JPS61235849A - Toner for electrostatic charge image - Google Patents

Abstract

PURPOSE:To prevent offset and to improve the fixability at low temp., the shelf stability and resistance to vinyl chloride resin by blending epoxy resin with coumarone-indene resin and using the blend as a resin binder. CONSTITUTION:One or more kinds of epoxy resins such as bisphenol type epoxy resin, novolak type epoxy resin, hydrogenated bisphenol type epoxy resin, halogenated epoxy resin and multifunctional epoxy resin are blended with coumarone-indene resin obtd. by polymerizing polymerizable components distilled together with coke oven gas in the presence of a polymn. catalyst without carrying out fractional distillation. The preferred average mol.wt. of the coumarone-indene resin is 500-900, and the preferred amount of the resin is 5-40wt% of the amount of the epoxy resins. The resin blend gives improved resistance to vinyl chloride resin, improved fixability, offset resistance and shelf stability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a toner for electrostatic charge images, which has good fixing properties especially at low temperatures when being fixed by a combination of heat and pressure, and which has good fixing performance on a fixing roll. The present invention relates to a toner that does not cause the phenomenon of toner adhesion (hereinafter referred to as offset) and has excellent storage stability.

[Background of the invention]

Binder resins commonly used for toners include styrene resins, epoxy resins, and polyester resins. In particular, styrene resins or styrene/acrylic resins are widely used because they have appropriate crushability, excellent charging properties, and powder fluidity. However, if an image is formed on paper or the like with a toner made of styrene or styrene/acrylic resin, and then left to press onto a polyvinyl chloride sheet, part or all of the toner image may peel off from the paper. There is a problem of transfer to polyvinyl chloride sheets. This is because the plasticizer such as dioctyl phthalate contained in the polyvinyl chloride sheet and the styrene resin have good compatibility. Since epoxy resins have a property of being difficult to be compatible with such plasticizers, toners using epoxy resins do not exhibit the phenomenon of transfer of toner images to polyvinyl chloride sheets.

In recent years, it has become common for copied materials to be filed and organized on polyvinyl chloride sheets, so that properties that prevent toner image transfer (hereinafter referred to as vinyl chloride resistance) have become required. In addition, as a PVC-resistant product, JP-A-58-1
There are No. 22554, No. 58-203452, etc.

On the other hand, as a method of fixing toner images, with the recent increase in high-speed printing, there has been a shift from the conventional heat fixing method using an oven to a heat pressure fixing method using five heating rolls. However, in this method, the roll and the toner come into contact in a molten state, so the toner used in the conventional heat fixing method causes a phenomenon in which the toner adheres to the roll (hereinafter referred to as offset), which is undesirable.

[Purpose of the invention]

In view of the above-mentioned points, an object of the present invention is to provide a toner for electrostatic images that has excellent vinyl chloride resistance, good fixing properties and anti-offset properties, and also has good storage stability.

[Summary of the invention]

The present invention prevents offset by using a resin blended with epoxy resin and coumaron-indene resin as a binder resin, and provides a toner with excellent fixing properties at low temperatures, storage stability, and PVC resistance. It is something.

The epoxy resins mentioned above include bisphenol type, novolak type, and hydrogenated bisphenol type.

One type or a combination of two or more types selected from halogenated epoxies, polyfunctional epoxies, etc. can also be used.

In addition, the coumaron-indene copolymer is a product that is produced when coke is manufactured by carbonizing coal, and the polymerization component that is mainly distilled out along with coke oven gas components is catalyzed without fractional distillation. It is preferable to use a resin obtained by polymerizing the resin and having an average molecular weight of 500 to 900. Although the blending ratio with the epoxy resin is not particularly limited, it is preferably 5 to 40% by weight based on the epoxy resin.

If it is less than 5% by weight, fixing properties will not be improved, and if it is more than 40% by weight, offset resistance and storage stability will be poor.

The toner of the present invention is prepared by appropriately blending the above-mentioned resin with auxiliary agents such as a coloring agent, a charge control agent, wax, and a filler, kneading the mixture using a kneader, co-kneader, etc., and pulverizing the mixture.

It can be manufactured by classification.

