JP2000314982A - Toner for forming electrostatic charge image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner excellent in releasability and not requiring the use of a silicon oil as a releasing agent for fixation when the toner is fixed on a transfer medium by using a composition containing a silicone solid having a melting point or a softening point. SOLUTION: The toner is a composition comprising a bonding resin, a silicone solid having a melting point or a softening point, a colorant and an electrostatic charge controlling agent. Since a silicone solid having a melting point or softening point is included, characteristics such as releasability and heat resistance peculiar to the silicone are imparted to the toner, the deterioration of flowability due to aggregation under heat is not caused and the toner has excellent anti-offsetting properties, that is, releasability. When the silicone solid is prepared by allowing an organic functional group-containing wax to react with an organic functional silicone, the toner is more excellent in releasability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a novel toner for forming an electrostatic image. More specifically, the present invention relates to a toner for forming an electrostatic charge image which contains a silicone-based solid as an essential component and does not require the use of a silicone-based oil as a fixing release agent when fixing the toner on a transfer medium such as paper.

[0002]

2. Description of the Related Art Conventionally, a general fixing method employed in an electrostatic image forming apparatus is to apply a certain pressure between a pair of rolls coated with Teflon or silicone rubber or the like heated at least one of them. This is a method in which an unfixed toner image is passed through a transfer medium such as paper carrying the unfixed toner image, and the unfixed toner image is fixed on the transfer medium. At this time, by applying a silicone oil such as polydimethylsilicone, amino-modified silicone or mercapto-modified silicone to the surface of the heating roll, a part of the toner is transferred to the heating roll, and is reprinted on the trailing edge of the same paper or the next paper. A method for preventing the offset phenomenon of being transferred and fixed is adopted (Japanese Patent Laid-Open No. 59-4699).
JP-A-59-74579, JP-A-60-74579
129768, JP-A-4-230784,
Japanese Patent Publication No. 7-97255).

In particular, in a color copying machine or the like, since an image is formed using a plurality of toners such as cyan, magenta, and yellow, the amount of toner to be fixed is large. Since a low melting point toner is often used as the toner resin, the adhesiveness tends to increase, and it is essential to apply silicone oil at the time of fixing as described above to enhance the releasability. For this reason, the silicone oil may adhere to the surface of the color copy, making writing with ink impossible. In addition, since the silicone oil adheres to the back side of the copy paper, there is a problem that double-sided copying cannot be performed.

Therefore, in order to impart releasability to the toner,
A technique has been proposed in which a wax which is a low softening point release agent is contained in a toner. For example, JP-A-51-1433
No. 3, JP-A-57-148752, JP-A-57-14752
JP-A-8-97056, JP-A-60-247250, JP-A-4-362953 and JP-A-6-2
No. 30,600 discloses solid silicone varnish, higher fatty acid-based wax, higher alcohol-based wax, natural plant-based wax (carnauba, rice), and montan-based ester wax as release agents. When such a low softening point release agent is contained in the toner, the fluidity of the toner is reduced, so that the developing property and the transfer property are easily deteriorated,
The chargeability, durability and storability tend to be adversely affected.
Therefore, it is necessary to further improve the offset resistance.

[0005] In order to solve such a problem, a modified wax obtained by grafting or block copolymerizing with various monomers has been proposed. For example, JP-A-59-121052 proposes to use a polyolefin obtained by graft / block copolymerization with an α-methylene aliphatic monocarboxylic acid ester monomer. Also, JP-A-56-15470 and JP-A-59-121053
JP, JP-A-60-93456 and JP-A-60-93456
3-34550 proposes to use a polyolefin grafted / block copolymerized with an aromatic vinyl monomer. These toners are improved in fluidity, but are inferior in offset resistance, and further need to further improve developability (chargeability) and durability.

Further, Japanese Patent Application Laid-Open No. 62-226260,
JP-A-63-139365, JP-A-3-5055
9, JP-A-6-208244, JP-A-10-208244
JP-A-90939 proposes a toner or toner resin composition containing a polypropylene modified with a carboxylic acid or maleic acid, but it is further desired to maintain fluidity and improve hot offset properties.

[0007]

As described above, the offset cannot be completely avoided by using any of the above techniques, and a toner having excellent releasability has not been provided. The present invention has been made in view of such problems, and when a toner image is fixed on a transfer medium, it is necessary to use a silicone-based oil as a releasing agent for fixing because of excellent releasability of the toner. The main object of the present invention is to provide a toner for forming an electrostatic image that does not have a high chargeability.

[0008]

Means for Solving the Problems The present invention has been made to solve the above problems, and the invention described in claim 1 of the present invention is directed to a silicone resin having at least a binder resin, a melting point or a softening point. A toner for forming an electrostatic image, which is a composition comprising a solid, a colorant and a charge control agent.

As described above, a toner for forming an electrostatic charge image characterized by being a composition comprising at least a binder resin, a silicone-based solid having a melting point or a softening point, a colorant and a charge controlling agent. Alternatively, since the toner contains a silicone-based solid having a softening point, the toner inherently has properties such as releasability and heat resistance. Accordingly, a toner having excellent offset resistance, that is, releasability, can be obtained without causing aggregation due to heat and deterioration in fluidity.

