JPH09281747A - Resin composition for toner and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin compsn. for a toner suitable for use as a full-color toner without deteriorating preservability, fixabilirty, anti-offsetting property, pulverizability and transparency or causing filming on a photoreceptor and to provide a toner. SOLUTION: Wax having a wt. average mol.wt. of 400-700, 60-100 deg.C peal by differential scanning calorimetry and 5-30dmm penetration at 35 deg.C is incorporated by 0.1-10wt.% into a vinyl copolymer composed of a styrene monomer and a (meth)acrylic ester monomer, having a peak within the mol.wt. range of 3×10<3> to 1.5×10<4> in the mol.wt. distribution by gel permeation chromatography and having a wt. average mol.wt. of <=150,000 to obtain the objective resin compsn, for a toner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a toner used in a full color copying machine used for developing an electrostatic image and a toner using the resin composition.

[0002]

2. Description of the Related Art In a dry developing system, toner is usually charged by friction with iron, glass beads, etc. called a carrier, and this is attached to an electrostatic latent image on a photoconductor by an electric attraction, and then paper. It is transferred onto the surface and fixed by a heat roll or the like to form a permanent visible image.

As a fixing method, a surface of a heating roller having a surface formed of a material having a releasing property with respect to toner is applied to the surface of the heating roller.
A heating roller method is often used in which a toner image image on a sheet to be fixed is passed while being in pressure contact. According to this method, the surface of the heating roller and the toner image on the sheet to be fixed come into contact with each other under pressure, so that the thermal efficiency at the time of fusing the toner image on the sheet to be fixed is extremely good, and quick fixing is performed. And is very effective in high speed electrophotographic copying machines.

However, when the surface of the heating roller and the toner image are in contact with each other in a molten state and under pressure, a part of the toner image adheres to and transfers to the surface of the fixing roller and retransfers to the next sheet to be fixed. In some cases, a so-called offset phenomenon occurs and the sheet to be fixed is soiled. JP-A-57-56
No. 850, a developing toner containing a resin obtained by mixing a wax having a functional group, a styrene monomer, and an ethylene acrylic derivative or an ethylene vinyl acetate copolymer and polymerizing the mixture is separated from a heat roller. Although a technique for improving the moldability is disclosed, since the wax does not participate in the fixability, the larger the addition amount, the more adverse effect such as filming on the photoreceptor.

Further, a method of crosslinking the resin to prevent the offset phenomenon is also used, but if the degree of crosslinking is increased, the pulverizability of the resin deteriorates and it becomes difficult to pulverize and classify it as toner particles, such as carbon. There is a problem such that the dispersion of the colorant is deteriorated. JP-A-56-158340 discloses at least one selected from the group consisting of a low molecular weight polymer and a high molecular weight polymer, which is selected from the group consisting of a styrene polymer, an acrylic polymer and a styrene-acrylic polymer. Therefore, a technique for preventing offset by a toner made of a resin having a specified glass transition temperature range has been disclosed, but there is a problem that if the amount of the high molecular weight resin is increased, the fixability is deteriorated. Due to these problems, conventionally, toners have been produced with a balance of offset resistance, fixing property and the like.

However, with the recent trend toward full color and higher resolution, the conventional toner has many problems.
In full-color conversion, it is necessary to prevent the fixed toner from diffusely reflecting the light and impairing the color reproducibility. However, if a conventional resin cross-linked or a high molecular weight resin is used, fixing is performed. There are problems such as unevenness on the surface and irregular reflection. However, when the crosslinking of the resin, the use of the high molecular weight resin, etc. were simply stopped, an offset phenomenon occurred this time, and not only the fixing surface became uneven but also the defect such as soiling the fixing sheet came to occur. . Further, since full-color toners produce intermediate colors by stacking toners of different color tones, transparency is required. Therefore, if a large amount of wax is added in order to prevent the offset phenomenon, the transparency is impaired, and there arises a drawback that it becomes difficult to use as a full-color toner. Further, due to the influence of the low melting point component of the wax, the storage stability is deteriorated, and problems such as blocking occur.

[0007]

SUMMARY OF THE INVENTION In view of the above, the present invention is a full-color toner that does not impair storage stability, fixability, offset resistance, crushability, transparency, and does not cause filming on a photoreceptor. An object of the present invention is to provide a resin composition for toner and a toner that can be suitably used as the toner.

