JP6774237B2 - Toner external additive and toner composition using the same - Google Patents

Description

The present invention relates to a toner external additive and a toner composition using the same.

An external additive is added to the toner used in the developing agent used in electrophotographic machines, copiers, printers, etc. in order to improve the fluidity, chargeability, and cleaning performance of photosensitive drums. There is.
As such an external additive, inorganic particles using an inorganic material and organic particles using an organic material are known. As the inorganic particles, those made of an inorganic material such as silica, titania or alumina are used (Patent Documents 1 and 2), and the organic particles are made of an organic material such as a (meth) acrylic resin and a styrene resin. Is used (Patent Document 3). Among these, silica particles are widely used as an external additive for improving the fluidity of toner.
Further, there is also a technique of using particles made of silicone resin as an external additive, and it is described in Patent Documents 1 and 2 that a toner having excellent image characteristics can be obtained by using this in combination with an external agent made of silica particles. Is listed.

Japanese Unexamined Patent Publication No. 7-92722 Japanese Unexamined Patent Publication No. 11-65165 Japanese Unexamined Patent Publication No. 2012-201862

As described above, in Patent Documents 1 and 2, silica particles and silicone resin particles are used in combination as an external additive, but silica particles are used to improve the fluidity of the toner, and Patent Document 1 further describes. It is stated that the fluidity of the toner deteriorates only with the silicone particles. Therefore, it has been a conventional wisdom that it is difficult to obtain sufficient slipperiness (fluidity) of the toner surface even if the silicone particles described in the above patent documents are used as a toner external additive.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a toner external additive having good slipperiness (toner fluidity) on the toner surface.

The present inventors have been diligently studying to solve the above problems, and when polymethylsilsesquioxane particles having a specific number average particle size are used as a toner external agent, the slipperiness (flow) of the toner The present invention was completed by finding that the property) becomes good. That is, the present invention includes the following inventions.
[1] A toner external preparation composed of polymethylsilsesquioxane particles and having a number average particle diameter of 0.001 μm or more and less than 0.10 μm.
[2] The toner external additive according to [1], wherein the coefficient of variation of the particle size of the polymethylsilsesquioxane particles is 50% or less.
[3] The toner external preparation according to [1] or [2], wherein the polymethylsilsesquioxane particles contain an anionic surfactant.
[4] A toner composition containing toner particles containing a binder resin and a colorant, and the toner external additive according to any one of [1] to [3].

The toner external preparation of the present invention, which is composed of polymethylsilsesquioxane particles and has a specific number average particle size, has suppressed aggregation and good dispersibility. Therefore, according to the toner external additive of the present invention, the surface of the toner particles can be uniformly coated, and a toner composition having good fluidity can be provided.

1. 1. Toner External Agent The toner external agent of the present invention is characterized in that it is composed of polymethylsilsesquioxane particles and has a number average particle diameter of 0.001 μm or more and less than 0.10 μm.
The silicone particles used in the above-mentioned patent documents have an average particle diameter of 0.1 μm or more, and a technique for using silicone particles having an average particle diameter smaller than this as a toner external additive has been known so far. Not done. In addition, as the particle size becomes smaller, the surface area increases and the intermolecular force becomes stronger, so that aggregation is likely to occur. In order to exert the effect as a toner external additive, it is ideal that the toner external additive adheres uniformly to the surface of the toner particles, and for that purpose, aggregation of the toner external additive is not preferable. Therefore, it is common general knowledge that a larger particle size is better for suppressing aggregation.
However, surprisingly, the toner external preparation composed of polymethylsilsesquioxane particles and having a number average particle diameter of 0.001 μm or more and less than 0.10 μm aggregates as the particle diameter becomes smaller, and the toner becomes more agglomerated. Contrary to the conventional recognition that the fluidity is deteriorated, the present inventors have found that good fluidity can be imparted to the toner composition, and have completed the present invention.

The number average particle size of the polymethylsilsesquioxane particles is preferably 0.005 μm or more, more preferably 0.007 μm or more, preferably 0.080 μm or less, and more preferably 0.050 μm or less. Is. If the number average particle size is too large, the number of polymethylsilsesquioxane particles adhering to the toner particles may be reduced and the improvement of toner fluidity may be insufficient when used as a toner external additive. On the other hand, even if the number average particle size is too small, the agglomeration of the polymethylsilsesquioxane particles becomes strong, it becomes difficult to uniformly adhere to the surface of the toner particles, and the improvement of the toner fluidity is insufficient. There is a risk of becoming. The polymethylsilsesquioxane particles having a number average particle diameter within the above range can impart fluidity to the toner, which exceeds that of the silica particles conventionally used for improving the toner fluidity. It is considered that one reason for improving the toner fluidity is that if the number average particle size is small, the number of particles adhering to the toner particles increases even with the same amount of addition, and the surface of the toner particles can be coated more uniformly. Further, the polymethylsilsesquioxane particles having the above-mentioned number average particle diameter have a small influence on the toner charge amount and can improve only the toner fluidity, so that there is an advantage that the toner design becomes easy. The particle size of the polymethylsilsesquioxane particles can be measured by a light scattering method.

