalyst such as an acid or base. The resulting emulsion is then hydrolyzed and polycondensed to obtain polycondensate particles. That is, step (ii) is preferably performed by adding a catalyst such as an acid or base to hydrolyze the hydrolyzable groups in the polymer obtained by step (i-1) or step (i-2) and polycondensate the hydrolyzable groups to obtain polycondensate particles. Furthermore, step (ii) is preferably performed under a pH of 2.0 or less and 4.0 or less. It has been found that performing the hydrolysis and polycondensation under these conditions tends to increase the proportion of T2 units among the T units in the polysiloxane moiety. Alternatively, the particles obtained by radical polymerization may be isolated from the emulsion by filtration, centrifugation, vacuum concentration, or other procedures, and then a catalyst may be added to perform hydrolysis and polycondensation.

[0076] When carrying out hydrolysis or polycondensation after particle formation by radical polymerization reaction, a catalyst such as acetic acid, hydrochloric acid, ammonia, urea, alkanolamine, tetraalkylammonium hydroxide, alkali metal hydroxide, or alkaline earth metal hydroxide may be used.

[0077] Examples of catalysts that are more preferred from the viewpoint of further promoting polycondensation include acetic acid, hydrochloric acid, organic titanium compounds such as titanium tetraisopropoxide, titanium tetrabutoxide, and diisopropoxy-bis(acetylacetonate)titanate, organic aluminum compounds such as aluminum triisopropoxide, aluminum tri-sec-butoxide, aluminum trisacetylacetonate, and aluminum isopropoxide-bisacetylacetonate, organic zirconium compounds such as zirconium tetrabutoxide and tetrakis(acetylacetonate)zirconium, organic tin compounds such as dibutyltin diacetate, dibutyltin diethylhexanoate, and dibutyltin dimaleate, and acidic phosphate esters. These may be used alone or in combination. Among these, at least one selected from the group consisting of organic tin compounds and acidic phosphate esters is preferred. From the viewpoint of suppressing the embedding of external additive particles in the toner surface, it is preferred to use at least one selected from acetic acid and hydrochloric acid.

[0078] The solvent used in producing the external additive particles may contain an organic solvent other than water and the catalyst. Specific examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, and 1,4-butanediol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, (cyclo)paraffins such as isooctane and cyclohexane, ethers such as dioxane and diethyl ether, and aromatic hydrocarbons such as benzene and toluene. Two or more of these organic solvents may be mixed and used.

[0079] The hydrolysis reaction and polycondensation reaction can be carried out, for example, by adding an appropriate catalyst to the emulsion prepared by the radical polymerization reaction and stirring at a temperature in the range of 0 to 100°C, preferably 0 to 70°C, for 3 to 24 hours.

[0080] <Reaction with an amine compound having a silyl group to which a hydrolyzable group is bonded (step (iii))> From the viewpoint of density stability of the output image, it is preferable to react the polycondensate particles obtained in step (ii) with an amine compound having a silyl group bonded to a hydrolyzable group to obtain particles containing a polymer in which the polycondensate and the amine compound are bonded via a siloxane bond. The reaction to form this siloxane bond is a hydrolysis reaction and a polycondensation reaction. By carrying out the above reaction, a siloxane bond is formed between a silicon atom bonded to a hydrolyzable group present in the polycondensate and a silicon atom (silyl group) bonded to a hydrolyzable group present in the amine compound. As a result, nitrogen atoms are incorporated into the produced polymer, and the ratio of nitrogen atoms in the surface region of the external additive particles is likely to fall within the above-mentioned range.

[0081] The amine compound used in step (iii) is preferably a compound represented by the following formula (4).

[0082] [ka]

[0083] (In formula (4), R 41 and R 42 are each independently an alkyl group having 1 to 6 carbon atoms which may have an amino group, or a hydrogen atom, and R 43 is an alkylene group having 1 to 6 carbon atoms, n is 0 to 2, and R 44 is an alkyl group having 1 to 6 carbon atoms, and Y is a hydrolyzable group.

[0084] R in the above formula (4) 41 and R 42 are preferably each independently an alkyl group having 1 to 3 carbon atoms which may have an amino group, or a hydrogen atom. 41 and R 42 are preferably each independently an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. 43 is preferably an alkylene group having 2 to 4 carbon atoms, and R 44is preferably an alkyl group having a carbon number of 1 to 3. Furthermore, n is preferably 0 or 1, and more preferably 0.

[0085] Specific examples include aminosilanes such as 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, and 3-(2-aminoethylamino)propyldimethoxydimethylsilane.

[0086] From the viewpoint of toner chargeability, it is preferable to treat the surface of the external additive particles with another surface treatment agent in order to treat the hydroxyl groups remaining on the surface of the external additive particles and to adjust the amount of negative charge. Examples of such other surface treatment agents include silicon compounds such as organoalkoxysilane and hexamethyldisilazane, titanium compounds such as tetrabutyl titanate, and hydrolyzates and condensates thereof.

[0087] The surface treatment using the other surface treatment agent may be carried out simultaneously with the reaction of the amine compound with the polycondensate particles, or may be carried out after the reaction.

