JPS63300241A - Electrostatic latent image developing toner - Google Patents

Abstract

PURPOSE:To prevent blocking of a toner fixable at low temperature by coating the surface of each specified particle with a specified F-containing silane compound. CONSTITUTION:The surface of each of the heat-fixable core particles A is coated by buring with smaller particles B in a depth not larger than the particle diameter of B, and further the surfaces of the particles B and those of the composite particles consisting of A and B are coated with the F-containing silane compound represented by formula I in which X is 1-6C alkyl containing F; Y is phenylene or SO3; R is H or 1-5C alkyl or alkoxy; (m) is 0-3; and (n) is 0 or 1. A compound of formula II and the like can be used for said compound of formula I. The particles B are made of an organic polymer higher in softening point and smaller in average particle diameter than the particles A, or the particles B have substantially not a softening point.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an improvement to a dry toner for developing electrostatic latent images in which small-sized organic polymer particles are embedded in the surface of large-sized heat-fixable base particles. As is well known, the dry toner used to develop electrostatic latent images formed on electrophotographic photoreceptors, electrostatic recording materials, etc. is mainly composed of thermoplastic resins such as styrene resin and acrylic resin. It is made up of this by adding colorants and magnetic powder as necessary, but dry toners that have a low softening point are generally used because they can be fixed at low temperatures and have good fixing properties. (average particle size is about S ~ 25 μm). However, since such toners have a low softening point, they have the disadvantage of causing so-called blocking, in which toner particles fuse together during storage or use, particularly in a high temperature atmosphere.

In order to solve this problem, a toner has been proposed in which toner particles having a low softening point and a large particle size are mixed with toner particles having a high softening point and a small particle size. However, in the case of this mixed toner, 1) especially when the amount of small-sized toner particles is small compared to large-sized toner particles,
2) During copying, sufficient blocking resistance cannot be ensured because large-sized toner particles easily come into contact with each other.

Large-sized toner particles are crushed by contact with the carrier, producing spent toner, resulting in decreased durability and formation of a film on the photoreceptor, carrier, etc. (so-called filming), deteriorating its performance. 3) During copying, large particle size toner tends to be consumed preferentially, and as a result, during copying, the toner composition in the developer container changes from the initial copying period, resulting in a decline in image quality and fixing performance. There were drawbacks such as:

Therefore, in order to eliminate these drawbacks, the present inventors previously disclosed in Japanese Patent Application No. 61-278069 that the heat-fixable base particles A have a surface having a softening point higher than that of the base particles A. , or small particles B mainly composed of an organic polymer substance having substantially no softening point and having an average particle size smaller than the average particle size of the base particles A, We proposed a toner for developing electrostatic latent images formed by a deep coating. However, in the case of this proposed toner, small organic polymer particles are obtained by various known polymerization methods using hydrophilic substances such as surfactants (as emulsifiers) and water-soluble polymers (as stabilizers). When using toner, due to the hydrophilic substances remaining on the surface of small particles, toner charging becomes unstable and environmental dependence occurs, or the triboelectric charging property is insufficient and the required amount of toner charging cannot be obtained. There was a problem.

(2) The first object of the present invention is to embed small-sized organic polymer particles on the surface of large-sized heat-fixable base particles, thereby making it possible to fix at low temperatures and to improve blocking resistance. Another object of the present invention is to provide a toner for developing electrostatic latent images that has improved durability, does not adversely affect photoreceptors, carriers, etc., does not change its composition during copying, and does not cause deterioration in image quality or fixability.

A second object of the present invention is to improve the charging properties of the toner in which small-sized organic polymer particles are embedded on the surface of the large-sized base particles, thereby eliminating environmental dependence, and at the same time, achieving a sufficient amount of charge. An object of the present invention is to provide a toner for developing an electrostatic latent image.

As shown in FIG. 1, the toner for developing electrostatic latent images of the present invention has a softening point higher than the softening point of the base particles A, or substantially burying small particles B mainly made of an organic polymer substance that does not have a softening point and has an average particle size smaller than the average particle size of the base particles A to a depth less than the particle size of the small particles B; In a toner for developing an electrostatic latent image formed by coating, the surface of the small particles B or the surface of a composite particle formed by coating the surface of the base particles A with the small particles B has a general formula (%) (where n is 0 or 1, m is 0, 1.2 or 3, or an alkyl group having 1 to 6 carbon atoms containing a fluorine atom, Y is phenylene or an SO3 group, R is hydrogen, or an alkyl group having 1 to 5 carbon atoms, or It is characterized by being coated with a fluorine-containing silane compound represented by (representing an alkoxy group).

