JP2000056514A - White toner composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide satisfactory fixability to provide a stable printing result in a long-time printing work and also provide a high shielding force by including toner resin consisting of polyester resin and a specified quantity of rutile type TiO2. SOLUTION: A nonmagnetic toner grain comprises 100 pts.wt. of toner resin at least 50 pts.wt. of which consists of polyester resin and 65-180 pts.wt. of rutile type TiO2 to 100 pts.wt. of the toner resin. The toner grain further may contain a wax, and a particularly useful wax is a monohydroxy compound having the formula: CH3(CH2)nOH wherein (n) is an integer of 21-360, a monocarboxy compound having the formula: CH3(CH2)nCOOH wherein (n) is an integer of 21-360, or an onium compound having at least 12C atoms and a maximum of 12C-atom alkyl group. Further, the toner grain may contain a fluorescent brightener emitting fluorescence under UV light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention is dry non containing a white pigment - comprising magnetic toner particles, especially rutile TiO ₂ dry non -
It relates to magnetic toner particles. The invention further relates to a method for printing an image on a transparent body, wherein the image contains a white background.

[0002]

BACKGROUND OF THE INVENTION White toner particles and their use are known in the art, particularly for printing on black backgrounds or for printing methods in which black and white toners are used for printing various gray levels.

[0003] EP-A-253 560 discloses an electrophotographic copying method which involves the use of a copying apparatus having a positive-image copying system, in which a toner image with colored toner is formed and a reverse image is formed. While selecting the color of the paper and the toner to be formed, it is transferred to a colored insulating paper of a color different from the color of the toner. White toner is disclosed having a rutile type TiO ₂ of acrylic resin and 20 parts by weight - 100 parts by weight of styrene in the examples.

In EP-A-280 378, a fixing resin and at least 99% by weight of Ti dispersed therein are disclosed.
O ₂ , Al ₂ O _{3 up to} 0.1% by weight and 0.05% by weight
The following high-purity titanium dioxide pigment containing SiO ₂ is contained as a white pigment.
A white toner having an average particle size of not less than μm is disclosed. In this disclosure, when TiO ₂ is not its purity, it has been emphasized that excellent charging quality of toner particles can not be achieved. It is said that up to 50 parts by weight, preferably up to 30 parts by weight of TiO ₂ can be used for 100 parts by weight of toner resin because toner having a large amount of TiO ₂ cannot be fixed. .

In JP-A-01 048067,
There are 5 to 20 wt% of TiO _2, preferably 8-1
White toner is disclosed that there is 0% by weight of TiO _2.

In US-A-4,943,506,
Binder resin and titanium dioxide having an average particle size of 0.20 to 0.35 μm are added based on 100 parts by weight of the binder resin.
A white toner comprising a content of ６０60 parts by weight is disclosed.

In US-A-5,077,158,
An image forming method including a step of developing an electrostatic latent image using a gray toner is disclosed, wherein a mixture of a white toner and a black toner is used as the gray toner. The white toner preferably contains TiO ₂ in a rutile crystal structure and up to 50 parts by weight for 100 parts by weight of toner resin.

[0008] Presently well accepted methods of printing labels are digital electrostatic printing means, such as CHR.
OMAPRESS (Agfa-Gevaert NV,
Mortsel, Belgium trade name) or DCP
1 (Xeikon NV, Mortsel, Belgium)
um product name). Transparent labels are also printed using such a printing device, and for opaque white images on a transparent support, it is preferable to use toner particles that provide high opacity, i.e. the hiding power of the layer of white toner is very high. There must be. When printing white lettering on a colored, transparent adhesive label for use on, for example, a red background, it is desirable that the lettering be truly white and slightly reddish non-white. If the bar-code has to be printed on a transparent label, it is also desirable to print it on a white background for better readability of the bar-code,
Therefore, the white must be very opaque. While the known toner particles are well suited for printing white images, the hiding power must be higher to print a white image on a transparent substrate.

[0009]

OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide TiO ₂ particles which are intimately mixed with the toner resin, have good fixability and provide stable printing results in long printing runs. And to provide white non-magnetic toner particles having high hiding power.

It is also an object of the present invention to provide an electrostatic printing method for printing a white image having high hiding power on a transparent substrate.

[0011] Further objects and advantages of the present invention will become apparent from the following detailed description.

An object of the present invention is to provide a non-woven fabric comprising 100 parts by weight of a toner resin having at least 50 parts by weight of a polyester resin, and 65 to 180 parts by weight of rutile-type TiO _{2 based} on 100 parts by weight of the toner resin. -Realized by providing magnetic toner particles.

