JPH05313413A - Resin composition for toner and toner - Google Patents

Abstract

PURPOSE:To provide a resin compsn. for a toner and to obtain the toner having improved low temp. fixing property, offset resistance, and noncohesive property which does not cause contamination in a white base. CONSTITUTION:This resin compsn. consists of vinyl copolymers into which ethylene or propylene and alpha-olefin copolymers are incorporated by 1-35wt.%. The vinyl copolymers contain styrene monomers and/or methacrylate monomers as the structural units and has a max. in 1X10<3> to 8X10<4> mol.wt. distribution range The copolymers also have a max. or shoulder point in 1X10<5> to 4X10<6> mol.wt. distribution range, or satisfy Mw/Mn>6, wherein Mw is the weight average mol.wt, and Mn is the number average mol.wt. The ethylene or propylene and alpha-olefin copolymers have <10000 poise in viscosity at 140 deg.C.

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, even with such conventional toners, sufficient fixing characteristics have not yet been obtained, and the toughness of the resin is low, so that the toner will not be removed when the fixed matter is rubbed. There was a problem of so-called white background stain, that is, the part of the white background that was not attached was stained.

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. Excellent fixability at lower temperatures. Excellent in offset resistance. Excellent in non-condensability. Does not cause white background stains.

[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 Propylene and α-olefin copolymer are contained in an amount of 1 to 35% by weight, the vinyl copolymer has a maximum value of the molecular weight distribution in 1 × 10 ³ to 8 × 10 ⁴ , and 1 × 10 ⁵ to It has a maximum or shoulder of the molecular weight distribution at 4 × 10 ⁶ , or has a weight average molecular weight Mw.
And the number average molecular weight Mn ratio Mw / Mn is 6 or more, and the viscosity of the copolymer of ethylene or propylene and α-olefin at 140 ° C. is 10,000 poise or less.

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 copolymer has a maximum value of the molecular weight distribution in 1 × 10 ³ to 8 × 10 ⁴ and a maximum value of the molecular weight distribution in 1 × 10 ⁵ to 4 × 10 ^6. Alternatively, it is characterized by having a shoulder or having a ratio Mw / Mn of the weight average molecular weight to the number average molecular weight of 6 or more. Such a molecular weight distribution can be measured by, for example, gel permeation chromatography (GPC). The maximum of the molecular weight distribution on the low molecular weight side is 1 x 1
If it is less than 0 ³ , the cohesiveness may deteriorate, and 8 × 1
If it is larger than 0 ⁴ , the fixability may decrease.

Further, if the maximum value of the molecular weight distribution on the high molecular weight side or the shoulder is smaller than 1 × 10 ⁵ , the offset resistance may be deteriorated, and if it is larger than 4 × 10 ⁶ , the fixability may be deteriorated. is there. If Mw / Mn is less than 6, offset resistance may deteriorate. The molecular weight distribution is 1 × 10 ³ to 8 × 10 ^{4 and} the low molecular weight portion is 1 × 1.
In the case where the polymer has a maximum value in each of the high molecular weight portion of 0 ⁵ to 4 × 10 ⁶ , the content of the high molecular weight polymer component is 15
It is preferably at least% by weight. When the content of the high molecular weight polymer component is less than 15% by weight, the offset resistance may be deteriorated.

In the present invention, the vinyl copolymer 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 1 to 35% by weight based on the vinyl copolymer. When the content of the α-olefin copolymer is less than 1% by weight, the effects of the present invention such as low temperature fixability are hardly obtained.
On the other hand, if the content exceeds 35% by weight, the toughness of the resin becomes too high and it becomes impossible to pulverize it into a toner. The more preferable content of these copolymers is 3 to 2
It is 5% 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. The component is preferably 50 mol% or more, and more preferably 70 mol% or more. Also,
When the amount of the other α-olefin component is small, the crystallinity is increased and the dispersibility with the vinyl-based copolymer may be deteriorated. Therefore, the amount of the other α-olefin component is preferably 4 mol% or more. As the α-olefin in this copolymer, ethylene, propylene, butene, pentene, hexene, methylpentene, tetradecene, pentadecene and the like can be used, and if necessary, two or more types may be used, but C7 or less α-olefin Olefin is preferred, butene is particularly preferred.

