JPS61124965A - Electrophotographic developing composition - Google Patents

Abstract

PURPOSE:To prevent an offset and to obtain the titled composition having a lower fixing temp. by incorporating to said composition, a polymer obtd. by reacting a 7-40C carboxylic acid having two or more valences as a main component of a binding agent. CONSTITUTION:The main component of the binding agent comprises a polymer obtd. by reacting the prescribed component (a) in the polymerization of the component (b) of styrene and/or its derivative and the component (c) of at least one of monomers selected from a group composed of methacrylic acid, acrylic acid and its ester. An ester or acrylic acid or methacrylic acid contg. at least one of a hydroxy group or an epoxy group contains in an equimolar or more amount on the basis of that of the component (a). The component (a) comprises 0.05-10wt% on the weight basis of the total monomer, and is an acid or its acid anhydride or its lower alkyl ester shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a developer composition for developing electrostatic images in electrophotography, electrostatic distribution, electrostatic printing, etc.

[Conventional technology and problems]

Conventional electrophotographic methods include, as described in U.S. Pat. No. 2,297,691, U.S. Pat.
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 during copying of tens 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 in order 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 that has a high degree of polymerization and also has a high softening point.

On the other hand, the heat roller fixed fixing method has extremely good thermal efficiency because the heating roller surface and the toner image surface of the fixing sheet come into pressure contact, 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 is large, expensive, and not only unwieldy but also complicated, which tends to cause trouble.

There are also methods to improve the offset phenomenon by widening the molecular weight distribution of the binder resin, as described in Japanese Patent Publication No. 55-6895 and Japanese Patent Publication No. 56-98202, but the degree of polymerization of the resin is high. It is also necessary to increase the fusing temperature.

As a further improved method, as described in Japanese Patent Publication No. 57-493, Japanese Patent Application Publication No. 50-44856, and Japanese Patent Application Publication No. 57-57555, there is a method of improving the offset phenomenon by making the resin asymmetrical and crosslinking. 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 hot offset 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 general, polyester resins and styrene resins are often used as resins, and economical styrene resins inherently have a high minimum fixing temperature.

Improvements in the resin composition and the addition of waxes naturally had their limits.

The present invention was made to meet these requirements, and its purpose is to prevent offset without applying an anti-offset liquid in a heat roller constant fixing method, and to achieve a low fixing temperature. The purpose is to provide a developer that can be fixed.

Another object of the present invention is to provide a developer which can prevent offset without adding an anti-offset agent in a heat roller fixed fixing method and which can be fixed at a much 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 (hard to deteriorate).

Another object of the present invention is to provide a developer that exhibits good crosstalk and pulverizability during developer production.

[Means for solving problems]

The present inventors have arrived at the present invention as a result of intensive research into rounding 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, in which the main components of the binder resin are:
(a) Styrene and/or styrene derivative, ←)
When polymerizing one or more monomers selected from methacrylic acid, acrylic acid, and esters thereof, (c) a polymer obtained by reacting with a divalent or higher carboxylic acid having 7 to 40 carbon atoms. The component (b) contains at least one ester of acrylic acid or methacrylic acid having a hydroxyl group or epoxy group in an amount equal to or more than the mole of the component (c), and (c) This relates to an electrophotographic developer composition characterized in that the content of the component is 0.05 to 10% by weight based on the total amount of monomers.

As the electrophotographic developer composition of the present invention, it is preferable that the binder resin has a softening point of 100 to 1 on a Koka type flow tester.
60C and a glass transition temperature of 500 or more, and more preferably, the compound (c) above is an acid represented by the following general formula, an acid anhydride thereof, or a lower alkyl ester thereof.

(In the formula, R is an alkyl group, alkenyl group, alkylene/group, or alkenylene group having 5 to 30 carbon atoms and having 3 or more carbon atoms!1it-1 or more, and n is an integer of O or 1) In the invention, component (c) may be reacted with component ← before polymerization, or may be reacted after polymerization of component (a) and component (b), or may be reacted during polymerization. You may let them. The polymerization reaction mainly proceeds by generally known vinyl polymerization, in which case a polymerization initiator such as a peroxide or an azo compound is used, and reaction conditions are appropriately selected depending on the monomers, initiator, etc. used.

