JPS61198248A - Toner - Google Patents

Abstract

PURPOSE:To form a toner good in pulverizability, rich in producibility, high in mechanical strength, and good in durability by specifying a mixing ratio of a positively triboelectrifiable resin to an org. carboxylic acid, and a ratio of a triboelectrification amt. of positively triboelectrifiable resin to that of a low triboelectrifiable resin. CONSTITUTION:An electrostatic charge developing toner contains the resin having a positively triboelectrifiable characteristic, the org. carboxylic acid, preferably, 12-30C fatty acid metal salt, such as lauric acid, in an amt. of 0.1-5pts.wt. per 100pts.wt. of the former resin, and the low tribo-electrifiable resin having triboelectrifiable amt. T2(muc/g), ¦T2¦<=1/5¦T1¦, where T1 is that of the former resin. A neutral resin, preferably, such as polystyrene, is used, preferably, in an amt. of 5-70wt% of the total resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic charge developing toner, and more particularly to a substantially non-magnetic positively charged toner used in electrophotography and the like.

Conventionally, developing methods for electrophotography, electrostatic recording, etc. are broadly classified into dry developing methods and wet developing methods. The former is
The method is further divided into two types: a method using a two-component developer and a method using a -component developer. Two-component developing methods include a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, etc., depending on the type of carrier for conveying the toner.

In the two-component development method, a mixed developer of carrier particles and toner particles is inevitably used.1 Because toner particles are consumed in much larger quantities than carrier particles during the normal development process, the mixing ratio of the two is This method has drawbacks such as the density of the suspended image fluctuates and the image quality deteriorates due to deterioration due to long-term use of carrier particles that are difficult to consume.

Furthermore, if toner that is not sufficiently triboelectrically charged is generated due to a change in the toner carrier mixing ratio, the toner contacts the front surface of the surface to be developed, that is, the image area and the non-image area indiscriminately. There was a problem in that it adhered to the surface and was easily absorbed, resulting in so-called soil burr and dirt.

Furthermore, since toner, which is substantially non-magnetic, can only be restrained by electrostatic attraction or physical adhesion, it often tends to stain the inside of the device or the image due to scattering or spillage.

An object of the present invention is to eliminate the above-mentioned problems and provide a toner that can maintain sufficiently stable triboelectric charging properties even against fluctuations in the mixing ratio of toner and carrier and fluctuations in the environment such as temperature and humidity. be.

A further object of the present invention is to provide a toner that has less tendency to contaminate images due to toner scattering and spillage.

Another object of the present invention is to provide a toner that has good crushability, high productivity, mechanical strength, and durability.

Another object of the present invention is to provide a toner that does not damage or contaminate the surface of a photoreceptor.

That is, an object of the present invention is to provide a toner for developing electrostatic images containing at least a positively charged resin having positive triboelectric charging properties, an organic carboxylic acid salt, and a low triboelectric charging resin.

(a) 0.1 to 5 parts by weight of the organic carboxylic acid salt is contained with respect to 100 parts by weight of the positively charged resin, and (b) the triboelectric charge amount of the positively charged resin is Tt (pc/ g
), the amount of triboelectric charge T2 of the low frictionally chargeable resin
(le c/g) is the formula IT21! - The resin must satisfy ITtl.

An object of the present invention is to provide an electrostatic charge developing toner characterized by the following.

In a developing method using toner and carrier, the interaction between the toner and carrier is extremely important.

That is, in order for the toner to be uniformly charged, the frictional charging between the toner and the carrier must be rapid and large in quantity to some extent.However, if the quantity is too large, it may cause problems during development. It is difficult to separate from the carrier, resulting in a decrease in image density.Also, even though the top toner appears to be uniformly charged, there are microscopic variations in the amount of triboelectric charge and toner with charge leakage. Doing so may cause an increase in soil smearing and toner scattering.

That is, as a result of intensive research aimed at solving the above-mentioned problems, the present invention has found that good results can be obtained when a toner that satisfies the above-mentioned conditions is used.