It is a further object of the present invention, - white non containing toner resin and a white pigment - the magnetic toner particles 7.5g / m ² ~15g / m ² is applied imagewise to the substrate, - non - magnetic Fixing toner particles on the substrate, the non-magnetic toner particles comprising at least 50
100 parts by weight of a toner resin whose weight part is a polyester resin and 65 to 18 parts by weight with respect to 100 parts by weight of the toner resin.
This is achieved by providing an electrostatic printing method for white toner images having an opacity OP of at least 60%, characterized by comprising 0 parts by weight of rutile TiO ₂ .

[0014]

DETAILED DESCRIPTION OF THE INVENTION The prior art describes that less than 60 parts by weight of rutile TiO ₂ per 100 parts by weight of toner resin.
Can be incorporated into the toner particles, but surprisingly, when the toner resin comprises at least 50 parts by weight of the polyester resin, 65 to 180 parts by weight per 100 parts by weight of the toner resin. Rutile TiO ₂
It has been found that it is possible to produce non-magnetic toner particles having There is no problem regarding the stability and fixability of the toner charge, and the purity of the rutile TiO ₂ is only 9
There was no problem even if it was 5 to 98%. Fixing is hot
In both the fusing system performed by roller fusing and the system in which fusing is performed by non-contact means, in particular by infrared, the quality of the fusing of the toner image was excellent irrespective of the high pigment to resin ratio.

This finding indicates that only 0.75 mg to 1.5 mg
mg / cm ² (7.5 g / m ^{2 to} 15 g / m ² ) white image with high opacity or high hiding power (ie at least 60% opacity) even when non-magnetic toner particles are deposited Pave the way to the possibility of producing non-magnetic toner particles that can be used to form According to the present invention, 0.9 mg to 1.1 mg / cm ² (9 g / m ²
It has been shown that it is possible to produce white non-magnetic toner particles that give at least 60% opacity when deposited at 11 g / m ² ) of toner particles.

The opacity or hiding power of a white image can be measured by applying white toner particles to a transparent support to form an image of a patch having a uniform white density, and applying the image to a light trap.
htrap) and opacity OP1 in reflection mode
= I _reflBL / I _o , where opacity is the ratio of the reflected light intensity to the intensity of the light emitted on the white image. Then put the same white image on the white tile,
The opacity OP2 = I _reflWH / I ₀ is measured again in the reflection mode. I ₀ is the same in both measurements. The opacity of the white image or the actual hiding power is (OP1 / OP2) x
100 = OP = (I _reflBL / I _reflWH ) _× 100 The greater the OP, the higher the hiding power.

It is found that the toner resin can be any resin known in the art, provided that at least 50 parts (weight / weight) of the polyester is present for 100 parts (weight / weight) of the toner resin. Was.
Preferably, the toner resin in the non-magnetic toner particles of the present invention contains at least 50 parts (weight / weight) of a polyester having an acid or hydroxyl number of 10 to 30 mg KOH / g. More preferably, the toner resin in the non-magnetic toner particles of the present invention is a polyester or a mixture of various polyesters. In that case, 10-30mg
When a polyester having an acid value or hydroxyl value of KOH / g is used, or when a mixture of various polyesters is used, 10 to 30 mg KO is contained in the mixture.
It preferably contains at least 50% (w / w) of a polyester having an acid or hydroxyl number of H / g.
Table 1 shows polyester resins that are very useful for use in the non-magnetic toner particles of the present invention.

[0018]

[Table 1] * AV: Acid value in mg of KOH per gram of resin ** HV: Hydroxyl value in mg of KOH per gram of resin + Mn: Number average molecular weight (x1000) † Mw: Weight average molecular weight (x1000) DIANOL 22 is bis-ethoxyl For 2,2-bis (4-hydroxyphenyl) propane
erlands AKZO CHEMIE.

DIANOL 33 is an AKZO CHEMI from Netherlands for bis-propoxylated 2,2-bis (4-hydroxyphenyl) propane.
E is the product name.

