JPH05289399A - Resin composition for toner and toner - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. for a toner and a toner having improved fixability at a low temp., anti-offsetting property and non-flocculating property and capable of improving the dirt of a white ground without deteriorating image characteristics. CONSTITUTION:A copolymer of ethylene or propylene with alpha-olefin is made to be contained in a vinyl copolymer by 0.5-15wt.%. The vinyl copolymer contains a styrene monomer and/or a (meth)acrylic ester monomer as constituent units and contains a low mol.wt. polymer component having 4X10<3>-8X10<4> max. value of the mol.wt. distribution and a high mol.wt. polymer component having 2X10<5>-2X10<6> max. value of the mol.wt. distribution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin for toner used in electrophotography and the like, and more specifically, it is a resin composition for toner used in a so-called dry developing method among methods for developing an electrostatic image. And a toner using the same.

[0002]

2. Description of the Related Art In a dry developing system, toner is usually charged by friction with iron powder or glass beads called a carrier, which is attached to an electrostatic latent image on a photoreceptor by an electric attraction, and then this is Transferred to the paper,
It is fixed by a heat roll or the like to form a permanent visible image. As a fixing method, a heating roller method is used in which a toner image image on a sheet to be fixed is caused to pass while being pressed against the surface of a heating roller having a surface formed of a material having releasability for toner. Is often used. In this heating roller method, a toner resin that can be fixed at a lower temperature is required in order to improve economy such as power consumption and increase the copying speed.

From the viewpoint of low-temperature fixability, it has been proposed to lower the molecular weight of the vinyl copolymer in the resin composition for toner. However, although these methods certainly improve the fixability of the toner, a part of the toner forming an image at the time of fixing is transferred to the surface of the heat roller, and the toner is re-applied to the paper sent next. There is a problem that a phenomenon (offset) of migrating and smearing an image is likely to occur, and further, there is a problem that toner is likely to aggregate. In order to solve these problems, JP-A-56-15834
No. 0 and JP-A-58-202455,
A technique has been proposed in which the resin of the toner is composed of a resin composed of a low molecular weight polymer component and a high molecular weight polymer component.

[0004]

However, since such conventional toner has a low resin toughness, when a fixed material is rubbed, a white background portion where the toner is not deposited is stained, that is, a so-called white background contamination problem. was there. In order to increase the toughness of the resin, a method of crosslinking the resin or adding a rubber can be considered, but the method of adding a crosslinking or a rubber causes poor dispersibility, fogging, and poor cohesiveness. The problem of becoming

An object of the present invention is to solve such conventional problems, and to provide a resin composition for toner having the following characteristics and a toner containing the same. Does not cause white background stains. Excellent low temperature fixability. Excellent in offset resistance. Excellent non-aggregating property. There is no fog in the image.

[0006]

The resin composition for a toner of the present invention comprises a vinyl-based copolymer containing a styrene-based monomer and / or a (meth) acrylic acid ester monomer as a constitutional unit, ethylene or The copolymer of propylene and α-olefin is contained in an amount of 0.5 to 15% by weight, and the vinyl-based copolymer contains a low molecular weight polymer component and a high molecular weight polymer component, The maximum value of the molecular weight distribution of the combined component is 4 × 10 ³ to 8 × 10 ⁴ , and the maximum value of the molecular weight distribution of the high molecular weight polymer component is 2 × 10 ⁵ to 2.
It is characterized in that it is × 10 ⁶ .

The vinyl copolymer used in the present invention contains a styrene monomer and / or a (meth) acrylic acid ester monomer as a constitutional unit. In addition to these monomers, other vinyl-based monomers can be included as a constituent unit. Specific examples of the styrene-based monomer in the present invention include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene and α.
-Methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-ter-
Butyl styrene, pn-hexyl styrene, pn-
Examples thereof include octyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chlorostyrene, and 3,4 dichlorostyrene.

Specific examples of the acrylic acid ester or methacrylic acid ester monomer in the present invention include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, Dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, etc. In addition to alkyl esters of acrylic acid or methacrylic acid, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, meta Diethylaminoethyl acrylic acid,
2-hydroxyethyl methacrylate, glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate, methacryloxyethyl phosphate and the like can be mentioned, and ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate. , Propyl methacrylate, butyl methacrylate and the like are particularly preferably used.