[0088] The method for the surface treatment is not particularly limited, as long as it can coat the particle surfaces with the surface treatment agent. For example, the surface treatment can be carried out by placing the particles in a suitable container, then adding the surface treatment agent, and mixing and contacting the particles with stirring at room temperature (25°C ± 5°C) to about 100°C for 3 to 24 hours. In this case, the surface treatment can be more uniformly carried out by dissolving the surface treatment agent in a solvent such as methanol and gradually adding this dropwise while mixing and contacting the particles. The amount of surface treatment agent present on the particle surfaces can be adjusted by appropriately selecting the type of surface treatment agent, the surface treatment time, the particle size of the external additive, and the like. If necessary, the surface-treated object can be washed with, for example, alcohol to obtain external additive particles from which unnecessary substances have been removed.

[0089] <Post-processing> The polymer-containing particles obtained by the method for producing external additive particles according to the present disclosure are isolated from the slurry using a method such as filtration, centrifugation, vacuum concentration, spray drying, or flash vacuum drying, and then preferably dried at 30 to 100° C., more preferably at 30 to 80° C., and even more preferably at 50 to 70° C. By carrying out the drying treatment, external additive particles having appropriate charging properties and appropriate mechanical strength are easily obtained.

[0090] <Toner> Furthermore, the external additive particles according to the present disclosure are preferably contained on the surface of toner particles. That is, one aspect of the present disclosure is a toner containing toner particles and external additive particles on the surface of the toner particles, wherein the external additive particles are the external additive particles according to the present disclosure.

[0091] The toner particles preferably contain a binder resin. Examples of the binder resin include polyester resins, vinyl resins, epoxy resins, and polyurethane resins. From the viewpoint of storage stability, the binder resin preferably has a glass transition temperature (Tg) of 45 to 70°C.

[0092] <Method of manufacturing toner particles> The method for producing the toner particles according to the present disclosure is not particularly limited, and for example, a pulverization method or a polymerization method such as an emulsion polymerization method, a suspension polymerization method, or a solution suspension method can be used.

[0093] The pulverization method will now be described. In the pulverization method, first, the binder resin, colorant, wax, charge control agent, etc. that constitute the toner particles are thoroughly mixed using a mixer such as a Henschel mixer or a ball mill. Next, the resulting mixture is melt-kneaded using a thermal kneader such as a twin-screw kneading extruder, a heated roll, a kneader, or an extruder, and then cooled and solidified, followed by pulverization and classification. In this way, the toner particles according to the present disclosure are obtained.

[0094] Examples of kneaders include the following: KRC kneader (manufactured by Kurimoto Iron Works); Buss-Co kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by The Japan Steel Works); PCM kneader (manufactured by Ikegai Iron Works); three-roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); Kneadex (manufactured by Mitsui Mining Co., Ltd.); MS-type pressure kneader, kneader-ruder (manufactured by Nippon Spindle Co., Ltd.); and Banbury mixer (manufactured by Kobe Steel, Ltd.).

[0095] Examples of pulverizers include the following: Counter Jet Mill, Micron Jet, Innomizer (manufactured by Hosokawa Micron Corporation); IDS-type mill, PJM jet pulverizer (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); Cross Jet Mill (manufactured by Kurimoto Iron Works Co., Ltd.); Urmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet-O-Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turbo Industrial Co., Ltd.); and Super Rotor (manufactured by Nisshin Engineering Co., Ltd.).

[0096] Examples of classifiers include the following: Cruseal, Micron Classifier, and Spedic Classifier (manufactured by Seishin Enterprise Co., Ltd.); Turbo Classifier (manufactured by Nisshin Engineering Co., Ltd.); Micron Separator, Turboplex (ATP), and TSP Separator (manufactured by Hosokawa Micron Corporation); Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.), and Dispersion Separator (manufactured by Nippon Pneumatic Industry Co., Ltd.); and YM Microcut (manufactured by Yaskawa Corporation).

[0097] The suspension polymerization method will be described. In the suspension polymerization method, first, a polymerizable monomer capable of producing a binder resin and various additives, if necessary, are mixed, and the materials are dissolved or dispersed using a disperser to prepare a polymerizable monomer composition. Examples of the various additives include colorants, waxes, charge control agents, polymerization initiators, and chain transfer agents. Examples of dispersers include homogenizers, ball mills, colloid mills, and ultrasonic dispersers. Next, the polymerizable monomer composition is added to an aqueous medium containing poorly water-soluble inorganic fine particles, and droplets of the polymerizable monomer composition are prepared using a high-speed disperser such as a high-speed stirrer or ultrasonic disperser (granulation step). The polymerizable monomer in the droplets is then polymerized to obtain toner particles (polymerization step). The polymerization initiator may be mixed during the preparation of the polymerizable monomer composition, or may be mixed into the polymerizable monomer composition immediately before forming droplets in the aqueous medium. Furthermore, the toner particles may be added in a state of being dissolved in a polymerizable monomer or another solvent, as required, during or after the granulation of the droplets, i.e., immediately before the start of the polymerization reaction. After the polymerizable monomer is polymerized to obtain a binder resin, the resulting mixture may be subjected to a solvent removal treatment as required to obtain a dispersion of toner particles.

[0098] <Method of Adding External Additive Particles to Toner Particles> The toner according to the present disclosure can be obtained by mixing toner particles and external additive particles using a mixer such as a Henschel mixer.