The coefficient of variation of the particle size of the polymethylsilsesquioxane particles is preferably 50% or less, more preferably 40% or less, further preferably 30% or less, and smaller is preferable, but the lower limit is, for example, 2%. , And even 3% is acceptable. When the coefficient of variation is within the above range, the polymethylsilsesquioxane particles adhere to each other to form convex portions having a uniform height on the surface of the toner particles, thereby preventing the adhesion between the toner particles. , Toner fluidity is improved. The coefficient of variation of the particle size is a value represented by the following formula.
Coefficient of variation of particle size (%) = (standard deviation of particle size / average number of particles) x 100

The polymethylsilsesquioxane particles preferably contain an anionic surfactant. Examples of the anionic surfactant include those that can be used in the method for producing polysilsesquioxane particles described later. The anionic surfactant preferably contains an oxyalkylene unit in the molecule.

The polymethylsilsesquioxane particles can be produced by hydrolysis and condensation of a trifunctional organosilicon monomer, and the conventionally known method for producing polymethylsilsesquioxane particles can also be adopted in the present invention. From the viewpoint of obtaining polymethylsilsesquioxane particles having a uniform particle size and few aggregates, hydrolysis of a compound represented by the formula (1) (hereinafter, may be referred to as “compound (1)”). Hydrolyzate (a) containing compound, water and anionic surfactant (s1),
CH ₃ Si (OR) ₃ ... (1)
[In formula (1), R represents an alkyl group having 1 to 6 carbon atoms. ]
It is preferably produced by a method including a step of mixing a precipitate (b) containing water, a base catalyst and an anionic surfactant (s2).
Since both the hydrolyzate (a) and the precipitate (b) contain an anionic surfactant, the reaction solution is uniform when the hydrolyzate (a) and the precipitate (b) are mixed. The condensation reaction of the hydrolyzate of the compound (1) can easily proceed uniformly. As a result, the polymethylsilsesquioxane particles can be produced with a uniform particle size, and the dispersion stability of the polymethylsilsesquioxane particles is also improved.

The hydrolyzate (a) contains a hydrolyzate of compound (1), water and an anionic surfactant (s1).
In the above formula (1), R is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms, more preferably 1 to 2 carbon atoms), and may be linear, branched, or cyclic. You may. Examples of R include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group, cyclohexyl group and the like. Be done.
As the compound (1), one kind or a combination of two or more kinds can be used, and examples thereof include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, and methyltriisopropoxysilane.

The hydrolyzate of compound (1) is a compound containing -OH (silanol group) formed by hydrolysis of -OR, and is CH ₃ Si (OR) ₂ (OH), CH ₃ Si (OR) ( Examples thereof include OH) ₂ , CH ₃ Si (OH) _{3, and the} like, and it is preferable that CH ₃ Si (OH) ₃ is contained. Further, the hydrolyzate of the compound (1) is a compound in which a part of -OH (silanol group) contained in the hydrolyzate is condensed to form a Si—O—Si bond (hereinafter, “partial condensate product”). ”) May be included. Even if a part of -OH (silanol group) contained in the hydrolyzate is condensed, the reaction is uniform because the hydrolyzate (a) and the precipitate (b) contain an anionic surfactant. You can proceed to.

In the hydrolyzate (a), the molar concentration of silicon atoms contained in the hydrolyzate of compound (1) is preferably 0.1 mmol / g or more, more preferably 1 mmol / g or more, still more preferably 2 mmol. It is more than / g, preferably 10 mmol / g or less, more preferably 7 mmol / g or less, still more preferably 5 mmol / g or less.

Examples of the anionic surfactant (s1) include carboxylic acid-type anionic surfactants such as aliphatic monocarboxylates, polyoxyethylene alkyl ether carboxylates, and fatty acid oils; dialkyl sulfosuccinates, and polyoxyethylene. Sulfonic acid type anionic surfactants such as alkyl sulfosulfates, alkane sulfonates, linear alkyl benzene sulfonates, branched chain alkyl benzene sulfonates, naphthalene sulfonate-formaldehyde condensates, alkyl naphthalene sulfonates; Sulfonate-type anionic surfactants such as alkyl sulfates, polyoxyalkylene alkyl ether sulfates, and fats and oils sulfates; alkyl phosphates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxy Phosphate-type anionic surfactants such as ethylene alkylaryl ether phosphate; and the like; sulfonic acid-type anionic surfactants and sulfate ester-type anionic surfactants are preferable, and sulfate ester-type anionic surfactants are preferable. Activators are more preferred.