In the present invention, the softening point of base particles A is 80°C.
Hereinafter, it is preferable that the outflow start temperature is 110° C. or lower and the average particle size is 5 to 25 μm. If the softening point is higher than 80° C., poor fixing is likely to occur even if the coverage of the small particles B is low. If the outflow start temperature exceeds 110℃, during fixing,
Since the viscosity of the toner does not decrease and the small particles B are not sufficiently embedded in the base particles A, it is difficult for the base particles A to come into contact with the copy paper, which tends to cause poor fixing. Furthermore, if the particle size is less than 5 μm, there will be a large amount of spent 1-ner, and if it exceeds 25 μm, the resolution will tend to deteriorate.

The softening point referred to here refers to the sample 1d in a cylinder with a diameter of 0.5+am under a plunger load of 10 kg/d and heating rate of 3°C/min using a Koka type flow tester (Shimadzu Corporation). , when extruded through a nozzle with a length of 1 mm, the plunger gradually descends, the sample is compressed, the voids in the cylinder disappear, and the sample becomes a uniform transparent body or phase. Further, the outflow start temperature is the temperature at which the plunger starts to descend again after the sample becomes a uniform transparent body or phase under these conditions and there are no obvious fluctuations in the position of the plunger.

On the other hand, the small particles B have a softening point that is preferably at least 5°C higher than the softening point of the base particles A, or have substantially no softening point, and have an average particle size of 0.1 μm or more. It is preferable that the average particle size of A is 1/4 or less, and when the softening point is less than 5°C than that of the base particle A, or when the average particle size is at the end of 0.1 μm, the original small particle B The function cannot be achieved, poor heat-resistant storage properties, and toner filming on the photoreceptor and carrier tend to occur.Furthermore, when small particles B are embedded in base particles A, the toner tends to aggregate, resulting in manufacturing problems. tends to become more difficult. In addition, if the particle size of small particles B is larger than 1/4 of the particle size of base particles A, the heat-resistant storage stability is very good, but during fixation, small particles B are not sufficiently embedded in base particles A, so Easy to cause defects.

Furthermore, in the present invention, in order to maintain good low-temperature fixability and sufficient blocking resistance, the coverage of small particles (as a projected area on the surface of the base particle) is equal to 4 of the surface area of the base particle.
It is preferably in the range of 0 to 100%. If it is less than 40%, the blocking prevention effect of small particles will be reduced, and it will tend to aggregate during production, and if it exceeds 100%, it will cause problems during fixing.
Since the small particles are not sufficiently embedded in the base particles, poor fixing tends to occur.

The coverage α (X100%) of the small particles B is determined as follows. That is, the diameter (as an average particle size) and true specific gravity of the small particle B are respectively d, the diameter (as an average particle size) and true specific gravity of the base particle A are kd and ρ, respectively, and the weight of one base particle. When W is large, the projected area to the base particle per individual is ・
Since Cwa′ holds true. Substitute equation (1) into equation (2) to obtain. Here, the particle size ratio k and true weight ratio ρ*/ of the base particle and the small particle are
When ρ small is known, the appropriate coverage α (X100%) is found by varying W small/W★, and it is found to be 40 to 100%.
It turned out to be within the range.

The base particles A as described above are mainly composed of a heat-melting resin or a wax, to which a colorant and/or a magnetic substance is added if necessary, and are mainly used for low-temperature fixing, coloring, etc. On the other hand, small particles B are mainly composed of an organic polymer substance, to which a colorant and/or a magnetic substance is added if necessary, and are mainly used to improve blocking resistance and toner filming on photoreceptors, carriers, etc. It is used to prevent electrostatic charges and to ensure particularly good charging properties.

In the present invention, in order to further improve the chargeability of a toner using small particles containing a hydrophilic substance, the surface of the small particles B or the composite particles is coated with a fluorine-containing silane compound of the above general formula.

Examples of materials used for the base particles include polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, and styrene-vinyl chloride. Copolymers, styrene-vinyl acetate copolymers, styrene-maleic acid copolymers, styrene-acrylic acid ester copolymers (styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-acrylic copolymers) Butyl acid copolymer, styrene-octyl acrylate copolymer.

Styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-methacrylate copolymer) acid phenyl copolymer, etc.), styrene-
Styrenic resins such as α-methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer (styrene or a monopolymer or copolymer containing a styrene substitute), vinyl chloride resin, styrene-acetic acid Vinyl copolymer, rosin-modified maleic acid resin, epoxy resin, polyester resin, polyethylene, polypropylene, ionomer resin, polyurethane resin, ketone resin,
Examples include heat-melting resins such as ethylene-ethyl acrylate copolymer, xylene resin, and polyvinyl butyral, and waxes such as natural or synthetic waxes. These may be used alone or in combination.

On the other hand, organic polymer substances for small particles can be selected from the above-mentioned matrix materials depending on the softening point of the matrix particles, and resins with high softening points that are unsuitable as matrix resins and For example, silicone resins, benzoguanamine/formaldehyde condensates, etc., which have substantially no softening point, can also be selectively used.

Specific examples of the fluorine-containing silane compound for coating the composite particles of the small particles B include the following.

(3) CF, CF, CH, CH, 5i (CH,).

(5) CF, CF2CH□CH2CH, Si(O
C2H,).

(6) CF3C)I, CH25i(OCH,).

(7) CF, CF2CF2CH25i(C2H4)3(
8) CF, CF, CF2CF2CH25i, 5iCQ3
(9) CF2CF2CH25i, CH2CH, 5iCQ
3(10)CF, CF2CF2CI(,5iCQ3(1
1) CF3CF, SiC island (12) CM(F)2CH, CH2CH25iCI2.
.

(13) CF, CH, 5iCI2. .

(14) CF3CF, CF, CF2CF2CH25i (
CH,) C bird (15) CF, CF, CF, CF2CH,
CH25i (OCH,) C bird (16) CF, CF, CF
2CF2CH25i, 5i(OCR,), (j2(17
)CF3CF,CF,CF,CF,CH,5i(C,H
,) C also (18) CF, CF2CF, CH, CH25i
(○CzHs)zcQ(19)CF3CF2CF, CH
,CH25i(○CH,)(CH3)CQ(20)
CF3CF, CF2CF2CH25i, 5i (CH3)
C & (21) CF, CH2CH, CH25i (CH,)
, CQ(22) CF, (CF2)3CH,CH,-
■-3iCQ3CH.

(23) CF, (cF, ), CH, CH, -◎-8
iC bird CH.

(24) CF2CF2CH25i, -◎-8iCQCH
.

C,H.

(25) CF, CH, -◎-8iCchi (26)
CH(F)2CH,CH,-■-3iCQ3CH2C8
2CH.

(27) CH(F), CH2CH2CH, CH2-◎-
5iC bird CH.

- (28) CF, (CF2), CH2CH2CH, -@-
3iCQC2H7 (29) CF, (CF,)3CH2-■-8iC is also CH.

(30) CF3(CF2)3-◎-3iCQ3CH
.

(31) CF, (CF,), CH, -@-3iCQ
CH.

(33) CF, So, 5i(QC2H,)3(34
) CF, 5o3Si(CH,)3(35) CF
, So, 5i (C2H5).

Note that the amount of these fluorine-containing silane compounds to be used is sufficient as long as it covers the entire surface of the small particles B or the composite particles. Moreover, as a coating method, methods such as spray coating and dip coating are usually adopted.

Coloring agents include carbon black, chromium-containing monoazo dye, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, quinoline yellow, methylene blue chloride, monastral blue, malachite green oxalate, lamp black, rose bengal, monas. Examples include Toral Red, Sudan Black BM, and mixtures thereof. Co, Fe as magnetic materials
e Metal powder such as Ni: AQ, Co, Cu, Fe, P
b, Ni, Mg, Sn, Zz, Au+Ag
.

Examples include alloys or mixtures of metals such as Se, Ti, W, and Zr; metal oxides such as iron oxide and nickel oxide, or metal compounds containing the same; ferromagnetic ferrite; and mixtures of soft materials.

Furthermore, the toner of the present invention contains silica,
Fine powder of alumina, titanium oxide, etc. can be added and mixed.

