KR100409078B1 - Two-component system color toner composition and a method for preparing the same - Google Patents

Abstract

The present invention relates to a two-component color toner composition and a method of manufacturing the same, and more particularly, toner base particles comprising a) i) a binder resin, ii) a colorant and iii) a charge control agent, and b) a surface of the toner base particles. It relates to a two-component color toner composition comprising a hydrophobized titanium oxide added to, and a method for producing the same.

The toner composition of the present invention is excellent in color reproducibility of the toner while preventing toner scattering.

Description

TWO-COMPONENT SYSTEM COLOR TONER COMPOSITION AND A METHOD FOR PREPARING THE SAME

The present invention relates to a dry two-component color toner composition and a method of manufacturing the same. More specifically, the present invention relates to a two-component full color toner composition having a superior color reproducibility and a method for producing the same, by preventing toner scattering in the sleeve of the developer and maintaining the color characteristics peculiar to each color.

Until now, copying and printing by electrophotographic methods were generally mainly black and white, but recently, with the rapid spread of PCs and networks in offices, the copier and printer market, where black and white was the mainstream, is changing to full color. Accordingly, market demand for electrophotographic copiers and printers, which have been advantageous in terms of image quality and speed, is increasing.

Currently, in order to obtain high quality copies or prints, the use of dry two-component color toners generally composed of a carrier and a toner is the mainstream. The dry two-component electrophotographic method uses a carrier and a toner as a developer by frictionally charging each other. As a magnetic material of the carrier core, ferrite, iron, magnetite, γ-iron oxide, and the like are used. The thing processed with resin etc. is mentioned. Moreover, as resin for coating the carrier surface, styrene acrylic acid, ester copolymer, styrene methacrylic acid ester copolymer, acrylic ester copolymer, silicone resin, fluorine-containing resin, polyamide, ionoma resin, polyphenylene sulfide resin These etc. are mentioned, It is also possible to use these mixtures. Generally, the mixing ratio of the toner and the carrier is suitably about 0.5 to 6 parts by weight based on 100 parts by weight of the carrier.

The dry two-component toner according to the present invention contains a binder resin, a colorant, and a charge control agent as essential components, and includes a release agent such as polypropylene and polyethylene as required. The average particle size of the toner particles is not necessarily limited, but is generally 5 to 30 µm and is usually produced by melt kneading pulverization, suspension polymerization, emulsion polymerization, or the like. Among these production methods, from the viewpoint of production stability and productivity, a kneading pulverization method is mainly employed.

The kneading pulverization method refers to manufacturing a toner by cooling and pulverizing a mixture obtained by melt kneading a mixture of toner raw materials such as a binder resin, a colorant, a charge control agent, a mold release agent, and then pulverizing it into toner particles having a desired particle size. . In the dry two-component color toner, when the particle size is large, the charging amount decreases, and therefore, toner scattering is likely to occur in the developer. In addition, the toner scattering in the drum is significantly increased, causing contamination of the image. Especially, in the case of color, four colors of cyan, magenta, yellow, and black are contaminated by scattering of each other, resulting in poor color reproducibility. The picture quality is degraded.

The developing toner is developed by the triboelectric charging method and retains positive or negative charges depending on the polarity of the developed electrostatic latent image. The charging performance of the toner can be secured to some extent by the binder resin, the colorant, and the charge control agent, which are the main components of the toner, but it is not enough.

Therefore, there is a need for a solution to solve the problem of scattering caused by the reduction of the charge amount and the problem of image contamination and color reproducibility.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the present inventors can reduce the scattering by adding titanium oxide during the production of the dry two-component color toner to produce a dry two-component color toner having no color contamination and excellent color reproducibility. It has been found that the present invention can be completed.

Accordingly, an object of the present invention is to provide a dry two-component toner composition having reduced toner scattering, no color contamination, and excellent color reproducibility.

It is also an object of the present invention to provide a method for producing a dry two-component toner composition having reduced scattering and excellent color reproducibility.

In order to achieve the above object, the present invention is a) i) a binder resin; ii) a coloring agent; And iii) a toner base particle comprising a charge control agent; And b) hydrophobized titanium oxide having L / L ₀ (L is the short axis length of the titanium oxide particles and L ₀ is the major axis length) of the titanium oxide particles added to the toner base particle surface, from 0.3 to 1.0.

