JPH01116561A - Toner for developing electrostatic image - Google Patents

Abstract

PURPOSE:To obtain a toner for developing an electrostatic image having superior offset preventing effect and having also high storage stability and fixing effect by incorporating a polymer consisting essentially of a specified monomer as binder. CONSTITUTION:A polymer consisting essentially of a monomer expressed by formula I is contained as binder in the title toner. In formula I, R1 is H or methyl group. It is preferred from the viewpoints of fixing effect and offset resistance of produced toner to produce the toner by mixing the monomer (A) expressed by formula I, another unifunctional vinyl monomer (B) copolymerizable with the monomer(A), and another polyfunctional vinyl monomer (C) copolymerizable with the monomer (A) so as to attain the sum of said three kinds of monomers to 100wt.% and polymerizing the monomers, wherein each individual proportion of the monomer (A), (B), and (C) is 1-100wt.%, 99-0wt.%, 0-1wt.% respectively. By this constitution, a toner having high fixing effect in a hot roll fixing and high offset resistance is obtained easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrostatic image developing toner for developing electrostatic latent images in electrophotography, electrostatic recording, and the like.

Methods for developing the entire electrostatic latent image can be roughly divided into liquid development methods and dry development methods. The present invention relates to toner used in the dry development method.

Furthermore, methods for fixing the developed toner particles on a support such as paper include heat roll methods, flash methods, high frequency heating methods, open methods and other heat fixing methods, pressure roll methods, and organic solvent methods. Methods such as this are known. The present invention relates to a toner particularly suitable for a hot roll fixing method.

(Prior art) In recent electrophotographic copying machines, the heat roll fixing method is most commonly used because it has good thermal efficiency, excellent fixing performance, and good 9-image resolution, and the device can be made smaller. ing. In particular, high-speed fixing VcFi and hot roll fixing methods are commonly used. However, in this fixing method, the toner is softened by heating, and a portion of the toner becomes sticky and adheres to the surface of the hot roll. A so-called offset phenomenon occurs.

Conventionally, various fixing devices and fixing methods have been proposed to prevent this offset phenomenon.

For example, a fixing device is used in which the surface of a hot roll is made of a material with excellent mold releasability, such as a fluororesin, and the surface is further coated with an anti-offset liquid such as silicone oil. Although this device is extremely effective in preventing the offset phenomenon, the anti-offset liquid is heated and deteriorates, producing a strange odor. Sixth, a device for supplying the anti-offset liquid is required. The machine became larger,
Another disadvantage is that the structure of the copying machine becomes complicated and high precision is required to obtain stability, making it expensive. For this reason, methods are being considered to prevent the offset phenomenon without requiring any anti-offset liquid or requiring only a small amount to the extent that supply, etc., is not a problem. for example.

JP-A No. 49-65231 describes that the offset phenomenon can be prevented by incorporating a small amount of low molecular weight polypropylene into the toner.

Further, nine different types of binders for toners have been studied. For example, Japanese Patent Application Laid-Open No. 51-23354 describes the use of crosslinkable polymers as binder resins.

Further, JP-A-50-134652 discloses the use of a resin having a large molecular weight distribution as a binder.

In addition, JP-A-58-68752 and JP-A-58
Publication No. 102246 describes that a vinyl polymer obtained by graft copolymerizing a modified epoxy resin having a vinyl group and a polyester resin having a vinyl group is used as a binder.

(Problems to be Solved by the Invention) However, when low molecular weight polypropylene is used as an anti-offset agent, the toner tends to become non-uniform;
It may cause capri and scattering, so it is preferable to use it in as small a quantity as possible. Furthermore, when crosslinking polymers or graft copolymers are used, fixing properties generally decrease, and this tendency is
This is particularly noticeable when fixing at high speeds. By using a resin with a large molecular weight distribution, offset prevention can be achieved without impairing fixing properties, but there are problems in that it is generally not easy to produce such a resin and it is less economical. .

An object of the present invention is to provide a toner that solves problems such as graininess, has excellent fixing properties in a hot roll fixing method, has excellent offset prevention properties, and can be easily manufactured.

(Means for Solving the Problems) The present invention uses a polymer as an essential component of a monomer represented by the general formula (I): (I R1 represents hydrogen or a methyl group) as a binder. It relates to an electrostatic image developing toner containing as follows.

The monomer represented by general formula (1) is produced by a known method. For example, dicyclopentadiene (tricyclo (s, zi, o") decane 3.8 diene) and water are subjected to a water conservation reaction in the presence of a catalyst such as sulfuric acid to form tricyclo (511,0"
λ6]3decene8ol and/or tricyclo(5,2
.