In this case, as described in claim 2, the silicone solid can be obtained by reacting an organic functional group-containing wax with an organic functional silicone. In this way, if the silicone-based solid is obtained by reacting an organic functional group-containing wax with an organic functional silicone, that is, a silicone-modified wax, the wax component inherently has releasability, Since the releasability of silicone can be imparted, a toner having more excellent releasability can be obtained from these synergistic effects.

According to a third aspect of the present invention, the silicone-based solid is a silicone graft copolymer obtained by copolymerizing a radically polymerizable group-containing silicone macromonomer with another radically polymerizable monomer. be able to. As described above, when the silicone-based solid is a silicone graft copolymer, the copolymer inherently has excellent compatibility, and thus contributes to uniform dispersion with the binder resin. Therefore, it is possible to obtain a toner that is excellent not only in releasability but also in dispersibility and fluidity.

Further, as described in claim 4, the silicone-based solid can be obtained by immobilizing a non-silicone-based wax component in silicone with an IPN structure. Thus, as long as the silicone-based solid is obtained by immobilizing the non-silicone-based wax component in the silicone with the IPN structure, even if they are incompatible with each other, they can be uniformly mixed and dispersed. . Therefore, if several types of base materials having different properties are selected and subjected to IPN, each property can be easily imparted to the toner.

Furthermore, as described in claim 5, the silicone-based solid can be made of a mixture of a non-silicone-based wax and a silicone compatible with the wax. As described above, if the silicone-based solid is a mixture of a non-silicone-based wax and a silicone compatible with the wax, it is easy to uniformly mix and disperse the silicone-based solid. A toner having improved fluidity and dispersibility can be easily obtained.

In this case, as described in claim 6, the silicone-based solid is 0.1 to 20% by weight based on the binder resin.
Preferably, the toner is a toner for forming an electrostatic charge image. If the amount is less than 0.1% by weight, sufficient release properties and fluidity may not be imparted to the toner in some cases. If the amount exceeds 20% by weight, the silicone-based solid may be uniformly dispersed in the binder resin. This is because it is not possible to impair the properties of the resin.

As described in claim 7, the silicone-based solid is preferably a toner for forming an electrostatic charge image uniformly dispersed in the binder resin or contained in the binder resin. As described above, if the silicone-based solid is a toner uniformly dispersed in the binder resin or included in the binder resin, the dispersibility and compatibility of each component in the toner become extremely good, and only the release property is improved. Instead, a toner having extremely excellent fluidity and dispersibility can be obtained.

Further, any one of claims 1 to 7
When the toner for forming an electrostatic image of the present invention described in the item is used, when fixing the toner on a transfer medium such as paper, it is not necessary to use a silicone oil, so that writing with ink becomes impossible, It is possible to avoid troubles such as the inability to perform double-sided copying (claim 8).

Further, when the toner for forming an electrostatic image of the present invention according to any one of claims 1 to 8 is used, the releasability is sufficiently improved, so that it is extremely useful for a color copying machine. (Claim 9).

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. The present inventors have conducted various studies on a toner for forming an electrostatic charge image which is excellent in releasing property of a toner when fixing a toner image on a transfer medium and does not require the use of a silicone oil in such fixing. It is conceived that a toner for forming an electrostatic charge image formed of a composition comprising at least a binder resin, a silicone-based solid having a melting point or a softening point, a colorant and a charge controlling agent may be used. The invention has been completed.

Hereinafter, the components of the toner for forming an electrostatic image of the present invention will be described in detail. The toner of the present invention
It is characterized by containing a silicone-based solid having a pour point, for example, a melting point or a softening point. Here, the reason that the silicone-based solid must have a pour point is an essential requirement for ensuring the fluidity of the toner. In other words, it does not include a resin that does not exhibit plasticity after being cured by heating, such as a cured resin, for example, a silicone resin.

The temperature at which the silicone-based solid exhibits fluidity is:
Usually, it is 50 to 160 ° C, preferably 70 to 150 ° C. When the temperature is lower than 50 ° C., the fluidity of the toner may be impaired. On the other hand, when the temperature is higher than 160 ° C., the toner may aggregate due to heat and impair the fluidity or the fixing property. Is desirable. The temperature indicating the fluidity includes a melting point or a softening point. The melting point may be measured according to the DSC method (measurement of an endothermic peak by differential thermal analysis), while the softening point may be measured according to JIS-K2207 (ring and ball type). it can. In addition, the siloxane chain portion in the silicone-based solid is composed of a low molecular weight substance or a high molecular weight substance. In particular, when the siloxane chain part is a high molecular weight substance, the effect such as releasability is surely exhibited. It is desirable to use a linear structure instead of a simple stitch structure.

[0021] Silicone solids that satisfy the above requirements and are suitable for realizing a toner having excellent releasability are obtained by reacting an organic functional group-containing wax with an organic functional silicone, A silicone graft copolymer obtained by copolymerizing a radical polymerizable group-containing silicone macromonomer with another radical polymerizable monomer, a non-silicone wax component immobilized in silicone with an IPN structure, or a non-silicone And a mixture of a silicone wax and a silicone compatible with the wax. Hereinafter, each will be described.

