JP5359556B2 - Packaging for two-component developer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for a two-component developer for maintaining a two-component developer in a package in a proper charging amount state and, as the result, stably forming a high-quality image without causing a defective image such as fogging and image density deterioration. <P>SOLUTION: The package for the two-component developer is made by packaging a negatively charging two-component developer comprising toner and carrier, and is formed of a resin containing at least polyglycolic acid. Further, the package for the two-component developer includes a lamination structure in which at least two resin layers are laminated, wherein a first resin layer is made of a resin containing at least polyglycolic acid, and a second resin layer is made of a resin containing at least one selected from polylactic acid, polybutylene succinate and copolymerized polyester of 3-hydroxy butyric acid and 3-hydroxy hexanoic acid. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a two-component developer package in which a negatively chargeable two-component developer composed of a toner and a carrier is packaged.

  2. Description of the Related Art In recent years, when an image is formed by an electrophotographic image forming method, as a means for forming a high-quality image, a two-component development including a toner as an image forming material and a carrier as a conveying / charging imparting material A method using an agent is known. In the performance required for such a two-component developer, the amount of charge caused by the friction between the toner and the carrier is an extremely important factor because it affects the image quality of the formed image.

  In general, the two-component developer for initial filling or filling is stored in a state of being packaged by an appropriate packaging material. Accordingly, even when a two-component developer adjusted to an appropriate charge amount state by mixing toner and carrier is stored for a long period of time, the two-component developer is required to be maintained in an appropriate charge amount state. Is done. That is, when an image is formed using a two-component developer that does not have an appropriate charge amount state when supplied to the developing device, the charge amount at the time of development is within the appropriate range of the target charge amount. Therefore, an image defect such as fogging or a decrease in image density occurs in the initial image.

  As for such fluctuations in the charge amount of the two-component developer, there is an effect due to the occurrence of charge leakage due to fluctuations in the amount of moisture in the environmental atmosphere during transportation or storage, or the two-component developer is packaged. The effect of excessive frictional charging between the inner surface of the packaged material and the toner constituting the two-component developer is considered to be large.

  The present invention has been made on the basis of the circumstances as described above, and the purpose thereof is to maintain the two-component developer in the package in an appropriate charge amount state, and as a result, such as fogging and image density reduction. An object of the present invention is to provide a package for a two-component developer capable of forming a high-quality image without causing image defects.

  The package for two-component developer of the present invention is a package for two-component developer in which a negatively chargeable two-component developer composed of a toner and a carrier is packaged, and the two-component developer package is It is formed of a resin containing at least polyglycolic acid.

  In the two-component developer packaging body of the present invention, the two-component developer packaging body has a laminated structure in which at least two resin layers are laminated, and the first resin layer is at least It is made of a resin containing polyglycolic acid, and the second resin layer contains at least one selected from polylactic acid, polybutylene succinate, and polyester copolymerized with 3-hydroxybutyric acid and 3-hydroxyhexanoic acid It can be set as the structure which consists of resin to do.

  According to the present invention, the two-component developer packaging body (hereinafter, also simply referred to as “packaging body”) is formed of a resin containing at least polyglycolic acid, so that the polyglycolic acid is water vapor permeable. Since the two-component developer packaged in the package is stored in a state that is not affected by the surrounding humidity, charge leakage is suppressed and the polyglycolic acid is suppressed. However, since it has a carboxyl group on the molecular skeleton and is easily negatively charged, the resin constituting the package and the negatively chargeable toner constituting the two-component developer in the package mutually interact with each other. As a result, excessive frictional charging is suppressed, and the two-component developer in the package is maintained in an appropriate charge amount state. Therefore, according to the two-component developer packaging body of the present invention, excessive frictional charging is caused by the packaging body and the toner when stored for a long time in a high-humidity environment or due to vibration during transportation. Even when exposed to the above, the two-component developer is maintained in an appropriate charge amount state, so that it has an appropriate range of the desired charge amount during development. An image defect does not occur, and a high-quality image can be stably formed.