Other vinyl monomers in the present invention include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid and its α- or β-alkyl derivatives, fumaric acid, maleic acid, Examples thereof include unsaturated dicarboxylic acids such as citraconic acid and itaconic acid, their monoester derivatives and diester derivatives, succinic acid monoacryloyloxyethyl ester, succinic acid monomethacryloyloxyethyl ester, acrylonitrile, methacrylonitrile, and acrylamide.

In the present invention, the vinyl-based copolymer is characterized by further containing a low molecular weight polymer component and a high molecular weight polymer component. Therefore, the vinyl-based copolymer of the present invention has at least two peaks in the molecular weight distribution curve measured by gel permeation chromatography (GPC) due to the inclusion of the low molecular weight polymer component and the high molecular weight polymer component. It is formed. In the present invention, the maximum value of the molecular weight distribution of the low molecular weight polymer component is 4 × 10 ³ to 8 × 10 ⁴ , and the maximum value of the molecular weight distribution of the high molecular weight polymer component is 2 × 10 ⁵ to 2 × 10. ⁶
Is. If the maximum value of the molecular weight distribution of the low molecular weight polymer component is smaller than the above range, the cohesiveness may be deteriorated, and if it is larger than the above range, the fixing property may be deteriorated.

If the maximum value of the molecular weight distribution of the high molecular weight polymer component is smaller than the above range, the offset resistance may be deteriorated, and if it is larger than the above range, the fixing property may be deteriorated. is there. In such a vinyl-based copolymer, the content of the high molecular weight polymer component is preferably 15% by weight or more. When the content of the high molecular weight polymer component is less than 15% by weight, the offset resistance may be deteriorated. Further, the polymer in the present invention preferably has a glass transition point of 50 ° C. or higher from the viewpoint of cohesiveness.

In the present invention, the copolymer of ethylene or propylene and α-olefin is contained in an amount of 0.5 to 15% by weight based on the vinyl copolymer. When the content of this copolymer is less than 0.5% by weight, the effects of the present invention such as improvement of white background stains are hardly obtained. On the other hand, if the content exceeds 15% by weight, the fixing property is deteriorated, and fogging or the like occurs due to poor dispersion. The more preferable content of these copolymers is 1 to 10% by weight.

The copolymer of ethylene or propylene and α-olefin in the present invention is not particularly limited as long as it is a copolymer of ethylene or propylene and α-olefin. It is preferable that the component is 50 mol% or more. Further, when the amount of α-olefin component is extremely small,
The crystallinity may increase and the dispersibility with the vinyl-based copolymer may deteriorate. Therefore, the α-olefin component is 5 mo
It is preferably contained at 1% or more. As the α-olefin in this copolymer, ethylene, propylene, butene, pentene, hexene, methylpentene and the like can be used, butene is particularly preferable. This copolymer has a molecular weight of 40,000 or more and 10 or more from the viewpoint of toughness, unlike wax having a molecular weight of about 3000 which is usually blended in toners.
It is preferably at most 0,000.

Styrene-based monomer and / or (meth)
Suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization and the like can be used for the constitution of the above vinyl-based copolymer containing an acrylic acid ester monomer as a constitutional unit. Various methods can be adopted as a method of incorporating a copolymer of ethylene or propylene and an α-olefin into the vinyl copolymer. For example, a vinyl-based copolymer and α
A method of heat melting and blending with an olefin copolymer can be adopted. In order to make it more homogeneously contained, it is preferable to disperse each copolymer in a solvent and then remove the solvent. More preferably, the vinyl copolymer is polymerized in the presence of the α-olefin copolymer.

In the toner resin composition of the present invention,
Vinyl acetate, vinyl chloride, ethylene and the like can be copolymerized with the vinyl-based copolymer within the range in which the object and effect of the present invention can be achieved. Moreover, you may blend the polymer of these monomers with the said vinyl-type copolymer. Further, a polyester resin or an epoxy resin may be mixed. Further, an aliphatic amide, a bis-aliphatic amide, a metallic soap and paraffin may be mixed.

Further, as long as it is within the range in which the objects and effects of the present invention can be achieved, a dye such as nigrosine or spirone black (manufactured by Hodogaya Chemical Co., Ltd.) as a charge control agent, or other phthalocyanine type pigment is added. You can Further, as the colorant, carbon black, chrome yellow, aniline blue or the like can be used. Further, low molecular weight polyethylene, polypropylene wax or the like may be added as a release agent, or hydrophobic silica or the like may be added to improve fluidity. To produce a toner using the toner resin composition of the present invention, a conventionally known toner additive such as a colorant as described above is added to a ribbon blender,
A method of mixing with a Henschel mixer or the like, kneading this with a roll mill, kneader, extruder or the like, then cooling and finely pulverizing can be adopted.