[0099] Examples of mixers include the following: Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); Super mixer (manufactured by Kawata Corporation); Ribocone (manufactured by Okawara Manufacturing Co., Ltd.); Nauta mixer, Turbulizer, Cyclomix (manufactured by Hosokawa Micron Corporation); Spiral pin mixer (manufactured by Pacific Machinery Works Co., Ltd.); and Lödige mixer (manufactured by Matsubo Corporation).

[0100] The toner particles preferably contain, on their surfaces, the above-described external additive particles as well as other external additives, such as those listed below.

[0101] Fluorine-based resin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; fine powder silica such as wet-process silica and dry-process silica, fine powder titanium oxide, fine powder alumina, treated silica obtained by surface-treating these with a silane compound, a titanium coupling agent, or silicone oil; oxides such as zinc oxide and tin oxide; double oxides such as strontium titanate, barium titanate, calcium titanate, strontium zirconate, and calcium zirconate; carbonate compounds such as calcium carbonate and magnesium carbonate, etc.

[0102] <Various additives for toner> If necessary, the toner may contain one or more additives selected from colorants, waxes, magnetic materials, charge control agents, etc. Various additives used in the toner will be specifically described below.

[0103] <Magnetic material> The toner may contain magnetic particles and be used as a magnetic toner. In this case, the magnetic particles may also serve as a colorant.

[0104] Examples of magnetic particles contained in the magnetic toner include the following.

[0105] Iron oxides such as magnetite, hematite, and ferrite, metals such as iron, cobalt, and nickel, or alloys and mixtures thereof of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, bismuth, calcium, manganese, titanium, tungsten, and vanadium.

[0106] The magnetic particles preferably have an average particle size of 2 μm or less, more preferably 0.05 μm or more and 0.5 μm or less, and the content of the magnetic particles is preferably 20 parts by mass or more and 200 parts by mass or less, more preferably 40 parts by mass or more and 150 parts by mass or less, per 100 parts by mass of the binder resin.

[0107] <Coloring agent> Examples of colorants include the following:

[0108] As a black colorant, for example, carbon black, grafted carbon, or the yellow / magenta / cyan colorants shown below are used to tone the color to black.

[0109] Yellow colorants include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

[0110] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, etc. Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, etc.

[0111] The colorants may be used alone or in combination, or in the form of a solid solution. The colorants are selected in consideration of hue angle, chroma, brightness, weather resistance, transparency for overhead projectors, and dispersibility in the toner.

[0112] The content of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0113] <Wax> Examples of waxes include the following:

[0114] Low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymers, aliphatic hydrocarbon waxes such as polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, block copolymers of aliphatic hydrocarbon waxes, and oxides thereof.

[0115] Ester waxes whose main component is fatty acid ester, such as carnauba wax; partially or completely deoxidized fatty acid esters, such as deoxidized carnauba wax.

[0116] <Charge control agent> The charge control agent is not particularly limited, but is preferably an organic metal complex or a chelate compound, such as a monoazo metal complex, an acetylacetone metal complex, or a metal complex or metal salt of an aromatic hydroxycarboxylic acid or an aromatic dicarboxylic acid.

[0117] Specific examples that can be used include Spilon Black TRH, T-77, and T-95 (Hodogaya Chemical Co., Ltd.), and BONTRON (registered trademark) S-34, S-44, S-54, E-84, E-88, and E-89 (Orient Chemical Co., Ltd.). Charge control resins can also be used in combination with the above-mentioned charge control agents.

[0118] <Developer> The toner can be used as a one-component developer, but in order to further improve dot reproducibility and to provide stable images over a long period of time, it may also be mixed with a magnetic carrier and used as a two-component developer.

[0119] As the magnetic carrier, for example, iron with an oxidized surface, iron with an unoxidized surface, nickel, cobalt, manganese, chromium, rare earth metals, and alloys or oxides thereof are preferably used.

[0120] Furthermore, it is preferable that the surface of the magnetic carrier contains or is coated with a styrene-based resin, an acrylic-based resin, a silicone-based resin, a fluorine-based resin, or a polyester.

[0121] <Various measurement methods, etc.> Various measurement methods will be described below.

[0122] <Method for measuring the ratio of the number of silicon atoms to the total number of carbon atoms, oxygen atoms, and silicon atoms that constitute external additive particles, and the abundance ratio of carbon atoms and silicon atoms that constitute external additive particles> Carbon and oxygen atoms The concentrations (atomic %) of carbon atoms and oxygen atoms present in the external additive particles are calculated using elemental analysis by combustion. The device for elemental analysis is shown below. Equipment used: PerkinElmer 2400II fully automatic elemental analyzer Silicon atoms The concentration (atomic %) of silicon atoms present in the external additive particles is measured by elemental analysis using inductively coupled plasma atomic emission spectrometry (ICP-AES) with alkali fusion. The ICP-AES device is shown below. Equipment used: Shimadzu ICPS-8100 The obtained composition ratio is converted into mol%, and the converted value is used to calculate the ratio of the number of silicon atoms to the total number of carbon atoms, oxygen atoms, and silicon atoms that constitute the external additive particles. Similarly, the ratio of the number of carbon atoms to the number of silicon atoms that constitute the external additive particles is calculated.