Further, when ethylene or propylene is highly blocked, the crystallinity is increased and the dispersibility with the vinyl copolymer may be deteriorated. Therefore, ethylene or propylene and the α-olefin copolymer are copolymerized. Is preferably close to random copolymerization. Further, the ethylene or propylene and α-olefin copolymer, if the molecular weight is too low, plasticizes the vinyl-based copolymer to deteriorate the storage stability, or the resin strength is significantly reduced, causing white background stains, The Mw (weight average molecular weight) is 1 because the fixed toner may cause cohesive failure at the interface of the fixed object.
It is preferably 000 or more, more preferably 2
It is more than 000.

Further, Mn (number average molecular weight) is about 80,000 or less in view of the pulverizability of the resin and the dispersibility with the vinyl copolymer, whereas the wax usually mixed in the toner is about 3,000. It is preferably 40,000 or less. In the present invention, the viscosity of the ethylene or propylene and α-olefin copolymer at 140 ° C. is 10,000 poise or less. This is because if the viscosity is higher than this, it cannot flow sufficiently at a low temperature and cannot be fixed at a lower temperature. The viscosity of the copolymer at 140 ° C. is more preferably 1000 poise or less.

Suspension polymerization, emulsion polymerization, bulk polymerization or the like can be used for the synthesis of the above vinyl copolymer containing a styrene monomer and / or a (meth) 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, it is possible to employ a method in which a vinyl-based copolymer and an α-olefin copolymer are heat-melted and blended. In order to make the content more uniform, 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, aliphatic amide, bis-aliphatic amide, metal soap, paraffin and the like may be mixed. Further, dyes such as nigrosine and spirone black (manufactured by Hodogaya Chemical Co., Ltd.) as charge control agents, and other phthalocyanine pigments can be added as long as the objects and effects of the present invention can be achieved. 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.

In order to produce a toner using the resin composition for a toner of the present invention, conventionally known additives for a toner such as a colorant as described above are mixed with a ribbon blender, a Hensell mixer, etc. After kneading with a roll mill, kneader, extruder or the like, a method of cooling and finely pulverizing can be adopted.

[0019]

In the toner resin composition of the present invention, the vinyl copolymer has a molecular weight distribution of 1 × 10 ³ to 8 × 10 ^4.
And has a maximum value or a shoulder of 1 × 10 ⁵ to 4 × 10 ⁶ or has Mw / Mn of 6 or more, and thus has excellent low-temperature fixability and offset resistance. Further, since it contains an α-olefin copolymer having a low viscosity at a relatively low temperature, a resin composition for toner which can be fixed at a low temperature can be obtained. Furthermore, according to the present invention, the toughness of the resin composition for a toner is high because the α-olefin copolymer, which is tough and easily dispersible in the vinyl-based copolymer, is contained in a specific ratio of 1 to 35% by weight. It is possible to obtain a toner that has improved properties, does not stain the white background, and is hard to aggregate.

[0020]

Description of Examples Example 1 70 parts by weight of styrene, 10 parts of methacrylic acid methyl ester
Parts by weight, 20 parts by weight of n-butyl acrylate are polymerized,
A resin having a maximum molecular weight distribution of 600,000 (6 × 10 ⁵ ) was obtained. 200 g of this resin and an ethylene-butene copolymer as an α-olefin copolymer (manufactured by Mitsui Petrochemical Co., Ltd., trade name: DTO24, Mw = 40,000, Mn = 10,000, 140 ° C.)
The mixture with 160 g of a viscosity of 27 poise) was placed in a 3 liter separable flask and dissolved with 1 liter of toluene. The gas phase was replaced with nitrogen gas, and then the system was heated to the boiling point of toluene.

While refluxing the toluene, with stirring, 440 g of styrene and 65 g of n-butyl acrylate.
And a mixture of 30 g of t-butylperoxy 2-ethylhexanoate as a polymerization initiator dissolved in 2.5
Solution polymerization was carried out while dropping over a period of time to polymerize the low molecular weight polymer component in the presence of the high molecular weight polymer component and the α-olefin copolymer. After the completion of dropping, the mixture was aged for 1 hour while stirring at the boiling temperature of toluene.
Then, while gradually raising the temperature of the system to 180 ° C., the solvent was removed under reduced pressure to obtain a resin A having a peak of molecular weight distribution on the low molecular weight side of 8000 (8 × 10 ³ ). The glass transition point of this resin A is 63 ° C., and Mw /
Mn was 27. Further, in the resin A, the content of the ethylene / butene copolymer as the α-olefin copolymer was 18% 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.).