According to the invention, the two-component developer packaging body has a laminated structure of two or more layers, the first resin layer is made of a resin containing at least polyglycolic acid, and the second resin layer is And a resin containing at least one selected from polylactic acid, polybutylene succinate, and copolymerized polyester of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid (hereinafter also referred to as “specific selection resin”). By becoming
(1) When the innermost layer in direct contact with the two-component developer is the first resin layer, the water vapor barrier property (water vapor permeability suppression) and the negative charge of the first resin layer related to polyglycolic acid Depending on the characteristics, the two-component developer in the package is maintained in an appropriate charge amount state,
(2) In the case where the innermost layer in direct contact with the two-component developer is the second resin layer, the specific selective resin has a carboxyl group as in the case of polyglycolic acid, so that it is negatively charged. Since the second resin layer has a negative charging characteristic and the first resin layer related to polyglycolic acid has a water vapor barrier property (water vapor permeability suppression), the two-component developer in the package Is maintained in an appropriate charge amount state.
Therefore, when the package of the present invention has such a laminated structure, excessive frictional charging due to the package and the toner occurs when stored for a long time in a high-humidity environment or due to vibration during transportation. Even when exposed to circumstances, the two-component developer is maintained in an appropriate charge amount state, so that it has an appropriate range of the target charge amount during development, resulting in a reduction in fog and image density. Therefore, it is possible to stably form a high-quality image.

  Furthermore, according to the present invention, since the resin constituting the two-component developer packaging body contains a biodegradable resin, the burden on the environment can be basically reduced.

It is sectional drawing for description which expands and shows an example of the laminated structure in the package for two-component developers of this invention. It is the schematic for description which shows an example of the package for two-component developers of this invention. It is the explanatory schematic diagram which shows an example of the packaging bag which comprises the package for two-component developers of this invention.

  Hereinafter, the present invention will be described in detail.

[Package for two-component developer]
The package of the present invention is a package in which a negatively chargeable two-component developer composed of a toner and a carrier is packaged, and is formed of a resin containing at least polyglycolic acid.
Since the package of the present invention is formed of a resin containing polyglycolic acid, the polyglycolic acid has low water vapor permeability, so that the two components packaged in the package Since the developer is stored in a state that is not affected by ambient humidity, charge leakage is suppressed, and the polyglycolic acid is negatively charged because it has a carboxyl group on the molecular skeleton. Since the resin constituting the package and the negatively chargeable toner constituting the two-component developer repel each other, excessive tribocharging is suppressed, so the two-component developer in the package Is maintained in an appropriate charge amount state.
Furthermore, in recent years, with the colorization of formed images, multi-color two-component developers have been used. When replacing such two-component developers, the two-component developers for each color can be surely used. There is a need to fill each developer. According to the package of the present invention, since polyglycolic acid has high transparency, before opening the package, the color of the two-component developer in the package can be recognized from the appearance, It is possible to prevent the two-component developer of another color from being accidentally charged when filling the developing device.

  The package of the present invention has a laminated structure in which at least two resin layers are laminated, the first resin layer is made of a resin containing at least polyglycolic acid, and the second resin layer is made of polylactic acid , Polybutylene succinate, and a resin containing at least one selected from a polyester copolymer of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid (hereinafter also referred to as “3HB / 3HH copolymer polyester”). It can be configured.

[First resin layer]
The resin constituting the first resin layer is not particularly limited as long as it contains at least polyglycolic acid.

[Second resin layer]
The resin constituting the second resin layer is not particularly limited as long as it contains at least one selected from polylactic acid, polybutylene succinate, and 3HB / 3HH copolyester. Even if 2 or more types are combined, other resin materials may be contained.

[Other resin layers]
In the case where the package of the present invention has a laminated structure of three or more layers, the resin constituting the other resin layers other than the first resin layer and the second resin layer is not particularly limited, The same resin as the resin constituting the resin layer or the second resin layer may be used, or a different resin such as a resin containing polyethylene may be used.