In the present invention, the polymer containing the monomer represented by the general formula +11 is selected from the monomers 1 to 1 represented by the general formula
00 weight, 99 to 0% by weight of other monofunctional vinyl monomers copolymerizable with the monomer represented by general formula +11 and copolymerizable with the monomer represented by general formula (I) It is preferable to mix O to 1 polyfunctional vinyl monomers in a total weight of 100 and polymerize them.

In the present invention, other monofunctional vinyl monomers copolymerizable with the monomer represented by general formula (1) and t, styrene, α-methylstyrene, p-methylstyrene, p- Styrene derivatives such as t-butylstyrene and p-lyrostyrene, 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, methacrylic acid Glycidyl, methoxyethyl methacrylate.

Propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate,
Ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxydipropylene glycol methacrylate, phenoxyethyl methacrylate,
Phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, be/zyl methacrylate, cyclohexyl methacrylate.

Tetrahydrofurfuryl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, N-vinyl-2-pyrrolidone methacrylate, methacrylonitrile, methacrylamide, N-methylolmethacrylamide.

2-hydroxyethyl methacrylate, hydroxyglobyl 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, glycidyl acrylate, methoxyethyl acrylate.

Propoxyethyl acrylate, butoxyethyl acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate.

Methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl acrylate,
Phenoxydiethylene glycol acrylate, phenoxytetate diethylene glycol acrylate, hensyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, acrylumi N-vinyl-2-pyrrolidone, Hydroxyethyl acrylate, hydroxypropyl acrylate.

Hydroxybutyl acrylate, 2-hydroxy-3-phenyloxyglobyl acrylate, glycidyl acrylate, acrylonitrile, acrylamide, N-methylolacrylamide, diacetone acrylamide, vinylpyridine, etc., which have one vinyl group in one molecule Examples include vinyl monomers. Examples of polyfunctional vinyl monomers copolymerizable with the monomer represented by general formula (1) include divinylbenzene, a reaction product of glycol and methacrylic acid or acrylic acid, 2 such as ethylene glycol dimethacrylate, 1 .3-butylene glycol dimethacrylate, 1.4-butanediol dimethacrylate, 1.5
-pentanediol dimethacrylate), 1,6-hexanediol diacrylate.

Neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, triethylene glycol dimethacrylate, hydroxypivalic acid neopentyl glycol ester dimethacrylate, trimethylolethane trimethacrylate.

Trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, trismethacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacrylyloxyethyl)isocyanurate, ethylene glycol diacrylate, 1.3-butylene glycol diacrylate), 1.4-butanediol diacrylate, 1.
5-bentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate,
Triethylene glycol diacrylate, polyethylene glycol diacrylate.

Tripropylene glycol diacrylate, neopentyl hydroxypivalate glycol diacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate.

Pentaerythritol triacrylate, pentaerythritol tetraacrylate, trisacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl in cyanurate, tris(methacryloyloxyethyl) in cyanurate, glycidyl methacrylate and methacrylic acid or acrylic acid. Half-esterified products, half-esterified products of bisphenol-type epoxy resin and methacrylic acid or acrylic acid, half-esterified products of glycicyl acrylate, methacrylic acid, or acrylic acid, etc.
Examples include vinyl monomers having two or more VC vinyl groups in the molecule.

Among these, preferred vinyl monomers are monofunctional vinyl monomers such as styrene, styrene derivatives,
methacrylic esters, acrylic esters, etc.
Particularly preferred are styrene and alkyl esters of methacrylic acid or acrylic acid having 1 to 5 carbon atoms in the alkyl group.

Preferred polyfunctional vinyl monomers having two or more vinyl groups in one molecule include divinylbenzene, dimethacrylates and diacrylates of alkylene glycols having 2 to 6 carbon atoms, and the like.

In the present invention, monomers of general formula (1) or general formula (1
) monomer and a vinyl monomer copolymerizable with
Radical polymerization occurs in the presence of a radical initiator.

Examples of radical initiators include benzoyl peroxide,
tert-butyl perbenzoate, 2-ethylhexyl perbenzoate, acetyl peroxide, inftiryl peroxide, te
rt-butyl peroxyisobutyrate, octanoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, tert-butyl peroxy-2-ethylhexanoate, cumene hydroperoxide, methyl ethyl ketone peroxide, 4,4゜6-dolimethyl Cyclohexanone di-tert-butyl peroxyketal, 1.1-
Bis(t-butylperoxy)-33,5-)limethylcyclohexane.

Cyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, cyclohexanone di-tert-butyl peroxyketal, acetone di-tert-butyl peroxyketal,
Peroxide-based radical initiators such as diimpropyl hydroperoxide, 2,2'-azobisisobutyronitrile,
42'-azobis(4-dimethylvaleronitrile),
2.2'-azobis(4-methoxyse-4-dimethylvaleronitrile).