(1) Silicone-modified wax A wax obtained by reacting an organic functional group-containing wax with an organic functional silicone, ie, a silicone-modified wax, is an organic functional group such as a hydroxyl group, a carboxyl group or an amino group. It can be obtained by reacting a wax which has a functional group and is solid at room temperature with a modified silicone reactive therewith by a conventional method. For example, it can be obtained by reacting an acid-modified polyolefin wax such as polyethylene wax or polypropylene wax with a modified silicone having an amino group, an epoxy group or the like. Further, a higher fatty acid such as stearic acid, palmitic acid or myristic acid may be reacted with an aminoalkyl-modified silicone, an epoxy-modified silicone, a carbinol-modified silicone or an isocyanate-modified silicone. Here, the reason why the modified silicone is selected is that the excellent release properties of the silicone can be most effectively imparted to the toner.

Specifically, when a maleic acid-modified polyethylene wax is used, the epoxy-modified silicone, which is reactive with respect to the carboxy equivalent, which is a functional group of the wax, is used in an amount of 0.1 to 10 mol. What is necessary is just to make it react. In this case, it is heated and melted above the melting point of the wax, and the epoxy-modified silicone is dropped into this,
By heating and aging for 1 to 10 hours after dropping, a polyethylene wax modified with silicone can be obtained. The weight average molecular weight of the obtained polyethylene wax modified with silicone is usually 500 to 50,000, preferably 1,000 to 30,000. Molecular weight 500
If it is smaller than this, the fluidity of the toner may be insufficient. On the other hand, if it is larger than 50,000, offset tends to occur.

Further, a higher fatty acid amine such as dioctadecylamine may be reacted with an epoxy-modified silicone, a carboxy-modified silicone or an isocyanate-modified silicone. Alternatively, it can also be obtained by reacting a higher fatty acid amide containing a hydroxyl group such as 12-hydroxystearic acid amide with an epoxy-modified silicone, a carboxy-modified silicone, an isocyanate-modified silicone, or the like in a similar manner. Further, a silicone having an amino group, a carboxy group or an isocyanate group capable of reacting with a hydroxyl group remaining in a plant wax such as carnauba wax, candelilla wax or rice wax may be reacted. Also in this case, in order to obtain a desired silicone-modified wax, similarly to the case of the acid-modified polyethylene wax, a predetermined wax is selected, and a charged amount is calculated from a functional group equivalent, and the wax is prepared. What is necessary is just to make the reactive modified silicone react.

In general, when the wax is polyfunctional, a monofunctional or bifunctional modified silicone is used,
On the other hand, when the modified silicone is polyfunctional, a monofunctional or bifunctional wax is used. Alternatively, a double bond may be introduced into the wax, and this may be synthesized with a hydrogen silicone having a SiH bond in the presence of a platinum catalyst by performing an addition reaction. For example, undecylenamide,
A reaction of a compound containing a double bond such as methyl undecylenate and allyl 12-hydroxystearate with hydrogen siloxane is exemplified. further,
A vinyl group, a hexenyl group, a decenyl group, a norobornenyl group, or the like may be introduced into the side chain of the polyethylene wax or the polypropylene wax and reacted with hydrogen siloxane.

(2) Silicone Graft Copolymer As the silicone graft copolymer, a low molecular weight resin having a softening point when a silicone macromonomer having a radical polymerizable group is copolymerized with another radical polymerizable monomer is used. Although obtained, such a silicone-modified organic resin that is solid at room temperature corresponds to this. Specifically, an acrylic resin, a polyester resin, an alkyd resin or the like is exemplified.

Here, examples of the radical polymerizable group of the silicone macromonomer having a radical polymerizable group include an acryl group or a methacryl group. Further, as the organopolysiloxane unit, a unit having an average degree of polymerization of 2 to 200 and comprising dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane or the like is exemplified. On the other hand, examples of other radical polymerizable monomers include acrylic acid or methacrylic acid such as butyl methacrylate and the like, alkyl esters thereof, styrene and styrene derivatives. In order to impart desired properties to the toner, a silicone macromonomer having a radical polymerizable group and another radical polymerizable monomer can be used alone or in combination of two or more.

The composition ratio of the silicone macromonomer having a radical polymerizable group and the other radical polymerizable monomer constituting the silicone graft copolymer is as follows.
80% by weight, the other radical polymerizable monomer is 95 to 2
0% by weight, preferably the former is 10 to 70% by weight, and the latter is 90 to 30% by weight. When the amount of the silicone macromonomer having a radical polymerizable group is too small in the entire constitutional ratio, the releasability of the toner may be insufficient.On the other hand, when the amount is too large, the compatibility is lowered and the dispersibility of the toner is reduced. This is because it may be damaged. On the other hand, if the amount of the other radically polymerizable monomer is too small, the compatibility may be reduced and the dispersibility of the toner may be impaired. On the other hand, if the amount is too large, the releasability of the toner may be insufficient. It is desirable.