Specific examples of the anionic surfactant (s1) include polyoxyethylene styrene phenyl ether ammonium sulfate, polyoxyalkylene branched decyl ether sulfate sodium (preferably polyoxyethylene branched decyl ether sulfate sodium), and polyoxyethylene. Polyoxyethylene such as ammonium isodecyl ether sulfate, sodium polyoxyethylene tridecyl ether sulfate, sodium polyoxyethylene lauryl ether sulfate, ammonium polyoxyethylene lauryl ether sulfate, ammonium polyoxyethylene oleylcetyl ether sulfate, and sodium polyoxyethylene oleylcetyl ether sulfate. Alkyl ether sulfate; polyoxyethylene tridecyl ether phosphate ester, polyoxyethylene lauryl ether phosphate ester / monoethanolamine salt, polyoxyethylene alkyl (C8) ether phosphate ester, polyoxyethylene alkyl (C8) ether phosphorus Polyoxyethylene alkyl ether phosphates such as acid ester monoethanolamine salts, polyoxyethylene alkyl (C12,13) ether phosphate esters, polyoxyethylene alkyl (C10) ether phosphate esters; polyoxyethylene lauryl ether acetate Polyoxyethylene alkyl ether carboxylate such as sodium; polyoxyethylene alkyl sulfosulfate such as disodium polyoxyethylene lauryl ether sulfosuccinate, polyoxyethylene alkyl (C12-14) sulfosulfate; polyoxy Polyoxyethylene alkylaryl ether phosphates such as ethylene styrenated phenyl ether phosphate; fatty acid oils such as sodium oleate and potash oil; alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulphate; sodium dodecylbenzene sulfonate Alkylbenzene sulfonates such as; alkylnaphthalene sulfonates; alkane sulfonates; dialkyl sulfosulfates; alkyl phosphate ester salts, naphthalene sulfonic acid-formaldehyde condensates, and the like.

The anionic surfactant (s1) is an oxyalkylene unit (-R ¹ O- unit (R ¹ represents an alkylene group having 2 to 3 carbon atoms, preferably an ethylene group) in the molecule). ) Is preferably included. It becomes easier to make the particle size of the polymethylsilsesquioxane particles more uniform, and it becomes easier to make the obtained polymethylsilsesquioxane particles closer to a spherical shape. Specifically, an anionic surfactant containing oxyethylene units such as polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl sulfosulfate, and polyoxyethylene alkyl aryl ether phosphate. Activators are preferred, polyoxyethylene alkyl ether sulfates are more preferred, and polyoxyethylene styrene phenyl ether sulfate ammonium salts, polyoxyethylene alkyl ether sodium sulfate, and polyoxyethylene alkyl ether sulfate ammonium are even more preferred.

The content of the anionic surfactant (s1) is preferably 0.1 part by mass or more, more preferably 1 part by mass with respect to 100 parts by mass of the compound (1) used in the hydrolyzed solution (a). Parts or more, more preferably 3 parts by mass or more, particularly preferably 5 parts by mass or more, further 10 parts by mass or more, preferably 50 parts by mass or less, and more preferably 30 parts by mass or less. , More preferably 20 parts by mass or less.
Increasing the amount of the anionic surfactant used makes it easier for the particle size of the polymethylsilsesquioxane particles to become uniform, and also makes it easier to suppress the aggregation of the polymethylsilsesquioxane particles. Further, when the amount of the anionic surfactant used is suppressed, it becomes easy to reduce the foaming of the reaction solution, and it becomes easy to suppress the formation of coarse particles.

The hydrolyzed solution (a) preferably further contains an acid catalyst. The inclusion of the acid catalyst in the hydrolyzate (a) facilitates the control of the hydrolysis reaction of the compound (1) and its hydrolyzate. As the acid catalyst contained in the hydrolysis solution (a), either an organic acid or an inorganic acid can be used, and an aqueous solution thereof is preferably used. Specifically, examples of organic acids include formic acid, acetic acid, propionic acid, oxalic acid, and citric acid, and examples of inorganic acids include hydrochloric acid, sulfuric acid, nitrate, and phosphoric acid, which are easily available and can be handled. Organic acids are preferable in terms of excellent properties, and acetic acid is particularly preferable.
When the hydrolyzed solution (a) contains an acid catalyst, the content thereof is preferably 0.001 mol or more with respect to 100 mol of silicon atoms contained in the hydrolyzate of the compound (1). It is preferably 0.01 mol or more, preferably 0.5 mol or less, more preferably 0.3 mol or less, still more preferably 0.1 mol or less.

The pH of the hydrolyzed solution (a) is preferably 2.0 or more, more preferably 2.5 or more, still more preferably 3.0 or more, and preferably 5.5 or less, more preferably. Is 4.5 or less, more preferably 4.0 or less.