Na: not available White pigments known in the art (eg BaSO
_4, ZnO, from among TiO _2, etc.), it was found that TiO ₂ is most effective in the rutile crystal disposed. Titanium dioxide useful in the present invention has a purity of at least 99.
% Need not be, but can be used rutile TiO ₂ having 99% and higher purity than that in the present invention, it can also be used of TiO ₂ having a purity of 94% to 98%, which is Al ₂ O ₃ and / or TiO ₂ of SiO ₂ is present in relatively large amounts or non of the present invention - which means that it is useful in magnetic toner particles. This non of the present invention - has the advantage that it is possible purity in the manufacture of the magnetic toner particles is used relatively low thus relatively inexpensive TiO _2. Non of the present invention containing TiO ₂ in the rutile crystal disposed - magnetic toner particles can further include a SiO ₂ or Al ₂ O ₃ is added deliberately to the TiO _2. Non-
Or may be added to these compounds in a mixture of toner resin and TiO ₂ between the melt-kneading step in the production of the magnetic toner particles, or first mixed SiO ₂ or A
l ₂ O ₃ can be fixed on the surface of TiO ₂ .
Such treatment of TiO ₂ is disclosed in US-A-4 943 5
06.

Before adding the surface of TiO ₂ for use in the toner particles of the present invention to the bulk of the toner particles, a silicone oil, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and It can also be treated with an organic compound selected from the group of zirconium-aluminum coupling agents.

Typical useful silane coupling agents are
For example, vinyl triacetoxy silane, methyl trimethoxy silane, vinyl tris (methoxy ethoxy silane), methyl triethoxy silane, and the like. Useful titanium coupling agents are, for example, isopropyl triisostearoyl titanate, isopropyl trioctanoyl titanate, and the like. A typical useful aluminum coupling agent is, for example, acetoxyalkoxyaluminum di-isopropylate. Are commercially available, non of the present invention - Examples of useful rutile TiO ₂ in the magnetic toner particles, for example, BAYERTITA
N RKB2 and BAYERTITAN RDFI (B
ayer AG, Leverkuson, German
y trade name) or RHODItan RL60 and RH
ODITAN RL67 (Rhone-Poulen
c, France). Among these commercially available rutile TiO _2, BAYERTI
Preferably, TAN RDFI is used.

The toner particles of the present invention may also contain a fluorescent whitening agent that fluoresces under UV-light. The addition of such a fluorescent whitening agent enhances the whiteness of images printed using the white non-magnetic toner particles of the present invention. Typical useful optical brighteners are, for example, Ciba-Geig
y, UVITEX OK by Swisserland
Sold under the trade name F

[0024]

Embedded image Sold by Ciba-Geigy, Switzerland under the trade name UVITEX OB

[0025]

Embedded image Or a stilbene derivative.

The addition of a fluorescent whitening agent to enhance the whiteness of the toner of the present invention is achieved by adding a blue colorant (blue colorant).
have the advantage over the addition of ing agents.
Images formed using the white toners of the present invention containing a fluorescent whitening agent do not exhibit a bluish tint and are therefore relatively high in density, ie, up to 1 per 100 parts (wt / wt) of toner resin.
0 parts (weight / weight) can be used. Preferably, the amount is 1 to 5 parts (weight / weight) based on 100 parts (weight / weight) of the toner resin.

[0027] White toner particles containing an optical brightener are very useful in security printing. Using such a toner, an image can be printed on a white paper, a white polymeric image receiving sheet without a fluorescent whitening agent. Such images are hardly visible under normal ambient lighting conditions, but become clearly visible under UV-light. Printing a first white image on a colored background using the toner particles of the present invention that does not contain an optical brightener;
Other images can then be printed (near or on the first image) using the non-magnetic toner particles of the present invention containing a fluorescent whitening agent. In this case, the first image will be visible under normal ambient lighting conditions and the second image will be visible under UV-illumination. UV (ultraviolet) for printing
One kind of “ghost image” that is visible only under illumination can be added. Such features are, for example, identification documents (ide
entity documents (secu)
rit).

[0028] The toner particles of the present invention can be used to provide a protective feature on printed matter without the presence of an optical brightener.
att.). On a transparent support (in most cases a polymeric support), a uniform white background is printed using the toner particles of the invention, in which different opacity (slight, ie less than 1% difference to 25% difference) ) Can be present. Images of different densities can be printed by applying more or less toner particles than the amount of toner particles used to print the background density. In this case, the same toner particles can be used. Images of different concentrations, a small amount of TiO ₂ than the amount of TiO ₂ present in the toner particles used to print the density of the background
Can be printed by applying toner particles containing In reflection mode, such a white background appears to have a uniform density, whereas in transmission, an image with lower white opacity is easily seen and introduces a type of "watermark". The white background can then be used for printing the image by other printing means. Obviously, the method for incorporating protective features as described above using white toner particles without a fluorescent whitening agent can be combined with the method using white toner particles with a fluorescent whitening agent.