[0008]

The toner resin composition of the present invention comprises a styrene monomer and a (meth) acrylic acid ester monomer, and has a molecular weight of 3 × 10 in a molecular weight distribution by gel permeation chromatography. ³ ~
A vinyl copolymer having a peak in the range of 1.5 × 10 ⁴ and a weight average molecular weight of 150,000 or less has a weight average molecular weight of 400 to 700 and a peak by differential scanning calorimetry of 60 to 100. ℃, the penetration is 5 to 3 at 35 ℃
It is characterized by containing 0.1 to 10% by weight of a wax of 0 dmm. Hereinafter, the present invention will be described in detail.

The vinyl copolymer in the present invention comprises a styrene monomer and a (meth) acrylic acid ester monomer. The styrene-based monomer is not particularly limited, and examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene,
p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene , 3,
4-dichlorostyrene etc. are mentioned.

The (meth) acrylic acid ester monomer is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, and n-acrylate.
Butyl, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid n
-Alkyl esters of acrylic acid or methacrylic acid such as octyl, dodecyl methacrylate, stearyl methacrylate; 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, methacrylic acid Diethylaminoethyl, 2-hydroxyethyl methacrylate, glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate,
Methacryloxyethyl phosphate and the like can be mentioned, and among them, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like are particularly preferable.

The vinyl copolymer may contain other vinyl monomers. The other vinyl-based monomer is not particularly limited, and examples thereof include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid, and crotonic acid, or an α-alkyl derivative or β-alkyl derivative thereof; fumaric acid, Unsaturated dicarboxylic acids such as maleic acid, citraconic acid and itaconic acid or their monoester or diester derivatives; succinic acid monoacryloyloxyethyl ester, succinic acid monomethacryloyloxyethyl ester, acrylonitrile, methacrylonitrile, acrylamide and the like. .

The above vinyl-based copolymer has a peak in the molecular weight range of 3 × 10 ^{3 to} 1.5 × 10 ^{4 in} the molecular weight distribution by gel permeation chromatography (GPC). When the peak is present in the molecular weight range of less than 3 × 10 ³ , a problem occurs in storability, and when the peak is present in the range of more than 1.5 × 10 ⁴ , the fixability is poor. More preferably, it is in the range of 4 × 10 ³ to 8 × 10 ³ . The molecular weight distribution may have multiple peaks or shoulders.

When the vinyl copolymer has two or more peaks in the molecular weight distribution, the low molecular weight polymer component and the high molecular weight polymer component may be hot melt blended, but more homogenously dispersed. Therefore, it is preferable to remove the solvent after dispersing it in the solvent. Further, it is preferable to polymerize the low molecular weight polymer component in the presence of the high molecular weight polymer component.

The vinyl copolymer has a weight average molecular weight (Mw) of 150,000 or less. If it exceeds 150,000, the surface smoothness (gloss) cannot be sufficiently obtained. If the Mw becomes small, the storage stability may decrease, so it is preferably 50
It is from 00 to 100,000. The vinyl-based copolymer preferably has a glass transition point of 50 to 100 ° C. 50 ℃
If it is less than 100 ° C, cohesiveness may deteriorate, and the temperature is 100 ° C.
If it exceeds, the fixability may decrease. More preferably, it is 55-80 degreeC.

The above-mentioned vinyl-based copolymer can be synthesized, for example, by
Although suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization and the like can be used, solution polymerization is preferable in order to improve the dispersibility of polyolefin and the like. It is more preferable to disperse the polyolefin or the like in advance during the above-mentioned polymerization, because the dispersion of the polyolefin or the like becomes very good and the physical properties of the toner become very good.

The toner resin composition of the present invention comprises a wax in addition to the vinyl copolymer. The above-mentioned wax is a gloss aid mainly for producing gloss. The wax has a weight average molecular weight of 400 to 700. Four
When it is less than 00, a problem occurs in storage stability, and when it exceeds 700, the gloss of the fixing surface cannot be maintained. More preferably, it is 450 to 650.

The above wax has a differential scanning calorimetry (DS).
The peak according to C) is 60 to 100 ° C. When the temperature is lower than 60 ° C, the storage stability is deteriorated and blocking occurs at the time of storage at room temperature, and when the temperature is higher than 100 ° C, it is difficult to melt during fixing, and the surface smoothness (gloss) during fixing is impaired. More preferably, it is 65 to 90 ° C.