The charging ratio (water / compound (1)) of water used in the hydrolyzed solution (a) to the compound (1) is preferably 2 or more, more preferably 4 or more, still more preferably 4 or more on a molar basis. It is 6 or more, preferably 20 or less, more preferably 15 or less, still more preferably 10 or less.

The hydrolyzed solution (a) may contain alcohol (ROH). Examples of the alcohol include a group in which -OH is bonded to the group exemplified as R.
The alcohol content is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, and 50% by mass or less in 100% by mass of the hydrolyzed solution (a). It is preferably 40% by mass or less, still more preferably 37% by mass or less.

The total content of the hydrolyzate of compound (1), water, an acid catalyst used as needed, an anionic surfactant (s1), and alcohol contained as needed is the hydrolyzate. (A) Of 100% by mass, it is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 99% by mass or more.

The hydrolyzed solution (a) can be produced by mixing compound (1), water, an anionic surfactant (s1), and an acid catalyst used as needed. By hydrolyzing compound (1) using an acid catalyst, the hydrolysis reaction can easily proceed uniformly.
Further, a step of preparing a preliminary hydrolysis solution by mixing the compound (1), water, and an acid catalyst used as needed, and the preliminary hydrolysis solution and the anionic surfactant (s1) are added. It is preferably produced by the step of mixing and preparing the hydrolyzed solution (a). By preparing a preliminary hydrolysis solution in advance and mixing this preliminary hydrolysis solution with the anionic surfactant (s1), the influence of the anionic surfactant (s1) on the hydrolysis reaction can be suppressed. It becomes easy to control the particle size of the polymethylsilsesquioxane particles.

The preliminary hydrolyzate contains a hydrolyzate of compound (1), an acid catalyst used as needed, and water, and may contain alcohol (ROH).

The pH of the preliminary hydrolyzed solution is preferably 2.0 or more, more preferably 2.5 or more, still more preferably 3.0 or more, preferably 5.5 or less, and more preferably 4 It is 5.5 or less, more preferably 4.0 or less.

The temperature at which the compound (1), water, the acid catalyst used as needed, and the anionic surfactant (s1) to be mixed simultaneously as needed is preferably 0 ° C. or higher, more preferably. It is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, preferably 80 ° C. or lower, more preferably 50 ° C. or lower, still more preferably 40 ° C. or lower.
The time for mixing the compound (1), water, the acid catalyst used as needed, and the anionic surfactant (s1) to be mixed at the same time as needed is preferably 10 minutes or more. , More preferably 20 minutes or more, further preferably 30 minutes or more, preferably 200 minutes or less, more preferably 120 minutes or less, still more preferably 90 minutes or less.
When compound (1) is hydrolyzed, -OR contained in compound (1) is sequentially converted to -OH, and the generated -OHs are condensed with each other to form a Si-O-Si bond. These hydrolysis / condensation reactions may proceed in parallel, and when the hydrolysis solution (a) and the precipitate solution (b) are mixed by controlling the temperature and time at the time of preparation within the above range. In addition, it becomes easy to control the degree of hydrolysis / condensation reaction of compound (1) within an appropriate range.

The precipitate (b) contains water, a base catalyst and an anionic surfactant (s2). By using a base catalyst in the precipitate (b), the rate of the condensation reaction can be increased.

Examples of the base catalyst include metal hydroxides (preferably alkali metal hydroxides) such as lithium hydroxide, sodium hydroxide and potassium hydroxide; amines such as ammonia, monomethylamine and dimethylamine; Among them, amines are preferable, and ammonia is particularly preferable, because impurities that limit the use of the produced polymethylsilsesquioxane particles can be reduced and removal from the particles is easy.

The content of the base catalyst contained in the precipitate (b) is 0.01 mol or more with respect to 100 mol of silicon atoms contained in the hydrolyzate of the compound (1) in the hydrolyzate (a). Is preferable, more preferably 0.05 mol or more, still more preferably 0.1 mol or more, particularly preferably 1 mol or more, preferably 20 mol or less, and more preferably 15 mol or less. , More preferably 10 mol or less.

The pH of the precipitate (b) is preferably 8.0 or more, more preferably 8.5 or more, still more preferably 9.0 or more, and preferably 13.0 or less. It is more preferably 12.5 or less, still more preferably 12.0 or less.

The anionic surfactant (s2) may be the same as or different from the anionic surfactant (s1), and examples thereof include compounds similar to those exemplified as the anionic surfactant (s1). Of these, sulfonic acid-type anionic surfactants and sulfate ester-type anionic surfactants are preferable, and sulfate ester-type anionic surfactants are more preferable.

