JPS60238846A - Electrostatic image developing toner and its preparation - Google Patents

Abstract

PURPOSE:To render toner particle diameter uniform and to enhance fluidity by polymerizing a polymerizable compsn. comprising at least a polymerizable monomer, a colorant, and a satd. polyester to form an electrostatic developing toner. CONSTITUTION:The electrostatic image developing toner is obtained by polymerizing a polymerizable compsn. prepared by mixing at least a polymerizable monomer, a colorant, and a satd. polyester. A preferable amt. of the satd. polyester to be added is 0.1-10wt%, especially, 1-7wt%. As the polymerizable monomer, such as o-methylstyrene, m-methylstyrene, and p-methylstyrene, and used. The mol.wt. of the polymer to be formed is optional, but a weight average mol.wt. of 50,000-1,000,000 is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner for developing electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, etc., and a method for manufacturing the same.

[Prior art]

In image recording methods that utilize electrostatic phenomena such as electrophotography, photoconductive photoreceptors such as selenium, silicon, acid, zinc oxide, cadmium sulfide, and various organic compounds with photoconductivity are used. The electrostatic image formed on the electrostatic image carrier is developed by attaching fine particles called toner consisting of a coloring agent, binder resin, etc. by electrostatic attraction, and developing the resulting toner image as it is or on paper etc. Usually, the image is transferred onto a support and fixed by a fixing process to obtain the desired recorded matter.

Development is roughly divided into two types: methods using a so-called two-component developer made of a mixture of a carrier made of magnetic powder and toner, and methods using a so-called one-component developer made only of toner containing a magnetic material. In either case, the toner is required to have fine particles, uniform particle size, and good fluidity.

In addition, a heat fixing method is widely used to fix toner images, in which the toner image is heated by various means to melt the binder resin and fix it to the support.The heating means involves rotating the support carrying the toner image. The most commonly used method is to pass the fixing roller between a pair of fixing rollers consisting of a heat roller and a pressure roller. In this case, since the toner is melted by directly contacting the heat roller, it is necessary that the toner can be melted and deposited at a relatively low temperature, and that the molten toner is difficult to adhere to the fixing roller.

The toner used in the above development method is conventionally made by mixing a binder resin and a coloring agent, kneading the mixture in a molten state for a long time using an extruder, etc., cooling the resulting mixture to room temperature, and then mixing it with the coloring agent necessary for the toner. It is manufactured through complicated processes such as pulverization into fine particles, further classification to make the particle size uniform, and in some cases, sphericalization of the particles by hot air treatment.

The toner manufacturing method described above requires melting, cross-mixing, and pulverization processes, so the toner materials, that is, the mixture of resin, colorant, charge control agent, etc., must be fluidized at an appropriate temperature so that they can be mixed uniformly. It is required that the particles be easily pulverized to a desired particle size. However, if a material that is easy to crush is used, it will be further crushed in the developing device during use, resulting in dirty equipment and fogging of the image, and if a material that is simply easy to melt is used, the toner will become caked or photoconductive. Problems such as easy formation of stains (toner filming) on the surface of the layer occur, and there is a problem in that the selection of the resin is severely restricted. Furthermore, it is difficult to completely uniformize the distribution of the charge control agent or the like within the particles by crosstalk alone, resulting in drawbacks such as unstable charging properties of the toner particles.

In order to solve these problems, for example,
JP 231, JP 47-51830, JP 51-14895, JP 53-17735, JP 53-17736, and JP 53-1
A production method using a polymerization method as disclosed in Japanese Patent No. 7736 has been proposed. Toner production by the polymerization method involves mixing colorants, polymerization initiators, other additives, etc. into polymerizable monomers, which are the materials for the binder resin, and homogenizing them to form a polymerizable composition. The method aims to obtain toner by polymerizing polymers to form a binder resin,
All of the above proposals involve a suspension polymerization method in which a polymerizable composition is dispersed and suspended in an aqueous medium and then polymerized to directly obtain a toner.