As the styrene or styrene derivative of (a) in the present invention, Ir1 Example 1 = Id styrene, O-methylstyrene, m-methylstyrene, p-)tylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene , p-n-bu? Rustyrene, Ri -tart-
7'tylstyrene% p-n-hexylstyrene, p
-n-: #ritylstyrene, pn-nonylstyrene,
D-n-f silstyrene, p-n-dodecylstyrene,
Mention may be made of p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, s,a-dichlorostyrene, and others.

(b) Examples of methacrylic acid, acrylic acid, or esters thereof include acrylic acid, methyl acrylate, ethyl acrylate, n-methyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and acrylic acid. Rtart-butyl, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, 2-human acrylate Cystoxyethyl, hydroxyglobyl acrylate, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate/ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate , n-butyl methacrylate, isobutyl methacrylate, tart-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-methacrylate
-Octyl, inoctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, hydroxyglobil methacrylate, glycidyl methacrylate, methacrylic acid Mention may be made of phenyl, dimethylamine ethyl methacrylate, diethylaminoethyl methacrylate, and others.

Component (c) can be easily obtained by a known method such as reaction of a divalent unsaturated carboxylic acid such as maleic acid with an unsaturated hydrocarbon, or a subsequent hydrogenation reaction. (Divalent components of /1 include, for example, inbutenylsuccinic acid, n-dodecenylsuccinic acid, indodecenylsuccinic acid, n-octenylsuccinic acid, inoctenylsuccinic acid, inbutyl;
Examples include uccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octylsuccinic acid, inoctylsuccinic acid, and acid anhydrides or lower alkyl esters thereof. The tetravalent components include (1) 4-neopentylizonyl-1,2,6,7-hebutanato-2-ruboxylic acid (2) 4-neopentyl-1,2,6,7-heptene (
4)-Tetracarboxylic acid (3) 5-methyl-4-hebutenyl-1,2,5,6-
Hexanetetracarboxylic acid (4) 5-methyl-5-hebutyl-5-methyl-1,2
,6,7-heptene(4)-tetracarboxylic acid(5)3
-nonyl-4-methylisonyl-1,2,5,6-hexanetetracarboxylic acid (6) 3-desylizonyl-1,2,5,6-hexanetetracarboxylic acid (7) 5-nonyl-1,2,6 ,7-heptene(4)-
Tetracarboxylic acid (8) 5-decenyl-1,2,5,6-hexanetetracarboxylic acid (9) 3-butyl-3-ethylenyl-1,2,5,6-
Hexanetetracarboxylic acid αQ 5-methyl-4-butyrizonyl-1,2,6,7
-hebutanetetracarboxylic acid an 5-meth-fk-4-pfk-1,2,6,7-heptene (4)-tetracarboxylic acid α33-methyl-5-octyl-1,2,6,7-heptene (4)-Tetracarboxylic acid and the like. The structural formulas of these compounds are shown below. For convenience, all are shown in the form of acid anhydrides.

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, determines the electric charge, and adjusts the amount of charge, and the component (c) lowers the fixing temperature and improves offset resistance. becomes. If the el component in the copolymer component is less than 0.05% by weight, the fixing properties cannot be improved, and if it exceeds 10% by weight, the storage stability as a toner decreases.

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

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

Coloring agents used in the present invention include carbon black, acetylene black, phthalocyanine blue, permanent plaquen FG, brilliant first scarlet, pigment clean B, 4-dyne-B pace,
Solvent Red 49, Solvent Red 146, Solvent Blue 35, etc., and mixtures thereof can be used, and usually about 1 to 15 parts by weight are used 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,
There is no need to add these property improvers during toner preparation.
Alternatively, even if it is added, it may be added in a small amount.