That is, by locally increasing the triboelectric charging ability of the standard positively charging resin by adding an organic acid salt such as a fatty acid salt, the resin can be considered to be substantially neutral while improving the charging ability due to contact friction with the carrier. It is thought that the addition of 20% dilutes the entire material and prevents the retention of an excessive amount of charge, thereby keeping the chargeability stable and balanced.

Further, with this configuration, it is possible to appropriately adjust the hardness and brittleness of the toner, so it is extremely easy to improve durability and prevent damage and φ contamination on the surface of the photoreceptor.

As the positively chargeable resin used in the present invention, resins that exhibit positive chargeability toward conductors such as metals or metal oxides can be used. Generally, acrylate derivatives such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dibutylaminoethyl acrylate, N-ethyl-N-phenylaminoethyl acrylate; Homopolymers of 7-minoacryl monomers such as methacrylate derivatives such as -N phenylaminoethyl acrylate, or styrenic monomers such as styrene, cross-styrene, vinyltoluene, acrylic acid, acrylic esters, methacrylic acid, methacrylic esters, etc. A copolymer with one or more monomers selected from the group consisting of acrylic monomer, acrylonitrile, butadiene, ethylene, and prolylene is used.

Since the positively chargeable resin serves as a reference for the positive chargeability of the toner, it is preferable that the positively chargeable resin is contained in an amount of 30% by weight or more of the binder resin in the toner.

Compatible dispersion of toner constituents is insufficient, resulting in phenomena such as a decrease in cohesive fluidity of the toner, and a decrease in triboelectric chargeability and charge controllability of the toner. If the amount is higher than this, the toner components will be sufficiently compatible and dispersed, but under high humidity,
Toner agglomeration phenomenon, density decrease phenomenon during durability, etc. occur.

Used in the present invention. As a resin that can be considered to be substantially neutral, its triboelectric charge amount T2 is equal to that of a positively chargeable resin.
For l, those satisfying the following conditions are used.

Generally, polystyrene, poly-p-chlorostyrene,
Monopolymers of styrene and its substituted products such as polyvinyltoluene; styrene-p-cross styrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-acrylics Acid methyl copolymer, styrene-acrylic ethyl copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer , styrene-butyl methacrylate copolymer, lythylene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Vinyl methyl ether copolymer.

Styrene-vinylethyl ether copolymer, styrene-
Styrenic copolymers such as vinyl ethyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, and styrene-maleic acid copolymer: polymethyl methacrylate, poly Butyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic resin, rosin, modified rosin, terpene resin, phenolic resin.

Aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, etc. can be used alone or in combination. Among them, temophoristyrene, styrene-acrylic copolymers, styrene-butadiene copolymers, epoxy resins, polyester resins, etc. are particularly preferred.

The content of the above-mentioned neutral resin may be set to an appropriate amount depending on the type and amount of the positively chargeable resin and the organic acid salt, but it is generally preferable that it is 5 to 70% by weight of the total binder resin. If it is less than this, the dilution effect as a neutral resin will be insufficient, and if it is more than this, the positive chargeability of the toner will be canceled out.

Further, as the organic acid salt used in the present invention, one can be used that improves the positive triboelectric chargeability of the resin when added in an amount of 2 parts by weight or less to 100 parts by weight of the above-mentioned positively chargeable resin. Generally, metal soaps, sulfonates, etc. derived from fatty acids having 12 to 30 carbon atoms are used, preferably metal salts of fatty acids having 12 to 30 carbon atoms, such as lauric acid, palmitic acid, and stearic acid.

Metal salts of saturated fatty acids such as naphthenic acid or metal salts of unsaturated fatty acids such as oleic acid are used. The amount of the organic acid salt added is generally preferably 0.1 to 5 parts by weight per 100 parts by weight of the positively charged resin in the toner. It is also possible to use coalescence.

In the toner, any suitable pigment or dye can be used as a colorant. Examples include known dyes and pigments such as carbon black, iron black, phthalocyanine blue, ultramarine blue, quinacridone, and benzidine yellow.

