JPS61124963A - Electrophotographic developing composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition capable of preventing an offset and fixing at a lower temp. by incorporating a polymer obtd. from two or more valence of carboxylic acid contg. a tertiary amino group to said composition as a main component of an adhesion resin. CONSTITUTION:The main component of the prescribed composition is a polymer obtd. by reacting a component (a) of the prescribed carboxylic acid in a polymerization of a component (b) of styrene and/or its derivative and a component (c) of at least one of monomers selected from the group of methacrylic acid, acrylic acid and its ester. The component (c) of an ester of acrylic acid or methacrylic acid contg. at least one of a hydroxy group or an epoxy group is contained in an equimolar or more amount on the basis of that of the component (a). The component (a) comprises 0.05-50wt% on the weight basis of the total monomer, and is the two or more valence carboxylic acid contg. the tertiary amino group and shown by formulas (I)-(IV).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a developer composition for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a developer composition.

[Conventional technology and problems]

As a conventional electrophotographic method, as described in U.S. Patent Nos. 2,297,691 and 2,357,809, etc.
A photoconductive insulating layer is uniformly charged, the layer is then exposed to light, and the charge on the exposed portions is dissipated to form an electrical latent image, which is then coated with a colored pigment called toner. After the visible image is transferred to a transfer material such as transfer paper (transfer process), it is heated,
It consists of a step of permanently fixing (fixing step) by pressure or other suitable fixing method.

In this way, toner is used not only in the development process but also in the transfer process.
It must have the functions required in each step of the fixing process.

Generally, toner is subjected to mechanical frictional force due to shearing force and impact force during mechanical operation in a developing device, and deteriorates while copying several thousand to tens of thousands of sheets. To prevent such toner deterioration, it is best to use a strong resin with a large molecular weight that can withstand mechanical friction, but these resins generally have a high softening point and are suitable for non-contact fixing methods such as oven fixing and infrared fixing. With radiant fixing, the thermal efficiency is poor, so fixing is not sufficient.Also, since the contact fixing method has good thermal efficiency, even in the widely used heat roller constant fixing method, it is necessary to use the heat roller to achieve sufficient fixing. It becomes necessary to raise the temperature, which not only causes adverse effects such as deterioration of the fixing device, curling of paper, and increased energy consumption, but also causes a significant drop in production efficiency when producing toner by pulverizing such resins. descend. Therefore, it is not possible to use a binder resin whose polymerization degree and even softening point are too high.

On the other hand, in the heat roller fixed fixing method, the heating roller surface and the toner image surface of the fixing sheet come into pressure contact, so the thermal efficiency is extremely high, and it is widely used from low speeds to high speeds.
When the heating roller surface and the toner image surface come into contact, a so-called offset phenomenon tends to occur, in which the toner adheres to the heating roller surface and is transferred to a subsequent transfer paper or the like. To prevent this phenomenon, the surface of the heating roller is treated with a material with excellent mold release properties such as fluorine-based resin, and in addition, a mold release agent such as silicone oil is applied to the surface of the heating roller to completely prevent the offset phenomenon. are doing.

However, the method of applying silicone oil etc.
This is not preferable because the fixing device becomes large, which not only increases cost but also makes it complicated, which tends to cause trouble.

In addition, as described in Japanese Patent Publication No. 55-6895 and Japanese Patent Application Laid-open No. 56-98202, there is a method to improve the offset phenomenon by widening the molecular weight distribution width of the binder resin, but the degree of polymerization of the resin increases and the fixation becomes difficult. The temperature also needs to be high.

As a further improved method, as described in Japanese Patent Publication No. 57-493, Japanese Patent Application Laid-open No. 50-44836, and Japanese Patent Application Publication No. 57-37353, there is a method of improving the offset phenomenon by making the resin asymmetrical and crosslinking it. However, the retention point has not improved.

Generally, the minimum fusing temperature is between cold offset and hot offset, so the usable temperature range is between the minimum fusing temperature and hot offset. By raising the temperature as much as possible, the fixing temperature used can be lowered and the usable temperature range can be expanded, resulting in energy savings, high-speed fixing, and prevention of paper curl. In addition, since double-sided copying can be performed without trouble, there are many advantages such as making the copying machine more intelligent, controlling the temperature of the fixing device more accurately, and relaxing the tolerance range.

Therefore, resins and toners with good fixing properties and offset resistance are always desired.