This method solves some of the problems in the kneading and pulverizing methods mentioned above, and also has the advantages that the resulting toner particles are spherical and have good fluidity, the manufacturing process is simple, and the cost is low. have However, polymerizable compositions tend to agglomerate in suspension, and especially when additives such as carbon black as a coloring agent or charge control agent are added, the suspension state becomes unstable and many This method has a major disadvantage in that aggregates are formed and the yield of the desired fine powder toner is significantly reduced.

[Purpose of the invention]

The purpose of the present invention is to provide a high-performance electrostatic image developing toner (hereinafter also simply referred to as toner) with uniform particle size and good fluidity.
Another object of the present invention is to provide a new toner manufacturing method capable of manufacturing the above-mentioned toner stably and with a high stroke rate. .

[Structure of the invention]

The above object is a toner obtained by polymerizing a polymerizable composition comprising at least a polymerizable monomer, a colorant and a saturated polyester, and a polymerizable composition comprising at least a polymerizable monomer, a colorant and a saturated polyester. This was achieved by a toner manufacturing method that includes a step of polymerizing.

When producing toner by cloud polymerization (as described above), agglomeration of the suspended polymerizable composition oil portion causes a decrease in yield. The present invention was based on the discovery that the presence of saturated polyester in the suspension is extremely effective in stabilizing the suspension.

Any saturated polyester useful in the present invention can be used as long as it is soluble in the polymerizable monomer. Although its mechanism of action is not clear, it is presumed that the presence of ester functional groups in the saturated polyester plays an important role.

Therefore, Bossester resins consisting of a wide variety of polybasic acids and polyhydric alcohols can be used. For example, acid component monomers include terephthalic acid, isophthalic acid,
Phthalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, ayalaic acid, sebacic acid, camphoric acid, cyclohexanedicarboxylic acid, trimethic acid, etc. are useful as alcohol component monomers. is ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1
．． Alkylene glycols and polyalkylene glycols such as 3-propylene glycol, 1,4-phthanediol, neopentyl glycol, 1,4-bis(hydroxymethyl)cyclohexane, bisphenol A,
Hydrogenated bisphenols, ethylene oxide adducts of bisphenols, propylene oxide adducts of bisphenols, glycerin, trimethylolpropane, pentaerythritol, etc. are useful, and saturated polyester resins obtained by any combination of these are:
It can be effectively used as long as it is soluble in the polymerizable monomer used in the present invention.

The amount of the saturated polyester added is preferably 0.1 to 10 weight percent, particularly preferably 1 to 7 weight percent, based on the polymerizable monomer used. If this amount is less than 0.1 weight percent, the effect is not achieved, and if it exceeds 10 weight percent, the polymerization becomes unstable due to the influence of the terminal functional groups of the polyester, which is not preferable.

Examples of the polymerizable monomer that can be used in the present invention include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene,
p-etherstyrene, 2,4-dimethylstyrene, p-
n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p,-n-dodecylstyrene, D -methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3.
Preferred examples include styrene monomers such as 4-dichlorostyrene. In addition, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and imbutylene; vinyl chloride, vinylene chloride,
Vinyl halides such as vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acid, vinyl propionate, vinyl benzoate, and vinyl butyrate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate , propyl acrylate, n-octyl acrylate,
Dodecyl acrylate, lauryl acrylate, 2-ethyl/~xyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, σ-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, methacrylate Propyl acid, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacrylate α-methylene resin group monocarboxylic acid esters such as dimethylaminoether acrylate and diethylaminoethyl methacrylate; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; vinylmethylnitrile, vinyl ethyl ether, vinyl Vinyl ethers such as isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl xyl ketone, methyl isopropenyl ketone; N-vinylvirol, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone, etc. (1') N - Examples include vinylnaphthalenes and others. This can be used, or the combination can be polymerized to give a copolymer.