Further, the anionic surfactant (s2) may contain a -R ¹ O- unit (R ¹ represents an alkylene group having 2 to 3 carbon atoms, preferably an ethylene group) in the molecule. preferable. It becomes easier to make the particle size of the polymethylsilsesquioxane particles more uniform.

The content of the anionic surfactant (s2) is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, still more preferably 0.% by mass, based on 100% by mass of the precipitate (b). It is 01% by mass or more, particularly preferably 0.1% by mass or more, further may be 0.2% by mass or more, preferably 5% by mass or less, more preferably 1% by mass or less, and further. It is preferably 0.5% by mass or less.

The precipitate (b) may contain polymethylsilsesquioxane seed particles (hereinafter, may be simply referred to as “seed particles”). Due to the coexistence of the seed particles, the -OH group (silanol group) contained in the seed particles and the -OH group (silanol group) contained in the compound (1) are condensed to form polymethyl around the seed particles. Since silsesquioxane is formed, it becomes easy to control the particle size of the obtained polymethylsilsesquioxane particles. As the seed particles, polymethylsilsesquioxane particles (a homopolymer of compound (1)) are preferable.

By mixing the hydrolyzed solution (a) and the precipitated solution (b), the condensation reaction of the −OH group (silanol group) contained in the hydrolyzate of the compound (1) proceeds, and Si—O— Si bonds are formed and polymethylsilsesquioxane particles are formed. Since both the hydrolyzed liquid (a) and the precipitated liquid (b) contain an anionic surfactant, it is easy to mix uniformly from the beginning of mixing, and the condensation reaction proceeds evenly, probably because the particles. It is possible to obtain polymethylsilsesquioxane particles having a uniform diameter. The obtained polymethylsilsesquioxane particles are preferably in a dispersed state in the reaction solution.

The method of mixing the hydrolyzed liquid (a) and the precipitated liquid (b) is not particularly limited. 1) After preparing the hydrolyzed liquid (a) and the precipitated liquid (b), the hydrolyzed liquid (a) is added all at once. , Continuous dropping, or feeding into the precipitate (b) via a nozzle or the like, 2) After preparing the hydrolyzed solution (a) and the precipitate (b), the precipitate (b) is added all at once. Any method can be applied, such as continuous dropping or feeding into the hydrolyzed solution (a) via a nozzle or the like.

Above all, a method in which the hydrolyzed liquid (a) and the precipitated liquid (b) are adjusted and then the hydrolyzed liquid (a) is continuously dropped onto the precipitated liquid (b) controls the particle size uniformly and aggregates the particles. Is preferable in that it can be efficiently prevented.
Here, when the hydrolyzed solution (a) is continuously added dropwise, the dropping time is preferably 10 minutes to 300 minutes, more preferably 30 minutes to 200 minutes. The dropping rate of the hydrolyzed solution (a) is preferably 0.5 g / min or more, more preferably 1 g / min or more, still more preferably 1.5 g / min or more, and 10 g / min or less. It is preferably 7 g / min or less, more preferably 5 g / min or less.

The hydrolyzed solution (a) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 12 parts by mass or more, and 60 parts by mass with respect to 100 parts by mass of the precipitate solution (b). It is preferably less than or equal to, more preferably 50 parts by mass or less, still more preferably 45 parts by mass or less.

Further, in the mixed solution (c) obtained by mixing the hydrolyzate (a) and the precipitate (b), the molar ratio of silicon atoms contained in the hydrolyzate of water and the compound (1) (water / Si). Is preferably 20 or more, more preferably 30 or more, further preferably 40 or more, preferably 120 or less, more preferably 100 or less, still more preferably 90 or less.

The pH of the mixed solution (c) is preferably 8.0 or more, more preferably 8.5 or more, still more preferably 9.0 or more, preferably 13.0 or less, and more preferably. Is 12.5 or less, more preferably 12.0 or less.

By mixing the hydrolyzate (a) and the precipitate (b), dehydration condensation of the hydrolyzate of the compound (1) proceeds, and polymethylsilsesquioxane particles are precipitated. The reaction temperature at the time of precipitation is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, preferably 40 ° C. or lower, and more preferably 35 ° C. or lower.

Further, from the viewpoint of promoting dehydration condensation of the hydrolyzate of compound (1), it is preferable to carry out aging after adding the entire amount of the hydrolyzate (a). The aging temperature is preferably 25 ° C. or higher, more preferably 40 ° C. or higher, further preferably 45 ° C. or higher, preferably 70 ° C. or lower, and even more preferably 65 ° C. or lower.