In addition, when using a styrene-based binder resin to achieve such requirements, Japanese Patent Application Laid-Open Nos. 49-65232 and 1972
As described in No. 0-28840 and JP-A No. 50-81342, methods of adding paraffin wax, low molecular weight polyolefin, etc. as anti-offset agents are known; In the case of polyester resin, applying the same offset preventive agent as described above has little effect, and the amount used must be increased.
It has also been confirmed that the developer deteriorates quickly.

Polyester resin inherently has good fixing properties, and can be sufficiently fixed even in a non-contact fixing method, as described in U.S. Pat. It was difficult to use.

As described in JP-A-50-44836, JP-A-57-37353, and JP-A-57-109875, polyester resins with improved offset resistance using polyhydric carboxylic acids have sufficient properties for use. Those that do not have anti-offset properties, or those that do, not only sacrifice the low-temperature fixing properties inherent to polyester resins, but also
Even in the toner production process, the crushability was extremely poor, and there were also problems in developer production.

Generally, a toner is composed of a binder resin, a colorant, and other additives, with the binder resin being the main component. As toner binder resin, coumarone indene resin,
Terpene resin, styrene resin or their copolymer resin,
Polyester resins, epoxy resins, and the like are generally used, but there are few binder resins that are strongly positively charged by friction. It is generally known to add additives such as nigrosine dye as a charge control agent to make the toner positive polarity, but this method has poor compatibility with the binder resin that constitutes the main component of the toner, and the toner particles If they are mixed for a long time in the developing device, the particles will be destroyed, and if nigrosine etc. is simply dispersed, particles of opposite (negative) polarity that do not contain nigrosine etc. will be generated, and the area where there is no image signal will be generated. A so-called smearing phenomenon occurs in which toner adheres to the toner. Furthermore, when nigrosine dye or the like is used, since it has hydrophilic properties, the amount of charge changes depending on the humidity of the environment, resulting in a decrease in image quality. In addition, nigrosine dyes generally have strong coloring (and have disadvantages such as being incompatible with color toners. For the above reasons, they are strongly positively charged,
It is desired to develop toner binder resins and toners that are not affected by environmental humidity and have excellent durability.

The present invention was made to meet these demands, and its purpose is to provide a developer that can prevent offset without applying an anti-offset liquid in a heat roller fixed fixing method, and that can be fixed at a lower fixing temperature. The goal is to provide the following.

Another object of the present invention is to provide a developer which can prevent offset without adding an offset preventive agent in a heat roller fixed fixing method and which can be fixed at a lower fixing temperature.

Another object of the present invention is to provide a developer that has good fluidity (does not cause blocking) and has a long life (does not easily deteriorate).

Another object of the present invention is to provide a developer with good kneading and pulverizing properties during developer production.

Another object of the present invention is to provide a dry developer for electrophotography,
The object of the present invention is to provide a toner that forms clear and fog-free images by using a toner binder resin that inherently has a strongly positive charging property, and more specifically, to provide a toner that is resistant to the influence of environmental humidity and that improves the above-mentioned drawbacks. The object of the present invention is to provide a toner which is extremely small and has excellent durability, and whose binder resin essentially has positive triboelectric charging properties.

Another object of the present invention is to provide a clear color developer with good transparency.

[Means for solving problems]

The present inventors have arrived at the present invention as a result of intensive research to achieve the above object.

That is, the present invention provides an electrophotographic developer composition containing a binder resin and a colorant as main components, wherein the main components of the binder resin are (
b) Styrene and/or styrene derivative; and (b)
When polymerizing with one or more monomers selected from methacrylic acid, acrylic acid, and esters thereof, (c) the third
A polymer obtained by reacting a divalent or higher carboxylic acid having a primary amino group, in which the component (b) is an ester of acrylic acid or methacrylic acid having at least one type of hydroxyl group or epoxy group. Contains at least the same mole as the component (c), and (c)
The present invention relates to an electrophotographic developer composition characterized in that the content of the component is 0.05 to 50% by weight based on the total amount of monomers.

In a preferable electrophotographic developer composition of the present invention, the component (c) used in the production of the binder resin has a divalent amino group having a tertiary amino group represented by the following general formulas CI) to (IV). These are the above carboxylic acids.

-Rh HOOC-Rs-N-Rt-COOH... (I
I) I5 (Formula [■] to [■], RIM Rt+ RIM R6
1RtlR11R91R1111R11, R+z+ R
I31 RII+ R1& is an alkylene group having 1 to 15 carbon atoms, R3 and R4 are an alkyl group having 1 to 10 carbon atoms, R1? + RIM represents an alkyl group having 1 to 4 carbon atoms, and R1? and R111 may form a heterocyclic ring of the same nitrogen atom. Indicates RIM. X represents a hydrogen atom or a carboxyl group. ) Further, the electrophotographic developer composition according to the present invention is preferably one having a resin softening temperature of 100
~160°C, and the glass transition temperature is 50°C or higher.