For the polymerization of vinyl monomers as described above, a polymerization initiator is usually used in an amount of 0.5 to 10% by weight based on the polymerizable monomer. Specific examples of typical polymerization initiators include acetelcyclohexylsulfonyl peroxatide, isodibutyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl oxydicarbonate, and 2,4-dichlorobenzoyl. Peroxide, t-butyl peroxypivalate, 3.5
．． 5-trimethylhexanoyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, nutaroyl peroxide, propionyl peroxide, succinic acid peroxide, acetyl peroxide, t-butyl peroxy-2-ethyl Hexanaut, benzoyl peroxide, parachlorobenzoyl peroxide, t
-Butelperoxyisopterate, t-butylperoxymaleic acid, t-butylperoxylaurate, cyclohexanone peroxide, t-buterperoxyisopropyl carbonate, 2,5-dimethyl-2,5-dibel Silver oxyhexane, t-butyl peroxyacetate, t-bucarboxybenzoate, diisobutel diperoxyphthalate, methyl ethyl ketone peroxide, dicumyl peroxide 2,5-dime% #-2,5-di t-butyl Peroxyhexane, t-butylcumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di-t-butyl peroxyhexane, diisopropylbenzene hydroperoxide, Paramenthane hydroperoxide, vinylane hydroperoxide, 2.5-dimetheterhexane-2.
Peroxide initiators such as 5-dihydroperoxide and cumene hydroperoxide, 2.2'-azobisisobutyronitrile, 1.1'-azobis(cyclohexane-1-carbonidimethylvaleronitrile, 2.2 '
Examples include azo initiators such as -azobis-2,4didimethylpaleronitrile.

In carrying out the method of the present invention, a plurality of polymerization initiators having different radical half-lives can be used. In this case, at a certain polymerization temperature, a polymerization initiator with a short half-life forms a so-called rapid initiation system, and a polymerization initiator with a long half-life forms a so-called slow initiation system, so that polymerization occurs in a rapid initiation system. A polymer with a low degree of polymerization and a low molecular weight is formed, and at the same time a polymer with a high degree of polymerization and a high molecular weight is formed in the slow initiation system. According to a toner made of a polymer consisting of a low molecular weight polymer portion and a high molecular weight polymer portion, the minimum fixing temperature is low due to the low molecular weight polymer portion, and the offset generation temperature is high due to the high molecular weight polymer portion. becomes.

Preferred examples of polymerization initiators with short half-lives include 2.2
'-azobis-4-methoxy-2,4-dimethylonitrile-2,27-azobis-2,4i) methylpaleronitrile, etc., and it is also suitable as a polymerization initiator with a long half-life. Examples include 1°1'-azobis(cyclohexane-1-carbonitrile).

As a coloring agent, carbon black, nigrone dye (
a, LP&L5041.5), Aniline Blue (C
I.

Nu50405 Eight Calco Oil Blue (0,1,Naa
zoicBlue3), Kurumi x o -(0,:[
, N114090), ultramarine glue (C,1
, floor 77103), DuPont Oil Red (a, r,
26105 ), quinoline yellow ((:!, 1.N
α47005), methylene blue chloride (c, ■
, N (L52015), lid crv animbu/L/
-(c, ■.

N[L74160), malachite green ocunarate 1.1. Sui 42000), Lamp Black (C!, I
.

77266), Rose Bengal (C, 1, porcelain 454
35), mixtures thereof, and others.

These colorants need to be contained in a sufficient proportion to form a visible image of sufficient concentration, and are usually contained in a proportion of about 1 to 20 parts by weight per 100 parts by weight of the binder resin. be done.

Although the molecular weight of the polymer according to the present invention is arbitrary, the weight average molecular weight is preferably 50,000 to 1,000,000.
and the number average molecular weight is 1,000-1.00,000
There is.