In addition, as charge control agents, amine compounds, quaternary ammonium compounds, organic dyes, especially basic dyes and their salts, benzyldimethyl-hexadecyl ammonium cumylide, decyl-trimethylammonium chloride, nigorosine base, nigrosine hydrochloride, safranin γ
Also, crystal violet, metal-containing dyes, salicylic acid-containing compounds, etc. may be added at 1/1 degree.Furthermore, magnetic powder may be added to an extent that does not impede the effects of the present invention.

Furthermore, magnetic powder may be added to the extent that the effects of the present invention are not impaired.

The toner structure described above may be used in a developer produced by a commonly used mixing-pulverization method, or may be used as a wall material or a core material, or both, of a microcapsule developer.

Examples of carriers used in the present invention include surface oxidized or unoxidized iron, nickel, conovert, manganese,
Metals such as chromium and rare earths, and their alloys or butyrides can be used. Moreover, there are no special restrictions on the manufacturing method.

Then, a treatment such as fixing a resin, a dye/pigment, a charge control agent, a fluidity control agent, etc. alone or in combination on the surface of the carrier may be performed.

Here, a method for measuring the amount of triboelectric charge of a positively chargeable resin, a positively chargeable resin containing an organic acid salt, and a neutral resin will be described in detail with reference to the accompanying drawings.

First, each resin powder was measured by Coulter Counter manufactured by Coulter Co., Ltd. to have a number average particle size of 9 to 11μ, a volume average particle size of 13 to 15JL, and 6.35p or more and 20% or less by number, 20.2 p or more is 15% by weight
The particles are adjusted so that they can be considered to have substantially the same particle size.

Next, the amount of triboelectric charge of each sample is measured using the apparatus shown in FIG. First, resin powder whose frictional charge amount is to be measured and particle size ZOO~300 are placed in a metal measurement container 12 with a conductive screen 13 of 400 mesh (can be changed as appropriate to a size that does not allow AI particles to pass through) at the bottom. Weight ratio of amorphous iron powder (the same type is used for the three types of resin) with no special treatment applied to the surface between the meshes: 1:
Pour about 4g of the mixture (developer) in step 9 into the metal lid 14.
do. Weigh the entire weight of the measurement container 2 at this time, Wl(
g) 0 Next, in the suction fill (at least the part in contact with the measurement container 2 is an insulator), suck from the suction port 17 and adjust the air volume control valve 16 to set the pressure on the vacuum gauge 15 to 70.
mm Hg. In this state, suction is applied sufficiently (for about 1 minute) to remove the resin powder. Electrometer 1 at this time
Let the potential of 9 be V (volt), here 18 is a capacitor and the capacity is C (#LF), and the weight of the entire measurement container after suction is weighed W2 (g). The amount of triboelectric charge T (gc/g) of the powder is calculated as shown in the following formula.

However, the measurement conditions are 23° C. and 50% RH.

Next, the present invention will be explained in more detail based on examples.

Note that 1 part is a part by weight.

〔Example〕

First, resin treatment is used as a positively charged resin, and II is used as a fatty acid salt.
, m, and (■) were selected, and the amount of triboelectric charge of a positively chargeable resin containing 2 parts of a fatty acid salt per 100 parts of the resin was measured in advance by a predetermined method. The results are shown in Table 1.

Furthermore, the amount of triboelectric charge was measured in the same manner for the neutral resins v, vt, vn, and ■. The results are shown in Table 2.

Table 3 shows the results of each example and comparative example in which these materials were combined.

[Example 1] A Canon NP-5000 copying machine was modified to be able to form negative and positive charge images and used for copying in this experiment.

Next, 150 parts of resin, 1 part of zinc palmitate, resin V
A positively chargeable toner having an average particle size of 8 µl was prepared, consisting of 2 parts of carbon black and 3 parts of carbon black.