[0123] <Method for measuring the ratio of the number of sulfur atoms and nitrogen atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms on the surface of external additive particles> The atomic ratio of sulfur atoms and nitrogen atoms present in the surface region of the external additive particles is measured by X-ray photoelectron spectroscopy using the following apparatus and measurement conditions. Equipment used: ULVAC-PHI PHI Quantera SXM ·X-ray photoelectron spectrometer measurement conditions: X-ray source Al Kα(1486.6eV) 200μmφ Pass Energy: 140 eV Charge neutralization: Combined use of electron neutralization gun and Ar ion neutralization gun Sweep number: C 20 times, N 100 times, O 20 times, Si 20 times, S 100 times From the measured peak intensity of each element, the atomic concentrations (all in atomic %) of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms present in the surface region of the external additive particle were calculated using relative sensitivity factors provided by ULVAC-PHI. From these results, the ratio of the number of nitrogen atoms and sulfur atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms on the surface of the external additive particle was calculated. Similarly, the ratio of the number of nitrogen atoms to the number of sulfur atoms in the surface region of the external additive particle was calculated.

[0124] <Measuring method for the 50% particle size (D50) of a particle sample based on its volume distribution> The 50% particle size (D50) of the volume distribution standard of the fine particle sample is measured using a dynamic light scattering particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso). Specifically, the range is set to 0.001 μm to 10 μm, and the measurement is performed according to the following procedure.

[0125] To prevent the sample from agglomerating, a dispersion of the sample is placed in an aqueous solution containing Family Fresh (Kao Corporation) and stirred. After stirring, the sample is poured into the above-mentioned device and measured twice to obtain the average value.

[0126] The measurement conditions are as follows: measurement time is 30 seconds, the refractive index of the sample particles is 1.49, the dispersion medium is water, and the refractive index of the dispersion medium is 1.33.

[0127] The volume particle size distribution of the measurement sample is measured, and the particle size at which the cumulative volume from the small particle diameter side in the cumulative volume distribution is 50% is defined as the 50% particle size (D50) of the volume distribution standard for each microparticle.

[0128] <Confirmation of vinyl polymer portion and siloxane portion in the polymer, and 29 About Si-NMR measurements> The presence of vinyl polymer moieties in a polymer can be confirmed by subjecting the polymer to pyrolysis GC / MS and identifying the monomer species produced by pyrolysis.

[0129] In the present disclosure, the pyrolysis GC / MS equipment used to confirm whether a polymer contains a vinyl polymer moiety was a combination of the following equipment. Agilent 7890A, 5975C (Agilent Technologies) PY-2020iD (Frontier Labs) In addition, solid-state NMR analysis and IR analysis can also be used in combination with pyrolysis GC / MS.

[0130] In addition, the presence of siloxane moieties in the polymer means that the polymer 29 This can be confirmed by the presence of at least one of Q units, T units, D units, and M units in Si-NMR measurements (solid-state NMR). In the present disclosure, an Avance III (manufactured by Bruker) solid-state NMR device was used to confirm whether or not the polymer contains siloxane moieties.

[0131] 29 In Si-NMR measurements (solid-state NMR), if Q units are present, a peak appears at -105 ppm to -118 ppm in the above spectrum, if T units are present, a peak appears at -40 ppm to -74 ppm or -94 ppm to -104 ppm, if D units are present, a peak appears at -13 ppm to -25 ppm, and if M units are present, a peak appears around 8.5 ppm.

[0132] Furthermore, these peaks are assigned, and the integral values of the respective peaks are calculated to be the respective integral values in the above formula (P1).

[0133] Among the peaks corresponding to the T units, the T0 unit appears as a peak between -40 ppm and -45 ppm, the T1 unit appears as a peak between -45 ppm and -53 ppm, the T2 unit appears as a peak between -53 ppm and -64 ppm, and the T3 unit appears as a peak between -64 ppm and -74 ppm.

[0134] To separate the peaks in the T0-T3 unit, we use the peak fitting program "SOLA-Solid LineShape Analysis" included in Burker's NMR analysis software TopSpin 3.5. The parameters below are used to calculate the integral value and ratio of each peak, thereby determining the values of the above formulas (P2) and (P3). Analysis range: 40 to -140 ppm Model function: Gaussian function Initial peak position: T3: Around -70 ppm T2: Around -60 ppm T1: Around -50 ppm T0: Around -40 ppm M: Around 10 ppm [Example]

[0135] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to these examples. Unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass," respectively. Furthermore, the respective measurement results in the examples were measured using the measurement methods described above.