[0029] The toner particles of the present invention may further comprise a wax, and particularly useful waxes are those wherein n is 21-360.
A monohydroxy compound having the formula CH ₃ (CH ₂ ) _n OH, or a formula CH wherein n is an integer of 21 to 360;
_It is a monocarboxy compound having ₃ (CH ₂ ) _n COOH. Such compounds are PETROLITE, 691
0 East 14th street, TULSA,
It is available from Oklahoma 74112, USA under the trade name UNICID for monocarboxy compounds and UNILIN for monohydroxy compounds. Onium compounds having an alkyl group of at least 12 C-atoms and up to 25 C-atoms can also be added to the non-magnetic toner particles of the present invention. Such onium compounds are useful as charge control agents as well as in US-A-562.
As disclosed in US Pat. No. 2,803,803 and US Pat. No. 5,532,097, it is beneficial to provide a narrow charge distribution to the toner particles. A typical member of the class of onium compounds useful for incorporation into the toner particles of the present invention is (CH
^{_{3) 3 N + C 16 H}} 33 Br - it is. Further, if at least 50 parts (weight / weight) of the polyester is present with respect to 100 parts (weight / weight) of the toner resin, TiO ₂ can be sufficiently dispersed in the toner resin.
A monohydroxy compound having the formula CH ₃ (CH ₂ ) _n OH, which is an integer of from 360 to 360; a monocarboxy compound having the formula CH ₃ (CH ₂ ) _n COOH, wherein n is an integer of from 21 to 360; When an onium compound having an alkyl group of at most 25 C-atoms is present,
The dispersion of TiO ₂ was found to be even better.

The toner particles of the present invention are preferably used in a non-magnetic single-component developer or a two-component developer where the non-magnetic toner particles are used together with magnetic carrier particles.
Most preferably, the non-magnetic toner particles of the invention are used in a two-component developer, wherein the non-magnetic toner particles comprise at least one resistivity-lowering substance having a volume resistivity lower than that of the resin. Wherein the substance is at least 3.3 times less when present in the resin at a concentration of 5% by weight, based on the weight of the resin (by a factor o).
3.3. fat at 3.3) The volume resistivity of the resin can be reduced. The non-magnetic toner particles preferably have an absolute median | q / d | charge / diameter value of less than 10 fc / 10 μm but greater than or equal to 1 fc / 10 μm, and the charge / diameter value distribution of the individual non-magnetic toner particles is Coefficient of variation η
≤ 0.33.

The white toner particles of the present invention are used in an amount of 10 to 200.
It can be used with any type of magnetic carrier particles known in the art, such as iron beads, composite carriers, etc., having an average particle size of μm, but: Tesla such that -M _sat > 0.30T Saturation magnetization value represented by (T), M _sat −30 μm <C _avg <60 μm Volume average particle size (C _avg ) —At least 90% of the particles are 0.5 C _avg <C <2 <C _avg
Particle size distribution based on volume having a particle size C such that is less than 25% of particles smaller than 25 mm, where b
= 0.35 x (M _sat ) 2 x P, where M _sat is T
Where P is the maximum field intensity of the magnetic pole expressed in kA / m (the maximal fi
eld strength of the magne
particle size distribution based on volume such that it is a tic developing pole)-Magnetic having core particles coated with a silicone resin coating in an amount (RC) such that 0.2% w / w <RC <2% w / w It is preferred to use the white non-magnetic toner particles of the present invention in a developer containing carrier particles.

[0032] The present invention also provides: - White non-containing toner resin and a white pigment - the magnetic toner particles 7.5g / m ² ~15g / m ² is applied imagewise to the substrate, - non - magnetic toner particles Fixing the toner particles on the substrate, wherein the toner particles comprise at least 50 parts by weight of a polyester resin, 100 parts by weight of a toner resin, and 65 to 180 parts by weight of rutile based on 100 parts by weight of the toner resin. includes a method for forming a white toner image having at least 60% opacity OP, characterized in that it comprises a mold TiO _2.

The present invention also provides:-applying the toner image to a white non-fluorescent substrate;-at least 50 parts by weight of a polyester resin.
0.5-5 parts per rutile TiO ₂ and the toner resin 100 parts by weight of 65 to 180 parts by weight of the toner resin and the toner resin 100 parts by weight of 0 parts by weight fluorescent whitening of (wt / wt) Applying an image of white non-magnetic toner particles comprising a whitening agent, comprising: fixing the image to the substrate; and incorporating a protective feature into the toner image.