It provides a two-component color toner composition comprising a.

That is, the present invention relates to a dry toner composition for electrostatic charge image development, which contains a binder resin, a colorant, and a charge control agent as essential components, and is characterized in that titanium oxide is externally added.

Titanium oxide has two different structures, an anatase and rutile structure, and in general, titanium oxide often has a rutile structure and an anatase structure at the same time. However, the inventors of the present invention have uniformity among titanium oxides having these two structures. Attention was paid to titanium oxide having a rutile structure, which has a charging property, is excellent in fluidity, is effective in preventing scattering in toner production, and is effective in improving color reproducibility in the case of color toner.

Here, considering the environmental quality of the toner, a hydrophobized titanium oxide should be used. In the case of titanium oxide, the hydrophobization treatment mainly uses a silane coupling agent. In addition, for uniform coating of the coupling agent, when the rutile type titanium oxide and the anatase type titanium oxide are mixed with each other, the ratio of the anatase type and the rutile type is 5:95 to 55:45, and more preferably 15 : 85 ~ 40: 60 is appropriate. The silane coupling agent used herein may be of a type such as chlorosilane, alkoxy silane, phenyltrimethoxysilane, silazane and the like, but particularly alkoxysilane is preferable, and examples thereof include vinyltrimethoxysilane and propyltrimethoxy silane. , n-hexyltrimethoxysilane, n-octyltrimethoxysilane n-dodecyl trimethoxy silane, phenyltrimethoxy silane and the like.

The toner added with the hydrophobic titanium oxide is excellent in fluidity without adversely affecting the toner in charging characteristics. However, hydrophobization of titanium oxide is not enough to reduce scattering and improve color reproducibility, and since the size and particle shape of the titanium oxide to be added greatly affect the reduction of scattering and improvement of color reproducibility, In selecting titanium, the size and shape of the particles are important.

The particle size of the titanium oxide used in the present invention is preferably about 40 to 300 nm, more preferably about 50 to 250 nm. When the size of the titanium oxide particles is less than 40 nm, the size of the titanium oxide particles attached to the toner particles is small, which adversely affects the flowability of the toner. When the size of the titanium oxide particles exceeds 300 nm, the coating performance on the toner drops and the scattering decreases. It has a bad effect on improving color reproducibility.

In addition, the external amount of titanium oxide used in the present invention is appropriately 0.1 to 3.0 parts by weight, more preferably 0.2 to 2.0 parts by weight. If the external amount exceeds 3 parts by weight, the consumption is increased, the scattering is increased and adversely affect the fixability. In addition, when the external amount of titanium oxide is less than 0.1 part by weight, the external amount is small, so that the effect is small in reducing scattering or improving color reproducibility.

Another important criterion in selecting titanium oxide to be added to the toner of the present invention is the shape of titanium oxide. This is because the adhesion thereof varies depending on the shape of the titanium oxide particles adhered to the toner surface, and the charging characteristics thereof vary.

Titanium oxide particles may have various shapes depending on the production method thereof. For example, even in the case of the same spherical shape, the titanium oxide particles may be completely spherical, elliptical, and elliptical close to acicular. Therefore, the following method was used to define the effect on the image according to the circularity of these particles.

The long axis of the titanium oxide particles was defined as L ₀ and the short axis was defined as L, and the shape of the particles was defined by L / L ₀ . Where L / L ₀ is 1, it represents a perfect sphere. Therefore, the value of L / L _{0 has} a value of 0 to 1, and the closer to 1, the closer to the sphere. As a result of experiments with the present inventors, L / L ₀ is appropriately 0.3 to 1.0, more preferably 0.5 to 1.0. In the case where L / L ₀ is less than 0.3, the surface adhesion of the toner particles deteriorates, so that scattering increases and image contamination occurs.

The toner of the present invention contains a binder resin, a charge control agent and a colorant as essential components, and contains a release agent as necessary.