The toner of the present invention is produced by heating the base particles to a temperature near the softening point of the particles to soften them, adding small particles coated or not coated with a fluorine-containing silane compound to the base particles, and stirring and mixing the uncoated small particles. When using fluorine-containing silane compound, the mixture can be further coated with a fluorine-containing silane compound. In this way, the toner of the present invention is obtained with small particles embedded in the surface of the base particles, but the depth of embedding is less than the average particle size of the small particles depending on stirring conditions, heating temperature, etc. in order to achieve good fixing. controlled by.

The toner of the present invention as described above contains a magnetic material in the base particles and/or small particles and is used as a one-component dry developer.
Alternatively, it may be mixed with a magnetic material and used as a two-component dry developer.

The present invention will be explained below by way of examples. Note that all parts are parts by weight. Furthermore, the evaluation methods for blocking resistance and fixing properties in Examples are as follows.

Blocking resistance (mm): Put 1°g of toner in a glass bottle with an inner diameter of 25mm and a height of 70mm, and leave it in a constant temperature bath at 55°C for 24 hours.
Check the penetration level using a 2530 penetrometer.

Fixing properties [as minimum fixing temperature ('C)]; Fixing roller: Teflon-coated roller, nip width: 6 mm, i speed 12
When toner is fixed on copy paper by varying the fixing roller temperature under a fixing condition of 0+++ m/see, the temperature at which the fixing rate reaches 70% using a Glock meter is determined.

Example 1 Styrene 90
Part 2-ethylhexyl acrylate-1-5 parts n-butyl methacrylate 5 parts t-butyl mercaptan 1.5 parts 1.5 parts
% sodium lauryl sulfate aqueous solution 200 parts ammonium persulfate (polymerization initiator) 0.2 parts was subjected to emulsion polymerization at 60° C. for 30 hours in an N2 atmosphere,
After thoroughly washing the obtained resin particles (obtained in a dispersed state), use a spray dryer to reduce the inlet temperature to 130°C.
It was dried at an outlet temperature of 70°C to produce small particles with an average particle size of 0.5 μm.

The softening point of this material is 120℃, and the temperature at which it begins to flow is 160℃.
Met.

Next, 100 parts of these small particles were mixed with fluorine-containing silane compound (4) 1
After stirring for 1 hour, the particles were air-dried and further incubated with S at 45°C.
After drying for hours, small particles coated with a fluorine-containing silane compound were obtained.

On the other hand, 90 parts of polyester resin and 1 part of carbon black
0 part was kneaded, pulverized, and classified to produce base particles with an average particle size of 12 μm. This material had a softening point of 62°C and a starting temperature of 78°C.

Next, the small particles coated with the fluorine-containing silane compound and the base particles were mixed at a weight ratio of 1.07/10, and the mixture was stirred in an atmosphere at 62° C. for 1 hour.

The coverage ratio of the small particles coated with a fluorine-containing silane compound in the obtained toner is ρ=1.10 g/cffl, ρ6=1°2
It was about 70% from 0 g/cJ. When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. Further, the blocking resistance of this toner was 26 parts m, which was very good.

Next, 3.5 parts by weight of the above toner was added to 100 parts by weight of a carrier made of ferrite powder with an average particle size of 100 μm coated with silicone resin to a thickness of 1 μm to prepare a two-component dry developer. When I checked the temperature), it was 1
Good low-temperature fixability was exhibited at 10°C.

Next, this developer (initial charge amount -22.3μc/g) was set in a commercially available plain paper copying machine (FT6080 manufactured by Ricoh), and when 100,000 copies were made, the charge amount was -21.4μc/g.
c/H, there was almost no difference from the initial copying, and no background stains occurred, so the initial high image quality was maintained. Further, when the toner was observed after copying 100,000 copies, no small particles were removed, and the lower limit fixing temperature was stable at 110°C. Furthermore, no toner filming on the surface of the photoreceptor drum was observed.

Example 2 Small resin particles made in Example 1 and base particles were mixed at a weight ratio of 1.07/10, and this was mixed with 62
The mixture was stirred in an atmosphere at ℃ for 1 hour.

The coverage of small particles in the obtained composite particles is ρ, s=1
．． 10g/aI? , ρ6: about 70% from 1.20g/-
Met. When this composite particle was subjected to tR observation using a scanning electron microscope, it was found that small particles were embedded in the surface of the base particle.