In the present invention, the component (c) may be reacted with the component (b) before the polymerization, or after the polymerization of the component (a) and the component (b), or during the polymerization. You may react. The polymerization reaction mainly proceeds by generally known vinyl polymerization, in which a polymerization initiator such as a peroxide or preferably an azo compound is used, and reaction conditions are appropriately selected depending on the monomers, initiator, etc. used.

Examples of the styrene or styrene derivative (a) in the present invention include styrene, 〇-methylstyrene, m
-Methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-7'tylstyrene, p-n-hexylstyrene, p -n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, and others. can be mentioned.

Examples of (b) methacrylic acid, acrylic acid, or ester thereof include acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and tert-butyl acrylate. , amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, acrylic Acid hydroxypropyl, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, methacrylic acid n-butyl, isobutyl methacrylate, tert-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-methacrylate
Examples include ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and others.

Further, as the divalent or higher carboxylic acids having a tertiary amino group represented by the general formulas (I) to C (iii) in the present invention, the following may be mentioned.

(1) Carboxylic acid represented by general formula (I) or its lower ester N, N''-bis(carboxymethyl)piperazine, N,
N'-bis(carboxyethyl)piperazine, N,N'
-bis(carboxymethyl)-2゜6-dimethylpiverazine, N,N"-bis(3-carboxypropyl)piperazine, N -(2-carboxyethyl) -N'
-(carboxymethyl)piperazine, etc.

(2) Carboxylic acid represented by general formula (If) or its lower ester N, N-bis(carboxymethyl)methylamine, N,
N-bis(2-carboxyethyl)methylamine, N,
N-bis(2-carboxyethyl)isopropylamine, N-carboxymethyl-N-(2-carboxyethyl)methylamine, nitriloacetic acid, etc.

(3) Carboxylic acid represented by general formula (III) or its lower ester N,N''-dimethyl-N,N'-bis(carboxymethyl)ethylenediamine, N,N''-dimethyl-N,N
'-bis(2-carboxyethyl)ethylenediamine,
N,N'-dimethyl-N,N''-bis(3-carboxypropyl)hexamethylenediamine and the like.

(4) Carboxylic acid represented by general formula (IV) or its lower ester 4-methyl-4-N,N-dimethylaminomethyl-azelaic acid, 5-methyl-5-N,N-diethylaminoethyl-undecanedioic acid , 6-ethyl-6-N, N-
di-n-propylaminomethyl-brassilic acid, 9-methyl-9-N, N-dimethylaminomethyl-nonadecanedioic acid, and the like.

Among the components constituting the binder resin according to the present invention, (a) styrene or styrene derivative forms the main skeleton of the resin,
(b) (Meth)acrylic acid or its ester adjusts the thermal properties such as the softening point of the resin, and the component (c) determines the charge and adjusts the amount of charge, lowers the fixing temperature, and improves offset resistance. However, if the content of component (c) is less than 0.05% by weight based on the total amount of monomers, the effect will be lost, and 5
If it exceeds 0% by weight, the moisture resistance of the toner will deteriorate.

Further, the softening point of the resin used in the developer composition of the present invention is preferably 100 to 160°C using a Koka type flow tester; if it is too low, the offset resistance will be insufficient, and if it is too high, the fixing property will be insufficient. Become.

The method for producing the binder resin of the present invention is carried out by a well-known addition polymerization reaction.

Colorants used in the present invention include carbon black, acetylene black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green 810-damine-B base,
Examples include Solvent Red 49, Solvent Red 146, Solvent Blue 35, and mixtures thereof, and are usually used in an amount of about 1 to 15 parts by weight per 100 parts by weight of the binder resin.

When making a magnetic toner using the binder resin according to the present invention,
Examples of magnetic materials include alloys or compounds containing ferromagnetic elements such as ferrite and magnetite.
The magnetic material can be used in the form of a fine powder with an average particle size of 0.1 to 1 μm and dispersed in a binder resin in an amount of 40 to 70% by weight.

Known property improving agents contained in toner include charge control agents, anti-offset agents, fluidizing agents, etc., but since the resin of the present invention has good properties by itself, these agents may not be used during toner preparation. It becomes unnecessary to add a property improver, or even if it is added, only a small amount is required.