Examples of the binder resin include styrenes such as styrene, chloro styrene and vinyl styrene, olefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate, methyl acrylate and ethyl acrylate. Esters of methylene aliphatic carboxylic acids such as butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl methyl ether, vinyl ethyl ether Homopolymers or copolymers such as vinyl ketones such as vinyl ethers such as vinyl butyl ether, vinyl methyl ketones, vinyl hexyl ketones, vinyl isopropenyl ketones, and the like. Particularly representative binder resins include polystyrene, alkyl styrene acrylate, Copolymer, Styrene Methacrylic Acid There may be mentioned copolymers, acrylonitrile styrene acrylate copolymers, styrene-butadiene copolymers, styrene-maleic anhydride copolymer, polyethylene, polypropylene or the like. Polyesters, polyurethanes, epoxy resins, silicone resins, polyamides, modified rosins, paraffins and the like can also be used.

Examples of the coloring agent include carbon black, magnetic powder, dyes and pigments such as nigurosine dye, aniline blue, carcoyl blue, chrome yellow, ultramarine blue, dupont oil red, methylene blue chloride, phthalocyanine blue, lamp black, rose Bengal, CI Pigment Red 48: 1, CI Pigment Red 122: 1, CI Pigment Red 57: 1, CI Pigment Yellow 97, CI Pigment Yellow 12, CI Pigment Blue 15: 1, CI Pigment Blue 15: 3, etc. can do.

In addition, the toner composition of the present invention is SiO ₂ , TiO ₂ , MgO, Al ₂ O ₂ , MnO, ZnO, Fe to which hydrophobization treatment such as hexamethyldisilazane, dimethyl dichlorosilane, octyl trimethoxy silane is applied _{2 O 2, CaO, BaSO 2} , CeO 2, K 2 O, Na 2 O, ZrO 2, CaO · SiO, K 2 O · (TiO 2) n, Al 2 O 3 · the inorganic oxide fine particles of 2SiO ₂ etc. It can be added as a flow promoter.

In the present invention, as the charge control agent included in the toner particles, a metal azo dye, a salicylic acid compound, or the like can be used when the charge is negative, and a quaternary ammonium salt or the like can be used when the charge is positive. Although the content in the toner of the charge control agent is not limited, it is generally preferably about 0.5 to 5% by weight.

As wax release agents contained in toner particles, various waxes, low molecular weight olefin resins, and the like are used. Polypropylene, polyethylene, and propylene-ethylene copolymer are used as the olefin resin, but polypropylene is particularly suitable.

The average particle diameter of the toner composition of the present invention is preferably 25 µm or less, particularly 3 to 20 µm.

In addition, the present invention

a) i) binder resin;

ii) colorants; And

iii) charging control agent

Melt kneading and grinding to prepare toner base particles; And

b) adding hydrophobized titanium oxide to the surface of the prepared toner base particles

It provides a method for producing a two-component color toner composition comprising a.

Hereinafter, the present invention will be described in more detail with reference to the following Examples and Comparative Examples, but these examples are only for illustrating the present invention, but the present invention is not limited thereto. In the following Examples and Comparative Examples, the numbers indicating the formulation and the like represent parts by weight.

EXAMPLE

Preparation of Cyan Toner Base Particles

Polyester resin (Molecular weight: 2.5 × 10 ⁵ ) 93 parts by weight

Phthalocyanine P.BI. 15: 3 3 parts by weight

Metal azo salts 1 part by weight

3 parts by weight of low molecular weight polypropylene

After mixing each of the above raw materials with a Henschel mixer, melt kneading at a temperature of 165 ° C. in a twin-screw melt kneader, pre-pulverizing with a jet mill grinder, and classifying in a wind classifier to obtain a volume average particle diameter of 15 μm The particles were obtained.

External attachment of titanium oxide

Table 1 and Table 2 show the size and composition of titanium oxide containing silica and tin oxide to be attached to the toner base particles, respectively.

TABLE 1

Titanium Oxide Classification Average particle size (nm) Particle Shape (L / L0) Remarks (Anatase: rutile) Titanium Oxide A 20 0.2 40:60 Titanium Oxide B 170 0.8 40:60 Titanium Oxide C 20 0.5 30:70 Titanium oxide D 200 0.1 40:60 Titanium Oxide E 50 0.6 65:35 Titanium Oxide F 380 0.1 40:60 Titanium Oxide G 180 0.2 70:30 Titanium Oxide H 400 0.7 70:30

As described above, the ratio of titanium oxide having an average particle diameter of 20 to 400 nm, different particle shapes, and different structures was attached to the toner base particles as shown in Table 1, followed by stirring for 3 minutes using a Henschel mixer. The mixture was adhered to the surface of the toner base particles, and the toners for nonmagnetic one-component development of the present invention of Examples 1 to 4 and the comparative toners of Comparative Examples 1 to 30 were prepared in the composition as shown in Table 2.