Also, 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 is DC-50 manufactured by Mita.
It is a modification of the 55. 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 the resin A was 140 ° C., which was sufficiently low. 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. Further, even if the image fixed at 170 ° C. was rubbed with gauze, no white background stain was observed.

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 are polymerized, and the maximum value of the molecular weight distribution is 5000 (5 × 10 ³ ).
Was obtained. Further, 80 parts by weight of styrene and 20 parts by weight of butyl methacrylic acid were polymerized to obtain a resin having a maximum molecular weight distribution of 600,000 (6 × 10 ⁵ ). The maximum value of the molecular weight distribution is 65% by weight of the resin, the maximum value of the molecular weight distribution is 60%, and the resin is 23% by weight, and the propylene-butene copolymer as an α-olefin copolymer (butene content 14 mol%, Mw = 20,000, Mn = 6000, 14
12 wt% of a mixture having a viscosity of 60 poise at 0 ° C.) was mixed, the mixture was placed in a 3 liter separable flask and 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.

The mixture was stirred for 2 hours while xylene was refluxed. Then, while gradually raising the temperature of the system to 180 ° C., the xylene was removed under reduced pressure to remove the glass transition point 59.
Resin B having a Mw / Mn of 38 ° C. was obtained. This resin B
In the above, the content of the propylene-butene copolymer as the α-olefin copolymer was 12% by weight. 100 parts by weight of the resin B 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., Product name: Viscor 660P) 3
1 part by weight 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.

Toner was prepared by adding 0.3 part by weight of hydrophobic silica powder (trade name: R-972, manufactured by Nippon Aerosil Co., Ltd.) to the toner powder. 10g of this toner
It was taken in a ml sample bottle, left for 16 hours in a constant temperature bath at 50 ° C., and the degree of aggregation was measured with a powder tester (manufactured by Hosokawa Micron Co., Ltd.). Further, a developer was prepared in the same manner as in Example 1, and the fixing temperature and the offset generation temperature were evaluated. As a result, the fixing temperature was 140 ° C., which was sufficiently low, and the offset generation temperature was 200 ° C. or higher, which was sufficiently high. No white background stain was observed.

Example 3 In a 3-liter separable flask, an ethylene-butene copolymer as an α-olefin copolymer (manufactured by Mitsui Petrochemical Co., Ltd., trade name: DTO32, butene content 8 mol%:
Mw = 50,000, Mn = 15,000, viscosity at 140 ° C. 2
8 poise) 85 g, styrene 300 g, acrylic acid n
-Butyl 120 g and toluene 700 g, and Kayaester HTP (manufactured by Kayaku Nouri Co.) 0.2 as a catalyst.
After adding 5 g and replacing the gas phase with nitrogen gas, the system was heated to the boiling point of toluene. Polymerize the high molecular weight substance while stirring for 10 hours in the state where toluene is refluxed,
Thereafter, solution polymerization was carried out while dropping a mixture of 500 g of styrene, 120 g of methacrylic acid butyl ester and 12 g of AIBN over 2 hours to produce a resin corresponding to a low molecular weight polymer. After completion of dropping, the mixture was aged for 3 hours while stirring at the boiling temperature of toluene. Then, while gradually raising the temperature of the system to 180 ° C., the solvent was removed under reduced pressure to remove toluene, and the maximum value of the molecular weight distribution was 20,000 (2
Resin C having a size of × 10 ⁴ ) and 300,000 (3 × 10 ⁵ ) was obtained. The glass transition point of this resin C is 57 ° C., and Mw /
Mn was 18. The content of the propylene-butene copolymer, which is an α-olefin copolymer, was 7% by weight.