The above wax has a penetration of 5 to 3 at 35 ° C.
It is 0 dmm. If it is less than 5 dmm, fixing is poor,
If the surface smoothness (gloss) of the fixing surface is impaired and exceeds 30 dmm, fine powder is generated when the resin is crushed, and even when toner is used for a long time, fine powder is generated, which causes toner deterioration. The toner resin composition of the present invention contains the above wax in an amount of 0.1 to 0.1%.
Contains 10% by weight. If it is less than 0.1% by weight, the gloss of the fixing surface cannot be maintained and offset easily occurs. If it exceeds 10% by weight, adverse effects such as filming on the photoreceptor and deterioration of transparency occur. It is more preferably 0.5 to 7% by weight.

The wax preferably has a melt viscosity at 130 ° C. in the range of 5 to 1 OcP due to the compatibility with the resin. Within this range, the wax bleeds out appropriately, and thus it is very good in imparting gloss and offset resistance. The wax preferably has a dispersity of 1.5 or less. When it exceeds 1.5, the amount of low molecular weight components is large, so that there is a problem in storage stability.
More preferably, it is 1.2 or less.

The above wax has a softening point of 60 to 150 ° C.
Is preferably within the range. If the temperature is lower than 60 ° C, blocking may occur at room temperature, and the temperature may be 150 ° C.
If it exceeds, it becomes difficult to melt during fixing, and the surface smoothness (gloss) during fixing may be impaired. More preferably, it is in the range of 70 to 100 ° C.

The above wax is not particularly limited, and examples thereof include synthetic waxes such as polyethylene wax and polypropylene wax; natural waxes such as paraffin wax and animal and vegetable wax, and the like. Paraffin wax, ethylene wax, propylene wax and the like, which are easy to handle, are preferably used.

In the toner resin composition of the present invention,
The vinyl copolymer may be copolymerized with vinyl acetate, vinyl chloride, ethylene or the like, or a polymer of these monomers may be blended. The toner resin composition of the present invention may be mixed with a synthetic resin such as a polyester resin or an epoxy resin; an aliphatic amide, a bisaliphatic amide, a metal soap or the like.

To the resin composition for toner of the present invention, dyes such as nigrosine and spirone black (manufactured by Hodogaya Chemical Co., Ltd.) as well as phthalocyanine pigments can be added as charge control agents. In the resin composition for a toner of the present invention, carbon black, chrome yellow, aniline blue, or the like can be used as a coloring material. Polyethylene wax, polypropylene wax or the like can be added as a release agent to the resin composition for toner of the present invention, and hydrophobic silica or the like may be added to improve fluidity. The resin composition for a toner of the present invention may be mixed with a magnetic powder and used as a magnetic toner.

The toner resin composition of the present invention is preferably used for a toner, and particularly preferably for a full color toner. Such toner is also one aspect of the present invention. The resin composition for a toner of the present invention can exhibit smoothness (gloss) on the fixing surface without impairing the transparency as the resin composition for a full-color toner by appropriately bleeding out the wax.

[0025]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 In a 3 L separable flask, 900 g of toluene and
Polyethylene wax (manufactured by China Essential Oil Co., Ltd.)
Nopalets MP-90, softening point 93.5 ° C, DSC peak 90.2 ° C, weight average molecular weight 634, 35 ° C penetration 1
After 30 g of 0.2 dmm, 130 ° C. melt viscosity of 7.8 cP and dispersity of 1.04) was added and stirred, and the gas phase was replaced with nitrogen gas, the system was heated to the boiling point of toluene. While refluxing toluene, with stirring, 800 g of styrene, 200 g of n-butyl acrylate, and azobisisobutyronitrile (AIBN) as a polymerization initiator.
Solution polymerization was performed while dropping a mixture in which 55 g was dissolved over 4 hours. After the completion of dropping, the mixture was aged for 2 hours while stirring at the boiling temperature of toluene. Then, while gradually raising the system temperature to 180 ° C., the solvent was removed from the toluene under reduced pressure to obtain a resin. This resin was cooled and pulverized to obtain a resin composition A for toner. The resin composition A for toner had a peak at 5 × 10 ³ in the molecular weight distribution, Tg of 55 ° C., and Mw of 1.2 × 10 ⁴ .