The polymer according to the present invention may be polymerized in the presence of a crosslinking agent to form a crosslinked polymer. Preferably used crosslinking agents are mainly compounds having two or more polymerizable double bonds, such as aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof, such as ethylene glycol dimethacrylate, diethylene glycol methacrylate. , triethylene glycol methacrylate, trimethylolpropane triacrylate, allyl methacrylate, t-butylaminoether methacrylate, tetraethylene glycol dimethacrylate, ■, diethylene carboxylic acid esters such as 3-butanediol dimethacrylate, N, N
All divinyl compounds such as didonylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, and compounds having three or more vinyl groups are selected singly or as a mixture.

The amount of such a crosslinking agent added to the monomer is selected to be in the range of 0.005 to 20% by weight, preferably 0.1 to 5% by weight.

If the amount added is too large, the toner will not melt and will tend to lose its fixing properties as a toner. In addition, if the amount is too low, it becomes difficult to impart toner properties such as durability, storage stability, and abrasion resistance, and the molecular weight distribution of the polymer expands due to crosslinking and as a result, especially in hot roll fixing type copiers, etc. Due to the properties of the toner itself, it becomes difficult to achieve the effect of preventing the offset phenomenon during fixing.

Further, the toner of the present invention can contain a low molecular weight olefin polymer known as a so-called mold release agent.

A prepolymer (particularly a reactive prepolymer) may be added to the toner of the present invention during the polymerization process for the purpose of improving fixing performance such as anti-offset effect. The reactive prepolymer has a reactive group in the main chain and/or side chain of the prepolymer, and examples of the prepolymer 2 include unsaturated polyester, unsaturated polybutadiene, and the like.

When the polymerizable composition is polymerized by a suspension polymerization method, the polymerized composition is dispersed and suspended in a dispersion medium such as water as dispersed particles of a desired particle size by mechanical stirring, and the polymerization is carried out. It is necessary to prevent the dispersed particles from coalescing into large particles due to increased stickiness as the polymerization progresses, and a suspension stabilizer is used for this purpose. ~ Such suspension stabilizers are generally classified into water-soluble polymeric substances and fine powders of poorly soluble inorganic compounds; the former includes gelatin, starch, polyvinyl alcohol, etc., and the latter includes are sparingly soluble salts and sparingly soluble salts such as barium sulfate, calcium sulfate, barium carbonate, calcium carbonate, and calcium lanate; surfactants such as sodium dodecylbenzene sulfonate and sodium dodecyl sulfate; Includes inorganic polymer substances such as diatomaceous earth, metal oxides, and other powders. In addition, when the polymer composition contains an ionic substance, for example, a cationic substance or anionic substance such as a nitrogen-containing polymerizable monomer or poorly water-soluble amines, the dispersed particles have a positive effect when dispersed in water. Or, in the case of being charged to one negative polarity, use an ionic dispersant that charges to the other polarity when dispersed in water, such as negatively charged colloidal silica, positively charged aluminum oxide, etc. It can be effectively used as a turbidity stabilizer.

In addition to these, the toner of the present invention may also contain magnetic materials, if necessary.
A charge control agent, a dispersant, etc. can be contained.

Magnetic materials include ferrite, magnetite, iron, cobalt, nickel, and other ferromagnetic metals or alloys, or compounds containing these elements, or materials that do not contain ferromagnetic elements but can be made ferromagnetic by applying appropriate heat treatment. Mention may be made of alloys which become magnetic, such as alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, or chromium dioxide, among others.

Furthermore, various known charge control agents, such as nigrosine dye, etc., may be added to the toner according to the present invention in order to adjust its friability.

In order to produce the toner according to the present invention by a suspension polymerization method, the above-mentioned saturated polyester, a colorant,
Add a heavy initiator, and if necessary, add a crosslinking agent, mold release agent,
Add additives such as a charge control agent, mix and homogenize using a sand stirrer to form a polymerizable composition, add this to an aqueous medium containing a suspension stabilizer, and disperse and suspend using a high-speed stirrer or the like. The polymerization reaction is allowed to proceed by adjusting temperature conditions, etc.