[0017]

The resin composition for a toner according to the present invention is composed of a vinyl-based copolymer containing a low molecular weight polymer component and a high molecular weight polymer component as described above, and therefore has low temperature fixability and resistance. Excellent in offset property. Further, according to the present invention, α is tough and easily dispersed in a vinyl-based copolymer.
Since the olefin copolymer is contained in a specific proportion of 0.5 to 15% by weight, the toughness of the resin composition for toner is enhanced, white background stains and image fog do not occur, and the toner does not easily aggregate. Can be

[0018]

Description of Examples Example 1 72 parts by weight of styrene, 10 parts of methacrylic acid methyl ester
By weight, 18 parts by weight of n-butyl acrylate are polymerized,
A resin as a high molecular weight polymer component was obtained. The maximum value of the molecular weight distribution of this high molecular weight polymer component is 400,000 (4 x
It was 10 ⁵ ). 135 g of this high molecular weight polymer component and 25 g of ethylene-butene copolymer (manufactured by Mitsui Petrochemical Co., Ltd., trade name: Tuffmer AA-4085: molecular weight about 200,000) as an α-olefin copolymer. The mixture was placed in a 3 liter separable flask, dissolved with 1 liter of xylene, and the gas phase was replaced with nitrogen gas.
The system was warmed to the boiling point of xylene.

With stirring under reflux of xylene, a mixture of 227 g of styrene, 31 g of methacrylic acid methyl ester, 57 g of n-butyl acrylate and 9 g of BPO as a polymerization initiator was stirred for 2.5 hours. While dropping, solution polymerization was carried out to polymerize the low molecular weight polymer component in the presence of the high molecular weight polymer component and the α-olefin copolymer. After completion of the dropping, the mixture was aged for 1 hour while stirring at the boiling temperature of xylene. Then, xylene was removed under reduced pressure while gradually raising the system temperature to 180 ° C. As described above, Resin A containing a low molecular weight polymer component having a molecular weight distribution peak of 10,000 (1 × 10 ⁴ ) was obtained. The glass transition point of this resin A was 62 ° C. In the resin A, the content of the ethylene / butene copolymer as the α-olefin copolymer is
It is about 5.3% by weight.

100 parts by weight of this resin A, 5 parts by weight of carbon black (manufactured by Mitsubishi Kasei, trade name: MA-100), 1 part by weight of Spiron Black TRH, and PP wax (manufactured by Sanyo Kasei Co., trade name: Viscole) 660P) was melt-blended, cooled, coarsely pulverized, and then finely pulverized with a jet mill to prepare a toner powder having an average particle size of about 12 to 15 microns. Hydrophobic silica powder (manufactured by Nippon Aerosil Co., Ltd., trade name: R-97
2) 0.3 parts by weight was added to prepare a toner. 10 g of this toner was placed in a 100 ml sample bottle, left in a constant temperature bath at 50 ° C. for 16 hours, and the degree of coagulation was measured with a powder tester (manufactured by Hosokawa Micron Co., Ltd.).

Further, 4 parts by weight of this toner is added to about 50-80.
A developer was prepared by mixing with 96 parts by weight of an iron powder carrier having an average particle size of micron, and a copy was obtained using this developer. The electrophotographic copying machine used was DC-40 manufactured by Mita.
85. The fixing temperature was set at a temperature at which the density of the copied image changed when the copy was rubbed with a sand eraser for a typewriter by changing the set temperature of the heat roller of the electrophotographic copying machine. The fixing temperature of the developer using resin A is 1
It was as low as 50 ° C. The offset generation temperature was set to a temperature when the offset was generated by variously changing the temperature settings of the heat roller of the electrophotographic copying machine. The offset generation temperature of the developer using the resin A was 200 ° C. or higher, which was sufficiently high. No fogging was observed in the image fixed at 170 ° C., and no white background stain was observed even when rubbed with gauze.