The present invention also relates to: 10) at least 50 parts by weight of a polyester resin;
0 with respect to the toner resin and the toner resin 100 parts by weight of the weight part comprises a rutile type TiO ₂ of from 65 to 180 parts by weight, a white non-fluorescent whitening agent is not present - the image of the magnetic toner particles onto the substrate 100 parts by weight of a toner resin and at least 50 parts by weight of a polyester resin on said substrate and said toner resin 1
65 to 180 parts by weight of rutile type Ti relative to 00 parts by weight
O ₂ and 0.5 to 5 with respect to the toner resin 100 parts by weight
Applying an image of white non-magnetic toner particles comprising parts (w / w) of a fluorescent whitening agent, including: fixing the image to the substrate to include protective features in the toner image. Method.

The present invention furthermore provides: a white image having an opacity (OP3) is deposited on a transparent support by depositing the white toner particles of the present invention in an amount of Ag / m ² which does not contain an optical brightener; Applied in a single step above: depositing Bg / m ² of the inventive white toner particles without optical brightener to form a uniform white color with opacity (OP4) around the image Apply the background,
The amount B is different from the amount A and forms an image that is visible in the transmission mode but not in the reflection mode; and to include a protective feature in the toner image comprising fixing the image to the support. Method.

The present invention further provides:-100 parts of a toner resin containing no optical brightener;
Per part C amount of TiO_TwoAg / m containing^TwoAmount of
By depositing the white toner particles of the present invention,
Apply white image with lightness (OP3) on transparent support
And 100 parts of toner resin, containing no optical brightener
Per part D amount of TiO _TwoAg / m containing^TwoThe present invention
Around the image by depositing white toner particles
A uniform white background with opacity (OP4)
However, the quantity D is different from the quantity C and is not visible in the reflection mode.
Forming an image that is visible in transmission mode at the same time; and fixing the image to the support.
-Includes methods for including protective features in images.

[0037]

EXAMPLES Preparation of Toner Particles 50 parts of resin No. 3 and 50 parts of resin N of Table 1
o. 5 was melt-blended with various amounts of TiO _{2 in a} laboratory kneader at 110 ° C. for 30 minutes.

After cooling, the solidified mass is pulverized and
NE Fliessbettgegenstrahlm
Uhle 100AFG type (trade name), and further ground by ALPINE multiplex zig
-Zag Separation Separation was performed using a 100MZR type (trade name). The average particle size of the separated toner is COULTER
COUNTER MODEL MULTIZERZER
(Trade name) and found to be 8.0 μM by volume.

In order to improve the flowability of the toner mass, the toner particles are made up of 0.5% hydrophobic colloidal silica particles (BE).
(T-value: 130 m ² / g) to obtain a toner composition.

Twelve different types of toner particles (T1 to T1)
2) producing the amount of TiO ₂ added to the toner particles,
Properties and manufacturers are shown in Table 2. Developer 1% dimethyl silicone is coated on a Cu-Zn ferrite core using a solution spray method in a fluidized bed,
A coated support based on Cu-Zn ferrite was produced by post-curing the coating.
The carrier exhibited a saturation magnetization (M _sat ) of 0.41 T. The particle size _{distribution: d v50% = 52.5μm, d} v10% = 32μm and d _v90
% = 65 μm. The amount of particles smaller than 25 μm is 4.9.
% W / w.

A developer was prepared by adding 7.5% of the toner composition to the carrier particles. Printing Example The developing agent thus obtained was X-35 (Agfa-Gev).
aert N.A. V. Used separately in electrophotographic copiers where photoconductive drums (photocon
The latent image is uniformly exposed to form a latent image, the latent image is developed using one of the above-described developers containing toner particles, and the image is subjected to a Jackstaedt Gmb.
H, a transparent support PROPYLUX 60, a label material available from Wuppertal, Germany.
It was transferred onto one side of Model 064 (trade name).

From the X-35 copier, a standard hot roller fuser is used.
The fuser was removed and the toner of the non-fixed copy was contactlessly fused by radiation using an infrared blackbody radiating component located 10 mm from the transparent support bearing the toner image. The support passed the radiating component at a rate of 5 cm per second. The average power provided to the radiant heating component is 375
W and a reflector was used to focus the radiant heat on the support, so that the part worked at a temperature of 600 ° C.