This toner satisfies the conditions of the present invention (17
21<lTll15), 10 parts of this toner and particle size 200
100 parts of amorphous iron powder carrier having a mesh size of 100 to 300 mesh were mixed and placed in the above-mentioned copying machine for development. The obtained copied image was good with no fog or unevenness. Furthermore, even after printing up to 10,000 copies while appropriately replenishing toner, there was no contamination or damage to the photosensitive drum and no change in the image. Also, 15℃, 1O%RH and 35℃, 9
Even in the special environment of 0% RH, there was no deterioration in image quality. Furthermore, after the durability test, there was almost no toner spillage or scattering.

[Example 2] 70 parts of resin I, zinc naphthenate II [1 part, resin VT3
Example 1 was carried out in the same manner as in Example 1, except that a positively chargeable toner having an average particle size of 9p and consisting of 0 parts of phthalocyanine pigment and 5 parts of phthalocyanine pigment was prepared and used, and similarly good results were obtained. It was done.

[Comparative Example 1] The same procedure as in Example 2 was carried out except that sodium laurate ■, which does not satisfy the conditions of the present invention, was used in place of zinc naphthenate M. However, the charging ability was drastically reduced, and a normal image could not be obtained. I couldn't get it. Furthermore, after the durability test, toner scattering was severe.

[Comparative Example 2] In place of resin ■, resin ■ (IT
When the same procedure as in Example 2 was carried out except that 2 l> lTt 115) was used, the toner chargeability was too high, resulting in an image with a lot of density unevenness.

[Example 3] Resin I 80 parts, zinc naphthenate m H 1.5 parts, resin V
It satisfies the conditions of the present invention, consisting of 20 parts of W and 5 parts of phthalocyanine pigment. The same good results as in Example 1 were obtained except that a positively chargeable toner having an average particle size of 8 IL was used.

Table 2 Medium resin

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a frictional charge measuring device according to the present invention. In fig. 11 is a suction machine, 12 is a measurement container, and 13 is a conductive screen. 15 is a vacuum gauge. 16 air volume control valve. 17 indicates a suction port, and 18 indicates a condenser. Procedural amendment (1) Indication of the case 1985 Patent Application No. 39059 2, Title of the invention - 3, Relationship to the person making the amendment Patent applicant address 3-30-2 Shimomaruko, Ota-ku, Tokyo Name (100
) Canon Co., Ltd. Representative Ryuzo Kaku
Department 1″, 2≧Canon Co., Ltd. (Telephone 758-21
11) 5. Specification to be amended: Amend the phrase ``We have worked hard to solve the problem'' to ``We have worked hard to solve the problem.'' (2) Add the following statement after "I." on page 7, line 3 during the period. ``Furthermore, as the organic acid salt used in the present invention, it is possible to use one that improves the positive triboelectric chargeability of the resin by adding 2 parts by weight or less to 100 parts by weight of the above-mentioned positively chargeable resin. Generally, metal soaps, sulfonates, etc. derived from fatty acids having 12 to 30 carbon atoms are used, preferably metal soaps of fatty acids having 12 to 30 carbon atoms, such as lauric acid, palmitic acid, stearic acid, and naphthenic acid. Metal salts of saturated fatty acids such as acids or metal salts of unsaturated fatty acids such as oleic acid are used.The amount of organic acid salts added is as follows:
In general, 0.00% by weight of the positively charged resin in the toner.
1 to 5 parts by weight is preferred. (3) Delete the phrase ``Furthermore, it is possible to make improvements to the present invention.'' from page 9, line 15 to page 10, line 9.

Claims (1)

[Claims] (1) A positively charged resin having positively charged triboelectric properties,
A toner for developing an electrostatic image containing at least an organic carboxylate and a low-frictional charging resin, wherein (a) the organic carboxylate is 0.1 to 100 parts by weight based on 100 parts by weight of the positively charged resin; (b) The amount of triboelectric charge of the positively charged resin is T_1 (μc/g
), the triboelectric charge amount T_ of the low frictional chargeable resin
2 (μc/g) satisfies the formula |T_2|≦1/5|T_1|.