Next, 30 parts of these composite particles were dispersed in 100 parts of the same fluorine-containing silane compound aqueous solution as in Example 1, and after stirring for 1 hour, the particles were air-dried, and further dried at 45°C for 5 hours to dissolve the fluorine-containing silane compound. A toner consisting of compound-coated composite particles was obtained.

When this toner was subjected to RIA using a scanning electron microscope, no small particles were observed to be detached from the toner surface.

Hereinafter, this toner was subjected to the same test as in Example 1, and very good results were obtained as shown in Example 1 below.

Comparative Example 1 A toner consisting of composite particles was prepared in the same manner as in Example 1 except that the small particles were not coated with the fluorine-containing silane compound (4).

The same test as in Example 1 was conducted on this toner, and as shown in Table 1, good results were obtained at the initial stage of copying, but after 30,000 copies were copied, toner scattering increased and background staining occurred. Ta.

Example 3 Methyl methacrylate 100 parts Distilled water 300 parts Potassium persulfate O,
S part polyoxyethylene nonylphenol
A mixture consisting of 0.8 parts of 3 parts of sodium lauryl sulfate was subjected to emulsion polymerization at 80°C for 30 hours in an N2 atmosphere, and the resulting fine resin particles (obtained in a dispersed state) were thoroughly washed and then treated using a spray dryer. Inlet temperature 1
Dry at 50℃ and outlet temperature of 85℃ to obtain an average particle size of 1.0μm.
small particles were created.

The softening point of this material is 130°C, and the temperature at which it begins to flow is 170°C.
Met.

Next, 100 parts of these small particles were mixed with fluorine-containing silane compound (6) 1
After stirring for 1 hour, the particles were air-dried and further dried at 45° C. for 5 hours to obtain small particles coated with a fluorine-containing silane compound.

Next, the fluorine-containing silane compound-coated small particles and the base particles prepared in Example 1 were mixed at a weight ratio of 2.14/10, and the mixture was stirred in an atmosphere at 64° C. for 1 hour.

The coverage rate of the small particles coated with a fluorine-containing silane compound in the obtained toner is ρ = 1.10 g/an? , ρ large = 1°20
g/- to about 70%. When this I.na was observed using a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particle.

When this toner was subjected to the same test as in Example 1, very good results were obtained as shown in Table 1.

Comparative Example 2 A toner made of composite particles was produced in the same manner as in Example 3, except that the small particles were not coated with the fluorine-containing silane compound (6).

The same test as in Example 1 was conducted on this toner, and as shown in Table 1, good results were obtained at the initial stage of copying, but after 30,000 copies were copied, toner scattering increased and background staining occurred. Ta.

Example 4 Styrene 1
00 parts divinylbenzene
2 parts sodium laurate
3 parts Distilled water 300 parts Potassium peroxide 0
．． Polystyrene fine particles having an average particle size of 0.15 μm were obtained in a dispersed state by polymerizing a mixture consisting of 3 parts at 70° C. for 15 hours in a N2 atmosphere, and then 7 parts of styrene was added to 20 parts of this dispersion.
0 parts divinylbenzene
30 parts polyvinyl alcohol
1 part benzoyl peroxide
Add a mixture consisting of 300 parts of 1 part distilled water and heat under N2 atmosphere for 75 minutes without stirring.
Polymerization was carried out at ℃ for 5 hours to produce crosslinked polystyrene fine particles with an average particle size of 0.5μ. Next, after thoroughly washing these particles,
Drying was carried out using a spray dryer at an inlet temperature of 150°C and an outlet temperature of 90°C.

The softening point of the obtained small particles was 150°C, and the temperature at which they began to flow was 2.
The temperature was 10°C.

Next, 100 parts of these small particles were mixed with fluorine-containing silane compound (9) 1
After stirring for 30 minutes, the particles were dried under reduced pressure and further dried at 45° C. for 5 hours to obtain small particles coated with a fluorine-containing silane compound.

Next, a toner was prepared in the same manner as in Example 1 using the small particles coated with a fluorine-containing silane compound. The coverage rate of the small particles coated with a fluorine-containing silane compound in this toner is ρ, =1.
It was about 70% from 10 g/cJ, ρ6 = 1.20 g/-.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 5 Uncoated small particles made of crosslinked resin fine particles prepared in Example 4 and base particles were mixed at a weight ratio of 1.07/10,
This was stirred in an atmosphere at 62°C for 1 hour.