100 parts by weight of the resin C thus obtained and carbon black (manufactured by Mitsubishi Kasei Co., Ltd., trade name: M
5 parts by weight of A-100) and 1 part by weight of Spiron Black TRH were 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 the toner powder, 0.3 part by weight of the hydrophobic silica powder was added in the same manner as in Example 1 to prepare a toner, and the aggregation degree of this toner was measured. As a result, no aggregation property was observed. A developer was prepared in the same manner as in Example 1, and the fixing temperature and the offset generation temperature of the developer were evaluated.
The fixing temperature was 140 ° C., which was sufficiently low, and the offset generation temperature was 200 ° C. or higher, which was sufficiently high. No white background stain was observed.

Comparative Example 1 In Example 1, 120 g of ethylene-butene copolymer
A developer was prepared and tested in the same manner as in Example 1 except that 4 g was used instead of. As a result, no cohesiveness was observed, the offset generation temperature was 200 ° C. or higher, but the fixing temperature was 150 ° C., and white background stain was observed.

Comparative Example 2 In Example 1, 2 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 was 20,000 (2 × 1).
A low molecular weight resin of 0 ⁴ ) was obtained. The glass transition point of this resin was 64 ° C. Using this resin, a developer was prepared in the same manner as in Example 1 and tested. As a result, no cohesiveness was observed, no white background stain was observed, 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 In Example 1, a developer was prepared and tested in the same manner as in Example 1 except that only the low molecular weight polymer was prepared and used. As a result, no cohesiveness was observed, the fixing temperature was 140 ° C., but the offset generation temperature was as low as 160 ° C., and white background stain was observed.

Comparative Example 4 In Example 1, 160 g of ethylene-butene copolymer
Resin was produced by using 400 g instead of, and 100 parts by weight of the obtained resin, 5 parts by weight of carbon black (trade name: MA-100, manufactured by Mitsubishi Kasei Co.), and Spiron Black T
1 part by weight of RH and 3 parts by weight of PP wax (manufactured by Sanyo Kasei Co., Ltd., trade name: viscose 660P) were melt blended, cooled, coarsely pulverized, and then finely pulverized by a jet mill. Only a toner having an average particle size of 100 microns was obtained, and a developer could not be prepared.

Comparative Example 5 In Example 3, instead of 30 g of the ethylene-butene copolymer, polyethylene having a molecular weight of about 4000 (Mitsui Petrochemical Co., Ltd., trade name: Hiwax 410P, viscosity 70 poise at 140 ° C.) was used. A developer was prepared and tested in the same manner as in Example 3 except for the above. As a result, although the offset generation temperature was 200 ° C. or higher, cohesiveness was recognized, the fixing temperature was 150 ° C., and white background stain was recognized.

Comparative Example 6 In Example 1, ethylene-butene copolymer DTO3
Instead of 2, Tuffmer A A-4085 (manufactured by Mitsui Petrochemical Co., butene content 8 mol%, molecular weight about 200,000, 14
A developer was prepared and tested in the same manner as in Example 1 except that the viscosity at 0 ° C. was 30,000 poise). However, since the pulverizability of the toner is poor, the average particle size is about 20 to 2
It was 5 microns. As a result of the test, cohesiveness was not recognized and the offset generation temperature was 200 ° C. or higher, but stains were recognized on a white background and the fixing temperature was 160 ° C.

[0035]

As described above, according to the present invention,
The vinyl-based copolymer has a molecular weight distribution value of 1 × 10.
Has a maximum value of ³ to 8 × 10 ⁴ and 1 × 10 ⁵ to 4 × 10
^Since it has a maximum value or a shoulder value of ⁶ or Mw / Mn of 6 or more, it has excellent low-temperature fixability and offset resistance. Further, since it contains an α-olefin copolymer having a low viscosity at a relatively low temperature, a toner resin composition which can be fixed at a lower temperature can be obtained. Furthermore, by containing such an α-olefin copolymer in a specific ratio, the toughness of the resin composition for a toner is enhanced, and a toner that does not cause white background stains and does not easily agglomerate 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, and having a maximum molecular weight distribution of 1 × 10 ³ to 8 × 10 ^4. It has a value and 1 × 10 ⁵ to 4 × 10
⁶ has a maximum or shoulder of the molecular weight distribution, or a ratio Mw / of the weight average molecular weight (Mw) and the number average molecular weight (Mn)
A vinyl-based copolymer having an Mn of 6 or more contains 1 to 35% by weight of a copolymer of ethylene or propylene and an α-olefin having a viscosity at 140 ° C. of 10,000 poise or less. A resin composition for toner. 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.