The silicone graft copolymer is prepared by, for example, combining a silicone macromonomer having a radical polymerizable group and a radical polymerizable monomer such as butyl methacrylate or styrene with a peroxide such as benzoyl peroxide or azobisisobutyrate. In the presence of a normal radical polymerization initiator such as azo compounds such as lonitrile, a solution polymerization method,
It can be obtained by applying any one of emulsion polymerization, suspension polymerization and bulk polymerization. For example, in the case of performing by a solution polymerization method in which the molecular weight of the copolymer is easily adjusted, a predetermined raw material is dissolved in a solvent such as toluene, and the mixture is heated to 50 to 180 ° C. in the presence of the catalyst and is heated for about 5 to 10 hours. By evaporating the solvent after the reaction, a desired silicone graft copolymer can be obtained.

The weight average molecular weight of the obtained silicone graft copolymer is usually 5,000 to 100,000, preferably 10,000 to 50,000. Molecular weight 5000
If it is smaller than this, the fluidity of the toner may be insufficient. On the other hand, if it is larger than 100,000, offset tends to occur.

(3) IPN Structure of Non-Silicone-Based Wax and Silicone The non-silicone-based wax component immobilized with an IPN structure in silicone can be obtained by mixing hydrogensiloxane and vinyl in the presence of a wax component such as polyethylene wax. It can be obtained by performing an addition reaction with siloxane in the same manner as described above. In this case, the polyethylene wax and the organopolysiloxane having low compatibility can be uniformly dispersed with each other. However, in order to uniformly disperse those having high compatibility with each other, for example, a silicone graft copolymer having relatively high compatibility with polyethylene wax, the radical polymerizable silicone macromonomer and other radical polymerization are performed in the presence of a wax component. A radical copolymerization reaction may be performed with the reactive monomer.

As described above, by appropriately selecting a base material having various different characteristics and performing IPN, the characteristics can be imparted to the toner, and thus a toner having desired characteristics can be easily manufactured. can do. Also,
In this case, several types of base materials are appropriately selected according to the properties to be imparted to the toner and further to further enhance the properties.
PN may be used.

Here, the ratio of coexistence of the non-silicone wax component and silicone is such that the non-silicone wax component is 10 to 90% by weight and the silicone is 90 to 1% by weight.
0% by weight, preferably the former is 20 to 80% by weight, and the latter is 80 to 20% by weight. If the amount of the non-silicone-based wax component is too small, the compatibility may be reduced and the dispersibility of the toner may be impaired. On the other hand, if the amount is too large, the release properties of the silicone may not be sufficiently imparted to the toner. On the other hand, if the amount of silicone is too small, the releasability of the toner may be insufficient.On the other hand, if the amount is too large, the compatibility may decrease and the dispersibility of the toner may be impaired.
It is desirable to be within the above range.

Examples of the non-silicone wax component include the above-mentioned polyolefin waxes and modified products thereof with acids and the like, higher fatty acids and substituted products thereof with amines and amides, and vegetable waxes.

(4) Mixture of Non-Silicone Wax and Silicone The mixture of non-silicone wax and silicone compatible with the wax includes, for example, a high-boiling α-olefin, hydrogen siloxane and Is subjected to an addition reaction in the presence of a platinum catalyst to obtain a solid long-chain alkyl-modified silicone. A mixture of the long-chain alkyl-modified silicone and polyethylene wax can be mentioned as an example. The long-chain alkyl-modified silicone has a characteristic of being excellent in compatibility with a polyolefin wax such as polyethylene wax, and therefore, the polyolefin wax and the long-chain alkyl-modified silicone can be uniformly mixed and dispersed. Therefore, a toner comprising such a mixture has good fluidity and dispersibility as well as releasability.

Here, the mixing ratio of the non-silicone wax component and the silicone is 10 to 90% by weight of the non-silicone wax component and 90 to 10% by weight of the silicone. 80% by weight, the latter being 80 to 20% by weight. If the amount of the non-silicone-based wax component is too small, the compatibility may be reduced and the dispersibility of the toner may be impaired. On the other hand, if the amount is too large, the release properties of the silicone may not be sufficiently imparted to the toner. On the other hand, if the amount of silicone is too small, the releasability of the toner may be insufficient. On the other hand, if the amount is too large, the compatibility may decrease and the dispersibility of the toner may be impaired.

As the non-silicone wax component, any of the above-mentioned wax groups may be selected. For example, when a wax composed of a higher fatty acid amine is selected, a higher fatty acid-modified silicone having a similar functional group is used. Or a mixture with two or more modified silicones. In addition, it is desirable to use an alkyl-modified silicone having an alkyl group in the range of 8 to 50 as the long-chain alkyl-modified silicone because the compatibility is extremely high.

The addition amount of the above-mentioned silicone solid is 0.1 to 20% by weight, preferably 0.5 to 5% by weight, based on the binder resin. If the addition amount is too small, the releasing effect may not be sufficiently obtained.On the other hand, if the addition amount is too large, the pigment dispersibility and fluidity of the toner may be reduced, and the cost may be increased economically. And the above range is preferable.

In the present invention, it is preferable that the silicone-based solid is uniformly dispersed in the binder resin or is contained in the binder resin. By doing so, the dispersibility of each component in the toner is kept in a good state, and the releasability is easily exhibited, so that the toner having excellent fluidity and releasability can be obtained. . As a method of uniformly dispersing, for example, when a polyester resin is used as a binder, condensation polymerization is carried out in the presence of a silicone-based solid at the time of the solution polymerization, and then a conventionally known crusher such as a cutter mill or a jet mill. It may be pulverized using a fine pulverizer. As a method of encapsulating a silicone-based solid in a binder resin, for example, when an acrylic resin is used as a binder, the silicone-based solid may be allowed to coexist during the emulsion polymerization or suspension polymerization. By doing so, a resin containing a silicone-based solid is obtained.