Example 2 80 parts by weight of styrene, 10 parts of methacrylic acid methyl ester
By weight, 10 parts by weight of 2-ethylhexyl acrylate were polymerized to obtain a resin as a low molecular weight polymer component. The maximum value of the molecular weight distribution of this resin was 5,000 (5 × 10 ³ ). Further, 80 parts by weight of styrene and 20 parts by weight of methacrylic acid butyl ester were polymerized to obtain a high molecular weight polymer component. The maximum molecular weight distribution of this resin is 800,000 (8 x 1
Was 0 ⁵ ). 70% by weight of the low molecular weight polymer component, 23% by weight of the high molecular weight polymer component, and α-
Propylene-ethylene copolymer as olefin copolymer (Mitsui Petrochemical Co., Ltd., trade name: Tufmer S S-4
030: molecular weight about 200,000) 7% by weight, and the mixture is put in a 3 liter separable flask and xylene 1 is added.
After dissolving in liter and replacing the gas phase with nitrogen gas, the system was heated to the boiling point of xylene.

The mixture was stirred for 2 hours while the xylene was refluxed. Then, while gradually raising the temperature of the system to 180 ° C., xylene was removed under reduced pressure to remove the solvent, and the glass transition point 60
C. Resin B was obtained. In this resin B, the content of the propylene-ethylene copolymer as the α-olefin copolymer was about 7% by weight.

100 parts by weight of the resin B obtained as described above and carbon black (manufactured by Mitsubishi Kasei Co., trade name: M
A-100) 5 parts by weight, spirone black TRH 1 part by weight, and PP wax (manufactured by Sanyo Chemical Co., Ltd., trade name: VISCOL 660P) 3 parts by weight are melt-blended, cooled and coarsely pulverized, and further finely divided by a jet mill. About 12 to 15 after crushing
A toner powder having an average particle size of micron was made. Toner was prepared by adding 0.3 parts by weight of hydrophobic silica powder (trade name: R-972, manufactured by Nippon Aerosil Co., Ltd.) to the toner powder. After taking 10 g of this toner in a 100 ml sample bottle and leaving it in a constant temperature bath at 50 ° C. for 16 hours,
When the cohesion degree was measured with a powder tester (manufactured by Hosokawa Micron), cohesion was not recognized.

In the same manner as in Example 1, this toner 4
96 parts by weight of iron powder carrier was mixed with parts by weight to prepare a developer, and the fixing temperature and the offset generation temperature were evaluated. As a result, the fixing temperature was 150 ° C., which was a sufficiently low temperature. The offset generation temperature was 200 ° C. or higher, which was a sufficiently high temperature. No fogging was observed in the image fixed at 170 ° C., and no white background stain was observed even when rubbed with gauze.

Example 3 30 g of a propylene-butene copolymer (manufactured by Mitsui Petrochemical Co., Ltd., trade name: Toughmer XR XR107L: molecular weight about 200,000) as an α-olefin copolymer was placed in a 3 liter separable flask, and styrene. 310 g, acrylic acid n
-Butyl 120 g, and toluene 700 g, and Kayaester HTP (manufactured by Kayaku Nouri Co.) 0.3 as a catalyst.
After adding g and replacing the gas phase with nitrogen gas, the system was heated to the boiling point of toluene. While the toluene was refluxing, the resin as the high molecular weight polymer component was polymerized while stirring for 10 hours. After that, 450 g of styrene and 100 g of methacrylic acid butyl ester were added to AIBN1.
Solution polymerization was carried out while dropping 0 g of the mixture over 2 hours to produce a resin corresponding to a low molecular weight polymer component. After completion of dropping, the mixture was aged for 3 hours while stirring at the boiling temperature of toluene. Then, the system temperature is set to 180
While gradually raising the temperature to 0 ° C., the solvent was removed under reduced pressure to obtain a resin C having a maximum molecular weight distribution of 20,000 (2 × 10 ⁴ ) and 250,000 (2.5 × 10 ⁵ ). The glass transition point of this resin C was 58 ° C. Further, the content of the propylene-butene copolymer, which is an α-olefin copolymer, was about 4.3% by weight. 100 parts by weight of the resin C obtained as described above, 5 parts by weight of carbon black (manufactured by Mitsubishi Kasei, trade name: MA-100), 1 part by weight of Spiron Black TRH, and PP wax (manufactured by Sanyo Kasei Co., 3 parts by weight of trade name: Viscole 660P) was melt-blended, cooled, coarsely pulverized, and then finely pulverized with a jet mill to prepare a toner powder having an average particle size of about 12 to 15 microns.

To this toner powder, 0.3 part by weight of hydrophobic silica powder was added in the same manner as in Example 1 to prepare a toner, and the degree of aggregation of this toner was measured. .. Also, in the same manner as in Example 1,
When 4 parts by weight of this toner was mixed with 96 parts by weight of an iron powder carrier to prepare a developer, and the fixing temperature and the offset generation temperature of this developer were evaluated, the fixing temperature was 15
The temperature was 0 ° C., which was a sufficiently low temperature. The offset generation temperature was 200 ° C. or higher, which was a sufficiently high temperature. No fogging was observed in the image fixed at 170 ° C.
No white background stain was seen even after rubbing with gauze.