  In the case where the package of the present invention has a laminated structure of two or more layers, an adhesive layer may be interposed between the resin layers.

When the package of the present invention has a two-layer laminated structure, the innermost layer in direct contact with the two-component developer may be the first resin layer or the second resin layer.
In the case where the package of the present invention has a laminated structure of three or more layers, if the innermost layer in direct contact with the two-component developer is the first resin layer or the second resin layer, the other laminated layers The order is not limited. This is because polyglycolic acid contained in the resin constituting the first resin layer, and polylactic acid, polybutylene succinate or 3HB / 3HH copolymer polyester contained in the resin constituting the second resin layer. This is because any of them has a carboxyl group, so that it is easy to be negatively charged and excessive frictional charging can be suppressed. Therefore, in the case where the innermost layer is the first resin layer, the two-component development in the package is performed due to the water vapor barrier property (water vapor permeability suppression) and the negative charging property of the first resin layer related to polyglycolic acid. Even when the agent is maintained in an appropriate charge amount state and the innermost layer is the second resin layer, the negative charge characteristic of the second resin layer related to the specific selection resin and the first related to the polyglycolic acid Due to the water vapor barrier property of the resin layer, the two-component developer in the package is maintained in an appropriate charge amount state.

  As shown in FIG. 1, the packaging body having such a laminated structure is specifically composed of a packaging material 35 having a laminated structure in which three resin layers are laminated. The second resin layer 20, the first resin layer 10, and the third resin layer 30 are stacked in this order from the side.

  Although the shape of a package is not specifically limited, For example, the rectangular thing as shown in FIG. 2 etc. are mentioned. For example, as shown in FIG. 3, such a packaging body 43 has an opening 42 on the upper side, and a packaging bag provided with a seal part 41 on the lower side and a seal part 41 extending along the center line in the longitudinal direction. 40, and a two-component developer is put into the packaging bag 40, and the opening 42 is sealed to form a seal portion 42A.

Such a package is produced using a continuous laminated film. The manufacturing method is not particularly limited as long as the laminated film has the above-described basic layer configuration. For example, adopt a processing method such as a method of laminating and laminating a single layer film separately, a method of extruding and coating another resin on one film, a method of laminating by a coextrusion method, etc. Can do.
The packaging body is obtained by using the laminated film-shaped packaging material 35 obtained as described above, and is sealed by heat or the like to form the sealing portion 41, whereby the packaging bag 40 is obtained by two-component development. It is obtained by charging the agent and sealing the opening 42 with heat or the like.

The thickness D of the package is preferably 20 to 300 μm, more preferably 50 to 200 μm. When the thickness D of the package is less than 20 μm, it may be difficult to produce a film-shaped packaging material. On the other hand, when the thickness D is greater than 300 μm, the flexibility is inferior, There is a risk of poor transportability.
The layer thickness d1 of the first resin layer 10 is preferably 5 to 50 μm, more preferably 15 to 50 μm. When the layer thickness d1 of the first resin layer 10 is in the above range, a sufficient water vapor barrier property can be ensured.
The layer thickness d2 of the second resin layer 20 is preferably 10 to 80 μm, and more preferably 15 to 50 μm.

[Polyglycolic acid]
The polyglycolic acid used in the package of the present invention is a glycolic acid homopolymer consisting only of glycolic acid repeating units represented by the following (formula) (a ring-opened polymer of glycolide which is a bimolecular cyclic ester of glycolic acid). Or a glycolic acid copolymer containing 55% by mass or more of the above glycolic acid repeating unit.
(Formula): - (- O-CH 2 -C (O) -) -

  Examples of comonomers that give glycolic acid copolymers together with glycolic acid monomers such as glycolide include ethylene oxalate (1,4-dioxane-2,3-dione), lactides, and lactones (for example, β-pro Piolactone, β-pivalolactone, γ-butyrolactone, β-valerolactone, β-methyl-δ valerolactone, ε-caprolactone, etc.), carbonates (eg, trimethyline carbonate, etc.), ethers (eg, 1,3- Cyclic monomers such as dioxane and the like, ether esters (for example, dioxanone) and amides (such as ε-caprolactam); hydroxycarboxylic acids such as lactic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, and 6-hydroxycaproic acid Or its alkyl ester; ethylene glycol And a substantially equimolar mixture of an aliphatic diol such as 1,4-butanediol and an aliphatic dicarboxylic acid such as succinic acid or adipic acid or an alkyl ester thereof.