In the above production method, the polymethylsilsesquioxane particles are obtained in a state of being dispersed in the reaction solution, but when used as a toner externalizing agent, the fine powder of the polymethylsilsesquioxane particles recovered from the reaction solution is used. It is preferable to use it. The method for recovering the fine powder of polymethylsilsesquioxane particles is not particularly limited, and for example, the polymethylsilsesquioxane particles dried by subjecting them to treatments such as filtration, drying, crushing and classification as necessary, etc. Fine powder) is obtained.
A dryer such as a spray dryer or a conical ribbon mixer can be used for drying to obtain fine powder. The dried polymethylsilsesquioxane may be subjected to steps such as crushing and classification, if necessary.

2. Toner Composition The toner composition of the present invention contains toner particles and the above-mentioned toner external additive. A toner external preparation composed of polymethylsilsesquioxane particles and having a specific particle size has good dispersibility, so that it is difficult to aggregate, and even if it is aggregated, it can be easily loosened. Can be done. Therefore, when used as a toner external additive, the polymethylsilsesquioxane particles adhere to the toner particles without overlapping, so that the surface of the toner particles can be uniformly coated. As a result, the fluidity of the toner composition (toner fluidity) becomes good.

The content of the toner external additive is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, based on 100 parts by mass of the toner particles, from the viewpoint of suppressing aggregation due to blocking between the toner particles. More preferably, it is 2 parts by mass or less. From the viewpoint of facilitating the preparation of toner while maintaining characteristics such as fixability and transferability, the content of the toner external additive should be 0.1 part by mass or more with respect to 100 parts by mass of toner particles. It is preferably 0.2 parts by mass or more, and further preferably 0.5 parts by mass or more.

As the toner particles, for example, those in which a binder resin contains a colorant or a charge control agent can be used. Examples of the binder resin include polyester resin, styrene-acrylic resin, and polyolefin resin. Examples of the colorant include carbon black, phthalocyanine pigment, azo pigment, azo dye, niglosin dye, extender pigment and the like. The content of these colorants is preferably 1 part by mass to 50 parts by mass, and more preferably 1 part by mass to 40 parts by mass with respect to 100 parts by mass of the binder resin. Examples of the charge control agent include niglosin dye, azine dye, metal complex salt, quaternary ammonium salt and the like. The content of the charge control agent is preferably 0 parts by mass to 20 parts by mass, and more preferably 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the binder resin. In addition to the colorant and the charge control agent, the toner particles may contain additives such as a mold release agent.

The number average particle size of the toner particles is preferably 1 μm or more and 25 μm or less, more preferably 3 μm or more, further preferably 5 μm or more, still more preferably 20 μm or less, still more preferably 15 μm or less, particularly. It is preferably 10 μm or less. The number average particle size of the toner particles can be measured by a precision particle size distribution measuring device using the Coulter principle.

The ratio of the average particle size of the toner particles to the toner external agent (toner particles / toner external agent) is, for example, preferably 10 or more, more preferably 50 or more, preferably 20000 or less, and more preferably. It is 1000 or less, more preferably 500 or less, and particularly preferably 200 or less.

In addition to the toner particles and the toner external additive, the toner composition may contain other components for the purpose of environmental stability, stabilization of charge amount, improvement of transfer efficiency and improvement of durability.

The toner composition can be produced by mixing toner particles, a toner external additive, and other components used if necessary. The method for mixing the constituent components of the toner composition is not particularly limited, and the polymethylsilsesquioxane particles obtained as fine powder and the toner particles may be mixed, and the reaction solution (polymethylsilsesquioxane particles) may be mixed. After mixing the dispersion) and the toner particles, the solvent may be removed from the mixture, but a method of mixing the polymethylsilsesquioxane particles, which are fine powders, with the toner particles is preferably used.

For the fluidity of the toner composition of the present invention, for example, using a powder tester (registered trademark) (PT-E type, manufactured by Hosokawa Micron Co., Ltd.), a sieve having a mesh size of 150 μm, 100 μm, and 45 μm (plain woven wire mesh, standard JIS Z8801-1). ) Is sieved under the condition of strength 4.0, 3 g to 10 g of the toner composition is sieved with these sieves for 10 seconds, and then the remaining amount of the toner composition on the sieve having a mesh opening of 150 μm is A and the mesh size is 100 μm. When the remaining amount of the toner composition is B and the remaining amount of the toner composition on the sieve having a mesh opening of 45 μm is C, the evaluation can be performed based on the fluidity index (%) represented by the following formula.
Liquidity index (%) = [(A + 0.6 × B + 0.2 × C) / weight of measured sample] × 100
The liquidity index (%) is preferably 80% or less, more preferably 60% or less, further preferably 40% or less, and particularly preferably 30% or less.
The toner composition is particularly suitable for toner (for example, static charge developing toner) applications.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples as well as the present invention, and appropriate modifications are made to the extent that it can be adapted to the gist of the above and the following. Of course, it is possible to carry out, and all of them are included in the technical scope of the present invention. In the following, unless otherwise specified, "part" means "part by mass" and "%" means "% by mass".
The measurement and evaluation of various physical properties were carried out by the following methods.