The polymerizable composition suspended in the form of fine oil droplets in the medium is polymerized and solidified as it is without agglomerating due to the effects of the saturated polynis glue added in advance to obtain spherical resin particles. The obtained resin particles may be further pulverized to obtain a toner of the desired particle size. However, since the particle size of the resin particles is determined by the dispersion state of the suspended polymerizable composition, the dispersion conditions must be adjusted in advance to obtain the desired toner size. It is preferable to suspend the resin particles so as to have a particle size, so that the obtained resin particles can be used as they are as a toner.

The toner of the present invention is mixed with a carrier made of iron powder, glass beads, etc. to make a two-component developer, but when it contains a magnetic material, it can be used as is for developing electrostatic images as a one-component developer. .

〔Example〕

The present invention will be specifically explained below with reference to Examples, but the embodiments of the present invention are not limited thereto. Note that the numbers in this example represent parts by weight unless otherwise specified.

Example 1 90 parts of styrene, 10 parts of n-butyl acrylate "Mitsubishi Carbon Black ÷ 30" (manufactured by Mitsubishi Chemical Industries (M)) 10 parts
part, low molecular weight polypropylene 1-viscol 550PJ
(10 parts manufactured by Mitsubishi Chemical Industries, Ltd., saturated polyester [
Byron 200J (Toyobo (manufactured by m) 3 parts, 2.2'
-7:/'bis(2,4-dimethylvaleronitrile)3
4% of this was mixed well to form a polymerizable composition, and 4% of this was added to an aqueous medium containing 3% by weight of calcium phosphate and sodium babsylbenzene sulfonate of 3% by weight of ODA in an amount of 30 cents. , using a homojetter (manufactured by Tokushu Kika Kogyo Co., Ltd.) at a rotation speed of 9.00.
The mixture was stirred at a stirring speed of Or, plm. The particle size range of the dispersed particles after stirring for 30 minutes was 10-15 microns. Thereafter, the temperature was raised to 50 DEG C., and the polymerization reaction was carried out for 20 hours while stirring at a stirring speed of 100 rpm using a conventional stirrer to complete the polymerization.

After completing the loading, the solid matter was separated and dried, and then passed through a classifier to remove particles with a particle size of 5 microns or less and 15 microns or more to obtain the toner of the present invention having an average particle size of 12 microns.

Example 2 A toner of the present invention was obtained in the same manner as in Example 1 except that "Vylon 200" in Example 1 was replaced with a different type of saturated polyester [Vylon 103J (manufactured by Toyobo Co., Ltd.)] .

Example 3 A toner according to the present invention was obtained in the same manner as in Example 1 except that ``1 Pylon 200'' in Example 1 was replaced with another type of saturated polyester [Vylon 300J (manufactured by Toyobo Co., Ltd.)].

Example 4 A toner was obtained by replacing ``Vylon 200'' in Example 1 with another type of saturated polyester ``Vylon 500''.

Example 5 The present invention was carried out in the same manner as in ``Execution example'' except that 85 parts of styrene and 15 parts of n-butyl acrylate were used as polymerizable monomers, a crosslinking agent ethylene glycol dimethacrylate was added, and the reaction temperature was 60°C. I got toner by.

Example 6 A toner according to the present invention was obtained in the same manner as in Example 5 except that "Byron 500" was used instead of "Byron 200 j."

Example 7 Stain ys2s, 18 parts of n-butyl acrylate, 3010 parts of Mitsubishi Carbon Blackna, Viscoel 550P
10 parts, 2,2'-azobis(2,4-dimethylvaleronitrile) 0.8 parts, 1.1'-azobis(cyclohexane 1-carbonitrile) 0.2 parts, Byron 2
A toner according to the present invention was obtained in the same manner as in Example 1, except that 0.005 parts was used and the reaction was carried out at a reaction temperature of 85° C. for 20 hours.