  In the polyglycolic acid, the glycolic acid repeating unit is 55% by mass or more, preferably 70% by mass or more, particularly preferably 90% by mass or more. When the ratio of the glycolic acid repeating unit is too small, the water vapor barrier property may not be sufficient.

The polyglycolic acid preferably has a melt viscosity of 100 to 10,000 Pa · sec, more preferably 300 to 8,000 Pa · sec, particularly preferably measured at a temperature of 270 ° C. and a shear rate of 122 sec ^−1. Is 400 to 5,000 Pa · sec.

[Polylactic acid]
The polylactic acid used in the package of the present invention is obtained from L-lactic acid and / or D-lactic acid. As such polylactic acid, those having a melt flow rate of 1 to 20 [g / 10 min], particularly 1 to 10 [g / 10 min] are preferable. In the case where the melt flow rate is less than 1, the melt viscosity becomes too high, and it may be difficult to form a package. On the other hand, when the melt flow rate exceeds 20, the melt viscosity becomes low, and it may be difficult to form the film thickness uniformly.
In addition, a melt flow rate shall be measured using a melt indexer on the conditions of 190 degreeC and 2.16 kg.

[Polybutylene succinate]
The polybutylene succinate used in the package of the present invention is obtained by dehydration polycondensation of succinic acid and 1,4-butanediol. As such polybutylene succinate, those having a melt flow rate of 1 to 30 [g / 10 min], particularly 1 to 20 [g / 10 min] are preferable. In the case where the melt flow rate is less than 1, the melt viscosity becomes too high, and it may be difficult to form a package. On the other hand, when the melt flow rate exceeds 30, the melt viscosity becomes low, and it may be difficult to form the film thickness uniformly.
In addition, a melt flow rate shall be measured using a melt indexer on the conditions of 190 degreeC and 2.16 kg.

[Copolyester of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid]
The 3HB / 3HH copolymer polyester used in the package of the present invention is obtained by accumulating biodegradable polyester in microorganisms, for example, by growing specific microorganisms in the presence of a carbon source. As the carbon source, sugar, natural fats and oils and the like can be used.

  The composition ratio of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid in the 3HB / 3HH copolymer polyester is 50 to 98 mol% for 3-hydroxybutyric acid and 50 to 2 mol% for 3-hydroxyhexanoic acid, preferably 3-hydroxybutyric acid is 75 to 95 mol% and 3-hydroxyhexanoic acid is 25 to 5 mol%. When the composition ratio of 3-hydroxybutyric acid in the 3HB / 3HH copolymer polyester is less than 50 mol%, the productivity of the resulting 3HB / 3HH copolymer polyester is remarkably reduced, whereas the composition of 3-hydroxybutyric acid When the ratio exceeds 98 mol%, the mechanical properties of the resulting 3HB / 3HH copolymer polyester may be deteriorated.

[Two-component developer]
The two-component developer packaged in the package of the present invention comprises a negatively charged toner and a carrier.

〔toner〕
The toner constituting the two-component developer contains at least a binder resin and a colorant, and contains a polymerization initiator, a wax or the like as necessary.

(Toner production method)
Examples of the method for producing the toner include kneading / pulverizing methods, suspension polymerization methods, emulsion polymerization methods, emulsion polymerization aggregation methods, encapsulation methods, and other known methods. Considering that it is necessary to obtain a toner having a reduced particle size in order to achieve high image quality, it is particularly preferable to use an emulsion polymerization aggregation method from the viewpoint of manufacturing cost and manufacturing stability.