〔Example〕

Examples of the invention will be described below, but the invention is not limited to these examples. It should be noted that all composition ratios shown in Examples are expressed in parts by weight.

Example 1 500 parts of xylene, N,
Charge 50 parts of N'-bis(carboxyethyl)piperazine and adjust the temperature to 80°C.

A mixed solution of 800 parts of styrene, 60 parts of 2-hydroxyethyl methacrylate, 90 parts of n-butyl acrylate, and 10 parts of α,α゛-azobisisobutyronitrile was dropwise polymerized over 4 hours under a nitrogen stream. . After aging at the same temperature for 10 hours after the dropwise addition, the temperature was gradually raised to 210°C while the pressure was reduced to 1 mvaHg, xylene was distilled off, and the molten resin was taken out into a stainless steel vat, left to cool, and pulverized. A powdered resin (softening point of Koka type flow tester: 125.5°C, Tg: 63.5°C) was obtained. This softening point was determined using a Koka type flow tester (manufactured by Shimadzu Corporation).
While heating the c113 sample at a heating rate of 6°C/min, a plunger applies a load of 20kg/cm'' to push out a nozzle with a diameter of 1111 and a length of 11IIIm, thereby lowering the plunger of the flow tester. When a quantity-temperature curve is drawn and the height of the S-curve is h, the temperature corresponding to h/2 is defined as the softening point.

93 parts of the resin and 7 parts of carbon black (SU-GAL 400R manufactured by Cabot Corporation) were mixed in a ball mill, coarsely pulverized in a hammer mill, further finely pulverized in a jet mill, and after classification, a toner with an average particle size of 13.0 μm was obtained. Obtained. The obtained toner was mixed with carrier iron powder (manufactured by Nippon Tetsuko Co., Ltd., EFV 200).
/300) and measured the charge amount with a blow-off measuring machine, it was found to be +17 μc/g. 91 g of the toner was mixed with 1209 g of carrier iron powder to prepare a developer, and a commercially available electrophotographic copying machine (the photoreceptor was Organic photoconductor, fixing roller has a diameter of 60 mm and a rotation speed of 2
When the image was produced at 55 mm/sec with the heat-roller temperature in the fixing device being variable and the oil coating device removed, the image was clear and free of background smudges, smearing, and black solid areas. was gotten.

When the fixing temperature was controlled at 140° C. to 220° C. and the image fixability and offset property were evaluated, the image was sufficiently fixed at 148° C. and no hot offset occurred. 5
When images were printed up to 10,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

The minimum fixing temperature here is 15 mm x 7.5 mm on the bottom.
A load of 500 g was placed on a 500 g sand eraser, and the image fixed through the fixing machine was rubbed back and forth 5 times. The optical reflection density was measured using a Macbeth reflection densitometer before and after rubbing, and the fixing rate was determined as defined below. This refers to the temperature of the fixing roller when the temperature exceeds 70%.

Example 2 500 parts of xylene and 20 parts of nitrilotriacetic acid are charged into the reactor of Example 1, and the temperature is adjusted to 80°C. 700 parts of α-methylstyrene and 2-acrylic acid under a nitrogen stream
A mixed solution of 40 parts of hydroxyethyl, 240 parts of 2-ethylhexyl acrylate, and 20 parts of α,α゛-azobisdimethylvaleronitrile was dropwise polymerized over 4 hours. After aging at the same temperature for 10 hours after the completion of the dropwise addition, the temperature was gradually raised to 210°C while the pressure was reduced to 'I n + n + Hg, xylene was distilled off, the molten resin was taken out into a stainless steel vat, allowed to cool, and pulverized. Powdered resin (high chemical 7O
-F-Star Softening Point 123.0'C1Tg 65.0
°C) was obtained.

After mixing 93 parts of the resin and 7 parts of carbon blank (Su-Gal 400R manufactured by Cabot) in a ball mill, kneading,
It was crushed and classified to obtain a toner with an average particle size of 13.2 μm. The amount of charge of the obtained toner was +16 μc/g. 91 g of the toner was mixed with 1209 g of carrier iron powder to prepare a developer, and an image was produced using the same evaluation machine as in Example 1. A clear image was obtained with no smudges or black solid areas. When the fixing temperature of the fixing device was controlled and the image fixing and offset properties were evaluated, the result was 1.
It was fixed at 45° C. and no hot offset occurred.