[0136] <External Additive 1 Manufacturing Example> The following materials were placed in a glass reactor equipped with a thermometer, a reflux condenser, a nitrogen gas inlet tube, and a stirrer. Phosphate buffer solution (pH = 7.0, prepared using sodium dihydrogen phosphate dihydrate (Kishida Chemical Co., Ltd.) and disodium hydrogen phosphate dodecahydrate (Kishida Chemical Co., Ltd.)) 200 parts Sulfur atom source: 0.13 parts sodium p-styrenesulfonate (Kishida Chemical Co., Ltd.) Monomer having a radical polymerizable group and a hydrolyzable group: 11.0 parts of 3-(trimethoxysilyl)propyl methacrylate (Tokyo Chemical Industry Co., Ltd.) Non-hydrolyzable monomer: styrene (Tokyo Chemical Industry Co., Ltd.) 4.7 parts The mixture was then heated to 65-70°C while aerating nitrogen gas and stirred for 30 minutes. Then, 0.51 parts of potassium peroxodisulfate (Kishida Chemical Co., Ltd.) was added as an initiator, and stirring was continued for 6 hours to obtain a particle emulsion. The resulting particle emulsion was treated with 28% by weight of ammonia water (Kishida Chemical Co., Ltd.) to adjust the emulsion's pH to 11.0, and then stirred at 50°C for 3 hours to hydrolyze the hydrolyzable groups contained in the particles and polycondense them. Ultrafiltration was then performed to remove excess solute, and the concentration / filtration process was repeated five times. Then, 0.13 parts of 3-aminopropyltrimethoxysilane (Tokyo Chemical Industry Co., Ltd.) as a nitrogen atom source and 27.0 parts of 1,1,1,3,3,3-hexamethyldisilazane (Kishida Chemical Co., Ltd.) as a hydrophobic treatment agent were added, and the mixture was stirred at 50°C for 24 hours. Thereafter, the mixture was dried by spray drying to obtain external additive 1, which is polymer particles having a volume distribution-based 50% particle size (hereinafter referred to as D50) of 130 nm. 29 Si-NMR measurement and pyrolysis GC / MS confirmed that the additive contained vinyl polymer moieties and siloxane moieties. The physical properties of the additive 1 are shown in Table 2.

[0137] <Production Examples of External Additives 2 to 16, 22, and 23> External additives 2 to 16, 22, and 23 were obtained by the same procedure as in the production example of external additive 1, except that the types and amounts of materials used were changed as shown in Table 1. For the obtained external additive particles 2 to 16, 22, and 23, 29 Si-NMR measurement and pyrolysis GC / MS confirmed that the external additives contained vinyl polymer moieties and siloxane moieties. The physical properties of external additives 2 to 16, 22, and 23 are shown in Table 2.

[0138] <Production example of external additive 17> In the production example of external additive 1, the same procedure was carried out except that instead of adding 28% by mass of ammonia water to adjust the pH of the emulsion to 11.0, acetic acid (manufactured by Kishida Chemical Co., Ltd.) was added to adjust the pH of the emulsion to 3.0, thereby obtaining external additive 17. 29Si-NMR measurement and pyrolysis GC / MS confirmed that the additive contained vinyl polymer moieties and siloxane moieties. The physical properties of the additive 17 are shown in Table 2.

[0139] <Production example of external additive 18> In the production example of external additive 1, the same operation was carried out except that instead of adding 28 mass % ammonia water to adjust the pH of the emulsion to 11.0, hydrochloric acid (manufactured by Kishida Chemical Co., Ltd.) was added to adjust the pH of the emulsion to 3.0, thereby obtaining external additive 18. 29 Si-NMR measurement and pyrolysis GC / MS confirmed that the external additive 18 contained a vinyl polymer moiety and a siloxane moiety. The physical properties of the external additive 18 are shown in Table 2.

[0140] <Production example of external additive 19> In the production example of external additive 1, the procedure of adding ammonia water to adjust the pH to 11.0 and then stirring at a temperature of 50°C for 3 hours was replaced by adding hydrochloric acid to adjust the pH to 3.0 and then stirring at a temperature of 50°C for 1 hour, and the same procedure was carried out to obtain external additive 19. 29 Si-NMR measurement and pyrolysis GC / MS confirmed that the additive contained vinyl polymer moieties and siloxane moieties. The physical properties of the additive 19 are shown in Table 2.

[0141] <Production example of external additive 20> A solution prepared by mixing the following materials was added to a solution prepared by mixing 46.7 parts of 28% by mass aqueous ammonia and 2114 parts of deionized water at room temperature, and the mixture was stirred for 2 hours to carry out hydrolysis and polycondensation of 3-(trimethoxysilyl)propyl methacrylate. 22.1 parts 3-(trimethoxysilyl)propyl methacrylate Methanol (Kishida Chemical Co., Ltd.) 73.7 parts Initiator: 2,2'-azobis(2,4-dimethylvaleronitrile) (V-65, Fujifilm Wako Pure Chemical Industries, Ltd.) 0.12 parts Next, the mixture was heated to 70-75°C while passing nitrogen gas through, and stirred for 2 hours to carry out radical polymerization. Ultrafiltration was then carried out to remove excess solute, and concentration / filtration was repeated a total of 5 times. Then, 0.22 parts of 3-aminopropyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) and 27.0 parts of 1,1,1,3,3,3-hexamethyldisilazane (manufactured by Kishida Chemical Co., Ltd.) as a hydrophobic treatment agent were added, and the mixture was stirred at a temperature of 50°C for 24 hours. The mixture was then dried by spray drying to obtain external additive 20, which is polymer particles. The obtained external additive particles 20 were then subjected to the following steps: 29 Si-NMR measurement and pyrolysis GC / MS confirmed that the external additive 20 contained a vinyl polymer moiety and a siloxane moiety. The physical properties of the external additive 20 are shown in Table 2.

