JPH04250460A - Binder resin composition for toner, production thereof and toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a toner having superior blocking resistance, anti-offsetting property and satisfactory fixability at low temp. CONSTITUTION:A cyclohexanone deriv. represented by formula 1 and binder resin are incorporated into a binder resin compsn. for a toner. In the formula 1, aeach of R1-R10 is H or aliphatic hydrocarbon and a compd. having H or 1-8C aliphatic hydrocarbon as each of R1R10 is more effective. Cyclohexanone, methylcyclohexanone or dimethylcyclohexanone may be used as the compd. represented by the formula 1. A styrene-acrylic copolymer, a styrene polymer or an acrylic polymer may be used as the binder resin. The amt. of the cyclohexanone deriv. incorporated is 0.1-5wt.%, preferably 0.5-3wt.% of the amt. of the binder resin.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a toner for developing electrostatic latent images formed in electrophotography, electrostatic printing, electrostatic recording, etc., and a binder used in the toner. The present invention relates to a resin composition and a method for producing the same.

0002

[Prior Art] In electrophotography, an electrostatic latent image is generally formed on a latent image carrier made of a photoconductive photoreceptor by charging and exposure, and then this electrostatic latent image is colored in a binder resin. The resulting toner image is developed with a fine particle toner containing an agent, and the resulting toner image is transferred to a support such as transfer paper and fixed to form a visible image.

Methods for fixing toner images include a hot roller fixing method, a flash fixing method, and an open fixing method, among which the hot roller fixing method is the most common. This hot roller fixing method is a method of fixing the toner image onto the support by transporting the support such as paper on which the toner image is carried so as to come into contact with a heated roller. This method is advantageous in reducing the size of the copying machine, and is also preferable in terms of energy saving, such as relatively little heat loss.

[0004] However, recently, as the amount of information to be processed has increased, it has been desired to increase the processing speed of copying machines and recording apparatuses, and it has become necessary to further improve the copying speed. The faster the copying speed is, the shorter the time it takes to pass through the fixing roll, and the lower the temperature of the paper support and the toner that adheres to it, so a toner that fixes at a low temperature is desired.

[0005]Furthermore, recently, there have been many requests for desktop type copying machines and smaller size copying machines, and it is necessary to make the copying machine energy-saving and compact by reducing the capacity of the heater for heating the heat roller. If the capacity of the heating heater is reduced, it takes time to heat the heat roller, resulting in a longer waiting time, or if continuous copying is performed, heat supply cannot be made in time, resulting in a drop in the temperature of the heat roller, resulting in poor fixing. is likely to occur.

On the other hand, when a hot roller fixing method is adopted, the toner comes into contact with the surface of the hot roller in a molten state during fixing, but if the viscoelasticity of the molten toner is too low or too high, A so-called offset phenomenon occurs in which a portion of the toner transfers and adheres to the surface of the heated roller, and this transfers again to the transfer paper that is sent next, staining the image. This offset phenomenon includes under-offset, which occurs when toner is insufficiently heated, and hot offset, which occurs when toner is heated excessively. Therefore, it is preferable that the toner has a low under-offset temperature and a high hot-offset temperature, that is, a wide fixable temperature range.

[0007]Furthermore, the toner needs to exist stably as a powder without agglomerating even under the use of a copying machine or under storage environmental conditions, that is, it needs to have excellent blocking resistance.

[0008] The following techniques have been disclosed to meet such required characteristics of toner. For example, JP-A-50-1
No. 3465 discloses the use of a resin with a wide molecular weight distribution as a binder. Also, JP-A-51-23
Publication No. 354 describes the use of a crosslinkable polymer as a binder resin. Other Japanese Patent Publication No. 59-344
Publication No. 6 discloses a technique in which a resin containing a mutually immiscible crystalline polymer and an amorphous polymer and in which the ratio of the crystalline polymer is 70 to 95% by weight is used as a binder resin. is listed.