Using each developing agent, 5 g / m ² to 1
By applying different amounts of toner particles in the range of 5 g / m ² , four patches with uniform white density but different opacity were printed. For each of these patches, the opacity was measured as described above. By interpolation, 1
The opacity achieved by applying 0 g / m ² (1 mg / cm ₂ ) of white toner particles was determined. The values are also shown in Table 2.

[0044]

[Table 2] * Type: A = anatase, R = rutile KRONOS A: Kronos NV, Brusse
l, Trade name of Belgium RHODITAN: Rhone-Poulenc, Fr
trade name BAYERTITAN: Bayer AG, Lever
Kusen, Germany trade name. The main features and aspects of the present invention are as follows.

1. The toner resin at least 50 parts by weight is a polyester resin, and drying the non-containing rutile type TiO ₂ of from 65 to 180 parts by weight relative to the toner resin 100 parts by weight - magnetic toner particles.

2. 2. The dry non-magnetic toner particles according to claim 1, wherein the toner resin is a polyester.

3. The dried non-magnetic toner particles according to claim 1 or 2, wherein the polyester is a polyester having an acid value of 10 to 30 mg KOH per 1 g of the polyester.

4. Drying non according to any one of the above 1 to 3, wherein said rutile-type TiO ₂ has a purity of 94-98% -
Magnetic toner particles.

5. The above 1 further comprising an optical brightener.
5. The dry non-magnetic toner particles according to any one of items 4 to 4.

6. Formula CH wherein n is an integer of 21-360
A monohydroxy compound having ₃ (CH ₂ ) _n OH, a compound of formula CH ₃ (CH ₂ ) _n COOH wherein n is an integer of 21 to 360
A monocarboxy compound having at least 12C
6. The dry non-magnetic toner particles according to any one of claims 1 to 5, further comprising a compound selected from the group consisting of an onium compound having an alkyl group of at most 25C-atoms.

7. Use of the dry non-magnetic toner particles according to any one of the above items 1 to 6 in a two-component developer containing magnetic carrier particles.

8. 7. Use of the dry non-magnetic toner particles according to any one of the above items 1 to 6 for including a protective feature in a printed matter.

9. - White non-containing toner resin and a white pigment - the magnetic toner particles 7.5g / m ² ~15g / m ² is applied imagewise to the substrate, - non - step of fixing the magnetic toner particles on said substrate Wherein the toner particles comprise at least 50 parts by weight of a polyester resin, and 65 to 180 parts by weight of rutile T based on 100 parts by weight of the toner resin.
at least 60% characterized by comprising iO ₂
Electrostatic printing for white toner images having an opacity of OP.

10. 9 g / m ^{2 to} 11 g of the toner particles
10. The method of claim 9 wherein the deposition is in an amount of / m ² .

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Sergiu Tavernier Belgium B 2640 Malt Cell Septes Trat 27 Agfa-Gevuert Na Mrose Fennoutjaps (72) Inventor Gerrit Derlen Belgium B 2640 Malt Cell・ Septes Trat 27 ・ Agfa-Gevuert Na Mrose / Fennault Shop

Claims (6)

[Claims] 1. Dry non-magnetic toner particles comprising at least 50 parts by weight of a toner resin, a polyester resin, and 65 to 180 parts by weight of rutile TiO _{2 based} on 100 parts by weight of the toner resin. 2. The method according to claim 1, further comprising a fluorescent whitening agent.
3. The dry non-magnetic toner particles according to 1. _{3. A} compound of the formula CH _{3 wherein} n is an integer from 21 to 360.
A monohydroxy compound having (CH ₂ ) _n OH, wherein n is 2
Monocarboxy compounds with formula CH ₃ (CH _{2) n} COOH is an integer of 1 to 360, and at least 12C-
3. Dry non-magnetic toner particles according to claim 1 or 2, further comprising a compound selected from the group consisting of onium compounds having an alkyl group of at most 25 C-atoms. 4. Use of the dry non-magnetic toner particles according to claim 1 in a two-component developer containing magnetic carrier particles. 5. The use of dry non-magnetic toner particles according to claim 1, for including security features in the printed matter. 6. - White non-containing toner resin and a white pigment - the magnetic toner particles 7.5g / m ² ~15g / m ² is applied imagewise to the substrate, - non - said substrate of magnetic toner particles Fixing the toner particles, wherein the toner particles comprise at least 50 parts by weight of a toner resin having a polyester resin, and 65 to 1 part by weight based on 100 parts by weight of the toner resin.
Electrostatic printing method for white toner images with at least 60% opacity OP, characterized in that it comprises a rutile type TiO ₂ of 80 parts by weight.