  In the emulsion polymerization aggregation method, a dispersion of fine particles (hereinafter referred to as “binder resin fine particles”) made of a binder resin produced by an emulsion polymerization method is used as a dispersion of toner particle components such as other colorant fine particles. At the same time as aggregating slowly while balancing the repulsive force of the fine particle surface by adjusting the pH and the cohesive force by adding an aggregating agent made of an electrolyte, controlling the average particle size and particle size distribution In this method, toner particles are produced by controlling the shape by fusing fine particles by heating and stirring.

  As a method for producing the toner, the binder resin fine particles formed when the emulsion polymerization aggregation method is used may have a structure of two or more layers made of binder resins having different compositions. In this configuration, a polymerization initiator and a polymerizable monomer are added to a dispersion of first resin particles prepared by an emulsion polymerization process (first stage polymerization) according to a conventional method, and this system is polymerized ( (Second stage polymerization).

As one specific example of using an emulsion polymerization aggregation method as a method for producing a toner, the toner production process is as follows:
(1) A colorant fine particle forming step for obtaining colorant fine particles containing a colorant and, if necessary, a surfactant.
(2) A binder resin fine particle polymerization step for obtaining binder resin fine particles containing an anti-offset agent, a charge control agent and the like as required.
(3) A salting out, aggregating, and fusing step in which toner particles are formed by salting out, aggregating, and fusing the binder resin fine particles and the colorant fine particles in an aqueous medium.
(4) A filtration and washing process for separating the toner particles from the toner particle dispersion (aqueous medium) and removing the surfactant from the toner particles.
(5) A drying step of drying the washed toner particles.
(6) A step of adding an external additive to the dried toner particles.
Consists of

  Here, the “aqueous medium” refers to a medium composed of 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, acetone, methyl ethyl ketone, and tetrahydrofuran, and alcohol-based organic solvents that do not dissolve the resulting resin are preferable.

(Coloring agent)
As the colorant constituting the toner, known inorganic or organic colorants can be used.
The addition amount of the colorant is in the range of 1 to 30% by mass, preferably 2 to 20% by mass with respect to the whole toner.

(Binder resin)
As the binder resin constituting the toner, it is preferable to use a thermoplastic resin capable of obtaining sufficient adhesion with the colorant fine particles, and particularly preferably a solvent-soluble one. Moreover, if the precursor is a solvent-soluble thing, even if it is curable resin which forms a three-dimensional structure, it can be used. As the binder resin constituting the toner, in addition to the above-mentioned conditions, it is preferable to use a resin that takes into consideration that high chargeability and fixability can be obtained in the toner.
As such a binder resin, those generally used as a binder resin constituting a toner can be used without particular limitation. Specifically, for example, styrene resins, alkyl acrylates, alkyl methacrylates, and the like can be used. Examples include acrylic resins, styrene-acrylic copolymer resins, polyester resins, silicone resins, olefin resins, amide resins, and epoxy resins. Among these, in order to improve transparency and color reproducibility of superimposed images Suitable examples include styrene resins, acrylic resins, styrene-acrylic copolymer resins, and polyester resins, which have high transparency, low melting properties, and high sharp melt properties. Therefore, a styrene-acrylic copolymer resin is preferable. These can be used alone or in combination of two or more.

  Examples of the polymerizable monomer for obtaining the binder resin include styrene monomers such as styrene, methylstyrene, methoxystyrene, butylstyrene, phenylstyrene, chlorostyrene; methyl (meth) acrylate, ethyl ( (Meth) acrylate ester monomers such as (meth) acrylate, butyl (meth) acrylate and ethylhexyl (meth) acrylate; use of carboxylic acid monomers such as acrylic acid, methacrylic acid and fumaric acid it can. These can be used alone or in combination of two or more.

  The binder resin constituting the toner preferably has a glass transition point (Tg) of 30 to 60 ° C.