Dimethyl 42'-azobisisobutyrate, 1. Examples include azobis-based radical initiators such as r-azobis(cyclohexane-1-carbonitrile). The radical initiator is preferably used in an amount of 0.01 to 15% by weight based on the total monomers.

A chain transfer agent can be appropriately added during polymerization.

Chain transfer agents include alkyl mercaptans such as t-dodecyl mercaptan, lower alkyl xanthogens such as diisopropyl xanthogen, carbon tetrachloride, carbon tetrabromide, etc., and are used in amounts of 0 to 3% by weight based on the total monomer. It is preferable to

The polymer in the present invention is suspension polymerized or solution polymerized.

It can be produced by emulsion polymerization, bulk polymerization, or any known polymerization method. Among these polymerization methods.

Partially saponified polyvinyl alcohol, alkylcellulose, hydroxyalkylcellulose, carboxyalkylcellulose, polyacrylamide.

Water-soluble polymer dispersants such as polyvinylpyrrolidone, polyacrylic acid and its alkali metal salts, polymethacrylic acid and its alkali metal salts, calcium phosphate, hydroxyapatite, magnesium phosphate.

An aqueous suspension polymerization method using a sparingly soluble inorganic dispersant such as magnesium pyrophosphate, calcium carbonate, barium sulfate, or hydrophobic silica is preferred from the viewpoint of economy, stability during production, and the like.

In the present invention, the binder is only one or two of the above polymers.
Although the resin contains at least one species, it may also be a polymer mixture of the above polymer and other resins.

Other resins include styrene resin, acrylic resin,
Styrene-acrylic resin, silicone resin.

Polyester carbonate resin, xylene resin.

Epoxy resin, phenolic resin, diene resin.

There are coumarone resins, amide resins, amino resins, urethane resins, etc.

In the present invention, when the binder is a polymer mixture containing two or more types of polymers as constituent components, methods for mixing them include (a) a method of heating, melting, and kneading separately produced polymers; , (b) a method of mixing separately produced polymers in a solution state, and (c) a method of producing another polymer in the presence of the polymer.

Among these, method (c) is preferred because it allows more uniform mixing.

In the present invention, the binder has a dispersity of 2 to 60. It is preferable to adjust the glass transition point from 40 to 80''eK.The weight average molecular weight and number average molecular weight are measured using a standard polystyrene calibration curve in gel permeation chromatography.

In the present invention, a coloring agent and/or magnetic powder and, if necessary, other additives such as a charge control agent may be appropriately added to the binder.

As the colorant, conventionally known pigments or dyes such as carbon black, iron oxide pigment, phthalocyanine blue, phthalocyanine riff, H-tamin 6G lake, watching red barium, watching red strontium, etc. can be used, and I/c1 in the toner can be used. It is selected and used as appropriate in the range of ~60 weights.

Magnetic powder is used when manufacturing magnetic toner. Magnetic powders include iron, manganese, and nickel.

Metal powders such as cobalt, iron, manganese, and nickel.

There are ferrites such as cobalt and zinc, and the average particle size is 1.
It is preferably 0 μm or less, especially 1 μm or less9 Usually,
It is used in toners in amounts of 1 to 80% by weight. 9. When using colorant and magnetic powder together.

Either one may be less than 1% by weight.

Charged i! 1. Nigrosine dyes, fatty acid-modified nigrosine dyes, metal-containing nigrosine dyes, metal-containing fatty acid-modified nigrosine dyes, chromium complexes of &5-di-tert-butylsalicylic acid, etc. can be used as the conditioner. 2. Usually, KO ~ Use 20% by weight.

Other additives include silica powder, hydrophobic silica powder, polyolefin, paraffin wax, fluorocarbon compounds, fat a! ester.

Partially saponified fatty acid esters, fatty acid metal salts, etc. can be used, and these usually have a KO to 10% in the toner.
Used in amounts of % by weight.

A toner for developing an electrostatic image can be produced by mixing these materials, for example, by the following method.

After premixing the weighed materials using a W cone, blender, Henschel mixer, etc., cross-mixing is performed using a pressure kneader, Banbury mixer 2 hot roll, extruder, etc. at a temperature that melts the binder. After cooling, it is coarsely pulverized using a feather mill, bottle mill, pulverizer, hammer mill, etc., and then finely pulverized using jet air. Next is AccuCut.

Sieve with an Albine classifier, preferably 5 to 30μ
Adjust the particle size to m. Note that a fluidity modifier such as silica powder can also be simply mixed.

(Example) Next, the present invention will be described in detail based on examples.

The present invention is not limited to this.

Examples 1 to 4 and Comparative Example 1 (1) Synthesis of copolymer 31! A cylindrical separable flask was equipped with a stirrer equipped with a stirring blade, a cooling tube, a gas introduction tube, and a thermometer, and 1500 parts by weight of ion-exchanged water was placed in the flask.