Examples of the binder resin used as one component of the toner of the present invention include styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene, and homopolymers thereof and styrene-p-chlorostyrene. Styrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer Styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-
Isobutylene copolymer, styrene-acrylonitrile-
Styrene-based copolymers such as indene copolymer are exemplified.

Further, polyvinyl chloride, phenol resin,
Naturally modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, cumarone Indene resin, petroleum resin and the like can also be used. Of these, styrene copolymers or polyester resins are preferred.

Here, as a comonomer for the styrene monomer constituting the styrene copolymer, for example, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, acrylic acid-2-acrylate Monocarboxylic acid having a double bond such as ethylhexyl, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. Acid, butyl maleate, methyl maleate, dimethyl maleate and the like having a double bond and derivatives thereof, and vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate. It is. Further, in addition to ethylene-based olefins such as ethylene, propylene, butylene and the like, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone, and vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether Any of these vinyl monomers such as ters may be used alone or in combination of two or more. The styrene-based polymer or styrene-based copolymer may be crosslinked, or may be a mixed resin.

As the crosslinking agent for the binder resin, a compound having two or more polymerizable double bonds may be mainly used. For example, vinylbenzene, in addition to aromatic divinyl compounds such as divinylnaphthalene, ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate, divinyl compounds such as divinylaniline, divinylether, divinylsulfide, divinylsulfone, and compounds having three or more vinyl groups Are used alone or as a mixture.

In the bulk polymerization method, a polymer having a low molecular weight can be obtained by increasing the termination reaction rate by polymerizing at a high temperature, but there is a problem that the reaction is difficult to control.
In the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in the chain transfer of radicals depending on the solution, and by adjusting the amount of the initiator and the reaction temperature. It is preferable when a low molecular weight compound is obtained in the composition.

As a solvent used in the solution polymerization, xylene, toluene, cumene, cellosolve acetate, isopropyl alcohol, benzene and the like are used. In the case of a styrene monomer mixture, xylene, toluene or cumene is preferred. It is appropriately selected depending on the polymer to be polymerized.

The reaction temperature varies depending on the solvent used, the initiator and the polymer to be polymerized.
C. is preferably performed at a temperature of. In solution polymerization, the solvent 10
It is preferred to carry out with 30 to 400 parts by weight of monomer per 0 parts by weight. At the end of the polymerization, another polymer may be mixed in the solution. In this case, several kinds of polymers may be mixed.

Further, as a polymerization method for obtaining a high molecular weight component or a gel component, an emulsion polymerization method or a suspension polymerization method is preferable. Among them, the emulsion polymerization method disperses a monomer (monomer) almost insoluble in water as small particles with an emulsifier in an aqueous phase,
In this method, polymerization is performed using a polymerization initiator in an aqueous solution. In this method, the reaction heat can be easily controlled, and the termination reaction rate is low because the phase in which the polymerization is performed (the oil phase composed of the polymer and the monomer) and the aqueous phase are different. As a result, the polymerization rate is high. , With a high degree of polymerization.

Further, the polymerization process is relatively simple, and since the polymerization product is fine particles, it is easy to mix with a colorant, a charge control agent and other additives in the production of toner. For this reason, it is more advantageous as a method for producing a binder resin for a toner than other methods. However, the resulting polymer tends to be impure due to the added emulsifier, and an operation such as salting out is required to take out the polymer. Therefore, suspension polymerization is a simple method. In the emulsion polymerization method, soapless polymerization using a reactive emulsifier is general.

In suspension polymerization, 100 parts by weight or less of the monomer (preferably 1 part by weight) is added to 100 parts by weight of the aqueous solvent.
(0 to 90 parts by weight). Usable dispersants include polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, and the like. The amount of the dispersant is an appropriate amount in terms of the amount of a monomer with respect to an aqueous solvent, and is generally 0.05 to 1 with respect to 100 parts by weight of an aqueous solvent. Used in parts by weight. The polymerization temperature is suitably from 50 to 95 ° C, but should be appropriately selected depending on the initiator used and the intended polymer. In addition, any initiator may be used as long as it is insoluble or hardly soluble in water.

As the initiator to be used, peroxides such as benzoyl peroxide, dicumyl peroxide, vinyl tris (t-butylperoxy) silane, and 2,2'-azobisisobutyronitrile, 2,2 Conventionally known compounds such as azo compounds such as' -azobis (2,4-dimethylvaleronitrile) are mentioned, and these can be used alone or in combination. The amount used is 0.05 parts by weight or more, preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the monomer.

When a polyester resin is used as the binder resin in the present invention, the composition is as follows. Examples of the dihydric alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, Examples thereof include 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, bisphenol represented by the following general formula (1), and derivatives thereof.

[0052]

Embedded image

(Wherein R is an ethylene or propylene group, x and y are each an integer of 0 or more;
The average value of x + y is 0-10. )

Further, diols represented by the following general formula (2) may be mentioned.