TABLE 2

Titanium oxide (parts, parts by weight) Example 1 Titanium oxide B, 0.1 Example 2 Titanium Oxide B, 1.0 Example 3 Titanium Oxide B, 2.0 Example 4 Titanium Oxide B, 2.5 Comparative Example 1 Titanium Oxide A, 0.1 Comparative Example 2 Titanium Oxide A, 1.0 Comparative Example 3 Titanium Oxide A, 2.0 Comparative Example 4 Titanium Oxide A, 2.5 Comparative Example 5 Titanium oxide C, 0.1 Comparative Example 6 Titanium Oxide C, 1.0 Comparative Example 7 Titanium Oxide C, 2.0 Comparative Example 8 Titanium Oxide C, 2.5 Comparative Example 9 Titanium Oxide D, 0.1 Comparative Example 10 Titanium Oxide D, 1.0 Comparative Example 11 Titanium Oxide D, 2.0 Comparative Example 12 Titanium Oxide D, 2.5 Comparative Example 13 Titanium Oxide E, 0.1 Comparative Example 14 Titanium Oxide E, 1.0 Comparative Example 15 Titanium Oxide E, 2.0 Comparative Example 16 Titanium Oxide E, 2.5 Comparative Example 17 Titanium Oxide F, 0.1 Comparative Example 18 Titanium Oxide F, 1.0 Comparative Example 19 Titanium Oxide F, 2.0 Comparative Example 20 Titanium Oxide F, 2.5 Comparative Example 21 Titanium oxide G, 0.1 Comparative Example 22 Titanium Oxide G, 1.0 Comparative Example 23 Titanium oxide G, 2.0 Comparative Example 24 Titanium Oxide G, 2.5 Comparative Example 25 Titanium oxide H, 0.1 Comparative Example 26 Titanium Oxide H, 1.0 Comparative Example 27 Titanium oxide H, 2.0 Comparative Example 28 Titanium Oxide H, 2.5 Comparative Example 29 Titanium Oxide B, 0.05 Comparative Example 30 Titanium Oxide B, 3.2

Each of the toners was then printed up to 5000 sheets at room temperature and humidity (20 ° C, 55% RH) using a commercially available non-magnetic binary printer (Hewlett-Packard Co., Ltd. HP Color Laser 5 / 5M). And the evaluation results are shown in Table 3.

TABLE 3

Burn Density (I.D.) Fog (background) Collar pollution arsenic acid Example 1 1.35 0 O 0 Example 2 1.38 0 O 0 Example 3 1.42 0 O 0 Example 4 1.39 0 O 0 Comparative Example 1 1.19 X X X Comparative Example 2 1.20 X X X Comparative Example 3 1.22 X X X Comparative Example 4 1.22 X X X Comparative Example 5 1.25 △ X X Comparative Example 6 1.22 X △ X Comparative Example 7 1.28 △ X X Comparative Example 8 1.22 X △ X Comparative Example 9 1.25 △ X X Comparative Example 10 1.24 X △ X Comparative Example 11 1.28 △ X X Comparative Example 12 1.28 X △ X Comparative Example 13 1.25 △ X X Comparative Example 14 1.28 △ △ △ Comparative Example 15 1.29 △ X X Comparative Example 16 1.29 △ X X Comparative Example 17 1.18 X X X Comparative Example 18 1.15 X X X Comparative Example 19 1.19 X X X Comparative Example 20 1.19 X X X Comparative Example 21 1.09 X X X Comparative Example 22 1.13 X X X Comparative Example 23 1.13 X X X Comparative Example 24 1.14 X X X Comparative Example 25 0.98 X X X Comparative Example 26 1.04 X X X Comparative Example 27 1.08 X X X Comparative Example 28 1.11 X X X Comparative Example 29 1.32 △ X X Comparative Example 30 1.35 △ X X

In Table 3, the image density (ID) was measured using a Macbeth reflection densitometer RD918 for solid area images (ID can be used if the value is 1.30 or more), and the fog (background) phenomenon of the image is determined by an optical microscope. It was measured and evaluated with the naked eye.