To 100 parts by weight of this resin composition A for toner, carbon black (MA-100, manufactured by Mitsubishi Chemical Corporation) was added.
6 parts by weight, wax (manufactured by Sanyo Kasei Co., Viscole 660
P) 1 part by weight, and a charge control agent (Hodogaya Chemical Co., Ltd., T
Melt blend 3 parts by weight of P-302) by a continuous kneader (manufactured by Kurimoto Steel Co., Ltd.), and after cooling, coffee mill (Carioca-MI manufactured by National Co.)
LL), and then finely crushed with a jet mill (Nippon Pneumatic Mfg. Co., Ltd., Lab Jet), and finely pulverized with a classifier (Nippon Pneumatic Mkg. Co., Ltd., MDS-2) to give a 50% average of about 9.3 microns. A toner powder having a particle size was prepared. 0.5 parts by weight of silica (Aerosil R972D, manufactured by Nippon Aerosil Co., Ltd.) was added as an external additive, and the mixture was sufficiently stirred.
A toner was obtained.

The color toner was similarly prepared by using disazo yellow for yellow, carmine 6B for magenta, and copper phthalocyanine for cyan instead of carbon black. 6 to 5 parts by weight of the toner
Ferrite carrier 9 having an average particle size of 0 micron
A developer was prepared by mixing with 4 parts by weight, and a copy was obtained using this developer. The electrophotographic copying machine used was a modification of Acolor 686 manufactured by Fuji Xerox Co., Ltd.

Evaluation Method The fixing temperature was set at a temperature at which the density of a copy image changed when the copy was rubbed with a sand eraser for a typewriter while variously setting the temperature of the heat roller of the electrophotographic copying machine. Regarding the offset and fixing surface smoothness (gloss), the setting temperature of the heat roller of the electrophotographic copying machine was 190 ° C., and the offset and fixing surface smoothness (gloss) at that time were observed.も の indicates that no offset occurred, and X indicates that an offset occurred. The fixing surface smoothness (gloss) was measured with a gloss meter (Gardner, Inc., USA, incident angle: 60).
Degree), gloss 50 or more is good (○), gloss 45
~ 50 is a little bad (△), gloss less than 45 is bad (x)
And

Toner durability and filming on the photosensitive member were determined by running running 10,000 sheets in a room at 30 ° C. and 50% humidity, and observing the deterioration of the toner and the degree of adhesion to the photosensitive member. The running was evaluated as ◯ when the toner was not deteriorated, Δ when the toner was slightly deteriorated, and x when the toner was deteriorated. Filming was evaluated as ◯ when adhesion did not occur to the photoconductor, and as x when adhesion occurred. Regarding the storage stability, the degree of blocking of the resin at that time was observed at 50 ° C. for 24 hours. Those in which blocking did not occur were marked with ◯, and those in which blocking occurred were marked with x. The transparency was evaluated by visually observing the tint of the halftone portion after fixing, and the one in which the halftone could be reproduced was evaluated as ◯, the one in which the halftone could not be reproduced was evaluated as Δ, and the one in which the halftone could not be reproduced was evaluated as x.

Results As a result of evaluation of the toner using the resin composition A for toner, the fixing temperature was as good as 160 ° C., no offset occurred, and the glossiness was good with gloss of 50 or more for all colors. It was As a result of a running test using this developer, the image was clear and toner deterioration hardly occurred. No filming on the photoreceptor was observed. In terms of storability, no blocking was observed and halftone could be reproduced neatly.

Example 2 In a 3 L separable flask, 900 g of xylene and
Polyethylene wax (manufactured by China Essential Oil Co., Ltd.)
Nopalets MP-80, softening point 84.5 ° C, DSC peak 79.8 ° C, weight average molecular weight 542, 35 ° C needle penetration 1
50 g of 3.3 dmm, 130 ° C. melt viscosity 6.2 cP, dispersity 1.05) was added and stirred, the gas phase was replaced with nitrogen gas, and then the system was heated to the boiling point of xylene. While refluxing xylene, while stirring, a mixture of styrene 700 g, n-butyl acrylate 150 g, methyl methacrylate 150 g and benzoyl peroxide 60 g as a polymerization initiator was added dropwise over 2 hours, Solution polymerization was performed. After completion of dropping, the mixture was aged for 2 hours while stirring at the boiling temperature of xylene. Thereafter, while gradually raising the temperature of the system to 180 ° C., xylene was desolvated under reduced pressure to obtain a resin. This resin was cooled and pulverized to obtain a resin composition B for toner.