[0142] <Production example of external additive 21> The types and amounts of materials used were changed as shown in Table 1, and 0.1 parts of (3-mercaptopropyl)trimethoxysilane was added simultaneously with the addition of the nitrogen atom source and the hydrophobic treatment agent, but the same operations as in the production example of external additive 1 were carried out to obtain external additive 21. 29 Si-NMR measurement and pyrolysis GC / MS confirmed that the external additive 21 contained a vinyl polymer moiety and a siloxane moiety. The physical properties of the external additive 21 are shown in Table 2.

[0143] <External Additive 24 Manufacturing Example> The following materials were placed in a glass reactor equipped with a thermometer, a reflux condenser, a nitrogen gas inlet tube, and a stirrer. 200 parts deionized water Sulfur atom source: 0.13 parts sodium p-styrenesulfonate Non-hydrolyzable monomer: 6.3 parts of butyl methacrylate (Tokyo Chemical Industry Co., Ltd.), and 4.7 parts of styrene Next, the mixture was heated to 65-70°C while passing nitrogen gas through it. After stirring for 30 minutes, 0.51 parts of potassium peroxodisulfate was added as an initiator, and stirring was continued for 6 hours to obtain a particle emulsion. Ultrafiltration was performed to remove excess solutes from the resulting emulsion, and the concentration / filtration process was repeated a total of five times. Then, 0.13 parts of 3-aminopropyltrimethoxysilane (Tokyo Chemical Industry Co., Ltd.) as a nitrogen atom source and 27.0 parts of 1,1,1,3,3,3-hexamethyldisilazane (Kishida Chemical Co., Ltd.) as a hydrophobic treatment agent were added, and the mixture was stirred at 50°C for 24 hours. It was then spray-dried to obtain external additive 24. The physical properties of external additive 24 are shown in Table 2.

[0144] [Table 1]

[0145] The abbreviations in Table 1 are as follows: MA-TMSP: 3-(trimethoxysilyl)propyl methacrylate MA-TESP: 3-(triethoxysilyl)propyl methacrylate AA-TMSP: 3-(trimethoxysilyl)propyl acrylate VTMS: vinyltrimethoxysilane MAB: butyl methacrylate St: styrene DSS: sodium bis(2-ethylhexyl) sulfosuccinate AP-TMS: 3-aminopropyltrimethoxysilane AMA-TMS: 3-(2-aminoethylamino)propyltrimethoxysilane AMA-PDMMS: 3-(2-aminoethylamino)propyldimethoxymethylsilane DMAP-TMS: [3-(N,N-dimethylamino)propyl]trimethoxysilane IP-TMS: (3-isocyanatopropyl)trimethoxysilane KPS: potassium peroxodisulfate V-65: 2,2'-azobis(2,4-dimethylvaleronitrile)

[0146] [Table 2]

[0147] In Table 2, N / (C+N+O+Si+S) is the ratio of the number of nitrogen atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms when the surface of the external additive particle is subjected to X-ray photoelectron spectroscopy. S / (C+N+O+Si+S) is the ratio of the number of sulfur atoms to the total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms when the surface of the external additive particle is subjected to X-ray photoelectron spectroscopy. S / N is the ratio of the number of sulfur atoms to the number of nitrogen atoms when the surface of the external additive particle is subjected to X-ray photoelectron spectroscopy. Si / (C+O+Si) is the ratio of the number of silicon atoms to the total number of carbon atoms, oxygen atoms, and silicon atoms that make up the external additive particle, and C / Si is the ratio of the number of carbon atoms to the number of silicon atoms that make up the external additive particle. T / (M+D+T+Q) is the value of formula (P1) according to the present disclosure. (T0+T1) / (T0+T1+T2+T3) is the value of formula (P2) according to the present disclosure. T2 / (T0+T1+T2+T3) is the value of formula (P3) according to the present disclosure. T2 / T3 is the ratio of the external additive particles to the 29 This is the integral value in T2 units relative to the integral value in T3 units when Si-NMR measurement was performed.

[0148] The inventors speculate that the sulfur atom source used in the production examples of external additives 8 and 9 does not bond to the polymer in the external additive particles and is therefore washed away from the surface of the external additive particles during the ultrafiltration process. However, the inventors believe that potassium peroxodisulfate used as a polymerization initiator introduces -OSO3K or -OSO3H into the polymer in the external additive particles, which is why sulfur atoms are detected on the surface of the external additive particles.

[0149] <Production Example of Toner Particle 1> The following materials were premixed in a Henschel mixer, and then melt-kneaded using a twin-screw extruder (product name: PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) with the temperature set so that the melt temperature at the discharge outlet would be 150°C, to obtain a kneaded material. Amorphous polyester (propylene oxide adduct of bisphenol A / terephthalic acid = 50 / 50, number average molecular weight: 3000, acid value: 12) 100 parts Magnetic iron oxide particles 75 parts Fischer-Tropsch wax (Sasol C105, melting point: 105°C) 2 parts Charge control agent (Hodogaya Chemical Co., Ltd., T-77) 2 parts The resulting kneaded product was cooled, coarsely pulverized with a hammer mill, and then finely pulverized with a pulverizer (product name: Turbo Mill T250, manufactured by Turbo Kogyo Co., Ltd.) to obtain a finely pulverized powder. The finely pulverized powder obtained was classified with a multi-division classifier utilizing the Coanda effect to obtain toner particles 1 having a weight average particle size of 7.2 μm.