The glass transition point of the binder resin is measured using a differential scanning calorimeter “DSC-7 (manufactured by PerkinElmer)” and a thermal analyzer controller “TAC7 / DX (manufactured by PerkinElmer)”.
Specifically, 4.50 mg of a sample is sealed in an aluminum pan “KITNO.0219-0041”, which is set in a sample holder of “DSC-7”, and an empty aluminum pan is used for reference measurement. Then, the temperature of heating-cooling-heating is controlled at the measurement temperature of 0-200 ° C. under the measurement conditions of the temperature increase rate of 10 ° C./min and the temperature decrease rate of 10 ° C./min. To do. A differential curve of the obtained curve C _2nd is obtained, and a peak top temperature T _p (° C.) on the lowest temperature side of 20 ° C. or higher of the differential curve is read. The intersection point of C _2nd at T _p and T _p −20 ° C. is shown as a glass transition point. When T _p cannot be clearly read, the endothermic side inflection point on the lowest temperature side at 20 ° C. or higher of C _2nd or the extension line of the baseline before the rise of the first endothermic peak and the first endothermic peak The point of intersection with the tangent showing the maximum slope between the rising part and the peak apex is shown as the glass transition point. In addition, it hold | maintains at 200 degreeC for 1 minute at the time of a 1st temperature rising.

  Furthermore, the softening point of the binder resin is preferably 80 to 130 ° C, more preferably 90 to 120 ° C.

(Polymerization initiator)
When the toner is produced by an emulsion polymerization aggregation method, a water-soluble polymerization initiator can be used as a polymerization initiator for obtaining a binder resin. Specific examples of the polymerization initiator include persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2 -Amidinopropane) salts), peroxide compounds and the like.

(Chain transfer agent)
When the toner is produced by an emulsion polymerization aggregation method, a commonly used chain transfer agent can be used for the purpose of adjusting the molecular weight of the binder resin. The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as 2-chloroethanol, octyl mercaptan, dodecyl mercaptan, and t-dodecyl mercaptan, and styrene dimers.

(Surfactant)
As the surfactant used when the toner is produced by the emulsion polymerization aggregation method, various conventionally known ionic surfactants, nonionic surfactants, and the like can be used.

(Flocculant)
As an aggregating agent used when a toner is produced by an emulsion polymerization aggregation method, for example, an alkali metal salt, an alkaline earth metal salt, or the like can be used. Examples of the alkali metal constituting the flocculant include lithium, potassium, and sodium, and examples of the alkaline earth metal constituting the flocculant include magnesium, calcium, strontium, and barium. Of these, potassium, sodium, magnesium, calcium, and barium are preferable. Examples of the counter ion (anion constituting the salt) of the alkali metal or alkaline earth metal include chloride ion, bromide ion, iodide ion, carbonate ion and sulfate ion.

(Offset prevention agent)
The toner may contain an offset preventing agent for suppressing the offset phenomenon. Here, the offset inhibitor is not particularly limited, and for example, polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, fatty acid ester wax, carnauba wax, sazol wax, rice wax, Candelilla wax, jojoba oil wax, beeswax wax and the like can be mentioned.

As a method of adding an offset preventive agent to the toner particles, a dispersion (wax emulsion) of the offset preventive agent particles is added in the salting-out, agglomeration, and fusing steps to form the toner particles, and the binder resin fine particles are colored. In the method of salting out, agglomerating, and fusing the agent fine particles and the offset inhibitor particles, and in the salting out, agglomerating, and fusing steps for forming the toner particles, And salting out, agglomerating and fusing, and these methods may be combined.
The content of the anti-offset agent in the toner particles is usually 1 to 30 parts by mass, and more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the binder resin for toner particle formation.

(Charge control agent)
The toner may contain a charge control agent. Preferred examples of the charge control agent include metal complexes of salicylic acid derivatives such as zinc and aluminum (salicylic acid metal complexes), calixarene compounds, organic boron compounds, and fluorine-containing quaternary ammonium salt compounds.
The content ratio of the charge control agent in the toner particles is usually 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the binder resin.