[0009]

However, when a resin with a wide molecular weight distribution is used, hot offset can be prevented, especially in high-speed machines, but there is a problem of poor fixing performance. The same problems as mentioned above arise when a crosslinkable polymer or a graft copolymer is used. Furthermore, in the method of containing a crystalline polymer and an amorphous polymer, since the proportion of the crystalline polymer is large, finely pulverized particles are generated in the pulverization process that is the toner manufacturing process, resulting in a low toner yield. There's a problem.

[0010] As a result of extensive research aimed at developing a toner for developing electrostatic images with good low-temperature fixing properties, anti-offset properties, and anti-blocking properties, the present inventors have developed a toner containing a specific compound. The present inventors have discovered that by using a binder resin or toner, excellent anti-blocking properties and anti-offset properties, and significant low-temperature fixing properties can be obtained, leading to the completion of the present invention.

[0011]

[Means for Solving the Problems] That is, the present invention provides general formula (I)

embedded image (However, R1, R2, R3, R4, R5, R6 in the formula
, R7, R8, R9 and R10 are hydrogen or aliphatic hydrocarbon groups. ) and a binder resin.

The present invention also provides a method for producing a binder resin composition for toner, which comprises carrying out suspension polymerization or emulsion polymerization of a vinyl monomer in the presence of the cyclohexanone derivative represented by the general formula (I). Regarding.

The present invention further relates to an electrostatic image developing toner containing a cyclohexanone derivative represented by the general formula (I), a binder resin, a colorant and/or a magnetic powder.

The cyclohexanone derivative represented by the general formula (I) used in the present invention is a known compound. In the present invention, it is highly effective and preferable to use a compound in which R1 to R10 in general formula (I) are hydrogen or an aliphatic hydrocarbon group having 1 to 8 carbon atoms. Specific compounds include, for example, cyclohexanone, 3-methylcyclohexanone, 5-methylcyclohexanone, 3,5-dimethylcyclohexanone, 3,3,5-trimethylcyclohexanone, 3-t-butylcyclohexanone, 5-t-butylhexanone, etc. Can be mentioned.

Methods for incorporating the cyclohexanone derivative into the toner include a method in which the binder resin, colorant, various additives, etc. are added and impregnated when the toner is prepared by melt-kneading, and a method in which the cyclohexanone derivative is added and impregnated at the time of melt-kneading the binder resin, colorant, various additives, etc. There is a method of manufacturing toner using the same.

Examples of the binder resin used in the present invention include vinyl resins such as styrene-acrylic copolymers, styrene polymers, and acrylic polymers, and polyester resins. When using a resin, a method for incorporating a cyclohexanone derivative is to melt the cyclohexanone derivative in a vinyl monomer and carry out suspension polymerization or emulsion polymerization in the presence of the cyclohexanone derivative. It is preferable in terms of workability and the like to produce a toner binder resin composition containing the above-mentioned components and use this in a toner.

The content of the cyclohexanone derivative is such that when a binder resin composition for a toner containing the derivative is prepared in advance, it is added to the composition, and when it is added at the time of toner kneading, it is added to the toner, relative to the binder resin. Te 0.1
From the viewpoint of various properties, the content is preferably from 5% by weight, particularly from 0.5 to 3% by weight. If it is less than 0.1% by weight, the fixing properties will be particularly poor, while if it exceeds 5% by weight, the stability and anti-offset properties of the toner will decrease. Note that the amount of the cyclohexanone derivative in the toner binder resin or in the toner can be measured by gas chromatography. Since the cyclohexanone derivative volatilizes to some extent during the polymerization process and melt-kneading process, it is preferable to take this into consideration when adding the derivative in an amount larger than the intended content.