[0055]

Embedded image

Wherein R ′ is —CH ₂ CH ₂ — or the following chemical formula (3):

[0057]

Embedded image

X 'and y' are integers of 0 or more;
The average value of x '+ y' is 0-10. )

Examples of the divalent acid component include phthalic acid,
Terephthalic acid, isophthalic acid, benzenedicarboxylic acids such as phthalic anhydride, in addition to their anhydrides or lower alkyl esters, succinic acid, adipic acid, sebacic acid, azelaic acid and other alkyldicarboxylic acids, their anhydrides or lower alkyl esters, Further, alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid, n-dodecyl succinic acid, anhydrides or lower alkyl esters thereof, and further, unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid; Examples thereof include anhydrides and lower alkyl esters.

Next, as a coloring agent, a conventionally known inorganic compound,
Organic dyes and pigments can be used, and specific examples thereof include carbon black, iron black, magenta, benzidine yellow, quinacdrine, rhodamine B, and phthalocyanine. In the toner of the present invention, the content of the colorant is in the range of 1 to 5 parts by weight based on 100 parts by weight of the binder resin.

Further, as the charge controlling agent, conventionally known nigrosine, quaternary ammonium salt and the like can be used. In the toner of the present invention, the content of the charge control agent is
It is in the range of 0.1 to 3 parts by weight based on 100 parts by weight of the binder resin.

The electrostatic image forming toner of the present invention can be obtained as follows. After dry-blending a binder resin, a silicone-based solid having a melting point or a softening point, a colorant and a charge control agent, melt kneading is performed.
Next, it is obtained by coarsely crushing, finely crushing using a jet crusher, and further classifying into fine powder having a particle size of 2 to 20 μm. Also, when the silicone solid is uniformly dispersed in the binder resin or included in the binder resin,
After dry blending such a colorant and a charge control agent, the same treatment as described above can be performed to obtain a desired particle-based toner for forming an electrostatic charge image. Further, the polymerizable component constituting the binder resin is subjected to suspension polymerization in the presence of the silicone-based solid, the colorant, and the charge control agent to obtain a polymer having a particle size of 2 to 2.
It can also be obtained by classification so as to obtain a fine powder of 0 μm.

The toner for forming an electrostatic image of the present invention may optionally be mixed with carrier particles such as iron powder, glass beads, nickel powder and ferrite, and used as a developer for an electric latent image. Further, a hydrophobic colloidal silica fine powder can be contained for improving the fluidity of the powder.

The toner for forming an electrostatic charge image of the present invention is fixed on a transfer medium such as paper or a polyester film by being heated by a heat roll section of a copying machine, for example, a heat fixing type copying machine or a printer. Served as a material. The toner for forming an electrostatic image of the present invention does not require the use of a silicone oil such as polydimethyl silicone or amino-modified silicone when fixing a toner image on a transfer medium, so that writing with ink is not possible. And the problem that double-sided copying cannot be performed is prevented. Therefore, the toner of the present invention is extremely useful especially for a color copying machine in which technical development is actively performed in recent years.

[0065]

The present invention will be described below with reference to examples and comparative examples.

(Synthesis Example 1) An epoxy-modified silicone represented by the following chemical formula (4) was prepared by treating a corresponding hydrogen siloxane and vinylcyclohexene oxide with a platinum catalyst.
It was synthesized by an addition reaction in a toluene solvent. The epoxy equivalent of the obtained epoxy-modified silicone was 2,690.

[0067]

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Acid-modified polyethylene wax (Mitsui High Wax 1105A, carboxy equivalent 935, melting point 104)
After heating 2690 g to 150 ° C., 269 g (0.1 mol) of the epoxy-modified silicone was added dropwise over 30 minutes. After the dropwise addition, the mixture was reacted at 150 ° C. for 2 hours to remove the silicone-modified polyethylene wax into 2820.
g was obtained. The melting point of the obtained silicone-modified polyethylene wax was 81 ° C.

(Synthesis Example 2) 733 g of hydrogen siloxane having an average composition formula represented by the following chemical formula (5)
504 g of an α-olefin having an average composition formula of C ₃₀ H ₆₀ (Dialen 30, manufactured by Mitsubishi Chemical Corporation) and toluene 100
0 g and 0.7 g of a 2% IPA solution of chloroplatinic acid were charged and reacted under reflux of toluene for 5 hours. After the completion of the reaction, the conversion was measured and found to be 95%. Next, toluene was distilled off under reduced pressure to obtain 1210 g of a long-chain alkyl-modified siloxane. The melting point of the obtained long-chain alkyl-modified silicone was 55 ° C.

[0070]

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Next, a 1: 1 mixture of the long-chain alkyl-modified silicone and polypropylene wax having a melting point of 148 ° C. (Mitsui High Wax NP105, manufactured by Mitsui Chemicals, Inc.) was prepared. In addition, this polypropylene wax is 14
A uniform liquid was obtained at a temperature of 8 ° C. or higher, and the mixture was excellent in compatibility with the long-chain alkyl-modified silicone, so that a uniformly dispersed mixture could be obtained.