(Particle size of toner particles)
The particle diameter of the toner particles is preferably 3 to 10 μm, and more preferably 4 to 8 μm, for example, as a volume-based median diameter. When the toner production method is, for example, an emulsion polymerization aggregation method, the volume-based median diameter is determined based on the concentration of the aggregating agent (salting-out agent) used, the amount of organic solvent added, the fusing time, It can be controlled by the composition.

The volume-based median diameter (D ₅₀ ) of the toner particles can be measured and calculated using an apparatus in which a computer system for data processing is connected to “Multisizer 3 (manufactured by Beckman Coulter)”.
Specifically, 0.02 g of a sample (toner) is used in 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of toner dispersion). After being blended, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is injected into a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand with a pipette until the measured concentration reaches 5 to 10%, and the measurement is set to 25000 counts. To do. The aperture diameter of “Multisizer 3” is 50 μm.

(External additive)
In order to improve fluidity, chargeability, cleaning properties, etc., the toner can be constituted by adding external additives such as a fluidizing agent and a cleaning aid to the toner particles.

Examples of the external additive include inorganic oxide fine particles composed of silica fine particles, alumina fine particles, titanium oxide fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, strontium titanate, titanium, and the like. Inorganic titanic acid compound fine particles such as zinc acid are listed. These can be used individually by 1 type or in combination of 2 or more types.
These inorganic fine particles are preferably subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil or the like in order to improve heat-resistant storage stability and environmental stability.

  The total amount of these various external additives added is 0.1 to 10 parts by mass with respect to 100 parts by mass of the toner. In addition, various external additives may be used in combination.

[Carrier]
The carrier constituting the two-component developer is not particularly limited as long as it imparts a negative charge to the toner. Examples of such a carrier include metals such as iron, ferrite, and magnetite, those metals and aluminum, lead, and the like. Magnetic particles made of conventionally known materials such as alloys with metals can be used, and ferrite particles are particularly preferable. Further, as the carrier, a coat carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, a binder type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.
The coating resin constituting the coat carrier is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene-acrylic resins, acrylic resins, silicone resins, ester resins, and fluorine resins. Moreover, it does not specifically limit as binder resin which comprises a binder type carrier, A well-known thing can be used, For example, a styrene-acrylic resin, a polyester resin, a fluororesin, a phenol resin etc. can be used. Among these, a coat carrier coated with a styrene-acrylic resin or an acrylic resin is preferable from the viewpoint of chargeability and durability.

  The carrier preferably has a volume average particle size of 20 to 100 μm, more preferably 25 to 80 μm, since a high-quality image can be obtained and carrier fog is suppressed. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS (manufactured by SYMPATEC)” equipped with a wet disperser.

  As described above, according to the present invention, when the package has a single layer structure, the two-component developer in the package has an appropriate charge amount due to the water vapor barrier property and the negative charge property of polyglycolic acid. Even when the package has a laminated structure of two or more layers, the water vapor barrier property and negative charging property of the first resin layer and the negative charging property of the second resin layer Thus, the two-component developer in the package is maintained in an appropriate charge amount state, and as a result, image defects such as fogging and image density reduction do not occur, and high-quality images can be stably formed.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

[Production example 1 of packaging bag]
Using a film-like packaging material in which a polyglycolic acid layer with a layer thickness of 25 μm was laminated on the inner layer and a polyethylene layer with a layer thickness of 50 μm on the outer layer in this order, a packaging bag [1] shown in FIG. 3 was produced. .

[Production Examples 2-8 of packaging bags]
Packaging bags [2] to [8] were produced in the same manner as in Production Example 1 of the packaging bag, except that the resin constituting each resin layer was changed to the combination shown in Table 1. Table 1 shows the thickness of each resin layer.