〔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 Into a reactor equipped with a stirrer, a 9 element inlet tube, a thermometer, a reflux condenser tube, and a dropping funnel were added 500 parts of 2-fluoride, 27 parts of indodecylsuccinic acid, and 11.5 parts of 2-hydroxyethyl acrylate. The temperature was adjusted to 80 CK, and the mixture was stirred at the same temperature for 1 hour under a nitrogen stream. A mixed solution of 820 parts of styrene, 130 parts of 2-ethylhexyl acrylate, 11.5 parts of 2- and do-tetraxyethyl acrylate, and 10 parts of benzoyl peroxide is dropwise polymerized over 4 hours under a nitrogen stream. After aging at the same temperature for 10 hours after dropping, the temperature was gradually raised to 210C while the pressure was reduced to 2 mHg, xylene was distilled off, the molten resin was taken out into a stainless steel vat, allowed to cool, and crushed to form a powder. Resin (Koka type flow tester softening point + 25.2 C, Tg60.3 C
) was obtained. This softening point was measured using a Koka type flow tester (manufactured by Shimadzu Corporation) while heating the 1- sample at a heating rate of 6 C/min, using a plunger (l) zo kg/c.
Apply a load of rri', push out a nozzle with a diameter of 1 inch and a length of 1 inch, draw a plunger drop-temperature curve of the flow tester, and calculate the height of the S-shaped curve by h. The softening point is the temperature corresponding to %.

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, finely pulverized in a jet mill, and classified to form a toner with an average particle size of 15.5μ. Obtained. The obtained toner was mixed with carrier iron powder (Nippon Iron Powder Co., Ltd. A11; EFV200/
300) and measured the amount of charge using a blow-off measuring device, it was -19 μc/11.

The toner 919 was mixed with carrier iron powder 1209J to prepare a developer, and a commercially available electrophotographic copying machine (the photoreceptor is amorphous selenium, the fixing roller has a diameter of 60I111I1)
The rotation speed was 2555 m/sec, the temperature of the heat roller in the fixing device was made variable, and the oil application device was removed.) When the image was produced, the image was clear with no background smudges, smearing, or removal of solid black areas. A great image was obtained.

When the fixing temperature was controlled at 140C to 220C and the image fixability and offset property were evaluated, the image was sufficiently fixed at 145C and no hot offset occurred. 5
After printing up to 10,000 images, clear images were obtained with no missing black areas.

The minimum fixing temperature here means that the bottom surface is I 5 w X 7.5
A load of 500I was placed on a trrx 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 image was fixed according to the following definition. This refers to the temperature of the fixing roller when the ratio exceeds 70%.

Example 2 500 parts of xylene and 5-decenyl-
20 parts of 2,5.6-hexanetetracarboxylic acid and 6 parts of 2-hydroxyethyl methacrylate were charged, the temperature was adjusted to 80tZ', and the mixture was stirred at the same temperature for 1 hour under a nitrogen stream. A mixed solution of 890 parts of α-methylstyrene, 74 parts of butyl acrylate, 10 parts of 2-hydroxyethyl methacrylate, and 15 parts of lauroyl peroxide was dropwise polymerized over 4 hours under a nitrogen stream. 1 at the same temperature after the completion of dropping.
After aging for 0 hours, the temperature was gradually raised to 210C while
The pressure was reduced to 1 I Hg, the xylene was distilled off, the molten resin was taken out into a stainless steel vat, and allowed to cool.
Grind, powdered resin (Koka type flow tester softening point 12
1. OClTg61.2G) was obtained.

After mixing 93 parts of the resin and 7 parts of carbon black (SU-GAL 400B manufactured by Cabot Corporation) in a ball mill,
It was crushed and classified to obtain a toner with an average particle size of 15.3 μm. The amount of charge of the obtained toner was -21 μc/i.

That toner? JP was mixed with carrier iron powder 12091, the developer was split into W4, and an image was produced using the same evaluation machine as in Example 1. A clear image was obtained with no background smudges or missing black areas. Six.

When the fixing temperature of the fixing device was controlled and the image fixability and offset properties were evaluated, the image was fixed at 150C and no hot offset occurred.

When images were printed up to 50,000 sheets, clear images were obtained with no missing areas or solid black areas.

Example 3 In the reactor of Example 1, 5 ounces of xylene, 50 parts of isododecenylsuccinic acid, 15 parts of glycidyl methacrylate, 780 parts of styrene, 55 parts of methyl methacrylate, 140 parts of butyl acrylate, and α,α'- Using 20 parts of azopisdimethylvaleronitrile, a powdered resin (softening point: 126.
4CTg 65.1 tZ').

After mixing 93 parts of the resin and 7 parts of carbon black (Cabot Inc. Hirasu-Gal 400R) in a ball mill, kneading,
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 -18 μc/l.