75 parts by weight of Supertite 10 (trade name of a hydroxyapatite water dispersant manufactured by Nippon Kagaku ■) and 9 parts by weight of a 1 weight 96 sodium dodecylbenzenesulfonate aqueous solution were added.

Weigh out the monomers and radical initiator in the formulation (■) shown in Table 1, and mix them to create 3I! into a separable flask.

Start flowing nitrogen gas and stir at room temperature for about 30 minutes.

Stabilized dispersion. Subsequently, the temperature was raised to 90°C over about 1 hour, and the mixture was stirred for 4 hours.

The mixture was stirred at 95°C for 2 hours and cooled to 50°C.

Next, the monomers and radical initiator in the formulation (1) shown in Table 1 were weighed, mixed, and placed in a separable flask (31) containing the polymer (1). After stirring at 50°C for 1 hour, the temperature was raised to 90°C, the temperature was further raised to 95°C for 4 hours, and the mixture was allowed to react at 95°C for 3 hours.
Polymerization was completed. Then, while stirring, 506
c, and add 20 parts by weight of concentrated hydrochloric acid to adjust the pH of the aqueous phase.
'li-3 or less. This was filtered under reduced pressure, washed three times with 1000 parts by weight of ion-exchanged water, and then dried overnight in a dryer at 50°C to obtain copolymer beads having the properties shown in Table 1.

Note that the glass transition point indicates the endothermic start point (° C.) measured by a differential scanning calorimeter (DSC).

(2) Production of toner and developer Copolymer 4509. Car pump rackener 44 (manufactured by Mitsubishi Chemical Corporation) 409. 10 g of Viscol 550P (a trademark of low molecular weight polypropylene manufactured by Sanyo Chemical Industries, Ltd.) and 259 g of Oil Black BY (nigrosine dye, manufactured by Orient Chemical Industries, Ltd.) were heated and melted and kneaded using a T-Conida mixed wire system, and then coarsely pulverized using a thermos mill. , finely ground using a jet air mill. This was classified into two particles with a diameter of 5 to 30.
μm.

A toner with an average particle size of 14 μm was obtained.

Next 11C, this) +-50g and EFV200/300 (
A developer was prepared by mixing Nippon Iron Powder 9509 and shaking it thoroughly.

(3) Evaluation of toner (a) Storage stability Toner of approximately 5 g was stored in a constant temperature and humidity chamber at 55° C. and humidity of 90° C. for 24 hours so that the toner had a uniform thickness in a glass petri dish. This was passed through a 't-100 mesh wire gauze, and the weight of the product passing through was measured, and the weight was evaluated based on the following criteria.

5: Passed 95 weight or higher 4 Near 0 weight % or higher Passed 95 weight or higher 3:30 #
#70 1 #2:5# #30
## 1: Passed less than 5 weight (b) Fixability and anti-offset developer was put into a tester modified from a copying machine 5F755 (manufactured by Sharp ■), and the top 1/3 of the A4 size plate was undetermined as black. I made a picture of myself wearing it.

This unfixed image was tested by changing the temperature in a 10°C range from 100°C to 240°C using a Teflon roll fixing tester and fixing it at a linear speed of 900 cm/min (A4 size, approximately 30 sheets/min). .

The fixing temperature was set to the minimum temperature at which the cellophane tape was peeled off at the fixing point peta portion and the ij image density change rate was 1 (l or less).The offset occurrence density was as follows.

The lowest temperature was set at which the image density (ID) of the white paper portion where the offset of the black pixel area occurred was 0.24 or more compared to the black pixel portion.

(C) Put the actual copying test developer into a copying machine 5F755 (manufactured by Sharp ■),
A continuous copying test of 500 sheets was conducted, and the initial image and changes in the image were observed.

The evaluation results of the toner are shown in Table 2 below.

Occasionally, offset occurred and the back side of 9 sheets was stained.

(Effects of the Invention) As is clear from the above results, the toner for developing electrostatic images according to the present invention has excellent storage stability and fixing properties, and is also excellent in anti-offset properties.

It can be easily manufactured.

Agent: Patent Attorney Kunihiko Wakabayashi

Claims (1)

[Claims] 1. General formula (I): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents hydrogen or a methyl group) A monomer shown as an essential component A toner for developing electrostatic images containing a polymer as a binder. 2. The polymer contains monomers 1 to 1 represented by the general formula (I)
00% by weight, 99-0% by weight of other monofunctional vinyl monomers copolymerizable with the monomer represented by general formula (I)
A polymer obtained by blending and polymerizing 0 to 1% by weight of a polyfunctional vinyl monomer copolymerizable with the monomer represented by general formula (I) so that the total amount is 100% by weight. A toner for developing an electrostatic image according to claim 1.