[0018] Examples of the vinyl monomer used as a raw material for the binder resin in the present invention include styrene, α
- Styrene derivatives such as methylstyrene, p-methylstyrene, p-t-butylstyrene, p-chlorostyrene,
Methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate , glycidyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxydipropylene glycol methacrylate,
Phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, N- methacrylate
Vinyl-2-pyrrolidone, methacrylonitrile, methacrylamide, N-methylolmethacrylamide, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, 2-hydroxy-3-phenyloxypropyl methacrylate, acrylic acid , methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, acrylic Glycidyl acrylate, methoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, acrylic acid Phenoxyethyl, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl-2 acrylate -pyrrolidone,
Hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, 2-acrylate
Hydroxy-3-phenyloxypropyl, glycidyl acrylate, acrylonitrile, acrylamide, N-
Vinyl monomers having one vinyl group per molecule are used as the main component, such as methylol acrylamide, diacetone acrylamide, and vinyl pyridine, but other products include divinylbenzene, reaction products of glycol, and methacrylic acid or acrylic acid. , such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1
, 5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, neopentyl hydroxypivalate Glycol ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, trismethacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacryloyloxy) ethyl) isocyanurate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,
4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene diacrylate , hydroxypivalic acid neopentyl glycol diacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trisacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate , tris (methacryloyloxyethyl) isocyanurate, half ester of glycidyl methacrylate and methacrylic acid or acrylic acid, half ester of bisphenol-type epoxy resin and methacrylic acid or acrylic acid, half of glycidyl acrylate and methacrylic acid or acrylic acid Esterified products, etc. 1
Vinyl monomers having two or more vinyl groups in the molecule can be used.

Among these, preferred vinyl monomers having one vinyl group in one molecule include styrene, styrene derivatives, methacrylic esters, acrylic esters, etc. In particular, alkyl esters of methacrylic acid or acrylic acid having 1 to 5 carbon atoms in the alkyl group are preferred. 2 in 1 molecule
Preferred vinyl monomers having at least 1 vinyl group include divinylbenzene, dimethacrylate and diacrylate of methylene glycol having 2 to 6 carbon atoms, and the like.

These monomers are blended in a total amount of 100 parts by weight. Among these, the amount of the vinyl monomer having two or more vinyl groups in one molecule is preferably 0 to 1 part by weight.

In the present invention, the monomer (mixture) preferably dissolves the cyclohexanone derivative and
Benzoyl peroxide, 2-ethylhexyl perbenzoate, lauroyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide,
4,4,6-trimethylcyclohexanone di-tert
-butyl peroxyketal, cyclohexanone peroxide, methyl cyclohexanone peroxide, acetylacetone peroxide, cyclohexanone di-ter
t-butyl peroxyketal, 2-octanone di-t
ert-butyl peroxyketal, acetone di-te
Peroxide radical initiators such as rt-butyl peroxyketal, diisopropyl hydroperoxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide and/or 2,2'-azobisisobutyronitrile, 2,
2'-azobis(2,4-dimethylvaleronitrile),
Azobis-based radical initiators such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, and 1,1'-azobis(cyclohexane-1-carbonitrile) is polymerized using

Polymerization methods include suspension polymerization, solution polymerization, and
It can be produced by any known polymerization method such as emulsion polymerization or bulk polymerization, but if a binder resin composition is produced by adding a cyclohexanone derivative in advance, suspension polymerization or emulsion polymerization is performed among these polymerization methods. It is preferable that
In particular, water-soluble polymer dispersants such as partially saponified polyvinyl alcohol, alkylcellulose, hydroxyalkylcellulose, carboxyalkylcellulose, polyacrylamide, polyvinylpyrrolidone, polyacrylic acid and its alkali metal salts, polymethacrylic acid and its alkali metal salts, phosphoric acid Aqueous suspension polymerization using a sparingly soluble inorganic dispersant such as calcium, hydroxyapatite, magnesium phosphate, magnesium pyrophosphate, calcium carbonate, barium sulfate, hydrophobic silica, etc. is preferred from the viewpoint of economy, stability during production, and the like.

[0023] In the present invention, when producing a toner, other additives such as a colorant and/or magnetic powder and, if necessary, a charge control agent may be appropriately added to the obtained binder resin (composition). can.

As the coloring agent, conventionally known pigments or dyes such as carbon black, iron oxide pigment, phthalocyanine blue, phthalocyanine green, rhodamine 6G lake, Watching Red Barium, Watching Red Strontium, etc. can be used. The amount is appropriately selected and used within the range of weight %.

Magnetic powders include metal powders such as iron, manganese, nickel, and cobalt, and ferrites such as iron, manganese, nickel, cobalt, and zinc, and have an average particle size of 10
It is preferably 1 μm or less, particularly 1 μm or less, and is usually used in an amount of 1 to 80% by weight in the toner. When a colorant and magnetic powder are used together, the amount of either one may be less than 1% by weight.