The coverage of small particles in the obtained composite particles is ρ small = 1.
It was about 70% from 10 g/aJ and ρ6=1.20 g/cd. When this composite particle was observed with a scanning electron microscope, it was found that small particles were embedded in the surface of the base particle.

Next, 30 parts of these composite particles were dispersed in 100 parts of the same fluorine-containing silane compound solution as in Example 4, and after stirring for 1 hour, the particles were dried under reduced pressure, and further dried at 45°C for 5 hours to dissolve the fluorine-containing silane compound. A toner consisting of compound-coated composite particles was obtained. When this toner was observed using a scanning electron microscope, no small particles were observed to be detached from the toner surface.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Comparative Example 3 A toner consisting of composite particles was produced in the same manner as in Example 4, except that the small particles were not coated with the fluorine-containing silane compound (9).

The same test as in Example 1 was conducted on this toner, and as shown in Table 1, good results were obtained at the initial stage of copying, but after 30,000 copies were copied, toner scattering increased and background staining occurred. Ta.

Example 6 A 1-ner was prepared in the same manner as in Example 4, except that the fluorine-containing silane compound (9) was replaced by the same compound (20). When this toner was examined under a scanning electron microscope at 1 ltaL, small particles coated with a fluorine-containing silane compound were found embedded in the surface of the base particles. The coverage rate of the small particles coated with a fluorine-containing silane compound in this toner is p, = 1.10 g/a+? , ρ6=1.20 g/cn, which was about 70%.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 7 The uncoated small particles and base particles used in Example 6 were treated in 1.
They were mixed at a weight ratio of 07/10 and stirred for 1 hour in an atmosphere at 62°C.

The coverage of small particles in the obtained composite particles is ρ+=1
．． 10g/ad, ρ*=1.20g/ai? From about 70
%Met. When this composite particle was observed with a scanning electron microscope, it was found that small particles were embedded in the surface of the base particle.

Next, 30 parts of these composite particles were dispersed in 100 parts of the same fluorine-containing silane compound aqueous solution as in Example 6, and after stirring for 1 hour, the particles were dried under reduced pressure, and further dried at 45°C for 5 hours to dissolve the fluorine-containing silane compound. A toner consisting of compound-coated composite particles was obtained.

When this toner was inspected for wA using a scanning electron microscope, no small particles were observed to be detached from the toner surface.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 8 A toner was prepared in the same manner as in Example 4 except that the fluorine-containing silane compound (22) was used instead of the fluorine-containing silane compound (9). WA observation of this toner using a scanning electron microscope revealed that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. The coverage of the small particles coated with a fluorine-containing silane compound in this toner is ρ = 1.10 g/j, ρ★ = 1.20 g
/a (about 70%.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 9 The uncoated small particles and base particles used in Example 8 were treated in 1.
They were mixed at a weight ratio of 07/10 and stirred for 1 hour in an atmosphere at 62°C.

The coverage of small particles in the obtained composite particles is ρ, = 1
．． Approximately 70% from 10g/ad, ρ★=1.20g/cd
Met. When this composite particle was observed with a scanning electron microscope, it was found that small particles were embedded in the surface of the base particle.

Next, 30 parts of these composite particles were dispersed in 100 parts of the same fluorine-containing silane compound aqueous solution as in Example 8, and after stirring for 1 hour, the particles were dried under reduced pressure, and further dried at 45°C for 5 hours to dissolve the fluorine-containing silane compound. A toner consisting of compound-coated composite particles was obtained.

When this toner was inspected under a scanning electron microscope, no small particles were observed to be detached from the toner surface.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 10 A 1-ner was prepared in the same manner as in Example 4 except that the fluorine-containing silane compound (23) was used instead of the fluorine-containing silane compound (9). When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. The coverage of the small particles coated with a fluorine-containing silane compound in this toner is ρ = 1.10 g/cd, ρ★ = 1.2
It was about 70% from 0 g/crJ.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 11 A toner was prepared in the same manner as in Example 4, except that the fluorine-containing silane compound (9) was replaced by the same compound (24). When this toner was inspected using a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. The coverage rate of the small particles coated with a fluorine-containing silane compound in this toner is ρ, =1. Log/all, ρ★=1.2
It was about 70% from 0g/-.

Hereinafter, the same test as in Example 1 was conducted on this I-ner, and very good results were obtained as shown in Table 1 below.