(Synthesis Example 3) 500 g of a silicone macromonomer having an average compositional formula represented by the following chemical formula (6):
Butyl methacrylate 200g and styrene 300g
Was charged into 1000 g of toluene, 10 g of AIBN was added, and a polymerization reaction was carried out at 80 ° C. for 6 hours. Next, toluene was distilled off under reduced pressure to obtain a weight average molecular weight of 2,000.
As a result, 950 g of a silicone-grafted acrylic resin of No. 0 was obtained.
The softening point of the obtained silicone graft acrylic resin is
102 ° C.

[0073]

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(Synthesis Example 4) Acid-modified polyethylene wax (Mitsui High Wax 1105A, carboxy equivalent 93)
5, 935 g) heated to 150 ° C.
346 g of epoxy-modified siloxane oligomer represented by the following chemical formula (7) (purity: 99%, epoxy equivalent: 346)
Was added dropwise. After dropping, react at 150 ° C for 2 hours,
119. Polyethylene wax modified with silicone
0 g was obtained. The melting point of the obtained polyethylene wax modified with silicone was 79 ° C.

[0075]

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(Synthesis Example 5) After heating 1190 g of an acid-modified polypropylene wax (Mitsui High Wax NP0555A, carboxy equivalent 1190, melting point 150 ° C.) to 170 ° C., 190 g of an isocyanate-modified siloxane oligomer represented by the following chemical formula (8): .5 mol, purity 9
8%) was added dropwise over 30 minutes. After the dropwise addition, the mixture was reacted at 170 ° C. for 1 hour to obtain 1,300 g of silicone-modified polypropylene wax. The melting point of the obtained polypropylene wax modified with silicone is 126 ° C.
Met.

[0077]

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Example 1 300 g of xylene was charged into a four-necked flask, and the mixture was heated and stirred under a nitrogen stream to reflux. Under the reflux, 84.5 g of styrene and acrylic acid-
A mixed solution of 15.5 g of n-butyl and 6 g of di-t-butyl peroxide was added dropwise over 4 hours, and the mixture was kept for 2 hours to obtain a low molecular weight solution. Xylene was distilled off from this solution under reduced pressure to remove a low molecular weight substance.

Next, 25 parts by weight of the low molecular weight substance, 58 parts by weight of styrene, 17 parts by weight of n-butyl acrylate,
A mixture of 0.5 parts by weight of divinylbenzene, 1.7 parts by weight of di-t-butyl peroxide and 3 parts by weight of the polyethylene wax modified with silicone obtained in Synthesis Example 1 was treated with 0.1 part of a partially saponified polyvinyl alcohol. Fifteen
The suspension was added for 12 hours to 200 parts by weight of dissolved water. After completion of the reaction, the suspension was filtered, washed with water, and dried to obtain a wax-containing resin in which a silicone-based solid was included in the styrene acrylic resin. 96 parts by weight of the wax-containing resin were mixed with 3 parts by weight of magenta as a coloring agent and 1 part by weight of nigrosine as a charge control agent.

Next, after powder blending the above compound,
The mixture was kneaded with a Labo Plastomill at 140 ° C. and 30 rpm for 10 minutes, and the kneaded material was finely pulverized with a jet mill PJM100 (manufactured by Nippon Pneumatic). Powder air classifier MSD
Fine powder having a particle size of 2 μm or less was removed from the finely pulverized product (manufactured by Nippon Pneumatic Co., Ltd.) to obtain a toner.

Example 2 Example 1 was repeated except that a 1: 1 mixture of the long-chain alkyl-modified silicone obtained in Synthesis Example 2 and polypropylene wax was used instead of the silicone-modified polyethylene wax. A toner was manufactured under the same conditions as in the above.

Example 3 A toner was produced under the same conditions as in Example 1 except that the silicone-grafted acrylic resin obtained in Synthesis Example 3 was used instead of the silicone-modified polyethylene wax. .

Example 4 50 mol of a bisphenol derivative represented by the following chemical formula (9) was placed in a four-necked flask.
%, Triethylene glycol 12 mol%, fumaric acid 1
1500 g of a mixed raw material comprising 7 mol% and 21 mol% of n-dodecylsuccinic acid was charged. 46 g (silicone-based solid / resin = 3/97 weight ratio) of the silicone-modified polyethylene wax obtained in Synthesis Example 4 was added thereto, and the temperature was raised under nitrogen aeration. Next, 0.05 g of dibutyltin oxide was added, and the temperature was kept at 210 ° C. for 1 hour.
After performing the polycondensation reaction for 2 hours, the obtained resin component was crushed using a jet mill crusher to obtain a wax-containing resin in which a silicone solid was uniformly dispersed in the polyester resin. Next, a toner was manufactured in the same manner as in Example 1.

[0084]

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Example 5 The same as Example 4 except that the silicone-modified polypropylene wax obtained in Synthesis Example 5 was used instead of the silicone-modified polyethylene wax obtained in Synthesis Example 4. The toner was manufactured under the following conditions.

Example 6 In order to confirm the releasability of the toners obtained in Examples 1 to 5, 10 cm × 10
cm of Teflon plate material, and prepare this
The temperature was controlled at 0 ° C. After pressing the transfer paper on which the unfixed toner image is formed on the surface of the Teflon plate material set at a predetermined temperature for 3 seconds, the transfer paper is rapidly released, and the offset toner image remaining on the plate is observed. Were evaluated as follows. Next, using a commercially available oil-based magic, a test was performed to determine whether or not both sides of the transfer paper could be written, and it was determined whether or not double-sided copying was possible. The results are shown in Table 1.