[Examples 1-4 and Comparative Examples 1-4]
The packaging bags [1] to [8] obtained as described above are charged with 250 g of a negatively chargeable two-component developer, the openings are sealed and sealed, and the packaging bodies [1] to [1] shown in FIG. 8] were prepared and evaluated as follows.

(1) Color identification For the packaging bodies [1] to [8], it was evaluated whether or not the color of the two-component developer in the packaging could be identified from the appearance without opening. The results are shown in Table 2.

(2) Charge amount The charge amount was measured by a parallel plate method. In other words, a developer is disposed between parallel plate (aluminum) electrodes, and the toner is developed under the conditions that the gap between the electrodes is 0.5 mm, the DC bias is 1.0 KV, the AC bias is 4.0 KV, and 2.0 KHz. The charge amount and mass of the toner thus obtained were measured, and the charge amount per unit mass Q / m (μC / g) was defined as the charge amount.
This amount of charge was measured by leaving the package [1] to [8] after standing still, leaving at high temperature and high humidity, opening the package [1] to [8], and taking out the two-component developer. The results are shown in Table 2.
Here, “after standing at rest” is after standing for 30 days in an environment of 20 ° C. and 50% RH, and “after leaving at high temperature and high humidity” is at 30 ° C. and 80%. This is after 30 days in an RH environment. “After the friction test” means that the upper and lower portions of the package are held by hand, rotated up and down at a speed of 20 times per minute, and performed 100 times for 5 minutes.

(3) Cover The package [1] to [8] is opened, the two-component developer is taken out, and the two-component developer is filled in the developing device of the image forming apparatus “bizhub C353” (manufactured by Konica Minolta Business Technologies). Then, in the black mode, the original image in which the character image portion, solid black image portion, and white background portion with a printing rate of 5% are each divided into 1/3 equal parts is used on A4 quality fine paper (64 g / m ² ). Ten sheets were printed and the fog density was measured. The evaluation of the fogging was performed three times in total after standing still, leaving at high temperature and high humidity, and after the friction test. The results are shown in Table 2.
The fog density is determined by measuring the absolute reflection density at 20 locations using a Macbeth reflection densitometer “RD-918” (manufactured by Macbeth) for a non-printed white paper, Similarly, for the tenth white background portion on which the original image is printed, the absolute reflection density at 20 locations is measured to calculate the average, and the difference between the average value and the blank paper density is calculated. If the fog density is 0.005 or less, there is no practical problem.

(4) Image density The image density is measured by measuring the absolute reflection density at 20 locations and calculating the average for the tenth solid black image portion on which the original image is printed. If the image density is 1.40 or more, there is no practical problem. The image density was evaluated 3 times in total after standing still, leaving at high temperature and high humidity, and after the friction test. The results are shown in Table 2.

  From the above results, according to Examples 1 to 4 according to the present invention, even when stored in a high temperature and high humidity environment for a long period of time or when exposed to a situation where excessive frictional charging occurs, It was confirmed that a high-quality image free from image defects such as a decrease in image density can be stably formed. In Comparative Examples 1 and 2, the package did not have transparency, and the color of the two-component developer in the package could not be recognized from the appearance.

DESCRIPTION OF SYMBOLS 10 1st resin layer 20 2nd resin layer 30 3rd resin layer 35 Packaging material 40 Packaging bag 41 Sealing part 42 Opening part 42A Sealing part 43 Packaging

Claims (2)

A package for a two-component developer in which a negatively chargeable two-component developer comprising a toner and a carrier is packaged,
The two-component developer packaging body, wherein the two-component developer packaging body is formed of a resin containing at least polyglycolic acid. The package for a two-component developer according to claim 1,
Having a laminated structure in which at least two resin layers are laminated;
The first resin layer is made of a resin containing at least polyglycolic acid,
The second resin layer is made of a resin containing at least one selected from polylactic acid, polybutylene succinate, and polyester copolymerized with 3-hydroxybutyric acid and 3-hydroxyhexanoic acid. Item 2. The package for a two-component developer according to Item 1.