When images were printed up to 50,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

Example 3 In the reactor of Example 1, 500 parts of xylene, 15 parts of N,N'-dimethyl-N,N'-bis(carboxymethyl)ethylenediamine, 845 parts of styrene, 20 parts of hydroxypropyl acrylate, and 120 parts of lauryl methacrylate were used. In the same manner as in Example 1, using 10 parts of α, α″-azobisdimethylwareconitrile, a powdered resin (Koka flow tester softening point: 124.5°C, Tg: 65.2°C) was obtained.
) was obtained.

After mixing 93 parts of the resin and 7 parts of carbon blank (SU-GAL 400R manufactured by CABOFT) in a ball mill,
It was pulverized and classified to obtain a toner with an average particle size of 12.9 μm. The amount of charge of the obtained toner was +16 μc/g.

Mixing 91 g of the toner with 1209 g of carrier iron powder,
When a developer was prepared and an image was produced using the same evaluation machine as in Example 1, a clear image was obtained without background smudges, bleeding, or missing solid black areas.

Controls the fixing temperature of the fixing device to improve image fixability,
When evaluating the offset property, it was fixed at 145℃,
No hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

Example 4 In the reactor of Example 1, 500 parts of xylene, 4-methyl-4
Example using 15 parts of -N,N-dimethylaminomethyl-azelaic acid, 845 parts of styrene, 10 parts of glycidyl methacrylate, 130 parts of butyl methacrylate, and 20 parts of α,α''-azobisdimethylwareconitrile. A powdered resin (softening point of Koka type flow tester: 123.5°C, Tg: 63.2°C) was obtained in the same manner as in 1.

93 parts of the resin and 7 parts of carbon black (Regal 400R, manufactured by Cavo-Nodo Co., Ltd.) were mixed in a ball mill, then kneaded, pulverized, and classified to obtain a toner with an average particle size of 13.1 μm.

The amount of charge of the obtained toner was +17 μc/g. 91 g of the toner was mixed with 1209 g of carrier iron powder,
When a developer was prepared and an image was produced using the same evaluation machine as in Example 1, a clear image was obtained without background smudges, blurring, or missing solid black areas.

Controls the fixing temperature of the fixing device to improve image fixability,
When evaluating the offset property, it was fixed at 147℃,
No hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

Comparative Example I A resin (
Koka type flow tester Softening point 129.5℃, Tg 72
．． 4°C).

After mixing 93 parts of the resin and 7 parts of carbon blank (Su-Gal 400R manufactured by Cabot) in a ball mill, kneading,
Grind and classify, average particle size: 13. A toner of oμ was obtained. When the obtained toner was mixed with carrier iron powder and the amount of charge was measured using a blow-off measuring device, it was found to be -8 μc/g.

Claims (1)

[Scope of Claims] 1. An electrophotographic developer composition containing a binder resin and a colorant as main components, wherein the main components of the binder resin are (a) styrene and/or a styrene derivative; and (b) When polymerizing one or more monomers selected from methacrylic acid, acrylic acid, and esters thereof, (c) a polymer obtained by reacting a divalent or higher carboxylic acid having a tertiary amino group. Component (B) contains an ester of acrylic acid or methacrylic acid having at least one type of hydroxyl group or epoxy group in an amount equal to or more than the mole of component (C), and An electrophotographic developer composition characterized in that the content is 0.05 to 50% by weight based on the total amount of monomers. The electrophotographic developer according to claim 1, wherein component 2 (c) is a divalent or higher carboxylic acid having a tertiary amino group represented by the following general formulas [I] to [IV]. Composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼……[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼……[II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼……[III] ▲Mathematical formulas, chemical formulas, There are tables, etc.▼...[IV] (In formulas [I] to [V], R_1, R_2, R_5, R
_6, R_7, R_8, R_9, R_1_0, R_1_
1, R_1_2, R_1_3, R_1_4, R_1_6
is an alkylene group having 1 to 15 carbon atoms, R_3, R_4
is an alkyl group having 1 to 10 carbon atoms, R_1_7, R_
1_8 represents an alkyl group having 1 to 4 carbon atoms, and R_1
_7 and R_1_8 may form a different ring of the same nitrogen atom. R_1_5 represents an alkyl group having 1 to 3 carbon atoms or ▲Numerical formula, chemical formula, table, etc. are available▼. X represents a hydrogen atom or a carboxyl group. ) 3 The softening temperature of the resin using a high-performance flow tester is 10.
The electrophotographic developer composition according to claim 1, which has a glass transition temperature of 0 to 160°C and a glass transition temperature of 50°C or higher.