(Comparative Example 1) The weight average molecular weight was 15,000
A toner was manufactured under the same conditions as in Example 1 except that 96 parts by weight of a polyester resin, 3 parts by weight of a magenta pigment and 1 part by weight of a charge controlling agent were blended and no silicone solid was contained. The releasability of the obtained toner was evaluated under the same conditions as in Example 6. The results are shown in Table 1.

(Comparative Example 2) Weight average molecular weight of 10,000
96 styrene acrylic resin, magenta pigment 3
A toner was manufactured under the same conditions as in Example 1 except that the mixture contained 1 part by weight of the charge control agent and 1 part by weight of the charge control agent, and did not contain a silicone solid. Regarding the releasability of the obtained toner,
The evaluation was performed under the same conditions as in Example 6. The results are shown in Table 1.

Comparative Example 3 A toner was manufactured under the same conditions as in Comparative Example 1 except that 3 parts by weight of a polypropylene wax (Mitsui High Wax NP105A, manufactured by Mitsui Chemicals) was further added. Example 6 shows the releasability of the obtained toner.
The evaluation was performed under the same conditions as described above. The results are shown in Table 1.

Comparative Example 4 A toner was produced under the same conditions as in Comparative Example 2 except that 3 parts by weight of a polypropylene wax (Mitsui High Wax NP105A, manufactured by Mitsui Chemicals) was further added. Example 6 shows the releasability of the obtained toner.
The evaluation was performed under the same conditions as described above. The results are shown in Table 1.

Comparative Example 5 Acid-Modified Polypropylene Wax (Mitsui High Wax NP0555A, manufactured by Mitsui Chemicals) 3
A toner was manufactured under the same conditions as in Comparative Example 1, except that the weight part was further added. Regarding the releasability of the obtained toner,
The evaluation was performed under the same conditions as in Example 6. The results are shown in Table 1.

Comparative Example 6 A toner was produced under the same conditions as in Comparative Example 2, except that 3 parts by weight of dimethyl silicone oil (KF-96 100 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) was further added. The releasability of the obtained toner was evaluated under the same conditions as in Example 6. The results are shown in Table 1.

[0093]

[Table 1] [Toner release property test] ：: When the toner is released without any problem ：: When the toner is released without offset Δ: When the toner is partially offset ×: The toner is completely removed Offset [Double-sided copyability test] Acceptable: Writing on both sides of the transfer paper with the fixed toner image using oil-based magic Not possible: Writing on both sides of the transfer paper with the fixed toner image with oil-based magic

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the claims of the present invention. Within the technical scope of

For example, in the present invention, the case where a polyolefin wax is used as the wax component has been described in detail. However, similar effects can be obtained by using other waxes such as carnauba wax.

[0096]

As described above in detail, the toner of the present invention, by using a composition containing a silicone-based solid having a melting point or a softening point, has a remarkably excellent releasability of the toner as compared with conventional products. Therefore, it is possible to avoid an offset phenomenon that tends to occur when fixing the toner on a transfer medium such as paper. As a result, when the toner is fixed on a transfer medium such as paper, it is not necessary to use a silicone oil as a fixing release agent. Further, since the silicone solid compounded in the toner of the present invention has a melting point or a softening point, the fluidity of the toner is good. Therefore, the present invention can be applied to a color copy where improvement of the toner is desired.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Asai 1-10 Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture F-term in Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory 2H005 AA06 AA15 AB02 CA12 CA14 CA18 DA01 DA06 EA03 EA07 FB02

Claims (9)

[Claims] 1. An electrostatic image forming toner comprising a composition comprising at least a binder resin, a silicone solid having a melting point or a softening point, a colorant and a charge control agent. 2. The electrostatic image forming toner according to claim 1, wherein the silicone-based solid is obtained by reacting an organic functional group-containing wax with an organic functional silicone. 3. The silicone-based solid according to claim 1, wherein the silicone-based solid is a silicone graft copolymer obtained by copolymerizing a radically polymerizable group-containing silicone macromonomer with another radically polymerizable monomer. 3. The toner for forming an electrostatic image according to item 1. 4. The electrostatic image forming toner according to claim 1, wherein the silicone-based solid is obtained by fixing a non-silicone-based wax component in silicone with an IPN structure. 5. The method according to claim 1, wherein the silicone-based solid comprises a mixture of a non-silicone-based wax and a silicone compatible with the wax.
3. The toner for forming an electrostatic image according to item 1. 6. The static electricity according to claim 1, wherein the silicone-based solid is contained in an amount of 0.1 to 20% by weight with respect to a binder resin. Charge image forming toner. 7. The method according to claim 1, wherein the silicone-based solid is uniformly dispersed in the binder resin or included in the binder resin. Electrostatic image forming toner. 8. The method according to claim 1, wherein the toner does not require the use of a silicone-based oil as a releasing agent for fixing when the toner is fixed on a transfer medium. 8. The toner for forming an electrostatic image according to any one of items 7 to 7. 9. The toner according to claim 1, wherein the toner is used in a color copying machine.