Comparative Example 1 A developer was prepared and tested in the same manner as in Example 1 except that the ethylene-butene copolymer was not used. As a result, no cohesiveness was observed and fixing was performed. The temperature was 150 ° C, the offset generation temperature was 200 ° C or higher, and no fog was observed in the fixed image at 170 ° C. However, white background stains were observed when rubbed with gauze.

Comparative Example 2 In Example 1, 1 g of divinylbenzene was added as a cross-linking agent to the low molecular weight polymerization solution without using the ethylene-butene copolymer, and the peak of the molecular weight distribution of the low molecular weight polymer component was A resin of 20,000 (2 × 10 ⁴ ) was obtained. The glass transition point of this resin was 63 ° C. Using this resin, a developer was prepared and tested in the same manner as in Example 1. As a result, no cohesiveness was observed and no fog was observed in the image. No white background stain was observed when rubbed with gauze, and the offset generation temperature was 200 ° C. or higher. However, the fixing temperature was 170 ° C., which was a higher temperature than the examples according to the present invention.

Comparative Example 3 A developer was prepared in the same manner as in Example 1 except that polyethylene having a molecular weight of about 50,000 (5 × 10 ⁴ ) was used in place of the ethylene-butene copolymer. Made,
Tested. As a result, no cohesiveness was observed, the fixing temperature was 150 ° C., and the offset generation temperature was 200.
It was above ℃. However, in the image fixed at 170 ° C., fog was observed and white background stain was observed when rubbing with gauze.

Comparative Example 4 In Example 1, the ethylene-butene copolymer was added to 0.4
A developer was prepared and tested in the same manner as in Example 1 except that 99.6% by weight of a low molecular weight polymer component was used. As a result, no cohesiveness was observed, the fixing temperature was 140 ° C., and no change was observed in the image. However, the offset generation temperature was as low as 160 ° C., and white background stain was observed when rubbing with gauze.

Comparative Example 5 Same as Example 1 except that high styrene rubber (manufactured by Japan Synthetic Rubber Co., Ltd.) having a rubber component of 30% by weight was used in place of the propylene-ethylene copolymer. Then, a developer was prepared and tested. As a result, although the offset generation temperature was 200 ° C. or higher, cohesiveness was observed, the fixing temperature was 170 ° C., fog was observed in the image, and white background stain was observed when rubbing with gauze.

Comparative Example 6 In Example 3, 30 g of propylene-butene copolymer
A developer was prepared in the same manner as in Example 3 except that 250 g was used instead of. In Comparative Example 6, the content of the propylene-butene copolymer was about 25.2.
%, Which is outside the scope of the present invention. When a test was conducted in the same manner as in Example 3 using the developer obtained as described above, no cohesiveness was observed and the offset generation temperature was 200 ° C. or higher, but the fixing temperature was 17
The temperature was 0 ° C., fog was observed in the image, and white background stain was observed when rubbing with gauze.

[0034]

As described above, the resin composition for a toner of the present invention uses a vinyl-based copolymer containing a low molecular weight polymer component and a high molecular weight polymer component.
Low temperature fixability and offset resistance are improved. Also,
In the present invention, such a vinyl-based copolymer contains a copolymer of ethylene or propylene and an α-olefin in a specific ratio. Due to the inclusion of the α-olefin copolymer, the toner resin The toughness of the composition is increased, white background stains and image fog can be improved,
A toner that does not easily aggregate can be obtained.

Claims (2)

[Claims] 1. A vinyl-based copolymer containing a styrene-based monomer and / or a (meth) acrylic acid ester monomer as a constitutional unit, wherein the maximum value of the molecular weight distribution is 4 × 1.
Ethylene was added to a vinyl-based copolymer containing a low molecular weight polymer component having a molecular weight distribution of 0 ³ to 8 × 10 ⁴ and a high molecular weight polymer component having a maximum molecular weight distribution of 2 × 10 ⁵ to 2 × 10 ^6. Alternatively, the copolymer of propylene and α-olefin is 0.5
A resin composition for a toner, characterized in that it is contained in an amount of -15% by weight. 2. A toner comprising a colorant and a resin composition for a toner as main components, and the resin composition for a toner is the resin composition for a toner according to claim 1.