[0150] <Toner 1 manufacturing example> The external additive was added to the toner particles 1 in a dry manner. 100 parts of toner particles, 1.3 parts of external additive 1, and 1.5 parts of fumed silica (BET specific surface area: 200 m) were added to a Henschel mixer. 2 / g) was added and externally mixed in. Thereafter, the mixture was sieved through a mesh with an opening of 150 μm, and toner 1 in which external additive 1 was externally added to toner particles 1 was obtained.

[0151] <Production example of toners 2 to 24> Toners 2 to 24 were obtained in the same manner as in the production example of Toner 1, except that the external additives added to Toner Particle 1 were changed to External Additives 2 to 24, respectively.

[0152] Example 1 Toner 1 was used to carry out the following evaluations.

[0153] <Evaluation of toner fluidity> The fluidity of the toner was measured by the following method.

[0154] First, using a powder tester (PT-X, manufactured by Hosokawa Micron Corporation), 3 g of toner 1 was sieved for 10 seconds through sieves (plain woven wire mesh, JIS Z8801-1 standard) with openings of 150 μm, 100 μm, and 45 μm, while the sieves were vibrated at a vibration intensity of 4.0. The fluidity of the toner was evaluated using the fluidity index (%) given by the following formula, where A is the amount of toner remaining on the 150 μm sieve, B is the amount of toner remaining on the 100 μm sieve, and C is the amount of toner remaining on the 45 μm sieve. The evaluation results are shown in Table 3. In this evaluation, a smaller fluidity index value indicates better toner fluidity.

[0155] Fluidity index (%) = [(A + 0.6 × B + 0.2 × C) / measured sample mass] × 100 <Evaluation of Toner Fluidity Maintenance> The fluidity maintenance property of the toner was evaluated after the above evaluations.

[0156] An HP LaserJet Enterprise M609dn (manufactured by HP) was used as the image forming apparatus, and Toner 1 was placed in a cartridge, and 5,000 images were output under the following conditions. ·Paper: GFC-081 (81.0g / m 2 )(Canon Marketing Japan Inc.) Toner coverage on paper: 0.35mg / cm 2 Process speed: 377 mm / sec Thereafter, the residual toner in the cartridge was removed, and the fluidity index was calculated for the residual toner, and this value was used as the fluidity index after durability testing. The fluidity index obtained in the evaluation of the toner fluidity described above was used as the fluidity index before durability testing to calculate the rate of change shown in the following formula, and this value was used to evaluate the fluidity maintenance property of the toner. Fluctuation rate (%) = (liquidity index after endurance - liquidity index before endurance) / liquidity index before endurance × 100 A rate of change of 100% or less was determined to be one in which the effects of the present disclosure were achieved.

[0157] <Evaluation of external additive particle crushing and detachment from toner particles> The crushing of the external additive particles and their detachment from the toner particles were evaluated after the above evaluation of the toner fluidity maintenance property was carried out.

[0158] After the 5,000 images were output, the remaining toner 1 in the cartridge was removed, and the surface of the removed toner 1 was observed using a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation) to obtain an SEM image. In the obtained image, if crushed deposits were observed on the toner surface, it was judged as having been crushed, and if depressions from which external additive particles had been detached were observed on the toner surface, it was judged as having been detached.

[0159] <Evaluation of image density stability> Using the image forming apparatus used in the evaluation of the toner fluidity maintenance property, Toner 1 was placed in a cartridge and 10,000 images were output under the following conditions. Under normal temperature and low humidity conditions (temperature 23°C, relative humidity 5%RH) ·Paper: GFC-081 (81.0g / m 2 )(Canon Marketing Japan Inc.) Toner coverage on paper: 0.35mg / cm 2 Process speed: 377 mm / sec During the continuous printing of 10,000 sheets, calibration was not performed, and the above-mentioned set conditions were not changed. The reflection density of all printed images was measured, and the image density stability was evaluated based on the standard deviation value. When the standard deviation was less than 0.100, it was determined that the effects of the present disclosure were achieved. An X-Rite color reflection densitometer (500 series: manufactured by X-Rite Corporation) was used to measure the reflection density of the images.

[0160] After that, 10,000 more images were output, for a total of 20,000 images, and the image density stability was evaluated in the same manner as above. After the image output, the remaining toner 1 in the cartridge was removed, and the surface of the removed toner 1 was observed using the scanning electron microscope described above, and an SEM image was obtained. The obtained image was checked to see if any of the external additives produced above were embedded in the toner particles. The results are shown in Table 3.

[0161] <Examples 2 to 19 and Comparative Examples 1 to 5> Toners 2 to 24 were used to carry out the same evaluation as in Example 1. The evaluation results are shown in Table 3.