Example 8 Byron 200 was replaced with Byron 3005 parts, 2,2'
-Azobis(4-methoxy-2,4-dimethylvaleronitrile) 1.8 parts, azobinuisoptilonitrile 0
．． Example 7 except that 4 parts were used and the reaction temperature was 65°C.
A toner was obtained in the same manner as in -.

Example 9 Saturated polyester resin obtained from ethylene glycol terephthalate (JIS-2
A toner was obtained in the same manner as in Example 1, except that 3 parts of a glass transition gelatin (130° C., 61° O.) was used according to the ring and ball method according to 581.

Example 10 Saturated polyester resin obtained from adipic acid and diethylene glycol (softening point 125) instead of Vylon 200
A toner was obtained in the same manner as in Example 7 except that 3 parts of the toner (glass transition temperature: 48°C) was used.

Example 11 A toner was obtained in the same manner as in Example 8, except that Vylon 300 was replaced with 5 parts of saturated bo9,-1 ster obtained from isophthalic acid and bisphenol A.

Comparative Example 1 A comparative test was conducted in the same manner as in Example 1 except that Byron 200 was not used.

Comparative Example 2 A comparative test was conducted in the same manner as in Example 7 except that Byron 200 was not used.

In Examples 1 to 11 in which the saturated polyester was added to the polymerizable composition according to the present invention, the suspension was extremely stable, and the fine oil droplets of the polymerizable composition were retained throughout the entire period of the polymerization reaction and polymerized as they were. On the other hand, in the case of Comparative Examples 1 and 2, which did not contain saturated polyester, the polymerizable composition was poorly dispersed. This occurred frequently, and an extremely large number of coarse particles were removed when the obtained toner was classified. The toner yield in each of the Examples and Comparative Examples, that is, the ratio of the toner weight after removing particles with a particle size of 5 microns or less and 1:5 ton or more by classification and the polymerizable composition used is the first. It was as shown in the table.

It is clear that the yields of the toners of Examples to 11 according to the present invention are all extremely high, whereas the yields of the toners of Comparative Examples 1 and 2 are significantly low.

2 parts by weight of each toner obtained by classification and 98 parts by weight of magnetic carrier
Prepare a developer by mixing parts by weight and use it in an electronic copying machine U-Bix.
1600 and a copying test was conducted, clear images were obtained with each toner, and no tendency to deteriorate the development characteristics of the toner with the addition of saturated polyester was observed.

[Effect of discovery]

By adding a saturated polyester to the polymerizable composition of the present invention, it has become possible to obtain a toner for electrostatic image development with high fluidity and uniform particle size in a high yield and in a stable manner.

Agent Patent Attorney No 1) Parent-in-law

Claims (1)

[Scope of Claims] α) A toner for electrostatic image development, characterized in that it is obtained by polymerizing a polymerizable composition comprising at least a single polymerizable colorant and a saturated polyester. (2) The electrostatic image development according to claim 1, wherein the content of the saturated polyester in the polymerizable composition is 0.1 to 10% by weight of the polymerizable monomer. toner. G) Electrostatic image development according to claim 1 or 2, wherein the polymerization of the polymerizable composition is carried out by suspending the polymerizable composition in an aqueous medium. toner. (4) A method for producing an electrostatic image developing toner, which comprises the step of polymerizing a polymerizable composition comprising at least a polymerizable monomer, a colorant, and a saturated polyester. (2) The electrostatic image developing device according to claim 4, wherein the content of the saturated polyester in the polymerizable composition is 0.1 to 10% by weight of the polymerizable monomer. Toner manufacturing method. (6) Electrostatic image development according to claim 4 or 5, wherein the polymerization of the polymerizable composition is carried out in a state where the polymerizable composition is suspended in an aqueous medium. method for producing toner for use in