As the charge control agent, nigrosine dye, fatty acid-modified nigrosine dye, metal-containing nigrosine dye, metal-containing fatty acid-modified nigrosine dye, 3,5-di-tert-
A chromium complex of butylsalicylic acid or the like can be used, and is usually used in the toner in an amount of 0 to 20% by weight.

Other additives that can be used include silica powder, hydrophobic silica powder, polyolefin, paraffin wax, fluorocarbon compounds, fatty acid esters, partially saponified fatty acid esters, fatty acid metal salts, and the like. Used in toners in amounts of 0 to 10% by weight.

These materials are mixed, for example, by the following method to produce a toner for developing electrostatic images. Weighed materials,
After preliminary mixing using a W cone, V blender, Henschel mixer, etc., the mixture is kneaded using a pressure kneader, Banbury mixer, hot roll, extruder, etc. at a temperature at which the binder melts. After cooling, it is coarsely ground using a feather mill, bottle mill, pulverizer, hammer mill, etc., and then finely ground using jet air. Next, the particles are sieved using an Accucut, Alpine classifier, etc., and adjusted to a particle size of preferably 5 to 30 μm. Note that a fluidity modifier such as silica powder can also be simply mixed.

[0029]

[Action] Since the cyclohexanone derivative represented by the general formula (I) has low solubility in the binder resin near room temperature, the blocking property of the toner is extremely stable.
Excellent storage stability. Further, since the cyclohexanone derivative acts as a plasticizer when heated, it exhibits good fluidity when heated and melted during hot roll fixing, and as a result, the toner exhibits excellent low-temperature fixability. Furthermore, it also has an offset prevention effect.

[0030]

[Examples] Next, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. Examples 1 to 4 and Comparative Example 1 (1) Synthesis of binder resin composition A 3-liter cylindrical separable flask was equipped with a stirrer with stirring blades, a cooling tube, a gas introduction tube, and a thermometer, and ions were added into the flask. 1500 parts by weight of exchange water, Supertight 10
75 parts by weight (trade name of hydroxyapatite water dispersant manufactured by Nippon Kagaku Co., Ltd.) and 9 parts by weight of a 1% by weight sodium dodecylbenzenesulfonate aqueous solution were added. The monomers and radical initiator in the formulation shown in Table 1 were weighed, mixed, and placed in a 3-liter separable flask. A flow of nitrogen gas was started, and the mixture was stirred at room temperature for about 30 minutes to stabilize the dispersion. Subsequently, the temperature was raised to 90°C over about 1 hour, stirred for 4 hours, and then stirred at 95°C for 2 hours until 50°C.
Cooled to ℃. Next, the monomers and radical initiator in the formulation (1) shown in Table 1 were weighed, mixed, and placed in a 3-liter separable flask in which the polymer (1) was present. After stirring at 50°C for 1 hour, the temperature was raised to 90°C,
The temperature was raised to 90°C for 4 hours, and the reaction was continued at 95°C for 3 hours to complete the polymerization. Thereafter, the mixture was cooled to 50° C. while stirring, and 20 parts by weight of concentrated hydrochloric acid was added to adjust the pH of the aqueous phase to 3 or less. This was filtered under reduced pressure and
After washing three times with 0 part by weight of ion-exchanged water, it was dried overnight in a dryer at 50°C to obtain a binder resin composition having the characteristics shown in Table 1.