[0162] [Table 3]

Claims

1. An external additive particle containing a polymer having sulfur atoms and nitrogen atoms, the polymer has a vinyl polymer portion and a siloxane portion; the ratio of the number of silicon atoms constituting the external additive particles to the total number of carbon atoms, oxygen atoms, and silicon atoms constituting the external additive particles is 4.0% or more and 25.0% or less; When X-ray photoelectron spectroscopy is performed on the surface of the external additive particle, the number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms is The ratio of the number of nitrogen atoms is 0.40% or more and 2.50% or less, The ratio of the number of sulfur atoms is 0.05% or more and 0.25% or less. The external additive particles are characterized by:

2. The external additive particle according to claim 1 , wherein the polymer contains a monomer unit represented by the following formula (1): 【Chemical 1】 (In formula (1), R １ is an alkylene group having 1 to 10 carbon atoms, and R' is a hydrogen atom or a methyl group.

3. 3. The external additive particles according to claim 1, wherein the ratio of the number of carbon atoms constituting said external additive particles to the number of silicon atoms constituting said external additive particles is 6.5 or more.

4. The polymer is -SO ３ H, -SO ３ Na, -SO ３ K, -OSO ３ H, -OSO ３ Na and -OSO ３ K, at least one functional group selected from the group consisting of an (alkyl)amino group, and an (alkyl)amino group.

5. The external additive particle according to any one of claims 1 to 4, wherein the polymer has a monomer unit represented by the following formula (S): 【Chemistry 2】 (In formula (S), R Ｓ１ ~R Ｓ４ are each independently a hydrogen atom or a methyl group, and X is a hydrogen atom or an alkali metal atom.

6. The external additive particle according to any one of claims 1 to 5, wherein when X-ray photoelectron spectroscopy is performed on the surface of the external additive particle, the ratio of the number of nitrogen atoms to the number of sulfur atoms is 2.0 or more.

7. With respect to the external additive particles ２９ The external additive particles according to any one of claims 1 to 6, which satisfy the following formula (P1) when Si-NMR measurement is performed: Integral value in T units / {(integral value in M units)+(integral value in D units)+(integral value in T units)+(integral value in Q units)}≧60% (P1).

8. With respect to the external additive particles ２９ The external additive particles according to claim 7, which satisfy the following formula (P2) when Si-NMR measurement is performed: {(integral value in T0 units) + (integral value in T1 units)} / {(integral value in T0 units) + (integral value in T1 units) + (integral value in T2 units) + (integral value in T3 units)} ≦ 0.1... (P2).

9. With respect to the external additive particles ２９ The external additive particles according to claim 7 or 8, which satisfy the following formula (P3) when Si-NMR measurement is performed: Integral value in T2 units / {(integral value in T0 units)+(integral value in T1 units)+(integral value in T2 units)+(integral value in T3 units)}≧0.35... (P3).

10. With respect to the external additive particles ２９ 10. The external additive particles according to claim 7, wherein, when Si-NMR measurement is carried out, the integral value of the T2 unit relative to the integral value of the T3 unit is 1 or more.

11. When the 50% particle size of the external additive particles based on the volume distribution is defined as D50, The external additive particles according to any one of claims 1 to 10, wherein the D50 is 50 nm or more and 200 nm or less.

12. The external additive particle according to any one of claims 1 to 11, wherein the polymer is a polymer in which a vinyl polymer is crosslinked by a siloxane bond.

13. A toner comprising toner particles and an external additive on the surface of the toner particles, The toner, wherein the external additive is the external additive particles according to any one of claims 1 to 12.

14. A method for producing external additive particles containing a polymer, comprising: A method for producing external additive particles, comprising steps (i-1), (ii), and (iii), or steps (i-2), (ii), and (iii): (i-1) a step of radically polymerizing a monomer raw material containing a radically polymerizable sulfonate and a compound represented by the following formula (2) to obtain a polymer having a hydrolyzable group in the formula (2): (i-2) a step of radically polymerizing a monomer raw material containing a compound represented by the following formula (2) using a persulfate as a radical polymerization initiator to obtain a polymer having a hydrolyzable group in the formula (2): (ii) a step of hydrolyzing the hydrolyzable groups in the polymer obtained by the step (i-1) or the step (i-2) and performing polycondensation to obtain polycondensate particles; (iii) a step of reacting particles of the polycondensate with an amine compound having a silyl group to which a hydrolyzable group is bonded, to obtain particles containing a polymer in which the polycondensate and the amine compound are bonded via a siloxane bond; R ５ ｍ SiX ４－ｍ ・・・(2) (In formula (2), X is a hydrolyzable group, and m is an integer of 1 to 3, When m=1, R ５ is a radical polymerizable group having 1 to 20 carbon atoms, When m=2 to 3, multiple R ５ At least one R ５ is a radical polymerizable group having 1 to 20 carbon atoms, and other R is not a radical polymerizable group. ５ are each independently an alkyl group having 1 to 20 carbon atoms.

15. The method for producing external additive particles according to claim 14, wherein the amine compound is a compound represented by the following formula (4): 【Chemistry 3】 (In formula (4), R ４１ and R ４２ are each independently an alkyl group having 1 to 6 carbon atoms which may have an amino group, or a hydrogen atom, and R ４３ is an alkylene group having 1 to 6 carbon atoms. n is an integer of 0 to 2, and R ４４ is an alkyl group having 1 to 6 carbon atoms, and Y is a hydrolyzable group.

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