[Measurement of average particle size and coefficient of variation (CV value) of polymethylsilsesquioxane particles]
The polymethylsilsesquioxane particle dispersion obtained in the following synthesis example was diluted with ion-exchanged water and measured with a light scattering particle size distribution measuring machine (“NicomMPMODEL380” manufactured by Particle Sigmaning Systems), and the number average particle diameter was measured. (Μm) was determined, and this value was taken as the average particle size of the polymethylsilsesquioxane particles. Further, the standard deviation was calculated based on the number average particle diameter and the particle diameter obtained by the above apparatus, and the coefficient of variation (CV value:%) was obtained from the following formula.
Coefficient of variation (CV value:%) = 100 x (standard deviation / number average particle size)

[Dispersion stability evaluation]
The dispersion stability of the obtained polymethylsilsesquioxane particle dispersion was evaluated according to the following procedure. The filtration performance when the dispersion of polymethylsilsesquioxane particles obtained in the following synthetic example was filtered using a wire mesh of 300 mesh (JIS mesh, standard JISG3556: 2002) was evaluated according to the following criteria. .. The presence or absence of agglomerates after filtration was visually determined.
◯: There is almost no agglomerate on the mesh after filtration.
Δ: There are agglomerates on the mesh after filtration.
X: The mesh was clogged during filtration.

[Liquidity evaluation]
Using a powder tester (registered trademark) (PT-E type, manufactured by Hosokawa Micron Co., Ltd.), shake a sieve (plain weave wire mesh, standard JIS Z8801-1) with a mesh size of 150 μm, 100 μm, and 45 μm for 10 seconds under the condition of strength 4.0. Then, the toner compositions obtained in Examples and Comparative Examples were sieved, and then the remaining amount of the toner composition on each sieve was measured and calculated using the formula shown below. The smaller the fluidity index, the better the fluidity of the toner composition.
Liquidity index (%) = [(A + 0.6 × B + 0.2 × C) / weight of measured sample] × 100
A: Remaining amount of toner composition on a sieve with an opening of 150 μm (g), B: Remaining amount of toner composition on a sieve with an opening of 100 μm (g), C: Remaining amount of toner composition on a sieve with an opening of 45 μm (G)

(Synthesis Example 1)
To a glass reaction kettle equipped with a stirrer, a thermometer, a dropping port and a cooler, add 100.5 parts by mass of deionized water and 0.21 parts by mass of a 10% aqueous acetic acid solution, and stir at room temperature to methyltrimethoxysilane. 100.5 parts by mass (hereinafter referred to as "MTMS") was added from the dropping port to hydrolyze MTMS. 50 minutes after the completion of MTMS dropping, a 20% aqueous solution of polyoxyethylene alkyl ether sulfate (Nucol (registered trademark) 1305-SN, manufactured by Nippon Emulsifier Co., Ltd.) as an aqueous solution of the anionic surfactant (s1) is 9.54 mass. Partially added to obtain a hydrolyzed solution (a1).

On the other hand, 686.6 parts by mass of deionized water and 3.18 parts by mass of 25% aqueous ammonia were added to a glass reaction kettle equipped with a stirrer, a thermometer, a dropping port and a cooler different from the above reaction kettle at room temperature. After stirring with, 10.32 parts by mass of a 20% aqueous solution of polyoxyethylene alkyl ether sulfate (Nucol (registered trademark) 1305-SN, manufactured by Nippon Emulsifier Co., Ltd.) was added as an aqueous solution of the anionic surfactant (s2). In addition, the mixture was further stirred at room temperature to prepare a precipitate (b1).

Next, while stirring the precipitate (b1) at room temperature, the hydrolyzate (a1) was added dropwise to the precipitate (b1) over 60 minutes from the dropping port, and the polymethylsilsesquioxane particles were precipitated. Then, after dropping the entire amount of the hydrolyzed solution (a1), the reaction solution is heated to 60 ° C. and aged at 60 ° C. for 1 hour, and then the reaction solution is cooled and filtered through a sieve having a mesh size of 300 mesh. As a result, the dispersion stability was evaluated, and a dispersion solution in which the polymethylsilsesquioxane particles (1) were dispersed was obtained. The number average particle size of the obtained polymethylsilsesquioxane particles was 0.018 μm, and the coefficient of variation was 22.6%. In addition, since there were almost no aggregates on the mesh after filtration of the polymethylsilsesquioxane particles (1) dispersion, the dispersion stability was judged to be ◯.

The dispersion of the polymethylsilsesquioxane particles (1) is spray-dried with a spray dryer equipped with a four-fluid nozzle (internal inlet temperature 150 ° C., outlet temperature 70 ° C.) to obtain the polymethylsilsesquioxane particles. The dry powder of (1) was obtained.