O: The fog (background) phenomenon of the image is not confirmed.

(Triangle | delta): The fog (background) phenomenon of an image is partially confirmed.

X: The fog (background) phenomenon of the image is clearly confirmed.

In addition, color contamination is evaluated by visually measuring the appearance of different colors when the yellow image is printed in solid through an optical microscope.

O: Color contamination was not confirmed.

Δ: Color contamination is partially confirmed.

X: Color contamination is clearly confirmed.

In addition, scattering is confirmed by taping with 3M tape that the toner scatters on the lower part of the roller of the developing machine.

O: No scattering was confirmed.

(Triangle | delta): A scattering is confirmed partially.

X: The scattering is clearly confirmed.

As can be seen in Table 3 above, the toner compositions of Examples 1 to 4 having titanium oxide attached to the surface can be used to have sufficient image density (Image Density) of 1.35 or more, and the fog ( There was also little background) and color contamination, so there was no problem in using. On the other hand, in Comparative Examples 1 to 30, which are not in the range of the examples, various evaluation results in each composition resulted in blurring of image density, fog, and scattering. It was confirmed.

As described above, the present invention can obtain a toner having no color scattering and excellent color reproducibility by using hydrophobization treatment of titanium oxide containing anatase and rutile structure in a fixed ratio, and externally using the toner. There is no problem such as deterioration of the life of the copier or the printer, and a uniform image without color contamination or background contamination can be obtained.

Claims (13)

a) i) binder resin; ii) colorants; And iii) charging control agent Toner base particles comprising a; And b) hydrophobized titanium oxide having L / L ₀ (L is the short axis length of the titanium oxide particles and L ₀ is the major axis length) of the titanium oxide particles added to the surface of the toner base particles; Two-component color toner composition comprising a. The two-component color toner composition according to claim 1, wherein the titanium oxide has a particle size of 40 to 300 nm. The two-component color toner composition according to claim 1, wherein the titanium oxide is added in an amount of 0.1 to 3 parts by weight based on 100 parts by weight of the total toner composition. The two-component color toner composition according to claim 1, wherein the titanium oxide is composed of an anatase type and a rutile titanium oxide of 5:95 to 55:45. delete 2. The two-component toner composition according to claim 1, wherein the titanium oxide is hydrophobized by a silane coupling agent. 7. The silane coupling agent according to claim 6, wherein the silane coupling agent is vinyltrimethoxysilane, propyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-dodecyltrimethoxysilane and phenyltri A two-component color toner composition, characterized in that it is selected from the group consisting of methoxysilane. The method of claim 1, wherein the binder resin is polystyrene, styrene alkyl acrylate copolymer, styrene methacrylate alkyl copolymer, styrene acrylonitrile copolymer, styrene butadiene copolymer, styrene maleic anhydride copolymer, polyethylene, polypropylene, A bicomponent color toner composition selected from the group consisting of polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin and paraffin. The method of claim 1, wherein the colorant is carbon black, magnetic powder, nigurosine dye, aniline blue, carcoyl blue, chrome yellow, ultramarine blue, dupont oil red, methylene blue chloride, phthalocyanine blue, lamp black, rosebengal, CI pigment red 48: 1, CI pigment red 122, CI pigment red 57: 1, CI pigment yellow 97, CI pigment yellow 12, CI pigment blue 15: 1 and CI pigment blue 15: 3 A two-component color toner composition, characterized in that. The two-component color toner composition according to claim 1, wherein the charge control agent is selected from the group consisting of metal azo dyes, salicylic acid compounds and quaternary ammonium salts. The two-component color toner composition according to claim 1, wherein the a) toner base particles further include a release agent. 12. The bicomponent color toner composition according to claim 11, wherein the release agent is selected from the group consisting of polypropylene, polyethylene, and propylene-ethylene copolymers. a) i) binder resin; ii) colorants; And iii) charging control agent Melt kneading and grinding to prepare toner base particles; And b) adding hydrophobized titanium oxide having 0.3 to 1.0 L / L ₀ (L is the short axis length of the titanium oxide particles and L ₀ is the major axis length) of the titanium oxide particles on the surface of the prepared toner base particles; Method of producing a two-component color toner composition comprising a.