Example 12 A toner was produced in the same manner as in Example 4, except that the fluorine-containing silane compound (9) was replaced by the same compound (26). When this toner was inspected under a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. The coverage of the small particles coated with a fluorine-containing silane compound in this toner is as follows: ρ small = 1.10 g/cd, ρ large = 1.20
g/cd to about 75%.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 13 A toner was prepared in the same manner as in Example 8, except that the amount of the fluorine-containing silane compound (22) was changed to 2 parts. When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. The coverage rate of the small particles coated with the fluorine-containing silane compound in this toner was approximately 80% based on ρ = 1.10 g/aJ and ρ = 1.20 g/aj.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 14 A toner was prepared in the same manner as in Example 4, except that the fluorine-containing silane compound (9) was replaced by the same compound (28). When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles.

The coverage ratio of the small particles coated with a fluorine-containing silane compound in this toner is ρ = 1.10 g/cd, ρ = 1.20 g
It was about 70% from /cd.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 15 A 1-ner was prepared in the same manner as in Example 4, except that the fluorine-containing silane compound (9) was replaced by the same compound (31). When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles. The coverage rate of the small particles coated with a fluorine-containing silane compound in this toner is ρ=1.10g/a&, ρ=1.2
It was about 75% from 0 g/ad.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 16 A toner was prepared in the same manner as in Example 1 except that the fluorine-containing silane compound (4) was replaced by the same compound (32). When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles.

The coverage rate of the small particles coated with a fluorine-containing silane compound in this toner is ρ, == 1.10 g/ad, ρ*=1.2
It was about 80% from 0g/a#.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 17 Each of the uncoated small particles and base particles used in Example 16 was
．． They were mixed at a weight ratio of 07/10 and stirred for 1 hour in an atmosphere at 62°C.

The coverage of small particles in the obtained composite particles was ρ = 1.
It was about 70% from Log/aJ, ρ★=1.20 g/cd. When this composite particle was observed with a scanning electron microscope, it was found that small particles were embedded in the surface of the base particle.

Next, 30 parts of these composite particles were dispersed in 100 parts of the same fluorine-containing silane compound aqueous solution as in Example 16, and after stirring for 1 hour,
The particles were dried under reduced pressure and further dried at 45° C. for 5 hours to obtain a toner comprising composite particles coated with a fluorine-containing silane compound. When this toner was observed using a scanning electron microscope, no small particles were observed to be detached from the toner surface.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

Example 18 A toner was prepared in the same manner as in Example 1, except that the fluorine-containing silane compound (33) was used instead of the fluorine-containing silane compound (4). When this toner was observed with a scanning electron microscope, it was found that small particles coated with a fluorine-containing silane compound were embedded in the surface of the base particles.

The coverage of the small particles coated with a fluorine-containing silane compound in this toner is ρ = 1.10 g/ad, ρ = 1.20 g
/ai? It was about 70%.

Hereinafter, the same test as in Example 1 was conducted on this toner, and very good results were obtained as shown in Table 1 below.

(The following is a blank space) Mr. As mentioned above, the toner of the present invention has small particles with a high softening point or no softening point embedded in at least a portion of the surface of the large-sized low-softening point base particles, and then Since the surface of these small particles or the surface of composite particles formed by coating the base particles with small particles is coated with a specific fluorine-containing silane compound, appropriate thermal properties and coverage by the small particles can be obtained. Therefore, even though it can be fixed at low temperatures like conventional mixed toners, it does not cause blocking or changes in composition during copying, so even if it is used repeatedly, it will not deteriorate image quality or fixing performance. It also has the advantage of exhibiting extremely stable charging and electrification properties.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional model diagram of the toner of the present invention. A... Base particle B... Small particle 111' 1! I Kaisho 63-300241 (11) Shima 1 map

Claims (1)

[Scope of Claims] 1. The surface of the heat-fixable base particle A has a softening point higher than that of the base particle A, or has substantially no softening point, and the base particle A Small particles B mainly composed of an organic polymer substance having an average particle size smaller than the average particle size of
In the toner for developing an electrostatic latent image formed by embedding and coating the small particles B at a depth less than the particle diameter of the small particles B, the surface of the small particles B or the composite particles formed by coating the small particles B on the base particles A. The surface has the general formula or SO_3 group, R represents hydrogen, or an alkyl group or an alkoxy group having 1 to 5 carbon atoms.