(Synthesis Example 2)
In Synthesis Example 1, the aqueous solution of the anionic surfactant (s1) used to prepare the hydrolyzed solution (a1) is a polyoxyethylene styrene phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., High Tenol (registered). The 20% aqueous solution of NF-08) was changed to 9.54 parts by mass (hydrolyzed solution (a2)), and the aqueous solution of the anionic surfactant (s2) used for preparing the precipitate solution (b1) was polyoxy. Change to 10.32 parts by mass of 20% aqueous solution of ethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hytenol (registered trademark) NF-08) (precipitate (b2)), and further hydrolyze. Polymethylsilsesquioki was prepared by the same method as in Synthesis Example 1 except that an aqueous solution of the anionic surfactant (s2) was added to the reaction vessel before the methyltrimethoxysilane was added dropwise during the preparation of the liquid (a2). A dispersion in which the sun particles (2) were dispersed was obtained. The number average particle diameter of the obtained polymethylsilsesquioxane particles (2) was 0.035 μm, and the coefficient of variation was 21.2%. In addition, since there were almost no aggregates on the mesh after filtration of the polymethylsilsesquioxane particles (2) dispersion, the dispersion stability was judged to be ◯.
In the same manner as in Synthesis Example 1, the dispersion liquid of the polymethylsilsesquioxane particles (2) was spray-dried to obtain a dry powder of the polymethylsilsesquioxane particles (2).

(Example 1)
50 parts by mass of toner particles having an average particle diameter of 10 μm in which carbon black is dispersed as a colorant in a binder resin made of a styrene-n-butyl acrylate copolymer, and the toner external preparation obtained in Synthesis Example 1 above. Polymethylsilsesquioxane particles (1) 0.5 parts by mass were mixed at room temperature with a mixer ("Labo Miller LM-PLUS" manufactured by Iwatani Sangyo Co., Ltd.) at a peripheral speed of 65 m / s (rotation speed 20,000 rpm). The toner composition (1) was obtained by uniformly mixing the mixture for 90 seconds. Table 1 shows the fluidity evaluation results of the obtained toner composition (1). In addition, the obtained toner composition (1) was in a smooth state with no agglomerates that could be visually confirmed.

(Example 2)
The toner composition (2) was obtained by the same method as in Example 1 except that the toner external preparation was changed to polymethylsilsesquioxane particles (2). The fluidity evaluation results of the toner composition (2) are shown in Table 1.

(Comparative Example 1)
The comparative toner composition (1) was prepared by the same method as in Example 1 except that the toner external additive was changed to commercially available silica particles (Aerosil (registered trademark) RX200, manufactured by EVONIK, average particle diameter 0.012 μm). Obtained. Table 1 shows the fluidity evaluation results of the comparative toner composition (1).

(Comparative Example 2)
The comparative toner composition (2) was prepared by the same method as in Example 1 except that the toner external additive was changed to commercially available silica particles (Aerosil (registered trademark) OX50, manufactured by EVONIK, with an average particle diameter of 0.040 μm). Obtained. Table 1 shows the fluidity evaluation results of the comparative toner composition (2).

From Table 1, the toner compositions of Examples 1 and 2 containing the toner additive of the present invention have a fluidity index as compared with the comparative toner compositions of Comparative Examples 1 and 2 using silica particles as the toner external agent. It was low and had high liquidity. In particular, from the comparison between Examples 1 and 2 and Comparative Example 1, the toner external preparation of the present invention, which is composed of polymethylsilsesquioxane particles and has a specific average particle size, is widely used for improving toner fluidity. It can be seen that the toner can be provided with higher fluidity than the silica particles having an average particle diameter of about 10 nm.
From these results, it can be seen that the toner external additive of the present invention can provide a toner composition having good fluidity.

Claims (5)

A toner external preparation composed of polymethylsilsesquioxane particles, which are hydrolyzed condensates of a compound represented by the following formula (1), and having a number average particle diameter of 0.001 μm or more and less than 0.10 μm. A toner external preparation in which the polymethylsilsesquioxane particles contain an anionic surfactant having an oxyalkylene unit in the molecule.
CH ₃ Si (OR) ₃ ... (1)
[In formula (1), R represents an alkyl group having 1 to 6 carbon atoms. ] The toner external additive according to claim 1, wherein the number average particle diameter is 0.001 μm or more and 0.035 μm or less. The toner external preparation according to claim 1 or 2, excluding those that have been hydrophobized with a hydrophobizing agent. The toner external preparation according to any one of claims 1 to 3, wherein the coefficient of variation of the particle size of the polymethylsilsesquioxane particles is 50% or less. Toner particles containing binder resin and colorant,
A toner composition containing the toner external additive according to any one of claims 1 to 4.