The resin composition B for toner has a molecular weight distribution of 7
There is a peak at × 10 ³ , Tg is 62 ° C, Mw is 1.4.
It was × 10 ⁴ . A developer was prepared and tested in the same manner as in Example 1 except that the toner resin composition B was used in place of the toner resin composition A. As a result, the fixing temperature was 160 ° C., which was good. Offset did not occur, and the glossiness of all colors was good, with gloss of 50 or more. As a result of a running test using this developer, the image was clear and toner deterioration hardly occurred.
No filming on the photoreceptor was observed. In terms of storability, no blocking was observed and halftone could be reproduced neatly.

Comparative Example 1 A developer was prepared in the same manner as in Example 1 except that 80 g of azobisisobutyronitrile (AIBN) was used and a resin composition for toner having a peak at 2 × 10 ³ in the molecular weight distribution was used. As a result of making and testing, the fixing temperature is 1
Although it was very good at 55 ° C, offset occurred. The glossiness of all colors was good with a gloss of 50 or more. As a result of a running test using this developer, the image was disturbed and the toner was deteriorated. No filming on the photoreceptor was observed, but terrible blocking was observed in storage stability. I was able to reproduce the halftones neatly.

Comparative Example 2 A developer was prepared in the same manner as in Example 2 except that 20 g of benzoyl peroxide was used and a resin composition for toner having a peak at 2 × 10 ⁴ in the molecular weight distribution was used.
As a result of the test, the fixing temperature deteriorated to 175 ° C., but no offset occurred. The glossiness was slightly inferior to all the glosses of 45 to 50. As a result of a running test using this developer, the image was clear and toner deterioration hardly occurred. No filming on the photoreceptor was observed. In terms of storability, no blocking was observed and halftone could be reproduced neatly.

Comparative Example 3 The dropping time was 6 hours, and the molecular weight distribution was 2.2 × 1.
A developer was prepared and tested in the same manner as in Example 2 except that the toner resin composition having a peak at 0 ⁴ was used. As a result, the fixing temperature was good at 165 ° C. and no offset occurred. It was All colors are gloss 40-50
It was a little inferior. As a result of a running test using this developer, the image was clear and toner deterioration hardly occurred. No filming on the photoreceptor was observed. In terms of storage stability, no blocking was observed, but halftone became somewhat dull.

Comparative Example 4 A developer was prepared and tested in the same manner as in Example 1 except that the wax having a weight average molecular weight of 3 × 10 ³ (manufactured by Sanyo Kasei Co., Ltd., Viscole 660P) was used. The fixing temperature was as good as 160 ° C., and no offset occurred, but the glossiness was inferior at 30 or less for all colors. As a result of a running test using this developer, the image was clear and toner deterioration hardly occurred. No filming on the photoreceptor was observed. In terms of storability, no blocking was observed and halftone could be reproduced neatly.

Comparative Example 5 A developer was prepared and tested in the same manner as in Example 1 except that no wax was used. As a result, the fixing temperature was 1
Although it was good at 60 ° C., offset occurred and the glossiness was gloss 30 or less for all colors. As a result of a running test using this developer, the image was clear and toner deterioration hardly occurred. No filming on the photoreceptor was observed. In terms of storability, no blocking was observed and halftone could be reproduced neatly.

Comparative Example 6 A developer was prepared and tested in the same manner as in Example 1 except that 200 g of wax was added. As a result, the fixing temperature was slightly inferior at 170 ° C., but no offset occurred. In terms of glossiness, all colors were good with a gloss of 50 or more. As a result of a running test using this developer, the image was somewhat disturbed and the toner was somewhat deteriorated. Filming on the photoconductor was strongly observed. In terms of storage stability, blocking was not seen, but halftone could hardly be reproduced. The results of Examples 1 and 2 and Comparative Examples 1 to 6 are summarized in Table 1.

[0040]

[Table 1]

[0041]

Since the resin composition for a toner of the present invention is as described above, it does not impair the storability, fixability, anti-offset property, pulverizability and transparency, and causes filming on the photoreceptor. Therefore, it can be preferably used as a full-color toner.

Claims (2)

[Claims] 1. A styrene-based monomer and a (meth) acrylic acid ester monomer, which have a molecular weight of 3 × 1 in a molecular weight distribution by gel permeation chromatography.
The vinyl copolymer having a peak in the range of 0 ^{3 to} 1.5 × 10 ⁴ and a weight average molecular weight of 150,000 or less has a weight average molecular weight of 400 to 700 and a peak by differential scanning calorimetry. 0.1 to 10% by weight of a wax having a penetration of 5 to 30 dmm at 35 ° C.
A resin composition for a toner, which is contained. 2. A toner comprising the resin composition for a toner according to claim 1.