The toner 91.9 was mixed with carrier iron powder 1209.9' to prepare a developer, and an image was produced using the same evaluation machine as in Example 1. There was no background smudge, no bleeding, and no missing black solid areas. A clear image was obtained. When we controlled the fixing temperature of the fixing device and evaluated the fixability and offset properties of the image, it was fixed at 146CK and no hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained with no omissions in the Jikabu 9 and black peta areas.

Example 4 In the reactor of Example 1, 500 parts of xylene, 40 parts of octylsuccinic acid, 820 parts of styrene, 20 parts of dimethylaminoethyl methacrylate, 20 parts of glycidyl methacrylate,
A powdered resin (Koka flow tester softening point 124.5 D, Tg 60.5 tZ') was obtained.

After mixing 95 parts of the resin and 7 parts of carbon black (S-GAL 400R manufactured by Cabot) in a ball mill, kneading,
After pulverization for 1 minute, a toner with an average particle size of 15.0 μm was obtained. The amount of charge of the obtained toner was +20 μc/I.

The toner 91. F is carrier iron powder +209. Prepare a developer by mixing with
5mm/sec, the temperature of the heat roller in the fixing device was made variable, and the oil application device was removed) to produce an image, and the image was clear with no background smudges, K smears, or black spots. A great image was obtained. When the fixing temperature of the fixing device was controlled and the image fixability and offset property were evaluated, the image was fixed at 149C and no hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained with no missing background or solid black areas.

Comparative Example 1 Using the reactor of Example 1, a mixed solution of 830 parts of styrene, 170 parts of 2-ethylhexyl acrylic acid, and 15 parts of benzoyl peroxide was added dropwise to anC, soo-oxylene over 4 hours, and then heated to the same temperature. Let it mature for 10 hours. Thereafter, xylene was distilled off by the method of Example 1, extracted and pulverized, and the powdered resin (Koka flow tester softening point 150.5C, 7
g62°OC) was obtained. Using the resin, a toner (charge 1: -18 μo/i) was produced using the same procedure as in Example 1, a developer was prepared, and an image was produced using the same evaluation machine as in Example 1. Scratches, K stains,
A clear image with no missing black areas was obtained. When the fixing temperature of the fixing device was controlled from 140C to 220GK and the image fixation and offset properties were evaluated, it was 175C.
Although it was fixed at 1/C, offset occurred at all temperatures from 140 to 220 r.

Comparative Example 2 Using the reactor of Example 1, a mixed solution of 850 parts of styrene, 140 parts of n-butyl acrylate, 15 parts of divinylbenzene, and 15 parts of lauroyl peroxide was added dropwise to 500 parts of xylene over 4 hours. After aging at the same temperature for 1 c, xylene was distilled off by the method of Example 1, extracted and pulverized, and powdered resin (Koka flow tester softening point + s
j, oC, Tg 62.2c) was obtained. Using this resin, a toner (charge amount: -1) was prepared in exactly the same manner as in Example 1.
When a developer was prepared and an image was produced using the same evaluation machine as in Example 1, a clear image was obtained with no background smudges, K smudges, or missing black solid areas. was gotten. When the fixing temperature of the fixing device was controlled and the image fixing and offset properties were evaluated, hot offset did not occur from 140C to 22or:t, but
The fixing temperature was 195C.

Applicant's agent Kaoru Furutani (Issuance of procedural amendment) November 18, 1985

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; (b) When polymerizing with one or more monomers selected from methacrylic acid, acrylic acid, and esters thereof, (c) Polymers obtained by reacting divalent or higher carboxylic acids having 7 to 40 carbon atoms. a combination, in which 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); 1. A developer composition for electrophotography, wherein the content of the component () is 0.05 to 10% by weight based on the total amount of monomers. 2. The electrophotographic developer composition according to claim 1, wherein component (c) is an acid represented by the following general formula, an acid anhydride thereof, or a lower alkyl ester thereof. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R is an alkyl group, alkenyl group, alkylene group, or alkenylene group having 5 to 30 carbon atoms and having one or more side chains with 3 or more carbon atoms, and n is an integer of 0 or 1.) 3. The softening temperature of the resin using a Koka type flow tester is 100 to 160°C, and the glass transition temperature is 5.
The electrophotographic developer composition according to claim 1, which has a temperature of 0° C. or higher.