[0031] The glass transition point can be determined using a differential scanning calorimeter (
DSC) shows the endothermic onset point (℃), the molecular weight is measured by gel permeation chromatography method,
The value is calculated in terms of standard polystyrene, and the cyclohexanone content is a value measured by gas chromatography, and is expressed in weight % with respect to the binder resin. The conditions for gas chromatography are as follows. Equipment: Hitachi G-3000 model Sample: 10-fold dilution in acetone, 1.0 μl injection column: D
C-550, 3mmφ×2m Carrier gas: 1.0kg
/cm2 Temperature: injection 250℃, detector 1
50℃, column 130℃ Detector: FID

[0032]

[Table 1]

(2) Production of toner and developer 450 g of each binder resin composition, 40 g of carbon black #44 (manufactured by Mitsubishi Chemical Industries, Ltd.), Viscoel 550P (manufactured by Sanyo Chemical Industries, Ltd., trademark of low molecular weight polypropylene) )1
0 g and 25 g of Oil Black BY (nigrosine dye manufactured by Orient Kagaku Kogyo Co., Ltd.) were heated and melted and kneaded using a Konida kneader, and then coarsely ground using a hammer mill.
It was pulverized using a jet air mill. This was classified to obtain a toner having a particle size of 5 to 30 μm and an average particle size of 14 μm. Next, 50 g of this toner and 950 g of EFV200/300 (amorphous iron oxide powder carrier manufactured by Nippon Tetsuko Co., Ltd.) were mixed and sufficiently shaken to prepare a developer.

(3) Evaluation of toner (a) Storage stability Approximately 5 g of toner was stored in a constant temperature and humidity chamber at 55° C. and 90% humidity for 24 hours so that it had a uniform thickness in a glass petri dish. This was passed through a 100-mesh wire mesh, the weight of the material passing through was measured, and the results were evaluated based on the following criteria. 5: Passing 95% by weight or more 4: Passing 70% or more but less than 95% by weight 3: Passing 30% by weight
More than 70% by weight Passed 2: 5% by weight or more and less than 30% by weight Passed 1: Less than 5% by weight passed

(b) Fixing properties and anti-offset properties The developer was put into a tester modified from a copying machine SF756 (manufactured by Sharp Corporation), and an unfixed image with the top 1/3 of an A4 size sheet solid black was created. Ta. This unfixed image was tested using a Teflon roll fixing tester, changing the temperature in 10°C steps from 100°C to 240°C, at a linear speed of 900 cm/min (A4 size, approximately 30 sheets/min).
The test was carried out after fixing for 1 minute). The fixing temperature is determined by peeling off cellophane tape on the fixed black solid area and setting the image density change rate to 10.
% or less. The offset occurrence density was defined as the lowest temperature at which the image density (ID) of the white paper portion where the offset of the black solid portion occurred was 0.2% or more compared to the black solid portion.

(c) Actual machine copying test The developer was placed in a copying machine SF756 (manufactured by Sharp Corporation), and a continuous copying test of 8,000 sheets was conducted to observe the initial image and changes in the image. The evaluation results of the toner are shown in Table 2 below.

[0037]

[Table 2]

[0038]

As is clear from the above results, the toner for developing electrostatic images of the present invention has excellent storage stability and low-temperature fixability, and is also excellent in offset resistance.

Claims (6)

[Claims] Claim 1: General formula (I) [Formula 1] (wherein R1, R2, R3, R4, R5, R6
, R7, R8, R9 and R10 are hydrogen or aliphatic hydrocarbon groups. ) A binder resin composition for a toner, comprising a cyclohexanone derivative represented by the following formula and a binder resin. Claim 2: The content of the cyclohexanone derivative is
The binder resin composition for toner according to claim 1, wherein the amount is 0.1 to 5% by weight based on the binder resin. Claim 3: General formula (I) [Formula 2] (wherein R1, R2, R3, R4, R5, R6
, R7, R8, R9 and R10 are hydrogen or aliphatic hydrocarbon groups. ) A method for producing a binder resin composition for a toner, which comprises subjecting a vinyl monomer to suspension polymerization or emulsion polymerization in the presence of a cyclohexanone derivative represented by the following formula. Claim 4: General formula (I) [Formula 3] (wherein R1, R2, R3, R4, R5, R6
, R7, R8, R9 and R10 are hydrogen or aliphatic hydrocarbon groups. ), a binder resin, a colorant and/or a magnetic powder, a toner for developing an electrostatic image. Claim 5: The content of the cyclohexanone derivative is
5. The toner for developing electrostatic images according to claim 4, wherein the amount is 0.1 to 5% by weight based on the binder resin. 6. A toner for developing an electrostatic image, comprising the binder resin composition for toner according to claim 1 or 2.