The coloring agents mentioned above include carbon black, nigrosine, iron black, metal complex dyes, chrome yellow, Hansa yellow, benzine yellow, red red, aniline red, navy blue 1 ultramarine, phthalocyanine blue, etc., and the charge control agents include:
Benzyl dimethyl mexadecyl ammonium chloride, tetrapentylammonium chloride, decyl trimethyl ammonium chloride, nigrosine base, nigrosine hydrochloride, safranin, alkoxylated amine, alkyl acid, ammonium sulfide, etc. Waxes include polyethylene, polypropylene, paraffin , microcrystal wax, hydrogenated wax, carnauba wax, beeswax, polyoxyethylene, natural wax, amide wax, silicone, fluororesin, polyolefin, stearic acid, etc. Fillers include hydrophobic silica, colloidal silica, polysulfone.

All known materials such as fused silica glass powder, clay, clay, wollastonite, titanic acid powder, and fluorine powder can be used.

[Embodiments of the invention]

Hereinafter, the present invention will be specifically explained using examples.

Example 1 63 parts by weight of bisphenol A epoxy resin EP1007 (manufactured by Yuka Shell Co., Ltd.), coumaron-indene resin V12
0 (manufactured by 8 Tetsu Kagaku Co., Ltd., average molecular weight 730), 20 parts by weight, carbon black #44 (Mitsubishi Chemical Co., Ltd. 10 parts by weight), oil black BY (manufactured by Orient Chemical Co., Ltd.) 5 parts by weight, Viscoel 660P (Sanyo Chemical Co., Ltd. 11 parts by weight) ”) Mix 2 parts by weight.

Mixing is performed with a kneader, and after cooling, pulverization and 1 classification are performed.
A toner with a particle size of ~25 μm was obtained.

Mix the obtained toner and carrier to make a developer.
Subjected to the development of an electrostatic charge image created by conventional electrophotography,
Next, the obtained image is transferred onto a transfer paper, and using a fixing roller whose surface is made of Teflon and a pressure roller whose surface is made of silicone rubber, the temperature of the fixing roller is varied to bring the image into pressure contact and fuse the image. After each fixing operation, transfer paper without an image was transferred to the fixing roller under the same conditions in order to investigate whether the fused image would be transferred to the surface of the fixing roller and cause offset development. The transfer paper was brought into pressure contact to aim at stains caused by toner offset on the transfer paper.

As a result, the non-offset range in which the toner offset phenomenon does not occur is 80 to 150°C, and the fixability was determined by a peel test using cellophane tape on the black solid developed area, and the fixability parameters D/D, is 0697
There was no practical problem at all, and the fixing performance was better than conventional heat fixing (0.66). Further, after fixing the image, the vinyl sheet was not contaminated even when it was brought into close contact with a polyvinyl chloride sheet containing 30% dioctyl phthalate at 50° C. for 3 days.

Example 2 Bisphenol A type epoxy resin Ep1007゜68 parts by weight, coumaron-indene resin, T-1051 Nippon Steel Chemical 8
A toner was prepared and tested in the same manner as in Example 1, except that 15 parts by weight (manufactured by Co., Ltd., average molecular weight: 650) was used. As a result, the non-offset range was 80 to 150°C, and the fixing parameter D/D was 0.95. Further, even when the film was brought into close contact with a polyvinyl chloride sheet at 50° C. for 3 days, the vinyl sheet was not contaminated.

Example 3 58 parts by weight of bisphenol A epoxy resin EplO07, 10 parts by weight of novolak epoxy resin ECN1299 (manufactured by Ciba Geigy), and 15 parts by weight of coumaron-indene resin (average molecular weight: 830) were used. A toner was prepared and tested in the same manner as in Example 1. As a result, the non-offset range was 80 to 160°C, and the fixability parameter D/D was 0.98. Further, even when the film was brought into close contact with a polyvinyl chloride sheet at 50° C. for 3 days, the vinyl sheet was not contaminated.

comparative example Styrene/acrylic acid resin (manufactured by Hitachi Chemical).

A toner was prepared and tested in the same manner as in Example 1 using 85 parts by weight, 344.10 parts by weight of carbon black, and 5 parts by weight of oil black BY.

Claims (1)

[Claims] 1. A toner for electrostatic images containing at least an epoxy resin and a coumaron/indene resin.